WorldWideScience

Sample records for human error based

  1. Game Design Principles based on Human Error

    Directory of Open Access Journals (Sweden)

    Guilherme Zaffari

    2016-03-01

    Full Text Available This paper displays the result of the authors’ research regarding to the incorporation of Human Error, through design principles, to video game design. In a general way, designers must consider Human Error factors throughout video game interface development; however, when related to its core design, adaptations are in need, since challenge is an important factor for fun and under the perspective of Human Error, challenge can be considered as a flaw in the system. The research utilized Human Error classifications, data triangulation via predictive human error analysis, and the expanded flow theory to allow the design of a set of principles in order to match the design of playful challenges with the principles of Human Error. From the results, it was possible to conclude that the application of Human Error in game design has a positive effect on player experience, allowing it to interact only with errors associated with the intended aesthetics of the game.

  2. Savannah River Site human error data base development for nonreactor nuclear facilities

    International Nuclear Information System (INIS)

    Benhardt, H.C.; Held, J.E.; Olsen, L.M.; Vail, R.E.; Eide, S.A.

    1994-01-01

    As part of an overall effort to upgrade and streamline methodologies for safety analyses of nonreactor nuclear facilities at the Savannah River Site (SRS), a human error data base has been developed and is presented in this report. The data base fulfills several needs of risk analysts supporting safety analysis report (SAR) development. First, it provides a single source for probabilities or rates for a wide variety of human errors associated with the SRS nonreactor nuclear facilities. Second, it provides a documented basis for human error probabilities or rates. And finally, it provides actual SRS-specific human error data to support many of the error probabilities or rates. Use of a single, documented reference source for human errors, supported by SRS-specific human error data, will improve the consistency and accuracy of human error modeling by SRS risk analysts. It is envisioned that SRS risk analysts will use this report as both a guide to identifying the types of human errors that may need to be included in risk models such as fault and event trees, and as a source for human error probabilities or rates. For each human error in this report, ffime different mean probabilities or rates are presented to cover a wide range of conditions and influencing factors. The ask analysts must decide which mean value is most appropriate for each particular application. If other types of human errors are needed for the risk models, the analyst must use other sources. Finally, if human enors are dominant in the quantified risk models (based on the values obtained fmm this report), then it may be appropriate to perform detailed human reliability analyses (HRAS) for the dominant events. This document does not provide guidance for such refined HRAS; in such cases experienced human reliability analysts should be involved

  3. Knowledge-base for the new human reliability analysis method, A Technique for Human Error Analysis (ATHEANA)

    International Nuclear Information System (INIS)

    Cooper, S.E.; Wreathall, J.; Thompson, C.M., Drouin, M.; Bley, D.C.

    1996-01-01

    This paper describes the knowledge base for the application of the new human reliability analysis (HRA) method, a ''A Technique for Human Error Analysis'' (ATHEANA). Since application of ATHEANA requires the identification of previously unmodeled human failure events, especially errors of commission, and associated error-forcing contexts (i.e., combinations of plant conditions and performance shaping factors), this knowledge base is an essential aid for the HRA analyst

  4. Analysis of measured data of human body based on error correcting frequency

    Science.gov (United States)

    Jin, Aiyan; Peipei, Gao; Shang, Xiaomei

    2014-04-01

    Anthropometry is to measure all parts of human body surface, and the measured data is the basis of analysis and study of the human body, establishment and modification of garment size and formulation and implementation of online clothing store. In this paper, several groups of the measured data are gained, and analysis of data error is gotten by analyzing the error frequency and using analysis of variance method in mathematical statistics method. Determination of the measured data accuracy and the difficulty of measured parts of human body, further studies of the causes of data errors, and summarization of the key points to minimize errors possibly are also mentioned in the paper. This paper analyses the measured data based on error frequency, and in a way , it provides certain reference elements to promote the garment industry development.

  5. Fault tree model of human error based on error-forcing contexts

    International Nuclear Information System (INIS)

    Kang, Hyun Gook; Jang, Seung Cheol; Ha, Jae Joo

    2004-01-01

    In the safety-critical systems such as nuclear power plants, the safety-feature actuation is fully automated. In emergency case, the human operator could also play the role of a backup for automated systems. That is, the failure of safety-feature-actuation signal generation implies the concurrent failure of automated systems and that of manual actuation. The human operator's manual actuation failure is largely affected by error-forcing contexts (EFC). The failures of sensors and automated systems are most important ones. The sensors, the automated actuation system and the human operators are correlated in a complex manner and hard to develop a proper model. In this paper, we will explain the condition-based human reliability assessment (CBHRA) method in order to treat these complicated conditions in a practical way. In this study, we apply the CBHRA method to the manual actuation of safety features such as reactor trip and safety injection in Korean Standard Nuclear Power Plants

  6. Human errors in NPP operations

    International Nuclear Information System (INIS)

    Sheng Jufang

    1993-01-01

    Based on the operational experiences of nuclear power plants (NPPs), the importance of studying human performance problems is described. Statistical analysis on the significance or frequency of various root-causes and error-modes from a large number of human-error-related events demonstrate that the defects in operation/maintenance procedures, working place factors, communication and training practices are primary root-causes, while omission, transposition, quantitative mistake are the most frequent among the error-modes. Recommendations about domestic research on human performance problem in NPPs are suggested

  7. In-plant reliability data base for nuclear plant components: a feasibility study on human error information

    International Nuclear Information System (INIS)

    Borkowski, R.J.; Fragola, J.R.; Schurman, D.L.; Johnson, J.W.

    1984-03-01

    This report documents the procedure and final results of a feasibility study which examined the usefulness of nuclear plant maintenance work requests in the IPRDS as tools for understanding human error and its influence on component failure and repair. Developed in this study were (1) a set of criteria for judging the quality of a plant maintenance record set for studying human error; (2) a scheme for identifying human errors in the maintenance records; and (3) two taxonomies (engineering-based and psychology-based) for categorizing and coding human error-related events

  8. Demonstration Integrated Knowledge-Based System for Estimating Human Error Probabilities

    Energy Technology Data Exchange (ETDEWEB)

    Auflick, Jack L.

    1999-04-21

    Human Reliability Analysis (HRA) is currently comprised of at least 40 different methods that are used to analyze, predict, and evaluate human performance in probabilistic terms. Systematic HRAs allow analysts to examine human-machine relationships, identify error-likely situations, and provide estimates of relative frequencies for human errors on critical tasks, highlighting the most beneficial areas for system improvements. Unfortunately, each of HRA's methods has a different philosophical approach, thereby producing estimates of human error probabilities (HEPs) that area better or worse match to the error likely situation of interest. Poor selection of methodology, or the improper application of techniques can produce invalid HEP estimates, where that erroneous estimation of potential human failure could have potentially severe consequences in terms of the estimated occurrence of injury, death, and/or property damage.

  9. Collection of offshore human error probability data

    International Nuclear Information System (INIS)

    Basra, Gurpreet; Kirwan, Barry

    1998-01-01

    Accidents such as Piper Alpha have increased concern about the effects of human errors in complex systems. Such accidents can in theory be predicted and prevented by risk assessment, and in particular human reliability assessment (HRA), but HRA ideally requires qualitative and quantitative human error data. A research initiative at the University of Birmingham led to the development of CORE-DATA, a Computerised Human Error Data Base. This system currently contains a reasonably large number of human error data points, collected from a variety of mainly nuclear-power related sources. This article outlines a recent offshore data collection study, concerned with collecting lifeboat evacuation data. Data collection methods are outlined and a selection of human error probabilities generated as a result of the study are provided. These data give insights into the type of errors and human failure rates that could be utilised to support offshore risk analyses

  10. A methodology for collection and analysis of human error data based on a cognitive model: IDA

    International Nuclear Information System (INIS)

    Shen, S.-H.; Smidts, C.; Mosleh, A.

    1997-01-01

    This paper presents a model-based human error taxonomy and data collection. The underlying model, IDA (described in two companion papers), is a cognitive model of behavior developed for analysis of the actions of nuclear power plant operating crew during abnormal situations. The taxonomy is established with reference to three external reference points (i.e. plant status, procedures, and crew) and four reference points internal to the model (i.e. information collected, diagnosis, decision, action). The taxonomy helps the analyst: (1) recognize errors as such; (2) categorize the error in terms of generic characteristics such as 'error in selection of problem solving strategies' and (3) identify the root causes of the error. The data collection methodology is summarized in post event operator interview and analysis summary forms. The root cause analysis methodology is illustrated using a subset of an actual event. Statistics, which extract generic characteristics of error prone behaviors and error prone situations are presented. Finally, applications of the human error data collection are reviewed. A primary benefit of this methodology is to define better symptom-based and other auxiliary procedures with associated training to minimize or preclude certain human errors. It also helps in design of control rooms, and in assessment of human error probabilities in the probabilistic risk assessment framework. (orig.)

  11. Human-simulation-based learning to prevent medication error: A systematic review.

    Science.gov (United States)

    Sarfati, Laura; Ranchon, Florence; Vantard, Nicolas; Schwiertz, Vérane; Larbre, Virginie; Parat, Stéphanie; Faudel, Amélie; Rioufol, Catherine

    2018-01-31

    In the past 2 decades, there has been an increasing interest in simulation-based learning programs to prevent medication error (ME). To improve knowledge, skills, and attitudes in prescribers, nurses, and pharmaceutical staff, these methods enable training without directly involving patients. However, best practices for simulation for healthcare providers are as yet undefined. By analysing the current state of experience in the field, the present review aims to assess whether human simulation in healthcare helps to reduce ME. A systematic review was conducted on Medline from 2000 to June 2015, associating the terms "Patient Simulation," "Medication Errors," and "Simulation Healthcare." Reports of technology-based simulation were excluded, to focus exclusively on human simulation in nontechnical skills learning. Twenty-one studies assessing simulation-based learning programs were selected, focusing on pharmacy, medicine or nursing students, or concerning programs aimed at reducing administration or preparation errors, managing crises, or learning communication skills for healthcare professionals. The studies varied in design, methodology, and assessment criteria. Few demonstrated that simulation was more effective than didactic learning in reducing ME. This review highlights a lack of long-term assessment and real-life extrapolation, with limited scenarios and participant samples. These various experiences, however, help in identifying the key elements required for an effective human simulation-based learning program for ME prevention: ie, scenario design, debriefing, and perception assessment. The performance of these programs depends on their ability to reflect reality and on professional guidance. Properly regulated simulation is a good way to train staff in events that happen only exceptionally, as well as in standard daily activities. By integrating human factors, simulation seems to be effective in preventing iatrogenic risk related to ME, if the program is

  12. Human errors and mistakes

    International Nuclear Information System (INIS)

    Wahlstroem, B.

    1993-01-01

    Human errors have a major contribution to the risks for industrial accidents. Accidents have provided important lesson making it possible to build safer systems. In avoiding human errors it is necessary to adapt the systems to their operators. The complexity of modern industrial systems is however increasing the danger of system accidents. Models of the human operator have been proposed, but the models are not able to give accurate predictions of human performance. Human errors can never be eliminated, but their frequency can be decreased by systematic efforts. The paper gives a brief summary of research in human error and it concludes with suggestions for further work. (orig.)

  13. Basic considerations in predicting error probabilities in human task performance

    International Nuclear Information System (INIS)

    Fleishman, E.A.; Buffardi, L.C.; Allen, J.A.; Gaskins, R.C. III

    1990-04-01

    It is well established that human error plays a major role in the malfunctioning of complex systems. This report takes a broad look at the study of human error and addresses the conceptual, methodological, and measurement issues involved in defining and describing errors in complex systems. In addition, a review of existing sources of human reliability data and approaches to human performance data base development is presented. Alternative task taxonomies, which are promising for establishing the comparability on nuclear and non-nuclear tasks, are also identified. Based on such taxonomic schemes, various data base prototypes for generalizing human error rates across settings are proposed. 60 refs., 3 figs., 7 tabs

  14. Analysis of Employee's Survey for Preventing Human-Errors

    International Nuclear Information System (INIS)

    Sung, Chanho; Kim, Younggab; Joung, Sanghoun

    2013-01-01

    Human errors in nuclear power plant can cause large and small events or incidents. These events or incidents are one of main contributors of reactor trip and might threaten the safety of nuclear plants. To prevent human-errors, KHNP(nuclear power plants) introduced 'Human-error prevention techniques' and have applied the techniques to main parts such as plant operation, operation support, and maintenance and engineering. This paper proposes the methods to prevent and reduce human-errors in nuclear power plants through analyzing survey results which includes the utilization of the human-error prevention techniques and the employees' awareness of preventing human-errors. With regard to human-error prevention, this survey analysis presented the status of the human-error prevention techniques and the employees' awareness of preventing human-errors. Employees' understanding and utilization of the techniques was generally high and training level of employee and training effect on actual works were in good condition. Also, employees answered that the root causes of human-error were due to working environment including tight process, manpower shortage, and excessive mission rather than personal negligence or lack of personal knowledge. Consideration of working environment is certainly needed. At the present time, based on analyzing this survey, the best methods of preventing human-error are personal equipment, training/education substantiality, private mental health check before starting work, prohibit of multiple task performing, compliance with procedures, and enhancement of job site review. However, the most important and basic things for preventing human-error are interests of workers and organizational atmosphere such as communication between managers and workers, and communication between employees and bosses

  15. Generalizing human error rates: A taxonomic approach

    International Nuclear Information System (INIS)

    Buffardi, L.; Fleishman, E.; Allen, J.

    1989-01-01

    It is well established that human error plays a major role in malfunctioning of complex, technological systems and in accidents associated with their operation. Estimates of the rate of human error in the nuclear industry range from 20-65% of all system failures. In response to this, the Nuclear Regulatory Commission has developed a variety of techniques for estimating human error probabilities for nuclear power plant personnel. Most of these techniques require the specification of the range of human error probabilities for various tasks. Unfortunately, very little objective performance data on error probabilities exist for nuclear environments. Thus, when human reliability estimates are required, for example in computer simulation modeling of system reliability, only subjective estimates (usually based on experts' best guesses) can be provided. The objective of the current research is to provide guidelines for the selection of human error probabilities based on actual performance data taken in other complex environments and applying them to nuclear settings. A key feature of this research is the application of a comprehensive taxonomic approach to nuclear and non-nuclear tasks to evaluate their similarities and differences, thus providing a basis for generalizing human error estimates across tasks. In recent years significant developments have occurred in classifying and describing tasks. Initial goals of the current research are to: (1) identify alternative taxonomic schemes that can be applied to tasks, and (2) describe nuclear tasks in terms of these schemes. Three standardized taxonomic schemes (Ability Requirements Approach, Generalized Information-Processing Approach, Task Characteristics Approach) are identified, modified, and evaluated for their suitability in comparing nuclear and non-nuclear power plant tasks. An agenda for future research and its relevance to nuclear power plant safety is also discussed

  16. Intervention strategies for the management of human error

    Science.gov (United States)

    Wiener, Earl L.

    1993-01-01

    This report examines the management of human error in the cockpit. The principles probably apply as well to other applications in the aviation realm (e.g. air traffic control, dispatch, weather, etc.) as well as other high-risk systems outside of aviation (e.g. shipping, high-technology medical procedures, military operations, nuclear power production). Management of human error is distinguished from error prevention. It is a more encompassing term, which includes not only the prevention of error, but also a means of disallowing an error, once made, from adversely affecting system output. Such techniques include: traditional human factors engineering, improvement of feedback and feedforward of information from system to crew, 'error-evident' displays which make erroneous input more obvious to the crew, trapping of errors within a system, goal-sharing between humans and machines (also called 'intent-driven' systems), paperwork management, and behaviorally based approaches, including procedures, standardization, checklist design, training, cockpit resource management, etc. Fifteen guidelines for the design and implementation of intervention strategies are included.

  17. Human Errors in Decision Making

    OpenAIRE

    Mohamad, Shahriari; Aliandrina, Dessy; Feng, Yan

    2005-01-01

    The aim of this paper was to identify human errors in decision making process. The study was focused on a research question such as: what could be the human error as a potential of decision failure in evaluation of the alternatives in the process of decision making. Two case studies were selected from the literature and analyzed to find the human errors contribute to decision fail. Then the analysis of human errors was linked with mental models in evaluation of alternative step. The results o...

  18. A theory of human error

    Science.gov (United States)

    Mcruer, D. T.; Clement, W. F.; Allen, R. W.

    1981-01-01

    Human errors tend to be treated in terms of clinical and anecdotal descriptions, from which remedial measures are difficult to derive. Correction of the sources of human error requires an attempt to reconstruct underlying and contributing causes of error from the circumstantial causes cited in official investigative reports. A comprehensive analytical theory of the cause-effect relationships governing propagation of human error is indispensable to a reconstruction of the underlying and contributing causes. A validated analytical theory of the input-output behavior of human operators involving manual control, communication, supervisory, and monitoring tasks which are relevant to aviation, maritime, automotive, and process control operations is highlighted. This theory of behavior, both appropriate and inappropriate, provides an insightful basis for investigating, classifying, and quantifying the needed cause-effect relationships governing propagation of human error.

  19. The probability and the management of human error

    International Nuclear Information System (INIS)

    Dufey, R.B.; Saull, J.W.

    2004-01-01

    Embedded within modern technological systems, human error is the largest, and indeed dominant contributor to accident cause. The consequences dominate the risk profiles for nuclear power and for many other technologies. We need to quantify the probability of human error for the system as an integral contribution within the overall system failure, as it is generally not separable or predictable for actual events. We also need to provide a means to manage and effectively reduce the failure (error) rate. The fact that humans learn from their mistakes allows a new determination of the dynamic probability and human failure (error) rate in technological systems. The result is consistent with and derived from the available world data for modern technological systems. Comparisons are made to actual data from large technological systems and recent catastrophes. Best estimate values and relationships can be derived for both the human error rate, and for the probability. We describe the potential for new approaches to the management of human error and safety indicators, based on the principles of error state exclusion and of the systematic effect of learning. A new equation is given for the probability of human error (λ) that combines the influences of early inexperience, learning from experience (ε) and stochastic occurrences with having a finite minimum rate, this equation is λ 5.10 -5 + ((1/ε) - 5.10 -5 ) exp(-3*ε). The future failure rate is entirely determined by the experience: thus the past defines the future

  20. Human error prediction and countermeasures based on CREAM in spent nuclear fuel (SNF) transportation

    International Nuclear Information System (INIS)

    Kim, Jae San

    2007-02-01

    Since the 1980s, in order to secure the storage capacity of spent nuclear fuel (SNF) at NPPs, SNF assemblies have been transported on-site from one unit to another unit nearby. However in the future the amount of the spent fuel will approach capacity in the areas used, and some of these SNFs will have to be transported to an off-site spent fuel repository. Most SNF materials used at NPPs will be transported by general cargo ships from abroad, and these SNFs will be stored in an interim storage facility. In the process of transporting SNF, human interactions will involve inspecting and preparing the cask and spent fuel, loading the cask onto the vehicle or ship, transferring the cask as well as storage or monitoring the cask. The transportation of SNF involves a number of activities that depend on reliable human performance. In the case of the transport of a cask, human errors may include spent fuel bundle misidentification or cask transport accidents among others. Reviews of accident events when transporting the Radioactive Material (RAM) throughout the world indicate that human error is the major causes for more than 65% of significant events. For the safety of SNF transportation, it is very important to predict human error and to deduce a method that minimizes the human error. This study examines the human factor effects on the safety of transporting spent nuclear fuel (SNF). It predicts and identifies the possible human errors in the SNF transport process (loading, transfer and storage of the SNF). After evaluating the human error mode in each transport process, countermeasures to minimize the human error are deduced. The human errors in SNF transportation were analyzed using Hollnagel's Cognitive Reliability and Error Analysis Method (CREAM). After determining the important factors for each process, countermeasures to minimize human error are provided in three parts: System design, Operational environment, and Human ability

  1. Understanding human management of automation errors

    Science.gov (United States)

    McBride, Sara E.; Rogers, Wendy A.; Fisk, Arthur D.

    2013-01-01

    Automation has the potential to aid humans with a diverse set of tasks and support overall system performance. Automated systems are not always reliable, and when automation errs, humans must engage in error management, which is the process of detecting, understanding, and correcting errors. However, this process of error management in the context of human-automation interaction is not well understood. Therefore, we conducted a systematic review of the variables that contribute to error management. We examined relevant research in human-automation interaction and human error to identify critical automation, person, task, and emergent variables. We propose a framework for management of automation errors to incorporate and build upon previous models. Further, our analysis highlights variables that may be addressed through design and training to positively influence error management. Additional efforts to understand the error management process will contribute to automation designed and implemented to support safe and effective system performance. PMID:25383042

  2. A qualitative description of human error

    International Nuclear Information System (INIS)

    Li Zhaohuan

    1992-11-01

    The human error has an important contribution to risk of reactor operation. The insight and analytical model are main parts in human reliability analysis. It consists of the concept of human error, the nature, the mechanism of generation, the classification and human performance influence factors. On the operating reactor the human error is defined as the task-human-machine mismatch. The human error event is focused on the erroneous action and the unfavored result. From the time limitation of performing a task, the operation is divided into time-limited and time-opened. The HCR (human cognitive reliability) model is suited for only time-limited. The basic cognitive process consists of the information gathering, cognition/thinking, decision making and action. The human erroneous action may be generated in any stage of this process. The more natural ways to classify human errors are presented. The human performance influence factors including personal, organizational and environmental factors are also listed

  3. A qualitative description of human error

    Energy Technology Data Exchange (ETDEWEB)

    Zhaohuan, Li [Academia Sinica, Beijing, BJ (China). Inst. of Atomic Energy

    1992-11-01

    The human error has an important contribution to risk of reactor operation. The insight and analytical model are main parts in human reliability analysis. It consists of the concept of human error, the nature, the mechanism of generation, the classification and human performance influence factors. On the operating reactor the human error is defined as the task-human-machine mismatch. The human error event is focused on the erroneous action and the unfavored result. From the time limitation of performing a task, the operation is divided into time-limited and time-opened. The HCR (human cognitive reliability) model is suited for only time-limited. The basic cognitive process consists of the information gathering, cognition/thinking, decision making and action. The human erroneous action may be generated in any stage of this process. The more natural ways to classify human errors are presented. The human performance influence factors including personal, organizational and environmental factors are also listed.

  4. A model-based and computer-aided approach to analysis of human errors in nuclear power plants

    International Nuclear Information System (INIS)

    Yoon, Wan C.; Lee, Yong H.; Kim, Young S.

    1996-01-01

    Since the operator's mission in NPPs is increasingly defined by cognitive tasks such as monitoring, diagnosis and planning, the focus of human error analysis should also move from external actions to internal decision-making processes. While more elaborate analysis of cognitive aspects of human errors will help understand their causes and derive effective countermeasures, a lack of framework and an arbitrary resolution of description may hamper the effectiveness of such analysis. This paper presents new model-based schemes of event description and error classification as well as an interactive computerized support system. The schemes and the support system were produced in an effort to develop an improved version of HPES. The use of a decision-making model enables the analyst to document cognitive aspects of human performance explicitly and in a proper resolution. The stage-specific terms used in the proposed schemes make the task of characterizing human errors easier and confident for field analysts. The support system was designed to help the analyst achieve a contextually well-integrated analysis throughout the different parts of HPES

  5. Analysis of Employee's Survey for Preventing Human-Errors

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Chanho; Kim, Younggab; Joung, Sanghoun [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    Human errors in nuclear power plant can cause large and small events or incidents. These events or incidents are one of main contributors of reactor trip and might threaten the safety of nuclear plants. To prevent human-errors, KHNP(nuclear power plants) introduced 'Human-error prevention techniques' and have applied the techniques to main parts such as plant operation, operation support, and maintenance and engineering. This paper proposes the methods to prevent and reduce human-errors in nuclear power plants through analyzing survey results which includes the utilization of the human-error prevention techniques and the employees' awareness of preventing human-errors. With regard to human-error prevention, this survey analysis presented the status of the human-error prevention techniques and the employees' awareness of preventing human-errors. Employees' understanding and utilization of the techniques was generally high and training level of employee and training effect on actual works were in good condition. Also, employees answered that the root causes of human-error were due to working environment including tight process, manpower shortage, and excessive mission rather than personal negligence or lack of personal knowledge. Consideration of working environment is certainly needed. At the present time, based on analyzing this survey, the best methods of preventing human-error are personal equipment, training/education substantiality, private mental health check before starting work, prohibit of multiple task performing, compliance with procedures, and enhancement of job site review. However, the most important and basic things for preventing human-error are interests of workers and organizational atmosphere such as communication between managers and workers, and communication between employees and bosses.

  6. Research on Human-Error Factors of Civil Aircraft Pilots Based On Grey Relational Analysis

    Directory of Open Access Journals (Sweden)

    Guo Yundong

    2018-01-01

    Full Text Available In consideration of the situation that civil aviation accidents involve many human-error factors and show the features of typical grey systems, an index system of civil aviation accident human-error factors is built using human factor analysis and classification system model. With the data of accidents happened worldwide between 2008 and 2011, the correlation between human-error factors can be analyzed quantitatively using the method of grey relational analysis. Research results show that the order of main factors affecting pilot human-error factors is preconditions for unsafe acts, unsafe supervision, organization and unsafe acts. The factor related most closely with second-level indexes and pilot human-error factors is the physical/mental limitations of pilots, followed by supervisory violations. The relevancy between the first-level indexes and the corresponding second-level indexes and the relevancy between second-level indexes can also be analyzed quantitatively.

  7. Human Errors and Bridge Management Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, A. S.

    on basis of reliability profiles for bridges without human errors are extended to include bridges with human errors. The first rehabilitation distributions for bridges without and with human errors are combined into a joint first rehabilitation distribution. The methodology presented is illustrated...... for reinforced concrete bridges....

  8. SCHEME (Soft Control Human error Evaluation MEthod) for advanced MCR HRA

    International Nuclear Information System (INIS)

    Jang, Inseok; Jung, Wondea; Seong, Poong Hyun

    2015-01-01

    The Technique for Human Error Rate Prediction (THERP), Korean Human Reliability Analysis (K-HRA), Human Error Assessment and Reduction Technique (HEART), A Technique for Human Event Analysis (ATHEANA), Cognitive Reliability and Error Analysis Method (CREAM), and Simplified Plant Analysis Risk Human Reliability Assessment (SPAR-H) in relation to NPP maintenance and operation. Most of these methods were developed considering the conventional type of Main Control Rooms (MCRs). They are still used for HRA in advanced MCRs even though the operating environment of advanced MCRs in NPPs has been considerably changed by the adoption of new human-system interfaces such as computer-based soft controls. Among the many features in advanced MCRs, soft controls are an important feature because the operation action in NPP advanced MCRs is performed by soft controls. Consequently, those conventional methods may not sufficiently consider the features of soft control execution human errors. To this end, a new framework of a HRA method for evaluating soft control execution human error is suggested by performing the soft control task analysis and the literature reviews regarding widely accepted human error taxonomies. In this study, the framework of a HRA method for evaluating soft control execution human error in advanced MCRs is developed. First, the factors which HRA method in advanced MCRs should encompass are derived based on the literature review, and soft control task analysis. Based on the derived factors, execution HRA framework in advanced MCRs is developed mainly focusing on the features of soft control. Moreover, since most current HRA database deal with operation in conventional type of MCRs and are not explicitly designed to deal with digital HSI, HRA database are developed under lab scale simulation

  9. Selection of anchor values for human error probability estimation

    International Nuclear Information System (INIS)

    Buffardi, L.C.; Fleishman, E.A.; Allen, J.A.

    1989-01-01

    There is a need for more dependable information to assist in the prediction of human errors in nuclear power environments. The major objective of the current project is to establish guidelines for using error probabilities from other task settings to estimate errors in the nuclear environment. This involves: (1) identifying critical nuclear tasks, (2) discovering similar tasks in non-nuclear environments, (3) finding error data for non-nuclear tasks, and (4) establishing error-rate values for the nuclear tasks based on the non-nuclear data. A key feature is the application of a classification system to nuclear and non-nuclear tasks to evaluate their similarities and differences in order to provide a basis for generalizing human error estimates across tasks. During the first eight months of the project, several classification systems have been applied to a sample of nuclear tasks. They are discussed in terms of their potential for establishing task equivalence and transferability of human error rates across situations

  10. Human errors, countermeasures for their prevention and evaluation

    International Nuclear Information System (INIS)

    Kohda, Takehisa; Inoue, Koichi

    1992-01-01

    The accidents originated in human errors have occurred as ever in recent large accidents such as the TMI accident and the Chernobyl accident. The proportion of the accidents originated in human errors is unexpectedly high, therefore, the reliability and safety of hardware are improved hereafter, but the improvement of human reliability cannot be expected. Human errors arise by the difference between the function required for men and the function actually accomplished by men, and the results exert some adverse effect to systems. Human errors are classified into design error, manufacture error, operation error, maintenance error, checkup error and general handling error. In terms of behavior, human errors are classified into forget to do, fail to do, do that must not be done, mistake in order and do at improper time. The factors in human error occurrence are circumstantial factor, personal factor and stress factor. As the method of analyzing and evaluating human errors, system engineering method such as probabilistic risk assessment is used. The technique for human error rate prediction, the method for human cognitive reliability, confusion matrix and SLIM-MAUD are also used. (K.I.)

  11. Research trend on human error reduction

    International Nuclear Information System (INIS)

    Miyaoka, Sadaoki

    1990-01-01

    Human error has been the problem in all industries. In 1988, the Bureau of Mines, Department of the Interior, USA, carried out the worldwide survey on the human error in all industries in relation to the fatal accidents in mines. There was difference in the results according to the methods of collecting data, but the proportion that human error took in the total accidents distributed in the wide range of 20∼85%, and was 35% on the average. The rate of occurrence of accidents and troubles in Japanese nuclear power stations is shown, and the rate of occurrence of human error is 0∼0.5 cases/reactor-year, which did not much vary. Therefore, the proportion that human error took in the total tended to increase, and it has become important to reduce human error for lowering the rate of occurrence of accidents and troubles hereafter. After the TMI accident in 1979 in USA, the research on man-machine interface became active, and after the Chernobyl accident in 1986 in USSR, the problem of organization and management has been studied. In Japan, 'Safety 21' was drawn up by the Advisory Committee for Energy, and also the annual reports on nuclear safety pointed out the importance of human factors. The state of the research on human factors in Japan and abroad and three targets to reduce human error are reported. (K.I.)

  12. The cost of human error intervention

    International Nuclear Information System (INIS)

    Bennett, C.T.; Banks, W.W.; Jones, E.D.

    1994-03-01

    DOE has directed that cost-benefit analyses be conducted as part of the review process for all new DOE orders. This new policy will have the effect of ensuring that DOE analysts can justify the implementation costs of the orders that they develop. We would like to argue that a cost-benefit analysis is merely one phase of a complete risk management program -- one that would more than likely start with a probabilistic risk assessment. The safety community defines risk as the probability of failure times the severity of consequence. An engineering definition of failure can be considered in terms of physical performance, as in mean-time-between-failure; or, it can be thought of in terms of human performance, as in probability of human error. The severity of consequence of a failure can be measured along any one of a number of dimensions -- economic, political, or social. Clearly, an analysis along one dimension cannot be directly compared to another but, a set of cost-benefit analyses, based on a series of cost-dimensions, can be extremely useful to managers who must prioritize their resources. Over the last two years, DOE has been developing a series of human factors orders, directed a lowering the probability of human error -- or at least changing the distribution of those errors. The following discussion presents a series of cost-benefit analyses using historical events in the nuclear industry. However, we would first like to discuss some of the analytic cautions that must be considered when we deal with human error

  13. PERANCANGAN COMPUTER AIDED SYSTEM DALAM MENGANALISA HUMAN ERROR DI PERKERETAAPIAN INDONESIA

    Directory of Open Access Journals (Sweden)

    Wiwik Budiawan

    2013-06-01

    Full Text Available Kecelakaan kereta api (KA yang terjadi secara beruntun di Indonesia sudah berada pada tingkat kritis. Berdasarkan data dari Direktorat Jendral Perkeretaapian, dalam kurun 5 tahun terakhir (2005-2009 total terdapat 611 kecelakaan KA.  Banyak faktor yang berkontribusi menyebabkan terjadinya kecelakaan, antara lain: sarana, prasarana, SDM operator (human error, eksternal, dan alam.  Kegagalan manusia (Human error merupakan salah satu faktor yang berpotensi menyebabkan terjadinya suatu kecelakaan KA dan dinyatakan sebagai faktor utama penyebab terjadinya suatu kecelakaan kereta api di Indonesia. Namun, tidak jelas bagaimana teknik analisis ini dilakukan. Kajian human error yang dilakukan Komite Nasional Keselamatan Transportasi (KNKT masih relatif terbatas, tidak dilengkapi dengan metode yang sistematis. Terdapat beberapa metode yang telah dikembangkan saat ini, tetapi untuk moda transportasi kereta api masih belum banyak dikembangkan. Human Factors Analysis and Classification System (HFACS merupakan metode analisis human error yang dikembangkan dan disesuaikan dengan sistem perkeretaapian Indonesia. Guna meningkatkan keandalan dalam analisis human error, HFACS kemudian dikembangkan dalam bentuk aplikasi berbasis web yang dapat diakses di komputer maupun smartphone. Hasil penelitian ini dapat dimanfaatkan oleh KNKT sebagai metode analisis kecelakaan kereta api khususnya terkait dengan human error. Kata kunci : human error, HFACS, CAS, kereta api   Abstract Train wreck (KA which occurred in quick succession in Indonesia already at a critical level. Based on data from the Directorate General of Railways, during the last 5 years (2005-2009 there were a total of 611 railway accidents. Many factors contribute to cause accidents, such as: facilities, infrastructure, human operator (human error, external, and natural. Human failure (Human error is one of the factors that could potentially cause a train accident and expressed as the main factors causing

  14. A Human Error Analysis Procedure for Identifying Potential Error Modes and Influencing Factors for Test and Maintenance Activities

    International Nuclear Information System (INIS)

    Kim, Jae Whan; Park, Jin Kyun

    2010-01-01

    Periodic or non-periodic test and maintenance (T and M) activities in large, complex systems such as nuclear power plants (NPPs) are essential for sustaining stable and safe operation of the systems. On the other hand, it also has been raised that human erroneous actions that might occur during T and M activities has the possibility of incurring unplanned reactor trips (RTs) or power derate, making safety-related systems unavailable, or making the reliability of components degraded. Contribution of human errors during normal and abnormal activities of NPPs to the unplanned RTs is known to be about 20% of the total events. This paper introduces a procedure for predictively analyzing human error potentials when maintenance personnel perform T and M tasks based on a work procedure or their work plan. This procedure helps plant maintenance team prepare for plausible human errors. The procedure to be introduced is focusing on the recurrent error forms (or modes) in execution-based errors such as wrong object, omission, too little, and wrong action

  15. Chernobyl - system accident or human error?

    International Nuclear Information System (INIS)

    Stang, E.

    1996-01-01

    Did human error cause the Chernobyl disaster? The standard point of view is that operator error was the root cause of the disaster. This was also the view of the Soviet Accident Commission. The paper analyses the operator errors at Chernobyl in a system context. The reactor operators committed errors that depended upon a lot of other failures that made up a complex accident scenario. The analysis is based on Charles Perrow's analysis of technological disasters. Failure possibility is an inherent property of high-risk industrial installations. The Chernobyl accident consisted of a chain of events that were both extremely improbable and difficult to predict. It is not reasonable to put the blame for the disaster on the operators. (author)

  16. Applying lessons learned to enhance human performance and reduce human error for ISS operations

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, W.R.

    1998-09-01

    A major component of reliability, safety, and mission success for space missions is ensuring that the humans involved (flight crew, ground crew, mission control, etc.) perform their tasks and functions as required. This includes compliance with training and procedures during normal conditions, and successful compensation when malfunctions or unexpected conditions occur. A very significant issue that affects human performance in space flight is human error. Human errors can invalidate carefully designed equipment and procedures. If certain errors combine with equipment failures or design flaws, mission failure or loss of life can occur. The control of human error during operation of the International Space Station (ISS) will be critical to the overall success of the program. As experience from Mir operations has shown, human performance plays a vital role in the success or failure of long duration space missions. The Department of Energy`s Idaho National Engineering and Environmental Laboratory (INEEL) is developed a systematic approach to enhance human performance and reduce human errors for ISS operations. This approach is based on the systematic identification and evaluation of lessons learned from past space missions such as Mir to enhance the design and operation of ISS. This paper describes previous INEEL research on human error sponsored by NASA and how it can be applied to enhance human reliability for ISS.

  17. Sleep quality, posttraumatic stress, depression, and human errors in train drivers: a population-based nationwide study in South Korea.

    Science.gov (United States)

    Jeon, Hong Jin; Kim, Ji-Hae; Kim, Bin-Na; Park, Seung Jin; Fava, Maurizio; Mischoulon, David; Kang, Eun-Ho; Roh, Sungwon; Lee, Dongsoo

    2014-12-01

    Human error is defined as an unintended error that is attributable to humans rather than machines, and that is important to avoid to prevent accidents. We aimed to investigate the association between sleep quality and human errors among train drivers. Cross-sectional. Population-based. A sample of 5,480 subjects who were actively working as train drivers were recruited in South Korea. The participants were 4,634 drivers who completed all questionnaires (response rate 84.6%). None. The Pittsburgh Sleep Quality Index (PSQI), the Center for Epidemiologic Studies Depression Scale (CES-D), the Impact of Event Scale-Revised (IES-R), the State-Trait Anxiety Inventory (STAI), and the Korean Occupational Stress Scale (KOSS). Of 4,634 train drivers, 349 (7.5%) showed more than one human error per 5 y. Human errors were associated with poor sleep quality, higher PSQI total scores, short sleep duration at night, and longer sleep latency. Among train drivers with poor sleep quality, those who experienced severe posttraumatic stress showed a significantly higher number of human errors than those without. Multiple logistic regression analysis showed that human errors were significantly associated with poor sleep quality and posttraumatic stress, whereas there were no significant associations with depression, trait and state anxiety, and work stress after adjusting for age, sex, education years, marital status, and career duration. Poor sleep quality was found to be associated with more human errors in train drivers, especially in those who experienced severe posttraumatic stress. © 2014 Associated Professional Sleep Societies, LLC.

  18. AGAPE-ET for human error analysis of emergency tasks and its application

    International Nuclear Information System (INIS)

    Kim, J. H.; Jeong, W. D.

    2002-01-01

    The paper presents a proceduralised human reliability analysis (HRA) methodology, AGAPE-ET (A Guidance And Procedure for Human Error Analysis for Emergency Tasks), covering both qualitative error analysis and quantification of human error probability (HEP) of emergency tasks in nuclear power plants. The AGAPE-ET method is based on the simplified cognitive model. By each cognitive function, error causes or error-likely situations have been identified considering the characteristics of the performance of each cognitive function and influencing mechanism of the performance influencing factors (PIFs) on the cognitive function. Then, error analysis items have been determined from the identified error causes or error-likely situations and a human error analysis procedure based on the error analysis items is organised to help the analysts cue or guide overall human error analysis. The basic scheme for the quantification of HEP consists in the multiplication of the BHEP assigned by the error analysis item and the weight from the influencing factors decision tree (IFDT) constituted by cognitive function. The method can be characterised by the structured identification of the weak points of the task required to perform and the efficient analysis process that the analysts have only to carry out with the necessary cognitive functions. The paper also presents the application of AGAPE-ET to 31 nuclear emergency tasks and its results

  19. A stochastic dynamic model for human error analysis in nuclear power plants

    Science.gov (United States)

    Delgado-Loperena, Dharma

    Nuclear disasters like Three Mile Island and Chernobyl indicate that human performance is a critical safety issue, sending a clear message about the need to include environmental press and competence aspects in research. This investigation was undertaken to serve as a roadmap for studying human behavior through the formulation of a general solution equation. The theoretical model integrates models from two heretofore-disassociated disciplines (behavior specialists and technical specialists), that historically have independently studied the nature of error and human behavior; including concepts derived from fractal and chaos theory; and suggests re-evaluation of base theory regarding human error. The results of this research were based on comprehensive analysis of patterns of error, with the omnipresent underlying structure of chaotic systems. The study of patterns lead to a dynamic formulation, serving for any other formula used to study human error consequences. The search for literature regarding error yielded insight for the need to include concepts rooted in chaos theory and strange attractors---heretofore unconsidered by mainstream researchers who investigated human error in nuclear power plants or those who employed the ecological model in their work. The study of patterns obtained from the rupture of a steam generator tube (SGTR) event simulation, provided a direct application to aspects of control room operations in nuclear power plant operations. In doing so, the conceptual foundation based in the understanding of the patterns of human error analysis can be gleaned, resulting in reduced and prevent undesirable events.

  20. A human error probability estimate methodology based on fuzzy inference and expert judgment on nuclear plants

    International Nuclear Information System (INIS)

    Nascimento, C.S. do; Mesquita, R.N. de

    2009-01-01

    Recent studies point human error as an important factor for many industrial and nuclear accidents: Three Mile Island (1979), Bhopal (1984), Chernobyl and Challenger (1986) are classical examples. Human contribution to these accidents may be better understood and analyzed by using Human Reliability Analysis (HRA), which has being taken as an essential part on Probabilistic Safety Analysis (PSA) of nuclear plants. Both HRA and PSA depend on Human Error Probability (HEP) for a quantitative analysis. These probabilities are extremely affected by the Performance Shaping Factors (PSF), which has a direct effect on human behavior and thus shape HEP according with specific environment conditions and personal individual characteristics which are responsible for these actions. This PSF dependence raises a great problem on data availability as turn these scarcely existent database too much generic or too much specific. Besides this, most of nuclear plants do not keep historical records of human error occurrences. Therefore, in order to overcome this occasional data shortage, a methodology based on Fuzzy Inference and expert judgment was employed in this paper in order to determine human error occurrence probabilities and to evaluate PSF's on performed actions by operators in a nuclear power plant (IEA-R1 nuclear reactor). Obtained HEP values were compared with reference tabled data used on current literature in order to show method coherence and valid approach. This comparison leads to a conclusion that this work results are able to be employed both on HRA and PSA enabling efficient prospection of plant safety conditions, operational procedures and local working conditions potential improvements (author)

  1. Modeling Human Error Mechanism for Soft Control in Advanced Control Rooms (ACRs)

    Energy Technology Data Exchange (ETDEWEB)

    Aljneibi, Hanan Salah Ali [Khalifa Univ., Abu Dhabi (United Arab Emirates); Ha, Jun Su; Kang, Seongkeun; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of)

    2015-10-15

    To achieve the switch from conventional analog-based design to digital design in ACRs, a large number of manual operating controls and switches have to be replaced by a few common multi-function devices which is called soft control system. The soft controls in APR-1400 ACRs are classified into safety-grade and non-safety-grade soft controls; each was designed using different and independent input devices in ACRs. The operations using soft controls require operators to perform new tasks which were not necessary in conventional controls such as navigating computerized displays to monitor plant information and control devices. These kinds of computerized displays and soft controls may make operations more convenient but they might cause new types of human error. In this study the human error mechanism during the soft controls is studied and modeled to be used for analysis and enhancement of human performance (or human errors) during NPP operation. The developed model would contribute to a lot of applications to improve human performance (or reduce human errors), HMI designs, and operators' training program in ACRs. The developed model of human error mechanism for the soft control is based on assumptions that a human operator has certain amount of capacity in cognitive resources and if resources required by operating tasks are greater than resources invested by the operator, human error (or poor human performance) is likely to occur (especially in 'slip'); good HMI (Human-machine Interface) design decreases the required resources; operator's skillfulness decreases the required resources; and high vigilance increases the invested resources. In this study the human error mechanism during the soft controls is studied and modeled to be used for analysis and enhancement of human performance (or reduction of human errors) during NPP operation.

  2. Modeling Human Error Mechanism for Soft Control in Advanced Control Rooms (ACRs)

    International Nuclear Information System (INIS)

    Aljneibi, Hanan Salah Ali; Ha, Jun Su; Kang, Seongkeun; Seong, Poong Hyun

    2015-01-01

    To achieve the switch from conventional analog-based design to digital design in ACRs, a large number of manual operating controls and switches have to be replaced by a few common multi-function devices which is called soft control system. The soft controls in APR-1400 ACRs are classified into safety-grade and non-safety-grade soft controls; each was designed using different and independent input devices in ACRs. The operations using soft controls require operators to perform new tasks which were not necessary in conventional controls such as navigating computerized displays to monitor plant information and control devices. These kinds of computerized displays and soft controls may make operations more convenient but they might cause new types of human error. In this study the human error mechanism during the soft controls is studied and modeled to be used for analysis and enhancement of human performance (or human errors) during NPP operation. The developed model would contribute to a lot of applications to improve human performance (or reduce human errors), HMI designs, and operators' training program in ACRs. The developed model of human error mechanism for the soft control is based on assumptions that a human operator has certain amount of capacity in cognitive resources and if resources required by operating tasks are greater than resources invested by the operator, human error (or poor human performance) is likely to occur (especially in 'slip'); good HMI (Human-machine Interface) design decreases the required resources; operator's skillfulness decreases the required resources; and high vigilance increases the invested resources. In this study the human error mechanism during the soft controls is studied and modeled to be used for analysis and enhancement of human performance (or reduction of human errors) during NPP operation

  3. Nursing Errors in Intensive Care Unit by Human Error Identification in Systems Tool: A Case Study

    Directory of Open Access Journals (Sweden)

    Nezamodini

    2016-03-01

    Full Text Available Background Although health services are designed and implemented to improve human health, the errors in health services are a very common phenomenon and even sometimes fatal in this field. Medical errors and their cost are global issues with serious consequences for the patients’ community that are preventable and require serious attention. Objectives The current study aimed to identify possible nursing errors applying human error identification in systems tool (HEIST in the intensive care units (ICUs of hospitals. Patients and Methods This descriptive research was conducted in the intensive care unit of a hospital in Khuzestan province in 2013. Data were collected through observation and interview by nine nurses in this section in a period of four months. Human error classification was based on Rose and Rose and Swain and Guttmann models. According to HEIST work sheets the guide questions were answered and error causes were identified after the determination of the type of errors. Results In total 527 errors were detected. The performing operation on the wrong path had the highest frequency which was 150, and the second rate with a frequency of 136 was doing the tasks later than the deadline. Management causes with a frequency of 451 were the first rank among identified errors. Errors mostly occurred in the system observation stage and among the performance shaping factors (PSFs, time was the most influencing factor in occurrence of human errors. Conclusions Finally, in order to prevent the occurrence and reduce the consequences of identified errors the following suggestions were proposed : appropriate training courses, applying work guidelines and monitoring their implementation, increasing the number of work shifts, hiring professional workforce, equipping work space with appropriate facilities and equipment.

  4. A New Human-Machine Interfaces of Computer-based Procedure System to Reduce the Team Errors in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Kim, Sa Kil; Sim, Joo Hyun; Lee, Hyun Chul

    2016-01-01

    In this study, we identify the emerging types of team errors, especially, in digitalized control room of nuclear power plants such as the APR-1400 main control room of Korea. Most works in nuclear industry are to be performed by a team of more than two persons. Even though the individual errors can be detected and recovered by the qualified others and/or the well trained team, it is rather seldom that the errors by team could be easily detected and properly recovered by the team itself. Note that the team is defined as two or more people who are appropriately interacting with each other, and the team is a dependent aggregate, which accomplishes a valuable goal. Organizational errors sometimes increase the likelihood of operator errors through the active failure pathway and, at the same time, enhance the possibility of adverse outcomes through defensive weaknesses. We incorporate the crew resource management as a representative approach to deal with the team factors of the human errors. We suggest a set of crew resource management training procedures under the unsafe environments where human errors can have devastating effects. We are on the way to develop alternative interfaces against team error in a condition of using a computer-based procedure system in a digitalized main control room. The computer-based procedure system is a representative feature of digitalized control room. In this study, we will propose new interfaces of computer-based procedure system to reduce feasible team errors. We are on the way of effectiveness test to validate whether the new interface can reduce team errors during operating with a computer-based procedure system in a digitalized control room

  5. A New Human-Machine Interfaces of Computer-based Procedure System to Reduce the Team Errors in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sa Kil; Sim, Joo Hyun; Lee, Hyun Chul [Korea Atomic Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    In this study, we identify the emerging types of team errors, especially, in digitalized control room of nuclear power plants such as the APR-1400 main control room of Korea. Most works in nuclear industry are to be performed by a team of more than two persons. Even though the individual errors can be detected and recovered by the qualified others and/or the well trained team, it is rather seldom that the errors by team could be easily detected and properly recovered by the team itself. Note that the team is defined as two or more people who are appropriately interacting with each other, and the team is a dependent aggregate, which accomplishes a valuable goal. Organizational errors sometimes increase the likelihood of operator errors through the active failure pathway and, at the same time, enhance the possibility of adverse outcomes through defensive weaknesses. We incorporate the crew resource management as a representative approach to deal with the team factors of the human errors. We suggest a set of crew resource management training procedures under the unsafe environments where human errors can have devastating effects. We are on the way to develop alternative interfaces against team error in a condition of using a computer-based procedure system in a digitalized main control room. The computer-based procedure system is a representative feature of digitalized control room. In this study, we will propose new interfaces of computer-based procedure system to reduce feasible team errors. We are on the way of effectiveness test to validate whether the new interface can reduce team errors during operating with a computer-based procedure system in a digitalized control room.

  6. Human error in remote Afterloading Brachytherapy

    International Nuclear Information System (INIS)

    Quinn, M.L.; Callan, J.; Schoenfeld, I.; Serig, D.

    1994-01-01

    Remote Afterloading Brachytherapy (RAB) is a medical process used in the treatment of cancer. RAB uses a computer-controlled device to remotely insert and remove radioactive sources close to a target (or tumor) in the body. Some RAB problems affecting the radiation dose to the patient have been reported and attributed to human error. To determine the root cause of human error in the RAB system, a human factors team visited 23 RAB treatment sites in the US. The team observed RAB treatment planning and delivery, interviewed RAB personnel, and performed walk-throughs, during which staff demonstrated the procedures and practices used in performing RAB tasks. Factors leading to human error in the RAB system were identified. The impact of those factors on the performance of RAB was then evaluated and prioritized in terms of safety significance. Finally, the project identified and evaluated alternative approaches for resolving the safety significant problems related to human error

  7. Human Error Assessmentin Minefield Cleaning Operation Using Human Event Analysis

    Directory of Open Access Journals (Sweden)

    Mohammad Hajiakbari

    2015-12-01

    Full Text Available Background & objective: Human error is one of the main causes of accidents. Due to the unreliability of the human element and the high-risk nature of demining operations, this study aimed to assess and manage human errors likely to occur in such operations. Methods: This study was performed at a demining site in war zones located in the West of Iran. After acquiring an initial familiarity with the operations, methods, and tools of clearing minefields, job task related to clearing landmines were specified. Next, these tasks were studied using HTA and related possible errors were assessed using ATHEANA. Results: de-mining task was composed of four main operations, including primary detection, technical identification, investigation, and neutralization. There were found four main reasons for accidents occurring in such operations; walking on the mines, leaving mines with no action, error in neutralizing operation and environmental explosion. The possibility of human error in mine clearance operations was calculated as 0.010. Conclusion: The main causes of human error in de-mining operations can be attributed to various factors such as poor weather and operating conditions like outdoor work, inappropriate personal protective equipment, personality characteristics, insufficient accuracy in the work, and insufficient time available. To reduce the probability of human error in de-mining operations, the aforementioned factors should be managed properly.

  8. The Relationship between Human Operators' Psycho-physiological Condition and Human Errors in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Kim, Arryum; Jang, Inseok; Kang, Hyungook; Seong, Poonghyun

    2013-01-01

    The safe operation of nuclear power plants (NPPs) is substantially dependent on the performance of the human operators who operate the systems. In this environment, human errors caused by inappropriate performance of operator have been considered to be critical since it may lead serious problems in the safety-critical plants. In order to provide meaningful insights to prevent human errors and enhance the human performance, operators' physiological conditions such as stress and workload have been investigated. Physiological measurements were considered as reliable tools to assess the stress and workload. T. Q. Tran et al. and J. B. Brooking et al pointed out that operators' workload can be assessed using eye tracking, galvanic skin response, electroencephalograms (EEGs), heart rate, respiration and other measurements. The purpose of this study is to investigate the effect of the human operators' tense level and knowledge level to the number of human errors. For this study, the experiments were conducted in the mimic of the main control rooms (MCR) in NPP. It utilized the compact nuclear simulator (CNS) which is modeled based on the three loop Pressurized Water Reactor, 993MWe, Kori unit 3 and 4 in Korea and the subjects were asked to follow the tasks described in the emergency operating procedures (EOP). During the simulation, three kinds of physiological measurement were utilized; Electrocardiogram (ECG), EEG and nose temperature. Also, subjects were divided into three groups based on their knowledge of the plant operation. The result shows that subjects who are tense make fewer errors. In addition, subjects who are in higher knowledge level tend to be tense and make fewer errors. For the ECG data, subjects who make fewer human errors tend to be located in higher tense level area of high SNS activity and low PSNS activity. The results of EEG data are also similar to ECG result. Beta power ratio of subjects who make fewer errors was higher. Since beta power ratio is

  9. A Conceptual Framework of Human Reliability Analysis for Execution Human Error in NPP Advanced MCRs

    Energy Technology Data Exchange (ETDEWEB)

    Jang, In Seok; Kim, Ar Ryum; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of); Jung, Won Dea [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-08-15

    The operation environment of Main Control Rooms (MCRs) in Nuclear Power Plants (NPPs) has changed with the adoption of new human-system interfaces that are based on computer-based technologies. The MCRs that include these digital and computer technologies, such as large display panels, computerized procedures, and soft controls, are called Advanced MCRs. Among the many features of Advanced MCRs, soft controls are a particularly important feature because the operation action in NPP Advanced MCRs is performed by soft control. Using soft controls such as mouse control, and touch screens, operators can select a specific screen, then choose the controller, and finally manipulate the given devices. Due to the different interfaces between soft control and hardwired conventional type control, different human error probabilities and a new Human Reliability Analysis (HRA) framework should be considered in the HRA for advanced MCRs. In other words, new human error modes should be considered for interface management tasks such as navigation tasks, and icon (device) selection tasks in monitors and a new framework of HRA method taking these newly generated human error modes into account should be considered. In this paper, a conceptual framework for a HRA method for the evaluation of soft control execution human error in advanced MCRs is suggested by analyzing soft control tasks.

  10. A Conceptual Framework of Human Reliability Analysis for Execution Human Error in NPP Advanced MCRs

    International Nuclear Information System (INIS)

    Jang, In Seok; Kim, Ar Ryum; Seong, Poong Hyun; Jung, Won Dea

    2014-01-01

    The operation environment of Main Control Rooms (MCRs) in Nuclear Power Plants (NPPs) has changed with the adoption of new human-system interfaces that are based on computer-based technologies. The MCRs that include these digital and computer technologies, such as large display panels, computerized procedures, and soft controls, are called Advanced MCRs. Among the many features of Advanced MCRs, soft controls are a particularly important feature because the operation action in NPP Advanced MCRs is performed by soft control. Using soft controls such as mouse control, and touch screens, operators can select a specific screen, then choose the controller, and finally manipulate the given devices. Due to the different interfaces between soft control and hardwired conventional type control, different human error probabilities and a new Human Reliability Analysis (HRA) framework should be considered in the HRA for advanced MCRs. In other words, new human error modes should be considered for interface management tasks such as navigation tasks, and icon (device) selection tasks in monitors and a new framework of HRA method taking these newly generated human error modes into account should be considered. In this paper, a conceptual framework for a HRA method for the evaluation of soft control execution human error in advanced MCRs is suggested by analyzing soft control tasks

  11. Can human error theory explain non-adherence?

    Science.gov (United States)

    Barber, Nick; Safdar, A; Franklin, Bryoney D

    2005-08-01

    To apply human error theory to explain non-adherence and examine how well it fits. Patients who were taking chronic medication were telephoned and asked whether they had been adhering to their medicine, and if not the reasons were explored and analysed according to a human error theory. Of 105 patients, 87 were contacted by telephone and they took part in the study. Forty-two recalled being non-adherent, 17 of them in the last 7 days; 11 of the 42 were intentionally non-adherent. The errors could be described by human error theory, and it explained unintentional non-adherence well, however, the application of 'rules' was difficult when considering mistakes. The consideration of error producing conditions and latent failures also revealed useful contributing factors. Human error theory offers a new and valuable way of understanding non-adherence, and could inform interventions. However, the theory needs further development to explain intentional non-adherence.

  12. Human errors in operation - what to do with them?

    International Nuclear Information System (INIS)

    Michalek, J.

    2009-01-01

    'It is human to make errors!' This saying of our predecessors is still current and will continue to be valid also in the future, until human is a human. Errors cannot be completely eliminated from human activities. In average human makes two simple errors in one hour. For example, how many typing errors do we make while typing on the computer keyboard? How many times we make mistakes in writing the date in the first days of a new year? These errors have no major consequences, however, in certain situations errors of humans are very unpleasant and may be also very costly, they may even endanger human lives. (author)

  13. A strategy for minimizing common mode human error in executing critical functions and tasks

    International Nuclear Information System (INIS)

    Beltracchi, L.; Lindsay, R.W.

    1992-01-01

    Human error in execution of critical functions and tasks can be costly. The Three Mile Island and the Chernobyl Accidents are examples of results from human error in the nuclear industry. There are similar errors that could no doubt be cited from other industries. This paper discusses a strategy to minimize common mode human error in the execution of critical functions and tasks. The strategy consists of the use of human redundancy, and also diversity in human cognitive behavior: skill-, rule-, and knowledge-based behavior. The authors contend that the use of diversity in human cognitive behavior is possible, and it minimizes common mode error

  14. SHERPA: A systematic human error reduction and prediction approach

    International Nuclear Information System (INIS)

    Embrey, D.E.

    1986-01-01

    This paper describes a Systematic Human Error Reduction and Prediction Approach (SHERPA) which is intended to provide guidelines for human error reduction and quantification in a wide range of human-machine systems. The approach utilizes as its basic current cognitive models of human performance. The first module in SHERPA performs task and human error analyses, which identify likely error modes, together with guidelines for the reduction of these errors by training, procedures and equipment redesign. The second module uses a SARAH approach to quantify the probability of occurrence of the errors identified earlier, and provides cost benefit analyses to assist in choosing the appropriate error reduction approaches in the third module

  15. Human Error and Organizational Management

    Directory of Open Access Journals (Sweden)

    Alecxandrina DEACONU

    2009-01-01

    Full Text Available The concern for performance is a topic that raises interest in the businessenvironment but also in other areas that – even if they seem distant from thisworld – are aware of, interested in or conditioned by the economy development.As individual performance is very much influenced by the human resource, wechose to analyze in this paper the mechanisms that generate – consciously or not–human error nowadays.Moreover, the extremely tense Romanian context,where failure is rather a rule than an exception, made us investigate thephenomenon of generating a human error and the ways to diminish its effects.

  16. Error-Based Accidents and Security Incidents in Nuclear Materials Management

    International Nuclear Information System (INIS)

    Pond, Daniel J.; Greitzer, Frank L.

    2005-01-01

    Hazard and risk assessments, along with human error analysis and mitigation techniques, have long been mainstays of effective safety programs. These tools have revealed that worker errors contributing to or resulting in accidents are often the consequence of ineffective system conditions, process features, or individual employee characteristics. At Los Alamos National Laboratory (LANL), security, safety, human error, and organizational analysts determined that the system-induced human errors that make accidents more likely also are contributing to security incidents. A similar set of system conditions has been found to underlie deliberate, non-malevolent deviations from proper security practices - termed breaches - that also can result in a security incident. In fiscal-year (FY) 2002, LANL's Security Division therefore established the ESTHER (Enhanced Security Through Human Error Reduction) program to identify and reduce the influence of the factors that underlie employee errors and breaches and, in turn, security incidents. Recognizing the potential benefits of this program and approach, in FY2004 the Department of Energy (DOE) Office of Security Policy (DOE-SO) funded an expansion of ESTHER implementation to the causal assessment and reporting of security incidents at other DOE sites. This presentation will focus on three applications of error/breach assessment and mitigation techniques. One use is proactive, accomplished through the elimination of contributors to error, whereas two are reactive, implemented in response to accidents or security incidents as well as to near misses, to prevent recurrence. The human performance and safety bases of these techniques will be detailed. Associated tools - including computer-based assessment training and web-based incident reporting modules developed by Pacific Northwest National Laboratory - will be discussed

  17. The Relationship between Human Operators' Psycho-physiological Condition and Human Errors in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Arryum; Jang, Inseok; Kang, Hyungook; Seong, Poonghyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-05-15

    The safe operation of nuclear power plants (NPPs) is substantially dependent on the performance of the human operators who operate the systems. In this environment, human errors caused by inappropriate performance of operator have been considered to be critical since it may lead serious problems in the safety-critical plants. In order to provide meaningful insights to prevent human errors and enhance the human performance, operators' physiological conditions such as stress and workload have been investigated. Physiological measurements were considered as reliable tools to assess the stress and workload. T. Q. Tran et al. and J. B. Brooking et al pointed out that operators' workload can be assessed using eye tracking, galvanic skin response, electroencephalograms (EEGs), heart rate, respiration and other measurements. The purpose of this study is to investigate the effect of the human operators' tense level and knowledge level to the number of human errors. For this study, the experiments were conducted in the mimic of the main control rooms (MCR) in NPP. It utilized the compact nuclear simulator (CNS) which is modeled based on the three loop Pressurized Water Reactor, 993MWe, Kori unit 3 and 4 in Korea and the subjects were asked to follow the tasks described in the emergency operating procedures (EOP). During the simulation, three kinds of physiological measurement were utilized; Electrocardiogram (ECG), EEG and nose temperature. Also, subjects were divided into three groups based on their knowledge of the plant operation. The result shows that subjects who are tense make fewer errors. In addition, subjects who are in higher knowledge level tend to be tense and make fewer errors. For the ECG data, subjects who make fewer human errors tend to be located in higher tense level area of high SNS activity and low PSNS activity. The results of EEG data are also similar to ECG result. Beta power ratio of subjects who make fewer errors was higher. Since beta

  18. Basic human error probabilities in advanced MCRs when using soft control

    International Nuclear Information System (INIS)

    Jang, In Seok; Seong, Poong Hyun; Kang, Hyun Gook; Lee, Seung Jun

    2012-01-01

    In a report on one of the renowned HRA methods, Technique for Human Error Rate Prediction (THERP), it is pointed out that 'The paucity of actual data on human performance continues to be a major problem for estimating HEPs and performance times in nuclear power plant (NPP) task'. However, another critical difficulty is that most current HRA databases deal with operation in conventional type of MCRs. With the adoption of new human system interfaces that are based on computer based technologies, the operation environment of MCRs in NPPs has changed. The MCRs including these digital and computer technologies, such as large display panels, computerized procedures, soft controls, and so on, are called advanced MCRs. Because of the different interfaces, different Basic Human Error Probabilities (BHEPs) should be considered in human reliability analyses (HRAs) for advanced MCRs. This study carries out an empirical analysis of human error considering soft controls. The aim of this work is not only to compile a database using the simulator for advanced MCRs but also to compare BHEPs with those of a conventional MCR database

  19. Human errors related to maintenance and modifications

    International Nuclear Information System (INIS)

    Laakso, K.; Pyy, P.; Reiman, L.

    1998-01-01

    The focus in human reliability analysis (HRA) relating to nuclear power plants has traditionally been on human performance in disturbance conditions. On the other hand, some studies and incidents have shown that also maintenance errors, which have taken place earlier in plant history, may have an impact on the severity of a disturbance, e.g. if they disable safety related equipment. Especially common cause and other dependent failures of safety systems may significantly contribute to the core damage risk. The first aim of the study was to identify and give examples of multiple human errors which have penetrated the various error detection and inspection processes of plant safety barriers. Another objective was to generate numerical safety indicators to describe and forecast the effectiveness of maintenance. A more general objective was to identify needs for further development of maintenance quality and planning. In the first phase of this operational experience feedback analysis, human errors recognisable in connection with maintenance were looked for by reviewing about 4400 failure and repair reports and some special reports which cover two nuclear power plant units on the same site during 1992-94. A special effort was made to study dependent human errors since they are generally the most serious ones. An in-depth root cause analysis was made for 14 dependent errors by interviewing plant maintenance foremen and by thoroughly analysing the errors. A more simple treatment was given to maintenance-related single errors. The results were shown as a distribution of errors among operating states i.a. as regards the following matters: in what operational state the errors were committed and detected; in what operational and working condition the errors were detected, and what component and error type they were related to. These results were presented separately for single and dependent maintenance-related errors. As regards dependent errors, observations were also made

  20. ADVANCED MMIS TOWARD SUBSTANTIAL REDUCTION IN HUMAN ERRORS IN NPPS

    Directory of Open Access Journals (Sweden)

    POONG HYUN SEONG

    2013-04-01

    Full Text Available This paper aims to give an overview of the methods to inherently prevent human errors and to effectively mitigate the consequences of such errors by securing defense-in-depth during plant management through the advanced man-machine interface system (MMIS. It is needless to stress the significance of human error reduction during an accident in nuclear power plants (NPPs. Unexpected shutdowns caused by human errors not only threaten nuclear safety but also make public acceptance of nuclear power extremely lower. We have to recognize there must be the possibility of human errors occurring since humans are not essentially perfect particularly under stressful conditions. However, we have the opportunity to improve such a situation through advanced information and communication technologies on the basis of lessons learned from our experiences. As important lessons, authors explained key issues associated with automation, man-machine interface, operator support systems, and procedures. Upon this investigation, we outlined the concept and technical factors to develop advanced automation, operation and maintenance support systems, and computer-based procedures using wired/wireless technology. It should be noted that the ultimate responsibility of nuclear safety obviously belongs to humans not to machines. Therefore, safety culture including education and training, which is a kind of organizational factor, should be emphasized as well. In regard to safety culture for human error reduction, several issues that we are facing these days were described. We expect the ideas of the advanced MMIS proposed in this paper to lead in the future direction of related researches and finally supplement the safety of NPPs.

  1. Advanced MMIS Toward Substantial Reduction in Human Errors in NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Poong Hyun; Kang, Hyun Gook [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Na, Man Gyun [Chosun Univ., Gwangju (Korea, Republic of); Kim, Jong Hyun [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of); Heo, Gyunyoung [Kyung Hee Univ., Yongin (Korea, Republic of); Jung, Yoensub [Korea Hydro and Nuclear Power Co., Ltd., Daejeon (Korea, Republic of)

    2013-04-15

    This paper aims to give an overview of the methods to inherently prevent human errors and to effectively mitigate the consequences of such errors by securing defense-in-depth during plant management through the advanced man-machine interface system (MMIS). It is needless to stress the significance of human error reduction during an accident in nuclear power plants (NPPs). Unexpected shutdowns caused by human errors not only threaten nuclear safety but also make public acceptance of nuclear power extremely lower. We have to recognize there must be the possibility of human errors occurring since humans are not essentially perfect particularly under stressful conditions. However, we have the opportunity to improve such a situation through advanced information and communication technologies on the basis of lessons learned from our experiences. As important lessons, authors explained key issues associated with automation, man-machine interface, operator support systems, and procedures. Upon this investigation, we outlined the concept and technical factors to develop advanced automation, operation and maintenance support systems, and computer-based procedures using wired/wireless technology. It should be noted that the ultimate responsibility of nuclear safety obviously belongs to humans not to machines. Therefore, safety culture including education and training, which is a kind of organizational factor, should be emphasized as well. In regard to safety culture for human error reduction, several issues that we are facing these days were described. We expect the ideas of the advanced MMIS proposed in this paper to lead in the future direction of related researches and finally supplement the safety of NPPs.

  2. Advanced MMIS Toward Substantial Reduction in Human Errors in NPPs

    International Nuclear Information System (INIS)

    Seong, Poong Hyun; Kang, Hyun Gook; Na, Man Gyun; Kim, Jong Hyun; Heo, Gyunyoung; Jung, Yoensub

    2013-01-01

    This paper aims to give an overview of the methods to inherently prevent human errors and to effectively mitigate the consequences of such errors by securing defense-in-depth during plant management through the advanced man-machine interface system (MMIS). It is needless to stress the significance of human error reduction during an accident in nuclear power plants (NPPs). Unexpected shutdowns caused by human errors not only threaten nuclear safety but also make public acceptance of nuclear power extremely lower. We have to recognize there must be the possibility of human errors occurring since humans are not essentially perfect particularly under stressful conditions. However, we have the opportunity to improve such a situation through advanced information and communication technologies on the basis of lessons learned from our experiences. As important lessons, authors explained key issues associated with automation, man-machine interface, operator support systems, and procedures. Upon this investigation, we outlined the concept and technical factors to develop advanced automation, operation and maintenance support systems, and computer-based procedures using wired/wireless technology. It should be noted that the ultimate responsibility of nuclear safety obviously belongs to humans not to machines. Therefore, safety culture including education and training, which is a kind of organizational factor, should be emphasized as well. In regard to safety culture for human error reduction, several issues that we are facing these days were described. We expect the ideas of the advanced MMIS proposed in this paper to lead in the future direction of related researches and finally supplement the safety of NPPs

  3. Notes on human error analysis and prediction

    International Nuclear Information System (INIS)

    Rasmussen, J.

    1978-11-01

    The notes comprise an introductory discussion of the role of human error analysis and prediction in industrial risk analysis. Following this introduction, different classes of human errors and role in industrial systems are mentioned. Problems related to the prediction of human behaviour in reliability and safety analysis are formulated and ''criteria for analyzability'' which must be met by industrial systems so that a systematic analysis can be performed are suggested. The appendices contain illustrative case stories and a review of human error reports for the task of equipment calibration and testing as found in the US Licensee Event Reports. (author)

  4. Exploring human error in military aviation flight safety events using post-incident classification systems.

    Science.gov (United States)

    Hooper, Brionny J; O'Hare, David P A

    2013-08-01

    Human error classification systems theoretically allow researchers to analyze postaccident data in an objective and consistent manner. The Human Factors Analysis and Classification System (HFACS) framework is one such practical analysis tool that has been widely used to classify human error in aviation. The Cognitive Error Taxonomy (CET) is another. It has been postulated that the focus on interrelationships within HFACS can facilitate the identification of the underlying causes of pilot error. The CET provides increased granularity at the level of unsafe acts. The aim was to analyze the influence of factors at higher organizational levels on the unsafe acts of front-line operators and to compare the errors of fixed-wing and rotary-wing operations. This study analyzed 288 aircraft incidents involving human error from an Australasian military organization occurring between 2001 and 2008. Action errors accounted for almost twice (44%) the proportion of rotary wing compared to fixed wing (23%) incidents. Both classificatory systems showed significant relationships between precursor factors such as the physical environment, mental and physiological states, crew resource management, training and personal readiness, and skill-based, but not decision-based, acts. The CET analysis showed different predisposing factors for different aspects of skill-based behaviors. Skill-based errors in military operations are more prevalent in rotary wing incidents and are related to higher level supervisory processes in the organization. The Cognitive Error Taxonomy provides increased granularity to HFACS analyses of unsafe acts.

  5. Human Errors - A Taxonomy for Describing Human Malfunction in Industrial Installations

    DEFF Research Database (Denmark)

    Rasmussen, Jens

    1982-01-01

    This paper describes the definition and the characteristics of human errors. Different types of human behavior are classified, and their relation to different error mechanisms are analyzed. The effect of conditioning factors related to affective, motivating aspects of the work situation as well...... as physiological factors are also taken into consideration. The taxonomy for event analysis, including human malfunction, is presented. Possibilities for the prediction of human error are discussed. The need for careful studies in actual work situations is expressed. Such studies could provide a better...

  6. Operator error and emotions. Operator error and emotions - a major cause of human failure

    International Nuclear Information System (INIS)

    Patterson, B.K.; Bradley, M.; Artiss, W.G.

    2000-01-01

    This paper proposes the idea that a large proportion of the incidents attributed to operator and maintenance error in a nuclear or industrial plant are actually founded in our human emotions. Basic psychological theory of emotions is briefly presented and then the authors present situations and instances that can cause emotions to swell and lead to operator and maintenance error. Since emotional information is not recorded in industrial incident reports, the challenge is extended to industry, to review incident source documents for cases of emotional involvement and to develop means to collect emotion related information in future root cause analysis investigations. Training must then be provided to operators and maintainers to enable them to know one's emotions, manage emotions, motivate one's self, recognize emotions in others and handle relationships. Effective training will reduce the instances of human error based in emotions and enable a cooperative, productive environment in which to work. (author)

  7. Operator error and emotions. Operator error and emotions - a major cause of human failure

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, B.K. [Human Factors Practical Incorporated (Canada); Bradley, M. [Univ. of New Brunswick, Saint John, New Brunswick (Canada); Artiss, W.G. [Human Factors Practical (Canada)

    2000-07-01

    This paper proposes the idea that a large proportion of the incidents attributed to operator and maintenance error in a nuclear or industrial plant are actually founded in our human emotions. Basic psychological theory of emotions is briefly presented and then the authors present situations and instances that can cause emotions to swell and lead to operator and maintenance error. Since emotional information is not recorded in industrial incident reports, the challenge is extended to industry, to review incident source documents for cases of emotional involvement and to develop means to collect emotion related information in future root cause analysis investigations. Training must then be provided to operators and maintainers to enable them to know one's emotions, manage emotions, motivate one's self, recognize emotions in others and handle relationships. Effective training will reduce the instances of human error based in emotions and enable a cooperative, productive environment in which to work. (author)

  8. Human Error Analysis by Fuzzy-Set

    International Nuclear Information System (INIS)

    Situmorang, Johnny

    1996-01-01

    In conventional HRA the probability of Error is treated as a single and exact value through constructing even tree, but in this moment the Fuzzy-Set Theory is used. Fuzzy set theory treat the probability of error as a plausibility which illustrate a linguistic variable. Most parameter or variable in human engineering been defined verbal good, fairly good, worst etc. Which describe a range of any value of probability. For example this analysis is quantified the human error in calibration task, and the probability of miscalibration is very low

  9. Estimation of the human error probabilities in the human reliability analysis

    International Nuclear Information System (INIS)

    Liu Haibin; He Xuhong; Tong Jiejuan; Shen Shifei

    2006-01-01

    Human error data is an important issue of human reliability analysis (HRA). Using of Bayesian parameter estimation, which can use multiple information, such as the historical data of NPP and expert judgment data to modify the human error data, could get the human error data reflecting the real situation of NPP more truly. This paper, using the numeric compute program developed by the authors, presents some typical examples to illustrate the process of the Bayesian parameter estimation in HRA and discusses the effect of different modification data on the Bayesian parameter estimation. (authors)

  10. HUMAN ERROR QUANTIFICATION USING PERFORMANCE SHAPING FACTORS IN THE SPAR-H METHOD

    Energy Technology Data Exchange (ETDEWEB)

    Harold S. Blackman; David I. Gertman; Ronald L. Boring

    2008-09-01

    This paper describes a cognitively based human reliability analysis (HRA) quantification technique for estimating the human error probabilities (HEPs) associated with operator and crew actions at nuclear power plants. The method described here, Standardized Plant Analysis Risk-Human Reliability Analysis (SPAR-H) method, was developed to aid in characterizing and quantifying human performance at nuclear power plants. The intent was to develop a defensible method that would consider all factors that may influence performance. In the SPAR-H approach, calculation of HEP rates is especially straightforward, starting with pre-defined nominal error rates for cognitive vs. action-oriented tasks, and incorporating performance shaping factor multipliers upon those nominal error rates.

  11. Investigations on human error hazards in recent unintended trip events of Korean nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sa Kil; Jang, Tong Il; Lee, Yong Hee; Shin, Kwang Hyeon [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    According to the Operational Performance Information System (OPIS) which has been operated to improve the public understanding by the KINS (Korea Institute of Nuclear Safety), unintended trip events by mainly human errors counted up to 38 cases (18.7%) from 2000 to 2011. Although the Nuclear Power Plant (NPP) industry in Korea has been making efforts to reduce the human errors which have largely contributed to trip events, the human error rate might keep increasing. Interestingly, digital based I and C systems is the one of the reduction factors of unintended reactor trips. Human errors, however, have occurred due to the digital based I and C systems because those systems require new or changed behaviors to the NPP operators. Therefore, it is necessary that the investigations of human errors consider a new methodology to find not only tangible behavior but also intangible behavior such as organizational behaviors. In this study we investigated human errors to find latent factors such as decisions and conditions in the all of the unintended reactor trip events during last dozen years. To find them, we applied the HFACS (Human Factors Analysis and Classification System) which is a commonly utilized tool for investigating human contributions to aviation accidents under a widespread evaluation scheme. The objective of this study is to find latent factors behind of human errors in nuclear reactor trip events. Therefore, a method to investigate unintended trip events by human errors and the results will be discussed in more detail.

  12. Investigations on human error hazards in recent unintended trip events of Korean nuclear power plants

    International Nuclear Information System (INIS)

    Kim, Sa Kil; Jang, Tong Il; Lee, Yong Hee; Shin, Kwang Hyeon

    2012-01-01

    According to the Operational Performance Information System (OPIS) which has been operated to improve the public understanding by the KINS (Korea Institute of Nuclear Safety), unintended trip events by mainly human errors counted up to 38 cases (18.7%) from 2000 to 2011. Although the Nuclear Power Plant (NPP) industry in Korea has been making efforts to reduce the human errors which have largely contributed to trip events, the human error rate might keep increasing. Interestingly, digital based I and C systems is the one of the reduction factors of unintended reactor trips. Human errors, however, have occurred due to the digital based I and C systems because those systems require new or changed behaviors to the NPP operators. Therefore, it is necessary that the investigations of human errors consider a new methodology to find not only tangible behavior but also intangible behavior such as organizational behaviors. In this study we investigated human errors to find latent factors such as decisions and conditions in the all of the unintended reactor trip events during last dozen years. To find them, we applied the HFACS (Human Factors Analysis and Classification System) which is a commonly utilized tool for investigating human contributions to aviation accidents under a widespread evaluation scheme. The objective of this study is to find latent factors behind of human errors in nuclear reactor trip events. Therefore, a method to investigate unintended trip events by human errors and the results will be discussed in more detail

  13. Trial application of a technique for human error analysis (ATHEANA)

    International Nuclear Information System (INIS)

    Bley, D.C.; Cooper, S.E.; Parry, G.W.

    1996-01-01

    The new method for HRA, ATHEANA, has been developed based on a study of the operating history of serious accidents and an understanding of the reasons why people make errors. Previous publications associated with the project have dealt with the theoretical framework under which errors occur and the retrospective analysis of operational events. This is the first attempt to use ATHEANA in a prospective way, to select and evaluate human errors within the PSA context

  14. A Human Reliability Analysis of Post- Accident Human Errors in the Low Power and Shutdown PSA of KSNP

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Daeil; Kim, J. H.; Jang, S. C

    2007-03-15

    Korea Atomic Energy Research Institute, using the ANS low power and shutdown (LPSD) probabilistic risk assessment (PRA) Standard, evaluated the LPSD PSA model of the KSNP, Yonggwang Units 5 and 6, and identified the items to be improved. The evaluation results of human reliability analysis (HRA) of the post-accident human errors in the LPSD PSA model for the KSNP showed that 10 items among 19 items of supporting requirements for those in the ANS PRA Standard were identified as them to be improved. Thus, we newly carried out a HRA for post-accident human errors in the LPSD PSA model for the KSNP. Following tasks are the improvements in the HRA of post-accident human errors of the LPSD PSA model for the KSNP compared with the previous one: Interviews with operators in the interpretation of the procedure, modeling of operator actions, and the quantification results of human errors, site visit. Applications of limiting value to the combined post-accident human errors. Documentation of information of all the input and bases for the detailed quantifications and the dependency analysis using the quantification sheets The assessment results for the new HRA results of post-accident human errors using the ANS LPSD PRA Standard show that above 80% items of its supporting requirements for post-accident human errors were graded as its Category II. The number of the re-estimated human errors using the LPSD Korea Standard HRA method is 385. Among them, the number of individual post-accident human errors is 253. The number of dependent post-accident human errors is 135. The quantification results of the LPSD PSA model for the KSNP with new HEPs show that core damage frequency (CDF) is increased by 5.1% compared with the previous baseline CDF It is expected that this study results will be greatly helpful to improve the PSA quality for the domestic nuclear power plants because they have sufficient PSA quality to meet the Category II of Supporting Requirements for the post

  15. A Human Reliability Analysis of Post- Accident Human Errors in the Low Power and Shutdown PSA of KSNP

    International Nuclear Information System (INIS)

    Kang, Daeil; Kim, J. H.; Jang, S. C.

    2007-03-01

    Korea Atomic Energy Research Institute, using the ANS low power and shutdown (LPSD) probabilistic risk assessment (PRA) Standard, evaluated the LPSD PSA model of the KSNP, Yonggwang Units 5 and 6, and identified the items to be improved. The evaluation results of human reliability analysis (HRA) of the post-accident human errors in the LPSD PSA model for the KSNP showed that 10 items among 19 items of supporting requirements for those in the ANS PRA Standard were identified as them to be improved. Thus, we newly carried out a HRA for post-accident human errors in the LPSD PSA model for the KSNP. Following tasks are the improvements in the HRA of post-accident human errors of the LPSD PSA model for the KSNP compared with the previous one: Interviews with operators in the interpretation of the procedure, modeling of operator actions, and the quantification results of human errors, site visit. Applications of limiting value to the combined post-accident human errors. Documentation of information of all the input and bases for the detailed quantifications and the dependency analysis using the quantification sheets The assessment results for the new HRA results of post-accident human errors using the ANS LPSD PRA Standard show that above 80% items of its supporting requirements for post-accident human errors were graded as its Category II. The number of the re-estimated human errors using the LPSD Korea Standard HRA method is 385. Among them, the number of individual post-accident human errors is 253. The number of dependent post-accident human errors is 135. The quantification results of the LPSD PSA model for the KSNP with new HEPs show that core damage frequency (CDF) is increased by 5.1% compared with the previous baseline CDF It is expected that this study results will be greatly helpful to improve the PSA quality for the domestic nuclear power plants because they have sufficient PSA quality to meet the Category II of Supporting Requirements for the post

  16. New method of classifying human errors at nuclear power plants and the analysis results of applying this method to maintenance errors at domestic plants

    International Nuclear Information System (INIS)

    Takagawa, Kenichi; Miyazaki, Takamasa; Gofuku, Akio; Iida, Hiroyasu

    2007-01-01

    Since many of the adverse events that have occurred in nuclear power plants in Japan and abroad have been related to maintenance or operation, it is necessary to plan preventive measures based on detailed analyses of human errors made by maintenance workers or operators. Therefore, before planning preventive measures, we developed a new method of analyzing human errors. Since each human error is an unsafe action caused by some misjudgement made by a person, we decided to classify them into six categories according to the stage in the judgment process in which the error was made. By further classifying each error into either an omission-type or commission-type, we produced 12 categories of errors. Then, we divided them into the two categories of basic error tendencies and individual error tendencies, and categorized background factors into four categories: imperfect planning; imperfect facilities or tools; imperfect environment; and imperfect instructions or communication. We thus defined the factors in each category to make it easy to identify factors that caused the error. Then using this method, we studied the characteristics of human errors that involved maintenance workers and planners since many maintenance errors have occurred. Among the human errors made by workers (worker errors) during the implementation stage, the following three types were prevalent with approximately 80%: commission-type 'projection errors', omission-type comprehension errors' and commission type 'action errors'. The most common among the individual factors of worker errors was 'repetition or habit' (schema), based on the assumption of a typical situation, and the half number of the 'repetition or habit' cases (schema) were not influenced by any background factors. The most common background factor that contributed to the individual factor was 'imperfect work environment', followed by 'insufficient knowledge'. Approximately 80% of the individual factors were 'repetition or habit' or

  17. Human errors evaluation for muster in emergency situations applying human error probability index (HEPI, in the oil company warehouse in Hamadan City

    Directory of Open Access Journals (Sweden)

    2012-12-01

    Full Text Available Introduction: Emergency situation is one of the influencing factors on human error. The aim of this research was purpose to evaluate human error in emergency situation of fire and explosion at the oil company warehouse in Hamadan city applying human error probability index (HEPI. . Material and Method: First, the scenario of emergency situation of those situation of fire and explosion at the oil company warehouse was designed and then maneuver against, was performed. The scaled questionnaire of muster for the maneuver was completed in the next stage. Collected data were analyzed to calculate the probability success for the 18 actions required in an emergency situation from starting point of the muster until the latest action to temporary sheltersafe. .Result: The result showed that the highest probability of error occurrence was related to make safe workplace (evaluation phase with 32.4 % and lowest probability of occurrence error in detection alarm (awareness phase with 1.8 %, probability. The highest severity of error was in the evaluation phase and the lowest severity of error was in the awareness and recovery phase. Maximum risk level was related to the evaluating exit routes and selecting one route and choosy another exit route and minimum risk level was related to the four evaluation phases. . Conclusion: To reduce the risk of reaction in the exit phases of an emergency situation, the following actions are recommended, based on the finding in this study: A periodic evaluation of the exit phase and modifying them if necessary, conducting more maneuvers and analyzing this results along with a sufficient feedback to the employees.

  18. Support of protective work of human error in a nuclear power plant

    International Nuclear Information System (INIS)

    Yoshizawa, Yuriko

    1999-01-01

    The nuclear power plant human factor group of the Tokyo Electric Power Co., Ltd. supports various protective work of human error conducted at the nuclear power plant. Its main researching theme are studies on human factor on operation of a nuclear power plant, and on recovery and common basic study on human factor. In addition, on a base of the obtained informations, assistance to protective work of human error conducted at the nuclear power plant as well as development for its actual use was also promoted. Especially, for actions sharing some dangerous informations, various assistances such as a proposal on actual example analytical method to effectively understand a dangerous information not facially but faithfully, construction of a data base to conveniently share such dangerous information, and practice on non-accident business survey for a hint of effective promotion of the protection work, were promoted. Here were introduced on assistance and investigation for effective sharing of the dangerous informations for various actions on protection of human error mainly conducted in nuclear power plant. (G.K.)

  19. Detailed semantic analyses of human error incidents occurring at nuclear power plants. Extraction of periodical transition of error occurrence patterns by applying multivariate analysis

    International Nuclear Information System (INIS)

    Hirotsu, Yuko; Suzuki, Kunihiko; Takano, Kenichi; Kojima, Mitsuhiro

    2000-01-01

    It is essential for preventing the recurrence of human error incidents to analyze and evaluate them with the emphasis on human factor. Detailed and structured analyses of all incidents at domestic nuclear power plants (NPPs) reported during last 31 years have been conducted based on J-HPES, in which total 193 human error cases are identified. Results obtained by the analyses have been stored into the J-HPES database. In the previous study, by applying multivariate analysis to above case studies, it was suggested that there were several occurrence patterns identified of how errors occur at NPPs. It was also clarified that the causes related to each human error are different depending on age of their occurrence. This paper described the obtained results in respects of periodical transition of human error occurrence patterns. By applying multivariate analysis to the above data, it was suggested there were two types of error occurrence patterns as to each human error type. First type is common occurrence patterns, not depending on the age, and second type is the one influenced by periodical characteristics. (author)

  20. Using a Delphi Method to Identify Human Factors Contributing to Nursing Errors.

    Science.gov (United States)

    Roth, Cheryl; Brewer, Melanie; Wieck, K Lynn

    2017-07-01

    The purpose of this study was to identify human factors associated with nursing errors. Using a Delphi technique, this study used feedback from a panel of nurse experts (n = 25) on an initial qualitative survey questionnaire followed by summarizing the results with feedback and confirmation. Synthesized factors regarding causes of errors were incorporated into a quantitative Likert-type scale, and the original expert panel participants were queried a second time to validate responses. The list identified 24 items as most common causes of nursing errors, including swamping and errors made by others that nurses are expected to recognize and fix. The responses provided a consensus top 10 errors list based on means with heavy workload and fatigue at the top of the list. The use of the Delphi survey established consensus and developed a platform upon which future study of nursing errors can evolve as a link to future solutions. This list of human factors in nursing errors should serve to stimulate dialogue among nurses about how to prevent errors and improve outcomes. Human and system failures have been the subject of an abundance of research, yet nursing errors continue to occur. © 2016 Wiley Periodicals, Inc.

  1. The contributions of human factors on human error in Malaysia aviation maintenance industries

    Science.gov (United States)

    Padil, H.; Said, M. N.; Azizan, A.

    2018-05-01

    Aviation maintenance is a multitasking activity in which individuals perform varied tasks under constant pressure to meet deadlines as well as challenging work conditions. These situational characteristics combined with human factors can lead to various types of human related errors. The primary objective of this research is to develop a structural relationship model that incorporates human factors, organizational factors, and their impact on human errors in aviation maintenance. Towards that end, a questionnaire was developed which was administered to Malaysian aviation maintenance professionals. Structural Equation Modelling (SEM) approach was used in this study utilizing AMOS software. Results showed that there were a significant relationship of human factors on human errors and were tested in the model. Human factors had a partial effect on organizational factors while organizational factors had a direct and positive impact on human errors. It was also revealed that organizational factors contributed to human errors when coupled with human factors construct. This study has contributed to the advancement of knowledge on human factors effecting safety and has provided guidelines for improving human factors performance relating to aviation maintenance activities and could be used as a reference for improving safety performance in the Malaysian aviation maintenance companies.

  2. Analysis of Human Error Types and Performance Shaping Factors in the Next Generation Main Control Room

    International Nuclear Information System (INIS)

    Sin, Y. C.; Jung, Y. S.; Kim, K. H.; Kim, J. H.

    2008-04-01

    Main control room of nuclear power plants has been computerized and digitalized in new and modernized plants, as information and digital technologies make great progresses and become mature. Survey on human factors engineering issues in advanced MCRs: Model-based approach, Literature survey-based approach. Analysis of human error types and performance shaping factors is analysis of three human errors. The results of project can be used for task analysis, evaluation of human error probabilities, and analysis of performance shaping factors in the HRA analysis

  3. Human error mechanisms in complex work environments

    International Nuclear Information System (INIS)

    Rasmussen, J.

    1988-01-01

    Human error taxonomies have been developed from analysis of industrial incident reports as well as from psychological experiments. In this paper the results of the two approaches are reviewed and compared. It is found, in both cases, that a fairly small number of basic psychological mechanisms will account for most of the action errors observed. In addition, error mechanisms appear to be intimately related to the development of high skill and know-how in a complex work context. This relationship between errors and human adaptation is discussed in detail for individuals and organisations. The implications for system safety and briefly mentioned, together with the implications for system design. (author)

  4. Human error mechanisms in complex work environments

    International Nuclear Information System (INIS)

    Rasmussen, Jens; Danmarks Tekniske Hoejskole, Copenhagen)

    1988-01-01

    Human error taxonomies have been developed from analysis of industrial incident reports as well as from psychological experiments. In this paper the results of the two approaches are reviewed and compared. It is found, in both cases, that a fairly small number of basic psychological mechanisms will account for most of the action errors observed. In addition, error mechanisms appear to be intimately related to the development of high skill and know-how in a complex work context. This relationship between errors and human adaptation is discussed in detail for individuals and organisations. The implications for system safety are briefly mentioned, together with the implications for system design. (author)

  5. Development of an integrated system for estimating human error probabilities

    Energy Technology Data Exchange (ETDEWEB)

    Auflick, J.L.; Hahn, H.A.; Morzinski, J.A.

    1998-12-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project had as its main objective the development of a Human Reliability Analysis (HRA), knowledge-based expert system that would provide probabilistic estimates for potential human errors within various risk assessments, safety analysis reports, and hazard assessments. HRA identifies where human errors are most likely, estimates the error rate for individual tasks, and highlights the most beneficial areas for system improvements. This project accomplished three major tasks. First, several prominent HRA techniques and associated databases were collected and translated into an electronic format. Next, the project started a knowledge engineering phase where the expertise, i.e., the procedural rules and data, were extracted from those techniques and compiled into various modules. Finally, these modules, rules, and data were combined into a nearly complete HRA expert system.

  6. Technique for human-error sequence identification and signification

    International Nuclear Information System (INIS)

    Heslinga, G.

    1988-01-01

    The aim of the present study was to investigate whether the event-tree technique can be used for the analysis of sequences of human errors that could cause initiating events. The scope of the study was limited to a consideration of the performance of procedural actions. The event-tree technique was modified to adapt it for this study and will be referred to as the 'Technique for Human-Error-Sequence Identification and Signification' (THESIS). The event trees used in this manner, i.e. THESIS event trees, appear to present additional problems if they are applied to human performance instead of technical systems. These problems, referred to as the 'Man-Related Features' of THESIS, are: the human capability to choose among several procedures, the ergonomics of the panel layout, human actions of a continuous nature, dependence between human errors, human capability to recover possible errors, the influence of memory during the recovery attempt, variability in human performance and correlations between human;erropr probabilities. The influence of these problems on the applicability of THESIS was assessed by means of mathematical analysis, field studies and laboratory experiments (author). 130 refs.; 51 figs.; 24 tabs

  7. An empirical study on the human error recovery failure probability when using soft controls in NPP advanced MCRs

    International Nuclear Information System (INIS)

    Jang, Inseok; Kim, Ar Ryum; Jung, Wondea; Seong, Poong Hyun

    2014-01-01

    Highlights: • Many researchers have tried to understand human recovery process or step. • Modeling human recovery process is not sufficient to be applied to HRA. • The operation environment of MCRs in NPPs has changed by adopting new HSIs. • Recovery failure probability in a soft control operation environment is investigated. • Recovery failure probability here would be important evidence for expert judgment. - Abstract: It is well known that probabilistic safety assessments (PSAs) today consider not just hardware failures and environmental events that can impact upon risk, but also human error contributions. Consequently, the focus on reliability and performance management has been on the prevention of human errors and failures rather than the recovery of human errors. However, the recovery of human errors is as important as the prevention of human errors and failures for the safe operation of nuclear power plants (NPPs). For this reason, many researchers have tried to find a human recovery process or step. However, modeling the human recovery process is not sufficient enough to be applied to human reliability analysis (HRA), which requires human error and recovery probabilities. In this study, therefore, human error recovery failure probabilities based on predefined human error modes were investigated by conducting experiments in the operation mockup of advanced/digital main control rooms (MCRs) in NPPs. To this end, 48 subjects majoring in nuclear engineering participated in the experiments. In the experiments, using the developed accident scenario based on tasks from the standard post trip action (SPTA), the steam generator tube rupture (SGTR), and predominant soft control tasks, which are derived from the loss of coolant accident (LOCA) and the excess steam demand event (ESDE), all error detection and recovery data based on human error modes were checked with the performance sheet and the statistical analysis of error recovery/detection was then

  8. Human decision error (HUMDEE) trees

    International Nuclear Information System (INIS)

    Ostrom, L.T.

    1993-01-01

    Graphical presentations of human actions in incident and accident sequences have been used for many years. However, for the most part, human decision making has been underrepresented in these trees. This paper presents a method of incorporating the human decision process into graphical presentations of incident/accident sequences. This presentation is in the form of logic trees. These trees are called Human Decision Error Trees or HUMDEE for short. The primary benefit of HUMDEE trees is that they graphically illustrate what else the individuals involved in the event could have done to prevent either the initiation or continuation of the event. HUMDEE trees also present the alternate paths available at the operator decision points in the incident/accident sequence. This is different from the Technique for Human Error Rate Prediction (THERP) event trees. There are many uses of these trees. They can be used for incident/accident investigations to show what other courses of actions were available and for training operators. The trees also have a consequence component so that not only the decision can be explored, also the consequence of that decision

  9. Review of U.S. Army Unmanned Aerial Systems Accident Reports: Analysis of Human Error Contributions

    Science.gov (United States)

    2018-03-20

    within report documents. The information presented was obtained through a request to use the U.S. Army Combat Readiness Center’s Risk Management ...controlled flight into terrain (13 accidents), fueling errors by improper techniques (7 accidents), and a variety of maintenance errors (10 accidents). The...and 9 of the 10 maintenance accidents. Table 4. Frequencies Based on Source of Human Error Human error source Presence Poor Planning

  10. Effects of human errors on the determination of surveillance test interval

    International Nuclear Information System (INIS)

    Chung, Dae Wook; Koo, Bon Hyun

    1990-01-01

    This paper incorporates the effects of human error relevant to the periodic test on the unavailability of the safety system as well as the component unavailability. Two types of possible human error during the test are considered. One is the possibility that a good safety system is inadvertently left in a bad state after the test (Type A human error) and the other is the possibility that bad safety system is undetected upon the test (Type B human error). An event tree model is developed for the steady-state unavailability of safety system to determine the effects of human errors on the component unavailability and the test interval. We perform the reliability analysis of safety injection system (SIS) by applying aforementioned two types of human error to safety injection pumps. Results of various sensitivity analyses show that; 1) the appropriate test interval decreases and steady-state unavailability increases as the probabilities of both types of human errors increase, and they are far more sensitive to Type A human error than Type B and 2) the SIS unavailability increases slightly as the probability of Type B human error increases, and significantly as the probability of Type A human error increases. Therefore, to avoid underestimation, the effects of human error should be incorporated in the system reliability analysis which aims at the relaxations of the surveillance test intervals, and Type A human error has more important effect on the unavailability and surveillance test interval

  11. A Conceptual Framework for Predicting Error in Complex Human-Machine Environments

    Science.gov (United States)

    Freed, Michael; Remington, Roger; Null, Cynthia H. (Technical Monitor)

    1998-01-01

    We present a Goals, Operators, Methods, and Selection Rules-Model Human Processor (GOMS-MHP) style model-based approach to the problem of predicting human habit capture errors. Habit captures occur when the model fails to allocate limited cognitive resources to retrieve task-relevant information from memory. Lacking the unretrieved information, decision mechanisms act in accordance with implicit default assumptions, resulting in error when relied upon assumptions prove incorrect. The model helps interface designers identify situations in which such failures are especially likely.

  12. Human Error Mechanisms in Complex Work Environments

    DEFF Research Database (Denmark)

    Rasmussen, Jens

    1988-01-01

    will account for most of the action errors observed. In addition, error mechanisms appear to be intimately related to the development of high skill and know-how in a complex work context. This relationship between errors and human adaptation is discussed in detail for individuals and organisations...

  13. Effects of digital human-machine interface characteristics on human error in nuclear power plants

    International Nuclear Information System (INIS)

    Li Pengcheng; Zhang Li; Dai Licao; Huang Weigang

    2011-01-01

    In order to identify the effects of digital human-machine interface characteristics on human error in nuclear power plants, the new characteristics of digital human-machine interface are identified by comparing with the traditional analog control systems in the aspects of the information display, user interface interaction and management, control systems, alarm systems and procedures system, and the negative effects of digital human-machine interface characteristics on human error are identified by field research and interviewing with operators such as increased cognitive load and workload, mode confusion, loss of situation awareness. As to the adverse effects related above, the corresponding prevention and control measures of human errors are provided to support the prevention and minimization of human errors and the optimization of human-machine interface design. (authors)

  14. Application of human error theory in case analysis of wrong procedures.

    Science.gov (United States)

    Duthie, Elizabeth A

    2010-06-01

    The goal of this study was to contribute to the emerging body of literature about the role of human behaviors and cognitive processes in the commission of wrong procedures. Case analysis of 5 wrong procedures in operative and nonoperative settings using James Reason's human error theory was performed. The case analysis showed that cognitive underspecification, cognitive flips, automode processing, and skill-based errors were contributory to wrong procedures. Wrong-site procedures accounted for the preponderance of the cases. Front-line supervisory staff used corrective actions that focused on the performance of the individual without taking into account cognitive factors. System fixes using human cognition concepts have a greater chance of achieving sustainable safety outcomes than those that are based on the traditional approach of counseling, education, and disciplinary action for staff.

  15. Sensitivity of risk parameters to human errors in reactor safety study for a PWR

    International Nuclear Information System (INIS)

    Samanta, P.K.; Hall, R.E.; Swoboda, A.L.

    1981-01-01

    Sensitivities of the risk parameters, emergency safety system unavailabilities, accident sequence probabilities, release category probabilities and core melt probability were investigated for changes in the human error rates within the general methodological framework of the Reactor Safety Study (RSS) for a Pressurized Water Reactor (PWR). Impact of individual human errors were assessed both in terms of their structural importance to core melt and reliability importance on core melt probability. The Human Error Sensitivity Assessment of a PWR (HESAP) computer code was written for the purpose of this study. The code employed point estimate approach and ignored the smoothing technique applied in RSS. It computed the point estimates for the system unavailabilities from the median values of the component failure rates and proceeded in terms of point values to obtain the point estimates for the accident sequence probabilities, core melt probability, and release category probabilities. The sensitivity measure used was the ratio of the top event probability before and after the perturbation of the constituent events. Core melt probability per reactor year showed significant increase with the increase in the human error rates, but did not show similar decrease with the decrease in the human error rates due to the dominance of the hardware failures. When the Minimum Human Error Rate (M.H.E.R.) used is increased to 10 -3 , the base case human error rates start sensitivity to human errors. This effort now allows the evaluation of new error rate data along with proposed changes in the man machine interface

  16. SHEAN (Simplified Human Error Analysis code) and automated THERP

    International Nuclear Information System (INIS)

    Wilson, J.R.

    1993-01-01

    One of the most widely used human error analysis tools is THERP (Technique for Human Error Rate Prediction). Unfortunately, this tool has disadvantages. The Nuclear Regulatory Commission, realizing these drawbacks, commissioned Dr. Swain, the author of THERP, to create a simpler, more consistent tool for deriving human error rates. That effort produced the Accident Sequence Evaluation Program Human Reliability Analysis Procedure (ASEP), which is more conservative than THERP, but a valuable screening tool. ASEP involves answering simple questions about the scenario in question, and then looking up the appropriate human error rate in the indicated table (THERP also uses look-up tables, but four times as many). The advantages of ASEP are that human factors expertise is not required, and the training to use the method is minimal. Although not originally envisioned by Dr. Swain, the ASEP approach actually begs to be computerized. That WINCO did, calling the code SHEAN, for Simplified Human Error ANalysis. The code was done in TURBO Basic for IBM or IBM-compatible MS-DOS, for fast execution. WINCO is now in the process of comparing this code against THERP for various scenarios. This report provides a discussion of SHEAN

  17. Human error theory: relevance to nurse management.

    Science.gov (United States)

    Armitage, Gerry

    2009-03-01

    Describe, discuss and critically appraise human error theory and consider its relevance for nurse managers. Healthcare errors are a persistent threat to patient safety. Effective risk management and clinical governance depends on understanding the nature of error. This paper draws upon a wide literature from published works, largely from the field of cognitive psychology and human factors. Although the content of this paper is pertinent to any healthcare professional; it is written primarily for nurse managers. Error is inevitable. Causation is often attributed to individuals, yet causation in complex environments such as healthcare is predominantly multi-factorial. Individual performance is affected by the tendency to develop prepacked solutions and attention deficits, which can in turn be related to local conditions and systems or latent failures. Blame is often inappropriate. Defences should be constructed in the light of these considerations and to promote error wisdom and organizational resilience. Managing and learning from error is seen as a priority in the British National Health Service (NHS), this can be better achieved with an understanding of the roots, nature and consequences of error. Such an understanding can provide a helpful framework for a range of risk management activities.

  18. A human error analysis methodology, AGAPE-ET, for emergency tasks in nuclear power plants and its application

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Whan; Jung, Won Dea [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-03-01

    This report presents a procedurised human reliability analysis (HRA) methodology, AGAPE-ET (A Guidance And Procedure for Human Error Analysis for Emergency Tasks), for both qualitative error analysis and quantification of human error probability (HEP) of emergency tasks in nuclear power plants. The AGAPE-ET is based on the simplified cognitive model. By each cognitive function, error causes or error-likely situations have been identified considering the characteristics of the performance of each cognitive function and influencing mechanism of PIFs on the cognitive function. Then, error analysis items have been determined from the identified error causes or error-likely situations to help the analysts cue or guide overall human error analysis. A human error analysis procedure based on the error analysis items is organised. The basic scheme for the quantification of HEP consists in the multiplication of the BHEP assigned by the error analysis item and the weight from the influencing factors decision tree (IFDT) constituted by cognitive function. The method can be characterised by the structured identification of the weak points of the task required to perform and the efficient analysis process that the analysts have only to carry out with the necessary cognitive functions. The report also presents the the application of AFAPE-ET to 31 nuclear emergency tasks and its results. 42 refs., 7 figs., 36 tabs. (Author)

  19. Development and evaluation of a computer-aided system for analyzing human error in railway operations

    International Nuclear Information System (INIS)

    Kim, Dong San; Baek, Dong Hyun; Yoon, Wan Chul

    2010-01-01

    As human error has been recognized as one of the major contributors to accidents in safety-critical systems, there has been a strong need for techniques that can analyze human error effectively. Although many techniques have been developed so far, much room for improvement remains. As human error analysis is a cognitively demanding and time-consuming task, it is particularly necessary to develop a computerized system supporting this task. This paper presents a computer-aided system for analyzing human error in railway operations, called Computer-Aided System for Human Error Analysis and Reduction (CAS-HEAR). It supports analysts to find multiple levels of error causes and their causal relations by using predefined links between contextual factors and causal factors as well as links between causal factors. In addition, it is based on a complete accident model; hence, it helps analysts to conduct a thorough analysis without missing any important part of human error analysis. A prototype of CAS-HEAR was evaluated by nine field investigators from six railway organizations in Korea. Its overall usefulness in human error analysis was confirmed, although development of its simplified version and some modification of the contextual factors and causal factors are required in order to ensure its practical use.

  20. Guidelines for system modeling: pre-accident human errors, rev.0

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dae Il; Jung, W. D.; Lee, Y. H.; Hwang, M. J.; Yang, J. E

    2004-01-01

    The evaluation results of Human Reliability Analysis (HRA) of pre-accident human errors in the probabilistic safety assessment (PSA) for the Korea Standard Nuclear Power Plant (KSNP) using the ASME PRA standard show that more than 50% of 10 items to be improved are related to the identification and screening analysis for them. Thus, we developed a guideline for modeling pre-accident human errors for the system analyst to resolve some items to be improved for them. The developed guideline consists of modeling criteria for the pre-accident human errors (identification, qualitative screening, and common restoration errors) and detailed guidelines for pre-accident human errors relating to testing, maintenance, and calibration works of nuclear power plants (NPPs). The system analyst use the developed guideline and he or she applies it to the system which he or she takes care of. The HRA analyst review the application results of the system analyst. We applied the developed guideline to the auxiliary feed water system of the KSNP to show the usefulness of it. The application results of the developed guideline show that more than 50% of the items to be improved for pre-accident human errors of auxiliary feed water system are resolved. The guideline for modeling pre-accident human errors developed in this study can be used for other NPPs as well as the KSNP. It is expected that both use of the detailed procedure, to be developed in the future, for the quantification of pre-accident human errors and the guideline developed in this study will greatly enhance the PSA quality in the HRA of pre-accident human errors.

  1. Guidelines for system modeling: pre-accident human errors, rev.0

    International Nuclear Information System (INIS)

    Kang, Dae Il; Jung, W. D.; Lee, Y. H.; Hwang, M. J.; Yang, J. E.

    2004-01-01

    The evaluation results of Human Reliability Analysis (HRA) of pre-accident human errors in the probabilistic safety assessment (PSA) for the Korea Standard Nuclear Power Plant (KSNP) using the ASME PRA standard show that more than 50% of 10 items to be improved are related to the identification and screening analysis for them. Thus, we developed a guideline for modeling pre-accident human errors for the system analyst to resolve some items to be improved for them. The developed guideline consists of modeling criteria for the pre-accident human errors (identification, qualitative screening, and common restoration errors) and detailed guidelines for pre-accident human errors relating to testing, maintenance, and calibration works of nuclear power plants (NPPs). The system analyst use the developed guideline and he or she applies it to the system which he or she takes care of. The HRA analyst review the application results of the system analyst. We applied the developed guideline to the auxiliary feed water system of the KSNP to show the usefulness of it. The application results of the developed guideline show that more than 50% of the items to be improved for pre-accident human errors of auxiliary feed water system are resolved. The guideline for modeling pre-accident human errors developed in this study can be used for other NPPs as well as the KSNP. It is expected that both use of the detailed procedure, to be developed in the future, for the quantification of pre-accident human errors and the guideline developed in this study will greatly enhance the PSA quality in the HRA of pre-accident human errors

  2. Risk Management and the Concept of Human Error

    DEFF Research Database (Denmark)

    Rasmussen, Jens

    1995-01-01

    by a stochastic coincidence of faults and human errors, but by a systemic erosion of the defenses due to decision making under competitive pressure in a dynamic environment. The presentation will discuss the nature of human error and the risk management problems found in a dynamic, competitive society facing...

  3. A chance to avoid mistakes human error

    International Nuclear Information System (INIS)

    Amaro, Pablo; Obeso, Eduardo; Gomez, Ruben

    2010-01-01

    Trying to give an answer to the lack of public information in the industry, in relationship with the different tools that are managed in the nuclear industry for minimizing the human error, a group of workers from different sections of the St. Maria de Garona NPP (Quality Assurance/ Organization and Human Factors) decided to embark on a challenging and exciting project: 'Write a book collecting all the knowledge accumulated during their daily activities, very often during lecture time of external information received from different organizations within the nuclear industry (INPO, WANO...), but also visiting different NPP's, maintaining meetings and participating in training courses related de Human and Organizational Factors'. Main objective of the book is presenting to the industry in general, the different tools that are used and fostered in the nuclear industry, in a practical way. In this way, the assimilation and implementation in others industries could be possible and achievable in and efficient context. One year of work, and our project is a reality. We have presented and abstract during the last Spanish Nuclear Society meeting in Sevilla, last October...and the best, the book is into the market for everybody in web-site: www.bubok.com. The book is structured in the following areas: 'Errare humanum est': Trying to present what is the human error to the reader, its origin and the different barriers. The message is that the reader see the error like something continuously present in our lives... even more frequently than we think. Studying its origin can be established aimed at barriers to avoid or at least minimize it. 'Error's bitter face': Shows the possible consequences of human errors. What better that presenting real experiences that have occurred in the industry. In the book, accidents in the nuclear industry, like Tree Mile Island NPP, Chernobyl NPP, and incidents like Davis Besse NPP in the past, helps to the reader to make a reflection about the

  4. A trend analysis of human error events for proactive prevention of accidents. Methodology development and effective utilization

    International Nuclear Information System (INIS)

    Hirotsu, Yuko; Ebisu, Mitsuhiro; Aikawa, Takeshi; Matsubara, Katsuyuki

    2006-01-01

    This paper described methods for analyzing human error events that has been accumulated in the individual plant and for utilizing the result to prevent accidents proactively. Firstly, a categorization framework of trigger action and causal factors of human error events were reexamined, and the procedure to analyze human error events was reviewed based on the framework. Secondly, a method for identifying the common characteristics of trigger action data and of causal factor data accumulated by analyzing human error events was clarified. In addition, to utilize the results of trend analysis effectively, methods to develop teaching material for safety education, to develop the checkpoints for the error prevention and to introduce an error management process for strategic error prevention were proposed. (author)

  5. Human Error Prediction and Countermeasures based on CREAM in Loading and Storage Phase of Spent Nuclear Fuel (SNF)

    International Nuclear Information System (INIS)

    Kim, Jae San; Kim, Min Su; Jo, Seong Youn

    2007-01-01

    With the steady demands for nuclear power energy in Korea, the amount of accumulated SNF has inevitably increased year by year. Thus far, SNF has been on-site transported from one unit to a nearby unit or an on-site dry storage facility. In the near future, as the amount of SNF generated approaches the capacity of these facilities, a percentage of it will be transported to another SNF storage facility. In the process of transporting SNF, human interactions involve inspecting and preparing the cask and spent fuel, loading the cask, transferring the cask and storage or monitoring the cask, etc. So, human actions play a significant role in SNF transportation. In analyzing incidents that have occurred during transport operations, several recent studies have indicated that 'human error' is a primary cause. Therefore, the objectives of this study are to predict and identify possible human errors during the loading and storage of SNF. Furthermore, after evaluating human error for each process, countermeasures to minimize human error are deduced

  6. How to Cope with the Rare Human Error Events Involved with organizational Factors in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sa Kil; Luo, Meiling; Lee, Yong Hee [Korea Atomic Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The current human error guidelines (e.g. US DOD handbooks, US NRC Guidelines) are representative tools to prevent human errors. These tools, however, have limits that they do not adapt all operating situations and circumstances such as design base events. In other words, these tools are only adapted foreseeable standardized operating situations and circumstances. In this study, our research team proposed an evidence-based approach such as UK's safety case to coping with the rare human error events such as TMI, Chernobyl, Fukushima accidents. These accidents are representative events involved with rare human errors. Our research team defined the 'rare human errors' as the follow three characterized events; Extremely low frequency Extremely high complicated structure Extremely serious damage of human life and property A safety case is a structured argument, supported by evidence, intended to justify that a system is acceptably safe. The definition by UK defense standard 00-56 issue 4 states that such an evidence-based approach can be contrast with a prescriptive approach to safety certification, which require safety to be justified using a prescribed process. Safety managements and safety regulatory activities based on safety case are effective to control organizational factors in terms of integrated safety management. Especially safety issues relevant with public acceptance are useful to provide practical evidences to the public reasonably. European Union including UK has developed the concept of engineered safety management system to deal with public acceptance using the safety case. In Korea nuclear industry, the Korean Atomic Research Institute has firstly performed a basic research to adapt the safety case in the field of radioactive waste according to the IAEA SSG-23(KAERI/TR-4497, 4531). Excepting the radioactive waste, there is no try to adapt the safety case yet. Most incidents and accidents involved human during operating NPPs have a tendency

  7. How to Cope with the Rare Human Error Events Involved with organizational Factors in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Kim, Sa Kil; Luo, Meiling; Lee, Yong Hee

    2014-01-01

    The current human error guidelines (e.g. US DOD handbooks, US NRC Guidelines) are representative tools to prevent human errors. These tools, however, have limits that they do not adapt all operating situations and circumstances such as design base events. In other words, these tools are only adapted foreseeable standardized operating situations and circumstances. In this study, our research team proposed an evidence-based approach such as UK's safety case to coping with the rare human error events such as TMI, Chernobyl, Fukushima accidents. These accidents are representative events involved with rare human errors. Our research team defined the 'rare human errors' as the follow three characterized events; Extremely low frequency Extremely high complicated structure Extremely serious damage of human life and property A safety case is a structured argument, supported by evidence, intended to justify that a system is acceptably safe. The definition by UK defense standard 00-56 issue 4 states that such an evidence-based approach can be contrast with a prescriptive approach to safety certification, which require safety to be justified using a prescribed process. Safety managements and safety regulatory activities based on safety case are effective to control organizational factors in terms of integrated safety management. Especially safety issues relevant with public acceptance are useful to provide practical evidences to the public reasonably. European Union including UK has developed the concept of engineered safety management system to deal with public acceptance using the safety case. In Korea nuclear industry, the Korean Atomic Research Institute has firstly performed a basic research to adapt the safety case in the field of radioactive waste according to the IAEA SSG-23(KAERI/TR-4497, 4531). Excepting the radioactive waste, there is no try to adapt the safety case yet. Most incidents and accidents involved human during operating NPPs have a tendency

  8. ERROR DETECTION BY ANTICIPATION FOR VISION-BASED CONTROL

    Directory of Open Access Journals (Sweden)

    A ZAATRI

    2001-06-01

    Full Text Available A vision-based control system has been developed.  It enables a human operator to remotely direct a robot, equipped with a camera, towards targets in 3D space by simply pointing on their images with a pointing device. This paper presents an anticipatory system, which has been designed for improving the safety and the effectiveness of the vision-based commands. It simulates these commands in a virtual environment. It attempts to detect hard contacts that may occur between the robot and its environment, which can be caused by machine errors or operator errors as well.

  9. The using of the control room automation against human errors

    International Nuclear Information System (INIS)

    Kautto, A.

    1993-01-01

    The control room automation has developed very strongly during the 80's in IVO (Imatran Voima Oy). The former work expanded strongly with building of the full scope training simulator to the Loviisa plant. The important milestones has been, for example the testing of the Critical Function Monitoring System, a concept developed by Combustion Eng. Inc., in Loviisa training simulator 1982, the replacing of the process and simulator computers in Loviisa 1989, and 1990 and the presenting the use of the computer based procedures in training of operators 1993. With developing of automation and procedures it is possible to minimize the probability of human error. However, it is not possible totally eliminate the risks caused by human errors. (orig.)

  10. Normalization of Deviation: Quotation Error in Human Factors.

    Science.gov (United States)

    Lock, Jordan; Bearman, Chris

    2018-05-01

    Objective The objective of this paper is to examine quotation error in human factors. Background Science progresses through building on the work of previous research. This requires accurate quotation. Quotation error has a number of adverse consequences: loss of credibility, loss of confidence in the journal, and a flawed basis for academic debate and scientific progress. Quotation error has been observed in a number of domains, including marine biology and medicine, but there has been little or no previous study of this form of error in human factors, a domain that specializes in the causes and management of error. Methods A study was conducted examining quotation accuracy of 187 extracts from 118 published articles that cited a control article (Vaughan's 1996 book: The Challenger Launch Decision: Risky Technology, Culture, and Deviance at NASA). Results Of extracts studied, 12.8% ( n = 24) were classed as inaccurate, with 87.2% ( n = 163) being classed as accurate. A second dimension of agreement was examined with 96.3% ( n = 180) agreeing with the control article and only 3.7% ( n = 7) disagreeing. The categories of accuracy and agreement form a two by two matrix. Conclusion Rather than simply blaming individuals for quotation error, systemic factors should also be considered. Vaughan's theory, normalization of deviance, is one systemic theory that can account for quotation error. Application Quotation error is occurring in human factors and should receive more attention. According to Vaughan's theory, the normal everyday systems that promote scholarship may also allow mistakes, mishaps, and quotation error to occur.

  11. Applications of human error analysis to aviation and space operations

    International Nuclear Information System (INIS)

    Nelson, W.R.

    1998-01-01

    For the past several years at the Idaho National Engineering and Environmental Laboratory (INEEL) we have been working to apply methods of human error analysis to the design of complex systems. We have focused on adapting human reliability analysis (HRA) methods that were developed for Probabilistic Safety Assessment (PSA) for application to system design. We are developing methods so that human errors can be systematically identified during system design, the potential consequences of each error can be assessed, and potential corrective actions (e.g. changes to system design or procedures) can be identified. These applications lead to different requirements when compared with HR.As performed as part of a PSA. For example, because the analysis will begin early during the design stage, the methods must be usable when only partial design information is available. In addition, the ability to perform numerous ''what if'' analyses to identify and compare multiple design alternatives is essential. Finally, since the goals of such human error analyses focus on proactive design changes rather than the estimate of failure probabilities for PRA, there is more emphasis on qualitative evaluations of error relationships and causal factors than on quantitative estimates of error frequency. The primary vehicle we have used to develop and apply these methods has been a series of prqjects sponsored by the National Aeronautics and Space Administration (NASA) to apply human error analysis to aviation operations. The first NASA-sponsored project had the goal to evaluate human errors caused by advanced cockpit automation. Our next aviation project focused on the development of methods and tools to apply human error analysis to the design of commercial aircraft. This project was performed by a consortium comprised of INEEL, NASA, and Boeing Commercial Airplane Group. The focus of the project was aircraft design and procedures that could lead to human errors during airplane maintenance

  12. Simulator data on human error probabilities

    International Nuclear Information System (INIS)

    Kozinsky, E.J.; Guttmann, H.E.

    1982-01-01

    Analysis of operator errors on NPP simulators is being used to determine Human Error Probabilities (HEP) for task elements defined in NUREG/CR 1278. Simulator data tapes from research conducted by EPRI and ORNL are being analyzed for operator error rates. The tapes collected, using Performance Measurement System software developed for EPRI, contain a history of all operator manipulations during simulated casualties. Analysis yields a time history or Operational Sequence Diagram and a manipulation summary, both stored in computer data files. Data searches yield information on operator errors of omission and commission. This work experimentally determines HEPs for Probabilistic Risk Assessment calculations. It is the only practical experimental source of this data to date

  13. Simulator data on human error probabilities

    International Nuclear Information System (INIS)

    Kozinsky, E.J.; Guttmann, H.E.

    1981-01-01

    Analysis of operator errors on NPP simulators is being used to determine Human Error Probabilities (HEP) for task elements defined in NUREG/CR-1278. Simulator data tapes from research conducted by EPRI and ORNL are being analyzed for operator error rates. The tapes collected, using Performance Measurement System software developed for EPRI, contain a history of all operator manipulations during simulated casualties. Analysis yields a time history or Operational Sequence Diagram and a manipulation summary, both stored in computer data files. Data searches yield information on operator errors of omission and commission. This work experimentally determined HEP's for Probabilistic Risk Assessment calculations. It is the only practical experimental source of this data to date

  14. BAYES-HEP: Bayesian belief networks for estimation of human error probability

    International Nuclear Information System (INIS)

    Karthick, M.; Senthil Kumar, C.; Paul, Robert T.

    2017-01-01

    Human errors contribute a significant portion of risk in safety critical applications and methods for estimation of human error probability have been a topic of research for over a decade. The scarce data available on human errors and large uncertainty involved in the prediction of human error probabilities make the task difficult. This paper presents a Bayesian belief network (BBN) model for human error probability estimation in safety critical functions of a nuclear power plant. The developed model using BBN would help to estimate HEP with limited human intervention. A step-by-step illustration of the application of the method and subsequent evaluation is provided with a relevant case study and the model is expected to provide useful insights into risk assessment studies

  15. A human error taxonomy and its application to an automatic method accident analysis

    International Nuclear Information System (INIS)

    Matthews, R.H.; Winter, P.W.

    1983-01-01

    Commentary is provided on the quantification aspects of human factors analysis in risk assessment. Methods for quantifying human error in a plant environment are discussed and their application to system quantification explored. Such a programme entails consideration of the data base and a taxonomy of factors contributing to human error. A multi-levelled approach to system quantification is proposed, each level being treated differently drawing on the advantages of different techniques within the fault/event tree framework. Management, as controller of organization, planning and procedure, is assigned a dominant role. (author)

  16. Detailed semantic analyses of human error incidents occurring at nuclear power plant in USA (interim report). Characteristics of human error incidents occurring in the period from 1992 to 1996

    International Nuclear Information System (INIS)

    Hirotsu, Yuko; Tsuge, Tadashi; Sano, Toshiaki; Takano, Kenichi; Gouda, Hidenori

    2001-01-01

    CRIEPI has been conducting detailed analyses of all human error incidents at domestic nuclear power plants (NPPs) collected from Japanese Licensee Event Reports (LERs) using J-HPES (Japanese version of HPES) as an analysis method. Results obtained by the analyses have been stored in J-HPES database. Since 1999, human error incidents have been selected from U.S. LERs, and they are analyzed using J-HPES. In this report, the results, which classified error action, cause, and preventive measure, are summarized for U.S. human error cases occurring in the period from 1992 to 1996. It was suggested as a result of classification that the categories of error action were almost the same as those of Japanese human error cases. Therefore, problems in the process of error action and checkpoints for preventing errors will be extracted by analyzing both U.S. and domestic human error cases. It was also suggested that the interrelations between error actions, causes, and organizational factors could be identified. While taking these suggestions into consideration, we will continue to analyze U.S. human error cases. (author)

  17. A Benefit/Cost/Deficit (BCD) model for learning from human errors

    International Nuclear Information System (INIS)

    Vanderhaegen, Frederic; Zieba, Stephane; Enjalbert, Simon; Polet, Philippe

    2011-01-01

    This paper proposes an original model for interpreting human errors, mainly violations, in terms of benefits, costs and potential deficits. This BCD model is then used as an input framework to learn from human errors, and two systems based on this model are developed: a case-based reasoning system and an artificial neural network system. These systems are used to predict a specific human car driving violation: not respecting the priority-to-the-right rule, which is a decision to remove a barrier. Both prediction systems learn from previous violation occurrences, using the BCD model and four criteria: safety, for identifying the deficit or the danger; and opportunity for action, driver comfort, and time spent; for identifying the benefits or the costs. The application of learning systems to predict car driving violations gives a rate over 80% of correct prediction after 10 iterations. These results are validated for the non-respect of priority-to-the-right rule.

  18. Analysis of Human Errors in Japanese Nuclear Power Plants using JHPES/JAESS

    International Nuclear Information System (INIS)

    Kojima, Mitsuhiro; Mimura, Masahiro; Yamaguchi, Osamu

    1998-01-01

    CRIEPI (Central Research Institute for Electric Power Industries) / HFC (Human Factors research Center) developed J-HPES (Japanese version of Human Performance Enhancement System) based on the HPES which was originally developed by INPO to analyze events resulted from human errors. J-HPES was systematized into a computer program named JAESS (J-HPES Analysis and Evaluation Support System) and both systems were distributed to all Japanese electric power companies to analyze events by themselves. CRIEPI / HFC also analyzed the incidents in Japanese nuclear power plants (NPPs) which were officially reported and identified as human error related with J-HPES / JAESS. These incidents have numbered up to 188 cases over the last 30 years. An outline of this analysis is given, and some preliminary findings are shown. (authors)

  19. An advanced human reliability analysis methodology: analysis of cognitive errors focused on

    International Nuclear Information System (INIS)

    Kim, J. H.; Jeong, W. D.

    2001-01-01

    The conventional Human Reliability Analysis (HRA) methods such as THERP/ASEP, HCR and SLIM has been criticised for their deficiency in analysing cognitive errors which occurs during operator's decision making process. In order to supplement the limitation of the conventional methods, an advanced HRA method, what is called the 2 nd generation HRA method, including both qualitative analysis and quantitative assessment of cognitive errors has been being developed based on the state-of-the-art theory of cognitive systems engineering and error psychology. The method was developed on the basis of human decision-making model and the relation between the cognitive function and the performance influencing factors. The application of the proposed method to two emergency operation tasks is presented

  20. Human error recovery failure probability when using soft controls in computerized control rooms

    International Nuclear Information System (INIS)

    Jang, Inseok; Kim, Ar Ryum; Seong, Poong Hyun; Jung, Wondea

    2014-01-01

    Many literatures categorized recovery process into three phases; detection of problem situation, explanation of problem causes or countermeasures against problem, and end of recovery. Although the focus of recovery promotion has been on categorizing recovery phases and modeling recovery process, research related to human recovery failure probabilities has not been perform actively. On the other hand, a few study regarding recovery failure probabilities were implemented empirically. Summarizing, researches that have performed so far have several problems in terms of use in human reliability analysis (HRA). By adopting new human-system interfaces that are based on computer-based technologies, the operation environment of MCRs in NPPs has changed from conventional MCRs to advanced MCRs. Because of the different interfaces between conventional and advanced MCRs, different recovery failure probabilities should be considered in the HRA for advanced MCRs. Therefore, this study carries out an empirical analysis of human error recovery probabilities under an advanced MCR mockup called compact nuclear simulator (CNS). The aim of this work is not only to compile a recovery failure probability database using the simulator for advanced MCRs but also to collect recovery failure probability according to defined human error modes to compare that which human error mode has highest recovery failure probability. The results show that recovery failure probability regarding wrong screen selection was lowest among human error modes, which means that most of human error related to wrong screen selection can be recovered. On the other hand, recovery failure probabilities of operation selection omission and delayed operation were 1.0. These results imply that once subject omitted one task in the procedure, they have difficulties finding and recovering their errors without supervisor's assistance. Also, wrong screen selection had an effect on delayed operation. That is, wrong screen

  1. Automation of Commanding at NASA: Reducing Human Error in Space Flight

    Science.gov (United States)

    Dorn, Sarah J.

    2010-01-01

    Automation has been implemented in many different industries to improve efficiency and reduce human error. Reducing or eliminating the human interaction in tasks has been proven to increase productivity in manufacturing and lessen the risk of mistakes by humans in the airline industry. Human space flight requires the flight controllers to monitor multiple systems and react quickly when failures occur so NASA is interested in implementing techniques that can assist in these tasks. Using automation to control some of these responsibilities could reduce the number of errors the flight controllers encounter due to standard human error characteristics. This paper will investigate the possibility of reducing human error in the critical area of manned space flight at NASA.

  2. Safety coaches in radiology: decreasing human error and minimizing patient harm

    Energy Technology Data Exchange (ETDEWEB)

    Dickerson, Julie M.; Adams, Janet M. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, MLC 5031, Cincinnati, OH (United States); Koch, Bernadette L.; Donnelly, Lane F. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, MLC 5031, Cincinnati, OH (United States); Cincinnati Children' s Hospital Medical Center, Department of Pediatrics, Cincinnati, OH (United States); Goodfriend, Martha A. [Cincinnati Children' s Hospital Medical Center, Department of Quality Improvement, Cincinnati, OH (United States)

    2010-09-15

    Successful programs to improve patient safety require a component aimed at improving safety culture and environment, resulting in a reduced number of human errors that could lead to patient harm. Safety coaching provides peer accountability. It involves observing for safety behaviors and use of error prevention techniques and provides immediate feedback. For more than a decade, behavior-based safety coaching has been a successful strategy for reducing error within the context of occupational safety in industry. We describe the use of safety coaches in radiology. Safety coaches are an important component of our comprehensive patient safety program. (orig.)

  3. Safety coaches in radiology: decreasing human error and minimizing patient harm

    International Nuclear Information System (INIS)

    Dickerson, Julie M.; Adams, Janet M.; Koch, Bernadette L.; Donnelly, Lane F.; Goodfriend, Martha A.

    2010-01-01

    Successful programs to improve patient safety require a component aimed at improving safety culture and environment, resulting in a reduced number of human errors that could lead to patient harm. Safety coaching provides peer accountability. It involves observing for safety behaviors and use of error prevention techniques and provides immediate feedback. For more than a decade, behavior-based safety coaching has been a successful strategy for reducing error within the context of occupational safety in industry. We describe the use of safety coaches in radiology. Safety coaches are an important component of our comprehensive patient safety program. (orig.)

  4. Safety coaches in radiology: decreasing human error and minimizing patient harm.

    Science.gov (United States)

    Dickerson, Julie M; Koch, Bernadette L; Adams, Janet M; Goodfriend, Martha A; Donnelly, Lane F

    2010-09-01

    Successful programs to improve patient safety require a component aimed at improving safety culture and environment, resulting in a reduced number of human errors that could lead to patient harm. Safety coaching provides peer accountability. It involves observing for safety behaviors and use of error prevention techniques and provides immediate feedback. For more than a decade, behavior-based safety coaching has been a successful strategy for reducing error within the context of occupational safety in industry. We describe the use of safety coaches in radiology. Safety coaches are an important component of our comprehensive patient safety program.

  5. An Approach to Human Error Hazard Detection of Unexpected Situations in NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sangjun; Oh, Yeonju; Shin, Youmin; Lee, Yong-Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Fukushima accident is a typical complex event including the extreme situations induced by the succeeding earthquake, tsunami, explosion, and human errors. And it is judged with incomplete cause of system build-up same manner, procedure as a deficiency of response manual, education and training, team capability and the discharge of operator from human engineering point of view. Especially, the guidelines of current operating NPPs are not enough including countermeasures to the human errors at the extreme situations. Therefore, this paper describes a trial to detect the hazards of human errors at extreme situation, and to define the countermeasures that can properly response to the human error hazards when an individual, team, organization, and working entities that encounter the extreme situation in NPPs. In this paper we try to propose an approach to analyzing and extracting human error hazards for suggesting additional countermeasures to the human errors in unexpected situations. They might be utilized to develop contingency guidelines, especially for reducing the human error accident in NPPs. But the trial application in this study is currently limited since it is not easy to find accidents cases in detail enough to enumerate the proposed steps. Therefore, we will try to analyze as more cases as possible, and consider other environmental factors and human error conditions.

  6. An Approach to Human Error Hazard Detection of Unexpected Situations in NPPs

    International Nuclear Information System (INIS)

    Park, Sangjun; Oh, Yeonju; Shin, Youmin; Lee, Yong-Hee

    2015-01-01

    Fukushima accident is a typical complex event including the extreme situations induced by the succeeding earthquake, tsunami, explosion, and human errors. And it is judged with incomplete cause of system build-up same manner, procedure as a deficiency of response manual, education and training, team capability and the discharge of operator from human engineering point of view. Especially, the guidelines of current operating NPPs are not enough including countermeasures to the human errors at the extreme situations. Therefore, this paper describes a trial to detect the hazards of human errors at extreme situation, and to define the countermeasures that can properly response to the human error hazards when an individual, team, organization, and working entities that encounter the extreme situation in NPPs. In this paper we try to propose an approach to analyzing and extracting human error hazards for suggesting additional countermeasures to the human errors in unexpected situations. They might be utilized to develop contingency guidelines, especially for reducing the human error accident in NPPs. But the trial application in this study is currently limited since it is not easy to find accidents cases in detail enough to enumerate the proposed steps. Therefore, we will try to analyze as more cases as possible, and consider other environmental factors and human error conditions

  7. Human errors identification using the human factors analysis and classification system technique (HFACS

    Directory of Open Access Journals (Sweden)

    G. A. Shirali

    2013-12-01

    .Result: In this study, 158 reports of accident in Ahvaz steel industry were analyzed by HFACS technique. This analysis showed that most of the human errors were: in the first level was related to the skill-based errors, in the second to the physical environment, in the third level to the inadequate supervision and in the fourth level to the management of resources. .Conclusion: Studying and analyzing of past events using the HFACS technique can identify the major and root causes of accidents and can be effective on prevent repetitions of such mishaps. Also, it can be used as a basis for developing strategies to prevent future events in steel industries.

  8. When soft controls get slippery: User interfaces and human error

    International Nuclear Information System (INIS)

    Stubler, W.F.; O'Hara, J.M.

    1998-01-01

    Many types of products and systems that have traditionally featured physical control devices are now being designed with soft controls--input formats appearing on computer-based display devices and operated by a variety of input devices. A review of complex human-machine systems found that soft controls are particularly prone to some types of errors and may affect overall system performance and safety. This paper discusses the application of design approaches for reducing the likelihood of these errors and for enhancing usability, user satisfaction, and system performance and safety

  9. Human Error Probability Assessment During Maintenance Activities of Marine Systems

    Directory of Open Access Journals (Sweden)

    Rabiul Islam

    2018-03-01

    Full Text Available Background: Maintenance operations on-board ships are highly demanding. Maintenance operations are intensive activities requiring high man–machine interactions in challenging and evolving conditions. The evolving conditions are weather conditions, workplace temperature, ship motion, noise and vibration, and workload and stress. For example, extreme weather condition affects seafarers' performance, increasing the chances of error, and, consequently, can cause injuries or fatalities to personnel. An effective human error probability model is required to better manage maintenance on-board ships. The developed model would assist in developing and maintaining effective risk management protocols. Thus, the objective of this study is to develop a human error probability model considering various internal and external factors affecting seafarers' performance. Methods: The human error probability model is developed using probability theory applied to Bayesian network. The model is tested using the data received through the developed questionnaire survey of >200 experienced seafarers with >5 years of experience. The model developed in this study is used to find out the reliability of human performance on particular maintenance activities. Results: The developed methodology is tested on the maintenance of marine engine's cooling water pump for engine department and anchor windlass for deck department. In the considered case studies, human error probabilities are estimated in various scenarios and the results are compared between the scenarios and the different seafarer categories. The results of the case studies for both departments are also compared. Conclusion: The developed model is effective in assessing human error probabilities. These probabilities would get dynamically updated as and when new information is available on changes in either internal (i.e., training, experience, and fatigue or external (i.e., environmental and operational conditions

  10. Quantitative estimation of the human error probability during soft control operations

    International Nuclear Information System (INIS)

    Lee, Seung Jun; Kim, Jaewhan; Jung, Wondea

    2013-01-01

    Highlights: ► An HRA method to evaluate execution HEP for soft control operations was proposed. ► The soft control tasks were analyzed and design-related influencing factors were identified. ► An application to evaluate the effects of soft controls was performed. - Abstract: In this work, a method was proposed for quantifying human errors that can occur during operation executions using soft controls. Soft controls of advanced main control rooms have totally different features from conventional controls, and thus they may have different human error modes and occurrence probabilities. It is important to identify the human error modes and quantify the error probability for evaluating the reliability of the system and preventing errors. This work suggests an evaluation framework for quantifying the execution error probability using soft controls. In the application result, it was observed that the human error probabilities of soft controls showed both positive and negative results compared to the conventional controls according to the design quality of advanced main control rooms

  11. Error management process for power stations

    International Nuclear Information System (INIS)

    Hirotsu, Yuko; Takeda, Daisuke; Fujimoto, Junzo; Nagasaka, Akihiko

    2016-01-01

    The purpose of this study is to establish 'error management process for power stations' for systematizing activities for human error prevention and for festering continuous improvement of these activities. The following are proposed by deriving concepts concerning error management process from existing knowledge and realizing them through application and evaluation of their effectiveness at a power station: an entire picture of error management process that facilitate four functions requisite for maraging human error prevention effectively (1. systematizing human error prevention tools, 2. identifying problems based on incident reports and taking corrective actions, 3. identifying good practices and potential problems for taking proactive measures, 4. prioritizeng human error prevention tools based on identified problems); detail steps for each activity (i.e. developing an annual plan for human error prevention, reporting and analyzing incidents and near misses) based on a model of human error causation; procedures and example of items for identifying gaps between current and desired levels of executions and outputs of each activity; stages for introducing and establishing the above proposed error management process into a power station. By giving shape to above proposals at a power station, systematization and continuous improvement of activities for human error prevention in line with the actual situation of the power station can be expected. (author)

  12. Perancangan Fasilitas Kerja untuk Mereduksi Human Error

    Directory of Open Access Journals (Sweden)

    Harmein Nasution

    2012-01-01

    Full Text Available Work equipments and environment which are not design ergonomically can cause physical exhaustion to the workers. As a result of that physical exhaustion, many defects in the production lines can happen due to human error and also cause musculoskeletal complaints. To overcome, those effects, we occupied methods for analyzing the workers posture based on the SNQ (Standard Nordic Questionnaire, plibel, QEC (Quick Exposure Check and biomechanism. Moreover, we applied those methods for designing rolling machines and grip egrek ergono-mically, so that the defects on those production lines can be minimized.

  13. Sensitivity of risk parameters to human errors for a PWR

    International Nuclear Information System (INIS)

    Samanta, P.; Hall, R.E.; Kerr, W.

    1980-01-01

    Sensitivities of the risk parameters, emergency safety system unavailabilities, accident sequence probabilities, release category probabilities and core melt probability were investigated for changes in the human error rates within the general methodological framework of the Reactor Safety Study for a Pressurized Water Reactor (PWR). Impact of individual human errors were assessed both in terms of their structural importance to core melt and reliability importance on core melt probability. The Human Error Sensitivity Assessment of a PWR (HESAP) computer code was written for the purpose of this study

  14. Derivation of main drivers affecting the possibility of human errors during low power and shutdown operation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ar Ryum; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of); Park, Jin Kyun; Kim, Jae Whan [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    In order to estimate the possibility of human error and identify its nature, human reliability analysis (HRA) methods have been implemented. For this, various HRA methods have been developed so far: techniques for human error rate prediction (THERP), cause based decision tree (CBDT), the cognitive reliability and error analysis method (CREAM) and so on. Most HRA methods have been developed with a focus on full power operation of NPPs even though human performance may more largely affect the safety of the system during low power and shutdown (LPSD) operation than it would when the system is in full power operation. In this regard, it is necessary to conduct a research for developing HRA method to be used in LPSD operation. For the first step of the study, main drivers which affect the possibility of human error have been developed. Drivers which are commonly called as performance shaping factors (PSFs) are aspects of the human's individual characteristics, environment, organization, or task that specifically decrements or improves human performance, thus respectively increasing or decreasing the likelihood of human errors. In order to estimate the possibility of human error and identify its nature, human reliability analysis (HRA) methods have been implemented. For this, various HRA methods have been developed so far: techniques for human error rate prediction (THERP), cause based decision tree (CBDT), the cognitive reliability and error analysis method (CREAM) and so on. Most HRA methods have been developed with a focus on full power operation of NPPs even though human performance may more largely affect the safety of the system during low power and shutdown (LPSD) operation than it would when the system is in full power operation. In this regard, it is necessary to conduct a research for developing HRA method to be used in LPSD operation. For the first step of the study, main drivers which affect the possibility of human error have been developed. Drivers

  15. Derivation of main drivers affecting the possibility of human errors during low power and shutdown operation

    International Nuclear Information System (INIS)

    Kim, Ar Ryum; Seong, Poong Hyun; Park, Jin Kyun; Kim, Jae Whan

    2016-01-01

    In order to estimate the possibility of human error and identify its nature, human reliability analysis (HRA) methods have been implemented. For this, various HRA methods have been developed so far: techniques for human error rate prediction (THERP), cause based decision tree (CBDT), the cognitive reliability and error analysis method (CREAM) and so on. Most HRA methods have been developed with a focus on full power operation of NPPs even though human performance may more largely affect the safety of the system during low power and shutdown (LPSD) operation than it would when the system is in full power operation. In this regard, it is necessary to conduct a research for developing HRA method to be used in LPSD operation. For the first step of the study, main drivers which affect the possibility of human error have been developed. Drivers which are commonly called as performance shaping factors (PSFs) are aspects of the human's individual characteristics, environment, organization, or task that specifically decrements or improves human performance, thus respectively increasing or decreasing the likelihood of human errors. In order to estimate the possibility of human error and identify its nature, human reliability analysis (HRA) methods have been implemented. For this, various HRA methods have been developed so far: techniques for human error rate prediction (THERP), cause based decision tree (CBDT), the cognitive reliability and error analysis method (CREAM) and so on. Most HRA methods have been developed with a focus on full power operation of NPPs even though human performance may more largely affect the safety of the system during low power and shutdown (LPSD) operation than it would when the system is in full power operation. In this regard, it is necessary to conduct a research for developing HRA method to be used in LPSD operation. For the first step of the study, main drivers which affect the possibility of human error have been developed. Drivers which

  16. Quantification of human errors in level-1 PSA studies in NUPEC/JINS

    International Nuclear Information System (INIS)

    Hirano, M.; Hirose, M.; Sugawara, M.; Hashiba, T.

    1991-01-01

    THERP (Technique for Human Error Rate Prediction) method is mainly adopted to evaluate the pre-accident and post-accident human error rates. Performance shaping factors are derived by taking Japanese operational practice into account. Several examples of human error rates with calculational procedures are presented. The important human interventions of typical Japanese NPPs are also presented. (orig./HP)

  17. The Concept of Human Error and the Design of Reliable Human-Machine Systems

    DEFF Research Database (Denmark)

    Rasmussen, Jens

    1995-01-01

    The concept of human error is unreliable as a basis for design of reliable human-machine systems. Humans are basically highly adaptive and 'errors' are closely related to the process of adaptation and learning. Therefore, reliability of system operation depends on an interface that is not designed...... so as to support a pre-conceived operating procedure, but, instead, makes visible the deep, functional structure of the system together with the boundaries of acceptable operation in away that allows operators to 'touch' the boundaries and to learn to cope with the effects of errors in a reversible...... way. The concepts behind such 'ecological' interfaces are discussed, an it is argued that a 'typology' of visualization concepts is a pressing research need....

  18. The treatment of commission errors in first generation human reliability analysis methods

    Energy Technology Data Exchange (ETDEWEB)

    Alvarengga, Marco Antonio Bayout; Fonseca, Renato Alves da, E-mail: bayout@cnen.gov.b, E-mail: rfonseca@cnen.gov.b [Comissao Nacional de Energia Nuclear (CNEN) Rio de Janeiro, RJ (Brazil); Melo, Paulo Fernando Frutuoso e, E-mail: frutuoso@nuclear.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear

    2011-07-01

    Human errors in human reliability analysis can be classified generically as errors of omission and commission errors. Omission errors are related to the omission of any human action that should have been performed, but does not occur. Errors of commission are those related to human actions that should not be performed, but which in fact are performed. Both involve specific types of cognitive error mechanisms, however, errors of commission are more difficult to model because they are characterized by non-anticipated actions that are performed instead of others that are omitted (omission errors) or are entered into an operational task without being part of the normal sequence of this task. The identification of actions that are not supposed to occur depends on the operational context that will influence or become easy certain unsafe actions of the operator depending on the operational performance of its parameters and variables. The survey of operational contexts and associated unsafe actions is a characteristic of second-generation models, unlike the first generation models. This paper discusses how first generation models can treat errors of commission in the steps of detection, diagnosis, decision-making and implementation, in the human information processing, particularly with the use of THERP tables of errors quantification. (author)

  19. The recovery factors analysis of the human errors for research reactors

    International Nuclear Information System (INIS)

    Farcasiu, M.; Nitoi, M.; Apostol, M.; Turcu, I.; Florescu, Ghe.

    2006-01-01

    The results of many Probabilistic Safety Assessment (PSA) studies show a very significant contribution of human errors to systems unavailability of the nuclear installations. The treatment of human interactions is considered one of the major limitations in the context of PSA. To identify those human actions that can have an effect on system reliability or availability applying the Human Reliability Analysis (HRA) is necessary. The recovery factors analysis of the human action is an important step in HRA. This paper presents how can be reduced the human errors probabilities (HEP) using those elements that have the capacity to recovery human error. The recovery factors modeling is marked to identify error likelihood situations or situations that conduct at development of the accident. This analysis is realized by THERP method. The necessary information was obtained from the operating experience of the research reactor TRIGA of the INR Pitesti. The required data were obtained from generic databases. (authors)

  20. Human reliability analysis during PSA at Trillo NPP: main characteristics and analysis of diagnostic errors

    International Nuclear Information System (INIS)

    Barquin, M.A.; Gomez, F.

    1998-01-01

    The design difference between Trillo NPP and other Spanish nuclear power plants (basic Westinghouse and General Electric designs) were made clear in the Human Reliability Analysis of the Probabilistic Safety Analysis (PSA) for Trillo NPP. The object of this paper is to describe the most significant characteristics of the Human Reliability Analysis carried out in the PSA, with special emphasis on the possible diagnostic errors and their consequences, based on the characteristics in the Emergency Operations Manual for Trillo NPP. - In the case of human errors before the initiating event (type 1), the existence of four redundancies in most of the plant safety systems, means that the impact of this type or error on the final results of the PSA is insignificant. However, in the case common cause errors, especially in certain calibration errors, some actions are significant in the final equation for core damage - The number of human actions that the operator has to carry out during the accidents (type 3) modelled, is relatively small in comparison with this value in other PSAs. This is basically due to the high level of automation at Rillo NPP - The Plant Operations Manual cannot be strictly considered to be a symptoms-based procedure. The operation Group must select the chapter from the Operations Manual to be followed, after having diagnosed the perturbing event, using for this purpose and Emergency and Anomaly Decision Tree (M.O.3.0.1) based on the different indications, alarms and symptoms present in the plant after the perturbing event. For this reason, it was decided to analyse the possible diagnosis errors. In the bibliography on diagnosis and commission errors available at the present time, there is no precise methodology for the analysis of this type of error and its incorporation into PSAs. The method used in the PSA for Trillo y NPP to evaluate this type of interaction, is to develop a Diagnosis Error Table, the object of which is to identify the situations in

  1. Error detection in spoken human-machine interaction

    NARCIS (Netherlands)

    Krahmer, E.J.; Swerts, M.G.J.; Theune, M.; Weegels, M.F.

    2001-01-01

    Given the state of the art of current language and speech technology, errors are unavoidable in present-day spoken dialogue systems. Therefore, one of the main concerns in dialogue design is how to decide whether or not the system has understood the user correctly. In human-human communication,

  2. Error detection in spoken human-machine interaction

    NARCIS (Netherlands)

    Krahmer, E.; Swerts, M.; Theune, Mariet; Weegels, M.

    Given the state of the art of current language and speech technology, errors are unavoidable in present-day spoken dialogue systems. Therefore, one of the main concerns in dialogue design is how to decide whether or not the system has understood the user correctly. In human-human communication,

  3. A technique for human error analysis (ATHEANA)

    International Nuclear Information System (INIS)

    Cooper, S.E.; Ramey-Smith, A.M.; Wreathall, J.; Parry, G.W.

    1996-05-01

    Probabilistic risk assessment (PRA) has become an important tool in the nuclear power industry, both for the Nuclear Regulatory Commission (NRC) and the operating utilities. Human reliability analysis (HRA) is a critical element of PRA; however, limitations in the analysis of human actions in PRAs have long been recognized as a constraint when using PRA. A multidisciplinary HRA framework has been developed with the objective of providing a structured approach for analyzing operating experience and understanding nuclear plant safety, human error, and the underlying factors that affect them. The concepts of the framework have matured into a rudimentary working HRA method. A trial application of the method has demonstrated that it is possible to identify potentially significant human failure events from actual operating experience which are not generally included in current PRAs, as well as to identify associated performance shaping factors and plant conditions that have an observable impact on the frequency of core damage. A general process was developed, albeit in preliminary form, that addresses the iterative steps of defining human failure events and estimating their probabilities using search schemes. Additionally, a knowledge- base was developed which describes the links between performance shaping factors and resulting unsafe actions

  4. A technique for human error analysis (ATHEANA)

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, S.E.; Ramey-Smith, A.M.; Wreathall, J.; Parry, G.W. [and others

    1996-05-01

    Probabilistic risk assessment (PRA) has become an important tool in the nuclear power industry, both for the Nuclear Regulatory Commission (NRC) and the operating utilities. Human reliability analysis (HRA) is a critical element of PRA; however, limitations in the analysis of human actions in PRAs have long been recognized as a constraint when using PRA. A multidisciplinary HRA framework has been developed with the objective of providing a structured approach for analyzing operating experience and understanding nuclear plant safety, human error, and the underlying factors that affect them. The concepts of the framework have matured into a rudimentary working HRA method. A trial application of the method has demonstrated that it is possible to identify potentially significant human failure events from actual operating experience which are not generally included in current PRAs, as well as to identify associated performance shaping factors and plant conditions that have an observable impact on the frequency of core damage. A general process was developed, albeit in preliminary form, that addresses the iterative steps of defining human failure events and estimating their probabilities using search schemes. Additionally, a knowledge- base was developed which describes the links between performance shaping factors and resulting unsafe actions.

  5. Frame-based safety analysis approach for decision-based errors

    International Nuclear Information System (INIS)

    Fan, Chin-Feng; Yihb, Swu

    1997-01-01

    A frame-based approach is proposed to analyze decision-based errors made by automatic controllers or human operators due to erroneous reference frames. An integrated framework, Two Frame Model (TFM), is first proposed to model the dynamic interaction between the physical process and the decision-making process. Two important issues, consistency and competing processes, are raised. Consistency between the physical and logic frames makes a TFM-based system work properly. Loss of consistency refers to the failure mode that the logic frame does not accurately reflect the state of the controlled processes. Once such failure occurs, hazards may arise. Among potential hazards, the competing effect between the controller and the controlled process is the most severe one, which may jeopardize a defense-in-depth design. When the logic and physical frames are inconsistent, conventional safety analysis techniques are inadequate. We propose Frame-based Fault Tree; Analysis (FFTA) and Frame-based Event Tree Analysis (FETA) under TFM to deduce the context for decision errors and to separately generate the evolution of the logical frame as opposed to that of the physical frame. This multi-dimensional analysis approach, different from the conventional correctness-centred approach, provides a panoramic view in scenario generation. Case studies using the proposed techniques are also given to demonstrate their usage and feasibility

  6. Evaluation of human error estimation for nuclear power plants

    International Nuclear Information System (INIS)

    Haney, L.N.; Blackman, H.S.

    1987-01-01

    The dominant risk for severe accident occurrence in nuclear power plants (NPPs) is human error. The US Nuclear Regulatory Commission (NRC) sponsored an evaluation of Human Reliability Analysis (HRA) techniques for estimation of human error in NPPs. Twenty HRA techniques identified by a literature search were evaluated with criteria sets designed for that purpose and categorized. Data were collected at a commercial NPP with operators responding in walkthroughs of four severe accident scenarios and full scope simulator runs. Results suggest a need for refinement and validation of the techniques. 19 refs

  7. A Human Error Analysis with Physiological Signals during Utilizing Digital Devices

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Hee; Oh, Yeon Ju; Shin, Kwang Hyeon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    The introduction of advanced MCR is accompanied with lots of changes and different forms and features through the virtue of new digital technologies. There are various kinds of digital devices such as flat panel displays, touch screens, and so on. The characteristics of these digital devices give many chances to the interface management, and can be integrated into a compact single workstation in an advanced MCR so that workers can operate the plant with minimum burden during any operating condition. However, these devices may introduce new types of human errors, and thus we need a means to evaluate and prevent such error, especially those related to the digital devices. Human errors have been retrospectively assessed for accident reviews and quantitatively evaluated through HRA for PSA. However, the ergonomic verification and validation is an important process to defend all human error potential in the NPP design. HRA is a crucial part of a PSA, and helps in preparing a countermeasure for design by drawing potential human error items that affect the overall safety of NPPs. Various HRA techniques are available however: they reveal shortages of the HMI design in the digital era. - HRA techniques depend on PSFs: this means that the scope dealing with human factors is previously limited, and thus all attributes of new digital devices may not be considered in HRA. - The data used to HRA are not close to the evaluation items. So, human error analysis is not easy to apply to design by several individual experiments and cases. - The results of HRA are not statistically meaningful because accidents including human errors in NPPs are rare and have been estimated as having an extremely low probability

  8. Modelling the basic error tendencies of human operators

    Energy Technology Data Exchange (ETDEWEB)

    Reason, J.

    1988-01-01

    The paper outlines the primary structural features of human cognition: a limited, serial workspace interacting with a parallel distributed knowledge base. It is argued that the essential computational features of human cognition - to be captured by an adequate operator model - reside in the mechanisms by which stored knowledge structures are selected and brought into play. Two such computational 'primitives' are identified: similarity-matching and frequency-gambling. These two retrieval heuristics, it is argued, shape both the overall character of human performance (i.e. its heavy reliance on pattern-matching) and its basic error tendencies ('strong-but-wrong' responses, confirmation, similarity and frequency biases, and cognitive 'lock-up'). The various features of human cognition are integrated with a dynamic operator model capable of being represented in software form. This computer model, when run repeatedly with a variety of problem configurations, should produce a distribution of behaviours which, in toto, simulate the general character of operator performance.

  9. Modelling the basic error tendencies of human operators

    International Nuclear Information System (INIS)

    Reason, J.

    1988-01-01

    The paper outlines the primary structural features of human cognition: a limited, serial workspace interacting with a parallel distributed knowledge base. It is argued that the essential computational features of human cognition - to be captured by an adequate operator model - reside in the mechanisms by which stored knowledge structures are selected and brought into play. Two such computational 'primitives' are identified: similarity-matching and frequency-gambling. These two retrieval heuristics, it is argued, shape both the overall character of human performance (i.e. its heavy reliance on pattern-matching) and its basic error tendencies ('strong-but-wrong' responses, confirmation, similarity and frequency biases, and cognitive 'lock-up'). The various features of human cognition are integrated with a dynamic operator model capable of being represented in software form. This computer model, when run repeatedly with a variety of problem configurations, should produce a distribution of behaviours which, in total, simulate the general character of operator performance. (author)

  10. Modelling the basic error tendencies of human operators

    International Nuclear Information System (INIS)

    Reason, James

    1988-01-01

    The paper outlines the primary structural features of human cognition: a limited, serial workspace interacting with a parallel distributed knowledge base. It is argued that the essential computational features of human cognition - to be captured by an adequate operator model - reside in the mechanisms by which stored knowledge structures are selected and brought into play. Two such computational 'primitives' are identified: similarity-matching and frequency-gambling. These two retrieval heuristics, it is argued, shape both the overall character of human performance (i.e. its heavy reliance on pattern-matching) and its basic error tendencies ('strong-but-wrong' responses, confirmation, similarity and frequency biases, and cognitive 'lock-up'). The various features of human cognition are integrated with a dynamic operator model capable of being represented in software form. This computer model, when run repeatedly with a variety of problem configurations, should produce a distribution of behaviours which, in toto, simulate the general character of operator performance. (author)

  11. A system engineer's Perspective on Human Errors For a more Effective Management of Human Factors in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Lee, Yong-Hee; Jang, Tong-Il; Lee, Soo-Kil

    2007-01-01

    The management of human factors in nuclear power plants (NPPs) has become one of the burden factors during their operating period after the design and construction period. Almost every study on the major accidents emphasizes the prominent importance of the human errors. Regardless of the regulatory requirements such as Periodic Safety Review, the management of human factors would be a main issue to reduce the human errors and to enhance the performance of plants. However, it is not easy to find out a more effective perspective on human errors to establish the engineering implementation plan for preventing them. This paper describes a system engineer's perspectives on human errors and discusses its application to the recent study on the human error events in Korean NPPs

  12. A Method and Support Tool for the Analysis of Human Error Hazards in Digital Devices

    International Nuclear Information System (INIS)

    Lee, Yong Hee; Kim, Seon Soo; Lee, Yong Hee

    2012-01-01

    In recent years, many nuclear power plants have adopted modern digital I and C technologies since they are expected to significantly improve their performance and safety. Modern digital technologies were expected to significantly improve both the economical efficiency and safety of nuclear power plants. However, the introduction of an advanced main control room (MCR) is accompanied with lots of changes in forms and features and differences through virtue of new digital devices. Many user-friendly displays and new features in digital devices are not enough to prevent human errors in nuclear power plants (NPPs). It may be an urgent to matter find the human errors potentials due to digital devices, and their detailed mechanisms. We can then consider them during the design of digital devices and their interfaces. The characteristics of digital technologies and devices may give many opportunities to the interface management, and can be integrated into a compact single workstation in an advanced MCR, such that workers can operate the plant with minimum burden under any operating condition. However, these devices may introduce new types of human errors, and thus we need a means to evaluate and prevent such errors, especially within digital devices for NPPs. This research suggests a new method named HEA-BIS (Human Error Analysis based on Interaction Segment) to confirm and detect human errors associated with digital devices. This method can be facilitated by support tools when used to ensure the safety when applying digital devices in NPPs

  13. The common mode failures analysis of the redundent system with dependent human error

    International Nuclear Information System (INIS)

    Kim, M.K.; Chang, S.H.

    1983-01-01

    Common mode failures (CMFs) have been a serious concern in the nuclear power plant. Thereis a broad category of the failure mechanisms that can cause common mode failures. This paper is a theoretical investigation of the CMFs on the unavailability of the redundent system. It is assumed that the total CMFs consist of the potential CMFs and the dependent human error CMFs. As the human error dependency is higher, the total CMFs are more effected by the dependent human error. If the human error dependence is lower, the system unavailability strongly depends on the potential CMFs, rather than the mechanical failure or the dependent human error. And it is shown that the total CMFs are dominant factor to the unavailability of the redundent system. (Author)

  14. Detailed semantic analyses of human error incidents occurring at domestic nuclear power plants to fiscal year 2000

    International Nuclear Information System (INIS)

    Tsuge, Tadashi; Hirotsu, Yuko; Takano, Kenichi; Ebisu, Mitsuhiro; Tsumura, Joji

    2003-01-01

    Analysing and evaluating observed cases of human error incidents with the emphasis on human factors and behavior involved was essential for preventing recurrence of those. CRIEPI has been conducting detailed and structures analyses of all incidents reported during last 35 year based on J-HPES, from the beginning of the first Tokai nuclear power operation till fiscal year of 2000, in which total 212 human error cases are identified. Results obtained by the analyses have been stored into the J-HPES data-base. This summarized the semantic analyses on all case-studies stored in the above data-base to grasp the practical and concrete contents and trend of more frequently observed human errors (as are called trigger actions here), causal factors and preventive measures. These semantic analyses have been executed by classifying all those items into some categories that could be considered as having almost the same meaning using the KJ method. Followings are obtained typical results by above analyses: (1) Trigger action-Those could be classified into categories of operation or categories of maintenance. Operational timing errors' and 'operational quantitative errors' were major actions in trigger actions of operation, those occupied about 20% among all actions. At trigger actions of maintenance, 'maintenance quantitative error' were major actions, those occupied quarter among all actions; (2) Causal factor- 'Human internal status' were major factors, as in concrete factors, those occupied 'improper persistence' and 'lack of knowledge'; (3) Preventive measure-Most frequent measures got were job management changes in procedural software improvements, which was from 70% to 80%. As for preventive measures of operation, software improvements have been implemented on 'organization and work practices' and 'individual consciousness'. Concerning preventive measures of maintenance, improvements have been implemented on 'organization and work practices'. (author)

  15. Collection and classification of human error and human reliability data from Indian nuclear power plants for use in PSA

    International Nuclear Information System (INIS)

    Subramaniam, K.; Saraf, R.K.; Sanyasi Rao, V.V.S.; Venkat Raj, V.; Venkatraman, R.

    2000-01-01

    Complex systems such as NPPs involve a large number of Human Interactions (HIs) in every phase of plant operations. Human Reliability Analysis (HRA) in the context of a PSA, attempts to model the HIs and evaluate/predict their impact on safety and reliability using human error/human reliability data. A large number of HRA techniques have been developed for modelling and integrating HIs into PSA but there is a significant lack of HAR data. In the face of insufficient data, human reliability analysts have had to resort to expert judgement methods in order to extend the insufficient data sets. In this situation, the generation of data from plant operating experience assumes importance. The development of a HRA data bank for Indian nuclear power plants was therefore initiated as part of the programme of work on HRA. Later, with the establishment of the coordinated research programme (CRP) on collection of human reliability data and use in PSA by IAEA in 1994-95, the development was carried out under the aegis of the IAEA research contract No. 8239/RB. The work described in this report covers the activities of development of a data taxonomy and a human error reporting form (HERF) based on it, data structuring, review and analysis of plant event reports, collection of data on human errors, analysis of the data and calculation of human error probabilities (HEPs). Analysis of plant operating experience does yield a good amount of qualitative data but obtaining quantitative data on human reliability in the form of HEPs is seen to be more difficult. The difficulties have been highlighted and some ways to bring about improvements in the data situation have been discussed. The implementation of a data system for HRA is described and useful features that can be incorporated in future systems are also discussed. (author)

  16. Faces in places: humans and machines make similar face detection errors.

    Directory of Open Access Journals (Sweden)

    Bernard Marius 't Hart

    Full Text Available The human visual system seems to be particularly efficient at detecting faces. This efficiency sometimes comes at the cost of wrongfully seeing faces in arbitrary patterns, including famous examples such as a rock configuration on Mars or a toast's roast patterns. In machine vision, face detection has made considerable progress and has become a standard feature of many digital cameras. The arguably most wide-spread algorithm for such applications ("Viola-Jones" algorithm achieves high detection rates at high computational efficiency. To what extent do the patterns that the algorithm mistakenly classifies as faces also fool humans? We selected three kinds of stimuli from real-life, first-person perspective movies based on the algorithm's output: correct detections ("real faces", false positives ("illusory faces" and correctly rejected locations ("non faces". Observers were shown pairs of these for 20 ms and had to direct their gaze to the location of the face. We found that illusory faces were mistaken for faces more frequently than non faces. In addition, rotation of the real face yielded more errors, while rotation of the illusory face yielded fewer errors. Using colored stimuli increases overall performance, but does not change the pattern of results. When replacing the eye movement by a manual response, however, the preference for illusory faces over non faces disappeared. Taken together, our data show that humans make similar face-detection errors as the Viola-Jones algorithm, when directing their gaze to briefly presented stimuli. In particular, the relative spatial arrangement of oriented filters seems of relevance. This suggests that efficient face detection in humans is likely to be pre-attentive and based on rather simple features as those encoded in the early visual system.

  17. Human error in maintenance: An investigative study for the factories of the future

    International Nuclear Information System (INIS)

    Dhillon, B S

    2014-01-01

    This paper presents a study of human error in maintenance. Many different aspects of human error in maintenance considered useful for the factories of the future are studied, including facts, figures, and examples; occurrence of maintenance error in equipment life cycle, elements of a maintenance person's time, maintenance environment and the causes for the occurrence of maintenance error, types and typical maintenance errors, common maintainability design errors and useful design guidelines to reduce equipment maintenance errors, maintenance work instructions, and maintenance error analysis methods

  18. Development of an Experimental Measurement System for Human Error Characteristics and a Pilot Test

    International Nuclear Information System (INIS)

    Jang, Tong-Il; Lee, Hyun-Chul; Moon, Kwangsu

    2017-01-01

    Some items out of individual and team characteristics were partially selected, and a pilot test was performed to measure and evaluate them using the experimental measurement system of human error characteristics. It is one of the processes to produce input data to the Eco-DBMS. And also, through the pilot test, it was tried to take methods to measure and acquire the physiological data, and to develop data format and quantification methods for the database. In this study, a pilot test to measure the stress and the tension level, and team cognitive characteristics out of human error characteristics was performed using the human error characteristics measurement and experimental evaluation system. In an experiment measuring the stress level, physiological characteristics using EEG was measured in a simulated unexpected situation. As shown in results, although this experiment was pilot, it was validated that relevant results for evaluating human error coping effects of workers’ FFD management guidelines and unexpected situation against guidelines can be obtained. In following researches, additional experiments including other human error characteristics will be conducted. Furthermore, the human error characteristics measurement and experimental evaluation system will be utilized to validate various human error coping solutions such as human factors criteria, design, and guidelines as well as supplement the human error characteristics database.

  19. A critique of recent models for human error rate assessment

    International Nuclear Information System (INIS)

    Apostolakis, G.E.

    1988-01-01

    This paper critically reviews two groups of models for assessing human error rates under accident conditions. The first group, which includes the US Nuclear Regulatory Commission (NRC) handbook model and the human cognitive reliability (HCR) model, considers as fundamental the time that is available to the operators to act. The second group, which is represented by the success likelihood index methodology multiattribute utility decomposition (SLIM-MAUD) model, relies on ratings of the human actions with respect to certain qualitative factors and the subsequent derivation of error rates. These models are evaluated with respect to two criteria: the treatment of uncertainties and the internal coherence of the models. In other words, this evaluation focuses primarily on normative aspects of these models. The principal findings are as follows: (1) Both of the time-related models provide human error rates as a function of the available time for action and the prevailing conditions. However, the HCR model ignores the important issue of state-of-knowledge uncertainties, dealing exclusively with stochastic uncertainty, whereas the model presented in the NRC handbook handles both types of uncertainty. (2) SLIM-MAUD provides a highly structured approach for the derivation of human error rates under given conditions. However, the treatment of the weights and ratings in this model is internally inconsistent. (author)

  20. Quality of IT service delivery — Analysis and framework for human error prevention

    KAUST Repository

    Shwartz, L.

    2010-12-01

    In this paper, we address the problem of reducing the occurrence of Human Errors that cause service interruptions in IT Service Support and Delivery operations. Analysis of a large volume of service interruption records revealed that more than 21% of interruptions were caused by human error. We focus on Change Management, the process with the largest risk of human error, and identify the main instances of human errors as the 4 Wrongs: request, time, configuration item, and command. Analysis of change records revealed that the humanerror prevention by partial automation is highly relevant. We propose the HEP Framework, a framework for execution of IT Service Delivery operations that reduces human error by addressing the 4 Wrongs using content integration, contextualization of operation patterns, partial automation of command execution, and controlled access to resources.

  1. HUMAN RELIABILITY ANALYSIS DENGAN PENDEKATAN COGNITIVE RELIABILITY AND ERROR ANALYSIS METHOD (CREAM

    Directory of Open Access Journals (Sweden)

    Zahirah Alifia Maulida

    2015-01-01

    Full Text Available Kecelakaan kerja pada bidang grinding dan welding menempati urutan tertinggi selama lima tahun terakhir di PT. X. Kecelakaan ini disebabkan oleh human error. Human error terjadi karena pengaruh lingkungan kerja fisik dan non fisik.Penelitian kali menggunakan skenario untuk memprediksi serta mengurangi kemungkinan terjadinya error pada manusia dengan pendekatan CREAM (Cognitive Reliability and Error Analysis Method. CREAM adalah salah satu metode human reliability analysis yang berfungsi untuk mendapatkan nilai Cognitive Failure Probability (CFP yang dapat dilakukan dengan dua cara yaitu basic method dan extended method. Pada basic method hanya akan didapatkan nilai failure probabailty secara umum, sedangkan untuk extended method akan didapatkan CFP untuk setiap task. Hasil penelitian menunjukkan faktor- faktor yang mempengaruhi timbulnya error pada pekerjaan grinding dan welding adalah kecukupan organisasi, kecukupan dari Man Machine Interface (MMI & dukungan operasional, ketersediaan prosedur/ perencanaan, serta kecukupan pelatihan dan pengalaman. Aspek kognitif pada pekerjaan grinding yang memiliki nilai error paling tinggi adalah planning dengan nilai CFP 0.3 dan pada pekerjaan welding yaitu aspek kognitif execution dengan nilai CFP 0.18. Sebagai upaya untuk mengurangi nilai error kognitif pada pekerjaan grinding dan welding rekomendasi yang diberikan adalah memberikan training secara rutin, work instrucstion yang lebih rinci dan memberikan sosialisasi alat. Kata kunci: CREAM (cognitive reliability and error analysis method, HRA (human reliability analysis, cognitive error Abstract The accidents in grinding and welding sectors were the highest cases over the last five years in PT. X and it caused by human error. Human error occurs due to the influence of working environment both physically and non-physically. This study will implement an approaching scenario called CREAM (Cognitive Reliability and Error Analysis Method. CREAM is one of human

  2. Some aspects of statistical modeling of human-error probability

    International Nuclear Information System (INIS)

    Prairie, R.R.

    1982-01-01

    Human reliability analyses (HRA) are often performed as part of risk assessment and reliability projects. Recent events in nuclear power have shown the potential importance of the human element. There are several on-going efforts in the US and elsewhere with the purpose of modeling human error such that the human contribution can be incorporated into an overall risk assessment associated with one or more aspects of nuclear power. An effort that is described here uses the HRA (event tree) to quantify and model the human contribution to risk. As an example, risk analyses are being prepared on several nuclear power plants as part of the Interim Reliability Assessment Program (IREP). In this process the risk analyst selects the elements of his fault tree that could be contributed to by human error. He then solicits the HF analyst to do a HRA on this element

  3. An Analysis and Quantification Method of Human Errors of Soft Controls in Advanced MCRs

    International Nuclear Information System (INIS)

    Lee, Seung Jun; Kim, Jae Whan; Jang, Seung Cheol

    2011-01-01

    In this work, a method was proposed for quantifying human errors that may occur during operation executions using soft control. Soft controls of advanced main control rooms (MCRs) have totally different features from conventional controls, and thus they may have different human error modes and occurrence probabilities. It is important to define the human error modes and to quantify the error probability for evaluating the reliability of the system and preventing errors. This work suggests a modified K-HRA method for quantifying error probability

  4. Statistical evaluation of major human errors during the development of new technological systems

    International Nuclear Information System (INIS)

    Campbell, G; Ott, K.O.

    1979-01-01

    Statistical procedures are presented to evaluate major human errors during the development of a new system, errors that have led or can lead to accidents or major failures. The first procedure aims at estimating the average residual occurrence rate for s or major failures after several have occurred. The procedure is solely based on the historical record. Certain idealizations are introduced that allow the application of a sound statistical evaluation procedure. These idealizations are practically realized to a sufficient degree such that the proposed estimation procedure yields meaningful results, even for situations with a sparse data base, represented by very few accidents. Under the assumption that the possible human-error-related failure times have exponential distributions, the statistical technique of isotonic regression is proposed to estimate the failure rates due to human design error at the failure times of the system. The last value in the sequence of estimates gives the residual accident chance. In addition, theactual situation is tested against the hypothesis that the failure rate of the system remains constant over time. This test determines the chance for a decreasing failure rate being incidental, rather than an indication of an actual learning process. Both techniques can be applied not merely to a single system but to an entire series of similar systems that a technology would generate, enabling the assessment of technological improvement. For the purpose of illustration, the nuclear decay of isotopes was chosen as an example, since the assumptions of the model are rigorously satisfied in this case. This application shows satisfactory agreement of the estimated and actual failure rates (which are exactly known in this example), although the estimation was deliberately based on a sparse historical record

  5. Using HET taxonomy to help stop human error

    OpenAIRE

    Li, Wen-Chin; Harris, Don; Stanton, Neville A.; Hsu, Yueh-Ling; Chang, Danny; Wang, Thomas; Young, Hong-Tsu

    2010-01-01

    Flight crews make positive contributions to the safety of aviation operations. Pilots have to assess continuously changing situations, evaluate potential risks, and make quick decisions. However, even well-trained and experienced pilots make errors. Accident investigations have identified that pilots’ performance is influenced significantly by the design of the flightdeck interface. This research applies hierarchical task analysis (HTA) and utilizes the Human Error Template (HET) taxonomy to ...

  6. Human Error and the International Space Station: Challenges and Triumphs in Science Operations

    Science.gov (United States)

    Harris, Samantha S.; Simpson, Beau C.

    2016-01-01

    Any system with a human component is inherently risky. Studies in human factors and psychology have repeatedly shown that human operators will inevitably make errors, regardless of how well they are trained. Onboard the International Space Station (ISS) where crew time is arguably the most valuable resource, errors by the crew or ground operators can be costly to critical science objectives. Operations experts at the ISS Payload Operations Integration Center (POIC), located at NASA's Marshall Space Flight Center in Huntsville, Alabama, have learned that from payload concept development through execution, there are countless opportunities to introduce errors that can potentially result in costly losses of crew time and science. To effectively address this challenge, we must approach the design, testing, and operation processes with two specific goals in mind. First, a systematic approach to error and human centered design methodology should be implemented to minimize opportunities for user error. Second, we must assume that human errors will be made and enable rapid identification and recoverability when they occur. While a systematic approach and human centered development process can go a long way toward eliminating error, the complete exclusion of operator error is not a reasonable expectation. The ISS environment in particular poses challenging conditions, especially for flight controllers and astronauts. Operating a scientific laboratory 250 miles above the Earth is a complicated and dangerous task with high stakes and a steep learning curve. While human error is a reality that may never be fully eliminated, smart implementation of carefully chosen tools and techniques can go a long way toward minimizing risk and increasing the efficiency of NASA's space science operations.

  7. Cause analysis and preventives for human error events in Daya Bay NPP

    International Nuclear Information System (INIS)

    Huang Weigang; Zhang Li

    1998-01-01

    Daya Bay Nuclear Power Plant is put into commercial operation in 1994 Until 1996, there are 368 human error events in operating and maintenance area, occupying 39% of total events. These events occurred mainly in the processes of maintenance, test equipment isolation and system on-line, in particular in refuelling and maintenance. The author analyses root causes for human errorievents, which are mainly operator omission or error procedure deficiency; procedure not followed; lack of training; communication failures; work management inadequacy. The protective measures and treatment principle for human error events are also discussed, and several examples applying them are given. Finally, it is put forward that key to prevent human error event lies in the coordination and management, person in charge of work, and good work habits of staffs

  8. The application of two recently developed human reliability techniques to cognitive error analysis

    International Nuclear Information System (INIS)

    Gall, W.

    1990-01-01

    Cognitive error can lead to catastrophic consequences for manned systems, including those whose design renders them immune to the effects of physical slips made by operators. Four such events, pressurized water and boiling water reactor accidents which occurred recently, were analysed. The analysis identifies the factors which contributed to the errors and suggests practical strategies for error recovery or prevention. Two types of analysis were conducted: an unstructured analysis based on the analyst's knowledge of psychological theory, and a structured analysis using two recently-developed human reliability analysis techniques. In general, the structured techniques required less effort to produce results and these were comparable to those of the unstructured analysis. (author)

  9. An empirical study on the basic human error probabilities for NPP advanced main control room operation using soft control

    International Nuclear Information System (INIS)

    Jang, Inseok; Kim, Ar Ryum; Harbi, Mohamed Ali Salem Al; Lee, Seung Jun; Kang, Hyun Gook; Seong, Poong Hyun

    2013-01-01

    Highlights: ► The operation environment of MCRs in NPPs has changed by adopting new HSIs. ► The operation action in NPP Advanced MCRs is performed by soft control. ► Different basic human error probabilities (BHEPs) should be considered. ► BHEPs in a soft control operation environment are investigated empirically. ► This work will be helpful to verify if soft control has positive or negative effects. -- Abstract: By adopting new human–system interfaces that are based on computer-based technologies, the operation environment of main control rooms (MCRs) in nuclear power plants (NPPs) has changed. The MCRs that include these digital and computer technologies, such as large display panels, computerized procedures, soft controls, and so on, are called Advanced MCRs. Among the many features in Advanced MCRs, soft controls are an important feature because the operation action in NPP Advanced MCRs is performed by soft control. Using soft controls such as mouse control, touch screens, and so on, operators can select a specific screen, then choose the controller, and finally manipulate the devices. However, because of the different interfaces between soft control and hardwired conventional type control, different basic human error probabilities (BHEPs) should be considered in the Human Reliability Analysis (HRA) for advanced MCRs. Although there are many HRA methods to assess human reliabilities, such as Technique for Human Error Rate Prediction (THERP), Accident Sequence Evaluation Program (ASEP), Human Error Assessment and Reduction Technique (HEART), Human Event Repository and Analysis (HERA), Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR), Cognitive Reliability and Error Analysis Method (CREAM), and so on, these methods have been applied to conventional MCRs, and they do not consider the new features of advance MCRs such as soft controls. As a result, there is an insufficient database for assessing human reliabilities in advanced

  10. Human error as a source of disturbances in Swedish nuclear power plants

    International Nuclear Information System (INIS)

    Sokolowski, E.

    1985-01-01

    Events involving human errors at the Swedish nuclear power plants are registered and periodically analyzed. The philosophy behind the scheme for data collection and analysis is discussed. Human errors cause about 10% of the disturbances registered. Only a small part of these errors are committed by operators in the control room. These and other findings differ from those in other countries. Possible reasons are put forward

  11. Quantification of human error and common-mode failures in man-machine systems

    International Nuclear Information System (INIS)

    Lisboa, J.J.

    1988-01-01

    Quantification of human performance, particularly the determination of human error, is essential for realistic assessment of overall system performance of man-machine systems. This paper presents an analysis of human errors in nuclear power plant systems when measured against common-mode failures (CMF). Human errors evaluated are improper testing, inadequate maintenance strategy, and miscalibration. The methodology presented in the paper represents a positive contribution to power plant systems availability by identifying sources of common-mode failure when operational functions are involved. It is also applicable to other complex systems such as chemical plants, aircraft and motor industries; in fact, any large man-created, man-machine system could be included

  12. A method for analysing incidents due to human errors on nuclear installations

    International Nuclear Information System (INIS)

    Griffon, M.

    1980-01-01

    This paper deals with the development of a methodology adapted to a detailed analysis of incidents considered to be due to human errors. An identification of human errors and a search for their eventual multiple causes is then needed. They are categorized in eight classes: education and training of personnel, installation design, work organization, time and work duration, physical environment, social environment, history of the plant and performance of the operator. The method is illustrated by the analysis of a handling incident generated by multiple human errors. (author)

  13. The Human Bathtub: Safety and Risk Predictions Including the Dynamic Probability of Operator Errors

    International Nuclear Information System (INIS)

    Duffey, Romney B.; Saull, John W.

    2006-01-01

    Reactor safety and risk are dominated by the potential and major contribution for human error in the design, operation, control, management, regulation and maintenance of the plant, and hence to all accidents. Given the possibility of accidents and errors, now we need to determine the outcome (error) probability, or the chance of failure. Conventionally, reliability engineering is associated with the failure rate of components, or systems, or mechanisms, not of human beings in and interacting with a technological system. The probability of failure requires a prior knowledge of the total number of outcomes, which for any predictive purposes we do not know or have. Analysis of failure rates due to human error and the rate of learning allow a new determination of the dynamic human error rate in technological systems, consistent with and derived from the available world data. The basis for the analysis is the 'learning hypothesis' that humans learn from experience, and consequently the accumulated experience defines the failure rate. A new 'best' equation has been derived for the human error, outcome or failure rate, which allows for calculation and prediction of the probability of human error. We also provide comparisons to the empirical Weibull parameter fitting used in and by conventional reliability engineering and probabilistic safety analysis methods. These new analyses show that arbitrary Weibull fitting parameters and typical empirical hazard function techniques cannot be used to predict the dynamics of human errors and outcomes in the presence of learning. Comparisons of these new insights show agreement with human error data from the world's commercial airlines, the two shuttle failures, and from nuclear plant operator actions and transient control behavior observed in transients in both plants and simulators. The results demonstrate that the human error probability (HEP) is dynamic, and that it may be predicted using the learning hypothesis and the minimum

  14. Human error probability estimation using licensee event reports

    International Nuclear Information System (INIS)

    Voska, K.J.; O'Brien, J.N.

    1984-07-01

    Objective of this report is to present a method for using field data from nuclear power plants to estimate human error probabilities (HEPs). These HEPs are then used in probabilistic risk activities. This method of estimating HEPs is one of four being pursued in NRC-sponsored research. The other three are structured expert judgment, analysis of training simulator data, and performance modeling. The type of field data analyzed in this report is from Licensee Event reports (LERs) which are analyzed using a method specifically developed for that purpose. However, any type of field data or human errors could be analyzed using this method with minor adjustments. This report assesses the practicality, acceptability, and usefulness of estimating HEPs from LERs and comprehensively presents the method for use

  15. Latent human error analysis and efficient improvement strategies by fuzzy TOPSIS in aviation maintenance tasks.

    Science.gov (United States)

    Chiu, Ming-Chuan; Hsieh, Min-Chih

    2016-05-01

    The purposes of this study were to develop a latent human error analysis process, to explore the factors of latent human error in aviation maintenance tasks, and to provide an efficient improvement strategy for addressing those errors. First, we used HFACS and RCA to define the error factors related to aviation maintenance tasks. Fuzzy TOPSIS with four criteria was applied to evaluate the error factors. Results show that 1) adverse physiological states, 2) physical/mental limitations, and 3) coordination, communication, and planning are the factors related to airline maintenance tasks that could be addressed easily and efficiently. This research establishes a new analytic process for investigating latent human error and provides a strategy for analyzing human error using fuzzy TOPSIS. Our analysis process complements shortages in existing methodologies by incorporating improvement efficiency, and it enhances the depth and broadness of human error analysis methodology. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  16. Analysis of human error and organizational deficiency in events considering risk significance

    International Nuclear Information System (INIS)

    Lee, Yong Suk; Kim, Yoonik; Kim, Say Hyung; Kim, Chansoo; Chung, Chang Hyun; Jung, Won Dea

    2004-01-01

    In this study, we analyzed human and organizational deficiencies in the trip events of Korean nuclear power plants. K-HPES items were used in human error analysis, and the organizational factors by Jacobs and Haber were used for organizational deficiency analysis. We proposed the use of CCDP as a risk measure to consider risk information in prioritizing K-HPES items and organizational factors. Until now, the risk significance of events has not been considered in human error and organizational deficiency analysis. Considering the risk significance of events in the process of analysis is necessary for effective enhancement of nuclear power plant safety by focusing on causes of human error and organizational deficiencies that are associated with significant risk

  17. The Countermeasures against the Human Errors in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Lee, Yong Hee; Kwon, Ki Chun; Lee, Jung Woon; Lee, Hyun; Jang, Tong Il

    2009-10-01

    Due to human error, the failure of nuclear power facilities essential for the prevention of accidents and related research in ergonomics and human factors, including the long term, comprehensive measures are considered technology is urgently required. Past nuclear facilities for the hardware in terms of continuing interest over subsequent definite improvement even have brought, now a nuclear facility to engage in people-related human factors for attention by nuclear facilities, ensuring the safety of its economic and industrial aspects. The point of the improvement is urgently required. The purpose of this research, including nuclear power plants in various nuclear facilities to minimize the possibility of human error by ensuring the safety for human engineering aspects will be implemented in the medium and long term preventive measures is to establish comprehensive

  18. The Countermeasures against the Human Errors in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Hee; Kwon, Ki Chun; Lee, Jung Woon; Lee, Hyun; Jang, Tong Il

    2009-10-15

    Due to human error, the failure of nuclear power facilities essential for the prevention of accidents and related research in ergonomics and human factors, including the long term, comprehensive measures are considered technology is urgently required. Past nuclear facilities for the hardware in terms of continuing interest over subsequent definite improvement even have brought, now a nuclear facility to engage in people-related human factors for attention by nuclear facilities, ensuring the safety of its economic and industrial aspects. The point of the improvement is urgently required. The purpose of this research, including nuclear power plants in various nuclear facilities to minimize the possibility of human error by ensuring the safety for human engineering aspects will be implemented in the medium and long term preventive measures is to establish comprehensive.

  19. Thresholds for human detection of patient setup errors in digitally reconstructed portal images of prostate fields

    International Nuclear Information System (INIS)

    Phillips, Brooke L.; Jiroutek, Michael R.; Tracton, Gregg; Elfervig, Michelle; Muller, Keith E.; Chaney, Edward L.

    2002-01-01

    Purpose: Computer-assisted methods to analyze electronic portal images for the presence of treatment setup errors should be studied in controlled experiments before use in the clinical setting. Validation experiments using images that contain known errors usually report the smallest errors that can be detected by the image analysis algorithm. This paper offers human error-detection thresholds as one benchmark for evaluating the smallest errors detected by algorithms. Unfortunately, reliable data are lacking describing human performance. The most rigorous benchmarks for human performance are obtained under conditions that favor error detection. To establish such benchmarks, controlled observer studies were carried out to determine the thresholds of detectability for in-plane and out-of-plane translation and rotation setup errors introduced into digitally reconstructed portal radiographs (DRPRs) of prostate fields. Methods and Materials: Seventeen observers comprising radiation oncologists, radiation oncology residents, physicists, and therapy students participated in a two-alternative forced choice experiment involving 378 DRPRs computed using the National Library of Medicine Visible Human data sets. An observer viewed three images at a time displayed on adjacent computer monitors. Each image triplet included a reference digitally reconstructed radiograph displayed on the central monitor and two DRPRs displayed on the flanking monitors. One DRPR was error free. The other DRPR contained a known in-plane or out-of-plane error in the placement of the treatment field over a target region in the pelvis. The range for each type of error was determined from pilot observer studies based on a Probit model for error detection. The smallest errors approached the limit of human visual capability. The observer was told what kind of error was introduced, and was asked to choose the DRPR that contained the error. Observer decisions were recorded and analyzed using repeated

  20. An assessment of the risk significance of human errors in selected PSAs and operating events

    International Nuclear Information System (INIS)

    Palla, R.L. Jr.; El-Bassioni, A.

    1991-01-01

    Sensitivity studies based on Probabilistic Safety Assessments (PSAs) for a pressurized water reactor and a boiling water reactor are described. In each case human errors modeled in the PSAs were categorized according to such factors as error type, location, timing, and plant personnel involved. Sensitivity studies were then conducted by varying the error rates in each category and evaluating the corresponding change in total core damage frequency and accident sequence frequency. Insights obtained are discussed and reasons for differences in risk sensitivity between plants are explored. A separate investigation into the role of human error in risk-important operating events is also described. This investigation involved the analysis of data from the USNRC Accident Sequence Precursor program to determine the effect of operator-initiated events on accident precursor trends, and to determine whether improved training can be correlated to current trends. The findings of this study are also presented. 5 refs., 15 figs., 1 tab

  1. Prediction-error of Prediction Error (PPE)-based Reversible Data Hiding

    OpenAIRE

    Wu, Han-Zhou; Wang, Hong-Xia; Shi, Yun-Qing

    2016-01-01

    This paper presents a novel reversible data hiding (RDH) algorithm for gray-scaled images, in which the prediction-error of prediction error (PPE) of a pixel is used to carry the secret data. In the proposed method, the pixels to be embedded are firstly predicted with their neighboring pixels to obtain the corresponding prediction errors (PEs). Then, by exploiting the PEs of the neighboring pixels, the prediction of the PEs of the pixels can be determined. And, a sorting technique based on th...

  2. New classification of operators' human errors at overseas nuclear power plants and preparation of easy-to-use case sheets

    International Nuclear Information System (INIS)

    Takagawa, Kenichi

    2004-01-01

    At nuclear power plants, plant operators examine other human error cases, including those that occurred at other plants, so that they can learn from such experiences and avoid making similar errors again. Although there is little data available on errors made at domestic plants, nuclear operators in foreign countries are reporting even minor irregularities and signs of faults, and a large amount of data on human errors at overseas plants could be collected and examined. However, these overseas data have not been used effectively because most of them are poorly organized or not properly classified and are often hard to understand. Accordingly, we carried out a study on the cases of human errors at overseas power plants in order to help plant personnel clearly understand overseas experiences and avoid repeating similar errors, The study produced the following results, which were put to use at nuclear power plants and other facilities. (1) ''One-Point-Advice'' refers to a practice where a leader gives pieces of advice to his team of operators in order to prevent human errors before starting work. Based on this practice and those used in the aviation industry, we have developed a new method of classifying human errors that consists of four basic actions and three applied actions. (2) We used this new classification method to classify human errors made by operators at overseas nuclear power plants. The results show that the most frequent errors caused not by operators themselves but due to insufficient team monitoring, for which superiors and/or their colleagues were responsible. We therefore analyzed and classified possible factors contributing to insufficient team monitoring, and demonstrated that the frequent errors have also occurred at domestic power plants. (3) Using the new classification formula, we prepared a human error case sheets that is easy for plant personnel to understand. The sheets are designed to make data more understandable and easier to remember

  3. The psychological background about human error and safety in NPP

    International Nuclear Information System (INIS)

    Zhang Li

    1992-01-01

    A human error is one of the factors which cause an accident in NPP. The in-situ psychological background plays an important role in inducing it. The author analyzes the structure of one's psychological background when one is at work, and gives a few examples of typical psychological background resulting in human errors. Finally it points out that the fundamental way to eliminate the unfavourable psychological background of safety production is to establish the safety culture in NPP along with its characteristics

  4. Review of human error analysis methodologies and case study for accident management

    International Nuclear Information System (INIS)

    Jung, Won Dae; Kim, Jae Whan; Lee, Yong Hee; Ha, Jae Joo

    1998-03-01

    In this research, we tried to establish the requirements for the development of a new human error analysis method. To achieve this goal, we performed a case study as following steps; 1. review of the existing HEA methods 2. selection of those methods which are considered to be appropriate for the analysis of operator's tasks in NPPs 3. choice of tasks for the application, selected for the case study: HRMS (Human reliability management system), PHECA (Potential Human Error Cause Analysis), CREAM (Cognitive Reliability and Error Analysis Method). And, as the tasks for the application, 'bleed and feed operation' and 'decision-making for the reactor cavity flooding' tasks are chosen. We measured the applicability of the selected methods to the NPP tasks, and evaluated the advantages and disadvantages between each method. The three methods are turned out to be applicable for the prediction of human error. We concluded that both of CREAM and HRMS are equipped with enough applicability for the NPP tasks, however, compared two methods. CREAM is thought to be more appropriate than HRMS from the viewpoint of overall requirements. The requirements for the new HEA method obtained from the study can be summarized as follows; firstly, it should deal with cognitive error analysis, secondly, it should have adequate classification system for the NPP tasks, thirdly, the description on the error causes and error mechanisms should be explicit, fourthly, it should maintain the consistency of the result by minimizing the ambiguity in each step of analysis procedure, fifty, it should be done with acceptable human resources. (author). 25 refs., 30 tabs., 4 figs

  5. Calculating method on human error probabilities considering influence of management and organization

    International Nuclear Information System (INIS)

    Gao Jia; Huang Xiangrui; Shen Zupei

    1996-01-01

    This paper is concerned with how management and organizational influences can be factored into quantifying human error probabilities on risk assessments, using a three-level Influence Diagram (ID) which is originally only as a tool for construction and representation of models of decision-making trees or event trees. An analytical model of human errors causation has been set up with three influence levels, introducing a method for quantification assessments (of the ID), which can be applied into quantifying probabilities) of human errors on risk assessments, especially into the quantification of complex event trees (system) as engineering decision-making analysis. A numerical case study is provided to illustrate the approach

  6. Study on a new framework of Human Reliability Analysis to evaluate soft control execution error in advanced MCRs of NPPs

    International Nuclear Information System (INIS)

    Jang, Inseok; Kim, Ar Ryum; Jung, Wondea; Seong, Poong Hyun

    2016-01-01

    Highlights: • The operation environment of MCRs in NPPs has changed by adopting new HSIs. • The operation action in NPP Advanced MCRs is performed by soft control. • New HRA framework should be considered in the HRA for advanced MCRs. • HRA framework for evaluation of soft control execution human error is suggested. • Suggested method will be helpful to analyze human reliability in advance MCRs. - Abstract: Since the Three Mile Island (TMI)-2 accident, human error has been recognized as one of the main causes of Nuclear Power Plant (NPP) accidents, and numerous studies related to Human Reliability Analysis (HRA) have been carried out. Most of these methods were developed considering the conventional type of Main Control Rooms (MCRs). However, the operating environment of MCRs in NPPs has changed with the adoption of new Human-System Interfaces (HSIs) that are based on computer-based technologies. The MCRs that include these digital technologies, such as large display panels, computerized procedures, and soft controls, are called advanced MCRs. Among the many features of advanced MCRs, soft controls are a particularly important feature because operating actions in NPP advanced MCRs are performed by soft control. Due to the differences in interfaces between soft control and hardwired conventional type control, different Human Error Probabilities (HEPs) and a new HRA framework should be considered in the HRA for advanced MCRs. To this end, a new framework of a HRA method for evaluating soft control execution human error is suggested by performing a soft control task analysis and the literature regarding widely accepted human error taxonomies is reviewed. Moreover, since most current HRA databases deal with operation in conventional MCRs and are not explicitly designed to deal with digital HSIs, empirical analysis of human error and error recovery considering soft controls under an advanced MCR mockup are carried out to collect human error data, which is

  7. Design for Error Tolerance

    DEFF Research Database (Denmark)

    Rasmussen, Jens

    1983-01-01

    An important aspect of the optimal design of computer-based operator support systems is the sensitivity of such systems to operator errors. The author discusses how a system might allow for human variability with the use of reversibility and observability.......An important aspect of the optimal design of computer-based operator support systems is the sensitivity of such systems to operator errors. The author discusses how a system might allow for human variability with the use of reversibility and observability....

  8. Human medial frontal cortex activity predicts learning from errors.

    Science.gov (United States)

    Hester, Robert; Barre, Natalie; Murphy, Kevin; Silk, Tim J; Mattingley, Jason B

    2008-08-01

    Learning from errors is a critical feature of human cognition. It underlies our ability to adapt to changing environmental demands and to tune behavior for optimal performance. The posterior medial frontal cortex (pMFC) has been implicated in the evaluation of errors to control behavior, although it has not previously been shown that activity in this region predicts learning from errors. Using functional magnetic resonance imaging, we examined activity in the pMFC during an associative learning task in which participants had to recall the spatial locations of 2-digit targets and were provided with immediate feedback regarding accuracy. Activity within the pMFC was significantly greater for errors that were subsequently corrected than for errors that were repeated. Moreover, pMFC activity during recall errors predicted future responses (correct vs. incorrect), despite a sizeable interval (on average 70 s) between an error and the next presentation of the same recall probe. Activity within the hippocampus also predicted future performance and correlated with error-feedback-related pMFC activity. A relationship between performance expectations and pMFC activity, in the absence of differing reinforcement value for errors, is consistent with the idea that error-related pMFC activity reflects the extent to which an outcome is "worse than expected."

  9. Human error and the problem of causality in analysis of accidents

    DEFF Research Database (Denmark)

    Rasmussen, Jens

    1990-01-01

    , designers or managers have played a major role. There are, however, several basic problems in analysis of accidents and identification of human error. This paper addresses the nature of causal explanations and the ambiguity of the rules applied for identification of the events to include in analysis......Present technology is characterized by complexity, rapid change and growing size of technical systems. This has caused increasing concern with the human involvement in system safety. Analyses of the major accidents during recent decades have concluded that human errors on part of operators...

  10. An experimental approach to validating a theory of human error in complex systems

    Science.gov (United States)

    Morris, N. M.; Rouse, W. B.

    1985-01-01

    The problem of 'human error' is pervasive in engineering systems in which the human is involved. In contrast to the common engineering approach of dealing with error probabilistically, the present research seeks to alleviate problems associated with error by gaining a greater understanding of causes and contributing factors from a human information processing perspective. The general approach involves identifying conditions which are hypothesized to contribute to errors, and experimentally creating the conditions in order to verify the hypotheses. The conceptual framework which serves as the basis for this research is discussed briefly, followed by a description of upcoming research. Finally, the potential relevance of this research to design, training, and aiding issues is discussed.

  11. Human error mode identification for NPP main control room operations using soft controls

    International Nuclear Information System (INIS)

    Lee, Seung Jun; Kim, Jaewhan; Jang, Seung-Cheol

    2011-01-01

    The operation environment of main control rooms (MCRs) in modern nuclear power plants (NPPs) has considerably changed over the years. Advanced MCRs, which have been designed by adapting digital and computer technologies, have simpler interfaces using large display panels, computerized displays, soft controls, computerized procedure systems, and so on. The actions for the NPP operations are performed using soft controls in advanced MCRs. Soft controls have different features from conventional controls. Operators need to navigate the screens to find indicators and controls and manipulate controls using a mouse, touch screens, and so on. Due to these different interfaces, different human errors should be considered in the human reliability analysis (HRA) for advanced MCRs. In this work, human errors that could occur during operation executions using soft controls were analyzed. This work classified the human errors in soft controls into six types, and the reasons that affect the occurrence of the human errors were also analyzed. (author)

  12. Plant specification of a generic human-error data through a two-stage Bayesian approach

    International Nuclear Information System (INIS)

    Heising, C.D.; Patterson, E.I.

    1984-01-01

    Expert judgement concerning human performance in nuclear power plants is quantitatively coupled with actuarial data on such performance in order to derive plant-specific human-error rate probability distributions. The coupling procedure consists of a two-stage application of Bayes' theorem to information which is grouped by type. The first information type contains expert judgement concerning human performance at nuclear power plants in general. Data collected on human performance at a group of similar plants forms the second information type. The third information type consists of data on human performance in a specific plant which has the same characteristics as the group members. The first and second information types are coupled in the first application of Bayes' theorem to derive a probability distribution for population performance. This distribution is then combined with the third information type in a second application of Bayes' theorem to determine a plant-specific human-error rate probability distribution. The two stage Bayesian procedure thus provides a means to quantitatively couple sparse data with expert judgement in order to obtain a human performance probability distribution based upon available information. Example calculations for a group of like reactors are also given. (author)

  13. Enhanced Pedestrian Navigation Based on Course Angle Error Estimation Using Cascaded Kalman Filters.

    Science.gov (United States)

    Song, Jin Woo; Park, Chan Gook

    2018-04-21

    An enhanced pedestrian dead reckoning (PDR) based navigation algorithm, which uses two cascaded Kalman filters (TCKF) for the estimation of course angle and navigation errors, is proposed. The proposed algorithm uses a foot-mounted inertial measurement unit (IMU), waist-mounted magnetic sensors, and a zero velocity update (ZUPT) based inertial navigation technique with TCKF. The first stage filter estimates the course angle error of a human, which is closely related to the heading error of the IMU. In order to obtain the course measurements, the filter uses magnetic sensors and a position-trace based course angle. For preventing magnetic disturbance from contaminating the estimation, the magnetic sensors are attached to the waistband. Because the course angle error is mainly due to the heading error of the IMU, and the characteristic error of the heading angle is highly dependent on that of the course angle, the estimated course angle error is used as a measurement for estimating the heading error in the second stage filter. At the second stage, an inertial navigation system-extended Kalman filter-ZUPT (INS-EKF-ZUPT) method is adopted. As the heading error is estimated directly by using course-angle error measurements, the estimation accuracy for the heading and yaw gyro bias can be enhanced, compared with the ZUPT-only case, which eventually enhances the position accuracy more efficiently. The performance enhancements are verified via experiments, and the way-point position error for the proposed method is compared with those for the ZUPT-only case and with other cases that use ZUPT and various types of magnetic heading measurements. The results show that the position errors are reduced by a maximum of 90% compared with the conventional ZUPT based PDR algorithms.

  14. An Empirical Study on Human Performance according to the Physical Environment (Potential Human Error Hazard) in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Kim, Ar Ryum; Jang, In Seok; Seong, Proong Hyun

    2014-01-01

    The management of the physical environment for safety is more effective than a nuclear industry. Despite the physical environment such as lighting, noise satisfy with management standards, it can be background factors may cause human error and affect human performance. Because the consequence of extremely human error and human performance is high according to the physical environment, requirement standard could be covered with specific criteria. Particularly, in order to avoid human errors caused by an extremely low or rapidly-changing intensity illumination and masking effect such as power disconnection, plans for better visual environment and better function performances should be made as a careful study on efficient ways to manage and continue the better conditions is conducted

  15. Identification and Evaluation of Human Errors in the Medication Process Using the Extended CREAM Technique

    Directory of Open Access Journals (Sweden)

    Iraj Mohammadfam

    2017-10-01

    Full Text Available Background Medication process is a powerful instrument for curing patients. Obeying the commands of this process has an important role in the treatment and provision of care to patients. Medication error, as a complicated process, can occur in any stage of this process, and to avoid it, appropriate decision-making, cognition, and performance of the hospital staff are needed. Objectives The present study aimed at identifying and evaluating the nature and reasons of human errors in the medication process in a hospital using the extended CREAM method. Methods This was a qualitative and cross-sectional study conducted in a hospital in Hamadan. In this study, first, the medication process was selected as a critical issue based on the opinions of experts, specialists, and experienced individuals in the nursing and medical departments. Then, the process was analyzed into relative steps and substeps using the method of HTA and was evaluated using extended CREAM technique considering the probability of human errors. Results Based on the findings achieved through the basic CREAM method, the highest CFPt was in the step of medicine administration to patients (0.056. Moreover, the results revealed that the highest CFPt was in the substeps of calculating the dose of medicine and determining the method of prescription and identifying the patient (0.0796 and 0.0785, respectively. Also, the least CFPt was related to transcribing the prescribed medicine from file to worksheet of medicine (0.0106. Conclusions Considering the critical consequences of human errors in the medication process, holding pharmacological retraining classes, using the principles of executing pharmaceutical orders, increasing medical personnel, reducing working overtime, organizing work shifts, and using error reporting systems are of paramount importance.

  16. Trend analysis of human error events and assessment of their proactive prevention measure at Rokkasho reprocessing plant

    International Nuclear Information System (INIS)

    Yamazaki, Satoru; Tanaka, Izumi; Wakabayashi, Toshio

    2012-01-01

    A trend analysis of human error events is important for preventing the recurrence of human error events. We propose a new method for identifying the common characteristics from results of trend analysis, such as the latent weakness of organization, and a management process for strategic error prevention. In this paper, we describe a trend analysis method for human error events that have been accumulated in the organization and the utilization of the results of trend analysis to prevent accidents proactively. Although the systematic analysis of human error events, the monitoring of their overall trend, and the utilization of the analyzed results have been examined for the plant operation, such information has never been utilized completely. Sharing information on human error events and analyzing their causes lead to the clarification of problems in the management and human factors. This new method was applied to the human error events that occurred in the Rokkasho reprocessing plant from 2010 October. Results revealed that the output of this method is effective in judging the error prevention plan and that the number of human error events is reduced to about 50% those observed in 2009 and 2010. (author)

  17. Group representations, error bases and quantum codes

    Energy Technology Data Exchange (ETDEWEB)

    Knill, E

    1996-01-01

    This report continues the discussion of unitary error bases and quantum codes. Nice error bases are characterized in terms of the existence of certain characters in a group. A general construction for error bases which are non-abelian over the center is given. The method for obtaining codes due to Calderbank et al. is generalized and expressed purely in representation theoretic terms. The significance of the inertia subgroup both for constructing codes and obtaining the set of transversally implementable operations is demonstrated.

  18. Comparison of risk sensitivity to human errors in the Oconee and LaSalle PRAs

    International Nuclear Information System (INIS)

    Wong, S.; Higgins, J.

    1991-01-01

    This paper describes the comparative analyses of plant risk sensitivity to human errors in the Oconee and La Salle Probabilistic Risk Assessment (PRAs). These analyses were performed to determine the reasons for the observed differences in the sensitivity of core melt frequency (CMF) to changes in human error probabilities (HEPs). Plant-specific design features, PRA methods, and the level of detail and assumptions in the human error modeling were evaluated to assess their influence risk estimates and sensitivities

  19. Interactive analysis of human error factors in NPP operation events

    International Nuclear Information System (INIS)

    Zhang Li; Zou Yanhua; Huang Weigang

    2010-01-01

    Interactive of human error factors in NPP operation events were introduced, and 645 WANO operation event reports from 1999 to 2008 were analyzed, among which 432 were found relative to human errors. After classifying these errors with the Root Causes or Causal Factors, and then applying SPSS for correlation analysis,we concluded: (1) Personnel work practices are restricted by many factors. Forming a good personnel work practices is a systematic work which need supports in many aspects. (2)Verbal communications,personnel work practices, man-machine interface and written procedures and documents play great roles. They are four interaction factors which often come in bundle. If some improvements need to be made on one of them,synchronous measures are also necessary for the others.(3) Management direction and decision process, which are related to management,have a significant interaction with personnel factors. (authors)

  20. Coping with human errors through system design: Implications for ecological interface design

    DEFF Research Database (Denmark)

    Rasmussen, Jens; Vicente, Kim J.

    1989-01-01

    Research during recent years has revealed that human errors are not stochastic events which can be removed through improved training programs or optimal interface design. Rather, errors tend to reflect either systematic interference between various models, rules, and schemata, or the effects...... of the adaptive mechanisms involved in learning. In terms of design implications, these findings suggest that reliable human-system interaction will be achieved by designing interfaces which tend to minimize the potential for control interference and support recovery from errors. In other words, the focus should...... be on control of the effects of errors rather than on the elimination of errors per se. In this paper, we propose a theoretical framework for interface design that attempts to satisfy these objectives. The goal of our framework, called ecological interface design, is to develop a meaningful representation...

  1. Quality assurance and human error effects on the structural safety

    International Nuclear Information System (INIS)

    Bertero, R.; Lopez, R.; Sarrate, M.

    1991-01-01

    Statistical surveys show that the frequency of failure of structures is much larger than that expected by the codes. Evidence exists that human errors (especially during the design process) is the main cause for the difference between the failure probability admitted by codes and the reality. In this paper, the attenuation of human error effects using tools of quality assurance is analyzed. In particular, the importance of the independent design review is highlighted, and different approaches are discussed. The experience from the Atucha II project, as well as the USA and German practice on independent design review, are summarized. (Author)

  2. Web-Based Information Management System for the Investigation, Reporting, and Analysis of Human Error in Naval Aviation Maintenance

    National Research Council Canada - National Science Library

    Boex, Anthony

    2001-01-01

    .... The Human Factors Analysis and Classification System-Maintenance Extension (HFACS-ME) taxonomy, a framework for classifying and analyzing the presence of maintenance errors that lead to mishaps, is the foundation of this tool...

  3. Operator errors

    International Nuclear Information System (INIS)

    Knuefer; Lindauer

    1980-01-01

    Besides that at spectacular events a combination of component failure and human error is often found. Especially the Rasmussen-Report and the German Risk Assessment Study show for pressurised water reactors that human error must not be underestimated. Although operator errors as a form of human error can never be eliminated entirely, they can be minimized and their effects kept within acceptable limits if a thorough training of personnel is combined with an adequate design of the plant against accidents. Contrary to the investigation of engineering errors, the investigation of human errors has so far been carried out with relatively small budgets. Intensified investigations in this field appear to be a worthwhile effort. (orig.)

  4. Human factors interventions to reduce human errors and improve productivity in maintenance tasks

    International Nuclear Information System (INIS)

    Isoda, Hachiro; Yasutake, J.Y.

    1992-01-01

    This paper describes work in progress to develop interventions to reduce human errors and increase maintenance productivity in nuclear power plants. The effort is part of a two-phased Human Factors research program being conducted jointly by the Central Research Institute of Electric Power Industry (CRIEPI) in Japan and the Electric Power Research Institute (EPRI) in the United States. The overall objective of this joint research program is to identify critical maintenance tasks and to develop, implement and evaluate interventions which have high potential for reducing human errors or increasing maintenance productivity. As a result of the Phase 1 effort, ten critical maintenance tasks were identified. For these tasks, over 25 candidate interventions were identified for potential development. After careful analysis, seven interventions were selected for development during Phase 2. This paper describes the methodology used to analyze and identify the most critical tasks, the process of identifying and developing selected interventions and some of the initial results. (author)

  5. Mistakes, Errors and Foul-Ups: Practice-Based Evidence for Evidence Based Practice

    Directory of Open Access Journals (Sweden)

    Mark Turner

    2016-11-01

    Full Text Available In human medicine, the management of care to ensure safety for the service-user constitutes an important element of the patient ‘journey.’ The name given to this discipline is patient safety. It is founded upon those elements of good medical practice which help avoid or mitigate human error.  Investigations in the U.S. first highlighted the alarming extent of medical error: Brennan et al. (1991 concluded that in the state of New York, the overall rate of adverse events was approximately 4% for hospitalised patients, which equated to over 13,000 deaths a year. Doctors looked to other safety critical industries and aviation in particular (Reason 1995, to address this phenomenon: there is now a wealth of research on the impact of various safety initiatives on measurable rates of harm. The World Health Organisation’s ‘Safe Surgery Saves Lives’ initiative - a campaign that advocates the use of a surgical checklist to standardise aspects of peri-operative care - is one example of aviation methodology successfully employed in a clinical setting (van Klei et al. 2012. The critical importance of effective communication, leadership and situational awareness has also been discussed at length in the human patient safety literature.ObjectivesVeterinary patient safety is an analogous discipline and researchers have attempted to understand more about the topic of veterinary medical error. However, the evidence-base for veterinary patient safety is sparse.  This presentation aims to summarise the evidence to date and highlight the benefits in practice of an emerging subject. MethodA search of the terms veterinary patient safety on the PubMed database from 1990 to 2016 was performed.Findings15 articles were identified as contributing to the veterinary patient safety literature.OutcomeThe available literature has addressed a number of areas. The use of checklists in a clinical setting has been proven to reduce the incidence of specific undesirable

  6. Self-assessment of human performance errors in nuclear operations

    International Nuclear Information System (INIS)

    Chambliss, K.V.

    1996-01-01

    One of the most important approaches to improving nuclear safety is to have an effective self-assessment process in place, whose cornerstone is the identification and improvement of human performance errors. Experience has shown that significant events usually have had precursors of human performance errors. If these precursors are left uncorrected or not understood, the symptoms recur and result in unanticipated events of greater safety significance. The Institute of Nuclear Power Operations (INPO) has been championing the cause of promoting excellence in human performance in the nuclear industry. INPO's report, open-quotes Excellence in Human Performance,close quotes emphasizes the importance of several factors that play a role in human performance. They include individual, supervisory, and organizational behaviors; real-time feedback that results in specific behavior to produce safe and reliable performance; and proactive measures that remove obstacles from excellent human performance. Zack Pate, chief executive officer and president of INPO, in his report, open-quotes The Control Room,close quotes provides an excellent discussion of serious events in the nuclear industry since 1994 and compares them with the results from a recent study by the National Transportation Safety Board of airline accidents in the 12-yr period from 1978 to 1990 to draw some common themes that relate to human performance issues in the control room

  7. Study of maintenance skill-work based on PSFs and error category

    International Nuclear Information System (INIS)

    Nagata, Manabu; Yukimachi, Takeo; Hasegawa, Toshio

    2001-01-01

    In this investigation, the skill-types of skill-work are clarified according to the human error data on the maintenance works at nuclear power plants. At first, the causal PSFs of the errors are extracted from the data and some of the skill-types are characterized as results from factor analysis. Moreover, the skill-work model is reexamined on the basis of the contents of the human error data and the error category corresponding to the data. Furthermore, integrating the tendency of the causal PSFs and the actual error category concerning each skill-type, an extended skill-work model was developed with a flow-chart representation as a tentative stage of the investigation. (author)

  8. Human error probability quantification using fuzzy methodology in nuclear plants

    International Nuclear Information System (INIS)

    Nascimento, Claudio Souza do

    2010-01-01

    This work obtains Human Error Probability (HEP) estimates from operator's actions in response to emergency situations a hypothesis on Research Reactor IEA-R1 from IPEN. It was also obtained a Performance Shaping Factors (PSF) evaluation in order to classify them according to their influence level onto the operator's actions and to determine these PSF actual states over the plant. Both HEP estimation and PSF evaluation were done based on Specialists Evaluation using interviews and questionnaires. Specialists group was composed from selected IEA-R1 operators. Specialist's knowledge representation into linguistic variables and group evaluation values were obtained through Fuzzy Logic and Fuzzy Set Theory. HEP obtained values show good agreement with literature published data corroborating the proposed methodology as a good alternative to be used on Human Reliability Analysis (HRA). (author)

  9. Human error: An essential problem of nuclear power plants

    International Nuclear Information System (INIS)

    Smidt, D.

    1981-01-01

    The author first defines the part played by man in the nuclear power plant and then deals in more detail with the structure of his valse behavior in tactical and strategic repect. The dicussion of tactical errors and their avoidance is follwed by a report on the actual state of plant technology and possible improvements. Subsequently a study of the strategic errors including the conclusion to be drawn until now (joint between plant and man, personal selection and education) is made. If the joints between man and machine are designed according and physiological strenghts and weaknesses of man are fully realized and taken into account human errors not be essential problem in nuclear power plant. (GL) [de

  10. Application of grey incidence analysis to connection between human errors and root cause

    International Nuclear Information System (INIS)

    Ren Yinxiang; Yu Ren; Zhou Gang; Chen Dengke

    2008-01-01

    By introducing grey incidence analysis, the relatively important impact of root cause upon human errors was researched in the paper. On the basis of WANO statistic data and grey incidence analysis, lack of alternate examine, bad basic operation, short of theoretical knowledge, relaxation of organization and management and deficiency of regulations are the important influence of root cause on human err ors. Finally, the question to reduce human errors was discussed. (authors)

  11. MMI design of K-CPS for preventing human errors and enhancing convenient operation

    International Nuclear Information System (INIS)

    Sung, Chan Ho; Jung, Yeon Sub; Oh, Eoung Se; Shin, Young Chul; Lee, Yong Kwan

    2001-01-01

    In order to supplement defects of paper procedure, reduce human errors and enhance convenient operation, computer-based procedure system is being developed. CPS (Computerized Procedure System) including human-factor engineering design concept for KNGR (Korean Next Generation Reactor) has been also developed with the same object. K-CPS(KNGR CPS) has higher level of automation than paper procedure. It is fully integrated with control and monitoring systems. Combining statements and relevant components, which changes dynamically according to plant status enhances readability of procedure. This paper shows general design criteria on computer-based procedure system, the MMI design characteristics of K-CPS and the results of suitability evaluation for K-CPS by operator

  12. THERP and HEART integrated methodology for human error assessment

    Science.gov (United States)

    Castiglia, Francesco; Giardina, Mariarosa; Tomarchio, Elio

    2015-11-01

    THERP and HEART integrated methodology is proposed to investigate accident scenarios that involve operator errors during high-dose-rate (HDR) treatments. The new approach has been modified on the basis of fuzzy set concept with the aim of prioritizing an exhaustive list of erroneous tasks that can lead to patient radiological overexposures. The results allow for the identification of human errors that are necessary to achieve a better understanding of health hazards in the radiotherapy treatment process, so that it can be properly monitored and appropriately managed.

  13. Object Detection and Tracking-Based Camera Calibration for Normalized Human Height Estimation

    Directory of Open Access Journals (Sweden)

    Jaehoon Jung

    2016-01-01

    Full Text Available This paper presents a normalized human height estimation algorithm using an uncalibrated camera. To estimate the normalized human height, the proposed algorithm detects a moving object and performs tracking-based automatic camera calibration. The proposed method consists of three steps: (i moving human detection and tracking, (ii automatic camera calibration, and (iii human height estimation and error correction. The proposed method automatically calibrates camera by detecting moving humans and estimates the human height using error correction. The proposed method can be applied to object-based video surveillance systems and digital forensic.

  14. An investigation on unintended reactor trip events in terms of human error hazards of Korean nuclear power plants

    International Nuclear Information System (INIS)

    Kim, Sa Kil; Lee, Yong Hee; Jang, Tong Il; Oh, Yeon Ju; Shin, Kwang Hyeon

    2014-01-01

    Highlights: • A methodology to identify human error hazards has been established. • The proposed methodology is a preventive approach to identify not only human error causes but also its hazards. • Using the HFACS framework we tried to find out not causations but all of the hazards and relationships among them. • We determined countermeasures against human errors through dealing with latent factors such as organizational influences. - Abstract: A new approach for finding the hazards of human errors, and not just their causes, in the nuclear industry is currently required. This is because finding causes of human errors is really impossible owing to the multiplicity of causes in each case. Thus, this study aims at identifying the relationships among human error hazards and determining the strategies for preventing human error events by means of a reanalysis of the reactor trip events in Korea NPPs. We investigated human errors to find latent factors such as decisions and conditions in all of the unintended reactor trip events during the last dozen years. In this study, we applied the HFACS (Human Factors Analysis and Classification System), which is a commonly utilized tool for investigating human contributions to aviation accidents under a widespread evaluation scheme. Using the HFACS framework, we tried to find out not the causations but all of the hazards and their relationships in terms of organizational factors. Through the trial, we proposed not only meaningful frequencies of each hazards also correlations of them. Also, considering the correlations of each hazards, we suggested useful strategies to prevent human error event. A method to investigate unintended nuclear reactor trips by human errors and the results will be discussed in more detail

  15. Human error identification for laparoscopic surgery: Development of a motion economy perspective.

    Science.gov (United States)

    Al-Hakim, Latif; Sevdalis, Nick; Maiping, Tanaphon; Watanachote, Damrongpan; Sengupta, Shomik; Dissaranan, Charuspong

    2015-09-01

    This study postulates that traditional human error identification techniques fail to consider motion economy principles and, accordingly, their applicability in operating theatres may be limited. This study addresses this gap in the literature with a dual aim. First, it identifies the principles of motion economy that suit the operative environment and second, it develops a new error mode taxonomy for human error identification techniques which recognises motion economy deficiencies affecting the performance of surgeons and predisposing them to errors. A total of 30 principles of motion economy were developed and categorised into five areas. A hierarchical task analysis was used to break down main tasks of a urological laparoscopic surgery (hand-assisted laparoscopic nephrectomy) to their elements and the new taxonomy was used to identify errors and their root causes resulting from violation of motion economy principles. The approach was prospectively tested in 12 observed laparoscopic surgeries performed by 5 experienced surgeons. A total of 86 errors were identified and linked to the motion economy deficiencies. Results indicate the developed methodology is promising. Our methodology allows error prevention in surgery and the developed set of motion economy principles could be useful for training surgeons on motion economy principles. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  16. Prediction of human errors by maladaptive changes in event-related brain networks

    NARCIS (Netherlands)

    Eichele, T.; Debener, S.; Calhoun, V.D.; Specht, K.; Engel, A.K.; Hugdahl, K.; Cramon, D.Y. von; Ullsperger, M.

    2008-01-01

    Humans engaged in monotonous tasks are susceptible to occasional errors that may lead to serious consequences, but little is known about brain activity patterns preceding errors. Using functional Mill and applying independent component analysis followed by deconvolution of hemodynamic responses, we

  17. An Estimation of Human Error Probability of Filtered Containment Venting System Using Dynamic HRA Method

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Seunghyun; Jae, Moosung [Hanyang University, Seoul (Korea, Republic of)

    2016-10-15

    The human failure events (HFEs) are considered in the development of system fault trees as well as accident sequence event trees in part of Probabilistic Safety Assessment (PSA). As a method for analyzing the human error, several methods, such as Technique for Human Error Rate Prediction (THERP), Human Cognitive Reliability (HCR), and Standardized Plant Analysis Risk-Human Reliability Analysis (SPAR-H) are used and new methods for human reliability analysis (HRA) are under developing at this time. This paper presents a dynamic HRA method for assessing the human failure events and estimation of human error probability for filtered containment venting system (FCVS) is performed. The action associated with implementation of the containment venting during a station blackout sequence is used as an example. In this report, dynamic HRA method was used to analyze FCVS-related operator action. The distributions of the required time and the available time were developed by MAAP code and LHS sampling. Though the numerical calculations given here are only for illustrative purpose, the dynamic HRA method can be useful tools to estimate the human error estimation and it can be applied to any kind of the operator actions, including the severe accident management strategy.

  18. Human error views : a framework for benchmarking organizations and measuring the distance between academia and industry

    NARCIS (Netherlands)

    Karanikas, Nektarios

    2015-01-01

    The paper presents a framework that through structured analysis of accident reports explores the differences between practice and academic literature as well amongst organizations regarding their views on human error. The framework is based on the hypothesis that the wording of accident reports

  19. Investigating the causes of human error-induced incidents in the maintenance operations of petrochemical industry by using HFACS

    Directory of Open Access Journals (Sweden)

    Mohammadreza Azhdari

    2017-03-01

    Full Text Available Background & Objectives: Maintenance is an important tool for the petrochemical industries to prevent of accidents and increase operational and process safety success. The purpose of this study was to identify the possible causes of incidents caused by human error in the petrochemical maintenance activities by using Human Factors Analysis and Classification System (HFACS. Methods: This study is a cross-sectional analysis that was conducted in Zagros Petrochemical Company, Asaluyeh-Iran. A checklist of human error-induced incidents was developed based on four HFACS main levels and nineteen sub-groups. Hierarchical task analysis (HTA technique was used to identify maintenance activities and tasks. The main causes of possible incidents were identified by checklist and recorded. Corrective and preventive actions were defined depending on priority.   Results: The content analysis of worksheets of 444 activities showed 37.6% of the causes at the level of unsafe actions, 27.5% at the level of unsafe supervision, 20.9% at the level of preconditions for unsafe acts and 14% of the causes at the level of organizational effects. The HFACS sub-groups showed errors (24.36% inadequate supervision (14.89% and violations (13.26% with the most frequency. Conclusion: In order to prevent and reduce the occurrence of the identified errors, reducing the rate of the detected errors is crucial. Findings of this study showed that appropriate controlling measures such as periodical training of work procedures and supervision improvement decrease the human error-induced incidents in petrochemical industry maintenance.

  20. HuRECA: Human Reliability Evaluator for Computer-based Control Room Actions

    International Nuclear Information System (INIS)

    Kim, Jae Whan; Lee, Seung Jun; Jang, Seung Cheol

    2011-01-01

    As computer-based design features such as computer-based procedures (CBP), soft controls (SCs), and integrated information systems are being adopted in main control rooms (MCR) of nuclear power plants, a human reliability analysis (HRA) method capable of dealing with the effects of these design features on human reliability is needed. From the observations of human factors engineering verification and validation experiments, we have drawn some major important characteristics on operator behaviors and design-related influencing factors (DIFs) from the perspective of human reliability. Firstly, there are new DIFs that should be considered in developing an HRA method for computer-based control rooms including especially CBP and SCs. In the case of the computer-based procedure rather than the paper-based procedure, the structural and managerial elements should be considered as important PSFs in addition to the procedural contents. In the case of the soft controllers, the so-called interface management tasks (or secondary tasks) should be reflected in the assessment of human error probability. Secondly, computer-based control rooms can provide more effective error recovery features than conventional control rooms. Major error recovery features for computer-based control rooms include the automatic logic checking function of the computer-based procedure and the information sharing feature of the general computer-based designs

  1. Monte Carlo simulation of expert judgments on human errors in chemical analysis--a case study of ICP-MS.

    Science.gov (United States)

    Kuselman, Ilya; Pennecchi, Francesca; Epstein, Malka; Fajgelj, Ales; Ellison, Stephen L R

    2014-12-01

    Monte Carlo simulation of expert judgments on human errors in a chemical analysis was used for determination of distributions of the error quantification scores (scores of likelihood and severity, and scores of effectiveness of a laboratory quality system in prevention of the errors). The simulation was based on modeling of an expert behavior: confident, reasonably doubting and irresolute expert judgments were taken into account by means of different probability mass functions (pmfs). As a case study, 36 scenarios of human errors which may occur in elemental analysis of geological samples by ICP-MS were examined. Characteristics of the score distributions for three pmfs of an expert behavior were compared. Variability of the scores, as standard deviation of the simulated score values from the distribution mean, was used for assessment of the score robustness. A range of the score values, calculated directly from elicited data and simulated by a Monte Carlo method for different pmfs, was also discussed from the robustness point of view. It was shown that robustness of the scores, obtained in the case study, can be assessed as satisfactory for the quality risk management and improvement of a laboratory quality system against human errors. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Human errors in test and maintenance of nuclear power plants. Nordic project work

    International Nuclear Information System (INIS)

    Andersson, H.; Liwaang, B.

    1985-08-01

    The present report is a summary of the NKA/LIT-1 project performed for the period 1981-1985. The report summarizes work on human error influence in test and calibration activities in nuclear power plants, reviews problems regarding optimization of the test intervals, organization of test and maintenance activities, and the analysis of human error contribution to the overall risk in test and mainenace tasks. (author)

  3. Assessing human error during collecting a hydrocarbon sample of ...

    African Journals Online (AJOL)

    This paper reports the assessment method of the hydrocarbon sample collection standard operation procedure (SOP) using THERP. The Performance Shaping Factors (PSF) from THERP analyzed and assessed the human errors during collecting a hydrocarbon sample of a petrochemical refinery plant. Twenty-two ...

  4. Bringing organizational factors to the fore of human error management

    International Nuclear Information System (INIS)

    Embrey, D.

    1991-01-01

    Human performance problems account for more than half of all significant events at nuclear power plants, even when these did not necessarily lead to severe accidents. In dealing with the management of human error, both technical and organizational factors need to be taken into account. Most important, a long-term commitment from senior management is needed. (author)

  5. Preventing marine accidents caused by technology-induced human error

    OpenAIRE

    Bielić, Toni; Hasanspahić, Nermin; Čulin, Jelena

    2017-01-01

    The objective of embedding technology on board ships, to improve safety, is not fully accomplished. The paper studies marine accidents caused by human error resulting from improper human-technology interaction. The aim of the paper is to propose measures to prevent reoccurrence of such accidents. This study analyses the marine accident reports issued by Marine Accidents Investigation Branch covering the period from 2012 to 2014. The factors that caused these accidents are examined and categor...

  6. Human errors and violations in computer and information security: the viewpoint of network administrators and security specialists.

    Science.gov (United States)

    Kraemer, Sara; Carayon, Pascale

    2007-03-01

    This paper describes human errors and violations of end users and network administration in computer and information security. This information is summarized in a conceptual framework for examining the human and organizational factors contributing to computer and information security. This framework includes human error taxonomies to describe the work conditions that contribute adversely to computer and information security, i.e. to security vulnerabilities and breaches. The issue of human error and violation in computer and information security was explored through a series of 16 interviews with network administrators and security specialists. The interviews were audio taped, transcribed, and analyzed by coding specific themes in a node structure. The result is an expanded framework that classifies types of human error and identifies specific human and organizational factors that contribute to computer and information security. Network administrators tended to view errors created by end users as more intentional than unintentional, while errors created by network administrators as more unintentional than intentional. Organizational factors, such as communication, security culture, policy, and organizational structure, were the most frequently cited factors associated with computer and information security.

  7. Deadline pressure and human error: a study of human failures on a particle accelerator at Brookhaven National Laboratory

    International Nuclear Information System (INIS)

    Tiagha, E.A.

    1982-01-01

    The decline in industrial efficiency may be linked to decreased reliability of complex automatic systems. This decline threatens the viability of complex organizations in industrialized economies. Industrial engineering techniques that minimize system failure by increasing the reliability of systems hardware are well developed in comparison with those available to reduce human operator errors. The problem of system reliability and the associated costs of breakdown can be reduced if we understand how highly skilled technical personnel function in complex operations and systems. The purpose of this research is to investigate how human errors are affected by deadline pressures, technical communication and other socio-dynamic factors. Through the analysis of a technologically complex particle accelerator prototype at Brookhaven National Laboratory, two failure mechanisms: (1) physical defects in the production process and (2) human operator errors were identified. Two instruments were used to collect information on human failures: objective laboratory data and a human failure questionnaire. The results of human failures from the objective data were used to test for the deadline hypothesis and also to validate the human failure questionnaire. To explain why the human failures occurred, data were collected from a four-part, closed choice questionnaire administered to two groups of scientists, engineers, and technicians, working together against a deadline to produce an engineering prototype of a particle accelerator

  8. Human reliability data, human error and accident models--illustration through the Three Mile Island accident analysis

    International Nuclear Information System (INIS)

    Le Bot, Pierre

    2004-01-01

    Our first objective is to provide a panorama of Human Reliability data used in EDF's Safety Probabilistic Studies, and then, since these concepts are at the heart of Human Reliability and its methods, to go over the notion of human error and the understanding of accidents. We are not sure today that it is actually possible to provide in this field a foolproof and productive theoretical framework. Consequently, the aim of this article is to suggest potential paths of action and to provide information on EDF's progress along those paths which enables us to produce the most potentially useful Human Reliability analyses while taking into account current knowledge in Human Sciences. The second part of this article illustrates our point of view as EDF researchers through the analysis of the most famous civil nuclear accident, the Three Mile Island unit accident in 1979. Analysis of this accident allowed us to validate our positions regarding the need to move, in the case of an accident, from the concept of human error to that of systemic failure in the operation of systems such as a nuclear power plant. These concepts rely heavily on the notion of distributed cognition and we will explain how we applied it. These concepts were implemented in the MERMOS Human Reliability Probabilistic Assessment methods used in the latest EDF Probabilistic Human Reliability Assessment. Besides the fact that it is not very productive to focus exclusively on individual psychological error, the design of the MERMOS method and its implementation have confirmed two things: the significance of qualitative data collection for Human Reliability, and the central role held by Human Reliability experts in building knowledge about emergency operation, which in effect consists of Human Reliability data collection. The latest conclusion derived from the implementation of MERMOS is that, considering the difficulty in building 'generic' Human Reliability data in the field we are involved in, the best

  9. Non-binary unitary error bases and quantum codes

    Energy Technology Data Exchange (ETDEWEB)

    Knill, E.

    1996-06-01

    Error operator bases for systems of any dimension are defined and natural generalizations of the bit-flip/ sign-change error basis for qubits are given. These bases allow generalizing the construction of quantum codes based on eigenspaces of Abelian groups. As a consequence, quantum codes can be constructed form linear codes over {ital Z}{sub {ital n}} for any {ital n}. The generalization of the punctured code construction leads to many codes which permit transversal (i.e. fault tolerant) implementations of certain operations compatible with the error basis.

  10. A classification scheme of erroneous behaviors for human error probability estimations based on simulator data

    International Nuclear Information System (INIS)

    Kim, Yochan; Park, Jinkyun; Jung, Wondea

    2017-01-01

    Because it has been indicated that empirical data supporting the estimates used in human reliability analysis (HRA) is insufficient, several databases have been constructed recently. To generate quantitative estimates from human reliability data, it is important to appropriately sort the erroneous behaviors found in the reliability data. Therefore, this paper proposes a scheme to classify the erroneous behaviors identified by the HuREX (Human Reliability data Extraction) framework through a review of the relevant literature. A case study of the human error probability (HEP) calculations is conducted to verify that the proposed scheme can be successfully implemented for the categorization of the erroneous behaviors and to assess whether the scheme is useful for the HEP quantification purposes. Although continuously accumulating and analyzing simulator data is desirable to secure more reliable HEPs, the resulting HEPs were insightful in several important ways with regard to human reliability in off-normal conditions. From the findings of the literature review and the case study, the potential and limitations of the proposed method are discussed. - Highlights: • A taxonomy of erroneous behaviors is proposed to estimate HEPs from a database. • The cognitive models, procedures, HRA methods, and HRA databases were reviewed. • HEPs for several types of erroneous behaviors are calculated as a case study.

  11. Human error data collection as a precursor to the development of a human reliability assessment capability in air traffic management

    International Nuclear Information System (INIS)

    Kirwan, Barry; Gibson, W. Huw; Hickling, Brian

    2008-01-01

    Quantified risk and safety assessments are now required for safety cases for European air traffic management (ATM) services. Since ATM is highly human-dependent for its safety, this suggests a need for formal human reliability assessment (HRA), as carried out in other industries such as nuclear power. Since the fundamental aspect of HRA is human error data, in the form of human error probabilities (HEPs), it was decided to take a first step towards development of an ATM HRA approach by deriving some HEPs in an ATM context. This paper reports a study, which collected HEPs via analysing the results of a real-time simulation involving air traffic controllers (ATCOs) and pilots, with a focus on communication errors. This study did indeed derive HEPs that were found to be concordant with other known communication human error data. This is a first step, and shows promise for HRA in ATM, since HEPs have been derived which could be used in safety assessments, although these HEPs are for only one (albeit critical) aspect of ATCOs' tasks (communications). The paper discusses options and potential ways forward for the development of a full HRA capability in ATM

  12. Spinocerebellar ataxia type 2 neurodegeneration differentially affects error-based and strategic-based visuomotor learning.

    Science.gov (United States)

    Vaca-Palomares, Israel; Díaz, Rosalinda; Rodríguez-Labrada, Roberto; Medrano-Montero, Jacqeline; Vázquez-Mojena, Yaimé; Velázquez-Pérez, Luis; Fernandez-Ruiz, Juan

    2013-12-01

    There are different types of visuomotor learning. Among the most studied is motor error-based learning where the sign and magnitude of the error are used to update motor commands. However, there are other instances where individuals show visuomotor learning even if the sign or magnitude of the error is precluded. Studies with patients suggest that the former learning is impaired after cerebellar lesions, while basal ganglia lesions disrupt the latter. Nevertheless, the cerebellar role is not restricted only to error-based learning, but it also contributes to several cognitive processes. Therefore, here, we tested if cerebellar ataxia patients are affected in two tasks, one that depends on error-based learning and the other that prevents the use of error-based learning. Our results showed that cerebellar patients have deficits in both visuomotor tasks; however, while error-based learning tasks deficits correlated with the motor impairments, the motor error-dependent task did not correlate with any motor measure.

  13. Task types and error types involved in the human-related unplanned reactor trip events

    International Nuclear Information System (INIS)

    Kim, Jae Whan; Park, Jin Kyun

    2008-01-01

    In this paper, the contribution of task types and error types involved in the human-related unplanned reactor trip events that have occurred between 1986 and 2006 in Korean nuclear power plants are analysed in order to establish a strategy for reducing the human-related unplanned reactor trips. Classification systems for the task types, error modes, and cognitive functions are developed or adopted from the currently available taxonomies, and the relevant information is extracted from the event reports or judged on the basis of an event description. According to the analyses from this study, the contributions of the task types are as follows: corrective maintenance (25.7%), planned maintenance (22.8%), planned operation (19.8%), periodic preventive maintenance (14.9%), response to a transient (9.9%), and design/manufacturing/installation (6.9%). According to the analysis of the error modes, error modes such as control failure (22.2%), wrong object (18.5%), omission (14.8%), wrong action (11.1%), and inadequate (8.3%) take up about 75% of the total unplanned trip events. The analysis of the cognitive functions involved in the events indicated that the planning function had the highest contribution (46.7%) to the human actions leading to unplanned reactor trips. This analysis concludes that in order to significantly reduce human-induced or human-related unplanned reactor trips, an aide system (in support of maintenance personnel) for evaluating possible (negative) impacts of planned actions or erroneous actions as well as an appropriate human error prediction technique, should be developed

  14. Task types and error types involved in the human-related unplanned reactor trip events

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Whan; Park, Jin Kyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-12-15

    In this paper, the contribution of task types and error types involved in the human-related unplanned reactor trip events that have occurred between 1986 and 2006 in Korean nuclear power plants are analysed in order to establish a strategy for reducing the human-related unplanned reactor trips. Classification systems for the task types, error modes, and cognitive functions are developed or adopted from the currently available taxonomies, and the relevant information is extracted from the event reports or judged on the basis of an event description. According to the analyses from this study, the contributions of the task types are as follows: corrective maintenance (25.7%), planned maintenance (22.8%), planned operation (19.8%), periodic preventive maintenance (14.9%), response to a transient (9.9%), and design/manufacturing/installation (6.9%). According to the analysis of the error modes, error modes such as control failure (22.2%), wrong object (18.5%), omission (14.8%), wrong action (11.1%), and inadequate (8.3%) take up about 75% of the total unplanned trip events. The analysis of the cognitive functions involved in the events indicated that the planning function had the highest contribution (46.7%) to the human actions leading to unplanned reactor trips. This analysis concludes that in order to significantly reduce human-induced or human-related unplanned reactor trips, an aide system (in support of maintenance personnel) for evaluating possible (negative) impacts of planned actions or erroneous actions as well as an appropriate human error prediction technique, should be developed.

  15. Identification of failure sequences sensitive to human error

    International Nuclear Information System (INIS)

    1987-06-01

    This report prepared by the participants of the technical committee meeting on ''Identification of Failure Sequences Sensitive to Human Error'' addresses the subjects discussed during the meeting and the conclusions reached by the committee. Chapter 1 reviews the INSAG recommendations and the main elements of the IAEA Programme in the area of human element. In Chapter 2 the role of human actions in nuclear power plants safety from insights of operational experience is reviewed. Chapter 3 is concerned with the relationship between probabilistic safety assessment and human performance associated with severe accident sequences. Chapter 4 addresses the role of simulators in view of training for accident conditions. Chapter 5 presents the conclusions and future trends. The seven papers presented by members of this technical committee are also included in this technical document. A separate abstract was prepared for each of these papers

  16. ATHEANA: A Technique for Human Error Analysis: An Overview of Its Methodological Basis

    International Nuclear Information System (INIS)

    Wreathall, John; Ramey-Smith, Ann

    1998-01-01

    The U.S. NRC has developed a new human reliability analysis (HRA) method, called A Technique for Human Event Analysis (ATHEANA), to provide a way of modeling the so-called 'errors of commission' - that is, situations in which operators terminate or disable engineered safety features (ESFs) or similar equipment during accident conditions, thereby putting the plant at an increased risk of core damage. In its reviews of operational events, NRC has found that these errors of commission occur with a relatively high frequency (as high as 2 or 3 per year), but are noticeably missing from the scope of most current probabilistic risk assessments (PRAs). This new method was developed through a formalized approach that describes what can occur when operators behave rationally but have inadequate knowledge or poor judgement. In particular, the method is based on models of decision-making and response planning that have been used extensively in the aviation field, and on the analysis of major accidents in both the nuclear and non-nuclear fields. Other papers at this conference present summaries of these event analyses in both the nuclear and non-nuclear fields. This paper presents an overview of ATHEANA and summarizes how the method structures the analysis of operationally significant events, and helps HRA analysts identify and model potentially risk-significant errors of commission in plant PRAs. (authors)

  17. PRA (probabilistic risk analysis) in the nuclear sector. Quantifying human error and human malice

    International Nuclear Information System (INIS)

    Heyes, A.G.

    1995-01-01

    Regardless of the regulatory style chosen ('command and control' or 'functional') a vital prerequisite for coherent safety regulations in the nuclear power industry is the ability to assess accident risk. In this paper we present a critical analysis of current techniques of probabilistic risk analysis applied in the industry, with particular regard to the problems of quantifying risks arising from, or exacerbated by, human risk and/or human error. (Author)

  18. Selection of the important performance influencing factors for the assessment of human error under accident management situations in nuclear power plants

    International Nuclear Information System (INIS)

    Kim, J. H.; Jung, W. J.

    1999-01-01

    This paper introduces the process and final results of selection of the important Performance Influencing Factors (PIFs) under emergency operation and accident management situations in nuclear power plants for use in the assessment of human errors. We collected two types of PIF taxonomies, one is the full set PIF list mainly developed for human error analysis, and the other is the PIFs for human reliability analysis (HRA) in probabilistic safety assessment (PSA). 5 PIF taxonomies among the full set PIF list and 10 PIF taxonomies among HRA methodologies (CREAM, SLIM, INTENT, were collected in this research. By reviewing and analyzing PIFs selected for HRA methodologies, the criterion could be established for the selection of appropriate PIFs under emergency operation and accident management situations. Based on this selection criteria, a new PIF taxonomy was proposed for the assessment of human error under emergency operation and accident management situations in nuclear power plants

  19. Human error as the root cause of severe accidents at nuclear reactors

    International Nuclear Information System (INIS)

    Kovács Zoltán; Rýdzi, Stanislav

    2017-01-01

    A root cause is a factor inducing an undesirable event. It is feasible for root causes to be eliminated through technological process improvements. Human error was the root cause of all severe accidents at nuclear power plants. The TMI accident was caused by a series of human errors. The Chernobyl disaster occurred after a badly performed test of the turbogenerator at a reactor with design deficiencies, and in addition, the operators ignored the safety principles and disabled the safety systems. At Fukushima the tsunami risk was underestimated and the project failed to consider the specific issues of the site. The paper describes the severe accidents and points out the human errors that caused them. Also, provisions that might have eliminated those severe accidents are suggested. The fact that each severe accident occurred on a different type of reactor is relevant – no severe accident ever occurred twice at the same reactor type. The lessons learnt from the severe accidents and the safety measures implemented on reactor units all over the world seem to be effective. (orig.)

  20. Human error probability evaluation as part of reliability analysis of digital protection system of advanced pressurized water reactor - APR 1400

    International Nuclear Information System (INIS)

    Varde, P. V.; Lee, D. Y.; Han, J. B.

    2003-03-01

    A case of study on human reliability analysis has been performed as part of reliability analysis of digital protection system of the reactor automatically actuates the shutdown system of the reactor when demanded. However, the safety analysis takes credit for operator action as a diverse mean for tripping the reactor for, though a low probability, ATWS scenario. Based on the available information two cases, viz., human error in tripping the reactor and calibration error for instrumentations in protection system, have been analyzed. Wherever applicable a parametric study has also been performed

  1. Complications: acknowledging, managing, and coping with human error.

    Science.gov (United States)

    Helo, Sevann; Moulton, Carol-Anne E

    2017-08-01

    Errors are inherent in medicine due to the imperfectness of human nature. Health care providers may have a difficult time accepting their fallibility, acknowledging mistakes, and disclosing errors. Fear of litigation, shame, blame, and concern about reputation are just some of the barriers preventing physicians from being more candid with their patients, despite the supporting body of evidence that patients cite poor communication and lack of transparency as primary drivers to file a lawsuit in the wake of a medical complication. Proper error disclosure includes a timely explanation of what happened, who was involved, why the error occurred, and how it will be prevented in the future. Medical mistakes afford the opportunity for individuals and institutions to be candid about their weaknesses while improving patient care processes. When a physician takes the Hippocratic Oath they take on a tremendous sense of responsibility for the care of their patients, and often bear the burden of their mistakes in isolation. Physicians may struggle with guilt, shame, and a crisis of confidence, which may thwart efforts to identify areas for improvement that can lead to meaningful change. Coping strategies for providers include discussing the event with others, seeking professional counseling, and implementing quality improvement projects. Physicians and health care organizations need to find adaptive ways to deal with complications that will benefit patients, providers, and their institutions.

  2. Value-based HR practices, i-deals and clinical error control with CSR as a moderator.

    Science.gov (United States)

    Luu, Tuan; Rowley, Chris; Siengthai, Sununta; Thanh Thao, Vo

    2017-05-08

    Purpose Notwithstanding the rising magnitude of system factors in patient safety improvement, "human factors" such as idiosyncratic deals (i-deals) which also contribute to the adjustment of system deficiencies should not be neglected. The purpose of this paper is to investigate the role of value-based HR practices in catalyzing i-deals, which then influence clinical error control. The research further examines the moderating role of corporate social responsibility (CSR) on the effect of value-based HR practices on i-deals. Design/methodology/approach The data were collected from middle-level clinicians from hospitals in the Vietnam context. Findings The research results confirmed the effect chain from value-based HR practices through i-deals to clinical error control with CSR as a moderator. Originality/value The HRM literature is expanded through enlisting i-deals and clinical error control as the outcomes of HR practices.

  3. Optimal design methods for a digital human-computer interface based on human reliability in a nuclear power plant

    International Nuclear Information System (INIS)

    Jiang, Jianjun; Zhang, Li; Xie, Tian; Wu, Daqing; Li, Min; Wang, Yiqun; Peng, Yuyuan; Peng, Jie; Zhang, Mengjia; Li, Peiyao; Ma, Congmin; Wu, Xing

    2017-01-01

    Highlights: • A complete optimization process is established for digital human-computer interfaces of Npps. • A quick convergence search method is proposed. • The authors propose an affinity error probability mapping function to test human reliability. - Abstract: This is the second in a series of papers describing the optimal design method for a digital human-computer interface of nuclear power plant (Npp) from three different points based on human reliability. The purpose of this series is to explore different optimization methods from varying perspectives. This present paper mainly discusses the optimal design method for quantity of components of the same factor. In monitoring process, quantity of components has brought heavy burden to operators, thus, human errors are easily triggered. To solve the problem, the authors propose an optimization process, a quick convergence search method and an affinity error probability mapping function. Two balanceable parameter values of the affinity error probability function are obtained by experiments. The experimental results show that the affinity error probability mapping function about human-computer interface has very good sensitivity and stability, and that quick convergence search method for fuzzy segments divided by component quantity has better performance than general algorithm.

  4. Intrinsic interactive reinforcement learning - Using error-related potentials for real world human-robot interaction.

    Science.gov (United States)

    Kim, Su Kyoung; Kirchner, Elsa Andrea; Stefes, Arne; Kirchner, Frank

    2017-12-14

    Reinforcement learning (RL) enables robots to learn its optimal behavioral strategy in dynamic environments based on feedback. Explicit human feedback during robot RL is advantageous, since an explicit reward function can be easily adapted. However, it is very demanding and tiresome for a human to continuously and explicitly generate feedback. Therefore, the development of implicit approaches is of high relevance. In this paper, we used an error-related potential (ErrP), an event-related activity in the human electroencephalogram (EEG), as an intrinsically generated implicit feedback (rewards) for RL. Initially we validated our approach with seven subjects in a simulated robot learning scenario. ErrPs were detected online in single trial with a balanced accuracy (bACC) of 91%, which was sufficient to learn to recognize gestures and the correct mapping between human gestures and robot actions in parallel. Finally, we validated our approach in a real robot scenario, in which seven subjects freely chose gestures and the real robot correctly learned the mapping between gestures and actions (ErrP detection (90% bACC)). In this paper, we demonstrated that intrinsically generated EEG-based human feedback in RL can successfully be used to implicitly improve gesture-based robot control during human-robot interaction. We call our approach intrinsic interactive RL.

  5. Development of an FAA-EUROCONTROL technique for the analysis of human error in ATM : final report.

    Science.gov (United States)

    2002-07-01

    Human error has been identified as a dominant risk factor in safety-oriented industries such as air traffic control (ATC). However, little is known about the factors leading to human errors in current air traffic management (ATM) systems. The first s...

  6. Seismic-load-induced human errors and countermeasures using computer graphics in plant-operator communication

    International Nuclear Information System (INIS)

    Hara, Fumio

    1988-01-01

    This paper remarks the importance of seismic load-induced human errors in plant operation by delineating the characteristics of the task performance of human beings under seismic loads. It focuses on man-machine communication via multidimensional data like that conventionally displayed on large panels in a plant control room. It demonstrates a countermeasure to human errors using a computer graphics technique that conveys the global state of the plant operation to operators through cartoon-like, colored graphs in the form of faces that, with different facial expressions, show the plant safety status. (orig.)

  7. Development of the Human Error Management Criteria and the Job Aptitude Evaluation Criteria for Rail Safety Personnel

    Energy Technology Data Exchange (ETDEWEB)

    Koo, In Soo; Seo, Sang Mun; Park, Geun Ok (and others)

    2008-08-15

    It has been estimated that up to 90% of all workplace accidents have human error as a cause. Human error has been widely recognized as a key factor in almost all the highly publicized accidents, including Daegu subway fire of February 18, 2003 killed 198 people and injured 147. Because most human behavior is 'unintentional', carried out automatically, root causes of human error should be carefully investigated and regulated by a legal authority. The final goal of this study is to set up some regulatory guidance that are supposed to be used by the korean rail organizations related to safety managements and the contents are : - to develop the regulatory guidance for managing human error, - to develop the regulatory guidance for managing qualifications of rail drivers - to develop the regulatory guidance for evaluating the aptitude of the safety-related personnel.

  8. Development of the Human Error Management Criteria and the Job Aptitude Evaluation Criteria for Rail Safety Personnel

    International Nuclear Information System (INIS)

    Koo, In Soo; Seo, Sang Mun; Park, Geun Ok

    2008-08-01

    It has been estimated that up to 90% of all workplace accidents have human error as a cause. Human error has been widely recognized as a key factor in almost all the highly publicized accidents, including Daegu subway fire of February 18, 2003 killed 198 people and injured 147. Because most human behavior is 'unintentional', carried out automatically, root causes of human error should be carefully investigated and regulated by a legal authority. The final goal of this study is to set up some regulatory guidance that are supposed to be used by the korean rail organizations related to safety managements and the contents are : - to develop the regulatory guidance for managing human error, - to develop the regulatory guidance for managing qualifications of rail drivers - to develop the regulatory guidance for evaluating the aptitude of the safety-related personnel

  9. Evolutionary enhancement of the SLIM-MAUD method of estimating human error rates

    International Nuclear Information System (INIS)

    Zamanali, J.H.; Hubbard, F.R.; Mosleh, A.; Waller, M.A.

    1992-01-01

    The methodology described in this paper assigns plant-specific dynamic human error rates (HERs) for individual plant examinations based on procedural difficulty, on configuration features, and on the time available to perform the action. This methodology is an evolutionary improvement of the success likelihood index methodology (SLIM-MAUD) for use in systemic scenarios. It is based on the assumption that the HER in a particular situation depends of the combined effects of a comprehensive set of performance-shaping factors (PSFs) that influence the operator's ability to perform the action successfully. The PSFs relate the details of the systemic scenario in which the action must be performed according to the operator's psychological and cognitive condition

  10. Human error in strabismus surgery: Quantification with a sensitivity analysis

    NARCIS (Netherlands)

    S. Schutte (Sander); J.R. Polling (Jan Roelof); F.C.T. van der Helm (Frans); H.J. Simonsz (Huib)

    2009-01-01

    textabstractBackground: Reoperations are frequently necessary in strabismus surgery. The goal of this study was to analyze human-error related factors that introduce variability in the results of strabismus surgery in a systematic fashion. Methods: We identified the primary factors that influence

  11. Classifying and quantifying human error in routine tasks in nuclear power plants

    International Nuclear Information System (INIS)

    Pederson, O.M.; Rasmussen, J.; Carnino, A.; Gagnolet, P.; Griffon, M.; Mancini, G.

    1982-01-01

    This paper results from the work of the OECD/NEA-CSNI Group of Experts on Human Error Data and Assessment. It proposes a classification system (or taxonomy) for use in reporting events involving human malfunction, especially those occurring during the execution of routine tasks. A set of data collection sheets based on this taxonomy has been designed. They include the information needed in order to ensure adequate quality and coherence of the raw data. The sources from which the various data should be obtainable are identified, as are the persons who should analyze them. Improving data collection systems is an iterative process. Therefore Group members are currently making trial applications of the taxonomy to previously analysed real incidents. Results from the initial round of trials are presented and discussed

  12. Human error in strabismus surgery : Quantification with a sensitivity analysis

    NARCIS (Netherlands)

    Schutte, S.; Polling, J.R.; Van der Helm, F.C.T.; Simonsz, H.J.

    2008-01-01

    Background- Reoperations are frequently necessary in strabismus surgery. The goal of this study was to analyze human-error related factors that introduce variability in the results of strabismus surgery in a systematic fashion. Methods- We identified the primary factors that influence the outcome of

  13. Model-free and model-based reward prediction errors in EEG.

    Science.gov (United States)

    Sambrook, Thomas D; Hardwick, Ben; Wills, Andy J; Goslin, Jeremy

    2018-05-24

    Learning theorists posit two reinforcement learning systems: model-free and model-based. Model-based learning incorporates knowledge about structure and contingencies in the world to assign candidate actions with an expected value. Model-free learning is ignorant of the world's structure; instead, actions hold a value based on prior reinforcement, with this value updated by expectancy violation in the form of a reward prediction error. Because they use such different learning mechanisms, it has been previously assumed that model-based and model-free learning are computationally dissociated in the brain. However, recent fMRI evidence suggests that the brain may compute reward prediction errors to both model-free and model-based estimates of value, signalling the possibility that these systems interact. Because of its poor temporal resolution, fMRI risks confounding reward prediction errors with other feedback-related neural activity. In the present study, EEG was used to show the presence of both model-based and model-free reward prediction errors and their place in a temporal sequence of events including state prediction errors and action value updates. This demonstration of model-based prediction errors questions a long-held assumption that model-free and model-based learning are dissociated in the brain. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Human dorsal striatum encodes prediction errors during observational learning of instrumental actions.

    Science.gov (United States)

    Cooper, Jeffrey C; Dunne, Simon; Furey, Teresa; O'Doherty, John P

    2012-01-01

    The dorsal striatum plays a key role in the learning and expression of instrumental reward associations that are acquired through direct experience. However, not all learning about instrumental actions require direct experience. Instead, humans and other animals are also capable of acquiring instrumental actions by observing the experiences of others. In this study, we investigated the extent to which human dorsal striatum is involved in observational as well as experiential instrumental reward learning. Human participants were scanned with fMRI while they observed a confederate over a live video performing an instrumental conditioning task to obtain liquid juice rewards. Participants also performed a similar instrumental task for their own rewards. Using a computational model-based analysis, we found reward prediction errors in the dorsal striatum not only during the experiential learning condition but also during observational learning. These results suggest a key role for the dorsal striatum in learning instrumental associations, even when those associations are acquired purely by observing others.

  15. Systematic Analysis of Video Data from Different Human-Robot Interaction Studies: A Categorisation of Social Signals During Error Situations

    OpenAIRE

    Manuel eGiuliani; Nicole eMirnig; Gerald eStollnberger; Susanne eStadler; Roland eBuchner; Manfred eTscheligi

    2015-01-01

    Human?robot interactions are often affected by error situations that are caused by either the robot or the human. Therefore, robots would profit from the ability to recognize when error situations occur. We investigated the verbal and non-verbal social signals that humans show when error situations occur in human?robot interaction experiments. For that, we analyzed 201 videos of five human?robot interaction user studies with varying tasks from four independent projects. The analysis shows tha...

  16. Trend analysis and comparison of operators' human error events occurred at overseas and domestic nuclear power plants

    International Nuclear Information System (INIS)

    Takagawa, Kenichi

    2006-01-01

    Human errors by operators at overseas and domestic nuclear power plants during the period from 2002 to 2005 were compared and their trends analyzed. The most frequently cited cause of such errors was 'insufficient team monitoring' (inadequate superiors' and other crews' instructions and supervision) both at overseas and domestic plants, followed by 'insufficient self-checking' (lack of cautions by the operator himself). A comparison of the effects of the errors on the operations of plants in Japan and the United Sates showed that the drop in plant output and plant shutdowns at plants in Japan were approximately one-tenth of those in the United States. The ratio of automatic reactor trips to the total number of human errors reported is about 6% for both Japanese and American plants. Looking at changes in the incidence of human errors by years of occurrence, although a distinctive trend cannot be identified for domestic nuclear power plants due to insufficient reported cases, 'inadequate self-checking' as a factor contributing to human errors at overseas nuclear power plants has decreased significantly over the past four years. Regarding changes in the effects of human errors on the operations of plants during the four-year period, events leading to an automatic reactor trip have tended to increase at American plants. Conceivable factors behind this increasing tendency included lack of operating experience by a team (e.g., plant transients and reactor shutdowns and startups) and excessive dependence on training simulators. (author)

  17. Good people who try their best can have problems: recognition of human factors and how to minimise error.

    Science.gov (United States)

    Brennan, Peter A; Mitchell, David A; Holmes, Simon; Plint, Simon; Parry, David

    2016-01-01

    Human error is as old as humanity itself and is an appreciable cause of mistakes by both organisations and people. Much of the work related to human factors in causing error has originated from aviation where mistakes can be catastrophic not only for those who contribute to the error, but for passengers as well. The role of human error in medical and surgical incidents, which are often multifactorial, is becoming better understood, and includes both organisational issues (by the employer) and potential human factors (at a personal level). Mistakes as a result of individual human factors and surgical teams should be better recognised and emphasised. Attitudes and acceptance of preoperative briefing has improved since the introduction of the World Health Organization (WHO) surgical checklist. However, this does not address limitations or other safety concerns that are related to performance, such as stress and fatigue, emotional state, hunger, awareness of what is going on situational awareness, and other factors that could potentially lead to error. Here we attempt to raise awareness of these human factors, and highlight how they can lead to error, and how they can be minimised in our day-to-day practice. Can hospitals move from being "high risk industries" to "high reliability organisations"? Copyright © 2015 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  18. Identification and Assessment of Human Errors in Postgraduate Endodontic Students of Kerman University of Medical Sciences by Using the SHERPA Method

    Directory of Open Access Journals (Sweden)

    Saman Dastaran

    2016-03-01

    Full Text Available Introduction: Human errors are the cause of many accidents, including industrial and medical, therefore finding out an approach for identifying and reducing them is very important. Since no study has been done about human errors in the dental field, this study aimed to identify and assess human errors in postgraduate endodontic students of Kerman University of Medical Sciences by using the SHERPA Method. Methods: This cross-sectional study was performed during year 2014. Data was collected using task observation and interviewing postgraduate endodontic students. Overall, 10 critical tasks, which were most likely to cause harm to patients were determined. Next, Hierarchical Task Analysis (HTA was conducted and human errors in each task were identified by the Systematic Human Error Reduction Prediction Approach (SHERPA technique worksheets. Results: After analyzing the SHERPA worksheets, 90 human errors were identified including (67.7% action errors, (13.3% checking errors, (8.8% selection errors, (5.5% retrieval errors and (4.4% communication errors. As a result, most of them were action errors and less of them were communication errors. Conclusions: The results of the study showed that the highest percentage of errors and the highest level of risk were associated with action errors, therefore, to reduce the occurrence of such errors and limit their consequences, control measures including periodical training of work procedures, providing work check-lists, development of guidelines and establishment of a systematic and standardized reporting system, should be put in place. Regarding the results of this study, the control of recovery errors with the highest percentage of undesirable risk and action errors with the highest frequency of errors should be in the priority of control

  19. Human factors evaluation of remote afterloading brachytherapy: Human error and critical tasks in remote afterloading brachytherapy and approaches for improved system performance. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Callan, J.R.; Kelly, R.T.; Quinn, M.L. [Pacific Science and Engineering Group, San Diego, CA (United States)] [and others

    1995-05-01

    Remote Afterloading Brachytherapy (RAB) is a medical process used in the treatment of cancer. RAB uses a computer-controlled device to remotely insert and remove radioactive sources close to a target (or tumor) in the body. Some RAB problems affecting the radiation dose to the patient have been reported and attributed to human error. To determine the root cause of human error in the RAB system, a human factors team visited 23 RAB treatment sites in the US The team observed RAB treatment planning and delivery, interviewed RAB personnel, and performed walk-throughs, during which staff demonstrated the procedures and practices used in performing RAB tasks. Factors leading to human error in the RAB system were identified. The impact of those factors on the performance of RAB was then evaluated and prioritized in terms of safety significance. Finally, the project identified and evaluated alternative approaches for resolving the safety significant problems related to human error.

  20. Human factors evaluation of remote afterloading brachytherapy: Human error and critical tasks in remote afterloading brachytherapy and approaches for improved system performance. Volume 1

    International Nuclear Information System (INIS)

    Callan, J.R.; Kelly, R.T.; Quinn, M.L.

    1995-05-01

    Remote Afterloading Brachytherapy (RAB) is a medical process used in the treatment of cancer. RAB uses a computer-controlled device to remotely insert and remove radioactive sources close to a target (or tumor) in the body. Some RAB problems affecting the radiation dose to the patient have been reported and attributed to human error. To determine the root cause of human error in the RAB system, a human factors team visited 23 RAB treatment sites in the US The team observed RAB treatment planning and delivery, interviewed RAB personnel, and performed walk-throughs, during which staff demonstrated the procedures and practices used in performing RAB tasks. Factors leading to human error in the RAB system were identified. The impact of those factors on the performance of RAB was then evaluated and prioritized in terms of safety significance. Finally, the project identified and evaluated alternative approaches for resolving the safety significant problems related to human error

  1. Process error rates in general research applications to the Human ...

    African Journals Online (AJOL)

    Objective. To examine process error rates in applications for ethics clearance of health research. Methods. Minutes of 586 general research applications made to a human health research ethics committee (HREC) from April 2008 to March 2009 were examined. Rates of approval were calculated and reasons for requiring ...

  2. Development of a framework to estimate human error for diagnosis tasks in advanced control room

    International Nuclear Information System (INIS)

    Kim, Ar Ryum; Jang, In Seok; Seong, Proong Hyun

    2014-01-01

    In the emergency situation of nuclear power plants (NPPs), a diagnosis of the occurring events is crucial for managing or controlling the plant to a safe and stable condition. If the operators fail to diagnose the occurring events or relevant situations, their responses can eventually inappropriate or inadequate Accordingly, huge researches have been performed to identify the cause of diagnosis error and estimate the probability of diagnosis error. D.I Gertman et al. asserted that 'the cognitive failures stem from erroneous decision-making, poor understanding of rules and procedures, and inadequate problem solving and this failures may be due to quality of data and people's capacity for processing information'. Also many researchers have asserted that human-system interface (HSI), procedure, training and available time are critical factors to cause diagnosis error. In nuclear power plants, a diagnosis of the event is critical for safe condition of the system. As advanced main control room is being adopted in nuclear power plants, the operators may obtain the plant data via computer-based HSI and procedure. Also many researchers have asserted that HSI, procedure, training and available time are critical factors to cause diagnosis error. In this regards, using simulation data, diagnosis errors and its causes were identified. From this study, some useful insights to reduce diagnosis errors of operators in advanced main control room were provided

  3. Analysis of Task Types and Error Types of the Human Actions Involved in the Human-related Unplanned Reactor Trip Events

    International Nuclear Information System (INIS)

    Kim, Jae Whan; Park, Jin Kyun; Jung, Won Dea

    2008-02-01

    This report provides the task types and error types involved in the unplanned reactor trip events that have occurred during 1986 - 2006. The events that were caused by the secondary system of the nuclear power plants amount to 67 %, and the remaining 33 % was by the primary system. The contribution of the activities of the plant personnel was identified as the following order: corrective maintenance (25.7 %), planned maintenance (22.8 %), planned operation (19.8 %), periodic preventive maintenance (14.9 %), response to a transient (9.9 %), and design/manufacturing/installation (9.9%). According to the analysis of error modes, the error modes such as control failure (22.2 %), wrong object (18.5 %), omission (14.8 %), wrong action (11.1 %), and inadequate (8.3 %) take up about 75 % of all the unplanned trip events. The analysis of the cognitive functions involved showed that the planning function makes the highest contribution to the human actions leading to unplanned reactor trips, and it is followed by the observation function (23.4%), the execution function (17.8 %), and the interpretation function (10.3 %). The results of this report are to be used as important bases for development of the error reduction measures or development of the error mode prediction system for the test and maintenance tasks in nuclear power plants

  4. Analysis of Task Types and Error Types of the Human Actions Involved in the Human-related Unplanned Reactor Trip Events

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Whan; Park, Jin Kyun; Jung, Won Dea

    2008-02-15

    This report provides the task types and error types involved in the unplanned reactor trip events that have occurred during 1986 - 2006. The events that were caused by the secondary system of the nuclear power plants amount to 67 %, and the remaining 33 % was by the primary system. The contribution of the activities of the plant personnel was identified as the following order: corrective maintenance (25.7 %), planned maintenance (22.8 %), planned operation (19.8 %), periodic preventive maintenance (14.9 %), response to a transient (9.9 %), and design/manufacturing/installation (9.9%). According to the analysis of error modes, the error modes such as control failure (22.2 %), wrong object (18.5 %), omission (14.8 %), wrong action (11.1 %), and inadequate (8.3 %) take up about 75 % of all the unplanned trip events. The analysis of the cognitive functions involved showed that the planning function makes the highest contribution to the human actions leading to unplanned reactor trips, and it is followed by the observation function (23.4%), the execution function (17.8 %), and the interpretation function (10.3 %). The results of this report are to be used as important bases for development of the error reduction measures or development of the error mode prediction system for the test and maintenance tasks in nuclear power plants.

  5. The role of human error in risk analysis: Application to pre- and post-maintenance procedures of process facilities

    International Nuclear Information System (INIS)

    Noroozi, Alireza; Khakzad, Nima; Khan, Faisal; MacKinnon, Scott; Abbassi, Rouzbeh

    2013-01-01

    Human factors play an important role in the safe operation of a facility. Human factors include the systematic application of information about human characteristics and behavior to increase the safety of a process system. A significant proportion of human errors occur during the maintenance phase. However, the quantification of human error probabilities in the maintenance phase has not been given the amount of attention it deserves. This paper focuses on a human factors analysis in pre-and post- pump maintenance operations. The procedures for removing process equipment from service (pre-maintenance) and returning the equipment to service (post-maintenance) are considered for possible failure scenarios. For each scenario, human error probability is calculated for each activity using the Success Likelihood Index Method (SLIM). Consequences are also assessed in this methodology. The risk assessment is conducted for each component and the overall risk is estimated by adding individual risks. The present study is aimed at highlighting the importance of considering human error in quantitative risk analyses. The developed methodology has been applied to a case study of an offshore process facility

  6. Accounting for measurement error in human life history trade-offs using structural equation modeling.

    Science.gov (United States)

    Helle, Samuli

    2018-03-01

    Revealing causal effects from correlative data is very challenging and a contemporary problem in human life history research owing to the lack of experimental approach. Problems with causal inference arising from measurement error in independent variables, whether related either to inaccurate measurement technique or validity of measurements, seem not well-known in this field. The aim of this study is to show how structural equation modeling (SEM) with latent variables can be applied to account for measurement error in independent variables when the researcher has recorded several indicators of a hypothesized latent construct. As a simple example of this approach, measurement error in lifetime allocation of resources to reproduction in Finnish preindustrial women is modelled in the context of the survival cost of reproduction. In humans, lifetime energetic resources allocated in reproduction are almost impossible to quantify with precision and, thus, typically used measures of lifetime reproductive effort (e.g., lifetime reproductive success and parity) are likely to be plagued by measurement error. These results are contrasted with those obtained from a traditional regression approach where the single best proxy of lifetime reproductive effort available in the data is used for inference. As expected, the inability to account for measurement error in women's lifetime reproductive effort resulted in the underestimation of its underlying effect size on post-reproductive survival. This article emphasizes the advantages that the SEM framework can provide in handling measurement error via multiple-indicator latent variables in human life history studies. © 2017 Wiley Periodicals, Inc.

  7. The error model and experiment of measuring angular position error based on laser collimation

    Science.gov (United States)

    Cai, Yangyang; Yang, Jing; Li, Jiakun; Feng, Qibo

    2018-01-01

    Rotary axis is the reference component of rotation motion. Angular position error is the most critical factor which impair the machining precision among the six degree-of-freedom (DOF) geometric errors of rotary axis. In this paper, the measuring method of angular position error of rotary axis based on laser collimation is thoroughly researched, the error model is established and 360 ° full range measurement is realized by using the high precision servo turntable. The change of space attitude of each moving part is described accurately by the 3×3 transformation matrices and the influences of various factors on the measurement results is analyzed in detail. Experiments results show that the measurement method can achieve high measurement accuracy and large measurement range.

  8. ATHEANA: open-quotes a technique for human error analysisclose quotes entering the implementation phase

    International Nuclear Information System (INIS)

    Taylor, J.; O'Hara, J.; Luckas, W.

    1997-01-01

    Probabilistic Risk Assessment (PRA) has become an increasingly important tool in the nuclear power industry, both for the Nuclear Regulatory Commission (NRC) and the operating utilities. The NRC recently published a final policy statement, SECY-95-126, encouraging the use of PRA in regulatory activities. Human reliability analysis (HRA), while a critical element of PRA, has limitations in the analysis of human actions in PRAs that have long been recognized as a constraint when using PRA. In fact, better integration of HRA into the PRA process has long been a NRC issue. Of particular concern, has been the omission of errors of commission - those errors that are associated with inappropriate interventions by operators with operating systems. To address these concerns, the NRC identified the need to develop an improved HRA method, so that human reliability can be better represented and integrated into PRA modeling and quantification. The purpose of the Brookhaven National Laboratory (BNL) project, entitled 'Improved HRA Method Based on Operating Experience' is to develop a new method for HRA which is supported by the analysis of risk-significant operating experience. This approach will allow a more realistic assessment and representation of the human contribution to plant risk, and thereby increase the utility of PRA. The project's completed, ongoing, and future efforts fall into four phases: (1) Assessment phase (FY 92/93); (2) Analysis and Characterization phase (FY 93/94); (3) Development phase (FY 95/96); and (4) Implementation phase (FY 96/97 ongoing)

  9. The current approach to human error and blame in the NHS.

    Science.gov (United States)

    Ottewill, Melanie

    There is a large body of research to suggest that serious errors are widespread throughout medicine. The traditional response to these adverse events has been to adopt a 'person approach' - blaming the individual seen as 'responsible'. The culture of medicine is highly complicit in this response. Such an approach results in enormous personal costs to the individuals concerned and does little to address the root causes of errors and thus prevent their recurrence. Other industries, such as aviation, where safety is a paramount concern and which have similar structures to the medical profession, have, over the past decade or so, adopted a 'systems' approach to error, recognizing that human error is ubiquitous and inevitable and that systems need to be developed with this in mind. This approach has been highly successful, but has necessitated, first and foremost, a cultural shift. It is in the best interests of patients, and medical professionals alike, that such a shift is embraced in the NHS.

  10. Basic design of multimedia system for the representation of human error cases in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Woon; Park, Geun Ok [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-04-01

    We have developed a multimedia system for the representation of human error cases with the education and training on human errors can be done effectively. The followings are major topics during the basic design; 1 Establishment of a basic concept for representing human error cases using multimedia, 2 Establishment of a design procedure for the multimedia system, 3 Establishment of a hardware and software environment for operating the multimedia system, 4 Design of multimedia input and output interfaces. In order to verify the results of this basic design, we implemented the basic design with an incident triggered by operator`s misaction which occurred at Uljin NPP Unit 1. (Author) 12 refs., 30 figs.,.

  11. Development of Human Factor Management Requirements and Human Error Classification for the Prevention of Railway Accident

    International Nuclear Information System (INIS)

    Kwak, Sang Log; Park, Chan Woo; Shin, Seung Ryoung

    2008-08-01

    Railway accident analysis results show that accidents cased by human factors are not decreasing, whereas H/W related accidents are steadily decreasing. For the efficient management of human factors, many expertise on design, conditions, safety culture and staffing are required. But current safety management activities on safety critical works are focused on training, due to the limited resource and information. In order to improve railway safety, human factors management requirements for safety critical worker and human error classification is proposed in this report. For this accident analysis, status of safety measure on human factor, safety management system on safety critical worker, current safety planning is analysis

  12. How we learn to make decisions: rapid propagation of reinforcement learning prediction errors in humans.

    Science.gov (United States)

    Krigolson, Olav E; Hassall, Cameron D; Handy, Todd C

    2014-03-01

    Our ability to make decisions is predicated upon our knowledge of the outcomes of the actions available to us. Reinforcement learning theory posits that actions followed by a reward or punishment acquire value through the computation of prediction errors-discrepancies between the predicted and the actual reward. A multitude of neuroimaging studies have demonstrated that rewards and punishments evoke neural responses that appear to reflect reinforcement learning prediction errors [e.g., Krigolson, O. E., Pierce, L. J., Holroyd, C. B., & Tanaka, J. W. Learning to become an expert: Reinforcement learning and the acquisition of perceptual expertise. Journal of Cognitive Neuroscience, 21, 1833-1840, 2009; Bayer, H. M., & Glimcher, P. W. Midbrain dopamine neurons encode a quantitative reward prediction error signal. Neuron, 47, 129-141, 2005; O'Doherty, J. P. Reward representations and reward-related learning in the human brain: Insights from neuroimaging. Current Opinion in Neurobiology, 14, 769-776, 2004; Holroyd, C. B., & Coles, M. G. H. The neural basis of human error processing: Reinforcement learning, dopamine, and the error-related negativity. Psychological Review, 109, 679-709, 2002]. Here, we used the brain ERP technique to demonstrate that not only do rewards elicit a neural response akin to a prediction error but also that this signal rapidly diminished and propagated to the time of choice presentation with learning. Specifically, in a simple, learnable gambling task, we show that novel rewards elicited a feedback error-related negativity that rapidly decreased in amplitude with learning. Furthermore, we demonstrate the existence of a reward positivity at choice presentation, a previously unreported ERP component that has a similar timing and topography as the feedback error-related negativity that increased in amplitude with learning. The pattern of results we observed mirrored the output of a computational model that we implemented to compute reward

  13. Hardware-efficient bosonic quantum error-correcting codes based on symmetry operators

    Science.gov (United States)

    Niu, Murphy Yuezhen; Chuang, Isaac L.; Shapiro, Jeffrey H.

    2018-03-01

    We establish a symmetry-operator framework for designing quantum error-correcting (QEC) codes based on fundamental properties of the underlying system dynamics. Based on this framework, we propose three hardware-efficient bosonic QEC codes that are suitable for χ(2 )-interaction based quantum computation in multimode Fock bases: the χ(2 ) parity-check code, the χ(2 ) embedded error-correcting code, and the χ(2 ) binomial code. All of these QEC codes detect photon-loss or photon-gain errors by means of photon-number parity measurements, and then correct them via χ(2 ) Hamiltonian evolutions and linear-optics transformations. Our symmetry-operator framework provides a systematic procedure for finding QEC codes that are not stabilizer codes, and it enables convenient extension of a given encoding to higher-dimensional qudit bases. The χ(2 ) binomial code is of special interest because, with m ≤N identified from channel monitoring, it can correct m -photon-loss errors, or m -photon-gain errors, or (m -1 )th -order dephasing errors using logical qudits that are encoded in O (N ) photons. In comparison, other bosonic QEC codes require O (N2) photons to correct the same degree of bosonic errors. Such improved photon efficiency underscores the additional error-correction power that can be provided by channel monitoring. We develop quantum Hamming bounds for photon-loss errors in the code subspaces associated with the χ(2 ) parity-check code and the χ(2 ) embedded error-correcting code, and we prove that these codes saturate their respective bounds. Our χ(2 ) QEC codes exhibit hardware efficiency in that they address the principal error mechanisms and exploit the available physical interactions of the underlying hardware, thus reducing the physical resources required for implementing their encoding, decoding, and error-correction operations, and their universal encoded-basis gate sets.

  14. Impact of human error on lumber yield in rough mills

    Science.gov (United States)

    Urs Buehlmann; R. Edward Thomas; R. Edward Thomas

    2002-01-01

    Rough sawn, kiln-dried lumber contains characteristics such as knots and bark pockets that are considered by most people to be defects. When using boards to produce furniture components, these defects are removed to produce clear, defect-free parts. Currently, human operators identify and locate the unusable board areas containing defects. Errors in determining a...

  15. A Simulation-Based Soft Error Estimation Methodology for Computer Systems

    OpenAIRE

    Sugihara, Makoto; Ishihara, Tohru; Hashimoto, Koji; Muroyama, Masanori

    2006-01-01

    This paper proposes a simulation-based soft error estimation methodology for computer systems. Accumulating soft error rates (SERs) of all memories in a computer system results in pessimistic soft error estimation. This is because memory cells are used spatially and temporally and not all soft errors in them make the computer system faulty. Our soft-error estimation methodology considers the locations and the timings of soft errors occurring at every level of memory hierarchy and estimates th...

  16. A Corpus-based Study of EFL Learners’ Errors in IELTS Essay Writing

    OpenAIRE

    Hoda Divsar; Robab Heydari

    2017-01-01

    The present study analyzed different types of errors in the EFL learners’ IELTS essays. In order to determine the major types of errors, a corpus of 70 IELTS examinees’ writings were collected, and their errors were extracted and categorized qualitatively. Errors were categorized based on a researcher-developed error-coding scheme into 13 aspects. Based on the descriptive statistical analyses, the frequency of each error type was calculated and the commonest errors committed by the EFL learne...

  17. Action errors, error management, and learning in organizations.

    Science.gov (United States)

    Frese, Michael; Keith, Nina

    2015-01-03

    Every organization is confronted with errors. Most errors are corrected easily, but some may lead to negative consequences. Organizations often focus on error prevention as a single strategy for dealing with errors. Our review suggests that error prevention needs to be supplemented by error management--an approach directed at effectively dealing with errors after they have occurred, with the goal of minimizing negative and maximizing positive error consequences (examples of the latter are learning and innovations). After defining errors and related concepts, we review research on error-related processes affected by error management (error detection, damage control). Empirical evidence on positive effects of error management in individuals and organizations is then discussed, along with emotional, motivational, cognitive, and behavioral pathways of these effects. Learning from errors is central, but like other positive consequences, learning occurs under certain circumstances--one being the development of a mind-set of acceptance of human error.

  18. The safety assessment system based on virtual networked environment for evaluation on the hazards from human errors during decommissioning of nuclear facilities

    International Nuclear Information System (INIS)

    Jeong, Kwan Seong; Choi, Byung Seon; Moon, Jei Kwon; Hyun, Dong Jun; Lee, Jong Hwan; Kim, Ik June; Kang, Shin Young; Choi, Jong Won; Ahn, Sang Myeon; Lee, Jung Jun; Lee, Byung Sik

    2016-01-01

    This paper is intended to suggest a system for evaluation on the hazards from human errors during decommissioning of nuclear facilities. The system was developed under virtual networked environment. The innovative features are real-time changing direction of workers in a scenario and real-time measuring personal exposure dose and collective exposure dose. The system will be expected to be utilized as a training tool for improving familiarization of a workplace and for preventing workers from accidents. - Highlights: • A system for evaluation on the hazards from human errors during decommissioning of nuclear facilities. • Real-time changing direction of workers in a scenario. • Real-time measuring personal exposure dose and collective exposure dose. • A tool for improving familiarization of a workplace and for preventing workers from accidents.

  19. Representing cognitive activities and errors in HRA trees

    International Nuclear Information System (INIS)

    Gertman, D.I.

    1992-01-01

    A graphic representation method is presented herein for adapting an existing technology--human reliability analysis (HRA) event trees, used to support event sequence logic structures and calculations--to include a representation of the underlying cognitive activity and corresponding errors associated with human performance. The analyst is presented with three potential means of representing human activity: the NUREG/CR-1278 HRA event tree approach; the skill-, rule- and knowledge-based paradigm; and the slips, lapses, and mistakes paradigm. The above approaches for representing human activity are integrated in order to produce an enriched HRA event tree -- the cognitive event tree system (COGENT)-- which, in turn, can be used to increase the analyst's understanding of the basic behavioral mechanisms underlying human error and the representation of that error in probabilistic risk assessment. Issues pertaining to the implementation of COGENT are also discussed

  20. A Corpus-based Study of EFL Learners’ Errors in IELTS Essay Writing

    Directory of Open Access Journals (Sweden)

    Hoda Divsar

    2017-03-01

    Full Text Available The present study analyzed different types of errors in the EFL learners’ IELTS essays. In order to determine the major types of errors, a corpus of 70 IELTS examinees’ writings were collected, and their errors were extracted and categorized qualitatively. Errors were categorized based on a researcher-developed error-coding scheme into 13 aspects. Based on the descriptive statistical analyses, the frequency of each error type was calculated and the commonest errors committed by the EFL learners in IELTS essays were identified. The results indicated that the two most frequent errors that IELTS candidates committed were related to word choice and verb forms. Based on the research results, pedagogical implications highlight analyzing EFL learners’ writing errors as a useful basis for instructional purposes including creating pedagogical teaching materials that are in line with learners’ linguistic strengths and weaknesses.

  1. Hierarchical learning induces two simultaneous, but separable, prediction errors in human basal ganglia.

    Science.gov (United States)

    Diuk, Carlos; Tsai, Karin; Wallis, Jonathan; Botvinick, Matthew; Niv, Yael

    2013-03-27

    Studies suggest that dopaminergic neurons report a unitary, global reward prediction error signal. However, learning in complex real-life tasks, in particular tasks that show hierarchical structure, requires multiple prediction errors that may coincide in time. We used functional neuroimaging to measure prediction error signals in humans performing such a hierarchical task involving simultaneous, uncorrelated prediction errors. Analysis of signals in a priori anatomical regions of interest in the ventral striatum and the ventral tegmental area indeed evidenced two simultaneous, but separable, prediction error signals corresponding to the two levels of hierarchy in the task. This result suggests that suitably designed tasks may reveal a more intricate pattern of firing in dopaminergic neurons. Moreover, the need for downstream separation of these signals implies possible limitations on the number of different task levels that we can learn about simultaneously.

  2. Findings from analysing and quantifying human error using current methods

    International Nuclear Information System (INIS)

    Dang, V.N.; Reer, B.

    1999-01-01

    In human reliability analysis (HRA), the scarcity of data means that, at best, judgement must be applied to transfer to the domain of the analysis what data are available for similar tasks. In particular for the quantification of tasks involving decisions, the analyst has to choose among quantification approaches that all depend to a significant degree on expert judgement. The use of expert judgement can be made more reliable by eliciting relative judgements rather than absolute judgements. These approaches, which are based on multiple criterion decision theory, focus on ranking the tasks to be analysed by difficulty. While these approaches remedy at least partially the poor performance of experts in the estimation of probabilities, they nevertheless require the calibration of the relative scale on which the actions are ranked in order to obtain the probabilities of interest. This paper presents some results from a comparison of some current HRA methods performed in the frame of a study of SLIM calibration options. The HRA quantification methods THERP, HEART, and INTENT were applied to derive calibration human error probabilities for two groups of operator actions. (author)

  3. Representing cognitive activities and errors in HRA trees

    International Nuclear Information System (INIS)

    Gertman, D.I.

    1992-01-01

    This paper discusses development of a means by which to present cognitive information in human reliability assessment (HRA) event trees. The descriptions found in probabilistic risk assessments (PRAs) regarding the demands on, and the resulting performance of, nuclear power plant (NPP) crews often make use of the technique for human error rate prediction (THERP), which provides a mechanism, the HRA event tree, for presenting the analyst's conceptualization of the activities underlying performance and the errors associated with that performance. When using THERP, analysts have often omitted the more complex elements of human cognition from these trees. There has yet to be a concerted effort to take theory, principles, and data from cognitive psychology and wed it to the logic structure of the HRA event tree. This paper attempts to do so. The COGENT modeling scheme (cognitively based HRA event trees) adds two taxonomies to the HRA event tree proposed by Swain and Guttman. The first taxonomy, the one proposed by Norman and Reason, describes the type of error committed and implies something about the underlying cognition as well. The second of these, the Rasmussen taxonomy, provides description regarding the skill-based, rule-based, or knowledge-based behavior underlying the execution of tasks. It is not apparent and must be deduced from the pattern of errors exhibited by personnel

  4. Human reliability analysis of errors of commission: a review of methods and applications

    Energy Technology Data Exchange (ETDEWEB)

    Reer, B

    2007-06-15

    Illustrated by specific examples relevant to contemporary probabilistic safety assessment (PSA), this report presents a review of human reliability analysis (HRA) addressing post initiator errors of commission (EOCs), i.e. inappropriate actions under abnormal operating conditions. The review addressed both methods and applications. Emerging HRA methods providing advanced features and explicit guidance suitable for PSA are: A Technique for Human Event Analysis (ATHEANA, key publications in 1998/2000), Methode d'Evaluation de la Realisation des Missions Operateur pour la Surete (MERMOS, 1998/2000), the EOC HRA method developed by the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS, 2003), the Misdiagnosis Tree Analysis (MDTA) method (2005/2006), the Cognitive Reliability and Error Analysis Method (CREAM, 1998), and the Commission Errors Search and Assessment (CESA) method (2002/2004). As a result of a thorough investigation of various PSA/HRA applications, this paper furthermore presents an overview of EOCs (termination of safety injection, shutdown of secondary cooling, etc.) referred to in predictive studies and a qualitative review of cases of EOC quantification. The main conclusions of the review of both the methods and the EOC HRA cases are: (1) The CESA search scheme, which proceeds from possible operator actions to the affected systems to scenarios, may be preferable because this scheme provides a formalized way for identifying relatively important scenarios with EOC opportunities; (2) an EOC identification guidance like CESA, which is strongly based on the procedural guidance and important measures of systems or components affected by inappropriate actions, however should pay some attention to EOCs associated with familiar but non-procedural actions and EOCs leading to failures of manually initiated safety functions. (3) Orientations of advanced EOC quantification comprise a) modeling of multiple contexts for a given scenario, b) accounting for

  5. Human reliability analysis of errors of commission: a review of methods and applications

    International Nuclear Information System (INIS)

    Reer, B.

    2007-06-01

    Illustrated by specific examples relevant to contemporary probabilistic safety assessment (PSA), this report presents a review of human reliability analysis (HRA) addressing post initiator errors of commission (EOCs), i.e. inappropriate actions under abnormal operating conditions. The review addressed both methods and applications. Emerging HRA methods providing advanced features and explicit guidance suitable for PSA are: A Technique for Human Event Analysis (ATHEANA, key publications in 1998/2000), Methode d'Evaluation de la Realisation des Missions Operateur pour la Surete (MERMOS, 1998/2000), the EOC HRA method developed by the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS, 2003), the Misdiagnosis Tree Analysis (MDTA) method (2005/2006), the Cognitive Reliability and Error Analysis Method (CREAM, 1998), and the Commission Errors Search and Assessment (CESA) method (2002/2004). As a result of a thorough investigation of various PSA/HRA applications, this paper furthermore presents an overview of EOCs (termination of safety injection, shutdown of secondary cooling, etc.) referred to in predictive studies and a qualitative review of cases of EOC quantification. The main conclusions of the review of both the methods and the EOC HRA cases are: (1) The CESA search scheme, which proceeds from possible operator actions to the affected systems to scenarios, may be preferable because this scheme provides a formalized way for identifying relatively important scenarios with EOC opportunities; (2) an EOC identification guidance like CESA, which is strongly based on the procedural guidance and important measures of systems or components affected by inappropriate actions, however should pay some attention to EOCs associated with familiar but non-procedural actions and EOCs leading to failures of manually initiated safety functions. (3) Orientations of advanced EOC quantification comprise a) modeling of multiple contexts for a given scenario, b) accounting for

  6. A basic framework for the analysis of the human error potential due to the computerization in nuclear power plants

    International Nuclear Information System (INIS)

    Lee, Y. H.

    1999-01-01

    Computerization and its vivid benefits expected in the nuclear power plant design cannot be realized without verifying the inherent safety problems. Human error aspect is also included in the verification issues. The verification spans from the perception of the changes in operation functions such as automation to the unfamiliar experience of operators due to the interface change. Therefore, a new framework for human error analysis might capture both the positive and the negative effect of the computerization. This paper suggest a basic framework for error identification through the review of the existing human error studies and the experience of computerizations in nuclear power plants

  7. Preventing Medication Error Based on Knowledge Management Against Adverse Event

    OpenAIRE

    Hastuti, Apriyani Puji; Nursalam, Nursalam; Triharini, Mira

    2017-01-01

    Introductions: Medication error is one of many types of errors that could decrease the quality and safety of healthcare. Increasing number of adverse events (AE) reflects the number of medication errors. This study aimed to develop a model of medication error prevention based on knowledge management. This model is expected to improve knowledge and skill of nurses to prevent medication error which is characterized by the decrease of adverse events (AE). Methods: This study consisted of two sta...

  8. Human Error Analysis in a Permit to Work System: A Case Study in a Chemical Plant

    Directory of Open Access Journals (Sweden)

    Mehdi Jahangiri

    2016-03-01

    Conclusion: The SPAR-H method applied in this study could analyze and quantify the potential human errors and extract the required measures for reducing the error probabilities in PTW system. Some suggestions to reduce the likelihood of errors, especially in the field of modifying the performance shaping factors and dependencies among tasks are provided.

  9. Error and discrepancy in radiology: inevitable or avoidable?

    Science.gov (United States)

    Brady, Adrian P

    2017-02-01

    Errors and discrepancies in radiology practice are uncomfortably common, with an estimated day-to-day rate of 3-5% of studies reported, and much higher rates reported in many targeted studies. Nonetheless, the meaning of the terms "error" and "discrepancy" and the relationship to medical negligence are frequently misunderstood. This review outlines the incidence of such events, the ways they can be categorized to aid understanding, and potential contributing factors, both human- and system-based. Possible strategies to minimise error are considered, along with the means of dealing with perceived underperformance when it is identified. The inevitability of imperfection is explained, while the importance of striving to minimise such imperfection is emphasised. • Discrepancies between radiology reports and subsequent patient outcomes are not inevitably errors. • Radiologist reporting performance cannot be perfect, and some errors are inevitable. • Error or discrepancy in radiology reporting does not equate negligence. • Radiologist errors occur for many reasons, both human- and system-derived. • Strategies exist to minimise error causes and to learn from errors made.

  10. Psychological scaling of expert estimates of human error probabilities: application to nuclear power plant operation

    International Nuclear Information System (INIS)

    Comer, K.; Gaddy, C.D.; Seaver, D.A.; Stillwell, W.G.

    1985-01-01

    The US Nuclear Regulatory Commission and Sandia National Laboratories sponsored a project to evaluate psychological scaling techniques for use in generating estimates of human error probabilities. The project evaluated two techniques: direct numerical estimation and paired comparisons. Expert estimates were found to be consistent across and within judges. Convergent validity was good, in comparison to estimates in a handbook of human reliability. Predictive validity could not be established because of the lack of actual relative frequencies of error (which will be a difficulty inherent in validation of any procedure used to estimate HEPs). Application of expert estimates in probabilistic risk assessment and in human factors is discussed

  11. Human errors during the simulations of an SGTR scenario: Application of the HERA system

    International Nuclear Information System (INIS)

    Jung, Won Dea; Whaley, April M.; Hallbert, Bruce P.

    2009-01-01

    Due to the need of data for a Human Reliability Analysis (HRA), a number of data collection efforts have been undertaken in several different organizations. As a part of this effort, a human error analysis that focused on a set of simulator records on a Steam Generator Tube Rupture (SGTR) scenario was performed by using the Human Event Repository and Analysis (HERA) system. This paper summarizes the process and results of the HERA analysis, including discussions about the usability of the HERA system for a human error analysis of simulator data. Five simulated records of an SGTR scenario were analyzed with the HERA analysis process in order to scrutinize the causes and mechanisms of the human related events. From this study, the authors confirmed that the HERA was a serviceable system that can analyze human performance qualitatively from simulator data. It was possible to identify the human related events in the simulator data that affected the system safety not only negatively but also positively. It was also possible to scrutinize the Performance Shaping Factors (PSFs) and the relevant contributory factors with regard to each identified human event

  12. Neural prediction errors reveal a risk-sensitive reinforcement-learning process in the human brain.

    Science.gov (United States)

    Niv, Yael; Edlund, Jeffrey A; Dayan, Peter; O'Doherty, John P

    2012-01-11

    Humans and animals are exquisitely, though idiosyncratically, sensitive to risk or variance in the outcomes of their actions. Economic, psychological, and neural aspects of this are well studied when information about risk is provided explicitly. However, we must normally learn about outcomes from experience, through trial and error. Traditional models of such reinforcement learning focus on learning about the mean reward value of cues and ignore higher order moments such as variance. We used fMRI to test whether the neural correlates of human reinforcement learning are sensitive to experienced risk. Our analysis focused on anatomically delineated regions of a priori interest in the nucleus accumbens, where blood oxygenation level-dependent (BOLD) signals have been suggested as correlating with quantities derived from reinforcement learning. We first provide unbiased evidence that the raw BOLD signal in these regions corresponds closely to a reward prediction error. We then derive from this signal the learned values of cues that predict rewards of equal mean but different variance and show that these values are indeed modulated by experienced risk. Moreover, a close neurometric-psychometric coupling exists between the fluctuations of the experience-based evaluations of risky options that we measured neurally and the fluctuations in behavioral risk aversion. This suggests that risk sensitivity is integral to human learning, illuminating economic models of choice, neuroscientific models of affective learning, and the workings of the underlying neural mechanisms.

  13. Error Evaluation in a Stereovision-Based 3D Reconstruction System

    Directory of Open Access Journals (Sweden)

    Kohler Sophie

    2010-01-01

    Full Text Available The work presented in this paper deals with the performance analysis of the whole 3D reconstruction process of imaged objects, specifically of the set of geometric primitives describing their outline and extracted from a pair of images knowing their associated camera models. The proposed analysis focuses on error estimation for the edge detection process, the starting step for the whole reconstruction procedure. The fitting parameters describing the geometric features composing the workpiece to be evaluated are used as quality measures to determine error bounds and finally to estimate the edge detection errors. These error estimates are then propagated up to the final 3D reconstruction step. The suggested error analysis procedure for stereovision-based reconstruction tasks further allows evaluating the quality of the 3D reconstruction. The resulting final error estimates enable lastly to state if the reconstruction results fulfill a priori defined criteria, for example, fulfill dimensional constraints including tolerance information, for vision-based quality control applications for example.

  14. Error Parsing: An alternative method of implementing social judgment theory

    OpenAIRE

    Crystal C. Hall; Daniel M. Oppenheimer

    2015-01-01

    We present a novel method of judgment analysis called Error Parsing, based upon an alternative method of implementing Social Judgment Theory (SJT). SJT and Error Parsing both posit the same three components of error in human judgment: error due to noise, error due to cue weighting, and error due to inconsistency. In that sense, the broad theory and framework are the same. However, SJT and Error Parsing were developed to answer different questions, and thus use different m...

  15. Scaling prediction errors to reward variability benefits error-driven learning in humans.

    Science.gov (United States)

    Diederen, Kelly M J; Schultz, Wolfram

    2015-09-01

    Effective error-driven learning requires individuals to adapt learning to environmental reward variability. The adaptive mechanism may involve decays in learning rate across subsequent trials, as shown previously, and rescaling of reward prediction errors. The present study investigated the influence of prediction error scaling and, in particular, the consequences for learning performance. Participants explicitly predicted reward magnitudes that were drawn from different probability distributions with specific standard deviations. By fitting the data with reinforcement learning models, we found scaling of prediction errors, in addition to the learning rate decay shown previously. Importantly, the prediction error scaling was closely related to learning performance, defined as accuracy in predicting the mean of reward distributions, across individual participants. In addition, participants who scaled prediction errors relative to standard deviation also presented with more similar performance for different standard deviations, indicating that increases in standard deviation did not substantially decrease "adapters'" accuracy in predicting the means of reward distributions. However, exaggerated scaling beyond the standard deviation resulted in impaired performance. Thus efficient adaptation makes learning more robust to changing variability. Copyright © 2015 the American Physiological Society.

  16. Systematic analysis of dependent human errors from the maintenance history at finnish NPPs - A status report

    Energy Technology Data Exchange (ETDEWEB)

    Laakso, K. [VTT Industrial Systems (Finland)

    2002-12-01

    Operating experience has shown missed detection events, where faults have passed inspections and functional tests to operating periods after the maintenance activities during the outage. The causes of these failures have often been complex event sequences, involving human and organisational factors. Especially common cause and other dependent failures of safety systems may significantly contribute to the reactor core damage risk. The topic has been addressed in the Finnish studies of human common cause failures, where experiences on latent human errors have been searched and analysed in detail from the maintenance history. The review of the bulk of the analysis results of the Olkiluoto and Loviisa plant sites shows that the instrumentation and control and electrical equipment is more prone to human error caused failure events than the other maintenance and that plant modifications and also predetermined preventive maintenance are significant sources of common cause failures. Most errors stem from the refuelling and maintenance outage period at the both sites, and less than half of the dependent errors were identified during the same outage. The dependent human errors originating from modifications could be reduced by a more tailored specification and coverage of their start-up testing programs. Improvements could also be achieved by a more case specific planning of the installation inspection and functional testing of complicated maintenance works or work objects of higher plant safety and availability importance. A better use and analysis of condition monitoring information for maintenance steering could also help. The feedback from discussions of the analysis results with plant experts and professionals is still crucial in developing the final conclusions and recommendations that meet the specific development needs at the plants. (au)

  17. Taking human error into account in the design of nuclear reactor centres

    International Nuclear Information System (INIS)

    Prouillac; Lerat; Janoir.

    1982-05-01

    The role of the operator in the centralized management of pressurized water reactors is studied. Different types of human error likely to arise, the means of their prevention and methods of mitigating their consequences are presented. Some possible improvements are outlined

  18. The application of human error prevention tool in Tianwan nuclear power station

    International Nuclear Information System (INIS)

    Qiao Zhiguo

    2013-01-01

    This paper mainly discusses the application and popularization of human error prevention tool in Tianwan nuclear power station, including the study on project implementation background, main contents and innovation, performance management, innovation practice and development, and performance of innovation application. (authors)

  19. The error in total error reduction.

    Science.gov (United States)

    Witnauer, James E; Urcelay, Gonzalo P; Miller, Ralph R

    2014-02-01

    Most models of human and animal learning assume that learning is proportional to the discrepancy between a delivered outcome and the outcome predicted by all cues present during that trial (i.e., total error across a stimulus compound). This total error reduction (TER) view has been implemented in connectionist and artificial neural network models to describe the conditions under which weights between units change. Electrophysiological work has revealed that the activity of dopamine neurons is correlated with the total error signal in models of reward learning. Similar neural mechanisms presumably support fear conditioning, human contingency learning, and other types of learning. Using a computational modeling approach, we compared several TER models of associative learning to an alternative model that rejects the TER assumption in favor of local error reduction (LER), which assumes that learning about each cue is proportional to the discrepancy between the delivered outcome and the outcome predicted by that specific cue on that trial. The LER model provided a better fit to the reviewed data than the TER models. Given the superiority of the LER model with the present data sets, acceptance of TER should be tempered. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Skills, rules and knowledge in aircraft maintenance: errors in context

    Science.gov (United States)

    Hobbs, Alan; Williamson, Ann

    2002-01-01

    Automatic or skill-based behaviour is generally considered to be less prone to error than behaviour directed by conscious control. However, researchers who have applied Rasmussen's skill-rule-knowledge human error framework to accidents and incidents have sometimes found that skill-based errors appear in significant numbers. It is proposed that this is largely a reflection of the opportunities for error which workplaces present and does not indicate that skill-based behaviour is intrinsically unreliable. In the current study, 99 errors reported by 72 aircraft mechanics were examined in the light of a task analysis based on observations of the work of 25 aircraft mechanics. The task analysis identified the opportunities for error presented at various stages of maintenance work packages and by the job as a whole. Once the frequency of each error type was normalized in terms of the opportunities for error, it became apparent that skill-based performance is more reliable than rule-based performance, which is in turn more reliable than knowledge-based performance. The results reinforce the belief that industrial safety interventions designed to reduce errors would best be directed at those aspects of jobs that involve rule- and knowledge-based performance.

  1. Control of Human Error and comparison Level risk after correction action With the SHERPA Method in a control Room of petrochemical industry

    Directory of Open Access Journals (Sweden)

    A. Zakerian

    2011-12-01

    Full Text Available Background and aims Today in many jobs like nuclear, military and chemical industries, human errors may result in a disaster. Accident in different places of the world emphasizes this subject and we indicate for example, Chernobyl disaster in (1986, tree Mile accident in (1974 and Flixborough explosion in (1974.So human errors identification especially in important and intricate systems is necessary and unavoidable for predicting control methods.   Methods Recent research is a case study and performed in Zagross Methanol Company in Asalouye (South pars.   Walking –Talking through method with process expert and control room operators, inspecting technical documents are used for collecting required information and completing Systematic Human Error Reductive and Predictive Approach (SHERPA worksheets.   Results analyzing SHERPA worksheet indicated that, were accepting capable invertebrate errors % 71.25, % 26.75 undesirable errors, % 2 accepting capable(with change errors, % 0 accepting capable errors, and after correction action forecast Level risk to this arrangement, accepting capable invertebrate errors % 0, % 4.35 undesirable errors , % 58.55 accepting capable(with change errors, % 37.1 accepting capable errors .   ConclusionFinally this result is comprehension that this method in different industries especially in chemical industries is enforceable and useful for human errors identification that may lead to accident and adventures.

  2. Human error and the associated recovery probabilities for soft control being used in the advanced MCRs of NPPs

    International Nuclear Information System (INIS)

    Jang, Inseok; Jung, Wondea; Seong, Poong Hyun

    2016-01-01

    Highlights: • The operation environment of MCRs in NPPs has changed by adopting digital HSIs. • Most current HRA databases are not explicitly designed to deal with digital HSI. • Empirical analysis for new HRA DB under an advanced MCR mockup are carried. • It is expected that the results can be used for advanced MCR HRA. - Abstract: Since the Three Mile Island (TMI)-2 accident, human error has been recognized as one of the main causes of Nuclear Power Plant (NPP) accidents, and numerous studies related to Human Reliability Analysis (HRA) have been carried out. Most of these studies were focused on considering the conventional Main Control Room (MCR) environment. However, the operating environment of MCRs in NPPs has changed with the adoption of new human-system interfaces (HSI) largely based on up-to-date digital technologies. The MCRs that include these digital and computer technologies, such as large display panels, computerized procedures, and soft controls, are called advanced MCRs. Among the many features of advanced MCRs, soft controls are a particularly important because operating actions in advanced MCRs are performed by soft control. Due to the difference in interfaces between soft control and hardwired conventional controls, different HEP should be used in the HRA for advanced MCRs. Unfortunately, most current HRA databases deal with operations in conventional MCRs and are not explicitly designed to deal with digital Human System Interface (HSI). For this reason, empirical human error and the associated error recovery probabilities were collected from the mockup of an advanced MCR equipped with soft controls. To this end, small-scaled experiments are conducted with 48 graduated students in the department of nuclear engineering in Korea Advanced Institute of Science and Technology (KAIST) are participated, and accident scenarios are designed with respect to the typical Design Basis Accidents (DBAs) in NPPs, such as Steam Generator Tube Rupture

  3. Human Error and General Aviation Accidents: A Comprehensive, Fine-Grained Analysis Using HFACS

    National Research Council Canada - National Science Library

    Wiegmann, Douglas; Faaborg, Troy; Boquet, Albert; Detwiler, Cristy; Holcomb, Kali; Shappell, Scott

    2005-01-01

    ... of both commercial and general aviation (GA) accidents. These analyses have helped to identify general trends in the types of human factors issues and aircrew errors that have contributed to civil aviation accidents...

  4. Determining The Factors Causing Human Error Deficiencies At A Public Utility Company

    Directory of Open Access Journals (Sweden)

    F. W. Badenhorst

    2004-11-01

    Full Text Available According to Neff (1977, as cited by Bergh (1995, the westernised culture considers work important for industrial mental health. Most individuals experience work positively, which creates a positive attitude. Should this positive attitude be inhibited, workers could lose concentration and become bored, potentially resulting in some form of human error. The aim of this research was to determine the factors responsible for human error events, which lead to power supply failures at Eskom power stations. Proposals were made for the reduction of these contributing factors towards improving plant performance. The target population was 700 panel operators in Eskom’s Power Generation Group. The results showed that factors leading to human error can be reduced or even eliminated. Opsomming Neff (1977 soos aangehaal deur Bergh (1995, skryf dat in die westerse kultuur werk belangrik vir bedryfsgeestesgesondheid is. Die meeste persone ervaar werk as positief, wat ’n positiewe gesindheid kweek. Indien hierdie positiewe gesindheid geïnhibeer word, kan dit lei tot ’n gebrek aan konsentrasie by die werkers. Werkers kan verveeld raak en dit kan weer lei tot menslike foute. Die doel van hierdie navorsing is om die faktore vas te stel wat tot menslike foute lei, en wat bydra tot onderbrekings in kragvoorsiening by Eskom kragstasies. Voorstelle is gemaak vir die vermindering van hierdie bydraende faktore ten einde die kragaanleg se prestasie te verbeter. Die teiken-populasie was 700 paneel-operateurs in die Kragopwekkingsgroep by Eskom. Die resultate dui daarop dat die faktore wat aanleiding gee tot menslike foute wel verminder, of geëlimineer kan word.

  5. A Preliminary Study on the Measures to Assess the Organizational Safety: The Cultural Impact on Human Error Potential

    International Nuclear Information System (INIS)

    Lee, Yong Hee; Lee, Yong Hee

    2011-01-01

    The Fukushima I nuclear accident following the Tohoku earthquake and tsunami on 11 March 2011 occurred after twelve years had passed since the JCO accident which was caused as a result of an error made by JCO employees. These accidents, along with the Chernobyl accident, associated with characteristic problems of various organizations caused severe social and economic disruptions and have had significant environmental and health impact. The cultural problems with human errors occur for various reasons, and different actions are needed to prevent different errors. Unfortunately, much of the research on organization and human error has shown widely various or different results which call for different approaches. In other words, we have to find more practical solutions from various researches for nuclear safety and lead a systematic approach to organizational deficiency causing human error. This paper reviews Hofstede's criteria, IAEA safety culture, safety areas of periodic safety review (PSR), teamwork and performance, and an evaluation of HANARO safety culture to verify the measures used to assess the organizational safety

  6. A Preliminary Study on the Measures to Assess the Organizational Safety: The Cultural Impact on Human Error Potential

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Hee; Lee, Yong Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    The Fukushima I nuclear accident following the Tohoku earthquake and tsunami on 11 March 2011 occurred after twelve years had passed since the JCO accident which was caused as a result of an error made by JCO employees. These accidents, along with the Chernobyl accident, associated with characteristic problems of various organizations caused severe social and economic disruptions and have had significant environmental and health impact. The cultural problems with human errors occur for various reasons, and different actions are needed to prevent different errors. Unfortunately, much of the research on organization and human error has shown widely various or different results which call for different approaches. In other words, we have to find more practical solutions from various researches for nuclear safety and lead a systematic approach to organizational deficiency causing human error. This paper reviews Hofstede's criteria, IAEA safety culture, safety areas of periodic safety review (PSR), teamwork and performance, and an evaluation of HANARO safety culture to verify the measures used to assess the organizational safety

  7. Errors and violations

    International Nuclear Information System (INIS)

    Reason, J.

    1988-01-01

    This paper is in three parts. The first part summarizes the human failures responsible for the Chernobyl disaster and argues that, in considering the human contribution to power plant emergencies, it is necessary to distinguish between: errors and violations; and active and latent failures. The second part presents empirical evidence, drawn from driver behavior, which suggest that errors and violations have different psychological origins. The concluding part outlines a resident pathogen view of accident causation, and seeks to identify the various system pathways along which errors and violations may be propagated

  8. Highly accurate fluorogenic DNA sequencing with information theory-based error correction.

    Science.gov (United States)

    Chen, Zitian; Zhou, Wenxiong; Qiao, Shuo; Kang, Li; Duan, Haifeng; Xie, X Sunney; Huang, Yanyi

    2017-12-01

    Eliminating errors in next-generation DNA sequencing has proved challenging. Here we present error-correction code (ECC) sequencing, a method to greatly improve sequencing accuracy by combining fluorogenic sequencing-by-synthesis (SBS) with an information theory-based error-correction algorithm. ECC embeds redundancy in sequencing reads by creating three orthogonal degenerate sequences, generated by alternate dual-base reactions. This is similar to encoding and decoding strategies that have proved effective in detecting and correcting errors in information communication and storage. We show that, when combined with a fluorogenic SBS chemistry with raw accuracy of 98.1%, ECC sequencing provides single-end, error-free sequences up to 200 bp. ECC approaches should enable accurate identification of extremely rare genomic variations in various applications in biology and medicine.

  9. Team errors: definition and taxonomy

    International Nuclear Information System (INIS)

    Sasou, Kunihide; Reason, James

    1999-01-01

    In error analysis or error management, the focus is usually upon individuals who have made errors. In large complex systems, however, most people work in teams or groups. Considering this working environment, insufficient emphasis has been given to 'team errors'. This paper discusses the definition of team errors and its taxonomy. These notions are also applied to events that have occurred in the nuclear power industry, aviation industry and shipping industry. The paper also discusses the relations between team errors and Performance Shaping Factors (PSFs). As a result, the proposed definition and taxonomy are found to be useful in categorizing team errors. The analysis also reveals that deficiencies in communication, resource/task management, excessive authority gradient, excessive professional courtesy will cause team errors. Handling human errors as team errors provides an opportunity to reduce human errors

  10. Multiple sequential failure model: A probabilistic approach to quantifying human error dependency

    International Nuclear Information System (INIS)

    Samanta

    1985-01-01

    This paper rpesents a probabilistic approach to quantifying human error dependency when multiple tasks are performed. Dependent human failures are dominant contributors to risks from nuclear power plants. An overview of the Multiple Sequential Failure (MSF) model developed and its use in probabilistic risk assessments (PRAs) depending on the available data are discussed. A small-scale psychological experiment was conducted on the nature of human dependency and the interpretation of the experimental data by the MSF model show remarkable accommodation of the dependent failure data. The model, which provides an unique method for quantification of dependent failures in human reliability analysis, can be used in conjunction with any of the general methods currently used for performing the human reliability aspect in PRAs

  11. Systematic analysis of video data from different human-robot interaction studies: a categorization of social signals during error situations.

    Science.gov (United States)

    Giuliani, Manuel; Mirnig, Nicole; Stollnberger, Gerald; Stadler, Susanne; Buchner, Roland; Tscheligi, Manfred

    2015-01-01

    Human-robot interactions are often affected by error situations that are caused by either the robot or the human. Therefore, robots would profit from the ability to recognize when error situations occur. We investigated the verbal and non-verbal social signals that humans show when error situations occur in human-robot interaction experiments. For that, we analyzed 201 videos of five human-robot interaction user studies with varying tasks from four independent projects. The analysis shows that there are two types of error situations: social norm violations and technical failures. Social norm violations are situations in which the robot does not adhere to the underlying social script of the interaction. Technical failures are caused by technical shortcomings of the robot. The results of the video analysis show that the study participants use many head movements and very few gestures, but they often smile, when in an error situation with the robot. Another result is that the participants sometimes stop moving at the beginning of error situations. We also found that the participants talked more in the case of social norm violations and less during technical failures. Finally, the participants use fewer non-verbal social signals (for example smiling, nodding, and head shaking), when they are interacting with the robot alone and no experimenter or other human is present. The results suggest that participants do not see the robot as a social interaction partner with comparable communication skills. Our findings have implications for builders and evaluators of human-robot interaction systems. The builders need to consider including modules for recognition and classification of head movements to the robot input channels. The evaluators need to make sure that the presence of an experimenter does not skew the results of their user studies.

  12. Estimation of genetic connectedness diagnostics based on prediction errors without the prediction error variance-covariance matrix.

    Science.gov (United States)

    Holmes, John B; Dodds, Ken G; Lee, Michael A

    2017-03-02

    An important issue in genetic evaluation is the comparability of random effects (breeding values), particularly between pairs of animals in different contemporary groups. This is usually referred to as genetic connectedness. While various measures of connectedness have been proposed in the literature, there is general agreement that the most appropriate measure is some function of the prediction error variance-covariance matrix. However, obtaining the prediction error variance-covariance matrix is computationally demanding for large-scale genetic evaluations. Many alternative statistics have been proposed that avoid the computational cost of obtaining the prediction error variance-covariance matrix, such as counts of genetic links between contemporary groups, gene flow matrices, and functions of the variance-covariance matrix of estimated contemporary group fixed effects. In this paper, we show that a correction to the variance-covariance matrix of estimated contemporary group fixed effects will produce the exact prediction error variance-covariance matrix averaged by contemporary group for univariate models in the presence of single or multiple fixed effects and one random effect. We demonstrate the correction for a series of models and show that approximations to the prediction error matrix based solely on the variance-covariance matrix of estimated contemporary group fixed effects are inappropriate in certain circumstances. Our method allows for the calculation of a connectedness measure based on the prediction error variance-covariance matrix by calculating only the variance-covariance matrix of estimated fixed effects. Since the number of fixed effects in genetic evaluation is usually orders of magnitudes smaller than the number of random effect levels, the computational requirements for our method should be reduced.

  13. Integration of error tolerance into the design of control rooms of nuclear power plants

    International Nuclear Information System (INIS)

    Sepanloo, Kamran

    1998-08-01

    Many complex technological systems' failures have been attributed to human errors. Today, based on extensive research on the role of human element in technological systems it is known that human error can not totally be eliminated in modern, flexible, or changing work environments by conventional style design strategies(e.g. defence in depth), or better instructions nor should they be. Instead, the operators' ability to explore degrees of freedom should be supported and means for recovering from the effects of errors should be included. This calls for innovative error tolerant design of technological systems. Integration of error tolerant concept into the design, construction, startup, and operation of nuclear power plants provides an effective means of reducing human error occurrence during all stages of life of it and therefore leads to considerable enhancement of plant's safety

  14. Error identification and recovery by student nurses using human patient simulation: opportunity to improve patient safety.

    Science.gov (United States)

    Henneman, Elizabeth A; Roche, Joan P; Fisher, Donald L; Cunningham, Helene; Reilly, Cheryl A; Nathanson, Brian H; Henneman, Philip L

    2010-02-01

    This study examined types of errors that occurred or were recovered in a simulated environment by student nurses. Errors occurred in all four rule-based error categories, and all students committed at least one error. The most frequent errors occurred in the verification category. Another common error was related to physician interactions. The least common errors were related to coordinating information with the patient and family. Our finding that 100% of student subjects committed rule-based errors is cause for concern. To decrease errors and improve safe clinical practice, nurse educators must identify effective strategies that students can use to improve patient surveillance. Copyright 2010 Elsevier Inc. All rights reserved.

  15. A Sensitivity Study of Human Errors in Optimizing Surveillance Test Interval (STI) and Allowed Outage Time (AOT) of Standby Safety System

    International Nuclear Information System (INIS)

    Chung, Dae Wook; Shin, Won Ky; You, Young Woo; Yang, Hui Chang

    1998-01-01

    In most cases, the surveillance test intervals (STIs), allowed outage times (AOTS) and testing strategies of safety components in nuclear power plant are prescribed in plant technical specifications. And, in general, it is required that standby safety system shall be redundant (i.e., composed of multiple components) and these components are tested by either staggered test strategy or sequential test strategy. In this study, a linear model is presented to incorporate the effects of human errors associated with test into the evaluation of unavailability. The average unavailabilities of 1/4, 2/4 redundant systems are computed considering human error and testing strategy. The adverse effects of test on system unavailability, such as component wear and test-induced transient have been modelled. The final outcome of this study would be the optimized human error domain from 3-D human error sensitivity analysis by selecting finely classified segment. The results of sensitivity analysis show that the STI and AOT can be optimized provided human error probability is maintained within allowable range. (authors)

  16. Quality of IT service delivery — Analysis and framework for human error prevention

    KAUST Repository

    Shwartz, L.; Rosu, D.; Loewenstern, D.; Buco, M. J.; Guo, S.; Lavrado, Rafael Coelho; Gupta, M.; De, P.; Madduri, V.; Singh, J. K.

    2010-01-01

    In this paper, we address the problem of reducing the occurrence of Human Errors that cause service interruptions in IT Service Support and Delivery operations. Analysis of a large volume of service interruption records revealed that more than 21

  17. Evaluating a medical error taxonomy.

    OpenAIRE

    Brixey, Juliana; Johnson, Todd R.; Zhang, Jiajie

    2002-01-01

    Healthcare has been slow in using human factors principles to reduce medical errors. The Center for Devices and Radiological Health (CDRH) recognizes that a lack of attention to human factors during product development may lead to errors that have the potential for patient injury, or even death. In response to the need for reducing medication errors, the National Coordinating Council for Medication Errors Reporting and Prevention (NCC MERP) released the NCC MERP taxonomy that provides a stand...

  18. FPGA Based Test Module for Error Bit Evaluation in Serial Links

    Directory of Open Access Journals (Sweden)

    J. Kolouch

    2006-04-01

    Full Text Available A test module for serial links is described. In the link transmitter, one module generates pseudorandom pulse signal that is transmitted by the link. Second module located in the link receiver generates the same signal and compares it to the received signal. Errors caused by the signal transmission can be then detected and results sent to a master computer for further processing like statistical evaluation. The module can be used for long-term error monitoring without need for human operator presence.

  19. Benchmark test cases for evaluation of computer-based methods for detection of setup errors: realistic digitally reconstructed electronic portal images with known setup errors

    International Nuclear Information System (INIS)

    Fritsch, Daniel S.; Raghavan, Suraj; Boxwala, Aziz; Earnhart, Jon; Tracton, Gregg; Cullip, Timothy; Chaney, Edward L.

    1997-01-01

    Purpose: The purpose of this investigation was to develop methods and software for computing realistic digitally reconstructed electronic portal images with known setup errors for use as benchmark test cases for evaluation and intercomparison of computer-based methods for image matching and detecting setup errors in electronic portal images. Methods and Materials: An existing software tool for computing digitally reconstructed radiographs was modified to compute simulated megavoltage images. An interface was added to allow the user to specify which setup parameter(s) will contain computer-induced random and systematic errors in a reference beam created during virtual simulation. Other software features include options for adding random and structured noise, Gaussian blurring to simulate geometric unsharpness, histogram matching with a 'typical' electronic portal image, specifying individual preferences for the appearance of the 'gold standard' image, and specifying the number of images generated. The visible male computed tomography data set from the National Library of Medicine was used as the planning image. Results: Digitally reconstructed electronic portal images with known setup errors have been generated and used to evaluate our methods for automatic image matching and error detection. Any number of different sets of test cases can be generated to investigate setup errors involving selected setup parameters and anatomic volumes. This approach has proved to be invaluable for determination of error detection sensitivity under ideal (rigid body) conditions and for guiding further development of image matching and error detection methods. Example images have been successfully exported for similar use at other sites. Conclusions: Because absolute truth is known, digitally reconstructed electronic portal images with known setup errors are well suited for evaluation of computer-aided image matching and error detection methods. High-quality planning images, such as

  20. A study on the critical factors of human error in civil aviation: An early warning management perspective in Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Salah Uddin Rajib

    2015-01-01

    Full Text Available The safety of civil aviation will be more secured if the errors in all the facets can be reduced. Like the other industrial sectors, human resource is one of the most complex and sensitive resources for the civil aviation. The error of human resources can cause fatal disasters. In these days, a good volume of researches have been conducted on the disaster of civil aviation. The researchers have identified the causes of the civil aviation disasters from various perspectives. They identified the areas where more concern is needed to reduce the disastrous impacts. This paper aims to find out the critical factors of human error in civil aviation in a developing country (Bangladesh as it is accepted that human error is one of main causes of civil aviation disasters. The paper reviews the previous research to find out the critical factors conceptually. Fuzzy analytical hierarchy process (FAHP has been used to find out the critical factors systematically. Analyses indicate that the concentration on precondition for unsafe acts (including sub-factors is required to ensure the aviation safety.

  1. Modeling and Experimental Study of Soft Error Propagation Based on Cellular Automaton

    Directory of Open Access Journals (Sweden)

    Wei He

    2016-01-01

    Full Text Available Aiming to estimate SEE soft error performance of complex electronic systems, a soft error propagation model based on cellular automaton is proposed and an estimation methodology based on circuit partitioning and error propagation is presented. Simulations indicate that different fault grade jamming and different coupling factors between cells are the main parameters influencing the vulnerability of the system. Accelerated radiation experiments have been developed to determine the main parameters for raw soft error vulnerability of the module and coupling factors. Results indicate that the proposed method is feasible.

  2. Comparison of subset-based local and FE-based global digital image correlation: Theoretical error analysis and validation

    KAUST Repository

    Pan, B.

    2016-03-22

    Subset-based local and finite-element-based (FE-based) global digital image correlation (DIC) approaches are the two primary image matching algorithms widely used for full-field displacement mapping. Very recently, the performances of these different DIC approaches have been experimentally investigated using numerical and real-world experimental tests. The results have shown that in typical cases, where the subset (element) size is no less than a few pixels and the local deformation within a subset (element) can be well approximated by the adopted shape functions, the subset-based local DIC outperforms FE-based global DIC approaches because the former provides slightly smaller root-mean-square errors and offers much higher computation efficiency. Here we investigate the theoretical origin and lay a solid theoretical basis for the previous comparison. We assume that systematic errors due to imperfect intensity interpolation and undermatched shape functions are negligibly small, and perform a theoretical analysis of the random errors or standard deviation (SD) errors in the displacements measured by two local DIC approaches (i.e., a subset-based local DIC and an element-based local DIC) and two FE-based global DIC approaches (i.e., Q4-DIC and Q8-DIC). The equations that govern the random errors in the displacements measured by these local and global DIC approaches are theoretically derived. The correctness of the theoretically predicted SD errors is validated through numerical translation tests under various noise levels. We demonstrate that the SD errors induced by the Q4-element-based local DIC, the global Q4-DIC and the global Q8-DIC are 4, 1.8-2.2 and 1.2-1.6 times greater, respectively, than that associated with the subset-based local DIC, which is consistent with our conclusions from previous work. © 2016 Elsevier Ltd. All rights reserved.

  3. Review of advances in human reliability analysis of errors of commission-Part 2: EOC quantification

    International Nuclear Information System (INIS)

    Reer, Bernhard

    2008-01-01

    In close connection with examples relevant to contemporary probabilistic safety assessment (PSA), a review of advances in human reliability analysis (HRA) of post-initiator errors of commission (EOCs), i.e. inappropriate actions under abnormal operating conditions, has been carried out. The review comprises both EOC identification (part 1) and quantification (part 2); part 2 is presented in this article. Emerging HRA methods in this field are: ATHEANA, MERMOS, the EOC HRA method developed by Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS), the MDTA method and CREAM. The essential advanced features are on the conceptual side, especially to envisage the modeling of multiple contexts for an EOC to be quantified (ATHEANA, MERMOS and MDTA), in order to explicitly address adverse conditions. There is promising progress in providing systematic guidance to better account for cognitive demands and tendencies (GRS, CREAM), and EOC recovery (MDTA). Problematic issues are associated with the implementation of multiple context modeling and the assessment of context-specific error probabilities. Approaches for task or error opportunity scaling (CREAM, GRS) and the concept of reference cases (ATHEANA outlook) provide promising orientations for achieving progress towards data-based quantification. Further development work is needed and should be carried out in close connection with large-scale applications of existing approaches

  4. A nucleotide-analogue-induced gain of function corrects the error-prone nature of human DNA polymerase iota.

    Science.gov (United States)

    Ketkar, Amit; Zafar, Maroof K; Banerjee, Surajit; Marquez, Victor E; Egli, Martin; Eoff, Robert L

    2012-06-27

    Y-family DNA polymerases participate in replication stress and DNA damage tolerance mechanisms. The properties that allow these enzymes to copy past bulky adducts or distorted template DNA can result in a greater propensity for them to make mistakes. Of the four human Y-family members, human DNA polymerase iota (hpol ι) is the most error-prone. In the current study, we elucidate the molecular basis for improving the fidelity of hpol ι through use of the fixed-conformation nucleotide North-methanocarba-2'-deoxyadenosine triphosphate (N-MC-dATP). Three crystal structures were solved of hpol ι in complex with DNA containing a template 2'-deoxythymidine (dT) paired with an incoming dNTP or modified nucleotide triphosphate. The ternary complex of hpol ι inserting N-MC-dATP opposite dT reveals that the adenine ring is stabilized in the anti orientation about the pseudo-glycosyl torsion angle, which mimics precisely the mutagenic arrangement of dGTP:dT normally preferred by hpol ι. The stabilized anti conformation occurs without notable contacts from the protein but likely results from constraints imposed by the bicyclo[3.1.0]hexane scaffold of the modified nucleotide. Unmodified dATP and South-MC-dATP each adopt syn glycosyl orientations to form Hoogsteen base pairs with dT. The Hoogsteen orientation exhibits weaker base-stacking interactions and is less catalytically favorable than anti N-MC-dATP. Thus, N-MC-dATP corrects the error-prone nature of hpol ι by preventing the Hoogsteen base-pairing mode normally observed for hpol ι-catalyzed insertion of dATP opposite dT. These results provide a previously unrecognized means of altering the efficiency and the fidelity of a human translesion DNA polymerase.

  5. A nucleotide analogue induced gain of function corrects the error-prone nature of human DNA polymerase iota

    Science.gov (United States)

    Ketkar, Amit; Zafar, Maroof K.; Banerjee, Surajit; Marquez, Victor E.; Egli, Martin; Eoff, Robert L

    2012-01-01

    Y-family DNA polymerases participate in replication stress and DNA damage tolerance mechanisms. The properties that allow these enzymes to copy past bulky adducts or distorted template DNA can result in a greater propensity for them to make mistakes. Of the four human Y-family members, human DNA polymerase iota (hpol ι) is the most error-prone. In the current study, we elucidate the molecular basis for improving the fidelity of hpol ι through use of the fixed-conformation nucleotide North-methanocarba-2′-deoxyadenosine triphosphate (N-MC-dATP). Three crystal structures were solved of hpol ι in complex with DNA containing a template 2′-deoxythymidine (dT) paired with an incoming dNTP or modified nucleotide triphosphate. The ternary complex of hpol ι inserting N-MC-dATP opposite dT reveals that the adenine ring is stabilized in the anti orientation about the pseudo-glycosyl torsion angle (χ), which mimics precisely the mutagenic arrangement of dGTP:dT normally preferred by hpol ι. The stabilized anti conformation occurs without notable contacts from the protein but likely results from constraints imposed by the bicyclo[3.1.0]hexane scaffold of the modified nucleotide. Unmodified dATP and South-MC-dATP each adopt syn glycosyl orientations to form Hoogsteen base pairs with dT. The Hoogsteen orientation exhibits weaker base stacking interactions and is less catalytically favorable than anti N-MC-dATP. Thus, N-MC-dATP corrects the error-prone nature of hpol ι by preventing the Hoogsteen base-pairing mode normally observed for hpol ι-catalyzed insertion of dATP opposite dT. These results provide a previously unrecognized means of altering the efficiency and the fidelity of a human translesion DNA polymerase. PMID:22632140

  6. The human error rate assessment and optimizing system HEROS - a new procedure for evaluating and optimizing the man-machine interface in PSA

    International Nuclear Information System (INIS)

    Richei, A.; Hauptmanns, U.; Unger, H.

    2001-01-01

    A new procedure allowing the probabilistic evaluation and optimization of the man-machine system is presented. This procedure and the resulting expert system HEROS, which is an acronym for Human Error Rate Assessment and Optimizing System, is based on the fuzzy set theory. Most of the well-known procedures employed for the probabilistic evaluation of human factors involve the use of vague linguistic statements on performance shaping factors to select and to modify basic human error probabilities from the associated databases. This implies a large portion of subjectivity. Vague statements are expressed here in terms of fuzzy numbers or intervals which allow mathematical operations to be performed on them. A model of the man-machine system is the basis of the procedure. A fuzzy rule-based expert system was derived from ergonomic and psychological studies. Hence, it does not rely on a database, whose transferability to situations different from its origin is questionable. In this way, subjective elements are eliminated to a large extent. HEROS facilitates the importance analysis for the evaluation of human factors, which is necessary for optimizing the man-machine system. HEROS is applied to the analysis of a simple diagnosis of task of the operating personnel in a nuclear power plant

  7. Modeling and Experimental Study of Soft Error Propagation Based on Cellular Automaton

    OpenAIRE

    He, Wei; Wang, Yueke; Xing, Kefei; Yang, Jianwei

    2016-01-01

    Aiming to estimate SEE soft error performance of complex electronic systems, a soft error propagation model based on cellular automaton is proposed and an estimation methodology based on circuit partitioning and error propagation is presented. Simulations indicate that different fault grade jamming and different coupling factors between cells are the main parameters influencing the vulnerability of the system. Accelerated radiation experiments have been developed to determine the main paramet...

  8. The development of human behaviour analysis techniques -The development of human factors technologies-

    International Nuclear Information System (INIS)

    Lee, Jung Woon; Cheon, Se Woo; Shu, Sang Moon; Park, Geun Ok; Lee, Yong Hee; Lee, Han Yeong; Park, Jae Chang; Lee, Eu Jin; Lee, Seung Hee

    1994-04-01

    This project has two major areas ; one is the development of an operator task simulation software and another is the development of human error analysis and application technologies. In this year project, the second year, for the development of an operator task simulation software, we studied the followings: - analysis of the characteristics of operator tasks, - development of operator task structures : Macro Structures, - development of an operator task simulation analyzes, - analysis of performance measures. And the followings for the development of human error analysis and application technologies : - analysis of human error mechanisms, - analysis of human error characteristics in tasks, - analysis of human error occurrence in Korean Nuclear Power Plants, - establishment of an experimental environment for human error data collection with Compact Nuclear Simulator, - basic design of a Multimedia-based Human Error Representing System. (Author)

  9. FRamework Assessing Notorious Contributing Influences for Error (FRANCIE): Perspective on Taxonomy Development to Support Error Reporting and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lon N. Haney; David I. Gertman

    2003-04-01

    Beginning in the 1980s a primary focus of human reliability analysis was estimation of human error probabilities. However, detailed qualitative modeling with comprehensive representation of contextual variables often was lacking. This was likely due to the lack of comprehensive error and performance shaping factor taxonomies, and the limited data available on observed error rates and their relationship to specific contextual variables. In the mid 90s Boeing, America West Airlines, NASA Ames Research Center and INEEL partnered in a NASA sponsored Advanced Concepts grant to: assess the state of the art in human error analysis, identify future needs for human error analysis, and develop an approach addressing these needs. Identified needs included the need for a method to identify and prioritize task and contextual characteristics affecting human reliability. Other needs identified included developing comprehensive taxonomies to support detailed qualitative modeling and to structure meaningful data collection efforts across domains. A result was the development of the FRamework Assessing Notorious Contributing Influences for Error (FRANCIE) with a taxonomy for airline maintenance tasks. The assignment of performance shaping factors to generic errors by experts proved to be valuable to qualitative modeling. Performance shaping factors and error types from such detailed approaches can be used to structure error reporting schemes. In a recent NASA Advanced Human Support Technology grant FRANCIE was refined, and two new taxonomies for use on space missions were developed. The development, sharing, and use of error taxonomies, and the refinement of approaches for increased fidelity of qualitative modeling is offered as a means to help direct useful data collection strategies.

  10. The human fallibility of scientists : Dealing with error and bias in academic research

    NARCIS (Netherlands)

    Veldkamp, Coosje

    2017-01-01

    THE HUMAN FALLIBILITY OF SCIENTISTS Dealing with error and bias in academic research Recent studies have highlighted that not all published findings in the scientific lit¬erature are trustworthy, suggesting that currently implemented control mechanisms such as high standards for the reporting of

  11. Accuracy Improvement of Multi-Axis Systems Based on Laser Correction of Volumetric Geometric Errors

    Science.gov (United States)

    Teleshevsky, V. I.; Sokolov, V. A.; Pimushkin, Ya I.

    2018-04-01

    The article describes a volumetric geometric errors correction method for CNC- controlled multi-axis systems (machine-tools, CMMs etc.). The Kalman’s concept of “Control and Observation” is used. A versatile multi-function laser interferometer is used as Observer in order to measure machine’s error functions. A systematic error map of machine’s workspace is produced based on error functions measurements. The error map results into error correction strategy. The article proposes a new method of error correction strategy forming. The method is based on error distribution within machine’s workspace and a CNC-program postprocessor. The postprocessor provides minimal error values within maximal workspace zone. The results are confirmed by error correction of precision CNC machine-tools.

  12. The spontaneous replication error and the mismatch discrimination mechanisms of human DNA polymerase β

    Science.gov (United States)

    Koag, Myong-Chul; Nam, Kwangho; Lee, Seongmin

    2014-01-01

    To provide molecular-level insights into the spontaneous replication error and the mismatch discrimination mechanisms of human DNA polymerase β (polβ), we report four crystal structures of polβ complexed with dG•dTTP and dA•dCTP mismatches in the presence of Mg2+ or Mn2+. The Mg2+-bound ground-state structures show that the dA•dCTP-Mg2+ complex adopts an ‘intermediate’ protein conformation while the dG•dTTP-Mg2+ complex adopts an open protein conformation. The Mn2+-bound ‘pre-chemistry-state’ structures show that the dA•dCTP-Mn2+ complex is structurally very similar to the dA•dCTP-Mg2+ complex, whereas the dG•dTTP-Mn2+ complex undergoes a large-scale conformational change to adopt a Watson–Crick-like dG•dTTP base pair and a closed protein conformation. These structural differences, together with our molecular dynamics simulation studies, suggest that polβ increases replication fidelity via a two-stage mismatch discrimination mechanism, where one is in the ground state and the other in the closed conformation state. In the closed conformation state, polβ appears to allow only a Watson–Crick-like conformation for purine•pyrimidine base pairs, thereby discriminating the mismatched base pairs based on their ability to form the Watson–Crick-like conformation. Overall, the present studies provide new insights into the spontaneous replication error and the replication fidelity mechanisms of polβ. PMID:25200079

  13. Uncorrected refractive errors.

    Science.gov (United States)

    Naidoo, Kovin S; Jaggernath, Jyoti

    2012-01-01

    Global estimates indicate that more than 2.3 billion people in the world suffer from poor vision due to refractive error; of which 670 million people are considered visually impaired because they do not have access to corrective treatment. Refractive errors, if uncorrected, results in an impaired quality of life for millions of people worldwide, irrespective of their age, sex and ethnicity. Over the past decade, a series of studies using a survey methodology, referred to as Refractive Error Study in Children (RESC), were performed in populations with different ethnic origins and cultural settings. These studies confirmed that the prevalence of uncorrected refractive errors is considerably high for children in low-and-middle-income countries. Furthermore, uncorrected refractive error has been noted to have extensive social and economic impacts, such as limiting educational and employment opportunities of economically active persons, healthy individuals and communities. The key public health challenges presented by uncorrected refractive errors, the leading cause of vision impairment across the world, require urgent attention. To address these issues, it is critical to focus on the development of human resources and sustainable methods of service delivery. This paper discusses three core pillars to addressing the challenges posed by uncorrected refractive errors: Human Resource (HR) Development, Service Development and Social Entrepreneurship.

  14. Uncorrected refractive errors

    Directory of Open Access Journals (Sweden)

    Kovin S Naidoo

    2012-01-01

    Full Text Available Global estimates indicate that more than 2.3 billion people in the world suffer from poor vision due to refractive error; of which 670 million people are considered visually impaired because they do not have access to corrective treatment. Refractive errors, if uncorrected, results in an impaired quality of life for millions of people worldwide, irrespective of their age, sex and ethnicity. Over the past decade, a series of studies using a survey methodology, referred to as Refractive Error Study in Children (RESC, were performed in populations with different ethnic origins and cultural settings. These studies confirmed that the prevalence of uncorrected refractive errors is considerably high for children in low-and-middle-income countries. Furthermore, uncorrected refractive error has been noted to have extensive social and economic impacts, such as limiting educational and employment opportunities of economically active persons, healthy individuals and communities. The key public health challenges presented by uncorrected refractive errors, the leading cause of vision impairment across the world, require urgent attention. To address these issues, it is critical to focus on the development of human resources and sustainable methods of service delivery. This paper discusses three core pillars to addressing the challenges posed by uncorrected refractive errors: Human Resource (HR Development, Service Development and Social Entrepreneurship.

  15. Dependence assessment in human reliability analysis based on D numbers and AHP

    International Nuclear Information System (INIS)

    Zhou, Xinyi; Deng, Xinyang; Deng, Yong; Mahadevan, Sankaran

    2017-01-01

    Highlights: • D numbers and AHP are combined to implement dependence assessment in HRA. • A new tool, called D numbers, is used to deal with the uncertainty in HRA. • The proposed method can well address the fuzziness and subjectivity in linguistic assessment. • The proposed method is well applicable in dependence assessment which inherently has a linguistic assessment process. - Abstract: Since human errors always cause heavy loss especially in nuclear engineering, human reliability analysis (HRA) has attracted more and more attention. Dependence assessment plays a vital role in HRA, measuring the dependence degree of human errors. Many researches have been done while still have improvement space. In this paper, a dependence assessment model based on D numbers and analytic hierarchy process (AHP) is proposed. Firstly, identify the factors used to measure the dependence level of two human operations. Besides, in terms of the suggested dependence level, determine and quantify the anchor points for each factor. Secondly, D numbers and AHP are adopted in model. Experts evaluate the dependence level of human operations for each factor. Then, the evaluation results are presented as D numbers and fused by D number’s combination rule that can obtain the dependence probability of human operations for each factor. The weights of factors can be determined by AHP. Thirdly, based on the dependence probability for each factor and its corresponding weight, the dependence probability of two human operations and its confidence can be obtained. The proposed method can well address the fuzziness and subjectivity in linguistic assessment. The proposed method is well applicable to assess the dependence degree of human errors in HRA which inherently has a linguistic assessment process.

  16. Dependence assessment in human reliability analysis based on D numbers and AHP

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xinyi; Deng, Xinyang [School of Computer and Information Science, Southwest University, Chongqing 400715 (China); Deng, Yong, E-mail: ydeng@swu.edu.cn [School of Computer and Information Science, Southwest University, Chongqing 400715 (China); Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China); Mahadevan, Sankaran [School of Engineering, Vanderbilt University, Nashville, TN 37235 (United States)

    2017-03-15

    Highlights: • D numbers and AHP are combined to implement dependence assessment in HRA. • A new tool, called D numbers, is used to deal with the uncertainty in HRA. • The proposed method can well address the fuzziness and subjectivity in linguistic assessment. • The proposed method is well applicable in dependence assessment which inherently has a linguistic assessment process. - Abstract: Since human errors always cause heavy loss especially in nuclear engineering, human reliability analysis (HRA) has attracted more and more attention. Dependence assessment plays a vital role in HRA, measuring the dependence degree of human errors. Many researches have been done while still have improvement space. In this paper, a dependence assessment model based on D numbers and analytic hierarchy process (AHP) is proposed. Firstly, identify the factors used to measure the dependence level of two human operations. Besides, in terms of the suggested dependence level, determine and quantify the anchor points for each factor. Secondly, D numbers and AHP are adopted in model. Experts evaluate the dependence level of human operations for each factor. Then, the evaluation results are presented as D numbers and fused by D number’s combination rule that can obtain the dependence probability of human operations for each factor. The weights of factors can be determined by AHP. Thirdly, based on the dependence probability for each factor and its corresponding weight, the dependence probability of two human operations and its confidence can be obtained. The proposed method can well address the fuzziness and subjectivity in linguistic assessment. The proposed method is well applicable to assess the dependence degree of human errors in HRA which inherently has a linguistic assessment process.

  17. A method to deal with installation errors of wearable accelerometers for human activity recognition

    International Nuclear Information System (INIS)

    Jiang, Ming; Wang, Zhelong; Shang, Hong; Li, Hongyi; Wang, Yuechao

    2011-01-01

    Human activity recognition (HAR) by using wearable accelerometers has gained significant interest in recent years in a range of healthcare areas, including inferring metabolic energy expenditure, predicting falls, measuring gait parameters and monitoring daily activities. The implementation of HAR relies heavily on the correctness of sensor fixation. The installation errors of wearable accelerometers may dramatically decrease the accuracy of HAR. In this paper, a method is proposed to improve the robustness of HAR to the installation errors of accelerometers. The method first calculates a transformation matrix by using Gram–Schmidt orthonormalization in order to eliminate the sensor's orientation error and then employs a low-pass filter with a cut-off frequency of 10 Hz to eliminate the main effect of the sensor's misplacement. The experimental results showed that the proposed method obtained a satisfactory performance for HAR. The average accuracy rate from ten subjects was 95.1% when there were no installation errors, and was 91.9% when installation errors were involved in wearable accelerometers

  18. Does the A-not-B error in adult pet dogs indicate sensitivity to human communication?

    Science.gov (United States)

    Kis, Anna; Topál, József; Gácsi, Márta; Range, Friederike; Huber, Ludwig; Miklósi, Adám; Virányi, Zsófia

    2012-07-01

    Recent dog-infant comparisons have indicated that the experimenter's communicative signals in object hide-and-search tasks increase the probability of perseverative (A-not-B) errors in both species (Topál et al. 2009). These behaviourally similar results, however, might reflect different mechanisms in dogs and in children. Similar errors may occur if the motor response of retrieving the object during the A trials cannot be inhibited in the B trials or if the experimenter's movements and signals toward the A hiding place in the B trials ('sham-baiting') distract the dogs' attention. In order to test these hypotheses, we tested dogs similarly to Topál et al. (2009) but eliminated the motor search in the A trials and 'sham-baiting' in the B trials. We found that neither an inability to inhibit previously rewarded motor response nor insufficiencies in their working memory and/or attention skills can explain dogs' erroneous choices. Further, we replicated the finding that dogs have a strong tendency to commit the A-not-B error after ostensive-communicative hiding and demonstrated the crucial effect of socio-communicative cues as the A-not-B error diminishes when location B is ostensively enhanced. These findings further support the hypothesis that the dogs' A-not-B error may reflect a special sensitivity to human communicative cues. Such object-hiding and search tasks provide a typical case for how susceptibility to human social signals could (mis)lead domestic dogs.

  19. An Evidential Reasoning-Based CREAM to Human Reliability Analysis in Maritime Accident Process.

    Science.gov (United States)

    Wu, Bing; Yan, Xinping; Wang, Yang; Soares, C Guedes

    2017-10-01

    This article proposes a modified cognitive reliability and error analysis method (CREAM) for estimating the human error probability in the maritime accident process on the basis of an evidential reasoning approach. This modified CREAM is developed to precisely quantify the linguistic variables of the common performance conditions and to overcome the problem of ignoring the uncertainty caused by incomplete information in the existing CREAM models. Moreover, this article views maritime accident development from the sequential perspective, where a scenario- and barrier-based framework is proposed to describe the maritime accident process. This evidential reasoning-based CREAM approach together with the proposed accident development framework are applied to human reliability analysis of a ship capsizing accident. It will facilitate subjective human reliability analysis in different engineering systems where uncertainty exists in practice. © 2017 Society for Risk Analysis.

  20. Evaluation of a Web-based Error Reporting Surveillance System in a Large Iranian Hospital.

    Science.gov (United States)

    Askarian, Mehrdad; Ghoreishi, Mahboobeh; Akbari Haghighinejad, Hourvash; Palenik, Charles John; Ghodsi, Maryam

    2017-08-01

    Proper reporting of medical errors helps healthcare providers learn from adverse incidents and improve patient safety. A well-designed and functioning confidential reporting system is an essential component to this process. There are many error reporting methods; however, web-based systems are often preferred because they can provide; comprehensive and more easily analyzed information. This study addresses the use of a web-based error reporting system. This interventional study involved the application of an in-house designed "voluntary web-based medical error reporting system." The system has been used since July 2014 in Nemazee Hospital, Shiraz University of Medical Sciences. The rate and severity of errors reported during the year prior and a year after system launch were compared. The slope of the error report trend line was steep during the first 12 months (B = 105.727, P = 0.00). However, it slowed following launch of the web-based reporting system and was no longer statistically significant (B = 15.27, P = 0.81) by the end of the second year. Most recorded errors were no-harm laboratory types and were due to inattention. Usually, they were reported by nurses and other permanent employees. Most reported errors occurred during morning shifts. Using a standardized web-based error reporting system can be beneficial. This study reports on the performance of an in-house designed reporting system, which appeared to properly detect and analyze medical errors. The system also generated follow-up reports in a timely and accurate manner. Detection of near-miss errors could play a significant role in identifying areas of system defects.

  1. A human error taxonomy for analysing healthcare incident reports: assessing reporting culture and its effects on safety perfomance

    DEFF Research Database (Denmark)

    Itoh, Kenji; Omata, N.; Andersen, Henning Boje

    2009-01-01

    The present paper reports on a human error taxonomy system developed for healthcare risk management and on its application to evaluating safety performance and reporting culture. The taxonomy comprises dimensions for classifying errors, for performance-shaping factors, and for the maturity...

  2. Dependent Human Error Probability Assessment

    International Nuclear Information System (INIS)

    Simic, Z.; Mikulicic, V.; Vukovic, I.

    2006-01-01

    This paper presents an assessment of the dependence between dynamic operator actions modeled in a Nuclear Power Plant (NPP) PRA and estimate the associated impact on Core damage frequency (CDF). This assessment was done improve HEP dependencies implementation inside existing PRA. All of the dynamic operator actions modeled in the NPP PRA are included in this assessment. Determining the level of HEP dependence and the associated influence on CDF are the major steps of this assessment. A decision on how to apply the results, i.e., should permanent HEP model changes be made, is based on the resulting relative CDF increase. Some CDF increase was selected as a threshold based on the NPP base CDF value and acceptance guidelines from the Regulatory Guide 1.174. HEP dependence resulting in a CDF increase of > 5E-07 would be considered potential candidates for specific incorporation into the baseline model. The approach used to judge the level of dependence between operator actions is based on dependency level categories and conditional probabilities developed in the Handbook of Human Reliability Analysis with Emphasis on Nuclear Power Plant Applications NUREG/CR-1278. To simplify the process, NUREG/CR-1278 identifies five levels of dependence: ZD (zero dependence), LD (low dependence), MD (moderate dependence), HD (high dependence), and CD (complete dependence). NUREG/CR-1278 also identifies several qualitative factors that could be involved in determining the level of dependence. Based on the NUREG/CR-1278 information, Time, Function, and Spatial attributes were judged to be the most important considerations when determining the level of dependence between operator actions within an accident sequence. These attributes were used to develop qualitative criteria (rules) that were used to judge the level of dependence (CD, HD, MD, LD, ZD) between the operator actions. After the level of dependence between the various HEPs is judged, quantitative values associated with the

  3. Study of Errors among Nursing Students

    Directory of Open Access Journals (Sweden)

    Ella Koren

    2007-09-01

    Full Text Available The study of errors in the health system today is a topic of considerable interest aimed at reducing errors through analysis of the phenomenon and the conclusions reached. Errors that occur frequently among health professionals have also been observed among nursing students. True, in most cases they are actually “near errors,” but these could be a future indicator of therapeutic reality and the effect of nurses' work environment on their personal performance. There are two different approaches to such errors: (a The EPP (error prone person approach lays full responsibility at the door of the individual involved in the error, whether a student, nurse, doctor, or pharmacist. According to this approach, handling consists purely in identifying and penalizing the guilty party. (b The EPE (error prone environment approach emphasizes the environment as a primary contributory factor to errors. The environment as an abstract concept includes components and processes of interpersonal communications, work relations, human engineering, workload, pressures, technical apparatus, and new technologies. The objective of the present study was to examine the role played by factors in and components of personal performance as compared to elements and features of the environment. The study was based on both of the aforementioned approaches, which, when combined, enable a comprehensive understanding of the phenomenon of errors among the student population as well as a comparison of factors contributing to human error and to error deriving from the environment. The theoretical basis of the study was a model that combined both approaches: one focusing on the individual and his or her personal performance and the other focusing on the work environment. The findings emphasize the work environment of health professionals as an EPE. However, errors could have been avoided by means of strict adherence to practical procedures. The authors examined error events in the

  4. Detecting Soft Errors in Stencil based Computations

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, V. [Univ. of Utah, Salt Lake City, UT (United States); Gopalkrishnan, G. [Univ. of Utah, Salt Lake City, UT (United States); Bronevetsky, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-05-06

    Given the growing emphasis on system resilience, it is important to develop software-level error detectors that help trap hardware-level faults with reasonable accuracy while minimizing false alarms as well as the performance overhead introduced. We present a technique that approaches this idea by taking stencil computations as our target, and synthesizing detectors based on machine learning. In particular, we employ linear regression to generate computationally inexpensive models which form the basis for error detection. Our technique has been incorporated into a new open-source library called SORREL. In addition to reporting encouraging experimental results, we demonstrate techniques that help reduce the size of training data. We also discuss the efficacy of various detectors synthesized, as well as our future plans.

  5. Working group of experts on rare events in human error analysis and quantification

    International Nuclear Information System (INIS)

    Goodstein, L.P.

    1977-01-01

    In dealing with the reference problem of rare events in nuclear power plants, the group has concerned itself with the man-machine system and, in particular, with human error analysis and quantification. The Group was requested to review methods of human reliability prediction, to evaluate the extent to which such analyses can be formalized and to establish criteria to be met by task conditions and system design which would permit a systematic, formal analysis. Recommendations are given on the Fessenheim safety system

  6. Short-term wind power combined forecasting based on error forecast correction

    International Nuclear Information System (INIS)

    Liang, Zhengtang; Liang, Jun; Wang, Chengfu; Dong, Xiaoming; Miao, Xiaofeng

    2016-01-01

    Highlights: • The correlation relationships of short-term wind power forecast errors are studied. • The correlation analysis method of the multi-step forecast errors is proposed. • A strategy selecting the input variables for the error forecast models is proposed. • Several novel combined models based on error forecast correction are proposed. • The combined models have improved the short-term wind power forecasting accuracy. - Abstract: With the increasing contribution of wind power to electric power grids, accurate forecasting of short-term wind power has become particularly valuable for wind farm operators, utility operators and customers. The aim of this study is to investigate the interdependence structure of errors in short-term wind power forecasting that is crucial for building error forecast models with regression learning algorithms to correct predictions and improve final forecasting accuracy. In this paper, several novel short-term wind power combined forecasting models based on error forecast correction are proposed in the one-step ahead, continuous and discontinuous multi-step ahead forecasting modes. First, the correlation relationships of forecast errors of the autoregressive model, the persistence method and the support vector machine model in various forecasting modes have been investigated to determine whether the error forecast models can be established by regression learning algorithms. Second, according to the results of the correlation analysis, the range of input variables is defined and an efficient strategy for selecting the input variables for the error forecast models is proposed. Finally, several combined forecasting models are proposed, in which the error forecast models are based on support vector machine/extreme learning machine, and correct the short-term wind power forecast values. The data collected from a wind farm in Hebei Province, China, are selected as a case study to demonstrate the effectiveness of the proposed

  7. Management and Evaluation System on Human Error, Licence Requirements, and Job-aptitude in Rail and the Other Industries

    Energy Technology Data Exchange (ETDEWEB)

    Koo, In Soo; Suh, S. M.; Park, G. O. (and others)

    2006-07-15

    Rail system is a system that is very closely related to the public life. When an accident happens, the public using this system should be injured or even be killed. The accident that recently took place in Taegu subway system, because of the inappropriate human-side task performance, showed demonstratively how its results could turn out to be tragic one. Many studies have shown that the most cases of the accidents have occurred because of performing his/her tasks in inappropriate way. It is generally recognised that the rail system without human element could never be happened quite long time. So human element in rail system is going to be the major factor to the next tragic accident. This state of the art report studied the cases of the managements and evaluation systems related to human errors, license requirements, and job aptitudes in the areas of rail and the other industries for the purpose of improvement of the task performance of personnel which consists of an element and finally enhancement of rail safety. The human errors, license requirements, and evaluation system of the job aptitude on people engaged in agencies with close relation to rail do much for development and preservation their abilities. But due to various inside and outside factors, to some extent it may have limitations to timely reflect overall trends of society, technology, and a sense of value. Removal and control of the factors of human errors will have epochal roles in safety of the rail system through the case studies of this report. Analytical results on case studies of this report will be used in the project 'Development of Management Criteria on Human Error and Evaluation Criteria on Job-aptitude of Rail Safe-operation Personnel' which has been carried out as a part of 'Integrated R and D Program for Railway Safety'.

  8. Management and Evaluation System on Human Error, Licence Requirements, and Job-aptitude in Rail and the Other Industries

    International Nuclear Information System (INIS)

    Koo, In Soo; Suh, S. M.; Park, G. O.

    2006-07-01

    Rail system is a system that is very closely related to the public life. When an accident happens, the public using this system should be injured or even be killed. The accident that recently took place in Taegu subway system, because of the inappropriate human-side task performance, showed demonstratively how its results could turn out to be tragic one. Many studies have shown that the most cases of the accidents have occurred because of performing his/her tasks in inappropriate way. It is generally recognised that the rail system without human element could never be happened quite long time. So human element in rail system is going to be the major factor to the next tragic accident. This state of the art report studied the cases of the managements and evaluation systems related to human errors, license requirements, and job aptitudes in the areas of rail and the other industries for the purpose of improvement of the task performance of personnel which consists of an element and finally enhancement of rail safety. The human errors, license requirements, and evaluation system of the job aptitude on people engaged in agencies with close relation to rail do much for development and preservation their abilities. But due to various inside and outside factors, to some extent it may have limitations to timely reflect overall trends of society, technology, and a sense of value. Removal and control of the factors of human errors will have epochal roles in safety of the rail system through the case studies of this report. Analytical results on case studies of this report will be used in the project 'Development of Management Criteria on Human Error and Evaluation Criteria on Job-aptitude of Rail Safe-operation Personnel' which has been carried out as a part of 'Integrated R and D Program for Railway Safety'

  9. Evolutionary modeling-based approach for model errors correction

    Directory of Open Access Journals (Sweden)

    S. Q. Wan

    2012-08-01

    Full Text Available The inverse problem of using the information of historical data to estimate model errors is one of the science frontier research topics. In this study, we investigate such a problem using the classic Lorenz (1963 equation as a prediction model and the Lorenz equation with a periodic evolutionary function as an accurate representation of reality to generate "observational data."

    On the basis of the intelligent features of evolutionary modeling (EM, including self-organization, self-adaptive and self-learning, the dynamic information contained in the historical data can be identified and extracted by computer automatically. Thereby, a new approach is proposed to estimate model errors based on EM in the present paper. Numerical tests demonstrate the ability of the new approach to correct model structural errors. In fact, it can actualize the combination of the statistics and dynamics to certain extent.

  10. Quantization-Based Adaptive Actor-Critic Tracking Control With Tracking Error Constraints.

    Science.gov (United States)

    Fan, Quan-Yong; Yang, Guang-Hong; Ye, Dan

    2018-04-01

    In this paper, the problem of adaptive actor-critic (AC) tracking control is investigated for a class of continuous-time nonlinear systems with unknown nonlinearities and quantized inputs. Different from the existing results based on reinforcement learning, the tracking error constraints are considered and new critic functions are constructed to improve the performance further. To ensure that the tracking errors keep within the predefined time-varying boundaries, a tracking error transformation technique is used to constitute an augmented error system. Specific critic functions, rather than the long-term cost function, are introduced to supervise the tracking performance and tune the weights of the AC neural networks (NNs). A novel adaptive controller with a special structure is designed to reduce the effect of the NN reconstruction errors, input quantization, and disturbances. Based on the Lyapunov stability theory, the boundedness of the closed-loop signals and the desired tracking performance can be guaranteed. Finally, simulations on two connected inverted pendulums are given to illustrate the effectiveness of the proposed method.

  11. MO-FG-202-07: Real-Time EPID-Based Detection Metric For VMAT Delivery Errors

    International Nuclear Information System (INIS)

    Passarge, M; Fix, M K; Manser, P; Stampanoni, M F M; Siebers, J V

    2016-01-01

    Purpose: To create and test an accurate EPID-frame-based VMAT QA metric to detect gross dose errors in real-time and to provide information about the source of error. Methods: A Swiss cheese model was created for an EPID-based real-time QA process. The system compares a treatmentplan- based reference set of EPID images with images acquired over each 2° gantry angle interval. The metric utilizes a sequence of independent consecutively executed error detection Methods: a masking technique that verifies infield radiation delivery and ensures no out-of-field radiation; output normalization checks at two different stages; global image alignment to quantify rotation, scaling and translation; standard gamma evaluation (3%, 3 mm) and pixel intensity deviation checks including and excluding high dose gradient regions. Tolerances for each test were determined. For algorithm testing, twelve different types of errors were selected to modify the original plan. Corresponding predictions for each test case were generated, which included measurement-based noise. Each test case was run multiple times (with different noise per run) to assess the ability to detect introduced errors. Results: Averaged over five test runs, 99.1% of all plan variations that resulted in patient dose errors were detected within 2° and 100% within 4° (∼1% of patient dose delivery). Including cases that led to slightly modified but clinically equivalent plans, 91.5% were detected by the system within 2°. Based on the type of method that detected the error, determination of error sources was achieved. Conclusion: An EPID-based during-treatment error detection system for VMAT deliveries was successfully designed and tested. The system utilizes a sequence of methods to identify and prevent gross treatment delivery errors. The system was inspected for robustness with realistic noise variations, demonstrating that it has the potential to detect a large majority of errors in real-time and indicate the error

  12. MO-FG-202-07: Real-Time EPID-Based Detection Metric For VMAT Delivery Errors

    Energy Technology Data Exchange (ETDEWEB)

    Passarge, M; Fix, M K; Manser, P [Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Bern (Switzerland); Stampanoni, M F M [Institute for Biomedical Engineering, ETH Zurich, and PSI, Villigen (Switzerland); Siebers, J V [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States)

    2016-06-15

    Purpose: To create and test an accurate EPID-frame-based VMAT QA metric to detect gross dose errors in real-time and to provide information about the source of error. Methods: A Swiss cheese model was created for an EPID-based real-time QA process. The system compares a treatmentplan- based reference set of EPID images with images acquired over each 2° gantry angle interval. The metric utilizes a sequence of independent consecutively executed error detection Methods: a masking technique that verifies infield radiation delivery and ensures no out-of-field radiation; output normalization checks at two different stages; global image alignment to quantify rotation, scaling and translation; standard gamma evaluation (3%, 3 mm) and pixel intensity deviation checks including and excluding high dose gradient regions. Tolerances for each test were determined. For algorithm testing, twelve different types of errors were selected to modify the original plan. Corresponding predictions for each test case were generated, which included measurement-based noise. Each test case was run multiple times (with different noise per run) to assess the ability to detect introduced errors. Results: Averaged over five test runs, 99.1% of all plan variations that resulted in patient dose errors were detected within 2° and 100% within 4° (∼1% of patient dose delivery). Including cases that led to slightly modified but clinically equivalent plans, 91.5% were detected by the system within 2°. Based on the type of method that detected the error, determination of error sources was achieved. Conclusion: An EPID-based during-treatment error detection system for VMAT deliveries was successfully designed and tested. The system utilizes a sequence of methods to identify and prevent gross treatment delivery errors. The system was inspected for robustness with realistic noise variations, demonstrating that it has the potential to detect a large majority of errors in real-time and indicate the error

  13. Post-event human decision errors: operator action tree/time reliability correlation

    International Nuclear Information System (INIS)

    Hall, R.E.; Fragola, J.; Wreathall, J.

    1982-11-01

    This report documents an interim framework for the quantification of the probability of errors of decision on the part of nuclear power plant operators after the initiation of an accident. The framework can easily be incorporated into an event tree/fault tree analysis. The method presented consists of a structure called the operator action tree and a time reliability correlation which assumes the time available for making a decision to be the dominating factor in situations requiring cognitive human response. This limited approach decreases the magnitude and complexity of the decision modeling task. Specifically, in the past, some human performance models have attempted prediction by trying to emulate sequences of human actions, or by identifying and modeling the information processing approach applicable to the task. The model developed here is directed at describing the statistical performance of a representative group of hypothetical individuals responding to generalized situations

  14. Post-event human decision errors: operator action tree/time reliability correlation

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R E; Fragola, J; Wreathall, J

    1982-11-01

    This report documents an interim framework for the quantification of the probability of errors of decision on the part of nuclear power plant operators after the initiation of an accident. The framework can easily be incorporated into an event tree/fault tree analysis. The method presented consists of a structure called the operator action tree and a time reliability correlation which assumes the time available for making a decision to be the dominating factor in situations requiring cognitive human response. This limited approach decreases the magnitude and complexity of the decision modeling task. Specifically, in the past, some human performance models have attempted prediction by trying to emulate sequences of human actions, or by identifying and modeling the information processing approach applicable to the task. The model developed here is directed at describing the statistical performance of a representative group of hypothetical individuals responding to generalized situations.

  15. Risk assessment of component failure modes and human errors using a new FMECA approach: application in the safety analysis of HDR brachytherapy

    International Nuclear Information System (INIS)

    Giardina, M; Castiglia, F; Tomarchio, E

    2014-01-01

    Failure mode, effects and criticality analysis (FMECA) is a safety technique extensively used in many different industrial fields to identify and prevent potential failures. In the application of traditional FMECA, the risk priority number (RPN) is determined to rank the failure modes; however, the method has been criticised for having several weaknesses. Moreover, it is unable to adequately deal with human errors or negligence. In this paper, a new versatile fuzzy rule-based assessment model is proposed to evaluate the RPN index to rank both component failure and human error. The proposed methodology is applied to potential radiological over-exposure of patients during high-dose-rate brachytherapy treatments. The critical analysis of the results can provide recommendations and suggestions regarding safety provisions for the equipment and procedures required to reduce the occurrence of accidental events. (paper)

  16. The Influence of Guided Error-Based Learning on Motor Skills Self-Efficacy and Achievement.

    Science.gov (United States)

    Chien, Kuei-Pin; Chen, Sufen

    2018-01-01

    The authors investigated the role of errors in motor skills teaching, specifically the influence of errors on skills self-efficacy and achievement. The participants were 75 undergraduate students enrolled in pétanque courses. The experimental group (guided error-based learning, n = 37) received a 6-week period of instruction based on the students' errors, whereas the control group (correct motion instruction, n = 38) received a 6-week period of instruction emphasizing correct motor skills. The experimental group had significantly higher scores in motor skills self-efficacy and outcomes than did the control group. Novices' errors reflect their schema in motor skills learning, which provides a basis for instructors to implement student-centered instruction and to facilitate the learning process. Guided error-based learning can effectively enhance beginners' skills self-efficacy and achievement in precision sports such as pétanque.

  17. ERROR DISTRIBUTION EVALUATION OF THE THIRD VANISHING POINT BASED ON RANDOM STATISTICAL SIMULATION

    Directory of Open Access Journals (Sweden)

    C. Li

    2012-07-01

    Full Text Available POS, integrated by GPS / INS (Inertial Navigation Systems, has allowed rapid and accurate determination of position and attitude of remote sensing equipment for MMS (Mobile Mapping Systems. However, not only does INS have system error, but also it is very expensive. Therefore, in this paper error distributions of vanishing points are studied and tested in order to substitute INS for MMS in some special land-based scene, such as ground façade where usually only two vanishing points can be detected. Thus, the traditional calibration approach based on three orthogonal vanishing points is being challenged. In this article, firstly, the line clusters, which parallel to each others in object space and correspond to the vanishing points, are detected based on RANSAC (Random Sample Consensus and parallelism geometric constraint. Secondly, condition adjustment with parameters is utilized to estimate nonlinear error equations of two vanishing points (VX, VY. How to set initial weights for the adjustment solution of single image vanishing points is presented. Solving vanishing points and estimating their error distributions base on iteration method with variable weights, co-factor matrix and error ellipse theory. Thirdly, under the condition of known error ellipses of two vanishing points (VX, VY and on the basis of the triangle geometric relationship of three vanishing points, the error distribution of the third vanishing point (VZ is calculated and evaluated by random statistical simulation with ignoring camera distortion. Moreover, Monte Carlo methods utilized for random statistical estimation are presented. Finally, experimental results of vanishing points coordinate and their error distributions are shown and analyzed.

  18. Error Distribution Evaluation of the Third Vanishing Point Based on Random Statistical Simulation

    Science.gov (United States)

    Li, C.

    2012-07-01

    POS, integrated by GPS / INS (Inertial Navigation Systems), has allowed rapid and accurate determination of position and attitude of remote sensing equipment for MMS (Mobile Mapping Systems). However, not only does INS have system error, but also it is very expensive. Therefore, in this paper error distributions of vanishing points are studied and tested in order to substitute INS for MMS in some special land-based scene, such as ground façade where usually only two vanishing points can be detected. Thus, the traditional calibration approach based on three orthogonal vanishing points is being challenged. In this article, firstly, the line clusters, which parallel to each others in object space and correspond to the vanishing points, are detected based on RANSAC (Random Sample Consensus) and parallelism geometric constraint. Secondly, condition adjustment with parameters is utilized to estimate nonlinear error equations of two vanishing points (VX, VY). How to set initial weights for the adjustment solution of single image vanishing points is presented. Solving vanishing points and estimating their error distributions base on iteration method with variable weights, co-factor matrix and error ellipse theory. Thirdly, under the condition of known error ellipses of two vanishing points (VX, VY) and on the basis of the triangle geometric relationship of three vanishing points, the error distribution of the third vanishing point (VZ) is calculated and evaluated by random statistical simulation with ignoring camera distortion. Moreover, Monte Carlo methods utilized for random statistical estimation are presented. Finally, experimental results of vanishing points coordinate and their error distributions are shown and analyzed.

  19. Error Propagation dynamics: from PIV-based pressure reconstruction to vorticity field calculation

    Science.gov (United States)

    Pan, Zhao; Whitehead, Jared; Richards, Geordie; Truscott, Tadd; USU Team; BYU Team

    2017-11-01

    Noninvasive data from velocimetry experiments (e.g., PIV) have been used to calculate vorticity and pressure fields. However, the noise, error, or uncertainties in the PIV measurements would eventually propagate to the calculated pressure or vorticity field through reconstruction schemes. Despite the vast applications of pressure and/or vorticity field calculated from PIV measurements, studies on the error propagation from the velocity field to the reconstructed fields (PIV-pressure and PIV-vorticity are few. In the current study, we break down the inherent connections between PIV-based pressure reconstruction and PIV-based vorticity calculation. The similar error propagation dynamics, which involve competition between physical properties of the flow and numerical errors from reconstruction schemes, are found in both PIV-pressure and PIV-vorticity reconstructions.

  20. A Sensor Dynamic Measurement Error Prediction Model Based on NAPSO-SVM.

    Science.gov (United States)

    Jiang, Minlan; Jiang, Lan; Jiang, Dingde; Li, Fei; Song, Houbing

    2018-01-15

    Dynamic measurement error correction is an effective way to improve sensor precision. Dynamic measurement error prediction is an important part of error correction, and support vector machine (SVM) is often used for predicting the dynamic measurement errors of sensors. Traditionally, the SVM parameters were always set manually, which cannot ensure the model's performance. In this paper, a SVM method based on an improved particle swarm optimization (NAPSO) is proposed to predict the dynamic measurement errors of sensors. Natural selection and simulated annealing are added in the PSO to raise the ability to avoid local optima. To verify the performance of NAPSO-SVM, three types of algorithms are selected to optimize the SVM's parameters: the particle swarm optimization algorithm (PSO), the improved PSO optimization algorithm (NAPSO), and the glowworm swarm optimization (GSO). The dynamic measurement error data of two sensors are applied as the test data. The root mean squared error and mean absolute percentage error are employed to evaluate the prediction models' performances. The experimental results show that among the three tested algorithms the NAPSO-SVM method has a better prediction precision and a less prediction errors, and it is an effective method for predicting the dynamic measurement errors of sensors.

  1. Human reliability

    International Nuclear Information System (INIS)

    Embrey, D.E.

    1987-01-01

    Concepts and techniques of human reliability have been developed and are used mostly in probabilistic risk assessment. For this, the major application of human reliability assessment has been to identify the human errors which have a significant effect on the overall safety of the system and to quantify the probability of their occurrence. Some of the major issues within human reliability studies are reviewed and it is shown how these are applied to the assessment of human failures in systems. This is done under the following headings; models of human performance used in human reliability assessment, the nature of human error, classification of errors in man-machine systems, practical aspects, human reliability modelling in complex situations, quantification and examination of human reliability, judgement based approaches, holistic techniques and decision analytic approaches. (UK)

  2. Errors in Neonatology

    OpenAIRE

    Antonio Boldrini; Rosa T. Scaramuzzo; Armando Cuttano

    2013-01-01

    Introduction: Danger and errors are inherent in human activities. In medical practice errors can lean to adverse events for patients. Mass media echo the whole scenario. Methods: We reviewed recent published papers in PubMed database to focus on the evidence and management of errors in medical practice in general and in Neonatology in particular. We compared the results of the literature with our specific experience in Nina Simulation Centre (Pisa, Italy). Results: In Neonatology the main err...

  3. The PoET (Prevention of Error-Based Transfers) Project.

    Science.gov (United States)

    Oliver, Jill; Chidwick, Paula

    2017-01-01

    The PoET (Prevention of Error-based Transfers) Project is one of the Ethics Quality Improvement Projects (EQIPs) taking place at William Osler Health System. This specific project is designed to reduce transfers from long-term care to hospital that are caused by legal and ethical errors related to consent, capacity and substitute decision-making. The project is currently operating in eight long-term care homes in the Central West Local Health Integration Network and has seen a 56% reduction in multiple transfers before death in hospital.

  4. Trend analysis of nuclear reactor automatic trip events subjected to operator's human error at United States nuclear power plants

    International Nuclear Information System (INIS)

    Takagawa, Kenichi

    2009-01-01

    Trends in nuclear reactor automatic trip events due to human errors during plant operating mode have been analyzed by extracting 20 events which took place in the United States during the period of seven years from 2002 to 2008, cited in the LERs (Licensee Event Reports) submitted to the US Nuclear Regulatory Commission (NRC). It was shown that the yearly number of events was relatively large before 2005, and thereafter the number decreased. A period of stable operation, in which the yearly number was kept very small, continued for about three years, and then the yearly number turned to increase again. Before 2005, automatic trip events occurred more frequently during periodic inspections or start-up/shut-down operations. The recent trends, however, indicate that trip events became more frequent due to human errors during daily operations. Human errors were mostly caused by the self-conceit and carelessness of operators through the whole period. The before mentioned trends in the yearly number of events might be explained as follows. The decrease in the automatic trip events is attributed to sharing trouble information, leading as a consequence to improvement of the manual and training for the operations which have a higher potential risk of automatic trip. Then, while the period of stable operation continued, some operators came to pay less attention to preventing human errors and not interest in the training, leading to automatic trip events in reality due to miss-operation. From these analyses on trouble experiences in the US, we learnt the followings to prevent the occurrence similar troubles in Japan: Operators should be thoroughly skilled in basic actions to prevent human errors as persons concerned. And it should be further emphasized that they should elaborate by imaging actual plant operations even though the simulator training gives them successful experiences. (author)

  5. Airborne LIDAR borsight error calibration based on surface coincide

    International Nuclear Information System (INIS)

    Yuan, Fangyan; Li, Guoqing; Zuo, Zhengli; Li, Dong; Qi, Zengying; Qiu, Wen; Tan, Junxiang

    2014-01-01

    Light Detection and Ranging (LIDAR) is a system which can directly collect three-dimensional coordinate information of ground point and laser reflection strength information. With the wide application of LIDAR system, users hope to get more accurate results. Boresight error has an important effect on data accuracy and thus, it is thought that eliminating the error is very important. In recent years, many methods have been proposed to eliminate the error. Generally, they can be categorized into tie point method and surface matching method. In this paper, we propose another method called try value method based on surface coincide that is used in actual production by many companies. The method is simple and operable. Further, the efficacy of the method was demonstrated by analyzing the data from Zhangye city

  6. Subsecond dopamine fluctuations in human striatum encode superposed error signals about actual and counterfactual reward

    Science.gov (United States)

    Kishida, Kenneth T.; Saez, Ignacio; Lohrenz, Terry; Witcher, Mark R.; Laxton, Adrian W.; Tatter, Stephen B.; White, Jason P.; Ellis, Thomas L.; Phillips, Paul E. M.; Montague, P. Read

    2016-01-01

    In the mammalian brain, dopamine is a critical neuromodulator whose actions underlie learning, decision-making, and behavioral control. Degeneration of dopamine neurons causes Parkinson’s disease, whereas dysregulation of dopamine signaling is believed to contribute to psychiatric conditions such as schizophrenia, addiction, and depression. Experiments in animal models suggest the hypothesis that dopamine release in human striatum encodes reward prediction errors (RPEs) (the difference between actual and expected outcomes) during ongoing decision-making. Blood oxygen level-dependent (BOLD) imaging experiments in humans support the idea that RPEs are tracked in the striatum; however, BOLD measurements cannot be used to infer the action of any one specific neurotransmitter. We monitored dopamine levels with subsecond temporal resolution in humans (n = 17) with Parkinson’s disease while they executed a sequential decision-making task. Participants placed bets and experienced monetary gains or losses. Dopamine fluctuations in the striatum fail to encode RPEs, as anticipated by a large body of work in model organisms. Instead, subsecond dopamine fluctuations encode an integration of RPEs with counterfactual prediction errors, the latter defined by how much better or worse the experienced outcome could have been. How dopamine fluctuations combine the actual and counterfactual is unknown. One possibility is that this process is the normal behavior of reward processing dopamine neurons, which previously had not been tested by experiments in animal models. Alternatively, this superposition of error terms may result from an additional yet-to-be-identified subclass of dopamine neurons. PMID:26598677

  7. Perspective of midwives working at hospitals affiliated to the Isfahan University of Medical Sciences regarding medical errors

    Directory of Open Access Journals (Sweden)

    Mahboubeh Valiani

    2015-01-01

    Conclusions: Based on the results of this study on the perspectives of participants, among the three factors of medical errors (human factors, structural factors, and management factors, human factors are the biggest threat in committing medical errors. Modification in the pattern of teaching by the midwifery professors and their presence in the hospitals, creating a no-blame culture, and sharing of alerts in medical errors are among appropriate actions in the dimensions of human, structural, and managerial factors.

  8. Error Concealment using Neural Networks for Block-Based Image Coding

    Directory of Open Access Journals (Sweden)

    M. Mokos

    2006-06-01

    Full Text Available In this paper, a novel adaptive error concealment (EC algorithm, which lowers the requirements for channel coding, is proposed. It conceals errors in block-based image coding systems by using neural network. In this proposed algorithm, only the intra-frame information is used for reconstruction of the image with separated damaged blocks. The information of pixels surrounding a damaged block is used to recover the errors using the neural network models. Computer simulation results show that the visual quality and the MSE evaluation of a reconstructed image are significantly improved using the proposed EC algorithm. We propose also a simple non-neural approach for comparison.

  9. Effective use of pre-job briefing as tool for the prevention of human error

    International Nuclear Information System (INIS)

    Schlump, Ansgar

    2015-01-01

    There is a fundamental demand to minimise the risks for workers and facilities while executing maintenance work. To ensure that facilities are secure and reliable, any deviation from normal operation behaviour has to be avoided. Accurate planning is the basis for minimising mistakes and making work more secure. All workers involved should understand how the work should be done and what is expected to avoid human errors. Especially in nuclear power plants, the human performance tools (HPT) have proved to be an effective instrument to minimise human errors. These human performance tools consist of numerous different tools that complement each other (e.g. pre-job briefing). The safety culture of the plants is also characterised by these tools. The choice of using the right HP-Tool is often a difficult task for the work planer. On the one hand, he wants to avoid mistakes during the execution of work but on the other hand he does not want to irritate the workers with unnecessary requirements. The proposed concept uses a simple risk analysis to take into account the complexity of the task, the experience of the past and the consequences of failure in to account. One main result of this risk analysis is a recommendation of the detailing of the pre-job briefing, to reduce the risks for the involved staff to a minimum.

  10. [Human factors in medicine].

    Science.gov (United States)

    Lazarovici, M; Trentzsch, H; Prückner, S

    2017-01-01

    The concept of human factors is commonly used in the context of patient safety and medical errors, all too often ambiguously. In actual fact, the term comprises a wide range of meanings from human-machine interfaces through human performance and limitations up to the point of working process design; however, human factors prevail as a substantial cause of error in complex systems. This article presents the full range of the term human factors from the (emergency) medical perspective. Based on the so-called Swiss cheese model by Reason, we explain the different types of error, what promotes their emergence and on which level of the model error prevention can be initiated.

  11. A system dynamic simulation model for managing the human error in power tools industries

    Science.gov (United States)

    Jamil, Jastini Mohd; Shaharanee, Izwan Nizal Mohd

    2017-10-01

    In the era of modern and competitive life of today, every organization will face the situations in which the work does not proceed as planned when there is problems occur in which it had to be delay. However, human error is often cited as the culprit. The error that made by the employees would cause them have to spend additional time to identify and check for the error which in turn could affect the normal operations of the company as well as the company's reputation. Employee is a key element of the organization in running all of the activities of organization. Hence, work performance of the employees is a crucial factor in organizational success. The purpose of this study is to identify the factors that cause the increasing errors make by employees in the organization by using system dynamics approach. The broadly defined targets in this study are employees in the Regional Material Field team from purchasing department in power tools industries. Questionnaires were distributed to the respondents to obtain their perceptions on the root cause of errors make by employees in the company. The system dynamics model was developed to simulate the factor of the increasing errors make by employees and its impact. The findings of this study showed that the increasing of error make by employees was generally caused by the factors of workload, work capacity, job stress, motivation and performance of employees. However, this problem could be solve by increased the number of employees in the organization.

  12. OOK power model based dynamic error testing for smart electricity meter

    International Nuclear Information System (INIS)

    Wang, Xuewei; Chen, Jingxia; Jia, Xiaolu; Zhu, Meng; Yuan, Ruiming; Jiang, Zhenyu

    2017-01-01

    This paper formulates the dynamic error testing problem for a smart meter, with consideration and investigation of both the testing signal and the dynamic error testing method. To solve the dynamic error testing problems, the paper establishes an on-off-keying (OOK) testing dynamic current model and an OOK testing dynamic load energy (TDLE) model. Then two types of TDLE sequences and three modes of OOK testing dynamic power are proposed. In addition, a novel algorithm, which helps to solve the problem of dynamic electric energy measurement’s traceability, is derived for dynamic errors. Based on the above researches, OOK TDLE sequence generation equipment is developed and a dynamic error testing system is constructed. Using the testing system, five kinds of meters were tested in the three dynamic power modes. The test results show that the dynamic error is closely related to dynamic power mode and the measurement uncertainty is 0.38%. (paper)

  13. OOK power model based dynamic error testing for smart electricity meter

    Science.gov (United States)

    Wang, Xuewei; Chen, Jingxia; Yuan, Ruiming; Jia, Xiaolu; Zhu, Meng; Jiang, Zhenyu

    2017-02-01

    This paper formulates the dynamic error testing problem for a smart meter, with consideration and investigation of both the testing signal and the dynamic error testing method. To solve the dynamic error testing problems, the paper establishes an on-off-keying (OOK) testing dynamic current model and an OOK testing dynamic load energy (TDLE) model. Then two types of TDLE sequences and three modes of OOK testing dynamic power are proposed. In addition, a novel algorithm, which helps to solve the problem of dynamic electric energy measurement’s traceability, is derived for dynamic errors. Based on the above researches, OOK TDLE sequence generation equipment is developed and a dynamic error testing system is constructed. Using the testing system, five kinds of meters were tested in the three dynamic power modes. The test results show that the dynamic error is closely related to dynamic power mode and the measurement uncertainty is 0.38%.

  14. Human error considerations and annunciator effects in determining optimal test intervals for periodically inspected standby systems

    International Nuclear Information System (INIS)

    McWilliams, T.P.; Martz, H.F.

    1981-01-01

    This paper incorporates the effects of four types of human error in a model for determining the optimal time between periodic inspections which maximizes the steady state availability for standby safety systems. Such safety systems are characteristic of nuclear power plant operations. The system is modeled by means of an infinite state-space Markov chain. Purpose of the paper is to demonstrate techniques for computing steady-state availability A and the optimal periodic inspection interval tau* for the system. The model can be used to investigate the effects of human error probabilities on optimal availability, study the benefits of annunciating the standby-system, and to determine optimal inspection intervals. Several examples which are representative of nuclear power plant applications are presented

  15. Geometrical error calibration in reflective surface testing based on reverse Hartmann test

    Science.gov (United States)

    Gong, Zhidong; Wang, Daodang; Xu, Ping; Wang, Chao; Liang, Rongguang; Kong, Ming; Zhao, Jun; Mo, Linhai; Mo, Shuhui

    2017-08-01

    In the fringe-illumination deflectometry based on reverse-Hartmann-test configuration, ray tracing of the modeled testing system is performed to reconstruct the test surface error. Careful calibration of system geometry is required to achieve high testing accuracy. To realize the high-precision surface testing with reverse Hartmann test, a computer-aided geometrical error calibration method is proposed. The aberrations corresponding to various geometrical errors are studied. With the aberration weights for various geometrical errors, the computer-aided optimization of system geometry with iterative ray tracing is carried out to calibration the geometrical error, and the accuracy in the order of subnanometer is achieved.

  16. Development of an analysis rule of diagnosis error for standard method of human reliability analysis

    International Nuclear Information System (INIS)

    Jeong, W. D.; Kang, D. I.; Jeong, K. S.

    2003-01-01

    This paper presents the status of development of Korea standard method for Human Reliability Analysis (HRA), and proposed a standard procedure and rules for the evaluation of diagnosis error probability. The quality of KSNP HRA was evaluated using the requirement of ASME PRA standard guideline, and the design requirement for the standard HRA method was defined. Analysis procedure and rules, developed so far, to analyze diagnosis error probability was suggested as a part of the standard method. And also a study of comprehensive application was performed to evaluate the suitability of the proposed rules

  17. Comprehensive analysis of a medication dosing error related to CPOE.

    Science.gov (United States)

    Horsky, Jan; Kuperman, Gilad J; Patel, Vimla L

    2005-01-01

    This case study of a serious medication error demonstrates the necessity of a comprehensive methodology for the analysis of failures in interaction between humans and information systems. The authors used a novel approach to analyze a dosing error related to computer-based ordering of potassium chloride (KCl). The method included a chronological reconstruction of events and their interdependencies from provider order entry usage logs, semistructured interviews with involved clinicians, and interface usability inspection of the ordering system. Information collected from all sources was compared and evaluated to understand how the error evolved and propagated through the system. In this case, the error was the product of faults in interaction among human and system agents that methods limited in scope to their distinct analytical domains would not identify. The authors characterized errors in several converging aspects of the drug ordering process: confusing on-screen laboratory results review, system usability difficulties, user training problems, and suboptimal clinical system safeguards that all contributed to a serious dosing error. The results of the authors' analysis were used to formulate specific recommendations for interface layout and functionality modifications, suggest new user alerts, propose changes to user training, and address error-prone steps of the KCl ordering process to reduce the risk of future medication dosing errors.

  18. Understanding and Confronting Our Mistakes: The Epidemiology of Error in Radiology and Strategies for Error Reduction.

    Science.gov (United States)

    Bruno, Michael A; Walker, Eric A; Abujudeh, Hani H

    2015-10-01

    Arriving at a medical diagnosis is a highly complex process that is extremely error prone. Missed or delayed diagnoses often lead to patient harm and missed opportunities for treatment. Since medical imaging is a major contributor to the overall diagnostic process, it is also a major potential source of diagnostic error. Although some diagnoses may be missed because of the technical or physical limitations of the imaging modality, including image resolution, intrinsic or extrinsic contrast, and signal-to-noise ratio, most missed radiologic diagnoses are attributable to image interpretation errors by radiologists. Radiologic interpretation cannot be mechanized or automated; it is a human enterprise based on complex psychophysiologic and cognitive processes and is itself subject to a wide variety of error types, including perceptual errors (those in which an important abnormality is simply not seen on the images) and cognitive errors (those in which the abnormality is visually detected but the meaning or importance of the finding is not correctly understood or appreciated). The overall prevalence of radiologists' errors in practice does not appear to have changed since it was first estimated in the 1960s. The authors review the epidemiology of errors in diagnostic radiology, including a recently proposed taxonomy of radiologists' errors, as well as research findings, in an attempt to elucidate possible underlying causes of these errors. The authors also propose strategies for error reduction in radiology. On the basis of current understanding, specific suggestions are offered as to how radiologists can improve their performance in practice. © RSNA, 2015.

  19. Facial motion parameter estimation and error criteria in model-based image coding

    Science.gov (United States)

    Liu, Yunhai; Yu, Lu; Yao, Qingdong

    2000-04-01

    Model-based image coding has been given extensive attention due to its high subject image quality and low bit-rates. But the estimation of object motion parameter is still a difficult problem, and there is not a proper error criteria for the quality assessment that are consistent with visual properties. This paper presents an algorithm of the facial motion parameter estimation based on feature point correspondence and gives the motion parameter error criteria. The facial motion model comprises of three parts. The first part is the global 3-D rigid motion of the head, the second part is non-rigid translation motion in jaw area, and the third part consists of local non-rigid expression motion in eyes and mouth areas. The feature points are automatically selected by a function of edges, brightness and end-node outside the blocks of eyes and mouth. The numbers of feature point are adjusted adaptively. The jaw translation motion is tracked by the changes of the feature point position of jaw. The areas of non-rigid expression motion can be rebuilt by using block-pasting method. The estimation approach of motion parameter error based on the quality of reconstructed image is suggested, and area error function and the error function of contour transition-turn rate are used to be quality criteria. The criteria reflect the image geometric distortion caused by the error of estimated motion parameters properly.

  20. Uncertainty quantification and error analysis

    Energy Technology Data Exchange (ETDEWEB)

    Higdon, Dave M [Los Alamos National Laboratory; Anderson, Mark C [Los Alamos National Laboratory; Habib, Salman [Los Alamos National Laboratory; Klein, Richard [Los Alamos National Laboratory; Berliner, Mark [OHIO STATE UNIV.; Covey, Curt [LLNL; Ghattas, Omar [UNIV OF TEXAS; Graziani, Carlo [UNIV OF CHICAGO; Seager, Mark [LLNL; Sefcik, Joseph [LLNL; Stark, Philip [UC/BERKELEY; Stewart, James [SNL

    2010-01-01

    UQ studies all sources of error and uncertainty, including: systematic and stochastic measurement error; ignorance; limitations of theoretical models; limitations of numerical representations of those models; limitations on the accuracy and reliability of computations, approximations, and algorithms; and human error. A more precise definition for UQ is suggested below.

  1. Utilizing measure-based feedback in control-mastery theory: A clinical error.

    Science.gov (United States)

    Snyder, John; Aafjes-van Doorn, Katie

    2016-09-01

    Clinical errors and ruptures are an inevitable part of clinical practice. Often times, therapists are unaware that a clinical error or rupture has occurred, leaving no space for repair, and potentially leading to patient dropout and/or less effective treatment. One way to overcome our blind spots is by frequently and systematically collecting measure-based feedback from the patient. Patient feedback measures that focus on the process of psychotherapy such as the Patient's Experience of Attunement and Responsiveness scale (PEAR) can be used in conjunction with treatment outcome measures such as the Outcome Questionnaire 45.2 (OQ-45.2) to monitor the patient's therapeutic experience and progress. The regular use of these types of measures can aid clinicians in the identification of clinical errors and the associated patient deterioration that might otherwise go unnoticed and unaddressed. The current case study describes an instance of clinical error that occurred during the 2-year treatment of a highly traumatized young woman. The clinical error was identified using measure-based feedback and subsequently understood and addressed from the theoretical standpoint of the control-mastery theory of psychotherapy. An alternative hypothetical response is also presented and explained using control-mastery theory. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  2. A methodology for analysing human errors of commission in accident scenarios for risk assessment

    International Nuclear Information System (INIS)

    Kim, J. H.; Jung, W. D.; Park, J. K

    2003-01-01

    As the concern on the impact of the operator's inappropriate interventions, so-called Errors Of Commissions(EOCs), on the plant safety has been raised, the interest in the identification and analysis of EOC events from the risk assessment perspective becomes increasing accordingly. To this purpose, we propose a new methodology for identifying and analysing human errors of commission that might be caused from the failures in situation assessment and decision making during accident progressions given an initiating event. The proposed methodology was applied to the accident scenarios of YGN 3 and 4 NPPs, which resulted in about 10 EOC situations that need careful attention

  3. Using human error theory to explore the supply of non-prescription medicines from community pharmacies.

    Science.gov (United States)

    Watson, M C; Bond, C M; Johnston, M; Mearns, K

    2006-08-01

    The importance of theory in underpinning interventions to promote effective professional practice is gaining recognition. The Medical Research Council framework for complex interventions has assisted in promoting awareness and adoption of theory into study design. Human error theory has previously been used by high risk industries but its relevance to healthcare settings and patient safety requires further investigation. This study used this theory as a framework to explore non-prescription medicine supply from community pharmacies. The relevance to other healthcare settings and behaviours is discussed. A 25% random sample was made of 364 observed consultations for non-prescription medicines. Each of the 91 consultations was assessed by two groups: a consensus group (stage 1) to identify common problems with the consultation process, and an expert group (stages 2 and 3) to apply human error theory to these consultations. Paired assessors (most of whom were pharmacists) categorised the perceived problems occurring in each consultation (stage 1). During stage 2 paired assessors from an expert group (comprising patient safety experts, community pharmacists and psychologists) considered whether each consultation was compliant with professional guidelines for the supply of pharmacy medicines. Each non-compliant consultation identified during stage 2 was then categorised as a slip/lapse, mistake, or violation using human error theory (stage 3). During stage 1 most consultations (n = 75, 83%) were deemed deficient in information exchange. At stage 2, paired assessors varied in attributing non-compliance to specific error types. Where agreement was achieved, the error type most often selected was "violation" (n = 27, 51.9%, stage 3). Consultations involving product requests were less likely to be guideline compliant than symptom presentations (OR 0.30, 95% CI 0.10 to 0.95, p = 0.05). The large proportion of consultations classified as violations suggests that either

  4. Minimizing human error in radiopharmaceutical preparation and administration via a bar code-enhanced nuclear pharmacy management system.

    Science.gov (United States)

    Hakala, John L; Hung, Joseph C; Mosman, Elton A

    2012-09-01

    The objective of this project was to ensure correct radiopharmaceutical administration through the use of a bar code system that links patient and drug profiles with on-site information management systems. This new combined system would minimize the amount of manual human manipulation, which has proven to be a primary source of error. The most common reason for dosing errors is improper patient identification when a dose is obtained from the nuclear pharmacy or when a dose is administered. A standardized electronic transfer of information from radiopharmaceutical preparation to injection will further reduce the risk of misadministration. Value stream maps showing the flow of the patient dose information, as well as potential points of human error, were developed. Next, a future-state map was created that included proposed corrections for the most common critical sites of error. Transitioning the current process to the future state will require solutions that address these sites. To optimize the future-state process, a bar code system that links the on-site radiology management system with the nuclear pharmacy management system was proposed. A bar-coded wristband connects the patient directly to the electronic information systems. The bar code-enhanced process linking the patient dose with the electronic information reduces the number of crucial points for human error and provides a framework to ensure that the prepared dose reaches the correct patient. Although the proposed flowchart is designed for a site with an in-house central nuclear pharmacy, much of the framework could be applied by nuclear medicine facilities using unit doses. An electronic connection between information management systems to allow the tracking of a radiopharmaceutical from preparation to administration can be a useful tool in preventing the mistakes that are an unfortunate reality for any facility.

  5. Updating expected action outcome in the medial frontal cortex involves an evaluation of error type.

    Science.gov (United States)

    Maier, Martin E; Steinhauser, Marco

    2013-10-02

    Forming expectations about the outcome of an action is an important prerequisite for action control and reinforcement learning in the human brain. The medial frontal cortex (MFC) has been shown to play an important role in the representation of outcome expectations, particularly when an update of expected outcome becomes necessary because an error is detected. However, error detection alone is not always sufficient to compute expected outcome because errors can occur in various ways and different types of errors may be associated with different outcomes. In the present study, we therefore investigate whether updating expected outcome in the human MFC is based on an evaluation of error type. Our approach was to consider an electrophysiological correlate of MFC activity on errors, the error-related negativity (Ne/ERN), in a task in which two types of errors could occur. Because the two error types were associated with different amounts of monetary loss, updating expected outcomes on error trials required an evaluation of error type. Our data revealed a pattern of Ne/ERN amplitudes that closely mirrored the amount of monetary loss associated with each error type, suggesting that outcome expectations are updated based on an evaluation of error type. We propose that this is achieved by a proactive evaluation process that anticipates error types by continuously monitoring error sources or by dynamically representing possible response-outcome relations.

  6. SLC beam line error analysis using a model-based expert system

    International Nuclear Information System (INIS)

    Lee, M.; Kleban, S.

    1988-02-01

    Commissioning particle beam line is usually a very time-consuming and labor-intensive task for accelerator physicists. To aid in commissioning, we developed a model-based expert system that identifies error-free regions, as well as localizing beam line errors. This paper will give examples of the use of our system for the SLC commissioning. 8 refs., 5 figs

  7. A decision support system prototype including human factors based on the TOGA meta-theory approach

    International Nuclear Information System (INIS)

    Cappelli, M.; Memmi, F.; Gadomski, A. M.; Sepielli, M.

    2012-01-01

    The human contribution to the risk of operation of complex technological systems is often not negligible and sometimes tends to become significant, as shown by many reports on incidents and accidents occurred in the past inside Nuclear Power Plants (NPPs). An error of a human operator of a NPP can derive by both omission and commission. For instance, complex commission errors can also lead to significant catastrophic technological accidents, as for the case of the Three Mile Island accident. Typically, the problem is analyzed by focusing on the single event chain that has provoked the incident or accident. What is needed is a general framework able to include as many parameters as possible, i.e. both technological and human factors. Such a general model could allow to envisage an omission or commission error before it can happen or, alternatively, suggest preferred actions to do in order to take countermeasures to neutralize the effect of the error before it becomes critical. In this paper, a preliminary Decision Support System (DSS) based on the so-called (-) TOGA meta-theory approach is presented. The application of such a theory to the management of nuclear power plants has been presented in the previous ICAPP 2011. Here, a human factor simulator prototype is proposed in order to include the effect of human errors in the decision path. The DSS has been developed using a TRIGA research reactor as reference plant, and implemented using the LabVIEW programming environment and the Finite State Machine (FSM) model The proposed DSS shows how to apply the Universal Reasoning Paradigm (URP) and the Universal Management Paradigm (UMP) to a real plant context. The DSS receives inputs from instrumentation data and gives as output a suggested decision. It is obtained as the result of an internal elaborating process based on a performance function. The latter, describes the degree of satisfaction and efficiency, which are dependent on the level of responsibility related to

  8. Knowledge-Based Trajectory Error Pattern Method Applied to an Active Force Control Scheme

    Directory of Open Access Journals (Sweden)

    Endra Pitowarno, Musa Mailah, Hishamuddin Jamaluddin

    2012-08-01

    Full Text Available The active force control (AFC method is known as a robust control scheme that dramatically enhances the performance of a robot arm particularly in compensating the disturbance effects. The main task of the AFC method is to estimate the inertia matrix in the feedback loop to provide the correct (motor torque required to cancel out these disturbances. Several intelligent control schemes have already been introduced to enhance the estimation methods of acquiring the inertia matrix such as those using neural network, iterative learning and fuzzy logic. In this paper, we propose an alternative scheme called Knowledge-Based Trajectory Error Pattern Method (KBTEPM to suppress the trajectory track error of the AFC scheme. The knowledge is developed from the trajectory track error characteristic based on the previous experimental results of the crude approximation method. It produces a unique, new and desirable error pattern when a trajectory command is forced. An experimental study was performed using simulation work on the AFC scheme with KBTEPM applied to a two-planar manipulator in which a set of rule-based algorithm is derived. A number of previous AFC schemes are also reviewed as benchmark. The simulation results show that the AFC-KBTEPM scheme successfully reduces the trajectory track error significantly even in the presence of the introduced disturbances.Key Words:  Active force control, estimated inertia matrix, robot arm, trajectory error pattern, knowledge-based.

  9. Adjoint-Based a Posteriori Error Estimation for Coupled Time-Dependent Systems

    KAUST Repository

    Asner, Liya; Tavener, Simon; Kay, David

    2012-01-01

    We consider time-dependent parabolic problem s coupled across a common interface which we formulate using a Lagrange multiplier construction and solve by applying a monolithic solution technique. We derive an adjoint-based a posteriori error representation for a quantity of interest given by a linear functional of the solution. We establish the accuracy of our error representation formula through numerical experimentation and investigate the effect of error in the adjoint solution. Crucially, the error representation affords a distinction between temporal and spatial errors and can be used as a basis for a blockwise time-space refinement strategy. Numerical tests illustrate the efficacy of the refinement strategy by capturing the distinctive behavior of a localized traveling wave solution. The saddle point systems considered here are equivalent to those arising in the mortar finite element technique for parabolic problems. © 2012 Society for Industrial and Applied Mathematics.

  10. The development of human factors technologies -The development of human behaviour analysis techniques-

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Woon; Lee, Yong Heui; Park, Keun Ok; Chun, Se Woo; Suh, Sang Moon; Park, Jae Chang [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-07-01

    In order to contribute to human error reduction through the studies on human-machine interaction in nuclear power plants, this project has objectives to develop SACOM(Simulation Analyzer with a Cognitive Operator Model) and techniques for human error analysis and application. In this year, we studied the followings: (1) Site investigation of operator tasks, (2) Development of operator task micro structure and revision of micro structure, (3) Development of knowledge representation software and SACOM prototype, (4) Development of performance assessment methodologies in task simulation and analysis of the effects of performance shaping factors. human error analysis and application techniques> (1) Classification of error shaping factors(ESFs) and development of software for ESF evaluation, (2) Analysis of human error occurrences and revision of analysis procedure, (3) Experiment for human error data collection using a compact nuclear simulator, (4) Development of a prototype data base system of the analyzed information on trip cases. 55 figs, 23 tabs, 33 refs. (Author).

  11. Learning Similar Actions by Reinforcement or Sensory-Prediction Errors Rely on Distinct Physiological Mechanisms.

    Science.gov (United States)

    Uehara, Shintaro; Mawase, Firas; Celnik, Pablo

    2017-09-14

    Humans can acquire knowledge of new motor behavior via different forms of learning. The two forms most commonly studied have been the development of internal models based on sensory-prediction errors (error-based learning) and success-based feedback (reinforcement learning). Human behavioral studies suggest these are distinct learning processes, though the neurophysiological mechanisms that are involved have not been characterized. Here, we evaluated physiological markers from the cerebellum and the primary motor cortex (M1) using noninvasive brain stimulations while healthy participants trained finger-reaching tasks. We manipulated the extent to which subjects rely on error-based or reinforcement by providing either vector or binary feedback about task performance. Our results demonstrated a double dissociation where learning the task mainly via error-based mechanisms leads to cerebellar plasticity modifications but not long-term potentiation (LTP)-like plasticity changes in M1; while learning a similar action via reinforcement mechanisms elicited M1 LTP-like plasticity but not cerebellar plasticity changes. Our findings indicate that learning complex motor behavior is mediated by the interplay of different forms of learning, weighing distinct neural mechanisms in M1 and the cerebellum. Our study provides insights for designing effective interventions to enhance human motor learning. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  12. Enhancing adaptive sparse grid approximations and improving refinement strategies using adjoint-based a posteriori error estimates

    Science.gov (United States)

    Jakeman, J. D.; Wildey, T.

    2015-01-01

    In this paper we present an algorithm for adaptive sparse grid approximations of quantities of interest computed from discretized partial differential equations. We use adjoint-based a posteriori error estimates of the physical discretization error and the interpolation error in the sparse grid to enhance the sparse grid approximation and to drive adaptivity of the sparse grid. Utilizing these error estimates provides significantly more accurate functional values for random samples of the sparse grid approximation. We also demonstrate that alternative refinement strategies based upon a posteriori error estimates can lead to further increases in accuracy in the approximation over traditional hierarchical surplus based strategies. Throughout this paper we also provide and test a framework for balancing the physical discretization error with the stochastic interpolation error of the enhanced sparse grid approximation.

  13. Enhancing adaptive sparse grid approximations and improving refinement strategies using adjoint-based a posteriori error estimates

    International Nuclear Information System (INIS)

    Jakeman, J.D.; Wildey, T.

    2015-01-01

    In this paper we present an algorithm for adaptive sparse grid approximations of quantities of interest computed from discretized partial differential equations. We use adjoint-based a posteriori error estimates of the physical discretization error and the interpolation error in the sparse grid to enhance the sparse grid approximation and to drive adaptivity of the sparse grid. Utilizing these error estimates provides significantly more accurate functional values for random samples of the sparse grid approximation. We also demonstrate that alternative refinement strategies based upon a posteriori error estimates can lead to further increases in accuracy in the approximation over traditional hierarchical surplus based strategies. Throughout this paper we also provide and test a framework for balancing the physical discretization error with the stochastic interpolation error of the enhanced sparse grid approximation

  14. Identification of causes of human errors in support of the development of intelligent computer-assisted instruction systems for plant operator training

    International Nuclear Information System (INIS)

    Furuhama, Yutaka; Furuta, Kazuo; Kondo, Shunsuke

    1995-01-01

    This paper proposes a methodology to identify causes of human error in the operation of plant systems to support the development of CAI system for operator training. The target task of this methodology is goal-driven and knowledge-based planning behaviour, the cognitive process of which is assumed to be modeled as means-end analysis. The methodology uses four criteria to classify errors in an operation into eight groups, and then asks the trainee several questions to prune the causes. To confirm the usefulness of this methodology, a prototype CAI system is developed for the operation of filling up sodium into the primary coolant system of a liquid-metal-cooled fast reactor. The experimental result indicates that the system has the capability of identifying causes of the trainee's error, and consequently of figuring out the characteristics of his/her defect. As a result of this study, several issues are identified for future research

  15. Distinct prediction errors in mesostriatal circuits of the human brain mediate learning about the values of both states and actions: evidence from high-resolution fMRI.

    Science.gov (United States)

    Colas, Jaron T; Pauli, Wolfgang M; Larsen, Tobias; Tyszka, J Michael; O'Doherty, John P

    2017-10-01

    Prediction-error signals consistent with formal models of "reinforcement learning" (RL) have repeatedly been found within dopaminergic nuclei of the midbrain and dopaminoceptive areas of the striatum. However, the precise form of the RL algorithms implemented in the human brain is not yet well determined. Here, we created a novel paradigm optimized to dissociate the subtypes of reward-prediction errors that function as the key computational signatures of two distinct classes of RL models-namely, "actor/critic" models and action-value-learning models (e.g., the Q-learning model). The state-value-prediction error (SVPE), which is independent of actions, is a hallmark of the actor/critic architecture, whereas the action-value-prediction error (AVPE) is the distinguishing feature of action-value-learning algorithms. To test for the presence of these prediction-error signals in the brain, we scanned human participants with a high-resolution functional magnetic-resonance imaging (fMRI) protocol optimized to enable measurement of neural activity in the dopaminergic midbrain as well as the striatal areas to which it projects. In keeping with the actor/critic model, the SVPE signal was detected in the substantia nigra. The SVPE was also clearly present in both the ventral striatum and the dorsal striatum. However, alongside these purely state-value-based computations we also found evidence for AVPE signals throughout the striatum. These high-resolution fMRI findings suggest that model-free aspects of reward learning in humans can be explained algorithmically with RL in terms of an actor/critic mechanism operating in parallel with a system for more direct action-value learning.

  16. Determination of optimal samples for robot calibration based on error similarity

    Directory of Open Access Journals (Sweden)

    Tian Wei

    2015-06-01

    Full Text Available Industrial robots are used for automatic drilling and riveting. The absolute position accuracy of an industrial robot is one of the key performance indexes in aircraft assembly, and can be improved through error compensation to meet aircraft assembly requirements. The achievable accuracy and the difficulty of accuracy compensation implementation are closely related to the choice of sampling points. Therefore, based on the error similarity error compensation method, a method for choosing sampling points on a uniform grid is proposed. A simulation is conducted to analyze the influence of the sample point locations on error compensation. In addition, the grid steps of the sampling points are optimized using a statistical analysis method. The method is used to generate grids and optimize the grid steps of a Kuka KR-210 robot. The experimental results show that the method for planning sampling data can be used to effectively optimize the sampling grid. After error compensation, the position accuracy of the robot meets the position accuracy requirements.

  17. On Inertial Body Tracking in the Presence of Model Calibration Errors.

    Science.gov (United States)

    Miezal, Markus; Taetz, Bertram; Bleser, Gabriele

    2016-07-22

    In inertial body tracking, the human body is commonly represented as a biomechanical model consisting of rigid segments with known lengths and connecting joints. The model state is then estimated via sensor fusion methods based on data from attached inertial measurement units (IMUs). This requires the relative poses of the IMUs w.r.t. the segments-the IMU-to-segment calibrations, subsequently called I2S calibrations-to be known. Since calibration methods based on static poses, movements and manual measurements are still the most widely used, potentially large human-induced calibration errors have to be expected. This work compares three newly developed/adapted extended Kalman filter (EKF) and optimization-based sensor fusion methods with an existing EKF-based method w.r.t. their segment orientation estimation accuracy in the presence of model calibration errors with and without using magnetometer information. While the existing EKF-based method uses a segment-centered kinematic chain biomechanical model and a constant angular acceleration motion model, the newly developed/adapted methods are all based on a free segments model, where each segment is represented with six degrees of freedom in the global frame. Moreover, these methods differ in the assumed motion model (constant angular acceleration, constant angular velocity, inertial data as control input), the state representation (segment-centered, IMU-centered) and the estimation method (EKF, sliding window optimization). In addition to the free segments representation, the optimization-based method also represents each IMU with six degrees of freedom in the global frame. In the evaluation on simulated and real data from a three segment model (an arm), the optimization-based method showed the smallest mean errors, standard deviations and maximum errors throughout all tests. It also showed the lowest dependency on magnetometer information and motion agility. Moreover, it was insensitive w.r.t. I2S position and

  18. A strategy to the development of a human error analysis method for accident management in nuclear power plants using industrial accident dynamics

    International Nuclear Information System (INIS)

    Lee, Yong Hee; Kim, Jae Whan; Jung, Won Dae; Ha, Jae Ju

    1998-06-01

    This technical report describes the early progress of he establishment of a human error analysis method as a part of a human reliability analysis(HRA) method for the assessment of the human error potential in a given accident management strategy. At first, we review the shortages and limitations of the existing HRA methods through an example application. In order to enhance the bias to the quantitative aspect of the HRA method, we focused to the qualitative aspect, i.e., human error analysis(HEA), during the proposition of a strategy to the new method. For the establishment of a new HEA method, we discuss the basic theories and approaches to the human error in industry, and propose three basic requirements that should be maintained as pre-requisites for HEA method in practice. Finally, we test IAD(Industrial Accident Dynamics) which has been widely utilized in industrial fields, in order to know whether IAD can be so easily modified and extended to the nuclear power plant applications. We try to apply IAD to the same example case and develop new taxonomy of the performance shaping factors in accident management and their influence matrix, which could enhance the IAD method as an HEA method. (author). 33 refs., 17 tabs., 20 figs

  19. Results of a nuclear power plant Application of a new technique for human error analysis (ATHEANA)

    International Nuclear Information System (INIS)

    Forester, J.A.; Whitehead, D.W.; Kolaczkowski, A.M.; Thompson, C.M.

    1997-01-01

    A new method to analyze human errors has been demonstrated at a pressurized water reactor (PWR) nuclear power plant. This was the first application of the new method referred to as A Technique for Human Error Analysis (ATHEANA). The main goals of the demonstration were to test the ATHEANA process as described in the frame-of-reference manual and the implementation guideline, test a training package developed for the method, test the hypothesis that plant operators and trainers have significant insight into the error-forcing-contexts (EFCs) that can make unsafe actions (UAs) more likely, and to identify ways to improve the method and its documentation. A set of criteria to evaluate the open-quotes successclose quotes of the ATHEANA method as used in the demonstration was identified. A human reliability analysis (HRA) team was formed that consisted of an expert in probabilistic risk assessment (PRA) with some background in HRA (not ATHEANA) and four personnel from the nuclear power plant. Personnel from the plant included two individuals from their PRA staff and two individuals from their training staff. Both individuals from training are currently licensed operators and one of them was a senior reactor operator open-quotes on shiftclose quotes until a few months before the demonstration. The demonstration was conducted over a 5 month period and was observed by members of the Nuclear Regulatory Commission's ATHEANA development team, who also served as consultants to the HRA team when necessary. Example results of the demonstration to date, including identified human failure events (HFEs), UAs, and EFCs are discussed. Also addressed is how simulator exercises are used in the ATHEANA demonstration project

  20. Error Detection-Based Model to Assess Educational Outcomes in Crisis Resource Management Training: A Pilot Study.

    Science.gov (United States)

    Bouhabel, Sarah; Kay-Rivest, Emily; Nhan, Carol; Bank, Ilana; Nugus, Peter; Fisher, Rachel; Nguyen, Lily Hp

    2017-06-01

    Otolaryngology-head and neck surgery (OTL-HNS) residents face a variety of difficult, high-stress situations, which may occur early in their training. Since these events occur infrequently, simulation-based learning has become an important part of residents' training and is already well established in fields such as anesthesia and emergency medicine. In the domain of OTL-HNS, it is gradually gaining in popularity. Crisis Resource Management (CRM), a program adapted from the aviation industry, aims to improve outcomes of crisis situations by attempting to mitigate human errors. Some examples of CRM principles include cultivating situational awareness; promoting proper use of available resources; and improving rapid decision making, particularly in high-acuity, low-frequency clinical situations. Our pilot project sought to integrate CRM principles into an airway simulation course for OTL-HNS residents, but most important, it evaluated whether learning objectives were met, through use of a novel error identification model.

  1. Learning time-dependent noise to reduce logical errors: real time error rate estimation in quantum error correction

    Science.gov (United States)

    Huo, Ming-Xia; Li, Ying

    2017-12-01

    Quantum error correction is important to quantum information processing, which allows us to reliably process information encoded in quantum error correction codes. Efficient quantum error correction benefits from the knowledge of error rates. We propose a protocol for monitoring error rates in real time without interrupting the quantum error correction. Any adaptation of the quantum error correction code or its implementation circuit is not required. The protocol can be directly applied to the most advanced quantum error correction techniques, e.g. surface code. A Gaussian processes algorithm is used to estimate and predict error rates based on error correction data in the past. We find that using these estimated error rates, the probability of error correction failures can be significantly reduced by a factor increasing with the code distance.

  2. Errors in MR-based attenuation correction for brain imaging with PET/MR scanners

    International Nuclear Information System (INIS)

    Rota Kops, Elena; Herzog, Hans

    2013-01-01

    Aim: Attenuation correction of PET data acquired by hybrid MR/PET scanners remains a challenge, even if several methods for brain and whole-body measurements have been developed recently. A template-based attenuation correction for brain imaging proposed by our group is easy to handle and delivers reliable attenuation maps in a short time. However, some potential error sources are analyzed in this study. We investigated the choice of template reference head among all the available data (error A), and possible skull anomalies of the specific patient, such as discontinuities due to surgery (error B). Materials and methods: An anatomical MR measurement and a 2-bed-position transmission scan covering the whole head and neck region were performed in eight normal subjects (4 females, 4 males). Error A: Taking alternatively one of the eight heads as reference, eight different templates were created by nonlinearly registering the images to the reference and calculating the average. Eight patients (4 females, 4 males; 4 with brain lesions, 4 w/o brain lesions) were measured in the Siemens BrainPET/MR scanner. The eight templates were used to generate the patients' attenuation maps required for reconstruction. ROI and VOI atlas-based comparisons were performed employing all the reconstructed images. Error B: CT-based attenuation maps of two volunteers were manipulated by manually inserting several skull lesions and filling a nasal cavity. The corresponding attenuation coefficients were substituted with the water's coefficient (0.096/cm). Results: Error A: The mean SUVs over the eight templates pairs for all eight patients and all VOIs did not differ significantly one from each other. Standard deviations up to 1.24% were found. Error B: After reconstruction of the volunteers' BrainPET data with the CT-based attenuation maps without and with skull anomalies, a VOI-atlas analysis was performed revealing very little influence of the skull lesions (less than 3%), while the filled

  3. Errors in MR-based attenuation correction for brain imaging with PET/MR scanners

    Science.gov (United States)

    Rota Kops, Elena; Herzog, Hans

    2013-02-01

    AimAttenuation correction of PET data acquired by hybrid MR/PET scanners remains a challenge, even if several methods for brain and whole-body measurements have been developed recently. A template-based attenuation correction for brain imaging proposed by our group is easy to handle and delivers reliable attenuation maps in a short time. However, some potential error sources are analyzed in this study. We investigated the choice of template reference head among all the available data (error A), and possible skull anomalies of the specific patient, such as discontinuities due to surgery (error B). Materials and methodsAn anatomical MR measurement and a 2-bed-position transmission scan covering the whole head and neck region were performed in eight normal subjects (4 females, 4 males). Error A: Taking alternatively one of the eight heads as reference, eight different templates were created by nonlinearly registering the images to the reference and calculating the average. Eight patients (4 females, 4 males; 4 with brain lesions, 4 w/o brain lesions) were measured in the Siemens BrainPET/MR scanner. The eight templates were used to generate the patients' attenuation maps required for reconstruction. ROI and VOI atlas-based comparisons were performed employing all the reconstructed images. Error B: CT-based attenuation maps of two volunteers were manipulated by manually inserting several skull lesions and filling a nasal cavity. The corresponding attenuation coefficients were substituted with the water's coefficient (0.096/cm). ResultsError A: The mean SUVs over the eight templates pairs for all eight patients and all VOIs did not differ significantly one from each other. Standard deviations up to 1.24% were found. Error B: After reconstruction of the volunteers' BrainPET data with the CT-based attenuation maps without and with skull anomalies, a VOI-atlas analysis was performed revealing very little influence of the skull lesions (less than 3%), while the filled nasal

  4. Examining Teaching Based on Errors in Mathematics Amongst Pupils with Learning Disabilities

    Science.gov (United States)

    Magen-Nagar, Noga

    2016-01-01

    Teaching mathematics while learning from students' mistakes, errors and misconceptions, is most important for meaningful learning. This study was based on intervention programs prepared by preservice teachers. It aimed to examine their knowledge of assessment of errors in mathematics amongst pupils with learning disabilities, and their use as a…

  5. A Parallel Decoding Algorithm for Short Polar Codes Based on Error Checking and Correcting

    Science.gov (United States)

    Pan, Xiaofei; Pan, Kegang; Ye, Zhan; Gong, Chao

    2014-01-01

    We propose a parallel decoding algorithm based on error checking and correcting to improve the performance of the short polar codes. In order to enhance the error-correcting capacity of the decoding algorithm, we first derive the error-checking equations generated on the basis of the frozen nodes, and then we introduce the method to check the errors in the input nodes of the decoder by the solutions of these equations. In order to further correct those checked errors, we adopt the method of modifying the probability messages of the error nodes with constant values according to the maximization principle. Due to the existence of multiple solutions of the error-checking equations, we formulate a CRC-aided optimization problem of finding the optimal solution with three different target functions, so as to improve the accuracy of error checking. Besides, in order to increase the throughput of decoding, we use a parallel method based on the decoding tree to calculate probability messages of all the nodes in the decoder. Numerical results show that the proposed decoding algorithm achieves better performance than that of some existing decoding algorithms with the same code length. PMID:25540813

  6. The action characterization matrix: A link between HERA (Human Events Reference for ATHEANA) and ATHEANA (a technique for human error analysis)

    International Nuclear Information System (INIS)

    Hahn, H.A.

    1997-01-01

    The Technique for Human Error Analysis (ATHEANA) is a newly developed human reliability analysis (HRA) methodology that aims to facilitate better representation and integration of human performance into probabilistic risk assessment (PRA) modeling and quantification by analyzing risk-significant operating experience in the context of existing behavior science models. The fundamental premise of ATHEANA is that error-forcing contexts (EFCs), which refer to combinations of equipment/material conditions and performance shaping factors (PSFs), set up or create the conditions under which unsafe actions (UAs) can occur. ATHEANA is being developed in the context of nuclear power plant (NPP) PRAs, and much of the language used to describe the method and provide examples of its application are specific to that industry. Because ATHEANA relies heavily on the analysis of operational events that have already occurred as a mechanism for generating creative thinking about possible EFCs, a database, called the Human Events Reference for ATHEANA (HERA), has been developed to support the methodology. Los Alamos National Laboratory's (LANL) Human Factors Group has recently joined the ATHEANA project team; LANL is responsible for further developing the database structure and for analyzing additional exemplar operational events for entry into the database. The Action Characterization Matrix (ACM) is conceived as a bridge between the HERA database structure and ATHEANA. Specifically, the ACM allows each unsafe action or human failure event to be characterized according to its representation along each of six different dimensions: system status, initiator status, unsafe action mechanism, information processing stage, equipment/material conditions, and performance shaping factors. This report describes the development of the ACM and provides details on the structure and content of its dimensions

  7. ERROR BOUNDS FOR SURFACE AREA ESTIMATORS BASED ON CROFTON’S FORMULA

    Directory of Open Access Journals (Sweden)

    Markus Kiderlen

    2011-05-01

    Full Text Available According to Crofton's formula, the surface area S(A of a sufficiently regular compact set A in Rd is proportional to the mean of all total projections pA (u on a linear hyperplane with normal u, uniformly averaged over all unit vectors u. In applications, pA (u is only measured in k directions and the mean is approximated by a finite weighted sum bS(A of the total projections in these directions. The choice of the weights depends on the selected quadrature rule. We define an associated zonotope Z (depending only on the projection directions and the quadrature rule, and show that the relative error bS (A/S (A is bounded from below by the inradius of Z and from above by the circumradius of Z. Applying a strengthened isoperimetric inequality due to Bonnesen, we show that the rectangular quadrature rule does not give the best possible error bounds for d =2. In addition, we derive asymptotic behavior of the error (with increasing k in the planar case. The paper concludes with applications to surface area estimation in design-based digital stereology where we show that the weights due to Bonnesen's inequality are better than the usual weights based on the rectangular rule and almost optimal in the sense that the relative error of the surface area estimator is very close to the minimal error.

  8. Analysis of translational errors in frame-based and frameless cranial radiosurgery using an anthropomorphic phantom

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Taynna Vernalha Rocha [Faculdades Pequeno Principe (FPP), Curitiba, PR (Brazil); Cordova Junior, Arno Lotar; Almeida, Cristiane Maria; Piedade, Pedro Argolo; Silva, Cintia Mara da, E-mail: taynnavra@gmail.com [Centro de Radioterapia Sao Sebastiao, Florianopolis, SC (Brazil); Brincas, Gabriela R. Baseggio [Centro de Diagnostico Medico Imagem, Florianopolis, SC (Brazil); Marins, Priscila; Soboll, Danyel Scheidegger [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil)

    2016-03-15

    Objective: To evaluate three-dimensional translational setup errors and residual errors in image-guided radiosurgery, comparing frameless and frame-based techniques, using an anthropomorphic phantom. Materials and Methods: We initially used specific phantoms for the calibration and quality control of the image-guided system. For the hidden target test, we used an Alderson Radiation Therapy (ART)-210 anthropomorphic head phantom, into which we inserted four 5- mm metal balls to simulate target treatment volumes. Computed tomography images were the taken with the head phantom properly positioned for frameless and frame-based radiosurgery. Results: For the frameless technique, the mean error magnitude was 0.22 ± 0.04 mm for setup errors and 0.14 ± 0.02 mm for residual errors, the combined uncertainty being 0.28 mm and 0.16 mm, respectively. For the frame-based technique, the mean error magnitude was 0.73 ± 0.14 mm for setup errors and 0.31 ± 0.04 mm for residual errors, the combined uncertainty being 1.15 mm and 0.63 mm, respectively. Conclusion: The mean values, standard deviations, and combined uncertainties showed no evidence of a significant differences between the two techniques when the head phantom ART-210 was used. (author)

  9. Development of a new cause classification method considering plant ageing and human errors for adverse events which occurred in nuclear power plants and some results of its application

    International Nuclear Information System (INIS)

    Miyazaki, Takamasa

    2007-01-01

    The adverse events which occurred in nuclear power plants are analyzed to prevent similar events, and in the analysis of each event, the cause of the event is classified by a cause classification method. This paper shows a new cause classification method which is improved in several points as follows: (1) the whole causes are systematically classified into three major categories such as machine system, operation system and plant outside causes, (2) the causes of the operation system are classified into several management errors normally performed in a nuclear power plant, (3) the content of ageing is defined in detail for their further analysis, (4) human errors are divided and defined by the error stage, (5) human errors can be related to background factors, and so on. This new method is applied to the adverse events which occurred in domestic and overseas nuclear power plants in 2005. From these results, it is clarified that operation system errors account for about 60% of the whole causes, of which approximately 60% are maintenance errors, about 40% are worker's human errors, and that the prevention of maintenance errors, especially worker's human errors is crucial. (author)

  10. Limitations in simulator time-based human reliability analysis methods

    International Nuclear Information System (INIS)

    Wreathall, J.

    1989-01-01

    Developments in human reliability analysis (HRA) methods have evolved slowly. Current methods are little changed from those of almost a decade ago, particularly in the use of time-reliability relationships. While these methods were suitable as an interim step, the time (and the need) has come to specify the next evolution of HRA methods. As with any performance-oriented data source, power plant simulator data have no direct connection to HRA models. Errors reported in data are normal deficiencies observed in human performance; failures are events modeled in probabilistic risk assessments (PRAs). Not all errors cause failures; not all failures are caused by errors. Second, the times at which actions are taken provide no measure of the likelihood of failures to act correctly within an accident scenario. Inferences can be made about human reliability, but they must be made with great care. Specific limitations are discussed. Simulator performance data are useful in providing qualitative evidence of the variety of error types and their potential influences on operating systems. More work is required to combine recent developments in the psychology of error with the qualitative data collected at stimulators. Until data become openly available, however, such an advance will not be practical

  11. Error modeling for surrogates of dynamical systems using machine learning: Machine-learning-based error model for surrogates of dynamical systems

    International Nuclear Information System (INIS)

    Trehan, Sumeet; Carlberg, Kevin T.; Durlofsky, Louis J.

    2017-01-01

    A machine learning–based framework for modeling the error introduced by surrogate models of parameterized dynamical systems is proposed. The framework entails the use of high-dimensional regression techniques (eg, random forests, and LASSO) to map a large set of inexpensively computed “error indicators” (ie, features) produced by the surrogate model at a given time instance to a prediction of the surrogate-model error in a quantity of interest (QoI). This eliminates the need for the user to hand-select a small number of informative features. The methodology requires a training set of parameter instances at which the time-dependent surrogate-model error is computed by simulating both the high-fidelity and surrogate models. Using these training data, the method first determines regression-model locality (via classification or clustering) and subsequently constructs a “local” regression model to predict the time-instantaneous error within each identified region of feature space. We consider 2 uses for the resulting error model: (1) as a correction to the surrogate-model QoI prediction at each time instance and (2) as a way to statistically model arbitrary functions of the time-dependent surrogate-model error (eg, time-integrated errors). We then apply the proposed framework to model errors in reduced-order models of nonlinear oil-water subsurface flow simulations, with time-varying well-control (bottom-hole pressure) parameters. The reduced-order models used in this work entail application of trajectory piecewise linearization in conjunction with proper orthogonal decomposition. Moreover, when the first use of the method is considered, numerical experiments demonstrate consistent improvement in accuracy in the time-instantaneous QoI prediction relative to the original surrogate model, across a large number of test cases. When the second use is considered, results show that the proposed method provides accurate statistical predictions of the time- and well

  12. Why do adult dogs (Canis familiaris) commit the A-not-B search error?

    Science.gov (United States)

    Sümegi, Zsófia; Kis, Anna; Miklósi, Ádám; Topál, József

    2014-02-01

    It has been recently reported that adult domestic dogs, like human infants, tend to commit perseverative search errors; that is, they select the previously rewarded empty location in Piagetian A-not-B search task because of the experimenter's ostensive communicative cues. There is, however, an ongoing debate over whether these findings reveal that dogs can use the human ostensive referential communication as a source of information or the phenomenon can be accounted for by "more simple" explanations like insufficient attention and learning based on local enhancement. In 2 experiments the authors systematically manipulated the type of human cueing (communicative or noncommunicative) adjacent to the A hiding place during both the A and B trials. Results highlight 3 important aspects of the dogs' A-not-B error: (a) search errors are influenced to a certain extent by dogs' motivation to retrieve the toy object; (b) human communicative and noncommunicative signals have different error-inducing effects; and (3) communicative signals presented at the A hiding place during the B trials but not during the A trials play a crucial role in inducing the A-not-B error and it can be induced even without demonstrating repeated hiding events at location A. These findings further confirm the notion that perseverative search error, at least partially, reflects a "ready-to-obey" attitude in the dog rather than insufficient attention and/or working memory.

  13. Information Management System Development for the Characterization and Analysis of Human Error in Naval Aviation Maintenance Related Mishaps

    National Research Council Canada - National Science Library

    Wood, Brian

    2000-01-01

    .... The Human Factors Analysis and Classification System-Maintenance Extension taxonomy, an effective framework for classifying and analyzing the presence of maintenance errors that lead to mishaps...

  14. Analysis of gross error rates in operation of commercial nuclear power stations

    International Nuclear Information System (INIS)

    Joos, D.W.; Sabri, Z.A.; Husseiny, A.A.

    1979-01-01

    Experience in operation of US commercial nuclear power plants is reviewed over a 25-month period. The reports accumulated in that period on events of human error and component failure are examined to evaluate gross operator error rates. The impact of such errors on plant operation and safety is examined through the use of proper taxonomies of error, tasks and failures. Four categories of human errors are considered; namely, operator, maintenance, installation and administrative. The computed error rates are used to examine appropriate operator models for evaluation of operator reliability. Human error rates are found to be significant to a varying degree in both BWR and PWR. This emphasizes the import of considering human factors in safety and reliability analysis of nuclear systems. The results also indicate that human errors, and especially operator errors, do indeed follow the exponential reliability model. (Auth.)

  15. Corpus-Based Websites to Promote Learner Autonomy in Correcting Writing Collocation Errors

    Directory of Open Access Journals (Sweden)

    Pham Thuy Dung

    2016-12-01

    Full Text Available The recent yet powerful emergence of E-learning and using online resources in learning EFL (English as a Foreign Language has helped promote learner autonomy in language acquisition including self-correcting their mistakes. This pilot study despite conducted on a modest sample of 25 second year students majoring in Business English at Hanoi Foreign Trade University is an initial attempt to investigate the feasibility of using corpus-based websites to promote learner autonomy in correcting collocation errors in EFL writing. The data is collected using a pre-questionnaire and a post-interview aiming to find out the participants’ change in belief and attitude toward learner autonomy in collocation errors in writing, the extent of their success in using the corpus-based websites to self-correct the errors and the change in their confidence in self-correcting the errors using the websites. The findings show that a significant majority of students have shifted their belief and attitude toward a more autonomous mode of learning, enjoyed a fair success of using the websites to self-correct the errors and become more confident. The study also yields an implication that a face-to-face training of how to use these online tools is vital to the later confidence and success of the learners

  16. Spacecraft and propulsion technician error

    Science.gov (United States)

    Schultz, Daniel Clyde

    Commercial aviation and commercial space similarly launch, fly, and land passenger vehicles. Unlike aviation, the U.S. government has not established maintenance policies for commercial space. This study conducted a mixed methods review of 610 U.S. space launches from 1984 through 2011, which included 31 failures. An analysis of the failure causal factors showed that human error accounted for 76% of those failures, which included workmanship error accounting for 29% of the failures. With the imminent future of commercial space travel, the increased potential for the loss of human life demands that changes be made to the standardized procedures, training, and certification to reduce human error and failure rates. Several recommendations were made by this study to the FAA's Office of Commercial Space Transportation, space launch vehicle operators, and maintenance technician schools in an effort to increase the safety of the space transportation passengers.

  17. Embracing Errors in Simulation-Based Training: The Effect of Error Training on Retention and Transfer of Central Venous Catheter Skills.

    Science.gov (United States)

    Gardner, Aimee K; Abdelfattah, Kareem; Wiersch, John; Ahmed, Rami A; Willis, Ross E

    2015-01-01

    Error management training is an approach that encourages exposure to errors during initial skill acquisition so that learners can be equipped with important error identification, management, and metacognitive skills. The purpose of this study was to determine how an error-focused training program affected performance, retention, and transfer of central venous catheter (CVC) placement skills when compared with traditional training methodologies. Surgical interns (N = 30) participated in a 1-hour session featuring an instructional video and practice performing internal jugular (IJ) and subclavian (SC) CVC placement with guided instruction. All interns underwent baseline knowledge and skill assessment for IJ and SC (pretest) CVC placement; watched a "correct-only" (CO) or "correct + error" (CE) instructional video; practiced for 30 minutes; and were posttested on knowledge and IJ and SC CVC placement. Skill retention and transfer (femoral CVC placement) were assessed 30 days later. All skills tests (pretest, posttest, and transfer) were videorecorded and deidentified for evaluation by a single blinded instructor using a validated 17-item checklist. Both the groups exhibited significant improvements (p error-based activities and discussions into training programs can be beneficial for skill retention and transfer. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  18. Model-based bootstrapping when correcting for measurement error with application to logistic regression.

    Science.gov (United States)

    Buonaccorsi, John P; Romeo, Giovanni; Thoresen, Magne

    2018-03-01

    When fitting regression models, measurement error in any of the predictors typically leads to biased coefficients and incorrect inferences. A plethora of methods have been proposed to correct for this. Obtaining standard errors and confidence intervals using the corrected estimators can be challenging and, in addition, there is concern about remaining bias in the corrected estimators. The bootstrap, which is one option to address these problems, has received limited attention in this context. It has usually been employed by simply resampling observations, which, while suitable in some situations, is not always formally justified. In addition, the simple bootstrap does not allow for estimating bias in non-linear models, including logistic regression. Model-based bootstrapping, which can potentially estimate bias in addition to being robust to the original sampling or whether the measurement error variance is constant or not, has received limited attention. However, it faces challenges that are not present in handling regression models with no measurement error. This article develops new methods for model-based bootstrapping when correcting for measurement error in logistic regression with replicate measures. The methodology is illustrated using two examples, and a series of simulations are carried out to assess and compare the simple and model-based bootstrap methods, as well as other standard methods. While not always perfect, the model-based approaches offer some distinct improvements over the other methods. © 2017, The International Biometric Society.

  19. Errors in Neonatology

    Directory of Open Access Journals (Sweden)

    Antonio Boldrini

    2013-06-01

    Full Text Available Introduction: Danger and errors are inherent in human activities. In medical practice errors can lean to adverse events for patients. Mass media echo the whole scenario. Methods: We reviewed recent published papers in PubMed database to focus on the evidence and management of errors in medical practice in general and in Neonatology in particular. We compared the results of the literature with our specific experience in Nina Simulation Centre (Pisa, Italy. Results: In Neonatology the main error domains are: medication and total parenteral nutrition, resuscitation and respiratory care, invasive procedures, nosocomial infections, patient identification, diagnostics. Risk factors include patients’ size, prematurity, vulnerability and underlying disease conditions but also multidisciplinary teams, working conditions providing fatigue, a large variety of treatment and investigative modalities needed. Discussion and Conclusions: In our opinion, it is hardly possible to change the human beings but it is likely possible to change the conditions under they work. Voluntary errors report systems can help in preventing adverse events. Education and re-training by means of simulation can be an effective strategy too. In Pisa (Italy Nina (ceNtro di FormazIone e SimulazioNe NeonAtale is a simulation center that offers the possibility of a continuous retraining for technical and non-technical skills to optimize neonatological care strategies. Furthermore, we have been working on a novel skill trainer for mechanical ventilation (MEchatronic REspiratory System SImulator for Neonatal Applications, MERESSINA. Finally, in our opinion national health policy indirectly influences risk for errors. Proceedings of the 9th International Workshop on Neonatology · Cagliari (Italy · October 23rd-26th, 2013 · Learned lessons, changing practice and cutting-edge research

  20. Failures without errors: quantification of context in HRA

    International Nuclear Information System (INIS)

    Fujita, Yushi; Hollnagel, Erik

    2004-01-01

    PSA-cum-human reliability analysis (HRA) has traditionally used individual human actions, hence individual 'human errors', as a meaningful unit of analysis. This is inconsistent with the current understanding of accidents, which points out that the notion of 'human error' is ill defined and that adverse events more often are the due to the working conditions than to people. Several HRA approaches, such as ATHEANA and CREAM have recognised this conflict and proposed ways to deal with it. This paper describes an improvement of the basic screening method in CREAM, whereby a rating of the performance conditions can be used to calculate a Mean Failure Rate directly without invoking the notion of human error

  1. SLIM-MAUD - a computer based technique for human reliability assessment

    International Nuclear Information System (INIS)

    Embrey, D.E.

    1985-01-01

    The Success Likelihood Index Methodology (SLIM) is a widely applicable technique which can be used to assess human error probabilities in both proceduralized and cognitive tasks (i.e. those involving decision making, problem solving, etc.). It assumes that expert assessors are able to evaluate the relative importance (or weights) of different factors called Performance Shaping Factors (PSFs), in determining the likelihood of error for the situations being assessed. Typical PSFs are the extent to which good procedures are available, operators are adequately trained, the man-machine interface is well designed, etc. If numerical ratings are made of the PSFs for the specific tasks being evaluated, these can be combined with the weights to give a numerical index, called the Success Likelihood Index (SLI). The SLI represents, in numerical form, the overall assessment of the experts of the likelihood of task success. The SLI can be subsequently transformed to a corresponding human error probability (HEP) estimate. The latest form of the SLIM technique is implemented using a microcomputer based system called MAUD (Multi-Attribute Utility Decomposition), the resulting technique being called SLIM-MAUD. A detailed description of the SLIM-MAUD technique and case studies of applications are available. An illustrative example of the application of SLIM-MAUD in probabilistic risk assessment is given

  2. Quantification of the effects of dependence on human error probabilities

    International Nuclear Information System (INIS)

    Bell, B.J.; Swain, A.D.

    1980-01-01

    In estimating the probabilities of human error in the performance of a series of tasks in a nuclear power plant, the situation-specific characteristics of the series must be considered. A critical factor not to be overlooked in this estimation is the dependence or independence that pertains to any of the several pairs of task performances. In discussing the quantification of the effects of dependence, the event tree symbology described will be used. In any series of tasks, the only dependence considered for quantification in this document will be that existing between the task of interest and the immediately preceeding task. Tasks performed earlier in the series may have some effect on the end task, but this effect is considered negligible

  3. Particle Filter with Novel Nonlinear Error Model for Miniature Gyroscope-Based Measurement While Drilling Navigation

    Directory of Open Access Journals (Sweden)

    Tao Li

    2016-03-01

    Full Text Available The derivation of a conventional error model for the miniature gyroscope-based measurement while drilling (MGWD system is based on the assumption that the errors of attitude are small enough so that the direction cosine matrix (DCM can be approximated or simplified by the errors of small-angle attitude. However, the simplification of the DCM would introduce errors to the navigation solutions of the MGWD system if the initial alignment cannot provide precise attitude, especially for the low-cost microelectromechanical system (MEMS sensors operated in harsh multilateral horizontal downhole drilling environments. This paper proposes a novel nonlinear error model (NNEM by the introduction of the error of DCM, and the NNEM can reduce the propagated errors under large-angle attitude error conditions. The zero velocity and zero position are the reference points and the innovations in the states estimation of particle filter (PF and Kalman filter (KF. The experimental results illustrate that the performance of PF is better than KF and the PF with NNEM can effectively restrain the errors of system states, especially for the azimuth, velocity, and height in the quasi-stationary condition.

  4. Particle Filter with Novel Nonlinear Error Model for Miniature Gyroscope-Based Measurement While Drilling Navigation.

    Science.gov (United States)

    Li, Tao; Yuan, Gannan; Li, Wang

    2016-03-15

    The derivation of a conventional error model for the miniature gyroscope-based measurement while drilling (MGWD) system is based on the assumption that the errors of attitude are small enough so that the direction cosine matrix (DCM) can be approximated or simplified by the errors of small-angle attitude. However, the simplification of the DCM would introduce errors to the navigation solutions of the MGWD system if the initial alignment cannot provide precise attitude, especially for the low-cost microelectromechanical system (MEMS) sensors operated in harsh multilateral horizontal downhole drilling environments. This paper proposes a novel nonlinear error model (NNEM) by the introduction of the error of DCM, and the NNEM can reduce the propagated errors under large-angle attitude error conditions. The zero velocity and zero position are the reference points and the innovations in the states estimation of particle filter (PF) and Kalman filter (KF). The experimental results illustrate that the performance of PF is better than KF and the PF with NNEM can effectively restrain the errors of system states, especially for the azimuth, velocity, and height in the quasi-stationary condition.

  5. Pollutant forecasting error based on persistence of wind direction

    International Nuclear Information System (INIS)

    Cooper, R.E.

    1978-01-01

    The purpose of this report is to provide a means of estimating the reliability of forecasts of downwind pollutant concentrations from atmospheric puff releases. These forecasts are based on assuming the persistence of wind direction as determined at the time of release. This initial forecast will be used to deploy survey teams, to predict population centers that may be affected, and to estimate the amount of time available for emergency response. Reliability of forecasting is evaluated by developing a cumulative probability distribution of error as a function of lapsed time following an assumed release. The cumulative error is determined by comparing the forecast pollutant concentration with the concentration measured by sampling along the real-time meteorological trajectory. It may be concluded that the assumption of meteorological persistence for emergency response is not very good for periods longer than 3 hours. Even within this period, the possibiity for large error exists due to wind direction shifts. These shifts could affect population areas totally different from those areas first indicated

  6. [Research on demodulation system for human body temperature measurement of intelligent clothing based on arrayed waveguide grating].

    Science.gov (United States)

    Yu, Xiao-gang; Miao, Chang-yun; Li, Hong-qiang; Li, En-bang; Liu, Zhi-hui; Wei, Ke-jia

    2012-08-01

    A system for demodulating distributed fiber Bragg grating sensors of the intelligent clothing was researched and realized, which is based on arrayed waveguide grating. The principle of demodulation method based on arrayed waveguide grating was analyzed, intensity--demodulating method was used to interrogate the wavelength of the fiber Bragg grating based on the building up of an experimental platform, and demodulation experiment of pre and post series of fiber Bragg grating was completed. The results show that the wavelength demodulation of the system has high linearity for fiber Bragg grating, the system gives a wavelength accuracy of 0.001 nm, and demodulation error caused by crosstalk between different sensors is 0.0005 nm. The measurement error of human body temperature is +/- 0.16 degrees C. It can be applied to the human body temperature measurement.

  7. The development of human factors technologies -The development of human behaviour analysis techniques-

    International Nuclear Information System (INIS)

    Lee, Jung Woon; Lee, Yong Heui; Park, Keun Ok; Chun, Se Woo; Suh, Sang Moon; Park, Jae Chang

    1995-07-01

    In order to contribute to human error reduction through the studies on human-machine interaction in nuclear power plants, this project has objectives to develop SACOM(Simulation Analyzer with a Cognitive Operator Model) and techniques for human error analysis and application. In this year, we studied the followings: 1) Site investigation of operator tasks, 2) Development of operator task micro structure and revision of micro structure, 3) Development of knowledge representation software and SACOM prototype, 4) Development of performance assessment methodologies in task simulation and analysis of the effects of performance shaping factors. 1) Classification of error shaping factors(ESFs) and development of software for ESF evaluation, 2) Analysis of human error occurrences and revision of analysis procedure, 3) Experiment for human error data collection using a compact nuclear simulator, 4) Development of a prototype data base system of the analyzed information on trip cases. 55 figs, 23 tabs, 33 refs. (Author)

  8. Evaluating the Performance Diagnostic Checklist-Human Services to Assess Incorrect Error-Correction Procedures by Preschool Paraprofessionals

    Science.gov (United States)

    Bowe, Melissa; Sellers, Tyra P.

    2018-01-01

    The Performance Diagnostic Checklist-Human Services (PDC-HS) has been used to assess variables contributing to undesirable staff performance. In this study, three preschool teachers completed the PDC-HS to identify the factors contributing to four paraprofessionals' inaccurate implementation of error-correction procedures during discrete trial…

  9. An Enhancement of Campaign Posters for Human Error Prevention in NPPs

    International Nuclear Information System (INIS)

    Lee, Yong Hee; Lee, Yong Hee; Kwon, Soon Il

    2010-01-01

    Accidents in high reliability systems such as nuclear power plants (NPPs) give rise to not only a loss of property and life, but also social problems. One of the most frequently used techniques to grasp the current situation for hazard factors in the NPPs is an event investigation analysis based on the INPO's Human Performance Enhancement System (HPES), and the Korean Human Performance Enhancement System (K-HPES) in Korea, respectively. There are many methods and approaches for an HE assessment that is valuable for investigating the causes of undesirable events and counter-plans to prevent their recurrence in the NPPs. They differ from each other according to the objectives of the analysis; the explanation of the event, the investigation of the causes, the allocation of the responsibility, and the establishment of the counter-plan. Event databases include their own events and information from various sources such as the IAEA, regulatory bodies, and also from the INPO and WANO. As many as 111 reactor trips have occurred in the past 5 years ('01∼'05), and 26 cases of them have occurred due to HE. The trend of human error rate didn't decrease in 2004, so the KHNP started to make efforts to decrease HEs. The KHNP created as many as 40 posters for human performance improvement in 2006. The INPO has been using a traditional form of poster; additionally, the Central Research Institute of Electric Power Industry (CRIEPI) developed a type of caution report. The caution report is comprised of a poster name, a serial number, a figure, work situations, the point at issue, and a countermeasure. The preceding posters which KHNP developed in 2006 give a message about specific information related to HE events. However, it is not enough to arouse interest in the effectiveness of the posters because most people are favorably disposed toward a simple poster with many illustrations. Therefore, we stressed the need for worker's receptiveness rather than notification of information

  10. A statistical approach to estimating effects of performance shaping factors on human error probabilities of soft controls

    International Nuclear Information System (INIS)

    Kim, Yochan; Park, Jinkyun; Jung, Wondea; Jang, Inseok; Hyun Seong, Poong

    2015-01-01

    Despite recent efforts toward data collection for supporting human reliability analysis, there remains a lack of empirical basis in determining the effects of performance shaping factors (PSFs) on human error probabilities (HEPs). To enhance the empirical basis regarding the effects of the PSFs, a statistical methodology using a logistic regression and stepwise variable selection was proposed, and the effects of the PSF on HEPs related with the soft controls were estimated through the methodology. For this estimation, more than 600 human error opportunities related to soft controls in a computerized control room were obtained through laboratory experiments. From the eight PSF surrogates and combinations of these variables, the procedure quality, practice level, and the operation type were identified as significant factors for screen switch and mode conversion errors. The contributions of these significant factors to HEPs were also estimated in terms of a multiplicative form. The usefulness and limitation of the experimental data and the techniques employed are discussed herein, and we believe that the logistic regression and stepwise variable selection methods will provide a way to estimate the effects of PSFs on HEPs in an objective manner. - Highlights: • It is necessary to develop an empirical basis for the effects of the PSFs on the HEPs. • A statistical method using a logistic regression and variable selection was proposed. • The effects of PSFs on the HEPs of soft controls were empirically investigated. • The significant factors were identified and their effects were estimated

  11. Investigation on coupling error characteristics in angular rate matching based ship deformation measurement approach

    Science.gov (United States)

    Yang, Shuai; Wu, Wei; Wang, Xingshu; Xu, Zhiguang

    2018-01-01

    The coupling error in the measurement of ship hull deformation can significantly influence the attitude accuracy of the shipborne weapons and equipments. It is therefore important to study the characteristics of the coupling error. In this paper, an comprehensive investigation on the coupling error is reported, which has a potential of deducting the coupling error in the future. Firstly, the causes and characteristics of the coupling error are analyzed theoretically based on the basic theory of measuring ship deformation. Then, simulations are conducted for verifying the correctness of the theoretical analysis. Simulation results show that the cross-correlation between dynamic flexure and ship angular motion leads to the coupling error in measuring ship deformation, and coupling error increases with the correlation value between them. All the simulation results coincide with the theoretical analysis.

  12. Uncertainty quantification in a chemical system using error estimate-based mesh adaption

    International Nuclear Information System (INIS)

    Mathelin, Lionel; Le Maitre, Olivier P.

    2012-01-01

    This paper describes a rigorous a posteriori error analysis for the stochastic solution of non-linear uncertain chemical models. The dual-based a posteriori stochastic error analysis extends the methodology developed in the deterministic finite elements context to stochastic discretization frameworks. It requires the resolution of two additional (dual) problems to yield the local error estimate. The stochastic error estimate can then be used to adapt the stochastic discretization. Different anisotropic refinement strategies are proposed, leading to a cost-efficient tool suitable for multi-dimensional problems of moderate stochastic dimension. The adaptive strategies allow both for refinement and coarsening of the stochastic discretization, as needed to satisfy a prescribed error tolerance. The adaptive strategies were successfully tested on a model for the hydrogen oxidation in supercritical conditions having 8 random parameters. The proposed methodologies are however general enough to be also applicable for a wide class of models such as uncertain fluid flows. (authors)

  13. Dopamine reward prediction error coding

    OpenAIRE

    Schultz, Wolfram

    2016-01-01

    Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards?an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less...

  14. Practical Insights from Initial Studies Related to Human Error Analysis Project (HEAP)

    International Nuclear Information System (INIS)

    Follesoe, Knut; Kaarstad, Magnhild; Droeivoldsmo, Asgeir; Hollnagel, Erik; Kirwan; Barry

    1996-01-01

    This report presents practical insights made from an analysis of the three initial studies in the Human Error Analysis Project (HEAP), and the first study in the US NRC Staffing Project. These practical insights relate to our understanding of diagnosis in Nuclear Power Plant (NPP) emergency scenarios and, in particular, the factors that influence whether a diagnosis will succeed or fail. The insights reported here focus on three inter-related areas: (1) the diagnostic strategies and styles that have been observed in single operator and team-based studies; (2) the qualitative aspects of the key operator support systems, namely VDU interfaces, alarms, training and procedures, that have affected the outcome of diagnosis; and (3) the overall success rates of diagnosis and the error types that have been observed in the various studies. With respect to diagnosis, certain patterns have emerged from the various studies, depending on whether operators were alone or in teams, and on their familiarity with the process. Some aspects of the interface and alarm systems were found to contribute to diagnostic failures while others supported performance and recovery. Similar results were found for training and experience. Furthermore, the availability of procedures did not preclude the need for some diagnosis. With respect to HRA and PSA, it was possible to record the failure types seen in the studies, and in some cases to give crude estimates of the failure likelihood for certain scenarios. Although these insights are interim in nature, they do show the type of information that can be derived from these studies. More importantly, they clarify aspects of our understanding of diagnosis in NPP emergencies, including implications for risk assessment, operator support systems development, and for research into diagnosis in a broader range of fields than the nuclear power industry. (author)

  15. Emmetropisation and the aetiology of refractive errors

    Science.gov (United States)

    Flitcroft, D I

    2014-01-01

    The distribution of human refractive errors displays features that are not commonly seen in other biological variables. Compared with the more typical Gaussian distribution, adult refraction within a population typically has a negative skew and increased kurtosis (ie is leptokurtotic). This distribution arises from two apparently conflicting tendencies, first, the existence of a mechanism to control eye growth during infancy so as to bring refraction towards emmetropia/low hyperopia (ie emmetropisation) and second, the tendency of many human populations to develop myopia during later childhood and into adulthood. The distribution of refraction therefore changes significantly with age. Analysis of the processes involved in shaping refractive development allows for the creation of a life course model of refractive development. Monte Carlo simulations based on such a model can recreate the variation of refractive distributions seen from birth to adulthood and the impact of increasing myopia prevalence on refractive error distributions in Asia. PMID:24406411

  16. Real-time prediction of atmospheric Lagrangian coherent structures based on forecast data: An application and error analysis

    Science.gov (United States)

    BozorgMagham, Amir E.; Ross, Shane D.; Schmale, David G.

    2013-09-01

    The language of Lagrangian coherent structures (LCSs) provides a new means for studying transport and mixing of passive particles advected by an atmospheric flow field. Recent observations suggest that LCSs govern the large-scale atmospheric motion of airborne microorganisms, paving the way for more efficient models and management strategies for the spread of infectious diseases affecting plants, domestic animals, and humans. In addition, having reliable predictions of the timing of hyperbolic LCSs may contribute to improved aerobiological sampling of microorganisms with unmanned aerial vehicles and LCS-based early warning systems. Chaotic atmospheric dynamics lead to unavoidable forecasting errors in the wind velocity field, which compounds errors in LCS forecasting. In this study, we reveal the cumulative effects of errors of (short-term) wind field forecasts on the finite-time Lyapunov exponent (FTLE) fields and the associated LCSs when realistic forecast plans impose certain limits on the forecasting parameters. Objectives of this paper are to (a) quantify the accuracy of prediction of FTLE-LCS features and (b) determine the sensitivity of such predictions to forecasting parameters. Results indicate that forecasts of attracting LCSs exhibit less divergence from the archive-based LCSs than the repelling features. This result is important since attracting LCSs are the backbone of long-lived features in moving fluids. We also show under what circumstances one can trust the forecast results if one merely wants to know if an LCS passed over a region and does not need to precisely know the passage time.

  17. Mitigating Errors in External Respiratory Surrogate-Based Models of Tumor Position

    International Nuclear Information System (INIS)

    Malinowski, Kathleen T.; McAvoy, Thomas J.; George, Rohini; Dieterich, Sonja; D'Souza, Warren D.

    2012-01-01

    Purpose: To investigate the effect of tumor site, measurement precision, tumor–surrogate correlation, training data selection, model design, and interpatient and interfraction variations on the accuracy of external marker-based models of tumor position. Methods and Materials: Cyberknife Synchrony system log files comprising synchronously acquired positions of external markers and the tumor from 167 treatment fractions were analyzed. The accuracy of Synchrony, ordinary-least-squares regression, and partial-least-squares regression models for predicting the tumor position from the external markers was evaluated. The quantity and timing of the data used to build the predictive model were varied. The effects of tumor–surrogate correlation and the precision in both the tumor and the external surrogate position measurements were explored by adding noise to the data. Results: The tumor position prediction errors increased during the duration of a fraction. Increasing the training data quantities did not always lead to more accurate models. Adding uncorrelated noise to the external marker-based inputs degraded the tumor–surrogate correlation models by 16% for partial-least-squares and 57% for ordinary-least-squares. External marker and tumor position measurement errors led to tumor position prediction changes 0.3–3.6 times the magnitude of the measurement errors, varying widely with model algorithm. The tumor position prediction errors were significantly associated with the patient index but not with the fraction index or tumor site. Partial-least-squares was as accurate as Synchrony and more accurate than ordinary-least-squares. Conclusions: The accuracy of surrogate-based inferential models of tumor position was affected by all the investigated factors, except for the tumor site and fraction index.

  18. Mitigating Errors in External Respiratory Surrogate-Based Models of Tumor Position

    Energy Technology Data Exchange (ETDEWEB)

    Malinowski, Kathleen T. [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States); McAvoy, Thomas J. [Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States); Department of Chemical and Biomolecular Engineering and Institute of Systems Research, University of Maryland, College Park, MD (United States); George, Rohini [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Dieterich, Sonja [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); D' Souza, Warren D., E-mail: wdsou001@umaryland.edu [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States)

    2012-04-01

    Purpose: To investigate the effect of tumor site, measurement precision, tumor-surrogate correlation, training data selection, model design, and interpatient and interfraction variations on the accuracy of external marker-based models of tumor position. Methods and Materials: Cyberknife Synchrony system log files comprising synchronously acquired positions of external markers and the tumor from 167 treatment fractions were analyzed. The accuracy of Synchrony, ordinary-least-squares regression, and partial-least-squares regression models for predicting the tumor position from the external markers was evaluated. The quantity and timing of the data used to build the predictive model were varied. The effects of tumor-surrogate correlation and the precision in both the tumor and the external surrogate position measurements were explored by adding noise to the data. Results: The tumor position prediction errors increased during the duration of a fraction. Increasing the training data quantities did not always lead to more accurate models. Adding uncorrelated noise to the external marker-based inputs degraded the tumor-surrogate correlation models by 16% for partial-least-squares and 57% for ordinary-least-squares. External marker and tumor position measurement errors led to tumor position prediction changes 0.3-3.6 times the magnitude of the measurement errors, varying widely with model algorithm. The tumor position prediction errors were significantly associated with the patient index but not with the fraction index or tumor site. Partial-least-squares was as accurate as Synchrony and more accurate than ordinary-least-squares. Conclusions: The accuracy of surrogate-based inferential models of tumor position was affected by all the investigated factors, except for the tumor site and fraction index.

  19. Human error risk management for engineering systems: a methodology for design, safety assessment, accident investigation and training

    International Nuclear Information System (INIS)

    Cacciabue, P.C.

    2004-01-01

    The objective of this paper is to tackle methodological issues associated with the inclusion of cognitive and dynamic considerations into Human Reliability methods. A methodology called Human Error Risk Management for Engineering Systems is presented that offers a 'roadmap' for selecting and consistently applying Human Factors approaches in different areas of application and contains also a 'body' of possible methods and techniques of its own. Two types of possible application are discussed to demonstrate practical applications of the methodology. Specific attention is dedicated to the issue of data collection and definition from specific field assessment

  20. Automated contouring error detection based on supervised geometric attribute distribution models for radiation therapy: A general strategy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hsin-Chen; Tan, Jun; Dolly, Steven; Kavanaugh, James; Harold Li, H.; Altman, Michael; Gay, Hiram; Thorstad, Wade L.; Mutic, Sasa; Li, Hua, E-mail: huli@radonc.wustl.edu [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States); Anastasio, Mark A. [Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63110 (United States); Low, Daniel A. [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California 90095 (United States)

    2015-02-15

    Purpose: One of the most critical steps in radiation therapy treatment is accurate tumor and critical organ-at-risk (OAR) contouring. Both manual and automated contouring processes are prone to errors and to a large degree of inter- and intraobserver variability. These are often due to the limitations of imaging techniques in visualizing human anatomy as well as to inherent anatomical variability among individuals. Physicians/physicists have to reverify all the radiation therapy contours of every patient before using them for treatment planning, which is tedious, laborious, and still not an error-free process. In this study, the authors developed a general strategy based on novel geometric attribute distribution (GAD) models to automatically detect radiation therapy OAR contouring errors and facilitate the current clinical workflow. Methods: Considering the radiation therapy structures’ geometric attributes (centroid, volume, and shape), the spatial relationship of neighboring structures, as well as anatomical similarity of individual contours among patients, the authors established GAD models to characterize the interstructural centroid and volume variations, and the intrastructural shape variations of each individual structure. The GAD models are scalable and deformable, and constrained by their respective principal attribute variations calculated from training sets with verified OAR contours. A new iterative weighted GAD model-fitting algorithm was developed for contouring error detection. Receiver operating characteristic (ROC) analysis was employed in a unique way to optimize the model parameters to satisfy clinical requirements. A total of forty-four head-and-neck patient cases, each of which includes nine critical OAR contours, were utilized to demonstrate the proposed strategy. Twenty-nine out of these forty-four patient cases were utilized to train the inter- and intrastructural GAD models. These training data and the remaining fifteen testing data sets

  1. Automated contouring error detection based on supervised geometric attribute distribution models for radiation therapy: A general strategy

    International Nuclear Information System (INIS)

    Chen, Hsin-Chen; Tan, Jun; Dolly, Steven; Kavanaugh, James; Harold Li, H.; Altman, Michael; Gay, Hiram; Thorstad, Wade L.; Mutic, Sasa; Li, Hua; Anastasio, Mark A.; Low, Daniel A.

    2015-01-01

    Purpose: One of the most critical steps in radiation therapy treatment is accurate tumor and critical organ-at-risk (OAR) contouring. Both manual and automated contouring processes are prone to errors and to a large degree of inter- and intraobserver variability. These are often due to the limitations of imaging techniques in visualizing human anatomy as well as to inherent anatomical variability among individuals. Physicians/physicists have to reverify all the radiation therapy contours of every patient before using them for treatment planning, which is tedious, laborious, and still not an error-free process. In this study, the authors developed a general strategy based on novel geometric attribute distribution (GAD) models to automatically detect radiation therapy OAR contouring errors and facilitate the current clinical workflow. Methods: Considering the radiation therapy structures’ geometric attributes (centroid, volume, and shape), the spatial relationship of neighboring structures, as well as anatomical similarity of individual contours among patients, the authors established GAD models to characterize the interstructural centroid and volume variations, and the intrastructural shape variations of each individual structure. The GAD models are scalable and deformable, and constrained by their respective principal attribute variations calculated from training sets with verified OAR contours. A new iterative weighted GAD model-fitting algorithm was developed for contouring error detection. Receiver operating characteristic (ROC) analysis was employed in a unique way to optimize the model parameters to satisfy clinical requirements. A total of forty-four head-and-neck patient cases, each of which includes nine critical OAR contours, were utilized to demonstrate the proposed strategy. Twenty-nine out of these forty-four patient cases were utilized to train the inter- and intrastructural GAD models. These training data and the remaining fifteen testing data sets

  2. A Model-based Framework for Risk Assessment in Human-Computer Controlled Systems

    Science.gov (United States)

    Hatanaka, Iwao

    2000-01-01

    The rapid growth of computer technology and innovation has played a significant role in the rise of computer automation of human tasks in modem production systems across all industries. Although the rationale for automation has been to eliminate "human error" or to relieve humans from manual repetitive tasks, various computer-related hazards and accidents have emerged as a direct result of increased system complexity attributed to computer automation. The risk assessment techniques utilized for electromechanical systems are not suitable for today's software-intensive systems or complex human-computer controlled systems. This thesis will propose a new systemic model-based framework for analyzing risk in safety-critical systems where both computers and humans are controlling safety-critical functions. A new systems accident model will be developed based upon modem systems theory and human cognitive processes to better characterize system accidents, the role of human operators, and the influence of software in its direct control of significant system functions. Better risk assessments will then be achievable through the application of this new framework to complex human-computer controlled systems.

  3. Organizational change and human expertise in nuclear power plants: some implications for training and error prevention

    International Nuclear Information System (INIS)

    Masson, M.; Malaise, N.; Housiaux, A.; Keyser, V. de

    1993-01-01

    Reliability and safety are two very important goals, which depend on technical and organizational factors, but also on human expertise. How to ensure a safe functioning of a nuclear power plant in a changing context, and what might be the role and aspects of training and transfer of knowledge? These are the questions we shall deal with in this paper, on the basis of two field studies. The two field studies stress the needs for setting up case based training, which best ensure the acquisition of know-how. Furthermore, as shown by the second one, gaining expertise involves developing large repertoires of highly skilled, semi-routinized activities. Supporting expert operators not only should tackle problem solving activities but should thus also include the prevention of routine errors, which go along with skill acquisition. (orig.)

  4. Human behaviour in PSA

    International Nuclear Information System (INIS)

    Schott, H.

    1999-01-01

    Based on the current international state of the art of methodology for evaluation of human errors for PSA, many research projects have been initiated by the competent departments of the BMU and the BfS (Federal Min. of the Environment and Reactor Safety, Federal Radiation Protection Office). Three major areas of the research activities are discussed: Database: - Specific investigations into the applicability of generic data (THERP) to other than the original cases, possibly elaboration of approaches for application-specific modification, further evaluation of operating results; - general enhancement of insight into human performance and errors, e.g. with respect to causes of error and application areas (influence of organisation, cognitive performance); interviews with experts as a supplementary approach for data verification and database enhancement. Sensitivity analysis: - Identification of information describing human errors essentially contributing to frequency of occurrence of incidents and system non-availability; - establishment of relevance rating system, methodology for uncertainty analysis. Further development of methodology: - Modelling of repair activities and knowledge-based behaviour. (orig./CB) [de

  5. An Error Analysis of Structured Light Scanning of Biological Tissue

    DEFF Research Database (Denmark)

    Jensen, Sebastian Hoppe Nesgaard; Wilm, Jakob; Aanæs, Henrik

    2017-01-01

    This paper presents an error analysis and correction model for four structured light methods applied to three common types of biological tissue; skin, fat and muscle. Despite its many advantages, structured light is based on the assumption of direct reflection at the object surface only......, statistical linear model based on the scan geometry. As such, scans can be corrected without introducing any specially designed pattern strategy or hardware. We can effectively reduce the error in a structured light scanner applied to biological tissue by as much as factor of two or three........ This assumption is violated by most biological material e.g. human skin, which exhibits subsurface scattering. In this study, we find that in general, structured light scans of biological tissue deviate significantly from the ground truth. We show that a large portion of this error can be predicted with a simple...

  6. Comprehensive Anti-error Study on Power Grid Dispatching Based on Regional Regulation and Integration

    Science.gov (United States)

    Zhang, Yunju; Chen, Zhongyi; Guo, Ming; Lin, Shunsheng; Yan, Yinyang

    2018-01-01

    With the large capacity of the power system, the development trend of the large unit and the high voltage, the scheduling operation is becoming more frequent and complicated, and the probability of operation error increases. This paper aims at the problem of the lack of anti-error function, single scheduling function and low working efficiency for technical support system in regional regulation and integration, the integrated construction of the error prevention of the integrated architecture of the system of dispatching anti - error of dispatching anti - error of power network based on cloud computing has been proposed. Integrated system of error prevention of Energy Management System, EMS, and Operation Management System, OMS have been constructed either. The system architecture has good scalability and adaptability, which can improve the computational efficiency, reduce the cost of system operation and maintenance, enhance the ability of regional regulation and anti-error checking with broad development prospects.

  7. Potentiometric Measurement of Transition Ranges and Titration Errors for Acid/Base Indicators

    Science.gov (United States)

    Flowers, Paul A.

    1997-07-01

    Sophomore analytical chemistry courses typically devote a substantial amount of lecture time to acid/base equilibrium theory, and usually include at least one laboratory project employing potentiometric titrations. In an effort to provide students a laboratory experience that more directly supports their classroom discussions on this important topic, an experiment involving potentiometric measurement of transition ranges and titration errors for common acid/base indicators has been developed. The pH and visually-assessed color of a millimolar strong acid/base system are monitored as a function of added titrant volume, and the resultant data plotted to permit determination of the indicator's transition range and associated titration error. Student response is typically quite positive, and the measured quantities correlate reasonably well to literature values.

  8. Sample Size Bounding and Context Ranking as Approaches to the Human Error Quantification Problem

    Energy Technology Data Exchange (ETDEWEB)

    Reer, B

    2004-03-01

    The paper describes a technique denoted as Sub-Sample-Size Bounding (SSSB), which is useable for the statistical derivation of context-specific probabilities from data available in existing reports on operating experience. Applications to human reliability analysis (HRA) are emphasised in the presentation of this technique. Exemplified by a sample of 180 abnormal event sequences, the manner in which SSSB can provide viable input for the quantification of errors of commission (EOCs) are outlined. (author)

  9. Sample Size Bounding and Context Ranking as Approaches to the Human Error Quantification Problem

    International Nuclear Information System (INIS)

    Reer, B.

    2004-01-01

    The paper describes a technique denoted as Sub-Sample-Size Bounding (SSSB), which is useable for the statistical derivation of context-specific probabilities from data available in existing reports on operating experience. Applications to human reliability analysis (HRA) are emphasised in the presentation of this technique. Exemplified by a sample of 180 abnormal event sequences, the manner in which SSSB can provide viable input for the quantification of errors of commission (EOCs) are outlined. (author)

  10. Differences among Job Positions Related to Communication Errors at Construction Sites

    Science.gov (United States)

    Takahashi, Akiko; Ishida, Toshiro

    In a previous study, we classified the communicatio n errors at construction sites as faulty intention and message pattern, inadequate channel pattern, and faulty comprehension pattern. This study seeks to evaluate the degree of risk of communication errors and to investigate differences among people in various job positions in perception of communication error risk . Questionnaires based on the previous study were a dministered to construction workers (n=811; 149 adminis trators, 208 foremen and 454 workers). Administrators evaluated all patterns of communication error risk equally. However, foremen and workers evaluated communication error risk differently in each pattern. The common contributing factors to all patterns wer e inadequate arrangements before work and inadequate confirmation. Some factors were common among patterns but other factors were particular to a specific pattern. To help prevent future accidents at construction sites, administrators should understand how people in various job positions perceive communication errors and propose human factors measures to prevent such errors.

  11. MEDICAL ERROR: CIVIL AND LEGAL ASPECT.

    Science.gov (United States)

    Buletsa, S; Drozd, O; Yunin, O; Mohilevskyi, L

    2018-03-01

    The scientific article is focused on the research of the notion of medical error, medical and legal aspects of this notion have been considered. The necessity of the legislative consolidation of the notion of «medical error» and criteria of its legal estimation have been grounded. In the process of writing a scientific article, we used the empirical method, general scientific and comparative legal methods. A comparison of the concept of medical error in civil and legal aspects was made from the point of view of Ukrainian, European and American scientists. It has been marked that the problem of medical errors is known since ancient times and in the whole world, in fact without regard to the level of development of medicine, there is no country, where doctors never make errors. According to the statistics, medical errors in the world are included in the first five reasons of death rate. At the same time the grant of medical services practically concerns all people. As a man and his life, health in Ukraine are acknowledged by a higher social value, medical services must be of high-quality and effective. The grant of not quality medical services causes harm to the health, and sometimes the lives of people; it may result in injury or even death. The right to the health protection is one of the fundamental human rights assured by the Constitution of Ukraine; therefore the issue of medical errors and liability for them is extremely relevant. The authors make conclusions, that the definition of the notion of «medical error» must get the legal consolidation. Besides, the legal estimation of medical errors must be based on the single principles enshrined in the legislation and confirmed by judicial practice.

  12. Self-test web-based pure-tone audiometry: validity evaluation and measurement error analysis.

    Science.gov (United States)

    Masalski, Marcin; Kręcicki, Tomasz

    2013-04-12

    Potential methods of application of self-administered Web-based pure-tone audiometry conducted at home on a PC with a sound card and ordinary headphones depend on the value of measurement error in such tests. The aim of this research was to determine the measurement error of the hearing threshold determined in the way described above and to identify and analyze factors influencing its value. The evaluation of the hearing threshold was made in three series: (1) tests on a clinical audiometer, (2) self-tests done on a specially calibrated computer under the supervision of an audiologist, and (3) self-tests conducted at home. The research was carried out on the group of 51 participants selected from patients of an audiology outpatient clinic. From the group of 51 patients examined in the first two series, the third series was self-administered at home by 37 subjects (73%). The average difference between the value of the hearing threshold determined in series 1 and in series 2 was -1.54dB with standard deviation of 7.88dB and a Pearson correlation coefficient of .90. Between the first and third series, these values were -1.35dB±10.66dB and .84, respectively. In series 3, the standard deviation was most influenced by the error connected with the procedure of hearing threshold identification (6.64dB), calibration error (6.19dB), and additionally at the frequency of 250Hz by frequency nonlinearity error (7.28dB). The obtained results confirm the possibility of applying Web-based pure-tone audiometry in screening tests. In the future, modifications of the method leading to the decrease in measurement error can broaden the scope of Web-based pure-tone audiometry application.

  13. VR-based training and assessment in ultrasound-guided regional anesthesia: from error analysis to system design.

    LENUS (Irish Health Repository)

    2011-01-01

    If VR-based medical training and assessment is to improve patient care and safety (i.e. a genuine health gain), it has to be based on clinically relevant measurement of performance. Metrics on errors are particularly useful for capturing and correcting undesired behaviors before they occur in the operating room. However, translating clinically relevant metrics and errors into meaningful system design is a challenging process. This paper discusses how an existing task and error analysis was translated into the system design of a VR-based training and assessment environment for Ultrasound Guided Regional Anesthesia (UGRA).

  14. Functional requirements for the man-vehicle systems research facility. [identifying and correcting human errors during flight simulation

    Science.gov (United States)

    Clement, W. F.; Allen, R. W.; Heffley, R. K.; Jewell, W. F.; Jex, H. R.; Mcruer, D. T.; Schulman, T. M.; Stapleford, R. L.

    1980-01-01

    The NASA Ames Research Center proposed a man-vehicle systems research facility to support flight simulation studies which are needed for identifying and correcting the sources of human error associated with current and future air carrier operations. The organization of research facility is reviewed and functional requirements and related priorities for the facility are recommended based on a review of potentially critical operational scenarios. Requirements are included for the experimenter's simulation control and data acquisition functions, as well as for the visual field, motion, sound, computation, crew station, and intercommunications subsystems. The related issues of functional fidelity and level of simulation are addressed, and specific criteria for quantitative assessment of various aspects of fidelity are offered. Recommendations for facility integration, checkout, and staffing are included.

  15. Estimating misclassification error: a closer look at cross-validation based methods

    Directory of Open Access Journals (Sweden)

    Ounpraseuth Songthip

    2012-11-01

    Full Text Available Abstract Background To estimate a classifier’s error in predicting future observations, bootstrap methods have been proposed as reduced-variation alternatives to traditional cross-validation (CV methods based on sampling without replacement. Monte Carlo (MC simulation studies aimed at estimating the true misclassification error conditional on the training set are commonly used to compare CV methods. We conducted an MC simulation study to compare a new method of bootstrap CV (BCV to k-fold CV for estimating clasification error. Findings For the low-dimensional conditions simulated, the modest positive bias of k-fold CV contrasted sharply with the substantial negative bias of the new BCV method. This behavior was corroborated using a real-world dataset of prognostic gene-expression profiles in breast cancer patients. Our simulation results demonstrate some extreme characteristics of variance and bias that can occur due to a fault in the design of CV exercises aimed at estimating the true conditional error of a classifier, and that appear not to have been fully appreciated in previous studies. Although CV is a sound practice for estimating a classifier’s generalization error, using CV to estimate the fixed misclassification error of a trained classifier conditional on the training set is problematic. While MC simulation of this estimation exercise can correctly represent the average bias of a classifier, it will overstate the between-run variance of the bias. Conclusions We recommend k-fold CV over the new BCV method for estimating a classifier’s generalization error. The extreme negative bias of BCV is too high a price to pay for its reduced variance.

  16. The organizational context of error tolerant interface systems

    International Nuclear Information System (INIS)

    Sepanloo, K.; Meshkati, N.; Kozuh, M.

    1995-01-01

    Human error has been recognized as the main contributor to the occurrence of incidents in large technological systems such as nuclear power plants. Recent researches have concluded that human errors are unavoidable side effects of exploration of acceptable performance during adaptation to the unknown changes in the environment. To assist the operators in coping with unforeseen situations, the innovative error tolerant interface systems have been proposed to provide the operators with opportunities to make hypothetical tests without having to carry them out directly on the plant in potentially irreversible conditions. On the other hand, the degree of success of introduction of any new system into a tightly-coupled complex socio-technological system is known to be a great deal dependent upon the degree of harmony of that system with the organization s framework and attitudes. Error tolerant interface systems with features of simplicity, transparency, error detectability and recoverability provide a forgiving cognition environment where the effects of errors are observable and recoverable. The nature of these systems are likely to be more consistent with flexible and rather plain organizational structures, in which static and punitive concepts of human error are modified on the favour of dynamic and adaptive approaches. In this paper the features of error tolerant interface systems are explained and their consistent organizational structures are explored. (author)

  17. The organizational context of error tolerant interface systems

    Energy Technology Data Exchange (ETDEWEB)

    Sepanloo, K [Nuclear Safety Department, Tehran (Iran, Islamic Republic of); Meshkati, N [Institute of Safety and Systems Management, Los Angeles (United States); Kozuh, M [Josef Stefan Institute, Ljubljana (Slovenia)

    1996-12-31

    Human error has been recognized as the main contributor to the occurrence of incidents in large technological systems such as nuclear power plants. Recent researches have concluded that human errors are unavoidable side effects of exploration of acceptable performance during adaptation to the unknown changes in the environment. To assist the operators in coping with unforeseen situations, the innovative error tolerant interface systems have been proposed to provide the operators with opportunities to make hypothetical tests without having to carry them out directly on the plant in potentially irreversible conditions. On the other hand, the degree of success of introduction of any new system into a tightly-coupled complex socio-technological system is known to be a great deal dependent upon the degree of harmony of that system with the organization s framework and attitudes. Error tolerant interface systems with features of simplicity, transparency, error detectability and recoverability provide a forgiving cognition environment where the effects of errors are observable and recoverable. The nature of these systems are likely to be more consistent with flexible and rather plain organizational structures, in which static and punitive concepts of human error are modified on the favour of dynamic and adaptive approaches. In this paper the features of error tolerant interface systems are explained and their consistent organizational structures are explored. (author) 11 refs.

  18. Alternatives to accuracy and bias metrics based on percentage errors for radiation belt modeling applications

    Energy Technology Data Exchange (ETDEWEB)

    Morley, Steven Karl [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-07-01

    This report reviews existing literature describing forecast accuracy metrics, concentrating on those based on relative errors and percentage errors. We then review how the most common of these metrics, the mean absolute percentage error (MAPE), has been applied in recent radiation belt modeling literature. Finally, we describe metrics based on the ratios of predicted to observed values (the accuracy ratio) that address the drawbacks inherent in using MAPE. Specifically, we define and recommend the median log accuracy ratio as a measure of bias and the median symmetric accuracy as a measure of accuracy.

  19. Review of advances in human reliability analysis of errors of commission, Part 1: EOC identification

    International Nuclear Information System (INIS)

    Reer, Bernhard

    2008-01-01

    In close connection with examples relevant to contemporary probabilistic safety assessment (PSA), a review of advances in human reliability analysis (HRA) of post-initiator errors of commission (EOCs), i.e. inappropriate actions under abnormal operating conditions, has been carried out. The review comprises both EOC identification (part 1) and quantification (part 2); part 1 is presented in this article. Emerging HRA methods addressing the problem of EOC identification are: A Technique for Human Event Analysis (ATHEANA), the EOC HRA method developed by Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS), the Misdiagnosis Tree Analysis (MDTA) method, and the Commission Errors Search and Assessment (CESA) method. Most of the EOCs referred to in predictive studies comprise the stop of running or the inhibition of anticipated functions; a few comprise the start of a function. The CESA search scheme-which proceeds from possible operator actions to the affected systems to scenarios and uses procedures and importance measures as key sources of input information-provides a formalized way for identifying relatively important scenarios with EOC opportunities. In the implementation however, attention should be paid regarding EOCs associated with familiar but non-procedural actions and EOCs leading to failures of manually initiated safety functions

  20. Standardized Procedure Content And Data Structure Based On Human Factors Requirements For Computer-Based Procedures

    International Nuclear Information System (INIS)

    Bly, Aaron; Oxstrand, Johanna; Le Blanc, Katya L

    2015-01-01

    Most activities that involve human interaction with systems in a nuclear power plant are guided by procedures. Traditionally, the use of procedures has been a paper-based process that supports safe operation of the nuclear power industry. However, the nuclear industry is constantly trying to find ways to decrease the human error rate, especially the human errors associated with procedure use. Advances in digital technology make computer-based procedures (CBPs) a valid option that provides further enhancement of safety by improving human performance related to procedure use. The transition from paper-based procedures (PBPs) to CBPs creates a need for a computer-based procedure system (CBPS). A CBPS needs to have the ability to perform logical operations in order to adjust to the inputs received from either users or real time data from plant status databases. Without the ability for logical operations the procedure is just an electronic copy of the paper-based procedure. In order to provide the CBPS with the information it needs to display the procedure steps to the user, special care is needed in the format used to deliver all data and instructions to create the steps. The procedure should be broken down into basic elements and formatted in a standard method for the CBPS. One way to build the underlying data architecture is to use an Extensible Markup Language (XML) schema, which utilizes basic elements to build each step in the smart procedure. The attributes of each step will determine the type of functionality that the system will generate for that step. The CBPS will provide the context for the step to deliver referential information, request a decision, or accept input from the user. The XML schema needs to provide all data necessary for the system to accurately perform each step without the need for the procedure writer to reprogram the CBPS. The research team at the Idaho National Laboratory has developed a prototype CBPS for field workers as well as the

  1. Standardized Procedure Content And Data Structure Based On Human Factors Requirements For Computer-Based Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Bly, Aaron; Oxstrand, Johanna; Le Blanc, Katya L

    2015-02-01

    Most activities that involve human interaction with systems in a nuclear power plant are guided by procedures. Traditionally, the use of procedures has been a paper-based process that supports safe operation of the nuclear power industry. However, the nuclear industry is constantly trying to find ways to decrease the human error rate, especially the human errors associated with procedure use. Advances in digital technology make computer-based procedures (CBPs) a valid option that provides further enhancement of safety by improving human performance related to procedure use. The transition from paper-based procedures (PBPs) to CBPs creates a need for a computer-based procedure system (CBPS). A CBPS needs to have the ability to perform logical operations in order to adjust to the inputs received from either users or real time data from plant status databases. Without the ability for logical operations the procedure is just an electronic copy of the paper-based procedure. In order to provide the CBPS with the information it needs to display the procedure steps to the user, special care is needed in the format used to deliver all data and instructions to create the steps. The procedure should be broken down into basic elements and formatted in a standard method for the CBPS. One way to build the underlying data architecture is to use an Extensible Markup Language (XML) schema, which utilizes basic elements to build each step in the smart procedure. The attributes of each step will determine the type of functionality that the system will generate for that step. The CBPS will provide the context for the step to deliver referential information, request a decision, or accept input from the user. The XML schema needs to provide all data necessary for the system to accurately perform each step without the need for the procedure writer to reprogram the CBPS. The research team at the Idaho National Laboratory has developed a prototype CBPS for field workers as well as the

  2. Study on the methodology for predicting and preventing errors to improve reliability of maintenance task in nuclear power plant

    International Nuclear Information System (INIS)

    Hanafusa, Hidemitsu; Iwaki, Toshio; Embrey, D.

    2000-01-01

    The objective of this study was to develop and effective methodology for predicting and preventing errors in nuclear power plant maintenance tasks. A method was established by which chief maintenance personnel can predict and reduce errors when reviewing the maintenance procedures and while referring to maintenance supporting systems and methods in other industries including aviation and chemical plant industries. The method involves the following seven steps: 1. Identification of maintenance tasks. 2. Specification of important tasks affecting safety. 3. Assessment of human errors occurring during important tasks. 4. Identification of Performance Degrading Factors. 5. Dividing important tasks into sub-tasks. 6. Extraction of errors using Predictive Human Error Analysis (PHEA). 7. Development of strategies for reducing errors and for recovering from errors. By way of a trial, this method was applied to the pump maintenance procedure in nuclear power plants. This method is believed to be capable of identifying the expected errors in important tasks and supporting the development of error reduction measures. By applying this method, the number of accidents resulting form human errors during maintenance can be reduced. Moreover, the maintenance support base using computers was developed. (author)

  3. Anisotropic mesh adaptation for solution of finite element problems using hierarchical edge-based error estimates

    Energy Technology Data Exchange (ETDEWEB)

    Lipnikov, Konstantin [Los Alamos National Laboratory; Agouzal, Abdellatif [UNIV DE LYON; Vassilevski, Yuri [Los Alamos National Laboratory

    2009-01-01

    We present a new technology for generating meshes minimizing the interpolation and discretization errors or their gradients. The key element of this methodology is construction of a space metric from edge-based error estimates. For a mesh with N{sub h} triangles, the error is proportional to N{sub h}{sup -1} and the gradient of error is proportional to N{sub h}{sup -1/2} which are optimal asymptotics. The methodology is verified with numerical experiments.

  4. Quality prediction modeling for sintered ores based on mechanism models of sintering and extreme learning machine based error compensation

    Science.gov (United States)

    Tiebin, Wu; Yunlian, Liu; Xinjun, Li; Yi, Yu; Bin, Zhang

    2018-06-01

    Aiming at the difficulty in quality prediction of sintered ores, a hybrid prediction model is established based on mechanism models of sintering and time-weighted error compensation on the basis of the extreme learning machine (ELM). At first, mechanism models of drum index, total iron, and alkalinity are constructed according to the chemical reaction mechanism and conservation of matter in the sintering process. As the process is simplified in the mechanism models, these models are not able to describe high nonlinearity. Therefore, errors are inevitable. For this reason, the time-weighted ELM based error compensation model is established. Simulation results verify that the hybrid model has a high accuracy and can meet the requirement for industrial applications.

  5. Observer-Based Human Knee Stiffness Estimation.

    Science.gov (United States)

    Misgeld, Berno J E; Luken, Markus; Riener, Robert; Leonhardt, Steffen

    2017-05-01

    We consider the problem of stiffness estimation for the human knee joint during motion in the sagittal plane. The new stiffness estimator uses a nonlinear reduced-order biomechanical model and a body sensor network (BSN). The developed model is based on a two-dimensional knee kinematics approach to calculate the angle-dependent lever arms and the torques of the muscle-tendon-complex. To minimize errors in the knee stiffness estimation procedure that result from model uncertainties, a nonlinear observer is developed. The observer uses the electromyogram (EMG) of involved muscles as input signals and the segmental orientation as the output signal to correct the observer-internal states. Because of dominating model nonlinearities and nonsmoothness of the corresponding nonlinear functions, an unscented Kalman filter is designed to compute and update the observer feedback (Kalman) gain matrix. The observer-based stiffness estimation algorithm is subsequently evaluated in simulations and in a test bench, specifically designed to provide robotic movement support for the human knee joint. In silico and experimental validation underline the good performance of the knee stiffness estimation even in the cases of a knee stiffening due to antagonistic coactivation. We have shown the principle function of an observer-based approach to knee stiffness estimation that employs EMG signals and segmental orientation provided by our own IPANEMA BSN. The presented approach makes realtime, model-based estimation of knee stiffness with minimal instrumentation possible.

  6. Neural Network Based Real-time Correction of Transducer Dynamic Errors

    Science.gov (United States)

    Roj, J.

    2013-12-01

    In order to carry out real-time dynamic error correction of transducers described by a linear differential equation, a novel recurrent neural network was developed. The network structure is based on solving this equation with respect to the input quantity when using the state variables. It is shown that such a real-time correction can be carried out using simple linear perceptrons. Due to the use of a neural technique, knowledge of the dynamic parameters of the transducer is not necessary. Theoretical considerations are illustrated by the results of simulation studies performed for the modeled second order transducer. The most important properties of the neural dynamic error correction, when emphasizing the fundamental advantages and disadvantages, are discussed.

  7. Minimum Probability of Error-Based Equalization Algorithms for Fading Channels

    Directory of Open Access Journals (Sweden)

    Janos Levendovszky

    2007-06-01

    Full Text Available Novel channel equalizer algorithms are introduced for wireless communication systems to combat channel distortions resulting from multipath propagation. The novel algorithms are based on newly derived bounds on the probability of error (PE and guarantee better performance than the traditional zero forcing (ZF or minimum mean square error (MMSE algorithms. The new equalization methods require channel state information which is obtained by a fast adaptive channel identification algorithm. As a result, the combined convergence time needed for channel identification and PE minimization still remains smaller than the convergence time of traditional adaptive algorithms, yielding real-time equalization. The performance of the new algorithms is tested by extensive simulations on standard mobile channels.

  8. The analysis of human error as causes in the maintenance of machines: a case study in mining companies

    Directory of Open Access Journals (Sweden)

    Kovacevic, Srdja

    2016-12-01

    Full Text Available This paper describes the two-step method used to analyse the factors and aspects influencing human error during the maintenance of mining machines. The first step is the cause-effect analysis, supported by brainstorming, where five factors and 21 aspects are identified. During the second step, the group fuzzy analytic hierarchy process is used to rank the identified factors and aspects. A case study is done on mining companies in Serbia. The key aspects are ranked according to an analysis that included experts who assess risks in mining companies (a maintenance engineer, a technologist, an ergonomist, a psychologist, and an organisational scientist. Failure to follow technical maintenance instructions, poor organisation of the training process, inadequate diagnostic equipment, and a lack of understanding of the work process are identified as the most important causes of human error.

  9. Learning from errors in super-resolution.

    Science.gov (United States)

    Tang, Yi; Yuan, Yuan

    2014-11-01

    A novel framework of learning-based super-resolution is proposed by employing the process of learning from the estimation errors. The estimation errors generated by different learning-based super-resolution algorithms are statistically shown to be sparse and uncertain. The sparsity of the estimation errors means most of estimation errors are small enough. The uncertainty of the estimation errors means the location of the pixel with larger estimation error is random. Noticing the prior information about the estimation errors, a nonlinear boosting process of learning from these estimation errors is introduced into the general framework of the learning-based super-resolution. Within the novel framework of super-resolution, a low-rank decomposition technique is used to share the information of different super-resolution estimations and to remove the sparse estimation errors from different learning algorithms or training samples. The experimental results show the effectiveness and the efficiency of the proposed framework in enhancing the performance of different learning-based algorithms.

  10. Radiation risk estimation based on measurement error models

    CERN Document Server

    Masiuk, Sergii; Shklyar, Sergiy; Chepurny, Mykola; Likhtarov, Illya

    2017-01-01

    This monograph discusses statistics and risk estimates applied to radiation damage under the presence of measurement errors. The first part covers nonlinear measurement error models, with a particular emphasis on efficiency of regression parameter estimators. In the second part, risk estimation in models with measurement errors is considered. Efficiency of the methods presented is verified using data from radio-epidemiological studies.

  11. Quantitative developments in the cognitive reliability and error analysis method (CREAM) for the assessment of human performance

    International Nuclear Information System (INIS)

    Marseguerra, Marzio; Zio, Enrico; Librizzi, Massimo

    2006-01-01

    The current 'second generation' approaches in human reliability analysis focus their attention on the contextual conditions under which a given action is performed rather than on the notion of inherent human error probabilities, as was done in the earlier 'first generation' techniques. Among the 'second generation' methods, this paper considers the Cognitive Reliability and Error Analysis Method (CREAM) and proposes some developments with respect to a systematic procedure for computing probabilities of action failure. The starting point for the quantification is a previously introduced fuzzy version of the CREAM paradigm which is here further extended to include uncertainty on the qualification of the conditions under which the action is performed and to account for the fact that the effects of the common performance conditions (CPCs) on performance reliability may not all be equal. By the proposed approach, the probability of action failure is estimated by rating the performance conditions in terms of their effect on the action

  12. Error function attack of chaos synchronization based encryption schemes.

    Science.gov (United States)

    Wang, Xingang; Zhan, Meng; Lai, C-H; Gang, Hu

    2004-03-01

    Different chaos synchronization based encryption schemes are reviewed and compared from the practical point of view. As an efficient cryptanalysis tool for chaos encryption, a proposal based on the error function attack is presented systematically and used to evaluate system security. We define a quantitative measure (quality factor) of the effective applicability of a chaos encryption scheme, which takes into account the security, the encryption speed, and the robustness against channel noise. A comparison is made of several encryption schemes and it is found that a scheme based on one-way coupled chaotic map lattices performs outstandingly well, as judged from quality factor. Copyright 2004 American Institute of Physics.

  13. Tropical systematic and random error energetics based on NCEP ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Systematic error growth rate peak is observed at wavenumber 2 up to 4-day forecast then .... the influence of summer systematic error and ran- ... total exchange. When the error energy budgets are examined in spectral domain, one may ask ques- tions on the error growth at a certain wavenum- ber from its interaction with ...

  14. Design of a single-borehole hydraulic test programme allowing for interpretation-based errors

    International Nuclear Information System (INIS)

    Black, J.H.

    1987-07-01

    Hydraulic testing using packers in single boreholes is one of the most important sources of data to safety assessment modelling in connection with the disposal of radioactive waste. It is also one of the most time-consuming and expensive. It is important that the results are as reliable as possible and as accurate as necessary for the use that is made of them. There are many causes of possible error and inaccuracy ranging from poor field practice to inappropriate interpretation procedure. The report examines and attempts to quantify the size of error arising from the accidental use of an inappropriate or inadequate interpretation procedure. In doing so, it can be seen which interpretation procedure or combination of procedures results in least error. Lastly, the report attempts to use the previous conclusions from interpretation to propose forms of field test procedure where interpretation-based errors will be minimised. Hydraulic tests (sometimes known as packer tests) come in three basic forms: slug/pulse, constant flow and constant head. They have different characteristics, some measuring a variable volume of rock (dependent on hydraulic conductivity) and some having a variable duration (dependent on hydraulic conductivity). A combination of different tests in the same interval is seen as desirable. For the purposes of assessing interpretation-based errors, slug and pulse tests are considered together as are constant flow and constant head tests. The same method is used in each case to assess errors. The method assumes that the simplest analysis procedure (cylindrical flow in homogeneous isotropic porous rock) will be used on each set of field data. The error is assessed by calculating synthetic data for alternative configurations (e.g. fissured rock, anisotropic rock, inhomogeneous rock - i.e. skin - etc.) and then analyzing this data using the simplest analysis procedure. 28 refs., 26 figs

  15. A new anisotropic mesh adaptation method based upon hierarchical a posteriori error estimates

    Science.gov (United States)

    Huang, Weizhang; Kamenski, Lennard; Lang, Jens

    2010-03-01

    A new anisotropic mesh adaptation strategy for finite element solution of elliptic differential equations is presented. It generates anisotropic adaptive meshes as quasi-uniform ones in some metric space, with the metric tensor being computed based on hierarchical a posteriori error estimates. A global hierarchical error estimate is employed in this study to obtain reliable directional information of the solution. Instead of solving the global error problem exactly, which is costly in general, we solve it iteratively using the symmetric Gauß-Seidel method. Numerical results show that a few GS iterations are sufficient for obtaining a reasonably good approximation to the error for use in anisotropic mesh adaptation. The new method is compared with several strategies using local error estimators or recovered Hessians. Numerical results are presented for a selection of test examples and a mathematical model for heat conduction in a thermal battery with large orthotropic jumps in the material coefficients.

  16. Constitutive error based parameter estimation technique for plate structures using free vibration signatures

    Science.gov (United States)

    Guchhait, Shyamal; Banerjee, Biswanath

    2018-04-01

    In this paper, a variant of constitutive equation error based material parameter estimation procedure for linear elastic plates is developed from partially measured free vibration sig-natures. It has been reported in many research articles that the mode shape curvatures are much more sensitive compared to mode shape themselves to localize inhomogeneity. Complying with this idea, an identification procedure is framed as an optimization problem where the proposed cost function measures the error in constitutive relation due to incompatible curvature/strain and moment/stress fields. Unlike standard constitutive equation error based procedure wherein a solution of a couple system is unavoidable in each iteration, we generate these incompatible fields via two linear solves. A simple, yet effective, penalty based approach is followed to incorporate measured data. The penalization parameter not only helps in incorporating corrupted measurement data weakly but also acts as a regularizer against the ill-posedness of the inverse problem. Explicit linear update formulas are then developed for anisotropic linear elastic material. Numerical examples are provided to show the applicability of the proposed technique. Finally, an experimental validation is also provided.

  17. Analysis of human error in occupational accidents in the power plant industries using combining innovative FTA and meta-heuristic algorithms

    Directory of Open Access Journals (Sweden)

    M. Omidvari

    2015-09-01

    Full Text Available Introduction: Occupational accidents are of the main issues in industries. It is necessary to identify the main root causes of accidents for their control. Several models have been proposed for determining the accidents root causes. FTA is one of the most widely used models which could graphically establish the root causes of accidents. The non-linear function is one of the main challenges in FTA compliance and in order to obtain the exact number, the meta-heuristic algorithms can be used. Material and Method: The present research was done in power plant industries in construction phase. In this study, a pattern for the analysis of human error in work-related accidents was provided by combination of neural network algorithms and FTA analytical model. Finally, using this pattern, the potential rate of all causes was determined. Result: The results showed that training, age, and non-compliance with safety principals in the workplace were the most important factors influencing human error in the occupational accident. Conclusion: According to the obtained results, it can be concluded that human errors can be greatly reduced by training, right choice of workers with regard to the type of occupations, and provision of appropriate safety conditions in the work place.

  18. Classification based upon gene expression data: bias and precision of error rates.

    Science.gov (United States)

    Wood, Ian A; Visscher, Peter M; Mengersen, Kerrie L

    2007-06-01

    Gene expression data offer a large number of potentially useful predictors for the classification of tissue samples into classes, such as diseased and non-diseased. The predictive error rate of classifiers can be estimated using methods such as cross-validation. We have investigated issues of interpretation and potential bias in the reporting of error rate estimates. The issues considered here are optimization and selection biases, sampling effects, measures of misclassification rate, baseline error rates, two-level external cross-validation and a novel proposal for detection of bias using the permutation mean. Reporting an optimal estimated error rate incurs an optimization bias. Downward bias of 3-5% was found in an existing study of classification based on gene expression data and may be endemic in similar studies. Using a simulated non-informative dataset and two example datasets from existing studies, we show how bias can be detected through the use of label permutations and avoided using two-level external cross-validation. Some studies avoid optimization bias by using single-level cross-validation and a test set, but error rates can be more accurately estimated via two-level cross-validation. In addition to estimating the simple overall error rate, we recommend reporting class error rates plus where possible the conditional risk incorporating prior class probabilities and a misclassification cost matrix. We also describe baseline error rates derived from three trivial classifiers which ignore the predictors. R code which implements two-level external cross-validation with the PAMR package, experiment code, dataset details and additional figures are freely available for non-commercial use from http://www.maths.qut.edu.au/profiles/wood/permr.jsp

  19. Bootstrap-Based Improvements for Inference with Clustered Errors

    OpenAIRE

    Doug Miller; A. Colin Cameron; Jonah B. Gelbach

    2006-01-01

    Microeconometrics researchers have increasingly realized the essential need to account for any within-group dependence in estimating standard errors of regression parameter estimates. The typical preferred solution is to calculate cluster-robust or sandwich standard errors that permit quite general heteroskedasticity and within-cluster error correlation, but presume that the number of clusters is large. In applications with few (5-30) clusters, standard asymptotic tests can over-reject consid...

  20. Dopamine reward prediction error coding.

    Science.gov (United States)

    Schultz, Wolfram

    2016-03-01

    Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards-an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less reward than predicted (negative prediction error). The dopamine signal increases nonlinearly with reward value and codes formal economic utility. Drugs of addiction generate, hijack, and amplify the dopamine reward signal and induce exaggerated, uncontrolled dopamine effects on neuronal plasticity. The striatum, amygdala, and frontal cortex also show reward prediction error coding, but only in subpopulations of neurons. Thus, the important concept of reward prediction errors is implemented in neuronal hardware.

  1. Study on Network Error Analysis and Locating based on Integrated Information Decision System

    Science.gov (United States)

    Yang, F.; Dong, Z. H.

    2017-10-01

    Integrated information decision system (IIDS) integrates multiple sub-system developed by many facilities, including almost hundred kinds of software, which provides with various services, such as email, short messages, drawing and sharing. Because the under-layer protocols are different, user standards are not unified, many errors are occurred during the stages of setup, configuration, and operation, which seriously affect the usage. Because the errors are various, which may be happened in different operation phases, stages, TCP/IP communication protocol layers, sub-system software, it is necessary to design a network error analysis and locating tool for IIDS to solve the above problems. This paper studies on network error analysis and locating based on IIDS, which provides strong theory and technology supports for the running and communicating of IIDS.

  2. Understanding Human Error in Naval Aviation Mishaps.

    Science.gov (United States)

    Miranda, Andrew T

    2018-04-01

    To better understand the external factors that influence the performance and decisions of aviators involved in Naval aviation mishaps. Mishaps in complex activities, ranging from aviation to nuclear power operations, are often the result of interactions between multiple components within an organization. The Naval aviation mishap database contains relevant information, both in quantitative statistics and qualitative reports, that permits analysis of such interactions to identify how the working atmosphere influences aviator performance and judgment. Results from 95 severe Naval aviation mishaps that occurred from 2011 through 2016 were analyzed using Bayes' theorem probability formula. Then a content analysis was performed on a subset of relevant mishap reports. Out of the 14 latent factors analyzed, the Bayes' application identified 6 that impacted specific aspects of aviator behavior during mishaps. Technological environment, misperceptions, and mental awareness impacted basic aviation skills. The remaining 3 factors were used to inform a content analysis of the contextual information within mishap reports. Teamwork failures were the result of plan continuation aggravated by diffused responsibility. Resource limitations and risk management deficiencies impacted judgments made by squadron commanders. The application of Bayes' theorem to historical mishap data revealed the role of latent factors within Naval aviation mishaps. Teamwork failures were seen to be considerably damaging to both aviator skill and judgment. Both the methods and findings have direct application for organizations interested in understanding the relationships between external factors and human error. It presents real-world evidence to promote effective safety decisions.

  3. Science-Based Simulation Model of Human Performance for Human Reliability Analysis

    International Nuclear Information System (INIS)

    Kelly, Dana L.; Boring, Ronald L.; Mosleh, Ali; Smidts, Carol

    2011-01-01

    Human reliability analysis (HRA), a component of an integrated probabilistic risk assessment (PRA), is the means by which the human contribution to risk is assessed, both qualitatively and quantitatively. However, among the literally dozens of HRA methods that have been developed, most cannot fully model and quantify the types of errors that occurred at Three Mile Island. Furthermore, all of the methods lack a solid empirical basis, relying heavily on expert judgment or empirical results derived in non-reactor domains. Finally, all of the methods are essentially static, and are thus unable to capture the dynamics of an accident in progress. The objective of this work is to begin exploring a dynamic simulation approach to HRA, one whose models have a basis in psychological theories of human performance, and whose quantitative estimates have an empirical basis. This paper highlights a plan to formalize collaboration among the Idaho National Laboratory (INL), the University of Maryland, and The Ohio State University (OSU) to continue development of a simulation model initially formulated at the University of Maryland. Initial work will focus on enhancing the underlying human performance models with the most recent psychological research, and on planning follow-on studies to establish an empirical basis for the model, based on simulator experiments to be carried out at the INL and at the OSU.

  4. A feasibility study of mutual information based setup error estimation for radiotherapy

    International Nuclear Information System (INIS)

    Kim, Jeongtae; Fessler, Jeffrey A.; Lam, Kwok L.; Balter, James M.; Haken, Randall K. ten

    2001-01-01

    We have investigated a fully automatic setup error estimation method that aligns DRRs (digitally reconstructed radiographs) from a three-dimensional planning computed tomography image onto two-dimensional radiographs that are acquired in a treatment room. We have chosen a MI (mutual information)-based image registration method, hoping for robustness to intensity differences between the DRRs and the radiographs. The MI-based estimator is fully automatic since it is based on the image intensity values without segmentation. Using 10 repeated scans of an anthropomorphic chest phantom in one position and two single scans in two different positions, we evaluated the performance of the proposed method and a correlation-based method against the setup error determined by fiducial marker-based method. The mean differences between the proposed method and the fiducial marker-based method were smaller than 1 mm for translational parameters and 0.8 degree for rotational parameters. The standard deviations of estimates from the proposed method due to detector noise were smaller than 0.3 mm and 0.07 degree for the translational parameters and rotational parameters, respectively

  5. Science, practice, and human errors in controlling Clostridium botulinum in heat-preserved food in hermetic containers.

    Science.gov (United States)

    Pflug, Irving J

    2010-05-01

    The incidence of botulism in canned food in the last century is reviewed along with the background science; a few conclusions are reached based on analysis of published data. There are two primary aspects to botulism control: the design of an adequate process and the delivery of the adequate process to containers of food. The probability that the designed process will not be adequate to control Clostridium botulinum is very small, probably less than 1.0 x 10(-6), based on containers of food, whereas the failure of the operator of the processing equipment to deliver the specified process to containers of food may be of the order of 1 in 40, to 1 in 100, based on processing units (retort loads). In the commercial food canning industry, failure to deliver the process will probably be of the order of 1.0 x 10(-4) to 1.0 x 10(-6) when U.S. Food and Drug Administration (FDA) regulations are followed. Botulism incidents have occurred in food canning plants that have not followed the FDA regulations. It is possible but very rare to have botulism result from postprocessing contamination. It may thus be concluded that botulism incidents in canned food are primarily the result of human failure in the delivery of the designed or specified process to containers of food that, in turn, result in the survival, outgrowth, and toxin production of C. botulinum spores. Therefore, efforts in C. botulinum control should be concentrated on reducing human errors in the delivery of the specified process to containers of food.

  6. The application of SHERPA (Systematic Human Error Reduction and Prediction Approach) in the development of compensatory cognitive rehabilitation strategies for stroke patients with left and right brain damage.

    Science.gov (United States)

    Hughes, Charmayne M L; Baber, Chris; Bienkiewicz, Marta; Worthington, Andrew; Hazell, Alexa; Hermsdörfer, Joachim

    2015-01-01

    Approximately 33% of stroke patients have difficulty performing activities of daily living, often committing errors during the planning and execution of such activities. The objective of this study was to evaluate the ability of the human error identification (HEI) technique SHERPA (Systematic Human Error Reduction and Prediction Approach) to predict errors during the performance of daily activities in stroke patients with left and right hemisphere lesions. Using SHERPA we successfully predicted 36 of the 38 observed errors, with analysis indicating that the proportion of predicted and observed errors was similar for all sub-tasks and severity levels. HEI results were used to develop compensatory cognitive strategies that clinicians could employ to reduce or prevent errors from occurring. This study provides evidence for the reliability and validity of SHERPA in the design of cognitive rehabilitation strategies in stroke populations.

  7. A framework to assess diagnosis error probabilities in the advanced MCR

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ar Ryum; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of); Kim, Jong Hyun [Chosun University, Gwangju (Korea, Republic of); Jang, Inseok; Park, Jinkyun [Korea Atomic Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The Institute of Nuclear Power Operations (INPO)’s operating experience database revealed that about 48% of the total events in world NPPs for 2 years (2010-2011) happened due to human errors. The purposes of human reliability analysis (HRA) method are to evaluate the potential for, and mechanism of, human errors that may affect plant safety. Accordingly, various HRA methods have been developed such as technique for human error rate prediction (THERP), simplified plant analysis risk human reliability assessment (SPAR-H), cognitive reliability and error analysis method (CREAM) and so on. Many researchers have asserted that procedure, alarm, and display are critical factors to affect operators’ generic activities, especially for diagnosis activities. None of various HRA methods was explicitly designed to deal with digital systems. SCHEME (Soft Control Human error Evaluation MEthod) considers only for the probability of soft control execution error in the advanced MCR. The necessity of developing HRA methods in various conditions of NPPs has been raised. In this research, the framework to estimate diagnosis error probabilities in the advanced MCR was suggested. The assessment framework was suggested by three steps. The first step is to investigate diagnosis errors and calculate their probabilities. The second step is to quantitatively estimate PSFs’ weightings in the advanced MCR. The third step is to suggest the updated TRC model to assess the nominal diagnosis error probabilities. Additionally, the proposed framework was applied by using the full-scope simulation. Experiments conducted in domestic full-scope simulator and HAMMLAB were used as data-source. Total eighteen tasks were analyzed and twenty-three crews participated in.

  8. Optimizing human-system interface automation design based on a skill-rule-knowledge framework

    International Nuclear Information System (INIS)

    Lin, Chiuhsiang Joe; Yenn, T.-C.; Yang, C.-W.

    2010-01-01

    This study considers the technological change that has occurred in complex systems within the past 30 years. The role of human operators in controlling and interacting with complex systems following the technological change was also investigated. Modernization of instrumentation and control systems and components leads to a new issue of human-automation interaction, in which human operational performance must be considered in automated systems. The human-automation interaction can differ in its types and levels. A system design issue is usually realized: given these technical capabilities, which system functions should be automated and to what extent? A good automation design can be achieved by making an appropriate human-automation function allocation. To our knowledge, only a few studies have been published on how to achieve appropriate automation design with a systematic procedure. Further, there is a surprising lack of information on examining and validating the influences of levels of automation (LOAs) on instrumentation and control systems in the advanced control room (ACR). The study we present in this paper proposed a systematic framework to help in making an appropriate decision towards types of automation (TOA) and LOAs based on a 'Skill-Rule-Knowledge' (SRK) model. From the evaluating results, it was shown that the use of either automatic mode or semiautomatic mode is insufficient to prevent human errors. For preventing the occurrences of human errors and ensuring the safety in ACR, the proposed framework can be valuable for making decisions in human-automation allocation.

  9. SU-E-T-392: Evaluation of Ion Chamber/film and Log File Based QA to Detect Delivery Errors

    International Nuclear Information System (INIS)

    Nelson, C; Mason, B; Kirsner, S; Ohrt, J

    2015-01-01

    Purpose: Ion chamber and film (ICAF) is a method used to verify patient dose prior to treatment. More recently, log file based QA has been shown as an alternative for measurement based QA. In this study, we delivered VMAT plans with and without errors to determine if ICAF and/or log file based QA was able to detect the errors. Methods: Using two VMAT patients, the original treatment plan plus 7 additional plans with delivery errors introduced were generated and delivered. The erroneous plans had gantry, collimator, MLC, gantry and collimator, collimator and MLC, MLC and gantry, and gantry, collimator, and MLC errors. The gantry and collimator errors were off by 4 0 for one of the two arcs. The MLC error introduced was one in which the opening aperture didn’t move throughout the delivery of the field. For each delivery, an ICAF measurement was made as well as a dose comparison based upon log files. Passing criteria to evaluate the plans were ion chamber less and 5% and film 90% of pixels pass the 3mm/3% gamma analysis(GA). For log file analysis 90% of voxels pass the 3mm/3% 3D GA and beam parameters match what was in the plan. Results: Two original plans were delivered and passed both ICAF and log file base QA. Both ICAF and log file QA met the dosimetry criteria on 4 of the 12 erroneous cases analyzed (2 cases were not analyzed). For the log file analysis, all 12 erroneous plans alerted a mismatch in delivery versus what was planned. The 8 plans that didn’t meet criteria all had MLC errors. Conclusion: Our study demonstrates that log file based pre-treatment QA was able to detect small errors that may not be detected using an ICAF and both methods of were able to detect larger delivery errors

  10. An Enhanced Error Model for EKF-Based Tightly-Coupled Integration of GPS and Land Vehicle's Motion Sensors.

    Science.gov (United States)

    Karamat, Tashfeen B; Atia, Mohamed M; Noureldin, Aboelmagd

    2015-09-22

    Reduced inertial sensor systems (RISS) have been introduced by many researchers as a low-cost, low-complexity sensor assembly that can be integrated with GPS to provide a robust integrated navigation system for land vehicles. In earlier works, the developed error models were simplified based on the assumption that the vehicle is mostly moving on a flat horizontal plane. Another limitation is the simplified estimation of the horizontal tilt angles, which is based on simple averaging of the accelerometers' measurements without modelling their errors or tilt angle errors. In this paper, a new error model is developed for RISS that accounts for the effect of tilt angle errors and the accelerometer's errors. Additionally, it also includes important terms in the system dynamic error model, which were ignored during the linearization process in earlier works. An augmented extended Kalman filter (EKF) is designed to incorporate tilt angle errors and transversal accelerometer errors. The new error model and the augmented EKF design are developed in a tightly-coupled RISS/GPS integrated navigation system. The proposed system was tested on real trajectories' data under degraded GPS environments, and the results were compared to earlier works on RISS/GPS systems. The findings demonstrated that the proposed enhanced system introduced significant improvements in navigational performance.

  11. Likelihood-Based Inference in Nonlinear Error-Correction Models

    DEFF Research Database (Denmark)

    Kristensen, Dennis; Rahbæk, Anders

    We consider a class of vector nonlinear error correction models where the transfer function (or loadings) of the stationary relation- ships is nonlinear. This includes in particular the smooth transition models. A general representation theorem is given which establishes the dynamic properties...... and a linear trend in general. Gaussian likelihood-based estimators are considered for the long- run cointegration parameters, and the short-run parameters. Asymp- totic theory is provided for these and it is discussed to what extend asymptotic normality and mixed normaity can be found. A simulation study...

  12. Volumetric error modeling, identification and compensation based on screw theory for a large multi-axis propeller-measuring machine

    Science.gov (United States)

    Zhong, Xuemin; Liu, Hongqi; Mao, Xinyong; Li, Bin; He, Songping; Peng, Fangyu

    2018-05-01

    Large multi-axis propeller-measuring machines have two types of geometric error, position-independent geometric errors (PIGEs) and position-dependent geometric errors (PDGEs), which both have significant effects on the volumetric error of the measuring tool relative to the worktable. This paper focuses on modeling, identifying and compensating for the volumetric error of the measuring machine. A volumetric error model in the base coordinate system is established based on screw theory considering all the geometric errors. In order to fully identify all the geometric error parameters, a new method for systematic measurement and identification is proposed. All the PIGEs of adjacent axes and the six PDGEs of the linear axes are identified with a laser tracker using the proposed model. Finally, a volumetric error compensation strategy is presented and an inverse kinematic solution for compensation is proposed. The final measuring and compensation experiments have further verified the efficiency and effectiveness of the measuring and identification method, indicating that the method can be used in volumetric error compensation for large machine tools.

  13. Proposal of procedures to prevent errors in radiotherapy based in learned lessons of accidental expositions

    International Nuclear Information System (INIS)

    Bueno, Giselle Oliveira Vieira

    2007-01-01

    In order to consider some procedures to prevent errors in radiotherapy based in learned lessons of accidental expositions and in accordance with information contained in international reports elaborated by International Atomic Energy Agency (IAEA) and of the data base availability by the European group Radiation Oncology Safety Information System (ROSIS) on the events, a research of the occurred errors was performed. For the evaluation of the incidents a data base based in the ROSIS and added plus a parameter was created 'type of error'. All the stored data make possible the evaluation of the 839 incidents in terms of frequency of the type of error, the process of detention, the number of reached patients and the degree of severity. Of the 50 types of found errors, the type of error more frequently was 'incorrect treatment coordinate', confirmed with the data of literature and representing 28,96 por cent of the total of the incidents. The results showed 44,44 por cent are discovered at the moment of the treatment and that the process of verification of the fiche or clinical revision of the patient is a verification more occurred insurance and in 43,33 por cent of the searched events. The results indicated that more than 50 por cent of the incidents the severity degree are void and approximately 62 por cent a patient are affected during the accomplishment of the radiotherapy. This work showed that to analyze the data base according to methodology proposal for Klein et al.; for Reason, and Dunscombe et al. is interesting to insert more characteristic detailed in the data base such as: the number of fractions for affected patient, number of fields of treatment for fraction that was affected, shunting line of the prescribed dose and shunting line of the volume prescribed in all the registered in cadastral map events. Some causes exist that can lead the errors when patient they are submitted to the radiotherapy. Some measures can be taken so that these errors do not

  14. An analysis of errors of commission in the Nordic nuclear power plants based on plant operating experience

    International Nuclear Information System (INIS)

    Pyy, P.; Bento, J.P.; Flodin, Y.

    2001-12-01

    The report presents the methodology followed, the material used and conclusions drawn in a study of active human failures. First, the report discusses the concept of active human failures in the context of human errors. Then, a simplified methodology is presented applicable to analysis of operating experience and documenting all kinds of human failures. Also the material and analysis procedure used in the three parts of the study are discussed. Finally, some selected highlights of results are presented with common conclusions and recommendations. (au)

  15. Improvement of the physically-based groundwater model simulations through complementary correction of its errors

    Directory of Open Access Journals (Sweden)

    Jorge Mauricio Reyes Alcalde

    2017-04-01

    Full Text Available Physically-Based groundwater Models (PBM, such MODFLOW, are used as groundwater resources evaluation tools supposing that the produced differences (residuals or errors are white noise. However, in the facts these numerical simulations usually show not only random errors but also systematic errors. For this work it has been developed a numerical procedure to deal with PBM systematic errors, studying its structure in order to model its behavior and correct the results by external and complementary means, trough a framework called Complementary Correction Model (CCM. The application of CCM to PBM shows a decrease in local biases, better distribution of errors and reductions in its temporal and spatial correlations, with 73% of reduction in global RMSN over an original PBM. This methodology seems an interesting chance to update a PBM avoiding the work and costs of interfere its internal structure.

  16. Joint Estimation of Contamination, Error and Demography for Nuclear DNA from Ancient Humans

    Science.gov (United States)

    Slatkin, Montgomery

    2016-01-01

    When sequencing an ancient DNA sample from a hominin fossil, DNA from present-day humans involved in excavation and extraction will be sequenced along with the endogenous material. This type of contamination is problematic for downstream analyses as it will introduce a bias towards the population of the contaminating individual(s). Quantifying the extent of contamination is a crucial step as it allows researchers to account for possible biases that may arise in downstream genetic analyses. Here, we present an MCMC algorithm to co-estimate the contamination rate, sequencing error rate and demographic parameters—including drift times and admixture rates—for an ancient nuclear genome obtained from human remains, when the putative contaminating DNA comes from present-day humans. We assume we have a large panel representing the putative contaminant population (e.g. European, East Asian or African). The method is implemented in a C++ program called ‘Demographic Inference with Contamination and Error’ (DICE). We applied it to simulations and genome data from ancient Neanderthals and modern humans. With reasonable levels of genome sequence coverage (>3X), we find we can recover accurate estimates of all these parameters, even when the contamination rate is as high as 50%. PMID:27049965

  17. Digital halftoning methods for selectively partitioning error into achromatic and chromatic channels

    Science.gov (United States)

    Mulligan, Jeffrey B.

    1990-01-01

    A method is described for reducing the visibility of artifacts arising in the display of quantized color images on CRT displays. The method is based on the differential spatial sensitivity of the human visual system to chromatic and achromatic modulations. Because the visual system has the highest spatial and temporal acuity for the luminance component of an image, a technique which will reduce luminance artifacts at the expense of introducing high-frequency chromatic errors is sought. A method based on controlling the correlations between the quantization errors in the individual phosphor images is explored. The luminance component is greatest when the phosphor errors are positively correlated, and is minimized when the phosphor errors are negatively correlated. The greatest effect of the correlation is obtained when the intensity quantization step sizes of the individual phosphors have equal luminances. For the ordered dither algorithm, a version of the method can be implemented by simply inverting the matrix of thresholds for one of the color components.

  18. Residents' surgical performance during the laboratory years: an analysis of rule-based errors.

    Science.gov (United States)

    Nathwani, Jay N; Wise, Brett J; Garren, Margaret E; Mohamadipanah, Hossein; Van Beek, Nicole; DiMarco, Shannon M; Pugh, Carla M

    2017-11-01

    Nearly one-third of surgical residents will enter into academic development during their surgical residency by dedicating time to a research fellowship for 1-3 y. Major interest lies in understanding how laboratory residents' surgical skills are affected by minimal clinical exposure during academic development. A widely held concern is that the time away from clinical exposure results in surgical skills decay. This study examines the impact of the academic development years on residents' operative performance. We hypothesize that the use of repeated, annual assessments may result in learning even without individual feedback on participants simulated performance. Surgical performance data were collected from laboratory residents (postgraduate years 2-5) during the summers of 2014, 2015, and 2016. Residents had 15 min to complete a shortened, simulated laparoscopic ventral hernia repair procedure. Final hernia repair skins from all participants were scored using a previously validated checklist. An analysis of variance test compared the mean performance scores of repeat participants to those of first time participants. Twenty-seven (37% female) laboratory residents provided 2-year assessment data over the 3-year span of the study. Second time performance revealed improvement from a mean score of 14 (standard error = 1.0) in the first year to 17.2 (SD = 0.9) in the second year, (F[1, 52] = 5.6, P = 0.022). Detailed analysis demonstrated improvement in performance for 3 grading criteria that were considered to be rule-based errors. There was no improvement in operative strategy errors. Analysis of longitudinal performance of laboratory residents shows higher scores for repeat participants in the category of rule-based errors. These findings suggest that laboratory residents can learn from rule-based mistakes when provided with annual performance-based assessments. This benefit was not seen with operative strategy errors and has important implications for

  19. The essential component in DNA-based information storage system: robust error-tolerating module

    Directory of Open Access Journals (Sweden)

    Aldrin Kay-Yuen eYim

    2014-11-01

    Full Text Available The size of digital data is ever increasing and is expected to grow to 40,000EB by 2020, yet the estimated global information storage capacity in 2011 is less than 300EB, indicating that most of the data are transient. DNA, as a very stable nano-molecule, is an ideal massive storage device for long-term data archive. The two most notable illustrations are from Church et al. and Goldman et al., whose approaches are well-optimized for most sequencing platforms – short synthesized DNA fragments without homopolymer. Here we suggested improvements on error handling methodology that could enable the integration of DNA-based computational process, e.g. algorithms based on self-assembly of DNA. As a proof of concept, a picture of size 438 bytes was encoded to DNA with Low-Density Parity-Check error-correction code. We salvaged a significant portion of sequencing reads with mutations generated during DNA synthesis and sequencing and successfully reconstructed the entire picture. A modular-based programming framework - DNAcodec with a XML-based data format was also introduced. Our experiments demonstrated the practicability of long DNA message recovery with high error-tolerance, which opens the field to biocomputing and synthetic biology.

  20. Rotational error in path integration: encoding and execution errors in angle reproduction.

    Science.gov (United States)

    Chrastil, Elizabeth R; Warren, William H

    2017-06-01

    Path integration is fundamental to human navigation. When a navigator leaves home on a complex outbound path, they are able to keep track of their approximate position and orientation and return to their starting location on a direct homebound path. However, there are several sources of error during path integration. Previous research has focused almost exclusively on encoding error-the error in registering the outbound path in memory. Here, we also consider execution error-the error in the response, such as turning and walking a homebound trajectory. In two experiments conducted in ambulatory virtual environments, we examined the contribution of execution error to the rotational component of path integration using angle reproduction tasks. In the reproduction tasks, participants rotated once and then rotated again to face the original direction, either reproducing the initial turn or turning through the supplementary angle. One outstanding difficulty in disentangling encoding and execution error during a typical angle reproduction task is that as the encoding angle increases, so does the required response angle. In Experiment 1, we dissociated these two variables by asking participants to report each encoding angle using two different responses: by turning to walk on a path parallel to the initial facing direction in the same (reproduction) or opposite (supplementary angle) direction. In Experiment 2, participants reported the encoding angle by turning both rightward and leftward onto a path parallel to the initial facing direction, over a larger range of angles. The results suggest that execution error, not encoding error, is the predominant source of error in angular path integration. These findings also imply that the path integrator uses an intrinsic (action-scaled) rather than an extrinsic (objective) metric.