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Sample records for integrated predictive maintenance

  1. Program integration of predictive maintenance with reliability centered maintenance

    International Nuclear Information System (INIS)

    Strong, D.K. Jr; Wray, D.M.

    1990-01-01

    This paper addresses improving the safety and reliability of power plants in a cost-effective manner by integrating the recently developed reliability centered maintenance techniques with the traditional predictive maintenance techniques of nuclear power plants. The topics of the paper include a description of reliability centered maintenance (RCM), enhancing RCM with predictive maintenance, predictive maintenance programs, condition monitoring techniques, performance test techniques, the mid-Atlantic Reliability Centered Maintenance Users Group, test guides and the benefits of shared guide development

  2. Developing a comprehensive training curriculum for integrated predictive maintenance

    Science.gov (United States)

    Wurzbach, Richard N.

    2002-03-01

    On-line equipment condition monitoring is a critical component of the world-class production and safety histories of many successful nuclear plant operators. From addressing availability and operability concerns of nuclear safety-related equipment to increasing profitability through support system reliability and reduced maintenance costs, Predictive Maintenance programs have increasingly become a vital contribution to the maintenance and operation decisions of nuclear facilities. In recent years, significant advancements have been made in the quality and portability of many of the instruments being used, and software improvements have been made as well. However, the single most influential component of the success of these programs is the impact of a trained and experienced team of personnel putting this technology to work. Changes in the nature of the power generation industry brought on by competition, mergers, and acquisitions, has taken the historically stable personnel environment of power generation and created a very dynamic situation. As a result, many facilities have seen a significant turnover in personnel in key positions, including predictive maintenance personnel. It has become the challenge for many nuclear operators to maintain the consistent contribution of quality data and information from predictive maintenance that has become important in the overall equipment decision process. These challenges can be met through the implementation of quality training to predictive maintenance personnel and regular updating and re-certification of key technology holders. The use of data management tools and services aid in the sharing of information across sites within an operating company, and with experts who can contribute value-added data management and analysis. The overall effectiveness of predictive maintenance programs can be improved through the incorporation of newly developed comprehensive technology training courses. These courses address the use of

  3. Integration of infrared thermography into various maintenance methodologies

    Science.gov (United States)

    Morgan, William T.

    1993-04-01

    Maintenance methodologies are in developmental stages throughout the world as global competitiveness drives all industries to improve operational efficiencies. Rapid progress in technical advancements has added an additional strain on maintenance organizations to progressively change. Accompanying needs for advanced training and documentation is the demand for utilization of various analytical instruments and quantitative methods. Infrared thermography is one of the primary elements of engineered approaches to maintenance. Current maintenance methodologies can be divided into six categories; Routine ('Breakdown'), Preventive, Predictive, Proactive, Reliability-Based, and Total Productive (TPM) maintenance. Each of these methodologies have distinctive approaches to achieving improved operational efficiencies. Popular though is that infrared thermography is a Predictive maintenance tool. While this is true, it is also true that it can be effectively integrated into each of the maintenance methodologies for achieving desired results. The six maintenance strategies will be defined. Infrared applications integrated into each will be composed in tabular form.

  4. Opportune maintenance and predictive maintenance decision support

    OpenAIRE

    Thomas , Edouard; Levrat , Eric; Iung , Benoît; Cocheteux , Pierre

    2009-01-01

    International audience; Conventional maintenance strategies on a single component are being phased out in favour of more predictive maintenance actions. These new kinds of actions are performed in order to control the global performances of the whole industrial system. They are anticipative in nature, which allows a maintenance expert to consider non-already-planned maintenance actions. Two questions naturally emerge: when to perform a predictive maintenance action; how a maintenance expert c...

  5. Integrated maintenance program (IMP)

    International Nuclear Information System (INIS)

    Zemdegs, R.T.; Chout, Q.B.

    1998-01-01

    the station's maintenance effectiveness and reduce maintenance costs including RCM4, callup overhauls, analysis of equipment and system failure history to name a few. It has become apparent that there is no single D o-All m aintenance strategy. What is needed is an integrated program combining the benefits of a variety of problem-specific strategies. Such a program should address both the short term and long term station requirements. The impact of the Integrated Maintenance Program (IMP) is expected to be high. In the short term, IMP will upgrade the call-up management system to provide accurate classification, effective monitoring and reporting, and develop a documented rationale (PMO) for each Preventive Maintenance task. To the greatest extent possible, IMP will utilize on-condition (predictive) maintenance and result in the elimination of replacement of many obsolete or ineffective preventive maintenance call-ups. The IMP described in this paper, will improve maintenance effectiveness, equipment reliability and have cost benefits to Ontario Hydro. In doing so it will reduce the cost of maintenance and improve system availability and reliability. (author)

  6. Predictive maintenance primer

    International Nuclear Information System (INIS)

    Flude, J.W.; Nicholas, J.R.

    1991-04-01

    This Predictive Maintenance Primer provides utility plant personnel with a single-source reference to predictive maintenance analysis methods and technologies used successfully by utilities and other industries. It is intended to be a ready reference to personnel considering starting, expanding or improving a predictive maintenance program. This Primer includes a discussion of various analysis methods and how they overlap and interrelate. Additionally, eighteen predictive maintenance technologies are discussed in sufficient detail for the user to evaluate the potential of each technology for specific applications. This document is designed to allow inclusion of additional technologies in the future. To gather the information necessary to create this initial Primer the Nuclear Maintenance Applications Center (NMAC) collected experience data from eighteen utilities plus other industry and government sources. NMAC also contacted equipment manufacturers for information pertaining to equipment utilization, maintenance, and technical specifications. The Primer includes a discussion of six methods used by analysts to study predictive maintenance data. These are: trend analysis; pattern recognition; correlation; test against limits or ranges; relative comparison data; and statistical process analysis. Following the analysis methods discussions are detailed descriptions for eighteen technologies analysts have found useful for predictive maintenance programs at power plants and other industrial facilities. Each technology subchapter has a description of the operating principles involved in the technology, a listing of plant equipment where the technology can be applied, and a general description of the monitoring equipment. Additionally, these descriptions include a discussion of results obtained from actual equipment users and preferred analysis techniques to be used on data obtained from the technology. 5 refs., 30 figs

  7. Crack Growth-Based Predictive Methodology for the Maintenance of the Structural Integrity of Repaired and Nonrepaired Aging Engine Stationary Components

    National Research Council Canada - National Science Library

    Barron, Michael

    1999-01-01

    .... Specifically, the FAA's goal was to develop "Crack Growth-Based Predictive Methodologies for the Maintenance of the Structural Integrity of Repaired and Nonrepaired Aging Engine Stationary Components...

  8. Maintenance management for nuclear power plant 'Integrated valve maintenance'

    International Nuclear Information System (INIS)

    Gerner, P.; Zanner, G.

    2001-01-01

    The deregulation of Europe's power market does force many utilities, and especially nuclear power plant operators, to introduce extensive cost-cutting measures in order to be able to compete within this new environment. The optimization of plant outages provides considerable potential for raising plant availability but can also lower operating costs by reducing e.g. expenditure on maintenance. Siemens Nuclear Power GmbH, in cooperation with plant operators, is currently implementing new and improved service concepts which can have a major effect on the way in which maintenance will be performed in the future. Innovative service packages for maintenance in nuclear power plants are available which can be used to perform a time- and cost-effective maintenance. The concepts encompass optimization of the overall sequence from planning in advance to the individual measures including reduction of the scope of maintenance activities, identification of cost cutting potential and bundling of maintenance activities. The main features of these maintenance activities are illustrated here using the examples of outage planning and integrated valve maintenance. In nuclear power plants approx. 5000 valves are periodically preventively, condition-based or breakdown-based maintained. Because of this large number of valves to be maintained a high potential of improvements and cost reductions can be achieved by performing an optimized, cost-effective maintenance based on innovative methods and tools. Siemens Nuclear Power GmbH has developed and qualified such tools which allow to reduce service costs while maintaining high standards of safety and availability. By changing from preventive to predictive (condition-based) maintenance - the number of valves to be maintained may be reduced considerably. The predictive maintenance is based on the Siemens Nuclear Power GmbH diagnostic and evaluation method (ADAM). ADAM is used to monitor the operability of valves by analytical verification of

  9. Integrated reliability condition monitoring and maintenance of equipment

    CERN Document Server

    Osarenren, John

    2015-01-01

    Consider a Viable and Cost-Effective Platform for the Industries of the Future (IOF) Benefit from improved safety, performance, and product deliveries to your customers. Achieve a higher rate of equipment availability, performance, product quality, and reliability. Integrated Reliability: Condition Monitoring and Maintenance of Equipment incorporates reliable engineering and mathematical modeling to help you move toward sustainable development in reliability condition monitoring and maintenance. This text introduces a cost-effective integrated reliability growth monitor, integrated reliability degradation monitor, technological inheritance coefficient sensors, and a maintenance tool that supplies real-time information for predicting and preventing potential failures of manufacturing processes and equipment. The author highlights five key elements that are essential to any improvement program: improving overall equipment and part effectiveness, quality, and reliability; improving process performance with maint...

  10. Application of IoT concept on predictive maintenance of industrial equipment

    Directory of Open Access Journals (Sweden)

    Parpala Radu Constantin

    2017-01-01

    Full Text Available The Internet of Things (IoT concept describes an intelligent connectivity of smart devices using the internet network. Nowadays, companies try different approaches for predictive maintenance as a solution to reduce costs and the frequency of maintenance activities. The IoT platforms provide a good support for predictive maintenance as it can integrate information from different machines and manufacturing systems. The main drawback in integrating production system with IoT dedicated platforms is the communication framework, knowing that the main industrial communication protocols are incompatible with modern communication protocols implemented on IoT platforms. In this context, the present paper proposes a new and simple method for on-line monitoring and predictive maintenance of industrial equipment. This method has two features of connected manufacturing. One of these is process monitoring for constant quality assurance, the other one is condition monitoring in order to prevent unplanned downtimes. A case study is presented to demonstrate the feasibility of the proposed method.

  11. Automated System Checkout to Support Predictive Maintenance for the Reusable Launch Vehicle

    Science.gov (United States)

    Patterson-Hine, Ann; Deb, Somnath; Kulkarni, Deepak; Wang, Yao; Lau, Sonie (Technical Monitor)

    1998-01-01

    The Propulsion Checkout and Control System (PCCS) is a predictive maintenance software system. The real-time checkout procedures and diagnostics are designed to detect components that need maintenance based on their condition, rather than using more conventional approaches such as scheduled or reliability centered maintenance. Predictive maintenance can reduce turn-around time and cost and increase safety as compared to conventional maintenance approaches. Real-time sensor validation, limit checking, statistical anomaly detection, and failure prediction based on simulation models are employed. Multi-signal models, useful for testability analysis during system design, are used during the operational phase to detect and isolate degraded or failed components. The TEAMS-RT real-time diagnostic engine was developed to utilize the multi-signal models by Qualtech Systems, Inc. Capability of predicting the maintenance condition was successfully demonstrated with a variety of data, from simulation to actual operation on the Integrated Propulsion Technology Demonstrator (IPTD) at Marshall Space Flight Center (MSFC). Playback of IPTD valve actuations for feature recognition updates identified an otherwise undetectable Main Propulsion System 12 inch prevalve degradation. The algorithms were loaded into the Propulsion Checkout and Control System for further development and are the first known application of predictive Integrated Vehicle Health Management to an operational cryogenic testbed. The software performed successfully in real-time, meeting the required performance goal of 1 second cycle time.

  12. Predicting older adults' maintenance in exercise participation using an integrated social psychological model

    NARCIS (Netherlands)

    Stiggelbout, M.; Hopman-Rock, M.; Crone, M.; Lechner, L.; Mechelen, W. van

    2006-01-01

    Little is known about the predictors of maintenance in organized exercise programmes. The aim of this study was to investigate the behavioral predictors of maintenance of exercise participation in older adults, using an integrated social psychological model. To this end, we carried out a prospective

  13. Wireless sensors for predictive maintenance of rotating equipment in research reactors

    International Nuclear Information System (INIS)

    Hashemian, H.M.

    2011-01-01

    In 2008-2009, the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) tested the potential of predictive or condition-based maintenance techniques to reduce maintenance costs, minimize the risk of catastrophic failures, and maximize system availability by attaching wireless-based sensors to selected rotating equipment at HFIR. Rotating equipment is an ideal 'test case' for the viability of integrated, online predictive maintenance strategies because motors, bearings, and shafts are ubiquitous in nuclear power plants and because the maintenance methods typically performed on rotating equipment today (such as portable or handheld vibration data collection equipment) are highly labor-intensive. The HFIR project achieved all five of its objectives: (1) to identify rotating machinery of the types used in research reactors and determine their operational characteristics, degradation mechanisms, and failure modes, (2) to establish a predictive maintenance program for rotating equipment in research reactors, (3) to identify wireless sensors that are suitable for predictive maintenance of rotating machinery and test them in a laboratory setting, (4) to establish the requirements and procedures to be followed when implementing wireless sensors for predictive maintenance in research reactors, and (5) to develop a conceptual design for a predictive maintenance system for research reactors based on wireless sensors. The project demonstrated that wireless sensors offer an effective method for monitoring key process conditions continuously and remotely, thereby enhancing the safety, reliability, and efficiency of the aging research reactor fleet.

  14. Selecting Suitable Candidates for Predictive Maintenance

    NARCIS (Netherlands)

    Tiddens, Wieger Willem; Braaksma, Anne Johannes Jan; Tinga, Tiedo

    2018-01-01

    Predictive maintenance (PdM) or Prognostics and Health Management (PHM) assists in better predicting the future state of physical assets and making timely and better-informed maintenance decisions. Many companies nowadays ambition the implementation of such an advanced maintenance policy. However,

  15. Improving the TRIGA facility maintenance by predictive maintenance techniques

    International Nuclear Information System (INIS)

    Preda, M.; Sabau, C.; Barbalata, E.

    1997-01-01

    This work deals with the specific operation of equipment in radioactive environment or in conditions allowing radioactive contamination. The requirements of remote operation ensuring the operators' protection are presented. Also, the requirements of international standards issued by IAEA-Vienna are reviewed. The organizational withdraws of the maintenance activities, based on the standards and maintenance and repair directives still in force, are shown. It is emphasized the fact that this type of maintenance was adequate to a given level of technical development, characteristic for pre-computerized industry, but, at present, it is obsolete and uneconomic both in utilization and maintenance. Such a system constitutes already a burden hindering the efforts of maximizing the availability, maintenance, prolongation the service life of equipment and utilities, finally, of increasing the efficiency of complex installations. Moreover, the predictive maintenance techniques are strongly requested by the character of radioactive installations precluding the direct access in given zones (a potential risk of irradiation or radioactive contamination) of installations during operation. The results obtained by applying the predictive maintenance techniques in the operation of the double circuit irradiation loop, used in the TRIGA reactors, are presented

  16. A VITAL service for predictive MOV maintenance

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    Motor-operated valve (MOV) maintenance can be a major contributor to unplanned plant downtime, either because valve malfunctions cause unscheduled outages, or because unnecessary valve maintenance lengthens scheduled outages. The cause of both situations is a preventive approach to valve maintenance, where maintenance is scheduled according to a timetable instead of according to a demonstrated need. To move towards a predictive maintenance approach, inexpensive methods of collecting and diagnosing real-time data on the conditions of a valve must be made available. Such a system must be capable of detecting and diagnosing degrading mechanical and electrical behaviour at an early stage, as well as being able to predict the time of failure. Without this data, a predictive approach to maintenance is impossible. Westinghouse is addressing the requirements for a predictive approach to MOV maintenance with the introduction of a third-generation of diagnostic systems for motor-operated valves -the portable Valve Intelligent Test and Analysis System (VITALS) and the on-line Valve Monitoring System (VMS). (author)

  17. Predicting maintenance of attendance at walking groups: testing constructs from three leading maintenance theories.

    Science.gov (United States)

    Kassavou, Aikaterini; Turner, Andrew; Hamborg, Thomas; French, David P

    2014-07-01

    Little is known about the processes and factors that account for maintenance, with several theories existing that have not been subject to many empirical tests. The aim of this study was to test how well theoretical constructs derived from the Health Action Process Approach, Rothman's theory of maintenance, and Verplanken's approach to habitual behavior predicted maintenance of attendance at walking groups. 114 participants, who had already attended walking groups in the community for at least 3 months, completed a questionnaire assessing theoretical constructs regarding maintenance. An objective assessment of attendance over the subsequent 3 months was gained. Multilevel modeling was used to predict maintenance, controlling for clustering within walking groups. Recovery self-efficacy predicted maintenance, even after accounting for clustering. Satisfaction with social outcomes, satisfaction with health outcomes, and overall satisfaction predicted maintenance, but only satisfaction with health outcomes significantly predicted maintenance after accounting for clustering. Self-reported habitual behavior did not predict maintenance despite mean previous attendance being 20.7 months. Recovery self-efficacy, and satisfaction with health outcomes of walking group attendance appeared to be important for objectively measured maintenance, whereas self-reported habit appeared not to be important for maintenance at walking groups. The findings suggest that there is a need for intervention studies to boost recovery self-efficacy and satisfaction with outcomes of walking group attendance, to assess impact on maintenance.

  18. Predictive maintenance: A new approach in maintenance of nuclear power plants

    International Nuclear Information System (INIS)

    Benvenuto, F.; Ferrari, L.

    2005-01-01

    The maintenance services for a Nuclear Power Plant are in general aimed at reaching the following goals: - Increase component availability and consequently decrease intervention frequency; - Reduce unexpected costs from unexpected repairs; - Progressively decrease the time of each intervention; - Improve the spare parts supply efficiency; - Improve spare parts and consumable warehouse managing; - Decrease maintenance costs. Most of the currently used maintenance activities refer to run-to-failure or preventive approaches: - Run-to-failure or Corrective Maintenance means that work is only carried out when a component or system is faulty and unable to perform its critical function. Non critical components such as filters or components with spare may be maintained in this way; - Preventive or Scheduled Maintenance involves a regular pre-set schedule programme of maintenance work. Programme outlined by the manufacturer of the component in question based on the design life of the component and based on past experience by operation. One step further than Preventive Maintenance is represented by Predictive Maintenance. Whereas Preventive Maintenance bases its schedules on past performance data, a predictive system acquires condition data from the machine to be maintained whilst the machine is in operation. The information obtained from this analysis indicates the condition in real time, provides a diagnosis of wear and shows any trend towards critical conditions. Predictive maintenance mainly consists of the following interventions: - Lubricant analysis; - Collection / analysis of functional parameters, such as motor absorption, flow rate, pressure, temperature, noise, vibration of rotating equipment, thermal efficiency, etc; - Periodical test of lifting systems; - Other operations to acquire sensitive equipment parameters. Predictive Maintenance can reduce the accidental intervention and extend the components life, and, in the end, is increasing the global availability

  19. Risk-Based Predictive Maintenance for Safety-Critical Systems by Using Probabilistic Inference

    Directory of Open Access Journals (Sweden)

    Tianhua Xu

    2013-01-01

    Full Text Available Risk-based maintenance (RBM aims to improve maintenance planning and decision making by reducing the probability and consequences of failure of equipment. A new predictive maintenance strategy that integrates dynamic evolution model and risk assessment is proposed which can be used to calculate the optimal maintenance time with minimal cost and safety constraints. The dynamic evolution model provides qualified risks by using probabilistic inference with bucket elimination and gives the prospective degradation trend of a complex system. Based on the degradation trend, an optimal maintenance time can be determined by minimizing the expected maintenance cost per time unit. The effectiveness of the proposed method is validated and demonstrated by a collision accident of high-speed trains with obstacles in the presence of safety and cost constrains.

  20. A dynamic predictive maintenance policy for complex multi-component systems

    International Nuclear Information System (INIS)

    Van Horenbeek, Adriaan; Pintelon, Liliane

    2013-01-01

    The use of prognostic methods in maintenance in order to predict remaining useful life is receiving more attention over the past years. The use of these techniques in maintenance decision making and optimization in multi-component systems is however a still underexplored area. The objective of this paper is to optimally plan maintenance for a multi-component system based on prognostic/predictive information while considering different component dependencies (i.e. economic, structural and stochastic dependence). Consequently, this paper presents a dynamic predictive maintenance policy for multi-component systems that minimizes the long-term mean maintenance cost per unit time. The proposed maintenance policy is a dynamic method as the maintenance schedule is updated when new information on the degradation and remaining useful life of components becomes available. The performance, regarding the objective of minimal long-term mean cost per unit time, of the developed dynamic predictive maintenance policy is compared to five other conventional maintenance policies, these are: block-based maintenance, age-based maintenance, age-based maintenance with grouping, inspection condition-based maintenance and continuous condition-based maintenance. The ability of the predictive maintenance policy to react to changing component deterioration and dependencies within a multi-component system is quantified and the results show significant cost savings

  1. A predictive maintenance approach for improved nuclear plant availability

    International Nuclear Information System (INIS)

    Verma, R.M.P.; Pandya, M.B.; Kini, M.P.

    1979-01-01

    Predictive maintenance programme as against preventive maintenance programme aims at diagnosing, inspecting, monitoring, and objective condition-checking of equipment. It helps in forecasting failures, and scheduling the optimal frequencies for overhauls, replacements, lubrication etc. It also helps in establishing work load, manpower, resource planning and inventory control. Various stages of predictive maintenance programme for a nuclear power plant are outlined. A partial list of instruments for predictive maintenance is given. (M.G.B.)

  2. Multi-level predictive maintenance for multi-component systems

    International Nuclear Information System (INIS)

    Nguyen, Kim-Anh; Do, Phuc; Grall, Antoine

    2015-01-01

    In this paper, a novel predictive maintenance policy with multi-level decision-making is proposed for multi-component system with complex structure. The main idea is to propose a decision-making process considered on two levels: system level and component one. The goal of the decision rules at the system level is to address if preventive maintenance actions are needed regarding the predictive reliability of the system. At component level the decision rules aim at identifying optimally a group of several components to be preventively maintained when preventive maintenance is trigged due to the system level decision. Selecting optimal components is based on a cost-based group improvement factor taking into account the predictive reliability of the components, the economic dependencies as well as the location of the components in the system. Moreover, a cost model is developed to find the optimal maintenance decision variables. A 14-component system is finally introduced to illustrate the use and the performance of the proposed predictive maintenance policy. Different sensitivity analysis are also investigated and discussed. Indeed, the proposed policy provides more flexibility in maintenance decision-making for complex structure systems, hence leading to significant profits in terms of maintenance cost when compared with existing policies. - Highlights: • A predictive maintenance policy for complex structure systems is proposed. • Multi-level decision process based on prognostic results is proposed. • A cost-based group importance measure is introduced for decision-making. • Both positive and negative dependencies between components are investigated. • A cost model and Monte Carlo simulation are developed for optimization process.

  3. Information-Based Maintenance Optimization with Focus on Predictive Maintenance (Informatiegebaseerde onderhoudsoptimalisatie met focus op predictief onderhoud)

    OpenAIRE

    Van Horenbeek, Adriaan

    2013-01-01

    This dissertation presents an information-based maintenance optimization methodology for physical assets; with focus on, but not limited to, predictive maintenance (PdM). The overall concept of information-based maintenance is that of updating maintenance decisions based on evolving knowledge of operation history and anticipated usage of the machinery, as well as the physics and dynamics of material degradation in critical machinery components. Within this concept, predictive maintenance is a...

  4. An integrated model of statistical process control and maintenance based on the delayed monitoring

    International Nuclear Information System (INIS)

    Yin, Hui; Zhang, Guojun; Zhu, Haiping; Deng, Yuhao; He, Fei

    2015-01-01

    This paper develops an integrated model of statistical process control and maintenance decision. The proposal of delayed monitoring policy postpones the sampling process till a scheduled time and contributes to ten-scenarios of the production process, where equipment failure may occur besides quality shift. The equipment failure and the control chart alert trigger the corrective maintenance and the predictive maintenance, respectively. The occurrence probability, the cycle time and the cycle cost of each scenario are obtained by integral calculation; therefore, a mathematical model is established to minimize the expected cost by using the genetic algorithm. A Monte Carlo simulation experiment is conducted and compared with the integral calculation in order to ensure the analysis of the ten-scenario model. Another ordinary integrated model without delayed monitoring is also established as comparison. The results of a numerical example indicate satisfactory economic performance of the proposed model. Finally, a sensitivity analysis is performed to investigate the effect of model parameters. - Highlights: • We develop an integrated model of statistical process control and maintenance. • We propose delayed monitoring policy and derive an economic model with 10 scenarios. • We consider two deterioration mechanisms, quality shift and equipment failure. • The delayed monitoring policy will help reduce the expected cost

  5. Mechatronics technology in predictive maintenance method

    Science.gov (United States)

    Majid, Nurul Afiqah A.; Muthalif, Asan G. A.

    2017-11-01

    This paper presents recent mechatronics technology that can help to implement predictive maintenance by combining intelligent and predictive maintenance instrument. Vibration Fault Simulation System (VFSS) is an example of mechatronics system. The focus of this study is the prediction on the use of critical machines to detect vibration. Vibration measurement is often used as the key indicator of the state of the machine. This paper shows the choice of the appropriate strategy in the vibration of diagnostic process of the mechanical system, especially rotating machines, in recognition of the failure during the working process. In this paper, the vibration signature analysis is implemented to detect faults in rotary machining that includes imbalance, mechanical looseness, bent shaft, misalignment, missing blade bearing fault, balancing mass and critical speed. In order to perform vibration signature analysis for rotating machinery faults, studies have been made on how mechatronics technology is used as predictive maintenance methods. Vibration Faults Simulation Rig (VFSR) is designed to simulate and understand faults signatures. These techniques are based on the processing of vibrational data in frequency-domain. The LabVIEW-based spectrum analyzer software is developed to acquire and extract frequency contents of faults signals. This system is successfully tested based on the unique vibration fault signatures that always occur in a rotating machinery.

  6. Multi-objective group scheduling optimization integrated with preventive maintenance

    Science.gov (United States)

    Liao, Wenzhu; Zhang, Xiufang; Jiang, Min

    2017-11-01

    This article proposes a single-machine-based integration model to meet the requirements of production scheduling and preventive maintenance in group production. To describe the production for identical/similar and different jobs, this integrated model considers the learning and forgetting effects. Based on machine degradation, the deterioration effect is also considered. Moreover, perfect maintenance and minimal repair are adopted in this integrated model. The multi-objective of minimizing total completion time and maintenance cost is taken to meet the dual requirements of delivery date and cost. Finally, a genetic algorithm is developed to solve this optimization model, and the computation results demonstrate that this integrated model is effective and reliable.

  7. Electrical predictive maintenance at Trillo I Nuclear Power Plant

    International Nuclear Information System (INIS)

    Vicente, L. R.; Fernandez de la Mata, R.; Cano Gonzalez, J. C.

    1998-01-01

    An electrical predictive maintenance plan is currently being put into effect at Trillo I Nuclear Power Plant which is initially being applied to three types of equipment: motors, transformers and motor-driven valves. This paper describes the different phases considered in the implementation of the Predictive Maintenance Plan: study of existing techniques for such equipment (tangoδ, spectral analysis of stator current, chromatographic analysis of gases, spectral analysis of the axial stray magnetic flux, etc), study of the special characteristics of the electrical equipment at Trillo NPP, analysis of applicable techniques (characteristic parameters, alert-alarm values, experience with such techniques, etc), analysis of machine history records, study of the optimum preventive-predictive case, study of applicable frequencies and definition of the computerised predictive maintenance management tool. With the exception of the computerised predictive maintenance management applications which are presently being implemented, all the activities described above have been carried out on the three types of equipment mentioned. (Author)

  8. Predictive maintenance strategy in the graphics departament of a tobacco company

    Directory of Open Access Journals (Sweden)

    Guilherme Francez Toazza

    2015-09-01

    Full Text Available The purpose of this article was to describe the implementation of a strategy for Predictive Maintenance in the graphics department of the company Souza Cruz SA after the techniques of Vibration Analysis, Thermography, Ferrography and Inspection Sensitive. The research method was the action-research. The proposed study is the application of a management Predictive Maintenance acting strategically within the context in which it is embedded. The article reviews the theoretical concepts and Predictive Maintenance techniques mentioned above. In the survey, were raised in the information system of the company, the rate of breakdown of equipment (downtime, waste energy costs, maintenance costs and availability of H / h (man / hour and availability of equipment for the production the period prior to the implementation of a predictive maintenance management and consistent compared with results after this deployment. From the results obtained, it was evident that only preventive maintenance, combined with a model predictive maintenance is not poor enough to maintain the desired reliability in a department of great importance to your company. So, it is possible to say that the implementation of a predictive maintenance strategy can make the Maintenance sector to work strategically with common goals to the company as a whole.

  9. MOV predictive maintenance program at Darlington NGS

    International Nuclear Information System (INIS)

    Morrison, J.F.

    1992-01-01

    This paper details the Motor Operated Valve (MOV) Predictive Maintenance program at Darlington Nuclear Generating Station. The program encompasses the use of diagnostics tooling in conjunction with more standard maintenance techniques, with the goal of improving performance of MOV's. Problems encountered and solutions developed during the first two phases of this program are presented, along with proposed actions for the final trending phase of the program. This paper also touches on the preventive and corrective maintenance aspects of an overall MOV maintenance program. 6 refs., 6 tabs., 6 figs

  10. Optimizing production and imperfect preventive maintenance planning's integration in failure-prone manufacturing systems

    International Nuclear Information System (INIS)

    Aghezzaf, El-Houssaine; Khatab, Abdelhakim; Tam, Phuoc Le

    2016-01-01

    This paper investigates the issue of integrating production and maintenance planning in a failure-prone manufacturing system. It is assumed that the system's operating state is stochastically predictable, in terms of its operating age, and that it can accordingly be preventively maintained during preplanned periods. Preventive maintenance is assumed to be imperfect, that is when performed, it brings the manufacturing system to an operating state that lies between ‘as bad as old’ and ‘as good as new’. Only an overhauling of the system brings it to a ‘as good as new’ operating state again. A practical integrated production and preventive maintenance planning model, that takes into account the system's manufacturing capacity and its operational reliability state, is developed. The model is naturally formulated as a mixed-integer non-linear optimization problem, for which an extended mixed-integer linear reformulation is proposed. This reformulation, while it solves the proposed integrated planning problem to optimality, remains quite demanding in terms of computational time. A fix-and-optimize procedure, that takes advantage of some properties of the original model, is then proposed. The reformulation and the fix-and-optimize procedure are tested on some test instances adapted from those available in the literature. The results show that the proposed fix-and-optimize procedure performs quite well and opens new research direction for future improvements. - Highlights: • Integration of production planning and imperfect preventive maintenance is explored. • Imperfect maintenance is modeled using a fitting age reduction hybrid hazard rate. • A practical approximate optimization model for this integration is proposed. • The resulting naturally MINL optimization model is reformulated and solved as a MILP. • An effective fix-and-optimize procedure is proposed for large instances of this MILP.

  11. Understanding and Predicting the Process of Software Maintenance Releases

    Science.gov (United States)

    Basili, Victor; Briand, Lionel; Condon, Steven; Kim, Yong-Mi; Melo, Walcelio L.; Valett, Jon D.

    1996-01-01

    One of the major concerns of any maintenance organization is to understand and estimate the cost of maintenance releases of software systems. Planning the next release so as to maximize the increase in functionality and the improvement in quality are vital to successful maintenance management. The objective of this paper is to present the results of a case study in which an incremental approach was used to better understand the effort distribution of releases and build a predictive effort model for software maintenance releases. This study was conducted in the Flight Dynamics Division (FDD) of NASA Goddard Space Flight Center(GSFC). This paper presents three main results: 1) a predictive effort model developed for the FDD's software maintenance release process; 2) measurement-based lessons learned about the maintenance process in the FDD; and 3) a set of lessons learned about the establishment of a measurement-based software maintenance improvement program. In addition, this study provides insights and guidelines for obtaining similar results in other maintenance organizations.

  12. Two Different Maintenance Strategies in the Hospital Environment: Preventive Maintenance for Older Technology Devices and Predictive Maintenance for Newer High-Tech Devices.

    Science.gov (United States)

    Sezdi, Mana

    2016-01-01

    A maintenance program generated through the consideration of characteristics and failures of medical equipment is an important component of technology management. However, older technology devices and newer high-tech devices cannot be efficiently managed using the same strategies because of their different characteristics. This study aimed to generate a maintenance program comprising two different strategies to increase the efficiency of device management: preventive maintenance for older technology devices and predictive maintenance for newer high-tech devices. For preventive maintenance development, 589 older technology devices were subjected to performance verification and safety testing (PVST). For predictive maintenance development, the manufacturers' recommendations were used for 134 high-tech devices. These strategies were evaluated in terms of device reliability. This study recommends the use of two different maintenance strategies for old and new devices at hospitals in developing countries. Thus, older technology devices that applied only corrective maintenance will be included in maintenance like high-tech devices.

  13. Knowledge representation for integrated plant operation and maintenance

    DEFF Research Database (Denmark)

    Lind, Morten

    2010-01-01

    Integrated operation and maintenance of process plants has many advantages. One advantage is the improved economy obtained by reducing the number of plant shutdowns. Another is to increase reliability of operation by monitoring of risk levels during on-line maintenance. Integrated plant operation...... and maintenance require knowledge bases which can capture the interactions between the two plant activities. As an example, taking out a component or a subsystem for maintenance during operation will require a knowledge base representing the interactions between plant structure, functions, operating states...... and goals and incorporate knowledge about redundancy and reliability data. Multilevel Flow Modeling can be used build knowledge bases representing plant goals and functions and has been applied for fault diagnosis and supervisory control but currently it does not take into account structural information...

  14. Electric motor predictive and preventive maintenance guide

    International Nuclear Information System (INIS)

    Oliver, J.A.

    1992-07-01

    Electric motor performance is vital to the reliable and efficient operation of power plants. The failure of one or more critical motors could cause lost capacity and excessive repair and maintenance cost. However, existing maintenance recommendations proposed by vendors for electric motors have sometimes encouraged many overly conservative maintenance practices. These practices have lead to excessive maintenance activities and costs which have provided no extra margin of operability. EPRI has sponsored RP2814-35 to develop a guide which provides power plants with information and guidance for establishing an effective maintenance program which will aid in preventing unexpected motor failures and assist in planning motor maintenance efforts. The guide includes a technical description which summarizes technical data relative to the four basic types of motors and their components in general use in power plants. The significant causes of motor failures are investigated and described in detail and methods to optimize service life and minimize maintenance cost through appropriate preventive maintenance and conditioning program are presented. This guide provides a foundation for an effective electric motor maintenance program and simplifies the selection of predictive and preventive maintenance tasks. Its use will enable maintenance personnel in nuclear and fossil plants to plan motor repairs during scheduled outages and avoid costly unexpected failures

  15. Adaptation and Implementation of Predictive Maintenance Technique with Nondestructive Testing for Power Plants

    International Nuclear Information System (INIS)

    Jung, Gye Jo; Jung, Nam Gun

    2010-01-01

    Many forces are pressuring utilities to reduce operating and maintenance costs without cutting back on reliability or availability. Many utility managers are re-evaluating maintenance strategies to meet these demands. To utilities how to reduce maintenance costs and extent the effective operating life of equipment, predictive maintenance technique can be adapted. Predictive maintenance had three types program which are in-house program, engineering company program and mixed program. We can approach successful predictive maintenance program with 'smart trust' concept

  16. Predictive maintenance of maritime systems : models and challenges

    NARCIS (Netherlands)

    Tinga, T.; Tiddens, W.W.; Amoiralis, F.; Politis, M.; Cepin, Marko; Bris, Radim

    2017-01-01

    To reduce maintenance and logistic costs and increase the asset availability, a predictive maintenance concept for maritime systems is developed. In the present paper, the physics-of-failure based prognostic methods will be introduced, but also other issues related to the development and application

  17. Developing Predictive Maintenance Expertise to Improve Plant Equipment Reliability

    International Nuclear Information System (INIS)

    Wurzbach, Richard N.

    2002-01-01

    On-line equipment condition monitoring is a critical component of the world-class production and safety histories of many successful nuclear plant operators. From addressing availability and operability concerns of nuclear safety-related equipment to increasing profitability through support system reliability and reduced maintenance costs, Predictive Maintenance programs have increasingly become a vital contribution to the maintenance and operation decisions of nuclear facilities. In recent years, significant advancements have been made in the quality and portability of many of the instruments being used, and software improvements have been made as well. However, the single most influential component of the success of these programs is the impact of a trained and experienced team of personnel putting this technology to work. Changes in the nature of the power generation industry brought on by competition, mergers, and acquisitions, has taken the historically stable personnel environment of power generation and created a very dynamic situation. As a result, many facilities have seen a significant turnover in personnel in key positions, including predictive maintenance personnel. It has become the challenge for many nuclear operators to maintain the consistent contribution of quality data and information from predictive maintenance that has become important in the overall equipment decision process. These challenges can be met through the implementation of quality training to predictive maintenance personnel and regular updating and re-certification of key technology holders. The use of data management tools and services aid in the sharing of information across sites within an operating company, and with experts who can contribute value-added data management and analysis. The overall effectiveness of predictive maintenance programs can be improved through the incorporation of newly developed comprehensive technology training courses. These courses address the use of

  18. Hidden Semi-Markov Models for Predictive Maintenance

    Directory of Open Access Journals (Sweden)

    Francesco Cartella

    2015-01-01

    Full Text Available Realistic predictive maintenance approaches are essential for condition monitoring and predictive maintenance of industrial machines. In this work, we propose Hidden Semi-Markov Models (HSMMs with (i no constraints on the state duration density function and (ii being applied to continuous or discrete observation. To deal with such a type of HSMM, we also propose modifications to the learning, inference, and prediction algorithms. Finally, automatic model selection has been made possible using the Akaike Information Criterion. This paper describes the theoretical formalization of the model as well as several experiments performed on simulated and real data with the aim of methodology validation. In all performed experiments, the model is able to correctly estimate the current state and to effectively predict the time to a predefined event with a low overall average absolute error. As a consequence, its applicability to real world settings can be beneficial, especially where in real time the Remaining Useful Lifetime (RUL of the machine is calculated.

  19. Establishing a predictive maintenance program at the Hanford Site

    International Nuclear Information System (INIS)

    Winslow, R.W.

    1994-05-01

    This document contains information about a new Predictive Maintenance Program being developed and implemented at the Hanford Reservation. Details of the document include: background on persons developing the program, history of predictive maintenance, implementation of new program, engineering task analysis, network development and new software, issues to be resolved, benefits expected, and appendix gives information about the symposium from which this paper is based

  20. Demonstration of Sensor Data Integration Across Naval Aviation Maintenance

    Science.gov (United States)

    2018-02-01

    Concepts, Programs and Processes; Maintenance Unit Department, Division Organization; Manpower Management ; and Aviation Officers.” http...Naval Aviation Maintenance Alejandra Jolodosky and Adi Zolotov February 2018 This work was performed under Federal Government Contract...underutilized sensor data. CNA proposed a pilot program that integrated sensor data across maintenance levels to expedite repairs of aviation parts

  1. A maintenance time prediction method considering ergonomics through virtual reality simulation.

    Science.gov (United States)

    Zhou, Dong; Zhou, Xin-Xin; Guo, Zi-Yue; Lv, Chuan

    2016-01-01

    Maintenance time is a critical quantitative index in maintainability prediction. An efficient maintenance time measurement methodology plays an important role in early stage of the maintainability design. While traditional way to measure the maintenance time ignores the differences between line production and maintenance action. This paper proposes a corrective MOD method considering several important ergonomics factors to predict the maintenance time. With the help of the DELMIA analysis tools, the influence coefficient of several factors are discussed to correct the MOD value and the designers can measure maintenance time by calculating the sum of the corrective MOD time of each maintenance therbligs. Finally a case study is introduced, by maintaining the virtual prototype of APU motor starter in DELMIA, designer obtains the actual maintenance time by the proposed method, and the result verifies the effectiveness and accuracy of the proposed method.

  2. Degradation mode analysis: An approach to establish effective predictive maintenance tasks

    International Nuclear Information System (INIS)

    Sonnett, D.E.; Douglass, P.T.; Barnard, D.D.

    1991-01-01

    A significant number of nuclear generating stations have been employing Reliability Centered Maintenance methodology to arrive at applicable and effective maintenance tasks for their plant equipment. The resultant endpoint of most programs has been an increased emphasis on predictive maintenance as the task of choice for monitoring and trending plant equipment condition to address failure mechanisms of the analyses. Many of these plants have spent several years conducting reliability centered analysis before they seriously begin implementing predictive program improvements. In this paper we present another methodology, entitled Degradation Mode Analysis, which provides a more direct method to quickly and economically achieve the major benefit of reliability centered analysis, namely predictive maintenance. (author)

  3. An evaluation system of the setting up of predictive maintenance programmes

    International Nuclear Information System (INIS)

    Carnero, MaCarmen

    2006-01-01

    Predictive Maintenance can provide an increase in safety, quality and availability in industrial plants. However, the setting up of a Predictive Maintenance Programme is a strategic decision that until now has lacked analysis of questions related to its setting up, management and control. In this paper, an evaluation system is proposed that carries out the decision making in relation to the feasibility of the setting up. The evaluation system uses a combination of tools belonging to operational research such as: Analytic Hierarchy Process, decision rules and Bayesian tools. This system is a help tool available to the managers of Predictive Maintenance Programmes which can both increase the number of Predictive Maintenance Programmes set up and avoid the failure of these programmes. The Evaluation System has been tested in a petrochemical plant and in a food industry

  4. An Approach to Integrating Tactical Decision-Making in Industrial Maintenance Balance Scorecards Using Principal Components Analysis and Machine Learning

    Directory of Open Access Journals (Sweden)

    Néstor Rodríguez-Padial

    2017-01-01

    Full Text Available The uncertainty of demand has led production systems to become increasingly complex; this can affect the availability of the machines and thus their maintenance. Therefore, it is necessary to adequately manage the information that facilitates decision-making. This paper presents a system for making decisions related to the design of customized maintenance plans in a production plant. This paper addresses this tactical goal and aims to provide greater knowledge and better predictions by projecting reliable behavior in the medium-term, integrating this new functionality into classic Balance Scorecards, and making it possible to extend their current measuring function to a new aptitude: predicting evolution based on historical data. In the proposed Custom Balance Scorecard design, an exploratory data phase is integrated with another analysis and prediction phase using Principal Component Analysis algorithms and Machine Learning that uses Artificial Neural Network algorithms. This new extension allows better control over the maintenance function of an industrial plant in the medium-term with a yearly horizon taken over monthly intervals which allows the measurement of the indicators of strategic productive areas and the discovery of hidden behavior patterns in work orders. In addition, this extension enables the prediction of indicator outcomes such as overall equipment efficiency and mean time to failure.

  5. Integrating Models of Diffusion and Behavior to Predict Innovation Adoption, Maintenance, and Social Diffusion.

    Science.gov (United States)

    Smith, Rachel A; Kim, Youllee; Zhu, Xun; Doudou, Dimi Théodore; Sternberg, Eleanore D; Thomas, Matthew B

    2018-01-01

    This study documents an investigation into the adoption and diffusion of eave tubes, a novel mosquito vector control, during a large-scale scientific field trial in West Africa. The diffusion of innovations (DOI) and the integrated model of behavior (IMB) were integrated (i.e., innovation attributes with attitudes and social pressures with norms) to predict participants' (N = 329) diffusion intentions. The findings showed that positive attitudes about the innovation's attributes were a consistent positive predictor of diffusion intentions: adopting it, maintaining it, and talking with others about it. As expected by the DOI and the IMB, the social pressure created by a descriptive norm positively predicted intentions to adopt and maintain the innovation. Drawing upon sharing research, we argued that the descriptive norm may dampen future talk about the innovation, because it may no longer be seen as a novel, useful topic to discuss. As predicted, the results showed that as the descriptive norm increased, the intention to talk about the innovation decreased. These results provide broad support for integrating the DOI and the IMB to predict diffusion and for efforts to draw on other research to understand motivations for social diffusion.

  6. Optimization of reliability centered predictive maintenance scheme for inertial navigation system

    International Nuclear Information System (INIS)

    Jiang, Xiuhong; Duan, Fuhai; Tian, Heng; Wei, Xuedong

    2015-01-01

    The goal of this study is to propose a reliability centered predictive maintenance scheme for a complex structure Inertial Navigation System (INS) with several redundant components. GO Methodology is applied to build the INS reliability analysis model—GO chart. Components Remaining Useful Life (RUL) and system reliability are updated dynamically based on the combination of components lifetime distribution function, stress samples, and the system GO chart. Considering the redundant design in INS, maintenance time is based not only on components RUL, but also (and mainly) on the timing of when system reliability fails to meet the set threshold. The definition of components maintenance priority balances three factors: components importance to system, risk degree, and detection difficulty. Maintenance Priority Number (MPN) is introduced, which may provide quantitative maintenance priority results for all components. A maintenance unit time cost model is built based on components MPN, components RUL predictive model and maintenance intervals for the optimization of maintenance scope. The proposed scheme can be applied to serve as the reference for INS maintenance. Finally, three numerical examples prove the proposed predictive maintenance scheme is feasible and effective. - Highlights: • A dynamic PdM with a rolling horizon is proposed for INS with redundant components. • GO Methodology is applied to build the system reliability analysis model. • A concept of MPN is proposed to quantify the maintenance sequence of components. • An optimization model is built to select the optimal group of maintenance components. • The optimization goal is minimizing the cost of maintaining system reliability

  7. Predicting cycle time distributions for integrated processing workstations : an aggregate modeling approach

    NARCIS (Netherlands)

    Veeger, C.P.L.; Etman, L.F.P.; Lefeber, A.A.J.; Adan, I.J.B.F.; Herk, van J.; Rooda, J.E.

    2011-01-01

    To predict cycle time distributions of integrated processing workstations, detailed simulation models are almost exclusively used; these models require considerable development and maintenance effort. As an alternative, we propose an aggregate model that is a lumped-parameter representation of the

  8. An approach to integrating surveillance and maintenance tasks to prevent the dominant failure causes of critical components

    International Nuclear Information System (INIS)

    Martorell, S.; Munoz, A.; Serradell, V.

    1995-01-01

    Surveillance requirements and maintenance activities in a nuclear power plant aim to preserve components' inherent reliability. Up to now, predictive and preventive maintenance mainly concerned plant staff, but the US Nuclear Regulatory Commission Maintenance Rule released in July 1991 will have significant impact on how nuclear power plants perform and document this maintenance. Reliability Centered Maintenance (RCM) is a systematic methodology to establish maintenance tasks for critical components in plant with a high degree of compliance with the goals of the Rule. RCM pursues the identification of applicable and efficient tasks to prevent these components from developing their dominant failure causes, and, in turn, towards achieving proper levels of components availability with low cost. In this paper, we present an approach for identifying the most suitable set of tasks to achieve this goal, which involves the integration of maintenance activities and surveillance requirements for each critical component based on the unavailability and cost associated with each individual task which is performed on it

  9. Integrated maintenance planning in manufacturing systems

    CERN Document Server

    Al-Turki, Umar M; Yilbas, Bekir Sami; Sahin, Ahmet Ziyaettin

    2014-01-01

    This book introduces the concept of integrated planning for maintenance and production taken into account quality and safety for high global socio-economic impact. It provides insight into the planning process at a global level starting from the business level and ending with the operational level where the plan is implemented and controlled.

  10. Predictive Maintenance (PdM) Centralization for Significant Energy Savings

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Dale

    2010-09-15

    Cost effective predictive maintenance (PdM) technologies and basic energy calculations can mine energy savings form processes or maintenance activities. Centralizing and packaging this information correctly empowers facility maintenance and reliability professionals to build financial justification and support for strategies and personnel to weather global economic downturns and competition. Attendees will learn how to: Systematically build a 'pilot project' for applying PdM and tracking systems; Break down a typical electrical bill to calculate energy savings; Use return on investment (ROI) calculations to identify the best and highest value options, strategies and tips for substantiating your energy reduction maintenance strategies.

  11. Integrated preventive maintenance and production decisions for imperfect processes

    International Nuclear Information System (INIS)

    Nourelfath, Mustapha; Nahas, Nabil; Ben-Daya, Mohamed

    2016-01-01

    This paper integrates production, maintenance, and quality for an imperfect process in a multi-period multi-product capacitated lot-sizing context. The production system is modeled as an imperfect machine, whose the status is considered to be either in-control or out-of-control. When the machine is out of control, it produces a fraction of nonconforming items. During each period, this machine is inspected and imperfect preventive maintenance activities are simultaneously performed to reduce its age, proportional to the preventive maintenance level. The objective is to minimize the total cost, while satisfying the demand for all products. Our optimization model allows for a joint selection of the optimal values of production plan, and the maintenance policy, while taking into account quality related costs. A solution algorithm is developed and illustrative numerical examples are presented. It is found that the increase in PM level leads to reductions in quality control costs. Furthermore, if the cost of performing PM is high to the point where it is not compensated for by reductions in the quality related costs, then performing PM is not justifiable. Finally, using non-periodic preventive maintenance with the possibility of different preventive maintenance levels may result in an improvement of the total cost. - Highlights: • We integrate production, maintenance, and quality. • We evaluate all the expected costs. • Our model allows for a joint selection of the optimal values. • A solution algorithm is developed. • Increasing PM level will decrease quality control costs.

  12. Integrated maintenance management model in the printing industry

    Directory of Open Access Journals (Sweden)

    Csaba Horváth

    2010-09-01

    Full Text Available Rapid technological and economic changes are setting radically new task for maintenance divisions of printingworks. In this dissertation the author provides a summary on the possible approaches for the adoption to the newrequirements. He formulates his situation analysis based on an exhaustive questionnaire survey, and points out thecurrents of changes and challenges caused by the expected developments in the maintenance field of the printingindustry.Based on the possible answers on these challenges, the Author has compiled a - yet missing - maintenance managementmodel that encompasses the maintenance specialties of the industry, as well as the professional heritage andthe latest scientific accomplishments in the discipline of maintenance.The model is based on the widely accepted quality focused maintenance approach, that is supplemented by theAuthor with four new aspects - 1 reliability-focused culture, 2 quality management system, 3 employment ofexternal service provides, 4 maintenance characteristics specific to printing machinery - determining their effectsand integrating them into one single system.In order to construct the model, the Author develops specific solutions that can be seen as own scientific achievementson the specification of maintenance characteristics of printing machinery; on the efficiency improving applicationsof quality management systems, modern knowledge management and reliability focused corporate culture;and on the implementation of a maintenance information system.

  13. Model-based fault diagnosis framework for effective predictive maintenance / B.B. Akindele

    OpenAIRE

    Akindele, Babatunde Babajide

    2010-01-01

    Predictive maintenance is a proactive maintenance strategy that is aimed at preventing the unexpected failure of equipment through condition monitoring of the health and performance of the equipment. Incessant equipment outage resulting in low availability of production facilities is a major issue in the Nigerian manufacturing environment. Improving equipment availability in Nigeria industry through institution of a full featured predictive maintenance has been suggested by many authors. T...

  14. Low-complexity Behavioral Model for Predictive Maintenance of Railway Turnouts

    DEFF Research Database (Denmark)

    Barkhordari, Pegah; Galeazzi, Roberto; Tejada, Alejandro de Miguel

    2017-01-01

    Maintenance of railway infrastructures represents a major cost driver for any infrastructure manager since reliability and dependability must be guaranteed at all times. Implementation of predictive maintenance policies relies on the availability of condition monitoring systems able to assess...

  15. Development of the predictive maintenance system prototype for the rod control system

    International Nuclear Information System (INIS)

    Lim, H. S.; Hong, H. P.; Koo, J. M.; Kim, Y. B.; Han, H. W.

    2003-01-01

    The demand for safety and reliability of Nuclear Power Plants (NPPs) has been constantly increasing and economical operation is also an important issue. Developing and adopting predictive maintenance technology for the major systems or equipment is considered as a way to achieve these goals. This paper describes the development of a predictive maintenance system prototype for the Rod Control System, which adopts an advanced methodology. Bayesian Belief Networks (BBN) has been adopted for the real time fault diagnosis and prediction of the system. Through a simulation test, it was confirmed that the prototype monitors and secures sound operability of rod drive mechanism and its control system, and also provides the predictive maintenance information

  16. Prediction of Combine Economic Life Based on Repair and Maintenance Costs Model

    Directory of Open Access Journals (Sweden)

    A Rohani

    2014-09-01

    Full Text Available Farm machinery managers often need to make complex economic decisions on machinery replacement. Repair and maintenance costs can have significant impacts on this economic decision. The farm manager must be able to predict farm machinery repair and maintenance costs. This study aimed to identify a regression model that can adequately represent the repair and maintenance costs in terms of machine age in cumulative hours of use. The regression model has the ability to predict the repair and maintenance costs for longer time periods. Therefore, it can be used for the estimation of the economic life. The study was conducted using field data collected from 11 John-Deer 955 combine harvesters used in several western provinces of Iran. It was found that power model has a better performance for the prediction of combine repair and maintenance costs. The results showed that the optimum replacement age of John-Deer 955 combine was 54300 cumulative hours.

  17. Operations and maintenance plan : Dallas Integrated Corridor Management (ICM) demonstration project.

    Science.gov (United States)

    2014-01-01

    This Operations and Maintenance (O&M) Plan describes how the Integrated Corridor Management System (ICMS) will be used in daily transportation operations and maintenance activities. The Plan addresses the activities needed to effectively operate the ...

  18. Dr. Mainte. Integrated simulator of maintenance optimization of LWRs

    International Nuclear Information System (INIS)

    Isobe, Yoshihiro; Sagisaka, Mitsuyuki; Etoh, Junji; Matsunaga, Takashi; Kosaka, Toru; Matsumoto, Satoshi; Yoshimura, Shinobu

    2014-01-01

    Dr. Mainte, an integrated simulator for maintenance optimization of LWRs (Light Water Reactors) has been developed based on PFM (Probabilistic Fracture Mechanics) analyses. The concept of the simulator is to provide a decision-making system to optimize maintenance activities for representative components and piping systems in nuclear power plants totally and quantitatively in terms of safety, availability and economic efficiency, environmental impact and social acceptance. For the further improvement of the safety and availability, the effect of human error and its reduction on the optimization of plant maintenance activities and approaches of reducing it have been studied. (author)

  19. Maintenance-based prognostics of nuclear plant equipment for long-term operation

    Energy Technology Data Exchange (ETDEWEB)

    Welz, Zachary; Coble, Jamie; Upadhyaya, Belle; Hines, Wes [University of Tennessee, Knoxville (United States)

    2017-08-15

    While industry understands the importance of keeping equipment operational and well maintained, the importance of tracking maintenance information in reliability models is often overlooked. Prognostic models can be used to predict the failure times of critical equipment, but more often than not, these models assume that all maintenance actions are the same or do not consider maintenance at all. This study investigates the influence of integrating maintenance information on prognostic model prediction accuracy. By incorporating maintenance information to develop maintenance-dependent prognostic models, prediction accuracy was improved by more than 40% compared with traditional maintenance-independent models. This study acts as a proof of concept, showing the importance of utilizing maintenance information in modern prognostics for industrial equipment.

  20. A novel integrated condition-based maintenance and stochastic flexible job shop scheduling problem

    DEFF Research Database (Denmark)

    Rahmati, Seyed Habib A.; Ahmadi, Abbas; Govindan, Kannan

    2018-01-01

    the level of the system optimization. By means of this equipment, managers can benefit from a condition-based maintenance (CBM) for monitoring and managing their system. The chief aim of the paper is to develop a stochastic maintenance problem based on CBM activities engaged with a complex applied......Integrated consideration of production planning and maintenance processes is a real world assumption. Specifically, by improving the monitoring equipment such as various sensors or product-embedded information devices in recent years, joint assessment of these processes is inevitable for enhancing...... production problem called flexible job shop scheduling problem (FJSP). This integrated problem considers two maintenance scenarios in terms of corrective maintenance (CM) and preventive maintenance (PM). The activation of scenario is done by monitoring the degradation condition of the system and comparing...

  1. Development the conceptual design of Knowledge Based System for Integrated Maintenance Strategy and Operation

    Science.gov (United States)

    Milana; Khan, M. K.; Munive, J. E.

    2014-07-01

    The importance of maintenance has escalated significantly by the increasing of automation in manufacturing process. This condition switches traditional maintenance perspective of inevitable cost into the business competitive driver. Consequently, maintenance strategy and operation decision needs to be synchronized to business and manufacturing concerns. This paper shows the development of conceptual design of Knowledge Based System for Integrated Maintenance Strategy and Operation (KBIMSO). The framework of KBIMSO is elaborated to show the process of how the KBIMSO works to reach the maintenance decision. By considering the multi-criteria of maintenance decision making, the KB system embedded with GAP and AHP to support integrated maintenance strategy and operation which is novel in this area. The KBIMSO is useful to review the existing maintenance system and give reasonable recommendation of maintenance decisions in respect to business and manufacturing perspective.

  2. Development the conceptual design of Knowledge Based System for Integrated Maintenance Strategy and Operation

    International Nuclear Information System (INIS)

    Milana; Khan, M K; Munive, J E

    2014-01-01

    The importance of maintenance has escalated significantly by the increasing of automation in manufacturing process. This condition switches traditional maintenance perspective of inevitable cost into the business competitive driver. Consequently, maintenance strategy and operation decision needs to be synchronized to business and manufacturing concerns. This paper shows the development of conceptual design of Knowledge Based System for Integrated Maintenance Strategy and Operation (KBIMSO). The framework of KBIMSO is elaborated to show the process of how the KBIMSO works to reach the maintenance decision. By considering the multi-criteria of maintenance decision making, the KB system embedded with GAP and AHP to support integrated maintenance strategy and operation which is novel in this area. The KBIMSO is useful to review the existing maintenance system and give reasonable recommendation of maintenance decisions in respect to business and manufacturing perspective

  3. Development of a prototype system for prediction of the group error at the maintenance work

    International Nuclear Information System (INIS)

    Yoshino, Kenji; Hirotsu, Yuuko

    2001-01-01

    This paper described on development and performance evaluation of a prototype system for prediction of the group error at the maintenance work. The results so far are as follows. (1) When a user inputs the existence and the grade of the feature factor of the maintenance work as a prediction object, an organization and an organization factor and a group PSF put into the system. The maintenance group error to target can be predicted through the prediction model which consists of a class of seven stages. (2) This system by utilizing the information on a prediction result database, it can be use not only for prediction of a maintenance group but for various safe Activity, such as KYT(Kiken Yochi Training) and TBM(Tool Box Meeting). (3) This system predicts a cooperation error at highest rate, and subsequently. Predicts the detection error at a high rate. and to the decision-making. Error, the transfer error and the state cognitive error, and state error, it has the characteristics predicted at almost same rate. (4) if it has full knowledge even if the feature, such as the enforcement conditions of maintenance work, and organization, even if the user has neither the knowledge about a human factor, users experience, anyone of this system is slight about the extent, generating of a maintenance group error made difficult from the former logically and systematically, it can predict with business time for about 15 minutes. (author)

  4. Motivational indictors predicting the engagement, frequency and adequacy of rainwater tank maintenance

    Science.gov (United States)

    Mankad, Aditi; Greenhill, Murni

    2014-01-01

    Rainwater tank maintenance is a key social behavior in our changing environment, as tanks are being adopted worldwide to augment household water supplies and reduce urban water stress. The maintenance of rainwater tanks in urban areas is an important pro-environmental behavior that prevents public health issues arising from unhygienic tank use. This study examined motivational differences in maintenance behavior between householders with retrofitted and mandated (compulsory) rainwater tanks on their property (N = 1988). Results showed that retrofitted tank owners were more self-determined in their motivation than mandated owners. Amotivation and integrated regulation were both dominant predictors of engagement in tank maintenance, frequency and adequacy of tank maintenance activities. Those involved in more maintenance activity were likely driven to do so because of feelings of adherence to personal goals and values (e.g., as "sustainable" citizens), whereas individuals who experienced a lack of control and alienation from the activity were likely to view maintenance as meaningless. Thus, people with higher integrated regulation engaged in more tank maintenance activities, whereas more amotivated individuals engaged in less maintenance. As cities begin relying more on citizen self-sufficiency with respect to water and energy resources, issues relating to infrastructure maintenance and operation become paramount. Results show that motivation is important in the impetus to engage in a pro-environmental behavior as well as the frequency and accuracy with which that behavior is undertaken. Policy implications are further discussed.

  5. Guidance for the design and management of a maintenance plan to assure safety and improve the predictability of a DOE nuclear irradiation facility. Final report

    International Nuclear Information System (INIS)

    Booth, R.S.; Kryter, R.C.; Shepard, R.L.; Smith, O.L.; Upadhyaya, B.R.; Rowan, W.J.

    1994-10-01

    A program is recommended for planning the maintenance of DOE nuclear facilities that will help safety and enhance availability throughout a facility's life cycle. While investigating the requirements for maintenance activities, a major difference was identified between the strategy suitable for a conventional power reactor and one for a research reactor facility: the latter should provide a high degree of predicted availability (referred to hereafter as ''predictability'') to its users, whereas the former should maximize total energy production. These differing operating goals necessitate different maintenance strategies. A strategy for scheduling research reactor facility operation and shutdown for maintenance must balance safety, reliability,and predicted availability. The approach developed here is based on three major elements: (1) a probabilistic risk analysis of the balance between assured reliability and predictability (presented in Appendix C), (2) an assessment of the safety and operational impact of maintenance activities applied to various components of the facility, and (3) a data base of historical and operational information on the performance and requirements for maintenance of various components. These factors are integrated into a set of guidelines for designing a new highly maintainable facility, for preparing flexible schedules for improved maintenance of existing facilities, and for anticipating the maintenance required to extend the life of an aging facility. Although tailored to research reactor facilities, the methodology has broader applicability and may therefore be used to improved the maintenance of power reactors, particularly in anticipation of peak load demands

  6. Integrated predictive maintenance program vibration and lube oil analysis: Part I - history and the vibration program

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, H.

    1996-12-01

    This paper is the first of two papers which describe the Predictive Maintenance Program for rotating machines at the Palo Verde Nuclear Generating Station. The organization has recently been restructured and significant benefits have been realized by the interaction, or {open_quotes}synergy{close_quotes} between the Vibration Program and the Lube Oil Analysis Program. This paper starts with the oldest part of the program - the Vibration Program and discusses the evolution of the program to its current state. The {open_quotes}Vibration{close_quotes} view of the combined program is then presented.

  7. Integrated predictive maintenance program vibration and lube oil analysis: Part I - history and the vibration program

    International Nuclear Information System (INIS)

    Maxwell, H.

    1996-01-01

    This paper is the first of two papers which describe the Predictive Maintenance Program for rotating machines at the Palo Verde Nuclear Generating Station. The organization has recently been restructured and significant benefits have been realized by the interaction, or open-quotes synergyclose quotes between the Vibration Program and the Lube Oil Analysis Program. This paper starts with the oldest part of the program - the Vibration Program and discusses the evolution of the program to its current state. The open-quotes Vibrationclose quotes view of the combined program is then presented

  8. Predictive Maintenance--An Effective Money Saving Tool Being Applied in Industry Today.

    Science.gov (United States)

    Smyth, Tom

    2000-01-01

    Looks at preventive/predictive maintenance as it is used in industry. Discusses core preventive maintenance tools that must be understood to prepare students. Includes a list of websites related to the topic. (JOW)

  9. Machine and lubricant condition monitoring for extended equipment lifetimes and predictive maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Lukas, M; Anderson, D P [Spectro Incorporated, Littleton, Massachusetts (United States)

    1998-12-31

    Predictive maintenance has gained wide acceptance as a cost cutting strategy in modern industry. Condition monitoring by lubricant analysis is one of the basic tools of a predictive maintenance program along with vibration monitoring, performance monitoring and thermography. In today`s modern power generation, manufacturing, refinery, transportation, mining, and military operations, the cost of equipment maintenance, service, and lubricants are ever increasing. Parts, labor, equipment downtime and lubricant prices and disposal costs are a primary concern in a well run maintenance management program. Machine condition monitoring based on oil analysis has become a prerequisite in most maintenance programs. Few operations can afford not to implement a program if they wish to remain competitive, and in some cases, profitable. This presentation describes a comprehensive Machine Condition Monitoring Program based on oil analysis. Actual operational condition monitoring programs will be used to review basic components and analytical requirements. Case histories will be cited as examples of cost savings, reduced equipment downtime and increased efficiencies of maintenance programs through a well managed oil analysis program. (orig.)

  10. Machine and lubricant condition monitoring for extended equipment lifetimes and predictive maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Lukas, M.; Anderson, D.P. [Spectro Incorporated, Littleton, Massachusetts (United States)

    1997-12-31

    Predictive maintenance has gained wide acceptance as a cost cutting strategy in modern industry. Condition monitoring by lubricant analysis is one of the basic tools of a predictive maintenance program along with vibration monitoring, performance monitoring and thermography. In today`s modern power generation, manufacturing, refinery, transportation, mining, and military operations, the cost of equipment maintenance, service, and lubricants are ever increasing. Parts, labor, equipment downtime and lubricant prices and disposal costs are a primary concern in a well run maintenance management program. Machine condition monitoring based on oil analysis has become a prerequisite in most maintenance programs. Few operations can afford not to implement a program if they wish to remain competitive, and in some cases, profitable. This presentation describes a comprehensive Machine Condition Monitoring Program based on oil analysis. Actual operational condition monitoring programs will be used to review basic components and analytical requirements. Case histories will be cited as examples of cost savings, reduced equipment downtime and increased efficiencies of maintenance programs through a well managed oil analysis program. (orig.)

  11. Historical maintenance relevant information road-map for a self-learning maintenance prediction procedural approach

    Science.gov (United States)

    Morales, Francisco J.; Reyes, Antonio; Cáceres, Noelia; Romero, Luis M.; Benitez, Francisco G.; Morgado, Joao; Duarte, Emanuel; Martins, Teresa

    2017-09-01

    A large percentage of transport infrastructures are composed of linear assets, such as roads and rail tracks. The large social and economic relevance of these constructions force the stakeholders to ensure a prolonged health/durability. Even though, inevitable malfunctioning, breaking down, and out-of-service periods arise randomly during the life cycle of the infrastructure. Predictive maintenance techniques tend to diminish the appearance of unpredicted failures and the execution of needed corrective interventions, envisaging the adequate interventions to be conducted before failures show up. This communication presents: i) A procedural approach, to be conducted, in order to collect the relevant information regarding the evolving state condition of the assets involved in all maintenance interventions; this reported and stored information constitutes a rich historical data base to train Machine Learning algorithms in order to generate reliable predictions of the interventions to be carried out in further time scenarios. ii) A schematic flow chart of the automatic learning procedure. iii) Self-learning rules from automatic learning from false positive/negatives. The description, testing, automatic learning approach and the outcomes of a pilot case are presented; finally some conclusions are outlined regarding the methodology proposed for improving the self-learning predictive capability.

  12. Bayesian based Prognostic Model for Predictive Maintenance of Offshore Wind Farms

    DEFF Research Database (Denmark)

    Asgarpour, Masoud; Sørensen, John Dalsgaard

    2018-01-01

    The operation and maintenance costs of offshore wind farms can be significantly reduced if existing corrective actions are performed as efficient as possible and if future corrective actions are avoided by performing sufficient preventive actions. In this paper a prognostic model for degradation...... monitoring, fault prediction and predictive maintenance of offshore wind components is defined. The diagnostic model defined in this paper is based on degradation, remaining useful lifetime and hybrid inspection threshold models. The defined degradation model is based on an exponential distribution...

  13. Bayesian based Prognostic Model for Predictive Maintenance of Offshore Wind Farms

    DEFF Research Database (Denmark)

    Asgarpour, Masoud; Sørensen, John Dalsgaard

    2018-01-01

    monitoring, fault prediction and predictive maintenance of offshore wind components is defined. The diagnostic model defined in this paper is based on degradation, remaining useful lifetime and hybrid inspection threshold models. The defined degradation model is based on an exponential distribution......The operation and maintenance costs of offshore wind farms can be significantly reduced if existing corrective actions are performed as efficient as possible and if future corrective actions are avoided by performing sufficient preventive actions. In this paper a prognostic model for degradation...

  14. Predictive maintenance policy for a gradually deteriorating system subject to stress

    Energy Technology Data Exchange (ETDEWEB)

    Deloux, E. [IRCCyN/Ecole des Mines de Nantes, Nantes (France); Castanier, B. [IRCCyN/Ecole des Mines de Nantes, Nantes (France)], E-mail: bruno.castanier@emn.fr; Berenguer, C. [Universite de Technologie de Troyes/CNRS, Troyes (France)

    2009-02-15

    This paper deals with a predictive maintenance policy for a continuously deteriorating system subject to stress. We consider a system with two failure mechanisms which are, respectively, due to an excessive deterioration level and a shock. To optimize the maintenance policy of the system, an approach combining statistical process control (SPC) and condition-based maintenance (CBM) is proposed. CBM policy is used to inspect and replace the system according to the observed deterioration level. SPC is used to monitor the stress covariate. In order to assess the performance of the proposed maintenance policy and to minimize the long-run expected maintenance cost per unit of time, a mathematical model for the maintained system cost is derived. Analysis based on numerical results are conducted to highlight the properties of the proposed maintenance policy in respect to the different maintenance parameters.

  15. Predictive maintenance policy for a gradually deteriorating system subject to stress

    International Nuclear Information System (INIS)

    Deloux, E.; Castanier, B.; Berenguer, C.

    2009-01-01

    This paper deals with a predictive maintenance policy for a continuously deteriorating system subject to stress. We consider a system with two failure mechanisms which are, respectively, due to an excessive deterioration level and a shock. To optimize the maintenance policy of the system, an approach combining statistical process control (SPC) and condition-based maintenance (CBM) is proposed. CBM policy is used to inspect and replace the system according to the observed deterioration level. SPC is used to monitor the stress covariate. In order to assess the performance of the proposed maintenance policy and to minimize the long-run expected maintenance cost per unit of time, a mathematical model for the maintained system cost is derived. Analysis based on numerical results are conducted to highlight the properties of the proposed maintenance policy in respect to the different maintenance parameters

  16. Failure time series prediction in industrial maintenance using neural networks; Previsao de series temporais de falhas em manutencao industrial usando redes neurais

    Energy Technology Data Exchange (ETDEWEB)

    Torres Junior, Rubiao G.; Machado, Maria Augusta S. [Instituto Brasileiro de Mercado de Capitais (IBMEC), Rio de Janeiro, RJ (Brazil); Souza, Reinaldo C. [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil)

    2005-07-01

    The objective of this work is the application of two failure prediction models in industrial maintenance with the use of Artificial Neural Networks (ANN). A characteristic of the modern industrial environment is a strong competition which leads companies to search for costs minimization methods. Thus, dada gathering and maintenance dada treatment becomes extremely important in this scenario for it aims the equipment and plant systems real repair necessity. Therefore, the objective becomes the widening of the system's full activity in a continuous manner, in the required period, without problems in their integrating parts. A daily time series is modeled based on maintenance interventions pauses dada from a five years period derived form many productive systems in the finalization areas of PETROFLEX Ind. and Com. S.A. Thus, the purpose is to introduce models based on neural networks and verify its system's pauses prediction capacity, so as to intervene with adequate timing before the system fails, extend the operational period and consequently increase its availability. The results obtained in this work demonstrate the employment of Neural Networks in the prediction of pauses in PETROFLEX industrial area maintenance. The ANN's prediction capacity in a group of dada with strong non-linear component where other statistical techniques have shown little efficient has also been confirmed. Discover neural models to predict failure systems time series has enable a breakthrough in the research field, especially due to the market demand. It's no doubt a technique that will evolve in the industrial maintenance area financing important managing decision. Prediction techniques, such as the ones illustrated in this study, work side by side maintenance planning and if carefully implemented and followed up can in the medium run supply a substantial increase in the available operational hours. (author)

  17. On line performance monitoring for predictive maintenance [Paper No.: VIA - 2

    International Nuclear Information System (INIS)

    Gupta, R.K.; Chandra, Rajesh

    1981-01-01

    There will always be progressive deterioration in the performance of dynamic equipment due to normal inevitable wear, malfunctions, failures and other reasons. In most cases it is possible to monitor some parameters of a system which would get progressively affected with the deterioration in the health of the system. By on-line monitoring of such predetermined parameters, compared with preset base data generated for a healthy system earlier, would prove very helpful in avoiding breakdowns and in proper planning of preventive and predictive maintenance. With increasing use of on-line computerised controls the generation of design base data and also the in-built self checking feature of monitoring the equipment health can be achieved by incorporating suitable software. This type of system will be helpful in: (a) predicting the life of component, (b) prewarning the operator about impending malfunctions, (c) establishing a maintenance schedule and spare inventory, and (d) analysing the failures. This type of centralised predictive maintenance is increasingly becoming important where: (a) the number of equipments are large, (b) the operation of equipment is critical from safety criteria, and (c) the minimum safety margin in the performance of the component is to be maintained. Keeping this in mind, the Fuel Handling System of Narora Atomic Power Project and the future power plants having computerised controls will have facility for on-line performance monitoring for predictive maintenance. The paper also describes methodology of the technique in detail, with a few representative cases. (author)

  18. Predictive Maintenance: One key to improved power plant availability

    International Nuclear Information System (INIS)

    Mobley; Allen, J.W.

    1986-01-01

    Recent developments in microprocessor technology has provided the ability to routinely monitor the actual mechanical condition of all rotating and reciprocating machinery and process variables (i.e. pressure, temperature, flow, etc.) of other process equipment within an operating electric power generating plant. This direct correlation between frequency domain vibration and actual mechanical condition of machinery and trending process variables of non-rotating equipment can provide the ''key'' to improving the availability and reliability, thermal efficiency and provide the baseline information necessary for developing a realistic plan for extending the useful life of power plants. The premise of utilizing microprocessor-based Predictive Maintenance to improve power plant operation has been proven by a number of utilities. This paper provides a comprehensive discussion of the TEC approach to Predictive Maintenance and examples of successful programs

  19. The application and practice of predictive maintenance at CANDU equipment management

    International Nuclear Information System (INIS)

    Yu Guangting

    2014-01-01

    The equipment in Qinshan CANDU unit is characterized by large number and complex structure. Some equipment failure has no relation with the operation time, it is impossible to avoid the failure of these equipment only by periodical maintenance. To improve the equipment reliability, increase the equipment usability and decrease the maintenance cost, for important equipment related to nuclear safety and generating electricity, it is required to perform condition monitoring and the predictive maintenance (PdM). According to different characteristics of equipment, it is required to use suitable equipment condition monitoring method, content and frequency. In this way, some potential equipment failure can be found, preventive maintenance can be arranged in advance, and equipment maintenance management can be optimized. (author)

  20. A framework to practical predictive maintenance modeling for multi-state systems

    International Nuclear Information System (INIS)

    Cher Ming Tan; Raghavan, Nagarajan

    2008-01-01

    A simple practical framework for predictive maintenance (PdM)-based scheduling of multi-state systems (MSS) is developed. The maintenance schedules are derived from a system-perspective using the failure times of the overall system as estimated from its performance degradation trends. The system analyzed in this work is a flow transmission water pipe system. The various factors influencing PdM-based scheduling are identified and their impact on the system reliability and performance are quantitatively studied. The estimated times to replacement of the MSS may also be derived from the developed model. The results of the model simulation demonstrate the significant impact of maintenance quality and the criteria for the call for maintenance (user demand) on the system reliability and mean performance characteristics. A slight improvement in maintenance quality is found to postpone the system replacement time by manifold. The consistency in the quality of maintenance work with minimal variance is also identified as a very important factor that enhances the system's future operational and downtime event predictability. The studies also reveal that in order to reduce the frequency of maintenance actions, it is necessary to lower the minimum user demand from the system if possible, ensuring at the same time that the system still performs its intended function effectively. The model proposed can be utilized to implement a PdM program in the industry with a few modifications to suit the individual industrial systems' needs

  1. On the Use of Time-Limited Information for Maintenance Decision Support: A Predictive Approach under Maintenance Constraints

    Directory of Open Access Journals (Sweden)

    E. Khoury

    2013-01-01

    Full Text Available This paper deals with a gradually deteriorating system operating under an uncertain environment whose state is only known on a finite rolling horizon. As such, the system is subject to constraints. Maintenance actions can only be planned at imposed times called maintenance opportunities that are available on a limited visibility horizon. This system can, for example, be a commercial vehicle with a monitored critical component that can be maintained only in some specific workshops. Based on the considered system, we aim to use the monitoring data and the time-limited information for maintenance decision support in order to reduce its costs. We propose two predictive maintenance policies based, respectively, on cost and reliability criteria. Classical age-based and condition-based policies are considered as benchmarks. The performance assessment shows the value of the different types of information and the best way to use them in maintenance decision making.

  2. Prediction of warfarin maintenance dose in Han Chinese patients using a mechanistic model based on genetic and non-genetic factors.

    Science.gov (United States)

    Lu, Yuan; Yang, Jinbo; Zhang, Haiyan; Yang, Jin

    2013-07-01

    Many attempts have been made to predict the warfarin maintenance dose in patients beginning warfarin therapy using a descriptive model based on multiple linear regression. Here we report the first attempt to develop a comprehensive mechanistic model integrating in vitro-in vivo extrapolation (IVIVE) with a pharmacokinetic-pharmacodynamic model to predict the warfarin maintenance dose in Han Chinese patients. The model incorporates demographic factors [sex, age, body weight (BW)] and the genetic polymorphisms of cytochrome P450 (CYP) 2C9 (CYP2C9) and vitamin K epoxide reductase complex subunit 1 (VKORC1). Information on the various factors, mean warfarin daily dose and International Normalized Ratio (INR) was available for a cohort of 197 Han Chinese patients. Based on in vitro enzyme kinetic parameters for S-warfarin metabolism, demographic data for Han Chinese and some scaling factors, the S-warfarin clearance (CL) was predicted for patients in the cohort with different CYP2C9 genotypes using IVIVE. The plasma concentration of S-warfarin after a single oral dose was simulated using a one-compartment pharmacokinetic model with first-order absorption and a lag time and was combined with a mechanistic coagulation model to simulate the INR response. The warfarin maintenance dose was then predicted based on the demographic data and genotypes of CYP2C9 and VKORC1 for each patient and using the observed steady-state INR (INRss) as a target value. Finally, sensitivity analysis was carried out to determine which factor(s) affect the warfarin maintenance dose most strongly. The predictive performance of this mechanistic model is not inferior to that of our previous descriptive model. There were significant differences in the mean warfarin daily dose in patients with different CYP2C9 and VKORC1 genotypes. Using IVIVE, the predicted mean CL of S-warfarin for patients with CYP2C9*1/*3 (0.092 l/h, n = 11) was 57 % less than for those with wild-type *1/*1 (0.215 l/h, n

  3. Prediction of the safety level in a tritium processing facility through predictive maintenance

    International Nuclear Information System (INIS)

    Anghel, Vasile

    2007-01-01

    Full text: The safety level of a nuclear facility for personnel and environment depends generally on the technological process quality of operation and maintenance and particularly on several technical, technological, economic, and human factors. The role of maintenance is fundamental because it is determined by all the technical, economic and human elements as parts of an integrated system dominated by an important feedback from upstream activities which eventually define the life cycle of the nuclear facility considered. In the maintenance activity as in case of any dynamic area, new elements may appear which, sometimes, require new methods of approach. For considered installation which is a Nuclear Detritiation Plant (NDP) operating as a division of the National Research and Development Institute for Cryogenics and Isotopic Technologies - ICSI, Rm.Valcea, in order to ensure a safety level in operation as high as possible through predictive maintenance, the fuzzy theory and software LabVIEW were applied. The final aim is to achieve the best practices in maintenance of the tritium processing plant. The safety in operation of the NDP equipment and installations is directly related with the maintenance achieved by improving the reliability through methods and advanced techniques. The maintainability is the capacity of an industrial product, in given utilization conditions, to be maintained and re-established up to achieve specified functions. In general the reliability on some interval is a probability conditioned by good operation at the beginning of the interval, representing thus the probability as the element which operated at t = t 0 to operate in the interval (t 0 , t 1 ). The failure is a fundamental event in the reliability theory. Breakdown (failure) is understood as the stop process of the function required from a given product, the failure representing the effect upon that process. The operation of a product on a certain duration can be a 'success' or a

  4. Predictive maintenance of critical equipment in industrial processes

    Science.gov (United States)

    Hashemian, Hashem M.

    This dissertation is an account of present and past research and development (R&D) efforts conducted by the author to develop and implement new technology for predictive maintenance and equipment condition monitoring in industrial processes. In particular, this dissertation presents the design of an integrated condition-monitoring system that incorporates the results of three current R&D projects with a combined funding of $2.8 million awarded to the author by the U.S. Department of Energy (DOE). This system will improve the state of the art in equipment condition monitoring and has applications in numerous industries including chemical and petrochemical plants, aviation and aerospace, electric power production and distribution, and a variety of manufacturing processes. The work that is presented in this dissertation is unique in that it introduces a new class of condition-monitoring methods that depend predominantly on the normal output of existing process sensors. It also describes current R&D efforts to develop data acquisition systems and data analysis algorithms and software packages that use the output of these sensors to determine the condition and health of industrial processes and their equipment. For example, the output of a pressure sensor in an operating plant can be used not only to indicate the pressure, but also to verify the calibration and response time of the sensor itself and identify anomalies in the process such as blockages, voids, and leaks that can interfere with accurate measurement of process parameters or disturb the plant's operation, safety, or reliability. Today, process data are typically collected at a rate of one sample per second (1 Hz) or slower. If this sampling rate is increased to 100 samples per second or higher, much more information can be extracted from the normal output of a process sensor and then used for condition monitoring, equipment performance measurements, and predictive maintenance. A fast analog-to-digital (A

  5. Integrated Program of Experimental Diagnostics at the NNSS: An Integrated, Prioritized Work Plan for Diagnostic Development and Maintenance and Supporting Capability

    International Nuclear Information System (INIS)

    2010-01-01

    This Integrated Program of Experimental Diagnostics at the NNSS is an integrated prioritized work plan for the Nevada National Security Site (NNSS), formerly the Nevada Test Site (NTS), program that is independent of individual National Security Enterprise Laboratories (Labs) requests or specific Subprograms being supported. This prioritized work plan is influenced by national priorities presented in the Predictive Capability Framework (PCF) and other strategy documents (Primary and Secondary Assessment Technologies Plans and the Plutonium Experiments Plan). This document satisfies completion criteria for FY 2010 MRT milestone No.3496: Document an integrated, prioritized work plan for diagnostic development, maintenance, and supporting capability. This document is an update of the 3-year NNSS plan written a year ago, September 21, 2009, to define and understand Lab requests for diagnostic implementation. This plan is consistent with Lab interpretations of the PCF, Primary Assessment Technologies, and Plutonium Experiment plans.

  6. Experiences with an integrated management system for aircraft maintenance

    International Nuclear Information System (INIS)

    Huber, U.

    1993-01-01

    For 20 years, SWISSAIR has employed an integrated information system for aircraft maintenance. To date, a wide range of functions has been set up in their own development. For the future SWISSAIR is increasingly basing on the use of SAP/standard software packages. 10 figs

  7. Low-complexity Behavioral Model for Predictive Maintenance of Railway Turnouts

    DEFF Research Database (Denmark)

    Barkhordari, Pegah; Galeazzi, Roberto; Tejada, Alejandro de Miguel

    2017-01-01

    together with the Eigensystem Realization Algorithm – a type of subspace identification – to identify a fourth order model of the infrastructure. The robustness and predictive capability of the low-complexity behavioral model to reproduce track responses under different types of train excitations have been......Maintenance of railway infrastructures represents a major cost driver for any infrastructure manager since reliability and dependability must be guaranteed at all times. Implementation of predictive maintenance policies relies on the availability of condition monitoring systems able to assess...... the infrastructure health state. The core of any condition monitoring system is the a-priori knowledge about the process to be monitored, in the form of either mathematical models of different complexity or signal features characterizing the healthy/faulty behavior. This study investigates the identification...

  8. Optimization of maintenance for power system equipment using a predictive health model

    NARCIS (Netherlands)

    Bajracharya, G.; Koltunowicz, T.; Negenborn, R.R.; Papp, Z.; Djairam, D.; Schutter, B.D. de; Smit, J.J.

    2009-01-01

    In this paper, a model-predictive control based framework is proposed for modeling and optimization of the health state of power system equipment. In the framework, a predictive health model is proposed that predicts the health state of the equipment based on its usage and maintenance actions. Based

  9. Predicting Use and Maintenance of Use of Substances in Scottish Adolescents.

    Science.gov (United States)

    Karatzias, A.; Power, K. G.; Swanson, V.

    2001-01-01

    Studied the roles of demographic, school, nonschool, and personality factors in predicting the use of tobacco, alcohol, and illicit drugs and maintenance of this use. Findings for 425 Scottish secondary school students show different predictive factors. Discusses implications of the findings for decreasing the prevalence of substance use. (SLD)

  10. Application of Dr. Mainte, integrated simulator of maintenance optimization, to LWRs

    International Nuclear Information System (INIS)

    Isobe, Yoshihiro; Sagisaka, Mitsuyuki; Etoh, Junji; Matsunaga, Takashi; Kosaka, Toru; Matsumoto, Satoshi; Yoshimura, Shinobu

    2015-01-01

    Dr. Mainte, an integrated simulator for maintenance optimization of LWRs (Light Water Reactors) is based on PFM (Probabilistic Fracture Mechanics) analyses. The concept of the simulator is to provide a decision-making system to optimize maintenance activities for typical components and piping systems in nuclear power plants totally and quantitatively in terms of safety, availability, economic rationality, environmental impact and social acceptance. For the further improvement of the safety and availability of nuclear power plants, the effect of human error and its reduction on the optimization of maintenance activities have been studied. In addition, an approach of reducing human error is proposed. (author)

  11. Engineering systems reliability, safety, and maintenance an integrated approach

    CERN Document Server

    Dhillon, B S

    2017-01-01

    Today, engineering systems are an important element of the world economy and each year billions of dollars are spent to develop, manufacture, operate, and maintain various types of engineering systems around the globe. Many of these systems are highly sophisticated and contain millions of parts. For example, a Boeing jumbo 747 is made up of approximately 4.5 million parts including fasteners. Needless to say, reliability, safety, and maintenance of systems such as this have become more important than ever before.  Global competition and other factors are forcing manufacturers to produce highly reliable, safe, and maintainable engineering products. Therefore, there is a definite need for the reliability, safety, and maintenance professionals to work closely during design and other phases. Engineering Systems Reliability, Safety, and Maintenance: An Integrated Approach eliminates the need to consult many different and diverse sources in the hunt for the information required to design better engineering syste...

  12. Modeling a Predictive Energy Equation Specific for Maintenance Hemodialysis.

    Science.gov (United States)

    Byham-Gray, Laura D; Parrott, J Scott; Peters, Emily N; Fogerite, Susan Gould; Hand, Rosa K; Ahrens, Sean; Marcus, Andrea Fleisch; Fiutem, Justin J

    2017-03-01

    Hypermetabolism is theorized in patients diagnosed with chronic kidney disease who are receiving maintenance hemodialysis (MHD). We aimed to distinguish key disease-specific determinants of resting energy expenditure to create a predictive energy equation that more precisely establishes energy needs with the intent of preventing protein-energy wasting. For this 3-year multisite cross-sectional study (N = 116), eligible participants were diagnosed with chronic kidney disease and were receiving MHD for at least 3 months. Predictors for the model included weight, sex, age, C-reactive protein (CRP), glycosylated hemoglobin, and serum creatinine. The outcome variable was measured resting energy expenditure (mREE). Regression modeling was used to generate predictive formulas and Bland-Altman analyses to evaluate accuracy. The majority were male (60.3%), black (81.0%), and non-Hispanic (76.7%), and 23% were ≥65 years old. After screening for multicollinearity, the best predictive model of mREE ( R 2 = 0.67) included weight, age, sex, and CRP. Two alternative models with acceptable predictability ( R 2 = 0.66) were derived with glycosylated hemoglobin or serum creatinine. Based on Bland-Altman analyses, the maintenance hemodialysis equation that included CRP had the best precision, with the highest proportion of participants' predicted energy expenditure classified as accurate (61.2%) and with the lowest number of individuals with underestimation or overestimation. This study confirms disease-specific factors as key determinants of mREE in patients on MHD and provides a preliminary predictive energy equation. Further prospective research is necessary to test the reliability and validity of this equation across diverse populations of patients who are receiving MHD.

  13. Preventative and predictive maintenance as a function of spare part management

    International Nuclear Information System (INIS)

    LaRose, R.; Sloski, P.

    2006-01-01

    Preventive and predictive maintenance has many aspects, such as vibration monitoring, lubricating oil analysis, thermography etc. This presentation focuses on the material and design application of sealing devices. (author)

  14. Advanced remote handling for future applications: The advanced integrated maintenance system

    International Nuclear Information System (INIS)

    Herndon, J.N.; Kring, C.T.; Rowe, J.C.

    1986-01-01

    The Consolidated Fuel Reprocessing Program at Oak Ridge National Laboratory has been developing advanced techniques for remote maintenance of future US fuel reprocessing plants. The developed technology has a wide spectrum of application for other hazardous environments. These efforts are based on the application of teleoperated, force-reflecting servomanipulators for dexterous remote handling with television viewing for large-volume hazardous applications. These developments fully address the nonrepetitive nature of remote maintenance in the unstructured environments encountered in fuel reprocessing. This paper covers the primary emphasis in the present program; the design, fabrication, installation, and operation of a prototype remote handling system for reprocessing applications, the Advanced Integrated Maintenance System

  15. Predictive maintenance technology development at G.A. Siwabessy multipurpose reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jupiter Sitorus Pane; Imron, M.; Sapto Hartoko; Sentot Alibasya Harahap [Multipurpose Research Reactor G.A. Siwabessy, National Nuclear Energy Agency (Indonesia)

    1999-10-01

    Safe operation of reactor is certainly influenced by condition of system and component equipped to the reactor's system. In order to maintain the condition of that systems and components, RSG-GAS has arranged maintenance program with time-basis. All 6 (six) groups of reactor systems are maintained within interval of weekly, monthly, three monthly, six-monthly, yearly, five-yearly appropriately. The experience showed that event though the maintenance was performed persistently, the condition of system and component are still not able to determine exactly. The possibility of accidental failure is open since the failure factor are varied and complicated. In order to limit an uncertainty of the component condition a based maintenance shall be introduced. An infrared investigation and manual vibration analysis had been used to diagnose the condition of some RSG-GAS' components. In addition, other alternative technology for predictive maintenance was developed. It is started by computerizing the database maintenance and doing historical review for its aging management, and developing data acquisition and processing equipment using Lab View computer program for collecting and processing signal data from dynamics system. This paper describes briefly the status of those development results. (author)

  16. Predictive maintenance technology development at G.A. Siwabessy multipurpose reactor

    International Nuclear Information System (INIS)

    Jupiter Sitorus Pane; Imron, M.; Sapto Hartoko; Sentot Alibasya Harahap

    1999-01-01

    Safe operation of reactor is certainly influenced by condition of system and component equipped to the reactor's system. In order to maintain the condition of that systems and components, RSG-GAS has arranged maintenance program with time-basis. All 6 (six) groups of reactor systems are maintained within interval of weekly, monthly, three monthly, six-monthly, yearly, five-yearly appropriately. The experience showed that event though the maintenance was performed persistently, the condition of system and component are still not able to determine exactly. The possibility of accidental failure is open since the failure factor are varied and complicated. In order to limit an uncertainty of the component condition a based maintenance shall be introduced. An infrared investigation and manual vibration analysis had been used to diagnose the condition of some RSG-GAS' components. In addition, other alternative technology for predictive maintenance was developed. It is started by computerizing the database maintenance and doing historical review for its aging management, and developing data acquisition and processing equipment using Lab View computer program for collecting and processing signal data from dynamics system. This paper describes briefly the status of those development results. (author)

  17. Weight Suppression Predicts Maintenance and Onset of Bulimic Syndromes at 10-Year Follow-up

    Science.gov (United States)

    Keel, Pamela K.; Heatherton, Todd F.

    2010-01-01

    Conflicting results have emerged regarding the prognostic significance of weight suppression for maintenance of bulimic symptoms. This study examined whether the magnitude of weight suppression would predict bulimic syndrome maintenance and onset in college-based samples of men (n=369) and women (n=968) at 10-year follow-up. Data come from a longitudinal study of body weight and disordered eating with high retention (80%). Among those with a bulimic syndrome at baseline, greater weight suppression significantly predicted maintenance of the syndrome, and, among those without a bulimic syndrome at baseline, greater weight suppression predicted onset of a bulimic syndrome at 10-year follow-up in multivariate models that included baseline body mass index, diet frequency, and weight perception. Future research should address mechanisms that could account for the effects of weight suppression over a long duration of follow-up. PMID:20455599

  18. Preventive and Predictive Maintenance, Warehousing of Spares, Periodic Testing and In-Service Inspection Activities at the Nigerian Research Reactor-1 Facility

    Energy Technology Data Exchange (ETDEWEB)

    Yusuf, I.; Mati, A. A.; Dewu, B. B.M., [Centre for Energy Research and Training, Ahmadu Bello University, Zaria (Nigeria)

    2014-08-15

    The Nigerian Research Reactor–1, or NIRR-1, is sited at Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria. Activities on preventive or routine maintenance have been institutionalized since the commissioning of the reactor in February 2004. This has grossly reduced the rates of corrective maintenance activities and helped the reactor management a great deal in predicting failure rates of reactor components and other auxiliary units. Routine maintenance of systems and components are being carried out on a weekly, quarterly and annual basis based on manufacturer’s recommendations, which have been reviewed and improved over the years. The paper presents the implementation of maintenance activities in NIRR-1 from its initial criticality in 2004 till today and the new scheme for periodic testing and in-service-inspection developed after an IAEA Integrated Safety Assessment of Research Reactors mission. The measures put in place are envisaged to reduce the negative impact of ageing on NIRR-1 and its auxiliary systems. (author)

  19. Development and performance evaluation of a prototype system for prediction of the group error at the maintenance work

    International Nuclear Information System (INIS)

    Yoshino, Kenji; Hirotsu, Yuko

    2000-01-01

    In order to attain zero-izing of much more error rather than it can set to a nuclear power plant, Authors development and its system-izing of the error prediction causal model which predicts group error action at the time of maintenance work were performed. This prototype system has the following feature. (1) When a user inputs the existence and the grade of the existence of the 'feature factor of the maintenance work' as a prediction object, 'an organization and an organization factor', and a 'group PSF (Performance Shaping Factor) factor' into this system. The maintenance group error to target can be predicted through the prediction model which consists of a class of seven stages. (2) This system by utilizing the information on a prediction result database, it can use not only for prediction of a maintenance group error but for various safe activity, such as KYT (dangerous forecast training) and TBM (Tool Box Meeting). (3) This system predicts a cooperation error' at highest rate, and, subsequently predicts the detection error' at a high rate. And to the 'decision-making error', the transfer error' and the 'state cognitive error', it has the characteristic predicted at almost same rate. (4) If it has full knowledge even of the features, such as the enforcement conditions of maintenance work, and organization, even if the user has neither the knowledge about a human factor, nor experience, anyone of this system is slight about the existence, its extent, etc. of generating of a maintenance group error made difficult from the former logically and systematically easily, it can predict in business time for about 15 minutes. (author)

  20. Analogical reasoning in working memory: resources shared among relational integration, interference resolution, and maintenance.

    Science.gov (United States)

    Cho, Soohyun; Holyoak, Keith J; Cannon, Tyrone D

    2007-09-01

    We report a series of experiments using a pictorial analogy task designed to manipulate relational integration, interference resolution, and active maintenance simultaneously. The difficulty of the problems was varied in terms of the number of relations to be integrated, the need for interference resolution, and the duration of maintenance required to correctly solve the analogy. The participants showed decreases in performance when integrating multiple relations, as compared with a single relation, and when interference resolution was required in solving the analogy. When the participants were required to integrate multiple relations while simultaneously engaged in interference resolution, performance was worse, as compared with problems that incorporated either of these features alone. Maintenance of information across delays in the range of 1-4.5 sec led to greater decrements in visual memory, as compared with analogical reasoning. Misleading information caused interference when it had been necessarily attended to and maintained in working memory and, hence, had to be actively suppressed. However, sources of conflict within information that had not been attended to or encoded into working memory did not interfere with the ongoing controlled information processing required for relational integration. The findings provide evidence that relational integration and interference resolution depend on shared cognitive resources in working memory during analogical reasoning.

  1. Influence of Genotype on Warfarin Maintenance Dose Predictions Produced Using a Bayesian Dose Individualization Tool.

    Science.gov (United States)

    Saffian, Shamin M; Duffull, Stephen B; Roberts, Rebecca L; Tait, Robert C; Black, Leanne; Lund, Kirstin A; Thomson, Alison H; Wright, Daniel F B

    2016-12-01

    A previously established Bayesian dosing tool for warfarin was found to produce biased maintenance dose predictions. In this study, we aimed (1) to determine whether the biased warfarin dose predictions previously observed could be replicated in a new cohort of patients from 2 different clinical settings, (2) to explore the influence of CYP2C9 and VKORC1 genotype on predictive performance of the Bayesian dosing tool, and (3) to determine whether the previous population used to develop the kinetic-pharmacodynamic model underpinning the Bayesian dosing tool was sufficiently different from the test (posterior) population to account for the biased dose predictions. The warfarin maintenance doses for 140 patients were predicted using the dosing tool and compared with the observed maintenance dose. The impact of genotype was assessed by predicting maintenance doses with prior parameter values known to be altered by genetic variability (eg, EC50 for VKORC1 genotype). The prior population was evaluated by fitting the published kinetic-pharmacodynamic model, which underpins the Bayesian tool, to the observed data using NONMEM and comparing the model parameter estimates with published values. The Bayesian tool produced positively biased dose predictions in the new cohort of patients (mean prediction error [95% confidence interval]; 0.32 mg/d [0.14-0.5]). The bias was only observed in patients requiring ≥7 mg/d. The direction and magnitude of the observed bias was not influenced by genotype. The prior model provided a good fit to our data, which suggests that the bias was not caused by different prior and posterior populations. Maintenance doses for patients requiring ≥7 mg/d were overpredicted. The bias was not due to the influence of genotype nor was it related to differences between the prior and posterior populations. There is a need for a more mechanistic model that captures warfarin dose-response relationship at higher warfarin doses.

  2. Bayesian based Prognostic Model for Predictive Maintenance of Offshore Wind Farms

    DEFF Research Database (Denmark)

    Asgarpour, Masoud

    2017-01-01

    monitoring, fault detection and predictive maintenance of offshore wind components is defined. The diagnostic model defined in this paper is based on degradation, remaining useful lifetime and hybrid inspection threshold models. The defined degradation model is based on an exponential distribution......The operation and maintenance costs of offshore wind farms can be significantly reduced if existing corrective actions are performed as efficient as possible and if future corrective actions are avoided by performing sufficient preventive actions. In this paper a prognostic model for degradation...

  3. Nuclear power plant maintenance personnel reliability prediction (NPP/MPRP) effort at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Knee, H.E.; Haas, P.M.; Siegel, A.I.

    1981-01-01

    Human errors committed during maintenance activities are potentially a major contribution to the overall risk associated with the operation of a nuclear power plant (NPP). An NRC-sponsored program at Oak Ridge National Laboratory is attempting to develop a quantitative predictive technique to evaluate the contribution of maintenance errors to the overall NPP risk. The current work includes a survey of the requirements of potential users to ascertain the need for and content of the proposed quantitative model, plus an initial job/task analysis to determine the scope and applicability of various maintenance tasks. In addition, existing human reliability prediction models are being reviewed and assessed with respect to their applicability to NPP maintenance tasks. This paper discusses the status of the program and summarizes the results to date

  4. Luminous flux and colour maintenance investigation of integrated LED lamps

    DEFF Research Database (Denmark)

    Corell, Dennis Dan; Thorseth, Anders; Dam-Hansen, Carsten

    2014-01-01

    This article will present an investigation of the luminous flux and colour maintenance of white LED based retrofit lamps. The study includes 23 different types of integrated LED lamps, covering 18 directional and 5 non-directional. Luminous flux and colour data for operation up to 20000 h has been...

  5. An integrated production, inventory and preventive maintenance model for a multi-product production system

    International Nuclear Information System (INIS)

    Liu, Xuejuan; Wang, Wenbin; Peng, Rui

    2015-01-01

    This paper considers a production system that can produce multiple products alternately. Products go through the system in a sequence and a complete run of all products forms a production cycle. An integrated production, inventory and preventive maintenance model is constructed, which is characterized by the delay-time concept. Two different situations are studied based on whether the unqualified products and downtime caused by the failures of the system, set-up and preventive maintenance can be ignored or not. Three cases are considered for each situation, depending on the position of the preventive maintenance epochs: the first case, where preventive maintenance is carried out at the end of each production cycle; the second case, where preventive maintenance is carried out at each set-up time of the products; and the third case, where preventive maintenance is carried out at some set-up times only, since it may not always be optimal to carry out preventive maintenance at the end of the production cycle or at each set-up time. The modeling objectives are to find the optimal number of production cycles per year and the optimal position of preventive maintenance that will maximize the expected profit per unit time. Numerical examples, using real data, are presented to illustrate the model. - Highlights: • We propose an integrated economic production quantity and preventive maintenance model. • The situation that multiple products are produced on the same system alternately is studied. • Two situations are studied based on whether the downtime and the product quality can be ignored or not. • We use enumeration method and analytical method to select the optimal preventive maintenance policy, respectively. • We use the delay-time concept to model the preventive maintenance policy

  6. Maintenance cost avoidance through comprehensive condition monitoring

    International Nuclear Information System (INIS)

    Miller, G.P.; McClymonds, S.L.

    1990-01-01

    Condition monitoring, the measurement and trending of a critical parameter for predictive maintenance, has reached new levels of acceptance and application within the utility and manufacturing industry. Commercially available systems extend well beyond traditional vibration-monitoring systems to include such areas as online wear, crack and leak detection, and stress monitoring. The challenge facing industry is to integrate the information generated from condition monitoring. Current studies indicate that the effectiveness of predictive maintenance depends much more on the program that is established to apply the monitoring techniques than on the monitoring equipment itself. This paper presents a five-phase approach to developing a condition monitoring program

  7. Health and Maintenance Status Determination and Predictive Fault Diagnosis System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this project is to demonstrate intelligent health and maintenance status determination and predictive fault diagnosis techniques for NASA rocket...

  8. Integrated service engineers and spare parts planning in the maintenance logistics

    NARCIS (Netherlands)

    Al Hanbali, Ahmad; Zijm, Willem H.M.

    2016-01-01

    We analyze the integrated tactical capacity planning of spare parts supply and workforce allocation in maintenance logistics of advanced equipment. The equipment time-to-failure, spare parts replenishment time, and equipment repair time are random and independent of each other.

  9. After reliability centred maintenance. Preventive maintenance living program implementation at Bruce Power

    International Nuclear Information System (INIS)

    Harazim, Michael L.; Ferguson, Brian J.

    2003-01-01

    Industrial preventive maintenance (PM) programs represent a large part of plant O and M costs. PM Optimization (PMO) projects represent an effective mechanism for identifying unnecessary PM, extending PM intervals and infusing predictive maintenance (PdM) methods. However, once optimized, what process prevents the PM program from returning to a state of disarray? This is the function of a PM living program (PMLP). In 1997, an independent performance assessment identified concerns with the applicability and effectiveness of all Ontario Power Generation, Inc. (OPGI) PM programs. In response, OPGI instituted an Integrated Maintenance Program (IMP) including Reliability Centred Maintenance (RCM) and a PMLP. It should be noted that the PMLP was developed for the 3 OPGI nuclear Sites (i.e. Bruce, Pickering, and Darlington). Effective 1 May 2001, the Bruce Site has been leased to a group of investors lead by British Energy. This paper is written in historical context and therefore refers to the Bruce Site as part of OPGI. The PMLP is made up of five elements: 1) process control, 2) change control, 3) worker feedback, 4) program performance metrics, and 5) deferral module. A PMLP software tool, originally applied to Duke Energy nuclear plants, was enhanced and customized specifically for the OPGI PMLP, and then implemented at all three of OPGI's nuclear sites. The objective of the OPGI PMLP was to: Provide processes/procedures for continual optimization of all site PM tasks, Ensure effective and timely revision of PM tasks in the work management system, Ensure PM tasks remain applicable/effective at all times, Maintain and enhance PM consistency on a component, system and Site basis, Ensure that new predictive maintenance techniques are applied and integrated with the PM program, Ensure that mandated PM tasks are identified and executed, Provide a mechanism for craft feedback, Meet regulatory requirements for PM program effectiveness, and Provide PM task deferral

  10. Neighborhood Integration and Connectivity Predict Cognitive Performance and Decline

    Directory of Open Access Journals (Sweden)

    Amber Watts PhD

    2015-08-01

    Full Text Available Objective: Neighborhood characteristics may be important for promoting walking, but little research has focused on older adults, especially those with cognitive impairment. We evaluated the role of neighborhood characteristics on cognitive function and decline over a 2-year period adjusting for measures of walking. Method: In a study of 64 older adults with and without mild Alzheimer’s disease (AD, we evaluated neighborhood integration and connectivity using geographical information systems data and space syntax analysis. In multiple regression analyses, we used these characteristics to predict 2-year declines in factor analytically derived cognitive scores (attention, verbal memory, mental status adjusting for age, sex, education, and self-reported walking. Results : Neighborhood integration and connectivity predicted cognitive performance at baseline, and changes in cognitive performance over 2 years. The relationships between neighborhood characteristics and cognitive performance were not fully explained by self-reported walking. Discussion : Clearer definitions of specific neighborhood characteristics associated with walkability are needed to better understand the mechanisms by which neighborhoods may impact cognitive outcomes. These results have implications for measuring neighborhood characteristics, design and maintenance of living spaces, and interventions to increase walking among older adults. We offer suggestions for future research measuring neighborhood characteristics and cognitive function.

  11. Rotating Machinery Predictive Maintenance Through Expert System

    Directory of Open Access Journals (Sweden)

    M. Sarath Kumar

    2000-01-01

    Full Text Available Modern rotating machines such as turbomachines, either produce or absorb huge amount of power. Some of the common applications are: steam turbine-generator and gas turbine-compressor-generator trains produce power and machines, such as pumps, centrifugal compressors, motors, generators, machine tool spindles, etc., are being used in industrial applications. Condition-based maintenance of rotating machinery is a common practice where the machine's condition is monitored constantly, so that timely maintenance can be done. Since modern machines are complex and the amount of data to be interpreted is huge, we need precise and fast methods in order to arrive at the best recommendations to prevent catastrophic failure and to prolong the life of the equipment. In the present work using vibration characteristics of a rotor-bearing system, the condition of a rotating machinery (electrical rotor is predicted using an off-line expert system. The analysis of the problem is carried out in an Object Oriented Programming (OOP framework using the finite element method. The expert system which is also developed in an OOP paradigm gives the type of the malfunctions, suggestions and recommendations. The system is implemented in C++.

  12. Establishing a predictive maintenance (PdM) program at the Hanford Site

    International Nuclear Information System (INIS)

    Murray, W.A.; Winslow, R.G.

    1994-02-01

    The production reactors have been shut down for some time. But for the rest of the site, there is currently about 16,000 people engaged in a multi-billion dollar effort to safely process wastes which have been stored at the site since the 1940's. This effort also includes demolition of some older facilities and environmental restoration of much of the site. This is expected to take approximately 30 to 40 years. The concept of a site-wide predictive maintenance (PdM) program began to form in early 1993. Several informal studies showed that the stand alone predictive maintenance groups which had prevailed on site to date were less than 15% effective at trending equipment conditions and predicting failures. To improve the effectiveness of PdM within the company, an engineering analysis by Rick Winslow confirmed that utilization of software networking technology which was now available would significantly overcome many of these built in handicaps. A site-wide predictive maintenance network would make PdM technology accessible to all of the areas and facilities at the site regardless of geographical distances and company division lines. Site resident vibration experts can easily be located and provide consultations on the network. However, it was recognized that strong leadership and management skills would be required within each of the two organizations for effective implementation. To start this process, a letter of understanding and agreement between the facilities and Tank Farm divisions was drafted and endorsed by company management. The agreement assigned the primary responsibility of acquiring the network software and licensee to the Tank Farms division. The acquisition and installation of the network server would be the responsibility of the facilities division. This paper describes the rest of the network development and implementation process

  13. Development of equipment reliability process using predictive technologies at Hamaoka Nuclear Power Station

    International Nuclear Information System (INIS)

    Taniguchi, Yuji; Sakuragi, Futoshi; Hamada, Seiichi

    2014-01-01

    Development of equipment reliability(ER) process, specifically for predictive maintenance (PdM) technologies integrated condition based maintenance (CBM) process, at Hamaoka Nuclear Power Station is introduced in this paper. Integration of predictive maintenance technologies such as vibration, oil analysis and thermo monitoring is more than important to establish strong maintenance strategies and to direct a specific technical development. In addition, a practical example of CBM is also presented to support the advantage of the idea. (author)

  14. The nuclear power plant maintenance personnel reliability prediction (NPP/MPRP) effort at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Knee, H.E.; Haas, P.M.; Siegel, A.I.

    1982-01-01

    Human errors committed during maintenance activities are potentially a major contribution to the overall risk associated with the operation of a nuclear power plant (NPP). An NRC-sponsored program at Oak Ridge National Laboratory is attempting to develop a quantitative predictive technique to evaluate the contribution of maintenance errors to the overall NPP risk. The current work includes a survey of the requirements of potential users to ascertain the need for and content of the proposed quantitative model, plus an initial job/task analysis to determine the scope and applicability of various maintenance tasks. In addition, existing human reliability prediction models are being reviewed and assessed with respect to their applicability to NPP maintenance tasks. This paper discusses the status of the program and summarizes the results to date

  15. 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)

  16. The role of data fusion in predictive maintenance using digital twin

    Science.gov (United States)

    Liu, Zheng; Meyendorf, Norbert; Mrad, Nezih

    2018-04-01

    Modern aerospace industry is migrating from reactive to proactive and predictive maintenance to increase platform operational availability and efficiency, extend its useful life cycle and reduce its life cycle cost. Multiphysics modeling together with data-driven analytics generate a new paradigm called "Digital Twin." The digital twin is actually a living model of the physical asset or system, which continually adapts to operational changes based on the collected online data and information, and can forecast the future of the corresponding physical counterpart. This paper reviews the overall framework to develop a digital twin coupled with the industrial Internet of Things technology to advance aerospace platforms autonomy. Data fusion techniques particularly play a significant role in the digital twin framework. The flow of information from raw data to high-level decision making is propelled by sensor-to-sensor, sensor-to-model, and model-to-model fusion. This paper further discusses and identifies the role of data fusion in the digital twin framework for aircraft predictive maintenance.

  17. Integrated fuzzy analytic hierarchy process and VIKOR method in the prioritization of pavement maintenance activities

    Directory of Open Access Journals (Sweden)

    Peyman Babashamsi

    2016-03-01

    Full Text Available Maintenance activities and pavement rehabilitation require the allocation of massive finances. Yet due to budget shortfalls, stakeholders and decision-makers must prioritize projects in maintenance and rehabilitation. This article addresses the prioritization of pavement maintenance alternatives by integrating the fuzzy analytic hierarchy process (AHP with the VIKOR method (which stands for ‘VlseKriterijumska Optimizacija I Kompromisno Resenje,’ meaning multi-criteria optimization and compromise solution for the process of multi-criteria decision analysis (MCDA by considering various pavement network indices. The indices selected include the pavement condition index (PCI, traffic congestion, pavement width, improvement and maintenance costs, and the time required to operate. In order to determine the weights of the indices, the fuzzy AHP is used. Subsequently, the alternatives’ priorities are ranked according to the indices weighted with the VIKOR model. The choice of these two independent methods was motivated by the fact that integrating fuzzy AHP with the VIKOR model can assist decision makers with solving MCDA problems. The case study was conducted on a pavement network within the same particular region in Tehran; three main streets were chosen that have an empirically higher maintenance demand. The most significant factors were evaluated and the project with the highest priority was selected for urgent maintenance. By comparing the index values of the alternative priorities, Delavaran Blvd. was revealed to have higher priority over the other streets in terms of maintenance and rehabilitation activities. Keywords: Maintenance and rehabilitation prioritization, Fuzzy analysis hierarchy process, VIKOR model, Pavement condition index, Multi-criteria decision analysis

  18. Developing a Predictive for Unscheduled Maintenance Requirements on United States Air Force Installations

    National Research Council Canada - National Science Library

    Kovich, Matthew D; Norton, J. D

    2008-01-01

    .... This paper develops one such method by using linear regression and time series analysis to develop a predictive model to forecast future year man-hour and funding requirements for unscheduled maintenance...

  19. Molecular constraints on synaptic tagging and maintenance of long-term potentiation: a predictive model.

    Science.gov (United States)

    Smolen, Paul; Baxter, Douglas A; Byrne, John H

    2012-01-01

    Protein synthesis-dependent, late long-term potentiation (LTP) and depression (LTD) at glutamatergic hippocampal synapses are well characterized examples of long-term synaptic plasticity. Persistent increased activity of protein kinase M ζ (PKMζ) is thought essential for maintaining LTP. Additional spatial and temporal features that govern LTP and LTD induction are embodied in the synaptic tagging and capture (STC) and cross capture hypotheses. Only synapses that have been "tagged" by a stimulus sufficient for LTP and learning can "capture" PKMζ. A model was developed to simulate the dynamics of key molecules required for LTP and LTD. The model concisely represents relationships between tagging, capture, LTD, and LTP maintenance. The model successfully simulated LTP maintained by persistent synaptic PKMζ, STC, LTD, and cross capture, and makes testable predictions concerning the dynamics of PKMζ. The maintenance of LTP, and consequently of at least some forms of long-term memory, is predicted to require continual positive feedback in which PKMζ enhances its own synthesis only at potentiated synapses. This feedback underlies bistability in the activity of PKMζ. Second, cross capture requires the induction of LTD to induce dendritic PKMζ synthesis, although this may require tagging of a nearby synapse for LTP. The model also simulates the effects of PKMζ inhibition, and makes additional predictions for the dynamics of CaM kinases. Experiments testing the above predictions would significantly advance the understanding of memory maintenance.

  20. Optimizing preventive maintenance with maintenance templates

    International Nuclear Information System (INIS)

    Dozier, I.J.

    1996-01-01

    Rising operating costs has caused maintenance professionals to rethink their strategy for preventive maintenance (PM) programs. Maintenance Templates are pre-engineered PM task recommendations for a component type based on application of the component. Development of the maintenance template considers the dominant failure cause of the component and the type of preventive maintenance that can predict or prevent the failure from occurring. Maintenance template development also attempts to replace fixed frequency tasks with condition monitoring tasks such as vibration analysis or thermography. For those components that have fixed frequency PM intervals, consideration is given to the maintenance drivers such as criticality, environment and usage. This helps to maximize the PM frequency intervals and maximize the component availability. Maintenance Templates have been used at PECO Energy's Limerick Generating Station during the Reliability Centered Maintenance (RCM) Process to optimize their PM program. This paper describes the development and uses of the maintenance templates

  1. North American nuclear maintenance best practices compared to Japanese utility maintenance practices

    International Nuclear Information System (INIS)

    Harazim, M.L.; Ferguson, B.J.

    2003-01-01

    The purpose of this paper is to compare the best practices in North America concerning Preventive Maintenance, Predictive Maintenance and Reliability Centered Maintenance (RCM) or Preventive Maintenance Optimization (PMO) with the time-directed maintenance philosophies utilized by Japanese utilities, and how the Japanese utilities are considering (and some have begun) adopting North American ways of doing business. Preventive Maintenance Living Programs are also discussed, along with the Institute of Nuclear Power Operations AP-913 process, Equipment Reliability Process. Also, a cost benefit analysis will be demonstrated showing how major cost savings can be achieved by shifting from a predominantly time-directed maintenance philosophy to a predominantly predictive strategy utilizing vibration analysis, lubricating oil analysis, thermography and other predictive technologies to better utilize resources, reduce spare part consumption and to minimize maintenance induced errors. As a result of the strides made while incorporating these new philosophies, we no longer advocate tearing apart perfectly good equipment. (author)

  2. Maintenance personnel performance simulation (MAPPS): a model for predicting maintenance performance reliability in nuclear power plants

    International Nuclear Information System (INIS)

    Knee, H.E.; Krois, P.A.; Haas, P.M.; Siegel, A.I.; Ryan, T.G.

    1983-01-01

    The NRC has developed a structured, quantitative, predictive methodology in the form of a computerized simulation model for assessing maintainer task performance. Objective of the overall program is to develop, validate, and disseminate a practical, useful, and acceptable methodology for the quantitative assessment of NPP maintenance personnel reliability. The program was organized into four phases: (1) scoping study, (2) model development, (3) model evaluation, and (4) model dissemination. The program is currently nearing completion of Phase 2 - Model Development

  3. A model for preemptive maintenance of medical linear accelerators—predictive maintenance

    International Nuclear Information System (INIS)

    Able, Charles M.; Baydush, Alan H.; Nguyen, Callistus; Gersh, Jacob; Ndlovu, Alois; Rebo, Igor; Booth, Jeremy; Perez, Mario; Sintay, Benjamin; Munley, Michael T.

    2016-01-01

    Unscheduled accelerator downtime can negatively impact the quality of life of patients during their struggle against cancer. Currently digital data accumulated in the accelerator system is not being exploited in a systematic manner to assist in more efficient deployment of service engineering resources. The purpose of this study is to develop an effective process for detecting unexpected deviations in accelerator system operating parameters and/or performance that predicts component failure or system dysfunction and allows maintenance to be performed prior to the actuation of interlocks. The proposed predictive maintenance (PdM) model is as follows: 1) deliver a daily quality assurance (QA) treatment; 2) automatically transfer and interrogate the resulting log files; 3) once baselines are established, subject daily operating and performance values to statistical process control (SPC) analysis; 4) determine if any alarms have been triggered; and 5) alert facility and system service engineers. A robust volumetric modulated arc QA treatment is delivered to establish mean operating values and perform continuous sampling and monitoring using SPC methodology. Chart limits are calculated using a hybrid technique that includes the use of the standard SPC 3σ limits and an empirical factor based on the parameter/system specification. There are 7 accelerators currently under active surveillance. Currently 45 parameters plus each MLC leaf (120) are analyzed using Individual and Moving Range (I/MR) charts. The initial warning and alarm rule is as follows: warning (2 out of 3 consecutive values ≥ 2σ hybrid ) and alarm (2 out of 3 consecutive values or 3 out of 5 consecutive values ≥ 3σ hybrid ). A customized graphical user interface provides a means to review the SPC charts for each parameter and a visual color code to alert the reviewer of parameter status. Forty-five synthetic errors/changes were introduced to test the effectiveness of our initial chart limits. Forty

  4. A model for preemptive maintenance of medical linear accelerators-predictive maintenance.

    Science.gov (United States)

    Able, Charles M; Baydush, Alan H; Nguyen, Callistus; Gersh, Jacob; Ndlovu, Alois; Rebo, Igor; Booth, Jeremy; Perez, Mario; Sintay, Benjamin; Munley, Michael T

    2016-03-10

    Unscheduled accelerator downtime can negatively impact the quality of life of patients during their struggle against cancer. Currently digital data accumulated in the accelerator system is not being exploited in a systematic manner to assist in more efficient deployment of service engineering resources. The purpose of this study is to develop an effective process for detecting unexpected deviations in accelerator system operating parameters and/or performance that predicts component failure or system dysfunction and allows maintenance to be performed prior to the actuation of interlocks. The proposed predictive maintenance (PdM) model is as follows: 1) deliver a daily quality assurance (QA) treatment; 2) automatically transfer and interrogate the resulting log files; 3) once baselines are established, subject daily operating and performance values to statistical process control (SPC) analysis; 4) determine if any alarms have been triggered; and 5) alert facility and system service engineers. A robust volumetric modulated arc QA treatment is delivered to establish mean operating values and perform continuous sampling and monitoring using SPC methodology. Chart limits are calculated using a hybrid technique that includes the use of the standard SPC 3σ limits and an empirical factor based on the parameter/system specification. There are 7 accelerators currently under active surveillance. Currently 45 parameters plus each MLC leaf (120) are analyzed using Individual and Moving Range (I/MR) charts. The initial warning and alarm rule is as follows: warning (2 out of 3 consecutive values ≥ 2σ hybrid) and alarm (2 out of 3 consecutive values or 3 out of 5 consecutive values ≥ 3σ hybrid). A customized graphical user interface provides a means to review the SPC charts for each parameter and a visual color code to alert the reviewer of parameter status. Forty-five synthetic errors/changes were introduced to test the effectiveness of our initial chart limits. Forty

  5. Remaining useful life prediction of degrading systems subjected to imperfect maintenance: Application to draught fans

    Science.gov (United States)

    Wang, Zhao-Qiang; Hu, Chang-Hua; Si, Xiao-Sheng; Zio, Enrico

    2018-02-01

    Current degradation modeling and remaining useful life prediction studies share a common assumption that the degrading systems are not maintained or maintained perfectly (i.e., to an as-good-as new state). This paper concerns the issues of how to model the degradation process and predict the remaining useful life of degrading systems subjected to imperfect maintenance activities, which can restore the health condition of a degrading system to any degradation level between as-good-as new and as-bad-as old. Toward this end, a nonlinear model driven by Wiener process is first proposed to characterize the degradation trajectory of the degrading system subjected to imperfect maintenance, where negative jumps are incorporated to quantify the influence of imperfect maintenance activities on the system's degradation. Then, the probability density function of the remaining useful life is derived analytically by a space-scale transformation, i.e., transforming the constructed degradation model with negative jumps crossing a constant threshold level to a Wiener process model crossing a random threshold level. To implement the proposed method, unknown parameters in the degradation model are estimated by the maximum likelihood estimation method. Finally, the proposed degradation modeling and remaining useful life prediction method are applied to a practical case of draught fans belonging to a kind of mechanical systems from steel mills. The results reveal that, for a degrading system subjected to imperfect maintenance, our proposed method can obtain more accurate remaining useful life predictions than those of the benchmark model in literature.

  6. The role of romantic attraction and conflict resolution in predicting shorter and longer relationship maintenance among adolescents.

    Science.gov (United States)

    Appel, Israel; Shulman, Shmuel

    2015-04-01

    This study examined the role of romantic attraction and conflict resolution patterns in shorter and longer relationship maintenance among adolescent couples. Data were used from 55 couples aged 15-18 years. Partners completed the Romantic Attraction scale and were observed negotiating a disagreement. Three and 6 months later, they were asked to report whether they were still together. Findings indicated that partners' romantic attraction and the tendency to minimize disagreements during interaction predicted shorter relationship maintenance. In contrast, longer relationship maintenance was predicted by partners' capability to resolve conflicts constructively in a positive atmosphere. Findings are embedded and discussed within Fisher's (2004) evolutionary theory of love.

  7. Molecular constraints on synaptic tagging and maintenance of long-term potentiation: a predictive model.

    Directory of Open Access Journals (Sweden)

    Paul Smolen

    Full Text Available Protein synthesis-dependent, late long-term potentiation (LTP and depression (LTD at glutamatergic hippocampal synapses are well characterized examples of long-term synaptic plasticity. Persistent increased activity of protein kinase M ζ (PKMζ is thought essential for maintaining LTP. Additional spatial and temporal features that govern LTP and LTD induction are embodied in the synaptic tagging and capture (STC and cross capture hypotheses. Only synapses that have been "tagged" by a stimulus sufficient for LTP and learning can "capture" PKMζ. A model was developed to simulate the dynamics of key molecules required for LTP and LTD. The model concisely represents relationships between tagging, capture, LTD, and LTP maintenance. The model successfully simulated LTP maintained by persistent synaptic PKMζ, STC, LTD, and cross capture, and makes testable predictions concerning the dynamics of PKMζ. The maintenance of LTP, and consequently of at least some forms of long-term memory, is predicted to require continual positive feedback in which PKMζ enhances its own synthesis only at potentiated synapses. This feedback underlies bistability in the activity of PKMζ. Second, cross capture requires the induction of LTD to induce dendritic PKMζ synthesis, although this may require tagging of a nearby synapse for LTP. The model also simulates the effects of PKMζ inhibition, and makes additional predictions for the dynamics of CaM kinases. Experiments testing the above predictions would significantly advance the understanding of memory maintenance.

  8. Component-Based Data-Driven Predictive Maintenance to Reduce Unscheduled Maintenance Events

    NARCIS (Netherlands)

    Verhagen, W.J.C.; Curran, R.; de Boer, L.W.M.; Chen, C.H.; Trappey, A.C.; Peruzzini, M.; Stjepandić, J.; Wognum, N.

    2017-01-01

    Costs associated with unscheduled and preventive maintenance can contribute significantly to an airline's expenditure. Reliability analysis can help to identify and plan for maintenance events. Reliability analysis in industry is often limited to statistically based

  9. Integrating Preventive Maintenance Scheduling As Probability Machine Failure And Batch Production Scheduling

    Directory of Open Access Journals (Sweden)

    Zahedi Zahedi

    2016-06-01

    Full Text Available This paper discusses integrated model of batch production scheduling and machine maintenance scheduling. Batch production scheduling uses minimize total actual flow time criteria and machine maintenance scheduling uses the probability of machine failure based on Weibull distribution. The model assumed no nonconforming parts in a planning horizon. The model shows an increase in the number of the batch (length of production run up to a certain limit will minimize the total actual flow time. Meanwhile, an increase in the length of production run will implicate an increase in the number of PM. An example was given to show how the model and algorithm work.

  10. Developing a Predictive Model for Unscheduled Maintenance Requirements on United States Air Force Installations

    National Research Council Canada - National Science Library

    Kovich, Matthew D; Norton, J. D

    2008-01-01

    .... This paper develops one such method by using linear regression and time series analysis to develop a predictive model to forecast future year man-hour and funding requirements for unscheduled maintenance...

  11. Full scale test platform for European TBM systems integration and maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Vála, Ladislav, E-mail: ladislav.vala@cvrez.cz; Reungoat, Mathieu; Vician, Martin

    2016-11-01

    Highlights: • A platform for EU-TBS maintenance and integration tests is described. • Its modular design allows adaptation to non-EU TBSs. • Assembling of the facility will be followed by initial tests in 2016. - Abstract: This article deals with description and current status of a project of a non-nuclear, full size (1:1 scale) test platform dedicated to tests, optimization and validation of integration and maintenance operations for the European TBM systems in the ITER port cell #16. The facility called TBM platform reproduces the ITER port cell #16 and port interspace with all the relevant interfaces and mock-ups of the corresponding main components. Thanks to the modular design of the platform, it is possible to adapt or change completely the interfaces in the future if needed or required according to the updated configuration of TBSs. In the same way, based on customer requirements, it will be possible to adapt the interfaces and piping inside the mock-ups in order to represent also the other, non-EU configurations of TBM systems designed for port cells #02 and #18. Construction of this test platform is realized and funded within the scope of the SUSEN project.

  12. Integrating Safety in the Aviation System: Interdepartmental Training for Pilots and Maintenance Technicians

    Science.gov (United States)

    Mattson, Marifran; Petrin, Donald A.; Young, John P.

    2001-01-01

    The study of human factors has had a decisive impact on the aviation industry. However, the entire aviation system often is not considered in researching, training, and evaluating human factors issues especially with regard to safety. In both conceptual and practical terms, we argue for the proactive management of human error from both an individual and organizational systems perspective. The results of a multidisciplinary research project incorporating survey data from professional pilots and maintenance technicians and an exploratory study integrating students from relevant disciplines are reported. Survey findings suggest that latent safety errors may occur during the maintenance discrepancy reporting process because pilots and maintenance technicians do not effectively interact with one another. The importance of interdepartmental or cross-disciplinary training for decreasing these errors and increasing safety is discussed as a primary implication.

  13. Integrated batch production and maintenance scheduling for multiple items processed on a deteriorating machine to minimize total production and maintenance costs with due date constraint

    Directory of Open Access Journals (Sweden)

    Zahedi Zahedi

    2016-04-01

    Full Text Available This paper discusses an integrated model of batch production and maintenance scheduling on a deteriorating machine producing multiple items to be delivered at a common due date. The model describes the trade-off between total inventory cost and maintenance cost as the increase of production run length. The production run length is a time bucket between two consecutive preventive maintenance activities. The objective function of the model is to minimize total cost consisting of in process and completed part inventory costs, setup cost, preventive and corrective maintenance costs and rework cost. The problem is to determine the optimal production run length and to schedule the batches obtained from determining the production run length in order to minimize total cost.

  14. Integrated management of information inside maintenance processes. From the building registry to BIM systems

    Directory of Open Access Journals (Sweden)

    Cinzia Talamo

    2014-10-01

    Full Text Available The paper presents objec- tives, methods and results of two researches dealing with the improvement of integrated information management within maintenance processes. Focusing on information needs regarding the last phases of the building process, the two researches draft approaches characterizing a path of progressive improve- ment of strategies for integration: from a building registry, unique for the whole construction process, to an integrated management of the building process with the support of BIM systems.

  15. Improving nuclear power plant reliability through predictive maintenance

    International Nuclear Information System (INIS)

    Geilhausen, R.; Kunze, U.

    1996-01-01

    Maintenance strategies can be assigned to one of three categories: failure maintenance, periodic maintenance or condition-oriented maintenance. The optimum maintenance scheme can be selected on the basis of a cost-benefit analysis but the safety of life and limb or the political climate for NPP can hardly expressed in numbers. The implementation of preventive maintenance needs two preconditions: high-performance instrumentation in the form of stationary and mobile monitoring systems for the determination of the condition of the nuclear power plant components and provision of a tool that can handle both the organization of the work and the evaluation of the results obtained. (authors)

  16. Impact logistics-technique study of generating predictive maintenance in SME sin Milagro, Ecuador

    Directory of Open Access Journals (Sweden)

    Erik Rolando Cedeño Anchundia

    2016-06-01

    Full Text Available This article is to discern the organizational culture regarding the acceptance of monitoring techniques and predictive inspections that help reduce the problems arising in the infrastructure of production processes within an industrial plant and thus optimize downtime that they occur due to ignorance or little attention and in some cases due to lack of awareness of operators or direct users of these computers. SMEs currently are optimizing their processes, automating their production line which implies that there should be better controls, to be more competitive because the increase in technology, greatly improves productivity. Before the technology boom happening in terms of machinery and processes, corrective measures were used to eliminate problems and these generated high rates in terms of costs for equipment maintenance, in the XXI century predictive maintenance techniques, consisting develops diagnose and maintain installed both in the electrical part and mechanical non-stop operational teams, allowing the reduction of lost production time and costs, costs of obtaining the most competitive end products in the market infrastructure. Also analyze the type of maintenance they currently possess SMEs in the city of Milagro-Ecuador and how it is influencing their productivity in order to develop proposals for improvements and recommendations in order to optimize their processes and increase profitability.

  17. Integrating availability and maintenance objectives in plant design. EDF approach

    International Nuclear Information System (INIS)

    Degrave, Claude; Martin-Onraet, Michel

    1995-01-01

    Energy self sufficiency is a major strategic necessity for France. Regarding the fossil fuels power, competitiveness of nuclear energy is a key goal for Electricite de France. Accordingly, for future nuclear power plants to remain competitive, it is necessary to maintain the kWh production costs of the future units at a level close to those of the latest units under construction (N4 series), while raising the safety level. EDF therefore decided to implement an analytical and systematic process for study of the new projects to optimize the design by integration of the maintenance (durations, costs), availability and radiation exposure goals from the related operating experience. This approach, CIDEM (French acronym for Design Integrating Availability, operating Experience and Maintenance) aims at a single goal: to minimize the kWh production cost incorporating investment, operation and fuel costs, allowing for the operating experience from French and foreign units. The implementation of the CIDEM process constitutes for EDF a new approach to the study of the new Nuclear Power Plant projects. The competitivity of nuclear energy greatly depends on the success of such an approach. The studies conducted in the availability field have already highlighted a number of critical points and have made it possible to define the corresponding goal allocations and to establish a first series of structuring specifications for the project. (J.P.N.)

  18. Machine remaining useful life prediction: An integrated adaptive neuro-fuzzy and high-order particle filtering approach

    Science.gov (United States)

    Chen, Chaochao; Vachtsevanos, George; Orchard, Marcos E.

    2012-04-01

    Machine prognosis can be considered as the generation of long-term predictions that describe the evolution in time of a fault indicator, with the purpose of estimating the remaining useful life (RUL) of a failing component/subsystem so that timely maintenance can be performed to avoid catastrophic failures. This paper proposes an integrated RUL prediction method using adaptive neuro-fuzzy inference systems (ANFIS) and high-order particle filtering, which forecasts the time evolution of the fault indicator and estimates the probability density function (pdf) of RUL. The ANFIS is trained and integrated in a high-order particle filter as a model describing the fault progression. The high-order particle filter is used to estimate the current state and carry out p-step-ahead predictions via a set of particles. These predictions are used to estimate the RUL pdf. The performance of the proposed method is evaluated via the real-world data from a seeded fault test for a UH-60 helicopter planetary gear plate. The results demonstrate that it outperforms both the conventional ANFIS predictor and the particle-filter-based predictor where the fault growth model is a first-order model that is trained via the ANFIS.

  19. The plant cell wall integrity maintenance mechanism--a case study of a cell wall plasma membrane signaling network.

    Science.gov (United States)

    Hamann, Thorsten

    2015-04-01

    Some of the most important functions of plant cell walls are protection against biotic/abiotic stress and structural support during growth and development. A prerequisite for plant cell walls to perform these functions is the ability to perceive different types of stimuli in both qualitative and quantitative manners and initiate appropriate responses. The responses in turn involve adaptive changes in cellular and cell wall metabolism leading to modifications in the structures originally required for perception. While our knowledge about the underlying plant mechanisms is limited, results from Saccharomyces cerevisiae suggest the cell wall integrity maintenance mechanism represents an excellent example to illustrate how the molecular mechanisms responsible for stimulus perception, signal transduction and integration can function. Here I will review the available knowledge about the yeast cell wall integrity maintenance system for illustration purposes, summarize the limited knowledge available about the corresponding plant mechanism and discuss the relevance of the plant cell wall integrity maintenance mechanism in biotic stress responses. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Risk-based Operation and Maintenance for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Nielsen, Jannie Jessen

    2011-01-01

    For offshore wind turbines, costs to Operation and Maintenance (OM) are substantial, and can be expected to increase when wind farms are placed at deeper water depths and in more harsh environments. Traditional strategies for OM include corrective and preventive (scheduled and condition...... statistics and costs of the different operations. The different OM strategies are described and compared in an illustrative example with focus on which types of information that are needed. Special focus is on comparison between risk-based maintenance strategies and the conventional maintenance planning...... and are often the driving mechanisms for failures / faults that need maintenance. Observations of the degree of damage can increase the reliability of predictions and decrease the costs of OM if integrated in a risk-based framework theoretically based on pre-posterior Bayesian decision theory. The mathematical...

  1. Hypertext-based integration for nuclear plant maintenance and operations

    International Nuclear Information System (INIS)

    Tsoukalas, L.H.; Upadhyaya, B.R.

    1991-01-01

    A methodology is presented that uses fuzzy graphs in the emerging paradigm of hypertext for the purpose of integrating data, information and multifaceted knowledge resources abounding in power plant operations and maintenance. A hypertext system is viewed as a set of nodes and links where with each link we associate membership functions embodying context-dependent criteria for navigating large information spaces. A general framework for navigation is outlined and graph-theory navigational tools are developed. A numerical example and a HyperCard-based prototype for monitoring special material in the MHTGR-NPR are included. 10 refs., 12 figs

  2. Westinghouse integrated protection system. An overview of the software design and maintenance features

    International Nuclear Information System (INIS)

    Gibson, R.J.

    1995-01-01

    The Westinghouse Integrated Protection System was designed with the goal of providing a system which can be easily verified, validated, and maintained. The software design and structure promote the ease of translation from functional requirements to applications function software while also improving the ability to verify and maintain the applications function software. The use of independent, reusable, common functions software modules focuses the design, verification, and validation of the software and reduces the likelihood of errors occurring during the application and maintenance of the software. The simple continuous loop method of operation used throughout the IPS provides a standard deterministic method of operation. The IPS design also incorporates the use of embedded self-diagnostics to perform continuous hardware oriented tests of the system and the use of an independent subsystem to automatically perform a functional test of the system. Maintenance interfaces also exist to readily identify and locate faults as well as providing other maintenance capabilities. These testing and maintenance features enhance the overall reliability and availability of the system. (orig.) (2 refs., 2 figs.)

  3. Transfer of infrared thermography predictive maintenance technologies to Soviet-designed nuclear power plants: experience at Chernobyl

    Science.gov (United States)

    Pugh, Ray; Huff, Roy

    1999-03-01

    The importance of infrared (IR) technology and analysis in today's world of predictive maintenance and reliability- centered maintenance cannot be understated. The use of infrared is especially important in facilities that are required to maintain a high degree of equipment reliability because of plant or public safety concerns. As with all maintenance tools, particularly those used in predictive maintenance approaches, training plays a key role in their effectiveness and the benefit gained from their use. This paper details an effort to transfer IR technology to Soviet- designed nuclear power plants in Russia, Ukraine, and Lithuania. Delivery of this technology and post-delivery training activities have been completed recently at the Chornobyl nuclear power plant in Ukraine. Many interesting challenges were encountered during this effort. Hardware procurement and delivery of IR technology to a sensitive country were complicated by United States regulations. Freight and shipping infrastructure and host-country customs policies complicated hardware transport. Training activities were complicated by special hardware, software and training material translation needs, limited communication opportunities, and site logistical concerns. These challenges and others encountered while supplying the Chornobyl plant with state-of-the-art IR technology are described in this paper.

  4. Framework for Maintenance Planning

    DEFF Research Database (Denmark)

    Soares, C. Guedes; Duarte, J. Caldeira; Garbatov, Y.

    2010-01-01

    the design and during the whole life span of operational use, within an integrated framework founded on risk and reliability based techniques. The document addresses designers, decision makers and professionals responsible for or involved in establishing maintenance plans. The purpose of this document......The present document presents a framework for maintenance planning. Maintenance plays a fundamental role in counteracting degradation effects, which are present in all infrastructure and industrial products. Therefore, maintenance planning is a very critical aspect to consider both during...... is to present maintenance as an integrated approach that needs to be planned, designed, engineered, and controlled by proper qualitative and quantitative techniques. This document outlines the basic premises for maintenance planning and provides the general philosophies that can be followed and points to a best...

  5. Atomic Energy Control Board (AECB) staff assessment and views of current maintenance practices of a four unit CANDU plant

    International Nuclear Information System (INIS)

    Malek, I.

    1995-01-01

    This paper discusses the AECB practices in assessing maintenance activities at one four unit CANDU nuclear plant.-it outlines the authority of the AECB in enforcing the licence condition concerned with maintenance, and how this is interpreted by AECB site staff to measure and report maintenance activities. The AECB staff attaches great importance to proper maintenance as it affects safe operation. Programs used by the licensee staff to identify safety important components, or to predict degradations and failures are of particular interest. In our experience, the application of such programs has been generally good. However, their integration into an overall maintenance scheme can be improved, and the possibilities of integration are not well understood. This paper includes examples of such integration to illustrate our views and to highlight the resultant benefits that AECB staff believes are possible. (author)

  6. Integrated services and maintenance in nuclear power plants

    International Nuclear Information System (INIS)

    Roos, Georg

    2001-01-01

    The general situation concerning services and nuclear power maintenance is reviewed following liberalization of Europa's power market. Issues relating to outsourcing maintenance services, effectiveness and reducing cost structure of maintenance are addressed on the cases of power markets in northern countries, Spain, Switzerland, Germany and Hungary. A special attention is paid on range of maintenance activity offered and performanced by Framatome. Ways of reducing costs in the field of maintenance as well as of reducing outage time are indicated. In conclusion, the following items are emphasized: - liberalization of Europe's power market in eastern Europe at its beginning; - in-house service in eastern Europe with numerous personnel; - Framatome ANP covers the entire range of maintenance competence; - consultance can be the first approach for a common co-operation

  7. Prediction accident triangle in maintenance of underground mine facilities using Poisson distribution analysis

    Science.gov (United States)

    Khuluqi, M. H.; Prapdito, R. R.; Sambodo, F. P.

    2018-04-01

    In Indonesia, mining is categorized as a hazardous industry. In recent years, a dramatic increase of mining equipment and technological complexities had resulted in higher maintenance expectations that accompanied by the changes in the working conditions, especially on safety. Ensuring safety during the process of conducting maintenance works in underground mine is important as an integral part of accident prevention programs. Accident triangle has provided a support to safety practitioner to draw a road map in preventing accidents. Poisson distribution is appropriate for the analysis of accidents at a specific site in a given time period. Based on the analysis of accident statistics in the underground mine maintenance of PT. Freeport Indonesia from 2011 through 2016, it is found that 12 minor accidents for 1 major accident and 66 equipment damages for 1 major accident as a new value of accident triangle. The result can be used for the future need for improving the accident prevention programs.

  8. Open system architecture for condition based maintenance applied to a hydroelectric power plant

    Energy Technology Data Exchange (ETDEWEB)

    Amaya, E.J.; Alvares, A.J. [University of Brasilia (UnB), DF (Brazil). Mechanical and Mechatronic Dept.], Emails: eamaya@unb.br, alvares@AlvaresTech.com; Gudwin, R.R. [State University of Campinas (UNICAMP), SP (Brazil). Computer Engineering and Industrial Automation Dept.], E-mail: gudwin@dca.fee.unicamp.br

    2009-07-01

    The hydroelectric power plant of Balbina is implementing a condition based maintenance system applying an open, modular and scalable integrated architecture to provide comprehensive solutions and support to the end users like operational and maintenance team. The system called SIMPREBAL (Predictive Maintenance System of Balbina) is advocate of open standards, in particular through collaborative research programmers. In the developing is clearly understands the need for both, industry standards and a simple to use software development tool chain, supporting the development of complex condition based maintenance systems with multiple partners. The Open System Architecture for Condition Based Maintenance (OSA-CBM) is a standard that consider seven hierarchic layers that represent a logic transition or performed data flow from the data acquisition layer, through the intermediates layers as signal processing, condition monitor, health assessment, prognostics and decision support, to arrive to the presentation layer. SIMPREBAL is being implementing as an OSA-CBM software framework and tool set that allows the creation of truly integrated, comprehensive maintenance solutions through the internet. This paper identifies specific benefits of the application of the OSA-CBM in comprehensive solutions of condition based maintenance for a hydroelectric power plant. (author)

  9. A decision-making framework to integrate maintenance contract conditions with critical spares management

    International Nuclear Information System (INIS)

    Godoy, David R.; Pascual, Rodrigo; Knights, Peter

    2014-01-01

    Maintenance outsourcing is a strategic driver for asset intensive industries pursuing to enhance supply chain performance. Spare parts management plays a relevant role in this premise since its significant impact on equipment availability, and hence on business success. Designing critical spares policies might therefore seriously affect maintenance contracts profitability, yet service receivers and external providers traditionally attempt to benefit separately. To coordinate both chain parties, we investigated whether the spare components pool should be managed in-house or contracted out. This paper provides a decision-making framework to efficiently integrate contractual conditions with critical spares stockholding. Using an imperfect maintenance strategy over a finite horizon, the scheme maximizes chain returns whilst evaluating the impact of an additional part to stock. As result, an original joint value – preventive interval and stock level – sets the optimal agreement to profitably allocate the components pool within the service contract. Subsidization bonuses on preventive interventions and pooling costs are also estimated to induce the service provider to adjust its policy when needed. The proposed contractual conditions motivate stakeholders to continuously improve maintenance performance and supply practices, thus obtaining higher joint benefits

  10. Condition based maintenance in the context of opportunistic maintenance

    NARCIS (Netherlands)

    Koochaki, Javid; Bokhorst, Jos A. C.; Wortmann, Hans; Klingenberg, Warse

    2012-01-01

    Condition based maintenance (CBM) uses the operating condition of a component to predict a failure event. Compared to age based replacement (ABR), CBM usually results in higher availability and lower maintenance costs, since it tries to prevent unplanned downtime and avoid unnecessary preventive

  11. Simulation based comparison of predictive maintenance policies

    NARCIS (Netherlands)

    Tinga, Tiedo; Janssen, R.H.P.; Steenbergen, R.; van Gelder, P.

    2013-01-01

    When an asset is operated in variable conditions, its operational efficiency can be improved significantly when the maintenance is performed in a dynamic manner. This means that variations in usage and operating environment are taken into account when deciding on the length of the maintenance

  12. Predictive techniques for river channel evolution and maintenance

    Science.gov (United States)

    Nelson, J.M.

    1996-01-01

    Predicting changes in alluvial channel morphology associated with anthropogenic and natural changes in flow and/or sediment supply is a critical part of the management of riverine systems. Over the past few years, advances in the understanding of the physics of sediment transport in conjunction with rapidly increasing capabilities in computational fluid dynamics have yielded now approaches to problems in river mechanics. Techniques appropriate for length scales ranging from reaches to bars and bedforms are described here. Examples of the use of these computational approaches are discussed for three cases: (1) the design of diversion scenarios that maintain channel morphology in steep cobble-bedded channels in Colorado, (2) determination of channel maintenance flows for the preservation of channel islands in the Snake River in Idaho, and (3) prediction of the temporal evolution of deposits in lateral separation zones for future assessment of the impacts of various dam release scenarios on lateral separation deposits in the Colorado River in Grand Canyon. With continued development of their scientific and technical components, the methodologies described here can provide powerful tools for the management of river environments in the future.

  13. Predictive modeling for corrective maintenance of imaging devices from machine logs.

    Science.gov (United States)

    Patil, Ravindra B; Patil, Meru A; Ravi, Vidya; Naik, Sarif

    2017-07-01

    In the cost sensitive healthcare industry, an unplanned downtime of diagnostic and therapy imaging devices can be a burden on the financials of both the hospitals as well as the original equipment manufacturers (OEMs). In the current era of connectivity, it is easier to get these devices connected to a standard monitoring station. Once the system is connected, OEMs can monitor the health of these devices remotely and take corrective actions by providing preventive maintenance thereby avoiding major unplanned downtime. In this article, we present an overall methodology of predicting failure of these devices well before customer experiences it. We use data-driven approach based on machine learning to predict failures in turn resulting in reduced machine downtime, improved customer satisfaction and cost savings for the OEMs. One of the use-case of predicting component failure of PHILIPS iXR system is explained in this article.

  14. Application of an integrated risk management system for improved maintenance in industrial plants

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, A.; Balos, D.T.; Vinod, G.; Balos, D. [Steinbeis Advanced Risk Technologies, Stuttgart (Germany); Stanojevic, P. [NIS - Petroleum Industry of Serbia, Novi Sad (Serbia)

    2007-06-15

    The paper presents the application of the Integrated Risk Management System (iRiS) and its application to the areas of Risk Based Inspection (RBI), Reliability Centered Maintenance (RCM), Root Cause Failure Analysis (RCFA) and Health, Safety and Environment (HSE). The web-based system integrates also the aspects of risk management related to data acquisition and management and interactive reporting and controlled use of single parts of the system by various individual users and/or user levels. A complementing part of the system is a tool for project management including the documentation and activity management, as well as scheduling and e-education and e-training. The complementing parts of the system are the CMMS part (maintenance management), the extension of HSE to HSSE (including the 'security' aspects and providing links to the disaster management system) and further interfacing towards general management system and process modeling and management systems. Experiences from the applications of system in Hungary (at over 60 units) and in Serbia, for several refineries and further units in upstream and downstream, are presented in the paper. (orig.)

  15. Integrated Toolset for WSN Application Planning, Development, Commissioning and Maintenance: The WSN-DPCM ARTEMIS-JU Project.

    Science.gov (United States)

    Antonopoulos, Christos; Asimogloy, Katerina; Chiti, Sarah; D'Onofrio, Luca; Gianfranceschi, Simone; He, Danping; Iodice, Antonio; Koubias, Stavros; Koulamas, Christos; Lavagno, Luciano; Lazarescu, Mihai T; Mujica, Gabriel; Papadopoulos, George; Portilla, Jorge; Redondo, Luis; Riccio, Daniele; Riesgo, Teresa; Rodriguez, Daniel; Ruello, Giuseppe; Samoladas, Vasilis; Stoyanova, Tsenka; Touliatos, Gerasimos; Valvo, Angela; Vlahoy, Georgia

    2016-06-02

    In this article we present the main results obtained in the ARTEMIS-JU WSN-DPCM project between October 2011 and September 2015. The first objective of the project was the development of an integrated toolset for Wireless sensor networks (WSN) application planning, development, commissioning and maintenance, which aims to support application domain experts, with limited WSN expertise, to efficiently develop WSN applications from planning to lifetime maintenance. The toolset is made of three main tools: one for planning, one for application development and simulation (which can include hardware nodes), and one for network commissioning and lifetime maintenance. The tools are integrated in a single platform which promotes software reuse by automatically selecting suitable library components for application synthesis and the abstraction of the underlying architecture through the use of a middleware layer. The second objective of the project was to test the effectiveness of the toolset for the development of two case studies in different domains, one for detecting the occupancy state of parking lots and one for monitoring air concentration of harmful gasses near an industrial site.

  16. Integrated Toolset for WSN Application Planning, Development, Commissioning and Maintenance: The WSN-DPCM ARTEMIS-JU Project

    Directory of Open Access Journals (Sweden)

    Christos Antonopoulos

    2016-06-01

    Full Text Available In this article we present the main results obtained in the ARTEMIS-JU WSN-DPCM project between October 2011 and September 2015. The first objective of the project was the development of an integrated toolset for Wireless sensor networks (WSN application planning, development, commissioning and maintenance, which aims to support application domain experts, with limited WSN expertise, to efficiently develop WSN applications from planning to lifetime maintenance. The toolset is made of three main tools: one for planning, one for application development and simulation (which can include hardware nodes, and one for network commissioning and lifetime maintenance. The tools are integrated in a single platform which promotes software reuse by automatically selecting suitable library components for application synthesis and the abstraction of the underlying architecture through the use of a middleware layer. The second objective of the project was to test the effectiveness of the toolset for the development of two case studies in different domains, one for detecting the occupancy state of parking lots and one for monitoring air concentration of harmful gasses near an industrial site.

  17. Nucleolar integrity is required for the maintenance of long-term synaptic plasticity.

    Directory of Open Access Journals (Sweden)

    Kim D Allen

    Full Text Available Long-term memory (LTM formation requires new protein synthesis and new gene expression. Based on our work in Aplysia, we hypothesized that the rRNA genes, stimulation-dependent targets of the enzyme Poly(ADP-ribose polymerase-1 (PARP-1, are primary effectors of the activity-dependent changes in synaptic function that maintain synaptic plasticity and memory. Using electrophysiology, immunohistochemistry, pharmacology and molecular biology techniques, we show here, for the first time, that the maintenance of forskolin-induced late-phase long-term potentiation (L-LTP in mouse hippocampal slices requires nucleolar integrity and the expression of new rRNAs. The activity-dependent upregulation of rRNA, as well as L-LTP expression, are poly(ADP-ribosylation (PAR dependent and accompanied by an increase in nuclear PARP-1 and Poly(ADP ribose molecules (pADPr after forskolin stimulation. The upregulation of PARP-1 and pADPr is regulated by Protein kinase A (PKA and extracellular signal-regulated kinase (ERK--two kinases strongly associated with long-term plasticity and learning and memory. Selective inhibition of RNA Polymerase I (Pol I, responsible for the synthesis of precursor rRNA, results in the segmentation of nucleoli, the exclusion of PARP-1 from functional nucleolar compartments and disrupted L-LTP maintenance. Taken as a whole, these results suggest that new rRNAs (28S, 18S, and 5.8S ribosomal components--hence, new ribosomes and nucleoli integrity--are required for the maintenance of long-term synaptic plasticity. This provides a mechanistic link between stimulation-dependent gene expression and the new protein synthesis known to be required for memory consolidation.

  18. Predictive analytics technology review: Similarity-based modeling and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Herzog, James; Doan, Don; Gandhi, Devang; Nieman, Bill

    2010-09-15

    Over 11 years ago, SmartSignal introduced Predictive Analytics for eliminating equipment failures, using its patented SBM technology. SmartSignal continues to lead and dominate the market and, in 2010, went one step further and introduced Predictive Diagnostics. Now, SmartSignal is combining Predictive Diagnostics with RCM methodology and industry expertise. FMEA logic reengineers maintenance work management, eliminates unneeded inspections, and focuses efforts on the real issues. This integrated solution significantly lowers maintenance costs, protects against critical asset failures, and improves commercial availability, and reduces work orders 20-40%. Learn how.

  19. Maintenance modeling and optimization integrating human and material resources

    International Nuclear Information System (INIS)

    Martorell, S.; Villamizar, M.; Carlos, S.; Sanchez, A.

    2010-01-01

    Maintenance planning is a subject of concern to many industrial sectors as plant safety and business depend on it. Traditionally, the maintenance planning is formulated in terms of a multi-objective optimization (MOP) problem where reliability, availability, maintainability and cost (RAM+C) act as decision criteria and maintenance strategies (i.e. maintenance tasks intervals) act as the only decision variables. However the appropriate development of each maintenance strategy depends not only on the maintenance intervals but also on the resources (human and material) available to implement such strategies. Thus, the effect of the necessary resources on RAM+C needs to be modeled and accounted for in formulating the MOP affecting the set of objectives and constraints. In this paper RAM+C models to explicitly address the effect of human resources and material resources (spare parts) on RAM+C criteria are proposed. This extended model allows accounting for explicitly how the above decision criteria depends on the basic model parameters representing the type of strategies, maintenance intervals, durations, human resources and material resources. Finally, an application case is performed to optimize the maintenance plan of a motor-driven pump equipment considering as decision variables maintenance and test intervals and human and material resources.

  20. Maintenance modeling and optimization integrating human and material resources

    Energy Technology Data Exchange (ETDEWEB)

    Martorell, S., E-mail: smartore@iqn.upv.e [Dpto. Ingenieria Quimica y Nuclear, Universidad Politecnica Valencia (Spain); Villamizar, M.; Carlos, S. [Dpto. Ingenieria Quimica y Nuclear, Universidad Politecnica Valencia (Spain); Sanchez, A. [Dpto. Estadistica e Investigacion Operativa Aplicadas y Calidad, Universidad Politecnica Valencia (Spain)

    2010-12-15

    Maintenance planning is a subject of concern to many industrial sectors as plant safety and business depend on it. Traditionally, the maintenance planning is formulated in terms of a multi-objective optimization (MOP) problem where reliability, availability, maintainability and cost (RAM+C) act as decision criteria and maintenance strategies (i.e. maintenance tasks intervals) act as the only decision variables. However the appropriate development of each maintenance strategy depends not only on the maintenance intervals but also on the resources (human and material) available to implement such strategies. Thus, the effect of the necessary resources on RAM+C needs to be modeled and accounted for in formulating the MOP affecting the set of objectives and constraints. In this paper RAM+C models to explicitly address the effect of human resources and material resources (spare parts) on RAM+C criteria are proposed. This extended model allows accounting for explicitly how the above decision criteria depends on the basic model parameters representing the type of strategies, maintenance intervals, durations, human resources and material resources. Finally, an application case is performed to optimize the maintenance plan of a motor-driven pump equipment considering as decision variables maintenance and test intervals and human and material resources.

  1. A review of a priori regression models for warfarin maintenance dose prediction.

    Directory of Open Access Journals (Sweden)

    Ben Francis

    Full Text Available A number of a priori warfarin dosing algorithms, derived using linear regression methods, have been proposed. Although these dosing algorithms may have been validated using patients derived from the same centre, rarely have they been validated using a patient cohort recruited from another centre. In order to undertake external validation, two cohorts were utilised. One cohort formed by patients from a prospective trial and the second formed by patients in the control arm of the EU-PACT trial. Of these, 641 patients were identified as having attained stable dosing and formed the dataset used for validation. Predicted maintenance doses from six criterion fulfilling regression models were then compared to individual patient stable warfarin dose. Predictive ability was assessed with reference to several statistics including the R-square and mean absolute error. The six regression models explained different amounts of variability in the stable maintenance warfarin dose requirements of the patients in the two validation cohorts; adjusted R-squared values ranged from 24.2% to 68.6%. An overview of the summary statistics demonstrated that no one dosing algorithm could be considered optimal. The larger validation cohort from the prospective trial produced more consistent statistics across the six dosing algorithms. The study found that all the regression models performed worse in the validation cohort when compared to the derivation cohort. Further, there was little difference between regression models that contained pharmacogenetic coefficients and algorithms containing just non-pharmacogenetic coefficients. The inconsistency of results between the validation cohorts suggests that unaccounted population specific factors cause variability in dosing algorithm performance. Better methods for dosing that take into account inter- and intra-individual variability, at the initiation and maintenance phases of warfarin treatment, are needed.

  2. A review of a priori regression models for warfarin maintenance dose prediction.

    Science.gov (United States)

    Francis, Ben; Lane, Steven; Pirmohamed, Munir; Jorgensen, Andrea

    2014-01-01

    A number of a priori warfarin dosing algorithms, derived using linear regression methods, have been proposed. Although these dosing algorithms may have been validated using patients derived from the same centre, rarely have they been validated using a patient cohort recruited from another centre. In order to undertake external validation, two cohorts were utilised. One cohort formed by patients from a prospective trial and the second formed by patients in the control arm of the EU-PACT trial. Of these, 641 patients were identified as having attained stable dosing and formed the dataset used for validation. Predicted maintenance doses from six criterion fulfilling regression models were then compared to individual patient stable warfarin dose. Predictive ability was assessed with reference to several statistics including the R-square and mean absolute error. The six regression models explained different amounts of variability in the stable maintenance warfarin dose requirements of the patients in the two validation cohorts; adjusted R-squared values ranged from 24.2% to 68.6%. An overview of the summary statistics demonstrated that no one dosing algorithm could be considered optimal. The larger validation cohort from the prospective trial produced more consistent statistics across the six dosing algorithms. The study found that all the regression models performed worse in the validation cohort when compared to the derivation cohort. Further, there was little difference between regression models that contained pharmacogenetic coefficients and algorithms containing just non-pharmacogenetic coefficients. The inconsistency of results between the validation cohorts suggests that unaccounted population specific factors cause variability in dosing algorithm performance. Better methods for dosing that take into account inter- and intra-individual variability, at the initiation and maintenance phases of warfarin treatment, are needed.

  3. Prediction of attendance at fitness center: a comparison between the theory of planned behavior, the social cognitive theory, and the physical activity maintenance theory

    OpenAIRE

    Jekauc, Darko; Völkle, Manuel; Wagner, Matthias O.; Mess, Filip; Reiner, Miriam; Renner, Britta

    2015-01-01

    In the processes of physical activity (PA) maintenance specific predictors are effective, which differ from other stages of PA development. Recently, Physical Activity Maintenance Theory (PAMT) was specifically developed for prediction of PA maintenance. The aim of the present study was to evaluate the predictability of the future behavior by the PAMT and compare it with the Theory of Planned Behavior (TPB) and Social Cognitive Theory (SCT). Participation rate in a fitness center was observed...

  4. A method for accounting for maintenance costs in flux balance analysis improves the prediction of plant cell metabolic phenotypes under stress conditions.

    Science.gov (United States)

    Cheung, C Y Maurice; Williams, Thomas C R; Poolman, Mark G; Fell, David A; Ratcliffe, R George; Sweetlove, Lee J

    2013-09-01

    Flux balance models of metabolism generally utilize synthesis of biomass as the main determinant of intracellular fluxes. However, the biomass constraint alone is not sufficient to predict realistic fluxes in central heterotrophic metabolism of plant cells because of the major demand on the energy budget due to transport costs and cell maintenance. This major limitation can be addressed by incorporating transport steps into the metabolic model and by implementing a procedure that uses Pareto optimality analysis to explore the trade-off between ATP and NADPH production for maintenance. This leads to a method for predicting cell maintenance costs on the basis of the measured flux ratio between the oxidative steps of the oxidative pentose phosphate pathway and glycolysis. We show that accounting for transport and maintenance costs substantially improves the accuracy of fluxes predicted from a flux balance model of heterotrophic Arabidopsis cells in culture, irrespective of the objective function used in the analysis. Moreover, when the new method was applied to cells under control, elevated temperature and hyper-osmotic conditions, only elevated temperature led to a substantial increase in cell maintenance costs. It is concluded that the hyper-osmotic conditions tested did not impose a metabolic stress, in as much as the metabolic network is not forced to devote more resources to cell maintenance. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  5. A multi-level maintenance policy for a multi-component and multifailure mode system with two independent failure modes

    International Nuclear Information System (INIS)

    Zhu, Wenjin; Fouladirad, Mitra; Bérenguer, Christophe

    2016-01-01

    This paper studies the maintenance modelling of a multi-component system with two independent failure modes with imperfect prediction signal in the context of a system of systems. Each individual system consists of multiple series components and the failure modes of all the components are divided into two classes due to their consequences: hard failure and soft failure, where the former causes system failure while the later results in inferior performance (production reduction) of system. Besides, the system is monitored and can be alerted by imperfect prediction signal before hard failure. Based on an illustration example of offshore wind farm, in this paper three maintenance strategies are considered: periodic routine, reactive and opportunistic maintenance. The periodic routine maintenance is scheduled at fixed period for each individual system in the perspective of system of systems. Between two successive routine maintenances, the reactive maintenance is instructed by the imperfect prediction signal according to two criterion proposed in this study for the system components. Due to the high setup cost and practical restraints of implementing maintenance activities, both routine and reactive maintenance can create the opportunities of maintenance for the other components of an individual system. The life cycle of the system and the cost of the proposed maintenance policies are analytically derived. Restrained by the complexity from both the system failure modelling and maintenance strategies, the performances and application scope of the proposed maintenance model are evaluated by numerical simulations. - Highlights: • We study the life behavior of a complex system with two failure modes. • We consider the imperfect prediction signal of potential failure by monitoring. • We propose an integrated maintenance policy with three levels based on wind turbine. • We derive the mathematical cost formulations for the proposed maintenance policy.

  6. Advanced maintenance research programs

    International Nuclear Information System (INIS)

    Marston, T.U.; Gelhaus, F.; Burke, R.

    1985-01-01

    The purpose of this paper is to provide the reader with an idea of the advanced maintenance research program at the Electric Power Research Institute (EPRI). A brief description of the maintenance-related activities is provided as a foundation for the advanced maintenance research projects. The projects can be divided into maintenance planning, preventive maintenance program development and implementation, predictive (or conditional) maintenance, and innovative maintenance techniques. The projects include hardware and software development, human factors considerations, and technology promotion and implementation. The advanced concepts include: the incorporation of artificial intelligence into outage planning; turbine and pump maintenance; rotating equipment monitoring and diagnostics with the aid of expert systems; and the development of mobile robots for nuclear power plant maintenance

  7. Predictive Maintenance and Robotic System Design

    African Journals Online (AJOL)

    pc

    2018-03-05

    Mar 5, 2018 ... Business objectives include: reduce equipment maintenance time, reduce ... Data Acquisition: Proprietary machine diagnostic systems and sensors .... and Logistics, Volume #IPart# http://www.ifac-papersonline.net,. Identifier ...

  8. Intelligent control and maintenance of management integrated system based on multi-agents for coal preparation plant

    Energy Technology Data Exchange (ETDEWEB)

    Meng, F.; Wang, Y. [China University of Mining and technology, Xuzhou (China). School of Information and Electrical Engineering

    2006-06-15

    This paper discusses the progress of computer integrated processing (CIPS) of coal preparation and then presents an intelligence controlled production process, device-maintenance and production-management system of coal preparation based on multi-agents (IICMMS-CP). The construction of the IICMMS-CP, the distributed network control system based on live intelligence control stations and the strategy of implementing a distributed intelligence control system are studied in order to overcome the disadvantages brought about by the wide use of the PLC system by coal preparation plants. The software frame, based on a Multi-Agent Intelligence Control and Maintenance Management integrated system, is studied and the implementation methods of IICMMS-CP are discussed. The characteristics of distributed architecture, cooperation and parallel computing meet the needs of integrated control of coal preparation plants with large-scale spatial production distribution, densely-related processes and complex systems. Its application further improves the reliability and precision of process control, accuracy of fault identification and intelligence of production adjustment, establishes a technical basis for system integration and flexible production. The main function of the system has been tested in a coal preparation plant to good effect in stabilizing product quality, improving efficiency and reducing consumption. 17 refs., 4 figs.

  9. Application of integrated logistic techniques to operation, maintenance and re engineering processes in Nuclear Power plants

    International Nuclear Information System (INIS)

    Santiago Diez, P.

    1997-01-01

    This paper addresses the advisability of adapting and applying management and Integrated Logistic engineering techniques to nuclear power plants instead of using more traditional maintenance management methods. It establishes a historical framework showing the origins of integrated approaches based on traditional logistic support concepts, their phases and the real results obtained in the aeronautic world where they originated. It reviews the application of integrated management philosophy, and logistic support and engineering analysis techniques regarding Availability, Reliability and Maintainability (ARM) and shows their inter dependencies in different phases of the system's life (Design, Development and Operation). It describes how these techniques are applied to nuclear power plant operation, their impact on plant availability and the optimisation of maintenance and replacement plans. The paper analyses the need for data (type and volume), which will have to be collected, and the different tools to manage such data. It examines the different CALS tools developed by EA for engineering and for logistic management. It also explains the possibility of using these tools for process and data operations through the INTERNET. It also focuses on the qualities of some simple examples of possible applications, and how they would be used in the framework of Integrated Logistic Support (ILS). (Author)

  10. Pigging the unpiggable: a total integrated maintenance approach of the Progreso Process Pipelines in Yucatan, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Graciano, Luis [PEMEX Refinacion, Mexico, MX (Mexico); Gonzalez, Oscar L. [NDT Systems and Services, Stutensee (Germany)

    2009-07-01

    Pemex Refinacion and NDT Systems and Services, executed a Total Integrated Maintenance Program of the Process Pipeline System in the Yucatan Peninsula in Mexico, in order to modernize, enhance and bring the pipeline system up to the best industry standards and ensure the integrity, reliability and safe operation of the system. This approach consisted in using multi-diameter ultrasonic inspection technology to determine the current status of the pipelines, repair every 'integrity diminishing' feature present on the system and establish a Certified Maintenance Program to ensure the future reliability and safety of the pipelines. Due to the complex nature of the pipeline construction, dated from 1984, several special modifications, integrations and solutions were necessary to improve the in line inspection survey as for all traditionally unpiggable systems. The Progreso Pipeline System consists in 3 major pipelines which transport diesel, jet fuel and gasoline respectively. The outside diameter of two pipelines varies along its length between 12 inches - 14 inches - 16 inches, making the inspection survey more difficult and particularly demanding an Inspection Tool solution. It is located on the coast of the Yucatan Peninsula, at the Mexican Caribbean, and its main purpose is to transport the product from the docked tanker ships to the Pemex Storage and Distribution Terminal. (author)

  11. Spectrotemporal dynamics of the EEG during working memory encoding and maintenance predicts individual behavioral capacity.

    Science.gov (United States)

    Bashivan, Pouya; Bidelman, Gavin M; Yeasin, Mohammed

    2014-12-01

    We investigated the effect of memory load on encoding and maintenance of information in working memory. Electroencephalography (EEG) signals were recorded while participants performed a modified Sternberg visual memory task. Independent component analysis (ICA) was used to factorise the EEG signals into distinct temporal activations to perform spectrotemporal analysis and localisation of source activities. We found 'encoding' and 'maintenance' operations were correlated with negative and positive changes in α-band power, respectively. Transient activities were observed during encoding of information in the bilateral cuneus, precuneus, inferior parietal gyrus and fusiform gyrus, and a sustained activity in the inferior frontal gyrus. Strong correlations were also observed between changes in α-power and behavioral performance during both encoding and maintenance. Furthermore, it was also found that individuals with higher working memory capacity experienced stronger neural oscillatory responses during the encoding of visual objects into working memory. Our results suggest an interplay between two distinct neural pathways and different spatiotemporal operations during the encoding and maintenance of information which predict individual differences in working memory capacity observed at the behavioral level. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  12. Industrial Maintenance Strategies

    International Nuclear Information System (INIS)

    Sajjad Akbar

    2006-01-01

    Industrial plants have become more complex due to technological advancement. This has made the task of maintenance more difficult. The maintenance costs in terms of resources and downtime loss are so high that maintenance function has become a critical factor in a plant's profitability. Industry should devote as much forethought to the management of maintenance function as to production. Maintenance has grown from an art to a precise, technical engineering science. Planning, organizing scheduling and control of maintenance using modern techniques pays dividends in the form of reduced costs and increased reliability. The magnitude and the dimension of maintenance have multiplied due to development in the engineering technologies. Production cost and capacities are directly affected by the breakdown time. Total operating cost including the maintenance cost plays an important role in replacement dimension. The integrated system approach would bring forth the desired results of high maintenance standards. The standards once achieved and sustained, would add to the reliability of the plan and relieve heavy stresses and strains on the engineering logistic support. (author)

  13. Proceedings of the third international conference on CANDU maintenance

    International Nuclear Information System (INIS)

    1995-01-01

    The third international conference on Candu maintenance included sessions on the following topics: predictive maintenance, reliability improvements, steam generator monitoring, tools and instrumentation, valve performance, fuel channel inspection and maintenance, steam generator maintenance, environmental qualification, predictive maintenance, instrumentation and control, steam generator cleaning, decontamination and radiation protection, inspection techniques, maintenance program strategies and valve packing experience, remote tooling/ robotics and fuel handling. The individual papers have been abstracted separately

  14. Proceedings of the third international conference on CANDU maintenance

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The third international conference on Candu maintenance included sessions on the following topics: predictive maintenance, reliability improvements, steam generator monitoring, tools and instrumentation, valve performance, fuel channel inspection and maintenance, steam generator maintenance, environmental qualification, predictive maintenance, instrumentation and control, steam generator cleaning, decontamination and radiation protection, inspection techniques, maintenance program strategies and valve packing experience, remote tooling/ robotics and fuel handling. The individual papers have been abstracted separately.

  15. Sensor/signal monitoring and plant maintenance

    International Nuclear Information System (INIS)

    Ciftcioglu, Oe.; Tuerkcan, E.

    1994-02-01

    Nuclear Power Plant (NPO) availability is determined by the intended functionality of safety related system and components. Therefore, maintenance is an important issue in a power plant connected to the plant's reliability and safety. The traditional maintenance policies proved to be rather costly and even not effectively addressing NPP requirements. Referring to these drawbacks, in the last decade, in the nuclear reliability centered maintenance (RCM) gained substantial interest due to its merits. In the formal implementation of RCM, apparently, predictive maintenance is not considered. However, with the impact of modern real-time and on-line surveillance and monitoring methodologies, the predictive maintenance procedures like sensor/signal verification and validation are to be included into RCM. (orig.)

  16. Integration of plant life management in operation and maintenance

    International Nuclear Information System (INIS)

    Hutin, Jean-Pierre

    2002-01-01

    Full text: 1 - INTRODUCTION. Electricite de France is now operating 58 PWR nuclear power plants which produce 75% of french electricity. Besides maintaining safety and availability on a routine basis, it is outmost important to protect the investment. Indeed, such an asset is a tremendous advantage just as the company is going to face the new european electricity market. That is the reason why EDF is devoting important effort to implement ageing management as an integral part of operation and maintenance programs. But it must be recognized that NPP lifetime is not threatened only by component-related problems: other less technical issues must be seriously considered like industrial support, information system, skilled people, public acceptance, etc. 2 - LIFE MANAGEMENT POLICY. In France, there is no limited licensing period for NPPs. The life management policy of nuclear power plants is based on three principles: - safe and cost-effective operation, looking for excellence in daily activities, with an effective experience feedback organisation taking advantage of the high level of standardization of the units, - every ten years, a new set of safety standards, a complete review of each facility and an upgrading of its safety level through appropriate modifications while maintaining unit standardization in all the fleet, - a Life Management Program, at corporate level, which permanently scrutinizes operation and maintenance activities to identify decisions which could impair plant lifetime and which surveys research and development programs related to ageing phenomenon understanding. 3 - INTEGRATION OF LIFETIME CONCERN IN O and M ACTIVITIES. It is outmost important to take in account lifetime concern in daily operation and maintenance activities and this must be done as early as possible in plant life. Even though sophisticated assessments require engineering capacity, many good ideas may arise from plant staff. For that reason, increasing lifetime awareness of plant

  17. Managed maintenance, the next step in power plant maintenance

    International Nuclear Information System (INIS)

    Butterworth, G.; Anderson, T.M.

    1984-01-01

    The Westinghouse Nuclear Services Integration Division managed maintenance services are described. Essential to the management and control of a total plant maintenance programme is the development of a comprehensive maintenance specification. During recent years Westinghouse has jointly developed total plant engineering-based maintenance specifications with a number of utilities. The process employed and the experience to date are described. To efficiently implement the maintenance programme Westinghouse has developed a computer software program specifically designed for day to day use at the power plant by maintenance personnel. This program retains an equipment maintenance history, schedules maintenance activities, issues work orders and performs a number of sophisticated analyses of the maintenance backlog and forecast, equipment failure rates, etc. The functions of this software program are described and details of Westinghouse efforts to support the utilities in reducing outage times through development of predefined outage plans for critical report maintenance activities are given. Also described is the experience gained in the training of specialized maintenance personnel, employing competency-based training techniques and equipment mock-ups, and the benefits experienced, in terms of improved quality and productivity of maintenance performed. The success experienced with these methods has caused Westinghouse to expand the use of these training techniques to the more routine skill areas of power plant maintenance. A significant reduction in the operating costs of nuclear power plants will only be brought about by a significant improvement in the quality of maintenance. Westinghouse intends to effect this change by expanding its international service capabilities and to make major investments in order to promote technological developments in the area of power plant maintenance. (author)

  18. Using predictive maintenance methods at Hanford Engineering Development Laboratory (HEDL) to increase equipment availability and reduce overall managed costs

    International Nuclear Information System (INIS)

    Stanton, G.A.; Grygiel, M.L.

    1986-08-01

    This paper describes the predictive maintenance program that is presently in place at Hanford Engineering Development Laboratory using vibration analysis and oil sampling techniques. A pilot program at the Fast Flux Test Facility (FFTF) has been established using reliability-based maintenance concepts such as trend and failure analysis techniques. The first system being analyzed at FFTF will be the electrical distribution system. 2 figs

  19. The advantages of reliability centered maintenance for standby safety systems

    International Nuclear Information System (INIS)

    Dam, R.F.; Ayazzudin, S.; Nickerson, J.H.; DeLong, A.I.

    2002-01-01

    Full text: On standby safety systems, nuclear plants have to balance the requirements of demonstrating the reliability of each system, while maintaining the system and plant availability. With the goal of demonstrating statistical reliability, these systems have extensive testing programs, which often makes the system unavailable and this can impact the plant capacity. The inputs to the process are often safety and regulatory related, resulting in programs that provide a high level of scrutiny on the systems being considered. In such cases, the value of the application of a maintenance optimization strategy, such as Reliability Centered Maintenance (RCM), is questioned. Part of the question stems from the use of the word 'Reliability' in RCM, which implies a level of redundancy when applied to a system maintenance program driven by reliability requirements. A deeper look at the RCM process, however, shows that RCM has the goal of ensuring that the system operates 'reliably' through the application of an integrated maintenance strategy. This is a subtle, but important distinction. Although the system reliability requirements are an important part of the strategy evaluation, RCM provides a broader context where testing is only one part of an overall strategy focused on ensuring that component function is maintained through a combination of monitoring technologies (including testing), predictive techniques, and intrusive maintenance strategies. Each strategy is targeted to identify known component degradation mechanisms. The conclusion is that a maintenance program driven by reliability requirements will tend to have testing defined at a frequency intended to support the needed statistics. The testing demonstrates that the desired function is available today. Maintenance driven by functional requirements and known failure causes, as developed through an RCM assessment, will have frequencies tied to industry experience with components and rely on a higher degree of

  20. New optimization strategies of pavement maintenance: A case study for national road network in Indonesia using integrated road management system

    Science.gov (United States)

    Hamdi, Hadiwardoyo, Sigit P.; Correia, A. Gomes; Pereira, Paulo

    2017-06-01

    A road network requires timely maintenance to keep the road surface in good condition onward better services to improve accessibility and mobility. Strategies and maintenance techniques must be chosen in order to maximize road service level through cost-effective interventions. This approach requires an updated database, which the road network in Indonesia is supported by a manual and visual survey, also using NAASRA profiler. Furthermore, in this paper, the deterministic model of deterioration was used. This optimization model uses life cycle cost analysis (LCCA), applied in an integrated manner, using IRI indicator, and allows determining the priority of treatment, type of treatment and its relation to the cost. The purpose of this paper was focussed on the aspects of road maintenance management, i.e., maintenance optimization models for different levels of traffic and various initial of road distress conditions on the national road network in Indonesia. The implementation of Integrated Road Management System (IRMS) can provide a solution to the problem of cost constraints in the maintenance of the national road network. The results from this study found that as the lowest as agency cost, it will affect the increasing of user cost. With the achievement of the target plan scenario Pl000 with initial value IRI 2, it was found that the routine management throughout the year and in early reconstruction and periodic maintenance with a 30 mm thick overlay, will simultaneously provide a higher net benefit value and has the lowest total cost of transportation.

  1. [Echocardiographic factors predictive of restoration and maintenance of sinus rhythm after reduction of atrial fibrillation].

    Science.gov (United States)

    Ben Khalfallah, A; Sanaa, I

    2007-09-01

    Atrial fibrillation (AF) is the most common cardiac arrhythmia. While the arrhythmia was initially thought to be little more than a nuisance, it is now clear that AF has a significant negative impact on quality of life and a corresponding increase in both morbidity and mortality. The aim of this study was to identify Doppler echographic patterns that allow prediction of atrial fibrillation reduction and maintenance of sinus rhythm within 12 months. One hundred and thirty patients having permanent atrial fibrillation, recent (51) or chronic (79) are included in the study, excepting those with valvular heart disease or thyroid dysfunction. The mean age was 63.5 +/- 11.3 years. Both transthoracic and transoesophageal echocardiography was performed using a Philips SONOS 5500 Echograph, before cardioversion. Were studied: end diastolic and systolic left ventricular diameters, left ventricular ejectionnal fraction, left atrial area (LAA), left atrial diameter, left atrial appendage area and peak emptying velocities of the left atrial appendage (PeV). Sinus rhythm was re-established in 102 patients (44 having recent and 58 chronic atrial fibrillation). Sinus rhythm was maintained for 12 months in 79 patients. Within the echographic parameters studied, the left atrial area (LAA) and peak emptying velocities of left atrial appendage (PeV) before cardioversion were the best predictors of restoration of sinus rhythm. On monovariate analysis, SOG is significantly lower and PicV is significantly higher in patients whose sinus rhythm had been restored in comparison with those with permanent atrial fibrillation. (Mean SOG: 27.7 +/- 7.62 vs. 34 +/- 7,6 cm2, ppredict on mono and multivariate analysis (p=0.05, OR=0.5, IC=0.36 à 3.56), re-establishing of sinus rhythm whereas in patients with chronic atrial fibrillation, peak emptying velocity of left atrial appendage predict better re-establishing of sinus rhythm (p=0.04, OR=1.29, IC=0.12 à 4.23). The threshold values of LAA and Pe

  2. Maintenance simulation: Software issues

    Energy Technology Data Exchange (ETDEWEB)

    Luk, C.H.; Jette, M.A.

    1995-07-01

    The maintenance of a distributed software system in a production environment involves: (1) maintaining software integrity, (2) maintaining and database integrity, (3) adding new features, and (4) adding new systems. These issues will be discussed in general: what they are and how they are handled. This paper will present our experience with a distributed resource management system that accounts for resources consumed, in real-time, on a network of heterogenous computers. The simulated environments to maintain this system will be presented relate to the four maintenance areas.

  3. The CIDEM project for integrating availability, operating experience and maintenance in the design of future nuclear power plants

    International Nuclear Information System (INIS)

    Degrave, C.; Martin-Onraet, M.

    1998-01-01

    To minimize the kWh cost of future nuclear plants EDF has decided to implement the CIDEM project (French acronym for Design Integrating Availability, Operating Experience and Maintenance), an analytic and systematic process for studying new projects. The first CIDEM application is centered on the future French nuclear unit construction program, known as the REP 2000 Program but the approach could be applied to other Reactor type. The CIDEM studies at the beginning, were oriented to the issues strongly impacting the availability. They have concerned: planned outages, forced outages and preventive maintenance. The studies were carried out by a team grouping engineers from the 3 EDF's Divisions (Engineering-Generation-Research), and working together in a Concurrent Engineering-Mode. This team works in close collaboration with the vendors and the German Utilities involved in the REP 2000 EPR program. The implementation of the CIDEM process constitutes for EDF a new approach to the study of the new Nuclear Power Plant projects. The studies conducted in the availability field have already highlighted a number of critical points and have made it possible to establish a series of specifications for the REP 2000/EPR project. The integration in the design process of Preventive Maintenance and Logistic Support studies will allow a better control of the maintenance cost. The competitiveness of nuclear energy greatly depends on the success of such an approach. (author)

  4. Cryogenic systems advanced monitoring, fault diagnostics, and predictive maintenance

    CERN Document Server

    Arpaia, Pasquale; Inglese, Vitaliano; Pezzetti, Marco

    2018-01-01

    Cryogenics, the study and technology of materials and systems at very low temperature, is widely used for sensors and instruments requiring very highly precise measurements with low electrical resistance, especially for measurements of materials and energies at a very small scale. Thus, the need to understand how instruments operate and perform over time at temperatures below -2920 F (-1800 C) is critical, for applications from Magnetic Resonance Imaging (MRI) to Nuclear Magnetic Resonance Spectroscopy to instrumentation for particle accelerators of all kinds. This book brings to the reader guidance learned from work at the European Laboratory for Nuclear Research (CERN), and its large scale particle accelerator in Switzerland to help engineers and technicians implement best practices in instrumentation at cryogenic temperatures, including a better understanding of fault detection and predictive maintenance. Special problems with devices like flow meters, pressure gauges, and temperature gauges when operating...

  5. Two Different Maintenance Strategies in the Hospital Environment: Preventive Maintenance for Older Technology Devices and Predictive Maintenance for Newer High-Tech Devices

    OpenAIRE

    Sezdi, Mana

    2016-01-01

    A maintenance program generated through the consideration of characteristics and failures of medical equipment is an important component of technology management. However, older technology devices and newer high-tech devices cannot be efficiently managed using the same strategies because of their different characteristics. This study aimed to generate a maintenance program comprising two different strategies to increase the efficiency of device management: preventive maintenance for older tec...

  6. Status of fusion maintenance

    International Nuclear Information System (INIS)

    Fuller, G.M.

    1984-01-01

    Effective maintenance will be an essential ingredient in determining fusion system productivity. This level of productivity will result only after close attention is paid to the entire system as an entity and appropriate integration of the elements is made. The status of fusion maintenance is reviewed in the context of the entire system. While there are many challenging developmental tasks ahead in fusion maintenance, the required technologies are available in several high-technology industries, including nuclear fission

  7. Fanconi anemia complementation group A (FANCA) localizes to centrosomes and functions in the maintenance of centrosome integrity.

    Science.gov (United States)

    Kim, Sunshin; Hwang, Soo Kyung; Lee, Mihee; Kwak, Heejin; Son, Kook; Yang, Jiha; Kim, Sung Hak; Lee, Chang-Hun

    2013-09-01

    Fanconi anemia (FA) proteins are known to play roles in the cellular response to DNA interstrand cross-linking lesions; however, several reports have suggested that FA proteins play additional roles. To elucidate novel functions of FA proteins, we used yeast two-hybrid screening to identify binding partners of the Fanconi anemia complementation group A (FANCA) protein. The candidate proteins included never-in-mitosis-gene A (NIMA)-related kinase 2 (Nek2), which functions in the maintenance of centrosome integrity. The interaction of FANCA and Nek2 was confirmed in human embryonic kidney (HEK) 293T cells. Furthermore, FANCA interacted with γ-tubulin and localized to centrosomes, most notably during the mitotic phase, confirming that FANCA is a centrosomal protein. Knockdown of FANCA increased the frequency of centrosomal abnormalities and enhanced the sensitivity of U2OS osteosarcoma cells to nocodazole, a microtubule-interfering agent. In vitro kinase assays indicated that Nek2 can phosphorylate FANCA at threonine-351 (T351), and analysis with a phospho-specific antibody confirmed that this phosphorylation occurred in response to nocodazole treatment. Furthermore, U2OS cells overexpressing the phosphorylation-defective T351A FANCA mutant showed numerical centrosomal abnormalities, aberrant mitotic arrest, and enhanced nocodazole sensitivity, implying that the Nek2-mediated T351 phosphorylation of FANCA is important for the maintenance of centrosomal integrity. Taken together, this study revealed that FANCA localizes to centrosomes and is required for the maintenance of centrosome integrity, possibly through its phosphorylation at T351 by Nek2. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Development of standardized component\\0x2010based equipment specifications and transition plan into a predictive maintenance strategy.

    Science.gov (United States)

    2015-12-01

    This project investigated INDOT equipment records and equipment industry standards to produce standard equipment specifications : and a predictive maintenance schedule for the more than 1100 single and tandem axle trucks in use at INDOT. The research...

  9. TECHNICAL MAINTENANCE EFFICIENCY OF THE AIRCRAFT MAINTENANCE-FREE ON-BOARD SYSTEM BETWEEN SCHEDULED MAINTENANCES

    Directory of Open Access Journals (Sweden)

    A. M. Bronnikov

    2017-01-01

    Full Text Available The avionics concept of the maintenance-free on-board equipment implies the absence of necessity to maintain onboard systems between scheduled maintenance, preserving the required operational and technical characteristics; it should be achieved by automatic diagnosis of the technical condition and the application of active means of ensuring a failsafe design, allowing to change the structure of the system to maintain its functions in case of failure. It is supposed that such equipment will reduce substantially and in the limit eliminate traditional maintenance of aircraft between scheduled maintenance, ensuring maximum readiness for use, along with improving safety. The paper proposes a methodology for evaluating the efficiency of maintenance-free between scheduled maintenance aircraft system with homogeneous redundancy. The excessive redundant elements allow the system to accumulate failures which are repaired during the routine maintenance. If the number of failures of any reserve is approaching a critical value, the recovery of the on-board system (elimination of all failures is carried out between scheduled maintenance by conducting rescue and recovery operations. It is believed that service work leads to the elimination of all failures and completely updates the on-board system. The process of system operational status changes is described with the discrete-continuous model in the flight time. The average losses in the sorties and the average cost of operation are used as integrated efficiency indicators of system operation. For example, the evaluation of the operation efficiency of formalized on-board system with homogeneous redundancy demonstrates the efficiency of the proposed methodology and the possibility of its use while analyzing the efficiency of the maintenance-free operation equipment between scheduled periods. As well as a comparative analysis of maintenance-free operation efficiency of the on-board system with excessive

  10. Technology success: Integration of power plant reliability and effective maintenance

    International Nuclear Information System (INIS)

    Ferguson, K.

    2008-01-01

    The nuclear power generation sector has a tradition of utilizing technology as a key attribute for advancement. Companies that own, manage, and operate nuclear power plants can be expected to continue to rely on technology as a vital element of success. Inherent with the operations of the nuclear power industry in many parts of the world is the close connection between efficiency of power plant operations and successful business survival. The relationship among power plant availability, reliability of systems and components, and viability of the enterprise is more evident than ever. Technology decisions need to be accomplished that reflect business strategies, work processes, as well as needs of stakeholders and authorities. Such rigor is needed to address overarching concerns such as power plant life extension and license renewal, new plant orders, outage management, plant safety, inventory management etc. Particular to power plant reliability, the prudent leveraging of technology as a key to future success is vital. A dominant concern is effective asset management as physical plant assets age. Many plants are in, or are entering in, a situation in which systems and component design life and margins are converging such that failure threats can come into play with increasing frequency. Wisely selected technologies can be vital to the identification of emerging threats to reliable performance of key plant features and initiating effective maintenance actions and investments that can sustain or enhance current reliability in a cost effective manner. This attention to detail is vital to investment in new plants as well This paper and presentation will address (1) specific technology success in place at power plants, including nuclear, that integrates attention to attaining high plant reliability and effective maintenance actions as well as (2) complimentary actions that maximize technology success. In addition, the range of benefits that accrue as a result of

  11. A COMPUTER BASED MAINTENANCE MANAGEMENT SYSTEM ...

    African Journals Online (AJOL)

    ... programs to schedule for maintenance or replacement of machines has been designed such that it enables the maintenance department control all jobs associated with plant maintenance and breakdown. It predicts the time to failure of designated plants and caters for the replacement analysis of some capital equipment.

  12. Maintenance and environmental qualification

    International Nuclear Information System (INIS)

    Martin, R.S.; Austin, D.G.

    1995-01-01

    The design of today's nuclear generating plants involves many detailed design considerations. This includes comprehensive look at aging effects on plant components over their expected lifetimes. This is important to ensuring that the plant operates safely throughout its life. The effects of aging are required to be documented in detail in today's designs. This documentation provides assurance that safe operating conditions are maintained throughout the station life cycle. This requirement is analogous to the longer standing requirement to ensure pressure boundary integrity. The pressure boundary integrity requirement has existed in the industry since its inception. The subject of plant aging effects and the maintenance of functionality is known as Environmental Qualification (EQ). This paper will attempt to explain the wisdom of EQ and the potential for optimizing maintenance activities (to move from reactive to proactive activities), within the context of the overall maintenance program. It is the author's intent to encourage the active involvement of maintenance professionals in the effective implementation of the ongoing EQ program so that the benefits are maximized

  13. Creating Value by Integrating Logistic Trains Services and Maintenance Activities

    NARCIS (Netherlands)

    Busstra, Marten; van Dongen, Leonardus Adriana Maria

    2015-01-01

    NedTrain is the Netherlands Railway's subsidiary responsible for rolling stock maintenance. Train sets are brought in for short-term routine maintenance after set intervals of some 75 to 120 days. When a major defect occurs, train sets are allocated to one of the three maintenance depots and are

  14. PRISMA: Program of Research to Integrate the Services for the Maintenance of Autonomy. A system-level integration model in Quebec

    Directory of Open Access Journals (Sweden)

    Margaret MacAdam

    2015-09-01

    Full Text Available The Program of Research to Integrate the Services for the Maintenance of Autonomy (PRISMA began in Quebec in 1999. Evaluation results indicated that the PRISMA Project improved the system of care for the frail elderly at no additional cost. In 2001, the Quebec Ministry of Health and Social Services made implementing the six features of the PRISMA approach a province-wide goal in the programme now known as RSIPA (French acronym. Extensive Province-wide progress has been made since then, but ongoing challenges include reducing unmet need for case management and home care services, creating incentives for increased physician participation in care planning and improving the computerized client chart, among others. PRISMA is the only evaluated international model of a coordination approach to integration and one of the few, if not the only, integration model to have been adopted at the system level by policy-makers.

  15. Maintenance for the Millennium: Another Approach

    International Nuclear Information System (INIS)

    Sculthorpe, Barruy R.

    2002-01-01

    Nuclear units nationwide are struggling to increase plant reliability and availability while at the same time reduce their operating and maintenance costs. Some very costly investments have been made in programs such as Reliability Centered Maintenance [RCM]. Florida Power and Light's approach at the St. Lucie Nuclear Plant has taken a slightly different approach. Building on our knowledge of the RCM process and an already existing 'World Class' Predictive Maintenance Program, a 'Condition-Based' Maintenance Program that takes advantage of the RCM philosophy and our toolbox full of advanced and highly successful predictive maintenance technologies. These tools currently consist of vibration analysis, lubricant analysis (both physical property and wear metals analysis, thermographic analysis, motor current signature analysis, tribology and process parameter trending. All employed with the intent to evaluate a machines health. This machine health check allows the forecasting of future preventative maintenance [PM's] tasks and the revision of existing PM's to maximize machine performance and eliminate 'no-value-added' maintenance activities/costs. Within the last year, the Condition-Based Maintenance Program has produced a cost saving of approximately $1.5 million dollars. As the program matures, these cost savings will accumulate well into the millennium. (authors)

  16. Music therapy-induced changes in salivary cortisol level are predictive of cardiovascular mortality in patients under maintenance hemodialysis.

    Science.gov (United States)

    Hou, Yi-Chou; Lin, Yen-Ju; Lu, Kuo-Cheng; Chiang, Han-Sun; Chang, Chia-Chi; Yang, Li-King

    2017-01-01

    Music therapy has been applied in hemodialysis (HD) patients for relieving mental stress. Whether the stress-relieving effect by music therapy is predictive of clinical outcome in HD patients is still unclear. We recruited a convenience sample of 99 patients on maintenance HD and randomly assigned them to the experimental (n=49) or control (n=50) group. The experimental group received relaxing music therapy for 1 week, whereas the control group received no music therapy. In the experimental group, we compared cardiovascular mortality in the patients with and without cortisol changes. The salivary cortisol level was lowered after 1 week of music therapy in the experimental group (-2.41±3.08 vs 1.66±2.11 pg/mL, P 0.6 pg/mL (83.8% vs 63.6%, P predict cardiovascular mortality in patients under maintenance HD.

  17. Initial Weight Loss after Restrictive Bariatric Procedures May Predict Mid-Term Weight Maintenance: Results From a 12-Month Pilot Trial

    OpenAIRE

    Nikolić, Marko; Kruljac, Ivan; Kirigin, Lora; Mirošević, Gorana; Ljubičić, Neven; Nikolić, Borka Pezo; Bekavac-Bešlin, Miroslav; Budimir, Ivan; Vrkljan, Milan

    2015-01-01

    Background: Bariatric procedures are effective options for weight loss (WL) in the morbidly obese. However, some patients fail to lose any weight after bariatric surgery, and mid-term weight maintenance is variable. The aim of this study was to investigate whether initial WL could predict mid-term weight maintenance. ----- Methods: Eighty patients were enrolled, of whom 44 were treated with the BioEnterics Intragastric Balloon (BIB), 21 with laparoscopic adjustable gastric lap-banding (LAGB),...

  18. VEHICLE REPAIR AND MAINTENANCE COSTS IN NIGERIA ...

    African Journals Online (AJOL)

    A standard model was established for the prediction of repair and maintenance costs of vehicles in a non-profit making government parastatal. The model was derived based on data collected over a ten year period from a non-profit making government parastatal, and it predicts repair and maintenance costs as a linear ...

  19. Performance measures for world class maintenance

    International Nuclear Information System (INIS)

    Labib, A.W.

    1998-01-01

    A main problem in maintenance in general, and in power plants and related equipment in particular, is the lack of a practical, consistent, and adaptive performance measure that provides a focused feedback and integrates preventive and corrective modes of maintenance. The presentation defines concepts of world class and benchmarking. Desirable features in an appropriate performance measure are identified. It then, demonstrates current practices in maintenance and criticises their shortcomings. An alternative model is presented through a case study. The model monitors performance from a general view, and then offers a focused analysis. The main conclusion is that the proposed model offers an adaptive and a dynamic framework, and hence production and maintenance are integrated in a 'real time' environment. The system is also flexible in working with any other criteria whether they are of a quantitative or a qualitative nature. (orig.) 16 refs

  20. Performance measures for world class maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Labib, A W [Department of Mechanical Engineering, University of Manchester, Institute of Science and Technology, Manchester (United Kingdom)

    1999-12-31

    A main problem in maintenance in general, and in power plants and related equipment in particular, is the lack of a practical, consistent, and adaptive performance measure that provides a focused feedback and integrates preventive and corrective modes of maintenance. The presentation defines concepts of world class and benchmarking. Desirable features in an appropriate performance measure are identified. It then, demonstrates current practices in maintenance and criticises their shortcomings. An alternative model is presented through a case study. The model monitors performance from a general view, and then offers a focused analysis. The main conclusion is that the proposed model offers an adaptive and a dynamic framework, and hence production and maintenance are integrated in a `real time` environment. The system is also flexible in working with any other criteria whether they are of a quantitative or a qualitative nature. (orig.) 16 refs.

  1. Performance measures for world class maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Labib, A.W. [Department of Mechanical Engineering, University of Manchester, Institute of Science and Technology, Manchester (United Kingdom)

    1998-12-31

    A main problem in maintenance in general, and in power plants and related equipment in particular, is the lack of a practical, consistent, and adaptive performance measure that provides a focused feedback and integrates preventive and corrective modes of maintenance. The presentation defines concepts of world class and benchmarking. Desirable features in an appropriate performance measure are identified. It then, demonstrates current practices in maintenance and criticises their shortcomings. An alternative model is presented through a case study. The model monitors performance from a general view, and then offers a focused analysis. The main conclusion is that the proposed model offers an adaptive and a dynamic framework, and hence production and maintenance are integrated in a `real time` environment. The system is also flexible in working with any other criteria whether they are of a quantitative or a qualitative nature. (orig.) 16 refs.

  2. Developing Mobile- and BIM-Based Integrated Visual Facility Maintenance Management System

    Directory of Open Access Journals (Sweden)

    Yu-Cheng Lin

    2013-01-01

    Full Text Available Facility maintenance management (FMM has become an important topic for research on the operation phase of the construction life cycle. Managing FMM effectively is extremely difficult owing to various factors and environments. One of the difficulties is the performance of 2D graphics when depicting maintenance service. Building information modeling (BIM uses precise geometry and relevant data to support the maintenance service of facilities depicted in 3D object-oriented CAD. This paper proposes a new and practical methodology with application to FMM using BIM technology. Using BIM technology, this study proposes a BIM-based facility maintenance management (BIMFMM system for maintenance staff in the operation and maintenance phase. The BIMFMM system is then applied in selected case study of a commercial building project in Taiwan to verify the proposed methodology and demonstrate its effectiveness in FMM practice. Using the BIMFMM system, maintenance staff can access and review 3D BIM models for updating related maintenance records in a digital format. Moreover, this study presents a generic system architecture and its implementation. The combined results demonstrate that a BIMFMM-like system can be an effective visual FMM tool.

  3. MOSEG code for safety oriented maintenance management Safety of management of maintenance oriented by MOSEG code

    International Nuclear Information System (INIS)

    Torres Valle, Antonio

    2005-01-01

    Full text: One of the main reasons that makes maintenance contribute highly when facing safety problems and facilities availability is the lack of maintenance management systems to solve these fields in a balanced way. Their main setbacks are shown in this paper. It briefly describes the development of an integrating algorithm for a safety and availability-oriented maintenance management by virtue of the MOSEG Win 1.0 code. (author)

  4. Infrared thermography application on predictive maintenance for exhaust fan motor

    International Nuclear Information System (INIS)

    I Wayan Widiana; Jakaria; Artadi Heru; Mulyono

    2013-01-01

    To determine the condition of the exhaust fan motor in terms of heat dissipation, predictive maintenance needs to be done. One way is to use infrared thermography. The method used is an infrared thermography with qualitative technique which the analysis focused on the distribution patterns of heat captured by the infrared camera. From measurement results expected to be obtained data of the heat distribution occurs in the motor exhaust fan so it can be given treatment or further improvements recommendations to avoid failure of the operation. Results of measurements on the motor exhaust fan 9 and the motor exhaust fan 10 indicates that there is excessive heat dissipation (over heating). The recommendation given is increasing the motor capacity of 11 kW to 18 kW with a consideration of the addition load on exhaust fan system and age of motor more than 22 years. (author)

  5. Usefulness of a rapid faecal calprotectin test to predict relapse in Crohn's disease patients on maintenance treatment with adalimumab.

    Science.gov (United States)

    Ferreiro-Iglesias, Rocio; Barreiro-de Acosta, Manuel; Lorenzo-Gonzalez, Aurelio; Dominguez-Muñoz, Juan Enrique

    2016-01-01

    Predicting relapse in Crohn's disease (CD) patients by measuring non-invasive biomarkers could allow for early changes of treatment. Data are scarce regarding the utility of monitoring calprotectin to predict relapse. The aim of the study was to evaluate the predictive value of a rapid test of faecal calprotectin (FC) to predict for flares in CD patients on maintenance treatment with adalimumab (ADA). A prospective, observational cohort study was designed. Inclusion criteria were CD patients in clinical remission on a standard dose of ADA therapy. Fresh FC was measured using a rapid test. Thirty patients were included (median age 38 years, 56.7% female). After the 4 months follow-up, 70.0% patients remained in clinical remission and 30.0% had a relapse. FC concentration at inclusion was significantly higher in those patients who relapsed during the follow-up (625 μg/g) compared to those who stayed in remission (45 μg/g). The optimal cut-off for FC to predict relapse was 204 μg/g. The area under the receiver-operating characteristic curve was 0.968. Sensitivity, specificity, positive, and negative predictive value of FC to predict relapse were 100%, 85.7%, 74.1%, and 100%, respectively. In CD patients on ADA maintenance therapy, FC levels measured with a rapid test allow relapse over the following months to be predicted with high accuracy. Low FC levels exclude relapse within at least 4 months after testing, whereas high levels are associated with relapse in three out of every four patients.

  6. CANDU plant maintenance: Recent developments

    International Nuclear Information System (INIS)

    Charlebois, P.

    2000-01-01

    CANDU units have long been recognized for their exceptional safety and reliability. Continuing development in the maintenance area has played a key role in achieving this performance level. For over two decades, safety system availability has been monitored closely and system maintenance programs adjusted accordingly to maintain high levels of performance. But as the plants approach mid life in a more competitive environment and component aging becomes a concern, new methods and techniques are necessary. As a result, recent developments are moving the maintenance program largely from a corrective and preventive approach to predictive and condition based maintenance. The application of these techniques is also being extended to safety related systems. These recent developments include use of reliability centred methods to define system maintenance requirements and strategies. This approach has been implemented on a number of systems at Canadian CANDU plants with positive results. The pilot projects demonstrated that the overall maintenance effort remained relatively constant while the system performance improved. It was also possible to schedule some of the redundant component maintenance during plant operation without adverse impact on system availability. The probabilistic safety assessment was found to be useful in determining the safety implications of component outages. These new maintenance strategies are now making use of predictive and condition based maintenance techniques to anticipate equipment breakdown and schedule preventive maintenance as the need arises rather than time based. Some of these techniques include valve diagnostics, vibration monitoring, oil analysis, thermography. Of course, these tools and techniques must form part of an overall maintenance management system to ensure that maintenance becomes a living program. To facilitate this process and contain costs, new information technology tools are being introduced to provide system engineers

  7. An integrated artificial neural networks approach for predicting global radiation

    International Nuclear Information System (INIS)

    Azadeh, A.; Maghsoudi, A.; Sohrabkhani, S.

    2009-01-01

    This article presents an integrated artificial neural network (ANN) approach for predicting solar global radiation by climatological variables. The integrated ANN trains and tests data with multi layer perceptron (MLP) approach which has the lowest mean absolute percentage error (MAPE). The proposed approach is particularly useful for locations where no available measurement equipment. Also, it considers all related climatological and meteorological parameters as input variables. To show the applicability and superiority of the integrated ANN approach, monthly data were collected for 6 years (1995-2000) in six nominal cities in Iran. Separate model for each city is considered and the quantity of solar global radiation in each city is calculated. Furthermore an integrated ANN model has been introduced for prediction of solar global radiation. The acquired results of the integrated model have shown high accuracy of about 94%. The results of the integrated model have been compared with traditional angstrom's model to show its considerable accuracy. Therefore, the proposed approach can be used as an efficient tool for prediction of solar radiation in the remote and rural locations with no direct measurement equipment.

  8. UK Environmental Prediction - integration and evaluation at the convective scale

    Science.gov (United States)

    Fallmann, Joachim; Lewis, Huw; Castillo, Juan Manuel; Pearson, David; Harris, Chris; Saulter, Andy; Bricheno, Lucy; Blyth, Eleanor

    2016-04-01

    Traditionally, the simulation of regional ocean, wave and atmosphere components of the Earth System have been considered separately, with some information on other components provided by means of boundary or forcing conditions. More recently, the potential value of a more integrated approach, as required for global climate and Earth System prediction, for regional short-term applications has begun to gain increasing research effort. In the UK, this activity is motivated by an understanding that accurate prediction and warning of the impacts of severe weather requires an integrated approach to forecasting. The substantial impacts on individuals, businesses and infrastructure of such events indicate a pressing need to understand better the value that might be delivered through more integrated environmental prediction. To address this need, the Met Office, NERC Centre for Ecology & Hydrology and NERC National Oceanography Centre have begun to develop the foundations of a coupled high resolution probabilistic forecast system for the UK at km-scale. This links together existing model components of the atmosphere, coastal ocean, land surface and hydrology. Our initial focus has been on a 2-year Prototype project to demonstrate the UK coupled prediction concept in research mode. This presentation will provide an update on UK environmental prediction activities. We will present the results from the initial implementation of an atmosphere-land-ocean coupled system, including a new eddy-permitting resolution ocean component, and discuss progress and initial results from further development to integrate wave interactions in this relatively high resolution system. We will discuss future directions and opportunities for collaboration in environmental prediction, and the challenges to realise the potential of integrated regional coupled forecasting for improving predictions and applications.

  9. Integrated internist - addiction medicine - hepatology model for hepatitis C management for individuals on methadone maintenance.

    Science.gov (United States)

    Martinez, A D; Dimova, R; Marks, K M; Beeder, A B; Zeremski, M; Kreek, M J; Talal, A H

    2012-01-01

    Despite a high prevalence of hepatitis C virus (HCV) among drug users, HCV evaluation and treatment acceptance are extremely low among these patients when referred from drug treatment facilities for HCV management. We sought to increase HCV treatment effectiveness among patients from a methadone maintenance treatment program (MMTP) by maintaining continuity of care. We developed, instituted and retrospectively assessed the effectiveness of an integrated, co-localized care model in which an internist-addiction medicine specialist from MMTP was embedded in the hepatitis clinic. Methadone maintenance treatment program patients were referred, evaluated by the internist and hepatologist in hepatitis clinic and provided HCV treatment with integration between both sites. Of 401 evaluated patients, anti-HCV antibody was detected in 257, 86% of whom were older than 40 years. Hepatitis C virus RNA levels were measured in 222 patients, 65 of whom were aviremic. Of 157 patients with detectable HCV RNA, 125 were eligible for referral to the hepatitis clinic, 76 (61%) of whom accepted and adhered with the referral. Men engaged in MMTP <36 months were significantly less likely to be seen in hepatitis clinic than men in MMTP more than 36 months (odds ratio = 7.7; 95% confidence interval 2.6-22.9) or women. We evaluated liver histology in 63 patients, and 83% had moderate to advanced liver disease. Twenty-four patients initiated treatment with 19 completing and 13 (54%) achieving sustained response. In conclusion, integrated care between the MMTP and the hepatitis clinic improves adherence with HCV evaluation and treatment compared to standard referral practices. © 2010 Blackwell Publishing Ltd.

  10. Integrated sign management system : ADOT maintenance group

    Science.gov (United States)

    2003-12-01

    The Arizona Department of Transportation (ADOT) maintains and manages an inventory of roadway signs. Before the implementation of this project, sign technicians maintained inventory records on individual laptops to track their daily sign maintenance ...

  11. An Integrated Ensemble-Based Operational Framework to Predict Urban Flooding: A Case Study of Hurricane Sandy in the Passaic and Hackensack River Basins

    Science.gov (United States)

    Saleh, F.; Ramaswamy, V.; Georgas, N.; Blumberg, A. F.; Wang, Y.

    2016-12-01

    Advances in computational resources and modeling techniques are opening the path to effectively integrate existing complex models. In the context of flood prediction, recent extreme events have demonstrated the importance of integrating components of the hydrosystem to better represent the interactions amongst different physical processes and phenomena. As such, there is a pressing need to develop holistic and cross-disciplinary modeling frameworks that effectively integrate existing models and better represent the operative dynamics. This work presents a novel Hydrologic-Hydraulic-Hydrodynamic Ensemble (H3E) flood prediction framework that operationally integrates existing predictive models representing coastal (New York Harbor Observing and Prediction System, NYHOPS), hydrologic (US Army Corps of Engineers Hydrologic Modeling System, HEC-HMS) and hydraulic (2-dimensional River Analysis System, HEC-RAS) components. The state-of-the-art framework is forced with 125 ensemble meteorological inputs from numerical weather prediction models including the Global Ensemble Forecast System, the European Centre for Medium-Range Weather Forecasts (ECMWF), the Canadian Meteorological Centre (CMC), the Short Range Ensemble Forecast (SREF) and the North American Mesoscale Forecast System (NAM). The framework produces, within a 96-hour forecast horizon, on-the-fly Google Earth flood maps that provide critical information for decision makers and emergency preparedness managers. The utility of the framework was demonstrated by retrospectively forecasting an extreme flood event, hurricane Sandy in the Passaic and Hackensack watersheds (New Jersey, USA). Hurricane Sandy caused significant damage to a number of critical facilities in this area including the New Jersey Transit's main storage and maintenance facility. The results of this work demonstrate that ensemble based frameworks provide improved flood predictions and useful information about associated uncertainties, thus

  12. What Predicts Exercise Maintenance and Well-Being? Examining The Influence of Health-Related Psychographic Factors and Social Media Communication.

    Science.gov (United States)

    Zhou, Xin; Krishnan, Archana

    2018-01-26

    Habitual exercising is an important precursor to both physical and psychological well-being. There is, thus, a strong interest in identifying key factors that can best motivate individuals to sustain regular exercise regimen. In addition to the importance of psychographic factors, social media use may act as external motivator by allowing users to interact and communicate about exercise. In this study, we examined the influence of health consciousness, health-oriented beliefs, intrinsic motivation, as willingness to communicate about health on social media, social media activity on exercise, and online social support on exercise maintenance and well-being on a sample of 532 American adults. Employing structural equation modeling, we found that health-oriented beliefs mediated the effect of health consciousness on intrinsic motivation which in turn was a significant predictor of exercise maintenance. Exercise maintenance significantly predicted both physical and psychological well-being. Extrinsic motivators, as measured by willingness to communicate about health on social media, social media activity on exercise, and online social support did not however significantly influence exercise maintenance. These findings have implications for the design and implementation of exercise-promoting interventions by identifying underlying factors that influence exercise maintenance.

  13. Prediction of attendance at fitness center: a comparison between the theory of planned behavior, the social cognitive theory, and the physical activity maintenance theory.

    Science.gov (United States)

    Jekauc, Darko; Völkle, Manuel; Wagner, Matthias O; Mess, Filip; Reiner, Miriam; Renner, Britta

    2015-01-01

    In the processes of physical activity (PA) maintenance specific predictors are effective, which differ from other stages of PA development. Recently, Physical Activity Maintenance Theory (PAMT) was specifically developed for prediction of PA maintenance. The aim of the present study was to evaluate the predictability of the future behavior by the PAMT and compare it with the Theory of Planned Behavior (TPB) and Social Cognitive Theory (SCT). Participation rate in a fitness center was observed for 101 college students (53 female) aged between 19 and 32 years (M = 23.6; SD = 2.9) over 20 weeks using a magnetic card. In order to predict the pattern of participation TPB, SCT and PAMT were used. A latent class zero-inflated Poisson growth curve analysis identified two participation patterns: regular attenders and intermittent exercisers. SCT showed the highest predictive power followed by PAMT and TPB. Impeding aspects as life stress and barriers were the strongest predictors suggesting that overcoming barriers might be an important aspect for working out on a regular basis. Self-efficacy, perceived behavioral control, and social support could also significantly differentiate between the participation patterns.

  14. Development of standardized component\\0x2010based equipment specifications and transition plan into a predictive maintenance strategy : final report.

    Science.gov (United States)

    2015-12-01

    This project investigated INDOT equipment records and equipment industry standards to produce standard equipment specifications : and a predictive maintenance schedule for the more than 1100 single and tandem axle trucks in use at INDOT. The research...

  15. GAPIT: genome association and prediction integrated tool.

    Science.gov (United States)

    Lipka, Alexander E; Tian, Feng; Wang, Qishan; Peiffer, Jason; Li, Meng; Bradbury, Peter J; Gore, Michael A; Buckler, Edward S; Zhang, Zhiwu

    2012-09-15

    Software programs that conduct genome-wide association studies and genomic prediction and selection need to use methodologies that maximize statistical power, provide high prediction accuracy and run in a computationally efficient manner. We developed an R package called Genome Association and Prediction Integrated Tool (GAPIT) that implements advanced statistical methods including the compressed mixed linear model (CMLM) and CMLM-based genomic prediction and selection. The GAPIT package can handle large datasets in excess of 10 000 individuals and 1 million single-nucleotide polymorphisms with minimal computational time, while providing user-friendly access and concise tables and graphs to interpret results. http://www.maizegenetics.net/GAPIT. zhiwu.zhang@cornell.edu Supplementary data are available at Bioinformatics online.

  16. Benefits of a systematic approach to maintenance for safety and safety related systems

    International Nuclear Information System (INIS)

    Dam, R.F.; Ayazzudin, S.; Nickerson, J.H.

    2003-01-01

    For safety and safety-related systems, nuclear plants have to balance the requirements of demonstrating the reliability of each system, while maintaining the system and plant availability. With the goal of demonstrating statistical reliability, these systems have extensive testing programs, which often results in system unavailability and this can impact the plant capacity. The inputs to the process are often safety and regulatory related, resulting in programs that provide a high level of scrutiny. In such cases, the value of the application of a Systematic Assessment of Maintenance (SAM) process, such as Reliability Centered Maintenance (RCM), is questioned. The special case of Standby-Safety systems was discussed in a previous paper, where it was demonstrated how SAM techniques provide useful insight into current system performance, the impact of testing on component and system reliability, and how PSA considerations can be integrated into a comprehensive Maintenance, Surveillance, and Inspection (MSI) strategy. Although the system reliability requirements are an important part of the strategy evaluation, SAM techniques provide a systematic assessment within a broader context. Testing is only one part of an overall strategy focused on ensuring that component function is maintained through a combination of monitoring technologies (including testing), predictive techniques, and intrusive maintenance strategies. Each strategy is targeted to known component degradation mechanisms. This thinking can be extended to safety and safety related systems in general. Over the past 6 years, AECL has been working with CANDU utilities in the development and implementation of a comprehensive and integrated Plant Life Management (PLiM) program. As part of developing a comprehensive plant asset management approach, SAM techniques are used to develop a technical basis that not only works towards ensuring reliable operation of plant systems, but also facilitates the optimization and

  17. Operational control and maintenance integrity of typical and atypical coil tube steam generating systems

    Energy Technology Data Exchange (ETDEWEB)

    Beardwood, E.S.

    1999-07-01

    Coil tube steam generators are low water volume to boiler horsepower (bhp) rating, rapid steaming units which occupy substantially less space per boiler horsepower than equivalent conventional tire tube and water tube boilers. These units can be retrofitted into existing steam systems with relative ease and are more efficient than the generators they replace. During the early 1970's they became a popular choice for steam generation in commercial, institutional and light to medium industrial applications. Although these boiler designs do not require skilled or certified operators, an appreciation for a number of the operational conditions that result in lower unscheduled maintenance, increased reliability and availability cycles would be beneficial to facility owners, managers, and operators. Conditions which afford lower operating and maintenance costs will be discussed from a practical point of view. An overview of boiler design and operation is also included. Pitfalls are provided for operational and idle conditions. Water treatment application, as well as steam system operations not conducive to maintaining long term system integrity; with resolutions, will be addressed.

  18. Integration of Multi-Modal Biomedical Data to Predict Cancer Grade and Patient Survival.

    Science.gov (United States)

    Phan, John H; Hoffman, Ryan; Kothari, Sonal; Wu, Po-Yen; Wang, May D

    2016-02-01

    The Big Data era in Biomedical research has resulted in large-cohort data repositories such as The Cancer Genome Atlas (TCGA). These repositories routinely contain hundreds of matched patient samples for genomic, proteomic, imaging, and clinical data modalities, enabling holistic and multi-modal integrative analysis of human disease. Using TCGA renal and ovarian cancer data, we conducted a novel investigation of multi-modal data integration by combining histopathological image and RNA-seq data. We compared the performances of two integrative prediction methods: majority vote and stacked generalization. Results indicate that integration of multiple data modalities improves prediction of cancer grade and outcome. Specifically, stacked generalization, a method that integrates multiple data modalities to produce a single prediction result, outperforms both single-data-modality prediction and majority vote. Moreover, stacked generalization reveals the contribution of each data modality (and specific features within each data modality) to the final prediction result and may provide biological insights to explain prediction performance.

  19. SYSTMS: Systematic approach for the development of strategies for maintenance and surveillance

    International Nuclear Information System (INIS)

    Yang, J.X.; McCrea, L.; Dam, R.F.; Nickerson, J.H.

    2004-01-01

    As part of AECL's Integrated PLiM program, the SYSTMS TM tool has been developed to assist in applying the Systematic Assessment of Maintenance (SAM) technology. SYSTMS builds upon AECL's experience in this area, capturing lessons learned to result in an efficient and effective assessment of system maintenance in NPPs. An important feature of SYSTMS is that it provides analysts with needed information that is easy to review and select for inclusion in the system maintenance assessment. This is accomplished through the use of maintenance templates which can be built and tracked using SYSTMS or imported from AECL's own Maintenance Template Database. This database was developed originally to capture information gathered in SAM studies for use in future studies. It has grown to become a central tool for organizing and integrating aging related knowledge from both within AECL and from outside resources. The SYSTMS tool and the Maintenance Template Database work together to provide an effective tool for performing SAM assessments. This combination also becomes an integral part of the Asset Management program development and System based Adaptive Maintenance Program applications. This paper looks at the features of the SYSTMS tool and Maintenance Database, and discusses how these tools are an important part of the AECL Integrated PLiM products and services. (author)

  20. New conceptual method in maintenance with application in cryogenics pilot plant (CPP)

    International Nuclear Information System (INIS)

    Anghel, Vasile

    2006-01-01

    Full text: This study concluded with a series of suggestions concerning the methodology of maintaining a Cryogenics Nuclear Plant where the maintenance is either fundamental or only of importance. The implementation of this methodology can be achieved in two main steps. The first step concerns the conception of the scientific basis for maintenance, while the second step regards the implementation. The first step describes the management of maintenance in conditions of quality, risk and cost constraints. The conditions are established on the basis of a project of research in maintenance. The second step notifies the aspects of design and technology in maintenance of nuclear industrial units. The nuclear complex technical systems of the Cryogenics Pilot Plant at ICSI - Rm Valcea implies the development of some dedicated software, to ensure the designing, realization and operation of the plant, and prototypes of integrated software modules, to ensure the systems operation during of the life cycle. The implementation method is based on vibration analyses and mechanical studies while a flexible data acquisition system for monitoring, and control must be developed as a platform to ensure a more precise diagnosis and prediction of machinery malfunction. With a flexible data acquisition and analysis system in operation it is possible to easily increase the number of input channels. (author)

  1. Toward integration of genomic selection with crop modelling: the development of an integrated approach to predicting rice heading dates.

    Science.gov (United States)

    Onogi, Akio; Watanabe, Maya; Mochizuki, Toshihiro; Hayashi, Takeshi; Nakagawa, Hiroshi; Hasegawa, Toshihiro; Iwata, Hiroyoshi

    2016-04-01

    It is suggested that accuracy in predicting plant phenotypes can be improved by integrating genomic prediction with crop modelling in a single hierarchical model. Accurate prediction of phenotypes is important for plant breeding and management. Although genomic prediction/selection aims to predict phenotypes on the basis of whole-genome marker information, it is often difficult to predict phenotypes of complex traits in diverse environments, because plant phenotypes are often influenced by genotype-environment interaction. A possible remedy is to integrate genomic prediction with crop/ecophysiological modelling, which enables us to predict plant phenotypes using environmental and management information. To this end, in the present study, we developed a novel method for integrating genomic prediction with phenological modelling of Asian rice (Oryza sativa, L.), allowing the heading date of untested genotypes in untested environments to be predicted. The method simultaneously infers the phenological model parameters and whole-genome marker effects on the parameters in a Bayesian framework. By cultivating backcross inbred lines of Koshihikari × Kasalath in nine environments, we evaluated the potential of the proposed method in comparison with conventional genomic prediction, phenological modelling, and two-step methods that applied genomic prediction to phenological model parameters inferred from Nelder-Mead or Markov chain Monte Carlo algorithms. In predicting heading dates of untested lines in untested environments, the proposed and two-step methods tended to provide more accurate predictions than the conventional genomic prediction methods, particularly in environments where phenotypes from environments similar to the target environment were unavailable for training genomic prediction. The proposed method showed greater accuracy in prediction than the two-step methods in all cross-validation schemes tested, suggesting the potential of the integrated approach in

  2. A review of e-maintenance capabilities and challenges

    OpenAIRE

    Adolfo Crespo Marquez; Benoit Iung

    2008-01-01

    Within the era of e-manufacturing and e-business, e-maintenance provides the opportunity for a new maintenance generation. E-maintenance integrates existing telemaintenance principles, with web-services and modern e-collaboration principles. Collaboration allows not only to share and exchange information but also knowledge and (e)-intelligence. This paper outlines the basic capabilities provided by e-maintenance to companies as well as describes emerging challenges to benefit from these new o...

  3. Application of reliability centered maintenance to Embalse NPP

    International Nuclear Information System (INIS)

    Torres, Antonio; Perdomo, Manuel; Fornero, Damian; Corchera, Roberto

    2010-01-01

    One of the most recent applications of Probabilistic Safety Analysis to Embalse NPP is the Safety Oriented Maintenance Program developed through the Reliability Centered Maintenance (RCM) methodology. Such an application was carried out by a cooperated effort between the staff of nuclear safety department of NPP and experts from Instituto Superior de Tecnologias y Ciencias Aplicadas of Cuba. So far 6 technological systems have been analyzed with important results regarding the optimization of preventive and predictive maintenance program of those systems. Any tasks of RCM were automated via MOSEG code. The results of this study were focused on the elaboration and modification of the Preventive Program, prioritization of stocks, reorientation of predictive techniques and modification in the time parameters of maintenance. (author)

  4. State-of-the-art Model M-2 Maintenance System

    International Nuclear Information System (INIS)

    Herndon, J.N.; Martin, H.L.; Satterlee, P.E. Jr.; Jelatis, D.G.; Jennrich, C.E.

    1984-04-01

    The Model M-2 Maintenance System is part of an ongoing program within the Consolidated Fuel Reprocessing Program (CFRP) at Oak Ridge National Laboratory (ORNL) to improve remote manipulation technology for future nuclear fuel reprocessing and other remote applications. Techniques, equipment, and guidelines which can improve the efficiency of remote maintenance are being developed. The Model M-2 Maintenance System, installed in the Integrated Equipment Test (IET) Facility at ORNL, provides a complete, integrated remote maintenance system for the demonstration and development of remote maintenance techniques. The system comprises a pair of force-reflecting servomanipulator arms, television viewing, lighting, and auxiliary lifting capabilities, thereby allowing manlike maintenance operations to be executed remotely within the remote cell mockup area in the IET. The Model M-2 Maintenance System incorporates an upgraded version of the proven Central Research Laboratories' Model M servomanipulator. Included are state-of-the-art brushless dc servomotors for improved performance, remotely removable wrist assemblies, geared azimuth drive, and a distributed microprocessor-based digital control system. 5 references, 8 figures

  5. A multimetric approach for predicting the ecological integrity of New Zealand streams

    Directory of Open Access Journals (Sweden)

    Clapcott J.E.

    2014-01-01

    Full Text Available Integrating multiple measures of stream health into a combined metric can provide a holistic assessment of the ecological integrity of a stream. The aim of this study was to develop a multimetric index (MMI of stream integrity based on predictive modelling of national data sets of water quality, macroinvertebrates, fish and ecosystem process metrics. We used a boosted regression tree approach to calculate an observed/expected score for each metric prior to combining metrics in a MMI based on data availability and the strength of predictive models. The resulting MMI provides a geographically meaningful prediction of the ecological integrity of rivers in New Zealand, but identifies limitations in data and approach, providing focus for ongoing research.

  6. Maintenance evaluation using risk based criteria

    International Nuclear Information System (INIS)

    Torres Valle, A.

    1996-01-01

    The maintenance evaluation is currently performed by using economic and, in some case, technical equipment failure criteria, however this is done to a specific equipment level. In general, when statistics are used the analysis for maintenance optimization are made isolated and whit a post mortem character; The integration provided by mean of Probabilistic Safety assessment (PSA) together with the possibilities of its applications, allow for evaluation of maintenance on the basis of broader scope criteria in regard to those traditionally used. The evaluate maintenance using risk based criteria, is necessary to follow a dynamic and systematic approach, in studying the maintenance strategy, to allow for updating the initial probabilistic models, for including operational changes that often take place during operation of complex facilities. This paper proposes a dynamic evaluation system of maintenance task. The system is illustrated by means of a practical example

  7. Machinery prognostics and prognosis oriented maintenance management

    CERN Document Server

    Yan, Jihong

    2014-01-01

    This book gives a complete presentatin of the basic essentials of machinery prognostics and prognosis oriented maintenance management, and takes a look at the cutting-edge discipline of intelligent failure prognosis technologies for condition-based maintenance.  Latest research results and application methods are introduced for signal processing, reliability moelling, deterioration evaluation, residual life prediction and maintenance-optimization as well as applications of these methods.

  8. Development of a methodology for maintenance optimization at Kozloduy NPP

    International Nuclear Information System (INIS)

    Kitchev, E.

    1997-01-01

    The paper presents the overview of a project for development of an applicable strategy and methods for Kozloduy NPP (KNPP) to optimize its maintenance program in order to meet the current risk based maintenance requirements. The strategy in a format of Integrated Maintenance Program (IMP) manual will define the targets of the optimization process, the major stages and elements of this process and their relationships. IMP embodies the aspects of the US NRC Maintenance Rule compliance and facilitates the integration of KNPP programs and processes which impact the plant maintenance and safety. The methods in a format of IMP Instructions (IM-PI) will define how the different IMP stages can be implemented and the IMP targets can be achieved at KNPP environment. (author). 8 refs

  9. Evaluation of implementation an Integrated Safety and Preventive Maintenance System for Improving of Safety Indexes

    Directory of Open Access Journals (Sweden)

    I mohammadfam

    2014-03-01

    Full Text Available Accident analysis shows that one of the main reasons for accidents is non-integration of maintenance units with safety. Merging these two processes through an integrated system can reduce and or eliminate accidents, diseases, and environmental pollution. These issues lead to improvement in organizational performance, as well. The aim of this study is to design and establish an integrated system for obtaining the aforementioned goal. Integration was carried out at Nirou Moharreke Machine Tools Company via Structured System Analysis & Design Method (SSADM. In order to measure the effectiveness of the system, selected indexes were compared using statistical methods prior and after system establishment. Results show that the accident severity index reduced from 135.46 in 2010, to 43.85 in 2012. Moreover, system effectiveness improved equipment reliability and availability (e.g. reliability of the Pfeiffer Milling machine (P (t>50 increased from 0.89 in 2010, to 0.9 in 2012. This system by forecasting various failures, and planning and designing the required operations for preventing occurrence of these failures, plays an important role in improving safety conditions of equipment, and increasing organizational performance, and is capable of presenting an excellent accident prevention program.

  10. A New Biobjective Model to Optimize Integrated Redundancy Allocation and Reliability-Centered Maintenance Problems in a System Using Metaheuristics

    Directory of Open Access Journals (Sweden)

    Shima MohammadZadeh Dogahe

    2015-01-01

    Full Text Available A novel integrated model is proposed to optimize the redundancy allocation problem (RAP and the reliability-centered maintenance (RCM simultaneously. A system of both repairable and nonrepairable components has been considered. In this system, electronic components are nonrepairable while mechanical components are mostly repairable. For nonrepairable components, a redundancy allocation problem is dealt with to determine optimal redundancy strategy and number of redundant components to be implemented in each subsystem. In addition, a maintenance scheduling problem is considered for repairable components in order to identify the best maintenance policy and optimize system reliability. Both active and cold standby redundancy strategies have been taken into account for electronic components. Also, net present value of the secondary cost including operational and maintenance costs has been calculated. The problem is formulated as a biobjective mathematical programming model aiming to reach a tradeoff between system reliability and cost. Three metaheuristic algorithms are employed to solve the proposed model: Nondominated Sorting Genetic Algorithm (NSGA-II, Multiobjective Particle Swarm Optimization (MOPSO, and Multiobjective Firefly Algorithm (MOFA. Several test problems are solved using the mentioned algorithms to test efficiency and effectiveness of the solution approaches and obtained results are analyzed.

  11. Maintenance philosophy and program at Cernavoda NPP

    International Nuclear Information System (INIS)

    Bobos, M.; Enciu, G.

    1994-01-01

    Maintenance plays a key role in ensuring safe and reliable operation. An effective maintenance program should ensure that installed equipment operates when needed and the equipment malfunctions or deficiencies are corrected in time and rarely recur. Maintenance includes not only the activities traditionally associated with identifying or correcting current or potential equipment deficiencies but also extends to supporting technical functions for the conduct of these activities (for example, engineering, technical support, chemistry control, radiological protection, industrial safety and training). The maintenance management program should clearly define the relationship among these supporting groups as it is related to overall plant maintenance and promotes the concept of a successful integrated team effort. (Author)

  12. The state-of-the-art Model M-2 Maintenance System

    International Nuclear Information System (INIS)

    Herndon, J.N.; Martin, H.L.; Satterlee, P.E. Jr.; Jelatis, D.G.; Jennrich, C.E.

    1984-01-01

    The Model M-2 Maintenance System is part of an ongoing program within the Consolidated Fuel Reprocessing Program (CFRP) at Oak Ridge National Laboratory (ORNL) to improve remote manipulation technology for future nuclear fuel reprocessing and other remote applications. Techniques, equipment, and guidelines which can improve the efficiency of remote maintenance are being developed. The Model M-2 Maintenance System, installed in the Integrated Equipment Test (IET) Facility at ORNL, provides a complete, integrated remote maintenance system for the demonstration and development of remote maintenance techniques. The system comprises a pair of force-reflecting servomanipulator arms, television viewing, lighting, and auxiliary lifting capabilities, thereby allowing manlike maintenance operations to be executed remotely within the remote cell mockup area in the IET. The Model M-2 Maintenance System incorporates an upgraded version of the proven Central Research Laboratories' Model M servomanipulator. Included are state-of-the-art brushless dc servomotors for improved performance, remotely removable wrist assemblies, geared azimuth drive, and a distributed microprocessor-based digital control system

  13. A review of e-maintenance capabilities and challenges

    Directory of Open Access Journals (Sweden)

    Adolfo Crespo Marquez

    2008-02-01

    Full Text Available Within the era of e-manufacturing and e-business, e-maintenance provides the opportunity for a new maintenance generation. E-maintenance integrates existing telemaintenance principles, with web-services and modern e-collaboration principles. Collaboration allows not only to share and exchange information but also knowledge and (e-intelligence. This paper outlines the basic capabilities provided by e-maintenance to companies as well as describes emerging challenges to benefit from these new operational improvement opportunities

  14. Predictive maintenance systems in continuous mine transport installations. Case study from Puentes mine. Sistemas de mantenimiento predictivo en instalaciones mineras de transporte continuo. Casa mina de Puentes

    Energy Technology Data Exchange (ETDEWEB)

    Arechaga Rodriguez, F; Roda Vazquez, C [ENDESA, Madrid (Spain)

    1988-01-01

    At some complex mining installations it is necessary to complement the corrective and preventive maintenance with new systems that enable the detection of failures before they become evident and cause a breakdown. These systems, called predictive maintenance, use several techniques, such as: vibration control, lubricant analysis, wear control, etc. This kind of maintenance provides good results, and although it is not expensive, it requires qualified personnel and good organisation.

  15. Construction of a test platform for Test Blanket Module (TBM) systems integration and maintenance in ITER Port Cell #16

    Energy Technology Data Exchange (ETDEWEB)

    Vála, Ladislav, E-mail: ladislav.vala@cvrez.cz [Centrum výzkumu Řež, Hlavní 130, 250 68 Husinec-Řež (Czech Republic); Reungoat, Mathieu, E-mail: mathieu.reungoat@cvrez.cz [Centrum výzkumu Řež, Hlavní 130, 250 68 Husinec-Řež (Czech Republic); Vician, Martin [Centrum výzkumu Řež, Hlavní 130, 250 68 Husinec-Řež (Czech Republic); Poitevin, Yves; Ricapito, Italo; Zmitko, Milan; Panayotov, Dobromir [Fusion for Energy, Josep Pla 2, Torres Diagonal Litoral B3, 08019 Barcelona (Spain)

    2015-10-15

    Highlights: • A non-nuclear, full size facility – TBM platform – is under construction in CVR. • It is designed for tests, optimization and validation of TBS maintenance operations. • It will allow testing and validation of specific maintenance tools and RH equipment. • It reproduces ITER Port Cell #16, as well as the TBS interfaces and main equipment. • The TBM platform will be available for full operation in the first half of 2016. - Abstract: This paper describes a project of a non-nuclear, 1:1 scale testing platform dedicated to tests, optimization and validation of integration and maintenance operations for the European TBM systems in the ITER Port Cell #16. This TBM platform is currently under construction in Centrum výzkumu Řež, Czech Republic. The facility is realized within the scope of the SUSEN project and its full operation is foreseen in the first half of 2016.

  16. Structural integrity of frontostriatal connections predicts longitudinal changes in self-esteem.

    Science.gov (United States)

    Chavez, Robert S; Heatherton, Todd F

    2017-06-01

    Diverse neurological and psychiatric conditions are marked by a diminished sense of positive self-regard, and reductions in self-esteem are associated with risk for these disorders. Recent evidence has shown that the connectivity of frontostriatal circuitry reflects individual differences in self-esteem. However, it remains an open question as to whether the integrity of these connections can predict self-esteem changes over larger timescales. Using diffusion magnetic resonance imaging and probabilistic tractography, we demonstrate that the integrity of white matter pathways linking the medial prefrontal cortex to the ventral striatum predicts changes in self-esteem 8 months after initial scanning in a sample of 30 young adults. Individuals with greater integrity of this pathway during the scanning session at Time 1 showed increased levels of self-esteem at follow-up, whereas individuals with lower integrity showed stifled or decreased levels of self-esteem. These results provide evidence that frontostriatal white matter integrity predicts the trajectory of self-esteem development in early adulthood, which may contribute to blunted levels of positive self-regard seen in multiple psychiatric conditions, including depression and anxiety.

  17. Maintenance Personnel Performance Simulation (MAPPS) model

    International Nuclear Information System (INIS)

    Siegel, A.I.; Bartter, W.D.; Wolf, J.J.; Knee, H.E.; Haas, P.M.

    1984-01-01

    A stochastic computer model for simulating the actions and behavior of nuclear power plant maintenance personnel is described. The model considers personnel, environmental, and motivational variables to yield predictions of maintenance performance quality and time to perform. The mode has been fully developed and sensitivity tested. Additional evaluation of the model is now taking place

  18. Integrated approach to optimize operation and maintenance costs for operating nuclear power plants

    International Nuclear Information System (INIS)

    2006-06-01

    In the context of increasingly open electricity markets and the 'unbundling' of generating companies from former utility monopolies, an area of major concern is the economic performance of the existing fleet of nuclear power plants. Nuclear power, inevitably, must compete directly with other electricity generation sources. Coping with this competitive pressure is a challenge that the nuclear industry should meet if the nuclear option is to remain a viable one. This competitive environment has significant implications for nuclear plant operations, including, among others, the need for the more cost effective management of plant activities, and the greater use of analytical tools to balance the costs and benefits of proposed activities, in order to optimize operation and maintenance costs, and thus insure the economic competitiveness of existing nuclear power plants. In the framework of the activities on Nuclear Economic Performance Information System (NEPIS), the IAEA embarked in developing guidance on optimization of operation and maintenance costs for nuclear power plants. The report was prepared building on the fundamental that optimization of operation and maintenance costs of a nuclear power plant is a key component of a broader integrated business strategic planning process, having as overall result achievement of organization's business objectives. It provides advice on optimization of O and M costs in the framework of strategic business planning, with additional details on operational planning and controlling. This TECDOC was elaborated in 2004-2005 in the framework of the IAEA's programme on Nuclear Power Plant Operating Performance and Life Cycle Management, with the support of two consultants meetings and one technical meeting and based on contributions provided by participants. It can serve as a useful reference for the management and operation staff within utilities, nuclear power plant operators and regulators and other organizations involved in

  19. Basic study of the plant maintenance model considering plant improvement/modification

    International Nuclear Information System (INIS)

    Tsumaya, Akira; Inoue, Kazuya; Mochizuki, Masahito; Wakamatsu, Hidefumi; Arai, Eiji

    2007-01-01

    This paper proposes a maintenance activity model that considers not only routine maintenance activity but also functional maintenance including improvement/modification. Required maintenance types are categorized, and limitation of Activity Domain Integration Diagram (ADID) proposed by ISO18435 are discussed based on framework for life cycle maintenance management of manufacturing assets. Then, we proposed extension ADID model for plant maintenance activity model considering functional improvement/modification. (author)

  20. An integrated logistic formula for prediction of complications from radiosurgery

    International Nuclear Information System (INIS)

    Flickinger, J.C.

    1989-01-01

    An integrated logistic model for predicting the probability of complications when small volumes of tissue receive an inhomogeneous radiation dose is described. This model can be used with either an exponential or linear quadratic correction for dose per fraction and time. Both the exponential and linear quadratic versions of this integrated logistic formula provide reasonable estimates of the tolerance of brain to radiosurgical dose distributions where there are small volumes of brain receiving high radiation doses and larger volumes receiving lower doses. This makes it possible to predict the probability of complications from stereotactic radiosurgery, as well as combinations of fractionated large volume irradiation with a radiosurgical boost. Complication probabilities predicted for single fraction radiosurgery with the Leksell Gamma Unit using 4, 8, 14, and 18 mm diameter collimators as well as for whole brain irradiation combined with a radiosurgical boost are presented. The exponential and linear quadratic versions of the integrated logistic formula provide useful methods of calculating the probability of complications from radiosurgical treatment

  1. Plant life management. An integral part of operation and maintenance policy

    International Nuclear Information System (INIS)

    Faidy, C.; Hutin, J.-P.

    2002-01-01

    Electricite de France is now operating 58 PWR nuclear power plants that produce 75% of electricity in France. Besides maintaining safety and availability on a routine basis, it is outmost important to protect the investment. That is the reason why EDF is devoting important resources to implement ageing management concern as an integral part of operation and maintenance programs (for example through appropriate data collection and analysis, specific repair and replacement projects and important anticipation efforts, taking in account the high level of standardisation of the units). A particular organisation has been set up to continuously observe and analyse all activities so as to make sure that ageing concern is correctly taken in account in strategies and that no decisions are susceptible to impair plant lifetime. This 'lifetime program' is paying attention to technical issues associated with main components but is also dealing with issues related to economics and industry situation. (orig.)

  2. Nuclear maintenance and management system

    International Nuclear Information System (INIS)

    Yamaji, Yoshihiro; Abe, Norihiko

    2000-01-01

    The Mitsubishi Electric Co., Ltd. has developed to introduce various computer systems for desk-top business assistance in a power plant such as system isolation assisting system, operation parameter management system, and so on under aiming at business effectiveness since these ten and some years. Recently, by further elapsed years of the plants when required for further cost reduction and together with change of business environment represented by preparation of individual personal computer, further effectiveness, preparation of the business environment, and upgrading of maintenance in power plant business have been required. Among such background, she has carried out various proposals and developments on construction of a maintenance and management system integrated the business assistant know-hows and the plant know-hows both accumulated previously. They are composed of three main points on rationalization of business management and document management in the further effectiveness, preparation of business environment, TBM maintenance, introduction of CBM maintenance and introduction of maintenance assistance in upgrading of maintenance. Here was introduced on system concepts aiming at the further effectiveness of the nuclear power plant business, preparation of business environment, upgrading of maintenance and maintenance, and so on, at a background of environment around maintenance business in the nuclear power plants (cost-down, highly elapsed year of the plant, change of business environment). (G.K)

  3. Development of a predictive energy equation for maintenance hemodialysis patients: a pilot study.

    Science.gov (United States)

    Byham-Gray, Laura; Parrott, J Scott; Ho, Wai Yin; Sundell, Mary B; Ikizler, T Alp

    2014-01-01

    The study objectives were to explore the predictors of measured resting energy expenditure (mREE) among a sample of maintenance hemodialysis (MHD) patients, to generate a predictive energy equation (MHDE), and to compare such models to another commonly used predictive energy equation in nutritional care, the Mifflin-St. Jeor equation (MSJE). The study was a retrospective, cross-sectional cohort design conducted at the Vanderbilt University Medical Center. Study subjects were adult MHD patients (N = 67). Data collected from several clinical trials were analyzed using Pearson's correlation and multivariate linear regression procedures. Demographic, anthropometric, clinical, and laboratory data were examined as potential predictors of mREE. Limits of agreement between the MHDE and the MSJE were evaluated using Bland-Altman plots. The a priori α was set at P lean body mass [LBM]) of mREE included (R(2) = 0.489) FFM, ALB, age, and CRP. Two additional models (MHDE-CRP and MHDE-CR) with acceptable predictability (R(2) = 0.460 and R(2) = 0.451) were derived to improve the clinical utility of the developed energy equation (MHDE-LBM). Using Bland-Altman plots, the MHDE over- and underpredicted mREE less often than the MSJE. Predictive models (MHDE) including selective demographic, clinical, and anthropometric data explained less than 50% variance of mREE but had better precision in determining energy requirements for MHD patients when compared with MSJE. Further research is necessary to improve predictive models of mREE in the MHD population and to test its validity and clinical application. Copyright © 2014 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  4. Integrated Design and Approach of Building Maintenance Management in the Built Environment

    Directory of Open Access Journals (Sweden)

    Md Azree Othuman Mydin

    2017-12-01

    Full Text Available Building maintenance is such a crucial aspect in the construction industry. The construction industry is characterized as a project-based industry that delivers one of a kind products and services. Thus, building maintenance can guarantee the safety of buildings including human health and property. To some extent, it plays as a guard to supervise the buildings protecting them being suffered collapse and deterioration. The most importantly, preparing for maintenance carried out on buildings is complex and it is related to procurement system dramatically, such as design-and-build, design-build-finance operate, and the private finance initiative and public/private partnerships, all of them need to give much consideration of operational and maintenance needs and costs which are ongoing.. This paper will focus on design and approach of building maintenance management in the construction industry.

  5. Paranal maintenance and CMMS experience

    Science.gov (United States)

    Montano, Nelson

    2004-10-01

    During the last four years of operations, low technical downtime has been one of the relevant records of the Paranal Observatory. From the beginning of the Very Large Telescope (VLT) project, European Southern Observatory (ESO) has considered the implementation of a proper maintenance strategy a fundamental point in order to ensure low technical down time and preserve the Observatory's assets. The implementation of the maintenance strategy was based on the following aspects: - Strong maintenance sense during the design stage. Line Replacement Unit (LRU) concept, standardization and modularity of the Observatory equipment - Creation of a dedicated team for Maintenance - The implementation of a Computerized Maintenance Management System After four operational years, the result of these aspects has exceeded the expectations; the Observatory has been operating with high availability under a sustainable strategy. The strengths of the maintenance strategy have been based on modern maintenance concepts applied by regular production companies, where any minute of down time involves high cost. The operation of the actual Paranal Maintenance System is based mainly on proactive activities, such as regular inspections, preventive maintenance (PM) and predictive maintenance (PdM) plans. Nevertheless, it has been necessary to implement a strong plan for corrective maintenance (CM). The Spare Parts Strategy has also been an important point linked to the Maintenance Strategy and CMMS implementation. At present, almost 4,000 items related to the Observatory spare parts are loaded into the CMMS database. Currently, we are studying the implementation of a Reliability Centered Maintenance (RCM) project in one of our critical systems The following document presents the actual status of the Paranal Maintenance Strategy and which have been the motivations to implement the established strategy.

  6. Prediction of L70 lumen maintenance and chromaticity for LEDs using extended Kalman filter models

    Energy Technology Data Exchange (ETDEWEB)

    Lall, Pradeep; Wei, Junchao; Davis, Lynn

    2013-09-30

    Solid-state lighting (SSL) luminaires containing light emitting diodes (LEDs) have the potential of seeing excessive temperatures when being transported across country or being stored in non-climate controlled warehouses. They are also being used in outdoor applications in desert environments that see little or no humidity but will experience extremely high temperatures during the day. This makes it important to increase our understanding of what effects high temperature exposure for a prolonged period of time will have on the usability and survivability of these devices. Traditional light sources “burn out” at end-of-life. For an incandescent bulb, the lamp life is defined by B50 life. However, the LEDs have no filament to “burn”. The LEDs continually degrade and the light output decreases eventually below useful levels causing failure. Presently, the TM-21 test standard is used to predict the L70 life of LEDs from LM-80 test data. Several failure mechanisms may be active in a LED at a single time causing lumen depreciation. The underlying TM-21 Model may not capture the failure physics in presence of multiple failure mechanisms. Correlation of lumen maintenance with underlying physics of degradation at system-level is needed. In this paper, Kalman Filter (KF) and Extended Kalman Filters (EKF) have been used to develop a 70-percent Lumen Maintenance Life Prediction Model for LEDs used in SSL luminaires. Ten-thousand hour LM-80 test data for various LEDs have been used for model development. System state at each future time has been computed based on the state space at preceding time step, system dynamics matrix, control vector, control matrix, measurement matrix, measured vector, process noise and measurement noise. The future state of the lumen depreciation has been estimated based on a second order Kalman Filter model and a Bayesian Framework. The measured state variable has been related to the underlying damage using physics-based models. Life

  7. The role of knowledge sharing and transactive memory system on condition based maintenance policy

    NARCIS (Netherlands)

    Koochaki, J.; Bouwhuis, I. M.

    2008-01-01

    Today, Condition Based Maintenance (CBM) has reached a sophisticated level in industry and the advantages of predictive maintenance are accepted globally. However, although lots of effort has been put into improving methods and techniques in CBM, most of predictive maintenance programs fail to

  8. Maintenance for life management

    International Nuclear Information System (INIS)

    Hevia, F.

    1997-01-01

    Life Management is based on the detection, monitoring and control of long-term degradation that affects individual plant components and important populations. Experience has shown that in many cases current maintenance practices do not attend to ageing directly; instead they deal with the consequences when it is already too late, when good Life Management is no longer practical. This has brought about the need for specific Maintenance Evaluation and Improvement Programmes to adjust to the basic objective of Life Management which is to project against, monitor and mitigate ageing that can affect the safe and profitable operating life of the facility. New regulatory requirements for ageing monitoring and effective maintenance to ensure safety (Maintenance Rule) have made it even more necessary to implement the Maintenance Evaluation Programme to cope with ageing, and to integrate that tasks in both programmes to optimise effort and use of tools. This paper presents a brief description of the objectives and methodologies of these Programmes which has been applied to plants around the world and in Spain at the Garona and Vandellos II plants in Spain as part of the PIE project for developing a Remanent Life Evaluation System for nuclear power plants. (Author)

  9. A new theoretical approach to the functional meaning of sleep and dreaming in humans based on the maintenance of 'predictive psychic homeostasis'.

    Science.gov (United States)

    Agnati, Luigi F; Barlow, Peter W; Baluška, František; Tonin, Paolo; Guescini, Michele; Leo, Giuseppina; Fuxe, Kjell

    2011-11-01

    Different theories have been put forward during the last decade to explain the functional meaning of sleep and dreaming in humans. In the present paper, a new theory is presented which, while taking advantage of these earlier theories, introduces the following new and original aspects:   • Circadian rhythms relevant to various organs of the body affect the reciprocal interactions which operate to maintain constancy of the internal milieu and thereby also affect the sleep/wakefulness cycle. Particular attention is given to the constancy of natraemia and osmolarity and to the permissive role that the evolution of renal function has had for the evolution of the central nervous system and its integrative actions. • The resetting of neuro-endocrine controls at the onset of wakefulness leads to the acquisition of new information and its integration within previously stored memories. This point is dealt with in relation to Moore-Ede's proposal for the existence of a 'predictive homeostasis'. • The concept of 'psychic homeostasis' is introduced and is considered as one of the most important states since it is aimed at the well-being, or eudemonia, of the human psyche. Sleep and dreaming in humans are discussed as important functions for the maintenance of a newly proposed composite state: that of 'predictive psychic homeostasis'. On the basis of these assumptions, and in accordance with the available neurobiological data, the present paper puts forward the novel hypothesis that sleep and dreaming play important functions in humans by compensating for psychic allostatic overloads. Hence, both consolatory dreams and disturbing nightmares can be part of the vis medicatrix naturae, the natural healing power, in this case, the state of eudemonia.

  10. Operational integrity using field buses; Integridade operacional utilizando barramentos de campo

    Energy Technology Data Exchange (ETDEWEB)

    Hennig, Carlos Henrique [Coester Automacao S.A., Sao Leopoldo, RS (Brazil)

    2004-07-01

    The device information is collected using standardized Filed Buses with high data transmission capacity, which allows the analysis of his operational status in real time. The quantity of information generated by the devices for the maintenance area is increasing and this data quantity transferred through the field bus should not interfere in the network performance to the point of degrade his control function. In this way, is presented a technique that can be used in different protocols, which allow sending of maintenance data using a small band of the communication channel. Operational integrity can be achieved using predictive maintenance techniques based on the collected data. (author)

  11. Building and integrating reliability models in a Reliability-Centered-Maintenance approach

    International Nuclear Information System (INIS)

    Verite, B.; Villain, B.; Venturini, V.; Hugonnard, S.; Bryla, P.

    1998-03-01

    Electricite de France (EDF) has recently developed its OMF-Structures method, designed to optimize preventive maintenance of passive structures such as pipes and support, based on risk. In particular, reliability performances of components need to be determined; it is a two-step process, consisting of a qualitative sort followed by a quantitative evaluation, involving two types of models. Initially, degradation models are widely used to exclude some components from the field of preventive maintenance. The reliability of the remaining components is then evaluated by means of quantitative reliability models. The results are then included in a risk indicator that is used to directly optimize preventive maintenance tasks. (author)

  12. Susquehanna SES maintenance supervisor training and certification

    International Nuclear Information System (INIS)

    Deckman, M.

    1991-01-01

    Susquehanna's program targets all Supervisors, Supervisor Candidates, and Temporary Supervisors that are responsible for in-plant maintenance or maintenance support activities, including: mechanical maintenance; electrical maintenance; maintenance support (labor support, radwaste, etc.); mobile construction support (mechanical and electrical); chemistry; health physics; maintenance planning; and instrument and controls. The program integrates the three major areas of direct Supervisory responsibilities: (1) Leadership and Management - Skills that require interpersonal activities that are typically humanistic and subjective; such as coaching, motivating, communications, etc. (2) Technical and Administrative - Knowledge that is directly related to the job of Supervising from the production, regulatory, accountability perspective. These topics are very objective and include training on topics such as workpackages, plant chemistry parameters, radiological concerns, etc. (3) Technical Skills - Ensure each Supervisor is technically competent in the plant systems, components, or equipment he/she is tasked with maintaining or overseeing. Typical skills found in this area are, circuit breaker maintenance, primary system sampling, or overhauling pumps

  13. The development of web based power plant maintenance management system

    International Nuclear Information System (INIS)

    Kim, Bum Shin; Kim, Eui Hyun; Jang, Dong Sik; Cho, Jae Min; Chae, Gil Seok; Jung, Gyu Chol

    2004-01-01

    Most power plants have operated many independent computerize systems for maintenance. Independence of systems have caused complexity of business process and inconvenience of computer system management. Because the equipment and material master data is not standardize and structurize, it is difficult to manage equipment maintenance history and material delivery. Especially equipment classification criterion is important for standardization of every maintenance information. It is necessary to integrate function of independent systems for business process simplification and rapid work flow. This paper provides equipment classification criterion design and system integration method with the case of live system development

  14. Predictive Solar-Integrated Commercial Building Load Control

    Energy Technology Data Exchange (ETDEWEB)

    Glasgow, Nathan [EdgePower Inc., Aspen, CO (United States)

    2017-01-31

    This report is the final technical report for the Department of Energy SunShot award number EE0007180 to EdgePower Inc., for the project entitled “Predictive Solar-Integrated Commercial Building Load Control.” The goal of this project was to successfully prove that the integration of solar forecasting and building load control can reduce demand charge costs for commercial building owners with solar PV. This proof of concept Tier 0 project demonstrated its value through a pilot project at a commercial building. This final report contains a summary of the work completed through he duration of the project. Clean Power Research was a sub-recipient on the award.

  15. Knowledge engineering thinking of maintenance

    International Nuclear Information System (INIS)

    2007-01-01

    Maintenance optimization problem could not always settled mathematically and was obliged to use quasi-optimum solution with omitting non-formulated limiting condition or neglecting part of optimization object. In such a case knowledge engineering thinking was encouraged. Maintenance of complicated plant and artificial system should be considered from artificial object (equipment/facility hardware and system), technical information and knowledge base, and organizational and human aspect or society and institution. Comprehensive management system in organization and society was necessary not only for assuring integrity of equipment but also for attaining higher performance, reliability and economics of system. For better judgment it was important to share mechanism to make use of more information with organization or whole society. It was required to create database and data mining for knowledge base management system of maintenance. Maintenance was called 'last fortress' to assure quality such as reliability and safety of required function of equipment. Strategic approach to develop maintenance technology under cooperation was considered. Life extension R and D road map was launched in 2005. (T. Tanaka)

  16. Online Sentence Comprehension in PPA: Verb-Based Integration and Prediction

    Directory of Open Access Journals (Sweden)

    Jennifer E Mack

    2015-05-01

    Full Text Available Introduction. Impaired language comprehension is frequently observed in primary progressive aphasia (PPA. Word comprehension deficits are characteristic of the semantic variant (PPA-S whereas sentence comprehension deficits are more prevalent in the agrammatic (PPA-G and logopenic (PPA-L variants (Amici et al., 2007; Gorno-Tempini et al., 2011; Thompson et al., 2013. Word and sentence comprehension deficits have also been shown to have distinct neural substrates in PPA (Mesulam, Thompson, Weintraub, & Rogalski, in press. However, little is known about the relationship between word and sentence comprehension processes in PPA, specifically how words are accessed, combined, and used to predict upcoming elements within a sentence. A previous study demonstrated that listeners with stroke-induced agrammatic aphasia rapidly access verb meanings and use them to semantically integrate verb-arguments; however, they show deficits in using verb meanings predictively (Mack, Ji, & Thompson, 2013. The present study tested whether listeners with PPA are able to access verb meanings and to use this information to integrate and predict verb-arguments. Methods. Fifteen adults with PPA (8 with PPA-G, 3 with PPA-L, and 4 with PPA-S and ten age-matched controls participated in two eyetracking experiments. In both experiments, participants heard sentences with restrictive verbs that were semantically compatible with only one object in a four-picture visual array (e.g., eat when the array included a cake and three non-edible objects and unrestrictive verbs (e.g., move that were compatible with all four objects. The verb-based integration experiment tested access to verb meaning and its effects on integration of the direct object (e.g., Susan will eat/move the cake; the verb-based prediction experiment examined prediction of the direct object (e.g., Susan will eat/move the …. The dependent variable was the rate of fixations on the target picture (e.g., the cake in the

  17. Application of guideline for the maintenance of guide tubes

    International Nuclear Information System (INIS)

    Matsubara, Toru

    2009-01-01

    Control Rod Cluster Guide Tubes (GTs) in PWR nuclear plant have the possibility to be worn due to fluid induced vibration of Control Rod Clusters. The maintenance rules for GTs had been established after the discussion with experts, and GTs in Japanese PWR plants have been already maintained in accordance with these maintenance rules. In these rules, the inspection period is decided based on the wear data and the wear progressing prediction with the assumption of constant wear speed. This paper describes the validity of the concepts about maintenance period based on the wear progressing prediction, by using the consecutive inspection data of actual plants. (author)

  18. Maintenance as a corporate strategy.

    Science.gov (United States)

    Clarke, D

    2000-11-01

    As we move towards the 21st century, those Manufacturing Industries that survive, will have changed their "efficiency" focus away from the conventional wisdom of "efficient individual tasks", to focus on the "effectiveness of a total manufacturing process". This seemingly insignificant change of emphasis, (from task to process) must include "the integration of process plant maintenance into the production process". Manufacturing companies, which do not include an effective plant maintenance strategy into their business strategy, will not survive the business environment of the 21st Century.

  19. Planning and control of maintenance systems modelling and analysis

    CERN Document Server

    Duffuaa, Salih O

    2015-01-01

    Analyzing maintenance as an integrated system with objectives, strategies and processes that need to be planned, designed, engineered, and controlled using statistical and optimization techniques, the theme of this book is the strategic holistic system approach for maintenance. This approach enables maintenance decision makers to view maintenance as a provider of a competitive edge not a necessary evil. Encompassing maintenance systems; maintenance strategic and capacity planning, planned and preventive maintenance, work measurements and standards, material (spares) control, maintenance operations and control, planning and scheduling, maintenance quality, training, and others, this book gives readers an understanding of the relevant methodology and how to apply it to real-world problems in industry. Each chapter includes a number exercises and is suitable as a textbook or a reference for a professionals and practitioners whilst being of interest to industrial engineering, mechanical engineering, electrical en...

  20. The IntFOLD server: an integrated web resource for protein fold recognition, 3D model quality assessment, intrinsic disorder prediction, domain prediction and ligand binding site prediction.

    Science.gov (United States)

    Roche, Daniel B; Buenavista, Maria T; Tetchner, Stuart J; McGuffin, Liam J

    2011-07-01

    The IntFOLD server is a novel independent server that integrates several cutting edge methods for the prediction of structure and function from sequence. Our guiding principles behind the server development were as follows: (i) to provide a simple unified resource that makes our prediction software accessible to all and (ii) to produce integrated output for predictions that can be easily interpreted. The output for predictions is presented as a simple table that summarizes all results graphically via plots and annotated 3D models. The raw machine readable data files for each set of predictions are also provided for developers, which comply with the Critical Assessment of Methods for Protein Structure Prediction (CASP) data standards. The server comprises an integrated suite of five novel methods: nFOLD4, for tertiary structure prediction; ModFOLD 3.0, for model quality assessment; DISOclust 2.0, for disorder prediction; DomFOLD 2.0 for domain prediction; and FunFOLD 1.0, for ligand binding site prediction. Predictions from the IntFOLD server were found to be competitive in several categories in the recent CASP9 experiment. The IntFOLD server is available at the following web site: http://www.reading.ac.uk/bioinf/IntFOLD/.

  1. Application of data mining in a maintenance system for failure prediction

    OpenAIRE

    Bastos, Pedro; Lopes, Isabel; Pires, L.C.M.

    2014-01-01

    In industrial environment, data generated during equipment maintenance and monitoring activities has become increasingly overwhelming. Data mining presents an opportunity to increase significantly the rate at which the volume of data can be turned into useful information. This paper presents an architecture designed to gather data generated in industrial units on their maintenance activities, and to forecast future failures based on data analysis. Rapid Miner is used to apply diff...

  2. The missing link between maintenance contracts and flexible asset management

    OpenAIRE

    Marttonen-Arola, Salla; Viskari, Sari; Kärri, Timo

    2013-01-01

    The paper shows how additional value can be created in maintenance collaboration through integrating the features of flexible asset management into maintenance contracts. We expand the traditional typology of maintenance contracts and introduce a new contract type, flexible asset management contracts. Also value sharing in the new contract type is discussed. Our logic for sharing the value is based on reaching for win-win situations in industrial maintenance collaboration. Finally, we present...

  3. Developing optimized prioritizing road maintenance

    Directory of Open Access Journals (Sweden)

    Ewadh Hussein Ali

    2018-01-01

    Full Text Available Increased demand for efficient maintenance of the existing roadway system needs optimal usage of the allocated funds. The paper demonstrates optimized methods for prioritizing maintenance implementation projects. A selected zone of roadway system in Kerbala city represents the study area to demonstrate the application of the developed prioritization process. Paver system PAVER integrated with GIS is used to estimate and display the pavement condition index PCI, thereby to establish a priority of maintenance. In addition to simple ranking method by PCI produced by the output of PAVER, the paper introduces PCI measure for each section of roadway. The paper introduces ranking by multiple measures investigated through expert knowledge about measures that affect prioritization and their irrespective weights due to a predesigned questionnaire. The maintenance priority index (MPI is related to cost of suitable proposed maintenance, easiness of proposed maintenance, average daily traffic and functional classification of the roadway in addition to PCI. Further, incremental benefit-cost analysis ranking provide an optimized process due to benefit and cost of maintenance. The paper introduces efficient display of layout and ranking for the selected zone of roadway system based on MPI index and incremental BCR method. Although the two developed methods introduce different layout display for priority, statistical test shows that no significant difference between ranking of all methods of prioritization.

  4. Predicting Protein Function via Semantic Integration of Multiple Networks.

    Science.gov (United States)

    Yu, Guoxian; Fu, Guangyuan; Wang, Jun; Zhu, Hailong

    2016-01-01

    Determining the biological functions of proteins is one of the key challenges in the post-genomic era. The rapidly accumulated large volumes of proteomic and genomic data drives to develop computational models for automatically predicting protein function in large scale. Recent approaches focus on integrating multiple heterogeneous data sources and they often get better results than methods that use single data source alone. In this paper, we investigate how to integrate multiple biological data sources with the biological knowledge, i.e., Gene Ontology (GO), for protein function prediction. We propose a method, called SimNet, to Semantically integrate multiple functional association Networks derived from heterogenous data sources. SimNet firstly utilizes GO annotations of proteins to capture the semantic similarity between proteins and introduces a semantic kernel based on the similarity. Next, SimNet constructs a composite network, obtained as a weighted summation of individual networks, and aligns the network with the kernel to get the weights assigned to individual networks. Then, it applies a network-based classifier on the composite network to predict protein function. Experiment results on heterogenous proteomic data sources of Yeast, Human, Mouse, and Fly show that, SimNet not only achieves better (or comparable) results than other related competitive approaches, but also takes much less time. The Matlab codes of SimNet are available at https://sites.google.com/site/guoxian85/simnet.

  5. Reliability centered maintenance streamlining through lessons learned

    International Nuclear Information System (INIS)

    Strong, D.K.

    1991-01-01

    In late 1986, PSE and G concluded that the Nuclear Department would develop a consistent approach to maintenance at Artificial Island (Salem and Hope Creak nuclear units). Preventive maintenance (PM) would be the heart of this approach. In the last six months of 1987 departments affected by the maintenance program participated on working groups that developed the Artificial Island maintenance philosophy. The central theme of the maintenance philosophy is the RCM (reliability centered maintenance) process. A pilot project tested the process in 1988. In 1989 the Central PM Group formed and in 1990 was given responsibility and authority to analyze, approve, implement, and control PM program changes. RCM is the central theme of the PM improvement effort but not the whole effort. Other important pieces included in this paper are: development of a common PM program, improvement of work instructions, development of predictive maintenance techniques into programs, development of a PM basis database, development of PM feedback from failure trends, root cause analysis, maintenance performance indicators, technicians, and engineers

  6. The integration of weighted human gene association networks based on link prediction.

    Science.gov (United States)

    Yang, Jian; Yang, Tinghong; Wu, Duzhi; Lin, Limei; Yang, Fan; Zhao, Jing

    2017-01-31

    Physical and functional interplays between genes or proteins have important biological meaning for cellular functions. Some efforts have been made to construct weighted gene association meta-networks by integrating multiple biological resources, where the weight indicates the confidence of the interaction. However, it is found that these existing human gene association networks share only quite limited overlapped interactions, suggesting their incompleteness and noise. Here we proposed a workflow to construct a weighted human gene association network using information of six existing networks, including two weighted specific PPI networks and four gene association meta-networks. We applied link prediction algorithm to predict possible missing links of the networks, cross-validation approach to refine each network and finally integrated the refined networks to get the final integrated network. The common information among the refined networks increases notably, suggesting their higher reliability. Our final integrated network owns much more links than most of the original networks, meanwhile its links still keep high functional relevance. Being used as background network in a case study of disease gene prediction, the final integrated network presents good performance, implying its reliability and application significance. Our workflow could be insightful for integrating and refining existing gene association data.

  7. Anthropometric Indicators Predict Metabolic Syndrome Diagnosis in Maintenance Hemodialysis Patients.

    Science.gov (United States)

    Vogt, Barbara Perez; Ponce, Daniela; Caramori, Jacqueline Costa Teixeira

    2016-06-01

    Obesity has been considered the key in metabolic syndrome (MetS) development, and fat accumulation may be responsible for the occurrence of metabolic abnormalities in hemodialysis patients. The use of gold-standard methods to evaluate obesity is limited, and anthropometric measures may be the simplest methods. However, no study has investigated the association between anthropometric indexes and MetS in these patients. Therefore, the aim was to determine which anthropometric indexes had the best association and prediction for MetS in patients undergoing hemodialysis. Cross-sectional study that included patients older than 18 years, undergoing hemodialysis for at least 3 months. Patients with liver disease and cancer or those receiving corticosteroids or antiretroviral therapy were excluded. Diagnostic criteria from Harmonizing Metabolic Syndrome were used for the diagnosis of MetS. Anthropometric indexes evaluated were body mass index (BMI); percent standard of triceps skinfold thickness and of middle arm muscle circumference; waist circumference (WC); sagittal abdominal diameter; neck circumference; waist-to-hip, waist-to-thigh, and waist-to-height ratios; sagittal index; conicity index; and body fat percentage. Ninety-eight patients were included, 54.1% male, and mean age was 57.8 ± 12.9 years. The prevalence of MetS was 74.5%. Individuals with MetS had increased accumulation of abdominal fat and general obesity. Waist-to-height ratio was the variable independently associated with MetS diagnosis (odds ratio, 1.21; 95% confidence interval, 1.09-1.34; P < .01) and that better predicts MetS, followed by WC and BMI (area under the curve of 0.840, 0.836, and 0.798, respectively, P < .01). Waist-to-height ratio was the best anthropometric predictor of MetS in maintenance hemodialysis patients. © 2015 American Society for Parenteral and Enteral Nutrition.

  8. TRUPACT-II container maintenance program plan

    International Nuclear Information System (INIS)

    1990-01-01

    This document details the maintenance/repair and replacement of components, as well as the documentation required and the procedures to be followed to maintain the integrity of the TRUPACT-II container

  9. Reliability Centered Maintenance - Methodologies

    Science.gov (United States)

    Kammerer, Catherine C.

    2009-01-01

    Journal article about Reliability Centered Maintenance (RCM) methodologies used by United Space Alliance, LLC (USA) in support of the Space Shuttle Program at Kennedy Space Center. The USA Reliability Centered Maintenance program differs from traditional RCM programs because various methodologies are utilized to take advantage of their respective strengths for each application. Based on operational experience, USA has customized the traditional RCM methodology into a streamlined lean logic path and has implemented the use of statistical tools to drive the process. USA RCM has integrated many of the L6S tools into both RCM methodologies. The tools utilized in the Measure, Analyze, and Improve phases of a Lean Six Sigma project lend themselves to application in the RCM process. All USA RCM methodologies meet the requirements defined in SAE JA 1011, Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes. The proposed article explores these methodologies.

  10. Development of hardware system using temperature and vibration maintenance models integration concepts for conventional machines monitoring: A case study

    OpenAIRE

    Adeyeri, Michael Kanisuru; Mpofu, Khumbulani; Kareem, Buliaminu

    2016-01-01

    This article describes the integration of temperature and vibration models for maintenance monitoring of conventional machinery parts in which their optimal andbest functionalities are affected by abnormal changes in temperature and vibration values thereby resulting in machine failures, machines breakdown, poor quality of products, inability to meeting customers' demand, poor inventory control and just to mention a few. The work entails the use of temperature and vibration sensors as monitor...

  11. Individual capacity for DNA repair and maintenance of genomic integrity: a fertile ground for studies in the field of assisted reproduction

    Directory of Open Access Journals (Sweden)

    Radoslava Vazharova

    2016-05-01

    Full Text Available Many factors may affect the chances for successful pregnancy, especially at a later age. Fertility evaluations including genetic analysis are recommended to couples that have not achieved pregnancy within 6–12 months of unprotected intercourse. This review discusses some of the common polymorphisms in genes coding for proteins functioning in DNA damage identification and repair and maintenance of genomic integrity that may affect the chances of success in natural conception as well as in assisted reproduction (AR. Common polymorphisms in genes coding for proteins functioning in DNA damage identification and repair and maintenance of genomic integrity may affect the chances of success in assisted reproduction as well as in natural conception. The effects of carriership of different alleles of key genes of DNA repair may have differential effects in men and women and at different ages, suggesting complex interactions with the mechanisms controlling cell and tissue aging and programmed cell death. Future studies in the field are needed in order to elucidate the genotype–phenotype relationships and to translate the knowledge about individual repair capacity and maintenance of genomic integrity to potential clinical applications. Abbreviations: aCGH: microarray-based comparative genomic hybridization; AR: assisted reproduction; ATM: ataxia-telangiectasia mutated; ATP: adenosine triphosphate; BER: base excision repair; BFE: basic fertility evaluation; DMSO: dimethyl sulfoxide; FSH: follicle-stimulating hormone; GNRHR: gonadotropin-releasing hormone receptor; HMG: high-mobility group; ICSI: intracytoplasmic sperm injection; IUI: intrauterine insemination; IVF: in vitro fertilization; LH: luteinizing hormone; LIF: leukaemia inhibitory factor; MTR: methionine synthase; MTRR: methionine synthase reductase; NGS: next-generation sequencing; NER: nucleotide excision repair; NHEJ: non-homologous end joining; PAH: polycyclic aromatic hydrocarbons; PCOS

  12. Design of Mobile Operation and Maintenance System Based on Power GIS and GPS

    Directory of Open Access Journals (Sweden)

    Jing TAO

    2017-01-01

    Full Text Available In order to solve the low efficiency of operation and maintenance and the problems of management coordination caused by the coexistence of off-line operation and maintenance and multi system coexistence in current power telecommunication operation and maintenance, this paper proposes a mobile operation and maintenance system based on power GIS and GPS location technology. The system is based on the C/S architecture, and the mobile operation and maintenance terminal is connected with the operation and maintenance management terminal through wireless and wired network. In addition to meeting basic business requirements, the system integrates power GIS functions to visually demonstrate communication resources, personnel, and failures. The staff can use the wireless mobile terminal which integrated GPS module for to operate and maintain, and can locate accurately in real time.

  13. Operation and maintenance cost data for residential photovoltaic modules/panels

    Science.gov (United States)

    Oster, J. R., Jr.; Zaremski, D. R., Jr.; Albert, E. M.; Hawkins, S. L.

    1980-01-01

    Costs associated with the operation and maintenance of residential photovoltaic modules and arrays are studied. Six basic topics related to operation and maintenance to photovoltaic arrays are investigated: maintenance; cleaning; panel replacement; gasket repair/replacement; wiring repair/replacement; and termination repair/replacement. The effects of the mounting types (rack mount, stand off mount, direct mount and integral mount) and the installation/replacement type (sequential, partial interruption and independent) are identified and described. Methods of reducing maintenance costs are suggested.

  14. Maintenance related to life management: Survey and control of equipment ageing

    International Nuclear Information System (INIS)

    Hevia Ruperez, F.

    2000-01-01

    The aim of this paper is to review relevant objectives and aspects of the Maintenance Evaluation and Improvement Programmes for Nuclear Power Plant Life Management. Recent experience shows that current maintenance practice often fails to directly address long-term degradation that affects singular plant components and equipment populations. Instead, delayed attention to the consequences makes good Life Management unfeasible. This has brought about the need for specific Maintenance Evaluation and Improvement Programmes to adjust to the basic objective of Life Management which is to protect against, mitigate and/or monitor ageing that affects the safe, profitable life of the facility. The paper analyses the methodologies used, incidents during their application and the main conclusions reached from the implementation of these programmes in Spanish nuclear power plants. Special attention is paid to recommended solutions for improving the efficiency of the utility's contributions, its leadership in task development and integration, and its interfaces with organisations specialised in providing services that support Life Management Programmes. The coexistence of these and other similar maintenance programmes make it necessary to integrate tasks to optimise effort and tools. The paper analyses the guidelines to be considered when integrating these Programmes with other maintenance optimisation programmes (economy and feasibility, RCM) and with tasks derived from the application of Maintenance Rule regulatory requirements. Lastly, the paper reports on the state of these Maintenance Evaluation and Improvement Programmes, their development, what prospects they have, and the Industry's initiative and actions concerning the matter. (author)

  15. Integration of RAMS in LCC analysis for linear transport infrastructures. A case study for railways.

    Science.gov (United States)

    Calle-Cordón, Álvaro; Jiménez-Redondo, Noemi; Morales-Gámiz, F. J.; García-Villena, F. A.; Garmabaki, Amir H. S.; Odelius, Johan

    2017-09-01

    Life-cycle cost (LCC) analysis is an economic technique used to assess the total costs associated with the lifetime of a system in order to support decision making in long term strategic planning. For complex systems, such as railway and road infrastructures, the cost of maintenance plays an important role in the LCC analysis. Costs associated with maintenance interventions can be more reliably estimated by integrating the probabilistic nature of the failures associated to these interventions in the LCC models. Reliability, Maintainability, Availability and Safety (RAMS) parameters describe the maintenance needs of an asset in a quantitative way by using probabilistic information extracted from registered maintenance activities. Therefore, the integration of RAMS in the LCC analysis allows obtaining reliable predictions of system maintenance costs and the dependencies of these costs with specific cost drivers through sensitivity analyses. This paper presents an innovative approach for a combined RAMS & LCC methodology for railway and road transport infrastructures being developed under the on-going H2020 project INFRALERT. Such RAMS & LCC analysis provides relevant probabilistic information to be used for condition and risk-based planning of maintenance activities as well as for decision support in long term strategic investment planning.

  16. Interspecific gene flow and maintenance of species integrity in oaks

    Directory of Open Access Journals (Sweden)

    Oliver Gailing

    2014-07-01

    Full Text Available Oak species show a wide variation in morphological and physiological characters, and species boundaries between closely related species are often not clear-cut. Still, despite frequent interspecific gene flow, oaks maintain distinct morphological and physiological adaptations. In sympatric stands, spatial distribution of species with different ecological requirements is not random but constrained by soil and other microenvironmental factors. Pre-zygotic isolation (e.g. cross incompatibilities, asynchrony in flowering, pollen competition and post-zygotic isolation (divergent selection contribute to the maintenance of species integrity in sympatric oak stands. The antagonistic effects of interspecific gene flow and divergent selection are reflected in the low genetic differentiation between hybridizing oak species at most genomic regions interspersed by regions with signatures of divergent selection (outlier regions. In the near future, the availability of high-density genetic linkage maps anchored to scaffolds of a sequenced Q. robur genome will allow to characterize the underlying genes in these outlier regions and their putative role in reproductive isolation between species. Reciprocal transplant experiments of seedlings between parental environments can be used to characterize selection on outlier genes. High transferability of gene-based markers will enable comparative outlier screens in different oak species.

  17. 40 CFR 68.56 - Maintenance.

    Science.gov (United States)

    2010-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Program 2 Prevention Program § 68.56 Maintenance. (a) The owner or operator shall prepare and implement procedures to maintain the on-going mechanical integrity of the process...

  18. The use of condition monitoring information for maintenance planning and decision-making

    Energy Technology Data Exchange (ETDEWEB)

    Laakso, K.; Rosqvist, T. [VTT Industrial Systems (Finland); Paulsen, J.L. [Risoe National Lab., Roskilde (Denmark)

    2002-12-01

    A survey is presented outlining the use of condition monitoring information in three Nordic nuclear power plants. The questions of the survey relate to the role of condition monitoring in strategic, as well as operative, maintenance planning and decision-making. The survey indicates that condition monitoring is increasingly implemented at nuclear power plants, but very selectively and in a rather slow pace for predictive maintenance. A combined strategy of condition based maintenance and predetermined preventive maintenance is applied for important equipment such as main circulation pumps and steam turbines. A realistic aim is to reduce the number of costly or error prone maintenance and disassembling inspection activities by condition monitoring given that the approach enables a good diagnosis and prediction. Systematic follow-up and analysis of such condition monitoring information followed by a case-specific planning and decision making of timely and rightly directed maintenance actions can justify an extension of the intervals of a number of predetermined inspection, maintenance or periodic testing tasks. (au)

  19. An application of oscillation damped motion for suspended payloads to the advanced integrated maintenance system

    International Nuclear Information System (INIS)

    Noakes, M.W.; Petterson, B.J.; Werner, J.C.

    1990-01-01

    Transportation of objects using overhead cranes can induce pendulum motion of the object, which usually must be damped or allowed to decay before the next process can take place. Recent work at Sandia National Laboratories (SNL) has shown that oscillation damped transport and swing-free stops are possible by properly programming the acceleration of the transporting crane. This paper reviews the theory associated with oscillation-damped trajectories for simply suspended objects and describes a specific, full-scale implementation of the damped oscillation methods for the Oak Ridge National Laboratory (ORNL) Advanced Integrated Maintenance System (AIMS). Hardware and software requirements and constraints for proper operation are discussed. Finally, test results and lessons learned are presented. 5 refs., 4 figs

  20. Observing the effect of a policy: a maintenance case

    NARCIS (Netherlands)

    Rijsdijk, Chris; Tinga, Tiedo

    2016-01-01

    Purpose – The purpose of this paper is to show that maintenance performance is potentially better predictable from recording routines. Design/methodology/approach – An attempt is made to observe an effect of a policy. Maintenance cases seem exceptional because of the efficiently obtainable evidence

  1. Integrating geophysics and hydrology for reducing the uncertainty of groundwater model predictions and improved prediction performance

    DEFF Research Database (Denmark)

    Christensen, Nikolaj Kruse; Christensen, Steen; Ferre, Ty

    the integration of geophysical data in the construction of a groundwater model increases the prediction performance. We suggest that modelers should perform a hydrogeophysical “test-bench” analysis of the likely value of geophysics data for improving groundwater model prediction performance before actually...... and the resulting predictions can be compared with predictions from the ‘true’ model. By performing this analysis we expect to give the modeler insight into how the uncertainty of model-based prediction can be reduced.......A major purpose of groundwater modeling is to help decision-makers in efforts to manage the natural environment. Increasingly, it is recognized that both the predictions of interest and their associated uncertainties should be quantified to support robust decision making. In particular, decision...

  2. Applying theory of planned behavior to predict exercise maintenance in sarcopenic elderly

    Science.gov (United States)

    Ahmad, Mohamad Hasnan; Shahar, Suzana; Teng, Nur Islami Mohd Fahmi; Manaf, Zahara Abdul; Sakian, Noor Ibrahim Mohd; Omar, Baharudin

    2014-01-01

    This study aimed to determine the factors associated with exercise behavior based on the theory of planned behavior (TPB) among the sarcopenic elderly people in Cheras, Kuala Lumpur. A total of 65 subjects with mean ages of 67.5±5.2 (men) and 66.1±5.1 (women) years participated in this study. Subjects were divided into two groups: 1) exercise group (n=34; 25 men, nine women); and 2) the control group (n=31; 22 men, nine women). Structural equation modeling, based on TPB components, was applied to determine specific factors that most contribute to and predict actual behavior toward exercise. Based on the TPB’s model, attitude (β=0.60) and perceived behavioral control (β=0.24) were the major predictors of intention to exercise among men at the baseline. Among women, the subjective norm (β=0.82) was the major predictor of intention to perform the exercise at the baseline. After 12 weeks, attitude (men’s, β=0.68; women’s, β=0.24) and subjective norm (men’s, β=0.12; women’s, β=0.87) were the predictors of the intention to perform the exercise. “Feels healthier with exercise” was the specific factor to improve the intention to perform and to maintain exercise behavior in men (β=0.36) and women (β=0.49). “Not motivated to perform exercise” was the main barrier among men’s intention to exercise. The intention to perform the exercise was able to predict actual behavior regarding exercise at the baseline and at 12 weeks of an intervention program. As a conclusion, TPB is a useful model to determine and to predict maintenance of exercise in the sarcopenic elderly. PMID:25258524

  3. Excellence method in maintenance with application for cryogenic nuclear unit (EMAC)

    International Nuclear Information System (INIS)

    Anghel, Vasile

    2006-01-01

    Full text: Cryogenic Nuclear Plant (CNP) has as main objectives the development of a technology for the removal of tritium from heavy water used in nuclear plants of CANDU type and finding of a methodology for complete inspection of the equipment used in the presence of tritium at very low temperatures. These aims imply achieving two main stages. The first stage concerns the maintenance conception on a scientific basis, while the second stage concerns the implementation. The first stage implies the management of maintenance in constraints relating to quality, risk and cost. The second stage regards the aspect of design and technology of CNP maintenance. The solution adequate with this conception will lead to a solution viable for implementation. The operative maintenance will be based on RCM (Reliability Centered Maintenance), using NOLAN and HEAP 1978 methodologies. The integrated maintenance through research and implementation demonstrates the design, realization of equipment, the dynamic and and the static complex uses of EMAC in CNP. It is a method of conception and implementation that integrates maintenance for the life cycle in the considered cryogenics systems. The implementation is achieved by means of the software LabVIEW applied to the specific objectives of the Program for Operative Maintenance in Temporal Dynamic Regime (POMTDR). (author)

  4. Integrated Simulation for HVAC Performance Prediction: State-of-the-Art Illustration

    NARCIS (Netherlands)

    Hensen, J.L.M.; Clarke, J.A.

    2000-01-01

    This paper aims to outline the current state-of-the-art in integrated building simulation for performance prediction of heating, ventilating and air-conditioning (HVAC) systems. The ESP-r system is used as an example where integrated simulation is a core philosophy behind the development. The

  5. Integrated Logistics Support Analysis of the International Space Station Alpha, Background and Summary of Mathematical Modeling and Failure Density Distributions Pertaining to Maintenance Time Dependent Parameters

    Science.gov (United States)

    Sepehry-Fard, F.; Coulthard, Maurice H.

    1995-01-01

    The process of predicting the values of maintenance time dependent variable parameters such as mean time between failures (MTBF) over time must be one that will not in turn introduce uncontrolled deviation in the results of the ILS analysis such as life cycle costs, spares calculation, etc. A minor deviation in the values of the maintenance time dependent variable parameters such as MTBF over time will have a significant impact on the logistics resources demands, International Space Station availability and maintenance support costs. There are two types of parameters in the logistics and maintenance world: a. Fixed; b. Variable Fixed parameters, such as cost per man hour, are relatively easy to predict and forecast. These parameters normally follow a linear path and they do not change randomly. However, the variable parameters subject to the study in this report such as MTBF do not follow a linear path and they normally fall within the distribution curves which are discussed in this publication. The very challenging task then becomes the utilization of statistical techniques to accurately forecast the future non-linear time dependent variable arisings and events with a high confidence level. This, in turn, shall translate in tremendous cost savings and improved availability all around.

  6. Research and Development of a Network-Based Intelligent Maintenance Information System

    Institute of Scientific and Technical Information of China (English)

    ZANG Tie-gang; YANG Ming-zhong; GUO Shun-sheng

    2003-01-01

    A maintenance information system is an important part of equipment management. An intelli gent maintenance information system ( IMIS) is a synthesis of network technology, information technology and intelligent technology. The IMIS is used to finish flexible maintenance decision-making and fast maintenance planning, which helps enterprises to effectively reduce maintenance cost and increase working efficiency. Because the IMIS integrates advanced technologies, its performance is better than a traditional one.The difference between an IMIS and a traditional maintenance information system, and the functions, structure, important realizations, and application of an IMIS are discussed in this paper.

  7. THE OFFICIAL AUDIT: THE MAINTENANCE OF THE STRUCTURES AND EQUIPMENTS

    Directory of Open Access Journals (Sweden)

    Claudio Biglia

    2008-12-01

    Full Text Available The author distinguishes the ordinary maintenance in corrective, preventive and predictive maintenance and describes the importance of the verifications of the maintenance procedures of the structures and the equipmentes in the food industy. He individualizes criterions to follow for an aware detective check. This approach offers a greater guarantee of food security and a greater responsibility of OSA

  8. Probabilistic methods for maintenance program optimization

    International Nuclear Information System (INIS)

    Liming, J.K.; Smith, M.J.; Gekler, W.C.

    1989-01-01

    In today's regulatory and economic environments, it is more important than ever that managers, engineers, and plant staff join together in developing and implementing effective management plans for safety and economic risk. This need applied to both power generating stations and other process facilities. One of the most critical parts of these management plans is the development and continuous enhancement of a maintenance program that optimizes plant or facility safety and profitability. The ultimate objective is to maximize the potential for station or facility success, usually measured in terms of projected financial profitability, while meeting or exceeding meaningful and reasonable safety goals, usually measured in terms of projected damage or consequence frequencies. This paper describes the use of the latest concepts in developing and evaluating maintenance programs to achieve maintenance program optimization (MPO). These concepts are based on significant field experience gained through the integration and application of fundamentals developed for industry and Electric Power Research Institute (EPRI)-sponsored projects on preventive maintenance (PM) program development and reliability-centered maintenance (RCM)

  9. Improving Maintenance Data Collection Via Point-Of-Maintenance (POMX) Implementation

    Science.gov (United States)

    2006-03-01

    accurate documentation, (3) identifying and correcting the root causes for poor data integrity, and (4) educating the unit on the critical need for data ...the validity of the results. The data in this study were analyzed using the SAS JMP 6.0 statistical software package. The results for the tests...traditional keyboard data entry methods at a computer terminal. These terminals are typically located in the aircraft maintenance unit (AMU) facility , away

  10. Edaphic history over seedling characters predicts integration and plasticity of integration across geologically variable populations of Arabidopsis thaliana.

    Science.gov (United States)

    Cousins, Elsa A; Murren, Courtney J

    2017-12-01

    Studies on phenotypic plasticity and plasticity of integration have uncovered functionally linked modules of aboveground traits and seedlings of Arabidopsis thaliana , but we lack details about belowground variation in adult plants. Functional modules can be comprised of additional suites of traits that respond to environmental variation. We assessed whether shoot and root responses to nutrient environments in adult A. thaliana were predictable from seedling traits or population-specific geologic soil characteristics at the site of origin. We compared 17 natural accessions from across the native range of A. thaliana using 14-day-old seedlings grown on agar or sand and plants grown to maturity across nutrient treatments in sand. We measured aboveground size, reproduction, timing traits, root length, and root diameter. Edaphic characteristics were obtained from a global-scale dataset and related to field data. We detected significant among-population variation in root traits of seedlings and adults and in plasticity in aboveground and belowground traits of adult plants. Phenotypic integration of roots and shoots varied by population and environment. Relative integration was greater in roots than in shoots, and integration was predicted by edaphic soil history, particularly organic carbon content, whereas seedling traits did not predict later ontogenetic stages. Soil environment of origin has significant effects on phenotypic plasticity in response to nutrients, and on phenotypic integration of root modules and shoot modules. Root traits varied among populations in reproductively mature individuals, indicating potential for adaptive and integrated functional responses of root systems in annuals. © 2017 Botanical Society of America.

  11. Integrated Technical Information for the Air Logistics Center: Enhancing Maintenance Technician Task Performance

    National Research Council Canada - National Science Library

    Mitta, Deborah

    1998-01-01

    This technical paper documents the final results of an analysis of the task environment under which depot maintenance technicians perform their jobs--specifically, programmed depot maintenance (PDM) for F-15 aircraft...

  12. COMPUTING THERAPY FOR PRECISION MEDICINE: COLLABORATIVE FILTERING INTEGRATES AND PREDICTS MULTI-ENTITY INTERACTIONS.

    Science.gov (United States)

    Regenbogen, Sam; Wilkins, Angela D; Lichtarge, Olivier

    2016-01-01

    Biomedicine produces copious information it cannot fully exploit. Specifically, there is considerable need to integrate knowledge from disparate studies to discover connections across domains. Here, we used a Collaborative Filtering approach, inspired by online recommendation algorithms, in which non-negative matrix factorization (NMF) predicts interactions among chemicals, genes, and diseases only from pairwise information about their interactions. Our approach, applied to matrices derived from the Comparative Toxicogenomics Database, successfully recovered Chemical-Disease, Chemical-Gene, and Disease-Gene networks in 10-fold cross-validation experiments. Additionally, we could predict each of these interaction matrices from the other two. Integrating all three CTD interaction matrices with NMF led to good predictions of STRING, an independent, external network of protein-protein interactions. Finally, this approach could integrate the CTD and STRING interaction data to improve Chemical-Gene cross-validation performance significantly, and, in a time-stamped study, it predicted information added to CTD after a given date, using only data prior to that date. We conclude that collaborative filtering can integrate information across multiple types of biological entities, and that as a first step towards precision medicine it can compute drug repurposing hypotheses.

  13. Equipment reliability process improvement and preventive maintenance optimization

    International Nuclear Information System (INIS)

    Darragi, M.; Georges, A.; Vaillancourt, R.; Komljenovic, D.; Croteau, M.

    2004-01-01

    The Gentilly-2 Nuclear Power Plant wants to optimize its preventive maintenance program through an Integrated Equipment Reliability Process. All equipment reliability related activities should be reviewed and optimized in a systematic approach especially for aging plants such as G2. This new approach has to be founded on best practices methods with the purpose of the rationalization of the preventive maintenance program and the performance monitoring of on-site systems, structures and components (SSC). A rational preventive maintenance strategy is based on optimized task scopes and frequencies depending on their applicability, critical effects on system safety and plant availability as well as cost-effectiveness. Preventive maintenance strategy efficiency is systematically monitored through degradation indicators. (author)

  14. Maintenance of radiation safety information system

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ho Sun [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of); Park, Moon Il; Chung, Chong Kyu; Lim, Bock Soo; Kim, Hyung Uk; Chang, Kwang Il; Nam, Kwan Hyun; Cho, Hye Ryan [AD center incubation LAB, Taejon (Korea, Republic of)

    2001-12-15

    The objectives of radiation safety information system maintenance are to maintain the requirement of users, change of job process and upgrade of the system performance stably and effectively while system maintenance. We conduct the code of conduct recommended by IAEA, management of radioisotope inventory database systematically using analysis for the state of inventory database integrated in this system. This system and database will be support the regulatory guidance, rule making and information to the MOST, KINS, other regulatory related organization and general public optimizationally.

  15. Clustering condition-based maintenance for a multi-unit system with aperiodic inspections

    NARCIS (Netherlands)

    Olde Keizer, Minou C.A.; Teunter, Ruud H.; Podofillini, Luca; Sudret, Bruno; Stojadinović, Božidar; Zio, Enrico; Kröger, Wolfgang

    2015-01-01

    Condition-Based Maintenance (CBM) is a predictive maintenance strategy, which bases the maintenance scheduling on condition measurements of the components. In this paper, we continue work on the CBM optimization approach proposed by Castanier, B., A. Grall & C. Bérenguer (2005). A condition-based

  16. Accuracy of Consecutive Fecal Calprotectin Measurements to Predict Relapse in Inflammatory Bowel Disease Patients Under Maintenance With Anti-TNF Therapy: A Prospective Longitudinal Cohort Study.

    Science.gov (United States)

    Ferreiro-Iglesias, Rocio; Barreiro-de Acosta, Manuel; Lorenzo-Gonzalez, Aurelio; Dominguez-Muñoz, Juan E

    2018-03-01

    Predicting relapse in inflammatory bowel disease (IBD) patients could allow early changes in therapy. We aimed at evaluating the accuracy of consecutive fecal calprotectin (FC) measurements to predict flares in IBD patients under maintenance treatment with anti-tumor necrosis factor (TNF) drugs. A prospective longitudinal cohort study with 16-month follow-up period was designed. IBD patients in clinical remission for at least 6 months under anti-TNF therapy were included. FC was quantified at 4-month intervals for 1 year, and patients were clinically evaluated for relapse at 2-month intervals. Diagnostic accuracy of FC for predicting relapse was evaluated by receiver-operating characteristic curve analysis. In total, 95 of 106 included patients finalized the study and were analyzed (median age 44 y, 50.5% female, 75% with Crohn's disease). A total of 30 patients (31.6%) had a relapse over follow-up. FC concentration was significantly higher in patients who relapsed (477 μg/g) than in patients who maintained in remission (65 μg/g) (Ppredict remission was 130 μg/g (negative predictive value of 100%), and 300 μg/g to predict relapse (positive predictive value of 78.3%). FC is a good predictor of clinical relapse and a particularly good predictor of remission over the following 4 months in patients with IBD on maintenance therapy with anti-TNF drugs. FC levels 300 μg/g allow predicting relapse with a high probability at any time over the following 4 months.

  17. Adalimumab Dose Tapering in Psoriasis: Predictive Factors for Maintenance of Complete Clearance.

    Science.gov (United States)

    Hansel, Katharina; Bianchi, Leonardo; Lanza, Francesco; Bini, Vittorio; Stingeni, Luca

    2017-03-10

    Psoriasis can be managed successfully with long-term biologics. Real-life clinical practice may require dose tapering as a therapeutic option to reduce the risk of drug-exposure and to increase cost-effectiveness. The responsiveness to extended intervals between adalimumab doses and the possible predictive factors of maintenance of complete clearance were studied in a retrospective 7-year single-centre analysis. Thirty patients who achieved complete clearance with adalimumab underwent dose tapering, progressively extending between-dose intervals (to 21-28 days). Sixty percent of subjects (group A) maintained complete clearance, whereas 40.0% (group B) relapsed and were switched back to the standard dosage to re-achieve complete clearance. Body mass index (BMI) and time to achieve Psoriasis Area Severity Index (PASI-100) with adalimumab standard treatment before dose tapering were significantly lower in group A than in group B (multi-variate Cox regression: p < 0.05, Kaplan-Meier analysis: p < 0.001, respectively). This study suggests that patients with lower BMI and shorter time to achieve PASI-100 with adalimumab standard dose were significantly more likely to be candidates for dose tapering.

  18. FY 2000 report on the results of the regional consortium R and D project - Regional consortium R and D. Third year report. R and D of the transversal maintenance technology; 2000 nendo chiiki consortium kenkyu kaihatsu jigyo - chiiki consortium kenkyu kaihatsu. Odanteki maintenance gijutsu no kenkyu kaihatsu (dai 3 nendo) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    For the purpose of eliminating bad effects of the maintenance/management of equipment/facilities of plants which are made separately and of heightening efficiency of work and improving technology, persons in charge of maintenance/management, persons requesting maintenance/management and official research institutes proceeded as one with the construction of a system doing maintenance/management work. Concretely, three parties cooperated in integration and enhancement of element technologies such as inspection/diagnosis and arrangement/repair and developed the maintenance/management system (maintenance center) which does not specify objects. Based on this system, development was made of the network connecting between the center and facilities, diagnosis car, and multi-functional repair car. Studies were made on the following three. As to the system development, conducted were the development of a deterioration mode prediction system, basic structuring of a remote maintenance network, and making of fatigue/corrosion/abrasion database. Concerning the tool development, technology to foresee damages on the static portion such as piping, etc. were developed. In the study of field application, conducted were analysis of maintenance flow, development of retrieval system of equipment parts/personnel/operation procedures and multi-functional repair car, etc. (NEDO)

  19. Development of advanced human-machine system for plant operation and maintenance

    International Nuclear Information System (INIS)

    Wu, Wei; Ohi, Tadashi; Yoshikawa, Hidekazu; Sawaragi, Tetsuo; Kitamura, Masaharu; Furuta, Kazuo; Gofuku, Akio; Ito, Koji

    2004-01-01

    With the worldwide deregulation of the power industry, and the aging of the nuclear power plants (NPPs), concerns are growing over the reliability and safety of the NPPs, because the regulation of man power may lower the current high level of reliability and safety. In this paper, a concept of overall integrated plant management mechanism is proposed, in order to meet the requirements of cutting costs of NPPs and the requirements of maintaining or increasing safety and reliability. The concept is called as satellite operation maintenance center (SOMC). SOMC integrates the operation and maintenance activities of several NPP units by utilizing advanced information technologies to support cooperation activities between workers allocated at SOMC and the field workers. As for the operation activities, a framework called as Advanced Operation System (AOS) is proposed in this paper. AOS consists of three support sub-systems: dynamic operation permission system(DyOPS), supervisor information presentation system using interface agent, and crew performance evaluation system. As for the maintenance activities, a framework called as Ubiquitous-Computing-based Maintenance support System (UCMS) is proposed next. Two case studies are described, in order to show the way of how UCMS support field workers to do maintenance tasks efficiently, safely, and infallibly as well. Finally, a prospect of SOMC is shown in order to explain the way of how the technology elements developed in this project could be integrated as a whole one system to support maintenance activities of NPPs in the future. (author)

  20. Maintenance cost models in deregulated power systems under opportunity costs

    International Nuclear Information System (INIS)

    Al-Arfaj, K.; Dahal, K.; Azaiez, M.N.

    2007-01-01

    In a centralized power system, the operator is responsible for scheduling maintenance. There are different types of maintenance, including corrective maintenance; predictive maintenance; preventive maintenance; and reliability-centred maintenance. The main cause of power failures is poor maintenance. As such, maintenance costs play a significant role in deregulated power systems. They include direct costs associated with material and labor costs as well as indirect costs associated with spare parts inventory, shipment, test equipment, indirect labor, opportunity costs and cost of failure. In maintenance scheduling and planning, the cost function is the only component of the objective function. This paper presented the results of a study in which different components of maintenance costs were modeled. The maintenance models were formulated as an optimization problem with single and multiple objectives and a set of constraints. The maintenance costs models could be used to schedule the maintenance activities of power generators more accurately and to identify the best maintenance strategies over a period of time as they consider failure and opportunity costs in a deregulated environment. 32 refs., 4 tabs., 4 figs

  1. Balancing preventive and corrective maintenance in Cernavoda Unit 1 NPP

    International Nuclear Information System (INIS)

    Riedel, M.; Marinescu, S.

    2000-01-01

    The paper presents a short reminder of Romania's Cernavoda NPP entering commercial operation and a brief description of the CANDU-6 project on which Unit 1 is based. The short term objectives of the maintenance management, the status of the existing maintenance programmes as well as future predictable maintenance programmes are outlined together with the Government plan to complete the balance of NPP. (author)

  2. An application of oscillation-damped motion for suspended payloads to the advanced integrated maintenance system in fuel cycle facilities

    International Nuclear Information System (INIS)

    Noakes, M.W.; Petterson, B.J.; Werner, J.C.

    1990-01-01

    The transportation of objects using overhead cranes can induce pendular motion of the object, which usually must be damped or allowed to decay before the next process can take place. Recent work at Sandia National Laboratories has shown that oscillation-damped transport and swing-free stops are possible by properly programming the acceleration of the transporting crane. Initial studies have been completed using a CIMCORP XR6100 gantry robot. The Advanced Integrated Maintenance System (AIMS) is an engineering and operations test bed developed for remote maintenance and handling studies within the Consolidated Fuel Reprocessing Program (CFRP) at Oak Ridge National Laboratory. The goal of CFRP has been to advanced the technology of in-cell systems planned for future nuclear fuel cycle facilities. The AIMS provides the capabilities to examine the needs and constraints necessary for hot-cell remote maintenance and includes a force-reflecting master/slave teleoperator and overhead transporter system. The associated control system provides a flexible programming environment conducive to controls experimentation. This paper reviews the theory associated with oscillation-damped trajectories for simply suspended objects and describes a specific implementation of the oscillation damping methods for the AIMS transporter. Hardware and software requirements and constraints for proper operation are discussed

  3. Architecture and Key Techniques of Augmented Reality Maintenance Guiding System for Civil Aircrafts

    Science.gov (United States)

    hong, Zhou; Wenhua, Lu

    2017-01-01

    Augmented reality technology is introduced into the maintenance related field for strengthened information in real-world scenarios through integration of virtual assistant maintenance information with real-world scenarios. This can lower the difficulty of maintenance, reduce maintenance errors, and improve the maintenance efficiency and quality of civil aviation crews. Architecture of augmented reality virtual maintenance guiding system is proposed on the basis of introducing the definition of augmented reality and analyzing the characteristics of augmented reality virtual maintenance. Key techniques involved, such as standardization and organization of maintenance data, 3D registration, modeling of maintenance guidance information and virtual maintenance man-machine interaction, are elaborated emphatically, and solutions are given.

  4. Integrated Detection and Prediction of Influenza Activity for Real-Time Surveillance: Algorithm Design.

    Science.gov (United States)

    Spreco, Armin; Eriksson, Olle; Dahlström, Örjan; Cowling, Benjamin John; Timpka, Toomas

    2017-06-15

    Influenza is a viral respiratory disease capable of causing epidemics that represent a threat to communities worldwide. The rapidly growing availability of electronic "big data" from diagnostic and prediagnostic sources in health care and public health settings permits advance of a new generation of methods for local detection and prediction of winter influenza seasons and influenza pandemics. The aim of this study was to present a method for integrated detection and prediction of influenza virus activity in local settings using electronically available surveillance data and to evaluate its performance by retrospective application on authentic data from a Swedish county. An integrated detection and prediction method was formally defined based on a design rationale for influenza detection and prediction methods adapted for local surveillance. The novel method was retrospectively applied on data from the winter influenza season 2008-09 in a Swedish county (population 445,000). Outcome data represented individuals who met a clinical case definition for influenza (based on International Classification of Diseases version 10 [ICD-10] codes) from an electronic health data repository. Information from calls to a telenursing service in the county was used as syndromic data source. The novel integrated detection and prediction method is based on nonmechanistic statistical models and is designed for integration in local health information systems. The method is divided into separate modules for detection and prediction of local influenza virus activity. The function of the detection module is to alert for an upcoming period of increased load of influenza cases on local health care (using influenza-diagnosis data), whereas the function of the prediction module is to predict the timing of the activity peak (using syndromic data) and its intensity (using influenza-diagnosis data). For detection modeling, exponential regression was used based on the assumption that the beginning

  5. Augmented reality application utility for aviation maintenance work instruction

    Science.gov (United States)

    Pourcho, John Bryan

    Current aviation maintenance work instructions do not display information effectively enough to prevent costly errors and safety concerns. Aircraft are complex assemblies of highly interrelated components that confound troubleshooting and can make the maintenance procedure difficult (Drury & Gramopadhye, 2001). The sophisticated nature of aircraft maintenance necessitates a revolutionized training intervention for aviation maintenance technicians (United States General Accounting Office, 2003). Quite simply, the paper based job task cards fall short of offering rapid access to technical data and the system or component visualization necessary for working on complex integrated aircraft systems. Possible solutions to this problem include upgraded standards for paper based task cards and the use of integrated 3D product definition used on various mobile platforms (Ropp, Thomas, Lee, Broyles, Lewin, Andreychek, & Nicol, 2013). Previous studies have shown that incorporation of 3D graphics in work instructions allow the user to more efficiently and accurately interpret maintenance information (Jackson & Batstone, 2008). For aircraft maintenance workers, the use of mobile 3D model-based task cards could make current paper task card standards obsolete with their ability to deliver relevant, synchronized information to and from the hangar. Unlike previous versions of 3D model-based definition task cards and paper task cards, which are currently used in the maintenance industry, 3D model based definition task cards have the potential to be more mobile and accessible. Utilizing augmented reality applications on mobile devices to seamlessly deliver 3D product definition on mobile devices could increase the efficiency, accuracy, and reduce the mental workload for technicians when performing maintenance tasks (Macchiarella, 2004). This proposal will serve as a literary review of the aviation maintenance industry, the spatial ability of maintenance technicians, and benefits of

  6. Scale Expansion of Community Investigations and Integration of the Effects of Abiotic and Biotic Processes on Maintenance of Species Diversity

    Directory of Open Access Journals (Sweden)

    Zhenhong Wang

    2011-01-01

    Full Text Available Information on the maintenance of diversity patterns from regional to local scales is dispersed among academic fields due to the local focus of community ecology. To better understand these patterns, the study of ecological communities needs to be expanded to larger scales and the various processes affecting them need to be integrated using a suitable quantitative method. We determined a range of communities on a flora-subregional scale in Yunnan province, China (383210.02 km2. A series of species pools were delimited from the regional to plot scales. Plant diversity was evaluated and abiotic and biotic processes identified at each pool level. The species pool effect was calculated using an innovative model, and the contribution of these processes to the maintenance of plant species diversity was determined and integrated: climate had the greatest effect at the flora-subregional scale, with historical and evolutionary processes contributing ∼11%; climate and human disturbance had the greatest effect at the local site pool scale; competition exclusion and stress limitation explained strong filtering at the successional stage pool scale; biotic processes contributed more on the local community scale than on the regional scale. Scale expansion combined with the filtering model approach solves the local problem in community ecology.

  7. Preventive Maintenance Interval Prediction: a Spare Parts Inventory Cost and Lost Earning Based Model

    Directory of Open Access Journals (Sweden)

    O. A. Adebimpe

    2015-06-01

    Full Text Available In this paper, some preventive maintenance parameters in manufacturing firms were identified and used to develop cost based functions in terms of machine preventive maintenance. The proposed cost based model considers system’s reliability, cost of keeping spare parts inventory and lost earnings in deriving optimal maintenance interval. A case of a manufacturing firm in Nigeria was observed and the data was used to evaluate the model.

  8. Elements of a total MOV maintenance program

    International Nuclear Information System (INIS)

    Lavallee, W.L.

    1989-01-01

    Establishing a good preventive and predictive maintenance program for motor-operated valves (MOVs) is an especially challenging task for nuclear power plants. Because of the sheer number of MOVs involved, all with somewhat different characteristics and requirements, and the extremely critical functions that some of the MOVs perform, the maintenance program quickly becomes a major exercise in coordination. This paper outlines a three-phase approach to achieving a comprehensive MOV maintenance program. It is based on experience in assisting nuclear plants with their MOV programs and encountering many of the pitfalls that can hamper these programs. The three phases include up-front engineering preparation, field diagnostic testing, and maintenance follow-up and trending. Each of these phases is discussed, and a flowchart describing the individual elements of each phase is provided

  9. Using systematic aging assessments to improve effectiveness of plant maintenance programs

    International Nuclear Information System (INIS)

    Watson, P.; Yang, J.X.; Dam, R.F.; Nickerson, J.H.

    2003-01-01

    Nuclear plant equipment aging assessment studies provided by AECL include life assessments, condition assessments or systematic assessments of maintenance. AECL has developed several tools to apply the results of aging assessment studies to improve the effectiveness of actual plant maintenance programs. The Systematic Assessment of Maintenance and the SYSTMS tool generate maintenance tasks for a system. The System Maintenance Datastore tool assesses the maintenance resources on a system basis, and can thus quantify the savings realized by optimizing the maintenance program. Long term trends in condition-based maintenance due to component aging can be predicted, and resource savings due to optimum timing of component replacement or general plant refurbishment can be quantified. The System based Adaptive Maintenance Process ensures the maintenance program is continually updated to reflect the latest plant equipment condition and maintenance strategy information. (author)

  10. Prediction of rotor blade-vortex interaction using Volterra integrals

    Energy Technology Data Exchange (ETDEWEB)

    Wong, A.; Nitzsche, F. [Carleton Univ., Dept. of Mechanical and Aerospace Engineering, Ottawa, Ontario (Canada)]. E-mail: Fred_Nitzsche@carleton.ca; Khalid, M. [National Research Council Canada, Inst. for Aerospace Research, Ottawa, Ontario (Canada)

    2004-07-01

    The theory of Volterra integral equations for nonlinear system is applied to the prediction of the nonlinear aerodynamic response of an NACA 0012 airfoil experiencing blade-vortex interaction. The phenomenon is first modeled in two-dimensions using an Euler/Navier-Stoke code, and the resulting unsteady aerodynamic flow field sequences are appropriately combined to form a training dataset. The Volterra kernels are identified in the time-domain characteristics of the selected data, which is in turn used to predict the nonlinear aerodynamic response of the airfoil. The Volterra kernel based data is then compared against a standard airfoil response. The predicted lift time histories of the airfoil are shown to be in good agreement with the aerodynamic data. (author)

  11. Prediction of rotor blade-vortex interaction using Volterra integrals

    International Nuclear Information System (INIS)

    Wong, A.; Nitzsche, F.; Khalid, M.

    2004-01-01

    The theory of Volterra integral equations for nonlinear system is applied to the prediction of the nonlinear aerodynamic response of an NACA 0012 airfoil experiencing blade-vortex interaction. The phenomenon is first modeled in two-dimensions using an Euler/Navier-Stoke code, and the resulting unsteady aerodynamic flow field sequences are appropriately combined to form a training dataset. The Volterra kernels are identified in the time-domain characteristics of the selected data, which is in turn used to predict the nonlinear aerodynamic response of the airfoil. The Volterra kernel based data is then compared against a standard airfoil response. The predicted lift time histories of the airfoil are shown to be in good agreement with the aerodynamic data. (author)

  12. Self-Esteem Maintenance in Family Dynamics.

    Science.gov (United States)

    Tesser, Abraham

    1980-01-01

    In this study, a self-esteem maintenance model is introduced and is used to test predictions about sibling identification, sibling friction, and the closeness of father-son relationships as they relate to sibling performance. (Author/SS)

  13. Maintenance Decision Making based on different types of data fusion

    OpenAIRE

    Galar, D.; Gustafson, A.; Tormos Martínez, Bernardo Vicente; Berges, Luis

    2012-01-01

    [EN] Over the last decade, system integration is applied more as it allows organizations to streamline business processes. A recent development in the asset engineering management is to leverage the investment already made in process control systems. This allows the operations, maintenance, and process control teams to monitor and determine new alarm level based on the physical condition data of the critical machines. Condition-based maintenance (CBM) is a maintenance philosophy base...

  14. Operation and maintenance support expert systems for BWR nuclear power plants

    International Nuclear Information System (INIS)

    Miyazawa, Tatsuo; Hayakawa, Hiroyasu; Fukutomi, Shigeki

    1990-01-01

    Toshiba has been developing expert systems for operation and maintenance support in BWRs. These expert systems are designed to be integrated with conventional plant monitoring systems, and maintenance management systems to provide both comprehensive and powerful support capabilities. Some of these expert systems are already being used on a trial basis both within Toshiba and in electric power utility companies. This paper describes expert systems for the support of plant and equipment monitoring, maintenance scheduling, and maintenance work procedure planning. (author)

  15. Payload maintenance cost model for the space telescope

    Science.gov (United States)

    White, W. L.

    1980-01-01

    An optimum maintenance cost model for the space telescope for a fifteen year mission cycle was developed. Various documents and subsequent updates of failure rates and configurations were made. The reliability of the space telescope for one year, two and one half years, and five years were determined using the failure rates and configurations. The failure rates and configurations were also used in the maintenance simulation computer model which simulate the failure patterns for the fifteen year mission life of the space telescope. Cost algorithms associated with the maintenance options as indicated by the failure patterns were developed and integrated into the model.

  16. Integrated prediction based on GIS for sandstone-type uranium deposits in the northwest of Ordos Basin

    International Nuclear Information System (INIS)

    Han Shaoyang; Ke Dan; Hu Shuiqing; Guo Qingyin; Hou Huiqun

    2005-01-01

    The integrated prediction model of sandstone-type uranium deposits and its integrated evaluation methods as well as flow of the work based on GIS are studied. A software for extracting metallogenic information is also developed. A multi-source exploring information database is established in the northwest of Ordos Basin, and an integrated digital mineral deposit prospecting model of sandstone-type uranium deposits is designed based on GIS. The authors have completed metallogenic information extraction and integrated evaluation of sandstone-type uranium deposits based on GIS in the study area. Research results prove that the integrated prediction of sandstone-type uranium deposits based on GIS may further delineate prospective target areas rapidly and improve the predictive precision. (authors)

  17. Predicting co-complexed protein pairs using genomic and proteomic data integration

    Directory of Open Access Journals (Sweden)

    King Oliver D

    2004-04-01

    Full Text Available Abstract Background Identifying all protein-protein interactions in an organism is a major objective of proteomics. A related goal is to know which protein pairs are present in the same protein complex. High-throughput methods such as yeast two-hybrid (Y2H and affinity purification coupled with mass spectrometry (APMS have been used to detect interacting proteins on a genomic scale. However, both Y2H and APMS methods have substantial false-positive rates. Aside from high-throughput interaction screens, other gene- or protein-pair characteristics may also be informative of physical interaction. Therefore it is desirable to integrate multiple datasets and utilize their different predictive value for more accurate prediction of co-complexed relationship. Results Using a supervised machine learning approach – probabilistic decision tree, we integrated high-throughput protein interaction datasets and other gene- and protein-pair characteristics to predict co-complexed pairs (CCP of proteins. Our predictions proved more sensitive and specific than predictions based on Y2H or APMS methods alone or in combination. Among the top predictions not annotated as CCPs in our reference set (obtained from the MIPS complex catalogue, a significant fraction was found to physically interact according to a separate database (YPD, Yeast Proteome Database, and the remaining predictions may potentially represent unknown CCPs. Conclusions We demonstrated that the probabilistic decision tree approach can be successfully used to predict co-complexed protein (CCP pairs from other characteristics. Our top-scoring CCP predictions provide testable hypotheses for experimental validation.

  18. Integrative approaches to the prediction of protein functions based on the feature selection

    Directory of Open Access Journals (Sweden)

    Lee Hyunju

    2009-12-01

    Full Text Available Abstract Background Protein function prediction has been one of the most important issues in functional genomics. With the current availability of various genomic data sets, many researchers have attempted to develop integration models that combine all available genomic data for protein function prediction. These efforts have resulted in the improvement of prediction quality and the extension of prediction coverage. However, it has also been observed that integrating more data sources does not always increase the prediction quality. Therefore, selecting data sources that highly contribute to the protein function prediction has become an important issue. Results We present systematic feature selection methods that assess the contribution of genome-wide data sets to predict protein functions and then investigate the relationship between genomic data sources and protein functions. In this study, we use ten different genomic data sources in Mus musculus, including: protein-domains, protein-protein interactions, gene expressions, phenotype ontology, phylogenetic profiles and disease data sources to predict protein functions that are labelled with Gene Ontology (GO terms. We then apply two approaches to feature selection: exhaustive search feature selection using a kernel based logistic regression (KLR, and a kernel based L1-norm regularized logistic regression (KL1LR. In the first approach, we exhaustively measure the contribution of each data set for each function based on its prediction quality. In the second approach, we use the estimated coefficients of features as measures of contribution of data sources. Our results show that the proposed methods improve the prediction quality compared to the full integration of all data sources and other filter-based feature selection methods. We also show that contributing data sources can differ depending on the protein function. Furthermore, we observe that highly contributing data sets can be similar among

  19. Anticipated affective consequences of physical activity adoption and maintenance.

    Science.gov (United States)

    Dunton, Genevieve Fridlund; Vaughan, Elaine

    2008-11-01

    The expected emotional consequences of future actions are thought to play an important role in health behavior change. This research examined whether anticipated affective consequences of success and failure vary across stages of physical activity change and differentially predict physical activity adoption as compared to maintenance. Using a prospective design over a 3-month period, a community sample of 329 healthy, middle-aged adults were assessed at 2 time points. Anticipated positive and negative emotions, stage of behavior change (precontemplation [PC], contemplation [C], preparation [P], action [A], maintenance [M]), and level of physical activity. At baseline, anticipated positive emotions were greater in C versus PC, whereas anticipated negative emotions were greater in M versus A and in M versus P. Higher anticipated positive but not negative emotions predicted physical activity adoption and maintenance after 3 months. Although the expected affective consequences of future success and failure differentiated among individuals in the early and later stages of physical activity change, respectively; only the anticipated affective consequences of success predicted future behavior.

  20. Evaluating and Predicting Patient Safety for Medical Devices With Integral Information Technology

    Science.gov (United States)

    2005-01-01

    323 Evaluating and Predicting Patient Safety for Medical Devices with Integral Information Technology Jiajie Zhang, Vimla L. Patel, Todd R...errors are due to inappropriate designs for user interactions, rather than mechanical failures. Evaluating and predicting patient safety in medical ...the users on the identified trouble spots in the devices. We developed two methods for evaluating and predicting patient safety in medical devices

  1. Subtask 2.4 - Integration and Synthesis in Climate Change Predictive Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Jaroslav Solc

    2009-06-01

    The Energy & Environmental Research Center (EERC) completed a brief evaluation of the existing status of predictive modeling to assess options for integration of our previous paleohydrologic reconstructions and their synthesis with current global climate scenarios. Results of our research indicate that short-term data series available from modern instrumental records are not sufficient to reconstruct past hydrologic events or predict future ones. On the contrary, reconstruction of paleoclimate phenomena provided credible information on past climate cycles and confirmed their integration in the context of regional climate history is possible. Similarly to ice cores and other paleo proxies, acquired data represent an objective, credible tool for model calibration and validation of currently observed trends. It remains a subject of future research whether further refinement of our results and synthesis with regional and global climate observations could contribute to improvement and credibility of climate predictions on a regional and global scale.

  2. Improving Allergen Prediction in Main Crops Using a Weighted Integrative Method.

    Science.gov (United States)

    Li, Jing; Wang, Jing; Li, Jing

    2017-12-01

    As a public health problem, food allergy is frequently caused by food allergy proteins, which trigger a type-I hypersensitivity reaction in the immune system of atopic individuals. The food allergens in our daily lives are mainly from crops including rice, wheat, soybean and maize. However, allergens in these main crops are far from fully uncovered. Although some bioinformatics tools or methods predicting the potential allergenicity of proteins have been proposed, each method has their limitation. In this paper, we built a novel algorithm PREAL W , which integrated PREAL, FAO/WHO criteria and motif-based method by a weighted average score, to benefit the advantages of different methods. Our results illustrated PREAL W has better performance significantly in the crops' allergen prediction. This integrative allergen prediction algorithm could be useful for critical food safety matters. The PREAL W could be accessed at http://lilab.life.sjtu.edu.cn:8080/prealw .

  3. Cross-frequency synchronization connects networks of fast and slow oscillations during visual working memory maintenance.

    Science.gov (United States)

    Siebenhühner, Felix; Wang, Sheng H; Palva, J Matias; Palva, Satu

    2016-09-26

    Neuronal activity in sensory and fronto-parietal (FP) areas underlies the representation and attentional control, respectively, of sensory information maintained in visual working memory (VWM). Within these regions, beta/gamma phase-synchronization supports the integration of sensory functions, while synchronization in theta/alpha bands supports the regulation of attentional functions. A key challenge is to understand which mechanisms integrate neuronal processing across these distinct frequencies and thereby the sensory and attentional functions. We investigated whether such integration could be achieved by cross-frequency phase synchrony (CFS). Using concurrent magneto- and electroencephalography, we found that CFS was load-dependently enhanced between theta and alpha-gamma and between alpha and beta-gamma oscillations during VWM maintenance among visual, FP, and dorsal attention (DA) systems. CFS also connected the hubs of within-frequency-synchronized networks and its strength predicted individual VWM capacity. We propose that CFS integrates processing among synchronized neuronal networks from theta to gamma frequencies to link sensory and attentional functions.

  4. Predictive regulatory models in Drosophila melanogaster by integrative inference of transcriptional networks

    Science.gov (United States)

    Marbach, Daniel; Roy, Sushmita; Ay, Ferhat; Meyer, Patrick E.; Candeias, Rogerio; Kahveci, Tamer; Bristow, Christopher A.; Kellis, Manolis

    2012-01-01

    Gaining insights on gene regulation from large-scale functional data sets is a grand challenge in systems biology. In this article, we develop and apply methods for transcriptional regulatory network inference from diverse functional genomics data sets and demonstrate their value for gene function and gene expression prediction. We formulate the network inference problem in a machine-learning framework and use both supervised and unsupervised methods to predict regulatory edges by integrating transcription factor (TF) binding, evolutionarily conserved sequence motifs, gene expression, and chromatin modification data sets as input features. Applying these methods to Drosophila melanogaster, we predict ∼300,000 regulatory edges in a network of ∼600 TFs and 12,000 target genes. We validate our predictions using known regulatory interactions, gene functional annotations, tissue-specific expression, protein–protein interactions, and three-dimensional maps of chromosome conformation. We use the inferred network to identify putative functions for hundreds of previously uncharacterized genes, including many in nervous system development, which are independently confirmed based on their tissue-specific expression patterns. Last, we use the regulatory network to predict target gene expression levels as a function of TF expression, and find significantly higher predictive power for integrative networks than for motif or ChIP-based networks. Our work reveals the complementarity between physical evidence of regulatory interactions (TF binding, motif conservation) and functional evidence (coordinated expression or chromatin patterns) and demonstrates the power of data integration for network inference and studies of gene regulation at the systems level. PMID:22456606

  5. Predictive regulatory models in Drosophila melanogaster by integrative inference of transcriptional networks.

    Science.gov (United States)

    Marbach, Daniel; Roy, Sushmita; Ay, Ferhat; Meyer, Patrick E; Candeias, Rogerio; Kahveci, Tamer; Bristow, Christopher A; Kellis, Manolis

    2012-07-01

    Gaining insights on gene regulation from large-scale functional data sets is a grand challenge in systems biology. In this article, we develop and apply methods for transcriptional regulatory network inference from diverse functional genomics data sets and demonstrate their value for gene function and gene expression prediction. We formulate the network inference problem in a machine-learning framework and use both supervised and unsupervised methods to predict regulatory edges by integrating transcription factor (TF) binding, evolutionarily conserved sequence motifs, gene expression, and chromatin modification data sets as input features. Applying these methods to Drosophila melanogaster, we predict ∼300,000 regulatory edges in a network of ∼600 TFs and 12,000 target genes. We validate our predictions using known regulatory interactions, gene functional annotations, tissue-specific expression, protein-protein interactions, and three-dimensional maps of chromosome conformation. We use the inferred network to identify putative functions for hundreds of previously uncharacterized genes, including many in nervous system development, which are independently confirmed based on their tissue-specific expression patterns. Last, we use the regulatory network to predict target gene expression levels as a function of TF expression, and find significantly higher predictive power for integrative networks than for motif or ChIP-based networks. Our work reveals the complementarity between physical evidence of regulatory interactions (TF binding, motif conservation) and functional evidence (coordinated expression or chromatin patterns) and demonstrates the power of data integration for network inference and studies of gene regulation at the systems level.

  6. Preventive maintenance and reliability-centered maintenance

    International Nuclear Information System (INIS)

    Anderson, J.G.

    1989-01-01

    In the recent past, the primary function of the preventive maintenance program at a nuclear power plant was to maintain the operability and reliability of the plant. Reducing overall maintenance costs by performing effective preventive maintenance, instead of more costly and disruptive corrective maintenance, instead of more costly and disruptive corrective maintenance, was a secondary consideration. In today's operating environment, the preventive maintenance program must meet the test of cost-effectiveness as well as many new standards for performance that are being required by rate regulators. The preventive maintenance program must be able to withstand the challenge of independent audit to a new standard of technical adequacy and compliance with recommendations from component vendors. In this new environment, the standard that is being applied at the San Onofre nuclear generating station (SONGS) is that the preventive maintenance program must meet the test of cost-effectiveness, improve equipment performance, support increased plant availability, and (a) literally implement the recommendations of the vendor, (b) provide other compensation for the vendor recommendation, or (c) provide technical justification for the deviation. The subject of this paper is the way that reliability-centered maintenance (RCM) is helping SONGS meet these challenges

  7. METHODOLOGY OF DETERMINATION OF QUALITY INDEX OF MAINTENANCE SERVICE SYSTEM OF POWER EQUIPMENT OF TRACTION SUBSTATIONS

    Directory of Open Access Journals (Sweden)

    O.O. Matusevych

    2016-03-01

    information was further developed. The author offers a number of options at first time. There are version of the document formalized quality evaluation of power equipment of traction substations by experts; expression to define the integral Quality systems maintenance and electrical power P TS, which is absent in the standard system maintenance and P; matrix of quality system with regard to steps (methods and ways of increasing service quality electrical power control systems. This method makes it possible to conduct an expert assessment of the maintenance system and to predict and select the option rational system of quality improvement and maintenance of power equipment of traction substations considering not only technical but also organizational, legal, financial and economic measures. Practical value. Improvement on electrified railways of Ukraine quality management system maintenance and P TS will improve the efficiency and quality of maintenance of power equipment and provide TA prevent or reduce the severity of possible equipment failures. Based on the relationships matrix components as systems maintenance and electrical power P TP were formed expressions calculating quality indices of integrated systems with directions and stages for specific equipment and systems in general. It was determined that an increase in the quality and maintenance of electrical PR, the rate of change of the measured value at step k during operation is reduced while the standard deviation parameter is also reduced, and the probability of electrical TA increases.

  8. SAP R/3 plant maintenance making it work for your business

    CERN Document Server

    Stengl, Britta

    2001-01-01

    SAP R/3 Plant Maintenance offers a clear introduction to this small but sophisticated component and provides a highly practical guide to implementing PM. Beginning with a examination of the key business processes underlying PM functionality, the book goes on to cover all the crucial aspects of maintenance planning and execution in R/3. Particular attention is given to integrating plant maintenance with a company's natural process flow.

  9. The contribution of lean thinking to the maintenance of manufacturing systems

    OpenAIRE

    Davies, Christopher

    2003-01-01

    Despite many significant contributions and advances of lean thinking recorded in articles, books, and industrial case studies, its impact upon the maintenance function has not been fully investigated. From a maintenance perspective, excluding TPM, little or no insight into the use of lean thinking concepts in maintenance can be found in the literature, despite prominent contributors advocating greater management and business integration. An objective of the research describe...

  10. MOSEG code for safety oriented maintenance management Safety of management of maintenance oriented by MOSEG code; Codigo MOSEG para la gestion de mantenimiento orientada a la seguridad

    Energy Technology Data Exchange (ETDEWEB)

    Torres Valle, Antonio [Instituto Superior de Tecnologias y Ciencias Aplicadas, La Habana (Cuba). Dept. Ingenieria Nuclear]. E-mail: atorres@fctn.isctn.edu.cu; Rivero Oliva, Jose de Jesus [Centro de Gestion de la Informacion y Desarrollo de la Energia (CUBAENERGIA) (Cuba)]. E-mail: jose@cubaenergia.cu

    2005-07-01

    Full text: One of the main reasons that makes maintenance contribute highly when facing safety problems and facilities availability is the lack of maintenance management systems to solve these fields in a balanced way. Their main setbacks are shown in this paper. It briefly describes the development of an integrating algorithm for a safety and availability-oriented maintenance management by virtue of the MOSEG Win 1.0 code. (author)

  11. Operation and maintenance requirements of system design bases

    International Nuclear Information System (INIS)

    Banerjee, A.K.; Hanley, N.E.

    1989-01-01

    All system designs make assumptions about system operation testing, inspection, and maintenance. Existing industry codes and standards explicitly address design requirements of new systems, while issues related to system and plant reliability, life, design margins, effects of service conditions, operation, maintenance, etc., usually are implicit. However, system/component design documents of existing power plants often address the code requirements without considering the operation, maintenance, inspection, and testing (OMIT) requirements. The nuclear industry is expending major efforts at most nuclear power plants to reassemble and/or reconstitute system design bases. Stone ampersand Webster Engineering Corporation (SWEC) recently addressed the OMIT requirements of system/component design as an integral part of a utility's preventive maintenance program. For each component, SWEC reviewed vendor recommendations, NPRDS data/industry experience, the existing maintenance program, component service conditions, and actual plant experience. A maintenance program that considers component service conditions and plant experience ensures a connection between maintenance and design basis. Root cause analysis of failure and engineering evaluation of service condition are part of the program. System/component OMIT requirements also are compared against system design, service condition, degradation mechanism, etc., through system/component life-cycle evaluation

  12. Towards total productive maintenance in the Eastern European mining industry

    Energy Technology Data Exchange (ETDEWEB)

    Buck, J.D. [Kepner-Tregoe (United Kingdom) Ltd., Windsor

    1999-08-01

    An European Union consultancy project was undertaken to install a `best-in-class` maintenance system for the lignite mines of Romania. The project, funded by PHARE, started with a critical analysis of the maintenance and repair systems of equipment in both the open-pit and underground mines operated by RALO (Regia Autonoma a Lignitului Octenia). This study paved the way for the introduction of a computerised maintenance system and the inception of a planned preventative maintenance scheme. A development strategy leading by a structural methodology towards predictive maintenance and total productive maintenance was drawn up and attention was given to multi-skilling, training and further facilitating activities to enable the success of the total productive maintenance strategy. An abridged version of the paper was presented at MAINTE 97, held in Birmingham, UK in 1997. 5 refs., 5 figs., 1 tab.

  13. TRUPACT-II Container Maintenance Program Plan

    International Nuclear Information System (INIS)

    1991-05-01

    This document details the maintenance, repair, and replacement of components, as well as the documentation required and the procedures to be followed to maintain the integrity of the TRUPACT-II container in accordance with OM-134, TRUPACT-II Container Operations and Maintenance Manual; and the TRUPACT-II Container Certificate of Compliance (Number 9218). The routine shipping and receiving inspections required by the Department of Transportation (DOT), Department of Energy (DOE), Nuclear Regulatory Commission (NRC) and other regulations are not addressed in this document. This document applies to all DOE shipping and receiving sites that use the TRUPACT-II containers

  14. Maintenance study for W-340 Waste Retrieval System

    International Nuclear Information System (INIS)

    Christensen, C.; Conner, C.C.; Sekot, J.P.

    1994-05-01

    This study was performed to identify attributes and maintainability requirements for the Tank Waste Retrieval System (TWRS). The system will be developed for Westinghouse Hanford Company in Richland, Washington, as an integrated system to perform waste removal in Tank C-106 and, thus, demonstrate technologies for tank remediation that will satisfy requirements of the Tri-Party Agreement. The study examines attributes of the TWRS, scope of maintenance operations required for the TWRS, maintenance requirements, and potential methods of performing maintenance functions. Recommendations are provided for consideration in the development of both the conceptual design and performance specification, which will be used in procuring the W-340 Waste Retrieval System

  15. Integrated Computational Solution for Predicting Skin Sensitization Potential of Molecules.

    Directory of Open Access Journals (Sweden)

    Konda Leela Sarath Kumar

    Full Text Available Skin sensitization forms a major toxicological endpoint for dermatology and cosmetic products. Recent ban on animal testing for cosmetics demands for alternative methods. We developed an integrated computational solution (SkinSense that offers a robust solution and addresses the limitations of existing computational tools i.e. high false positive rate and/or limited coverage.The key components of our solution include: QSAR models selected from a combinatorial set, similarity information and literature-derived sub-structure patterns of known skin protein reactive groups. Its prediction performance on a challenge set of molecules showed accuracy = 75.32%, CCR = 74.36%, sensitivity = 70.00% and specificity = 78.72%, which is better than several existing tools including VEGA (accuracy = 45.00% and CCR = 54.17% with 'High' reliability scoring, DEREK (accuracy = 72.73% and CCR = 71.44% and TOPKAT (accuracy = 60.00% and CCR = 61.67%. Although, TIMES-SS showed higher predictive power (accuracy = 90.00% and CCR = 92.86%, the coverage was very low (only 10 out of 77 molecules were predicted reliably.Owing to improved prediction performance and coverage, our solution can serve as a useful expert system towards Integrated Approaches to Testing and Assessment for skin sensitization. It would be invaluable to cosmetic/ dermatology industry for pre-screening their molecules, and reducing time, cost and animal testing.

  16. Integrated Instrumentation and Sensor Systems Enabling Condition-Based Maintenance of Aerospace Equipment

    Directory of Open Access Journals (Sweden)

    Richard C. Millar

    2012-01-01

    Full Text Available The objective of the work reported herein was to use a systems engineering approach to guide development of integrated instrumentation/sensor systems (IISS incorporating communications, interconnections, and signal acquisition. These require enhanced suitability and effectiveness for diagnostics and health management of aerospace equipment governed by the principles of Condition-based maintenance (CBM. It is concluded that the systems engineering approach to IISS definition provided clear benefits in identifying overall system requirements and an architectural framework for categorizing and evaluating alternative architectures, relative to a bottom up focus on sensor technology blind to system level user needs. CBM IISS imperatives identified include factors such as tolerance of the bulk of aerospace equipment operational environments, low intrusiveness, rapid reconfiguration, and affordable life cycle costs. The functional features identified include interrogation of the variety of sensor types and interfaces common in aerospace equipment applications over multiplexed communication media with flexibility to allow rapid system reconfiguration to adapt to evolving sensor needs. This implies standardized interfaces at the sensor location (preferably to open standards, reduced wire/connector pin count in harnesses (or their elimination through use of wireless communications.

  17. Conceptual design of in-service inspection and maintenance for KALIMER

    International Nuclear Information System (INIS)

    Ju, Y. S.; Kim, S. H.; Koo, K. H.; You, B.

    1999-01-01

    In-service inspection and maintenance are very important for the safety and availability of nuclear power plants. The conceptual requirements of in-service inspection and maintenance should be reflected in the earlier design process for the verification of the plant operability and reliability. In this paper the fundamental approaches of the inspection and maintenance for KALIMER are established to ensure the structural integrity and operability for KALIMER. The general strategy and methodology of maintenance and inspection for the reactor system and components are proposed and described for satisfying the intents of the Section XI, Division 3, of ASME code and considering the design characteristics of KALIMER

  18. Proactive maintenance initiatives at Argonne National Laboratory-West

    International Nuclear Information System (INIS)

    Duckwitz, N.R.; Duncan, L.W.; Whipple, J.J.

    1995-01-01

    In the late 1980's, ANL-W Management foresaw a need to provide dedicated technical support for maintenance supervisors. Maintenance supervisors were facing increased challenges to ensure all environmental, safety, and waste management regulations were followed in daily maintenance activities. This increased burden was diverting supervisory time away from on-the-job supervision. Supervisors were finding less time for their ''mentor'' roles to ensure maintenance focused on finding and correcting root causes. Additionally the traditional maintenance organization could not keep up with the explosion in predictive maintenance technologies. As a result, engineers were tasked to provide direct technical support to the maintenance organization. Today the maintenance technical support group consists of two mechanical engineers, two electrical engineers and an I ampersand C engineer. The group provides a readily available, quick response resource for crafts people and their supervisors. They can and frequently do ask the support group for help to determine the root cause and to effect permanent fixes. Crafts and engineers work together informally to make an effective maintenance team. In addition to day-to-day problem solving, the technical support group has established several maintenance improvement programs for the site. This includes vibration analysis of rotating machinery, testing of fuel for emergency diesel generators, improving techniques for testing of high efficiency particulate air (HEPA) filters, and capacity testing of UPS and emergency diesel starting batteries. These programs have increased equipment reliability, reduced conventional routine maintenance, reduced unexpected maintenance, and improved testing accuracy. This paper will discuss the interaction of the technical support group within the maintenance department. Additionally the maintenance improvement programs will be presented along with actual cases encountered, the resolutions and lessons learned

  19. On condition based maintenance policy

    Directory of Open Access Journals (Sweden)

    Jong-Ho Shin

    2015-04-01

    Full Text Available In the case of a high-valuable asset, the Operation and Maintenance (O&M phase requires heavy charges and more efforts than the installation (construction phase, because it has long usage life and any accident of an asset during this period causes catastrophic damage to an industry. Recently, with the advent of emerging Information Communication Technologies (ICTs, we can get the visibility of asset status information during its usage period. It gives us new challenging issues for improving the efficiency of asset operations. One issue is to implement the Condition-Based Maintenance (CBM approach that makes a diagnosis of the asset status based on wire or wireless monitored data, predicts the assets abnormality, and executes suitable maintenance actions such as repair and replacement before serious problems happen. In this study, we have addressed several aspects of CBM approach: definition, related international standards, procedure, and techniques with the introduction of some relevant case studies that we have carried out.

  20. Advanced diagnostics and predictive maintenance to improve availability and reliability of ENEL plants

    Energy Technology Data Exchange (ETDEWEB)

    Cenci, V.; Ghironi, M.; Guidi, L.; Lauro, M.; Pestonesi, D. [ENEL (Italy). Generation and Energy Management Division

    2007-07-01

    This paper reviews the ENEL Generation and Energy Management strategy for diagnostics and predictive maintenance of power plants and provides a comprehensive description of effective applications and systems. Exploiting the most advanced information and communication technologies makes it possible to capture weak and hidden signals and powerful processing can be used to discover forewarning symptoms and identify anomalies both in the process and, above all, inside the devices. The following systems and applications are presented together with results and impact on plant profitability: expert system for the diagnostics of plant main machinery; advanced diagnostics of 'intelligent' fieldbus devices such as on/off valve motor-driven actuators, control-valve positioners and pneumatic actuators, transmitters; control loop and control valve diagnostics in order to investigate valve friction with an estimation of the residual time to failure; multisensorial diagnostics for coal transport and storage systems aimed at preventing firing and structural damages; and wireless sensor networks for the diagnostics of medium and small size components. 4 refs., 14 figs., 1 tab.

  1. Surveying the elements of successful infrared predictive maintenance programs

    Science.gov (United States)

    Snell, John R., Jr.; Spring, Robert W.

    1991-03-01

    This paper summarizes the results of a survey of over three hundred maintenance personnel who use imaging equipment within their company or organization. All had previously participated in one or more of our training programs. The companies took in a broad range of industry, including, among other, power generation, pulp and paper, metals, mining, petrochemical, automotive and general manufacturing. The organizations were mainly quite large, either commercial or public, and included governmental agencies, military, colleges and universities, municipalities, and utilities. Although we had a very tight time line for the survey, we were pleased to have a 15% response rate. The results show that some of the causes of success and failure in infrared programs are not unlike those associated with any type of program in an organizational structure, i.e. the need for accurate and timely communications; justification requirements; etc. Another set of problems was shared more closely with other startup maintenance technologies (for example, vibration monitoring), such as the need for trending data; providing appropriate technical training; achieving reproducible results; etc. Finally, some of the driving mechanisms are more specific to this technology, such as re-designing equipment so that it can be thermally inspected; establishing effective documentation strategies; etc.

  2. Sustainable resilience in property maintenance: encountering changing weather conditions

    DEFF Research Database (Denmark)

    Cox, Rimante Andrasiunaite; Nielsen, Susanne Balslev

    2014-01-01

    Purpose: The purpose of the study is to develop a methodological approach for project management to integrate sustainability and resilience planning in property maintenance as an incremental strategy for upgrading existing properties to meet new standards for sustainable and climate resilient...... buildings. Background: Current maintenance practice is focused on the technical standard of buildings, with little consideration of sustainability and resilience. There is a need to develop tools for incorporating sustainable resilience into maintenance planning. Approach: The study is primarily theoretical......, developing the concept of sustainable resilience for changing weather conditions Results: The paper suggests a decision support methodology that quantifies sustainable resilience for the analytical stages of property maintenance planning. Practical Implications: The methodology is generic and expected users...

  3. Management of maintenance activities at Cernavoda NPP

    International Nuclear Information System (INIS)

    Riedel, M.; Urjan, R.; Marinescu, S.; Corlan, L.

    2000-01-01

    After the Construction and Commissioning phases are over, the safety and economic performances of each nuclear unit are determined by the quality of its operation as well as by the combination of reliability and availability of the systems consisting the whole unit. Therefore, the value of a good maintenance program in making a safe and profitable operation is now widely recognized; all stations operating with excellent performance have well-defined policies and effectively administered programs to govern maintenance activities. The Cernavoda maintenance optimization initiative is derived from good practices suggested by such recognized bodies as the IAEA, INPO and EPRI. It should be noted that the program is evolving at this time and that this paper is an attempt to summarize the myriad of activities and plans required to finally implement the maintenance program. Although many of the elements of the program are in place, many are in various stages of completion. The main components of the program (policy's objectives, strategies used, specific subprograms, maintenance plans and their integration) are presented in brief along with the performance indicators used to assess the effectiveness of the program and maintenance activities. The new programs intended to be developed are also specified, as well as the main comments and recommendations received from IAEA experts. (author)

  4. Supervisory Model Predictive Control of the Heat Integrated Distillation Column

    DEFF Research Database (Denmark)

    Meyer, Kristian; Bisgaard, Thomas; Huusom, Jakob Kjøbsted

    2017-01-01

    This paper benchmarks a centralized control system based on model predictive control for the operation of the heat integrated distillation column (HIDiC) against a fully decentralized control system using the most complete column model currently available in the literature. The centralized control...... system outperforms the decentralized system, because it handles the interactions in the HIDiC process better. The integral absolute error (IAE) is reduced by a factor of 2 and a factor of 4 for control of the top and bottoms compositions, respectively....

  5. Risk mitigation strategies for operations and maintenance activities.

    Science.gov (United States)

    2012-04-01

    The objective of this research was to investigate the application of integrated risk modeling to operations and maintenance activities, specifically moving operations, such as pavement testing, pavement marking, painting, snow removal, shoulder work,...

  6. Advanced decision support for winter road maintenance

    Science.gov (United States)

    2008-01-01

    This document provides an overview of the Federal Highway Administration's winter Maintenance Decision Support System (MDSS). The MDSS is a decision support tool that has the ability to provide weather predictions focused toward the road surface. The...

  7. Ageing Management Based Maintenance at ETRR-II

    Energy Technology Data Exchange (ETDEWEB)

    Kamoon, A.; Ali, A., E-mail: akamoun2004@yahoo.com [Inshas Nuclear Research Centre, Egyptian Atomic Energy Authority (EAEA), Cairo (Egypt)

    2014-08-15

    The second research reactor of Egypt, ETRR-II, is an open pool type multi-purpose reactor of 22 MW that has been in operation since 1998. The main purposes of ETRR-II are the production of radioisotopes, personnel training, research and development. Ageing management of ETRR-II is based on the maintenance programme. This programme was planned to have a proactive maintenance strategy that mainly depends on adequate preventive and predictive maintenance. Screening of SSCs is based on safety classes, needs and quality levels. The operation condition and maintenance history are the basis to assess the level of degradation. The ultimate aim of the maintenance team is to perform adequate maintenance work only when it is really necessary. The objectives of the ageing management based maintenance are to maintain and improve equipment availability, confirm compliance with operational limits and conditions, and detect and correct any abnormal condition that might affect reactor safety. The programme also helps to detect trends in ageing so that a plan for mitigating ageing effects can be prepared and implemented. Reactor service conditions are monitored through many parameters and conditions such as conductivity and pH of coolant water, water radiochemical analysis, thermal and hydraulic parameters, a leak detection system, corrosion rate of piping, vibration level of rotating equipment and control rod drop time.

  8. Optimization of maintenance policy using the proportional hazard model

    Energy Technology Data Exchange (ETDEWEB)

    Samrout, M. [Information Sciences and Technologies Institute, University of Technology of Troyes, 10000 Troyes (France)], E-mail: mohamad.el_samrout@utt.fr; Chatelet, E. [Information Sciences and Technologies Institute, University of Technology of Troyes, 10000 Troyes (France)], E-mail: chatelt@utt.fr; Kouta, R. [M3M Laboratory, University of Technology of Belfort Montbeliard (France); Chebbo, N. [Industrial Systems Laboratory, IUT, Lebanese University (Lebanon)

    2009-01-15

    The evolution of system reliability depends on its structure as well as on the evolution of its components reliability. The latter is a function of component age during a system's operating life. Component aging is strongly affected by maintenance activities performed on the system. In this work, we consider two categories of maintenance activities: corrective maintenance (CM) and preventive maintenance (PM). Maintenance actions are characterized by their ability to reduce this age. PM consists of actions applied on components while they are operating, whereas CM actions occur when the component breaks down. In this paper, we expound a new method to integrate the effect of CM while planning for the PM policy. The proportional hazard function was used as a modeling tool for that purpose. Interesting results were obtained when comparison between policies that take into consideration the CM effect and those that do not is established.

  9. Development of an integrated method for long-term water quality prediction using seasonal climate forecast

    Directory of Open Access Journals (Sweden)

    J. Cho

    2016-10-01

    Full Text Available The APEC Climate Center (APCC produces climate prediction information utilizing a multi-climate model ensemble (MME technique. In this study, four different downscaling methods, in accordance with the degree of utilizing the seasonal climate prediction information, were developed in order to improve predictability and to refine the spatial scale. These methods include: (1 the Simple Bias Correction (SBC method, which directly uses APCC's dynamic prediction data with a 3 to 6 month lead time; (2 the Moving Window Regression (MWR method, which indirectly utilizes dynamic prediction data; (3 the Climate Index Regression (CIR method, which predominantly uses observation-based climate indices; and (4 the Integrated Time Regression (ITR method, which uses predictors selected from both CIR and MWR. Then, a sampling-based temporal downscaling was conducted using the Mahalanobis distance method in order to create daily weather inputs to the Soil and Water Assessment Tool (SWAT model. Long-term predictability of water quality within the Wecheon watershed of the Nakdong River Basin was evaluated. According to the Korean Ministry of Environment's Provisions of Water Quality Prediction and Response Measures, modeling-based predictability was evaluated by using 3-month lead prediction data issued in February, May, August, and November as model input of SWAT. Finally, an integrated approach, which takes into account various climate information and downscaling methods for water quality prediction, was presented. This integrated approach can be used to prevent potential problems caused by extreme climate in advance.

  10. How digital revolution has an impact on maintenance

    International Nuclear Information System (INIS)

    Thevenon, J.B.

    2017-01-01

    Digital technologies can manage a huge quantity of data from a variety of sensors which draws an accurate picture of the real state of a component or even a complete plant. Combined with predictive models, the knowledge of the real state of a component can lead to predictive maintenance in which components are repaired or replaced before they fail. EDF takes the opportunity of the ten-yearly outage of a plant to draw a digital twin of this plant with the help of 3-dimensional photography and laser scans. This digital twin will be used to visualize and validate any change or maintenance operation. The digital twin will be also useful to communicate efficiently with sub-contractors and visualize the work to be done. In the future, new applications will be added to the twin and for instance the level of contamination could be implemented in order to increase safety for maintenance operations. Needless to say that a digital twin will be very useful for the dismantling of the installation. (A.C.)

  11. Corrosion Sensor Development for Condition-Based Maintenance of Aircraft

    Directory of Open Access Journals (Sweden)

    Gino Rinaldi

    2012-01-01

    Full Text Available Aircraft routinely operate in atmospheric environments that, over time, will impact their structural integrity. Material protection and selection schemes notwithstanding, recurrent exposure to chlorides, pollution, temperature gradients, and moisture provide the necessary electrochemical conditions for the development and profusion of corrosion in aircraft structures. For aircraft operators, this becomes an important safety matter as corrosion found in a given aircraft must be assumed to be present in all of that type of aircraft. This safety protocol and its associated unscheduled maintenance requirement drive up the operational costs of the fleet and limit the availability of the aircraft. Hence, there is an opportunity at present for developing novel sensing technologies and schemes to aid in shifting time-based maintenance schedules towards condition-based maintenance procedures. In this work, part of the ongoing development of a multiparameter integrated corrosion sensor is presented. It consists of carbon nanotube/polyaniline polymer sensors and commercial-off-the-shelf sensors. It is being developed primarily for monitoring environmental and material factors for the purpose of providing a means to more accurately assess the structural integrity of aerospace aluminium alloys through fusion of multiparameter sensor data. Preliminary experimental test results are presented for chloride ion concentration, hydrogen gas evolution, humidity variations, and material degradation.

  12. TRUPACT-II container maintenance program plan

    International Nuclear Information System (INIS)

    1990-11-01

    This document details the maintenance/repair and replacement of components, as well as the documentation required and the procedures to be followed to maintain the integrity of the TRUPACT-II container, in accordance with requirements of the TRUPACT-II Container Operations and Maintenance Manual, OM-134, the TRUPACT-II Container Safety Analysis Report (SARP), and the TRUPACT-II Container Certificate of Compliance (Number 9218). The routine shipping and receiving inspections required by the Department of Transportation (DOT), Department of Energy (DOE), Nuclear Regulatory Commission (NRC) and other regulations are not addressed in this document. This document applies to all DOE shipping and receiving sites that use the TRUPACT-II containers

  13. Drosophila Sld5 is essential for normal cell cycle progression and maintenance of genomic integrity

    Energy Technology Data Exchange (ETDEWEB)

    Gouge, Catherine A. [Department of Biology, East Carolina University East Carolina University, Greenville, NC 27858 (United States); Christensen, Tim W., E-mail: christensent@ecu.edu [Department of Biology, East Carolina University East Carolina University, Greenville, NC 27858 (United States)

    2010-09-10

    Research highlights: {yields} Drosophila Sld5 interacts with Psf1, PPsf2, and Mcm10. {yields} Haploinsufficiency of Sld5 leads to M-phase delay and genomic instability. {yields} Sld5 is also required for normal S phase progression. -- Abstract: Essential for the normal functioning of a cell is the maintenance of genomic integrity. Failure in this process is often catastrophic for the organism, leading to cell death or mis-proliferation. Central to genomic integrity is the faithful replication of DNA during S phase. The GINS complex has recently come to light as a critical player in DNA replication through stabilization of MCM2-7 and Cdc45 as a member of the CMG complex which is likely responsible for the processivity of helicase activity during S phase. The GINS complex is made up of 4 members in a 1:1:1:1 ratio: Psf1, Psf2, Psf3, And Sld5. Here we present the first analysis of the function of the Sld5 subunit in a multicellular organism. We show that Drosophila Sld5 interacts with Psf1, Psf2, and Mcm10 and that mutations in Sld5 lead to M and S phase delays with chromosomes exhibiting hallmarks of genomic instability.

  14. Predicting Athletes’ Pre-Exercise Fluid Intake: A Theoretical Integration Approach

    Directory of Open Access Journals (Sweden)

    Chunxiao Li

    2018-05-01

    Full Text Available Pre-exercise fluid intake is an important healthy behavior for maintaining athletes’ sports performances and health. However, athletes’ behavioral adherence to fluid intake and its underlying psychological mechanisms have not been investigated. This prospective study aimed to use a health psychology model that integrates the self-determination theory and the theory of planned behavior for understanding pre-exercise fluid intake among athletes. Participants (n = 179 were athletes from college sport teams who completed surveys at two time points. Baseline (Time 1 assessment comprised psychological variables of the integrated model (i.e., autonomous and controlled motivation, attitude, subjective norm, perceived behavioral control, and intention and fluid intake (i.e., behavior was measured prospectively at one month (Time 2. Path analysis showed that the positive association between autonomous motivation and intention was mediated by subjective norm and perceived behavioral control. Controlled motivation positively predicted the subjective norm. Intentions positively predicted pre-exercise fluid intake behavior. Overall, the pattern of results was generally consistent with the integrated model, and it was suggested that athletes’ pre-exercise fluid intake behaviors were associated with the motivational and social cognitive factors of the model. The research findings could be informative for coaches and sport scientists to promote athletes’ pre-exercise fluid intake behaviors.

  15. PRM-based patterns for knowledge formalisation of industrial systems to support maintenance strategies assessment

    International Nuclear Information System (INIS)

    Medina-Oliva, G.; Weber, P.; Iung, B.

    2013-01-01

    The production system and its maintenance system must be now developed on “system thinking” paradigm in order to guarantee that Key Performance Indicators (KPI) will be optimized all along the production system (operation) life. In a recursive way, maintenance system engineering has to integrate also KPI considerations with regards to its own enabling systems. Thus this paper develops a system-based methodology wherein a set of KPIs is computed in order to verify if the objectives of the production and maintenance systems are satisfied. In order to help the decision-making process for maintenance managers, a “unified” generic model have been developed. This model integrates (a) the interactions of the maintenance system with its enabling systems, (b) the impact of the maintenance strategies through the computation of some key performance indicators, and (c) different kinds of knowledge regarding the maintenance system and the system of interest, including quantitative and qualitative knowledge. This methodology is based on an executable unified model built with Probabilistic Relational Model (PRM). PRM allows a modular representation and inferences computation of large size models. The methodology added-value is shown on a test-bench

  16. Effective utilization of maintenance staff in design and implementation of major project work

    International Nuclear Information System (INIS)

    Wyman, D.; Dingle, J.; Brown, R.

    1995-01-01

    The reorganization of Pickering Nuclear Division some 2 years ago resulted in the formation of the Projects and Modifications department. This department takes an integrated approach to manage all aspects of large projects at Pickering. The integration of Design, Drafting, Procurement, Construction and Operations functions into project teams represents a fundamental change to project management at Pickering. The development of integrated teams has great potential for reducing both the time and cost associated with project implementation, while at the same time improving the quality, and maintainability of the commissioned in service project. The Pickering Rehab organization 1989-1993, established to perform the rehab / retube of Units 3 and 4 had proven that a team environment will produce effective results. The outcome was astounding, critical categories such as Safety, Quality of Work, and Timeliness, had proven the team's effectiveness. The integration of operations maintenance staff into the project work activities is still evolving, and has probably required the most adaptation to change for both the former Construction and Operations organizations. Maximizing the utilization of the maintenance staff in the design and implementation of major project work will prove to be a key to a long term operating success of these projects. This paper will focus in on the effective usage of Maintenance staff in the design and implementation phases of major project work at Pickering, and on the benefits realized using this approach. It will be divided into 5 sections as indicated. 1. Past Project Shortfalls. 2. Benefits of the inclusion of Maintenance staff in the Calandria Vault Rehab Project. 3. Maintenance involvement in the Pickering 'A' Shutdown System Enhancement (SDSE) Project. 4. Challenges resulting from the inclusion of Maintenance staff project teams. 5. Summary. (author)

  17. JRR-3 maintenance program utilizing accumulated maintenance data

    International Nuclear Information System (INIS)

    Izumo, Hironobu; Kato, Tomoaki; Kinase, Masami; Torii, Yoshiya; Murayama, Yoji

    2007-07-01

    JRR-3(Japan Research Reactor No.3) has been operated for more than 15 years after the modification, without significant troubles by carrying out maintenance such as the preventive maintenance (mainly time-based maintenance) for the safety-grade equipments and the breakdown maintenance for the non-safety-grade equipments. Unscheduled shutdowns causes by aged non-safety-grade equipments have been increasing, and the resources such as budgets have been decreasing year by year. In this situation, JRR-3 maintenance program was reviewed about safety, reliability and economic efficiency. This report offers the policy of the maintenance review and the future direction of maintenance programs. (author)

  18. Maintenance and Outage Management Assessment (MOMA)

    International Nuclear Information System (INIS)

    2005-01-01

    a small team of experienced nuclear experts/specialists in the world. It can be requested for a single area or multiple ones, such as a) In-Service Inspection program review and optimization, including inspection qualification and risk informed inspection, b) maintenance program optimization by means of equipment reliability, performance based approach, risk informed on-line maintenance, condition based maintenance, c) outage improvement be means of streamlined integration of technologies and process, work planning and scheduling, plant modifications and configuration control, indicators and operating experience feedback system, safety culture, outsourcing and contract management, and spare parts

  19. Principles of MONJU maintenance. Characteristic of MONJU maintenance and reflection of LWR maintenance experience to FBR

    International Nuclear Information System (INIS)

    Nakai, Satoru; Nishio, Ryuichi; Uchihashi, Masaya; Kaneko, Yoshihisa; Yamashita, Hironobu; Yamaguchi, Atsunori; Aoki, Takayuki

    2014-01-01

    A sodium cooled fast breeder reactor (FBR) has unique systems and components and different degradation mechanism from light water reactor (LWR) so that need to establish maintenance technology in accordance with its features. The examination of the FBR maintenance technology is carried out in the special committee for considering the maintenance for Monju established in the Japan Society of Maintenology (JSM). As a result of the study such as extraction of Monju maintenance feature, maintenance technology benchmark between Monju and LWR components and survey of LWR maintenance experience, it is clear that principles of maintenance are same as LWR, necessity of LWR maintenance experience reflection and points to be considered in Monju maintenance. The road map to establish a FBR maintenance technology in the technical aspect became clear and it is vital to acquire operation and maintenance experience of the plant to implement this road map, and to establish a fast reactor maintenance. (author)

  20. Complete guide to preventive and predictive maintenance

    CERN Document Server

    Levitt, Joel

    2011-01-01

    This book shares the best practices, mistakes, victories, and essential steps for success which the author has gleaned from working with countless organizations. Unlike other books that only focus on the engineering issues (task lists) or management issues (CMMS), this in-depth resource is the first to give true emphasize to the four aspects of success in preventive maintenance systems - engineering, management, economic, and psychological - thereby enabling readers to have a balanced view and understanding of what is happening in their organizations. Additionally, it blends concrete actionable steps and structures with the theory behind the steps. It includes check sheets, history of PM, stories, photographs, and case histories. It contains a glossary of terms. It provides sample task lists for a variety of equipment with some of the logic behind each task. It offers templates for developing your own tasking. It includes protocols for detailed economic analysis with examples.

  1. Recent Educational Experiences in Electric Machine Maintenance Teaching

    Directory of Open Access Journals (Sweden)

    Jose Alfonso Antonino-Daviu

    2013-05-01

    Full Text Available Maintenance of electric machines and installations is a particularly important area; eventual faults in these devices may lead to significant losses in terms of time and money. The investment and concern in developing proper maintenance protocols have been gradually increasing over recent decades. As a consequence, there is a need to instruct future engineers in the electric machines and installations maintenance area. The subject "Maintenance of Electric Machines and Installations" has been designed under this idea. It is taught within an official master degree in Maintenance Engineering. This work describes the educational experiences reached during the initial years of the teaching of the subject. Aspects such as student profiles, subject approaches, design of the syllabus, methodology and structure of the laboratory sessions are remarked in the work. In addition, the paper discusses other educational strategies which are being introduced to increase the interest in the subject, such as integration of Information and Communication Technologies (ICT, promotion of the collaborative work, inclusion of the possibility of remote learning or development of new assessment systems.

  2. Potential of Computerized Maintenance Management System in Facilities Management

    Directory of Open Access Journals (Sweden)

    Noor Farisya Azahar

    2014-07-01

    Full Text Available For some time it has been clear that managing buildings or estates has been carried out in the context of what has become known as facilities management. British Institute of Facilities Management defined facilities management is the integration of multi-disciplinary activities within the built environment and the management of their impact upon people and the workplace. Effective facilities management is vital to the success of an organisation by contributing to the delivery of its strategic and operational objectives. Maintenance of buildings should be given serious attention before (stage design, during and after a building is completed. But total involvement in building maintenance is after the building is completed and during its operations. Residents of and property owners require their building to look attractive, durable and have a peaceful indoor environment and efficient. The objective of the maintenance management system is to stream line the vast maintenance information system to improve the productivity of an industrial plant. a good maintenance management system makes equipment and facilities available. This paper will discuss the fundamental steps of maintenance management program and Computerized Maintenance Management System (CMMS

  3. Applying theory of planned behavior to predict exercise maintenance in sarcopenic elderly

    Directory of Open Access Journals (Sweden)

    Ahmad MH

    2014-09-01

    to predict maintenance of exercise in the sarcopenic elderly.Keywords: theory planned behavior, aging, elderly, sarcopenic, exercise

  4. Optimización del mantenimiento preventivo, utilizando las técnicas de diagnóstico integral. Resultados finales y evaluación económica; Optimization of the Preventive Maintenance Using the Techniques of Integral Diagnosis. Final Results and Economic Evalua

    Directory of Open Access Journals (Sweden)

    Pedro L Hernández Domínguez

    2011-02-01

    Full Text Available En este trabajo se obtienen los resultados finales y la evaluación económica de la aplicación de la metodologíaque aporta el diagnóstico integral (DI, presentada por los autores en los artículos anteriores, con la finalidad deintroducir el mantenimiento basado en la condición (MBC como una forma de mejoramiento o perfeccionamientodel mantenimiento preventivo planificado (MPP que se desarrolla en las centrales termoeléctricas (CCTT cubanas. In this paper, the authors obtained the final results and the economic evaluation of the application methodologythat contributes the integral diagnosis (ID, presented by they in a previous articles, with the purpose of introducingthe condition based maintenance (CBM like a form of improvement the Planned Preventive Maintenance(PPM that is developed in the cuban thermoelectric power stations.

  5. Preliminary conceptual design of inspection and maintenance for KALIMER reactor system

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Young Sang; Kim, Seok Hun; Yoo, Bong

    2000-08-01

    In-service inspection and maintenance are very important for improving the safety and availability of nuclear power plants. The conceptual requirements of in-service inspection and maintenance should be reflected in the earlier design process for the verification of the plant operability and reliability. In this report the fundamental approaches of the inspection and maintenance for KALIMER are established to ensure the structural integrity and operability for KALIMER. The general strategy and methodology of maintenance and inspection for the reactor system and components are proposed and described for satisfying the intents of the section XI, division 3, of ASME code and considering the design characteristics of KALIMER.

  6. Valve leakage inspection testing and maintenance process

    International Nuclear Information System (INIS)

    Aikin, J.A.; Reinwald, J.W.; Kittmer, C.A.

    1991-01-01

    In valve maintenance, packing rings that prevent leakage along the valve stem must periodically be replaced, either during routine maintenance or to correct a leak or valve malfunction. Tools and procedures currently in use for valve packing removal and inspection are generally of limited value due to various access and application problems. A process has been developed by AECL Research that addresses these problems. The process, using incompressible fluid pressure, quickly and efficiently confirms the integrity of the valve backseat, extracts hard-to-remove valve packing sets, and verifies the leak tightness of the repacked valve

  7. A strategic value management approach for energy and maintenance management in a building

    Science.gov (United States)

    Nawi, Mohd Nasrun Mohd; Dahlan, Nofri Yenita; Nadarajan, Santhirasegaran

    2015-05-01

    Fragmentation process is always been highlighted by the stakeholders in the construction industry as one of the `critical' issue that diminishing the opportunity for stakeholders that involved during the operation and maintenance stage to influence design decisions. Failure of design professionals to consider how a maintenance contractor or facility manager will construct the design thus results in higher operating cost, wastage, defects during the maintenance and operation process. Moving towards team integration is considered a significant strategy for overcoming the issue. Value Management is a style of management dedicated to guiding people and promoting innovation with the aim to improve overall building performance through structured, team-oriented exercises which make explicit, and appraise subsequent decisions, by reference to the value requirements of the clients. Accordingly, this paper discusses the fragmentation issue in more detail including the definition, causes and effects to the maintenance and operation of building and at the same time will highlighted the potential of VM integrated team approach as a strategic management approach for overcoming that issue. It also explores that the team integration strategy alleviates scheduling problems, delays and disputes during the construction process, and, hence, prevent harming the overall building performance.

  8. 40 CFR 94.211 - Emission-related maintenance instructions for purchasers.

    Science.gov (United States)

    2010-07-01

    ... agreement) which is identified by brand, trade, or corporate name. Such instructions also will not directly... whose function is not integral to the design and performance of the engine). (f) Scheduled maintenance... significantly degrade emission control and whose function is not integral to the design and performance of the...

  9. Kalman-predictive-proportional-integral-derivative (KPPID)

    International Nuclear Information System (INIS)

    Fluerasu, A.; Sutton, M.

    2004-01-01

    With third generation synchrotron X-ray sources, it is possible to acquire detailed structural information about the system under study with time resolution orders of magnitude faster than was possible a few years ago. These advances have generated many new challenges for changing and controlling the state of the system on very short time scales, in a uniform and controlled manner. For our particular X-ray experiments on crystallization or order-disorder phase transitions in metallic alloys, we need to change the sample temperature by hundreds of degrees as fast as possible while avoiding over or under shooting. To achieve this, we designed and implemented a computer-controlled temperature tracking system which combines standard Proportional-Integral-Derivative (PID) feedback, thermal modeling and finite difference thermal calculations (feedforward), and Kalman filtering of the temperature readings in order to reduce the noise. The resulting Kalman-Predictive-Proportional-Integral-Derivative (KPPID) algorithm allows us to obtain accurate control, to minimize the response time and to avoid over/under shooting, even in systems with inherently noisy temperature readings and time delays. The KPPID temperature controller was successfully implemented at the Advanced Photon Source at Argonne National Laboratories and was used to perform coherent and time-resolved X-ray diffraction experiments.

  10. Incarcerated intravenous heroin users: predictors of post-release utilization of methadone maintenance treatment.

    Science.gov (United States)

    Lin, Huang-Chi; Wang, Peng-Wei; Yang, Yi-Hsin; Tsai, Jih-Jin; Yen, Cheng-Fang

    2016-01-01

    Incarcerated intravenous heroin users have more problematic patterns of heroin use, but are less likely to access methadone maintenance treatment by their own initiative than heroin users in the community. The present study examined predictors for receiving methadone maintenance treatment post-release among incarcerated intravenous heroin users within a 24-month period. This cohort study recruited 315 incarcerated intravenous heroin users detained in 4 prisons in southern Taiwan and followed up within the 24-month period post-release. Cox proportional hazards regression analysis was applied to determine the predictive effects of sociodemographic and drug-use characteristics, attitude toward methadone maintenance treatment, human immunodeficiency virus serostatus, perceived family support, and depression for access to methadone maintenance treatment after release. There were 295 (93.7%) incarcerated intravenous heroin users released that entered the follow-up phase of the study. During the 24-month follow-up period, 50.8% of them received methadone maintenance treatment. After controlling for the effects of the detainment period before and after recruitment by Cox proportional hazards regression analysis, incarcerated intravenous heroin users who had positive human immunodeficiency virus serostatus (HR = 2.85, 95% CI = 1.80-4.52, p maintenance treatment before committal (HR = 1.94, 95% CI = 1.23-3.05, p maintenance treatment within the 24-month follow-up period. Positive human immunodeficiency virus serostatus with fully subsidized treatment and previous methadone maintenance treatment experiences predicted access of methadone maintenance treatment post-release. Strategies for getting familiar with methadone maintenance treatment during detainment, including providing methadone maintenance treatment prior to release and lowering the economic burden of receiving treatment, may facilitate entry of methadone maintenance treatment for incarcerated intravenous heroin

  11. Maintenance treatment with azathioprine in ulcerative colitis: outcome and predictive factors after drug withdrawal.

    Science.gov (United States)

    Cassinotti, Andrea; Actis, Giovanni C; Duca, Piergiorgio; Massari, Alessandro; Colombo, Elisabetta; Gai, Elisa; Annese, Vito; D'Albasio, Giuseppe; Manes, Gianpiero; Travis, Simon; Porro, Gabriele Bianchi; Ardizzone, Sandro

    2009-11-01

    Whether the duration of maintenance treatment with azathioprine (AZA) affects the outcome of ulcerative colitis (UC) is unclear. We investigated clinical outcomes and any predictive factors after withdrawal of AZA in UC. In this multicenter observational retrospective study, 127 Italian UC patients, who were in steroid-free remission at the time of withdrawal of AZA, were followed-up for a median of 55 months or until relapse. The frequency of clinical relapse or colectomy after AZA withdrawal was analyzed according to demographic, clinical, and endoscopic variables. After drug withdrawal, a third of the patients relapsed within 12 months, half within 2 years and two-thirds within 5 years. After multivariable analysis, predictors of relapse after drug withdrawal were lack of sustained remission during AZA maintenance (hazard ratio, HR 2.350, confidence interval, CI 95% 1.434-3.852; P=0.001), extensive colitis (HR 1.793, CI 95% 1.064-3.023, P=0.028 vs. left-sided colitis; HR 2.024, CI 95% 1.103-3.717, P=0.023 vs. distal colitis), and treatment duration, with short treatments (3-6 months) more disadvantaged than >48-month treatments (HR 2.783, CI 95% 1.267-6.114, P=0.008). Concomitant aminosalicylates were the only predictors of sustained remission during AZA therapy (P=0.009). The overall colectomy rate was 10%. Predictors of colectomy were drug-related toxicity as the cause of AZA withdrawal (P=0.041), no post-AZA drug therapy (P=0.031), and treatment duration (P<0.0005). Discontinuation of AZA while UC is in remission is associated with a high relapse rate. Disease extent, lack of sustained remission during AZA, and discontinuation due to toxicity could stratify relapse risk. Concomitant aminosalicylates were advantageous. Prospective randomized controlled trials are needed to confirm whether treatment duration is inversely associated with outcome.

  12. Incorporation of Outcome-Based Contract Requirements in a Real Options Approach for Maintenance Planning

    Science.gov (United States)

    2016-04-30

    corrective maintenance (which increases as the RUL is used up), while maximizing the revenue earned during the RUL (which increases as the RUL is used up...running the system to failure, then performing corrective maintenance The value from exercising the option is the sum of the cumulative revenue loss...and the avoided corrective maintenance cost. The cumulative revenue loss is what the system would earn between the predictive maintenance event and

  13. Evaluation of mental workload on digital maintenance systems in nuclear power plants

    International Nuclear Information System (INIS)

    Hwang, S. L.; Huang, F. H.; Lin, J. C.; Liang, G. F.; Yenn, T. C.; Hsu, C. C.

    2006-01-01

    The purpose of this study is to evaluate operators' mental workload dealing with digital maintenance systems in Nuclear Power Plants. First of all, according to the factors affected the mental workload, a questionnaire was designed to evaluate the mental workload of maintenance operators at the second Nuclear Power (NPP) in Taiwan. Then, sixteen maintenance engineers of the Second NPP participated in the questionnaire survey. The results indicated that the mental workload was lower in digital systems than that in analog systems. Finally, a mental workload model based on Neural Network technique was developed to predict the workload of maintenance operators in digital maintenance systems. (authors)

  14. Pemetrexed in maintenance treatment of advanced non-squamous non-small-cell lung cancer.

    Science.gov (United States)

    Minami, Seigo; Kijima, Takashi

    2015-01-01

    Pemetrexed, a multitargeting antifolate cytotoxic drug, plays a leading role in front-line chemotherapy for patients with advanced non-squamous non-small-cell lung cancer (NSCLC). Following its approval as second-line monotherapy for locally advanced or metastatic non-squamous NSCLC, pemetrexed has established itself as the first-line regimen in combination with cisplatin, and its powerful antitumor effects and less cumulative toxicities were then taken advantage of in the JMEN and PARAMOUNT trials, respectively, to pioneer a new treatment strategy of switch and continuation maintenance monotherapy. These developments have brought about a marked paradigm shift, and made pemetrexed indispensable in the treatment for non-squamous NSCLC. So far, only three drugs have been approved for maintenance therapy; pemetrexed both by switch and continuation maintenance, erlotinib by switch maintenance, and bevacizumab by continuation maintenance. Compared with observation alone after defined cycles of the first-line chemotherapy, subsequent pemetrexed maintenance therapy has provided significantly longer survival and infrequent severe adverse events. The cost-effectiveness of pemetrexed maintenance therapy is controversial, as well as the other two maintenance drugs, bevacizumab and erlotinib. The latest attractive attention is a combination maintenance therapy. We may have to consider epidermal growth factor receptor (EGFR) mutation status for selection of a combination pattern. A combination maintenance therapy of pemetrexed plus bevacizumab is potential for patients with wild-type EGFR status, while a EGFR tyrosine kinase inhibitor-containing combination is promising for patients with active EGFR mutation status. Pemetrexed will be a pivotal drug when a combination maintenance therapy is used in practice. For future maintenance therapy, we need to explore reliable predictive selection or exclusion markers that can predict who will really benefit from maintenance therapy.

  15. To select the best tool for generating 3D maintenance data and to set the detailed process for obtaining the 3D maintenance data

    Science.gov (United States)

    Prashanth, B. N.; Roy, Kingshuk

    2017-07-01

    Three Dimensional (3D) maintenance data provides a link between design and technical documentation creating interactive 3D graphical training and maintenance material. It becomes difficult for an operator to always go through huge paper manuals or come running to the computer for doing maintenance of a machine which makes the maintenance work fatigue. Above being the case, a 3D animation makes maintenance work very simple since, there is no language barrier. The research deals with the generation of 3D maintenance data of any given machine. The best tool for obtaining the 3D maintenance is selected and the tool is analyzed. Using the same tool, a detailed process for extracting the 3D maintenance data for any machine is set. This project aims at selecting the best tool for obtaining 3D maintenance data and to select the detailed process for obtaining 3D maintenance data. 3D maintenance reduces use of big volumes of manuals which creates human errors and makes the work of an operator fatiguing. Hence 3-D maintenance would help in training and maintenance and would increase productivity. 3Dvia when compared with Cortona 3D and Deep Exploration proves to be better than them. 3Dvia is good in data translation and it has the best renderings compared to the other two 3D maintenance software. 3Dvia is very user friendly and it has various options for creating 3D animations. Its Interactive Electronic Technical Publication (IETP) integration is also better than the other two software. Hence 3Dvia proves to be the best software for obtaining 3D maintenance data of any machine.

  16. Managing the maintenance inventory of a cement manufacturer

    Directory of Open Access Journals (Sweden)

    Morne Eloff

    2013-11-01

    Full Text Available Inventory management is a crucial aspect of managing a company successfully. This is even more apparent in the case of maintenance inventories for production equipment, which impact directly on production equipment efficiency. This is a typical inventory management issue for a cement manufacturer that faces the problem of managing its maintenance inventories optimally when certain maintenance items have exceptionally long lead times (100 weeks and values in excess of R500 000. An assessment of the cement manufacturer’s approach to managing its maintenance inventories indicated various shortcomings, which have resulted in a significant level of obsolescence. One approach to managing maintenance inventories efficiently is to implement a classification of the inventory items in terms of their criticality to the cement production process. The critical nature of a component could be established through a risk-based approach (minimisation of the risk of production loss and taking into account the type of maintenance (planned vs unplanned that the component is required for. A risk-based approach should form the basis of the maintenance inventory management of the cement manufacturer as this would allow the cement manufacturer to utilise other inventory management methods effectively. In addition, it is important to ensure that employees are well versed in the different inventory management approaches utilised and that high levels of integration between departments are pursued.

  17. A maintenance performance measurement framework that includesmaintenenace human factors: a case study from the electricity transmission industry

    Directory of Open Access Journals (Sweden)

    Peach, Rina

    2016-08-01

    Full Text Available Over the past two to three decades, maintenance management has undergone a paradigm shift; it is no longer seen as a necessary evil, but as an integral part of the business process that creates value for the organisation. The next step in the evolution of maintenance management is a maintenance performance measurement that includes human factors. The human factors in maintenance are well- known in the aviation industry, as it gained momentum in the early 1990s after a series of serious aviation accidents. Other industries, however, have been slow to integrate the human factor in their maintenance performance measurements. This paper discusses the results of a research project that investigated the use and importance of maintenance management performance measurements that focus specifically on human factors as part of the overall performance management system. From the research presented in this paper, ‘motivation’ and ‘competence’ were identified as the most important human performance factors in the maintenance of electricity transmission systems.

  18. Predictors of children's sleep onset and maintenance problems after road traffic accidents.

    Science.gov (United States)

    Wittmann, Lutz; Zehnder, Daniel; Jenni, Oskar G; Landolt, Markus A

    2012-01-01

    Sleep onset and maintenance problems are a frequent complaint after traumatic events in children. However, the association of traumatic experiences and disturbed sleep remains to be explained. To examine the incidence of sleep onset and maintenance problems in children after road traffic accidents and identify potential predictors of sleep onset and maintenance problems, including putative psychopathological mechanisms as well as stressors affecting the family system. In 33 children treated for injuries after road traffic accidents, sleep and measures of psychopathology were assessed 10 days, 2 months, and 6 months after hospital admission. The predictive value of four clusters of predictor variables for children's sleep onset and maintenance problems was prospectively tested by multiple regression analyses. These clusters included socio-demographic, injury- and accident-related, and psychopathological variable clusters as well as factors reflecting stressors concerning mothers and family. Children suffering from posttraumatic stress reported a prolonged subjective sleep latency. The severity of sleep onset and maintenance problems was predicted by female sex and the child's as well as mothers' posttraumatic stress disorder (PTSD) severity. Sleep onset and maintenance problems in children after trauma appear to result from a complex interaction of multiple factors. Our findings support the transactional model of sleep-wake regulation that bears implications for the development of adequate intervention strategies.

  19. Fast integration-based prediction bands for ordinary differential equation models.

    Science.gov (United States)

    Hass, Helge; Kreutz, Clemens; Timmer, Jens; Kaschek, Daniel

    2016-04-15

    To gain a deeper understanding of biological processes and their relevance in disease, mathematical models are built upon experimental data. Uncertainty in the data leads to uncertainties of the model's parameters and in turn to uncertainties of predictions. Mechanistic dynamic models of biochemical networks are frequently based on nonlinear differential equation systems and feature a large number of parameters, sparse observations of the model components and lack of information in the available data. Due to the curse of dimensionality, classical and sampling approaches propagating parameter uncertainties to predictions are hardly feasible and insufficient. However, for experimental design and to discriminate between competing models, prediction and confidence bands are essential. To circumvent the hurdles of the former methods, an approach to calculate a profile likelihood on arbitrary observations for a specific time point has been introduced, which provides accurate confidence and prediction intervals for nonlinear models and is computationally feasible for high-dimensional models. In this article, reliable and smooth point-wise prediction and confidence bands to assess the model's uncertainty on the whole time-course are achieved via explicit integration with elaborate correction mechanisms. The corresponding system of ordinary differential equations is derived and tested on three established models for cellular signalling. An efficiency analysis is performed to illustrate the computational benefit compared with repeated profile likelihood calculations at multiple time points. The integration framework and the examples used in this article are provided with the software package Data2Dynamics, which is based on MATLAB and freely available at http://www.data2dynamics.org helge.hass@fdm.uni-freiburg.de Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e

  20. Development and integration of programmatic performance indicators

    International Nuclear Information System (INIS)

    Wreathall, J.; Appignani, P.; Modarres, M.

    1990-01-01

    Work is currently being performed to develop and integrate programmatic performance indicators, that is, indicators of performance associated with the influence on safety associated with plant functional areas like maintenance, operations and training. The process for identifying and evaluating indicators associated with maintenance and training has been described earlier. Since that time, the authors have evaluated the maintenance indicators: inadvertent engineered safety feature actuations due to test and maintenance errors, and daily power loss (DPL), which seemingly show relationships to safety. Work on training process will lead to characteristic sorts of behavior. In the integration study, several frameworks have been developed to provide a basis for describing the interrelationships of plant behavior, personnel behavior, and safety. These will be applied in the next phase of the work to perform the nominal integration

  1. Integrative EEG biomarkers predict progression to Alzheimer's disease at the MCI stage

    Directory of Open Access Journals (Sweden)

    Simon-Shlomo ePoil

    2013-10-01

    Full Text Available Alzheimer's disease (AD is a devastating disorder of increasing prevalence in modern society. Mild cognitive impairment (MCI is considered a transitional stage between normal aging and AD; however, not all subjects with MCI progress to AD. Prediction of conversion to AD at an early stage would enable an earlier, and potentially more effective, treatment of AD. Electroencephalography (EEG biomarkers would provide a non-invasive and relatively cheap screening tool to predict conversion to AD; however, traditional EEG biomarkers have not been considered accurate enough to be useful in clinical practice. Here, we aim to combine the information from multiple EEG biomarkers into a diagnostic classification index in order to improve the accuracy of predicting conversion from MCI to AD within a two-year period. We followed 86 patients initially diagnosed with MCI for two years during which 25 patients converted to AD. We show that multiple EEG biomarkers mainly related to activity in the beta-frequency range (13–30 Hz can predict conversion from MCI to AD. Importantly, by integrating six EEG biomarkers into a diagnostic index using logistic regression the prediction improved compared with the classification using the individual biomarkers, with a sensitivity of 88% and specificity of 82%, compared with a sensitivity of 64% and specificity of 62% of the best individual biomarker in this index. In order to identify this diagnostic index we developed a data mining approach implemented in the Neurophysiological Biomarker Toolbox (http://www.nbtwiki.net/. We suggest that this approach can be used to identify optimal combinations of biomarkers (integrative biomarkers also in other modalities. Potentially, these integrative biomarkers could be more sensitive to disease progression and response to therapeutic intervention.

  2. Towards an integrative model of visual short-term memory maintenance: Evidence from the effects of attentional control, load, decay, and their interactions in childhood.

    Science.gov (United States)

    Shimi, Andria; Scerif, Gaia

    2017-12-01

    Over the past decades there has been a surge of research aiming to shed light on the nature of capacity limits to visual short-term memory (VSTM). However, an integrative account of this evidence is currently missing. We argue that investigating parameters constraining VSTM in childhood suggests a novel integrative model of VSTM maintenance, and that this in turn informs mechanisms of VSTM maintenance in adulthood. Over 3 experiments with 7-year-olds and young adults (total N=206), we provide evidence for multiple cognitive processes interacting to constrain VSTM performance. While age-related increases in storage capacity are undisputable, we replicate the finding that attentional processes control what information will be encoded and maintained in VSTM in the face of increased competition. Therefore, a central process to the current model is attentional refreshment, a mechanism that it is thought to reactivate and strengthen the signal of the visual representations. Critically, here we also show that attentional influences on VSTM are further constrained by additional factors, traditionally studied to the exclusion of each other, such as memory load and temporal decay. We propose that these processes work synergistically in an elegant manner to capture the adult-end state, whereas their less refined efficiency and modulations in childhood account for the smaller VSTM capacity that 7-year-olds demonstrate compared to older individuals. We conclude that going beyond the investigation of single cognitive mechanisms, to their interactions, holds the promise to understand both developing and fully developed maintenance in VSTM. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Predictive Attitude Maintenance For A Space Station

    Science.gov (United States)

    Hattis, Philip D.

    1989-01-01

    Paper provides mathematical basis for predictive management of angular momenta of control-moment gyroscopes (CMG's) to control attitude of orbiting space station. Numerical results presented for pitch control of proposed power-tower space station. Based on prior orbit history and mathematical model of density of atmosphere, predictions made of requirements on dumping and storage of angular momentum in relation to current loading state of CMG's and to acceptable attitude tolerances.

  4. On the concept of e-maintenance: Review and current research

    International Nuclear Information System (INIS)

    Muller, Alexandre; Crespo Marquez, Adolfo; Iung, Benoit

    2008-01-01

    The importance of the maintenance function has increased because of its role in keeping and improving system availability and safety, as well as product quality. To support this role, the development of the communication and information technologies has allowed the emergence of the concept of e-maintenance. Within the era of e-manufacturing and e-business, e-maintenance provides the opportunity for a new maintenance generation. As we will discuss later in this paper, e-maintenance integrates existing telemaintenance principles, with Web services and modern e-collaboration principles. Collaboration allows to share and exchange not only information but also knowledge and (e)-intelligence. By means of a collaborative environment, pertinent knowledge and intelligence become available and usable at the right place and time, in order to facilitate reaching the best maintenance decisions. This paper outlines the basic ideas within the e-maintenance concept and then provides an overview of the current research and challenges in this emerging field. An underlying objective is to identify the industrial/academic actors involved in the technological, organizational or management issues related to the development of e-maintenance. Today, this heterogeneous community has to be federated in order to bring up e-maintenance as a new scientific discipline

  5. Integrating the sequence dependent setup time open shop problem and preventive maintenance policies

    Directory of Open Access Journals (Sweden)

    K. Naboureh

    2016-09-01

    Full Text Available In most industrial environments, it is usually considered that machines are accessible throughout the planning horizon, but in real situation, machines may be unavailable due to a scheduled preventive maintenance where the periods of unavailability are known in advance. The main idea of this paper is to consider different preventive maintenance policies on machines regarding open shop scheduling problem (OSSP with sequence dependent setup times (SDST using immune algorithm. The preventive maintenance (PM policies are planned for maximizing availability of machines or keeping minimum level of reliability through the production horizon. The objective function of the paper is to minimize makespan. In total, the proposed algorithm extensively is compared with six adaptations of existing heuristic and meta-heuristic methods for the problem through data sets from benchmarks based on Taillard’s instances with some adjustments. The results show that the proposed algorithm outperforms other algorithms for this problem.

  6. A modeling framework for deteriorating control system and predictive maintenance of actuators

    International Nuclear Information System (INIS)

    Langeron, Y.; Grall, A.; Barros, A.

    2015-01-01

    Actuators play a central role in industrial automation systems. They are costly, and therefore studying their dependability needs all attention. Usually, an actuator is inserted in a feedback control system, and its mission is to implement a control action delivered by a controller. In this paper, a monotonic actuator deterioration is considered and it is assumed that a relationship exists between the control action and the physical actuator's deterioration. A modeling framework is proposed including a non-decreasing stochastic degradation process driving the inability for an actuator to fully implement its role. The prognosis of the actuator's residual useful lifetime is derived and used to update the controller's setting. The controller reconfiguration completes the maintenance corrective and preventive actions. This new action is suggested as an alternative for maintenance strategy. - Highlights: • A degrading control system model is proposed focusing on actuator deterioration. • It is assumed a relationship between this degradation and its loss of efficiency. • The actuator RUL is quantified as a quantile of its conditional survival function. • RUL prognosis is used to reconfigure the control input law. • This new action is suggested as an alternative for maintenance strategy

  7. Three AREVA tools for maintenance and outage support

    International Nuclear Information System (INIS)

    Lumpe, A.

    2012-01-01

    WlS is a knowledge-based database for the support of nuclear maintenance for components of different types It is productive since 2004 and has been continuously developed according to customer requirements. WIS allows for a centralized management of maintenance information and knowledge, including strategies, scheduling and reporting. WIS is already utilized in national and international NPPs. lts main advantages are: Support of service documentation for plant and service company employees, Support of integration into already existing IT infrastructure, Support of information and knowledge sharing, Easy and intuitive information usage, Savings by using standardized approach.

  8. Integrated Logistics Support Analysis of the International Space Station Alpha: An Overview of the Maintenance Time Dependent Parameter Prediction Methods Enhancement

    Science.gov (United States)

    Sepehry-Fard, F.; Coulthard, Maurice H.

    1995-01-01

    The objective of this publication is to introduce the enhancement methods for the overall reliability and maintainability methods of assessment on the International Space Station. It is essential that the process to predict the values of the maintenance time dependent variable parameters such as mean time between failure (MTBF) over time do not in themselves generate uncontrolled deviation in the results of the ILS analysis such as life cycle costs, spares calculation, etc. Furthermore, the very acute problems of micrometeorite, Cosmic rays, flares, atomic oxygen, ionization effects, orbital plumes and all the other factors that differentiate maintainable space operations from non-maintainable space operations and/or ground operations must be accounted for. Therefore, these parameters need be subjected to a special and complex process. Since reliability and maintainability strongly depend on the operating conditions that are encountered during the entire life of the International Space Station, it is important that such conditions are accurately identified at the beginning of the logistics support requirements process. Environmental conditions which exert a strong influence on International Space Station will be discussed in this report. Concurrent (combined) space environments may be more detrimental to the reliability and maintainability of the International Space Station than the effects of a single environment. In characterizing the logistics support requirements process, the developed design/test criteria must consider both the single and/or combined environments in anticipation of providing hardware capability to withstand the hazards of the International Space Station profile. The effects of the combined environments (typical) in a matrix relationship on the International Space Station will be shown. The combinations of the environments where the total effect is more damaging than the cumulative effects of the environments acting singly, may include a

  9. Planning of maintenance of electrical equipment in nuclear plants/laboratories [Paper No.: VB-3

    International Nuclear Information System (INIS)

    Narasinga Rao, S.N.; Bhattacharyya, A.K.

    1981-01-01

    Satisfactory operating performance of electrical systems ensures continuous availability of power to the various plants and machinery in nuclear plant and laboratories. For effective optimal functioning of the electrical equipment and to reduce their down time, scheduled planning of maintenance to the equipment is essential. Maintenance of power plant, nuclear or fossil, and industrial plant and research laboratories demands essential ingredients such as right type of trained and motivated technical personnel, adoption of standard procedures for maintenance, adequate safety and protection for equipment, safety procedures adopted in the installation to prevent hazards to the workers, provision of adequate stores and inventories, facilities for quick repairs and testing of equipment and effective planning of procedures for their maintenance. While breakdown maintenance allows equipment to operate before it is repaired or replaced, preventive maintenance makes use of scheduled inspection and periodical equipment overhaul and has little value for predicting future continuous performances of equipment. The engineered maintenance is most advantageous and offers maximum operating time to reduce down time of the equipment while adding predictive testing technique to aid in determining the frequency of overhaul of equipment. The important checks to be conducted and preventive maintenance programme to be scheduled are discussed in this paper. The safety and reliable functioning of the electrical equipment depend on proper optimal design, selection of equipment, their installation, subsequent maintenance and strict compliance with safety regulations. (author)

  10. Disturbance metrics predict a wetland Vegetation Index of Biotic Integrity

    Science.gov (United States)

    Stapanian, Martin A.; Mack, John; Adams, Jean V.; Gara, Brian; Micacchion, Mick

    2013-01-01

    Indices of biological integrity of wetlands based on vascular plants (VIBIs) have been developed in many areas in the USA. Knowledge of the best predictors of VIBIs would enable management agencies to make better decisions regarding mitigation site selection and performance monitoring criteria. We use a novel statistical technique to develop predictive models for an established index of wetland vegetation integrity (Ohio VIBI), using as independent variables 20 indices and metrics of habitat quality, wetland disturbance, and buffer area land use from 149 wetlands in Ohio, USA. For emergent and forest wetlands, predictive models explained 61% and 54% of the variability, respectively, in Ohio VIBI scores. In both cases the most important predictor of Ohio VIBI score was a metric that assessed habitat alteration and development in the wetland. Of secondary importance as a predictor was a metric that assessed microtopography, interspersion, and quality of vegetation communities in the wetland. Metrics and indices assessing disturbance and land use of the buffer area were generally poor predictors of Ohio VIBI scores. Our results suggest that vegetation integrity of emergent and forest wetlands could be most directly enhanced by minimizing substrate and habitat disturbance within the wetland. Such efforts could include reducing or eliminating any practices that disturb the soil profile, such as nutrient enrichment from adjacent farm land, mowing, grazing, or cutting or removing woody plants.

  11. Maintenance Planning of Offshore Wind Turbine using Condition Monitoring Information

    DEFF Research Database (Denmark)

    Ramírez, José G. Rangel; Sørensen, John Dalsgaard

    2009-01-01

    Deterioration processes such as fatigue and corrosion are typically affecting offshore structures. To "control" this deterioration, inspection and maintenance activities are developed. Probabilistic methodologies represent an important tool to identify the suitable strategy to inspect and control...... the deterioration in structures such as offshore wind turbines (OWT). Besides these methods, the integration of condition monitoring information (CMI) can optimize the mitigation activities as an updating tool. In this paper, a framework for risk-based inspection and maintenance planning (RBI) is applied for OWT....... With the integration of CMI by means Bayesian inference, a slightly change of first inspection times are coming up, influenced by the reduction of the uncertainty and harsher or milder external agents....

  12. Predicting adverse drug reaction profiles by integrating protein interaction networks with drug structures.

    Science.gov (United States)

    Huang, Liang-Chin; Wu, Xiaogang; Chen, Jake Y

    2013-01-01

    The prediction of adverse drug reactions (ADRs) has become increasingly important, due to the rising concern on serious ADRs that can cause drugs to fail to reach or stay in the market. We proposed a framework for predicting ADR profiles by integrating protein-protein interaction (PPI) networks with drug structures. We compared ADR prediction performances over 18 ADR categories through four feature groups-only drug targets, drug targets with PPI networks, drug structures, and drug targets with PPI networks plus drug structures. The results showed that the integration of PPI networks and drug structures can significantly improve the ADR prediction performance. The median AUC values for the four groups were 0.59, 0.61, 0.65, and 0.70. We used the protein features in the best two models, "Cardiac disorders" (median-AUC: 0.82) and "Psychiatric disorders" (median-AUC: 0.76), to build ADR-specific PPI networks with literature supports. For validation, we examined 30 drugs withdrawn from the U.S. market to see if our approach can predict their ADR profiles and explain why they were withdrawn. Except for three drugs having ADRs in the categories we did not predict, 25 out of 27 withdrawn drugs (92.6%) having severe ADRs were successfully predicted by our approach. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Inventory-transportation integrated optimization for maintenance spare parts of high-speed trains

    Science.gov (United States)

    Wang, Jiaxi; Wang, Huasheng; Wang, Zhongkai; Li, Jian; Lin, Ruixi; Xiao, Jie; Wu, Jianping

    2017-01-01

    This paper presents a 0–1 programming model aimed at obtaining the optimal inventory policy and transportation mode for maintenance spare parts of high-speed trains. To obtain the model parameters for occasionally-replaced spare parts, a demand estimation method based on the maintenance strategies of China’s high-speed railway system is proposed. In addition, we analyse the shortage time using PERT, and then calculate the unit time shortage cost from the viewpoint of train operation revenue. Finally, a real-world case study from Shanghai Depot is conducted to demonstrate our method. Computational results offer an effective and efficient decision support for inventory managers. PMID:28472097

  14. Operations and maintenance - Safety challenges

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Liv [Oljedirektoratet, Stavanger (Norway)

    1999-07-01

    With the unsteady oil prices and the possible consequences of the deregulation of the European energy markets one may expect further optimization of operating and maintenance costs. One may also expect extended use of various risk-based optimization techniques such as RCM (Reliability Centered Maintenance) and RBI (Risk Based Inspection). This presentation addresses the need for further research and development in this area. Maintenance work is necessary, but it can also create risk. The accident statistics show many examples of this. The Norwegian petroleum industry's ability to learn from previous incidents is questioned. Maintenance staff must be well trained and possess the necessary routines. Technical documentation must be updated. Uncertainties with respect to future oil and gas prices combined with the effect of the deregulation of the European energy markets will lead to even more focus on cost-effective operations and maintenance. The need for long-term research and development is stressed. Risk based techniques such as RCM and RBI are extensively used in the defence industry and the nuclear industry, but applying them to the petroleum industry requires improved risk models. Ageing effects such as corrosion, erosion, fatigue etc. can be expected, but the capability to predict, monitor and control them should be improved. At present, not even the most sophisticated risk analysis can model ageing effects. The importance of efficient use of information technology (IT) is stressed. Improving the product quality and safety often requires new technology and so research and development is important. Close cooperation with the industry is required.

  15. Parameters affecting tooth loss during periodontal maintenance in a Greek population.

    Science.gov (United States)

    Tsami, Alexandra; Pepelassi, Eudoxie; Kodovazenitis, George; Komboli, Mado

    2009-09-01

    Investigators have evaluated predictive parameters of tooth loss during the maintenance phase (MP). The authors conducted a retrospective study to evaluate the rate of tooth loss and to explore the parameters that affect tooth loss during MP in a Greek population. A periodontist administered periodontal treatment and maintenance care to 280 participants with severe periodontitis for a mean period +/- standard deviation of 10.84 +/- 2.13 years. The periodontist recorded the following parameters for each participant: oral hygiene index level, simplified gingival index level, clinical attachment level, probing depth measurements, initial tooth prognosis, smoking status, tooth loss during active periodontal treatment and MP, and compliance with suggested maintenance visits. The authors found that total tooth loss during active treatment (n = 1,427) was greater than during MP (n = 918) and was associated with the initial tooth prognosis, tooth type group, participants' compliance with suggested maintenance visits, smoking status and acceptability of the quality of tooth restorations. Most of the teeth extracted during maintenance had an initial guarded prognosis (n = 612). Participants whose compliance was erratic had a greater risk of undergoing tooth extraction than did participants whose compliance was complete. Participants' initial tooth prognosis, tooth type, compliance with suggested maintenance visits and smoking status affected tooth loss during MP. Initial guarded prognosis and erratic compliance increased the risk of undergoing tooth extraction during maintenance. Determining predictive parameters for disease progression and tooth loss provides critical information to clinicians so that they can develop and implement rational treatment planning.

  16. APPLICATION OF ROUGH SET THEORY TO MAINTENANCE LEVEL DECISION-MAKING FOR AERO-ENGINE MODULES BASED ON INCREMENTAL KNOWLEDGE LEARNING

    Institute of Scientific and Technical Information of China (English)

    陆晓华; 左洪福; 蔡景

    2013-01-01

    The maintenance of an aero-engine usually includes three levels ,and the maintenance cost and period greatly differ depending on the different maintenance levels .To plan a reasonable maintenance budget program , airlines would like to predict the maintenance level of aero-engine before repairing in terms of performance parame-ters ,which can provide more economic benefits .The maintenance level decision rules are mined using the histori-cal maintenance data of a civil aero-engine based on the rough set theory ,and a variety of possible models of upda-ting rules produced by newly increased maintenance cases added to the historical maintenance case database are in-vestigated by the means of incremental machine learning .The continuously updated rules can provide reasonable guidance suggestions for engineers and decision support for planning a maintenance budget program before repai-ring .The results of an example show that the decision rules become more typical and robust ,and they are more accurate to predict the maintenance level of an aero-engine module as the maintenance data increase ,which illus-trates the feasibility of the represented method .

  17. Value centric approaches to the design, operations and maintenance of wind turbines

    Science.gov (United States)

    Khadabadi, Madhur Aravind

    Wind turbine maintenance is emerging as an unexpectedly high component of turbine operating cost, and there is an increasing interest in managing this cost. This thesis presents an alternative view of maintenance as a value-driver, and develops an optimization algorithm to evaluate the value delivered by different maintenance techniques. I view maintenance as an operation that moves the turbine to an improved state in which it can generate more power and, thus, earn more revenue. To implement this approach, I model the stochastic deterioration of the turbine in two dimensions: the deterioration rate, and the extent of deterioration, and then use maintenance to improve the state of the turbine. The value of the turbine is the difference between the revenue from to the power generation and the costs incurred in operation and maintenance. With a focus on blade deterioration, I evaluate the value delivered by implementing two different maintenance schemes, predictive maintenance and scheduled maintenance. An example of predictive maintenance technique is the use of Condition Monitoring Systems to precisely detect deterioration. I model Condition Monitoring System (CMS) of different degrees of fidelity, where a higher fidelity CMS would allow the blade state to be determined with a higher precision. The same model is then applied for the scheduled maintenance technique. The improved state information obtained from these techniques is then used to derive an optimal maintenance strategy. The difference between the value of the turbine with and without the inspection type can be interpreted as the value of the inspection. The results indicate that a higher fidelity (and more expensive) inspection method does not necessarily yield the highest value, and, that there is an optimal level of fidelity that results in maximum value. The results also aim to inform the operator of the impact of regional parameters such as wind speed, variance and maintenance costs to the optimal

  18. Integrated predictive modelling simulations of burning plasma experiment designs

    International Nuclear Information System (INIS)

    Bateman, Glenn; Onjun, Thawatchai; Kritz, Arnold H

    2003-01-01

    Models for the height of the pedestal at the edge of H-mode plasmas (Onjun T et al 2002 Phys. Plasmas 9 5018) are used together with the Multi-Mode core transport model (Bateman G et al 1998 Phys. Plasmas 5 1793) in the BALDUR integrated predictive modelling code to predict the performance of the ITER (Aymar A et al 2002 Plasma Phys. Control. Fusion 44 519), FIRE (Meade D M et al 2001 Fusion Technol. 39 336), and IGNITOR (Coppi B et al 2001 Nucl. Fusion 41 1253) fusion reactor designs. The simulation protocol used in this paper is tested by comparing predicted temperature and density profiles against experimental data from 33 H-mode discharges in the JET (Rebut P H et al 1985 Nucl. Fusion 25 1011) and DIII-D (Luxon J L et al 1985 Fusion Technol. 8 441) tokamaks. The sensitivities of the predictions are evaluated for the burning plasma experimental designs by using variations of the pedestal temperature model that are one standard deviation above and below the standard model. Simulations of the fusion reactor designs are carried out for scans in which the plasma density and auxiliary heating power are varied

  19. Development of an Integrated Moisture Index for predicting species composition

    Science.gov (United States)

    Louis R. Iverson; Charles T. Scott; Martin E. Dale; Anantha Prasad

    1996-01-01

    A geographic information system (GIS) approach was used to develop an Integrated Moisture Index (IMI), which was used to predict species composition for Ohio forests. Several landscape features (a slope-aspect shading index, cumulative flow of water downslope, curvature of the landscape, and the water-holding capacity of the soil) were derived from elevation and soils...

  20. Optimización del mantenimiento preventivo utilizando las técnicas de diagnóstico integral. Resultados parciales teórico-prácticos; Optimization of the Preventive Maintenance Using the Technique of Integral Diagnosis. Partial Results Theoretical- Practical

    Directory of Open Access Journals (Sweden)

    Pedro L Hernández Domínguez

    2011-02-01

    Full Text Available En este trabajo se continúa desarrollando la metodología que aporta el diagnóstico integral (DI presentada porlos autores en un artículo anterior, con la finalidad de introducir el mantenimiento basado en la condición (MBCcomo una forma de mejoramiento o perfeccionamiento del mantenimiento preventivo planificado (MPP que sedesarrolla en las centrales termoeléctricas cubanas, y cuya base radica en encontrar la relación fallas - variableso parámetros de estado de diagnóstico de un equipo o sistema. In the present paper, the authors continues developing the methodology that contributes the integral diagnosis(ID presented by they in a previous article, with the purpose of introducing the condition based maintenance(CBM like a form of improvement the planned preventive maintenance (PPM that is developed in the cubanthermoelectric power stations, and whose base resides in finding the relationship failures - variables or parametersof state of diagnosis of a equiepment or system. 

  1. A CMMS Expert using BIM for IBS Building Maintenance

    Directory of Open Access Journals (Sweden)

    Hamzah Noraini

    2016-01-01

    Full Text Available In the IBS building maintenance, the conventional methods to the project delivery and its failure to form effective communication channel between complementary knowledge on IBS construction and related members that is conducted in the sequential manner has resulted in ineffectiveness for managing building maintenance, where a paradigm shift within the IBS traditional approach is necessary. The research results described are concerned with i an integrated system to record, diagnose and analyse information for IBS building maintenance to detect patent or latent defect, select an effective repair method, provide appropriate planning decision and reduce risks of defect throughout the building lifetime. ii building a decision making support in diagnosis in IBS building maintenance based on robust data collection about concrete defects and causes including in the selection of a durable replacement design and material or the proper rehabilitation method. The system development was based on analysis of number of interviews and case studies conducted with professional engineers working in IBS building maintenance departments. The paper concludes that implementing a CMMS Expert using BIM can help improve the performance of IBS building design, construction and maintenance operations.

  2. Integration of Fast Predictive Model and SLM Process Development Chamber, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This STTR project seeks to develop a fast predictive model for selective laser melting (SLM) processes and then integrate that model with an SLM chamber that allows...

  3. Robustness evaluation of cutting tool maintenance planning for soft ground tunneling projects

    Directory of Open Access Journals (Sweden)

    Alena Conrads

    2018-03-01

    Full Text Available Tunnel boring machines require extensive maintenance and inspection effort to provide a high availability. The cutting tools of the cutting wheel must be changed timely upon reaching a critical condition. While one possible maintenance strategy is to change tools only when it is absolutely necessary, tools can also be changed preventively to avoid further damages. Such different maintenance strategies influence the maintenance duration and the overall project performance. However, determine downtime related to a particular maintenance strategy is still a challenging task. This paper shows an analysis of the robustness to achieve the planned project performance of a maintenance strategy considering uncertainties of wear behavior of the cutting tools. A simulation based analysis is presented, implementing an empirical wear prediction model. Different strategies of maintenance planning are compared by performing a parameter variation study including Monte-Carlo simulations. The maintenance costs are calculated and evaluated with respect to their robustness. Finally, an improved and robust maintenance strategy has been determined. Keywords: Mechanized tunneling, Maintenance, Wear of cutting tools, Process simulation, Robustness, Uncertainty modeling

  4. Effective maintenance practices to manage system aging

    International Nuclear Information System (INIS)

    Chockie, A.; Bjorkelo, K.

    1992-01-01

    For a variety of economic and technical reasons, there has been a growing concern with the aging of complex systems and components and the role that maintenance can play in reducing this degradation. A study for the Nuclear Regulatory Commission was recently undertaken to identify effective maintenance practices that could be adapted by the nuclear industry in the United States to assist in managing the aging degradation of plant systems and components. Four organizations were examined to assess the influence that their maintenance programs have on their ability to address the systems and component aging degradation issues. An effective maintenance program was found to be essential to the management of system and component aging. The four key elements of an effective maintenance program that are important to an aging management program were identified. These are: the selection of critical systems and components; the development of an understanding of aging through the collection and analysis of equipment performance information; the development of appropriate preventive and predictive maintenance tasks to manage equipment and system aging degradation; the use of feedback mechanisms to continuously improve the management of aging systems and components. These elements were found to be common to all four organizations. In examining how the four organizations have structured their maintenance programs to include these key elements provides valuable lessons not only for the nuclear power industry, but also for any industrial organization that is concerned with the management of system and component aging degradation. This document provides detail, of these studies

  5. Pemetrexed in maintenance treatment of advanced non-squamous non-small-cell lung cancer

    Directory of Open Access Journals (Sweden)

    Minami S

    2015-01-01

    a pivotal drug when a combination maintenance therapy is used in practice. For future maintenance therapy, we need to explore reliable predictive selection or exclusion markers that can predict who will really benefit from maintenance therapy. Keywords: pemetrexed, maintenance therapy, continuation, switch, non-squamous non-small cell carcinoma, cost-effectiveness, epidermal growth factor mutation

  6. Production and Maintenance Planning for a Deteriorating System with Operation-Dependent Defectives

    Directory of Open Access Journals (Sweden)

    Héctor Rivera-Gómez

    2018-01-01

    Full Text Available This paper provides new insights to the area of sustainable manufacturing systems at analyzing the novel paradigm of integrated production logistics, quality, and maintenance design. For this purpose, we investigate the optimal production and repair/major maintenance switching strategy of an unreliable deteriorating manufacturing system. The effects of the deterioration process are mainly observed on the failure intensity and on the quality of the parts produced, where the rate of defectives depends on the production rate. When unplanned failures occur, either a minimal repair or a major maintenance could be conducted. The integration of availability and quality deterioration led us to propose a new stochastic dynamic programming model where optimality conditions are derived through the Hamilton-Jacobi-Bellman equations. The model defined the joint production and repair/major maintenance switching strategies minimizing the total cost over an infinite planning horizon. In the results, the influence of the deterioration process were evident in both the production and maintenances control parameters. A numerical example and an extensive sensitivity analysis were conducted to illustrate the usefulness of the results. Finally, the proposed control policy was compared with alternative strategies based on common assumptions of the literature in order to illustrate its efficiency.

  7. Framework for implementation of maintenance management in distribution network service providers

    International Nuclear Information System (INIS)

    Gomez Fernandez, Juan Francisco; Crespo Marquez, Adolfo

    2009-01-01

    Distribution network service providers (DNSP) are companies dealing with network infrastructure, such as distribution of gas, water, electricity or telecommunications, and they require the development of special maintenance management (MM) capabilities in order to satisfy the needs of their customers. In this sector, maintenance management information systems are essential to ensure control, gain knowledge and improve decision making. The aim of this paper is the study of specific characteristics of maintenance in these types of companies. We will investigate existing standards and best management practices with the scope of defining a suitable ad-hoc framework for implementation of maintenance management. The conclusion of the work supports the proposition of a framework consisting on a processes framework based on a structure of systems, integrated for continuous improvement of maintenance activities. The paper offers a very practical approach to the problem, as a result of more of 10 years of professional experience within this sector, and specially focused to network maintenance.

  8. Paper number: ID 576... Monitoring and maintenance of pumps in LWR

    International Nuclear Information System (INIS)

    Heller, M.; Einzmann, K.

    2001-01-01

    Due to the liberalization of the European Market for electrical power nuclear power plants are progressively subjected to high pressure in respect of reducing the overall costs including for maintenance actions. This concerns also the maintenance of active components as pumps or valves. Siemens Nuclear Power (SNP) has developed a concept for the transition to an integrated condition based maintenance especially for pumps which shall be presented below. It is proposed to make up future decisions on maintenance of pumps only depending on condition data of the component. The concept must be supported by modern monitoring systems, which shall be installed at pumps which are relevant for the safety and availability of the plants. The main technical features of the SNP monitoring system DIROM are presented in detail as an example. First results of acquiring condition related data of a nuclear feed water pump are reported too. The new maintenance concept promises attractive cost benefits in comparison to a former preventive maintenance concept. (author)

  9. Rac1 is crucial for hair follicle integrity but is not essential for maintenance of the epidermis

    DEFF Research Database (Denmark)

    Chrostek, Anna; Wu, Xunwei; Quondamatteo, Fabio

    2006-01-01

    Rac1 is a small GTPase that regulates the actin cytoskeleton but also other cellular processes. To investigate the function of Rac1 in skin, we generated mice with a keratinocyte-restricted deletion of the rac1 gene. Rac1-deficient mice lost nearly all of their hair within a few weeks after birth....... The nonpermanent part of mutant hair follicles developed constrictions; lost expression of hair follicle-specific keratins, E-cadherin, and alpha6 integrin; and was eventually removed by macrophages. The permanent part of hair follicles and the sebaceous glands were maintained, but no regrowth of full-length hair...... defect and slightly impaired adhesion. These data show that Rac1 plays an important role in sustaining the integrity of the lower part of hair follicles but not in maintenance of the epidermis....

  10. Availability objectives integration to design. The CIDEM approach

    International Nuclear Information System (INIS)

    Degrave, C.; Martin-Onraet, M.

    1994-01-01

    Considering the operation experience feedback from its nuclear park and from foreign parks, and considering new approaches and design tools such as concurrent engineering, total quality, etc., EDF (Electricite de France) has decided to start the CIDEM approach (integration of availability, operating experience feedback and maintenance into design), an analytical and systematical study process for new projects (REP2000 (or PWR2000)), in order to optimize as much as possible the design phase while integrating maintenance, availability and safety objectives, with the view of a minimized kWh cost. This process, already used in other industries, employs concepts such as RAM (Reliability Availability Maintainability), RCM (Reliability Centered Maintenance) and ILS (Integrated Logistic Support). The availability and maintenance scheduling studies for the REP2000 project are detailed. 10 fig., 6 tab

  11. Brain systems for probabilistic and dynamic prediction: computational specificity and integration.

    Directory of Open Access Journals (Sweden)

    Jill X O'Reilly

    2013-09-01

    Full Text Available A computational approach to functional specialization suggests that brain systems can be characterized in terms of the types of computations they perform, rather than their sensory or behavioral domains. We contrasted the neural systems associated with two computationally distinct forms of predictive model: a reinforcement-learning model of the environment obtained through experience with discrete events, and continuous dynamic forward modeling. By manipulating the precision with which each type of prediction could be used, we caused participants to shift computational strategies within a single spatial prediction task. Hence (using fMRI we showed that activity in two brain systems (typically associated with reward learning and motor control could be dissociated in terms of the forms of computations that were performed there, even when both systems were used to make parallel predictions of the same event. A region in parietal cortex, which was sensitive to the divergence between the predictions of the models and anatomically connected to both computational networks, is proposed to mediate integration of the two predictive modes to produce a single behavioral output.

  12. Development and integration of programmatic performance indicators

    International Nuclear Information System (INIS)

    Modarres, M.; Wrethall, J.; Appignani, P.L.

    1989-01-01

    This paper describes the results of an evaluation of maintenance-related programmatic performance indicators, and summarizes the direction being taken in a new project to integrate indirect performance indicators for nuclear power plants. Programmatic indicators allow NRC to monitor, at a distance, trends in functional activities before a significant impact appears on safety. Previously presented work described the selection of candidate performance indicators associated with maintenance for continued analysis. This evaluation focused on two aspects of the selected indicators: (1) an evaluation of the state of maintenance programs in the narrative text of SALP reports versus the frequencies of inadvertent ESF actuations from test and maintenance errors; and (2) an evaluation of alternative methods for analyzing the thermal performance of plants as an integral indicator of maintenance program effectiveness. 1 ref., 1 fig

  13. The Prediction-Focused Approach: An opportunity for hydrogeophysical data integration and interpretation

    Science.gov (United States)

    Hermans, Thomas; Nguyen, Frédéric; Klepikova, Maria; Dassargues, Alain; Caers, Jef

    2017-04-01

    Hydrogeophysics is an interdisciplinary field of sciences aiming at a better understanding of subsurface hydrological processes. If geophysical surveys have been successfully used to qualitatively characterize the subsurface, two important challenges remain for a better quantification of hydrological processes: (1) the inversion of geophysical data and (2) their integration in hydrological subsurface models. The classical inversion approach using regularization suffers from spatially and temporally varying resolution and yields geologically unrealistic solutions without uncertainty quantification, making their utilization for hydrogeological calibration less consistent. More advanced techniques such as coupled inversion allow for a direct use of geophysical data for conditioning groundwater and solute transport model calibration. However, the technique is difficult to apply in complex cases and remains computationally demanding to estimate uncertainty. In a recent study, we investigate a prediction-focused approach (PFA) to directly estimate subsurface physical properties from geophysical data, circumventing the need for classic inversions. In PFA, we seek a direct relationship between the data and the subsurface variables we want to predict (the forecast). This relationship is obtained through a prior set of subsurface models for which both data and forecast are computed. A direct relationship can often be derived through dimension reduction techniques. PFA offers a framework for both hydrogeophysical "inversion" and hydrogeophysical data integration. For hydrogeophysical "inversion", the considered forecast variable is the subsurface variable, such as the salinity. An ensemble of possible solutions is generated, allowing uncertainty quantification. For hydrogeophysical data integration, the forecast variable becomes the prediction we want to make with our subsurface models, such as the concentration of contaminant in a drinking water production well. Geophysical

  14. Integrating inventory control and capacity management at a maintenance service provider

    NARCIS (Netherlands)

    Buyukkaramikli, N.C.; Ooijen, van H.P.G.; Bertrand, J.W.M.

    2015-01-01

    In this paper, we study the capacity flexibility problem of a maintenance service provider, who is running a repair shop and is responsible for the availability of numerous specialized systems which contain a critical component that is prone to failure. Upon a critical component failure, the

  15. Predicting Elementary Education Candidates' Technology Integration during Their Field Placement Instruction.

    Science.gov (United States)

    Negishi, Meiko; Elder, Anastasia D.; Hamil, J. Burnette; Mzoughi, Taha

    A growing concern in teacher education programs is technology training. Research confirms that training positively affects perservice teachers' attitudes and technology proficiency. However, little is known about the kinds of factors that may predict preservice teachers' integration of technology into their own instruction. The goal of this study…

  16. A network integration approach for drug-target interaction prediction and computational drug repositioning from heterogeneous information.

    Science.gov (United States)

    Luo, Yunan; Zhao, Xinbin; Zhou, Jingtian; Yang, Jinglin; Zhang, Yanqing; Kuang, Wenhua; Peng, Jian; Chen, Ligong; Zeng, Jianyang

    2017-09-18

    The emergence of large-scale genomic, chemical and pharmacological data provides new opportunities for drug discovery and repositioning. In this work, we develop a computational pipeline, called DTINet, to predict novel drug-target interactions from a constructed heterogeneous network, which integrates diverse drug-related information. DTINet focuses on learning a low-dimensional vector representation of features, which accurately explains the topological properties of individual nodes in the heterogeneous network, and then makes prediction based on these representations via a vector space projection scheme. DTINet achieves substantial performance improvement over other state-of-the-art methods for drug-target interaction prediction. Moreover, we experimentally validate the novel interactions between three drugs and the cyclooxygenase proteins predicted by DTINet, and demonstrate the new potential applications of these identified cyclooxygenase inhibitors in preventing inflammatory diseases. These results indicate that DTINet can provide a practically useful tool for integrating heterogeneous information to predict new drug-target interactions and repurpose existing drugs.Network-based data integration for drug-target prediction is a promising avenue for drug repositioning, but performance is wanting. Here, the authors introduce DTINet, whose performance is enhanced in the face of noisy, incomplete and high-dimensional biological data by learning low-dimensional vector representations.

  17. Preventive maintenance: optimization of time - based discard decisions at the bruce nuclear generating station

    International Nuclear Information System (INIS)

    Doyle, E.K.; Jardine, A.K.S.

    2001-01-01

    The use of various maintenance optimization techniques at Bruce has lead to cost effective preventive maintenance applications for complex systems. As previously reported at ICONE 6 in New Orleans, 1996, several innovative practices reduced Reliability Centered Maintenance costs while maintaining the accuracy of the analysis. The optimization strategy has undergone further evolution and at the present an Integrated Maintenance Program (IMP) is in place where an Expert Panel consisting of all players/experts proceed through each system in a disciplined fashion and reach agreement on all items under a rigorous time frame. It is well known that there are essentially 3 maintenance based actions that can flow from a Maintenance Optimization Analysis: condition based maintenance, time based maintenance and time based discard. The present effort deals with time based discard decisions. Maintenance data from the Remote On-Power Fuel Changing System was used. (author)

  18. Predicting emergency diesel starting performance

    International Nuclear Information System (INIS)

    DeBey, T.M.

    1989-01-01

    The US Department of Energy effort to extend the operational lives of commercial nuclear power plants has examined methods for predicting the performance of specific equipment. This effort focuses on performance prediction as a means for reducing equipment surveillance, maintenance, and outages. Realizing these goals will result in nuclear plants that are more reliable, have lower maintenance costs, and have longer lives. This paper describes a monitoring system that has been developed to predict starting performance in emergency diesels. A prototype system has been built and tested on an engine at Sandia National Laboratories. 2 refs

  19. A whole-school approach to facilities maintenance / Velaphi Aaron Nhlapo.

    OpenAIRE

    Nhlapo, Velaphi Aaron

    2009-01-01

    The area of school facilities maintenance as an integral component of schools' educational programmes is only beginning to receive attention in South Africa, through the publishing of Notice 1438 of 2008 of the National Education Policy, which is a call for comments on the National Policy for an Equitable Provision of an Enabling School Physical Teaching and Learning Environment. This implies that, while it is a critical aspect of teaching and learning, school facilities maintenance has not b...

  20. Preventive maintenance-A countermeasure to plant aging

    International Nuclear Information System (INIS)

    Hlubek, W.

    1985-01-01

    The aging of power plants is caused by manifold and different influences. For instance, mechanical and thermal stress, radiation exposure, denting or wastage can considerably affect the aging of plant components and thus cause premature failures of components. In this presentation, the term 'Plant Aging' in nuclear power plants is to be understood more comprehensively than wear on components and material fatigue. In addition, nuclear power plants are to be adjusted to the advancing state of the science and technology (state-of-the-art) in order to guarantee safe operation at all times. The preventive maintenance - as a countermeasure to plant aging - comprises the systematic checks and servicing of the plant systems in operation and follows aging by inspection and tests. Experience with Rheinisch-Westfaelisches Elektrizitaetswerk AG (RWE) preventive maintenance program at the Biblis NNP (1300 MW, PWR) is discussed. The concept of an 'Integrated Maintenance System' as a means to avoid 'Plant Aging' is presented

  1. Systematic analysis of ECG predictors of sinus rhythm maintenance after electrical cardioversion for persistent atrial fibrillation.

    Science.gov (United States)

    Lankveld, Theo; de Vos, Cees B; Limantoro, Ione; Zeemering, Stef; Dudink, Elton; Crijns, Harry J; Schotten, Ulrich

    2016-05-01

    Electrical cardioversion (ECV) is one of the rhythm control strategies in patients with persistent atrial fibrillation (AF). Unfortunately, recurrences of AF are common after ECV, which significantly limits the practical benefit of this treatment in patients with AF. The objectives of this study were to identify noninvasive complexity or frequency parameters obtained from the surface electrocardiogram (ECG) to predict sinus rhythm (SR) maintenance after ECV and to compare these ECG parameters with clinical predictors. We studied a wide variety of ECG-derived time- and frequency-domain AF complexity parameters in a prospective cohort of 502 patients with persistent AF referred for ECV. During 1-year follow-up, 161 patients (32%) maintained SR. The best clinical predictor of SR maintenance was antiarrhythmic drug (AAD) treatment. A model including clinical parameters predicted SR maintenance with a mean cross-validated area under the receiver operating characteristic curve (AUC) of 0.62 ± 0.05. The best single ECG parameter was the dominant frequency (DF) on lead V6. Combining several ECG parameters predicted SR maintenance with a mean AUC of 0.64 ± 0.06. Combining clinical and ECG parameters improved prediction to a mean AUC of 0.67 ± 0.05. Although the DF was affected by AAD treatment, excluding patients taking AADs did not significantly lower the predictive performance captured by the ECG. ECG-derived parameters predict SR maintenance during 1-year follow-up after ECV at least as good as known clinical predictors of rhythm outcome. The DF proved to be the most powerful ECG-derived predictor. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  2. Integrated vibration-based maintenance: an approach for continuous reduction in LCC. A case study

    Energy Technology Data Exchange (ETDEWEB)

    Najjar, B [ER Konsult Utveckling AB, Vaexjoe (Sweden)

    1999-12-31

    The biggest thread in achieving and maintaining high equipment effectiveness can be stated as: whether the improved manufacturing processes capable of producing quality products at a competitive cost. The effect of a new vibration-based maintenance concept, called Total Quality Maintenance (TQMain), is introduced. It aims to make intensive use of the real-time data acquisition and analysis to detect causes behind product quality deviation and failures in machinery, and following defect development at an early stage to increase machine mean effective life and improve company`s economics. The effect of TQMain on LCC of machinery and company`s economics is discussed. A case study to reveal savings in maintenance cost when a vibration-based policy involved, is presented. Using TQMain, company`s economics can be improved effectively through continuous improvement of the technical and economic effectiveness of production processes. (orig.) 14 refs.

  3. Integrated vibration-based maintenance: an approach for continuous reduction in LCC. A case study

    Energy Technology Data Exchange (ETDEWEB)

    Najjar, B. [ER Konsult Utveckling AB, Vaexjoe (Sweden)

    1998-12-31

    The biggest thread in achieving and maintaining high equipment effectiveness can be stated as: whether the improved manufacturing processes capable of producing quality products at a competitive cost. The effect of a new vibration-based maintenance concept, called Total Quality Maintenance (TQMain), is introduced. It aims to make intensive use of the real-time data acquisition and analysis to detect causes behind product quality deviation and failures in machinery, and following defect development at an early stage to increase machine mean effective life and improve company`s economics. The effect of TQMain on LCC of machinery and company`s economics is discussed. A case study to reveal savings in maintenance cost when a vibration-based policy involved, is presented. Using TQMain, company`s economics can be improved effectively through continuous improvement of the technical and economic effectiveness of production processes. (orig.) 14 refs.

  4. Maintenance methods

    International Nuclear Information System (INIS)

    Sanchis, H.; Aucher, P.

    1990-01-01

    The maintenance method applied at the Hague is summarized. The method was developed in order to solve problems relating to: the different specialist fields, the need for homogeneity in the maintenance work, the equipment diversity, the increase of the materials used at the Hague's new facilities. The aim of the method is to create a knowhow formalism, to facilitate maintenance, to ensure the running of the operations and to improve the estimation of the maintenance cost. One of the method's difficulties is the demonstration of the profitability of the maintenance operations [fr

  5. Development of maintenance knowledge management system for power plant

    International Nuclear Information System (INIS)

    Ohi, Tadashi; Hirai, Kenji

    2004-01-01

    This paper describes the knowledge management framework to systematize maintenance knowledge in power plant. The features of the framework are (1) to construct a decision tree of trouble cases incrementally based on Ripple Down Rules (RDR) method and (2) to decide the timing of installing new knowledge based on several metrics obtained by evaluating a structure of a decision tree. We are developing the experimental prototype of maintenance knowledge management system. The system is integrated with plant database (ex. the operation journals and maintenance records). The management of trouble cases is based on the format of XML. For practical purpose, each trouble case is linked with related data (ex. maintenance manuals, equipment configuration, records). Plant workers can easily search for maintenance knowledge and relevant data by specifying observed status. On the other hand, knowledge engineers can monitor occurrence counts of exceptional cases to each node. The metrics calculation gives a cue to locate the effective node for improving the efficiency of retrieval. We are evaluating the functionality and the effectiveness of the system through the application to maintenance work of controller systems. We believe that this framework will be helpful to share common knowledge among plant sites as well as to manage site-specific knowledge. (author)

  6. Integrated Guidelines for Management of Alloy 600 Locations

    Energy Technology Data Exchange (ETDEWEB)

    Na, Kyung-Hwan; Chung, Hansub; Yang, Jun-Seog; Lee, Kyoung-Soo [KHNP-Central Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The locations experiencing PWSCC include steam generator tubes, pressurizer instrumental nozzles, control rod driving mechanism(CRDM) penetration nozzles, reactor outlet nozzles, and bottom mounted instrumental(BMI) nozzles. Korea Hydro and Nuclear Power Co.(KHNP) has developed integrated guidelines for management of alloy 600 locations and the guidelines are under review by the regulator. The guidelines consist of alloy 600 location database, inspection program, maintenance/preventive maintenance method, and finally water chemistry management for PWSCC mitigation. In this paper, the detailed contents are presented. The integrated guidelines collected all relevant information on the management of alloy 600 locations. This information may be useful for establishing the most effective preventive maintenance strategies by prioritization in addition to maintenance strategies. Table II summarize maintenance strategies for alloy 600 locations.

  7. Interval of Routine Maintenance and Maintenance Performance: A Literature Review

    Directory of Open Access Journals (Sweden)

    Au-Yong Cheong Peng

    2016-01-01

    Full Text Available In high-rise residential buildings, the quality of facilities management services is significant to the normal operation of the facilities. Unfortunately, lack of concern towards building maintenance, especially preventive maintenance, happens in domestic housing industry in Malaysia. Majority of the maintenance operations of condominiums suffer from lack of planning, lack of proactive maintenance plan, and lack of proper implementation. Thus, this paper reviews the implementation of preventive maintenance strategy, routine maintenance in specific. An extensive review of literature published in 1987 to 2014 is performed for the purpose of this research. The publications are sourced from journal articles, conference proceedings and books. The literature analysis confirms that the routine maintenance of facilities and building services is vital and it can be influential towards the maintenance performance. Subsequently, a theoretical framework is developed, which shows the relationship between routine maintenance of building facilities & services and maintenance performance. The building facilities & services are divided into two categories. They are essential facilities & services that ensure the safety, health, habitability, and operability of buildings; while value-added facilities & services deal with property value, return on investment, and quality living of buildings. Based on the findings, a future research is proposed, which aims to identify the appropriate routine of maintenance for the facilities and services in high-rise residential buildings to improve the maintenance performance.

  8. Parasites and deleterious mutations: interactions influencing the evolutionary maintenance of sex.

    Science.gov (United States)

    Park, A W; Jokela, J; Michalakis, Y

    2010-05-01

    The restrictive assumptions associated with purely genetic and purely ecological mechanisms suggest that neither of the two forces, in isolation, can offer a general explanation for the evolutionary maintenance of sex. Consequently, attention has turned to pluralistic models (i.e. models that apply both ecological and genetic mechanisms). Existing research has shown that combining mutation accumulation and parasitism allows restrictive assumptions about genetic and parasite parameter values to be relaxed while still predicting the maintenance of sex. However, several empirical studies have shown that deleterious mutations and parasitism can reduce fitness to a greater extent than would be expected if the two acted independently. We show how interactions between these genetic and ecological forces can completely reverse predictions about the evolution of reproductive modes. Moreover, we demonstrate that synergistic interactions between infection and deleterious mutations can render sex evolutionarily stable even when there is antagonistic epistasis among deleterious mutations, thereby widening the conditions for the evolutionary maintenance of sex.

  9. Integration of Predictive Display and Aircraft Flight Control System

    Directory of Open Access Journals (Sweden)

    Efremov A.V.

    2017-01-01

    Full Text Available The synthesis of predictive display information and direct lift control system are considered for the path control tracking tasks (in particular landing task. The both solutions are based on pilot-vehicle system analysis and requirements to provide the highest accuracy and lowest pilot workload. The investigation was carried out for cases with and without time delay in aircraft dynamics. The efficiency of the both ways for the flying qualities improvement and their integration is tested by ground based simulation.

  10. Music therapy-induced changes in salivary cortisol level are predictive of cardiovascular mortality in patients under maintenance hemodialysis

    Directory of Open Access Journals (Sweden)

    Hou YC

    2017-02-01

    Full Text Available Yi-Chou Hou,1 Yen-Ju Lin,2 Kuo-Cheng Lu,1 Han-Sun Chiang,3 Chia-Chi Chang,4 Li-King Yang1 1Department of Internal Medicine, Cardinal Tien Hospital, School of Medicine, Fu-Jen Catholic University, 2Department of Nursing, Taipei Medical University, 3Graduate Institute of Basic Medicine, College of Medicine, Fu Jen Catholic University, New Taipei City, 4School of Gerontology Health Management, College of Nursing, Taipei Medical University, Taipei, Taiwan, Republic of China Background: Music therapy has been applied in hemodialysis (HD patients for relieving mental stress. Whether the stress-relieving effect by music therapy is predictive of clinical outcome in HD patients is still unclear.Methods: We recruited a convenience sample of 99 patients on maintenance HD and randomly assigned them to the experimental (n=49 or control (n=50 group. The experimental group received relaxing music therapy for 1 week, whereas the control group received no music therapy. In the experimental group, we compared cardiovascular mortality in the patients with and without cortisol changes.Results: The salivary cortisol level was lowered after 1 week of music therapy in the experimental group (−2.41±3.08 vs 1.66±2.11 pg/mL, P<0.05, as well as the frequency of the adverse reaction score (−3.35±5.76 vs −0.81±4.59, P<0.05, the severity of adverse reactions score (−1.93±2.73 vs 0.33±2.71, P<0.05, and hemodialysis stressor scale (HSS score (−6.00±4.68 vs −0.877±7.08, P<0.05. The difference in salivary cortisol correlated positively with HD stress score scales (r=0.231, P<0.05, systolic blood pressure (r=0.264, P<0.05, and respiratory rates (r=0.369, P<0.05 and negatively with finger temperature (r=−0.235, P<0.05 in the total study population. The 5-year cardiovascular survival in the experimental group was higher in patients whose salivary cortisol lowered by <0.6 pg/mL than that in patients whose salivary cortisol lowered by >0.6 pg/mL (83.8% vs

  11. An electrically actuated imperfect microbeam: Dynamical integrity for interpreting and predicting the device response

    KAUST Repository

    Ruzziconi, Laura

    2013-02-20

    In this study we deal with a microelectromechanical system (MEMS) and develop a dynamical integrity analysis to interpret and predict the experimental response. The device consists of a clamped-clamped polysilicon microbeam, which is electrostatically and electrodynamically actuated. It has non-negligible imperfections, which are a typical consequence of the microfabrication process. A single-mode reduced-order model is derived and extensive numerical simulations are performed in a neighborhood of the first symmetric natural frequency, via frequency response diagrams and behavior chart. The typical softening behavior is observed and the overall scenario is explored, when both the frequency and the electrodynamic voltage are varied. We show that simulations based on direct numerical integration of the equation of motion in time yield satisfactory agreement with the experimental data. Nevertheless, these theoretical predictions are not completely fulfilled in some aspects. In particular, the range of existence of each attractor is smaller in practice than in the simulations. This is because these theoretical curves represent the ideal limit case where disturbances are absent, which never occurs under realistic conditions. A reliable prediction of the actual (and not only theoretical) range of existence of each attractor is essential in applications. To overcome this discrepancy and extend the results to the practical case where disturbances exist, a dynamical integrity analysis is developed. After introducing dynamical integrity concepts, integrity profiles and integrity charts are drawn. They are able to describe if each attractor is robust enough to tolerate the disturbances. Moreover, they detect the parameter range where each branch can be reliably observed in practice and where, instead, becomes vulnerable, i.e. they provide valuable information to operate the device in safe conditions according to the desired outcome and depending on the expected disturbances

  12. Maintenance strategy for tilting table of rolling mill based on reliability considerations

    International Nuclear Information System (INIS)

    Deshpande, V.S.; Modak, J.P.

    2003-01-01

    Reliability centred maintenance (RCM) is a new strategic framework for ensuring that any asset continues to perform, as its users want it to perform. RCM is a process used to determine the maintenance requirement of any physical asset in its operating context. RCM process entails asking seven questions about each of the selected assets. It makes use of two documents namely, RCM information worksheet and RCM decision worksheet. RCM decision diagram integrates all the decision processes into a single strategic framework. RCM concept developed by US commercial airlines industry has been successfully implemented by Military, Navy, Nuclear power plants, electric power generation and distribution undertakings and several other sectors. These projects have been carried out in the United Kingdom, The Republic of Ireland, the United States, Hong Kong, Australia, Spain and Singapore. The fact that people has enthusiastically received RCM at all levels and has enabled users to achieve some remarkable successes in all of these countries, suggests that it can be universally employed. Literature review indicates that RCM approach is not conventionally applied in process industries in India. Presently, predictive maintenance (PDM) approach along with conventional preventive maintenance is used in continuous/process industries. This approach if implemented in totality will increase the production cost to a large degree and make the production uneconomical. Similarly breakdown maintenance (BDM) approach cannot be applied in such industries as each breakdown involves huge costs. RCM approach is a compromise between PDM and BDM approach for optimising the cost and ensuring the availability of machine. The RCM approach has been applied to the tilting table system of rolling mill for the research work reported in this paper. In the present study, preventive maintenance tasks suggested for power transmission subsystem, guiding and transportation subsystem and hydraulic subsystem in

  13. An integrated model for estimating energy cost of a tidal current turbine farm

    International Nuclear Information System (INIS)

    Li, Ye; Lence, Barbara J.; Calisal, Sander M.

    2011-01-01

    A tidal current turbine is a device for harnessing energy from tidal currents and functions in a manner similar to a wind turbine. A tidal current turbine farm consists of a group of tidal current turbines distributed in a site where high-speed current is available. The accurate prediction of energy cost of a tidal current turbine farm is important to the justification of planning and constructing such a farm. However, the existing approaches used to predict energy cost of tidal current turbine farms oversimplify the hydrodynamic interactions between turbines in energy prediction and oversimplify the operation and maintenance strategies involved in cost estimation as well as related fees. In this paper, we develop a model, which integrates a marine hydrodynamic model with high accuracy for predicting energy output and a comprehensive cost-effective operation and maintenance model for estimating the cost that may be incurred in producing the energy, to predict energy cost from a tidal current turbine farm. This model is expected to be able to simulate more complicated cases and generate more accurate results than existing models. As there is no real tidal current turbine farm, we validate this model with offshore wind studies. Finally, case studies about Vancouver are conducted with a scenario-based analysis. We minimize the energy cost by minimizing the total cost and maximizing the total power output under constraints related to the local conditions (e.g., geological and labor information) and the turbine specifications. The results suggest that tidal current energy is about ready to penetrate the electricity market in some major cities in North America if learning curve for the operational and maintenance is minimum. (author)

  14. Dynamics of Implementation and Maintenance of Organizational Health Interventions.

    Science.gov (United States)

    Jalali, Mohammad S; Rahmandad, Hazhir; Bullock, Sally Lawrence; Ammerman, Alice

    2017-08-15

    In this study, we present case studies to explore the dynamics of implementation and maintenance of health interventions. We analyze how specific interventions are built and eroded, how the building and erosion mechanisms are interconnected, and why we can see significantly different erosion rates across otherwise similar organizations. We use multiple comparative obesity prevention case studies to provide empirical information on the mechanisms of interest, and use qualitative systems modeling to integrate our evolving understanding into an internally consistent and transparent theory of the phenomenon. Our preliminary results identify reinforcing feedback mechanisms, including design of organizational processes, motivation of stakeholders, and communication among stakeholders, which influence implementation and maintenance of intervention components. Over time, these feedback mechanisms may drive a wedge between otherwise similar organizations, leading to distinct configurations of implementation and maintenance processes.

  15. Building a maintenance policy through a multi-criterion decision-making model

    Science.gov (United States)

    Faghihinia, Elahe; Mollaverdi, Naser

    2012-08-01

    A major competitive advantage of production and service systems is establishing a proper maintenance policy. Therefore, maintenance managers should make maintenance decisions that best fit their systems. Multi-criterion decision-making methods can take into account a number of aspects associated with the competitiveness factors of a system. This paper presents a multi-criterion decision-aided maintenance model with three criteria that have more influence on decision making: reliability, maintenance cost, and maintenance downtime. The Bayesian approach has been applied to confront maintenance failure data shortage. Therefore, the model seeks to make the best compromise between these three criteria and establish replacement intervals using Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE II), integrating the Bayesian approach with regard to the preference of the decision maker to the problem. Finally, using a numerical application, the model has been illustrated, and for a visual realization and an illustrative sensitivity analysis, PROMETHEE GAIA (the visual interactive module) has been used. Use of PROMETHEE II and PROMETHEE GAIA has been made with Decision Lab software. A sensitivity analysis has been made to verify the robustness of certain parameters of the model.

  16. Integration of Signaling Pathways with the Epigenetic Machinery in the Maintenance of Stem Cells

    Directory of Open Access Journals (Sweden)

    Luca Fagnocchi

    2016-01-01

    Full Text Available Stem cells balance their self-renewal and differentiation potential by integrating environmental signals with the transcriptional regulatory network. The maintenance of cell identity and/or cell lineage commitment relies on the interplay of multiple factors including signaling pathways, transcription factors, and the epigenetic machinery. These regulatory modules are strongly interconnected and they influence the pattern of gene expression of stem cells, thus guiding their cellular fate. Embryonic stem cells (ESCs represent an invaluable tool to study this interplay, being able to indefinitely self-renew and to differentiate towards all three embryonic germ layers in response to developmental cues. In this review, we highlight those mechanisms of signaling to chromatin, which regulate chromatin modifying enzymes, histone modifications, and nucleosome occupancy. In addition, we report the molecular mechanisms through which signaling pathways affect both the epigenetic and the transcriptional state of ESCs, thereby influencing their cell identity. We propose that the dynamic nature of oscillating signaling and the different regulatory network topologies through which those signals are encoded determine specific gene expression programs, leading to the fluctuation of ESCs among multiple pluripotent states or to the establishment of the necessary conditions to exit pluripotency.

  17. A New Hybrid Approach for Augmented Reality Maintenance in Scientific Facilities

    Directory of Open Access Journals (Sweden)

    Héctor Martínez

    2013-09-01

    Full Text Available Maintenance in scientific facilities is a difficult issue, especially in large and hazardous facilities, due to the complexity of tasks and equipment. Augmented reality is a technology that has already shown great promise in the maintenance field. With the help of augmented reality applications, maintenance tasks can be carried out faster and more safely. The problem with current applications is that they are small-scale prototypes that do not easily scale to large facility maintenance applications. This paper presents a new hybrid approach that enables the creation of augmented reality maintenance applications for large and hazardous scientific facilities. In this paper, a new augmented reality marker and the algorithm for its recognition is proposed. The performance of the algorithm is verified in three test cases, showing promising results in two of them. Improvements in robustness in the third test case in which the camera is moving quickly or when light conditions are extreme are subject to further studies. The proposed new approach will be integrated into an existing augmented reality maintenance system.

  18. Comparison of a Handheld Indirect Calorimetry Device and Predictive Energy Equations Among Individuals on Maintenance Hemodialysis.

    Science.gov (United States)

    Morrow, Ellis A; Marcus, Andrea; Byham-Gray, Laura

    2017-11-01

    Practical methods for determining resting energy expenditure (REE) among individuals on maintenance hemodialysis (MHD) are needed because of the limitations of indirect calorimetry. Two disease-specific predictive energy equations (PEEs) have been developed for this metabolically complex population. The aim of this study was to compare estimated REE (eREE) by PEEs to measured REE (mREE) with a handheld indirect calorimetry device (HICD). A prospective pilot study of adults on MHD (N = 40) was conducted at 2 dialysis clinics in Houston and Texas City, Texas. mREE by an HICD was compared with eREE determined by 6 PEEs using Bland-Altman analysis with a band of acceptable agreement of ±10% of the group mean mREE. Paired t-test and the intraclass correlation coefficient were also used to compare the alternate methods of measuring REE. A priori alpha was set at P Maintenance Hemodialysis Equation-Creatinine version (MHCD-CR) was the most accurate PEE with 52.5% of values within the band of acceptable agreement, followed by the Mifflin-St. Jeor Equation and the Vilar et al. Equation at 45.0% and 42.5%, respectively. When compared with mREE by the HICD, the MHDE-CR was more accurate and precise than other PEEs evaluated; however, this must be interpreted with caution as mREE was consistently lower than eREE from all PEEs. Further research is needed to validate the MHDE-CR and other practical methods for determining REE among individuals on MHD. Copyright © 2017 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  19. Computer-aided acquisition and logistics support (CALS): Concept of Operations for Depot Maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Bourgeois, N.C.; Greer, D.K.

    1993-04-01

    This CALS Concept of Operations for Depot Maintenance provides the foundation strategy and the near term tactical plan for CALS implementation in the depot maintenance environment. The user requirements enumerated and the overarching architecture outlined serve as the primary framework for implementation planning. The seamless integration of depot maintenance business processes and supporting information systems with the emerging global CALS environment will be critical to the efficient realization of depot user's information requirements, and as, such will be a fundamental theme in depot implementations.

  20. Just In-Time Maintenance of Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    DR. Alexander G. Parlos

    2002-01-22

    The goal of this project has been to develop and demonstrate the feasibility of a new technology for maintenance engineering: a Just-In-Time Maintenance (JITM) system for rotating machines. The JITM system is based on several key developments at Texas A and M over the past ten years in emerging intelligent information technologies, which if integrated into a single system could provide a revolutionary approach in the way maintenance is performed. Rotating machines, such as induction motors, range from a few horse power (hp) to several thousand hp in size, and they are widely used in nuclear power plants and in other industries. Forced outages caused by induction motor failures are the reason for as much as 15% - 40% of production costs to be attributable to maintenance, whereas plant shutdowns caused by induction motor failures result in daily financial losses to the utility and process industries of $1 M or more. The basic components of the JITM system are the available machine sensors, that is electric current sensors and accelerometers, and the computational algorithms used in the analysis and interpretation of the occurring incipient failures. The JITM system can reduce the costs attributable to maintenance by about 40% and it can lower the maintenance budgets of power and process plants by about 35%, while requiring no additional sensor installation. As a result, the JITM system can improve the competitiveness of US nuclear utilities at minimal additional cost.

  1. Just In-Time Maintenance of Nuclear Power Plants

    International Nuclear Information System (INIS)

    Parlos, Alexander G.

    2002-01-01

    The goal of this project has been to develop and demonstrate the feasibility of a new technology for maintenance engineering: a Just-In-Time Maintenance (JITM) system for rotating machines. The JITM system is based on several key developments at Texas A and M over the past ten years in emerging intelligent information technologies, which if integrated into a single system could provide a revolutionary approach in the way maintenance is performed. Rotating machines, such as induction motors, range from a few horse power (hp) to several thousand hp in size, and they are widely used in nuclear power plants and in other industries. Forced outages caused by induction motor failures are the reason for as much as 15% - 40% of production costs to be attributable to maintenance, whereas plant shutdowns caused by induction motor failures result in daily financial losses to the utility and process industries of $1 M or more. The basic components of the JITM system are the available machine sensors, that is electric current sensors and accelerometers, and the computational algorithms used in the analysis and interpretation of the occurring incipient failures. The JITM system can reduce the costs attributable to maintenance by about 40% and it can lower the maintenance budgets of power and process plants by about 35%, while requiring no additional sensor installation. As a result, the JITM system can improve the competitiveness of US nuclear utilities at minimal additional cost

  2. Accounting for maintenance in the design of nuclear power plants

    International Nuclear Information System (INIS)

    Meuwisse, C.; Martin-Mattei, C.; Hamon, L.

    1997-01-01

    The objective of the CIDEM project (French acronym for Design Integrating Availability, Operating Experience and Maintenance) is to control the per-kW production cost of future Electricite de France REP 2000 nuclear plants. In particular, such cost control requires accounting for maintenance and logistic support from the time of design of the future installations. This technical and economic optimization is based on assessment and comparison of possible choices in terms of materials and maintenance, and on the search for potential improvements. In the Basic Design phase, the method involves identifying reference components which are supposed highly similar to the components to be designed. In the Construction phase, it culminates in the early definition of a detailed maintenance and support plant. To be effective, the approach requires realistic tailoring of the studies to be undertaken, and the participation of multidisciplinary teams working in the framework of concurrent engineering. (author)

  3. Innovations within DBFMO projects from a maintenance and energy-use point of view

    NARCIS (Netherlands)

    Hansen, R.; Prins, M.; Straub, A.

    2011-01-01

    In most literature integrated contracting and procurement is assumed to result in more innovative solutions as a result of the intended process integration. This paper explores Design Build Finance Maintain Operate (DBFMO) cases in the Netherlands on resulting innovations focusing on maintenance and

  4. ITER Remote Maintenance System (IRMS) lifecycle management

    Energy Technology Data Exchange (ETDEWEB)

    Tesini, Alessandro, E-mail: alessandro.tesini@iter.org [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Otto' , Bede [Oxford Technologies Ltd, 7, Nuffield Way, Abingdon, Oxon OX14 1RJ (United Kingdom); Blight, John [FAAST 31c Allee de la Granette, 13600 Ceyreste (France); Choi, Chang-Hwan; Friconneau, Jean-Pierre; Gotewal, Krishan Kumar; Hamilton, David [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Heckendorn, Frank [FD Technologies, PO Box 6686, Aiken, SC (United States); Martins, Jean-Pierre [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Marty, Thomas [Westinghouse, 122, avenue de Hambourg, 13008 Marseille (France); Nakahira, Masataka; Palmer, Jim; Subramanian, Rajendran [ITER Organization, CS 90 046, 13067 St. Paul Lez Durance Cedex (France)

    2011-10-15

    The availability of the ITER machine to perform its scientific program is strongly dependent on the performance of the different Remote Handling (RH) systems constituting the ITER Remote Maintenance System (IRMS). The lifecycle of the IRMS will largely exceed 40 years from initial concept design and proof testing through to machine decommissioning. Such a long lifecycle requires that a rigorous approach is put in place to guarantee the technical capabilities of the highly innovative IRMS, its efficiency and its availability. For this purpose, an IRMS System Engineering and IRMS lifecycle management approach has been adopted by ITER. The approach aims at ensuring the IRMS full operability and availability at an acceptable cost of ownership over the full ITER machine assembly and operations period. The IRMS lifecycle management method described in this paper covers such subjects as specific requirements for IRMS design reviews, monitoring during manufacture, factory and site acceptance testing, integrated commissioning, decontamination, maintenance and re-qualification strategies, requirements for Integrated Logistical Support during operations. The updating and implementation of the IRMS lifecycle strategy and this procedure will be managed and monitored by the Remote Handling Integrated Product Team (RH-IPT). Although developed for the IRMS, the basic principles and procedures of lifecycle management could be applied to other ITER plant systems whose reliability and availability will be essential for the continued operation of the ITER machine.

  5. ITER Remote Maintenance System (IRMS) lifecycle management

    International Nuclear Information System (INIS)

    Tesini, Alessandro; Otto', Bede; Blight, John; Choi, Chang-Hwan; Friconneau, Jean-Pierre; Gotewal, Krishan Kumar; Hamilton, David; Heckendorn, Frank; Martins, Jean-Pierre; Marty, Thomas; Nakahira, Masataka; Palmer, Jim; Subramanian, Rajendran

    2011-01-01

    The availability of the ITER machine to perform its scientific program is strongly dependent on the performance of the different Remote Handling (RH) systems constituting the ITER Remote Maintenance System (IRMS). The lifecycle of the IRMS will largely exceed 40 years from initial concept design and proof testing through to machine decommissioning. Such a long lifecycle requires that a rigorous approach is put in place to guarantee the technical capabilities of the highly innovative IRMS, its efficiency and its availability. For this purpose, an IRMS System Engineering and IRMS lifecycle management approach has been adopted by ITER. The approach aims at ensuring the IRMS full operability and availability at an acceptable cost of ownership over the full ITER machine assembly and operations period. The IRMS lifecycle management method described in this paper covers such subjects as specific requirements for IRMS design reviews, monitoring during manufacture, factory and site acceptance testing, integrated commissioning, decontamination, maintenance and re-qualification strategies, requirements for Integrated Logistical Support during operations. The updating and implementation of the IRMS lifecycle strategy and this procedure will be managed and monitored by the Remote Handling Integrated Product Team (RH-IPT). Although developed for the IRMS, the basic principles and procedures of lifecycle management could be applied to other ITER plant systems whose reliability and availability will be essential for the continued operation of the ITER machine.

  6. At the Nexus of History, Ecology, and Hydrobiogeochemistry: Improved Predictions across Scales through Integration.

    Science.gov (United States)

    Stegen, James C

    2018-01-01

    To improve predictions of ecosystem function in future environments, we need to integrate the ecological and environmental histories experienced by microbial communities with hydrobiogeochemistry across scales. A key issue is whether we can derive generalizable scaling relationships that describe this multiscale integration. There is a strong foundation for addressing these challenges. We have the ability to infer ecological history with null models and reveal impacts of environmental history through laboratory and field experimentation. Recent developments also provide opportunities to inform ecosystem models with targeted omics data. A major next step is coupling knowledge derived from such studies with multiscale modeling frameworks that are predictive under non-steady-state conditions. This is particularly true for systems spanning dynamic interfaces, which are often hot spots of hydrobiogeochemical function. We can advance predictive capabilities through a holistic perspective focused on the nexus of history, ecology, and hydrobiogeochemistry.

  7. Optimización del mantenimiento preventivo utilizando las técnicas de diagnóstico integral. Fundamento teóricopráctico; Optimization of the Preventive Maintenance Using the Technique of Integral Diagnosis. Base Theoretical-Practical

    Directory of Open Access Journals (Sweden)

    Pedro L Hernández Domínguez

    2011-02-01

    Full Text Available Se expone un método para la optimización del mantenimiento preventivo planificado (MPP a partir de laintroducción del mantenimiento basado en la condición (MBC en las turbinas y generadores de vapor de unacentral termoeléctrica cubana, utilizando las técnicas de diagnóstico integral. Se presenta el estado del arte deldesarrollo del mantenimiento y se caracteriza este en las centrales termoeléctricas cubanas; además, se realizaun estudio estadístico de las fallas y se presentan varios casos de estudio con la finalidad que el lector puedacomprender la necesidad de implantación de esta técnica, cuyos únicos costos son la organización de los datosde fallas y la colaboración del personal técnico ligado a las mismas. In this present paper the author exposed a method for the optimization of the planned preventive maintenance(PPM starting from the introduction of the condition based maintenance (CBM in the steam turbines and generatorsin a cuban thermoelectric power station, using the techniques of Integral Diagnosis. In the same one thestate of the art of the development of the maintenance is presented and the last one is characterized in the cubanthermoelectric power station, it is also carried out a statistical study of the failures and several cases of study arepresented with the purpose that the reader can understand the necessity of installation of this technique whoseonly costs belong the organization of the data of failures and the collaboration from the bound technical personnelto the same ones.

  8. Scheduling Maintenance Jobs in Networks

    OpenAIRE

    Abed, Fidaa; Chen, Lin; Disser, Yann; Groß, Martin; Megow, Nicole; Meißner, Julie; Richter, Alexander T.; Rischke, Roman

    2017-01-01

    We investigate the problem of scheduling the maintenance of edges in a network, motivated by the goal of minimizing outages in transportation or telecommunication networks. We focus on maintaining connectivity between two nodes over time; for the special case of path networks, this is related to the problem of minimizing the busy time of machines. We show that the problem can be solved in polynomial time in arbitrary networks if preemption is allowed. If preemption is restricted to integral t...

  9. Homeostatic maintenance via degradation and repair of elastic fibers under tension

    Science.gov (United States)

    Alves, Calebe; Araújo, Ascanio D.; Oliveira, Cláudio L. N.; Imsirovic, Jasmin; Bartolák-Suki, Erzsébet; Andrade, José S.; Suki, Béla

    2016-06-01

    Cellular maintenance of the extracellular matrix requires an effective regulation that balances enzymatic degradation with the repair of collagen fibrils and fibers. Here, we investigate the long-term maintenance of elastic fibers under tension combined with diffusion of general degradative and regenerative particles associated with digestion and repair processes. Computational results show that homeostatic fiber stiffness can be achieved by assuming that cells periodically probe fiber stiffness to adjust the production and release of degradative and regenerative particles. However, this mechanism is unable to maintain a homogeneous fiber. To account for axial homogeneity, we introduce a robust control mechanism that is locally governed by how the binding affinity of particles is modulated by mechanical forces applied to the ends of the fiber. This model predicts diameter variations along the fiber that are in agreement with the axial distribution of collagen fibril diameters obtained from scanning electron microscopic images of normal rat thoracic aorta. The model predictions match the experiments only when the applied force on the fiber is in the range where the variance of local stiffness along the fiber takes a minimum value. Our model thus predicts that the biophysical properties of the fibers play an important role in the long-term regulatory maintenance of these fibers.

  10. Financial Motivation Undermines Maintenance in an Intensive Diet and Activity Intervention

    Directory of Open Access Journals (Sweden)

    Arlen C. Moller

    2012-01-01

    Full Text Available Financial incentives are widely used in health behavior interventions. However, self-determination theory posits that emphasizing financial incentives can have negative consequences if experienced as controlling. Feeling controlled into performing a behavior tends to reduce enjoyment and undermine maintenance after financial contingencies are removed (the undermining effect. We assessed participants’ context-specific financial motivation to participate in the Make Better Choices trial—a trial testing four different strategies for improving four health risk behaviors: low fruit and vegetable intake, high saturated fat intake, low physical activity, and high sedentary screen time. The primary outcome was overall healthy lifestyle change; weight loss was a secondary outcome. Financial incentives were contingent upon meeting behavior goals for 3 weeks and became contingent upon merely providing data during the 4.5-month maintenance period. Financial motivation for participation was assessed at baseline using a 7-item scale (=.97. Across conditions, a main effect of financial motivation predicted a steeper rate of weight regained during the maintenance period, (165=2.15, =.04. Furthermore, financial motivation and gender interacted significantly in predicting maintenance of healthy diet and activity changes, (160=2.42, =.016, such that financial motivation had a more deleterious influence among men. Implications for practice and future research on incentivized lifestyle and weight interventions are discussed.

  11. Monitoring and maintenance of breakwaters which protect port entrances

    CSIR Research Space (South Africa)

    Tulsi, K

    2009-07-01

    Full Text Available breakwaters which have dolos armouring. These require regular monitoring and maintenance, especially in the light of predicted sea level rise and extreme sea conditions caused by global warming. TNPA, the local Port Authority, has commissioned the CSIR...

  12. Integrated petrophysical and reservoir characterization workflow to enhance permeability and water saturation prediction

    Science.gov (United States)

    Al-Amri, Meshal; Mahmoud, Mohamed; Elkatatny, Salaheldin; Al-Yousef, Hasan; Al-Ghamdi, Tariq

    2017-07-01

    Accurate estimation of permeability is essential in reservoir characterization and in determining fluid flow in porous media which greatly assists optimize the production of a field. Some of the permeability prediction techniques such as Porosity-Permeability transforms and recently artificial intelligence and neural networks are encouraging but still show moderate to good match to core data. This could be due to limitation to homogenous media while the knowledge about geology and heterogeneity is indirectly related or absent. The use of geological information from core description as in Lithofacies which includes digenetic information show a link to permeability when categorized into rock types exposed to similar depositional environment. The objective of this paper is to develop a robust combined workflow integrating geology and petrophysics and wireline logs in an extremely heterogeneous carbonate reservoir to accurately predict permeability. Permeability prediction is carried out using pattern recognition algorithm called multi-resolution graph-based clustering (MRGC). We will bench mark the prediction results with hard data from core and well test analysis. As a result, we showed how much better improvements are achieved in the permeability prediction when geology is integrated within the analysis. Finally, we use the predicted permeability as an input parameter in J-function and correct for uncertainties in saturation calculation produced by wireline logs using the classical Archie equation. Eventually, high level of confidence in hydrocarbon volumes estimation is reached when robust permeability and saturation height functions are estimated in presence of important geological details that are petrophysically meaningful.

  13. ERC Maintenance Implementation Plan for nuclear facilities

    International Nuclear Information System (INIS)

    Franquero, R.C.

    1997-05-01

    The inactive and surplus facilities assigned to the Environmental Restoration Contractor are shut down and have no operating production processes or production materials except for residual contamination. There is a minimal number of operating systems to support surveillance and maintenance or decontamination and decommissioning activities (D ampersand D). These systems may include heating and ventilation, air conditioning, lighting, and other electrical systems. Inactive and surplus facilities will be subject to periodic long-term surveillance to ensure the integrity of structures until D ampersand D. D ampersand D projects are of relatively short duration and end with all systems deactivated. Therefore, a rigorous in-depth maintenance program such as that required for producing nuclear facilities is not required or cost effective

  14. Distinct electrophysiological indices of maintenance in auditory and visual short-term memory.

    Science.gov (United States)

    Lefebvre, Christine; Vachon, François; Grimault, Stephan; Thibault, Jennifer; Guimond, Synthia; Peretz, Isabelle; Zatorre, Robert J; Jolicœur, Pierre

    2013-11-01

    We compared the electrophysiological correlates for the maintenance of non-musical tones sequences in auditory short-term memory (ASTM) to those for the short-term maintenance of sequences of coloured disks held in visual short-term memory (VSTM). The visual stimuli yielded a sustained posterior contralateral negativity (SPCN), suggesting that the maintenance of sequences of coloured stimuli engaged structures similar to those involved in the maintenance of simultaneous visual displays. On the other hand, maintenance of acoustic sequences produced a sustained negativity at fronto-central sites. This component is named the Sustained Anterior Negativity (SAN). The amplitude of the SAN increased with increasing load in ASTM and predicted individual differences in the performance. There was no SAN in a control condition with the same auditory stimuli but no memory task, nor one associated with visual memory. These results suggest that the SAN is an index of brain activity related to the maintenance of representations in ASTM that is distinct from the maintenance of representations in VSTM. © 2013 Elsevier Ltd. All rights reserved.

  15. Opportunistic or event-driven maintenance at the Stanford Linear Accelerator Center

    International Nuclear Information System (INIS)

    Allen, C.W.; Anderson, S.; Erickson, R.; Linebarger, W.; Sheppard, J.C.; Stanek, M.

    1997-03-01

    The Stanford Linear Accelerator Center (SLAC) uses a maintenance management philosophy that is best described as opportunistic or event-driven. Opportunistic maintenance can be defined as a systematic method of collecting, investigating, pre-planning, and publishing a set of proposed maintenance tasks and acting on them when there is an unscheduled failure or repair ''opportunity''. Opportunistic maintenance can be thought of as a modification of the run-to-fail maintenance management philosophy. This maintenance plan was adopted and developed to improve the overall availability of SLAC's linear accelerator, beam delivery systems, and associated controls, power systems, and utilities. In the late 1980's, as the technical complexity of the accelerator facility increased, variations on a conventional maintenance plan were used with mixed results. These variations typically included some type of regular periodic interruption to operations. The periodic shutdowns and unscheduled failures were additive and resulted in unsatisfactory availability. Maintenance issues are evaluated in a daily meeting that includes the accelerator managers, maintenance supervisors and managers, safety office personnel, program managers, and accelerator operators. Lists of pending maintenance tasks are made available to the general SLAC population by a World Wide Web site on a local internet. A conventional information system which pre-dates the WWW site is still being used to provide paper copies to groups that are not yet integrated into the WWW system. The local internet provides real time maintenance information, allowing people throughout the facility to track progress on tasks with essentially real-time status updates. With the introduction of opportunistic maintenance, the accelerator's availability has been measurably better. This paper will discuss processes, rolls and responsibilities of key maintenance groups, and management tools developed to support opportunistic maintenance

  16. Hardware-oriented reliability centered maintenance for the diesel generators of Wolsong unit 1

    International Nuclear Information System (INIS)

    Bae, Sang Min; Park, Jin Hee; Kim, Tae Woon; Lee, Yoon Kee; Song, Jin Bae

    1997-01-01

    The DGs (Diesel Generators) in NPP (Nuclear Power Plant) has been used for the emergency electric power source to shut down the nuclear reactor safely in case of station blackout. The RCM (Reliability Centered Maintenance) has been applied to DGs for increasing the safety of NPP. The structured defects of DG were not remedied by the improvement of maintenance method. As the first stage of RCM, to find the structured defects, its failure modes were searched and analyzed through the ten year maintenance information. The structured defects such as the air compressor, the lubricating oil pressure, and the insufficient load were the root causes of main failures. The air reservoir reinstallation, the lubricating oil tube modification, the load bank installation, and the qualitative instrumentation were the solutions for the hardware oriented RCM of DGs. There remains the software oriented RCM such as the rejection of useless maintenance, the preventive maintenance, the database of maintenance information, and the predictive maintenance

  17. Research and Application of Construction of Operation Integration for Smart Power Distribution and Consumption Based on “Integration of Marketing with Distribution”

    Directory of Open Access Journals (Sweden)

    Zhenbao Feng

    2014-05-01

    Full Text Available The “information integrated platform of marketing and distribution integration system” researched and developed by this article is an advanced application platform to concurrently design and develop the automation of marketing and power distribution through integration and analysis of existing data based on the data platform of Jiaozuo Power Supply Corporation. It uses data mining and data bus technology, uniform analysis of comprehensive marketing and distribution data. And it conducts a real time monitoring on power utilization information for marketing and early warning maintenance business of power distribution according to electric business model, which realizes an integration of marketing and distribution business, achieves the target of integrated operation of marketing and distribution, improves the operation level of business, reduces maintenance costs of distribution grid, increases electricity sales of distribution grid and provide reliable practical basis for operation and maintenance of Jiaozuo power marketing and distribution.

  18. A novel approach for modelling complex maintenance systems using discrete event simulation

    International Nuclear Information System (INIS)

    Alrabghi, Abdullah; Tiwari, Ashutosh

    2016-01-01

    Existing approaches for modelling maintenance rely on oversimplified assumptions which prevent them from reflecting the complexity found in industrial systems. In this paper, we propose a novel approach that enables the modelling of non-identical multi-unit systems without restrictive assumptions on the number of units or their maintenance characteristics. Modelling complex interactions between maintenance strategies and their effects on assets in the system is achieved by accessing event queues in Discrete Event Simulation (DES). The approach utilises the wide success DES has achieved in manufacturing by allowing integration with models that are closely related to maintenance such as production and spare parts systems. Additional advantages of using DES include rapid modelling and visual interactive simulation. The proposed approach is demonstrated in a simulation based optimisation study of a published case. The current research is one of the first to optimise maintenance strategies simultaneously with their parameters while considering production dynamics and spare parts management. The findings of this research provide insights for non-conflicting objectives in maintenance systems. In addition, the proposed approach can be used to facilitate the simulation and optimisation of industrial maintenance systems. - Highlights: • This research is one of the first to optimise maintenance strategies simultaneously. • New insights for non-conflicting objectives in maintenance systems. • The approach can be used to optimise industrial maintenance systems.

  19. The maintenance management framework models and methods for complex systems maintenance

    CERN Document Server

    Crespo Márquez, Adolfo

    2010-01-01

    “The Maintenance Management Framework” describes and reviews the concept, process and framework of modern maintenance management of complex systems; concentrating specifically on modern modelling tools (deterministic and empirical) for maintenance planning and scheduling. It will be bought by engineers and professionals involved in maintenance management, maintenance engineering, operations management, quality, etc. as well as graduate students and researchers in this field.

  20. Departure Queue Prediction for Strategic and Tactical Surface Scheduler Integration

    Science.gov (United States)

    Zelinski, Shannon; Windhorst, Robert

    2016-01-01

    A departure metering concept to be demonstrated at Charlotte Douglas International Airport (CLT) will integrate strategic and tactical surface scheduling components to enable the respective collaborative decision making and improved efficiency benefits these two methods of scheduling provide. This study analyzes the effect of tactical scheduling on strategic scheduler predictability. Strategic queue predictions and target gate pushback times to achieve a desired queue length are compared between fast time simulations of CLT surface operations with and without tactical scheduling. The use of variable departure rates as a strategic scheduler input was shown to substantially improve queue predictions over static departure rates. With target queue length calibration, the strategic scheduler can be tuned to produce average delays within one minute of the tactical scheduler. However, root mean square differences between strategic and tactical delays were between 12 and 15 minutes due to the different methods the strategic and tactical schedulers use to predict takeoff times and generate gate pushback clearances. This demonstrates how difficult it is for the strategic scheduler to predict tactical scheduler assigned gate delays on an individual flight basis as the tactical scheduler adjusts departure sequence to accommodate arrival interactions. Strategic/tactical scheduler compatibility may be improved by providing more arrival information to the strategic scheduler and stabilizing tactical scheduler changes to runway sequence in response to arrivals.

  1. Optimization of Two-Level Disassembly/Remanufacturing/Assembly System with an Integrated Maintenance Strategy

    Directory of Open Access Journals (Sweden)

    Zouhour Guiras

    2018-04-01

    Full Text Available With an increase of environmental pressure on economic activities, reverse flow is increasingly important. It seeks to save resources, eliminate waste, and improve productivity. This paper investigates the optimization of the disassembly, remanufacturing and assembly system, taking into account assembly-disassembly system degradation. An analytical model is developed to consider disassembly, remanufacturing of used/end-of-life product and assembly of the finished product. The finished product is composed of remanufactured and new components. A maintenance policy is sequentially integrated to reduce the system unavailability. The aim of this study is to help decision-makers, under certain conditions, choose the most cost-effective process for them to satisfy the customer as well as to adapt to the potential risk that can perturb the disassembly-assembly system. A heuristic is developed to determine the optimal ordered date of the used end-of-life product as well as the optimum release dates of new external components. The results reveal that considering some remanufacturing and purchase components costs, the proposed model is more economical in comparison with a model without remanufactured parts. Numerical results are provided to illustrate the impact of the variation of the ordering cost and quality of the used end-of-life product on the system profitability. Finally, the risk due to system repair periods is discussed, which has an impact on managerial decision-making.

  2. Energy-Efficient Integration of Continuous Context Sensing and Prediction into Smartwatches

    Directory of Open Access Journals (Sweden)

    Reza Rawassizadeh

    2015-09-01

    Full Text Available As the availability and use of wearables increases, they are becoming a promising platform for context sensing and context analysis. Smartwatches are a particularly interesting platform for this purpose, as they offer salient advantages, such as their proximity to the human body. However, they also have limitations associated with their small form factor, such as processing power and battery life, which makes it difficult to simply transfer smartphone-based context sensing and prediction models to smartwatches. In this paper, we introduce an energy-efficient, generic, integrated framework for continuous context sensing and prediction on smartwatches. Our work extends previous approaches for context sensing and prediction on wrist-mounted wearables that perform predictive analytics outside the device. We offer a generic sensing module and a novel energy-efficient, on-device prediction module that is based on a semantic abstraction approach to convert sensor data into meaningful information objects, similar to human perception of a behavior. Through six evaluations, we analyze the energy efficiency of our framework modules, identify the optimal file structure for data access and demonstrate an increase in accuracy of prediction through our semantic abstraction method. The proposed framework is hardware independent and can serve as a reference model for implementing context sensing and prediction on small wearable devices beyond smartwatches, such as body-mounted cameras.

  3. Energy-Efficient Integration of Continuous Context Sensing and Prediction into Smartwatches.

    Science.gov (United States)

    Rawassizadeh, Reza; Tomitsch, Martin; Nourizadeh, Manouchehr; Momeni, Elaheh; Peery, Aaron; Ulanova, Liudmila; Pazzani, Michael

    2015-09-08

    As the availability and use of wearables increases, they are becoming a promising platform for context sensing and context analysis. Smartwatches are a particularly interesting platform for this purpose, as they offer salient advantages, such as their proximity to the human body. However, they also have limitations associated with their small form factor, such as processing power and battery life, which makes it difficult to simply transfer smartphone-based context sensing and prediction models to smartwatches. In this paper, we introduce an energy-efficient, generic, integrated framework for continuous context sensing and prediction on smartwatches. Our work extends previous approaches for context sensing and prediction on wrist-mounted wearables that perform predictive analytics outside the device. We offer a generic sensing module and a novel energy-efficient, on-device prediction module that is based on a semantic abstraction approach to convert sensor data into meaningful information objects, similar to human perception of a behavior. Through six evaluations, we analyze the energy efficiency of our framework modules, identify the optimal file structure for data access and demonstrate an increase in accuracy of prediction through our semantic abstraction method. The proposed framework is hardware independent and can serve as a reference model for implementing context sensing and prediction on small wearable devices beyond smartwatches, such as body-mounted cameras.

  4. Theoretical explanations for maintenance of behaviour change: a systematic review of behaviour theories.

    Science.gov (United States)

    Kwasnicka, Dominika; Dombrowski, Stephan U; White, Martin; Sniehotta, Falko

    2016-09-01

    Behaviour change interventions are effective in supporting individuals in achieving temporary behaviour change. Behaviour change maintenance, however, is rarely attained. The aim of this review was to identify and synthesise current theoretical explanations for behaviour change maintenance to inform future research and practice. Potentially relevant theories were identified through systematic searches of electronic databases (Ovid MEDLINE, Embase, PsycINFO). In addition, an existing database of 80 theories was searched, and 25 theory experts were consulted. Theories were included if they formulated hypotheses about behaviour change maintenance. Included theories were synthesised thematically to ascertain overarching explanations for behaviour change maintenance. Initial theoretical themes were cross-validated. One hundred and seventeen behaviour theories were identified, of which 100 met the inclusion criteria. Five overarching, interconnected themes representing theoretical explanations for behaviour change maintenance emerged. Theoretical explanations of behaviour change maintenance focus on the differential nature and role of motives, self-regulation, resources (psychological and physical), habits, and environmental and social influences from initiation to maintenance. There are distinct patterns of theoretical explanations for behaviour change and for behaviour change maintenance. The findings from this review can guide the development and evaluation of interventions promoting maintenance of health behaviours and help in the development of an integrated theory of behaviour change maintenance.

  5. Knowledge based maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, A [Hamburgische Electacitaets-Werke AG Hamburg (Germany)

    1998-12-31

    The establishment of maintenance strategies is of crucial significance for the reliability of a plant and the economic efficiency of maintenance measures. Knowledge about the condition of components and plants from the technical and business management point of view therefore becomes one of the fundamental questions and the key to efficient management and maintenance. A new way to determine the maintenance strategy can be called: Knowledge Based Maintenance. A simple method for determining strategies while taking the technical condition of the components of the production process into account to the greatest possible degree which can be shown. A software with an algorithm for Knowledge Based Maintenance leads the user during complex work to the determination of maintenance strategies for this complex plant components. (orig.)

  6. Knowledge based maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, A. [Hamburgische Electacitaets-Werke AG Hamburg (Germany)

    1997-12-31

    The establishment of maintenance strategies is of crucial significance for the reliability of a plant and the economic efficiency of maintenance measures. Knowledge about the condition of components and plants from the technical and business management point of view therefore becomes one of the fundamental questions and the key to efficient management and maintenance. A new way to determine the maintenance strategy can be called: Knowledge Based Maintenance. A simple method for determining strategies while taking the technical condition of the components of the production process into account to the greatest possible degree which can be shown. A software with an algorithm for Knowledge Based Maintenance leads the user during complex work to the determination of maintenance strategies for this complex plant components. (orig.)

  7. Mobile devices applied in the maintenance; Dispositivos moveis aplicados na manutencao

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Robison Tirre; Monteiro, Claudio Rogerio; Oliveira, Hudson Texeira de; Pacheco, Rogerio da Silva; Milrad, Shlomo [Transportadora Brasileira Gasoduto Bolivia Brasil S.A., Rio de Janeiro, RJ (Brazil)

    2004-07-01

    In natural gas pipeline companies, like TBG (Transportadora Brasileira Gasoduto Bolivia Brasil S.A.), with large extensions of pipes and installations distributed so far from each other it is usual that maintenance personnel go to the field job and sometimes do not come back to the office at the same day. In addition, the need to access the corporate network to input maintenance data in the Maintenance Module of Enterprise Resource Planning means that maintenance registries are something that do not flow easily from field to database. Technicians also spend a lot of time in front of the computer decreasing their productive working hours. Being aware of the importance of data to a consistent integrity pipeline program and to solve the problems related above, TBG implemented Maintenance in the Palm of the Hand project and distributed hand held PCs to all technicians, with software that works like an electronic maintenance work order. This system permits to collect maintenance data in real time and also providing important information to help technicians perform their jobs. If necessary, they can start a maintenance request. At any moment it is possible to connect to the corporate network and download data to CMMS. This project allowed TBG to increase quality and reliability of maintenance data and speed of information flow from field to CMMS, eliminating the need to print work orders and data sheets, increasing the productivity of technicians and reducing the time spent on boring tasks such as taking notes. (author)

  8. Managing aging in nuclear power plants: Insights from NRC's Maintenance Team Inspection reports

    International Nuclear Information System (INIS)

    Fresco, A.; Subudhi, M.

    1992-01-01

    A plant's maintenance program is the principal vehicle through which age-related degradation is managed. From 1988 to 1991, the NRC evaluated the maintenance program of every nuclear power plant in the United States. Forty-four out of a total of sixty-seven of the reports issued on these in-depth team inspections have been reviewed for insights into the strengths and weaknesses of the programs as related to the need to understand and manage the effects of aging on nuclear plant structures, systems, and components (SSCs). Relevant information has been extracted from these inspection reports sorted into several categories; including Specific Aging Insights, Preventive Maintenance, Predictive Maintenance and Condition Monitoring, Post Maintenance Testing, Failure Trending, Root Cause Analysis and Usage of Probabilistic Risk Assessment in the Maintenance Process. Specific examples of inspection and monitoring techniques successfully used by utilities to detect degradation due to aging have been identified

  9. System of management of maintenance oriented to the safety and the readiness

    International Nuclear Information System (INIS)

    Torres V, A.; Rivero O, J.J.

    2004-01-01

    One of the fundamental causes of the high contribution of the maintenance to those problems of security and readiness of the facilities is the inadequacy of those systems of maintenance administration to solve of form to balanced the problems of security and readiness of the same ones. Leaving of this statement, in the article a synthesis of the investigation of the current state of the management systems is presented of the maintenance in their relationship with the security of the facilities. Likewise, it summarizes the development of an integrative algorithm for the administration of the maintenance guided to the security and the readiness, which has been materialized in the code MOSEG Win to See 1.0. Finally some of the applications are presented carried out with the system. (Author)

  10. Conceptual design and assessment of in-service inspection and maintenance of KALIMER

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Young Sang; Kim, Seok Hun; Kim, Jong Bum; Lee, Jae Han [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-05-01

    In the conceptual design stage of KALIMER, the philosophy and methodology of in-service inspection (ISI) and maintenance for the reactor system and components are proposed and described. The ISI and maintenance should be carried out throughout plant life to ensure the structural integrity and safety of KALIMER. The conceptual design of ISI and maintenance are performed for considering the design characteristics of KALIMER and the intents of the ASME XI Division 3. This report describes and summarizes the requirements and available methods of ISI and maintenance. The visual inspection and continuous monitoring play a great role in the in-service inspection of KALIMER. The major structures of KALIMER reactor system are designed for maintenance free operation for the plant life time and the maintenance philosophy is to replace major components rather than repair them. The assessment of the ISI accessibility and maintainability is performed and reviewed each major component. The postulated failure defects for each component are estimated and evaluated for KALIMER safety and reliability. 8 refs., 16 figs., 13 tabs. (Author)

  11. An integrative approach to ortholog prediction for disease-focused and other functional studies.

    Science.gov (United States)

    Hu, Yanhui; Flockhart, Ian; Vinayagam, Arunachalam; Bergwitz, Clemens; Berger, Bonnie; Perrimon, Norbert; Mohr, Stephanie E

    2011-08-31

    Mapping of orthologous genes among species serves an important role in functional genomics by allowing researchers to develop hypotheses about gene function in one species based on what is known about the functions of orthologs in other species. Several tools for predicting orthologous gene relationships are available. However, these tools can give different results and identification of predicted orthologs is not always straightforward. We report a simple but effective tool, the Drosophila RNAi Screening Center Integrative Ortholog Prediction Tool (DIOPT; http://www.flyrnai.org/diopt), for rapid identification of orthologs. DIOPT integrates existing approaches, facilitating rapid identification of orthologs among human, mouse, zebrafish, C. elegans, Drosophila, and S. cerevisiae. As compared to individual tools, DIOPT shows increased sensitivity with only a modest decrease in specificity. Moreover, the flexibility built into the DIOPT graphical user interface allows researchers with different goals to appropriately 'cast a wide net' or limit results to highest confidence predictions. DIOPT also displays protein and domain alignments, including percent amino acid identity, for predicted ortholog pairs. This helps users identify the most appropriate matches among multiple possible orthologs. To facilitate using model organisms for functional analysis of human disease-associated genes, we used DIOPT to predict high-confidence orthologs of disease genes in Online Mendelian Inheritance in Man (OMIM) and genes in genome-wide association study (GWAS) data sets. The results are accessible through the DIOPT diseases and traits query tool (DIOPT-DIST; http://www.flyrnai.org/diopt-dist). DIOPT and DIOPT-DIST are useful resources for researchers working with model organisms, especially those who are interested in exploiting model organisms such as Drosophila to study the functions of human disease genes.

  12. Uncertainty and sensitivity analyses for age-dependent unavailability model integrating test and maintenance

    International Nuclear Information System (INIS)

    Kančev, Duško; Čepin, Marko

    2012-01-01

    Highlights: ► Application of analytical unavailability model integrating T and M, ageing, and test strategy. ► Ageing data uncertainty propagation on system level assessed via Monte Carlo simulation. ► Uncertainty impact is growing with the extension of the surveillance test interval. ► Calculated system unavailability dependence on two different sensitivity study ageing databases. ► System unavailability sensitivity insights regarding specific groups of BEs as test intervals extend. - Abstract: The interest in operational lifetime extension of the existing nuclear power plants is growing. Consequently, plants life management programs, considering safety components ageing, are being developed and employed. Ageing represents a gradual degradation of the physical properties and functional performance of different components consequently implying their reduced availability. Analyses, which are being made in the direction of nuclear power plants lifetime extension are based upon components ageing management programs. On the other side, the large uncertainties of the ageing parameters as well as the uncertainties associated with most of the reliability data collections are widely acknowledged. This paper addresses the uncertainty and sensitivity analyses conducted utilizing a previously developed age-dependent unavailability model, integrating effects of test and maintenance activities, for a selected stand-by safety system in a nuclear power plant. The most important problem is the lack of data concerning the effects of ageing as well as the relatively high uncertainty associated to these data, which would correspond to more detailed modelling of ageing. A standard Monte Carlo simulation was coded for the purpose of this paper and utilized in the process of assessment of the component ageing parameters uncertainty propagation on system level. The obtained results from the uncertainty analysis indicate the extent to which the uncertainty of the selected

  13. Managing wind turbine reliability and maintenance via performance-based contract

    DEFF Research Database (Denmark)

    Jin, Tongdan; Ding, Yi; Guo, Huairui

    2012-01-01

    between system cost, reliability and spare parts stocking. This analytical insight into the system performance allows the turbine manufacturer to optimize design, production, and after-sales services. The study aims to create a theoretical basis to facilitate the transition of the maintenance paradigm......Performance-based contracting (PBC) is reshaping the acquisition, operation, and maintenance of capital equipment. Under the PBC scheme, we propose a holistic approach for lowering the cost of wind turbine ownership while meeting the availability requirement. Our effects are focused on integrated...... firms who design and market wind turbines, and also provide maintenance and repair service. PBC differs from conventional service contracts in that the wind farmers compensate the service provider for the system performance, not the spare parts and repair labor. We explore the analytical relationship...

  14. The right maintenance on the right components, at the right time, with the right parts: maintaining high plant reliability through an effective maintenance program

    International Nuclear Information System (INIS)

    Von Hatten, P.

    2008-01-01

    The objective of the maintenance program at a Nuclear Power Plant is to be proactive and prevent unexpected failures of equipment that can impact on Nuclear or Conventional Safety and Plant Production. This does not mean that all equipment failures will be prevented; in a number of cases the most cost effective solution is to allow equipment to run to failure. Deciding what components are critical to the plant is the first step. The industry uses guidance from INPO Advanced Process, AP913, to classify components as Critical, Non Critical or Run to Failure based on the consequence of the failure. Once this is complete, then the right maintenance program needs to be specified. This is done through utilization of experience from the industry based on the type of component. Maintenance strategies and templates have been produced for most power plant components. Each station or fleet needs then to apply the criteria, with exceptions as required, to determine the maintenance requirements and frequency for their components. This includes predictive and preventative maintenance. The more critical the component is the more rigorous the maintenance requirements. Once the maintenance program is defined it can be implemented. This requires that the Preventative Maintenance (PM's) are updated to ensure the correct tasks are in place and the frequency is correct. Work Management will group the PM's so they can scheduled efficiently and to minimize equipment down time. The last element is to ensure that the required parts are specified and are stocked or readily available for the maintenance when it is scheduled. This is an ongoing effort since components become obsolete or suppliers go out of business or change hands. (author)

  15. The study of the maintenance for a cryogenics pilot plant in nuclear regime

    International Nuclear Information System (INIS)

    Anghel, Vasile

    2002-01-01

    The Cryogenic Pilot Plant, CPP, has as goal the extraction of tritium from heavy water at the CANDU Reactors in Cernavoda. Its operation allows a continuos nuclear regime. CPP consists in several modules, each of them implying static and dynamical complex equipment in which fluids circulate at cryogenic temperatures. From these reasons it results that the CPP maintenance is essential. The relational structure regarding the integrated maintenance systems in the whole ICSI's activity is presented in the frame of management decision system and contains a procedural program of maintenance (PPM). PPM includes adoption strategy for maintenance activity in the conditions required by the Manuals worked out in compliance with QA of ICSI and specific regulations of operation in nuclear regime. An explanation based on a thorough analysis is given for the strategy of maintenance, the structure of modules and the use of informatics subsystems. The structure of PPM strategy has a flowchart implying: - Reorganization, Scientific background, and Operative Maintenance strategy (inside/outside strategy) as well as PPM stage realization and specifications for maintenance assurance (manuals, cards and subsystems). Also, provided in the maintenance strategy are the PPM preparatory and proper stage conceptions

  16. Age-related changes of frontal-midline theta is predictive of efficient memory maintenance.

    Science.gov (United States)

    Kardos, Z; Tóth, B; Boha, R; File, B; Molnár, M

    2014-07-25

    Frontal areas are thought to be the coordinators of working memory processes by controlling other brain areas reflected by oscillatory activities like frontal-midline theta (4-7 Hz). With aging substantial changes can be observed in the frontal brain areas, presumably leading to age-associated changes in cortical correlates of cognitive functioning. The present study aimed to test whether altered frontal-midline theta dynamics during working memory maintenance may underlie the capacity deficits observed in older adults. 33-channel EEG was recorded in young (18-26 years, N=20) and old (60-71 years, N=16) adults during the retention period of a visual delayed match-to-sample task, in which they had to maintain arrays of 3 or 5 colored squares. An additional visual odd-ball task was used to be able to measure the electrophysiological indices of sustained attentional processes. Old participants showed reduced frontal theta activity during both tasks compared to the young group. In the young memory maintenance-related frontal-midline theta activity was shown to be sensitive both to the increased memory demands and to efficient subsequent memory performance, whereas the old adults showed no such task-related difference in the frontal theta activity. The decrease of frontal-midline theta activity in the old group indicates that cerebral aging may alter the cortical circuitries of theta dynamics, thereby leading to age-associated decline of working memory maintenance function. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  17. Region-specific role for Pten in maintenance of epithelial phenotype and integrity

    Science.gov (United States)

    Flodby, Per; Sunohara, Mitsuhiro; Castillo, Dan R.; McConnell, Alicia M.; Krishnaveni, Manda S.; Banfalvi, Agnes; Li, Min; Stripp, Barry; Zhou, Beiyun; Crandall, Edward D.; Minoo, Parviz

    2017-01-01

    Previous studies have demonstrated resistance to naphthalene-induced injury in proximal airways of mice with lung epithelial-specific deletion of the tumor-suppressor gene Pten, attributed to increased proliferation of airway progenitors. We tested effects of Pten loss following bleomycin injury, a model typically used to study distal lung epithelial injury, in conditional PtenSFTPC-cre knockout mice. Pten-deficient airway epithelium exhibited marked hyperplasia, particularly in small bronchioles and at bronchoalveolar duct junctions, with reduced E-cadherin and β-catenin expression between cells toward the luminal aspect of the hyperplastic epithelium. Bronchiolar epithelial and alveolar epithelial type II (AT2) cells in PtenSFTPC-cre mice showed decreased expression of epithelial markers and increased expression of mesenchymal markers, suggesting at least partial epithelial-mesenchymal transition at baseline. Surprisingly, and in contrast to previous studies, mutant mice were exquisitely sensitive to bleomycin, manifesting rapid weight loss, respiratory distress, increased early mortality (by day 5), and reduced dynamic lung compliance. This was accompanied by sloughing of the hyperplastic airway epithelium with occlusion of small bronchioles by cellular debris, without evidence of increased parenchymal lung injury. Increased airway epithelial cell apoptosis due to loss of antioxidant defenses, reflected by decreased expression of superoxide dismutase 3, in combination with deficient intercellular adhesion, likely predisposed to airway sloughing in knockout mice. These findings demonstrate an important role for Pten in maintenance of airway epithelial phenotype integrity and indicate that responses to Pten deletion in respiratory epithelium following acute lung injury are highly context-dependent and region-specific. PMID:27864284

  18. Proceedings of the CIM maintenance engineering/mine operators' conference; Comptes rendus du colloque de ICM sur l'ingenierie de maintenance et l'exploitation miniere

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This conference provided a forum to exchange knowledge and best practices that apply to to modern underground mining. It highlighted the synergy and co-operation that is essential for successful operations and maintenance practices. Solutions to mitigate increasing ventilation costs were presented along with possible alternatives to diesel powered equipment in order to maintain air quality at a level that is acceptable for human workers. The themes for the technical program were innovation and performance improvement; maintenance, and mining. The sessions were entitled: deep mining; environment; mining best practices; ground control; energy efficiency; research and development in mining; mining methods; narrow-vein mining; innovative equipment; predictive maintenance; research and development in maintenance; and, planning and scheduling. The conference featured 24 presentations, of which 5 have been catalogued separately for inclusion in this database. refs., tabs., figs.

  19. Application of the Delphi technique in healthcare maintenance.

    Science.gov (United States)

    Njuangang, Stanley; Liyanage, Champika; Akintoye, Akintola

    2017-10-09

    Purpose The purpose of this paper is to examine the research design, issues and considerations in the application of the Delphi technique to identify, refine and rate the critical success factors and performance measures in maintenance-associated infections. Design/methodology/approach In-depth literature review through the application of open and axial coding were applied to formulate the interview and research questions. These were used to conduct an exploratory case study of two healthcare maintenance managers, randomly selected from two National Health Service Foundation Trusts in England. The results of exploratory case study provided the rationale for the application of the Delphi technique in this research. The different processes in the application of the Delphi technique in healthcare research are examined thoroughly. Findings This research demonstrates the need to apply and integrate different research methods to enhance the validity of the Delphi technique. The rationale for the application of the Delphi technique in this research is because some healthcare maintenance managers lack knowledge about basic infection control (IC) principles to make hospitals safe for patient care. The result of first round of the Delphi exercise is a useful contribution in its own rights. It identified a number of salient issues and differences in the opinions of the Delphi participants, noticeably between healthcare maintenance managers and members of the infection control team. It also resulted in useful suggestions and comments to improve the quality and presentation of the second- and third-round Delphi instruments. Practical implications This research provides a research methodology that can be adopted by researchers investigating new and emerging issues in the healthcare sector. As this research demonstrates, the Delphi technique is relevant in soliciting expert knowledge and opinion to identify performance measures to control maintenance-associated infections in

  20. Perencanaan Kegiatan Maintenance Dengan Metode Reability Centered Maintenance (Rcm) II

    OpenAIRE

    Rachmad Hidayat; Nachnul Ansori; Ali Imron

    2010-01-01

    Maintenance Activity Planning by Reability Centered Maintenance (RCM) II Method. This research discussmaintenance activity by using RCM II method to determine failure function risk at compresor screw. Calculation isgiven to magnitude optimum time maintenance interval by considering the cost maintenance and the cost reparation.From the research results with RPN points out that critical component that needs to get main priority in givemaintenance on compresor screw are bust logistic on timeworn...

  1. Financial Motivation Undermines Maintenance in an Intensive Diet and Activity Intervention

    Science.gov (United States)

    Moller, Arlen C.; McFadden, H. Gene; Hedeker, Donald; Spring, Bonnie

    2012-01-01

    Financial incentives are widely used in health behavior interventions. However, self-determination theory posits that emphasizing financial incentives can have negative consequences if experienced as controlling. Feeling controlled into performing a behavior tends to reduce enjoyment and undermine maintenance after financial contingencies are removed (the undermining effect). We assessed participants' context-specific financial motivation to participate in the Make Better Choices trial—a trial testing four different strategies for improving four health risk behaviors: low fruit and vegetable intake, high saturated fat intake, low physical activity, and high sedentary screen time. The primary outcome was overall healthy lifestyle change; weight loss was a secondary outcome. Financial incentives were contingent upon meeting behavior goals for 3 weeks and became contingent upon merely providing data during the 4.5-month maintenance period. Financial motivation for participation was assessed at baseline using a 7-item scale (α = .97). Across conditions, a main effect of financial motivation predicted a steeper rate of weight regained during the maintenance period, t(165) = 2.15, P = .04. Furthermore, financial motivation and gender interacted significantly in predicting maintenance of healthy diet and activity changes, t(160) = 2.42, P = .016, such that financial motivation had a more deleterious influence among men. Implications for practice and future research on incentivized lifestyle and weight interventions are discussed. PMID:22548152

  2. Predictive Coding and Multisensory Integration: An Attentional Account of the Multisensory Mind

    Directory of Open Access Journals (Sweden)

    Durk eTalsma

    2015-03-01

    Full Text Available Multisensory integration involves a host of different cognitive processes, occurring at different stages of sensory processing. Here I argue that, despite recent insights suggesting that multisensory interactions can occur at very early latencies, the actual integration of individual sensory traces into an internally consistent mental representation is dependent on both top-down and bottom-up processes. Moreover, I argue that this integration is not limited to just sensory inputs, but that internal cognitive processes also shape the resulting mental representation. Studies showing that memory recall is affected by the initial multisensory context in which the stimuli were presented will be discussed, as well as several studies showing that mental imagery can affect multisensory illusions. This empirical evidence will be discussed from a predictive coding perspective, in which a central top-down attentional process is proposed to play a central role in coordinating the integration of all these inputs into a coherent mental representation.

  3. Lean Maintenance Applied to Improve Maintenance Efficiency in Thermoelectric Power Plants

    Directory of Open Access Journals (Sweden)

    Orlando Duran

    2017-10-01

    Full Text Available Thermoelectric power plants consist of a set of critical equipment that require high levels of availability and reliability. Due to this, maintenance of these physical assets is gaining momentum in industry. Maintenance is considered as an activity that contributes to improving the availability, efficiency and productivity of each piece of equipment. Several techniques have been used to achieve greater efficiencies in maintenance, among which we can find the lean maintenance philosophy. Despite the wide diffusion of lean maintenance, there is no structured method that supports the prescription of lean tools applied to the maintenance function. This paper presents the experience gathered in two lean maintenance projects in thermoelectric power plants. The application of lean techniques was based on using a previously developed multicriterial decision making process that uses the Fuzzy Analytic Hierarchy Process (AHP methodology to carry out a diagnosis and prescription tasks. That methodology allowed the prescription of the appropriated lean techniques to resolve the main deficiencies in maintenance function. The results of applying such lean tools show that important results can be obtained, making the maintenance function in thermoelectric power plants more efficient and lean.

  4. The probability distribution of maintenance cost of a system affected by the gamma process of degradation: Finite time solution

    International Nuclear Information System (INIS)

    Cheng, Tianjin; Pandey, Mahesh D.; Weide, J.A.M. van der

    2012-01-01

    The stochastic gamma process has been widely used to model uncertain degradation in engineering systems and structures. The optimization of the condition-based maintenance (CBM) policy is typically based on the minimization of the asymptotic cost rate. In the financial planning of a maintenance program, however, a more accurate prediction interval for the cost is needed for prudent decision making. The prediction interval cannot be estimated unless the probability distribution of cost is known. In this context, the asymptotic cost rate has a limited utility. This paper presents the derivation of the probability distribution of maintenance cost, when the system degradation is modelled as a stochastic gamma process. A renewal equation is formulated to derive the characteristic function, then the discrete Fourier transform of the characteristic function leads to the complete probability distribution of cost in a finite time setting. The proposed approach is useful for a precise estimation of prediction limits and optimization of the maintenance cost.

  5. Brain Activation during Associative Short-Term Memory Maintenance is Not Predictive for Subsequent Retrieval

    Directory of Open Access Journals (Sweden)

    Heiko eBergmann

    2015-09-01

    Full Text Available Performance on working memory (WM tasks may partially be supported by long-term memory (LTM processing. Hence, brain activation recently being implicated in WM may actually have been driven by (incidental LTM formation. We examined which brain regions actually support successful WM processing, rather than being confounded by LTM processes, during the maintenance and probe phase of a WM task. We administered a four-pair (faces and houses associative delayed-match-to-sample (WM task using event-related fMRI and a subsequent associative recognition LTM task, using the same stimuli. This enabled us to analyze subsequent memory effects for both the WM and the LTM test by contrasting correctly recognized pairs with incorrect pairs for either task. Critically, with respect to the subsequent WM effect, we computed this analysis exclusively for trials that were forgotten in the subsequent LTM recognition task. Hence, brain activity associated with successful WM processing was less likely to be confounded by incidental LTM formation. The subsequent LTM effect, in contrast, was analyzed exclusively for pairs that previously had been correctly recognized in the WM task, disclosing brain regions involved in successful LTM formation after successful WM processing. Results for the subsequent WM effect showed no significantly activated brain areas for WM maintenance, possibly due to an insensitivity of fMRI to mechanisms underlying active WM maintenance. In contrast, a correct decision at WM probe was linked to activation in the retrieval success network (anterior and posterior midline brain structures. The subsequent LTM analyses revealed greater activation in left dorsolateral prefrontal cortex and posterior parietal cortex in the early phase of the maintenance stage. No supra-threshold activation was found during the WM probe. Together, we obtained clearer insights in which brain regions support successful WM and LTM without the potential confound of the

  6. Brain activation during associative short-term memory maintenance is not predictive for subsequent retrieval.

    Science.gov (United States)

    Bergmann, Heiko C; Daselaar, Sander M; Beul, Sarah F; Rijpkema, Mark; Fernández, Guillén; Kessels, Roy P C

    2015-01-01

    Performance on working memory (WM) tasks may partially be supported by long-term memory (LTM) processing. Hence, brain activation recently being implicated in WM may actually have been driven by (incidental) LTM formation. We examined which brain regions actually support successful WM processing, rather than being confounded by LTM processes, during the maintenance and probe phase of a WM task. We administered a four-pair (faces and houses) associative delayed-match-to-sample (WM) task using event-related functional MRI (fMRI) and a subsequent associative recognition LTM task, using the same stimuli. This enabled us to analyze subsequent memory effects for both the WM and the LTM test by contrasting correctly recognized pairs with incorrect pairs for either task. Critically, with respect to the subsequent WM effect, we computed this analysis exclusively for trials that were forgotten in the subsequent LTM recognition task. Hence, brain activity associated with successful WM processing was less likely to be confounded by incidental LTM formation. The subsequent LTM effect, in contrast, was analyzed exclusively for pairs that previously had been correctly recognized in the WM task, disclosing brain regions involved in successful LTM formation after successful WM processing. Results for the subsequent WM effect showed no significantly activated brain areas for WM maintenance, possibly due to an insensitivity of fMRI to mechanisms underlying active WM maintenance. In contrast, a correct decision at WM probe was linked to activation in the "retrieval success network" (anterior and posterior midline brain structures). The subsequent LTM analyses revealed greater activation in left dorsolateral prefrontal cortex and posterior parietal cortex in the early phase of the maintenance stage. No supra-threshold activation was found during the WM probe. Together, we obtained clearer insights in which brain regions support successful WM and LTM without the potential confound of

  7. OPTIMALISASI KINERJA PERSEDIAAN SUKU CADANG UNTUK PELAKSANAAN MAINTENANCE REPAIR OVERHAUL (MRO DENGAN PENERAPAN COMPUTERIZED MAINTENANCE MANAGEMENT SYSTEMS (CMMS (Studi Kasus di PT. Indonesia Asahan Aluminium

    Directory of Open Access Journals (Sweden)

    Sutrisno Sutrisno

    2015-04-01

    Full Text Available PT.Inalum is a manufacturing company engaged in the aluminum smelting industry. PT.Inalum pengendaliaan system requires an inventory of spare parts to conduct maintenance, repair and overhaul (MRO. CMMS (Computerized Maintenance Management System is a computerized maintenance system running on a LAN (Local Area Network. CMMS is influenced by three variables, namely an integrated maintenance, inventory and procurement so as to create a good maintenance should be supported by the inventory control of spare parts used in maintenance. CMMS aims to make the work more efficient and effective, especially in matters relating to maintenance. That as a benchmark to measure the performance of CMMs for spare parts inventory control is a key performance indicator (KPI. This study aims to evaluate and compare key performance indicators before and after implementation of CMMS for the implementation of MRO activities. Another goal to be achieved is to determine the factors that affect the value of the inventory of spare parts. Based on the results of data processing and analysis can be seen that by looking at a comparison of before and after implementation of CMMS on key performance indicators, it appears that there is an improvement in every parameter, one of which is the value of the inventory prior to the implementation of CMMS for $ 34,790,000.00 compared to after the application of the inventory value fell to $ 19,632,000.00. Factors that affect the value of the inventory is the inventory of spare parts, maintenance, procurement, and human resources.

  8. Proteomic analysis of the dysferlin protein complex unveils its importance for sarcolemmal maintenance and integrity.

    Directory of Open Access Journals (Sweden)

    Antoine de Morrée

    Full Text Available Dysferlin is critical for repair of muscle membranes after damage. Mutations in dysferlin lead to a progressive muscular dystrophy. Recent studies suggest additional roles for dysferlin. We set out to study dysferlin's protein-protein interactions to obtain comprehensive knowledge of dysferlin functionalities in a myogenic context. We developed a robust and reproducible method to isolate dysferlin protein complexes from cells and tissue. We analyzed the composition of these complexes in cultured myoblasts, myotubes and skeletal muscle tissue by mass spectrometry and subsequently inferred potential protein functions through bioinformatics analyses. Our data confirm previously reported interactions and support a function for dysferlin as a vesicle trafficking protein. In addition novel potential functionalities were uncovered, including phagocytosis and focal adhesion. Our data reveal that the dysferlin protein complex has a dynamic composition as a function of myogenic differentiation. We provide additional experimental evidence and show dysferlin localization to, and interaction with the focal adhesion protein vinculin at the sarcolemma. Finally, our studies reveal evidence for cross-talk between dysferlin and its protein family member myoferlin. Together our analyses show that dysferlin is not only a membrane repair protein but also important for muscle membrane maintenance and integrity.

  9. A multicriteria decision making approach applied to improving maintenance policies in healthcare organizations.

    Science.gov (United States)

    Carnero, María Carmen; Gómez, Andrés

    2016-04-23

    Healthcare organizations have far greater maintenance needs for their medical equipment than other organization, as many are used directly with patients. However, the literature on asset management in healthcare organizations is very limited. The aim of this research is to provide more rational application of maintenance policies, leading to an increase in quality of care. This article describes a multicriteria decision-making approach which integrates Markov chains with the multicriteria Measuring Attractiveness by a Categorical Based Evaluation Technique (MACBETH), to facilitate the best choice of combination of maintenance policies by using the judgements of a multi-disciplinary decision group. The proposed approach takes into account the level of acceptance that a given alternative would have among professionals. It also takes into account criteria related to cost, quality of care and impact of care cover. This multicriteria approach is applied to four dialysis subsystems: patients infected with hepatitis C, infected with hepatitis B, acute and chronic; in all cases, the maintenance strategy obtained consists of applying corrective and preventive maintenance plus two reserve machines. The added value in decision-making practices from this research comes from: (i) integrating the use of Markov chains to obtain the alternatives to be assessed by a multicriteria methodology; (ii) proposing the use of MACBETH to make rational decisions on asset management in healthcare organizations; (iii) applying the multicriteria approach to select a set or combination of maintenance policies in four dialysis subsystems of a health care organization. In the multicriteria decision making approach proposed, economic criteria have been used, related to the quality of care which is desired for patients (availability), and the acceptance that each alternative would have considering the maintenance and healthcare resources which exist in the organization, with the inclusion of a

  10. Joint optimization of economic production quantity and preventive maintenance with considering multi-products and reserve time

    International Nuclear Information System (INIS)

    Liu, Xuejuan; Wang, Binrong

    2017-01-01

    Purpose: We deal with the problem of the joint determination of optimal economic production quantity (EPQ) and optimal preventive maintenance (PM) for a system that can produce multiple products alternately. The objective is to find the optimal number of production cycles and the PM policy simultaneously by minimizing the cost model. Design/methodology/approach: Considering the products go through the system in a sequence and a complete run of all products forms a production cycle. In each cycle, beyond production time we also consider some reserve time for maintenance and setup, shortage and overproduction may occur. We study the integrated problem based on two PM policies, and explain the situation with the other PM policies. The delay – time concept is used to model PM decisions. Findings: Using the integrated EPQ and PM model, we can calculate the optimal production planning and PM schedule simultaneously, especially we consider multiple products in each production cycle, which is more practical and economic than previous works. Originality/value: In modern companies, the production planning and maintenance schedule share the same system, and traditional research about two activities is separated, that always generate conflicts, such as inadequate or excessive maintenance, and shortages, etc., so we develop the integrated EPQ and PM model to avoid these undesirable effects.

  11. Joint optimization of economic production quantity and preventive maintenance with considering multi-products and reserve time

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xuejuan; Wang, Binrong

    2017-07-01

    Purpose: We deal with the problem of the joint determination of optimal economic production quantity (EPQ) and optimal preventive maintenance (PM) for a system that can produce multiple products alternately. The objective is to find the optimal number of production cycles and the PM policy simultaneously by minimizing the cost model. Design/methodology/approach: Considering the products go through the system in a sequence and a complete run of all products forms a production cycle. In each cycle, beyond production time we also consider some reserve time for maintenance and setup, shortage and overproduction may occur. We study the integrated problem based on two PM policies, and explain the situation with the other PM policies. The delay – time concept is used to model PM decisions. Findings: Using the integrated EPQ and PM model, we can calculate the optimal production planning and PM schedule simultaneously, especially we consider multiple products in each production cycle, which is more practical and economic than previous works. Originality/value: In modern companies, the production planning and maintenance schedule share the same system, and traditional research about two activities is separated, that always generate conflicts, such as inadequate or excessive maintenance, and shortages, etc., so we develop the integrated EPQ and PM model to avoid these undesirable effects.

  12. Testing Predictive Models of Technology Integration in Mexico and the United States

    Science.gov (United States)

    Velazquez, Cesareo Morales

    2008-01-01

    Data from Mexico City, Mexico (N = 978) and from Texas, USA (N = 932) were used to test the predictive validity of the teacher professional development component of the Will, Skill, Tool Model of Technology Integration in a cross-cultural context. Structural equation modeling (SEM) was used to test the model. Analyses of these data yielded…

  13. Maintenance management systems

    International Nuclear Information System (INIS)

    Rohan, M. de

    1989-01-01

    This paper is concerned principally with Maintenance Management systems and their effective introduction into organisations. Maintenance improvement is basically a problem of managing the maintenance department in the broadest sense. Improvement does not only lie in the area of special techniques, systems or procedures; although they are valuable tools, but rather in a balanced attack, carefully guided by management. Over recent years, maintenance systems have received the major emphasis and in many instances the selection of the system has become a pre-occupation, whereas the importance of each maintenance function must be recognised and good management practices applied to all maintenance activities. The ingredients for success in the implementation of maintenance management systems are summarised as: having a management committee, clear objectives, project approach using project management techniques and an enthusiastic leader, user managed and data processing supported project, realistic budget and an understanding of the financial audit requirements. (author)

  14. Guidelineness of the parameters using integrated test in down syndrome risk prediction

    International Nuclear Information System (INIS)

    Lee, Jin Won; Go, Sung Jin; Kang, Se Sik; Kim, Chang Soo

    2016-01-01

    This study was an evaluation of the significance of each parameter through aimed at pregnant women subjected to screening test(integrated test) in predicting risk of Down syndrome. We retrospectively analysed the correlation of risk of Down's syndrome with Nuchal Translucency(NT) images measured by ultrasound, Pregnancy Associated Plasma Protein A(PAPP-A), alpha-fetoprotein(AFP), unconjugated estriol(uE3), human chorionic gonadotrophin(hCG) and Inhibin A by maternal serum. As a result, a significant correlation with NT, uE3, hCG, Inhibin A is revealed with Down's syndrome risk(P<.001). In ROC analysis, AUC of Inhibin A is analysed as the biggest predictor of Down's syndrome(0.859). And the criterion for cut-off was inhibin A 1.4 MoM(sensitivity 81.8%, specificity 75.9%). In conclusion, Inhibin A was the most useful in parameters to predict Down's syndrome in the integrated test. If we make up for the weakness based on the cut-off value of parameters they will be able to be used as an independent indicator in the risk of Down's syndrome screening

  15. Theoretical explanations for maintenance of behaviour change: a systematic review of behaviour theories

    Science.gov (United States)

    Kwasnicka, Dominika; Dombrowski, Stephan U; White, Martin; Sniehotta, Falko

    2016-01-01

    ABSTRACT Background: Behaviour change interventions are effective in supporting individuals in achieving temporary behaviour change. Behaviour change maintenance, however, is rarely attained. The aim of this review was to identify and synthesise current theoretical explanations for behaviour change maintenance to inform future research and practice. Methods: Potentially relevant theories were identified through systematic searches of electronic databases (Ovid MEDLINE, Embase, PsycINFO). In addition, an existing database of 80 theories was searched, and 25 theory experts were consulted. Theories were included if they formulated hypotheses about behaviour change maintenance. Included theories were synthesised thematically to ascertain overarching explanations for behaviour change maintenance. Initial theoretical themes were cross-validated. Findings: One hundred and seventeen behaviour theories were identified, of which 100 met the inclusion criteria. Five overarching, interconnected themes representing theoretical explanations for behaviour change maintenance emerged. Theoretical explanations of behaviour change maintenance focus on the differential nature and role of motives, self-regulation, resources (psychological and physical), habits, and environmental and social influences from initiation to maintenance. Discussion: There are distinct patterns of theoretical explanations for behaviour change and for behaviour change maintenance. The findings from this review can guide the development and evaluation of interventions promoting maintenance of health behaviours and help in the development of an integrated theory of behaviour change maintenance. PMID:26854092

  16. METHODS AND TECHNIQUES OF PREDICTION OF KEY PERFORMANCE INDICATORS FOR IMPLEMENTATION OF CHANGES IN MAINTENANCE ORGANISATION

    Directory of Open Access Journals (Sweden)

    Andrzej WIECZOREK

    2012-01-01

    Full Text Available The article presents the concept of how to assess the future state of the organization in the area of using and maintenance of technical means, basing on the combination of "classic" prognostic model with models ‐ components of the selected computer tools. Presentation of this concept was preceded by the definition and characteristics of maintenance key performance indicators. It also presents a requirements and method of KPIs selection.

  17. Joint optimization of economic production quantity and preventive maintenance with considering multi-products and reserve time

    Directory of Open Access Journals (Sweden)

    Xuejuan Liu

    2017-07-01

    Originality/value: In modern companies, the production planning and maintenance schedule share the same system, and traditional research about two activities is separated, that always generate conflicts, such as inadequate or excessive maintenance, and shortages, etc., so we develop the integrated EPQ and PM model to avoid these undesirable effects.

  18. A generic Approach for Reliability Predictions considering non-uniformly Deterioration Behaviour

    International Nuclear Information System (INIS)

    Krause, Jakob; Kabitzsch, Klaus

    2012-01-01

    Predictive maintenance offers the possibility to prognosticate the remaining time until a maintenance action of a machine has to be scheduled. Unfortunately, current predictive maintenance solutions are only suitable for very specific use cases like reliability predictions based on vibration monitoring. Furthermore, they do not consider the fact that machines may deteriorate non-uniformly, depending on external influences (e.g., the work piece material in a milling machine or the changing fruit acid concentration in a bottling plant). In this paper two concepts for a generic predictive maintenance solution which also considers non-uniformly aging behaviour are introduced. The first concept is based on system models representing the health state of a technical system. As these models are usually statically (viz. without a timely dimension) their coefficients are determined periodically and the resulting time series is used as aging indicator. The second concept focuses on external influences (contexts) which change the behaviour of the previous mentioned aging indicators in order to increase the accuracy of reliability predictions. Therefore, context-depended time series models are determined and used to predict machine reliability. Both concepts were evaluated on data of an air ventilation system. Thereby, it could be shown that they are suitable to determine aging indicators in a generic way and to incorporate external influences in the reliability prediction. Through this, the quality of reliability predictions can be significantly increased. In reality this leads to a more accurate scheduling of maintenance actions. Furthermore, the generic character of the solutions makes the concepts suitable for a wide range of aging processes.

  19. Design of casks: incorporating operational feedback from maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Bimet, F.; Hartenstein, M. [COGEMA Logistics, Saint Quentin (France)

    2004-07-01

    Casks are designed to conform to regulations and to client specifications. Essential areas such as easy operation, low costs of maintenance, low operation and maintenance doses, limited waste, are not explicitly covered. Notwithstanding, COGEMA LOGISTICS uses all feedback available, so that casks are designed to be easy, safe and economical to operate and maintain. Maintenance is an activity where you do spot items that old-time designers could have made better, and things that users should not have done. Thanks to quality assurance, there are a number of data available, waiting to be collected and exploited; they have to be identified, located, retrieved, and analysed. Using information such as wear, damage, use of spare parts, access problems helps to make casks ever better. It leads to more efficient concepts, and to upgrades on existing designs; it also allows to integrate environmental considerations, inter alia in the choice of materials and in maintenance methods. It is necessary for the designer to interact with the users, the cask owners, the maintenance providers, in order to gather all relevant information and events. This is made easier when all these actors are ''under one roof'', or have very close ties. This paper presents COGEMA LOGISTICS methods for collecting and analysing all these experiences waiting to be used. It explains our process for analysing data, preparing yearly reports that are made available to our designers. It describes how each new design is subject to a maintainability study, using this feedback, so that the cask safety is always assured, that radiological doses are kept to a minimum, and that operating and maintenance costs will remain as low as possible.

  20. Design of casks: incorporating operational feedback from maintenance

    International Nuclear Information System (INIS)

    Bimet, F.; Hartenstein, M.

    2004-01-01

    Casks are designed to conform to regulations and to client specifications. Essential areas such as easy operation, low costs of maintenance, low operation and maintenance doses, limited waste, are not explicitly covered. Notwithstanding, COGEMA LOGISTICS uses all feedback available, so that casks are designed to be easy, safe and economical to operate and maintain. Maintenance is an activity where you do spot items that old-time designers could have made better, and things that users should not have done. Thanks to quality assurance, there are a number of data available, waiting to be collected and exploited; they have to be identified, located, retrieved, and analysed. Using information such as wear, damage, use of spare parts, access problems helps to make casks ever better. It leads to more efficient concepts, and to upgrades on existing designs; it also allows to integrate environmental considerations, inter alia in the choice of materials and in maintenance methods. It is necessary for the designer to interact with the users, the cask owners, the maintenance providers, in order to gather all relevant information and events. This is made easier when all these actors are ''under one roof'', or have very close ties. This paper presents COGEMA LOGISTICS methods for collecting and analysing all these experiences waiting to be used. It explains our process for analysing data, preparing yearly reports that are made available to our designers. It describes how each new design is subject to a maintainability study, using this feedback, so that the cask safety is always assured, that radiological doses are kept to a minimum, and that operating and maintenance costs will remain as low as possible