WorldWideScience

Sample records for online error detection

  1. Online detection of error-related potentials boosts the performance of mental typewriters

    OpenAIRE

    2012-01-01

    Published by BioMed Central Schmidt, Nico M. ; Blankertz, Benjamin ; Treder, Matthias S. : Online detection of error-related potentials boosts the performance of mental typewriters. - In: BMC Neuroscience. - ISSN 1471-2202 (online). - 13 (2012), art. 19. - doi:10.1186/1471-2202-13-19. Background: Increasing the communication speed of brain-computer interfaces (BCIs) is a major aim of current BCI-research. The idea to automatically detect error-related potentials (ErrPs) in order to veto...

  2. Online detection of error-related potentials boosts the performance of mental typewriters

    OpenAIRE

    2012-01-01

    Abstract Background Increasing the communication speed of brain-computer interfaces (BCIs) is a major aim of current BCI-research. The idea to automatically detect error-related potentials (ErrPs) in order to veto erroneous decisions of a BCI has been existing for more than one decade, but this approach was so far little investigated in online mode. Methods In our study with eleven participants, an ErrP detection mechanism was implemented in an electroencephalography (EEG) based gaze-independ...

  3. Online detection of P300 and error potentials in a BCI speller.

    Science.gov (United States)

    Dal Seno, Bernardo; Matteucci, Matteo; Mainardi, Luca

    2010-01-01

    Error potentials (ErrPs), that is, alterations of the EEG traces related to the subject perception of erroneous responses, have been suggested to be an elegant way to recognize misinterpreted commands in brain-computer interface (BCI) systems. We implemented a P300-based BCI speller that uses a genetic algorithm (GA) to detect P300s, and added an automatic error-correction system (ECS) based on the single-sweep detection of ErrPs. The developed system was tested on-line on three subjects and here we report preliminary results. In two out of three subjects, the GA provided a good performance in detecting P300 (90% and 60% accuracy with 5 repetitions), and it was possible to detect ErrP with an accuracy (roughly 60%) well above the chance level. In our knowledge, this is the first time that ErrP detection is performed on-line in a P300-based BCI. Preliminary results are encouraging, but further refinements are needed to improve performances.

  4. Online Detection of P300 and Error Potentials in a BCI Speller

    Directory of Open Access Journals (Sweden)

    Bernardo Dal Seno

    2010-01-01

    Full Text Available Error potentials (ErrPs, that is, alterations of the EEG traces related to the subject perception of erroneous responses, have been suggested to be an elegant way to recognize misinterpreted commands in brain-computer interface (BCI systems. We implemented a P300-based BCI speller that uses a genetic algorithm (GA to detect P300s, and added an automatic error-correction system (ECS based on the single-sweep detection of ErrPs. The developed system was tested on-line on three subjects and here we report preliminary results. In two out of three subjects, the GA provided a good performance in detecting P300 (90% and 60% accuracy with 5 repetitions, and it was possible to detect ErrP with an accuracy (roughly 60% well above the chance level. In our knowledge, this is the first time that ErrP detection is performed on-line in a P300-based BCI. Preliminary results are encouraging, but further refinements are needed to improve performances.

  5. Online detection of error-related potentials boosts the performance of mental typewriters

    Directory of Open Access Journals (Sweden)

    Schmidt Nico M

    2012-02-01

    Full Text Available Abstract Background Increasing the communication speed of brain-computer interfaces (BCIs is a major aim of current BCI-research. The idea to automatically detect error-related potentials (ErrPs in order to veto erroneous decisions of a BCI has been existing for more than one decade, but this approach was so far little investigated in online mode. Methods In our study with eleven participants, an ErrP detection mechanism was implemented in an electroencephalography (EEG based gaze-independent visual speller. Results Single-trial ErrPs were detected with a mean accuracy of 89.1% (AUC 0.90. The spelling speed was increased on average by 49.0% using ErrP detection. The improvement in spelling speed due to error detection was largest for participants with low spelling accuracy. Conclusion The performance of BCIs can be increased by using an automatic error detection mechanism. The benefit for patients with motor disorders is potentially high since they often have rather low spelling accuracies compared to healthy people.

  6. Error detection capability of a novel transmission detector: a validation study for online VMAT monitoring

    Science.gov (United States)

    Pasler, Marlies; Michel, Kilian; Marrazzo, Livia; Obenland, Michael; Pallotta, Stefania; Björnsgard, Mari; Lutterbach, Johannes

    2017-09-01

    The purpose of this study was to characterize a new single large-area ionization chamber, the integral quality monitor system (iRT, Germany), for online and real-time beam monitoring. Signal stability, monitor unit (MU) linearity and dose rate dependence were investigated for static and arc deliveries and compared to independent ionization chamber measurements. The dose verification capability of the transmission detector system was evaluated by comparing calculated and measured detector signals for 15 volumetric modulated arc therapy plans. The error detection sensitivity was tested by introducing MLC position and linac output errors. Deviations in dose distributions between the original and error-induced plans were compared in terms of detector signal deviation, dose-volume histogram (DVH) metrics and 2D γ-evaluation (2%/2 mm and 3%/3 mm). The detector signal is linearly dependent on linac output and shows negligible (good correlation between DVH metrics and detector signal deviation was found (e.g. PTV D mean: R 2  =  0.97). Positional MLC errors of 1 mm and errors in linac output of 2% were identified with the transmission detector system. The extensive tests performed in this investigation show that the new transmission detector provides a stable and sensitive cumulative signal output and is suitable for beam monitoring during patient treatment.

  7. A Generic Transferable EEG Decoder for Online Detection of Error Potential in Target Selection

    Directory of Open Access Journals (Sweden)

    Saugat Bhattacharyya

    2017-05-01

    Full Text Available Reliable detection of error from electroencephalography (EEG signals as feedback while performing a discrete target selection task across sessions and subjects has a huge scope in real-time rehabilitative application of Brain-computer Interfacing (BCI. Error Related Potentials (ErrP are EEG signals which occur when the participant observes an erroneous feedback from the system. ErrP holds significance in such closed-loop system, as BCI is prone to error and we need an effective method of systematic error detection as feedback for correction. In this paper, we have proposed a novel scheme for online detection of error feedback directly from the EEG signal in a transferable environment (i.e., across sessions and across subjects. For this purpose, we have used a P300-speller dataset available on a BCI competition website. The task involves the subject to select a letter of a word which is followed by a feedback period. The feedback period displays the letter selected and, if the selection is wrong, the subject perceives it by the generation of ErrP signal. Our proposed system is designed to detect ErrP present in the EEG from new independent datasets, not involved in its training. Thus, the decoder is trained using EEG features of 16 subjects for single-trial classification and tested on 10 independent subjects. The decoder designed for this task is an ensemble of linear discriminant analysis, quadratic discriminant analysis, and logistic regression classifier. The performance of the decoder is evaluated using accuracy, F1-score, and Area Under the Curve metric and the results obtained is 73.97, 83.53, and 73.18%, respectively.

  8. [Research on modeling method to analyze Lonicerae Japonicae Flos extraction process with online MEMS-NIR based on two types of error detection theory].

    Science.gov (United States)

    Du, Chen-Zhao; Wu, Zhi-Sheng; Zhao, Na; Zhou, Zheng; Shi, Xin-Yuan; Qiao, Yan-Jiang

    2016-10-01

    To establish a rapid quantitative analysis method for online monitoring of chlorogenic acid in aqueous solution of Lonicera Japonica Flos extraction by using micro-electromechanical near infrared spectroscopy (MEMS-NIR). High performance liquid chromatography(HPLC) was used as reference method.Kennard-Stone (K-S) algorithm was used to divide sample sets, and partial least square(PLS) regression was adopted to establish the multivariate analysis model between the HPLC analysis contents and NIR spectra. The synergy interval partial least squares (SiPLS) was used to selected modeling waveband to establish PLS models. RPD was used to evaluate the prediction performance of the models. MDLs was calculated based on two types of error detection theory, on-line analytical modeling approach of Lonicera Japonica Flos extraction process was expressed scientifically by MDL. The result shows that the model established by multiplicative scatter correction(MSC) was the best, with the root mean square with cross validation(RMSECV), root mean square error of correction(RMSEC) and root mean square error of prediction(RMSEP) of chlorogenic acid as 1.707, 1.489, 2.362, respectively, the determination coefficient of the calibration model was 0.998 5, and the determination coefficient of the prediction was 0.988 1.The value of RPD is 9.468.The MDL (0.042 15 g•L⁻¹) selected by SiPLS is less than the original,which demonstrated that SiPLS was beneficial to improve the prediction performance of the model. In this study, a more accurate expression of the prediction performance of the model from the two types of error detection theory, to further illustrate MEMS-NIR spectroscopy can be used for on-line monitoring of Lonicera Japonica Flos extraction process. Copyright© by the Chinese Pharmaceutical Association.

  9. ROBOT'S MOTION ERROR AND ONLINE COMPENSATION BASED ON FORCE SENSOR

    Institute of Scientific and Technical Information of China (English)

    GAN Fangjian; LIU Zhengshi; REN Chuansheng; ZHANG Ping

    2007-01-01

    Robot's dynamic motion error and on-line compensation based on multi-axis force sensor are dealt with. It is revealed that the reasons of the error are formed and the relations of the error are delivered. A motion equation of robot's termination with the error is established, and then, an error matrix and an error compensation matrix of the motion equation are also defined. An on-line error's compensation method is put forward to decrease the displacement error, which is a degree of millimeter, shown by the result of Simulation of PUMA562 robot.

  10. Using Online Annotations to Support Error Correction and Corrective Feedback

    Science.gov (United States)

    Yeh, Shiou-Wen; Lo, Jia-Jiunn

    2009-01-01

    Giving feedback on second language (L2) writing is a challenging task. This research proposed an interactive environment for error correction and corrective feedback. First, we developed an online corrective feedback and error analysis system called "Online Annotator for EFL Writing". The system consisted of five facilities: Document Maker,…

  11. Error handling for the CDF online silicon vertex tracker

    CERN Document Server

    Bari, M; Cerri, A; Dell'Orso, Mauro; Donati, S; Galeotti, S; Giannetti, P; Morsani, F; Punzi, G; Ristori, L; Spinella, F; Zanetti, A M

    2001-01-01

    The online silicon vertex tracker (SVT) is composed of 104 VME 9U digital boards (of eight different types). Since the data output from the SVT (few MB/s) are a small fraction of the input data (200 MB/s), it is extremely difficult to track possible internal errors by using only the output stream. For this reason, several diagnostic tools have been implemented: local error registers, error bits propagated through the data streams, and the Spy Buffer system. Data flowing through each input and output stream of every board are continuously copied to memory banks named spy buffers, which act as built-in logic state analyzers hooked continuously to internal data streams. The contents of all buffers can be frozen at any time (e.g., on error detection) to take a snapshot of all data flowing through each SVT board. The spy buffers are coordinated at system level by the Spy Control Board. The architecture, design, and implementation of this system are described. (4 refs).

  12. Error detection and reduction in blood banking.

    Science.gov (United States)

    Motschman, T L; Moore, S B

    1996-12-01

    Error management plays a major role in facility process improvement efforts. By detecting and reducing errors, quality and, therefore, patient care improve. It begins with a strong organizational foundation of management attitude with clear, consistent employee direction and appropriate physical facilities. Clearly defined critical processes, critical activities, and SOPs act as the framework for operations as well as active quality monitoring. To assure that personnel can detect an report errors they must be trained in both operational duties and error management practices. Use of simulated/intentional errors and incorporation of error detection into competency assessment keeps employees practiced, confident, and diminishes fear of the unknown. Personnel can clearly see that errors are indeed used as opportunities for process improvement and not for punishment. The facility must have a clearly defined and consistently used definition for reportable errors. Reportable errors should include those errors with potentially harmful outcomes as well as those errors that are "upstream," and thus further away from the outcome. A well-written error report consists of who, what, when, where, why/how, and follow-up to the error. Before correction can occur, an investigation to determine the underlying cause of the error should be undertaken. Obviously, the best corrective action is prevention. Correction can occur at five different levels; however, only three of these levels are directed at prevention. Prevention requires a method to collect and analyze data concerning errors. In the authors' facility a functional error classification method and a quality system-based classification have been useful. An active method to search for problems uncovers them further upstream, before they can have disastrous outcomes. In the continual quest for improving processes, an error management program is itself a process that needs improvement, and we must strive to always close the circle

  13. Real-time Texture Error Detection

    Directory of Open Access Journals (Sweden)

    Dan Laurentiu Lacrama

    2008-01-01

    Full Text Available This paper advocates an improved solution for the real-time error detection of texture errors that occurs in the production process in textile industry. The research is focused on the mono-color products with 3D texture model (Jacquard fabrics. This is a more difficult task than, for example, 2D multicolor textures.

  14. Topic Detection in Online Chat

    Science.gov (United States)

    2009-09-01

    including the time for reviewing instruction, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the...you. “ … Of making many books there is no end, and much study is a weariness of the flesh.” Ecclesiastes 12:12 , ESV xvi THIS PAGE INTENTIONALLY...topic detection," Online Information Review , vol. 30, pp. 496–516, 2006. [2] D. Jurafsky and J. H. Martin, Speech and Language Processing : An

  15. Effects of Listening Conditions, Error Types, and Ensemble Textures on Error Detection Skills

    Science.gov (United States)

    Waggoner, Dori T.

    2011-01-01

    This study was designed with three main purposes: (a) to investigate the effects of two listening conditions on error detection accuracy, (b) to compare error detection responses for rhythm errors and pitch errors, and (c) to examine the influences of texture on error detection accuracy. Undergraduate music education students (N = 18) listened to…

  16. Parallel Error Detection for Leading Zero Anticipation

    Institute of Scientific and Technical Information of China (English)

    Ge Zhang; Wei-Wu Hu; Zi-Chu Qi

    2006-01-01

    The algorithm and its implementation of the leading zero anticipation (LZA) are very vital for the performance of a high-speed floating-point adder in today's state of art microprocessor design. Unfortunately, in predicting "shift amount"by a conventional LZA design, the result could be off by one position. This paper presents a novel parallel error detection algorithm for a general-case LZA. The proposed approach enables parallel execution of conventional LZA and its error detection, so that the error-indication signal can be generated earlier in the stage of normalization, thus reducing the critical path and improving overall performance. The circuit implementation of this algorithm also shows its advantages of area and power compared with other previous work.

  17. Reversible Logic Based Concurrent Error Detection Methodology For Emerging Nanocircuits

    CERN Document Server

    Thapliyal, Himanshu

    2011-01-01

    Reversible logic has promising applications in emerging nanotechnologies, such as quantum computing, quantum dot cellular automata and optical computing, etc. Faults in reversible logic circuits that result in multi-bit error at the outputs are very tough to detect, and thus in literature, researchers have only addressed the problem of online testing of faults that result single-bit error at the outputs based on parity preserving logic. In this work, we propose a methodology for the concurrent error detection in reversible logic circuits to detect faults that can result in multi-bit error at the outputs. The methodology is based on the inverse property of reversible logic and is termed as 'inverse and compare' method. By using the inverse property of reversible logic, all the inputs can be regenerated at the outputs. Thus, by comparing the original inputs with the regenerated inputs, the faults in reversible circuits can be detected. Minimizing the garbage outputs is one of the main goals in reversible logic ...

  18. Error detection based on MB types

    Institute of Scientific and Technical Information of China (English)

    FANG Yong; JEONG JeChang; WU ChengKe

    2008-01-01

    This paper proposes a method of error detection based on macroblock (MB) types for video transmission. For decoded inter MBs, the absolute values of received residues are accumulated. At the same time, the intra textural complexity of the current MB is estimated by that of the motion compensated reference block. We compare the inter residue with the intra textural complexity. If the inter residue is larger than the intra textural complexity by a predefined threshold, the MB is con-sidered to be erroneous and errors are concealed. For decoded intra MBs, the connective smoothness of the current MB with neighboring MBs is tested to find erroneous MBs. Simulation results show that the new method can remove those seriously-corrupted MBs efficiently. Combined with error concealment, the new method improves the recovered quality at the decoder by about 0.5-1 dB.

  19. Detection of error related neuronal responses recorded by electrocorticography in humans during continuous movements.

    Directory of Open Access Journals (Sweden)

    Tomislav Milekovic

    Full Text Available BACKGROUND: Brain-machine interfaces (BMIs can translate the neuronal activity underlying a user's movement intention into movements of an artificial effector. In spite of continuous improvements, errors in movement decoding are still a major problem of current BMI systems. If the difference between the decoded and intended movements becomes noticeable, it may lead to an execution error. Outcome errors, where subjects fail to reach a certain movement goal, are also present during online BMI operation. Detecting such errors can be beneficial for BMI operation: (i errors can be corrected online after being detected and (ii adaptive BMI decoding algorithm can be updated to make fewer errors in the future. METHODOLOGY/PRINCIPAL FINDINGS: Here, we show that error events can be detected from human electrocorticography (ECoG during a continuous task with high precision, given a temporal tolerance of 300-400 milliseconds. We quantified the error detection accuracy and showed that, using only a small subset of 2×2 ECoG electrodes, 82% of detection information for outcome error and 74% of detection information for execution error available from all ECoG electrodes could be retained. CONCLUSIONS/SIGNIFICANCE: The error detection method presented here could be used to correct errors made during BMI operation or to adapt a BMI algorithm to make fewer errors in the future. Furthermore, our results indicate that smaller ECoG implant could be used for error detection. Reducing the size of an ECoG electrode implant used for BMI decoding and error detection could significantly reduce the medical risk of implantation.

  20. Robust online face tracking-by-detection

    NARCIS (Netherlands)

    Comaschi, F.; Stuijk, S.; Basten, T.; Corporaal, H.

    2016-01-01

    The problem of online face tracking from unconstrained videos is still unresolved. Challenges range from coping with severe online appearance variations to coping with occlusion. We propose RFTD (Robust Face Tracking-by-Detection), a system which combines tracking and detection into a single framewo

  1. Anomaly detection in online social networks

    CERN Document Server

    Savage, David; Yu, Xinghuo; Chou, Pauline; Wang, Qingmai

    2016-01-01

    Anomalies in online social networks can signify irregular, and often illegal behaviour. Anomalies in online social networks can signify irregular, and often illegal behaviour. Detection of such anomalies has been used to identify malicious individuals, including spammers, sexual predators, and online fraudsters. In this paper we survey existing computational techniques for detecting anomalies in online social networks. We characterise anomalies as being either static or dynamic, and as being labelled or unlabelled, and survey methods for detecting these different types of anomalies. We suggest that the detection of anomalies in online social networks is composed of two sub-processes; the selection and calculation of network features, and the classification of observations from this feature space. In addition, this paper provides an overview of the types of problems that anomaly detection can address and identifies key areas of future research.

  2. Detecting Soft Errors in Stencil based Computations

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, V. [Univ. of Utah, Salt Lake City, UT (United States); Gopalkrishnan, G. [Univ. of Utah, Salt Lake City, UT (United States); Bronevetsky, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-05-06

    Given the growing emphasis on system resilience, it is important to develop software-level error detectors that help trap hardware-level faults with reasonable accuracy while minimizing false alarms as well as the performance overhead introduced. We present a technique that approaches this idea by taking stencil computations as our target, and synthesizing detectors based on machine learning. In particular, we employ linear regression to generate computationally inexpensive models which form the basis for error detection. Our technique has been incorporated into a new open-source library called SORREL. In addition to reporting encouraging experimental results, we demonstrate techniques that help reduce the size of training data. We also discuss the efficacy of various detectors synthesized, as well as our future plans.

  3. MPI Runtime Error Detection with MUST: Advances in Deadlock Detection

    Directory of Open Access Journals (Sweden)

    Tobias Hilbrich

    2013-01-01

    Full Text Available The widely used Message Passing Interface (MPI is complex and rich. As a result, application developers require automated tools to avoid and to detect MPI programming errors. We present the Marmot Umpire Scalable Tool (MUST that detects such errors with significantly increased scalability. We present improvements to our graph-based deadlock detection approach for MPI, which cover future MPI extensions. Our enhancements also check complex MPI constructs that no previous graph-based detection approach handled correctly. Finally, we present optimizations for the processing of MPI operations that reduce runtime deadlock detection overheads. Existing approaches often require (p analysis time per MPI operation, for p processes. We empirically observe that our improvements lead to sub-linear or better analysis time per operation for a wide range of real world applications.

  4. Latent error detection: A golden two hours for detection.

    Science.gov (United States)

    Saward, Justin R E; Stanton, Neville A

    2017-03-01

    Undetected error in safety critical contexts generates a latent condition that can contribute to a future safety failure. The detection of latent errors post-task completion is observed in naval air engineers using a diary to record work-related latent error detection (LED) events. A systems view is combined with multi-process theories to explore sociotechnical factors associated with LED. Perception of cues in different environments facilitates successful LED, for which the deliberate review of past tasks within two hours of the error occurring and whilst remaining in the same or similar sociotechnical environment to that which the error occurred appears most effective. Identified ergonomic interventions offer potential mitigation for latent errors; particularly in simple everyday habitual tasks. It is thought safety critical organisations should look to engineer further resilience through the application of LED techniques that engage with system cues across the entire sociotechnical environment, rather than relying on consistent human performance. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  5. OCR Post-Processing Error Correction Algorithm using Google Online Spelling Suggestion

    CERN Document Server

    Bassil, Youssef

    2012-01-01

    With the advent of digital optical scanners, a lot of paper-based books, textbooks, magazines, articles, and documents are being transformed into an electronic version that can be manipulated by a computer. For this purpose, OCR, short for Optical Character Recognition was developed to translate scanned graphical text into editable computer text. Unfortunately, OCR is still imperfect as it occasionally mis-recognizes letters and falsely identifies scanned text, leading to misspellings and linguistics errors in the OCR output text. This paper proposes a post-processing context-based error correction algorithm for detecting and correcting OCR non-word and real-word errors. The proposed algorithm is based on Google's online spelling suggestion which harnesses an internal database containing a huge collection of terms and word sequences gathered from all over the web, convenient to suggest possible replacements for words that have been misspelled during the OCR process. Experiments carried out revealed a signific...

  6. Overlapping Community Detection by Online Cluster Aggregation

    CERN Document Server

    Kozdoba, Mark

    2015-01-01

    We present a new online algorithm for detecting overlapping communities. The main ingredients are a modification of an online k-means algorithm and a new approach to modelling overlap in communities. An evaluation on large benchmark graphs shows that the quality of discovered communities compares favorably to several methods in the recent literature, while the running time is significantly improved.

  7. A Mechanism for Error Detection in Speeded Response Time Tasks

    Science.gov (United States)

    Holroyd, Clay B.; Yeung, Nick; Coles, Michael G. H.; Cohen, Jonathan D.

    2005-01-01

    The concept of error detection plays a central role in theories of executive control. In this article, the authors present a mechanism that can rapidly detect errors in speeded response time tasks. This error monitor assigns values to the output of cognitive processes involved in stimulus categorization and response generation and detects errors…

  8. Data Properties Categorization to Improve Scientific Sensor Data Error Detection

    Science.gov (United States)

    Gallegos, I.; Gates, A.; Tweedie, C. E.

    2009-12-01

    Recent advancements in scientific sensor data acquisition technologies have increased the amount of data collected in near-real time. Although the need for error detection in such data sets is widely acknowledged, few organizations to date have automated random and systematic error detection. This poster presents the results of a broad survey of the literature on scientific sensor data collected through networks and environmental observatories with the aim of identifying research priorities needed for the development of automated error detection mechanisms. The key finding of this survey is that there appears to be no overarching consensus about error detection criteria in the environmental sciences and that this likely limits the development and implementation of automated error detection in this domain. The literature survey focused on identifying scientific projects from institutions that have incorporated error detection into their systems, the type of analyzed data, and the type of sensor error detection properties as defined by each project. The projects have mechanisms that perform error detection in both the field sites and data centers. The literature survey was intended to capture a representative sample of projects with published error detection criteria. Several scientific projects have included error detection, mostly as part of the system’s source code; however, error detection properties, which are embedded or hard-coded in the source code, are difficult to refine and require a software developer to modify the source code every time a new error detection property or a modification to an existing property is needed. An alternative to hard-coded error detection properties is an error-detection mechanism, independent of the system used to collect the sensor data, which will automatically detect errors in the supported type of data. Such a mechanism would allow scientists to specify and reuse error detection properties and uses the specified properties

  9. Using Online Error Analysis Items to Support Preservice Teachers' Pedagogical Content Knowledge in Mathematics

    Science.gov (United States)

    McGuire, Patrick

    2013-01-01

    This article describes how a free, web-based intelligent tutoring system, (ASSISTment), was used to create online error analysis items for preservice elementary and secondary mathematics teachers. The online error analysis items challenged preservice teachers to analyze, diagnose, and provide targeted instructional remediation intended to help…

  10. The Detection and Monitoring of Comprehension Errors by Preschool Children with and without Language Impairment

    Science.gov (United States)

    Skarakis-Doyle, Elizabeth; Dempsey, Lynn

    2008-01-01

    Purpose: In this study, the authors examined emerging comprehension monitoring, including error detection, evaluation, and correction within the context of story understanding in preschool children with and without language impairment. Method: Thirty-seven children between the ages of 30 and 61 months completed an online comprehension monitoring…

  11. Error detection, handling and recovery at the High Level Trigger of the ATLAS experiment at the LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00223972; The ATLAS collaboration

    2016-01-01

    The complexity of the ATLAS High Level Trigger (HLT) requires a robust system for error detection and handling during online data-taking; it also requires an offline system for the recovery of events where no trigger decision could be made online. The error detection and handling ensure smooth operation of the trigger system and provide debugging information necessary for offline analysis and diagnosis. In this presentation, we give an overview of the error detection, handling and recovery of problematic events at the HLT of ATLAS.

  12. Error Detection and Error Classification: Failure Awareness in Data Transfer Scheduling

    Energy Technology Data Exchange (ETDEWEB)

    Louisiana State University; Balman, Mehmet; Kosar, Tevfik

    2010-10-27

    Data transfer in distributed environment is prone to frequent failures resulting from back-end system level problems, like connectivity failure which is technically untraceable by users. Error messages are not logged efficiently, and sometimes are not relevant/useful from users point-of-view. Our study explores the possibility of an efficient error detection and reporting system for such environments. Prior knowledge about the environment and awareness of the actual reason behind a failure would enable higher level planners to make better and accurate decisions. It is necessary to have well defined error detection and error reporting methods to increase the usability and serviceability of existing data transfer protocols and data management systems. We investigate the applicability of early error detection and error classification techniques and propose an error reporting framework and a failure-aware data transfer life cycle to improve arrangement of data transfer operations and to enhance decision making of data transfer schedulers.

  13. Plagiarism Detection by Online Solutions.

    Science.gov (United States)

    Masic, Izet; Begic, Edin; Dobraca, Amra

    2017-01-01

    The problem of plagiarism represents one of the burning issues of the modern scientific world. Detection of plagiarism is a problem that the Editorial Board encounters in their daily work. Software solutions represent a good solution for the detection of plagiarism. The problem of plagiarism will become most discussed topic of the modern scientific world, especially due to the development of standard measures, which rank the work of one author. Investment in education, education of young research personnel about the importance of scientific research, with paying particular attention on ethical behavior, becomes an imperative of academic staff. Editors have to invest additional effort in the development of the base of reviewers team as well as in their proper guidance, because after all, despite the software solutions, they are the best weapon to fight plagiarism. Peer review process should be a key of successful operation of each journal.

  14. Threshold computations for detection of failures in SISO systems with transfer function errors

    Science.gov (United States)

    Weiss, Jerold L.

    1988-01-01

    The author considers the problem of detecting failures in SISO systems using analytic redundancy concepts. Since the models used are subject to error, a method of determining the detection thresholds that account for these errors is sought. The methodology presented utilizes a straightforward application of Parseval's relation to develop a threshold computation that is performed online as a function of the input signal. The threshold is set at a quiescent value to account for sensor noise and is adjusted (upward) according to the activity of the input signal. An application to detection of actuator failures is presented.

  15. Error detection and reduction within DriftLessTM

    NARCIS (Netherlands)

    Hall, E.W. van der

    2013-01-01

    This thesis presents an algorithm that can reduce the estimation errors made with the DriftLessTM bias estimation technique. The algorithm utilizes the autocorrelation function to detect the presence of errors, and a minimization function to reduce these errors. The algorithm has been validated with

  16. Online referrals one way capitated groups gain efficiencies, reduce errors.

    Science.gov (United States)

    2002-08-01

    An online referral system is just the latest money and time-saving tool in the e-commerce arsenal at Hill Physicians Medical Group. Using a modified version of Healinx Corp.'s secure e-mail messaging platform, Hill is testing a custom-made online referral system at two primary care practices that appear to be helping the practice boost its bottom line under capitation.

  17. A study of the laser power online detecting

    Science.gov (United States)

    Zhang, Qiue; Zhang, Rong; Li, Yongzheng

    2008-12-01

    This article introduced a fundamental of new intelligent instruments. It can be used in laser power online detecting. Based in this theory, we have made a new intelligent mini-power meter. The device adopt SPCE061A MPU to control and process the all detected data, Its CPU core is used 16-bits MPU, it is a perfect unit in industry field. It can process complicated digital signals. Its detecting parts adopt high-speed responding and high-sensitive photoelectric dynatron 3DU13 to detecting the beam's output. It respond spectrum is from 0.4 to 1.1µm, can detect any other laser source's online detecting. Which locate in this spectrum range, optical design is made up of 45 degrees high reflect device and dark body scattering structure. The detector receive a little scatter light, use on-chip ADC to sampling the detector's output. By subsection, insert value linearity, proportion calculate to beam's output powers. And then real-time to displaying by LCD. It can communicate to PC by RS232. By communicate to upper instrument and others, the users can use detected data to achieve laser power's closed-loop control, to control laser source's real time output correctly and calibrating by itself. This mini-power meter need use standard power meter to calibrate in installing, after this process, the device can detect laser power's output from 1 to 200 watts correctly. It error is less than 5 percent.

  18. Adaptive skin detection based on online training

    Science.gov (United States)

    Zhang, Ming; Tang, Liang; Zhou, Jie; Rong, Gang

    2007-11-01

    Skin is a widely used cue for porn image classification. Most conventional methods are off-line training schemes. They usually use a fixed boundary to segment skin regions in the images and are effective only in restricted conditions: e.g. good lightness and unique human race. This paper presents an adaptive online training scheme for skin detection which can handle these tough cases. In our approach, skin detection is considered as a classification problem on Gaussian mixture model. For each image, human face is detected and the face color is used to establish a primary estimation of skin color distribution. Then an adaptive online training algorithm is used to find the real boundary between skin color and background color in current image. Experimental results on 450 images showed that the proposed method is more robust in general situations than the conventional ones.

  19. Arduino-based noise robust online heart-rate detection.

    Science.gov (United States)

    Das, Sangita; Pal, Saurabh; Mitra, Madhuchhanda

    2017-04-01

    This paper introduces a noise robust real time heart rate detection system from electrocardiogram (ECG) data. An online data acquisition system is developed to collect ECG signals from human subjects. Heart rate is detected using window-based autocorrelation peak localisation technique. A low-cost Arduino UNO board is used to implement the complete automated process. The performance of the system is compared with PC-based heart rate detection technique. Accuracy of the system is validated through simulated noisy ECG data with various levels of signal to noise ratio (SNR). The mean percentage error of detected heart rate is found to be 0.72% for the noisy database with five different noise levels.

  20. Robust Principal Component Test in Gross Error Detection and Identification

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Principle component analysis (PCA) based chi-square test is more sensitive to subtle gross errors and has greater power to correctly detect gross errors than classical chi-square test. However, classical principal component test (PCT) is non-robust and can be very sensitive to one or more outliers. In this paper, a Huber function liked robust weight factor was added in the collective chi-square test to eliminate the influence of gross errors on the PCT. Meanwhile, robust chi-square test was applied to modified simultaneous estimation of gross error (MSEGE) strategy to detect and identify multiple gross errors. Simulation results show that the proposed robust test can reduce the possibility of type Ⅱ errors effectively. Adding robust chi-square test into MSEGE does not obviously improve the power of multiple gross error identification, the proposed approach considers the influence of outliers on hypothesis statistic test and is more reasonable.

  1. A proposal for the detection and classification of discourse errors

    OpenAIRE

    Mestre, Eva M. Mestre; Carrió-Pastor, María Luisa

    2013-01-01

    Our interest lies in error from the point of view of language in context,therefore we will focus on errors produced at the discourse level. The main objective of this paper is to detect discourse competence errors and their implications through the analysis of a corpus of English written texts produced by Higher Education students with a B1 level (following the Common European Framework of Reference for Languages). Further objectives are to propose categories which could help us to c...

  2. Comparing different approaches for automatic pronunciation error detection

    NARCIS (Netherlands)

    Strik, Helmer; Truong, Khiet Phuong; de Wet, Febe; Cucchiarini, Catia

    2009-01-01

    One of the biggest challenges in designing computer assisted language learning (CALL) applications that provide automatic feedback on pronunciation errors consists in reliably detecting the pronunciation errors at such a detailed level that the information provided can be useful to learners. In our

  3. Comparing different approaches for automatic pronunciation error detection

    NARCIS (Netherlands)

    Strik, Helmer; Truong, Khiet; Wet, de Febe; Cucchiarini, Catia

    2009-01-01

    One of the biggest challenges in designing computer assisted language learning (CALL) applications that provide automatic feedback on pronunciation errors consists in reliably detecting the pronunciation errors at such a detailed level that the information provided can be useful to learners. In our

  4. Medication error detection in two major teaching hospitals: What are the types of errors?

    Directory of Open Access Journals (Sweden)

    Fatemeh Saghafi

    2014-01-01

    Full Text Available Background: Increasing number of reports on medication errors and relevant subsequent damages, especially in medical centers has become a growing concern for patient safety in recent decades. Patient safety and in particular, medication safety is a major concern and challenge for health care professionals around the world. Our prospective study was designed to detect prescribing, transcribing, dispensing, and administering medication errors in two major university hospitals. Materials and Methods: After choosing 20 similar hospital wards in two large teaching hospitals in the city of Isfahan, Iran, the sequence was randomly selected. Diagrams for drug distribution were drawn by the help of pharmacy directors. Direct observation technique was chosen as the method for detecting the errors. A total of 50 doses were studied in each ward to detect prescribing, transcribing and administering errors in each ward. The dispensing error was studied on 1000 doses dispensed in each hospital pharmacy. Results: A total of 8162 number of doses of medications were studied during the four stages, of which 8000 were complete data to be analyzed. 73% of prescribing orders were incomplete and did not have all six parameters (name, dosage form, dose and measuring unit, administration route, and intervals of administration. We found 15% transcribing errors. One-third of administration of medications on average was erroneous in both hospitals. Dispensing errors ranged between 1.4% and 2.2%. Conclusion: Although prescribing and administrating compromise most of the medication errors, improvements are needed in all four stages with regard to medication errors. Clear guidelines must be written and executed in both hospitals to reduce the incidence of medication errors.

  5. Detecting and correcting hard errors in a memory array

    Energy Technology Data Exchange (ETDEWEB)

    Kalamatianos, John; John, Johnsy Kanjirapallil; Gelinas, Robert; Sridharan, Vilas K.; Nevius, Phillip E.

    2015-11-19

    Hard errors in the memory array can be detected and corrected in real-time using reusable entries in an error status buffer. Data may be rewritten to a portion of a memory array and a register in response to a first error in data read from the portion of the memory array. The rewritten data may then be written from the register to an entry of an error status buffer in response to the rewritten data read from the register differing from the rewritten data read from the portion of the memory array.

  6. Online Distributed Fault Detection of Sensor Measurements

    Institute of Scientific and Technical Information of China (English)

    GAO Jianliang; XU Yongjun; LI Xiaowei

    2007-01-01

    In wireless sensor networks (WSNs), a faulty sensor may produce incorrect data and transmit them to the other sensors. This would consume the limited energy and bandwidth of WSNs. Furthermore, the base station may make inappropriate decisions when it receives the incorrect data sent by the faulty sensors. To solve these problems, this paper develops an online distributed algorithm to detect such faults by exploring the weighted majority vote scheme. Considering the spatial correlations in WSNs, a faulty sensor can diagnose itself through utilizing the spatial and time information provided by its neighbor sensors. Simulation results show that even when as many as 30% of the sensors are faulty, over 95% of faults can be correctly detected with our algorithm. These results indicate that the proposed algorithm has excellent performance in detecting fault of sensor measurements in WSNs.

  7. Detecting Predatory Behaviour in Online Game Chats

    DEFF Research Database (Denmark)

    Gudnadottir, Elin Rut; Jensen, Alaina K.; Cheong, Yun-Gyung;

    This paper describes a machine learning approach to detect sexually predatory behaviour in the massively multiplayer online game for children, MovieStarPlanet. The goal of this work is to take a chat log as an input and outputs its label as either the predatory category or the non-predatory categ......This paper describes a machine learning approach to detect sexually predatory behaviour in the massively multiplayer online game for children, MovieStarPlanet. The goal of this work is to take a chat log as an input and outputs its label as either the predatory category or the non......-predatory category. From the raw in-game chat logs provided by MovieStarPlanet, we first prepared three sub datasets via extensive preprocessing. Then, two machine learning algorithms, naive Bayes and Decision Tree, were employed to model the predatory behaviour using different feature sets. Our evaluation has...... revealed that the proposed approach achieved high accuracies in detecting predatory chats...

  8. Context-Aware Online Commercial Intention Detection

    Science.gov (United States)

    Hu, Derek Hao; Shen, Dou; Sun, Jian-Tao; Yang, Qiang; Chen, Zheng

    With more and more commercial activities moving onto the Internet, people tend to purchase what they need through Internet or conduct some online research before the actual transactions happen. For many Web users, their online commercial activities start from submitting a search query to search engines. Just like the common Web search queries, the queries with commercial intention are usually very short. Recognizing the queries with commercial intention against the common queries will help search engines provide proper search results and advertisements, help Web users obtain the right information they desire and help the advertisers benefit from the potential transactions. However, the intentions behind a query vary a lot for users with different background and interest. The intentions can even be different for the same user, when the query is issued in different contexts. In this paper, we present a new algorithm framework based on skip-chain conditional random field (SCCRF) for automatically classifying Web queries according to context-based online commercial intention. We analyze our algorithm performance both theoretically and empirically. Extensive experiments on several real search engine log datasets show that our algorithm can improve more than 10% on F1 score than previous algorithms on commercial intention detection.

  9. SENTIMENT ANALYSIS FOR ONLINE FORUMS HOTSPOT DETECTION

    Directory of Open Access Journals (Sweden)

    K. Nirmala Devi

    2012-01-01

    Full Text Available The user generated content on the web grows rapidly in this emergent information age. The evolutionary changes in technology make use of such information to capture only the user’s essence and finally the useful information are exposed to information seekers. Most of the existing research on text information processing, focuses in the factual domain rather than the opinion domain. Text mining plays a vital role in online forum opinion mining. But opinion mining from online forum is much more difficult than pure text process due to their semi structured characteristics. In this paper we detect online hotspot forums by computing sentiment analysis for text data available in each forum. This approach analyzes the forum text data and computes value for each piece of text. The proposed approach combines K-means clustering and Support Vector Machine (SVM classification algorithm that can be used to group the forums into two clusters forming hotspot forums and non-hotspot forums within the current time span. The experiment helps to identify that K-means and SVM together achieve highly consistent results. The prediction result of SVM is also compared with other classifiers such as Naïve Bayes, Decision tree and among them SVM performs the best.

  10. Detecting Predatory Behaviour in Online Game Chats

    DEFF Research Database (Denmark)

    Gudnadottir, Elin Rut; Jensen, Alaina K.; Cheong, Yun-Gyung

    -predatory category. From the raw in-game chat logs provided by MovieStarPlanet, we first prepared three sub datasets via extensive preprocessing. Then, two machine learning algorithms, naive Bayes and Decision Tree, were employed to model the predatory behaviour using different feature sets. Our evaluation has......This paper describes a machine learning approach to detect sexually predatory behaviour in the massively multiplayer online game for children, MovieStarPlanet. The goal of this work is to take a chat log as an input and outputs its label as either the predatory category or the non...

  11. Error detection and rectification in digital terrain models

    Science.gov (United States)

    Hannah, M. J.

    1979-01-01

    Digital terrain models produced by computer correlation of stereo images are likely to contain occasional gross errors in terrain elevation. These errors typically result from having mismatched sub-areas of the two images, a problem which can occur for a variety of image- and terrain-related reasons. Such elevation errors produce undesirable effects when the models are further processed, and should be detected and corrected as early in the processing as possible. Algorithms have been developed to detect and correct errors in digital terrain models. These algorithms focus on the use of constraints on both the allowable slope and the allowable change in slope in local areas around each point. Relaxation-like techniques are employed in the iteration of the detection and correction phases to obtain best results.

  12. Patient identification errors: the detective in the laboratory.

    Science.gov (United States)

    Salinas, Maria; López-Garrigós, Maite; Lillo, Rosa; Gutiérrez, Mercedes; Lugo, Javier; Leiva-Salinas, Carlos

    2013-11-01

    The eradication of errors regarding patients' identification is one of the main goals for safety improvement. As clinical laboratory intervenes in 70% of clinical decisions, laboratory safety is crucial in patient safety. We studied the number of Laboratory Information System (LIS) demographic data errors registered in our laboratory during one year. The laboratory attends a variety of inpatients and outpatients. The demographic data of outpatients is registered in the LIS, when they present to the laboratory front desk. The requests from the primary care centers (PCC) are made electronically by the general practitioner. A manual step is always done at the PCC to conciliate the patient identification number in the electronic request with the one in the LIS. Manual registration is done through hospital information system demographic data capture when patient's medical record number is registered in LIS. Laboratory report is always sent out electronically to the patient's electronic medical record. Daily, every demographic data in LIS is manually compared to the request form to detect potential errors. Fewer errors were committed when electronic order was used. There was great error variability between PCC when using the electronic order. LIS demographic data manual registration errors depended on patient origin and test requesting method. Even when using the electronic approach, errors were detected. There was a great variability between PCC even when using this electronic modality; this suggests that the number of errors is still dependent on the personnel in charge of the technology. © 2013.

  13. Automatic pronunciation error detection in non-native speech: the case of vowel errors in Dutch.

    Science.gov (United States)

    van Doremalen, Joost; Cucchiarini, Catia; Strik, Helmer

    2013-08-01

    This research is aimed at analyzing and improving automatic pronunciation error detection in a second language. Dutch vowels spoken by adult non-native learners of Dutch are used as a test case. A first study on Dutch pronunciation by L2 learners with different L1s revealed that vowel pronunciation errors are relatively frequent and often concern subtle acoustic differences between the realization and the target sound. In a second study automatic pronunciation error detection experiments were conducted to compare existing measures to a metric that takes account of the error patterns observed to capture relevant acoustic differences. The results of the two studies do indeed show that error patterns bear information that can be usefully employed in weighted automatic measures of pronunciation quality. In addition, it appears that combining such a weighted metric with existing measures improves the equal error rate by 6.1 percentage points from 0.297, for the Goodness of Pronunciation (GOP) algorithm, to 0.236.

  14. IMRT QA: Selecting gamma criteria based on error detection sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Steers, Jennifer M. [Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, California 90048 and Physics and Biology in Medicine IDP, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095 (United States); Fraass, Benedick A., E-mail: benedick.fraass@cshs.org [Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, California 90048 (United States)

    2016-04-15

    Purpose: The gamma comparison is widely used to evaluate the agreement between measurements and treatment planning system calculations in patient-specific intensity modulated radiation therapy (IMRT) quality assurance (QA). However, recent publications have raised concerns about the lack of sensitivity when employing commonly used gamma criteria. Understanding the actual sensitivity of a wide range of different gamma criteria may allow the definition of more meaningful gamma criteria and tolerance limits in IMRT QA. We present a method that allows the quantitative determination of gamma criteria sensitivity to induced errors which can be applied to any unique combination of device, delivery technique, and software utilized in a specific clinic. Methods: A total of 21 DMLC IMRT QA measurements (ArcCHECK®, Sun Nuclear) were compared to QA plan calculations with induced errors. Three scenarios were studied: MU errors, multi-leaf collimator (MLC) errors, and the sensitivity of the gamma comparison to changes in penumbra width. Gamma comparisons were performed between measurements and error-induced calculations using a wide range of gamma criteria, resulting in a total of over 20 000 gamma comparisons. Gamma passing rates for each error class and case were graphed against error magnitude to create error curves in order to represent the range of missed errors in routine IMRT QA using 36 different gamma criteria. Results: This study demonstrates that systematic errors and case-specific errors can be detected by the error curve analysis. Depending on the location of the error curve peak (e.g., not centered about zero), 3%/3 mm threshold = 10% at 90% pixels passing may miss errors as large as 15% MU errors and ±1 cm random MLC errors for some cases. As the dose threshold parameter was increased for a given %Diff/distance-to-agreement (DTA) setting, error sensitivity was increased by up to a factor of two for select cases. This increased sensitivity with increasing dose

  15. Straight to the Source: Detecting Aggregate Objects in Astronomical Images with Proper Error Control.

    Science.gov (United States)

    Friedenberg, David A; Genovese, Christopher R

    2013-07-01

    The next generation of telescopes, coming on-line in the next decade, will acquire terabytes of image data each night. Collectively, these large images will contain billions of interesting objects, which astronomers call sources. One critical task for astronomers is to construct from the image data a detailed source catalog that gives the sky coordinates and other properties of all detected sources. The source catalog is the primary data product produced by most telescopes and serves as an important input for studies that build and test new astrophysical theories. To construct an accurate catalog, the sources must first be detected in the image. A variety of effective source detection algorithms exist in the astronomical literature, but few if any provide rigorous statistical control of error rates. A variety of multiple testing procedures exist in the statistical literature that can provide rigorous error control over pixelwise errors, but these do not provide control over errors at the level of sources, which is what astronomers need. In this paper, we propose a technique that is effective at source detection while providing rigorous control on source-wise error rates. We demonstrate our approach with data from the Chandra X-ray Observatory Satellite. Our method is competitive with existing astronomical methods, even finding two new sources that were missed by previous studies, while providing stronger performance guarantees and without requiring costly follow up studies that are commonly required with current techniques.

  16. Online community detection for large complex networks.

    Directory of Open Access Journals (Sweden)

    Gang Pan

    Full Text Available Complex networks describe a wide range of systems in nature and society. To understand complex networks, it is crucial to investigate their community structure. In this paper, we develop an online community detection algorithm with linear time complexity for large complex networks. Our algorithm processes a network edge by edge in the order that the network is fed to the algorithm. If a new edge is added, it just updates the existing community structure in constant time, and does not need to re-compute the whole network. Therefore, it can efficiently process large networks in real time. Our algorithm optimizes expected modularity instead of modularity at each step to avoid poor performance. The experiments are carried out using 11 public data sets, and are measured by two criteria, modularity and NMI (Normalized Mutual Information. The results show that our algorithm's running time is less than the commonly used Louvain algorithm while it gives competitive performance.

  17. Chinese and Thai Bilingual Topic Detection Online

    Directory of Open Access Journals (Sweden)

    Rang Ziqiang

    2017-01-01

    Full Text Available Bilingual topic detection is a vital application of natural language processing in the Internet plus Era and trend of economic globalization. At present, the method of bilingual topic detection can’t solve the problem of bilingual topic inconsistent distribution. Aiming at the shortcoming, this paper introduces a based on maximal clique method to find bilingual topic detection of Chinese and Thai feature words. First of all, extract the information of news with keywords of each Chinese and Thai documents through the TextRank algorithm. Next, disambiguate by means of the similarity combined with Chinese and Thai dictionary. Then, use credible association rules to cluster Chinese and Thai feature words, which generates maximal clique of bilingual topic. Finally, cluster similar maximal clique of topic to obtain the collection of final topic. According to the needs of users, the method can recommend a bilingual topic of different sizes. The test of Chinese and Thai news texts in January 2016 made good achievement. From the perspective of cross-language word clustering, the algorithm effectively solves the problem of inconsistency of bilingual topic distribution reasonably, and has the advantages of no need to estimate the number of topics and low time complexity, so it is suitable for the application of online discovery in ilingual topic.

  18. Online microchannel preconcentrator for carbofuran detection.

    Science.gov (United States)

    Siritham, Charinrat; Thammakhet, Chongdee; Thavarungkul, Panote; Kanatharana, Proespichaya

    2013-01-01

    A simple and rapid online microchannel preconcentrator coupled with an amperometric detection for the analysis of carbofuran using polyethylene glycol coated onto magnetic particle (PEG-magnetic particles) sorbents was developed. This simple-to-prepare microchannel preconcentrator used an external magnet to retain the PEG-magnetic particle sorbents inside the microchannel. Under optimum conditions, the system provided two linear ranges, from 0.01 to 10.0 mg L(-1) and from 10.0 to 130.0 mg L(-1) with a limit of detection of 8.7 ± 0.1 μg L(-1). The microchannel preconcentrator provided very good stability; it can be used for up to 326 consecutive injections of 5.0 mg L(-1) carbofuran with a relative standard deviation of less than 3%. The developed system provided a good microchannel-to-microchannel and a good electrode-to-electrode reproducibility (n = 6, %RSD < 1). It also provided an excellent selectivity when it was tested with two other carbamate pesticides, carbaryl and methomyl, with a 43 and 256 times higher detection sensitivity for carbofuran, respectively. The developed system was successfully applied to detect carbofuran in surface water samples obtained near vegetable plantation areas. The concentrations of carbofuran in these samples were found to be in the range of non-detectable to 0.047 ± 0.001 mg L(-1). The developed system is easy to operate and easy to couple with other analytical instruments and it could be easily adapted for the analysis of other polar organic contaminants.

  19. Online Adaptive Error Compensation SVM-Based Sliding Mode Control of an Unmanned Aerial Vehicle

    Directory of Open Access Journals (Sweden)

    Kaijia Xue

    2016-01-01

    Full Text Available Unmanned Aerial Vehicle (UAV is a nonlinear dynamic system with uncertainties and noises. Therefore, an appropriate control system has an obligation to ensure the stabilization and navigation of UAV. This paper mainly discusses the control problem of quad-rotor UAV system, which is influenced by unknown parameters and noises. Besides, a sliding mode control based on online adaptive error compensation support vector machine (SVM is proposed for stabilizing quad-rotor UAV system. Sliding mode controller is established through analyzing quad-rotor dynamics model in which the unknown parameters are computed by offline SVM. During this process, the online adaptive error compensation SVM method is applied in this paper. As modeling errors and noises both exist in the process of flight, the offline SVM one-time mode cannot predict the uncertainties and noises accurately. The control law is adjusted in real-time by introducing new training sample data to online adaptive SVM in the control process, so that the stability and robustness of flight are ensured. It can be demonstrated through the simulation experiments that the UAV that joined online adaptive SVM can track the changing path faster according to its dynamic model. Consequently, the proposed method that is proved has the better control effect in the UAV system.

  20. Error detection and prevention in Embedded Systems Software

    DEFF Research Database (Denmark)

    Kamel, Hani Fouad

    1996-01-01

    Despite many efforts to structure the development and design processes of embedded systems, errors are discovered at the final stages of production and sometimes after the delivery of the products. The cost of such errors can be prohibitive.Different design techniques to detect such errors...... systems, a formal model for such systems is introduced. The main characteristics of embedded systems design and the interaction of these properties are described. A taxonomy for the structure of the software developed for such systems based on the amount of processes and processors involved is presented...... will be presented. Moreover, we will try to describe the causes of these errors and the countermeasures that can be taken to avoid them. The main theme is that prevention is better than cure.The presentation is structured in three parts. The first part deals with an introduction to the subject area of embedded...

  1. Prediction of XRF analyzers error for elements on-line assaying using Kalman Filter

    Institute of Scientific and Technical Information of China (English)

    Nakhaei F; Sam A; Mosavi MR; Nakhaei A

    2012-01-01

    Determination of chemical elements assay plays an important role in mineral processing operations.This factor is used to control process accuracy,recovery calculation and plant profitability.The new assaying methods including chemical methods,X-ray fluorescence and atomic absorption spectrometry are advanced and accurate.However,in some applications,such as on-line assaying process,high accuracy is required.In this paper,an algorithm based on Kalman Filter is presented to predict on-line XRF errors.This research has been carried out on the basis of based the industrial real data collection for evaluating the performance of the presented algorithm.The measurements and analysis for this study were conducted at the Sarcheshmeh Copper Concentrator Plant located in Iran.The quality of the obtained results was very satisfied; so that the RMS errors of prediction obtained for Cu and Mo grade assaying errors in rougher feed were less than 0.039 and 0.002 and in final flotation concentration less than 0.58 and 0.074,respectively.The results indicate that the mentioned method is quite accurate to reduce the on-line XRF errors measurement.

  2. Recursive prediction error methods for online estimation in nonlinear state-space models

    Directory of Open Access Journals (Sweden)

    Dag Ljungquist

    1994-04-01

    Full Text Available Several recursive algorithms for online, combined state and parameter estimation in nonlinear state-space models are discussed in this paper. Well-known algorithms such as the extended Kalman filter and alternative formulations of the recursive prediction error method are included, as well as a new method based on a line-search strategy. A comparison of the algorithms illustrates that they are very similar although the differences can be important for the online tracking capabilities and robustness. Simulation experiments on a simple nonlinear process show that the performance under certain conditions can be improved by including a line-search strategy.

  3. Detection of Patients at High Risk of Medication Errors

    DEFF Research Database (Denmark)

    Sædder, Eva Aggerholm; Lisby, Marianne; Nielsen, Lars Peter

    2016-01-01

    Medication errors (MEs) are preventable and can result in patient harm and increased expenses in the healthcare system in terms of hospitalization, prolonged hospitalizations and even death. We aimed to develop a screening tool to detect acutely admitted patients at low or high risk of MEs...

  4. Automatic error detection in alignments for speech synthesis

    CSIR Research Space (South Africa)

    Barnard, E

    2006-11-01

    Full Text Available of the errors that existed in a manual segmentation were detected by this process, while flagging less than a quarter of all segments. Different phoneme classes are handled with differing amounts of success, with vowels being the most troublesome...

  5. Detection and Classification of Measurement Errors in Bioimpedance Spectroscopy.

    Science.gov (United States)

    Ayllón, David; Gil-Pita, Roberto; Seoane, Fernando

    2016-01-01

    Bioimpedance spectroscopy (BIS) measurement errors may be caused by parasitic stray capacitance, impedance mismatch, cross-talking or their very likely combination. An accurate detection and identification is of extreme importance for further analysis because in some cases and for some applications, certain measurement artifacts can be corrected, minimized or even avoided. In this paper we present a robust method to detect the presence of measurement artifacts and identify what kind of measurement error is present in BIS measurements. The method is based on supervised machine learning and uses a novel set of generalist features for measurement characterization in different immittance planes. Experimental validation has been carried out using a database of complex spectra BIS measurements obtained from different BIS applications and containing six different types of errors, as well as error-free measurements. The method obtained a low classification error (0.33%) and has shown good generalization. Since both the features and the classification schema are relatively simple, the implementation of this pre-processing task in the current hardware of bioimpedance spectrometers is possible.

  6. Detection and Classification of Measurement Errors in Bioimpedance Spectroscopy.

    Directory of Open Access Journals (Sweden)

    David Ayllón

    Full Text Available Bioimpedance spectroscopy (BIS measurement errors may be caused by parasitic stray capacitance, impedance mismatch, cross-talking or their very likely combination. An accurate detection and identification is of extreme importance for further analysis because in some cases and for some applications, certain measurement artifacts can be corrected, minimized or even avoided. In this paper we present a robust method to detect the presence of measurement artifacts and identify what kind of measurement error is present in BIS measurements. The method is based on supervised machine learning and uses a novel set of generalist features for measurement characterization in different immittance planes. Experimental validation has been carried out using a database of complex spectra BIS measurements obtained from different BIS applications and containing six different types of errors, as well as error-free measurements. The method obtained a low classification error (0.33% and has shown good generalization. Since both the features and the classification schema are relatively simple, the implementation of this pre-processing task in the current hardware of bioimpedance spectrometers is possible.

  7. Bayesian network models for error detection in radiotherapy plans.

    Science.gov (United States)

    Kalet, Alan M; Gennari, John H; Ford, Eric C; Phillips, Mark H

    2015-04-07

    The purpose of this study is to design and develop a probabilistic network for detecting errors in radiotherapy plans for use at the time of initial plan verification. Our group has initiated a multi-pronged approach to reduce these errors. We report on our development of Bayesian models of radiotherapy plans. Bayesian networks consist of joint probability distributions that define the probability of one event, given some set of other known information. Using the networks, we find the probability of obtaining certain radiotherapy parameters, given a set of initial clinical information. A low probability in a propagated network then corresponds to potential errors to be flagged for investigation. To build our networks we first interviewed medical physicists and other domain experts to identify the relevant radiotherapy concepts and their associated interdependencies and to construct a network topology. Next, to populate the network's conditional probability tables, we used the Hugin Expert software to learn parameter distributions from a subset of de-identified data derived from a radiation oncology based clinical information database system. These data represent 4990 unique prescription cases over a 5 year period. Under test case scenarios with approximately 1.5% introduced error rates, network performance produced areas under the ROC curve of 0.88, 0.98, and 0.89 for the lung, brain and female breast cancer error detection networks, respectively. Comparison of the brain network to human experts performance (AUC of 0.90 ± 0.01) shows the Bayes network model performs better than domain experts under the same test conditions. Our results demonstrate the feasibility and effectiveness of comprehensive probabilistic models as part of decision support systems for improved detection of errors in initial radiotherapy plan verification procedures.

  8. Runtime Verification in Context : Can Optimizing Error Detection Improve Fault Diagnosis

    Science.gov (United States)

    Dwyer, Matthew B.; Purandare, Rahul; Person, Suzette

    2010-01-01

    Runtime verification has primarily been developed and evaluated as a means of enriching the software testing process. While many researchers have pointed to its potential applicability in online approaches to software fault tolerance, there has been a dearth of work exploring the details of how that might be accomplished. In this paper, we describe how a component-oriented approach to software health management exposes the connections between program execution, error detection, fault diagnosis, and recovery. We identify both research challenges and opportunities in exploiting those connections. Specifically, we describe how recent approaches to reducing the overhead of runtime monitoring aimed at error detection might be adapted to reduce the overhead and improve the effectiveness of fault diagnosis.

  9. ERROR DETECTION BY ANTICIPATION FOR VISION-BASED CONTROL

    Directory of Open Access Journals (Sweden)

    A ZAATRI

    2001-06-01

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

  10. Large-scale detection of in vivo transcription errors.

    Science.gov (United States)

    Gout, Jean-François; Thomas, W Kelley; Smith, Zachary; Okamoto, Kazufusa; Lynch, Michael

    2013-11-12

    Accurate transmission and expression of genetic information are crucial for the survival of all living organisms. Recently, the coupling of mutation accumulation experiments and next-generation sequencing has greatly expanded our knowledge of the genomic mutation rate in both prokaryotes and eukaryotes. However, because of their transient nature, transcription errors have proven extremely difficult to quantify, and current estimates of transcription fidelity are derived from artificial constructs applied to just a few organisms. Here we report a unique cDNA library preparation technique that allows error detection in natural transcripts at the transcriptome-wide level. Application of this method to the model organism Caenorhabditis elegans revealed a base misincorporation rate in mRNAs of ~4 × 10(-6) per site, with a very biased molecular spectrum. Because the proposed method is readily applicable to other organisms, this innovation provides unique opportunities for studying the incidence of transcription errors across the tree of life.

  11. Detecting errors in micro and trace analysis by using statistics

    DEFF Research Database (Denmark)

    Heydorn, K.

    1993-01-01

    By assigning a standard deviation to each step in an analytical method it is possible to predict the standard deviation of each analytical result obtained by this method. If the actual variability of replicate analytical results agrees with the expected, the analytical method is said...... to results for chlorine in freshwater from BCR certification analyses by highly competent analytical laboratories in the EC. Titration showed systematic errors of several percent, while radiochemical neutron activation analysis produced results without detectable bias....

  12. The Effect of Error Correction vs. Error Detection on Iranian Pre-Intermediate EFL Learners' Writing Achievement

    Science.gov (United States)

    Abedi, Razie; Latifi, Mehdi; Moinzadeh, Ahmad

    2010-01-01

    This study tries to answer some ever-existent questions in writing fields regarding approaching the most effective ways to give feedback to students' errors in writing by comparing the effect of error correction and error detection on the improvement of students' writing ability. In order to achieve this goal, 60 pre-intermediate English learners…

  13. Online Synthesis for Error Recovery in Digital Microfluidic Biochips with Operation Variability

    DEFF Research Database (Denmark)

    Alistar, Mirela; Pop, Paul; Madsen, Jan

    2012-01-01

    , but as discrete droplets. Researchers have presented approaches for the synthesis of digital microfluidic biochips, which, starting from a biochemical application and a given biochip architecture, determine the allocation, resource binding, scheduling, placement and routing of the operations in the application......Microfluidic-based biochips are replacing the conventional biochemical analyzers, and are able to integrate on-chip all the necessary functions for biochemical analysis using microfluidics. The digital microfluidic biochips are based on the manipulation of liquids not as a continuous flow....... The droplet volumes can vary erroneously due to parametric faults, thus impacting negatively the correctness of the application. Researchers have proposed approaches that synthesize offline predetermined recovery subroutines, which are activated online when errors occur. In this paper, we propose an online...

  14. Scalable in situ qubit calibration during repetitive error detection

    Science.gov (United States)

    Kelly, J.; Barends, R.; Fowler, A. G.; Megrant, A.; Jeffrey, E.; White, T. C.; Sank, D.; Mutus, J. Y.; Campbell, B.; Chen, Yu; Chen, Z.; Chiaro, B.; Dunsworth, A.; Lucero, E.; Neeley, M.; Neill, C.; O'Malley, P. J. J.; Quintana, C.; Roushan, P.; Vainsencher, A.; Wenner, J.; Martinis, John M.

    2016-09-01

    We present a method to optimize qubit control parameters during error detection which is compatible with large-scale qubit arrays. We demonstrate our method to optimize single or two-qubit gates in parallel on a nine-qubit system. Additionally, we show how parameter drift can be compensated for during computation by inserting a frequency drift and using our method to remove it. We remove both drift on a single qubit and independent drifts on all qubits simultaneously. We believe this method will be useful in keeping error rates low on all physical qubits throughout the course of a computation. Our method is O (1 ) scalable to systems of arbitrary size, providing a path towards controlling the large numbers of qubits needed for a fault-tolerant quantum computer.

  15. Online Detection of Abnormal Events in Video Streams

    Directory of Open Access Journals (Sweden)

    Tian Wang

    2013-01-01

    an image descriptor and online nonlinear classification method. We introduce the covariance matrix of the optical flow and image intensity as a descriptor encoding moving information. The nonlinear online support vector machine (SVM firstly learns a limited set of the training frames to provide a basic reference model then updates the model and detects abnormal events in the current frame. We finally apply the method to detect abnormal events on a benchmark video surveillance dataset to demonstrate the effectiveness of the proposed technique.

  16. An online detection system for aggregate sizes and shapes based on digital image processing

    Science.gov (United States)

    Yang, Jianhong; Chen, Sijia

    2016-07-01

    Traditional aggregate size measuring methods are time-consuming, taxing, and do not deliver online measurements. A new online detection system for determining aggregate size and shape based on a digital camera with a charge-coupled device, and subsequent digital image processing, have been developed to overcome these problems. The system captures images of aggregates while falling and flat lying. Using these data, the particle size and shape distribution can be obtained in real time. Here, we calibrate this method using standard globules. Our experiments show that the maximum particle size distribution error was only 3 wt%, while the maximum particle shape distribution error was only 2 wt% for data derived from falling aggregates, having good dispersion. In contrast, the data for flat-lying aggregates had a maximum particle size distribution error of 12 wt%, and a maximum particle shape distribution error of 10 wt%; their accuracy was clearly lower than for falling aggregates. However, they performed well for single-graded aggregates, and did not require a dispersion device. Our system is low-cost and easy to install. It can successfully achieve online detection of aggregate size and shape with good reliability, and it has great potential for aggregate quality assurance.

  17. Glaucoma detection with damato multifixation campimetry online

    DEFF Research Database (Denmark)

    Olsen, Ane Sophie; Alberti, M.; Serup, L.;

    2016-01-01

    Purpose To evaluate Damato Multifixation Campimetry Online (DMCO), a free-of-charge internet-based visual field test. DMCO exists in three versions: DMCO BASIC, DMCO STANDARD, and DMCO ADVANCED. The main focus was (i) to investigate the sensitivity and the specificity of the existing DMCO versions...... eye to complete the DMCO STANDARD test was 86 s for the control group and 125 s in participants with glaucoma. Conclusions DMCO shows promise as a free-of-charge online tool to identify glaucomatous visual field defects in a preselected population. Ongoing studies are evaluating the use of DMCO...

  18. Efficient online detection of temporal patterns

    Directory of Open Access Journals (Sweden)

    Shlomi Dolev

    2016-04-01

    Full Text Available Identifying a temporal pattern of events is a fundamental task of online (real-time verification. We present efficient schemes for online monitoring of events for identifying desired/undesired patterns of events. The schemes use preprocessing to ensure that the number of comparisons during run-time is minimized. In particular, the first comparison following the time point when an execution sub-sequence cannot be further extended to satisfy the temporal requirements halts the process that monitors the sub-sequence.

  19. Online adaptation of a c-VEP Brain-computer Interface(BCI) based on error-related potentials and unsupervised learning.

    Science.gov (United States)

    Spüler, Martin; Rosenstiel, Wolfgang; Bogdan, Martin

    2012-01-01

    The goal of a Brain-Computer Interface (BCI) is to control a computer by pure brain activity. Recently, BCIs based on code-modulated visual evoked potentials (c-VEPs) have shown great potential to establish high-performance communication. In this paper we present a c-VEP BCI that uses online adaptation of the classifier to reduce calibration time and increase performance. We compare two different approaches for online adaptation of the system: an unsupervised method and a method that uses the detection of error-related potentials. Both approaches were tested in an online study, in which an average accuracy of 96% was achieved with adaptation based on error-related potentials. This accuracy corresponds to an average information transfer rate of 144 bit/min, which is the highest bitrate reported so far for a non-invasive BCI. In a free-spelling mode, the subjects were able to write with an average of 21.3 error-free letters per minute, which shows the feasibility of the BCI system in a normal-use scenario. In addition we show that a calibration of the BCI system solely based on the detection of error-related potentials is possible, without knowing the true class labels.

  20. On-line detecting of transformer winding deformation based on parameter identification of leakage inductance

    Institute of Scientific and Technical Information of China (English)

    Hao Zhiguo; Zhang Baohui; Li Peng

    2007-01-01

    Transformers are required to demonstrate the ability to withstand short circuit currents. Over currents caused by short circuit can give rise to windings deformation. In this paper, a novel method is proposed to monitor the state of transformer windings, which is achieved through on-line detecting the leakage inductance of the windings. Specifically, the mathematical model is established for on-line identifying the leakage inductance of the windings by applying least square algorithm (LSA) to the equivalent circuit equations. The effect of measurement and model inaccuracy on the identification error is analyzed, and the corrected model is also given to decrease these adverse effect on the results. Finally, dynamic test is carried out to verify our method. The test results clearly show that our method is very accurate even under the fluctuation of load or power factor. Therefore, our method can be effectively used to on-line detect the windings deformation.

  1. Runtime Detection of C-Style Errors in UPC Code

    Energy Technology Data Exchange (ETDEWEB)

    Pirkelbauer, P; Liao, C; Panas, T; Quinlan, D

    2011-09-29

    Unified Parallel C (UPC) extends the C programming language (ISO C 99) with explicit parallel programming support for the partitioned global address space (PGAS), which provides a global memory space with localized partitions to each thread. Like its ancestor C, UPC is a low-level language that emphasizes code efficiency over safety. The absence of dynamic (and static) safety checks allows programmer oversights and software flaws that can be hard to spot. In this paper, we present an extension of a dynamic analysis tool, ROSE-Code Instrumentation and Runtime Monitor (ROSECIRM), for UPC to help programmers find C-style errors involving the global address space. Built on top of the ROSE source-to-source compiler infrastructure, the tool instruments source files with code that monitors operations and keeps track of changes to the system state. The resulting code is linked to a runtime monitor that observes the program execution and finds software defects. We describe the extensions to ROSE-CIRM that were necessary to support UPC. We discuss complications that arise from parallel code and our solutions. We test ROSE-CIRM against a runtime error detection test suite, and present performance results obtained from running error-free codes. ROSE-CIRM is released as part of the ROSE compiler under a BSD-style open source license.

  2. The Detection of Structural Deformation Errors in Attitude Determination

    Institute of Scientific and Technical Information of China (English)

    M. J. Moore; C. Rizos; J. Wang

    2003-01-01

    In the determination of the attitude parameters from a multi-antenna GPS array, one of the major assumptions is that the body frame is rigid at all times. If this assumption is not true then the derived attitude parameters will be in error. It is well known that in airborne platforms the wings often experience some displacement during flight, especially during periods of initializing maneouvres, such as taking off, landing,and banking. Often it is at these points in time that it is most critical to have the most precise attitude parameters.There are a number of techniques available for the detection of modeling errors.The CUSUM algorithm has successfully been implemented in the past to detect small persistent changes. In this paper the authors investigate different methods of generating the residuals, to be tested by the CUSUM algorithm, in an effort to determine which technique is best suited for the detection of structural deformation of an airborne platform. The methods investigated include monitoring the mean of the residuals generated from the difference between the known body frame coordinates, and those calculated from the derived attitude parameters. The generated residuals are then passed to a CUSUM algorithm to detect any small persistent changes. An alternative method involves transforming the generated residuals into the frequency domain through the use of the Fast Fourier Transform. The CUSUM algorithm is then used to detect any frequency changes. The final technique investigated involves transforming the generated residuals using the Haar wavelet. The wavelet coefficients are then monitored by the CUSUM algorithm in order to detect any significant change to the rigidity of the body frame.Detecting structural deformation, and quantifying the degree of deformation, during flight will ensure that these effects can be removed from the system, thus ensuring the most precise and reliable attitude parameter solutions. This paper, through a series

  3. Minimizing detection errors in single molecule localization microscopy.

    Science.gov (United States)

    Křížek, Pavel; Raška, Ivan; Hagen, Guy M

    2011-02-14

    Fluorescence microscopy using single molecule imaging and localization (PALM, STORM, and similar approaches) has quickly been adopted as a convenient method for obtaining multicolor, 3D superresolution images of biological samples. Using an approach based on extensive Monte Carlo simulations, we examined the performance of various noise reducing filters required for the detection of candidate molecules. We determined a suitable noise reduction method and derived an optimal, nonlinear threshold which minimizes detection errors introduced by conventional algorithms. We also present a new technique for visualization of single molecule localization microscopy data based on adaptively jittered 2D histograms. We have used our new methods to image both Atto565-phalloidin labeled actin in fibroblast cells, and mCitrine-erbB3 expressed in A431 cells. The enhanced methods developed here were crucial in processing the data we obtained from these samples, as the overall signal to noise ratio was quite low.

  4. A Novel Chip-based Spectrophotometer for Online Detection

    Institute of Scientific and Technical Information of China (English)

    Haoyuan Cai; Min-Hsien Wu; Zheng Cui

    2006-01-01

    A chip-based spectrophotometer integrated with optical fiber is successfully demonstrated. Grade concentration of lactate solution flowed through the chip to perform an online detection. The response time (100s) and Limit of Detection (LOD,50mg/L) of the device were measured. This device shows comparable performance with traditional commercial instrument,while greatly decreases the sample requirement per detection and reduces the size of total system, introducing a novel method for real-time detection.

  5. Decoding of DBEC-TBED Reed-Solomon codes. [Double-Byte-Error-Correcting, Triple-Byte-Error-Detecting

    Science.gov (United States)

    Deng, Robert H.; Costello, Daniel J., Jr.

    1987-01-01

    A problem in designing semiconductor memories is to provide some measure of error control without requiring excessive coding overhead or decoding time. In LSI and VLSI technology, memories are often organized on a multiple bit (or byte) per chip basis. For example, some 256 K bit DRAM's are organized in 32 K x 8 bit-bytes. Byte-oriented codes such as Reed-Solomon (RS) codes can provide efficient low overhead error control for such memories. However, the standard iterative algorithm for decoding RS codes is too slow for these applications. The paper presents a special decoding technique for double-byte-error-correcting, triple-byte-error-detecting RS codes which is capable of high-speed operation. This technique is designed to find the error locations and the error values directly from the syndrome without having to use the iterative algorithm to find the error locator polynomial.

  6. An On-Line Method for Thermal Diffusivity Detection of Thin Films Using Infrared Video

    Directory of Open Access Journals (Sweden)

    Dong Huilong

    2016-03-01

    Full Text Available A novel method for thermal diffusivity evolution of thin-film materials with pulsed Gaussian beam and infrared video is reported. Compared with common pulse methods performed in specialized labs, the proposed method implements a rapid on-line measurement without producing the off-centre detection error. Through mathematical deduction of the original heat conduction model, it is discovered that the area s, which is encircled by the maximum temperature curve rTMAX(θ, increases linearly over elapsed time. The thermal diffusivity is acquired from the growth rate of the area s. In this study, the off-centre detection error is avoided by performing the distance regularized level set evolution formulation. The area s was extracted from the binary images of temperature variation rate, without inducing errors from determination of the heat source centre. Thermal diffusivities of three materials, 304 stainless steel, titanium, and zirconium have been measured with the established on-line detection system, and the measurement errors are: −2.26%, −1.07%, and 1.61% respectively.

  7. Detecting Positioning Errors and Estimating Correct Positions by Moving Window.

    Science.gov (United States)

    Song, Ha Yoon; Lee, Jun Seok

    2015-01-01

    In recent times, improvements in smart mobile devices have led to new functionalities related to their embedded positioning abilities. Many related applications that use positioning data have been introduced and are widely being used. However, the positioning data acquired by such devices are prone to erroneous values caused by environmental factors. In this research, a detection algorithm is implemented to detect erroneous data over a continuous positioning data set with several options. Our algorithm is based on a moving window for speed values derived by consecutive positioning data. Both the moving average of the speed and standard deviation in a moving window compose a moving significant interval at a given time, which is utilized to detect erroneous positioning data along with other parameters by checking the newly obtained speed value. In order to fulfill the designated operation, we need to examine the physical parameters and also determine the parameters for the moving windows. Along with the detection of erroneous speed data, estimations of correct positioning are presented. The proposed algorithm first estimates the speed, and then the correct positions. In addition, it removes the effect of errors on the moving window statistics in order to maintain accuracy. Experimental verifications based on our algorithm are presented in various ways. We hope that our approach can help other researchers with regard to positioning applications and human mobility research.

  8. Corpus-based error detection in a multilingual medical thesaurus.

    Science.gov (United States)

    Andrade, Roosewelt L; Pacheco, Edson; Cancian, Pindaro S; Nohama, Percy; Schulz, Stefan

    2007-01-01

    Cross-language document retrieval systems require support by some kind of multilingual thesaurus for semantically indexing documents in different languages. The peculiarities of the medical sublanguage, together with the subjectivism of lexicographers' choices, complicates the thesaurus construction process. It furthermore requires a high degree of communication and interaction between the lexicographers involved. In order to detect errors, a systematic procedure is therefore necessary. We here describe a method which supports the maintenance of the multilingual medical subword repository of the MorphoSaurus system which assigns language-independent semantic identifiers to medical texts. Based on the assumption that the distribution of these semantic identifiers should be similar whenever comparing closely related texts in different languages, our approach identifies those semantic identifiers that vary most in distribution comparing language pairs. The revision of these identifiers and the lexical items related to them revealed multiple errors which were subsequently classified and fixed by the lexicographers. The overall quality improvement of the thesaurus was finally measured using the OHSUMED IR benchmark, resulting in a significant improvement of the retrieval quality for one of the languages tested.

  9. Laser-based Online Sliding-window Approach for UAV Loop-closure Detection in Urban Environments

    Directory of Open Access Journals (Sweden)

    Anqing Wang

    2016-04-01

    Full Text Available Online loop-closure detection serves as an essential task for Unmanned Aerial Vehicles (UAVs equipped with laser scanners. Due to the inherent errors in UAVs’ pose estimation, a 3-D reconstruction algorithm is adopted to perform 3-D map building, which establishes probabilistic models of the system according to the assumption of errors. To meet the demand of online loop-closure detection using sequential 2-D laser data, a robust ISW-NDT (incremental sliding-window-based NDT approach is proposed, which compares the appearance similarity between two scans by sliding a window with fixed size. Compared with the conventional 3-D NDT approach, the proposed loop-closure detection algorithm is capable of providing superior performance in large-scale outdoor environments, achieving higher recall rate at 100% precision and ensuring successful online implementation. Experimental results show the validity and robustness of the proposed method.

  10. Online damage detection using recursive principal component analysis and recursive condition indicators

    Science.gov (United States)

    Krishnan, M.; Bhowmik, B.; Tiwari, A. K.; Hazra, B.

    2017-08-01

    In this paper, a novel baseline free approach for continuous online damage detection of multi degree of freedom vibrating structures using recursive principal component analysis (RPCA) in conjunction with online damage indicators is proposed. In this method, the acceleration data is used to obtain recursive proper orthogonal modes in online using the rank-one perturbation method, and subsequently utilized to detect the change in the dynamic behavior of the vibrating system from its pristine state to contiguous linear/nonlinear-states that indicate damage. The RPCA algorithm iterates the eigenvector and eigenvalue estimates for sample covariance matrices and new data point at each successive time instants, using the rank-one perturbation method. An online condition indicator (CI) based on the L2 norm of the error between actual response and the response projected using recursive eigenvector matrix updates over successive iterations is proposed. This eliminates the need for offline post processing and facilitates online damage detection especially when applied to streaming data. The proposed CI, named recursive residual error, is also adopted for simultaneous spatio-temporal damage detection. Numerical simulations performed on five-degree of freedom nonlinear system under white noise and El Centro excitations, with different levels of nonlinearity simulating the damage scenarios, demonstrate the robustness of the proposed algorithm. Successful results obtained from practical case studies involving experiments performed on a cantilever beam subjected to earthquake excitation, for full sensors and underdetermined cases; and data from recorded responses of the UCLA Factor building (full data and its subset) demonstrate the efficacy of the proposed methodology as an ideal candidate for real-time, reference free structural health monitoring.

  11. Vision based error detection for 3D printing processes

    Directory of Open Access Journals (Sweden)

    Baumann Felix

    2016-01-01

    Full Text Available 3D printers became more popular in the last decade, partly because of the expiration of key patents and the supply of affordable machines. The origin is located in rapid prototyping. With Additive Manufacturing (AM it is possible to create physical objects from 3D model data by layer wise addition of material. Besides professional use for prototyping and low volume manufacturing they are becoming widespread amongst end users starting with the so called Maker Movement. The most prevalent type of consumer grade 3D printers is Fused Deposition Modelling (FDM, also Fused Filament Fabrication FFF. This work focuses on FDM machinery because of their widespread occurrence and large number of open problems like precision and failure. These 3D printers can fail to print objects at a statistical rate depending on the manufacturer and model of the printer. Failures can occur due to misalignment of the print-bed, the print-head, slippage of the motors, warping of the printed material, lack of adhesion or other reasons. The goal of this research is to provide an environment in which these failures can be detected automatically. Direct supervision is inhibited by the recommended placement of FDM printers in separate rooms away from the user due to ventilation issues. The inability to oversee the printing process leads to late or omitted detection of failures. Rejects effect material waste and wasted time thus lowering the utilization of printing resources. Our approach consists of a camera based error detection mechanism that provides a web based interface for remote supervision and early failure detection. Early failure detection can lead to reduced time spent on broken prints, less material wasted and in some cases salvaged objects.

  12. On-line intermittent connector anomaly detection

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper investigates a non-traditional use of differential current sensor and current sensor to detect intermittent disconnection problems in connectors. An...

  13. Solutions to Detect and Analyze Online Radicalization : A Survey

    CERN Document Server

    Correa, Denzil

    2013-01-01

    Online Radicalization (also called Cyber-Terrorism or Extremism or Cyber-Racism or Cyber- Hate) is widespread and has become a major and growing concern to the society, governments and law enforcement agencies around the world. Research shows that various platforms on the Internet (low barrier to publish content, allows anonymity, provides exposure to millions of users and a potential of a very quick and widespread diffusion of message) such as YouTube (a popular video sharing website), Twitter (an online micro-blogging service), Facebook (a popular social networking website), online discussion forums and blogosphere are being misused for malicious intent. Such platforms are being used to form hate groups, racist communities, spread extremist agenda, incite anger or violence, promote radicalization, recruit members and create virtual organi- zations and communities. Automatic detection of online radicalization is a technically challenging problem because of the vast amount of the data, unstructured and noisy ...

  14. Non-Linguistic Vocal Event Detection Using Online Random

    DEFF Research Database (Denmark)

    Abou-Zleikha, Mohamed; Tan, Zheng-Hua; Christensen, Mads Græsbøll

    2014-01-01

    Accurate detection of non-linguistic vocal events in social signals can have a great impact on the applicability of speech enabled interactive systems. In this paper, we investigate the use of random forest for vocal event detection. Random forest technique has been successfully employed in many...... areas such as object detection, face recognition, and audio event detection. This paper proposes to use online random forest technique for detecting laughter and filler and for analyzing the importance of various features for non-linguistic vocal event classification through permutation. The results...... show that according to the Area Under Curve measure the online random forest achieved 88.1% compared to 82.9% obtained by the baseline support vector machines for laughter classification and 86.8% to 83.6% for filler classification....

  15. The Detection of Human Spreadsheet Errors by Humans versus Inspection (Auditing) Software

    CERN Document Server

    Aurigemma, Salvatore

    2010-01-01

    Previous spreadsheet inspection experiments have had human subjects look for seeded errors in spreadsheets. In this study, subjects attempted to find errors in human-developed spreadsheets to avoid the potential artifacts created by error seeding. Human subject success rates were compared to the successful rates for error-flagging by spreadsheet static analysis tools (SSATs) applied to the same spreadsheets. The human error detection results were comparable to those of studies using error seeding. However, Excel Error Check and Spreadsheet Professional were almost useless for correctly flagging natural (human) errors in this study.

  16. Detecting Communities and Surveying the Most Influence of Online Users

    Directory of Open Access Journals (Sweden)

    Thanh Ho

    2015-11-01

    Full Text Available Social network is a virtual environment that provides services for connecting users with the same interests, points of view, gender, space and time. Beside connection, information exchange, communication, entertainment and so on. Social network is also an environment for users who work in online business, advertisement or politics, criminal investigation. How to know what users discuss topics via exchanged contents and communities which users join in? In this paper, we propose a model by using topic model combined with K-means to detect communities of online users. Each user in social network is represented by a vector in which the components are the distribution probabilities of interested topics of that user. Based on the components of this vector, we discover the interested topics of online users to detect communities and survey users who are the most influence in communities to recommend for spreading information on social network.

  17. Medication errors detected in non-traditional databases

    DEFF Research Database (Denmark)

    Perregaard, Helene; Aronson, Jeffrey K; Dalhoff, Kim

    2015-01-01

    AIMS: We have looked for medication errors involving the use of low-dose methotrexate, by extracting information from Danish sources other than traditional pharmacovigilance databases. We used the data to establish the relative frequencies of different types of errors. METHODS: We searched four...... errors, whereas knowledge-based errors more often resulted in near misses. CONCLUSIONS: The medication errors in this survey were most often action-based (50%) and knowledge-based (34%), suggesting that greater attention should be paid to education and surveillance of medical personnel who prescribe...

  18. Online scene change detection of multicast (MBone) video

    Science.gov (United States)

    Zhou, Wensheng; Shen, Ye; Vellaikal, Asha; Kuo, C.-C. Jay

    1998-10-01

    Many multimedia applications, such as multimedia data management systems and communication systems, require efficient representation of multimedia content. Thus semantic interpretation of video content has been a popular research area. Currently, most content-based video representation involves the segmentation of video based on key frames which are generated using scene change detection techniques as well as camera/object motion. Then, video features can be extracted from key frames. However most of such research performs off-line video processing in which the whole video scope is known as a priori which allows multiple scans of the stored video files during video processing. In comparison, relatively not much research has been done in the area of on-line video processing, which is crucial in video communication applications such as on-line collaboration, news broadcasts and so on. Our research investigates on-line real-time scene change detection of multicast video over the Internet. Our on-line processing system are designed to meet the requirements of real-time video multicasting over the Internet and to utilize the successful video parsing techniques available today. The proposed algorithms extract key frames from video bitstreams sent through the MBone network, and the extracted key frames are multicasted as annotations or metadata over a separate channel to assist in content filtering such as those anticipated to be in use by on-line filtering proxies in the Internet. The performance of the proposed algorithms are demonstrated and discussed in this paper.

  19. Error Budgeting and Tolerancing of Starshades for Exoplanet Detection

    Science.gov (United States)

    Shaklan, Stuart B.; Noecker, M. Charley; Glassman, Tiffany; Lo, Amy S.; Dumont, Philip J.; Kasdin, N. Jeremy; Cady, Eric J.; Vanderbei, Robert; Lawson, Peter R.

    2010-01-01

    A flower-like starshade positioned between a star and a space telescope is an attractive option for blocking the starlight to reveal the faint reflected light of an orbiting Earth-like planet. Planet light passes around the petals and directly enters the telescope where it is seen along with a background of scattered light due to starshade imperfections. We list the major perturbations that are expected to impact the performance of a starshade system and show that independent models at NGAS and JPL yield nearly identical optical sensitivities. We give the major sensitivities in the image plane for a design consisting of a 34-m diameter starshade, and a 2-m diameter telescope separated by 39,000 km, operating between 0.25 and 0.55 um. These sensitivities include individual petal and global shape terms evaluated at the inner working angle. Following a discussion of the combination of individual perturbation terms, we then present an error budget that is consistent with detection of an Earth-like planet 26 magnitudes fainter than its host star.

  20. A Graph-Based Min-# and Error-Optimal Trajectory Simplification Algorithm and Its Extension towards Online Services

    Directory of Open Access Journals (Sweden)

    Fan Wu

    2017-01-01

    Full Text Available Trajectory simplification has become a research hotspot since it plays a significant role in the data preprocessing, storage, and visualization of many offline and online applications, such as online maps, mobile health applications, and location-based services. Traditional heuristic-based algorithms utilize greedy strategy to reduce time cost, leading to high approximation error. An Optimal Trajectory Simplification Algorithm based on Graph Model (OPTTS is proposed to obtain the optimal solution in this paper. Both min-# and min-ε problems are solved by the construction and regeneration of the breadth-first spanning tree and the shortest path search based on the directed acyclic graph (DAG. Although the proposed OPTTS algorithm can get optimal simplification results, it is difficult to apply in real-time services due to its high time cost. Thus, a new Online Trajectory Simplification Algorithm based on Directed Acyclic Graph (OLTS is proposed to deal with trajectory stream. The algorithm dynamically constructs the breadth-first spanning tree, followed by real-time minimizing approximation error and real-time output. Experimental results show that OPTTS reduces the global approximation error by 82% compared to classical heuristic methods, while OLTS reduces the error by 77% and is 32% faster than the traditional online algorithm. Both OPTTS and OLTS have leading superiority and stable performance on different datasets.

  1. Effect of translational and rotational errors on complex dose distributions with off-line and on-line position verification

    NARCIS (Netherlands)

    I.M. Lips; U.A. van der Heide; A.N.T.J. Kotte; M. van Vulpen; A. Bel

    2009-01-01

    PURPOSE: To investigate the influence of translational and rotational errors on prostate intensity-modulated radiotherapy (IMRT) with an integrated boost to the tumor and to evaluate the effect of the use of an on-line correction protocol. METHODS AND MATERIALS: For 19 patients, who had been treated

  2. Methods of Profile Cloning Detection in Online Social Networks

    Directory of Open Access Journals (Sweden)

    Zabielski Michał

    2016-01-01

    Full Text Available With the arrival of online social networks, the importance of privacy on the Internet has increased dramatically. Thus, it is important to develop mechanisms that will prevent our hidden personal data from unauthorized access and use. In this paper an attempt was made to present a concept of profile cloning detection in Online Social Networks (OSN using Graph and Networks Theory. By analysing structural similarity of network and value of attributes of user personal profile, we will be able to search for attackers which steal our identity.

  3. Fast online detection of body defect of glass containers

    Science.gov (United States)

    Wen, Zhangbin; Ge, Jia; Xia, Lijia; Luo, Yunhan; Chen, Zhe

    2011-11-01

    Online inspection of glass containers is important to guarantee the high quality production, safe use and effective recovery, so high precision and low cost online detection system has important practical value. The system introduced in this paper consists of LED linear array as the light source, a linear CCD as the detector, and a dual core processor with ARM and DSP as well. The self rotating stage for glass bottles and the digital image process technology enable this system to acquire the complete data and improve the traditional detection method. As a result, a detection speed over 100 bottles per minute, and a precision over 99.99% were achieved with the relatively simple structure and low cost.

  4. Detecting General and Specific Errors in Expository Texts.

    Science.gov (United States)

    Yussen, Steven R.; Smith, M. Cecil

    1990-01-01

    In three experiments, a total of 148 college students read or listened to expository passages containing general or specific errors. In all 3 experiments, students were more likely to spot general errors. Results do not indicate that monitoring skills were substantially different for listening or reading. (SLD)

  5. Online machining error estimation method of numerical control gear grinding machine tool based on data analysis of internal sensors

    Science.gov (United States)

    Zhao, Fei; Zhang, Chi; Yang, Guilin; Chen, Chinyin

    2016-12-01

    This paper presents an online estimation method of cutting error by analyzing of internal sensor readings. The internal sensors of numerical control (NC) machine tool are selected to avoid installation problem. The estimation mathematic model of cutting error was proposed to compute the relative position of cutting point and tool center point (TCP) from internal sensor readings based on cutting theory of gear. In order to verify the effectiveness of the proposed model, it was simulated and experimented in gear generating grinding process. The cutting error of gear was estimated and the factors which induce cutting error were analyzed. The simulation and experiments verify that the proposed approach is an efficient way to estimate the cutting error of work-piece during machining process.

  6. Role of clinical pharmacists' interventions in detection and prevention of medication errors in a medical ward.

    Science.gov (United States)

    Khalili, Hossein; Farsaei, Shadi; Rezaee, Haleh; Dashti-Khavidaki, Simin

    2011-04-01

    Frequency and type of medication errors and role of clinical pharmacists in detection and prevention of these errors were evaluated in this study. During this interventional study, clinical pharmacists monitored 861 patients' medical records and detected, reported, and prevented medication errors in the infectious disease ward of a major referral teaching hospital in Tehran, Iran. Error was defined as any preventable events that lead to inappropriate medication use related to the health care professionals or patients regardless of outcomes. Classification of the errors was done based on Pharmaceutical Care Network Europe Foundation drug-related problem coding. During the study period, 112 medication errors (0.13 errors per patient) were detected by clinical pharmacists. Physicians, nurses, and patients were responsible for 55 (49.1%), 54 (48.2%), and 3 (2.7%) of medication errors, respectively. Drug dosing, choice, use and interactions were the most causes of error in medication processes, respectively. All of these errors were detected, reported, and prevented by infectious diseases ward clinical pharmacists. Medication errors occur frequently in medical wards. Clinical pharmacists' interventions can effectively prevent these errors. The types of errors indicate the need for continuous education and implementation of clinical pharmacist's interventions.

  7. Detecting self-produced speech errors before and after articulation: An ERP investigation

    Directory of Open Access Journals (Sweden)

    Kevin Michael Trewartha

    2013-11-01

    Full Text Available It has been argued that speech production errors are monitored by the same neural system involved in monitoring other types of action errors. Behavioral evidence has shown that speech errors can be detected and corrected prior to articulation, yet the neural basis for such pre-articulatory speech error monitoring is poorly understood. The current study investigated speech error monitoring using a phoneme-substitution task known to elicit speech errors. Stimulus-locked event-related potential (ERP analyses comparing correct and incorrect utterances were used to assess pre-articulatory error monitoring and response-locked ERP analyses were used to assess post-articulatory monitoring. Our novel finding in the stimulus-locked analysis revealed that words that ultimately led to a speech error were associated with a larger P2 component at midline sites (FCz, Cz, and CPz. This early positivity may reflect the detection of an error in speech formulation, or a predictive mechanism to signal the potential for an upcoming speech error. The data also revealed that general conflict monitoring mechanisms are involved during this task as both correct and incorrect responses elicited an anterior N2 component typically associated with conflict monitoring. The response-locked analyses corroborated previous observations that self-produced speech errors led to a fronto-central ERN. These results demonstrate that speech errors can be detected prior to articulation, and that speech error monitoring relies on a central error monitoring mechanism.

  8. Error Detection And Correction Systems For Optical Disk: Issues Of Media Defect Distribution, Defect Growth, Error Management, And Disk Longevity

    Science.gov (United States)

    Nugent, William R.

    1987-01-01

    We examine the principal systems of Error Detection and Correction (EDAC) which have been recently proposed as U.S. standards for optical disks and discuss the the two principal methodologies employed: Reed-Solomon Codes and Product Codes, and describe the variations in their operating characteristics and their overhead in disk space. We then present current knowledge of the nature of defect distributions on optical media including bit error rates, the incidence and extents of clustered errors and burst errors, and the controversial aspects of correlation between these forms of error. We show that if such forms are correlated then stronger EDAC systems are needed than if they are not. We discuss the nature of defect growth over time and its likely causes, and present the differing views on the growth of burst errors including nucleation and incubation effects which are not detectable in new media. We exhibit a mathematical model of a currently proposed end-of-life defect distribution for write once media and discuss its implications in EDAC selection. We show that standardization of an EDAC system unifies the data recording process and is permissive to data interchange, but that enhancements in EDAC computation during reading can achieve higher than normal EDAC performance, though sometimes at the expense of decoding time. Finally we examine vendor estimates of disk longevity and possible means of life extension where archival recording is desired.

  9. Automatic Registration and Error Detection of Multiple Slices Using Landmarks

    Directory of Open Access Journals (Sweden)

    Hans Frimmel

    2001-01-01

    Full Text Available Objectives. When analysing the 3D structure of tissue, serial sectioning and staining of the resulting slices is sometimes the preferred option. This leads to severe registration problems. In this paper, a method for automatic registration and error detection of slices using landmark needles has been developed. A cost function takes some parameters from the current state of the problem to be solved as input and gives a quality of the current solution as output. The cost function used in this paper, is based on a model of the slices and the landmark needles. The method has been used to register slices of prostates in order to create 3D computer models. Manual registration of the same prostates has been undertaken and compared with the results from the algorithm. Methods. Prostates from sixteen men who underwent radical prostatectomy were formalin fixed with landmark needles, sliced and the slices were computer reconstructed. The cost function takes rotation and translation for each prostate slice, as well as slope and offset for each landmark needle as input. The current quality of fit of the model, using the input parameters given, is returned. The function takes the built‐in instability of the model into account. The method uses a standard algorithm to optimize the prostate slice positions. To verify the result, s standard method in statistics was used. Results. The methods were evaluated for 16 prostates. When testing blindly, a physician could not determine whether the registration shown to him were created by the automated method described in this paper, or manually by an expert, except in one out of 16 cases. Visual inspection and analysis of the outlier confirmed that the input data had been deformed. The automatic detection of erroneous slices marked a few slices, including the outlier, as suspicious. Conclusions. The model based registration performs better than traditional simple slice‐wise registration. In the case of prostate

  10. The detection and prevention of errors in laboratory medicine.

    Science.gov (United States)

    Plebani, Mario

    2010-03-01

    The last few decades have seen a significant decrease in the rates of analytical errors in clinical laboratories. Evidence demonstrates that pre- and post-analytical steps of the total testing process (TTP) are more error-prone than the analytical phase. Most errors are identified in pre-pre-analytic and post-post-analytic steps outside of the laboratory. In a patient-centred approach to the delivery of health-care services, there is the need to investigate, in the TTP, any possible defect that may have a negative impact on the patient. In the interests of patients, any direct or indirect negative consequence related to a laboratory test must be considered, irrespective of which step is involved and whether the error depends on a laboratory professional (e.g. calibration/testing error) or non-laboratory operator (e.g. inappropriate test request, error in patient identification and/or blood collection). Patient misidentification and problems communicating results, which affect the delivery of diagnostic services, are recognized as the main goals for quality improvement. International initiatives aim at improving these aspects. Grading laboratory errors on the basis of their seriousness should help identify priorities for quality improvement and encourage a focus on corrective/preventive actions. It is important to consider not only the actual patient harm sustained but also the potential worst-case outcome if such an error were to reoccur. The most important lessons we have learned are that system theory also applies to laboratory testing and that errors and injuries can be prevented by redesigning systems that render it difficult for all health-care professionals to make mistakes.

  11. Methods and apparatus using commutative error detection values for fault isolation in multiple node computers

    Science.gov (United States)

    Almasi, Gheorghe [Ardsley, NY; Blumrich, Matthias Augustin [Ridgefield, CT; Chen, Dong [Croton-On-Hudson, NY; Coteus, Paul [Yorktown, NY; Gara, Alan [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Hoenicke, Dirk I [Ossining, NY; Singh, Sarabjeet [Mississauga, CA; Steinmacher-Burow, Burkhard D [Wernau, DE; Takken, Todd [Brewster, NY; Vranas, Pavlos [Bedford Hills, NY

    2008-06-03

    Methods and apparatus perform fault isolation in multiple node computing systems using commutative error detection values for--example, checksums--to identify and to isolate faulty nodes. When information associated with a reproducible portion of a computer program is injected into a network by a node, a commutative error detection value is calculated. At intervals, node fault detection apparatus associated with the multiple node computer system retrieve commutative error detection values associated with the node and stores them in memory. When the computer program is executed again by the multiple node computer system, new commutative error detection values are created and stored in memory. The node fault detection apparatus identifies faulty nodes by comparing commutative error detection values associated with reproducible portions of the application program generated by a particular node from different runs of the application program. Differences in values indicate a possible faulty node.

  12. Systematic error detection in experimental high-throughput screening

    OpenAIRE

    2011-01-01

    Abstract Background High-throughput screening (HTS) is a key part of the drug discovery process during which thousands of chemical compounds are screened and their activity levels measured in order to identify potential drug candidates (i.e., hits). Many technical, procedural or environmental factors can cause systematic measurement error or inequalities in the conditions in which the measurements are taken. Such systematic error has the potential to critically affect the hit selection proces...

  13. Incorporating profile information in community detection for online social networks

    Science.gov (United States)

    Fan, W.; Yeung, K. H.

    2014-07-01

    Community structure is an important feature in the study of complex networks. It is because nodes of the same community may have similar properties. In this paper we extend two popular community detection methods to partition online social networks. In our extended methods, the profile information of users is used for partitioning. We apply the extended methods in several sample networks of Facebook. Compared with the original methods, the community structures we obtain have higher modularity. Our results indicate that users' profile information is consistent with the community structure of their friendship network to some extent. To the best of our knowledge, this paper is the first to discuss how profile information can be used to improve community detection in online social networks.

  14. Ensembles of detectors for online detection of transient changes

    Science.gov (United States)

    Artemov, Alexey; Burnaev, Evgeny

    2015-12-01

    Classical change-point detection procedures assume a change-point model to be known and a change consisting in establishing a new observations regime, i.e. the change lasts infinitely long. These modeling assumptions contradicts applied problems statements. Therefore, even theoretically optimal statistics in practice very often fail when detecting transient changes online. In this work in order to overcome limitations of classical change-point detection procedures we consider approaches to constructing ensembles of change-point detectors, i.e. algorithms that use many detectors to reliably identify a change-point. We propose a learning paradigm and specific implementations of ensembles for change detection of short-term (transient) changes in observed time series. We demonstrate by means of numerical experiments that the performance of an ensemble is superior to that of the conventional change-point detection procedures.

  15. Methods of Run-Time Error Detection in Distributed Process Control Software

    DEFF Research Database (Denmark)

    Drejer, N.

    of generic run-time error types, design of methods of observing application software behaviorduring execution and design of methods of evaluating run time constraints. In the definition of error types it is attempted to cover all relevant aspects of the application softwaree behavior. Methods of observation...... and constraint evaluation is designed for the modt interesting error types. These include: a) semantical errors in data communicated between application tasks; b) errors in the execution of application tasks; and c) errors in the timing of distributed events emitted by the application software. The design......In this thesis, methods of run-time error detection in application software for distributed process control is designed. The error detection is based upon a monitoring approach in which application software is monitored by system software during the entire execution. The thesis includes definition...

  16. Real-time detection and elimination of nonorthogonality error in interference fringe processing.

    Science.gov (United States)

    Hu, Haijiang; Zhang, Fengdeng

    2011-05-20

    In the measurement system of interference fringe, the nonorthogonality error is a main error source that influences the precision and accuracy of the measurement system. The detection and elimination of the error has been an important target. A novel method that only uses the cross-zero detection and the counting is proposed to detect and eliminate the nonorthogonality error in real time. This method can be simply realized by means of the digital logic device, because it does not invoke trigonometric functions and inverse trigonometric functions. And it can be widely used in the bidirectional subdivision systems of a Moiré fringe and other optical instruments.

  17. Anthropometric data error detecting and correction with a computer

    Science.gov (United States)

    Chesak, D. D.

    1981-01-01

    Data obtained with automated anthropometric data aquisition equipment was examined for short term errors. The least squares curve fitting technique was used to ascertain which data values were erroneous and to replace them, if possible, with corrected values. Errors were due to random reflections of light, masking of the light rays, and other types of optical and electrical interference. It was found that the signals were impossible to eliminate from the initial data produced by the television cameras, and that this was primarily a software problem requiring a digital computer to refine the data off line. The specific data of interest was related to the arm reach envelope of a human being.

  18. Crowdsourcing for error detection in cortical surface delineations

    DEFF Research Database (Denmark)

    Ganz, Melanie; Kondermann, Daniel; Andrulis, Jonas

    2017-01-01

    crowdsourcing platform were asked to annotate errors in automatic cortical surface delineations on 100 central, coronal slices of MR images. RESULTS: On average, annotations for 100 images were obtained in less than an hour. When using expert annotations as reference, the crowd on average achieves a sensitivity...

  19. Error detection in spoken human-machine interaction

    NARCIS (Netherlands)

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

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

  20. Error detection in spoken human-machine interaction

    NARCIS (Netherlands)

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

    2001-01-01

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

  1. Multivariate detection limits of on-line NIR model for extraction process of chlorogenic acid from Lonicera japonica.

    Science.gov (United States)

    Wu, Zhisheng; Sui, Chenglin; Xu, Bing; Ai, Lu; Ma, Qun; Shi, Xinyuan; Qiao, Yanjiang

    2013-04-15

    A methodology is proposed to estimate the multivariate detection limits (MDL) of on-line near-infrared (NIR) model in Chinese Herbal Medicines (CHM) system. In this paper, Lonicera japonica was used as an example, and its extraction process was monitored by on-line NIR spectroscopy. Spectra of on-line NIR could be collected by two fiber optic probes designed to transmit NIR radiation by a 2mm-flange. High performance liquid chromatography (HPLC) was used as a reference method to determine the content of chlorogenic acid in the extract solution. Multivariate calibration models were carried out including partial least squares regression (PLS) and interval partial least-squares (iPLS). The result showed improvement of model performance: compared with PLS model, the root mean square errors of prediction (RMSEP) of iPLS model decreased from 0.111mg to 0.068mg, and the R(2) parameter increased from 0.9434 to 0.9801. Furthermore, MDL values were determined by a multivariate method using the type of errors and concentration ranges. The MDL of iPLS model was about 14ppm, which confirmed that on-line NIR spectroscopy had the ability to detect trace amounts of chlorogenic acid in L. japonica. As a result, the application of on-line NIR spectroscopy for monitoring extraction process in CHM could be very encouraging and reliable.

  2. The role of extensive recasts in error detection and correction by adult ESL students

    Directory of Open Access Journals (Sweden)

    Laura Hawkes

    2016-03-01

    Full Text Available Most of the laboratory studies on recasts have examined the role of intensive recasts provided repeatedly on the same target structure. This is different from the original definition of recasts as the reformulation of learner errors as they occur naturally and spontaneously in the course of communicative interaction. Using a within-group research design and a new testing methodology (video-based stimulated correction posttest, this laboratory study examined whether extensive and spontaneous recasts provided during small-group work were beneficial to adult L2 learners. Participants were 26 ESL learners, who were divided into seven small groups (3-5 students per group, and each group participated in an oral activity with a teacher. During the activity, the students received incidental and extensive recasts to half of their errors; the other half of their errors received no feedback. Students’ ability to detect and correct their errors in the three types of episodes was assessed using two types of tests: a stimulated correction test (a video-based computer test and a written test. Students’ reaction time on the error detection portion of the stimulated correction task was also measured. The results showed that students were able to detect more errors in error+recast (error followed by the provision of a recast episodes than in error-recast (error and no recast provided episodes (though this difference did not reach statistical significance. They were also able to successfully and partially successfully correct more errors in error+recast episodes than in error-recast episodes, and this difference was statistically significant on the written test. The reaction time results also point towards a benefit from recasts, as students were able to complete the task (slightly more quickly for error+recast episodes than for error-recast episodes.

  3. Design and scheduling for periodic concurrent error detection and recovery in processor arrays

    Science.gov (United States)

    Wang, Yi-Min; Chung, Pi-Yu; Fuchs, W. Kent

    1992-01-01

    Periodic application of time-redundant error checking provides the trade-off between error detection latency and performance degradation. The goal is to achieve high error coverage while satisfying performance requirements. We derive the optimal scheduling of checking patterns in order to uniformly distribute the available checking capability and maximize the error coverage. Synchronous buffering designs using data forwarding and dynamic reconfiguration are described. Efficient single-cycle diagnosis is implemented by error pattern analysis and direct-mapped recovery cache. A rollback recovery scheme using start-up control for local recovery is also presented.

  4. SU-E-J-235: Varian Portal Dosimetry Accuracy at Detecting Simulated Delivery Errors

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, J; Bellon, M; Barton, K; Gulam, M; Chetty, I [Henry Ford Health System, Dept. Radiation Oncology, Detroit, MI (United States)

    2014-06-01

    Purpose: To use receiver operating characteristic (ROC) analysis to quantify the Varian Portal Dosimetry (VPD) application's ability to detect delivery errors in IMRT fields. Methods: EPID and VPD were calibrated/commissioned using vendor-recommended procedures. Five clinical plans comprising 56 modulated fields were analyzed using VPD. Treatment sites were: pelvis, prostate, brain, orbit, and base of tongue. Delivery was on a Varian Trilogy linear accelerator at 6MV using a Millenium120 multi-leaf collimator. Image pairs (VPD-predicted and measured) were exported in dicom format. Each detection test imported an image pair into Matlab, optionally inserted a simulated error (rectangular region with intensity raised or lowered) into the measured image, performed 3%/3mm gamma analysis, and saved the gamma distribution. For a given error, 56 negative tests (without error) were performed, one per 56 image pairs. Also, 560 positive tests (with error) with randomly selected image pairs and randomly selected in-field error location. Images were classified as errored (or error-free) if percent pixels with γ<κ was < (or ≥) τ. (Conventionally, κ=1 and τ=90%.) A ROC curve was generated from the 616 tests by varying τ. For a range of κ and τ, true/false positive/negative rates were calculated. This procedure was repeated for inserted errors of different sizes. VPD was considered to reliably detect an error if images were correctly classified as errored or error-free at least 95% of the time, for some κ+τ combination. Results: 20mm{sup 2} errors with intensity altered by ≥20% could be reliably detected, as could 10mm{sup 2} errors with intensity was altered by ≥50%. Errors with smaller size or intensity change could not be reliably detected. Conclusion: Varian Portal Dosimetry using 3%/3mm gamma analysis is capable of reliably detecting only those fluence errors that exceed the stated sizes. Images containing smaller errors can pass mathematical analysis

  5. Students versus Plagiarism: How is Online Plagiarism Detection Service Perceived?

    Directory of Open Access Journals (Sweden)

    Muhammad Affan Ramadhana

    2016-08-01

    Full Text Available The development of information and communication technology plays a considerable role for students in writing their theses. The positive side, it will help the students to find countless number of academic sources ranging from journal articles to complete theses written by other scholars. On the other hand, it will also create a chance for the students to commit plagiarism easier. Unoriginal writing and plagiarism in this digital era can be detected in the digital way by using plagiarism detection software. This paper elaborates how students understand the concept of plagiarism, how they avoid plagiarism, and how they perceive online plagiarism detection service. The data was taken from interviews to MA students during their period of thesis writing. This paper concludes several important outlines to be learning guidelines for the students in improving their academic writing.

  6. Online multi-face detection and tracking using detector confidence and structured SVMs

    NARCIS (Netherlands)

    Comaschi, F.; Stuijk, S.; Basten, A.A.; Corporaal, H.

    2015-01-01

    Online detection and tracking of a variable number of faces in video is a crucial component in many real-world applications ranging from video-surveillance to online gaming. In this paper we propose FAST-DT, a fully automated system capable of detecting and tracking a variable number of faces online

  7. Real-time in vivo dosimetry and error detection during afterloading brachytherapy

    DEFF Research Database (Denmark)

    Kertzscher Schwencke, Gustavo Adolfo Vladimir

    error scenarios, in order to quantify the error detection sensitivity of the real-time point dosimetry system used by means of a statistical error detection concept that incorporated a full uncertainty analysis. The limiting effects of the dependence on the a priori reconstruction of the dosimeter...... sources, even small discrepancies of the planned source position may result in largely modified dose distributions that could lead to an insufficient dose to the tumor and/or increased doses to OARs. One way to monitor the integrity of a BT treatment delivery and to detect potential treatment errors......, is to perform real-time in vivo dosimetry (IVD) inside the target region during the treatment. That way, an independent and patient specific verification of the agreement between delivered and planned treatments can be performed. If a treatment error is detected, modifications of the treatment parameters...

  8. Research of on-line detection system for power capacitor

    Science.gov (United States)

    Yao, Junda; Qian, Zheng; Yu, Hao; Xia, Jiuyun

    2016-01-01

    The hidden danger exists in the power capacitor of power system due to long-time operation under the environment of high voltage. Thus, it is possible to induce serious fault, and the on-line detection system is urgently required. In this paper, two methods of the on-line detection system are compared in order to realize the better real-time condition detection. The first method is based on the STM microprocessor with an internal 12 bit A/D converter, which converts analog signals which is arrived from the sample circuit into digital signals, and then the FFT algorithm is used to accomplish the measurement of the voltage and current values of the capacitor. The second method is based on the special electric energy metering IC, which can obtain RMS (Root Mean Square) of voltage and current by processing the sampled data of the voltage and current, and store RMS of voltage and current in its certain registers. The operating condition of the capacitor can be obtained after getting the values of voltage and current. By comparing the measuring results of two methods, the second method could achieve a higher measurement accuracy and more simple construction.

  9. Online Botnet Detection Based on Incremental Discrete Fourier Transform

    Directory of Open Access Journals (Sweden)

    Xiaocong Yu

    2010-05-01

    Full Text Available Botnet detection has attracted lots of attention since botnet attack is becoming one of the most serious threats on the Internet. But little work has considered the online detection. In this paper, we propose a novel approach that can monitor the botnet activities in an online way. We define the concept of “feature streams” to describe raw network traffic. If some feature streams show high similarities, the corresponding hosts will be regarded as suspected bots which will be added into the suspected bot hosts set. After activity analysis, bot hosts will be confirmed as soon as possible. We present a simple method by computing the average Euclidean distance for similarity measurement.  To avoid huge calculation among feature streams, classical Discrete Fourier Transform (DFT technique is adopted. Then an incremental calculation of DFT coefficients is introduced to obtain the optimal execution time. The experimental evaluations show that our approach can detect both centralized and distributed botnet activities successfully with high efficiency and low false positive rate.

  10. Using Neighbor Diversity to Detect Fraudsters in Online Auctions

    Directory of Open Access Journals (Sweden)

    Jun-Lin Lin

    2014-05-01

    Full Text Available Online auctions attract not only legitimate businesses trying to sell their products but also fraudsters wishing to commit fraudulent transactions. Consequently, fraudster detection is crucial to ensure the continued success of online auctions. This paper proposes an approach to detect fraudsters based on the concept of neighbor diversity. The neighbor diversity of an auction account quantifies the diversity of all traders that have transactions with this account. Based on four different features of each trader (i.e., the number of received ratings, the number of cancelled transactions, k-core, and the joined date, four measurements of neighbor diversity are proposed to discern fraudsters from legitimate traders. An experiment is conducted using data gathered from a real world auction website. The results show that, although the use of neighbor diversity on k-core or on the joined date shows little or no improvement in detecting fraudsters, both the neighbor diversity on the number of received ratings and the neighbor diversity on the number of cancelled transactions improve classification accuracy, compared to the state-of-the-art methods that use k-core and center weight.

  11. Real-time error detection but not error correction drives automatic visuomotor adaptation.

    Science.gov (United States)

    Hinder, Mark R; Riek, Stephan; Tresilian, James R; de Rugy, Aymar; Carson, Richard G

    2010-03-01

    We investigated the role of visual feedback of task performance in visuomotor adaptation. Participants produced novel two degrees of freedom movements (elbow flexion-extension, forearm pronation-supination) to move a cursor towards visual targets. Following trials with no rotation, participants were exposed to a 60 degrees visuomotor rotation, before returning to the non-rotated condition. A colour cue on each trial permitted identification of the rotated/non-rotated contexts. Participants could not see their arm but received continuous and concurrent visual feedback (CF) of a cursor representing limb position or post-trial visual feedback (PF) representing the movement trajectory. Separate groups of participants who received CF were instructed that online modifications of their movements either were, or were not, permissible as a means of improving performance. Feedforward-mediated performance improvements occurred for both CF and PF groups in the rotated environment. Furthermore, for CF participants this adaptation occurred regardless of whether feedback modifications of motor commands were permissible. Upon re-exposure to the non-rotated environment participants in the CF, but not PF, groups exhibited post-training aftereffects, manifested as greater angular deviations from a straight initial trajectory, with respect to the pre-rotation trials. Accordingly, the nature of the performance improvements that occurred was dependent upon the timing of the visual feedback of task performance. Continuous visual feedback of task performance during task execution appears critical in realising automatic visuomotor adaptation through a recalibration of the visuomotor mapping that transforms visual inputs into appropriate motor commands.

  12. Selective error detection for error-resilient wavelet-based image coding.

    Science.gov (United States)

    Karam, Lina J; Lam, Tuyet-Trang

    2007-12-01

    This paper introduces the concept of a similarity check function for error-resilient multimedia data transmission. The proposed similarity check function provides information about the effects of corrupted data on the quality of the reconstructed image. The degree of data corruption is measured by the similarity check function at the receiver, without explicit knowledge of the original source data. The design of a perceptual similarity check function is presented for wavelet-based coders such as the JPEG2000 standard, and used with a proposed "progressive similarity-based ARQ" (ProS-ARQ) scheme to significantly decrease the retransmission rate of corrupted data while maintaining very good visual quality of images transmitted over noisy channels. Simulation results with JPEG2000-coded images transmitted over the Binary Symmetric Channel, show that the proposed ProS-ARQ scheme significantly reduces the number of retransmissions as compared to conventional ARQ-based schemes. The presented results also show that, for the same number of retransmitted data packets, the proposed ProS-ARQ scheme can achieve significantly higher PSNR and better visual quality as compared to the selective-repeat ARQ scheme.

  13. Online Learners' Reading Ability Detection Based on Eye-Tracking Sensors.

    Science.gov (United States)

    Zhan, Zehui; Zhang, Lei; Mei, Hu; Fong, Patrick S W

    2016-09-10

    The detection of university online learners' reading ability is generally problematic and time-consuming. Thus the eye-tracking sensors have been employed in this study, to record temporal and spatial human eye movements. Learners' pupils, blinks, fixation, saccade, and regression are recognized as primary indicators for detecting reading abilities. A computational model is established according to the empirical eye-tracking data, and applying the multi-feature regularization machine learning mechanism based on a Low-rank Constraint. The model presents good generalization ability with an error of only 4.9% when randomly running 100 times. It has obvious advantages in saving time and improving precision, with only 20 min of testing required for prediction of an individual learner's reading ability.

  14. Online Learners’ Reading Ability Detection Based on Eye-Tracking Sensors

    Science.gov (United States)

    Zhan, Zehui; Zhang, Lei; Mei, Hu; Fong, Patrick S. W.

    2016-01-01

    The detection of university online learners’ reading ability is generally problematic and time-consuming. Thus the eye-tracking sensors have been employed in this study, to record temporal and spatial human eye movements. Learners’ pupils, blinks, fixation, saccade, and regression are recognized as primary indicators for detecting reading abilities. A computational model is established according to the empirical eye-tracking data, and applying the multi-feature regularization machine learning mechanism based on a Low-rank Constraint. The model presents good generalization ability with an error of only 4.9% when randomly running 100 times. It has obvious advantages in saving time and improving precision, with only 20 min of testing required for prediction of an individual learner’s reading ability. PMID:27626418

  15. Single Epoch GPS Deformation Signals Extraction and Gross Error Detection Technique Based on Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    WANG Jian; GAO Jingxiang; XU Changhui

    2006-01-01

    Wavelet theory is efficient as an adequate tool for analyzing single epoch GPS deformation signal. Wavelet analysis technique on gross error detection and recovery is advanced. Criteria of wavelet function choosing and Mallat decomposition levels decision are discussed. An effective deformation signal extracting method is proposed, that is wavelet noise reduction technique considering gross error recovery, which combines wavelet multi-resolution gross error detection results. Time position recognizing of gross errors and their repairing performance are realized. In the experiment, compactly supported orthogonal wavelet with short support block is more efficient than the longer one when discerning gross errors, which can obtain more finely analyses. And the shape of discerned gross error of short support wavelet is simpler than that of the longer one. Meanwhile, the time scale is easier to identify.

  16. Timely online chatter detection in end milling process

    Science.gov (United States)

    Fu, Yang; Zhang, Yun; Zhou, Huamin; Li, Dequn; Liu, Hongqi; Qiao, Haiyu; Wang, Xiaoqiang

    2016-06-01

    Chatter is one of the most unexpected and uncontrollable phenomenon during the milling operation. It is very important to develop an effective monitoring method to identify the chatter as soon as possible, while existing methods still cannot detect it before the workpiece has been damaged. This paper proposes an energy aggregation characteristic-based Hilbert-Huang transform method for online chatter detection. The measured vibration signal is firstly decomposed into a series of intrinsic mode functions (IMFs) using ensemble empirical mode decomposition. Feature IMFs are then selected according to the majority energy rule. Subsequently Hilbert spectral analysis is applied on these feature IMFs to calculate the Hilbert time/frequency spectrum. Two indicators are proposed to quantify the spectrum and thresholds are automatically calculated using Gaussian mixed model. Milling experiments prove the proposed method to be effective in protecting the workpiece from severe chatter damage within acceptable time complexity.

  17. Did I say dog or cat? A study of semantic error detection and correction in children.

    Science.gov (United States)

    Hanley, J Richard; Cortis, Cathleen; Budd, Mary-Jane; Nozari, Nazbanou

    2016-02-01

    Although naturalistic studies of spontaneous speech suggest that young children can monitor their speech, the mechanisms for detection and correction of speech errors in children are not well understood. In particular, there is little research on monitoring semantic errors in this population. This study provides a systematic investigation of detection and correction of semantic errors in children between the ages of 5 and 8years as they produced sentences to describe simple visual events involving nine highly familiar animals (the moving animals task). Results showed that older children made fewer errors and corrected a larger proportion of the errors that they made than younger children. We then tested the prediction of a production-based account of error monitoring that the strength of the language production system, and specifically its semantic-lexical component, should be correlated with the ability to detect and repair semantic errors. Strength of semantic-lexical mapping, as well as lexical-phonological mapping, was estimated individually for children by fitting their error patterns, obtained from an independent picture-naming task, to a computational model of language production. Children's picture-naming performance was predictive of their ability to monitor their semantic errors above and beyond age. This relationship was specific to the strength of the semantic-lexical part of the system, as predicted by the production-based monitor.

  18. Detection of prescription errors by a unit-based clinical pharmacist in a nephrology ward.

    Science.gov (United States)

    Vessal, Ghazal

    2010-02-01

    To determine the impact of a clinical pharmacist on detection and prevention of prescription errors at the nephrology ward of a referral hospital. Nephrology ward of a major referral hospital in Southern Iran. During a 4-month period, a clinical pharmacist was assigned to review medication order sheets and drug orders three times a week at the nephrology ward. Besides chart review, the clinical pharmacist participated in medical rounds once a week. The occurrence of prescribing errors, and related harm was determined on hospitalized patients in this ward during the 4 month period. When an error was detected, intervention was made after agreement of the attending physician. Number and types of prescribing errors, level of harm, and number of interventions were determined. Seventy six patient charts were reviewed during the 4-month period. A total of 818 medications were ordered in these patients. Eighty six prescribing errors were detected in 46 hospital admissions. The mean age of the patients was 47.7 +/- 17.2. Fifty five percent were male while 45% were female. Different types of prescribing errors and their frequencies were as follows: wrong frequency (37.2%), wrong drug selection (19.8%), overdose (12.8%), failure to discontinue (10.5%), failure to order (7 %), under- dose (3.5%), wrong time (3.5%), monitoring (3.5%), wrong route (1.2%), and drug interaction (1.2 %). The attending physician agreed to 96.5% of the prescription errors detected, and interventions were made. Although 89.5% of the detected errors caused no harm, 4(4.7%) of the errors increased the need for monitoring, 2 (2.3%) increased length of stay, and 2 (2.3%) led to permanent patient harm. presence of a clinical pharmacist at the nephrology ward helps in early detection of prescription errors, and therefore potential prevention of negative consequences due to drug administration.

  19. Neural Bases of Unconscious Error Detection in a Chinese Anagram Solution Task: Evidence from ERP Study.

    Directory of Open Access Journals (Sweden)

    Hua-Zhan Yin

    Full Text Available In everyday life, error monitoring and processing are important for improving ongoing performance in response to a changing environment. However, detecting an error is not always a conscious process. The temporal activation patterns of brain areas related to cognitive control in the absence of conscious awareness of an error remain unknown. In the present study, event-related potentials (ERPs in the brain were used to explore the neural bases of unconscious error detection when subjects solved a Chinese anagram task. Our ERP data showed that the unconscious error detection (UED response elicited a more negative ERP component (N2 than did no error (NE and detect error (DE responses in the 300-400-ms time window, and the DE elicited a greater late positive component (LPC than did the UED and NE in the 900-1200-ms time window after the onset of the anagram stimuli. Taken together with the results of dipole source analysis, the N2 (anterior cingulate cortex might reflect unconscious/automatic conflict monitoring, and the LPC (superior/medial frontal gyrus might reflect conscious error recognition.

  20. Real-time modeling and online filtering of the stochastic error in a fiber optic current transducer

    Science.gov (United States)

    Wang, Lihui; Wei, Guangjin; Zhu, Yunan; Liu, Jian; Tian, Zhengqi

    2016-10-01

    The stochastic error characteristics of a fiber optic current transducer (FOCT) influence the relay protection, electric-energy metering, and other devices in the spacer layer. Real-time modeling and online filtering of the FOCT’s stochastic error tends to be an effective method for improving the measurement accuracy of the FOCT. This paper first pretreats and inspects the FOCT data, statistically. Then, the model order is set by the AIC principle to establish an ARMA (2,1) model and model’s applicability is tested. Finally, a Kalman filter is adopted to reduce the noise in the FOCT data. The results of the experiment and the simulation demonstrate that there is a notable decrease in the stochastic error after time series modeling and Kalman filtering. Besides, the mean-variance is decreased by two orders. All the stochastic error coefficients are decreased by the total variance method; the BI is decreased by 41.4%, the RRW is decreased by 67.5%, and the RR is decreased by 53.4%. Consequently, the method can reduce the stochastic error and improve the measurement accuracy of the FOCT, effectively.

  1. Instantaneous detection of spatial gradient errors in differential GNSS

    Science.gov (United States)

    Jing, Jing

    Global Navigation Satellite Systems (GNSS) have become a critical element of modern engineering and scientific applications. GPS is currently being used in the design of navigation systems for both civil and military aviation applications. Differential GPS carrier phase measurements between antennas provide a very precise measurement that is useful for these applications. In fact, ground infrastructure has already been implemented in the Ground Based Augmentation System (GBAS) to take advantage of these precise measurements for use in civil aviation. Furthermore, these antennas can also be used to detect and isolate certain signal-in-space (SIS) failures and anomalies that are hazardous to aviation applications, for example the ionospheric anomalies and ephemeris failures. This realization, in turn, has led to the development of numerous carrier-phase based monitors. One drawback of the majority of these monitors is that their performance within a given configuration is dependent on how antennas are paired to form double differences. In contrast, the null space monitor approach is developed to provide consistent detection performance regardless of how the antennas are paired which combines measurements from multiple, spatially separated ground antennas through a null space transformation. The instantaneous carrier phase monitor cannot detect all gradients due to the presence of integer ambiguities. These ambiguities cannot be resolved because the gradient magnitude is unknown a priori. Furthermore, it has been shown that the performance of such monitors is highly dependent on the reference antenna topology. The range of detectable gradients for all carrier phase monitors depends on two factors: the number of antennas and their configuration. Antenna configuration is often overlooked as a means to improve performance. and heuristic arguments typically prevail in the associated siting decisions. However. such heuristics do not provide the maximum detectable range of

  2. Filter design for failure detection and isolation in the presence of modeling errors and disturbances

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    1996-01-01

    The design problem of filters for robust failure detection and isolation, (FDI) is addressed in this paper. The failure detection problem will be considered with respect to both modeling errors and disturbances. Both an approach based on failure detection observers as well as an approach based...

  3. Improvement of the Error-detection Mechanism in Adults with Dyslexia Following Reading Acceleration Training.

    Science.gov (United States)

    Horowitz-Kraus, Tzipi

    2016-05-01

    The error-detection mechanism aids in preventing error repetition during a given task. Electroencephalography demonstrates that error detection involves two event-related potential components: error-related and correct-response negativities (ERN and CRN, respectively). Dyslexia is characterized by slow, inaccurate reading. In particular, individuals with dyslexia have a less active error-detection mechanism during reading than typical readers. In the current study, we examined whether a reading training programme could improve the ability to recognize words automatically (lexical representations) in adults with dyslexia, thereby resulting in more efficient error detection during reading. Behavioural and electrophysiological measures were obtained using a lexical decision task before and after participants trained with the reading acceleration programme. ERN amplitudes were smaller in individuals with dyslexia than in typical readers before training but increased following training, as did behavioural reading scores. Differences between the pre-training and post-training ERN and CRN components were larger in individuals with dyslexia than in typical readers. Also, the error-detection mechanism as represented by the ERN/CRN complex might serve as a biomarker for dyslexia and be used to evaluate the effectiveness of reading intervention programmes. Copyright © 2016 John Wiley & Sons, Ltd.

  4. Local concurrent error detection and correction in data structures using virtual backpointers

    Science.gov (United States)

    Li, Chung-Chi Jim; Chen, Paul Peichuan; Fuchs, W. Kent

    1989-01-01

    A new technique, based on virtual backpointers, for local concurrent error detection and correction in linked data strutures is presented. Two new data structures, the Virtual Double Linked List, and the B-tree with Virtual Backpointers, are described. For these structures, double errors can be detected in 0(1) time and errors detected during forward moves can be corrected in 0(1) time. The application of a concurrent auditor process to data structure error detection and correction is analyzed, and an implementation is described, to determine the effect on mean time to failure of a multi-user shared database system. The implementation utilizes a Sequent shared memory multiprocessor system operating on a shared database of Virtual Double Linked Lists.

  5. Maximum Likelihood Approach for RFID Tag Set Cardinality Estimation with Detection Errors

    DEFF Research Database (Denmark)

    Nguyen, Chuyen T.; Hayashi, Kazunori; Kaneko, Megumi

    2013-01-01

    Abstract Estimation schemes of Radio Frequency IDentification (RFID) tag set cardinality are studied in this paper using Maximum Likelihood (ML) approach. We consider the estimation problem under the model of multiple independent reader sessions with detection errors due to unreliable radio...... is evaluated under dierent system parameters and compared with that of the conventional method via computer simulations assuming flat Rayleigh fading environments and framed-slotted ALOHA based protocol. Keywords RFID tag cardinality estimation maximum likelihood detection error...

  6. Error detection in core loading in the condition of asymmetrical distribution of power

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhov, Andrei; Pinegin, Anatoly [National Research Centre ' Kurchatov Institute' , Moscow (Russian Federation)

    2016-09-15

    The error detection in core loading in many cases happens in conditions of a significant asymmetry in the distribution of power density, which is caused by thermal mechanical deformations of reactor core, and temperature differences in the cold legs of coolant. The asymmetry of power distribution essentially decreases the effectiveness of algorithms used to detect errors in the core loading using ICIS data. The paper proposes the ways for solving this problem by means of special filtration algorithms.

  7. Detecting MLC errors in stereotactic radiotherapy plans with a liquid filled ionization chamber array.

    Science.gov (United States)

    O'Connor, Patrick; Seshadri, Venkatakrisnan; Charles, Paul

    2016-03-01

    Quality assurance of stereotactic radiotherapy demands the use of equipment with the highest resolution and sensitivity available. This study examines the sensitivity of a commercially available liquid-filled ionization chamber array--the Octavius 1000 SRS (PTW, Frieburg, Germany) for detecting small (sub-millimetre) multi-leaf collimator (MLC) alignment errors in static square fields (side length 16-40 mm). Furthermore, the effectiveness of detecting small MLC errors in clinical stereotactic radiotherapy patient plans using the device was also evaluated. The commonly used gamma pass rate metric (of the measurements compared with treatment planning system generated results) was used. The gamma pass rates were then evaluated as a function of MLC position error (MLC error size 0.1-2.5 mm). The detector array exhibited a drop in pass rate between plans without error and those which had MLC errors induced. For example a drop in pass rate of 4.5% (gamma criteria 3%, 1 mm) was observed when a 0.8 mm error was introduced into a 16 mm square field. Furthermore the drop in pass rate increased as the MLC position error increased. This study showed that the Octavius 1000 SRS array could be a useful tool for applications requiring the detection of small geometric delivery uncertainties.

  8. Detection method of nonlinearity errors by statistical signal analysis in heterodyne Michelson interferometer.

    Science.gov (United States)

    Hu, Juju; Hu, Haijiang; Ji, Yinghua

    2010-03-15

    Periodic nonlinearity that ranges from tens of nanometers to a few nanometers in heterodyne interferometer limits its use in high accuracy measurement. A novel method is studied to detect the nonlinearity errors based on the electrical subdivision and the analysis method of statistical signal in heterodyne Michelson interferometer. Under the movement of micropositioning platform with the uniform velocity, the method can detect the nonlinearity errors by using the regression analysis and Jackknife estimation. Based on the analysis of the simulations, the method can estimate the influence of nonlinearity errors and other noises for the dimensions measurement in heterodyne Michelson interferometer.

  9. Status of Research on Online Fuel Damage Detection and Core Damage Assessment System

    Institute of Scientific and Technical Information of China (English)

    XU; Xi-an; JI; Song-tao; GAO; Yong-guang; SHI; Xiao-lei

    2012-01-01

    <正>The technique research on the online fuel element damage detection and reactor core damage assessment is one project in the research program of the technical research for reactor key equipment maintenance and detection. The main research objective is to develop an online fuel damage detection system (FDDS), a core damage assessment system (CDAS) and make the integration of the two systems.

  10. Maximum error-bounded Piecewise Linear Representation for online stream approximation

    KAUST Repository

    Xie, Qing

    2014-04-04

    Given a time series data stream, the generation of error-bounded Piecewise Linear Representation (error-bounded PLR) is to construct a number of consecutive line segments to approximate the stream, such that the approximation error does not exceed a prescribed error bound. In this work, we consider the error bound in L∞ norm as approximation criterion, which constrains the approximation error on each corresponding data point, and aim on designing algorithms to generate the minimal number of segments. In the literature, the optimal approximation algorithms are effectively designed based on transformed space other than time-value space, while desirable optimal solutions based on original time domain (i.e., time-value space) are still lacked. In this article, we proposed two linear-time algorithms to construct error-bounded PLR for data stream based on time domain, which are named OptimalPLR and GreedyPLR, respectively. The OptimalPLR is an optimal algorithm that generates minimal number of line segments for the stream approximation, and the GreedyPLR is an alternative solution for the requirements of high efficiency and resource-constrained environment. In order to evaluate the superiority of OptimalPLR, we theoretically analyzed and compared OptimalPLR with the state-of-art optimal solution in transformed space, which also achieves linear complexity. We successfully proved the theoretical equivalence between time-value space and such transformed space, and also discovered the superiority of OptimalPLR on processing efficiency in practice. The extensive results of empirical evaluation support and demonstrate the effectiveness and efficiency of our proposed algorithms.

  11. Descriptive analysis of medication errors reported to the Egyptian national online reporting system during six months.

    Science.gov (United States)

    Shehata, Zahraa Hassan Abdelrahman; Sabri, Nagwa Ali; Elmelegy, Ahmed Abdelsalam

    2016-03-01

    This study analyzes reports to the Egyptian medication error (ME) reporting system from June to December 2014. Fifty hospital pharmacists received training on ME reporting using the national reporting system. All received reports were reviewed and analyzed. The pieces of data analyzed were patient age, gender, clinical setting, stage, type, medication(s), outcome, cause(s), and recommendation(s). Over the course of 6 months, 12,000 valid reports were gathered and included in this analysis. The majority (66%) came from inpatient settings, while 23% came from intensive care units, and 11% came from outpatient departments. Prescribing errors were the most common type of MEs (54%), followed by monitoring (25%) and administration errors (16%). The most frequent error was incorrect dose (20%) followed by drug interactions, incorrect drug, and incorrect frequency. Most reports were potential (25%), prevented (11%), or harmless (51%) errors; only 13% of reported errors lead to patient harm. The top three medication classes involved in reported MEs were antibiotics, drugs acting on the central nervous system, and drugs acting on the cardiovascular system. Causes of MEs were mostly lack of knowledge, environmental factors, lack of drug information sources, and incomplete prescribing. Recommendations for addressing MEs were mainly staff training, local ME reporting, and improving work environment. There are common problems among different healthcare systems, so that sharing experiences on the national level is essential to enable learning from MEs. Internationally, there is a great need for standardizing ME terminology, to facilitate knowledge transfer. Underreporting, inaccurate reporting, and a lack of reporter diversity are some limitations of this study. Egypt now has a national database of MEs that allows researchers and decision makers to assess the problem, identify its root causes, and develop preventive strategies. © The Author 2015. Published by Oxford University

  12. Minimum Error Entropy Filter for Fault Detection of Networked Control Systems

    OpenAIRE

    Guolian Hou; Mifeng Ren; Lilong Du; Jianhua Zhang

    2012-01-01

    In this paper, fault detection of networked control systems with random delays, packet dropout and noises is studied. The filter is designed using a minimum error entropy criterion. The residual generated by the filter is then evaluated to detect faults in networked control systems. An illustrative networked control system is used to verify the effectiveness of the proposed approach.

  13. Minimum Error Entropy Filter for Fault Detection of Networked Control Systems

    Directory of Open Access Journals (Sweden)

    Guolian Hou

    2012-03-01

    Full Text Available In this paper, fault detection of networked control systems with random delays, packet dropout and noises is studied. The filter is designed using a minimum error entropy criterion. The residual generated by the filter is then evaluated to detect faults in networked control systems. An illustrative networked control system is used to verify the effectiveness of the proposed approach.

  14. Effects of Individual Tree Detection Error Sources on Forest Management Planning Calculations

    Directory of Open Access Journals (Sweden)

    Harri Kaartinen

    2011-07-01

    Full Text Available The objective was to investigate the error sources of the airborne laser scanning based individual tree detection (ITD, and its effects on forest management planning calculations. The investigated error sources were detection of trees (etd, error in tree height prediction (eh and error in tree diameter prediction (ed. The effects of errors were analyzed with Monte Carlo simulations. etd was modeled empirically based on a tree’s relative size. A total of five different tree detection scenarios were tested. Effect of eh was investigated using 5% and 0% and effect of ed using 20%, 15%, 10%, 5%, 0% error levels, respectively. The research material comprised 15 forest stands located in Southern Finland. Measurements of 5,300 trees and their timber assortments were utilized as a starting point for the Monte Carlo simulated ITD inventories. ITD carried out for the same study area provided a starting point (Scenario 1 for etd. In Scenario 1, 60.2% from stem number and 75.9% from total volume (Vtotal were detected. When the only error source was etd (tree detection varying from 75.9% to 100% of Vtotal, root mean square errors (RMSEs in stand characteristics ranged between the scenarios from 32.4% to 0.6%, 29.0% to 0.5%, 7.8% to 0.2% and 5.4% to 0.1% in stand basal area (BA, Vtotal, mean height (Hg and mean diameter (Dg, respectively. Saw wood volume RMSE varied from 25.1% to 0.2%, as pulp wood volume respective varied from 37.8% to 1.0% when errors stemmed only from etd. The effect of ed was most significant for Vtotal and BA and the decrease in RMSE was from 12.0% to 0.6% (BA and from 10.9% to 0.5% (Vtotal in the most accurate tree detection scenario when ed varied from 20% to 0%. The effect of increased accuracy in tree height prediction was minor for all the stand characteristics. The results show that the most important error source in ITD is tree detection. At stand level, unbiased predictions for tree height and diameter are enough, given the

  15. Coherent detection of position errors in inter-satellite laser communications

    Science.gov (United States)

    Xu, Nan; Liu, Liren; Liu, De'an; Sun, Jianfeng; Luan, Zhu

    2007-09-01

    Due to the improved receiver sensitivity and wavelength selectivity, coherent detection became an attractive alternative to direct detection in inter-satellite laser communications. A novel method to coherent detection of position errors information is proposed. Coherent communication system generally consists of receive telescope, local oscillator, optical hybrid, photoelectric detector and optical phase lock loop (OPLL). Based on the system composing, this method adds CCD and computer as position error detector. CCD captures interference pattern while detection of transmission data from the transmitter laser. After processed and analyzed by computer, target position information is obtained from characteristic parameter of the interference pattern. The position errors as the control signal of PAT subsystem drive the receiver telescope to keep tracking to the target. Theoretical deviation and analysis is presented. The application extends to coherent laser rang finder, in which object distance and position information can be obtained simultaneously.

  16. Chromatographic on-line detection of bioactives in food

    Directory of Open Access Journals (Sweden)

    Remmelt Van der Werf

    2013-08-01

    Full Text Available ABSTRACTFindings were focused on the anti-oxidative activity of numerous fruits and vegetables by means of an on-line HPLC radical scavenging detection method. The reactant used was the ABTS•+ green radical cation. The system has been optimized in terms of reactor design, and chemical reactions kinetics. It has been qualified to classify molecules in order of their increasing activity to scavenge exogenous radicals. It may be used as a powerful high resolution screening tool to investigate the radical scavenging activities of natural plants. Bioassays consisting in cellular in vitro antioxidant assay using pancreatic β-cells have been used to confirm the bioactivity of the selected micronutrients. This study demonstrated that it is possible to screen at the molecular level, the bioactivity of numerous natural samples and to point out the richness of the local biodiversity in terms of natural resource of functional food ingredients usable for their potential benefits for consumer’s health, wellbeing and wellaging.Key words: HPLC radical scavenging detection method, bioactivity of natural samples

  17. An Empirical Study of End-User Behaviour in Spreadsheet Error Detection & Correction

    CERN Document Server

    Bishop, Brian

    2008-01-01

    Very little is known about the process by which end-user developers detect and correct spreadsheet errors. Any research pertaining to the development of spreadsheet testing methodologies or auditing tools would benefit from information on how end-users perform the debugging process in practice. Thirteen industry-based professionals and thirty-four accounting & finance students took part in a current ongoing experiment designed to record and analyse end-user behaviour in spreadsheet error detection and correction. Professionals significantly outperformed students in correcting certain error types. Time-based cell activity analysis showed that a strong correlation exists between the percentage of cells inspected and the number of errors corrected. The cell activity data was gathered through a purpose written VBA Excel plug-in that records the time and detail of all cell selection and cell change actions of individuals.

  18. An automatic 3D CAD model errors detection method of aircraft structural part for NC machining

    Directory of Open Access Journals (Sweden)

    Bo Huang

    2015-10-01

    Full Text Available Feature-based NC machining, which requires high quality of 3D CAD model, is widely used in machining aircraft structural part. However, there has been little research on how to automatically detect the CAD model errors. As a result, the user has to manually check the errors with great effort before NC programming. This paper proposes an automatic CAD model errors detection approach for aircraft structural part. First, the base faces are identified based on the reference directions corresponding to machining coordinate systems. Then, the CAD models are partitioned into multiple local regions based on the base faces. Finally, the CAD model error types are evaluated based on the heuristic rules. A prototype system based on CATIA has been developed to verify the effectiveness of the proposed approach.

  19. Simulating and Detecting Radiation-Induced Errors for Onboard Machine Learning

    Science.gov (United States)

    Wagstaff, Kiri L.; Bornstein, Benjamin; Granat, Robert; Tang, Benyang; Turmon, Michael

    2009-01-01

    Spacecraft processors and memory are subjected to high radiation doses and therefore employ radiation-hardened components. However, these components are orders of magnitude more expensive than typical desktop components, and they lag years behind in terms of speed and size. We have integrated algorithm-based fault tolerance (ABFT) methods into onboard data analysis algorithms to detect radiation-induced errors, which ultimately may permit the use of spacecraft memory that need not be fully hardened, reducing cost and increasing capability at the same time. We have also developed a lightweight software radiation simulator, BITFLIPS, that permits evaluation of error detection strategies in a controlled fashion, including the specification of the radiation rate and selective exposure of individual data structures. Using BITFLIPS, we evaluated our error detection methods when using a support vector machine to analyze data collected by the Mars Odyssey spacecraft. We found ABFT error detection for matrix multiplication is very successful, while error detection for Gaussian kernel computation still has room for improvement.

  20. Simulating and Detecting Radiation-Induced Errors for Onboard Machine Learning

    Science.gov (United States)

    Wagstaff, Kiri L.; Bornstein, Benjamin; Granat, Robert; Tang, Benyang; Turmon, Michael

    2009-01-01

    Spacecraft processors and memory are subjected to high radiation doses and therefore employ radiation-hardened components. However, these components are orders of magnitude more expensive than typical desktop components, and they lag years behind in terms of speed and size. We have integrated algorithm-based fault tolerance (ABFT) methods into onboard data analysis algorithms to detect radiation-induced errors, which ultimately may permit the use of spacecraft memory that need not be fully hardened, reducing cost and increasing capability at the same time. We have also developed a lightweight software radiation simulator, BITFLIPS, that permits evaluation of error detection strategies in a controlled fashion, including the specification of the radiation rate and selective exposure of individual data structures. Using BITFLIPS, we evaluated our error detection methods when using a support vector machine to analyze data collected by the Mars Odyssey spacecraft. We found ABFT error detection for matrix multiplication is very successful, while error detection for Gaussian kernel computation still has room for improvement.

  1. NGS-eval: NGS Error analysis and novel sequence VAriant detection tooL.

    Science.gov (United States)

    May, Ali; Abeln, Sanne; Buijs, Mark J; Heringa, Jaap; Crielaard, Wim; Brandt, Bernd W

    2015-07-01

    Massively parallel sequencing of microbial genetic markers (MGMs) is used to uncover the species composition in a multitude of ecological niches. These sequencing runs often contain a sample with known composition that can be used to evaluate the sequencing quality or to detect novel sequence variants. With NGS-eval, the reads from such (mock) samples can be used to (i) explore the differences between the reads and their references and to (ii) estimate the sequencing error rate. This tool maps these reads to references and calculates as well as visualizes the different types of sequencing errors. Clearly, sequencing errors can only be accurately calculated if the reference sequences are correct. However, even with known strains, it is not straightforward to select the correct references from databases. We previously analysed a pyrosequencing dataset from a mock sample to estimate sequencing error rates and detected sequence variants in our mock community, allowing us to obtain an accurate error estimation. Here, we demonstrate the variant detection and error analysis capability of NGS-eval with Illumina MiSeq reads from the same mock community. While tailored towards the field of metagenomics, this server can be used for any type of MGM-based reads. NGS-eval is available at http://www.ibi.vu.nl/programs/ngsevalwww/.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-15

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

  3. A Case for Soft Error Detection and Correction in Computational Chemistry.

    Science.gov (United States)

    van Dam, Hubertus J J; Vishnu, Abhinav; de Jong, Wibe A

    2013-09-10

    High performance computing platforms are expected to deliver 10(18) floating operations per second by the year 2022 through the deployment of millions of cores. Even if every core is highly reliable the sheer number of them will mean that the mean time between failures will become so short that most application runs will suffer at least one fault. In particular soft errors caused by intermittent incorrect behavior of the hardware are a concern as they lead to silent data corruption. In this paper we investigate the impact of soft errors on optimization algorithms using Hartree-Fock as a particular example. Optimization algorithms iteratively reduce the error in the initial guess to reach the intended solution. Therefore they may intuitively appear to be resilient to soft errors. Our results show that this is true for soft errors of small magnitudes but not for large errors. We suggest error detection and correction mechanisms for different classes of data structures. The results obtained with these mechanisms indicate that we can correct more than 95% of the soft errors at moderate increases in the computational cost.

  4. OLAWSDS:An Online Arabic Web Spam Detection System

    Directory of Open Access Journals (Sweden)

    Mohammed N. Al-Kabi

    2014-01-01

    Full Text Available For marketing purposes, Some Websites designers and administrators use illegal Search Engine Optimization (SEO techniques to optimize the ranking of their Web pages and mislead the search engines. Some Arabic Web pages use both content and link features, to increase artificially the rank of their Web pages in the Search Engine Results Pages (SERPs. This study represents an enhancement to previous work in this field. It includes the design and implementation of an online Arabic Web spam detection system, based on algorithms and mathematical foundations, which can detect the Arabic content and link web spam depending on the tree of the spam detection conditions, beside depending on the user’s feedback through a custom Web browser. The users can participate in making the decision about any Web page, through their feedbacks, so they judge if the Arabic Web pages in the browser are relevant for their particular queries or not. The proposed system uses the extracted content and link features from Arabic Web pages to determine whether to label each Web page as a spam or as a non-spam. This system also attempts to learn from the user’s feedback to enhance automatically its performance. Statistical analysis is adopted in this study to evaluate the proposed system. Statistical Package for the Social Sciences (SPSS software is used to evaluate this new system which considers the users feedbacks as dependent variables, while Arabic content and links features on the other hand are considered independent variables. The statistical analysis with the SPSS is used to apply a variety of tests, such as the test of the analysis of variance (ANOVA. ANOVA is used to show the relationships between the dependent and independent variables in the dataset, which leads to solving problems and building intelligent decisions and results.

  5. Combustion Control of Diesel Engine using Feedback Error Learning with Kernel Online Learning Approach

    Science.gov (United States)

    Widayaka, Elfady Satya; Ohmori, Hiromitsu

    2016-09-01

    This paper shows how to design Multivariable Model Reference Adaptive Control System (MRACS) for “Tokyo University discrete-time engine model” proposed by Yasuda et al (2014). This controller configuration has the structure of “Feedback error learning (FEL)” and adaptive law is based on kernel method. Simulation results indicate that “kernelized” adaptive controllers can improve the tracking performance, the speed of convergence and the robustness to disturbances.

  6. High Speed Error Detection and Data Recovery Architecture for Video Applications

    Directory of Open Access Journals (Sweden)

    D. Kranthi Kumar,

    2014-05-01

    Full Text Available Given the critical role of motion estimation (ME in a video coder, testing such a module is of priority concern. While focusing on the testing of ME in a video coding system, this work presents an error detection and data recovery (EDDR design, based on the residue-and-quotient (RQ code, to embed into ME for video coding testing applications. An error in processing elements (PEs, i.e. key components of a ME, can be detected and recovered effectively by using the proposed EDDR design. Experimental results indicate that the proposed EDDR design for ME testing can detect errors and recover data with an acceptable area overhead and timing penalty. Importantly, the proposed EDDR design performs satisfactorily in terms of throughput and reliability for ME testing applications.

  7. Research on vision-based error detection system for optic fiber winding

    Science.gov (United States)

    Lu, Wenchao; Li, Huipeng; Yang, Dewei; Zhang, Min

    2011-11-01

    Optic fiber coils are the hearts of fiber optic gyroscopes (FOGs). To detect the irresistible errors during the process of winding of optical fibers, such as gaps, climbs and partial rises between fibers, when fiber optic winding machines are operated, and to enable fully automated winding, we researched and designed this vision-based error detection system for optic fiber winding, on the basis of digital image collection and process[1]. When a Fiber-optic winding machine is operated, background light is used as illumination system to strength the contrast of images between fibers and background. Then microscope and CCD as imaging system and image collecting system are used to receive the analog images of fibers. After that analog images are shifted into digital imagines, which can be processed and analyzed by computers. Canny edge detection and a contour-tracing algorithm are used as the main image processing method. The distances between the fiber peaks were then measured and compared with the desired values. If these values fall outside of a predetermined tolerance zone, an error is detected and classified either as a gap, climb or rise. we used OpenCV and MATLAB database as basic function library and used VC++6.0 as the platform to show the results. The test results showed that the system was useful, and the edge detection and contour-tracing algorithm were effective, because of the high rate of accuracy. At the same time, the results of error detection are correct.

  8. Magnetic-field sensing with quantum error detection under the effect of energy relaxation

    Science.gov (United States)

    Matsuzaki, Yuichiro; Benjamin, Simon

    2017-03-01

    A solid state spin is an attractive system with which to realize an ultrasensitive magnetic field sensor. A spin superposition state will acquire a phase induced by the target field, and we can estimate the field strength from this phase. Recent studies have aimed at improving sensitivity through the use of quantum error correction (QEC) to detect and correct any bit-flip errors that may occur during the sensing period. Here we investigate the performance of a two-qubit sensor employing QEC and under the effect of energy relaxation. Surprisingly, we find that the standard QEC technique to detect and recover from an error does not improve the sensitivity compared with the single-qubit sensors. This is a consequence of the fact that the energy relaxation induces both a phase-flip and a bit-flip noise where the former noise cannot be distinguished from the relative phase induced from the target fields. However, we have found that we can improve the sensitivity if we adopt postselection to discard the state when error is detected. Even when quantum error detection is moderately noisy, and allowing for the cost of the postselection technique, we find that this two-qubit system shows an advantage in sensing over a single qubit in the same conditions.

  9. Early error detection predicted by reduced pre-response control process: an ERP topographic mapping study.

    Science.gov (United States)

    Pourtois, Gilles

    2011-01-01

    Advanced ERP topographic mapping techniques were used to study error monitoring functions in human adult participants, and test whether proactive attentional effects during the pre-response time period could later influence early error detection mechanisms (as measured by the ERN component) or not. Participants performed a speeded go/nogo task, and made a substantial number of false alarms that did not differ from correct hits as a function of behavioral speed or actual motor response. While errors clearly elicited an ERN component generated within the dACC following the onset of these incorrect responses, I also found that correct hits were associated with a different sequence of topographic events during the pre-response baseline time-period, relative to errors. A main topographic transition from occipital to posterior parietal regions (including primarily the precuneus) was evidenced for correct hits ~170-150 ms before the response, whereas this topographic change was markedly reduced for errors. The same topographic transition was found for correct hits that were eventually performed slower than either errors or fast (correct) hits, confirming the involvement of this distinctive posterior parietal activity in top-down attentional control rather than motor preparation. Control analyses further ensured that this pre-response topographic effect was not related to differences in stimulus processing. Furthermore, I found a reliable association between the magnitude of the ERN following errors and the duration of this differential precuneus activity during the pre-response baseline, suggesting a functional link between an anticipatory attentional control component subserved by the precuneus and early error detection mechanisms within the dACC. These results suggest reciprocal links between proactive attention control and decision making processes during error monitoring.

  10. Detection of overlay error in double patterning gratings using phase-structured illumination.

    Science.gov (United States)

    Peterhänsel, Sandy; Gödecke, Maria Laura; Paz, Valeriano Ferreras; Frenner, Karsten; Osten, Wolfgang

    2015-09-21

    With the help of simulations we study the benefits of using coherent, phase-structured illumination to detect the overlay error in resist gratings fabricated by double patterning. Evaluating the intensity and phase distribution along the focused spot of a high numerical aperture microscope, the capability of detecting magnitude and direction of overlay errors in the range of a few nanometers is investigated for a wide range of gratings. Furthermore, two measurement approaches are presented and tested for their reliability in the presence of white Gaussian noise.

  11. Detection and correct handling of prescribing errors in Dutch hospital pharmacies using test patients.

    Science.gov (United States)

    Beex-Oosterhuis, Marieke M; de Vogel, Ed M; van der Sijs, Heleen; Dieleman, Hetty G; van den Bemt, Patricia M L A

    2013-12-01

    Hospital pharmacists and pharmacy technicians play a major role in detecting prescribing errors by medication surveillance. At present the frequency of detected and correctly handled prescribing errors is unclear, as are factors associated with correct handling. To examine the frequency of detection of prescribing errors and the frequency of correct handling, as well as factors associated with correct handling of prescribing errors by hospital pharmacists and pharmacy technicians. This study was conducted in 57 Dutch hospital pharmacies. Prospective observational study with test patients, using a case-control design to identify factors associated with correct handling. A questionnaire was used to collect the potential factors. Test patients containing prescribing errors were developed by an expert panel of hospital pharmacists (a total of 40 errors in nine medication records divided among three test patients; each test patient was used in 3 rounds; on average 4.5 prescribing error per patient per round). Prescribing errors were defined as dosing errors or therapeutic errors (contra-indication, drug-drug interaction, (pseudo)duplicate medication). The errors were selected on relevance and unequivocalness. The panel also defined how the errors should be handled in practice using national guidelines and this was defined as 'correct handling'. The test patients had to be treated as real patients while conducting medication surveillance. The pharmacists and technicians were asked to report detected errors to the investigator. The percentages of detected and correctly handled prescribing errors were the main outcome measures. Factors associated with correct handling were determined, using multivariate logistic regression analysis. Fifty-nine percent of the total number of intentionally added prescribing errors were detected and 57 % were handled correctly by the hospital pharmacists and technicians. The use of a computer system for medication surveillance compared to no

  12. Ultraspectral sounder data compression using error-detecting reversible variable-length coding

    Science.gov (United States)

    Huang, Bormin; Ahuja, Alok; Huang, Hung-Lung; Schmit, Timothy J.; Heymann, Roger W.

    2005-08-01

    Nonreversible variable-length codes (e.g. Huffman coding, Golomb-Rice coding, and arithmetic coding) have been used in source coding to achieve efficient compression. However, a single bit error during noisy transmission can cause many codewords to be misinterpreted by the decoder. In recent years, increasing attention has been given to the design of reversible variable-length codes (RVLCs) for better data transmission in error-prone environments. RVLCs allow instantaneous decoding in both directions, which affords better detection of bit errors due to synchronization losses over a noisy channel. RVLCs have been adopted in emerging video coding standards--H.263+ and MPEG-4--to enhance their error-resilience capabilities. Given the large volume of three-dimensional data that will be generated by future space-borne ultraspectral sounders (e.g. IASI, CrIS, and HES), the use of error-robust data compression techniques will be beneficial to satellite data transmission. In this paper, we investigate a reversible variable-length code for ultraspectral sounder data compression, and present its numerical experiments on error propagation for the ultraspectral sounder data. The results show that the RVLC performs significantly better error containment than JPEG2000 Part 2.

  13. Precision and shortcomings of yaw error estimation using spinner-based light detection and ranging

    DEFF Research Database (Denmark)

    Kragh, Knud Abildgaard; Hansen, Morten Hartvig; Mikkelsen, Torben

    2013-01-01

    was developed and tested. In this study, the simulation parameter space is extended to include higher levels of turbulence intensity. Furthermore, the method is applied to experimental data and compared with met-mast data corrected for a calibration error that was not discovered during previous work. Finally......, the shortcomings of using a spinner mounted LIDAR for yaw error estimation are discussed. The extended simulation study shows that with the applied method, the yaw error can be estimated with a precision of a few degrees, even in highly turbulent flows. Applying the method to experimental data reveals an average......When extracting energy from the wind using horizontal axis wind turbines, the ability to align the rotor axis with the mean wind direction is crucial. In previous work, a method for estimating the yaw error based on measurements from a spinner mounted light detection and ranging (LIDAR) device...

  14. Spreadsheet Error Detection: an Empirical Examination in the Context of Greece

    Directory of Open Access Journals (Sweden)

    Dimitrios Maditinos

    2012-06-01

    Full Text Available The personal computers era made advanced programming tasks available to end users. Spreadsheet models are one of the most widely used applications that can produce valuable results with minimal training and effort. However, errors contained in most spreadsheets may be catastrophic and difficult to detect. This study attempts to investigate the influence of experience and spreadsheet presentation on the error finding performance by end users. To reach the target of the study, 216 business and finance students participated in a task of finding errors in a simple free cash flow model. The findings of the study reveal that presentation of the spreadsheet is of major importance as far as the error finding performance is concerned, while experience does not seem to affect students on their performance. Further research proposals and limitations of the study are, moreover, discussed.

  15. Online Detection of Mixed Layer Depth for Autonomous Underwater Vehicles

    Science.gov (United States)

    Chu, S.; Estlin, T.; Castano, R.; Woodward, G.; Gierach, M. M.; Thompson, A. F.; Schaffer, S.

    2015-12-01

    The accurate determination of the mixed layer depth (MLD) plays a crucial role in studying ocean dynamics and climate change. Various methods to estimate MLD have been proposed [1, 2]. However there is no current consensus on the best model, which leads to large uncertainty in the estimation. The variability, coupled with the complexity of physical, chemical and biological processes involved and the uncertainty and instabilities of the upper ocean surface, makes estimating MLD a challenging task. MLD varies significantly, even across a small spatial area (autonomous underwater vehicle (AUV). Using an online method permits a more adaptive approach to estimating MLD. Our proposed algorithm is based on an ensemble approach, which includes data mining techniques for real-time peak and change detection, learned seasonal variability profile, combined with MLD estimation criteria in [1]. In this study, we analyze measurements using glider data collected from the OSMOSIS (Ocean Surface Mixing, Ocean Submesoscale Interaction Study) project, concatenated into a year-long time series [3]. The glider data consists of nine full-depth moorings, which were deployed in a 15 km by 15 km box at the Porcupine Abyssal Plain in the northeast Atlantic, centered at 16.2°W, 48.7°N. Our algorithm utilizes direct measurements of salinity, temperature, depth and time and the design is based on the spatial and temporal variability of MLD learned. We will present our initial work on tracking the MLD based on real-time simulations using the OSMOSIS glider data and discussed for the case of deploying on a single AUV. Using an online algorithm for estimating MLD in-situ enables the system to rapidly adapt to the variability in a real-world environment and also allows for the intelligent operation of the limited sampling resources available on an AUV. We will discuss the autonomy architecture and algorithm design for implementing this methodology and present results from our initial

  16. Detection and management of medication errors in internal wards of a teaching hospital by clinical pharmacists.

    Science.gov (United States)

    Abbasinazari, Mohammad; Hajhossein Talasaz, Azita; Eshraghi, Azadeh; Sahraei, Zahra

    2013-08-07

    Any suboptimum treatment in the management of patients can lead to medication errors (MEs) that may increase morbidity and mortality in hospitalized individuals. By establishing well-designed patient care activities within the managed care setting, clinical pharmacists can cooperate with other health care professionals to provide quality care and maximize safety. The aim of this study was to evaluate the frequency and prevention of MEs by clinical pharmacists. This was a cross-sectional interventional study conducted in internal wards of a teaching hospital during a two-month period. During this period, patient records, and physician orders were reviewed by clinical pharmacists. Any prescription error identified was documented. Incorrect drug selection, dose, dosage form, frequency, or route of administration all were considered as medication errors. Then, the clinical pharmacist discuss about findings with the clinical fellows to change faulty orders. The frequency and types of MEs in different wards that were detected and prevented by clinical pharmacists was documented. During the study period, in 132 patients, 262 errors were detected (1.98 per each). Wrong frequency 71 (27%), forget to order 37 (14.1%), wrong selection 33 (12.5%), drug interactions 26 (9.9%), forget to discontinue 25 (9.5%) and inappropriate dose adjustment in renal impairment 25 (9.5%) were the most types of errors. Cardiovascular medications were the class with the highest detected errors (31.6%) followed by gastrointestinal agents (15.6%). Medication errors are common problems in medical wards that their frequency can be restricted by the intervention of clinical pharmacists.

  17. Detection and management of medication errors in internal wards of a teaching hospital by clinical pharmacists.

    Directory of Open Access Journals (Sweden)

    Mohammad Abbasinazari

    2013-07-01

    Full Text Available Any suboptimum treatment in the management of patients can lead to medication errors (MEs that may increase morbidity and mortality in hospitalized individuals. By establishing well-designed patient care activities within the managed care setting, clinical pharmacists can cooperate with other health care professionals to provide quality care and maximize safety. The aim of this study was to evaluate the frequency and prevention of MEs by clinical pharmacists. This was a cross-sectional interventional study conducted in internal wards of a teaching hospital during a two-month period. During this period, patient records, and physician orders were reviewed by clinical pharmacists. Any prescription error identified was documented. Incorrect drug selection, dose, dosage form, frequency, or route of administration all were considered as medication errors. Then, the clinical pharmacist discuss about findings with the clinical fellows to change faulty orders. The frequency and types of MEs in different wards that were detected and prevented by clinical pharmacists was documented. During the study period, in 132 patients, 262 errors were detected (1.98 per each. Wrong frequency 71 (27%, forget to order 37 (14.1%, wrong selection 33 (12.5%, drug interactions 26 (9.9%, forget to discontinue 25 (9.5% and inappropriate dose adjustment in renal impairment 25 (9.5% were the most types of errors. Cardiovascular medications were the class with the highest detected errors (31.6% followed by gastrointestinal agents (15.6%. Medication errors are common problems in medical wards that their frequency can be restricted by the intervention of clinical pharmacists.

  18. Wavefront error correction and Earth-like planet detection by Self-Coherent Camera in space

    CERN Document Server

    Galicher, R; Rousset, G

    2008-01-01

    In the context of exoplanet detection, the performance of coronagraphs is limited by wavefront errors. To efficiently correct for these aberrations with a deformable mirror, it is mandatory to measure them using the science detector with a very high accuracy. The Self-Coherent Camera which is based on light incoherence between star and its environment enables an estimation of these wavefront errors. That estimation is directly derived from the encoded speckles in the science image. This avoids differential errors due to beam separation and non common optics. Earth-like planet detection is demonstrated by numerical simulations under realistic assumptions for a space telescope. The Self-Coherent Camera is an attractive technique for future space telescopes. It is also one of the techniques under investigation for the E-ELT planet finder so-called EPICS.

  19. [Two Data Inversion Algorithms of Aerosol Horizontal Distributiol Detected by MPL and Error Analysis].

    Science.gov (United States)

    Lü, Li-hui; Liu, Wen-qing; Zhang, Tian-shu; Lu, Yi-huai; Dong, Yun-sheng; Chen, Zhen-yi; Fan, Guang-qiang; Qi, Shao-shuai

    2015-07-01

    Atmospheric aerosols have important impacts on human health, the environment and the climate system. Micro Pulse Lidar (MPL) is a new effective tool for detecting atmosphere aerosol horizontal distribution. And the extinction coefficient inversion and error analysis are important aspects of data processing. In order to detect the horizontal distribution of atmospheric aerosol near the ground, slope and Fernald algorithms were both used to invert horizontal MPL data and then the results were compared. The error analysis showed that the error of the slope algorithm and Fernald algorithm were mainly from theoretical model and some assumptions respectively. Though there still some problems exist in those two horizontal extinction coefficient inversions, they can present the spatial and temporal distribution of aerosol particles accurately, and the correlations with the forward-scattering visibility sensor are both high with the value of 95%. Furthermore relatively speaking, Fernald algorithm is more suitable for the inversion of horizontal extinction coefficient.

  20. Error-detection-based quantum fault tolerance against discrete Pauli noise

    CERN Document Server

    Reichardt, B W

    2006-01-01

    A quantum computer -- i.e., a computer capable of manipulating data in quantum superposition -- would find applications including factoring, quantum simulation and tests of basic quantum theory. Since quantum superpositions are fragile, the major hurdle in building such a computer is overcoming noise. Developed over the last couple of years, new schemes for achieving fault tolerance based on error detection, rather than error correction, appear to tolerate as much as 3-6% noise per gate -- an order of magnitude better than previous procedures. But proof techniques could not show that these promising fault-tolerance schemes tolerated any noise at all. With an analysis based on decomposing complicated probability distributions into mixtures of simpler ones, we rigorously prove the existence of constant tolerable noise rates ("noise thresholds") for error-detection-based schemes. Numerical calculations indicate that the actual noise threshold this method yields is lower-bounded by 0.1% noise per gate.

  1. Quantum-state anomaly detection for arbitrary errors using a machine-learning technique

    Science.gov (United States)

    Hara, Satoshi; Ono, Takafumi; Okamoto, Ryo; Washio, Takashi; Takeuchi, Shigeki

    2016-10-01

    The accurate detection of small deviations in given density matrice is important for quantum information processing, which is a difficult task because of the intrinsic fluctuation in density matrices reconstructed using a limited number of experiments. We previously proposed a method for decoherence error detection using a machine-learning technique [S. Hara, T. Ono, R. Okamoto, T. Washio, and S. Takeuchi, Phys. Rev. A 89, 022104 (2014), 10.1103/PhysRevA.89.022104]. However, the previous method is not valid when the errors are just changes in phase. Here, we propose a method that is valid for arbitrary errors in density matrices. The performance of the proposed method is verified using both numerical simulation data and real experimental data.

  2. ERROR ANALYSIS OF 3D DETECTING SYSTEM BASED ON WHOLE-FIELD PARALLEL CONFOCAL MICROSCOPE

    Institute of Scientific and Technical Information of China (English)

    Wang Yonghong; Yu Xiaofen

    2005-01-01

    Compared with the traditional scanning confocal microscopy, the effect of various factors on characteristic in multi-beam parallel confocal system is discussed, the error factors in multi-beam parallel confocal system are analyzed. The factors influencing the characteristics of the multi-beam parallel confocal system are discussed. The construction and working principle of the non-scanning 3D detecting system is introduced, and some experiment results prove the effect of various factors on the detecting system.

  3. The Effect of Piano Playing on Preservice Teachers' Ability to Detect Errors in a Choral Score

    Science.gov (United States)

    Napoles, Jessica; Babb, Sandra L.; Bowers, Judy; Hankle, Steven; Zrust, Adam

    2017-01-01

    The purpose of this study was to examine and empirically test the pedagogical claim that playing the piano while listening to choral singers impedes error detection ability. In a within-subjects design, participants (N = 55 preservice teachers) either listened to four excerpts of choral hymns or played a single part (soprano/bass) on the piano…

  4. The Effect of Piano Playing on Preservice Teachers' Ability to Detect Errors in a Choral Score

    Science.gov (United States)

    Napoles, Jessica; Babb, Sandra L.; Bowers, Judy; Hankle, Steven; Zrust, Adam

    2017-01-01

    The purpose of this study was to examine and empirically test the pedagogical claim that playing the piano while listening to choral singers impedes error detection ability. In a within-subjects design, participants (N = 55 preservice teachers) either listened to four excerpts of choral hymns or played a single part (soprano/bass) on the piano…

  5. Automatic detection of frequent pronunciation errors made by L2-learners

    NARCIS (Netherlands)

    Truong, K.P.; Neri, A.; Wet, F. de; Cucchiarini, C.; Strik, H.

    2005-01-01

    In this paper, we present an acoustic-phonetic approach to automatic pronunciation error detection. Classifiers using techniques such as Linear Discriminant Analysis and Decision Trees were developed for three sounds that are frequently pronounced incorrectly by L2-learners of Dutch: /a/, /y/ and /x

  6. Error detection in GPS observations by means of Multi-process models

    DEFF Research Database (Denmark)

    Thomsen, Henrik F.

    2001-01-01

    The main purpose of this article is to present the idea of using Multi-process models as a method of detecting errors in GPS observations. The theory behind Multi-process models, and double differenced phase observations in GPS is presented shortly. It is shown how to model cycle slips in the Multi...

  7. Automatic detection of frequent pronunciation errors made by L2-learners

    NARCIS (Netherlands)

    Truong, K.P.; Neri, A.; Wet, F. de; Cucchiarini, C.; Strik, H.

    2005-01-01

    In this paper, we present an acoustic-phonetic approach to automatic pronunciation error detection. Classifiers using techniques such as Linear Discriminant Analysis and Decision Trees were developed for three sounds that are frequently pronounced incorrectly by L2-learners of Dutch: /a/, /y/ and

  8. Extending Dylan's type system for better type inference and error detection

    DEFF Research Database (Denmark)

    Mehnert, Hannes

    2010-01-01

    Whereas dynamic typing enables rapid prototyping and easy experimentation, static typing provides early error detection and better compile time optimization. Gradual typing [26] provides the best of both worlds. This paper shows how to define and implement gradual typing in Dylan, traditionally a...

  9. Visual acuity measures do not reliably detect childhood refractive error--an epidemiological study.

    Directory of Open Access Journals (Sweden)

    Lisa O'Donoghue

    Full Text Available PURPOSE: To investigate the utility of uncorrected visual acuity measures in screening for refractive error in white school children aged 6-7-years and 12-13-years. METHODS: The Northern Ireland Childhood Errors of Refraction (NICER study used a stratified random cluster design to recruit children from schools in Northern Ireland. Detailed eye examinations included assessment of logMAR visual acuity and cycloplegic autorefraction. Spherical equivalent refractive data from the right eye were used to classify significant refractive error as myopia of at least 1DS, hyperopia as greater than +3.50DS and astigmatism as greater than 1.50DC, whether it occurred in isolation or in association with myopia or hyperopia. RESULTS: Results are presented from 661 white 12-13-year-old and 392 white 6-7-year-old school-children. Using a cut-off of uncorrected visual acuity poorer than 0.20 logMAR to detect significant refractive error gave a sensitivity of 50% and specificity of 92% in 6-7-year-olds and 73% and 93% respectively in 12-13-year-olds. In 12-13-year-old children a cut-off of poorer than 0.20 logMAR had a sensitivity of 92% and a specificity of 91% in detecting myopia and a sensitivity of 41% and a specificity of 84% in detecting hyperopia. CONCLUSIONS: Vision screening using logMAR acuity can reliably detect myopia, but not hyperopia or astigmatism in school-age children. Providers of vision screening programs should be cognisant that where detection of uncorrected hyperopic and/or astigmatic refractive error is an aspiration, current UK protocols will not effectively deliver.

  10. The effects of alignment error and alignment filtering on the sitewise detection of positive selection.

    Science.gov (United States)

    Jordan, Gregory; Goldman, Nick

    2012-04-01

    When detecting positive selection in proteins, the prevalence of errors resulting from misalignment and the ability of alignment filters to mitigate such errors are not well understood, but filters are commonly applied to try to avoid false positive results. Focusing on the sitewise detection of positive selection across a wide range of divergence levels and indel rates, we performed simulation experiments to quantify the false positives and false negatives introduced by alignment error and the ability of alignment filters to improve performance. We found that some aligners led to many false positives, whereas others resulted in very few. False negatives were a problem for all aligners, increasing with sequence divergence. Of the aligners tested, PRANK's codon-based alignments consistently performed the best and ClustalW performed the worst. Of the filters tested, GUIDANCE performed the best and Gblocks performed the worst. Although some filters showed good ability to reduce the error rates from ClustalW and MAFFT alignments, none were found to substantially improve the performance of PRANK alignments under most conditions. Our results revealed distinct trends in error rates and power levels for aligners and filters within a biologically plausible parameter space. With the best aligner, a low false positive rate was maintained even with extremely divergent indel-prone sequences. Controls using the true alignment and an optimal filtering method suggested that performance improvements could be gained by improving aligners or filters to reduce the prevalence of false negatives, especially at higher divergence levels and indel rates.

  11. Detection and correction of inconsistency-based errors in non-rigid registration

    Science.gov (United States)

    Gass, Tobias; Szekely, Gabor; Goksel, Orcun

    2014-03-01

    In this paper we present a novel post-processing technique to detect and correct inconsistency-based errors in non-rigid registration. While deformable registration is ubiquitous in medical image computing, assessing its quality has yet been an open problem. We propose a method that predicts local registration errors of existing pairwise registrations between a set of images, while simultaneously estimating corrected registrations. In the solution the error is constrained to be small in areas of high post-registration image similarity, while local registrations are constrained to be consistent between direct and indirect registration paths. The latter is a critical property of an ideal registration process, and has been frequently used to asses the performance of registration algorithms. In our work, the consistency is used as a target criterion, for which we efficiently find a solution using a linear least-squares model on a coarse grid of registration control points. We show experimentally that the local errors estimated by our algorithm correlate strongly with true registration errors in experiments with known, dense ground-truth deformations. Additionally, the estimated corrected registrations consistently improve over the initial registrations in terms of average deformation error or TRE for different registration algorithms on both simulated and clinical data, independent of modality (MRI/CT), dimensionality (2D/3D) and employed primary registration method (demons/Markov-randomfield).

  12. Controversies in modern evolutionary biology: the imperative for error detection and quality control

    Directory of Open Access Journals (Sweden)

    Prosdocimi Francisco

    2012-01-01

    Full Text Available Abstract Background The data from high throughput genomics technologies provide unique opportunities for studies of complex biological systems, but also pose many new challenges. The shift to the genome scale in evolutionary biology, for example, has led to many interesting, but often controversial studies. It has been suggested that part of the conflict may be due to errors in the initial sequences. Most gene sequences are predicted by bioinformatics programs and a number of quality issues have been raised, concerning DNA sequencing errors or badly predicted coding regions, particularly in eukaryotes. Results We investigated the impact of these errors on evolutionary studies and specifically on the identification of important genetic events. We focused on the detection of asymmetric evolution after duplication, which has been the subject of controversy recently. Using the human genome as a reference, we established a reliable set of 688 duplicated genes in 13 complete vertebrate genomes, where significantly different evolutionary rates are observed. We estimated the rates at which protein sequence errors occur and are accumulated in the higher-level analyses. We showed that the majority of the detected events (57% are in fact artifacts due to the putative erroneous sequences and that these artifacts are sufficient to mask the true functional significance of the events. Conclusions Initial errors are accumulated throughout the evolutionary analysis, generating artificially high rates of event predictions and leading to substantial uncertainty in the conclusions. This study emphasizes the urgent need for error detection and quality control strategies in order to efficiently extract knowledge from the new genome data.

  13. On-Line Multichannel Raman Spectroscopic Detection System For Capillary Zone Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An on-line multichannel Raman spectroscopic detection system for capillary electrophoresis was established by using an Ar+ laser and a cryogenically cooled ICCD. Resonant excitation Raman spectra of methyl red and methyl orange were employed to test the system. The result shows that it could yield on-line electrophoretogram and time series of Raman spectra.

  14. Predictive error detection in pianists: A combined ERP and motion capture study

    Directory of Open Access Journals (Sweden)

    Clemens eMaidhof

    2013-09-01

    Full Text Available Performing a piece of music involves the interplay of several cognitive and motor processes and requires extensive training to achieve a high skill level. However, even professional musicians commit errors occasionally. Previous event-related potential (ERP studies have investigated the neurophysiological correlates of pitch errors during piano performance, and reported pre-error negativity already occurring approximately 70-100 ms before the error had been committed and audible. It was assumed that this pre-error negativity reflects predictive control processes that compare predicted consequences with actual consequences of one’s own actions. However, in previous investigations, correct and incorrect pitch events were confounded by their different tempi. In addition, no data about the underlying movements were available. In the present study, we exploratively recorded the ERPs and 3D movement data of pianists’ fingers simultaneously while they performed fingering exercises from memory. Results showed a pre-error negativity for incorrect keystrokes when both correct and incorrect keystrokes were performed with comparable tempi. Interestingly, even correct notes immediately preceding erroneous keystrokes elicited a very similar negativity. In addition, we explored the possibility of computing ERPs time-locked to a kinematic landmark in the finger motion trajectories defined by when a finger makes initial contact with the key surface, that is, at the onset of tactile feedback. Results suggest that incorrect notes elicited a small difference after the onset of tactile feedback, whereas correct notes preceding incorrect ones elicited negativity before the onset of tactile feedback. The results tentatively suggest that tactile feedback plays an important role in error-monitoring during piano performance, because the comparison between predicted and actual sensory (tactile feedback may provide the information necessary for the detection of an

  15. Mechanistically-informed damage detection using dynamic measurements: Extended constitutive relation error

    Science.gov (United States)

    Hu, X.; Prabhu, S.; Atamturktur, S.; Cogan, S.

    2017-02-01

    Model-based damage detection entails the calibration of damage-indicative parameters in a physics-based computer model of an undamaged structural system against measurements collected from its damaged counterpart. The approach relies on the premise that changes identified in the damage-indicative parameters during calibration reveal the structural damage in the system. In model-based damage detection, model calibration has traditionally been treated as a process, solely operating on the model output without incorporating available knowledge regarding the underlying mechanistic behavior of the structural system. In this paper, the authors propose a novel approach for model-based damage detection by implementing the Extended Constitutive Relation Error (ECRE), a method developed for error localization in finite element models. The ECRE method was originally conceived to identify discrepancies between experimental measurements and model predictions for a structure in a given healthy state. Implementing ECRE for damage detection leads to the evaluation of a structure in varying healthy states and determination of discrepancy between model predictions and experiments due to damage. The authors developed an ECRE-based damage detection procedure in which the model error and structural damage are identified in two distinct steps and demonstrate feasibility of the procedure in identifying the presence, location and relative severity of damage on a scaled two-story steel frame for damage scenarios of varying type and severity.

  16. Improved assessment of multiple sclerosis lesion segmentation agreement via detection and outline error estimates

    Directory of Open Access Journals (Sweden)

    Wack David S

    2012-07-01

    Full Text Available Abstract Background Presented is the method “Detection and Outline Error Estimates” (DOEE for assessing rater agreement in the delineation of multiple sclerosis (MS lesions. The DOEE method divides operator or rater assessment into two parts: 1 Detection Error (DE -- rater agreement in detecting the same regions to mark, and 2 Outline Error (OE -- agreement of the raters in outlining of the same lesion. Methods DE, OE and Similarity Index (SI values were calculated for two raters tested on a set of 17 fluid-attenuated inversion-recovery (FLAIR images of patients with MS. DE, OE, and SI values were tested for dependence with mean total area (MTA of the raters' Region of Interests (ROIs. Results When correlated with MTA, neither DE (ρ = .056, p=.83 nor the ratio of OE to MTA (ρ = .23, p=.37, referred to as Outline Error Rate (OER, exhibited significant correlation. In contrast, SI is found to be strongly correlated with MTA (ρ = .75, p  Conclusions The DE and OER indices are proposed as a better method than SI for comparing rater agreement of ROIs, which also provide specific information for raters to improve their agreement.

  17. Error Detection, Factorization and Correction for Multi-View Scene Reconstruction from Aerial Imagery

    Energy Technology Data Exchange (ETDEWEB)

    Hess-Flores, Mauricio [Univ. of California, Davis, CA (United States)

    2011-11-10

    Scene reconstruction from video sequences has become a prominent computer vision research area in recent years, due to its large number of applications in fields such as security, robotics and virtual reality. Despite recent progress in this field, there are still a number of issues that manifest as incomplete, incorrect or computationally-expensive reconstructions. The engine behind achieving reconstruction is the matching of features between images, where common conditions such as occlusions, lighting changes and texture-less regions can all affect matching accuracy. Subsequent processes that rely on matching accuracy, such as camera parameter estimation, structure computation and non-linear parameter optimization, are also vulnerable to additional sources of error, such as degeneracies and mathematical instability. Detection and correction of errors, along with robustness in parameter solvers, are a must in order to achieve a very accurate final scene reconstruction. However, error detection is in general difficult due to the lack of ground-truth information about the given scene, such as the absolute position of scene points or GPS/IMU coordinates for the camera(s) viewing the scene. In this dissertation, methods are presented for the detection, factorization and correction of error sources present in all stages of a scene reconstruction pipeline from video, in the absence of ground-truth knowledge. Two main applications are discussed. The first set of algorithms derive total structural error measurements after an initial scene structure computation and factorize errors into those related to the underlying feature matching process and those related to camera parameter estimation. A brute-force local correction of inaccurate feature matches is presented, as well as an improved conditioning scheme for non-linear parameter optimization which applies weights on input parameters in proportion to estimated camera parameter errors. Another application is in

  18. An all-optical method of developing data communication system with error detection circuit

    Science.gov (United States)

    Mandal, Sumana; Mandal, Dhoumendra; Garai, Sisir Kumar

    2014-03-01

    The basic criterion of data communication is that received data should exactly be the replica of the transmitting data. If any error is introduced in the received data, then data transmission should be stopped immediately. In this article the authors have developed an all-optical method of data communication system with error detection mechanism that works with frequency encoded data. Basic building blocks of the proposed data communication scheme are parity generator and parity checker which are developed from all optical XOR logic gates. Simulation results testify the feasibility of the proposed scheme. These logic gates are developed exploiting nonlinear polarization rotation based frequency conversion and switching character of semiconductor optical amplifiers. The scheme with frequency encoded data, high speed of frequency conversion and polarization switching action of semiconductor optical amplifier offers secure, error free, faster data communication network.

  19. From error detection to behaviour observation: first results from screen capture analysis

    CERN Document Server

    Bruillard, Francoise Tort; Francois-Marie Blondel; Eric

    2009-01-01

    This paper deals with errors in using spreadsheets and analysis of automatic recording of user interaction with spreadsheets. After a review of literature devoted to spreadsheet errors, we advocate the importance of going from error detection to interaction behaviour analysis. We explain how we analyze screen captures and give the main results we have obtained using this specific methodology with secondary school students (N=24). Transcription provides general characteristics: time, sequence of performed tasks, unsuccessful attempts and user preferences. Analysis reveals preferred modes of actions (toolbar buttons or menu commands), ways of writing formulas, and typical approaches in searching for solutions. Time, rhythm and density appear to be promising indicators. We think such an approach (to analyze screen captures) could be used with more advanced spreadsheet users.

  20. Spatial Support Vector Regression to Detect Silent Errors in the Exascale Era

    Energy Technology Data Exchange (ETDEWEB)

    Subasi, Omer; Di, Sheng; Bautista-Gomez, Leonardo; Balaprakash, Prasanna; Unsal, Osman; Labarta, Jesus; Cristal, Adrian; Cappello, Franck

    2016-01-01

    As the exascale era approaches, the increasing capacity of high-performance computing (HPC) systems with targeted power and energy budget goals introduces significant challenges in reliability. Silent data corruptions (SDCs) or silent errors are one of the major sources that corrupt the executionresults of HPC applications without being detected. In this work, we explore a low-memory-overhead SDC detector, by leveraging epsilon-insensitive support vector machine regression, to detect SDCs that occur in HPC applications that can be characterized by an impact error bound. The key contributions are three fold. (1) Our design takes spatialfeatures (i.e., neighbouring data values for each data point in a snapshot) into training data, such that little memory overhead (less than 1%) is introduced. (2) We provide an in-depth study on the detection ability and performance with different parameters, and we optimize the detection range carefully. (3) Experiments with eight real-world HPC applications show thatour detector can achieve the detection sensitivity (i.e., recall) up to 99% yet suffer a less than 1% of false positive rate for most cases. Our detector incurs low performance overhead, 5% on average, for all benchmarks studied in the paper. Compared with other state-of-the-art techniques, our detector exhibits the best tradeoff considering the detection ability and overheads.

  1. SU-E-T-363: Error Detection Comparison of EPID and MLC Log File Based IMRT QA Systems

    Energy Technology Data Exchange (ETDEWEB)

    Defoor, D; Obeidat, M; Linden, P; Kirby, N; Papanikolaou, N; Stathakis, S [University of Texas Health Science Center at San Antonio, San Antonio, TX (United States); Mavroidis, P [University of North Carolina, Chapel Hill, NC (United States)

    2015-06-15

    Purpose: In this study we will compare the ability of three QA methods (Delta4, MU-EPID, Dynalog QA) to detect specific errors. Methods: A Varian Novalis Tx with a HD120 MLC and aS1000 Electronic Portal Imaging Device (EPID) was used in our study. Multi-leaf collimator (MLC) errors, gantry angle and dose errors were introduced into 5 volumetric arc therapy (VMAT) plans. 3D dose distributions calculated with data from the EPID and Dynalog QA methods were compared with the planned dose distribution. The gamma passing percentages as well as percentage error of planning target volume (PTV) dose were used for passing determination. Baselines for gamma passing percentages and PTV dose were established by measuring the original plan 5 times consecutively. Standard passing thresholds as well as thresholds derived from receiver operator characteristic (ROC) analysis and 2 standard deviation (SD) criteria were used. Results: When applying the standard 95% pass rate at 3%/3mm gamma analysis 14, 21 and 8 of 30 errors were detected by the Delta4, MU-EPID and Dynalog QA methods respectively. Thresholds set at 2 SD from our base line measurements resulted in the detection of 18, 9 and 14 of 30 errors for the Delta4, MU-EPID and Dynalog QA methods respectively. When using D2 of the PTV as a metric the Dynalog QA detected 20 of 30 errors while the EPID method detected 14 of 30 errors. Using D98 of the PTV, Dynalog QA detected 13 of 30 while the EPID detected 3 of 30 errors. Conclusion: Although MU-EPID detected the most errors at the standard 95% cutoff it also produced the most false detections in the baseline data. The Dynalog QA was the most effective when the ROC adjusted passing threshold was used. D2 was more effective as a metric for detecting errors than D98.

  2. Detection of gross errors using mixed integer optimization approach in process industry

    Institute of Scientific and Technical Information of China (English)

    MEI Cong-li; SU Hong-ye; CHU Jian

    2007-01-01

    A novel mixed integer linear programming (NMILP) model for detection of gross errors is presented in this paper.Yamamura et al.(1988) designed a model for detection of gross errors and data reconciliation based on Akaike information criterion (AIC). But much computational cost is needed due to its combinational nature. A mixed integer linear programming (MILP)approach was performed to reduce the computational cost and enhance the robustness. But it loses the super performance of maximum likelihood estimation. To reduce the computational cost and have the merit of maximum likelihood estimation, the simultaneous data reconciliation method in an MILP framework is decomposed and replaced by an NMILP subproblem and a quadratic programming (QP) or a least squares estimation (LSE) subproblem. Simulation result of an industrial case shows the high efficiency of the method.

  3. Detecting user needs for new online dictionary projects

    DEFF Research Database (Denmark)

    Tarp, Sven

    2014-01-01

    This contribution first refers to one of the problems affecting modern e-lexicography, viz. information overload, and proposes six general principles which could guide the design of future online dictionaries. It then discusses some of the techniques and methods which can be used in order to apply...

  4. Impact of Channel Estimation Errors on Multiuser Detection via the Replica Method

    Directory of Open Access Journals (Sweden)

    Li Husheng

    2005-01-01

    Full Text Available For practical wireless DS-CDMA systems, channel estimation is imperfect due to noise and interference. In this paper, the impact of channel estimation errors on multiuser detection (MUD is analyzed under the framework of the replica method. System performance is obtained in the large system limit for optimal MUD, linear MUD, and turbo MUD, and is validated by numerical results for finite systems.

  5. Decoding the dynamics of action, intention, and error detection for conscious and subliminal stimuli.

    Science.gov (United States)

    Charles, Lucie; King, Jean-Rémi; Dehaene, Stanislas

    2014-01-22

    How do we detect our own errors, even before we receive any external feedback? One model hypothesizes that error detection results from the confrontation of two signals: a fast and unconscious motor code, based on a direct sensory-motor pathway; and a slower conscious intention code that computes the required response given the stimulus and task instructions. To test this theory and assess how the chain of cognitive processes leading to error detection is modulated by consciousness, we applied multivariate decoding methods to single-trial magnetoencephalography and electroencephalography data. Human participants performed a fast bimanual number comparison task on masked digits presented at threshold, such that about half of them remained unseen. By using both erroneous and correct trials, we designed orthogonal decoders for the actual response (left or right), the required response (left or right), and the response accuracy (correct or incorrect). While perceptual stimulus information and the actual response hand could be decoded on both conscious and non-conscious trials, the required response could only be decoded on conscious trials. Moreover, whether the current response was correct or incorrect could be decoded only when the target digits were conscious, at a time and with a certainty that varied with the amount of evidence in favor of the correct response. These results are in accordance with the proposed dual-route model of conscious versus nonconscious evidence accumulation, and suggest that explicit error detection is possible only when the brain computes a conscious representation of the desired response, distinct from the ongoing motor program.

  6. A Corpus-Based System of Error Detection and Revision Suggestion for Spanish Learners in Taiwan: A Case Study

    Science.gov (United States)

    Lu, Hui-Chuan; Chu, Yu-Hsin; Chang, Cheng-Yu

    2013-01-01

    Compared with English learners, Spanish learners have fewer resources for automatic error detection and revision and following the current integrative Computer Assisted Language Learning (CALL), we combined corpus-based approach and CALL to create the System of Error Detection and Revision Suggestion (SEDRS) for learning Spanish. Through…

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

    Directory of Open Access Journals (Sweden)

    Bernard Marius 't Hart

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

  8. Robust Online State of Charge Estimation of Lithium-Ion Battery Pack Based on Error Sensitivity Analysis

    Directory of Open Access Journals (Sweden)

    Ting Zhao

    2015-01-01

    Full Text Available Accurate and reliable state of charge (SOC estimation is a key enabling technique for large format lithium-ion battery pack due to its vital role in battery safety and effective management. This paper tries to make three contributions to existing literatures through robust algorithms. (1 Observer based SOC estimation error model is established, where the crucial parameters on SOC estimation accuracy are determined by quantitative analysis, being a basis for parameters update. (2 The estimation method for a battery pack in which the inconsistency of cells is taken into consideration is proposed, ensuring all batteries’ SOC ranging from 0 to 1, effectively avoiding the battery overcharged/overdischarged. Online estimation of the parameters is also presented in this paper. (3 The SOC estimation accuracy of the battery pack is verified using the hardware-in-loop simulation platform. The experimental results at various dynamic test conditions, temperatures, and initial SOC difference between two cells demonstrate the efficacy of the proposed method.

  9. Minimum Symbol Error Rate Detection in Single-Input Multiple-Output Channels with Markov Noise

    DEFF Research Database (Denmark)

    Christensen, Lars P.B.

    2005-01-01

    Minimum symbol error rate detection in Single-Input Multiple- Output(SIMO) channels with Markov noise is presented. The special case of zero-mean Gauss-Markov noise is examined closer as it only requires knowledge of the second-order moments. In this special case, it is shown that optimal detection...... can be achieved by a Multiple-Input Multiple- Output(MIMO) whitening filter followed by a traditional BCJR algorithm. The Gauss-Markov noise model provides a reasonable approximation for co-channel interference, making it an interesting single-user detector for many multiuser communication systems...

  10. Online Least Squares One-Class Support Vector Machines-Based Abnormal Visual Event Detection

    Directory of Open Access Journals (Sweden)

    Tian Wang

    2013-12-01

    Full Text Available The abnormal event detection problem is an important subject in real-time video surveillance. In this paper, we propose a novel online one-class classification algorithm, online least squares one-class support vector machine (online LS-OC-SVM, combined with its sparsified version (sparse online LS-OC-SVM. LS-OC-SVM extracts a hyperplane as an optimal description of training objects in a regularized least squares sense. The online LS-OC-SVM learns a training set with a limited number of samples to provide a basic normal model, then updates the model through remaining data. In the sparse online scheme, the model complexity is controlled by the coherence criterion. The online LS-OC-SVM is adopted to handle the abnormal event detection problem. Each frame of the video is characterized by the covariance matrix descriptor encoding the moving information, then is classified into a normal or an abnormal frame. Experiments are conducted, on a two-dimensional synthetic distribution dataset and a benchmark video surveillance dataset, to demonstrate the promising results of the proposed online LS-OC-SVM method.

  11. Detection of microcalcifications in mammograms using error of prediction and statistical measures

    Science.gov (United States)

    Acha, Begoña; Serrano, Carmen; Rangayyan, Rangaraj M.; Leo Desautels, J. E.

    2009-01-01

    A two-stage method for detecting microcalcifications in mammograms is presented. In the first stage, the determination of the candidates for microcalcifications is performed. For this purpose, a 2-D linear prediction error filter is applied, and for those pixels where the prediction error is larger than a threshold, a statistical measure is calculated to determine whether they are candidates for microcalcifications or not. In the second stage, a feature vector is derived for each candidate, and after a classification step using a support vector machine, the final detection is performed. The algorithm is tested with 40 mammographic images, from Screen Test: The Alberta Program for the Early Detection of Breast Cancer with 50-μm resolution, and the results are evaluated using a free-response receiver operating characteristics curve. Two different analyses are performed: an individual microcalcification detection analysis and a cluster analysis. In the analysis of individual microcalcifications, detection sensitivity values of 0.75 and 0.81 are obtained at 2.6 and 6.2 false positives per image, on the average, respectively. The best performance is characterized by a sensitivity of 0.89, a specificity of 0.99, and a positive predictive value of 0.79. In cluster analysis, a sensitivity value of 0.97 is obtained at 1.77 false positives per image, and a value of 0.90 is achieved at 0.94 false positive per image.

  12. A novel approach for pilot error detection using Dynamic Bayesian Networks.

    Science.gov (United States)

    Saada, Mohamad; Meng, Qinggang; Huang, Tingwen

    2014-06-01

    In the last decade Dynamic Bayesian Networks (DBNs) have become one type of the most attractive probabilistic modelling framework extensions of Bayesian Networks (BNs) for working under uncertainties from a temporal perspective. Despite this popularity not many researchers have attempted to study the use of these networks in anomaly detection or the implications of data anomalies on the outcome of such models. An abnormal change in the modelled environment's data at a given time, will cause a trailing chain effect on data of all related environment variables in current and consecutive time slices. Albeit this effect fades with time, it still can have an ill effect on the outcome of such models. In this paper we propose an algorithm for pilot error detection, using DBNs as the modelling framework for learning and detecting anomalous data. We base our experiments on the actions of an aircraft pilot, and a flight simulator is created for running the experiments. The proposed anomaly detection algorithm has achieved good results in detecting pilot errors and effects on the whole system.

  13. An approach for online evaluations of dose consequences caused by small rotational setup errors in intracranial stereotactic radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lu Bo; Li, Jonathan; Kahler, Darren; Yan Guanghua; Mittauer, Kathryn; Shi Wenyin; Okunieff, Paul; Liu, Chihray [Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, Florida 32607 (United States)

    2011-11-15

    Purpose: The purpose of this work is to investigate the impact of small rotational errors on the magnitudes and distributions of spatial dose variations for intracranial stereotactic radiotherapy (SRT) treatment setups, and to assess the feasibility of using the original dose map overlaid with rotated contours (ODMORC) method as a fast, online evaluation tool to estimate dose changes (using DVHs) to clinical target volumes (CTVs) and organs-at-risks (OARs) caused by small rotational setup errors. Methods: Fifteen intracranial SRT cases treated with either three-dimensional conformal radiation therapy (3DCRT) or intensity-modulated radiation therapy (IMRT) techniques were chosen for the study. Selected cases have a variety of anatomical dimensions and pathologies. Angles of {+-}3 deg. and {+-}5 deg. in all directions were selected to simulate the rotational errors. Dose variations in different regions of the brain, CTVs, and OARs were evaluated to illustrate the various spatial effects of dose differences before and after rotations. DVHs accounting for rotations that were recomputed by the treatment planning system (TPS) and those generated by the ODMORC method were compared. A framework of a fast algorithm for multicontour rotation implemented by ODMORC is introduced as well. Results: The average values of relative dose variations between original dose and recomputed dose accounting for rotations were greater than 4.0% and 10.0% in absolute mean and in standard deviation, respectively, at the skull and adjacent regions for all cases. They were less than 1.0% and 2.5% in absolute mean and in standard deviation, respectively, for dose points 3 mm away from the skull. The results indicated that spatial dose to any part of the brain organs or tumors separated from the skull or head surface would be relatively stable before and after rotations. Statistical data of CTVs and OARs indicate the lens and cochleas have the large dose variations before and after rotations

  14. Effective Connectivity Associated With Auditory Error Detection In Musicians With Absolute Pitch

    Directory of Open Access Journals (Sweden)

    Amy L Parkinson

    2014-03-01

    Full Text Available It is advantageous to study a wide range of vocal abilities in order to fully understand how vocal control measures vary across the full spectrum. Individuals with absolute pitch (AP are able to assign a verbal label to musical notes and have enhanced abilities in pitch identification without reliance on an external referent. In this study we used dynamic causal modeling (DCM to model effective connectivity of ERP responses to pitch perturbation in voice auditory feedback in musicians with relative pitch (RP, absolute pitch and non-musician controls. We identified a network compromising left and right hemisphere superior temporal gyrus (STG, primary motor cortex (M1 and premotor cortex (PM. We specified nine models and compared two main factors examining various combinations of STG involvement in feedback pitch error detection/correction process. Our results suggest that modulation of left to right STG connections are important in the identification of self-voice error and sensory motor integration in AP musicians. We also identify reduced connectivity of left hemisphere PM to STG connections in AP and RP groups during the error detection and corrections process relative to non-musicians. We suggest that this suppression may allow for enhanced connectivity relating to pitch identification in the right hemisphere in those with more precise pitch matching abilities. Musicians with enhanced pitch identification abilities likely have an improved auditory error detection and correction system involving connectivity of STG regions. Our findings here also suggest that individuals with AP are more adept at using feedback related to pitch from the right hemisphere.

  15. Applications of Graph Theory to Gross Error Detection for GPS Geodetic Control Networks

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper describes a broad perspective of the application of graph theory to establishment of GPS control networks whereby the GPS network is considered as a connected and directed graph with three components.In this algorithm the gross error detection is undertaken through loops of different spanning trees using the "Loop Law" in which the individual components ΔX,ΔY and ΔZ sum up to zero.If the sum of the respective vector components ∑X,∑Y and ∑Z in a loop is not zero and if the error is beyond the tolerable limit (ε>w),it indicates the existence of gross errors in one of the baselines in the loop and therefore the baseline must be removed or re-observed.After successful screening of errors by graph theory,network adjustment can be carried out.In this paper,the GPS data from the control network established as reference system for the HP Dam at Baishan county in Liaoning province is presented to illustrate the algorithm.

  16. Detecting Role Errors in the Gene Hierarchy of the NCI Thesaurus

    Directory of Open Access Journals (Sweden)

    Yehoshua Perl

    2008-01-01

    Full Text Available Gene terminologies are playing an increasingly important role in the ever-growing field of genomic research. While errors in large, complex terminologies are inevitable, gene terminologies are even more susceptible to them due to the rapid growth of genomic knowledge and the nature of its discovery. It is therefore very important to establish quality- assurance protocols for such genomic-knowledge repositories. Different kinds of terminologies oftentimes require auditing methodologies adapted to their particular structures. In light of this, an auditing methodology tailored to the characteristics of the NCI Thesaurus’s (NCIT’s Gene hierarchy is presented. The Gene hierarchy is of particular interest to the NCIT’s designers due to the primary role of genomics in current cancer research. This multiphase methodology focuses on detecting role-errors, such as missing roles or roles with incorrect or incomplete target structures, occurring within that hierarchy. The methodology is based on two kinds of abstraction networks, called taxonomies, that highlight the role distribution among concepts within the IS-A (subsumption hierarchy. These abstract views tend to highlight portions of the hierarchy having a higher concentration of errors. The errors found during an application of the methodology

  17. Detecting Role Errors in the Gene Hierarchy of the NCI Thesaurus

    Science.gov (United States)

    Min, Hua; Cohen, Barry; Halper, Michael; Oren, Marc; Perl, Yehoshua

    2008-01-01

    Gene terminologies are playing an increasingly important role in the ever-growing field of genomic research. While errors in large, complex terminologies are inevitable, gene terminologies are even more susceptible to them due to the rapid growth of genomic knowledge and the nature of its discovery. It is therefore very important to establish quality-assurance protocols for such genomic-knowledge repositories. Different kinds of terminologies oftentimes require auditing methodologies adapted to their particular structures. In light of this, an auditing methodology tailored to the characteristics of the NCI Thesaurus’s (NCIT’s) Gene hierarchy is presented. The Gene hierarchy is of particular interest to the NCIT’s designers due to the primary role of genomics in current cancer research. This multiphase methodology focuses on detecting role-errors, such as missing roles or roles with incorrect or incomplete target structures, occurring within that hierarchy. The methodology is based on two kinds of abstraction networks, called taxonomies, that highlight the role distribution among concepts within the IS-A (subsumption) hierarchy. These abstract views tend to highlight portions of the hierarchy having a higher concentration of errors. The errors found during an application of the methodology are reported. Hypotheses pertaining to the efficacy of our methodology are investigated. PMID:19221606

  18. Note: On-line weak signal detection via adaptive stochastic resonance.

    Science.gov (United States)

    Lu, Siliang; He, Qingbo; Kong, Fanrang

    2014-06-01

    We design an instrument with a novel embedded adaptive stochastic resonance (SR) algorithm that consists of a SR module and a digital zero crossing detection module for on-line weak signal detection in digital signal processing applications. The two modules are responsible for noise filtering and adaptive parameter configuration, respectively. The on-line weak signal detection can be stably achieved in seconds. The prototype instrument exhibits an advance of 20 dB averaged signal-to-noise ratio and 5 times averaged adjust R-square as compared to the input noisy signal, in considering different driving frequencies and noise levels.

  19. Development of on-line FTIR spectroscopy for siloxane detection in biogas to enhance carbon contactor management.

    Science.gov (United States)

    Hepburn, C A; Vale, P; Brown, A S; Simms, N J; McAdam, E J

    2015-08-15

    Activated carbon filters are used to limit engine damage by siloxanes when biogas is utilised to provide electricity. However, carbon filter siloxane removal performance is poorly understood as until recently, it had not been possible to measure siloxanes on-line. In this study, on-line Fourier Transform Infrared (FTIR) spectroscopy was developed to measure siloxane concentration in real biogas both upstream (86.1-157.5mg m(-3)) and downstream (2.2-4.3mg m(-3)) of activated carbon filters. The FTIR provided reasonable precision upstream of the carbon vessel with a root mean square error of 10% using partial least squares analysis. However, positive interference from volatile organic carbons was observed in downstream gas measurements limiting precision at the outlet to an RMSE of 1.5mg m(-3) (47.8%). Importantly, a limit of detection of 3.2mg m(-3) was identified which is below the recommended siloxane limit and evidences the applicability of on-line FTIR for this application.

  20. On the use of on-line detection for maintenance of gradually deteriorating systems

    Energy Technology Data Exchange (ETDEWEB)

    Fouladirad, Mitra [Institut Charles Delaunay, Universite de Technologie de Troyes, FRE CNRS 2848, LM2S 12 rue Marie Curie, 10010 Troyes (France); Grall, Antoine [Institut Charles Delaunay, Universite de Technologie de Troyes, FRE CNRS 2848, LM2S 12 rue Marie Curie, 10010 Troyes (France)], E-mail: antoine.grall@utt.fr; Dieulle, Laurence [Institut Charles Delaunay, Universite de Technologie de Troyes, FRE CNRS 2848, LM2S 12 rue Marie Curie, 10010 Troyes (France)

    2008-12-15

    This paper deals with condition-based maintenance and non-stationary degradation process due to sudden changes. This is an attempt to propose an adaptive maintenance policy based on the on-line change detection procedure which can help to detect switches from a nominal mode to an accelerated mode in a non-informative context about the change mode time.

  1. On-line matrix addition for detecting aerosol particles

    Institute of Scientific and Technical Information of China (English)

    ZHOU; Liuzhu; ZHU; Yuan; GUO; Xiaoyong; ZHAO; Wenwu; ZHENG; Haiyang; Gu; Xuejun; FANG; Li; ZHANG; Weijun

    2006-01-01

    Single aerosol particles were measured by matrix-assisted laser desorption/ionization (MALDI) with an aerosol time-of-flight mass spectrometer (ATOFMS). The inlet to the ATOFMS was coupled with an evaporation/condensation flow cell that allowed matrix addition by condensation onto the particles. The coated particles entered the ion source through three-stage differentially pumped capillary inlet and were then ionized by a focused 266 nm Nd:YAG laser. The mass spectra and aerodynamic size of the single particles can be obtained simultaneously. The on-line matrix addition technique makes it possible to identify biological aerosols in real-time.

  2. Plagiarism by Adult Learners Online: A case study in detection and remediation

    OpenAIRE

    Christine Jocoy

    2006-01-01

    Detecting and combating plagiarism from Web-based sources is a concern for administrators and instructors involved in online distance education. In this paper, we quantify copy-and-paste plagiarism among adult learners in an online geography course offered through Penn State’s World Campus Geographic Information Systems (GIS) certificate program. We also evaluate the effectiveness of an “expectation management” strategy intended to discourage adult learners from unintentional violations. We f...

  3. Identity Verification Mechanism for Detecting Fake Profiles in Online Social Networks

    OpenAIRE

    Ali M. Meligy; Hani M. Ibrahim; Mohamed F. Torky

    2017-01-01

    Impersonating users' identity in Online Social Networks (OSNs) is one of the open dilemmas from security and privacy point of view. Scammers and adversaries seek to create set of fake profiles to carry out malicious behaviors and online social crimes in social media. Recognizing the identity of Fake Profiles is an urgent issue of concern to the attention of researchers. In this paper, we propose a detection technique called Fake Profile Recognizer (FPR) for verifying the identity of profiles,...

  4. EEG error potentials detection and classification using time-frequency features for robot reinforcement learning.

    Science.gov (United States)

    Boubchir, Larbi; Touati, Youcef; Daachi, Boubaker; Chérif, Arab Ali

    2015-08-01

    In thought-based steering of robots, error potentials (ErrP) can appear when the action resulting from the brain-machine interface (BMI) classifier/controller does not correspond to the user's thought. Using the Steady State Visual Evoked Potentials (SSVEP) techniques, ErrP, which appear when a classification error occurs, are not easily recognizable by only examining the temporal or frequency characteristics of EEG signals. A supplementary classification process is therefore needed to identify them in order to stop the course of the action and back up to a recovery state. This paper presents a set of time-frequency (t-f) features for the detection and classification of EEG ErrP in extra-brain activities due to misclassification observed by a user exploiting non-invasive BMI and robot control in the task space. The proposed features are able to characterize and detect ErrP activities in the t-f domain. These features are derived from the information embedded in the t-f representation of EEG signals, and include the Instantaneous Frequency (IF), t-f information complexity, SVD information, energy concentration and sub-bands' energies. The experiment results on real EEG data show that the use of the proposed t-f features for detecting and classifying EEG ErrP achieved an overall classification accuracy up to 97% for 50 EEG segments using 2-class SVM classifier.

  5. SU-E-T-51: Bayesian Network Models for Radiotherapy Error Detection

    Energy Technology Data Exchange (ETDEWEB)

    Kalet, A; Phillips, M; Gennari, J [UniversityWashington, Seattle, WA (United States)

    2014-06-01

    Purpose: To develop a probabilistic model of radiotherapy plans using Bayesian networks that will detect potential errors in radiation delivery. Methods: Semi-structured interviews with medical physicists and other domain experts were employed to generate a set of layered nodes and arcs forming a Bayesian Network (BN) which encapsulates relevant radiotherapy concepts and their associated interdependencies. Concepts in the final network were limited to those whose parameters are represented in the institutional database at a level significant enough to develop mathematical distributions. The concept-relation knowledge base was constructed using the Web Ontology Language (OWL) and translated into Hugin Expert Bayes Network files via the the RHugin package in the R statistical programming language. A subset of de-identified data derived from a Mosaiq relational database representing 1937 unique prescription cases was processed and pre-screened for errors and then used by the Hugin implementation of the Estimation-Maximization (EM) algorithm for machine learning all parameter distributions. Individual networks were generated for each of several commonly treated anatomic regions identified by ICD-9 neoplasm categories including lung, brain, lymphoma, and female breast. Results: The resulting Bayesian networks represent a large part of the probabilistic knowledge inherent in treatment planning. By populating the networks entirely with data captured from a clinical oncology information management system over the course of several years of normal practice, we were able to create accurate probability tables with no additional time spent by experts or clinicians. These probabilistic descriptions of the treatment planning allow one to check if a treatment plan is within the normal scope of practice, given some initial set of clinical evidence and thereby detect for potential outliers to be flagged for further investigation. Conclusion: The networks developed here support the

  6. Study of geometric errors detection method for NC machine tools based on non-contact circular track

    Science.gov (United States)

    Yan, Kejun; Liu, Jun; Gao, Feng; Wang, Huan

    2008-12-01

    This paper presents a non-contact measuring method of geometric errors for NC machine tools based on circular track testing method. Let the machine spindle move along a circular path, the position error of every tested position in the circle can be obtained using two laser interferometers. With a volumetric error model, the 12 components of geometric error apart from angular error components can be derived. It has characteristics of wide detection range and high precision. Being obtained geometric errors respectively, it is of great significance for the error compensation of NC machine tools. This method has been tested on a MCV-510 NC machine tool. The experiment result has been proved to be feasible for this method.

  7. A study of redundancy management strategy for tetrad strap-down inertial systems. [error detection codes

    Science.gov (United States)

    Hruby, R. J.; Bjorkman, W. S.; Schmidt, S. F.; Carestia, R. A.

    1979-01-01

    Algorithms were developed that attempt to identify which sensor in a tetrad configuration has experienced a step failure. An algorithm is also described that provides a measure of the confidence with which the correct identification was made. Experimental results are presented from real-time tests conducted on a three-axis motion facility utilizing an ortho-skew tetrad strapdown inertial sensor package. The effects of prediction errors and of quantization on correct failure identification are discussed as well as an algorithm for detecting second failures through prediction.

  8. Adaptive error detection for HDR/PDR brachytherapy: Guidance for decision making during real-time in vivo point dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Kertzscher, Gustavo, E-mail: guke@dtu.dk; Andersen, Claus E., E-mail: clan@dtu.dk [Centre for Nuclear Technologies, Technical University of Denmark, DTU Nutech, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Tanderup, Kari, E-mail: karitand@rm.dk [Department of Oncology, Aarhus University Hospital and Institute of Clinical Medicine, Aarhus University, Norrebrogade 44, DK-8000 Aarhus (Denmark)

    2014-05-15

    Purpose: This study presents an adaptive error detection algorithm (AEDA) for real-timein vivo point dosimetry during high dose rate (HDR) or pulsed dose rate (PDR) brachytherapy (BT) where the error identification, in contrast to existing approaches, does not depend on an a priori reconstruction of the dosimeter position. Instead, the treatment is judged based on dose rate comparisons between measurements and calculations of the most viable dosimeter position provided by the AEDA in a data driven approach. As a result, the AEDA compensates for false error cases related to systematic effects of the dosimeter position reconstruction. Given its nearly exclusive dependence on stable dosimeter positioning, the AEDA allows for a substantially simplified and time efficient real-time in vivo BT dosimetry implementation. Methods: In the event of a measured potential treatment error, the AEDA proposes the most viable dosimeter position out of alternatives to the original reconstruction by means of a data driven matching procedure between dose rate distributions. If measured dose rates do not differ significantly from the most viable alternative, the initial error indication may be attributed to a mispositioned or misreconstructed dosimeter (false error). However, if the error declaration persists, no viable dosimeter position can be found to explain the error, hence the discrepancy is more likely to originate from a misplaced or misreconstructed source applicator or from erroneously connected source guide tubes (true error). Results: The AEDA applied on twoin vivo dosimetry implementations for pulsed dose rate BT demonstrated that the AEDA correctly described effects responsible for initial error indications. The AEDA was able to correctly identify the major part of all permutations of simulated guide tube swap errors and simulated shifts of individual needles from the original reconstruction. Unidentified errors corresponded to scenarios where the dosimeter position was

  9. Online Anomaly Energy Consumption Detection Using Lambda Architecture

    DEFF Research Database (Denmark)

    Liu, Xiufeng; Iftikhar, Nadeem; Nielsen, Per Sieverts;

    2016-01-01

    With the widely use of smart meters in the energy sector, anomaly detection becomes a crucial mean to study the unusual consumption behaviors of customers, and to discover unexpected events of using energy promptly. Detecting consumption anomalies is, essentially, a real-time big data analytics p...

  10. Detecting user needs for new online dictionary projects

    DEFF Research Database (Denmark)

    Tarp, Sven

    2014-01-01

    This contribution first refers to one of the problems affecting modern e-lexicography, viz. information overload, and proposes six general principles which could guide the design of future online dictionaries. It then discusses some of the techniques and methods which can be used in order to apply......, it then discusses various methods to determine these needs which are considered the point of departure of any new dictionary project. Finally it argues that although the required specific knowledge may be achieved by means of some of the old and new methods used in lexicographical user research, these methods...... are nonetheless too time-consuming and costly to be applied to each and every new dictionary project. It therefore recommends the deductive method, which is embedded in the function theory, as an efficient, cheap and easy method in this regards....

  11. Detecting and Diagnosing Grammatical Errors for Beginning Learners of German: From Learner Corpus Annotation to Constraint Satisfaction Problems

    Science.gov (United States)

    Boyd, Adriane

    2012-01-01

    This thesis presents a corpus of beginning learner German with a reliable error annotation scheme and an approach for detecting and diagnosing grammatical errors in learner language. A constraint-based dependency parser provides the foundation for a flexible and modular analysis of German by representing parsing as a constraint satisfaction…

  12. Adaptive error detection for HDR/PDR brachytherapy: Guidance for decision making during real-time in vivo point dosimetry

    DEFF Research Database (Denmark)

    Kertzscher Schwencke, Gustavo Adolfo Vladimir; Andersen, Claus E.; Tanderup, Kari

    2014-01-01

    Purpose:This study presents an adaptive error detection algorithm (AEDA) for real-timein vivo point dosimetry during high dose rate (HDR) or pulsed dose rate (PDR) brachytherapy (BT) where the error identification, in contrast to existing approaches, does not depend on an a priori reconstruction...

  13. A New Model for Intrusion Detection based on Reduced Error Pruning Technique

    Directory of Open Access Journals (Sweden)

    Mradul Dhakar

    2013-09-01

    Full Text Available The increasing counterfeit of the internet usage has raised concerns of the security agencies to work very hard in order to diminish the presence of the abnormal users from the web. The motive of these illicit users (called intruders is to harm the system or the network either by gaining access to the system or prohibiting genuine users to access the resources. Hence in order to tackle the abnormalities Intrusion Detection System (IDS with Data Mining has evolved as the most demanding approach. On the one end IDS aims to detect the intrusions by monitoring a given environment while on the other end Data Mining allows mining of these intrusions hidden among genuine users. In this regard, IDS with Data Mining has been through several revisions in consideration to meet the current requirements with efficient detection of intrusions. Also several models have been proposed for enhancing the system performance. In context to improved performance, the paper presents a new model for intrusion detection. This improved model, named as REP (Reduced Error Pruning based Intrusion Detection Model results in higher accuracy along with the increased number of correctly classified instances.

  14. Tiresias: Online Anomaly Detection for Hierarchical Operational Network Data

    CERN Document Server

    Hong, Chi-Yao; Duffield, Nick; Wang, Jia

    2012-01-01

    Operational network data, management data such as customer care call logs and equipment system logs, is a very important source of information for network operators to detect problems in their networks. Unfortunately, there is lack of efficient tools to automatically track and detect anomalous events on operational data, causing ISP operators to rely on manual inspection of this data. While anomaly detection has been widely studied in the context of network data, operational data presents several new challenges, including the volatility and sparseness of data, and the need to perform fast detection (complicating application of schemes that require offline processing or large/stable data sets to converge). To address these challenges, we propose Tiresias, an automated approach to locating anomalous events on hierarchical operational data. Tiresias leverages the hierarchical structure of operational data to identify high-impact aggregates (e.g., locations in the network, failure modes) likely to be associated w...

  15. Online Real-Time Tribology Failure Detection System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Under NASA Phase I funding, we have developed a system for the ball bearing fault detection and identification. Our system can effectively identify multiple fault...

  16. Carrier Phase Error Detection Method and Synchronization Control of Parallel-Connected PWM Inverters without Signal Line

    Science.gov (United States)

    Kohara, Tatsuya; Noguchi, Toshihiko; Kondo, Seiji

    In recent years, parallel-operation of inverters is employed to increase reliability and capacity in an uninterruptible power supply (UPS) system. A phase error in PWM carrier-signals of each inverter causes high frequency loop current between inverters. Therefore, the PWM carrier-signal of each inverter should be adjusted in phase. This paper proposes a detection method of phase error in PWM carrier-signal and its application to synchronization control for parallel-connected inverters. A simple definite-integral circuit achieves the detection of carrier phase error from high frequency loop current using no signal line between inverters. The detected carrier phase error is applied to synchronize the PWM carrier-signal through a PI-compensator, and then the high frequency loop current can be suppressed. Several experimental test-results show the validity of the proposed detection method and synchronization control.

  17. Timing-Error Detection Design Considerations in Subthreshold: An 8-bit Microprocessor in 65 nm CMOS

    Directory of Open Access Journals (Sweden)

    Lauri Koskinen

    2012-06-01

    Full Text Available This paper presents the first known timing-error detection (TED microprocessor able to operate in subthreshold. Since the minimum energy point (MEP of static CMOS logic is in subthreshold, there is a strong motivation to design ultra-low-power systems that can operate in this region. However, exponential dependencies in subthreshold, require systems with either excessively large safety margins or that utilize adaptive techniques. Typically, these techniques include replica paths, sensors, or TED. Each of these methods adds system complexity, area, and energy overhead. As a run-time technique, TED is the only method that accounts for both local and global variations. The microprocessor presented in this paper utilizes adaptable error-detection sequential (EDS circuits that can adjust to process and environmental variations. The results demonstrate the feasibility of the microprocessor, as well as energy savings up to 28%, when using the TED method in subthreshold. The microprocessor is an 8-bit core, which is compatible with a commercial microcontroller. The microprocessor is fabricated in 65 nm CMOS, uses as low as 4.35 pJ/instruction, occupies an area of 50,000 μm2, and operates down to 300 mV.

  18. Error analysis in a stereo vision-based pedestrian detection sensor for collision avoidance applications.

    Science.gov (United States)

    Llorca, David F; Sotelo, Miguel A; Parra, Ignacio; Ocaña, Manuel; Bergasa, Luis M

    2010-01-01

    This paper presents an analytical study of the depth estimation error of a stereo vision-based pedestrian detection sensor for automotive applications such as pedestrian collision avoidance and/or mitigation. The sensor comprises two synchronized and calibrated low-cost cameras. Pedestrians are detected by combining a 3D clustering method with Support Vector Machine-based (SVM) classification. The influence of the sensor parameters in the stereo quantization errors is analyzed in detail providing a point of reference for choosing the sensor setup according to the application requirements. The sensor is then validated in real experiments. Collision avoidance maneuvers by steering are carried out by manual driving. A real time kinematic differential global positioning system (RTK-DGPS) is used to provide ground truth data corresponding to both the pedestrian and the host vehicle locations. The performed field test provided encouraging results and proved the validity of the proposed sensor for being used in the automotive sector towards applications such as autonomous pedestrian collision avoidance.

  19. Error Analysis in a Stereo Vision-Based Pedestrian Detection Sensor for Collision Avoidance Applications

    Directory of Open Access Journals (Sweden)

    David F. Llorca

    2010-04-01

    Full Text Available This paper presents an analytical study of the depth estimation error of a stereo vision-based pedestrian detection sensor for automotive applications such as pedestrian collision avoidance and/or mitigation. The sensor comprises two synchronized and calibrated low-cost cameras. Pedestrians are detected by combining a 3D clustering method with Support Vector Machine-based (SVM classification. The influence of the sensor parameters in the stereo quantization errors is analyzed in detail providing a point of reference for choosing the sensor setup according to the application requirements. The sensor is then validated in real experiments. Collision avoidance maneuvers by steering are carried out by manual driving. A real time kinematic differential global positioning system (RTK-DGPS is used to provide ground truth data corresponding to both the pedestrian and the host vehicle locations. The performed field test provided encouraging results and proved the validity of the proposed sensor for being used in the automotive sector towards applications such as autonomous pedestrian collision avoidance.

  20. Identity Verification Mechanism for Detecting Fake Profiles in Online Social Networks

    Directory of Open Access Journals (Sweden)

    Ali M. Meligy

    2017-01-01

    Full Text Available Impersonating users' identity in Online Social Networks (OSNs is one of the open dilemmas from security and privacy point of view. Scammers and adversaries seek to create set of fake profiles to carry out malicious behaviors and online social crimes in social media. Recognizing the identity of Fake Profiles is an urgent issue of concern to the attention of researchers. In this paper, we propose a detection technique called Fake Profile Recognizer (FPR for verifying the identity of profiles, and detecting the fake profiles in OSNs. The detection method in our proposed technique is based on utilizing Regular Expression (RE and Deterministic Finite Automaton (DFA approaches. We evaluated our proposed detection technique on three datasets types of OSNs: Facebook, Google+, and Twitter. The results explored high Precision, Recall, accuracy, and low False Positive Rates (FPR of detecting Fake Profiles in the three datasets.

  1. Towards an Enhanced Aspect-based Contradiction Detection Approach for Online Review Content

    Science.gov (United States)

    Nuradilah Azman, Siti; Ishak, Iskandar; Sharef, Nurfadhlina Mohd; Sidi, Fatimah

    2017-09-01

    User generated content as such online reviews plays an important role in customer’s purchase decisions. Many works have focused on identifying satisfaction of the reviewer in social media through the study of sentiment analysis (SA) and opinion mining. The large amount of potential application and the increasing number of opinions expresses on the web results in researchers interest on sentiment analysis and opinion mining. However, due to the reviewer’s idiosyncrasy, reviewer may have different preferences and point of view for a particular subject which in this case hotel reviews. There is still limited research that focuses on this contradiction detection in the perspective of tourism online review especially in numerical contradiction. Therefore, the aim of this paper to investigate the type of contradiction in online review which mainly focusing on hotel online review, to provide useful material on process or methods for identifying contradiction which mainly on the review itself and to determine opportunities for relevant future research for online review contradiction detection. We also proposed a model to detect numerical contradiction in user generated content for tourism industry.

  2. Estimation of the limit of detection with a bootstrap-derived standard error by a partly non-parametric approach. Application to HPLC drug assays

    DEFF Research Database (Denmark)

    Linnet, Kristian

    2005-01-01

    Bootstrap, HPLC, limit of blank, limit of detection, non-parametric statistics, type I and II errors......Bootstrap, HPLC, limit of blank, limit of detection, non-parametric statistics, type I and II errors...

  3. An Efficient Silent Data Corruption Detection Method with Error-Feedback Control and Even Sampling for HPC Applications

    Energy Technology Data Exchange (ETDEWEB)

    Di, Sheng; Berrocal, Eduardo; Cappello, Franck

    2015-01-01

    The silent data corruption (SDC) problem is attracting more and more attentions because it is expected to have a great impact on exascale HPC applications. SDC faults are hazardous in that they pass unnoticed by hardware and can lead to wrong computation results. In this work, we formulate SDC detection as a runtime one-step-ahead prediction method, leveraging multiple linear prediction methods in order to improve the detection results. The contributions are twofold: (1) we propose an error feedback control model that can reduce the prediction errors for different linear prediction methods, and (2) we propose a spatial-data-based even-sampling method to minimize the detection overheads (including memory and computation cost). We implement our algorithms in the fault tolerance interface, a fault tolerance library with multiple checkpoint levels, such that users can conveniently protect their HPC applications against both SDC errors and fail-stop errors. We evaluate our approach by using large-scale traces from well-known, large-scale HPC applications, as well as by running those HPC applications on a real cluster environment. Experiments show that our error feedback control model can improve detection sensitivity by 34-189% for bit-flip memory errors injected with the bit positions in the range [20,30], without any degradation on detection accuracy. Furthermore, memory size can be reduced by 33% with our spatial-data even-sampling method, with only a slight and graceful degradation in the detection sensitivity.

  4. Automatic detection of MLC relative position errors for VMAT using the EPID-based picket fence test

    Science.gov (United States)

    Christophides, Damianos; Davies, Alex; Fleckney, Mark

    2016-12-01

    Multi-leaf collimators (MLCs) ensure the accurate delivery of treatments requiring complex beam fluences like intensity modulated radiotherapy and volumetric modulated arc therapy. The purpose of this work is to automate the detection of MLC relative position errors  ⩾0.5 mm using electronic portal imaging device-based picket fence tests and compare the results to the qualitative assessment currently in use. Picket fence tests with and without intentional MLC errors were measured weekly on three Varian linacs. The picket fence images analysed covered a time period ranging between 14-20 months depending on the linac. An algorithm was developed that calculated the MLC error for each leaf-pair present in the picket fence images. The baseline error distributions of each linac were characterised for an initial period of 6 months and compared with the intentional MLC errors using statistical metrics. The distributions of median and one-sample Kolmogorov-Smirnov test p-value exhibited no overlap between baseline and intentional errors and were used retrospectively to automatically detect MLC errors in routine clinical practice. Agreement was found between the MLC errors detected by the automatic method and the fault reports during clinical use, as well as interventions for MLC repair and calibration. In conclusion the method presented provides for full automation of MLC quality assurance, based on individual linac performance characteristics. The use of the automatic method has been shown to provide early warning for MLC errors that resulted in clinical downtime.

  5. FLEAD: online frequency likelihood estimation anomaly detection for mobile sensing

    NARCIS (Netherlands)

    Le, Viet-Duc; Scholten, Hans; Havinga, Paul

    2013-01-01

    With the rise of smartphone platforms, adaptive sensing becomes an predominant key to overcome intricate constraints such as smartphone's capabilities and dynamic data. One way to do this is estimating the event probability based on anomaly detection to invoke heavy processes, such as switching on m

  6. Online Anomaly Energy Consumption Detection Using Lambda Architecture

    DEFF Research Database (Denmark)

    Liu, Xiufeng; Iftikhar, Nadeem; Nielsen, Per Sieverts

    2016-01-01

    problem, which does data mining on a large amount of parallel data streams from smart meters. In this paper, we propose a supervised learning and statistical-based anomaly detection method, and implement a Lambda system using the in-memory distributed computing framework, Spark and its extension Spark...

  7. On-Line Hyperspectral Transmittance Imaging for Internal Defect Detection of Pickling Cucumbers

    Science.gov (United States)

    Hyperspectral imaging technique under transmittance mode was investigated for detection of internal defect in pickling cucumbers such as carpel suture separation or hollow cucumbers caused by mechanical stress. A prototype of on-line hyperspectral transmittance imaging system was developed for real...

  8. PageFocus: Using paradata to detect and prevent cheating on online achievement tests.

    Science.gov (United States)

    Diedenhofen, Birk; Musch, Jochen

    2016-08-29

    Cheating threatens the validity of unproctored online achievement tests. To address this problem, we developed PageFocus, a JavaScript that detects when participants abandon test pages by switching to another window or browser tab. In a first study, we aimed at testing whether PageFocus could detect and prevent cheating. We asked 115 lab and 186 online participants to complete a knowledge test comprising items that were difficult to answer but easy to look up on the Internet. Half of the participants were invited to look up the solutions, which significantly increased their test scores. The PageFocus script detected test takers who abandoned the test page with very high sensitivity and specificity, and successfully reduced cheating by generating a popup message that asked participants not to cheat. In a second study, 510 online participants completed a knowledge test comprising items that could easily be looked up and a reasoning task involving matrices that were impossible to look up. In a first group, a performance-related monetary reward was promised to the top scorers; in a second group, participants took part in a lottery that provided performance-unrelated rewards; and in a third group, no incentive was offered. PageFocus revealed that participants cheated more when performance-related incentives were offered. As expected, however, this effect was limited to items that could easily be looked up. We recommend that PageFocus be routinely employed to detect and prevent cheating on online achievement tests.

  9. Mastitis therapy and control - Automatic on-line detection of abnormal milk.

    NARCIS (Netherlands)

    Hogeveen, H.

    2011-01-01

    Automated online detection of mastitis and abnormal milk is an important subject in the dairy industry, especially because of the introduction of automatic milking systems and the growing farm sizes with consequently less labor available per cow. Demands for performance, which is expressed as sensit

  10. Determination of Peroxide-Based Explosives Using Liquid Chromatography with On-Line Infrared Detection

    NARCIS (Netherlands)

    Schulte-Ladbeck, Rasmus; Edelmann, Andrea; Quintas, Guillermo; Lendl, Bernhard; Karst, U.

    2006-01-01

    A nondestructive analytical method for peroxide-based explosives determination in solid samples is described. Reversed-phase high-performance liquid chromatography in combination with on-line Fourier transform infrared (FT-IR) detection is used for the analysis of triacetonetriperoxide (TATP) and

  11. Determination of Peroxide-Based Explosives Using Liquid Chromatography with On-Line Infrared Detection

    NARCIS (Netherlands)

    Schulte-Ladbeck, Rasmus; Edelmann, Andrea; Quintas, Guillermo; Lendl, Bernhard; Karst, Uwe

    2006-01-01

    A nondestructive analytical method for peroxide-based explosives determination in solid samples is described. Reversed-phase high-performance liquid chromatography in combination with on-line Fourier transform infrared (FT-IR) detection is used for the analysis of triacetonetriperoxide (TATP) and he

  12. Plagiarism by Adult Learners Online: A case study in detection and remediation

    Directory of Open Access Journals (Sweden)

    Christine Jocoy

    2006-06-01

    Full Text Available Detecting and combating plagiarism from Web-based sources is a concern for administrators and instructors involved in online distance education. In this paper, we quantify copy-and-paste plagiarism among adult learners in an online geography course offered through Penn State’s World Campus Geographic Information Systems (GIS certificate program. We also evaluate the effectiveness of an “expectation management” strategy intended to discourage adult learners from unintentional violations. We found that while manual methods detected plagiarism in only about 3 percent of assignments, Turnitin.com revealed a 13 percent plagiarism rate among the same assignments. Our attempts to increase awareness and manage expectations decreased infractions measurably, but not significantly. In contrast, Turnitin.com substantially improved our ability to detect infractions. We conclude that raising awareness and managing expectations about plagiarism may be worthwhile, but is no substitute for systematic detection and vigilant enforcement, even among adult learners.

  13. The use of concept maps to detect and correct concept errors (mistakes

    Directory of Open Access Journals (Sweden)

    Ladislada del Puy Molina Azcárate

    2013-02-01

    Full Text Available This work proposes to detect and correct concept errors (EECC to obtain Meaningful Learning (AS. The Conductive Model does not respond to the demand of meaningful learning that implies gathering thought, feeling and action to lead students up to both compromise and responsibility. In order to respond to the society competition about knowledge and information it is necessary to change the way of teaching and learning (from conductive model to constructive model. In this context it is important not only to learn meaningfully but also to create knowledge so as to developed dissertive, creative and critical thought, and the EECC are and obstacle to cope with this. This study tries to get ride of EECC in order to get meaningful learning. For this, it is essential to elaborate a Teaching Module (MI. This teaching Module implies the treatment of concept errors by a teacher able to change the dynamic of the group in the classroom. This M.I. was used among sixth grade primary school and first grade secondary school in some state assisted schools in the North of Argentina (Tucumán and Jujuy. After evaluation, the results showed great and positive changes among the experimental groups taking into account the attitude and the academic results. Meaningful Learning was shown through pupilʼs creativity, expressions and also their ability of putting this into practice into everyday life.

  14. A Comparison of Error Bounds for a Nonlinear Tracking System with Detection Probability Pd < 1

    Science.gov (United States)

    Tong, Huisi; Zhang, Hao; Meng, Huadong; Wang, Xiqin

    2012-01-01

    Error bounds for nonlinear filtering are very important for performance evaluation and sensor management. This paper presents a comparative study of three error bounds for tracking filtering, when the detection probability is less than unity. One of these bounds is the random finite set (RFS) bound, which is deduced within the framework of finite set statistics. The others, which are the information reduction factor (IRF) posterior Cramer-Rao lower bound (PCRLB) and enumeration method (ENUM) PCRLB are introduced within the framework of finite vector statistics. In this paper, we deduce two propositions and prove that the RFS bound is equal to the ENUM PCRLB, while it is tighter than the IRF PCRLB, when the target exists from the beginning to the end. Considering the disappearance of existing targets and the appearance of new targets, the RFS bound is tighter than both IRF PCRLB and ENUM PCRLB with time, by introducing the uncertainty of target existence. The theory is illustrated by two nonlinear tracking applications: ballistic object tracking and bearings-only tracking. The simulation studies confirm the theory and reveal the relationship among the three bounds. PMID:23242274

  15. A Comparison of Error Bounds for a Nonlinear Tracking System with Detection Probability Pd < 1

    Directory of Open Access Journals (Sweden)

    Xiqin Wang

    2012-12-01

    Full Text Available Error bounds for nonlinear filtering are very important for performance evaluation and sensor management. This paper presents a comparative study of three error bounds for tracking filtering, when the detection probability is less than unity. One of these bounds is the random finite set (RFS bound, which is deduced within the framework of finite set statistics. The others, which are the information reduction factor (IRF posterior Cramer-Rao lower bound (PCRLB and enumeration method (ENUM PCRLB are introduced within the framework of finite vector statistics. In this paper, we deduce two propositions and prove that the RFS bound is equal to the ENUM PCRLB, while it is tighter than the IRF PCRLB, when the target exists from the beginning to the end. Considering the disappearance of existing targets and the appearance of new targets, the RFS bound is tighter than both IRF PCRLB and ENUM PCRLB with time, by introducing the uncertainty of target existence. The theory is illustrated by two nonlinear tracking applications: ballistic object tracking and bearings-only tracking. The simulation studies confirm the theory and reveal the relationship among the three bounds.

  16. A comparison of error bounds for a nonlinear tracking system with detection probability Pd < 1.

    Science.gov (United States)

    Tong, Huisi; Zhang, Hao; Meng, Huadong; Wang, Xiqin

    2012-12-14

    Error bounds for nonlinear filtering are very important for performance evaluation and sensor management. This paper presents a comparative study of three error bounds for tracking filtering, when the detection probability is less than unity. One of these bounds is the random finite set (RFS) bound, which is deduced within the framework of finite set statistics. The others, which are the information reduction factor (IRF) posterior Cramer-Rao lower bound (PCRLB) and enumeration method (ENUM) PCRLB are introduced within the framework of finite vector statistics. In this paper, we deduce two propositions and prove that the RFS bound is equal to the ENUM PCRLB, while it is tighter than the IRF PCRLB, when the target exists from the beginning to the end. Considering the disappearance of existing targets and the appearance of new targets, the RFS bound is tighter than both IRF PCRLB and ENUM PCRLB with time, by introducing the uncertainty of target existence. The theory is illustrated by two nonlinear tracking applications: ballistic object tracking and bearings-only tracking. The simulation studies confirm the theory and reveal the relationship among the three bounds.

  17. Cognitive Detection and Error Correction Task in Narrative Text Comprehension in Elementary School Children

    Directory of Open Access Journals (Sweden)

    Diana Carolina Latorre Velásquez

    2010-02-01

    Full Text Available This paper aims to present the construction and development of a cognitive task located in the problematic area of language understanding, which is an alternative methodology to capture the self-regulatory process during the reading of a narrative text. From the functional perspective, the task leads to the detection and correction of errors semantic, syntactic and pragmatic on the part of whoever is running. The psychometric task with great fortitude(Cronbach’s alpha .820 entered in the paradigm of contradiction arose from the interest in building tools valid and reliable measurement also constitute alternative methodologies for the development of cognitive skills and metacognitive skills crucial in understanding narrative texts.

  18. Detection and Correction of Errors on Digital Photos Due to Technical Imperfections in the Registration System

    Directory of Open Access Journals (Sweden)

    HUYLEBROECK, J.

    2007-04-01

    Full Text Available This article describes the study of the detection and correction of diverse errors that can occur while taking digital photographs of flat objects such as pages from a book or magazine. This paper deals with uneven lighting conditions and the consequences thereof on the brightness of the photographed subject, geometric image distortions due to the technical characteristics and the chosen settings on the camera, and possible distortions because of the surface on which the photographed material is positioned. The processing of the data is done with Matlab. The user is supposed to make correct use of adequate reference material as a means for the identification of the imperfections in the registration system to make the necessary corrections. The final purpose of all these procedures is to reproduce the photographed material as truthfully as possible.

  19. Trial and error? Decision support for combinatorial online-optimization problems in logistics; Probieren geht ueber Studieren? Entscheidungshilfen fuer kombinatorische Online-Optimierungsprobleme in der innerbetrieblichen Logistik

    Energy Technology Data Exchange (ETDEWEB)

    Krumke, S.O.; Rambau, J. [Zuse-Institut Berlin, Berlin (Germany)

    2002-07-01

    The automation of in-house logistic systems requires - beyond the physical control of the machinery - an efficient organization of transport requests: a field of combinatorial optimization. With the help of three concrete applications, this article illustrates the online-issues (incomplete knowledge) and the real-time issues (short time frame for computations) frequently occuring in logistic systems. We give an overview over general purpose methods to construct online-algorithms and over analysis methods which help to decide which algorithms are suitable for a particular problem setting. (orig.) [German] Die Automatisierung von innerbetrieblicher Logistik erfordert - ueber die physikalische Steuerung von Geraeten hinaus - auch eine effiziente Organisation der Transporte: ein Aufgabenfeld der kombinatorischen Optimierung. Dieser Artikel illustriert anhand von konkreten Aufgabenstellungen die Online-Problematik (unvollstaendiges Wissen) sowie die Echtzeit-Problematik (beschraenkte Rechenzeit), auf die man in der innerbetrieblichen Logistik trifft. Der Text gibt einen Ueberblick ueber allgemeine Konstruktionsprinzipien fuer Online-Algorithmen und Bewertungsmethoden, die bei der Entscheidung helfen, welche Algorithmen fuer eine vorliegende Problemstellung geeignet sind. (orig.)

  20. The Case of the Pilfered Paper: Implications of Online Writing Assistance and Web-Based Plagiarism Detection Services

    Science.gov (United States)

    Morgan, Phoebe; Vaughn, Jacqueline

    2010-01-01

    While there is nothing new about academic dishonesty, how it is committed, prevented, and detected has been dramatically transformed by the advent of online technologies. This article briefly describes the concurrent emergence of online writing assistance services and Web-based plagiarism detection tools and examines the implications of both for…

  1. Detection and reconstruction of error control codes for engineered and biological regulatory systems.

    Energy Technology Data Exchange (ETDEWEB)

    May, Elebeoba Eni; Rintoul, Mark Daniel; Johnston, Anna Marie; Pryor, Richard J.; Hart, William Eugene; Watson, Jean-Paul

    2003-10-01

    A fundamental challenge for all communication systems, engineered or living, is the problem of achieving efficient, secure, and error-free communication over noisy channels. Information theoretic principals have been used to develop effective coding theory algorithms to successfully transmit information in engineering systems. Living systems also successfully transmit biological information through genetic processes such as replication, transcription, and translation, where the genome of an organism is the contents of the transmission. Decoding of received bit streams is fairly straightforward when the channel encoding algorithms are efficient and known. If the encoding scheme is unknown or part of the data is missing or intercepted, how would one design a viable decoder for the received transmission? For such systems blind reconstruction of the encoding/decoding system would be a vital step in recovering the original message. Communication engineers may not frequently encounter this situation, but for computational biologists and biotechnologist this is an immediate challenge. The goal of this work is to develop methods for detecting and reconstructing the encoder/decoder system for engineered and biological data. Building on Sandia's strengths in discrete mathematics, algorithms, and communication theory, we use linear programming and will use evolutionary computing techniques to construct efficient algorithms for modeling the coding system for minimally errored engineered data stream and genomic regulatory DNA and RNA sequences. The objective for the initial phase of this project is to construct solid parallels between biological literature and fundamental elements of communication theory. In this light, the milestones for FY2003 were focused on defining genetic channel characteristics and providing an initial approximation for key parameters, including coding rate, memory length, and minimum distance values. A secondary objective addressed the question of

  2. Bioaerosol Analysis by Online Fluorescence Detection and Fluorescence Microscopy

    Science.gov (United States)

    Huffman, Alex; Pöhlker, Christopher; Treutlein, Bärbel; Pöschl, Ulrich

    2010-05-01

    Primary biological aerosol particles (PBAPs), including bacteria, spores and pollen, are essential for the spread of organisms and disease in the biosphere, and numerous studies have suggested that they may be important for atmospheric processes, including the formation of clouds and precipitation. The atmospheric abundance and size distribution of PBAPs, however, are largely unknown. At a semi-urban site in Mainz, Germany, we used an ultraviolet aerodynamic particle sizer (UV-APS) to measure fluorescent biological aerosol particles (FBAPs), which can be regarded as viable bioaerosol particles representing a lower limit for the actual abundance of PBAPs. Fluorescence of non-biological aerosol components are likely to influence the measurement results obtained for fine particles (concentration of coarse FBAPs was 3x10-2 cm-3, corresponding to 4% of total coarse particle number [1]. The mean mass concentration of FBAPs was 1 ?g m-3, corresponding to 20% of total coarse particle mass. The FBAP number size distributions exhibited alternating patterns with peaks at various diameters, though a pronounced peak at 3 μm was essentially always observed. This peak is likely due to fungal spores or agglomerated bacteria, and it exhibited a pronounced diel cycle with maximum intensity during early/mid-morning. FBAP peaks around 1.5 μm, 5 μm, and 13 μm were also observed, but less pronounced and less frequent. These may be explained by single bacterial cells, larger fungal spores, and pollen grains, respectively. The observed number concentrations and characteristic sizes of FBAPs are consistent with microscopic, biological and chemical analyses of PBAPs in aerosol filter samples. To our knowledge, however, this is the first study reporting continuous online measurements of bioaerosol particles over several months, a range of characteristic size distribution patterns, and a persistent bioaerosol peak at 3 μm. The measurement results confirm that PBAPs account for a

  3. Towards online multiresolution community detection in large-scale networks.

    Directory of Open Access Journals (Sweden)

    Jianbin Huang

    Full Text Available The investigation of community structure in networks has aroused great interest in multiple disciplines. One of the challenges is to find local communities from a starting vertex in a network without global information about the entire network. Many existing methods tend to be accurate depending on a priori assumptions of network properties and predefined parameters. In this paper, we introduce a new quality function of local community and present a fast local expansion algorithm for uncovering communities in large-scale networks. The proposed algorithm can detect multiresolution community from a source vertex or communities covering the whole network. Experimental results show that the proposed algorithm is efficient and well-behaved in both real-world and synthetic networks.

  4. A New Approach to Detection of Systematic Errors in Secondary Substation Monitoring Equipment Based on Short Term Load Forecasting.

    Science.gov (United States)

    Moriano, Javier; Rodríguez, Francisco Javier; Martín, Pedro; Jiménez, Jose Antonio; Vuksanovic, Branislav

    2016-01-12

    In recent years, Secondary Substations (SSs) are being provided with equipment that allows their full management. This is particularly useful not only for monitoring and planning purposes but also for detecting erroneous measurements, which could negatively affect the performance of the SS. On the other hand, load forecasting is extremely important since they help electricity companies to make crucial decisions regarding purchasing and generating electric power, load switching, and infrastructure development. In this regard, Short Term Load Forecasting (STLF) allows the electric power load to be predicted over an interval ranging from one hour to one week. However, important issues concerning error detection by employing STLF has not been specifically addressed until now. This paper proposes a novel STLF-based approach to the detection of gain and offset errors introduced by the measurement equipment. The implemented system has been tested against real power load data provided by electricity suppliers. Different gain and offset error levels are successfully detected.

  5. A New Approach to Detection of Systematic Errors in Secondary Substation Monitoring Equipment Based on Short Term Load Forecasting

    Directory of Open Access Journals (Sweden)

    Javier Moriano

    2016-01-01

    Full Text Available In recent years, Secondary Substations (SSs are being provided with equipment that allows their full management. This is particularly useful not only for monitoring and planning purposes but also for detecting erroneous measurements, which could negatively affect the performance of the SS. On the other hand, load forecasting is extremely important since they help electricity companies to make crucial decisions regarding purchasing and generating electric power, load switching, and infrastructure development. In this regard, Short Term Load Forecasting (STLF allows the electric power load to be predicted over an interval ranging from one hour to one week. However, important issues concerning error detection by employing STLF has not been specifically addressed until now. This paper proposes a novel STLF-based approach to the detection of gain and offset errors introduced by the measurement equipment. The implemented system has been tested against real power load data provided by electricity suppliers. Different gain and offset error levels are successfully detected.

  6. Drug errors and related interventions reported by United States clinical pharmacists: the American College of Clinical Pharmacy practice-based research network medication error detection, amelioration and prevention study.

    Science.gov (United States)

    Kuo, Grace M; Touchette, Daniel R; Marinac, Jacqueline S

    2013-03-01

    To describe and evaluate drug errors and related clinical pharmacist interventions. Cross-sectional observational study with an online data collection form. American College of Clinical Pharmacy practice-based research network (ACCP PBRN). A total of 62 clinical pharmacists from the ACCP PBRN who provided direct patient care in the inpatient and outpatient practice settings. Clinical pharmacist participants identified drug errors in their usual practices and submitted online error reports over a period of 14 consecutive days during 2010. The 62 clinical pharmacists submitted 924 reports; of these, 779 reports from 53 clinical pharmacists had complete data. Drug errors occurred in both the inpatient (61%) and outpatient (39%) settings. Therapeutic categories most frequently associated with drug errors were systemic antiinfective (25%), hematologic (21%), and cardiovascular (19%) drugs. Approximately 95% of drug errors did not result in patient harm; however, 33 drug errors resulted in treatment or medical intervention, 6 resulted in hospitalization, 2 required treatment to sustain life, and 1 resulted in death. The types of drug errors were categorized as prescribing (53%), administering (13%), monitoring (13%), dispensing (10%), documenting (7%), and miscellaneous (4%). Clinical pharmacist interventions included communication (54%), drug changes (35%), and monitoring (9%). Approximately 89% of clinical pharmacist recommendations were accepted by the prescribers: 5% with drug therapy modifications, 28% due to clinical pharmacist prescriptive authority, and 56% without drug therapy modifications. This study provides insight into the role clinical pharmacists play with regard to drug error interventions using a national practice-based research network. Most drug errors reported by clinical pharmacists in the United States did not result in patient harm; however, severe harm and death due to drug errors were reported. Drug error types, therapeutic categories, and

  7. New method for online interturn faults detection in power transformer with using probabilistic neural network

    Directory of Open Access Journals (Sweden)

    S. hajiaghasi

    2014-07-01

    Full Text Available In recent years with notice increase reliability in power system and Intelligent Systems and also notice that transformers are one of the main part of the transmission and distribution systems, online monitoring of these equipment in power system are require. In this paper, a new method for online interturn fault detection base on leakage flux in power transformer are propose. When an interturn fault occur the symmetry of flux destruction and leakage flux increase or decrease and for various location and severity of fault leakage flux is different and it can be used for fault detection. In this paper for measure these flux we using search coils that mounted on HV winding. To fault detection and classify we using probabilistic neural network. and for decrease the information volume PCA is used. The simulation results are compare and verified with experimental result and show that this propose method is very good.

  8. Online technique for detecting state of onboard fiber optic gyroscope.

    Science.gov (United States)

    Miao, Zhiyong; Xu, Dingjie; He, Kunpeng; Pang, Shuwan; Tian, Chunmiao

    2015-02-01

    Although angle random walk (ARW) of fiber optic gyroscope (FOG) has been well modeled and identified before being integrated into the high-accuracy attitude control system of satellite, aging and unexpected failures can affect the performance of FOG after launch, resulting in the variation of ARW coefficient. Therefore, the ARW coefficient can be regarded as an indicator of "state of health" for FOG diagnosis in some sense. The Allan variance method can be used to estimate ARW coefficient of FOG, however, it requires a large amount of data to be stored. Moreover, the procedure of drawing slope lines for estimation is painful. To overcome the barriers, a weighted state-space model that directly models the ARW to obtain a nonlinear state-space model was established for FOG. Then, a neural extended-Kalman filter algorithm was implemented to estimate and track the variation of ARW in real time. The results of experiment show that the proposed approach is valid to detect the state of FOG. Moreover, the proposed technique effectively avoids the storage of data.

  9. Online technique for detecting state of onboard fiber optic gyroscope

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Zhiyong; He, Kunpeng, E-mail: pengkhe@126.com; Pang, Shuwan [Department of Automation, Harbin Engineering University, Harbin, Heilongjiang 150000 (China); Xu, Dingjie [School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin, Heilongjiang 150000 (China); Tian, Chunmiao [Department of Information and Communication Engineering, Harbin Engineering University, Harbin, Heilongjiang 150000 (China)

    2015-02-15

    Although angle random walk (ARW) of fiber optic gyroscope (FOG) has been well modeled and identified before being integrated into the high-accuracy attitude control system of satellite, aging and unexpected failures can affect the performance of FOG after launch, resulting in the variation of ARW coefficient. Therefore, the ARW coefficient can be regarded as an indicator of “state of health” for FOG diagnosis in some sense. The Allan variance method can be used to estimate ARW coefficient of FOG, however, it requires a large amount of data to be stored. Moreover, the procedure of drawing slope lines for estimation is painful. To overcome the barriers, a weighted state-space model that directly models the ARW to obtain a nonlinear state-space model was established for FOG. Then, a neural extended-Kalman filter algorithm was implemented to estimate and track the variation of ARW in real time. The results of experiment show that the proposed approach is valid to detect the state of FOG. Moreover, the proposed technique effectively avoids the storage of data.

  10. Utility Change Point Detection in Online Social Media: A Revealed Preference Framework

    Science.gov (United States)

    Aprem, Anup; Krishnamurthy, Vikram

    2017-04-01

    This paper deals with change detection of utility maximization behaviour in online social media. Such changes occur due to the effect of marketing, advertising, or changes in ground truth. First, we use the revealed preference framework to detect the unknown time point (change point) at which the utility function changed. We derive necessary and sufficient conditions for detecting the change point. Second, in the presence of noisy measurements, we propose a method to detect the change point and construct a decision test. Also, an optimization criteria is provided to recover the linear perturbation coefficients. Finally, to reduce the computational cost, a dimensionality reduction algorithm using Johnson-Lindenstrauss transform is presented. The results developed are illustrated on two real datasets: Yahoo! Tech Buzz dataset and Youstatanalyzer dataset. By using the results developed in the paper, several useful insights can be gleaned from these data sets. First, the changes in ground truth affecting the utility of the agent can be detected by utility maximization behaviour in online search. Second, the recovered utility functions satisfy the single crossing property indicating strategic substitute behaviour in online search. Third, due to the large number of videos in YouTube, the utility maximization behaviour was verified through the dimensionality reduction algorithm. Finally, using the utility function recovered in the lower dimension, we devise an algorithm to predict total traffic in YouTube.

  11. Error Detection and Recovery Techniques for Variation-Aware CMOS Computing: A Comprehensive Review

    Directory of Open Access Journals (Sweden)

    Joseph Crop

    2011-10-01

    Full Text Available While Moore’s law scaling continues to double transistor density every technology generation, new design challenges are introduced. One of these challenges is variation, resulting in deviations in the behavior of transistors, most importantly in switching delays. These exaggerated delays widen the gap between the average and the worst case behavior of a circuit. Conventionally, circuits are designed to accommodate the worst case delay and are therefore becoming very limited in their performance advantages. Thus, allowing for an average case oriented design is a promising solution, maintaining the pace of performance improvement over future generations. However, to maintain correctness, such an approach will require on the fly mechanisms to prevent, detect, and resolve violations. This paper explores such mechanisms, allowing the improvement of circuit performance under intensifying variations. We present speculative error detection techniques along with recovery mechanisms. We continue by discussing their ability to operate under extreme variations including sub-threshold operation. While the main focus of this survey is on circuit approaches, for its completeness, we discuss higher-level, architectural and algorithmic techniques as well.

  12. Error Detection Mechanism for Words and Sentences: A Comparison between Readers with Dyslexia and Skilled Readers

    Science.gov (United States)

    Horowitz-Kraus, Tzipi; Breznitz, Zvia

    2011-01-01

    The activity level of the error monitoring system for processing isolated versus contextual words in Hebrew was studied in adults with dyslexia and skilled readers while committing reading errors. Behavioural measures and event-related potentials were measured during a lexical decision task using words in a list and sentences. Error-related…

  13. Online Trajectory Reshaping for a Launch Vehicle to Minimize the Final Error Caused by Navigation and Guidance

    Directory of Open Access Journals (Sweden)

    Tessy Thomas

    2013-05-01

    Full Text Available Autonomous launch vehicles, once lifted off from the launch pad, equipped with an onboard intelligence which aids in achieving the mission objectives with high accuracy. The accuracy of the mission depends basically on navigation and guidance errors caused at burnout condition, after which the vehicle follows an elliptical path upto impact. The paper describes how to handle the final impact and injection error caused by these navigation and guidance errors. In the current work the initial burnout conditions are tuned and corrected such that the terminal impact point is achieved within the desired tolerance bounds. A two point boundary value problem is solved using the gradient method, for determining the impact errors. The algorithm is validated by simulation studies for various burnout conditions.Defence Science Journal, 2013, 63(3, pp.254-261, DOI:http://dx.doi.org/10.14429/dsj.63.2414

  14. High Accuracy On-line Measurement Method of Motion Error on Machine Tools Straight-going Parts

    Institute of Scientific and Technical Information of China (English)

    苏恒; 洪迈生; 魏元雷; 李自军

    2003-01-01

    Harmonic suppression, non-periodic and non-closing in straightness profile error that will bring about harmonic component distortion in measurement result are analyzed. The countermeasure-a novel accurate two-probe method in time domain is put forward to measure straight-going component motion error in machine tools based on the frequency domain 3-point method after symmetrical continuation of probes' primitive signal. Both straight-going component motion error in machine tools and the profile error in workpiece that is manufactured on this machine can be measured at the same time. The information is available to diagnose the fault origin of machine tools. The analysis result is proved to be correct by the experiment.

  15. Online Trajectory Reshaping for a Launch Vehicle to Minimize the Final Error Caused by Navigation and Guidance

    Directory of Open Access Journals (Sweden)

    Tessy Thomas

    2013-05-01

    Full Text Available Autonomous launch vehicles, once lifted off from the launch pad, equipped with an onboard intelligence which aids in achieving the mission objectives with high accuracy. The accuracy of the mission depends basically on navigation and guidance errors caused at burnout condition, after which the vehicle follows an elliptical path upto impact. The paper describes how to handle the final impact and injection error caused by these navigation and guidance errors. In the current work the initial burnout conditions are tuned and corrected such that the terminal impact point is achieved within the desired tolerance bounds. A two point boundary value problem is solved using the gradient method, for determining the impact errors. The algorithm is validated by simulation studies for various burnout conditions.

  16. Theory analysis and experimental research on on-line contamination detecting technology in hydraulic oil

    Institute of Scientific and Technical Information of China (English)

    YAO Cheng-yu; ZHAO Jing-yi; ZHANG Qi-sheng

    2006-01-01

    A system of on-line contamination detecting in hydraulic oil based on silting principle is accomplished, where, metal filter membrane as detector, solenoid as active force to propel piston to blotter and gain differential pressure, step motor drives the membrane to filtrate and counter-flush, LabVIEW as detecting software platform, oil's contamination detecting indirectly by gauging differential pressure. Based on theory analysis, accomplished is relation between contamination level and differential pressure, realizing polynomial curve fitting, and calibration experiment. Field experiment is simulated in the condition of experimental laboratory, has credible precision and real-time performance, which can popularize to the field of production.

  17. Design of an online video edge detection device for bottle caps based on FPGA

    Directory of Open Access Journals (Sweden)

    Donghui LIU

    2015-06-01

    Full Text Available An online video edge detection device for bottle caps is designed and implemented using OV7670 video module and FPGA based control unit. By Verilog language programming, the device realizes the menu type parametric setting of the external VGA display, and completes the Roberts edge detection of real-time video image, which improves the speed of image processing. By improving the detection algorithm, the noise is effectively suppressed, and clear and coherent edge images are derived. The design improves the working environment, and avoids the harm to human body.

  18. Gusts detection in a horizontal wind turbine by monitoring of innovations error of an extended Kalman filter

    Science.gov (United States)

    Recalde, L. F.; Hur, S.; Leithead, W. E.

    2016-09-01

    This paper presents a novel model-based detection scheme capable of detecting and diagnosing gusts. Detection is achieved by monitoring the innovations error (i.e., the difference between the estimated and measured outputs) of an extended discrete Kalman filter. It is designed to trigger a detection/confirmation alarm in the presence of wind anomalies. Simulation results are presented to demonstrate that both operating and coherent extreme wind gusts can successfully be detected. The wind anomaly is identified in magnitude and shape through maximum likelihood ratio and goodness of fit, respectively. The detector is capable of isolating extreme wind gusts before the turbine over speeds.

  19. An investigation into soft error detection efficiency at operating system level.

    Science.gov (United States)

    Asghari, Seyyed Amir; Kaynak, Okyay; Taheri, Hassan

    2014-01-01

    Electronic equipment operating in harsh environments such as space is subjected to a range of threats. The most important of these is radiation that gives rise to permanent and transient errors on microelectronic components. The occurrence rate of transient errors is significantly more than permanent errors. The transient errors, or soft errors, emerge in two formats: control flow errors (CFEs) and data errors. Valuable research results have already appeared in literature at hardware and software levels for their alleviation. However, there is the basic assumption behind these works that the operating system is reliable and the focus is on other system levels. In this paper, we investigate the effects of soft errors on the operating system components and compare their vulnerability with that of application level components. Results show that soft errors in operating system components affect both operating system and application level components. Therefore, by providing endurance to operating system level components against soft errors, both operating system and application level components gain tolerance.

  20. 对数控机床在线测量进行误差分析%Error Analysis of CNC Machine Tools Online Measurement

    Institute of Scientific and Technical Information of China (English)

    于佃清

    2015-01-01

    The paper split CNC machine tools online measurement system into 2 parts for optimizing online measurement system, CNC machine tools body and probe measurement system. According to the analysis of the structure and working principle of CNC machine tools online system, the structure composition and measurement principle of the probe system were analysed, then the error sources and characters as well.%本文为优化数控机床在线测量系统,将数控机床在线测量系统拆分为数控机床本体和测头测量系统两部分,通过对数控机床在线系统的结构组成和工作原理分析,再对测头系统的结构组成及测量原理分析,然后对其开展深层次的分析误差来源及性质.以期能够为数控机床在线测量有效优化提供有价值的参考依据.

  1. Automatic on-line detection system design research on internal defects of metal materials based on optical fiber F-P sensing technology

    Science.gov (United States)

    Xia, Liu; Shan, Ning; Chao, Ban; Caoshan, Wang

    2016-10-01

    Metal materials have been used in aerospace and other industrial fields widely because of its excellent characteristics, so its internal defects detection is very important. Ultrasound technology is used widely in the fields of nondestructive detection because of its excellent characteristic. But the conventional detection instrument for ultrasound, which has shortcomings such as low intelligent level and long development cycles, limits its development. In this paper, the theory of ultrasound detection is analyzed. A computational method of the defects distributional position is given. The non-contact type optical fiber F-P interference cavity structure is designed and the length of origin cavity is given. The real-time on-line ultrasound detecting experiment devices for internal defects of metal materials is established based on the optical fiber F-P sensing system. The virtual instrument of automation ultrasound detection internal defects is developed based on LabVIEW software and the experimental study is carried out. The results show that this system can be used in internal defect real-time on-line locating of engineering structures effectively. This system has higher measurement precision. Relative error is 6.7%. It can be met the requirement of engineering practice. The system is characterized by simple operation, easy realization. The software has a friendly interface, good expansibility, and high intelligent level.

  2. Robust bivariate error detection in skewed data with application to historical radiosonde winds

    KAUST Repository

    Sun, Ying

    2017-01-18

    The global historical radiosonde archives date back to the 1920s and contain the only directly observed measurements of temperature, wind, and moisture in the upper atmosphere, but they contain many random errors. Most of the focus on cleaning these large datasets has been on temperatures, but winds are important inputs to climate models and in studies of wind climatology. The bivariate distribution of the wind vector does not have elliptical contours but is skewed and heavy-tailed, so we develop two methods for outlier detection based on the bivariate skew-t (BST) distribution, using either distance-based or contour-based approaches to flag observations as potential outliers. We develop a framework to robustly estimate the parameters of the BST and then show how the tuning parameter to get these estimates is chosen. In simulation, we compare our methods with one based on a bivariate normal distribution and a nonparametric approach based on the bagplot. We then apply all four methods to the winds observed for over 35,000 radiosonde launches at a single station and demonstrate differences in the number of observations flagged across eight pressure levels and through time. In this pilot study, the method based on the BST contours performs very well.

  3. A Novel Approach For Error Detection And Correction Using Prefix-Adders

    Directory of Open Access Journals (Sweden)

    B. Naga Jyothi

    2016-06-01

    Full Text Available The variable latency speculative Han-Carlson adder is a newly proposed adder to perform high speed arithmetic operations. Han-Carlson adder gives accurate results with error detection when compared to other adders like Kogge-Stone adder. In this paper, number of parallel prefix adders can be sub divided into number of stages and perform arithmetic operations. By using the Xilinx 14.2 software, the design of Kogge-Stone adder and Han-Carlson adder is developed. This paper focuses on the implementation and simulation of 8-bit, 16-bit Kogge-stone adder and Han- Carlson adder based on Verilog code and compared for their performance in Xilinx. When compared to other adders the delay performance for Han Carlson adder is less and it reduces the complexity. It is concluded that the proposed adder is better in terms of computational delay. By using Brent –Kung and Kogge-stone adder the parallel prefix Han-Carlson adder also be proposed.

  4. Detection of Digital Elevation Model Errors Using X-band Weather Radar

    Science.gov (United States)

    Young, Steven D.; deHaag, Maatren Uijt

    2007-01-01

    Flight in Instrument Meteorological Conditions requires pilots to manipulate flight controls while referring to a Primary Flight Display. The Primary Flight Display indicates aircraft attitude along with, in some cases, many other state variables such as altitude, speed, and guidance cues. Synthetic Vision Systems have been proposed that overlay the traditional information provided on Primary Flight Displays onto a scene depicting the location of terrain and other geo-spatial features.Terrain models used by these displays must have sufficient quality to avoid providing misleading information. This paper describes how X-band radar measurements can be used as part of a monitor, and/or maintenance system, to quantify the integrity of terrain models that are used by systems such as Synthetic Vision. Terrain shadowing effects, as seen by the radar, are compared in a statistical manner against estimated shadow feature elements extracted from the stored terrain model from the perspective of the airborne observer. A test statistic is defined that enables detection of errors as small as the range resolution of the radar. Experimental results obtained from two aircraft platforms hosting certified commercial-off-the-shelf X-band radars test the premise and illustrate its potential.

  5. Detecting bit-flip errors in a logical qubit using stabilizer measurements.

    Science.gov (United States)

    Ristè, D; Poletto, S; Huang, M-Z; Bruno, A; Vesterinen, V; Saira, O-P; DiCarlo, L

    2015-04-29

    Quantum data are susceptible to decoherence induced by the environment and to errors in the hardware processing it. A future fault-tolerant quantum computer will use quantum error correction to actively protect against both. In the smallest error correction codes, the information in one logical qubit is encoded in a two-dimensional subspace of a larger Hilbert space of multiple physical qubits. For each code, a set of non-demolition multi-qubit measurements, termed stabilizers, can discretize and signal physical qubit errors without collapsing the encoded information. Here using a five-qubit superconducting processor, we realize the two parity measurements comprising the stabilizers of the three-qubit repetition code protecting one logical qubit from physical bit-flip errors. While increased physical qubit coherence times and shorter quantum error correction blocks are required to actively safeguard the quantum information, this demonstration is a critical step towards larger codes based on multiple parity measurements.

  6. WE-AB-BRA-09: Sensitivity of Plan Re-Optimization to Errors in Deformable Image Registration in Online Adaptive Image-Guided Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    McClain, B; Olsen, J; Green, O; Yang, D; Santanam, L; Olsen, L; Zhao, T; Rodriguez, V; Wooten, H; Mutic, S; Kashani, R [Washington University School of Medicine, St. Louis, Missouri (United States); Victoria, J; Dempsey, J [ViewRay Incorporated, Oakwood Village, OH (United States)

    2015-06-15

    Purpose: Online adaptive therapy (ART) relies on auto-contouring using deformable image registration (DIR). DIR’s inherent uncertainties require user intervention and manual edits while the patient is on the table. We investigated the dosimetric impact of DIR errors on the quality of re-optimized plans, and used the findings to establish regions for focusing manual edits to where DIR errors can Result in clinically relevant dose differences. Methods: Our clinical implementation of online adaptive MR-IGRT involves using DIR to transfer contours from CT to daily MR, followed by a physicians’ edits. The plan is then re-optimized to meet the organs at risk (OARs) constraints. Re-optimized abdomen and pelvis plans generated based on physician edited OARs were selected as the baseline for evaluation. Plans were then re-optimized on auto-deformed contours with manual edits limited to pre-defined uniform rings (0 to 5cm) around the PTV. A 0cm ring indicates that the auto-deformed OARs were used without editing. The magnitude of the variations caused by the non-deterministic optimizer was quantified by repeat re-optimizations on the same geometry to determine the mean and standard deviation (STD). For each re-optimized plan, various volumetric parameters for the PTV, the OARs were extracted along with DVH and isodose evaluation. A plan was deemed acceptable if the variation from the baseline plan was within one STD. Results: Initial results show that for abdomen and pancreas cases, a minimum of 5cm margin around the PTV is required for contour corrections, while for pelvic and liver cases a 2–3 cm margin is sufficient. Conclusion: Focusing manual contour edits to regions of dosimetric relevance can reduce contouring time in the online ART process while maintaining a clinically comparable plan. Future work will further refine the contouring region by evaluating the path along the beams, dose gradients near the target and OAR dose metrics.

  7. Uncertain Reasoning for Detection of Selling Stolen Goods in Online Auctions Using Contextual Information

    Directory of Open Access Journals (Sweden)

    Ladislav Beranek

    2014-01-01

    Full Text Available This work describes the design of a decision support system for detection of fraudulent behavior of selling stolen goods in online auctions. In this system, each seller is associated with a type of certification, namely “proper seller,” “suspect seller,” and “selling stolen goods.” The certification level is determined on the basis of a seller’s behaviors and especially on the basis of contextual information whose origin is outside online auctions portals. In this paper, we focus on representing knowledge about sellers in online auctions, the influence of additional information available from other Internet source, and reasoning on bidders’ trustworthiness under uncertainties using Dempster-Shafer theory of evidence. To demonstrate the practicability of our approach, we performed a case study using real auction data from Czech auction portal Aukro. The analysis results show that our approach can be used to detect selling stolen goods. By applying Dempster-Shafer theory to combine multiple sources of evidence for the detection of this fraudulent behavior, the proposed approach can reduce the number of false positive results in comparison to approaches using a single source of evidence.

  8. Automated contouring error detection based on supervised geometric attribute distribution models for radiation therapy: A general strategy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hsin-Chen; Tan, Jun; Dolly, Steven; Kavanaugh, James; Harold Li, H.; Altman, Michael; Gay, Hiram; Thorstad, Wade L.; Mutic, Sasa; Li, Hua, E-mail: huli@radonc.wustl.edu [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States); Anastasio, Mark A. [Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63110 (United States); Low, Daniel A. [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California 90095 (United States)

    2015-02-15

    Purpose: One of the most critical steps in radiation therapy treatment is accurate tumor and critical organ-at-risk (OAR) contouring. Both manual and automated contouring processes are prone to errors and to a large degree of inter- and intraobserver variability. These are often due to the limitations of imaging techniques in visualizing human anatomy as well as to inherent anatomical variability among individuals. Physicians/physicists have to reverify all the radiation therapy contours of every patient before using them for treatment planning, which is tedious, laborious, and still not an error-free process. In this study, the authors developed a general strategy based on novel geometric attribute distribution (GAD) models to automatically detect radiation therapy OAR contouring errors and facilitate the current clinical workflow. Methods: Considering the radiation therapy structures’ geometric attributes (centroid, volume, and shape), the spatial relationship of neighboring structures, as well as anatomical similarity of individual contours among patients, the authors established GAD models to characterize the interstructural centroid and volume variations, and the intrastructural shape variations of each individual structure. The GAD models are scalable and deformable, and constrained by their respective principal attribute variations calculated from training sets with verified OAR contours. A new iterative weighted GAD model-fitting algorithm was developed for contouring error detection. Receiver operating characteristic (ROC) analysis was employed in a unique way to optimize the model parameters to satisfy clinical requirements. A total of forty-four head-and-neck patient cases, each of which includes nine critical OAR contours, were utilized to demonstrate the proposed strategy. Twenty-nine out of these forty-four patient cases were utilized to train the inter- and intrastructural GAD models. These training data and the remaining fifteen testing data sets

  9. Role of Clinical Pharmacists in Early Detection, Reporting and Prevention of Medication Errors in a Medical Ward

    Directory of Open Access Journals (Sweden)

    Solmaz Hassani

    2017-03-01

    Full Text Available Background: Drug utilization evaluation (DUE is an effective process in order to identifying variability in drug use and subsequent application of effective interventions for improving  patient outcomes. In this study, appropriate uses of drugs were evaluated by pharmacy service.Methods: A prospective, interventional study was designed for determining frequency and type of clinical pharmacists’ interventions and medication errors occurred in the infectious disease ward of Loghman hospital, affiliated to Shahid Beheshti University of Medical Sciences, Tehran, Iran during 8 months. Results: During the 8 months of the study period, 498 errors were detected among 419 patients that admitted to infectious disease ward of Loghman hospital. Most common errors were related to DVT prophylaxis, SUP and vancomycin monitoring. Discussion: Our result showed that clinical pharmacy interventions can have an important role in reducing adverse drug events and their activities can be effective for reducing of medication error.

  10. [Study on the concentration of mineral oil in water by online intelligent detection based on fluorescence spectrum].

    Science.gov (United States)

    Tang, Yuan-he; Liu, Qing-song; Ivieng, Lei; Liu, Han-chen; Liu, Qian; Li, Cun-xia

    2015-02-01

    In order to monitor the oil pollution of water real time and accurately for the environmental protection, an intelligent online detection system for the mineral oil in water is put forward in the present paper, based on the technology of ultraviolet fluorescence and internet of things (IOT). For this system, the resolution can be improved by using the higher precision asymmetric Czemy-Turner monochromator; the impact of light fluctuations on the results of exploration can be corrected by a bunch reference light; the optical system deviation caused by the instrument vibration can be reduced by optical fiber transmission; the coupling efficiency of fiber and output signal can be increased by a special fiber beam; the real-time measurement, data processing and remote control can be achieved by the control module and wireless communication module. This system has characteristics of high integration, high precision and good stability etc. The concentration of the unknown sample can be accurately calculated by the methods of parallel algorithms of chemometric metrology and the calculation errors caused by different components can be reduced by the theory of chemical correction factor analysis. The fluorescence spectra of three kinds of sample solution, diesel, engine and crude oil in preparative concentration of 10, 25, 50 and 100 mg x L(-1) were measured by this system respectively. The absorption wavelengths of the above-mentioned three oils were measured to be 256, 365 and 397 nm by a grating spectrometer; their absorbances were measured to be 0.028, 0.036 and 0.041 by fluorescence spectrophotometer, respectively. Their fluorescence emission wavelengths are 355, 419 and 457 nm respectively. Finally the concentration detection limits of the mineral oil in water of diesel, engine and crude oil were obtained, i.e., 0.03, 0.04 and 0.06 mg x L(-1) respectively. Their relative errors are 2.1%, 1.0% and 2.8% respectively.

  11. On-line detection of atmospheric formaldehyde by a conductometric biosensor.

    Science.gov (United States)

    Vianello, Fabio; Boscolo-Chio, Raffaella; Signorini, Stefano; Rigo, Adelio

    2007-01-15

    Atmospheric formaldehyde (CH(2)O) was detected under continuous flow conditions by an on-line system comprising of a wet scrubber for a continuous transfer of the pollutant to an aqueous solution, a micro-reactor containing immobilized formaldehyde dehydrogenase (FDH) and a conductometric transducer. By this system atmospheric formaldehyde concentrations in the range 0.05-2 ppm were detected with a sensitivity of 20 microS/ppm. In this concentration range the immobilized enzyme oxidized all the sampled formaldehyde molecules to formic acid, avoiding cumbersome calibration procedures. The operational stability of the biosensor was at least 3 months, working continuously 10 h/day at room temperature.

  12. Health Monitoring of Offshore Wind Turbines Online Fault Detection and Identification Module Test Case: Pitch Offset

    DEFF Research Database (Denmark)

    Perisic, Nevena; Pedersen, Bo Juul; Kirkegaard, Poul Henning

    LACobserver is a model based health monitoring (HM) system for wind turbines (WTGs) which provides an intuitive engineering link between load and strength parameters. The present work demonstrates a newly developed LACobserver Fault Detection and Identification (FDI) module for online detection...... of pitch offset and corresponding root causes. Blade-to-blade pitch offset slowly degrade the WTG performance and results in lower WTG annual energy production and higher structural loads. Thus, a FDI strategy will increase wind turbine efficiency, performance and operational lifetime....

  13. Pitfalls and sources of error of color duplex ultrasonography in detecting deep vein thrombosis of proximal lower extremities

    Institute of Scientific and Technical Information of China (English)

    GAO Jing; YI Lianhua; Auh Yong Ho

    2004-01-01

    Purpose To analyze the sources of errors and discuss the techniques to eliminate pitfalls in detecting deep vein thrombosis (DVT) of the proximal lower extremities with color duplex ultrasonography (CDUS). Methods Sixty-eight cases with initial and repeat venous CDUS of the proximal lower extremities were retrospectively reviewed. The repeat was done within 24 hours after initial CDUS scanning. Comparing repeated images to initial ones, the pitfalls and sources of error in CDUS of the proximal lower extremities were discussed. Results In total 68 repeat studies, there were 62 results as same as initials and 4 cases of false negative DVT and 2 cases of false positive DVT. Conclusion Venous CDUS in detecting DVT is observer dependent. Some pitfalls and errors can be eliminated and corrected with proper scan techniques. CDUS is the most valuable imaging modality for assessing suspected DVT in the proximal lower extremities.

  14. Improving Preceptors' Knowledge on Medication Error Reduction Strategies.

    Science.gov (United States)

    Harris, Rosiland

    2014-01-01

    Preceptors are in an ideal position to change the paradigm for medication error reduction and detection. However, they must receive ongoing training and preparation for this role. An online learning module with specific focus on medication error reduction strategies could help preceptors meet the challenge of orienting novice nurses about safe medication administration.

  15. The role of comprehensive check at the blood bank reception on blood requisitions in detecting potential transfusion errors.

    Science.gov (United States)

    Jain, Ashish; Kumari, Sonam; Marwaha, Neelam; Sharma, Ratti Ram

    2015-06-01

    Pre-transfusion testing includes proper requisitions, compatibility testing and pre-release checks. Proper labelling of samples and blood units and accurate patient details check helps to minimize the risk of errors in transfusion. This study was aimed to identify requisition errors before compatibility testing. The study was conducted in the blood bank of a tertiary care hospital in north India over a period of 3 months. The requisitions were screened at the reception counter and inside the pre-transfusion testing laboratory for errors. This included checking the Central Registration number (C.R. No.) and name of patient on the requisition form and the sample label; appropriateness of sample container and sample label; incomplete requisitions; blood group discrepancy. Out of the 17,148 blood requisitions, 474 (2.76 %) requisition errors were detected before the compatibility testing. There were 192 (1.11 %) requisitions where the C.R. No. on the form and the sample were not tallying and in 70 (0.40 %) requisitions patient's name on the requisition form and the sample were different. Highest number of requisitions errors were observed in those received from the Emergency and Trauma services (27.38 %) followed by Medical wards (15.82 %) and the lowest number (3.16 %) of requisition errors were observed from Hematology and Oncology wards. C.R. No. error was the most common error observed in our study. Thus a careful check of the blood requisitions at the blood bank reception counter helps in identifying the potential transfusion errors.

  16. Developing an EEG based On-line Closed-loop Lapse Detection and Mitigation System

    Directory of Open Access Journals (Sweden)

    Yu-Te eWang

    2014-10-01

    Full Text Available In America, sixty percent of adults reported that they have driven a motor vehicle while feeling drowsy, and at least 15-20% of fatal car accidents are fatigue-related. This study translates previous laboratory-oriented neurophysiological research to design, develop, and test an On-line Closed-loop Lapse Detection and Mitigation (OCLDM System featuring a mobile wireless dry-sensor EEG headgear and a cell-phone based real-time EEG processing platform. Eleven subjects participated in an event-related lane-keeping task, in which they were instructed to manipulate a randomly deviated, fixed-speed cruising car on a 4-lane highway. This was simulated in a 1st person view with an 8-screen and 8-projector immersive virtual-realty environment. When the subjects experienced lapses or failed to respond to events during the experiment, auditory feedback was delivered to rectify the performance decrements. However, the arousing auditory signals were not always effective. The EEG spectra exhibited statistically significant differences between effective and ineffective arousing signals, suggesting that EEG spectra could be used as a countermeasure of the efficacy of arousing signals. In this on-line pilot study, the proposed OCLDM System was able to continuously detect EEG signatures of fatigue, deliver arousing feedback to subjects suffering momentary cognitive lapses, and assess the efficacy of the feedback in near real-time to rectify cognitive lapses. The on-line testing results of the OCLDM System validated the efficacy of the arousing signals in improving subjects' response times to the subsequent lane-departure events. This study may lead to a practical on-line lapse detection and mitigation system in real-world environments.

  17. Cost-benefit analysis of the detection of prescribing errors by hospital pharmacy staff

    NARCIS (Netherlands)

    van den Bemt, PMLA; Postma, MJ; van Roon, EN; Chow, MCC; Fijn, R; Brouwers, JRBJ

    2002-01-01

    Objective: Prescribing errors are a major cause of iatrogenic patient morbidity and therefore interventions aimed at preventing the adverse outcomes of these errors are likely to result in cost reduction. However, it is unclear whether the costs associated with these preventive measures are

  18. Item Discrimination and Type I Error in the Detection of Differential Item Functioning

    Science.gov (United States)

    Li, Yanju; Brooks, Gordon P.; Johanson, George A.

    2012-01-01

    In 2009, DeMars stated that when impact exists there will be Type I error inflation, especially with larger sample sizes and larger discrimination parameters for items. One purpose of this study is to present the patterns of Type I error rates using Mantel-Haenszel (MH) and logistic regression (LR) procedures when the mean ability between the…

  19. Description of medication errors detected at a drug information centre in Southern Brazil

    Directory of Open Access Journals (Sweden)

    dos Santos L

    2015-03-01

    Full Text Available Objective: To identify and describe actual or potential medication errors related to drug information inquiries made by staff members of a teaching hospital to a Drug Information Centre from January 2012 to December 2013. Methods: Data were collected from the records of inquiries made by health care professionals to the Drug Information Centre throughout this period. Results: During the study period, the Drug Information Centre received 3,500 inquiries. Of these, 114 inquiries had medication errors. Most errors were related to prescribing, preparation, and administration and were classified according to severity as category B (57% (potential errors and categories C (26.3% and D (15.8% (actual errors that did not result in harm to the patient. Error causes included overdose (13.2%, wrong route of administration (11.4%, inadequate drug storage (11.4%, and wrong dosage form (8.8%. The drugs most frequently involved in errors were vitamin K (4.4%, vancomycin (3.5%, and meropenem (3.5%. Conclusion: In this study, it was not possible to measure the reduction in error rate involving medication use because of the lack of previous data on this process in the institution. However, our findings indicate that the Drug Information Centre may be used as a strategy to seek improvements in processes involving medication use.

  20. Cost-benefit analysis of the detection of prescribing errors by hospital pharmacy staff

    NARCIS (Netherlands)

    van den Bemt, PMLA; Postma, MJ; van Roon, EN; Chow, MCC; Fijn, R; Brouwers, JRBJ

    2002-01-01

    Objective: Prescribing errors are a major cause of iatrogenic patient morbidity and therefore interventions aimed at preventing the adverse outcomes of these errors are likely to result in cost reduction. However, it is unclear whether the costs associated with these preventive measures are outweigh

  1. Executive function and error detection: The effect of motivation on cingulate and ventral striatum activity.

    Science.gov (United States)

    Simões-Franklin, Cristina; Hester, Robert; Shpaner, Marina; Foxe, John J; Garavan, Hugh

    2010-03-01

    Reacting appropriately to errors during task performance is fundamental to successful negotiation of our environment. This is especially true when errors will result in a significant penalty for the person performing a given task, be they financial or otherwise. Error responses and monitoring states were manipulated in a GO/NOGO task by introducing a financial punishment for errors. This study employed a mixed block design alternating between punishment and no punishment (neutral) conditions, enabling an assessment of tonic changes associated with cognitive control as well as trial-specific effects. Behavioural results revealed slower responses and fewer commission errors in the punishment condition. The dorsal anterior cingulate cortex (ACC) had equal trial-specific activity for errors in the neutral and punishment conditions but had greater tonic activity throughout the punishment condition. A region of interest analysis revealed different activation patterns between the dorsal and the rostral parts of the ACC with the rostral ACC having only trial-specific activity for errors in the punishment condition, an activity profile similar to one observed in the nucleus accumbens. This study suggests that there is a motivational influence on cognitive processes in the ACC and nucleus accumbens and hints at a dissociation between tonic proactive activity and phasic reactive error-related activity.

  2. Improvement of Methods for Detection of Signs of Errors and Omissions in the Financial Statements Based on Analytical Procedures

    OpenAIRE

    Kostyantyn Bezverkhiy

    2014-01-01

    Analytical work within enterprises aimed to prevent omissions of financial reporting data should play a leading role in the work program of accountant, analyst and auditor. The article is devoted to the improvement of methods for detection signs of errors and omissions in the financial statements by applying analytical procedures. It was established that the main issues at implementation of the concept of financial statements control in the enterprise are the lack of adopted methods to detect...

  3. Potentiometric online detection of aromatic hydrocarbons in aqueous phase using carbon nanotube-based sensors.

    Science.gov (United States)

    Washe, Alemayehu P; Macho, Santiago; Crespo, Gastón A; Rius, F Xavier

    2010-10-01

    Surfaces made of entangled networks of single-walled carbon nanotubes (SWCNTs) display a strong adsorption affinity for aromatic hydrocarbons. Adsorption of these compounds onto the walls of SWCNTs changes the electrical characteristics of the SWCNT-solution interface. Using these features, we have developed a potentiometric sensor to detect neutral aromatic species. Specifically, we can detect online aromatic hydrocarbons in industrial coolant water. Our chromatographic results confirm the adsorption of toluene onto the walls of carbon nanotubes, and our impedance spectroscopy data show the change in the double layer capacitance of the carbon nanotube-solution interface upon addition of toluene, thus confirming the proposed sensing mechanism. The sensor showed a toluene concentration dependent EMF response that follows the shape of an adsorption isotherm and displayed an immediate response to the presence of toluene with a detection limit of 2.1 ppm. The sensor does not respond to other nonaromatic hydrocarbons that may coexist with aromatic hydrocarbons in water. It shows a qualitative sensitivity and selectivity of 100% and 83%, respectively, which confirms its ability to detect aromatic hydrocarbons in aqueous solutions. The sensor showed an excellent ability to immediately detect the presence of toluene in actual coolant water. Its operational characteristics, including its fast response, low cost, portability, and easy use in online industrial applications, improve those of current chromatographic or spectroscopic techniques.

  4. Assessing segmentation processes by click detection: online measure of statistical learning, or simple interference?

    Science.gov (United States)

    Franco, Ana; Gaillard, Vinciane; Cleeremans, Axel; Destrebecqz, Arnaud

    2015-12-01

    Statistical learning can be used to extract the words from continuous speech. Gómez, Bion, and Mehler (Language and Cognitive Processes, 26, 212-223, 2011) proposed an online measure of statistical learning: They superimposed auditory clicks on a continuous artificial speech stream made up of a random succession of trisyllabic nonwords. Participants were instructed to detect these clicks, which could be located either within or between words. The results showed that, over the length of exposure, reaction times (RTs) increased more for within-word than for between-word clicks. This result has been accounted for by means of statistical learning of the between-word boundaries. However, even though statistical learning occurs without an intention to learn, it nevertheless requires attentional resources. Therefore, this process could be affected by a concurrent task such as click detection. In the present study, we evaluated the extent to which the click detection task indeed reflects successful statistical learning. Our results suggest that the emergence of RT differences between within- and between-word click detection is neither systematic nor related to the successful segmentation of the artificial language. Therefore, instead of being an online measure of learning, the click detection task seems to interfere with the extraction of statistical regularities.

  5. Online Detection Approach for Rectangle Ceramic Tile Based on Sequenced Scenery Image

    Directory of Open Access Journals (Sweden)

    Yang Lei

    2013-06-01

    Full Text Available Image based ceramic tile detection is a way to labor liberation in the production process of ceramic tile. Shapes of ceramic tiles studied in this study are rectangle with different sizes. Many existed researches are based on a situation that only a piece of tile goes through special rail one time, resulting in one or less piece of tile hold in the image from CCD sensor. But in fact, multiple tiles with the same sizes run in a row simultaneously at most factories’ rails, and a 'scenery' image is obtained from CCD sensor. And the image processing method based on close-up images is not satisfied in such cases. To detect different rectangle ceramic tiles online according to a sequence of scenery images, this study provide a vector corner method to decide the rectangle tiles with known size information, and a valley detection method via key-image-frames strategy to distinguish the first row in images. Finally, our Online Approach for Rectangle Tile Detection (OARTD was embedded into a detection system and applied to a factory; testing results validated its good performance. Indeed, the use of such an automatic system, to control a tile plant for shape classifying has a good prospect.

  6. Phase Error Caused by Speed Mismatch Analysis in the Line-Scan Defect Detection by Using Fourier Transform Technique

    Directory of Open Access Journals (Sweden)

    Eryi Hu

    2015-01-01

    Full Text Available The phase error caused by the speed mismatch issue is researched in the line-scan images capturing 3D profile measurement. The experimental system is constructed by a line-scan CCD camera, an object moving device, a digital fringe pattern projector, and a personal computer. In the experiment procedure, the detected object is moving relative to the image capturing system by using a motorized translation stage in a stable velocity. The digital fringe pattern is projected onto the detected object, and then the deformed patterns are captured and recorded in the computer. The object surface profile can be calculated by the Fourier transform profilometry. However, the moving speed mismatch error will still exist in most of the engineering application occasion even after an image system calibration. When the moving speed of the detected object is faster than the expected value, the captured image will be compressed in the moving direction of the detected object. In order to overcome this kind of measurement error, an image recovering algorithm is proposed to reconstruct the original compressed image. Thus, the phase values can be extracted much more accurately by the reconstructed images. And then, the phase error distribution caused by the speed mismatch is analyzed by the simulation and experimental methods.

  7. Error analysis in cross-correlation of sky maps: application to the ISW detection

    CERN Document Server

    Cabre, A; Manera, E G M; Cabre, Anna; Fosalba, Pablo; Manera, Enrique Gaztanaga & Marc

    2007-01-01

    Constraining cosmological parameters from measurements of the Integrated Sachs-Wolfe effect requires developing robust and accurate methods for computing statistical errors in the cross-correlation between maps. This paper presents a detailed comparison of such error estimation applied to the case of cross-correlation of Cosmic Microwave Background (CMB) and large-scale structure data. We compare theoretical models for error estimation with montecarlo simulations where both the galaxy and the CMB maps vary around a fiducial auto-correlation and cross-correlation model which agrees well with the current concordance LCDM cosmology. Our analysis compares estimators both in harmonic and configuration (or real) space, quantifies the accuracy of the error analysis and discuss the impact of partial sky survey area and the choice of input fiducial model on dark-energy constraints. We show that purely analytic approaches yield accurate errors even in surveys that cover only 10% of the sky and that parameter constraint...

  8. A comparative study for detection and measurement of voltage disturbance in online condition

    Directory of Open Access Journals (Sweden)

    Vijay Gajanan Neve

    2015-05-01

    Full Text Available Voltage disturbance is the most important power quality problem faced by many industrial customers. It includes voltage sag, swell, spikes and harmonics. Real time detection of these voltage disturbances posed various problems. This paper compares the various methods of detection of voltage sag and swells in real time on the basis of detection time, magnitude, effect of windowing and effect of sampling frequencies. The RMS, Peak, Fourier transform and Missing Voltage algorithm are introduced and discussed in them for real time implementation. Comparative analysis reveals that quantification of voltage sag and swell is possible using these measurements. The main focus is given on to these points and all the voltage sag and swell detection technique tested online with the help of advantech card data acquisition. The voltage sag and swell events are generated by using practical experimentation in laboratory.

  9. Uric acid, an important screening tool to detect inborn errors of metabolism: a case series.

    Science.gov (United States)

    Jasinge, Eresha; Kularatnam, Grace Angeline Malarnangai; Dilanthi, Hewa Warawitage; Vidanapathirana, Dinesha Maduri; Jayasena, Kandana Liyanage Subhashinie Priyadarshika Kapilani Menike; Chandrasiri, Nambage Dona Priyani Dhammika; Indika, Neluwa Liyanage Ruwan; Ratnayake, Pyara Dilani; Gunasekara, Vindya Nandani; Fairbanks, Lynette Dianne; Stiburkova, Blanka

    2017-09-06

    Uric acid is the metabolic end product of purine metabolism in humans. Altered serum and urine uric acid level (both above and below the reference ranges) is an indispensable marker in detecting rare inborn errors of metabolism. We describe different case scenarios of 4 Sri Lankan patients related to abnormal uric acid levels in blood and urine. CASE 1: A one-and-half-year-old boy was investigated for haematuria and a calculus in the bladder. Xanthine crystals were seen in microscopic examination of urine sediment. Low uric acid concentrations in serum and low urinary fractional excretion of uric acid associated with high urinary excretion of xanthine and hypoxanthine were compatible with xanthine oxidase deficiency. CASE 2: An 8-month-old boy presented with intractable seizures, feeding difficulties, screaming episodes, microcephaly, facial dysmorphism and severe neuro developmental delay. Low uric acid level in serum, low fractional excretion of uric acid and radiological findings were consistent with possible molybdenum cofactor deficiency. Diagnosis was confirmed by elevated levels of xanthine, hypoxanthine and sulfocysteine levels in urine. CASE 3: A 3-year-10-month-old boy presented with global developmental delay, failure to thrive, dystonia and self-destructive behaviour. High uric acid levels in serum, increased fractional excretion of uric acid and absent hypoxanthine-guanine phosphoribosyltransferase enzyme level confirmed the diagnosis of Lesch-Nyhan syndrome. CASE 4: A 9-year-old boy was investigated for lower abdominal pain, gross haematuria and right renal calculus. Low uric acid level in serum and increased fractional excretion of uric acid pointed towards hereditary renal hypouricaemia which was confirmed by genetic studies. Abnormal uric acid level in blood and urine is a valuable tool in screening for clinical conditions related to derangement of the nucleic acid metabolic pathway.

  10. Adaptive Error Detection Method for P300-based Spelling Using Riemannian Geometry

    Directory of Open Access Journals (Sweden)

    Attaullah Sahito

    2016-11-01

    Full Text Available Brain-Computer Interface (BCI systems have be-come one of the valuable research area of ML (Machine Learning and AI based techniques have brought significant change in traditional diagnostic systems of medical diagnosis. Specially; Electroencephalogram (EEG, which is measured electrical ac-tivity of the brain and ionic current in neurons is result of these activities. A brain-computer interface (BCI system uses these EEG signals to facilitate humans in different ways. P300 signal is one of the most important and vastly studied EEG phenomenon that has been studied in Brain Computer Interface domain. For instance, P300 signal can be used in BCI to translate the subject’s intention from mere thoughts using brain waves into actual commands, which can eventually be used to control different electro mechanical devices and artificial human body parts. Since low Signal-to-Noise-Ratio (SNR in P300 is one of the major challenge because concurrently ongoing heterogeneous activities and artifacts of brain creates lots of challenges for doctors to understand the human intentions. In order to address above stated challenge this research proposes a system so called Adaptive Error Detection method for P300-Based Spelling using Riemannian Geometry, the system comprises of three main steps, in first step raw signal is cleaned by preprocessing. In second step most relevant features are extracted using xDAWN spatial filtering along with covariance matrices for handling high dimensional data and in final step elastic net classification algorithm is applied after converting from Riemannian manifold to Euclidean space using tangent space mapping. Results obtained by proposed method are comparable to state-of-the-art methods, as they decrease time drastically; as results suggest six times decrease in time and perform better during the inter-session and inter-subject variability.

  11. Secure Access Control and Large Scale Robust Representation for Online Multimedia Event Detection

    Directory of Open Access Journals (Sweden)

    Changyu Liu

    2014-01-01

    Full Text Available We developed an online multimedia event detection (MED system. However, there are a secure access control issue and a large scale robust representation issue when we want to integrate traditional event detection algorithms into the online environment. For the first issue, we proposed a tree proxy-based and service-oriented access control (TPSAC model based on the traditional role based access control model. Verification experiments were conducted on the CloudSim simulation platform, and the results showed that the TPSAC model is suitable for the access control of dynamic online environments. For the second issue, inspired by the object-bank scene descriptor, we proposed a 1000-object-bank (1000OBK event descriptor. Feature vectors of the 1000OBK were extracted from response pyramids of 1000 generic object detectors which were trained on standard annotated image datasets, such as the ImageNet dataset. A spatial bag of words tiling approach was then adopted to encode these feature vectors for bridging the gap between the objects and events. Furthermore, we performed experiments in the context of event classification on the challenging TRECVID MED 2012 dataset, and the results showed that the robust 1000OBK event descriptor outperforms the state-of-the-art approaches.

  12. Secure access control and large scale robust representation for online multimedia event detection.

    Science.gov (United States)

    Liu, Changyu; Lu, Bin; Li, Huiling

    2014-01-01

    We developed an online multimedia event detection (MED) system. However, there are a secure access control issue and a large scale robust representation issue when we want to integrate traditional event detection algorithms into the online environment. For the first issue, we proposed a tree proxy-based and service-oriented access control (TPSAC) model based on the traditional role based access control model. Verification experiments were conducted on the CloudSim simulation platform, and the results showed that the TPSAC model is suitable for the access control of dynamic online environments. For the second issue, inspired by the object-bank scene descriptor, we proposed a 1000-object-bank (1000OBK) event descriptor. Feature vectors of the 1000OBK were extracted from response pyramids of 1000 generic object detectors which were trained on standard annotated image datasets, such as the ImageNet dataset. A spatial bag of words tiling approach was then adopted to encode these feature vectors for bridging the gap between the objects and events. Furthermore, we performed experiments in the context of event classification on the challenging TRECVID MED 2012 dataset, and the results showed that the robust 1000OBK event descriptor outperforms the state-of-the-art approaches.

  13. Does raising type 1 error rate improve power to detect interactions in linear regression models? A simulation study.

    Directory of Open Access Journals (Sweden)

    Casey P Durand

    Full Text Available INTRODUCTION: Statistical interactions are a common component of data analysis across a broad range of scientific disciplines. However, the statistical power to detect interactions is often undesirably low. One solution is to elevate the Type 1 error rate so that important interactions are not missed in a low power situation. To date, no study has quantified the effects of this practice on power in a linear regression model. METHODS: A Monte Carlo simulation study was performed. A continuous dependent variable was specified, along with three types of interactions: continuous variable by continuous variable; continuous by dichotomous; and dichotomous by dichotomous. For each of the three scenarios, the interaction effect sizes, sample sizes, and Type 1 error rate were varied, resulting in a total of 240 unique simulations. RESULTS: In general, power to detect the interaction effect was either so low or so high at α = 0.05 that raising the Type 1 error rate only served to increase the probability of including a spurious interaction in the model. A small number of scenarios were identified in which an elevated Type 1 error rate may be justified. CONCLUSIONS: Routinely elevating Type 1 error rate when testing interaction effects is not an advisable practice. Researchers are best served by positing interaction effects a priori and accounting for them when conducting sample size calculations.

  14. Improving transfusion safety: implementation of a comprehensive computerized bar code-based tracking system for detecting and preventing errors.

    Science.gov (United States)

    Askeland, R W; McGrane, S; Levitt, J S; Dane, S K; Greene, D L; Vandeberg, J A; Walker, K; Porcella, A; Herwaldt, L A; Carmen, L T; Kemp, J D

    2008-07-01

    To transfuse blood products safely, health care workers must accurately identify patients, blood samples, and the blood components. A comprehensive bar code-based computerized tracking system was developed and implemented to identify and prevent transfusion errors. A data network, wireless devices, and bar-coded labels were pilot tested before the system was introduced hospitalwide. The system provided a complete audit trail for all transactions. Data from before and after implementation were analyzed. Incident reports decreased from a mean of 41.5 reports per month in the 6 months before the system was implemented to a mean of 7.2 reports per month after implementation. The blood sample rejection rate decreased from 1.82 percent to a mean of 0.17 percent after implementation. Errors detected by the new system were sorted into misscans, skipped steps, wrong steps, and prevented identification errors (PIEs). Misscans and skipped steps were the most common errors in the first 10 months after implementation. During the final transfusion step, PIEs occurred at the rate of about one per month and scans were omitted approximately 1 percent of the time. Therefore, it is estimated that mistransfusions could occur about once every 100 months on average with the new system. The bar code-based computerized tracking system detected and prevented identification and matching errors, thereby reducing the proportion of blood samples rejected and increasing patient safety.

  15. Online Detection of Change on Information Streams in Wireless Sensor Network Modeled Using Gaussian Distribution

    Directory of Open Access Journals (Sweden)

    B. Victoria Jancee

    2014-01-01

    Full Text Available Wireless sensor network (WSN is deployed to monitor certain physical quantities in a region. This monitoring problem could be stated as the problem of detecting a change in the parameters of a static or dynamic stochastic system. A moving window procedure is proposed to detect the systematic error, which occurs at an unknown time. It can detect the deviation in the mean of sensor measurements keeping variance as constant. The performance measures, such as the average run length (ARL to detection delay and false alarms are computed for various window sizes. The performance comparison is done against traditional cumulative sum (CUSUM method. The detection of change in mean using CUSUM is done with smaller delay compared to the proposed moving window detection procedure. In order to calculate CUSUM statistics, the number of measurements to keep in sensor memory increases with time. However, in the proposed moving window detection procedure, the number of stored measurements is limited by the size of the window. Therefore, it is advantageous to use the moving window procedure for change detection in sensor nodes that have very limited memory. A high probability of detection is achieved at the cost of larger window size and higher detection delay. However, we are able to achieve the maximum probability of detection even at a window size of 11.

  16. On-Line Fault Detection in Wind Turbine Transmission System using Adaptive Filter and Robust Statistical Features

    Directory of Open Access Journals (Sweden)

    Mark Frogley

    2013-01-01

    Full Text Available To reduce the maintenance cost, avoid catastrophic failure, and improve the wind transmission system reliability, online condition monitoring system is critical important. In the real applications, many rotating mechanical faults, such as bearing surface defect, gear tooth crack, chipped gear tooth and so on generate impulsive signals. When there are these types of faults developing inside rotating machinery, each time the rotating components pass over the damage point, an impact force could be generated. The impact force will cause a ringing of the support structure at the structural natural frequency. By effectively detecting those periodic impulse signals, one group of rotating machine faults could be detected and diagnosed. However, in real wind turbine operations, impulsive fault signals are usually relatively weak to the background noise and vibration signals generated from other healthy components, such as shaft, blades, gears and so on. Moreover, wind turbine transmission systems work under dynamic operating conditions. This will further increase the difficulties in fault detection and diagnostics. Therefore, developing advanced signal processing methods to enhance the impulsive signals is in great needs.In this paper, an adaptive filtering technique will be applied for enhancing the fault impulse signals-to-noise ratio in wind turbine gear transmission systems. Multiple statistical features designed to quantify the impulsive signals of the processed signal are extracted for bearing fault detection. The multiple dimensional features are then transformed into one dimensional feature. A minimum error rate classifier will be designed based on the compressed feature to identify the gear transmission system with defect. Real wind turbine vibration signals will be used to demonstrate the effectiveness of the presented methodology.

  17. Entropy-functional-based online adaptive decision fusion framework with application to wildfire detection in video.

    Science.gov (United States)

    Gunay, Osman; Toreyin, Behçet Ugur; Kose, Kivanc; Cetin, A Enis

    2012-05-01

    In this paper, an entropy-functional-based online adaptive decision fusion (EADF) framework is developed for image analysis and computer vision applications. In this framework, it is assumed that the compound algorithm consists of several subalgorithms, each of which yields its own decision as a real number centered around zero, representing the confidence level of that particular subalgorithm. Decision values are linearly combined with weights that are updated online according to an active fusion method based on performing entropic projections onto convex sets describing subalgorithms. It is assumed that there is an oracle, who is usually a human operator, providing feedback to the decision fusion method. A video-based wildfire detection system was developed to evaluate the performance of the decision fusion algorithm. In this case, image data arrive sequentially, and the oracle is the security guard of the forest lookout tower, verifying the decision of the combined algorithm. The simulation results are presented.

  18. Development of a Compton camera for online ion beam range verification via prompt γ detection

    Energy Technology Data Exchange (ETDEWEB)

    Aldawood, S. [LMU Munich, Garching (Germany); King Saud University, Riyadh (Saudi Arabia); Liprandi, S.; Marinsek, T.; Bortfeldt, J.; Lang, C.; Lutter, R.; Dedes, G.; Parodi, K.; Thirolf, P.G. [LMU Munich, Garching (Germany); Maier, L.; Gernhaeuser, R. [TU Munich, Garching (Germany); Kolff, H. van der [LMU Munich, Garching (Germany); TU Delft (Netherlands); Castelhano, I. [LMU Munich, Garching (Germany); University of Lisbon, Lisbon (Portugal); Schaart, D.R. [TU Delft (Netherlands)

    2015-07-01

    Precise and preferably online ion beam range verification is a mandatory prerequisite to fully exploit the advantages of hadron therapy in cancer treatment. An imaging system is being developed in Garching aiming to detect promptγ rays induced by nuclear reactions between the ion beam and biological tissue. The Compton camera prototype consists of a stack of six customized double-sided Si-strip detectors (DSSSD, 50 x 50 mm{sup 2}, 0.5 mm thick, 128 strips/side) acting as scatterer, while the absorber is formed by a monolithic LaBr{sub 3}:Ce scintillator crystal (50 x 50 x 30 mm{sup 3}) read out by a position-sensitive multi-anode photomultiplier (Hamamatsu H9500). The on going characterization of the Compton camera properties and its individual components both offline in the laboratory as well as online using proton beam are presented.

  19. Online coupling of digital microfluidic devices with mass spectrometry detection using an eductor with electrospray ionization.

    Science.gov (United States)

    Baker, Christopher A; Roper, Michael G

    2012-03-20

    MS detection coupled with digital microfluidic (DMF) devices has most commonly been demonstrated in an offline manner using matrix assisted laser desorption ionization. In this work, an eductor is demonstrated which facilitated online coupling of DMF with electrospray ionization MS detection. The eductor consisted of a transfer capillary, a standard ESI needle, and a tapered gas nozzle. As a pulse of N(2) was applied to the nozzle, a pressure differential was induced at the outlet of the ESI needle that pulled droplets from the DMF, past the ESI needle, and into the flow of gas exiting the nozzle, allowing detection by MS. Operating position, ionization potential, and N(2) pressure were optimized, with the optimum ionization potential and N(2) pressure found to be 3206 V and 80 psi, respectively. Online MS detection was demonstrated from both open and closed DMF devices using 2.5 μL and 630 nL aqueous droplets, respectively. Relative quantitation by DMF-MS was demonstrated by mixing droplets of caffeine with droplets of theophylline on an open DMF device and comparing the peak area ratio obtained to an on-chip generated calibration curve. This eductor-based method for transferring droplets has the potential for rapid, versatile, and high-throughput microfluidic analyses.

  20. Retinopathy online challenge: automatic detection of microaneurysms in digital color fundus photographs.

    Science.gov (United States)

    Niemeijer, Meindert; van Ginneken, Bram; Cree, Michael J; Mizutani, Atsushi; Quellec, Gwénolé; Sanchez, Clara I; Zhang, Bob; Hornero, Roberto; Lamard, Mathieu; Muramatsu, Chisako; Wu, Xiangqian; Cazuguel, Guy; You, Jane; Mayo, Agustín; Li, Qin; Hatanaka, Yuji; Cochener, Béatrice; Roux, Christian; Karray, Fakhri; Garcia, María; Fujita, Hiroshi; Abramoff, Michael D

    2010-01-01

    The detection of microaneurysms in digital color fundus photographs is a critical first step in automated screening for diabetic retinopathy (DR), a common complication of diabetes. To accomplish this detection numerous methods have been published in the past but none of these was compared with each other on the same data. In this work we present the results of the first international microaneurysm detection competition, organized in the context of the Retinopathy Online Challenge (ROC), a multiyear online competition for various aspects of DR detection. For this competition, we compare the results of five different methods, produced by five different teams of researchers on the same set of data. The evaluation was performed in a uniform manner using an algorithm presented in this work. The set of data used for the competition consisted of 50 training images with available reference standard and 50 test images where the reference standard was withheld by the organizers (M. Niemeijer, B. van Ginneken, and M. D. Abràmoff). The results obtained on the test data was submitted through a website after which standardized evaluation software was used to determine the performance of each of the methods. A human expert detected microaneurysms in the test set to allow comparison with the performance of the automatic methods. The overall results show that microaneurysm detection is a challenging task for both the automatic methods as well as the human expert. There is room for improvement as the best performing system does not reach the performance of the human expert. The data associated with the ROC microaneurysm detection competition will remain publicly available and the website will continue accepting submissions.

  1. A Parallel Error Detection Structure Design of SPARC V8 Architecture Compatible ALU%一种SPARC V8结构ALU的并行错误检测结构设计

    Institute of Scientific and Technical Information of China (English)

    张洵颖

    2011-01-01

    针对嵌入式处理器在线错误检测的需求,文中基于编码预测的并行错误检测策略,选择Berger编码作为编码预测错误检测编码,设计了SPARC V8结构的加/减、逻辑和移位运算的B0编码预测结构.该结构可以直接集成为带有并行错误检测结构的SPARC V8结构ALU,相比于电路复制这样的结构实现了硬件资源的节省.与对偶复执这样两倍的执行时间并且附带结果比较的策略相比,具有明显的性能优势.%According to the on-line error detection requirement of embedded processors, this paper presents a parallel error detection structure of SPARC V8 architecture compatible ALU, which takes the B0 encoding of Berger code prediction as the parallel on-line error detection strategy. This structure can be integrated into the SPARC V8 architecture compatible ALU directly, and forms a parallel error detection ALU. Comparing with the two-rail logic method, this structure gets the hardware cost decrease. Comparing with pseudoduplication method, in which the same circuit successively processes data twice but along different data path, this structure has an obviously performance advantage.

  2. A hierarchical approach for online temporal lobe seizure detection in long-term intracranial EEG recordings

    Science.gov (United States)

    Liang, Sheng-Fu; Chen, Yi-Chun; Wang, Yu-Lin; Chen, Pin-Tzu; Yang, Chia-Hsiang; Chiueh, Herming

    2013-08-01

    Objective. Around 1% of the world's population is affected by epilepsy, and nearly 25% of patients cannot be treated effectively by available therapies. The presence of closed-loop seizure-triggered stimulation provides a promising solution for these patients. Realization of fast, accurate, and energy-efficient seizure detection is the key to such implants. In this study, we propose a two-stage on-line seizure detection algorithm with low-energy consumption for temporal lobe epilepsy (TLE). Approach. Multi-channel signals are processed through independent component analysis and the most representative independent component (IC) is automatically selected to eliminate artifacts. Seizure-like intracranial electroencephalogram (iEEG) segments are fast detected in the first stage of the proposed method and these seizures are confirmed in the second stage. The conditional activation of the second-stage signal processing reduces the computational effort, and hence energy, since most of the non-seizure events are filtered out in the first stage. Main results. Long-term iEEG recordings of 11 patients who suffered from TLE were analyzed via leave-one-out cross validation. The proposed method has a detection accuracy of 95.24%, a false alarm rate of 0.09/h, and an average detection delay time of 9.2 s. For the six patients with mesial TLE, a detection accuracy of 100.0%, a false alarm rate of 0.06/h, and an average detection delay time of 4.8 s can be achieved. The hierarchical approach provides a 90% energy reduction, yielding effective and energy-efficient implementation for real-time epileptic seizure detection. Significance. An on-line seizure detection method that can be applied to monitor continuous iEEG signals of patients who suffered from TLE was developed. An IC selection strategy to automatically determine the most seizure-related IC for seizure detection was also proposed. The system has advantages of (1) high detection accuracy, (2) low false alarm, (3) short

  3. Microreactors with integrated UV/Vis spectroscopic detection for online process analysis under segmented flow.

    Science.gov (United States)

    Yue, Jun; Falke, Floris H; Schouten, Jaap C; Nijhuis, T Alexander

    2013-12-21

    Combining reaction and detection in multiphase microfluidic flow is becoming increasingly important for accelerating process development in microreactors. We report the coupling of UV/Vis spectroscopy with microreactors for online process analysis under segmented flow conditions. Two integration schemes are presented: one uses a cross-type flow-through cell subsequent to a capillary microreactor for detection in the transmission mode; the other uses embedded waveguides on a microfluidic chip for detection in the evanescent wave field. Model experiments reveal the capabilities of the integrated systems in real-time concentration measurements and segmented flow characterization. The application of such integration for process analysis during gold nanoparticle synthesis is demonstrated, showing its great potential in process monitoring in microreactors operated under segmented flow.

  4. SafeVchat: Detecting Obscene Content and Misbehaving Users in Online Video Chat Services

    CERN Document Server

    Xing, Xinyu; Cheng, Hanqiang; Dang, Jianxun; Huang, Sui; Han, Richard; Liu, Xue; Lv, Qin; Mishra, Shivakant

    2011-01-01

    Online video chat services such as Chatroulette, Omegle, and vChatter that randomly match pairs of users in video chat sessions are fast becoming very popular, with over a million users per month in the case of Chatroulette. A key problem encountered in such systems is the presence of flashers and obscene content. This problem is especially acute given the presence of underage minors in such systems. This paper presents SafeVchat, a novel solution to the problem of flasher detection that employs an array of image detection algorithms. A key contribution of the paper concerns how the results of the individual detectors are fused together into an overall decision classifying the user as misbehaving or not, based on Dempster-Shafer Theory. The paper introduces a novel, motion-based skin detection method that achieves significantly higher recall and better precision. The proposed methods have been evaluated over real world data and image traces obtained from Chatroulette.com.

  5. Measuring and Detecting Errors in Occupational Coding: an Analysis of SHARE Data

    Directory of Open Access Journals (Sweden)

    Belloni Michele

    2016-12-01

    Full Text Available This article studies coding errors in occupational data, as the quality of this data is important but often neglected. In particular, we recoded open-ended questions on occupation for last and current job in the Dutch sample of the “Survey of Health, Ageing and Retirement in Europe” (SHARE using a high-quality software program for ex-post coding (CASCOT software. Taking CASCOT coding as our benchmark, our results suggest that the incidence of coding errors in SHARE is high, even when the comparison is made at the level of one-digit occupational codes (28% for last job and 30% for current job. This finding highlights the complexity of occupational coding and suggests that processing errors due to miscoding should be taken into account when undertaking statistical analyses or writing econometric models. Our analysis suggests strategies to alleviate such coding errors, and we propose a set of equations that can predict error. These equations may complement coding software and improve the quality of occupational coding.

  6. SafeVchat: Detecting Obscene Content and Misbehaving Users in Online Video Chat Services

    OpenAIRE

    2011-01-01

    Online video chat services such as Chatroulette, Omegle, and vChatter that randomly match pairs of users in video chat sessions are fast becoming very popular, with over a million users per month in the case of Chatroulette. A key problem encountered in such systems is the presence of flashers and obscene content. This problem is especially acute given the presence of underage minors in such systems. This paper presents SafeVchat, a novel solution to the problem of flasher detection that empl...

  7. Deception Detection: The Relationship of Levels of Trust and Perspective Taking in Real-Time Online and Offline Communication Environments.

    Science.gov (United States)

    Friend, Catherine; Fox Hamilton, Nicola

    2016-09-01

    Where humans have been found to detect lies or deception only at the rate of chance in offline face-to-face communication (F2F), computer-mediated communication (CMC) online can elicit higher rates of trust and sharing of personal information than F2F. How do levels of trust and empathetic personality traits like perspective taking (PT) relate to deception detection in real-time CMC compared to F2F? A between groups correlational design (N = 40) demonstrated that, through a paired deceptive conversation task with confederates, levels of participant trust could predict accurate detection online but not offline. Second, participant PT abilities could not predict accurate detection in either conversation medium. Finally, this study found that conversation medium also had no effect on deception detection. This study finds support for the effects of the Truth Bias and online disinhibition in deception, and further implications in law enforcement are discussed.

  8. A Novel Hybrid Error Criterion-Based Active Control Method for on-Line Milling Vibration Suppression with Piezoelectric Actuators and Sensors.

    Science.gov (United States)

    Zhang, Xingwu; Wang, Chenxi; Gao, Robert X; Yan, Ruqiang; Chen, Xuefeng; Wang, Shibin

    2016-01-06

    Milling vibration is one of the most serious factors affecting machining quality and precision. In this paper a novel hybrid error criterion-based frequency-domain LMS active control method is constructed and used for vibration suppression of milling processes by piezoelectric actuators and sensors, in which only one Fast Fourier Transform (FFT) is used and no Inverse Fast Fourier Transform (IFFT) is involved. The correction formulas are derived by a steepest descent procedure and the control parameters are analyzed and optimized. Then, a novel hybrid error criterion is constructed to improve the adaptability, reliability and anti-interference ability of the constructed control algorithm. Finally, based on piezoelectric actuators and acceleration sensors, a simulation of a spindle and a milling process experiment are presented to verify the proposed method. Besides, a protection program is added in the control flow to enhance the reliability of the control method in applications. The simulation and experiment results indicate that the proposed method is an effective and reliable way for on-line vibration suppression, and the machining quality can be obviously improved.

  9. A Novel Hybrid Error Criterion-Based Active Control Method for on-Line Milling Vibration Suppression with Piezoelectric Actuators and Sensors

    Directory of Open Access Journals (Sweden)

    Xingwu Zhang

    2016-01-01

    Full Text Available Milling vibration is one of the most serious factors affecting machining quality and precision. In this paper a novel hybrid error criterion-based frequency-domain LMS active control method is constructed and used for vibration suppression of milling processes by piezoelectric actuators and sensors, in which only one Fast Fourier Transform (FFT is used and no Inverse Fast Fourier Transform (IFFT is involved. The correction formulas are derived by a steepest descent procedure and the control parameters are analyzed and optimized. Then, a novel hybrid error criterion is constructed to improve the adaptability, reliability and anti-interference ability of the constructed control algorithm. Finally, based on piezoelectric actuators and acceleration sensors, a simulation of a spindle and a milling process experiment are presented to verify the proposed method. Besides, a protection program is added in the control flow to enhance the reliability of the control method in applications. The simulation and experiment results indicate that the proposed method is an effective and reliable way for on-line vibration suppression, and the machining quality can be obviously improved.

  10. MUST: A Scalable Approach to Runtime Error Detection in MPI Programs

    Energy Technology Data Exchange (ETDEWEB)

    Hilbrich, T; Schulz, M; de Supinski, B R; Muller, M

    2010-03-24

    The Message-Passing Interface (MPI) is large and complex. Therefore, programming MPI is error prone. Several MPI runtime correctness tools address classes of usage errors, such as deadlocks or nonportable constructs. To our knowledge none of these tools scales to more than about 100 processes. However, some of the current HPC systems use more than 100,000 cores and future systems are expected to use far more. Since errors often depend on the task count used, we need correctness tools that scale to the full system size. We present a novel framework for scalable MPI correctness tools to address this need. Our fine-grained, module-based approach supports rapid prototyping and allows correctness tools built upon it to adapt to different architectures and use cases. The design uses PnMPI to instantiate a tool from a set of individual modules. We present an overview of our design, along with first performance results for a proof of concept implementation.

  11. Association rule mining on grid monitoring data to detect error sources

    CERN Document Server

    Maier, G; Kranzlmueller, D; Gaidioz, B

    2010-01-01

    Error handling is a crucial task in an infrastructure as complex as a grid. There are several monitoring tools put in place, which report failing grid jobs including exit codes. However, the exit codes do not always denote the actual fault, which caused the job failure. Human time and knowledge is required to manually trace back errors to the real fault underlying an error. We perform association rule mining on grid job monitoring data to automatically retrieve knowledge about the grid components' behavior by taking dependencies between grid job characteristics into account. Therewith, problematic grid components are located automatically and this information – expressed by association rules – is visualized in a web interface. This work achieves a decrease in time for fault recovery and yields an improvement of a grid's reliability

  12. Power analysis to detect treatment effect in longitudinal studies with heterogeneous errors and incomplete data

    OpenAIRE

    Vallejo Seco, Guillermo; Ato García, Manuel; Fernández García, María Paula; Livacic Rojas, Pablo Esteban; Tuero Herrero, Ellián

    2016-01-01

    Antecedentes: S. Usami (2014) describe un método que permite determinar de forma realista el tamaño de muestra en la investigación longitudinal utilizando un modelo multinivel. En la presente investigación se extiende el trabajo aludido a situaciones donde es probable que se incumpla el supuesto de homogeneidad de los errores a través de los grupos y la estructura del término de error no sea de identidad escalada. Método: para ello, se ha seguido procedimiento basado en transformar los compon...

  13. Dosimetric effect of intrafraction motion and residual setup error for hypofractionated prostate intensity-modulated radiotherapy with online cone beam computed tomography image guidance.

    LENUS (Irish Health Repository)

    Adamson, Justus

    2012-02-01

    PURPOSE: To quantify the dosimetric effect and margins required to account for prostate intrafractional translation and residual setup error in a cone beam computed tomography (CBCT)-guided hypofractionated radiotherapy protocol. METHODS AND MATERIALS: Prostate position after online correction was measured during dose delivery using simultaneous kV fluoroscopy and posttreatment CBCT in 572 fractions to 30 patients. We reconstructed the dose distribution to the clinical tumor volume (CTV) using a convolution of the static dose with a probability density function (PDF) based on the kV fluoroscopy, and we calculated the minimum dose received by 99% of the CTV (D(99)). We compared reconstructed doses when the convolution was performed per beam, per patient, and when the PDF was created using posttreatment CBCT. We determined the minimum axis-specific margins to limit CTV D(99) reduction to 1%. RESULTS: For 3-mm margins, D(99) reduction was <\\/=5% for 29\\/30 patients. Using post-CBCT rather than localizations at treatment delivery exaggerated dosimetric effects by ~47%, while there was no such bias between the dose convolved with a beam-specific and patient-specific PDF. After eight fractions, final cumulative D(99) could be predicted with a root mean square error of <1%. For 90% of patients, the required margins were <\\/=2, 4, and 3 mm, with 70%, 40%, and 33% of patients requiring no right-left (RL), anteroposterior (AP), and superoinferior margins, respectively. CONCLUSIONS: For protocols with CBCT guidance, RL, AP, and SI margins of 2, 4, and 3 mm are sufficient to account for translational errors; however, the large variation in patient-specific margins suggests that adaptive management may be beneficial.

  14. A Starshade Petal Error Budget for Exo-Earth Detection and Characterization

    Science.gov (United States)

    Shaklan, Stuart B.; Marchen, Luis; Lisman, P. Douglas; Cady, Eric; Martin, Stefan; Thomson, Mark; Dumont, Philip; Kasdin, N. Jeremy

    2011-01-01

    We present a starshade error budget with engineering requirements that are well within the current manufacturing and metrology capabilities. The error budget is based on an observational scenario in which the starshade spins about its axis on timescales short relative to the zodi-limited integration time, typically several hours. The scatter from localized petal errors is smoothed into annuli around the center of the image plane, resulting in a large reduction in the background flux variation while reducing thermal gradients caused by structural shadowing. Having identified the performance sensitivity to petal shape errors with spatial periods of 3-4 cycles/petal as the most challenging aspect of the design, we have adopted and modeled a manufacturing approach that mitigates these perturbations with 1-meter-long precision edge segments positioned using commercial metrology that readily meets assembly requirements. We have performed detailed thermal modeling and show that the expected thermal deformations are well within the requirements as well. We compare the requirements for four cases: a 32 meter diameter starshade with a 1.5 meter telescope, analyzed at 75 and 90 milliarcseconds, and a 40 meter diameter starshade with a 4 meter telescope, analyzed at 60 and 75 milliarcseconds.

  15. Error Estimation Techniques to Refine Overlapping Aerial Image Mosaic Processes via Detected Parameters

    Science.gov (United States)

    Bond, William Glenn

    2012-01-01

    In this paper, I propose to demonstrate a means of error estimation preprocessing in the assembly of overlapping aerial image mosaics. The mosaic program automatically assembles several hundred aerial images from a data set by aligning them, via image registration using a pattern search method, onto a GIS grid. The method presented first locates…

  16. Effectiveness of Visualisations for Detection of Errors in Segmentation of Blood Vessels

    NARCIS (Netherlands)

    Schooten, van B.W.; Dijk, van E.M.A.G.; Suinesiaputra, A.; Reiber, J.H.C.

    2010-01-01

    Vascular disease diagnosis often requires a precise segmentation of the vessel lumen. When 3D (Magnetic Resonance Angiography, MRA, or Computed Tomography Angiography, CTA) imaging is available, this can be done automatically, but occasional errors are inevitable. So, the segmentation has to be chec

  17. Leveraging Automatic Speech Recognition Errors to Detect Challenging Speech Segments in TED Talks

    Science.gov (United States)

    Mirzaei, Maryam Sadat; Meshgi, Kourosh; Kawahara, Tatsuya

    2016-01-01

    This study investigates the use of Automatic Speech Recognition (ASR) systems to epitomize second language (L2) listeners' problems in perception of TED talks. ASR-generated transcripts of videos often involve recognition errors, which may indicate difficult segments for L2 listeners. This paper aims to discover the root-causes of the ASR errors…

  18. Sharp Threshold Detection Based on Sup-norm Error rates in High-dimensional Models

    DEFF Research Database (Denmark)

    Callot, Laurent; Caner, Mehmet; Kock, Anders Bredahl

    focused almost exclusively on estimation errors in stronger norms. We show that this sup-norm bound can be used to distinguish between zero and non-zero coefficients at a much finer scale than would have been possible using classical oracle inequalities. Thus, our sup-norm bound is tailored to consistent...

  19. Sharp threshold detection based on sup-norm error rates in high-dimensional models

    DEFF Research Database (Denmark)

    Callot, Laurent; Caner, Mehmet; Kock, Anders Bredahl

    2017-01-01

    almost exclusively on ℓ1 and ℓ2 estimation errors. We show that this sup-norm bound can be used to distinguish between zero and non-zero coefficients at a much finer scale than would have been possible using classical oracle inequalities. Thus, our sup-norm bound is tailored to consistent variable...

  20. Detection of reflector surface error from near-field data: Effect of edge diffracted field

    Science.gov (United States)

    Cherrette, Alan R.; Lee, Shong W.; Acosta, Roberto J.

    1987-01-01

    The surface accuracy of large reflector antennas must be maintained within certain tolerances if high gain/low sidelobe performance is to be achieved. Thus the measurement of the surface profile is an important part of the quality control procedure when constructing antennas of this type. An efficient method for surface profile measurement has been proposed, i.e., the reflector surface is calculated from the measured near-field phase data using the theory of geometric optics. For a surface profile calculation of this kind, it is necessary to know the margin of error built into the method of calculation. This will enable a specification of the tolerance from which the surface profile can be determined. When calculating the surface profile from near-field phase data, there are two main sources of error. The first is the measurement error in near-field phase data. The second arises from the edge diffracted fields that are superimposed on the reflected fields in the measured near-field data. The error in the calculated surface profile produced by the edge diffracted fields is examined.

  1. Detecting causality from online psychiatric texts using inter-sentential language patterns

    Directory of Open Access Journals (Sweden)

    Wu Jheng-Long

    2012-07-01

    Full Text Available Abstract Background Online psychiatric texts are natural language texts expressing depressive problems, published by Internet users via community-based web services such as web forums, message boards and blogs. Understanding the cause-effect relations embedded in these psychiatric texts can provide insight into the authors’ problems, thus increasing the effectiveness of online psychiatric services. Methods Previous studies have proposed the use of word pairs extracted from a set of sentence pairs to identify cause-effect relations between sentences. A word pair is made up of two words, with one coming from the cause text span and the other from the effect text span. Analysis of the relationship between these words can be used to capture individual word associations between cause and effect sentences. For instance, (broke up, life and (boyfriend, meaningless are two word pairs extracted from the sentence pair: “I broke up with my boyfriend. Life is now meaningless to me”. The major limitation of word pairs is that individual words in sentences usually cannot reflect the exact meaning of the cause and effect events, and thus may produce semantically incomplete word pairs, as the previous examples show. Therefore, this study proposes the use of inter-sentential language patterns such as ≪broke up, boyfriend>, Results Performance was evaluated on a corpus of texts collected from PsychPark (http://www.psychpark.org, a virtual psychiatric clinic maintained by a group of volunteer professionals from the Taiwan Association of Mental Health Informatics. Experimental results show that the use of inter-sentential language patterns outperformed the use of word pairs proposed in previous studies. Conclusions This study demonstrates the acquisition of inter-sentential language patterns for causality detection from online psychiatric texts. Such semantically more complete and precise features can improve causality detection performance.

  2. Detecting causality from online psychiatric texts using inter-sentential language patterns.

    Science.gov (United States)

    Wu, Jheng-Long; Yu, Liang-Chih; Chang, Pei-Chann

    2012-07-18

    Online psychiatric texts are natural language texts expressing depressive problems, published by Internet users via community-based web services such as web forums, message boards and blogs. Understanding the cause-effect relations embedded in these psychiatric texts can provide insight into the authors' problems, thus increasing the effectiveness of online psychiatric services. Previous studies have proposed the use of word pairs extracted from a set of sentence pairs to identify cause-effect relations between sentences. A word pair is made up of two words, with one coming from the cause text span and the other from the effect text span. Analysis of the relationship between these words can be used to capture individual word associations between cause and effect sentences. For instance, (broke up, life) and (boyfriend, meaningless) are two word pairs extracted from the sentence pair: "I broke up with my boyfriend. Life is now meaningless to me". The major limitation of word pairs is that individual words in sentences usually cannot reflect the exact meaning of the cause and effect events, and thus may produce semantically incomplete word pairs, as the previous examples show. Therefore, this study proposes the use of inter-sentential language patterns such as ≪broke up, boyfriend>, mining framework by extending the classical association rule mining algorithm such that it can discover frequently co-occurring patterns across the sentence boundary. Performance was evaluated on a corpus of texts collected from PsychPark (http://www.psychpark.org), a virtual psychiatric clinic maintained by a group of volunteer professionals from the Taiwan Association of Mental Health Informatics. Experimental results show that the use of inter-sentential language patterns outperformed the use of word pairs proposed in previous studies. This study demonstrates the acquisition of inter-sentential language patterns for causality detection from online psychiatric texts. Such semantically

  3. Measuring and detecting molecular adaptation in codon usage against nonsense errors during protein translation.

    Science.gov (United States)

    Gilchrist, Michael A; Shah, Premal; Zaretzki, Russell

    2009-12-01

    Codon usage bias (CUB) has been documented across a wide range of taxa and is the subject of numerous studies. While most explanations of CUB invoke some type of natural selection, most measures of CUB adaptation are heuristically defined. In contrast, we present a novel and mechanistic method for defining and contextualizing CUB adaptation to reduce the cost of nonsense errors during protein translation. Using a model of protein translation, we develop a general approach for measuring the protein production cost in the face of nonsense errors of a given allele as well as the mean and variance of these costs across its coding synonyms. We then use these results to define the nonsense error adaptation index (NAI) of the allele or a contiguous subset thereof. Conceptually, the NAI value of an allele is a relative measure of its elevation on a specific and well-defined adaptive landscape. To illustrate its utility, we calculate NAI values for the entire coding sequence and across a set of nonoverlapping windows for each gene in the Saccharomyces cerevisiae S288c genome. Our results provide clear evidence of adaptation to reduce the cost of nonsense errors and increasing adaptation with codon position and expression. The magnitude and nature of this adaptation are also largely consistent with simulation results in which nonsense errors are the only selective force driving CUB evolution. Because NAI is derived from mechanistic models, it is both easier to interpret and more amenable to future refinement than other commonly used measures of codon bias. Further, our approach can also be used as a starting point for developing other mechanistically derived measures of adaptation such as for translational accuracy.

  4. Online BCI with Stable Sources

    OpenAIRE

    2012-01-01

    In this paper, we show that the estimated intra-cranial sources using source localization on EEG signals can be used for online Brain Computer Interation (BCI) and the discriminant sources remain stable over days. Classifiers are trained on discriminant sources obtained for Error-related Potential (ErrP) based BCI on day 1 and then tested online on day 2. The results for nine subjects show that the source localization with discriminant sources can be used for online detection of ErrPs. Furthe...

  5. A virtual sensor for online fault detection of multitooth-tools.

    Science.gov (United States)

    Bustillo, Andres; Correa, Maritza; Reñones, Anibal

    2011-01-01

    The installation of suitable sensors close to the tool tip on milling centres is not possible in industrial environments. It is therefore necessary to design virtual sensors for these machines to perform online fault detection in many industrial tasks. This paper presents a virtual sensor for online fault detection of multitooth tools based on a bayesian classifier. The device that performs this task applies mathematical models that function in conjunction with physical sensors. Only two experimental variables are collected from the milling centre that performs the machining operations: the electrical power consumption of the feed drive and the time required for machining each workpiece. The task of achieving reliable signals from a milling process is especially complex when multitooth tools are used, because each kind of cutting insert in the milling centre only works on each workpiece during a certain time window. Great effort has gone into designing a robust virtual sensor that can avoid re-calibration due to, e.g., maintenance operations. The virtual sensor developed as a result of this research is successfully validated under real conditions on a milling centre used for the mass production of automobile engine crankshafts. Recognition accuracy, calculated with a k-fold cross validation, had on average 0.957 of true positives and 0.986 of true negatives. Moreover, measured accuracy was 98%, which suggests that the virtual sensor correctly identifies new cases.

  6. A Virtual Sensor for Online Fault Detection of Multitooth-Tools

    Directory of Open Access Journals (Sweden)

    Andres Bustillo

    2011-03-01

    Full Text Available The installation of suitable sensors close to the tool tip on milling centres is not possible in industrial environments. It is therefore necessary to design virtual sensors for these machines to perform online fault detection in many industrial tasks. This paper presents a virtual sensor for online fault detection of multitooth tools based on a Bayesian classifier. The device that performs this task applies mathematical models that function in conjunction with physical sensors. Only two experimental variables are collected from the milling centre that performs the machining operations: the electrical power consumption of the feed drive and the time required for machining each workpiece. The task of achieving reliable signals from a milling process is especially complex when multitooth tools are used, because each kind of cutting insert in the milling centre only works on each workpiece during a certain time window. Great effort has gone into designing a robust virtual sensor that can avoid re-calibration due to, e.g., maintenance operations. The virtual sensor developed as a result of this research is successfully validated under real conditions on a milling centre used for the mass production of automobile engine crankshafts. Recognition accuracy, calculated with a k-fold cross validation, had on average 0.957 of true positives and 0.986 of true negatives. Moreover, measured accuracy was 98%, which suggests that the virtual sensor correctly identifies new cases.

  7. Offline and online detection of damage using autoregressive models and artificial neural networks

    Science.gov (United States)

    Omenzetter, Piotr; de Lautour, Oliver R.

    2007-04-01

    Developed to study long, regularly sampled streams of data, time series analysis methods are being increasingly investigated for the use of Structural Health Monitoring. In this research, Autoregressive (AR) models are used in conjunction with Artificial Neural Networks (ANNs) for damage detection, localisation and severity assessment. In the first reported experimental exercise, AR models were used offline to fit the acceleration time histories of a 3-storey test structure in undamaged and various damaged states when excited by earthquake motion simulated on a shake table. Damage was introduced into the structure by replacing the columns with those of a thinner thickness. Analytical models of the structure in both damaged and undamaged states were also developed and updated using experimental data in order to determine structural stiffness. The coefficients of AR models were used as damage sensitive features and input into an ANN to build a relationship between them and the remaining structural stiffness. In the second, analytical exercise, a system with gradually progressing damage was numerically simulated and acceleration AR models with exogenous inputs were identified recursively. A trained ANN was then required to trace the structural stiffness online. The results for the offline and online approach showed the efficiency of using AR coefficient as damage sensitive features and good performance of the ANNs for damage detection, localization and quantification.

  8. On-line estimation of myoelectric signal spectral parameters and nonstationarities detection.

    Science.gov (United States)

    D'Alessio, T; Knaflitz, M; Balestra, G; Paggi, S

    1993-09-01

    In this communication, we present a method for detecting nonstationarities of random time series with an approximately Gaussian distribution of amplitudes. This method is suitable for real time implementation. Here we report some results obtained by applying them to a time series of spectral parameters of surface myoelectric signals, collected during voluntary isometric contractions of human muscles. Moreover, we describe the computerized system that we used to implement our detector of nonstationarity. This system is based on the TMS 320C25 DSP chip and realizes on-line estimation and display of spectral parameters, as well as detection of their nonstationarities, featuring a sampling frequency up to 20 k samples/s. A friendly user interface, fully menu driven, allows the user to select different options during the system's operation by means of hot keys. The accuracy of the system was tested by comparing its estimates with those of an off-line system, previously characterized, which we took as a reference. The estimates of spectral parameters obtained by means of the two systems were always consistent. The on-line stationarity detector was able to recognize rates of variation of the spectral parameters as small as 1%/s during contractions lasting 10-15 s. This sensitivity makes it suitable for clinical application. The set of results herein presented has been selected to highlight the main characteristics of the system.

  9. An Online Change of Activity in Energy Spectrum for Detection on an Early Intervention Robot

    Energy Technology Data Exchange (ETDEWEB)

    Boudergui, K.; Laine, F. [CEA, LIST, Laboratoire Capteurs et Architectures Electroniques, F-91191 Gif Sur Yvette (France); Montagu, T. [CEA, LIST, Laboratoire de Modelisation et de Simulation des Systemes, 91191 Gif-sur-Yvette (France); Blanc, P. [IMS, Innovation and Measurement Systems, 94100 Saint-Maur-des-Fosses (France); Deltour, A. [ECA Robotics, 91892 Orsay Cedex (France); Mozziconacci, S. [SDIS13, 13110 Port de Bouc (France)

    2015-07-01

    With the growth of industrial risks and the multiplication of CBRNe (Chemical Biological Radiological and explosive) attacks through toxic chemicals, biological or radiological threats, public services and military authorities face with increasingly critical situations, whose management is strongly conditioned by fast and reliable establishment of an informative diagnostic. Right after an attack, the five first minutes are crucial to define the various scenarios and the most dangerous for a human intervention. Therefore the use of robots is considered essential by all stakeholders of security. In this context, the SISPEO project (Systeme d'Intervention Sapeurs Pompiers Robotise) aims to create/build/design a robust response through a robotic platform for early intervention services such as civil and military security in hostile environments. CEA LIST has proposed an adapted solution to detect and characterize nuclear and radiological risks online and in motion, using a miniature embedded CdZnTe (CZT) crystal Gamma-ray spectrometer. This paper presents experimental results for this miniature embedded CZT spectrometer and its associated mathematical method to detect and characterize radiological threats online and in motion. (authors)

  10. Smart Sensor for Online Detection of Multiple-Combined Faults in VSD-Fed Induction Motors

    Science.gov (United States)

    Garcia-Ramirez, Armando G.; Osornio-Rios, Roque A.; Granados-Lieberman, David; Garcia-Perez, Arturo; Romero-Troncoso, Rene J.

    2012-01-01

    Induction motors fed through variable speed drives (VSD) are widely used in different industrial processes. Nowadays, the industry demands the integration of smart sensors to improve the fault detection in order to reduce cost, maintenance and power consumption. Induction motors can develop one or more faults at the same time that can be produce severe damages. The combined fault identification in induction motors is a demanding task, but it has been rarely considered in spite of being a common situation, because it is difficult to identify two or more faults simultaneously. This work presents a smart sensor for online detection of simple and multiple-combined faults in induction motors fed through a VSD in a wide frequency range covering low frequencies from 3 Hz and high frequencies up to 60 Hz based on a primary sensor being a commercially available current clamp or a hall-effect sensor. The proposed smart sensor implements a methodology based on the fast Fourier transform (FFT), RMS calculation and artificial neural networks (ANN), which are processed online using digital hardware signal processing based on field programmable gate array (FPGA).

  11. Development of a Compton camera for online ion beam range verification via prompt γ detection

    Energy Technology Data Exchange (ETDEWEB)

    Aldawood, Saad [Ludwig-Maximilians-Universitaet Muenchen (Germany); King Saud University, Riyadh (Saudi Arabia); Lang, Christian; Lutter, Rudolf; Bortfeldt, Jonathan; Parodi, Katia; Thirolf, Peter G. [Ludwig-Maximilians-Universitaet Muenchen (Germany); Kolff, Hugh van der [Ludwig-Maximilians-Universitaet Muenchen (Germany); Delft University of Technology (Netherlands); Maier, Ludwig [Technische Universitaet Muenchen (Germany)

    2014-07-01

    Precise and preferably online ion beam range verification is a mandatory prerequisite to fully exploit the advantages of hadron-therapy in cancer treatment. Our aim is to develop an imaging system based on a Compton camera designed to detect prompt γ rays induced by nuclear reactions between ion beam and biological tissue. The Compton camera prototype consists of a stack of double-sided Si-strip detectors (DSSSD) acting as scatterers, while the absorber is formed by a LaBr{sub 3} scintillator crystal read out by a position-sensitive multi-anode photomultiplier. The LaBr{sub 3} detector was characterized with both absorptive and reflective side-face wrapping materials. Comparative studies of energy and time resolution, photopeak detection efficiency and spatial resolution are presented together with first tests of the complete camera system.

  12. Adaptive hidden Markov model-based online learning framework for bearing faulty detection and performance degradation monitoring

    Science.gov (United States)

    Yu, Jianbo

    2017-01-01

    This study proposes an adaptive-learning-based method for machine faulty detection and health degradation monitoring. The kernel of the proposed method is an "evolving" model that uses an unsupervised online learning scheme, in which an adaptive hidden Markov model (AHMM) is used for online learning the dynamic health changes of machines in their full life. A statistical index is developed for recognizing the new health states in the machines. Those new health states are then described online by adding of new hidden states in AHMM. Furthermore, the health degradations in machines are quantified online by an AHMM-based health index (HI) that measures the similarity between two density distributions that describe the historic and current health states, respectively. When necessary, the proposed method characterizes the distinct operating modes of the machine and can learn online both abrupt as well as gradual health changes. Our method overcomes some drawbacks of the HIs (e.g., relatively low comprehensibility and applicability) based on fixed monitoring models constructed in the offline phase. Results from its application in a bearing life test reveal that the proposed method is effective in online detection and adaptive assessment of machine health degradation. This study provides a useful guide for developing a condition-based maintenance (CBM) system that uses an online learning method without considerable human intervention.

  13. On-line coupled LC-LC-GC for irradiation detection in complex lipid matrices

    Energy Technology Data Exchange (ETDEWEB)

    Schulzki, G. (Laboratory Group, Irradiation of Foods and Pharmaceuticals, Alternative Techniques, Inst. for Social Medicine and Epidemiology, Federal Health Office (BGA), Berlin (Germany)); Spiegelberg, A. (Laboratory Group, Irradiation of Foods and Pharmaceuticals, Alternative Techniques, Inst. for Social Medicine and Epidemiology, Federal Health Office (BGA), Berlin (Germany)); Helle, N. (Laboratory Group, Irradiation of Foods and Pharmaceuticals, Alternative Techniques, Inst. for Social Medicine and Epidemiology, Federal Health Office (BGA), Berlin (Germany)); Boegl, K.W. (Laboratory Group, Irradiation of Foods and Pharmaceuticals, Alternative Techniques, Inst. for Social Medicine and Epidemiology, Federal Health Office (BGA), Berlin (Germany)); Schreiber, G.A. (Laboratory Group, Irradiation of Foods and Pharmaceuticals, Alternative Techniques, Inst. for Social Medicine and Epidemiology, Federal Health Office (BGA), Berlin (Germany))

    1993-01-01

    Since sample preparation with HPLC coupled on-line to the GC has been performed for only a few weeks in our laboratory, the results presented give a first look at what can be done by means of this technique. Even difficult samples as the described fish species, where an unequivocal identification regarding an irradiation treatment seemed to become a hopeless enterprise, could be managed. Because of the greater variety of fatty acids in fish ''new'' radiation-induced hydrocarbons were available. According to the theory of Nawar in addition to 16:2 and 17:2 hydrocarbons we have looked for in irradiated meat, further alkadienes appeared in irradiated fish, which were 14:2, 18:2 and 20:2. Analysis of the alkadiene-fraction, transferred to the GC after a two step LC clean up, resulted in an unequivocal identification of all fish samples as well as the fruits and sponge cake. For fruits and sponge cake the detection limit seems to be clearly below 0.5 kGy. It can further be lowered by increasing the amount of lipid whereas the upper limit for a certain LC column has to be determined. In contrast to these samples only qualitative results were obtained for fish. In the case of sponge cake for the first time irradiation of a component of a heat treated food was detected. Further investigations regarding reproducibility, dose dependence and detection limit have to be done. On-line coupled (LC-)LC-GC was proved to be a highly efficient method for analysis of complex samples. In contrast to off-line Florisil column chromatography only a small part of the initial lipid material is needed because the complete hydrocarbon fraction is transferred on-line to the GC. This offers the possibility to analyze even foods with a low fat content like various seafoods. Classification of the hydrocarbon fraction by a two step LC may facilitate the identification of the radiolytic products also if no mass spectrometric detection system is available. (orig./vhe)

  14. [The fate of scientific articles when errors and scientific misconduct are detected].

    Science.gov (United States)

    Vinther, Siri; Rosenberg, Jacob

    2014-01-20

    When a minor error is noted in a scientific article, the publishing journal should issue a correction. Issuing an expression of concern is relevant when scientific misconduct is suspected. If the suspicion proves to be well founded, the journal should retract the article. The number of retractions is increasing, and this emphasizes the need for unequivocal concepts and guidelines. The reason a given article is corrected or retracted should be unambiguous and articles as well as notices should be indexed properly.

  15. Protein sequence alignment analysis by local covariation: coevolution statistics detect benchmark alignment errors.

    Directory of Open Access Journals (Sweden)

    Russell J Dickson

    Full Text Available The use of sequence alignments to understand protein families is ubiquitous in molecular biology. High quality alignments are difficult to build and protein alignment remains one of the largest open problems in computational biology. Misalignments can lead to inferential errors about protein structure, folding, function, phylogeny, and residue importance. Identifying alignment errors is difficult because alignments are built and validated on the same primary criteria: sequence conservation. Local covariation identifies systematic misalignments and is independent of conservation. We demonstrate an alignment curation tool, LoCo, that integrates local covariation scores with the Jalview alignment editor. Using LoCo, we illustrate how local covariation is capable of identifying alignment errors due to the reduction of positional independence in the region of misalignment. We highlight three alignments from the benchmark database, BAliBASE 3, that contain regions of high local covariation, and investigate the causes to illustrate these types of scenarios. Two alignments contain sequential and structural shifts that cause elevated local covariation. Realignment of these misaligned segments reduces local covariation; these alternative alignments are supported with structural evidence. We also show that local covariation identifies active site residues in a validated alignment of paralogous structures. Loco is available at https://sourceforge.net/projects/locoprotein/files/.

  16. Limit of detection in the presence of instrumental and non-instrumental errors: study of the possible sources of error and application to the analysis of 41 elements at trace levels by inductively coupled plasma-mass spectrometry technique

    Energy Technology Data Exchange (ETDEWEB)

    Badocco, Denis; Lavagnini, Irma; Mondin, Andrea; Tapparo, Andrea; Pastore, Paolo, E-mail: paolo.pastore@unipd.it

    2015-05-01

    In this paper the detection limit was estimated when signals were affected by two error contributions, namely instrumental errors and operational-non-instrumental errors. The detection limit was theoretically obtained following the hypothesis testing schema implemented with the calibration curve methodology. The experimental calibration design was based on J standards measured I times with non-instrumental errors affecting each standard systematically but randomly among the J levels. A two-component variance regression was performed to determine the calibration curve and to define the detection limit in these conditions. The detection limit values obtained from the calibration at trace levels of 41 elements by ICP-MS resulted larger than those obtainable from a one component variance regression. The role of the reagent impurities on the instrumental errors was ascertained and taken into account. Environmental pollution was studied as source of non-instrumental errors. The environmental pollution role was evaluated by Principal Component Analysis technique (PCA) applied to a series of nine calibrations performed in fourteen months. The influence of the seasonality of the environmental pollution on the detection limit was evidenced for many elements usually present in the urban air particulate. The obtained results clearly indicated the need of using the two-component variance regression approach for the calibration of all the elements usually present in the environment at significant concentration levels. - Highlights: • Limit of detection was obtained considering a two variance component regression. • Calibration data may be affected by instrumental and operational conditions errors. • Calibration model was applied to determine 41 elements at trace level by ICP-MS. • Non instrumental errors were evidenced by PCA analysis.

  17. Detection and Localization of Tooth Breakage Fault on Wind Turbine Planetary Gear System considering Gear Manufacturing Errors

    Directory of Open Access Journals (Sweden)

    Y. Gui

    2014-01-01

    Full Text Available Sidebands of vibration spectrum are sensitive to the fault degree and have been proved to be useful for tooth fault detection and localization. However, the amplitude and frequency modulation due to manufacturing errors (which are inevitable in actual planetary gear system lead to much more complex sidebands. Thus, in the paper, a lumped parameter model for a typical planetary gear system with various types of errors is established. In the model, the influences of tooth faults on time-varying mesh stiffness and tooth impact force are derived analytically. Numerical methods are then utilized to obtain the response spectra of the system with tooth faults with and without errors. Three system components (including sun, planet, and ring gears with tooth faults are considered in the discussion, respectively. Through detailed comparisons of spectral sidebands, fault characteristic frequencies of the system are acquired. Dynamic experiments on a planetary gear-box test rig are carried out to verify the simulation results and these results are of great significances for the detection and localization of tooth faults in wind turbines.

  18. Array processing——a new method to detect and correct errors on array resistivity logging tool measurements

    Institute of Scientific and Technical Information of China (English)

    Philip D.RABINOWITZ; Zhiqiang ZHOU

    2007-01-01

    In recent years more and more multi-array logging tools, such as the array induction and the array lateralog, are applied in place of conventional logging tools resulting in increased resolution, better radial and vertical sounding capability and other features. Multi-array logging tools acquire several times more individual measurements than conventional logging tools. In addition to new information contained in these data, there is a certain redundancy among the measurements. The sum of the measurements actually composes a large matrix. Providing the measurements are error-free, the elements of this matrix show certain consistencies. Taking advantage of these consistencies, an innovative method is developed to detect and correct errors in the array resistivity logging tool raw measurements, and evaluate the quality of the data. The method can be described in several steps. First, data consistency patterns are identified based onthe physics of the measurements. Second, the measurements are compared against the consistency patterns for error and bad data detection. Third, the erroneous data are eliminated and the measurements are re-constructed according to the consistency patterns. Finally, the data quality is evaluated by comparing the raw measurements with the re-constructed measurements. The method can be applied to all array type logging tools, such as array induction tool and array resistivity tool. This paper describes the method and illustrates its application with the High Definition Lateral Log (HDLL, Baker Atlas) instrument. To demonstrate the efficiency of the method, several field examples are shown and discussed.

  19. Detecting the Online Image of “Average” Restaurants on TripAdvisor

    Directory of Open Access Journals (Sweden)

    Hrvoje Jakopović

    2016-06-01

    Full Text Available Collective intelligence can be interpreted as the actions of individuals that provide collective effects. In online spaces, the more user comments about a matter of discussion, the higher the potential that certain repeated points of view will be used as a story frame. This observation can be a very useful explanation for the value of user comments, reviews and the ratings in the field of public relations. Nowadays, it has become noticeable that many indecisive people who are thinking of buying a product or using a certain service rely on information left by users who already have some kind of experience with the product or service. This information has an effect on decision-making and taking action. In the case of contemporary PR, collective intelligence, facilitated through user comments/reviews, is involved in the image making process. This paper uses the idea of collective intelligence to measure restaurants’ online image, using sentiment analysis to gain insight to users’ attitudes and opinions. Image is interpreted as a short-term outcome of organizational activities that can be identified through individual attitudes and opinions in this study. The author uses sentiment analysis, the use of natural language processing applications, to examine user comments and reviews for restaurants in Dubrovnik rated as “average” on the website TripAdvisor. This paper tests the accuracy of sentiment analysis software, therefore the efficiency of automated sentiment analysis is compared to human sentiment analysis. The results indicate that sentiment analysis tools could be important instruments for the estimation of a positive, negative, or neutral sentiment and detection of organization’s online image.

  20. The Metal Detecting Forum - an online community. Resource, education and co-operation

    Directory of Open Access Journals (Sweden)

    Tom Redmayne

    2013-03-01

    Full Text Available This article discusses the potential of the internet-based, metal detecting forum for interaction and dialogue between the profession of archaeology and the hobby of metal detecting. It also discusses its role as a focal point for those interested in, and requiring information and guidance on, all aspects of metal detecting and its associated disciplines, with particular reference to the United Kingdom Detector Net (UKDN forum. Since its inception in 2002, UKDN has grown from being a small group of like-minded enthusiasts discussing their hobby into an online community of over 5800 people from all walks of life, with a great variety of professions and interests represented. Members have a wealth of knowledge and information to draw on, such as: ◦Finds identification, including non-metallic finds ◦The law relating to metal detecting, including the Treasure Act ◦Political issues affecting the hobby and associated disciplines ◦Different machines available and how to get the most from them and ◦How best to record and report finds. Best practice is promoted at all times in recording finds with the Portable Antiquities Scheme (PAS and encouraging dialogue with the profession of archaeology. Many members have assisted on both professional and amateur digs both with, and without, their detectors. Forum members have also assisted in campaigns that they feel strongly about, such as the threat of PAS funding cuts in 2008.

  1. Examining Type I Error and Power for Detection of Differential Item and Testlet Functioning

    Science.gov (United States)

    Lee, Young-Sun; Cohen, Allan; Toro, Maritsa

    2009-01-01

    In this study, the effectiveness of detection of differential item functioning (DIF) and testlet DIF using SIBTEST and Poly-SIBTEST were examined in tests composed of testlets. An example using data from a reading comprehension test showed that results from SIBTEST and Poly-SIBTEST were not completely consistent in the detection of DIF and testlet…

  2. On-line concentration of trace genistein by acid barrage stacking in capillary electrophoresis with UV detection

    Institute of Scientific and Technical Information of China (English)

    Hai Yan Feng; Xiang Jun Li; Shu Rong Hou; Na Zheng; Zhong Bo Hu; Zhuo Bin Yuan

    2008-01-01

    A capillary electrophoresis method with UV detection was developed for high sensitively determining genistein. In this method, the online acid barrage stacking was applied. Four key factors influencing the stacking efficiency were systematically optimized. Genistein can be detected within 5 rain at the concentration of 10 nmol/L, which was 300 times lower than that from conventional hydrodynamic injection. The repeatability, linear range, and limit of detection of the method were investigated with satisfactory result.

  3. APPROACH TO FAULT ON-LINE DETECTION AND DIAGNOSIS BASED ON NEURAL NETWORKS FOR ROBOT IN FMS

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Based on radial basis function (RBF) neural networks, the healthy working model of each sub-system of robot in FMS is established. A new approach to fault on-line detection and diagnosis according to neural networks model is presented. Fault double detection based on neural network model and threshold judgement and quick fault identification based on multi-layer feedforward neural networks are applied, which can meet quickness and reliability of fault detection and diagnosis for robot in FMS.

  4. Followers are not enough: a multifaceted approach to community detection in online social networks.

    Science.gov (United States)

    Darmon, David; Omodei, Elisa; Garland, Joshua

    2015-01-01

    In online social media networks, individuals often have hundreds or even thousands of connections, which link these users not only to friends, associates, and colleagues, but also to news outlets, celebrities, and organizations. In these complex social networks, a 'community' as studied in the social network literature, can have very different meaning depending on the property of the network under study. Taking into account the multifaceted nature of these networks, we claim that community detection in online social networks should also be multifaceted in order to capture all of the different and valuable viewpoints of 'community.' In this paper we focus on three types of communities beyond follower-based structural communities: activity-based, topic-based, and interaction-based. We analyze a Twitter dataset using three different weightings of the structural network meant to highlight these three community types, and then infer the communities associated with these weightings. We show that interesting insights can be obtained about the complex community structure present in social networks by studying when and how these four community types give rise to similar as well as completely distinct community structure.

  5. Improving Fraudster Detection in Online Auctions by Using Neighbor-Driven Attributes

    Directory of Open Access Journals (Sweden)

    Jun-Lin Lin

    2015-12-01

    Full Text Available Online auction websites use a simple reputation system to help their users to evaluate the trustworthiness of sellers and buyers. However, to improve their reputation in the reputation system, fraudulent users can easily deceive the reputation system by creating fake transactions. This inflated-reputation fraud poses a major problem for online auction websites because it can lead legitimate users into scams. Numerous approaches have been proposed in the literature to address this problem, most of which involve using social network analysis (SNA to derive critical features (e.g., k-core, center weight, and neighbor diversity for distinguishing fraudsters from legitimate users. This paper discusses the limitations of these SNA features and proposes a class of SNA features referred to as neighbor-driven attributes (NDAs. The NDAs of users are calculated from the features of their neighbors. Because fraudsters require collusive neighbors to provide them with positive ratings in the reputation system, using NDAs can be helpful for detecting fraudsters. Although the idea of NDAs is not entirely new, experimental results on a real-world dataset showed that using NDAs improves classification accuracy compared with state-of-the-art methods that use the k-core, center weight, and neighbor diversity.

  6. Impulse feature extraction method for machinery fault detection using fusion sparse coding and online dictionary learning

    Directory of Open Access Journals (Sweden)

    Deng Sen

    2015-04-01

    Full Text Available Impulse components in vibration signals are important fault features of complex machines. Sparse coding (SC algorithm has been introduced as an impulse feature extraction method, but it could not guarantee a satisfactory performance in processing vibration signals with heavy background noises. In this paper, a method based on fusion sparse coding (FSC and online dictionary learning is proposed to extract impulses efficiently. Firstly, fusion scheme of different sparse coding algorithms is presented to ensure higher reconstruction accuracy. Then, an improved online dictionary learning method using FSC scheme is established to obtain redundant dictionary and it can capture specific features of training samples and reconstruct the sparse approximation of vibration signals. Simulation shows that this method has a good performance in solving sparse coefficients and training redundant dictionary compared with other methods. Lastly, the proposed method is further applied to processing aircraft engine rotor vibration signals. Compared with other feature extraction approaches, our method can extract impulse features accurately and efficiently from heavy noisy vibration signal, which has significant supports for machinery fault detection and diagnosis.

  7. 隔离型换热节能系统的粗大误差检测研究%Research on gross error detection in isolated heat exchange energy-saving system

    Institute of Scientific and Technical Information of China (English)

    王瑞华; 王普

    2012-01-01

    In the process of real-time optimization of isolated heat exchange energy-saving system,the gross error detection is an important research part. In order to solve the problem of gross error detection in the system output variables, the generation of gross error and the significance of detection,moreover the characteristics of several detection criterions are introduced. Based on the features of real-time and on-line running,dixon criterion is used to detect the gross error in the system output variables. Using practical data in field,experiment research is carried out. The experiment result shows that the method is feasible and it is fit for being used on-line.%在对隔离型换热节能系统进行实时优化的过程中,数据的粗大误差检测是一个重要的研究内容.为了解决系统输出变量的粗大误差检测问题,对粗大误差的产生、检测的意义和几种检测准则的特点进行了介绍.针对系统实时在线运行特点,提出采用狄克逊准则对系统输出变量的粗大误差进行检测,同时利用实际现场采集的数据进行了实验研究.实验结果表明,文中所采用方法是可行的,并且适合在线应用.

  8. Threshold-based detection for amplify-and-forward cooperative communication systems with channel estimation error

    KAUST Repository

    Abuzaid, Abdulrahman I.

    2014-09-01

    Efficient receiver designs for cooperative communication systems are becoming increasingly important. In previous work, cooperative networks communicated with the use of $L$ relays. As the receiver is constrained, it can only process $U$ out of $L$ relays. Channel shortening and reduced-rank techniques were employed to design the preprocessing matrix. In this paper, a receiver structure is proposed which combines the joint iterative optimization (JIO) algorithm and our proposed threshold selection criteria. This receiver structure assists in determining the optimal $U-{opt}$. Furthermore, this receiver provides the freedom to choose $U ≤ U-{opt}$ for each frame depending upon the tolerable difference allowed for mean square error (MSE). Our study and simulation results show that by choosing an appropriate threshold, it is possible to gain in terms of complexity savings without affecting the BER performance of the system. Furthermore, in this paper the effect of channel estimation errors is investigated on the MSE performance of the amplify-and-forward (AF) cooperative relaying system.

  9. Online Sensor Fault Detection Based on an Improved Strong Tracking Filter

    Science.gov (United States)

    Wang, Lijuan; Wu, Lifeng; Guan, Yong; Wang, Guohui

    2015-01-01

    We propose a method for online sensor fault detection that is based on the evolving Strong Tracking Filter (STCKF). The cubature rule is used to estimate states to improve the accuracy of making estimates in a nonlinear case. A residual is the difference in value between an estimated value and the true value. A residual will be regarded as a signal that includes fault information. The threshold is set at a reasonable level, and will be compared with residuals to determine whether or not the sensor is faulty. The proposed method requires only a nominal plant model and uses STCKF to estimate the original state vector. The effectiveness of the algorithm is verified by simulation on a drum-boiler model. PMID:25690553

  10. Parameters Online Detection and Model Predictive Control during the Grain Drying Process

    Directory of Open Access Journals (Sweden)

    Lihui Zhang

    2013-01-01

    Full Text Available In order to improve the grain drying quality and automation level, combined with the structural characteristics of the cross-flow circulation grain dryer designed and developed by us, the temperature, moisture, and other parameters measuring sensors were placed on the dryer, to achieve online automatic detection of process parameters during the grain drying process. A drying model predictive control system was set up. A grain dry predictive control model at constant velocity and variable temperature was established, in which the entire process was dried at constant velocity (i.e., precipitation rate per hour is a constant and variable temperature. Combining PC with PLC, and based on LabVIEW, a system control platform was designed.

  11. Liking and hyperlinking: Community detection in online child sexual exploitation networks.

    Science.gov (United States)

    Westlake, Bryce G; Bouchard, Martin

    2016-09-01

    The online sexual exploitation of children is facilitated by websites that form virtual communities, via hyperlinks, to distribute images, videos, and other material. However, how these communities form, are structured, and evolve over time is unknown. Collected using a custom-designed webcrawler, we begin from known child sexual exploitation (CE) seed websites and follow hyperlinks to connected, related, websites. Using a repeated measure design we analyze 10 networks of 300 + websites each - over 4.8 million unique webpages in total, over a period of 60 weeks. Community detection techniques reveal that CE-related networks were dominated by two large communities hosting varied material -not necessarily matching the seed website. Community stability, over 60 weeks, varied across networks. Reciprocity in hyperlinking between community members was substantially higher than within the full network, however, websites were not more likely to connect to homogeneous-content websites.

  12. Optimal Parameter Exploration for Online Change-Point Detection in Activity Monitoring Using Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Naveed Khan

    2016-10-01

    Full Text Available In recent years, smart phones with inbuilt sensors have become popular devices to facilitate activity recognition. The sensors capture a large amount of data, containing meaningful events, in a short period of time. The change points in this data are used to specify transitions to distinct events and can be used in various scenarios such as identifying change in a patient’s vital signs in the medical domain or requesting activity labels for generating real-world labeled activity datasets. Our work focuses on change-point detection to identify a transition from one activity to another. Within this paper, we extend our previous work on multivariate exponentially weighted moving average (MEWMA algorithm by using a genetic algorithm (GA to identify the optimal set of parameters for online change-point detection. The proposed technique finds the maximum accuracy and F_measure by optimizing the different parameters of the MEWMA, which subsequently identifies the exact location of the change point from an existing activity to a new one. Optimal parameter selection facilitates an algorithm to detect accurate change points and minimize false alarms. Results have been evaluated based on two real datasets of accelerometer data collected from a set of different activities from two users, with a high degree of accuracy from 99.4% to 99.8% and F_measure of up to 66.7%.

  13. Fast Flux Watch: A mechanism for online detection of fast flux networks.

    Science.gov (United States)

    Al-Duwairi, Basheer N; Al-Hammouri, Ahmad T

    2014-07-01

    Fast flux networks represent a special type of botnets that are used to provide highly available web services to a backend server, which usually hosts malicious content. Detection of fast flux networks continues to be a challenging issue because of the similar behavior between these networks and other legitimate infrastructures, such as CDNs and server farms. This paper proposes Fast Flux Watch (FF-Watch), a mechanism for online detection of fast flux agents. FF-Watch is envisioned to exist as a software agent at leaf routers that connect stub networks to the Internet. The core mechanism of FF-Watch is based on the inherent feature of fast flux networks: flux agents within stub networks take the role of relaying client requests to point-of-sale websites of spam campaigns. The main idea of FF-Watch is to correlate incoming TCP connection requests to flux agents within a stub network with outgoing TCP connection requests from the same agents to the point-of-sale website. Theoretical and traffic trace driven analysis shows that the proposed mechanism can be utilized to efficiently detect fast flux agents within a stub network.

  14. The Relative Importance of Random Error and Observation Frequency in Detecting Trends in Upper Tropospheric Water Vapor

    Science.gov (United States)

    Whiteman, David N.; Vermeesch, Kevin C.; Oman, Luke D.; Weatherhead, Elizabeth C.

    2011-01-01

    Recent published work assessed the amount of time to detect trends in atmospheric water vapor over the coming century. We address the same question and conclude that under the most optimistic scenarios and assuming perfect data (i.e., observations with no measurement uncertainty) the time to detect trends will be at least 12 years at approximately 200 hPa in the upper troposphere. Our times to detect trends are therefore shorter than those recently reported and this difference is affected by data sources used, method of processing the data, geographic location and pressure level in the atmosphere where the analyses were performed. We then consider the question of how instrumental uncertainty plays into the assessment of time to detect trends. We conclude that due to the high natural variability in atmospheric water vapor, the amount of time to detect trends in the upper troposphere is relatively insensitive to instrumental random uncertainty and that it is much more important to increase the frequency of measurement than to decrease the random error in the measurement. This is put in the context of international networks such as the Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) and the Network for the Detection of Atmospheric Composition Change (NDACC) that are tasked with developing time series of climate quality water vapor data.

  15. A wearable device for real-time motion error detection and vibrotactile instructional cuing.

    Science.gov (United States)

    Lee, Beom-Chan; Chen, Shu; Sienko, Kathleen H

    2011-08-01

    We have developed a mobile instrument for motion instruction and correction (MIMIC) that enables an expert (i.e., physical therapist) to map his/her movements to a trainee (i.e., patient) in a hands-free fashion. MIMIC comprises an expert module (EM) and a trainee module (TM). Both the EM and TM are composed of six-degree-of-freedom inertial measurement units, microcontrollers, and batteries. The TM also has an array of actuators that provide the user with vibrotactile instructional cues. The expert wears the EM, and his/her relevant body position is computed by an algorithm based on an extended Kalman filter that provides asymptotic state estimation. The captured expert body motion information is transmitted wirelessly to the trainee, and based on the computed difference between the expert and trainee motion, directional instructions are displayed via vibrotactile stimulation to the skin. The trainee is instructed to move in the direction of the vibration sensation until the vibration is eliminated. Two proof-of-concept studies involving young, healthy subjects were conducted using a simplified version of the MIMIC system (pre-specified target trajectories representing ideal expert movements and only two actuators) during anterior-posterior trunk movements. The first study was designed to investigate the effects of changing the expert-trainee error thresholds (0.5(°), 1.0(°), and 1.5(°)) and varying the nature of the control signal (proportional, proportional plus derivative). Expert-subject cross-correlation values were maximized (0.99) and average position errors (0.33(°)) and time delays (0.2 s) were minimized when the controller used a 0.5(°) error threshold and proportional plus derivative feedback control signal. The second study used the best performing activation threshold and control signal determined from the first study to investigate subject performance when the motion task complexity and speed were varied. Subject performance decreased as motion

  16. Research on the Error Characteristics of a 110 kV Optical Voltage Transformer under Three Conditions: In the Laboratory, Off-Line in the Field and During On-Line Operation

    Directory of Open Access Journals (Sweden)

    Xia Xiao

    2016-08-01

    Full Text Available Optical voltage transformers (OVTs have been applied in power systems. When performing accuracy performance tests of OVTs large differences exist between the electromagnetic environment and the temperature variation in the laboratory and on-site. Therefore, OVTs may display different error characteristics under different conditions. In this paper, OVT prototypes with typical structures were selected to be tested for the error characteristics with the same testing equipment and testing method. The basic accuracy, the additional error caused by temperature and the adjacent phase in the laboratory, the accuracy in the field off-line, and the real-time monitoring error during on-line operation were tested. The error characteristics under the three conditions—laboratory, in the field off-line and during on-site operation—were compared and analyzed. The results showed that the effect of the transportation process, electromagnetic environment and the adjacent phase on the accuracy of OVTs could be ignored for level 0.2, but the error characteristics of OVTs are dependent on the environmental temperature and are sensitive to the temperature gradient. The temperature characteristics during on-line operation were significantly superior to those observed in the laboratory.

  17. Research on the Error Characteristics of a 110 kV Optical Voltage Transformer under Three Conditions: In the Laboratory, Off-Line in the Field and During On-Line Operation.

    Science.gov (United States)

    Xiao, Xia; Hu, Haoliang; Xu, Yan; Lei, Min; Xiong, Qianzhu

    2016-01-01

    Optical voltage transformers (OVTs) have been applied in power systems. When performing accuracy performance tests of OVTs large differences exist between the electromagnetic environment and the temperature variation in the laboratory and on-site. Therefore, OVTs may display different error characteristics under different conditions. In this paper, OVT prototypes with typical structures were selected to be tested for the error characteristics with the same testing equipment and testing method. The basic accuracy, the additional error caused by temperature and the adjacent phase in the laboratory, the accuracy in the field off-line, and the real-time monitoring error during on-line operation were tested. The error characteristics under the three conditions-laboratory, in the field off-line and during on-site operation-were compared and analyzed. The results showed that the effect of the transportation process, electromagnetic environment and the adjacent phase on the accuracy of OVTs could be ignored for level 0.2, but the error characteristics of OVTs are dependent on the environmental temperature and are sensitive to the temperature gradient. The temperature characteristics during on-line operation were significantly superior to those observed in the laboratory.

  18. Research on the Error Characteristics of a 110 kV Optical Voltage Transformer under Three Conditions: In the Laboratory, Off-Line in the Field and During On-Line Operation

    Science.gov (United States)

    Xiao, Xia; Hu, Haoliang; Xu, Yan; Lei, Min; Xiong, Qianzhu

    2016-01-01

    Optical voltage transformers (OVTs) have been applied in power systems. When performing accuracy performance tests of OVTs large differences exist between the electromagnetic environment and the temperature variation in the laboratory and on-site. Therefore, OVTs may display different error characteristics under different conditions. In this paper, OVT prototypes with typical structures were selected to be tested for the error characteristics with the same testing equipment and testing method. The basic accuracy, the additional error caused by temperature and the adjacent phase in the laboratory, the accuracy in the field off-line, and the real-time monitoring error during on-line operation were tested. The error characteristics under the three conditions—laboratory, in the field off-line and during on-site operation—were compared and analyzed. The results showed that the effect of the transportation process, electromagnetic environment and the adjacent phase on the accuracy of OVTs could be ignored for level 0.2, but the error characteristics of OVTs are dependent on the environmental temperature and are sensitive to the temperature gradient. The temperature characteristics during on-line operation were significantly superior to those observed in the laboratory. PMID:27537895

  19. Short-chain fluorescent tryptophan tags for on-line detection of functional recombinant proteins

    Directory of Open Access Journals (Sweden)

    Siepert Eva-Maria

    2012-09-01

    Full Text Available Abstract Background Conventional fluorescent proteins, such as GFP, its derivatives and flavin mononucleotide based fluorescent proteins (FbFPs are often used as fusion tags for detecting recombinant proteins during cultivation. These reporter tags are state-of-the-art; however, they have some drawbacks, which can make on-line monitoring challenging. It is discussed in the literature that the large molecular size of proteins of the GFP family may stress the host cell metabolism during production. In addition, fluorophore formation of GFP derivatives is oxygen-dependent resulting in a lag-time between expression and fluorescence detection and the maturation of the protein is suppressed under oxygen-limited conditions. On the contrary, FbFPs are also applicable in an oxygen-limited or even anaerobic environment but are still quite large (58% of the size of GFP. Results As an alternative to common fluorescent tags we developed five novel tags based on clustered tryptophan residues, called W-tags. They are only 5-11% of the size of GFP. Based on the property of tryptophan to fluoresce in absence of oxygen it is reasonable to assume that the functionality of our W-tags is also given under anaerobic conditions. We fused these W-tags to a recombinant protein model, the anti-CD30 receptor single-chain fragment variable antibody (scFv Ki-4(scFv and the anti-MucI single-chain fragment variable M12(scFv. During cultivation in Microtiter plates, the overall tryptophan fluorescence intensity of all cultures was measured on-line for monitoring product formation via the different W-tags. After correlation of the scattered light signal representing biomass concentration and tryptophan fluorescence for the uninduced cultures, the fluorescence originating from the biomass was subtracted from the overall tryptophan signal. The resulting signal, thus, represents the product fluorescence of the tagged and untagged antibody fragments. The product fluorescence signal

  20. A new method for immunoassays using field-flow fractionation with on-line, continuous chemiluminescence detection.

    Science.gov (United States)

    Melucci, D; Guardigli, M; Roda, B; Zattoni, A; Reschiglian, P; Roda, A

    2003-06-13

    Chemiluminescence detection has already been combined with different separation techniques such as HPLC and capillary electrophoresis. In this work, it was applied to gravitational field-flow fractionation, a low-cost, flow-assisted separation technique for micronsized particles suited to further on-line detection of the separated analytes. Horseradish peroxidase was used as model sample, either free in solution or immobilized onto micronsized, polystyrene beads. The chemiluminescent substrates were added directly into the mobile phase, and the continuous, steady-state chemiluminescence generated during elution was detected on-line by either a flow-through luminometer or a CCD camera. Ultra-low detection limits, two orders of magnitude lower than those achievable with spectrophotometric detection, were found. The possibility to fully separate and quantitate free and bead-immobilized enzymes is reported, as a step towards the development of multianalyte, ultra-sensitive, micronsized beads-based flow-assisted immunoassays.

  1. Detecting Translation Errors in CAD Surfaces and Preparing Geometries for Mesh Generation

    Energy Technology Data Exchange (ETDEWEB)

    Petersson, N Anders; Chand, K K

    2001-08-27

    The authors have developed tools for the efficient preparation of CAD geometries for mesh generation. Geometries are read from IGES files and then maintained in a boundary-representation consisting of a patchwork of trimmed and untrimmed surfaces. Gross errors in the geometry can be identified and removed automatically while a user interface is provided for manipulating the geometry (such as correcting invalid trimming curves or removing unwanted details). Modifying the geometry by adding or deleting surfaces and/or sectioning it by arbitrary planes (e.g. symmetry planes) is also supported. These tools are used for robust and accurate geometry models for initial mesh generation and will be applied to in situ mesh generation requirements of moving and adaptive grid simulations.

  2. Robust and Adaptive OMR System Including Fuzzy Modeling, Fusion of Musical Rules, and Possible Error Detection

    Directory of Open Access Journals (Sweden)

    Isabelle Bloch

    2007-01-01

    Full Text Available This paper describes a system for optical music recognition (OMR in case of monophonic typeset scores. After clarifying the difficulties specific to this domain, we propose appropriate solutions at both image analysis level and high-level interpretation. Thus, a recognition and segmentation method is designed, that allows dealing with common printing defects and numerous symbol interconnections. Then, musical rules are modeled and integrated, in order to make a consistent decision. This high-level interpretation step relies on the fuzzy sets and possibility framework, since it allows dealing with symbol variability, flexibility, and imprecision of music rules, and merging all these heterogeneous pieces of information. Other innovative features are the indication of potential errors and the possibility of applying learning procedures, in order to gain in robustness. Experiments conducted on a large data base show that the proposed method constitutes an interesting contribution to OMR.

  3. Robust and Adaptive OMR System Including Fuzzy Modeling, Fusion of Musical Rules, and Possible Error Detection

    Science.gov (United States)

    Rossant, Florence; Bloch, Isabelle

    2006-12-01

    This paper describes a system for optical music recognition (OMR) in case of monophonic typeset scores. After clarifying the difficulties specific to this domain, we propose appropriate solutions at both image analysis level and high-level interpretation. Thus, a recognition and segmentation method is designed, that allows dealing with common printing defects and numerous symbol interconnections. Then, musical rules are modeled and integrated, in order to make a consistent decision. This high-level interpretation step relies on the fuzzy sets and possibility framework, since it allows dealing with symbol variability, flexibility, and imprecision of music rules, and merging all these heterogeneous pieces of information. Other innovative features are the indication of potential errors and the possibility of applying learning procedures, in order to gain in robustness. Experiments conducted on a large data base show that the proposed method constitutes an interesting contribution to OMR.

  4. System for detecting operating errors in a variable valve timing engine using pressure sensors

    Science.gov (United States)

    Wiles, Matthew A.; Marriot, Craig D

    2013-07-02

    A method and control module includes a pressure sensor data comparison module that compares measured pressure volume signal segments to ideal pressure volume segments. A valve actuation hardware remedy module performs a hardware remedy in response to comparing the measured pressure volume signal segments to the ideal pressure volume segments when a valve actuation hardware failure is detected.

  5. NGS-eval: NGS Error analysis and novel sequence VAriant detection tooL

    NARCIS (Netherlands)

    A. May; S. Abeln; M.J. Buijs; J. Heringa; W. Crielaard; B.W. Brandt

    2015-01-01

    Massively parallel sequencing of microbial genetic markers (MGMs) is used to uncover the species composition in a multitude of ecological niches. These sequencing runs often contain a sample with known composition that can be used to evaluate the sequencing quality or to detect novel sequence varian

  6. On-line Detection of Gas Pipeline Based on the Real-Time Algorithm and Network Technology with Robot

    Institute of Scientific and Technical Information of China (English)

    YAN Bo; YAN Guo-zheng; DING Guo-qing; ZHOU Bing; FU Xi-guang; ZUO Jian-yong

    2004-01-01

    The detection system integrates control technology, network technology, video encoding and decoding, video transmiss-ion, multi-single chip microcomputer communication, dat-abase technology, computer software and robot technology. The robot can adaptively adjust its status according to diameter (from 400 mm to 650 mm) of pipeline. The maximum detection distance is up to 1 000 m. The method of video coding in the system is based on fractal transformation. The experiments show that the coding scheme is fast and good PSNR. The precision of on-line detection is up to 3% thickness of pipeline wall. The robot can also have a high precision of location up to 0.03 m. The control method is based on network and characterized by on-line and real-time. The experiment in real gas pipeline shows that the performance of the detection system is good.

  7. Moving object detection based on on-line block-robust principal component analysis decomposition

    Science.gov (United States)

    Yang, Biao; Cao, Jinmeng; Zou, Ling

    2017-07-01

    Robust principal component analysis (RPCA) decomposition is widely applied in moving object detection due to its ability in suppressing environmental noises while separating sparse foreground from low rank background. However, it may suffer from constant punishing parameters (resulting in confusion between foreground and background) and holistic processing of all input frames (leading to bad real-time performance). Improvements to these issues are studied in this paper. A block-RPCA decomposition approach was proposed to handle the confusion while separating foreground from background. Input frame was initially separated into blocks using three-frame difference. Then, punishing parameter of each block was computed by its motion saliency acquired based on selective spatio-temporal interesting points. Aiming to improve the real-time performance of the proposed method, an on-line solution to block-RPCA decomposition was utilized. Both qualitative and quantitative tests were implemented and the results indicate the superiority of our method to some state-of-the-art approaches in detection accuracy or real-time performance, or both of them.

  8. An online sleep apnea detection method based on recurrence quantification analysis.

    Science.gov (United States)

    Nguyen, Hoa Dinh; Wilkins, Brek A; Cheng, Qi; Benjamin, Bruce Allen

    2014-07-01

    This paper introduces an online sleep apnea detection method based on heart rate complexity as measured by recurrence quantification analysis (RQA) statistics of heart rate variability (HRV) data. RQA statistics can capture nonlinear dynamics of a complex cardiorespiratory system during obstructive sleep apnea. In order to obtain a more robust measurement of the nonstationarity of the cardiorespiratory system, we use different fixed amount of neighbor thresholdings for recurrence plot calculation. We integrate a feature selection algorithm based on conditional mutual information to select the most informative RQA features for classification, and hence, to speed up the real-time classification process without degrading the performance of the system. Two types of binary classifiers, i.e., support vector machine and neural network, are used to differentiate apnea from normal sleep. A soft decision fusion rule is developed to combine the results of these classifiers in order to improve the classification performance of the whole system. Experimental results show that our proposed method achieves better classification results compared with the previous recurrence analysis-based approach. We also show that our method is flexible and a strong candidate for a real efficient sleep apnea detection system.

  9. Selective screening of 650 high risk Iranian patients for detection of inborn error of metabolism

    Directory of Open Access Journals (Sweden)

    Narges Pishva

    2015-02-01

    Full Text Available Objective: Although metabolic diseases individually are rare ,but overall have an incidence of 1/2000 and can cause devastating and irreversible effect if not diagnosed early and treated promptly. selective screening is an acceptable method for detection of these multi presentation diseases.Method: using panel neonatal screening for detection of metabolic diseases in 650 high risk Iranian patients in Fars province. The following clinical features were used as inclusion criteria for investigation of the patients.Lethargy, poor feeding ,persistent vomiting, cholestasis, intractable seizure ,decreased level of consciousness ,persistent hypoglycemia, unexplained acid base disturbance and unexplained neonatal death.Result: Organic acidemia with 40 cases (42% was the most frequent disorder diagnosed in our high risk populations, followed by disorder of galactose metabolism(30%, 15 patient had classic galactosemia(GALT

  10. Selective screening of 650 high risk Iranian patients for detection of inborn error of metabolism

    Directory of Open Access Journals (Sweden)

    Narges Pishva

    2015-02-01

    Full Text Available Objective: Although metabolic diseases individually are rare ,but overall have an incidence of 1/2000 and can cause devastating and irreversible effect if not diagnosed early and treated promptly. selective screening is an acceptable method for detection of these multi presentation diseases. Method: using panel neonatal screening for detection of metabolic diseases in 650 high risk Iranian patients in Fars province. The following clinical features were used as inclusion criteria for investigation of the patients. Lethargy, poor feeding ,persistent vomiting, cholestasis, intractable seizure ,decreased level of consciousness ,persistent hypoglycemia, unexplained acid base disturbance and unexplained neonatal death. Result: Organic acidemia with 40 cases (42% was the most frequent disorder diagnosed in our high risk populations, followed by disorder of galactose metabolism(30%, 15 patient had classic galactosemia(GALT

  11. Development of an on-line radiation detection and measurements laboratory course

    Science.gov (United States)

    Kopp, Derick G.

    An on-line radiation detection and measurements lab is being developed with a grant from the U.S. Nuclear Regulatory Commission. The on-line laboratory experiments are designed to provide a realistic laboratory experience and will be offered to students at colleges/universities where such a course is not offered. This thesis presents four web-based experiments: 1) nuclear electronics, 2) gamma-ray spectroscopy with scintillation detectors, 3) gamma-ray attenuation in matter and external dosimetry, and 4) alpha spectroscopy and absorption in matter. The students access the experiments through a broad-band internet connection. Computer-controlled instrumentation developed in National Instruments (NI) LabVIEW(TM) communicates with the URSA-II (SE International, Inc.) data acquisition system, which controls the detector bias voltage, pulse shaping, amplifier gain, and ADC. Detector and amplifier output pulses can be displayed with other instrumentation developed in LabVIEW(TM) for the digital oscilloscope (USB-5132, NI). Additional instrumentation developed in LabVIEW(TM) is used to control the positions of all sources with stepper motor controllers (VXM-1, Velmex, Inc.) and to adjust pressure in the alpha chamber with a digital vacuum regulator (Model 200, J-KEM, Inc.). Unique interactive interfaces are created by integrating all of the necessary instrumentation to conduct each lab. These interfaces provide students with seamless functionality for data acquisition, experimental control, and live data display with real-time updates for each experiment. A webcam is set up to stream the experiment live so the student can observe the physical instruments and receive visual feedback from the system in real time.

  12. High sensitive gas detection and isotopic measurement for the applications of industrial emission online monitoring and air pollution source tracking

    Science.gov (United States)

    Dong, Fengzhong; Zhang, Zhirong; Xia, Hua; Cui, Xiaojuan; Pang, Tao; Wu, Bian; Chen, Weidong; Sigrist, Markus

    2015-04-01

    High sensitive gas detection and isotopic measurements have been widely employed in the industrial and safety production. The recent progress made by our group on high sensitive gas detection with technologies of TDLAS, off-axis integrated cavity output spectroscopy (OA-ICOS) and cavity ring-down spectroscopy (CRDS) will be briefly summarized in this report. Some works for field applications of industrial emission online monitoring and gas leakage detection in oil tank farm with TDLAS are first presented, and then part of our most recent researches on isotopic gas detection with OA-ICOS and CRDS for tracking of pollution sources are also introduced.

  13. Incidence of error in oestrus detection based on secondary oestrus signs in a 24-h tie-stalled dairy herd with low fertility.

    Science.gov (United States)

    Ranasinghe, R M S B K; Nakao, T; Kobayashi, A

    2009-08-01

    Oestrus detection error and conception rates after AI based only on secondary oestrus signs were evaluated in a high yielding, 24-h tie-stalled dairy herd with low fertility, using milk progesterone profiles. Oestrus detection was based on the secondary oestrus signs such as restlessness, swelling, congestion of vulva and clear mucus discharge. Sixty eight AI conducted after observing the secondary oestrus signs in 44 animals were included in the study. Of the 68 AI, 53 (77.9%) were conducted in the follicular phase, and 13 (19.1%) and 2 (2.9%) were carried out in the luteal phase and during pregnancy, respectively. The overall error in oestrus detection based on milk progesterone profiles was 22.1%. The oestrus detection error did not differ significantly among different secondary oestrus signs. None of the AI conducted in the luteal phase resulted in conception, whereas 20.8% of AI conducted in the follicular phase resulted in conception. No significant difference in the conception rates among the groups of cows with different secondary oestrus signs was shown. The high incidence of oestrus detection error in this study might have been caused by the detection of cows in oestrus based only on secondary oestrus signs due to the confinement of animals. In conclusion, there was a high incidence of heat detection error in the 24-h tie-stalled dairy herd and oestrus detection based only on secondary oestrus signs resulted in low conception rate.

  14. Analysis and asynchronous detection of gradually unfolding errors during monitoring tasks

    Science.gov (United States)

    Omedes, Jason; Iturrate, Iñaki; Minguez, Javier; Montesano, Luis

    2015-10-01

    Human studies on cognitive control processes rely on tasks involving sudden-onset stimuli, which allow the analysis of these neural imprints to be time-locked and relative to the stimuli onset. Human perceptual decisions, however, comprise continuous processes where evidence accumulates until reaching a boundary. Surpassing the boundary leads to a decision where measured brain responses are associated to an internal, unknown onset. The lack of this onset for gradual stimuli hinders both the analyses of brain activity and the training of detectors. This paper studies electroencephalographic (EEG)-measurable signatures of human processing for sudden and gradual cognitive processes represented as a trajectory mismatch under a monitoring task. Time-locked potentials and brain-source analysis of the EEG of sudden mismatches revealed the typical components of event-related potentials and the involvement of brain structures related to cognitive control processing. For gradual mismatch events, time-locked analyses did not show any discernible EEG scalp pattern, despite related brain areas being, to a lesser extent, activated. However, and thanks to the use of non-linear pattern recognition algorithms, it is possible to train an asynchronous detector on sudden events and use it to detect gradual mismatches, as well as obtaining an estimate of their unknown onset. Post-hoc time-locked scalp and brain-source analyses revealed that the EEG patterns of detected gradual mismatches originated in brain areas related to cognitive control processing. This indicates that gradual events induce latency in the evaluation process but that similar brain mechanisms are present in sudden and gradual mismatch events. Furthermore, the proposed asynchronous detection model widens the scope of applications of brain-machine interfaces to other gradual processes.

  15. Method for detection and correction of errors in speech pitch period estimates

    Science.gov (United States)

    Bhaskar, Udaya (Inventor)

    1989-01-01

    A method of detecting and correcting received values of a pitch period estimate of a speech signal for use in a speech coder or the like. An average is calculated of the nonzero values of received pitch period estimate since the previous reset. If a current pitch period estimate is within a range of 0.75 to 1.25 times the average, it is assumed correct, while if not, a correction process is carried out. If correction is required successively for more than a preset number of times, which will most likely occur when the speaker changes, the average is discarded and a new average calculated.

  16. A classifier model for detecting pronunciation errors regarding the Nasa Yuwe language’s 32 vowels

    Directory of Open Access Journals (Sweden)

    Roberto Carlos Naranjo Cuervo

    2012-08-01

    Full Text Available The Nasa Yuwe language has 32 oral and nasal vowels thereby leading to one being used instead of the other; such confusion can change the meaning of the spoken word in Nasa Yuwe. A set of classifier models have been developed to support correct learning of this language which is in danger of extinction aimed at detecting confusion in the pronunciation of the 32 vowels; about 85% were obtained after experimenting with a variety of linear and nonlinear classifiers, rates of sensitivity, specificity and accuracy. A support software prototype was designed with these trained classifiers for the correct pronunciation of the language’s vowels.

  17. The Scientific Method, Diagnostic Bayes, and How to Detect Epistemic Errors

    Science.gov (United States)

    Vrugt, J. A.

    2015-12-01

    evaluation. This hybrid approach, coined diagnostic Bayes, uses the summary metrics as prior distribution and original data in the likelihood function, or P(x|\\hat {D}) ∝ P(x|S(\\hat {D})) L(x|\\hat {D}). A case study illustrates the ability of the proposed methodology to diagnose epistemic errors and provide guidance on model refinement.

  18. Use of a Web Forum and an Online Questionnaire in the Detection and Investigation of an Outbreak

    Science.gov (United States)

    Stuart Chester, Tammy L.; Taylor, Marsha; Sandhu, Jat; Forsting, Sara; Ellis, Andrea; Stirling, Rob; Galanis, Eleni

    2011-01-01

    A campylobacteriosis outbreak investigation provides relevant examples of how two web-based technologies were used in an outbreak setting and potential reasons for their usefulness. A web forum aided in outbreak detection and provided contextual insights for hypothesis generation and questionnaire development. An online questionnaire achieved a high response rate and enabled rapid preliminary data analysis that allowed for a targeted environmental investigation. The usefulness of these tools may in part be attributed to the existence of an internet savvy, close-knit community. Given the right population, public health officials should consider web-based technologies, including web fora and online questionnaires as valuable tools in public health investigations. PMID:23569598

  19. SU-E-T-310: Targeting Safety Improvements Through Analysis of Near-Miss Error Detection Points in An Incident Learning Database

    Energy Technology Data Exchange (ETDEWEB)

    Novak, A; Nyflot, M; Sponseller, P; Howard, J; Logan, W; Holland, L; Jordan, L; Carlson, J; Ermoian, R; Kane, G; Ford, E; Zeng, J [University of Washington, Seattle, WA (United States)

    2014-06-01

    Purpose: Radiation treatment planning involves a complex workflow that can make safety improvement efforts challenging. This study utilizes an incident reporting system to identify detection points of near-miss errors, in order to guide our departmental safety improvement efforts. Previous studies have examined where errors arise, but not where they are detected or their patterns. Methods: 1377 incidents were analyzed from a departmental nearmiss error reporting system from 3/2012–10/2013. All incidents were prospectively reviewed weekly by a multi-disciplinary team, and assigned a near-miss severity score ranging from 0–4 reflecting potential harm (no harm to critical). A 98-step consensus workflow was used to determine origination and detection points of near-miss errors, categorized into 7 major steps (patient assessment/orders, simulation, contouring/treatment planning, pre-treatment plan checks, therapist/on-treatment review, post-treatment checks, and equipment issues). Categories were compared using ANOVA. Results: In the 7-step workflow, 23% of near-miss errors were detected within the same step in the workflow, while an additional 37% were detected by the next step in the workflow, and 23% were detected two steps downstream. Errors detected further from origination were more severe (p<.001; Figure 1). The most common source of near-miss errors was treatment planning/contouring, with 476 near misses (35%). Of those 476, only 72(15%) were found before leaving treatment planning, 213(45%) were found at physics plan checks, and 191(40%) were caught at the therapist pre-treatment chart review or on portal imaging. Errors that passed through physics plan checks and were detected by therapists were more severe than other errors originating in contouring/treatment planning (1.81 vs 1.33, p<0.001). Conclusion: Errors caught by radiation treatment therapists tend to be more severe than errors caught earlier in the workflow, highlighting the importance of safety

  20. Error exponents for Neyman-Pearson detection of a continuous-time Gaussian Markov process from noisy irregular samples

    CERN Document Server

    Hachem, Walid; Roueff, Francois

    2009-01-01

    This paper addresses the detection of a stochastic process in noise from irregular samples. We consider two hypotheses. The \\emph{noise only} hypothesis amounts to model the observations as a sample of a i.i.d. Gaussian random variables (noise only). The \\emph{signal plus noise} hypothesis models the observations as the samples of a continuous time stationary Gaussian process (the signal) taken at known but random time-instants corrupted with an additive noise. Two binary tests are considered, depending on which assumptions is retained as the null hypothesis. Assuming that the signal is a linear combination of the solution of a multidimensional stochastic differential equation (SDE), it is shown that the minimum Type II error probability decreases exponentially in the number of samples when the False Alarm probability is fixed. This behavior is described by \\emph{error exponents} that are completely characterized. It turns out that they are related with the asymptotic behavior of the Kalman Filter in random s...

  1. Identification of error making patterns in lesion detection on digital breast tomosynthesis using computer-extracted image features

    Science.gov (United States)

    Wang, Mengyu; Zhang, Jing; Grimm, Lars J.; Ghate, Sujata V.; Walsh, Ruth; Johnson, Karen S.; Lo, Joseph Y.; Mazurowski, Maciej A.

    2016-03-01

    Digital breast tomosynthesis (DBT) can improve lesion visibility by eliminating the issue of overlapping breast tissue present in mammography. However, this new modality likely requires new approaches to training. The issue of training in DBT is not well explored. We propose a computer-aided educational approach for DBT training. Our hypothesis is that the trainees' educational outcomes will improve if they are presented with cases individually selected to address their weaknesses. In this study, we focus on the question of how to select such cases. Specifically, we propose an algorithm that based on previously acquired reading data predicts which lesions will be missed by the trainee for future cases (i.e., we focus on false negative error). A logistic regression classifier was used to predict the likelihood of trainee error and computer-extracted features were used as the predictors. Reader data from 3 expert breast imagers was used to establish the ground truth and reader data from 5 radiology trainees was used to evaluate the algorithm performance with repeated holdout cross validation. Receiver operating characteristic (ROC) analysis was applied to measure the performance of the proposed individual trainee models. The preliminary experimental results for 5 trainees showed the individual trainee models were able to distinguish the lesions that would be detected from those that would be missed with the average area under the ROC curve of 0.639 (95% CI, 0.580-0.698). The proposed algorithm can be used to identify difficult cases for individual trainees.

  2. 高精密机床主轴回转误差在线测试系统%Spindle rotary error online test system of high precision machine tool

    Institute of Scientific and Technical Information of China (English)

    周继昆; 张荣; 凌明祥; 张毅

    2016-01-01

    To realize real-time online measurement of spindle rotary error of high precision machine tool,based on the mechanical structure of machine tool,the standard ball and external reference measurement method was used to measure the radial displacement of the spindle indirectly and three-point method (error separation algorithm) was used to separate the spindle roundness error and rotary error so as to obtain the pure rotary error. According to the proposed test method, the hardware part of test system was created based on PXI bus data acquisition technology and the PXI external clock synchronization collection card was used to realize the equiangular and synchronous collection of spindle radial displacement information. Online test software was developed in LabVIEW development environment,with which the spindle rotary error can be separated on line. A machine tool was tested online with the developed test system and the test results showed that the developed test system can separate pure spindle rotary error from radial displacement information online with a high accuracy.%为实现对高精度机床主轴回转误差的在线实时测量,根据机床机械结构特点,采用标准球及外基准测量方法间接对机床主轴径向位移进行测量,并利用三点法误差分离算法将主轴圆度误差与回转误差分离,得到纯回转误差。依据所提出的测试方法,基于PXI总线数据采集技术建立测试系统硬件部分,并利用PXI外部时钟同步采集卡实现主轴径向位移信息的等角度同步采样;在LabVIEW开发环境下,开发在线测试软件,对回转误差进行在线分离。利用该系统对某机床进行在线测试,测试结果表明,测试系统可以在线将机床主轴纯回转误差从径向位移信息中分离出来,并达到较高的测试准确度。

  3. Asymmetrical flow field-flow fractionation with on-line detection for drug transfer studies: a feasibility study

    DEFF Research Database (Denmark)

    Hinna, A.; Steiniger, F.; Hupfeld, S.

    2014-01-01

    Knowledge about drug retention within colloidal carriers is of uppermost importance particularly if drug targeting is anticipated. The aim of the present study was to evaluate asymmetrical flow field-flow fractionation (AF4) with on-line UV/VIS drug quantification for its suitability to determine...... both release and transfer of drug from liposomal carriers to a model acceptor phase consisting of large liposomes. The hydrophobic porphyrin 5,10,15,20-tetrakis(4-hydroxyphenyl)21H,23H-porphine (p-THPP), a fluorescent dye with an absorbance maximum in the visible range and structural similarity...... channel geometries. Drug quantification by on-line absorbance measurements was established by comprehensive evaluation of the size-dependent turbidity contribution in on-line UV/VIS detection and by comparison with off-line results obtained for the respective dye-loaded donor formulations (dissolved...

  4. Delay Error with Meta - Stability Detection and Correction Using CMOS Transmission Logic

    Directory of Open Access Journals (Sweden)

    Bhawna Kankane

    2012-08-01

    Full Text Available The new technologies are giving the advance systems which are capable to perform multiple operations simultaneously. This all is possible by the scaling technology where the overall chip size get reduced but due to manufacturing and fabrication defects, certain design uncertainty arises thereby affecting the transistor performance by timing related effect. The robust circuit where sufficient margins are given sometime is nothing but a wastage of power to overcome this, hybrid technique called Razor was innovated which scaled the voltage dynamically and automatically detect and correct the timing related defects. This paper proposed a new design for the razor flip flop with CMOS transmission logic. The traditional design used the dynamic logic approach which has the drawback of threshold voltage attenuation which is removed by CMOS transmission logic and the transparency of the logic data at input and output is highly achieved. The overall purpose for such design is to reduce the power and delay of the circuit which is reduced by 0.6 mW and 12.11ns respectively and thus increased the overall performance. The complexity of the circuit is also reduced. The analyses of the circuit is done using Cadence virtuoso tool with 45 n technology.

  5. Delay Error with Meta - Stability Detection and Correction Using CMOS Transmission Logic

    Directory of Open Access Journals (Sweden)

    Bhawna Kankane

    2012-09-01

    Full Text Available The new technologies are giving the advance systems which are capable to perform multiple operations simultaneously. This all is possible by the scaling technology where the overall chip size get reduced but due to manufacturing and fabrication defects, certain design uncertainty arises thereby affecting the transistor performance by timing related effect. The robust circuit where sufficient margins are givensometime is nothing but a wastage of power to overcome this, hybrid technique called Razor was innovated which scaled the voltage dynamically and automatically detect and correct the timing related defects. This paper proposed a new design for the razor flip flop with CMOS transmission logic. The traditional design used the dynamic logic approach which has the drawback of threshold voltage attenuation which is removed by CMOS transmission logic and the transparency of the logic data at input and output is highly achieved. The overall purpose for such design is to reduce the power and delay of the circuit which isreduced by 0.6mW and 12.11ns respectively and thus increased the overall performance. The complexity of the circuit is also reduced. The analyses of the circuit is done using Cadence virtuoso tool with 45n technology.

  6. Online Damage Detection on Metal and Composite Space Structures by Active and Passive Acoustic Methods

    Science.gov (United States)

    Scheerer, M.; Cardone, T.; Rapisarda, A.; Ottaviano, S.; Ftancesconi, D.

    2012-07-01

    In the frame of ESA funded programme Future Launcher Preparatory Programme Period 1 “Preparatory Activities on M&S”, Aerospace & Advanced Composites and Thales Alenia Space-Italia, have conceived and tested a structural health monitoring approach based on integrated Acoustic Emission - Active Ultrasound Damage Identification. The monitoring methods implemented in the study are both passive and active methods and the purpose is to cover large areas with a sufficient damage size detection capability. Two representative space sub-structures have been built and tested: a composite overwrapped pressure vessel (COPV) and a curved, stiffened Al-Li panel. In each structure, typical critical damages have been introduced: delaminations caused by impacts in the COPV and a crack in the stiffener of the Al-Li panel which was grown during a fatigue test campaign. The location and severity of both types of damages have been successfully assessed online using two commercially available systems: one 6 channel AE system from Vallen and one 64 channel AU system from Acellent.

  7. Design and experimental research of the on-line detection system for diamond arc grinding wheel

    Science.gov (United States)

    Zhang, Feihu; Li, Chen; Liu, Zhongde; Ren, Lele; Xie, Haisheng

    2016-10-01

    The principle of measuring displacement by eddy current sensor was derived. The calibration experiment was carried out for 5 kinds of different materials, which showed that the linearity of eddy current sensor was better, and the sensitivity of eddy current sensor varied with different materials. Based on the principle of measuring displacement by eddy current sensor, the on-line detection system for diamond circular wheel was designed, and the data acquisition was realized by using LABVIEW software. By moving the eddy current sensor in the vertical direction with the grinding wheel fixed, the coordinate of arc in the grinding wheel was obtained. The radius of the grinding wheel was fitted by using the genetic algorithm, which showed that the fitting results were accurate. The data acquisition of the grinding wheel was carried out in a cycle by fixing the electric eddy current sensor and the circulars of the grinding wheel in different processes, namely before dressing, after dressing and after shaping. The results showed that the circular of the grinding wheel after dressing and after shaping were significantly improved compared with that before dressing.

  8. An online visual loop closure detection method for indoor robotic navigation

    Science.gov (United States)

    Erhan, Can; Sariyanidi, Evangelos; Sencan, Onur; Temeltas, Hakan

    2015-01-01

    In this paper, we present an enhanced loop closure method* based on image-to-image matching relies on quantized local Zernike moments. In contradistinction to the previous methods, our approach uses additional depth information to extract Zernike moments in local manner. These moments are used to represent holistic shape information inside the image. The moments in complex space that are extracted from both grayscale and depth images are coarsely quantized. In order to find out the similarity between two locations, nearest neighbour (NN) classification algorithm is performed. Exemplary results and the practical implementation case of the method are also given with the data gathered on the testbed using a Kinect. The method is evaluated in three different datasets of different lighting conditions. Additional depth information with the actual image increases the detection rate especially in dark environments. The results are referred as a successful, high-fidelity online method for visual place recognition as well as to close navigation loops, which is a crucial information for the well known simultaneously localization and mapping (SLAM) problem. This technique is also practically applicable because of its low computational complexity, and performing capability in real-time with high loop closing accuracy.

  9. A New Model for the Error Detection Delay of Finite Precision Binary Arithmetic Codes with a Forbidden Symbol

    Science.gov (United States)

    Pang, Yuye; Sun, Jun; Wang, Jia; Wang, Peng

    In this paper, the statistical characteristic of the Error Detection Delay (EDD) of Finite Precision Binary Arithmetic Codes (FPBAC) is discussed. It is observed that, apart from the probability of the Forbidden Symbol (FS) inserted into the list of the source symbols, the probability of the source sequence and the operation precision as well as the position of the FS in the coding interval can affect the statistical characteristic of the EDD. Experiments demonstrate that the actual distribution of the EDD of FPBAC is quite different from the geometric distribution of infinite precision arithmetic codes. This phenomenon is researched deeply, and a new statistical model (gamma distribution) of the actual distribution of the EDD is proposed, which can make a more precise prediction of the EDD. Finally, the relation expressions between the parameters of gamma distribution and the related factors affecting the distribution are given.

  10. A novel onset detection technique for brain-computer interfaces using sound-production related cognitive tasks in simulated-online system

    Science.gov (United States)

    Song, YoungJae; Sepulveda, Francisco

    2017-02-01

    Objective. Self-paced EEG-based BCIs (SP-BCIs) have traditionally been avoided due to two sources of uncertainty: (1) precisely when an intentional command is sent by the brain, i.e., the command onset detection problem, and (2) how different the intentional command is when compared to non-specific (or idle) states. Performance evaluation is also a problem and there are no suitable standard metrics available. In this paper we attempted to tackle these issues. Approach. Self-paced covert sound-production cognitive tasks (i.e., high pitch and siren-like sounds) were used to distinguish between intentional commands (IC) and idle states. The IC states were chosen for their ease of execution and negligible overlap with common cognitive states. Band power and a digital wavelet transform were used for feature extraction, and the Davies-Bouldin index was used for feature selection. Classification was performed using linear discriminant analysis. Main results. Performance was evaluated under offline and simulated-online conditions. For the latter, a performance score called true-false-positive (TFP) rate, ranging from 0 (poor) to 100 (perfect), was created to take into account both classification performance and onset timing errors. Averaging the results from the best performing IC task for all seven participants, an 77.7% true-positive (TP) rate was achieved in offline testing. For simulated-online analysis the best IC average TFP score was 76.67% (87.61% TP rate, 4.05% false-positive rate). Significance. Results were promising when compared to previous IC onset detection studies using motor imagery, in which best TP rates were reported as 72.0% and 79.7%, and which, crucially, did not take timing errors into account. Moreover, based on our literature review, there is no previous covert sound-production onset detection system for spBCIs. Results showed that the proposed onset detection technique and TFP performance metric have good potential for use in SP-BCIs.

  11. RESEARCH ON GROSS ERROR DETECTION BASED ON BIO-POLE METHOD%基于双极差的粗差探测方法研究

    Institute of Scientific and Technical Information of China (English)

    刘陶胜; 黄声享; 李沛鸿

    2012-01-01

    粗差对数学期望值计算有偏态影响,并会传递到残差序列中,仅用3σ准则探测粗差,极易产生“去真”或“纳伪”的错误.通过分析观测序列极差、观测值改正数极差与粗差之间的关系,推导了粗差的判断条件,构造双极差判断矩阵进行粗差探测,同时比较了小样本和大样本序列探测的不同之处,通过实例分析,验证了该方法是一种有效的探测手段.%Gross errors make skewness influence on mathematical expectation of series, which will transfer to the residual sequence. The gross errors detection only with 3σ criterion may make a mistake of discarding the truth or accepting the wrong. The relationship between the poor of observations or error correction and gross errors was analyzed and the formulae to judge gross errors were deduced. The judgment condition matrix based on bio-poor for detecting gross errors was constructed and the difference of small sample with large sample in detecting gross errors was compared. This method is verified effective through example analyses.

  12. Sparse representation for infrared Dim target detection via a discriminative over-complete dictionary learned online.

    Science.gov (United States)

    Li, Zheng-Zhou; Chen, Jing; Hou, Qian; Fu, Hong-Xia; Dai, Zhen; Jin, Gang; Li, Ru-Zhang; Liu, Chang-Ju

    2014-05-27

    It is difficult for structural over-complete dictionaries such as the Gabor function and discriminative over-complete dictionary, which are learned offline and classified manually, to represent natural images with the goal of ideal sparseness and to enhance the difference between background clutter and target signals. This paper proposes an infrared dim target detection approach based on sparse representation on a discriminative over-complete dictionary. An adaptive morphological over-complete dictionary is trained and constructed online according to the content of infrared image by K-singular value decomposition (K-SVD) algorithm. Then the adaptive morphological over-complete dictionary is divided automatically into a target over-complete dictionary describing target signals, and a background over-complete dictionary embedding background by the criteria that the atoms in the target over-complete dictionary could be decomposed more sparsely based on a Gaussian over-complete dictionary than the one in the background over-complete dictionary. This discriminative over-complete dictionary can not only capture significant features of background clutter and dim targets better than a structural over-complete dictionary, but also strengthens the sparse feature difference between background and target more efficiently than a discriminative over-complete dictionary learned offline and classified manually. The target and background clutter can be sparsely decomposed over their corresponding over-complete dictionaries, yet couldn't be sparsely decomposed based on their opposite over-complete dictionary, so their residuals after reconstruction by the prescribed number of target and background atoms differ very visibly. Some experiments are included and the results show that this proposed approach could not only improve the sparsity more efficiently, but also enhance the performance of small target detection more effectively.

  13. ASCS online fault detection and isolation based on an improved MPCA

    Science.gov (United States)

    Peng, Jianxin; Liu, Haiou; Hu, Yuhui; Xi, Junqiang; Chen, Huiyan

    2014-09-01

    Multi-way principal component analysis (MPCA) has received considerable attention and been widely used in process monitoring. A traditional MPCA algorithm unfolds multiple batches of historical data into a two-dimensional matrix and cut the matrix along the time axis to form subspaces. However, low efficiency of subspaces and difficult fault isolation are the common disadvantages for the principal component model. This paper presents a new subspace construction method based on kernel density estimation function that can effectively reduce the storage amount of the subspace information. The MPCA model and the knowledge base are built based on the new subspace. Then, fault detection and isolation with the squared prediction error (SPE) statistic and the Hotelling ( T 2) statistic are also realized in process monitoring. When a fault occurs, fault isolation based on the SPE statistic is achieved by residual contribution analysis of different variables. For fault isolation of subspace based on the T 2 statistic, the relationship between the statistic indicator and state variables is constructed, and the constraint conditions are presented to check the validity of fault isolation. Then, to improve the robustness of fault isolation to unexpected disturbances, the statistic method is adopted to set the relation between single subspace and multiple subspaces to increase the corrective rate of fault isolation. Finally fault detection and isolation based on the improved MPCA is used to monitor the automatic shift control system (ASCS) to prove the correctness and effectiveness of the algorithm. The research proposes a new subspace construction method to reduce the required storage capacity and to prove the robustness of the principal component model, and sets the relationship between the state variables and fault detection indicators for fault isolation.

  14. ASCS Online Fault Detection and Isolation Based on an Improved MPCA

    Institute of Scientific and Technical Information of China (English)

    PENG Jianxin; LIU Haiou; HU Yuhui; XI Junqiang; CHEN Huiyan

    2014-01-01

    Multi-way principal component analysis (MPCA) has received considerable attention and been widely used in process monitoring. A traditional MPCA algorithm unfolds multiple batches of historical data into a two-dimensional matrix and cut the matrix along the time axis to form subspaces. However, low efficiency of subspaces and difficult fault isolation are the common disadvantages for the principal component model. This paper presents a new subspace construction method based on kernel density estimation function that can effectively reduce the storage amount of the subspace information. The MPCA model and the knowledge base are built based on the new subspace. Then, fault detection and isolation with the squared prediction error (SPE) statistic and the Hotelling (T2) statistic are also realized in process monitoring. When a fault occurs, fault isolation based on the SPE statistic is achieved by residual contribution analysis of different variables. For fault isolation of subspace based on the T2 statistic, the relationship between the statistic indicator and state variables is constructed, and the constraint conditions are presented to check the validity of fault isolation. Then, to improve the robustness of fault isolation to unexpected disturbances, the statistic method is adopted to set the relation between single subspace and multiple subspaces to increase the corrective rate of fault isolation. Finally fault detection and isolation based on the improved MPCA is used to monitor the automatic shift control system (ASCS) to prove the correctness and effectiveness of the algorithm. The research proposes a new subspace construction method to reduce the required storage capacity and to prove the robustness of the principal component model, and sets the relationship between the state variables and fault detection indicators for fault isolation.

  15. DNA-Inspired Online Behavioral Modeling and Its Application to Spambot Detection

    DEFF Research Database (Denmark)

    Cresci, Stefano; Di Pietro, Roberto; Petrocchi, Marinella

    2016-01-01

    A novel, simple, and effective approach to modeling online user behavior extracts and analyzes digital DNA sequences from user online actions and uses Twitter as a benchmark to test the proposal. Specifically, the model obtains an incisive and compact DNA-inspired characterization of user actions...... methodology is platform and technology agnostic, paving the way for diverse behavioral characterization tasks....

  16. Detecting and estimating errors in 3D restoration methods using analog models.

    Science.gov (United States)

    José Ramón, Ma; Pueyo, Emilio L.; Briz, José Luis

    2015-04-01

    Some geological scenarios may be important for a number of socio-economic reasons, such as water or energy resources, but the available underground information is often limited, scarce and heterogeneous. A truly 3D reconstruction, which is still necessary during the decision-making process, may have important social and economic implications. For this reason, restoration methods were developed. By honoring some geometric or mechanical laws, they help build a reliable image of the subsurface. Pioneer methods were firstly applied in 2D (balanced and restored cross-sections) during the sixties and seventies. Later on, and due to the improvements of computational capabilities, they were extended to 3D. Currently, there are some academic and commercial restoration solutions; Unfold by the Université de Grenoble, Move by Midland Valley Exploration, Kine3D (on gOcad code) by Paradigm, Dynel3D by igeoss-Schlumberger. We have developed our own restoration method, Pmag3Drest (IGME-Universidad de Zaragoza), which is designed to tackle complex geometrical scenarios using paleomagnetic vectors as a pseudo-3D indicator of deformation. However, all these methods have limitations based on the assumptions they need to establish. For this reason, detecting and estimating uncertainty in 3D restoration methods is of key importance to trust the reconstructions. Checking the reliability and the internal consistency of every method, as well as to compare the results among restoration tools, is a critical issue never tackled so far because of the impossibility to test out the results in Nature. To overcome this problem we have developed a technique using analog models. We built complex geometric models inspired in real cases of superposed and/or conical folding at laboratory scale. The stratigraphic volumes were modeled using EVA sheets (ethylene vinyl acetate). Their rheology (tensile and tear strength, elongation, density etc) and thickness can be chosen among a large number of values

  17. Final Technical Report Recovery Act: Online Nonintrusive Condition Monitoring and Fault Detection for Wind Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Wei Qiao

    2012-05-29

    The penetration of wind power has increased greatly over the last decade in the United States and across the world. The U.S. wind power industry installed 1,118 MW of new capacity in the first quarter of 2011 alone and entered the second quarter with another 5,600 MW under construction. By 2030, wind energy is expected to provide 20% of the U.S. electricity needs. As the number of wind turbines continues to grow, the need for effective condition monitoring and fault detection (CMFD) systems becomes increasingly important [3]. Online CMFD is an effective means of not only improving the reliability, capacity factor, and lifetime, but it also reduces the downtime, energy loss, and operation and maintenance (O&M) of wind turbines. The goal of this project is to develop novel online nonintrusive CMFD technologies for wind turbines. The proposed technologies use only the current measurements that have been used by the control and protection system of a wind turbine generator (WTG); no additional sensors or data acquisition devices are needed. Current signals are reliable and easily accessible from the ground without intruding on the wind turbine generators (WTGs) that are situated on high towers and installed in remote areas. Therefore, current-based CMFD techniques have great economic benefits and the potential to be adopted by the wind energy industry. Specifically, the following objectives and results have been achieved in this project: (1) Analyzed the effects of faults in a WTG on the generator currents of the WTG operating at variable rotating speed conditions from the perspective of amplitude and frequency modulations of the current measurements; (2) Developed effective amplitude and frequency demodulation methods for appropriate signal conditioning of the current measurements to improve the accuracy and reliability of wind turbine CMFD; (3) Developed a 1P-invariant power spectrum density (PSD) method for effective signature extraction of wind turbine faults with

  18. An Approach for Implementing State Machines with Online Testability

    Directory of Open Access Journals (Sweden)

    P. K. Lala

    2010-01-01

    Full Text Available During the last two decades, significant amount of research has been performed to simplify the detection of transient or soft errors in VLSI-based digital systems. This paper proposes an approach for implementing state machines that uses 2-hot code for state encoding. State machines designed using this approach allow online detection of soft errors in registers and output logic. The 2-hot code considerably reduces the number of required flip-flops and leads to relatively straightforward implementation of next state and output logic. A new way of designing output logic for online fault detection has also been presented.

  19. [Modal failure analysis and effects in the detection of errors in the transport of samples to the clinical laboratory].

    Science.gov (United States)

    Parés-Pollán, L; Gonzalez-Quintana, A; Docampo-Cordeiro, J; Vargas-Gallego, C; García-Álvarez, G; Ramos-Rodríguez, V; Diaz Rubio-García, M P

    2014-01-01

    Owing to the decrease in values of biochemical glucose parameter in some samples from external extraction centres, and the risk this implies to patient safety; it was decided to apply an adaptation of the «Health Services Failure Mode and Effects Analysis» (HFMEA) to manage risk during the pre-analytical phase of sample transportation from external centres to clinical laboratories. A retrospective study of glucose parameter was conducted during two consecutive months. The analysis was performed in its different phases: to define the HFMEA topic, assemble the team, graphically describe the process, conduct a hazard analysis, design the intervention and indicators, and identify a person to be responsible for ensuring completion of each action. The results of glucose parameter in one of the transport routes, were significantly lower (P=.006). The errors and potential causes of this problem were analysed, and criteria of criticality and detectability were applied (score≥8) in the decision tree. It was decided to: develop a document management system; reorganise extractions and transport routes in some centres; quality control of the sample container ice-packs, and the time and temperature during transportation. This work proposes quality indicators for controlling time and temperature of transported samples in the pre-analytical phase. Periodic review of certain laboratory parameters can help to detect problems in transporting samples. The HFMEA technique is useful for the clinical laboratory. Copyright © 2013 SECA. Published by Elsevier Espana. All rights reserved.

  20. Trichinella detection: identification and statistical evaluation of sources of error in the magnetic stirrer method for pooled sample digestion.

    Science.gov (United States)

    Riehn, Katharina; Hasenclever, Dirk; Petroff, David; Nöckler, Karsten; Mayer-Scholl, Anne; Makrutzki, Gregor; Lücker, Ernst

    2013-05-20

    Proficiency testing (PT) is the use of inter-laboratory comparisons to determine the performance of individual laboratories for specific tests or measurements, and to monitor a laboratory's performance. Participation in proficiency testing provides laboratories with an objective means of assessing and demonstrating the reliability of the data they are producing. To ensure the reliability of Trichinella detection and meat hygiene within the European Union and afford optimal protection to the consumer, PT is conducted under the direction of the European National Reference Laboratories for Trichinella. Evaluation of data from the national PT showed that lab-internal shortcomings are frequent. These shortcomings are specifically related to: (1) improper sample collection and preparation; (2) incorrect transposition and application of the protocol as laid down in Annex I, Chapter I, Nr. 3 (a-g) of the Commission Regulation (EC) No. 2075/2005; (3) insufficient sedimentation times; and (4) improper equipment.(e.g. Prost and Nowakowski, 1990; Rossi and Pozio, 2008; Forbes and Gajadhar, 1999; Rossi and Pozio, 2008). To test the hypothesis that both method based errors as well as internal lab errors can influence the accuracy and precision of the magnetic stirrer method for pooled sample digestion (MSM), we initiated a study to evaluate the analytical uncertainty of the MSM. Results presented here are based on: (i) data from PT in Germany (2008, 2009, and 2010); (ii) within-lab performance conducting high volumes of MSM; (iii) larval recovery experiments; and (iv) statistical evaluation of data resulting from these procedures. Quantitative data from the PT show that on average only 60% of Trichinella larvae were detected. Even laboratories that showed relatively good performance (>80% larva recovery, no false negative or false positive results), frequently reported samples with an unexpectedly low larval count (loss of >2 larvae). In our own laboratory, high numbers of

  1. Use of Online Records for Detection of Diseases and Heat in Dairy Cattle Stocks

    OpenAIRE

    Hansen, Jørgen Vinsløv

    2008-01-01

    In recent years management of cattle herds has become a much more automated process and machinery for measuring a number of biological entities online has been developed. Analysis of such online data can be helpful to the farmer in the management of the herd. This thesis is a contribution to the ongoing research in analysing online data. The focus here is on using state space models, which are a class of models suited for analysing time series. In the thesis the developed techniques are appli...

  2. Application of magnetoelastic biosensors for detection of foodborne pathogens on fresh produce with emphasis on statistical methods for elimination of detection errors

    Science.gov (United States)

    Shen, Wen; Li, Suiqiong; Horikawa, Shin; Petrenko, Valery A.; Barbaree, James; Chin, Bryan A.

    2011-06-01

    This work demonstrated a direct detection of Salmonella on fresh food produce using groups of magnetoelastic biosensors. The magnetoelastic biosensors were coated with E2 phage, which specifically binds with S. typhimurium. The resonance frequency of the biosensor is measured using a pulse excitation system, which allows simultaneous detection of multiple sensors. Multiple measurement and control biosensors were placed on fresh food surfaces that had been spiked with a known amount of Salmonella. Binding with bacteria was allowed to occur for 30 minutes in a humid air environment. The resonance frequencies of the groups of biosensors were then measured to determine the amount of bound bacteria. By using a statistical experimental design and by taking the average of repeated measurements, possible detection errors are decreased. By using multiple sensors at each site of interest, a higher portion of the contaminated surface has contact with biosensors, allowing for more complete information on the food produce surface. Results from SEM pictures of the sensor surface agree with the sensor frequency response results.

  3. Determining the solution conformational entropy of oligosaccharides by SEC with on-line viscometry detection.

    Science.gov (United States)

    Morris, Mallory J; Striegel, André M

    2014-06-15

    Introduced here is a method for determining the solution conformational entropy of oligosaccharides (-ΔS) that relies on the on-line coupling of size-exclusion chromatography (SEC), an entropically-controlled separation technique, and differential viscometry (VISC). Results from this SEC/VISC method were compared, for the same injections of the same sample dissolutions and under identical solvent/temperature conditions, to results from a benchmark SEC/differential refractometry (SEC/DRI) method which has been applied successfully over the last decade to determining -ΔS of a variety of mono-, di-, and oligosaccharides. The accuracy (as compared to SEC/DRI) and precision of SEC/VISC were found to be excellent, as was the sensitivity of the viscometer in the oligomeric region. The experiments presented here contrast three sets of (1→4)-β-d-oligosaccharides, namely manno-, cello-, and N-acetylchitooligosaccharides of degree of polymerization (DP) 2 through 6. For each series, the dependence of -ΔS on DP was found to be monotonic while, between series, differences at each DP could be ascribed to either the additional degrees of freedom imparted by large, multi-atomic substituent groups, or to the presence or absence of additional intramolecular hydrogen bonds, depending on the axial versus equatorial arrangement of particular hydroxyl groups. An hypothesis is advanced to explain the unexpectedly high sensitivity of viscometric detection for low-molar-mass analytes. The method presented can be extended to the analysis of oligosaccharides other than those studied here. Published by Elsevier Ltd.

  4. On-line detection of Escherichia coli intrusion in a pilot-scale drinking water distribution system.

    Science.gov (United States)

    Ikonen, Jenni; Pitkänen, Tarja; Kosse, Pascal; Ciszek, Robert; Kolehmainen, Mikko; Miettinen, Ilkka T

    2017-08-01

    Improvements in microbial drinking water quality monitoring are needed for the better control of drinking water distribution systems and for public health protection. Conventional water quality monitoring programmes are not always able to detect a microbial contamination of drinking water. In the drinking water production chain, in addition to the vulnerability of source waters, the distribution networks are prone to contamination. In this study, a pilot-scale drinking-water distribution network with an on-line monitoring system was utilized for detecting bacterial intrusion. During the experimental Escherichia coli intrusions, the contaminant was measured by applying a set of on-line sensors for electric conductivity (EC), pH, temperature (T), turbidity, UV-absorbance at 254 nm (UVAS SC) and with a device for particle counting. Monitored parameters were compared with the measured E. coli counts using the integral calculations of the detected peaks. EC measurement gave the strongest signal compared with the measured baseline during the E. coli intrusion. Integral calculations showed that the peaks in the EC, pH, T, turbidity and UVAS SC data were detected corresponding to the time predicted. However, the pH and temperature peaks detected were barely above the measured baseline and could easily be mixed with the background noise. The results indicate that on-line monitoring can be utilized for the rapid detection of microbial contaminants in the drinking water distribution system although the peak interpretation has to be performed carefully to avoid being mixed up with normal variations in the measurement data. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. An Online Detection Model of Granary Storage Quantity%粮仓储粮数量在线检测模型

    Institute of Scientific and Technical Information of China (English)

    张德贤; 杨铁军; 傅洪亮; 樊超; 张元

    2014-01-01

    Granary storage quantity online detection is a key technology for national food quantity safety, and it is also an important content of grain inventory check. According to the randomness of the granary pressure distribution, a new measurement method based on the estimation of zero internal friction pressure at the bottom of granary is proposed. First, a granary pressure sensor layout model is set up, in which the storage quantity detection accuracy and reliability of the detection system are considered comprehensively. Then, the methods of eliminating the grain heap bottom and side pressure distribution randomness and compensating side friction are presented. The granary storage quantity detection model based on the mean of the bottom pressure sensor values and a fast modeling method are proposed in the end. Experiment results show that the error of the proposed storage quantity detection model is far less than 3%and that the system cost is low, which can meet the actual need of real-time online monitoring of national grain storage quantity and distribution.%粮仓储粮数量在线检测是国家粮食数量安全的重要保障技术,是粮食库存检查的重要内容。本文根据储粮数量在线检测精度和可靠性的要求,针对粮仓压强分布的随机性,提出了基于粮仓底面零内摩擦压强估计的粮仓储粮数量检测的新思路,建立了粮仓压力传感器布置模型,给出了粮堆底面与侧面压力分布随机性消除和侧面摩擦力影响补偿的具体方法,提出了基于底面压力传感器检测均值的粮仓储粮数量检测模型和快速建模方法。实仓实验结果表明,所提出的储粮数量检测模型检测误差远小于3%,且检测系统成本低,可有效满足国家粮库储粮数量在线实时监测的实际需要。

  6. Detecting single-trial EEG evoked potential using a wavelet domain linear mixed model: application to error potentials classification

    Science.gov (United States)

    Spinnato, J.; Roubaud, M.-C.; Burle, B.; Torrésani, B.

    2015-06-01

    Objective. The main goal of this work is to develop a model for multisensor signals, such as magnetoencephalography or electroencephalography (EEG) signals that account for inter-trial variability, suitable for corresponding binary classification problems. An important constraint is that the model be simple enough to handle small size and unbalanced datasets, as often encountered in BCI-type experiments. Approach. The method involves the linear mixed effects statistical model, wavelet transform, and spatial filtering, and aims at the characterization of localized discriminant features in multisensor signals. After discrete wavelet transform and spatial filtering, a projection onto the relevant wavelet and spatial channels subspaces is used for dimension reduction. The projected signals are then decomposed as the sum of a signal of interest (i.e., discriminant) and background noise, using a very simple Gaussian linear mixed model. Main results. Thanks to the simplicity of the model, the corresponding parameter estimation problem is simplified. Robust estimates of class-covariance matrices are obtained from small sample sizes and an effective Bayes plug-in classifier is derived. The approach is applied to the detection of error potentials in multichannel EEG data in a very unbalanced situation (detection of rare events). Classification results prove the relevance of the proposed approach in such a context. Significance. The combination of the linear mixed model, wavelet transform and spatial filtering for EEG classification is, to the best of our knowledge, an original approach, which is proven to be effective. This paper improves upon earlier results on similar problems, and the three main ingredients all play an important role.

  7. An attempt to determine the effect of increase of observation correlations on detectability and identifiability of a single gross error

    Science.gov (United States)

    Prószyński, Witold; Kwaśniak, Mieczysław

    2016-12-01

    The paper presents the results of investigating the effect of increase of observation correlations on detectability and identifiability of a single gross error, the outlier test sensitivity and also the response-based measures of internal reliability of networks. To reduce in a research a practically incomputable number of possible test options when considering all the non-diagonal elements of the correlation matrix as variables, its simplest representation was used being a matrix with all non-diagonal elements of equal values, termed uniform correlation. By raising the common correlation value incrementally, a sequence of matrix configurations could be obtained corresponding to the increasing level of observation correlations. For each of the measures characterizing the above mentioned features of network reliability the effect is presented in a diagram form as a function of the increasing level of observation correlations. The influence of observation correlations on sensitivity of the w-test for correlated observations (Förstner 1983, Teunissen 2006) is investigated in comparison with the original Baarda's w-test designated for uncorrelated observations, to determine the character of expected sensitivity degradation of the latter when used for correlated observations. The correlation effects obtained for different reliability measures exhibit mutual consistency in a satisfactory extent. As a by-product of the analyses, a simple formula valid for any arbitrary correlation matrix is proposed for transforming the Baarda's w-test statistics into the w-test statistics for correlated observations.

  8. Inborn Errors of Metabolism in the United Arab Emirates: Disorders Detected by Newborn Screening (2011-2014).

    Science.gov (United States)

    Al-Jasmi, Fatma A; Al-Shamsi, Aisha; Hertecant, Jozef L; Al-Hamad, Sania M; Souid, Abdul-Kader

    2016-01-01

    This study reports on the inborn errors of metabolism (IEM) detected by our national newborn screening between 2011 and 2014. One hundred fourteen patients (55 UAE citizens and 59 residents) were diagnosed during this period. The program was most comprehensive (tested 29 IEM) and universally applied in 2013, giving an incidence of 1 in 1,787 citizens. This relatively high prevalence resulted from the frequent consanguineous marriages (81.5%) among affected families. The following eight disorders accounted for 80% of the entities: biotinidase deficiency (14 of 55), phenylketonuria (11 of 55), 3-methylcrotonyl glycinuria (9 of 55), medium-chain acyl-CoA dehydrogenase deficiency (4 of 55), argininosuccinic aciduria, glutaric aciduria type 1, glutaric aciduria type 2, and methylmalonyl-CoA mutase deficiency (2 of 55 each). Mutation analysis was performed in 48 (87%) of the 55 patients, and 33 distinct mutations were identified. Twenty-nine (88%) mutations were clinically significant and, thus, could be included in our premarital screening. Most mutations were homozygous, except for the biotinidase deficiency. The BTD mutations c.1207T>G (found in citizens) and c.424C>A (found in Somalians) were associated with undetectable biotinidase activity. Thus, the high prevalence of IEM in our region is amenable to newborn and premarital screening, which is expected to halt most of these diseases.

  9. Reversed-phase liquid chromatography coupled on-line to estrogen receptor bioaffinity detection based on fluorescence polarization.

    Science.gov (United States)

    Reinen, Jelle; Kool, Jeroen; Vermeulen, Nico P E

    2008-04-01

    We describe the development and validation of a high-resolution screening (HRS) platform which couples gradient reversed-phase high-performance liquid chromatography (RP-HPLC) on-line to estrogen receptor alpha (ERalpha) affinity detection using fluorescence polarization (FP). FP, which allows detection at high wavelengths, limits the occurrence of interference from the autofluorescence of test compounds in the bioassay. A fluorescein-labeled estradiol derivative (E2-F) was synthesized and a binding assay was optimized in platereader format. After subsequent optimization in flow-injection analysis (FIA) mode, the optimized parameters were translated to the on-line HRS bioassay. Proof of principle was demonstrated by separating a mixture of five compounds known to be estrogenic (17beta-estradiol, 17alpha-ethinylestradiol and the phytoestrogens coumestrol, coumarol and zearalenone), followed by post-column bioaffinity screening of the individual affinities for ERalpha. Using the HRS-based FP setup, we were able to screen affinities of off-line-generated metabolites of zearalenone for ERalpha. It is concluded that the on-line FP-based bioassay can be used to screen for the affinity of compounds without the disturbing occurrence of autofluorescence.

  10. A Support Vector Regression Approach for Recursive Simultaneous Data Reconciliation and Gross Error Detection in Nonlinear Dynamical Systems%非线性动态系统迭代的同步数据协调与显著误差检测的支持向量回归方法

    Institute of Scientific and Technical Information of China (English)

    苗宇; 苏宏业; 禇健

    2009-01-01

    The quality of process data in a chemical plant significantly affects the performance and benefits gained from activities like performance monitoring, online optimization, and control. Since many chemical processes often show nonlinear dynamics, techniques like extended Kalman filter (EKF) and nonlinear dynamic data reconciliation (NDDR) have been developed to improve the data quality. Recently, the recursive nonlinear dynamic data reconciliation (RNDDR) technique has been proposed, which combines the merits of EKF and NDDR techniques. However, the RNDDR technique cannot handle measurements with gross errors. In this paper, a support vector (SV) regression approach for recursive simultaneous data reconciliation and gross error detection in nonlinear dynamical systems is proposed. SV regression is a compromise between the empirical risk and the model complexity, and for data reconciliation it is robust to random and gross errors. By minimizing the regularized risk instead of the maximum likelihood in the RNDDR, our approach could achieve not only recursive nonlinear dynamic data reconciliation but also gross error detection simultaneously. The nonlinear dynamic system simulation results in this paper show that the proposed approach is robust, efficient, stable, and accurate for simultaneous data reconciliation and gross error detection in nonlinear dynamic systems within a recursive real-time estimation framework. It can also give better performance of control.

  11. Final Technical Report Recovery Act: Online Nonintrusive Condition Monitoring and Fault Detection for Wind Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Wei Qiao

    2012-05-29

    The penetration of wind power has increased greatly over the last decade in the United States and across the world. The U.S. wind power industry installed 1,118 MW of new capacity in the first quarter of 2011 alone and entered the second quarter with another 5,600 MW under construction. By 2030, wind energy is expected to provide 20% of the U.S. electricity needs. As the number of wind turbines continues to grow, the need for effective condition monitoring and fault detection (CMFD) systems becomes increasingly important [3]. Online CMFD is an effective means of not only improving the reliability, capacity factor, and lifetime, but it also reduces the downtime, energy loss, and operation and maintenance (O&M) of wind turbines. The goal of this project is to develop novel online nonintrusive CMFD technologies for wind turbines. The proposed technologies use only the current measurements that have been used by the control and protection system of a wind turbine generator (WTG); no additional sensors or data acquisition devices are needed. Current signals are reliable and easily accessible from the ground without intruding on the wind turbine generators (WTGs) that are situated on high towers and installed in remote areas. Therefore, current-based CMFD techniques have great economic benefits and the potential to be adopted by the wind energy industry. Specifically, the following objectives and results have been achieved in this project: (1) Analyzed the effects of faults in a WTG on the generator currents of the WTG operating at variable rotating speed conditions from the perspective of amplitude and frequency modulations of the current measurements; (2) Developed effective amplitude and frequency demodulation methods for appropriate signal conditioning of the current measurements to improve the accuracy and reliability of wind turbine CMFD; (3) Developed a 1P-invariant power spectrum density (PSD) method for effective signature extraction of wind turbine faults with

  12. Can the error detection mechanism benefit from training the working memory? A comparison between dyslexics and controls--an ERP study.

    Directory of Open Access Journals (Sweden)

    Tzipi Horowitz-Kraus

    Full Text Available BACKGROUND: Based on the relationship between working memory and error detection, we investigated the capacity of adult dyslexic readers' working memory to change as a result of training, and the impact of training on the error detection mechanism. METHODOLOGY: 27 dyslexics and 34 controls, all university students, participated in the study. ERP methodology and behavioral measures were employed prior to, immediately after, and 6 months after training. The CogniFit Personal Coach Program, which consists of 24 sessions of direct training of working memory skills, was used. FINDINGS: Both groups of readers gained from the training program but the dyslexic readers gained significantly more. In the dyslexic group, digit span increased from 9.84+/-3.15 to 10.79+/-3.03. Working memory training significantly increased the number of words per minute read correctly by 14.73%. Adult brain activity changed as a result of training, evidenced by an increase in both working memory capacity and the amplitude of the Error-related Negativity (ERN component (24.71%. When ERN amplitudes increased, the percentage of errors on the Sternberg tests decreased. CONCLUSIONS: We suggest that by expanding the working memory capacity, larger units of information are retained in the system, enabling more effective error detection. The crucial functioning of the central-executive as a sub-component of the working memory is also discussed.

  13. When errors are rewarding

    NARCIS (Netherlands)

    Bruijn, E.R.A. de; Lange, F.P. de; Cramon, D.Y. von; Ullsperger, M.

    2009-01-01

    For social beings like humans, detecting one's own and others' errors is essential for efficient goal-directed behavior. Although one's own errors are always negative events, errors from other persons may be negative or positive depending on the social context. We used neuroimaging to disentangle br

  14. Online Adaptive Decision Fusion Framework Based on Entropic Projections onto Convex Sets with Application to Wildfire Detection in Video

    CERN Document Server

    Gunay, Osman; Kose, Kivanc; Cetin, A Enis

    2011-01-01

    In this paper, an Entropy functional based online Adaptive Decision Fusion (EADF) framework is developed for image analysis and computer vision applications. In this framework, it is assumed that the compound algorithm consists of several sub-algorithms each of which yielding its own decision as a real number centered around zero, representing the confidence level of that particular sub-algorithm. Decision values are linearly combined with weights which are updated online according to an active fusion method based on performing entropic projections onto convex sets describing sub-algorithms. It is assumed that there is an oracle, who is usually a human operator, providing feedback to the decision fusion method. A video based wildfire detection system is developed to evaluate the performance of the algorithm in handling the problems where data arrives sequentially. In this case, the oracle is the security guard of the forest lookout tower verifying the decision of the combined algorithm. Simulation results are...

  15. A pilot study on the vacuum degree online detection of vacuum interrupter using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Wang, X. H.; Yuan, H.; Liu, D. X.; Yang, A. J.; Liu, P.; Gao, L.; Ding, H. B.; Wang, W. T.; Rong, M. Z.

    2016-11-01

    Vacuum degree online detection of vacuum interrupter has been a great challenge for decades. In this letter, a novel approach based on laser induced breakdown spectroscopy (LIBS) was proposed to solve this tough problem, which is suitable for non-intrusive, electro-magnetic interference free and remote detection. The spectral lines of Cu, H, N and O elements from the interrupter shield were detected for a large gas pressure range from p  =  1  ×  10-3 Pa to 1  ×  105 Pa. It was found that the spectral intensities of O and H increase monotonically with gas pressure, in contrast the spectral intensity of Cu first decreases slightly and then increases. Their intensity ratios, especially for that of Cu to O, change dramatically and monotonically with the gas pressure when p  ⩽  0.1 Pa, indicating that they can be used for determining the vacuum degree values. Spectral ratio method fundamentally reduces the influences of the possible variation in measuring distance and the laser power fluctuation, making LIBS a promising method for vacuum degree online detection of vacuum interrupters.

  16. Determination of organic peroxides by liquid chromatography with on-line post-column ultraviolet irradiation and peroxyoxalate chemiluminescence detection.

    Science.gov (United States)

    Wada, Mitsuhiro; Inoue, Keiyu; Thara, Ayuko; Kishikawa, Naoya; Nakashima, Kenichiro; Kuroda, Naotaka

    2003-02-14

    A HPLC method was developed for the simultaneous determination of organic peroxides and hydrogen peroxide with peroxyoxalate chemiluminescence (PO-CL) detection following on-line UV irradiation. Organic peroxides [i.e., benzoyl peroxide (BP), tert.-butyl hydroperoxide (BHP), tert.-butyl perbenzoate (BPB), cumene hydroperoxide (CHP)] were UV irradiated (254 nm, 15 W) to generate hydrogen peroxide, which was determined by PO-CL detection. The conditions for UV irradiation and PO-CL detection were optimized by a flow injection analysis (FIA) system. Generation of hydrogen peroxide from peroxides with on-line UV irradiation also was confirmed by the FIA system by incorporating an enzyme column reactor immobilized with catalase. The separation of four organic peroxides and hydrogen peroxide by HPLC was accomplished isocratically on an ODS column within 30 min. The detection limits (signal-to-noise ratio=3) were 1.1 microM for hydrogen peroxide, 6.8 microM for BP, 31.3 microM for BHP, 7.5 microM for BPB and 1.3 microM for CHP. The proposed method was applied to the determination of BP in wheat flour.

  17. Parity Codes Used for On-Line Testing in FPGA

    Directory of Open Access Journals (Sweden)

    P. Kubalík

    2005-01-01

    Full Text Available This paper deals with on-line error detection in digital circuits implemented in FPGAs. Error detection codes have been used to ensure the self-checking property. The adopted fault model is discussed. A fault in a given combinational circuit must be detected and signalized at the time of its appearance and before further distribution of errors. Hence safe operation of the designed system is guaranteed. The check bits generator and the checker were added to the original combinational circuit to detect an error during normal circuit operation. This concurrent error detection ensures the Totally Self-Checking property. Combinational circuit benchmarks have been used in this work in order to compute the quality of the proposed codes. The description of the benchmarks is based on equations and tables. All of our experimental results are obtained by XILINX FPGA implementation EDA tools. A possible TSC structure consisting of several TSC blocks is presented. 

  18. One strategy to reduce medication errors: the effect of an online continuing education module on nurses' use of the Lexi-Comp feature of the Pyxis MedStation 2000.

    Science.gov (United States)

    Straight, Maureen

    2008-01-01

    This study sought to evaluate the impact of an online self-learning module on nurse knowledge and use of the Lexi-Comp feature of the Pyxis MedStation Rx 2000 system, a point-of-care medication delivery system. Data were collected among nurse-users at a community-based healthcare organization (N = 41). Pre- and post-training surveys were used to evaluate training effects. After training, completion of the tutorial and knowledge and use of the Lexi-Comp feature increased by 23% and 56%, respectively. One month after training, a drop in medication errors on administration at the healthcare organization was observed. These findings suggest that use of evaluative and instructional tools would improve integration of technology and clinical practice and improve patient outcomes in medication error reduction.

  19. Development of an iterative reconstruction method to overcome 2D detector low resolution limitations in MLC leaf position error detection for 3D dose verification in IMRT

    NARCIS (Netherlands)

    Visser, Ruurd; Godart, J.; Wauben, D. J. L.; Langendijk, J. A.; van't Veld, A. A.; Korevaar, E. W.

    2016-01-01

    The objective of this study was to introduce a new iterative method to reconstruct multi leaf collimator (MLC) positions based on low resolution ionization detector array measurements and to evaluate its error detection performance. The iterative reconstruction method consists of a fluence model, a

  20. CVT附加相差对容性设备介损在线监测的影响%Effect of CVT Additional Phase Error on On-Line Monitoring of Dielectric Loss Factor for Capacitive Equipment

    Institute of Scientific and Technical Information of China (English)

    李璿; 余春雨; 王晓琪; 吴士普; 冯宇

    2013-01-01

    电容式电压互感器(CVT)在我国变电站中广泛应用,并作为电容型高压设备介质损耗因数在线监测的电压参考信号。研究表明,电压参考信号相位误差对介质损耗因数测量结果造成影响。本文对电容式电压互感器附加误差进行分析,并通过试验得出电网频率及环境温度对CVT相位误差的影响量,结果表明,由于电网频率和环境温度引起的CVT相位误差变化量与电容型高压设备自身绝缘缺陷引起的介质损耗角变化量在同一个数量级,极容易引起电容型高压设备绝缘状态的误判。应开展CVT误差在线校准相关研究,为电容型高压设备介质损耗因数在线监测提供高精度参考电压。%Capacitor voltage transformer (CVT) has been widely used in electrical power system for its high dielectric strength and low cost, and is also used to supply voltage reference signal in on-line monitoring of dielectric loss factor for capacitive equipment. Research indicates that phase error of CVT can affect measurement results of dielectric loss. In this paper, the additional phase error of CVT is analyzed, and the influence quantity of CVT phase error caused by power system frequency and ambient temperature is tested. Results indicate that the influence quantity of additional phase error is of the same magnitude as the dielectric loss angle caused by insulation defect of capacitive high-voltage apparatus, therefore is easy to cause the misjudgment of capacitive high-voltage insulation status. Research on on-line calibration of CVT error should be done to improve the precision of reference signal voltage, which is helpful for on-line monitoring of dielectric loss factor for capacitive equipment.

  1. An energy-based sparse representation of ultrasonic guided-waves for online damage detection of pipelines under varying environmental and operational conditions

    Science.gov (United States)

    Eybpoosh, Matineh; Berges, Mario; Noh, Hae Young

    2017-01-01

    This work addresses the main challenges in real-world application of guided-waves for damage detection of pipelines, namely their complex nature and sensitivity to environmental and operational conditions (EOCs). Different propagation characteristics of the wave modes, their distinctive sensitivities to different types and ranges of EOCs, and to different damage scenarios, make the interpretation of diffuse-field guided-wave signals a challenging task. This paper proposes an unsupervised feature-extraction method for online damage detection of pipelines under varying EOCs. The objective is to simplify diffuse-field guided-wave signals to a sparse subset of the arrivals that contains the majority of the energy carried by the signal. We show that such a subset is less affected by EOCs compared to the complete time-traces of the signals. Moreover, it is shown that the effects of damage on the energy of this subset suppress those of EOCs. A set of signals from the undamaged state of a pipe are used as reference records. The reference dataset is used to extract the aforementioned sparse representation. During the monitoring stage, the sparse subset, representing the undamaged pipe, will not accurately reconstruct the energy of a signal from a damaged pipe. In other words, such a sparse representation of guided-waves is sensitive to occurrence of damage. Therefore, the energy estimation errors are used as damage-sensitive features for damage detection purposes. A diverse set of experimental analyses are conducted to verify the hypotheses of the proposed feature-extraction approach, and to validate the detection performance of the damage-sensitive features. The empirical validation of the proposed method includes (1) detecting a structural abnormality in an aluminum pipe, under varying temperature at different ranges, (2) detecting multiple small damages of different types, at different locations, in a steel pipe, under varying temperature, (3) detecting a structural

  2. Online gait event detection using a large force platform embedded in a treadmill

    NARCIS (Netherlands)

    Roerdink, Melvyn; Coolen, Bert (H.); Clairbois, Bert (H.)E.; Lamoth, Claudine J.C.; Beek, Peter J.

    2008-01-01

    Gait research and clinical gait training may benefit from movement-dependent event control, that is, technical applications in which events such as obstacle appearance or visual/acoustic cueing are (co)determined online on the basis of current gait properties. A prerequisite for successful gait-depe

  3. Crawling and Detecting Community Structure in Online Social Networks using Local Information

    NARCIS (Netherlands)

    Blenn, N.; Doerr, C.; Van Kester, B.; Van Mieghem, P.

    As Online Social Networks (OSNs) become an intensive sub- ject of research for example in computer science, networking, social sci- ences etc., a growing need for valid and useful datasets is present. The time taken to crawl the network is however introducing a bias which should be minimized. Usual

  4. Use of Online Records for Detection of Diseases and Heat in Dairy Cattle Stocks

    DEFF Research Database (Denmark)

    Hansen, Jørgen Vinsløv

    to the ongoing research in analysing online data. The focus here is on using state space models, which are a class of models suited for analysing time series. In the thesis the developed techniques are applied to specific datasets. For example a state space model is developed to predict the time of heat in cows...

  5. Automatic Detection of Online Recruitment Frauds: Characteristics, Methods, and a Public Dataset

    Directory of Open Access Journals (Sweden)

    Sokratis Vidros

    2017-03-01

    Full Text Available The critical process of hiring has relatively recently been ported to the cloud. Specifically, the automated systems responsible for completing the recruitment of new employees in an online fashion, aim to make the hiring process more immediate, accurate and cost-efficient. However, the online exposure of such traditional business procedures has introduced new points of failure that may lead to privacy loss for applicants and harm the reputation of organizations. So far, the most common case of Online Recruitment Frauds (ORF, is employment scam. Unlike relevant online fraud problems, the tackling of ORF has not yet received the proper attention, remaining largely unexplored until now. Responding to this need, the work at hand defines and describes the characteristics of this severe and timely novel cyber security research topic. At the same time, it contributes and evaluates the first to our knowledge publicly available dataset of 17,880 annotated job ads, retrieved from the use of a real-life system.

  6. An on-line high performance liquid chromatography-crocin bleaching assay for detection of antioxidants

    NARCIS (Netherlands)

    Bountagkidou, O.; Klift, van der E.J.C.; Tsimidou, M.Z.; Ordoudi, S.A.; Beek, van T.A.

    2012-01-01

    An on-line HPLC (high performance liquid chromatography) method for the rapid screening of individual antioxidants in mixtures was developed using crocin as a substrate (i.e. oxidation probe) and 2,2'-azobis(2-amidinopropane dihydrochloride (AAPH)) in phosphate buffer (pH 7.5) as a radical generator

  7. Electrochemical oxidation and cleavage of peptides analyzed with on-line mass spectrometric detection

    NARCIS (Netherlands)

    Permentier, H.P.; Jurva, U; Barroso, B.; Bruins, A.P.

    2003-01-01

    An on-line electrochernistry/electrospray mass spectrometry system (EC/MS) is described that allows fast analysis of the oxidation products of peptides. A range of peptides was oxidized in an electrochemical cell by application of a potential ramp from 0 to 1.5 V during passage of the sample. Electr

  8. "Newbies" and "Celebrities": Detecting Social Roles in an Online Network of Teachers via Participation Patterns

    Science.gov (United States)

    Smith Risser, H.; Bottoms, SueAnn

    2014-01-01

    The advent of social networking tools allows teachers to create online networks and share information. While some virtual networks have a formal structure and defined boundaries, many do not. These unstructured virtual networks are difficult to study because they lack defined boundaries and a formal structure governing leadership roles and the…

  9. Comparison of simultaneous on-line optical and acoustic laser damage detection methods in the nanosecond pulse duration domain

    Science.gov (United States)

    Somoskoi, T.; Vass, Cs; Mero, M.; Mingesz, R.; Bozoki, Z.; Osvay, K.

    2015-05-01

    We carried out single-shot laser-induced damage threshold measurements on dielectric high reflectors guided by the corresponding ISO standard. Four simultaneous on-line detection techniques were tested and compared using 532 nm, 9 ns and 266 nm, 6 ns laser pulses. Two methods, microscope aided visual inspection and detection of scattered light off the damaged surface, were based on optical signals. The other two techniques exploited the acoustic waves accompanying a damage event in ambient air and in the substrate by a microphone and a piezoelectric sensor, respectively. A unified criterion based on the statistical analysis of the detector signals was applied to assign an objective and unambiguous damage threshold value for all of our diverse detection methods. Microscope aided visual inspection showed the lowest damage thresholds for both wavelengths. However, the sensitivity of the other three techniques proved to be only slightly lower.

  10. Evaluation of Suwannee River NOM electrophoretic fractions by RP-HPLC with online absorbance and fluorescence detection.

    Science.gov (United States)

    Trubetskaya, Olga E; Richard, Claire; Trubetskoj, Oleg A

    2015-07-01

    Reversed-phase high-performance liquid chromatography (RP-HPLC) with online absorbance and fluorescence detections was used for the evaluation of Suwannee River natural organic matter (SRNOM) and its fractions A, B, and C+D, obtained by conventional size exclusion chromatography-polyacrylamide gel electrophoresis (SEC-PAGE) setup, for which the electrophoretic mobility (EM) and the absorptivity varied in the order C+D > B > A, and the molecular size (MS) in the opposite order. Analysis of SRNOM and its fractions in part of their relative irreversible adsorption on C18-column and relative distribution of eluted from the column matter on hydrophobic and hydrophilic peaks showed that hydrophobicity of fractions decreased in order: A > B > C+D. The online fluorescence detection showed that SRNOM and its fractions contained at least three groups of humic substances (HS)-like fluorophores with emission maxima at 435, 455-465, and 455/420 nm and two protein-like fluorophores with emission maxima at around 300 and 340 nm. The HS-like fluorophore with emission maximum at 435 nm was located in the hydrophilic peak in all the samples. Those with maxima at 455-465 nm were detected in hydrophobic peaks of fractions A and B. SEC-PAGE setup followed by RP-HPLC allowed us to develop new approach of SRNOM separation on less heterogeneous compounds mixture for their further study and structural identification.

  11. Online Doppler Effect Elimination Based on Unequal Time Interval Sampling for Wayside Acoustic Bearing Fault Detecting System.

    Science.gov (United States)

    Ouyang, Kesai; Lu, Siliang; Zhang, Shangbin; Zhang, Haibin; He, Qingbo; Kong, Fanrang

    2015-08-27

    The railway occupies a fairly important position in transportation due to its high speed and strong transportation capability. As a consequence, it is a key issue to guarantee continuous running and transportation safety of trains. Meanwhile, time consumption of the diagnosis procedure is of extreme importance for the detecting system. However, most of the current adopted techniques in the wayside acoustic defective bearing detector system (ADBD) are offline strategies, which means that the signal is analyzed after the sampling process. This would result in unavoidable time latency. Besides, the acquired acoustic signal would be corrupted by the Doppler effect because of high relative speed between the train and the data acquisition system (DAS). Thus, it is difficult to effectively diagnose the bearing defects immediately. In this paper, a new strategy called online Doppler effect elimination (ODEE) is proposed to remove the Doppler distortion online by the introduced unequal interval sampling scheme. The steps of proposed strategy are as follows: The essential parameters are acquired in advance. Then, the introduced unequal time interval sampling strategy is used to restore the Doppler distortion signal, and the amplitude of the signal is demodulated as well. Thus, the restored Doppler-free signal is obtained online. The proposed ODEE method has been employed in simulation analysis. Ultimately, the ODEE method is implemented in the embedded system for fault diagnosis of the train bearing. The results are in good accordance with the bearing defects, which verifies the good performance of the proposed strategy.

  12. Online Doppler Effect Elimination Based on Unequal Time Interval Sampling for Wayside Acoustic Bearing Fault Detecting System

    Directory of Open Access Journals (Sweden)

    Kesai Ouyang

    2015-08-01

    Full Text Available The railway occupies a fairly important position in transportation due to its high speed and strong transportation capability. As a consequence, it is a key issue to guarantee continuous running and transportation safety of trains. Meanwhile, time consumption of the diagnosis procedure is of extreme importance for the detecting system. However, most of the current adopted techniques in the wayside acoustic defective bearing detector system (ADBD are offline strategies, which means that the signal is analyzed after the sampling process. This would result in unavoidable time latency. Besides, the acquired acoustic signal would be corrupted by the Doppler effect because of high relative speed between the train and the data acquisition system (DAS. Thus, it is difficult to effectively diagnose the bearing defects immediately. In this paper, a new strategy called online Doppler effect elimination (ODEE is proposed to remove the Doppler distortion online by the introduced unequal interval sampling scheme. The steps of proposed strategy are as follows: The essential parameters are acquired in advance. Then, the introduced unequal time interval sampling strategy is used to restore the Doppler distortion signal, and the amplitude of the signal is demodulated as well. Thus, the restored Doppler-free signal is obtained online. The proposed ODEE method has been employed in simulation analysis. Ultimately, the ODEE method is implemented in the embedded system for fault diagnosis of the train bearing. The results are in good accordance with the bearing defects, which verifies the good performance of the proposed strategy.

  13. Evaluating IMRT and VMAT dose accuracy: Practical examples of failure to detect systematic errors when applying a commonly used metric and action levels

    Energy Technology Data Exchange (ETDEWEB)

    Nelms, Benjamin E. [Canis Lupus LLC, Merrimac, Wisconsin 53561 (United States); Chan, Maria F. [Memorial Sloan-Kettering Cancer Center, Basking Ridge, New Jersey 07920 (United States); Jarry, Geneviève; Lemire, Matthieu [Hôpital Maisonneuve-Rosemont, Montréal, QC H1T 2M4 (Canada); Lowden, John [Indiana University Health - Goshen Hospital, Goshen, Indiana 46526 (United States); Hampton, Carnell [Levine Cancer Institute/Carolinas Medical Center, Concord, North Carolina 28025 (United States); Feygelman, Vladimir [Moffitt Cancer Center, Tampa, Florida 33612 (United States)

    2013-11-15

    Purpose: This study (1) examines a variety of real-world cases where systematic errors were not detected by widely accepted methods for IMRT/VMAT dosimetric accuracy evaluation, and (2) drills-down to identify failure modes and their corresponding means for detection, diagnosis, and mitigation. The primary goal of detailing these case studies is to explore different, more sensitive methods and metrics that could be used more effectively for evaluating accuracy of dose algorithms, delivery systems, and QA devices.Methods: The authors present seven real-world case studies representing a variety of combinations of the treatment planning system (TPS), linac, delivery modality, and systematic error type. These case studies are typical to what might be used as part of an IMRT or VMAT commissioning test suite, varying in complexity. Each case study is analyzed according to TG-119 instructions for gamma passing rates and action levels for per-beam and/or composite plan dosimetric QA. Then, each case study is analyzed in-depth with advanced diagnostic methods (dose profile examination, EPID-based measurements, dose difference pattern analysis, 3D measurement-guided dose reconstruction, and dose grid inspection) and more sensitive metrics (2% local normalization/2 mm DTA and estimated DVH comparisons).Results: For these case studies, the conventional 3%/3 mm gamma passing rates exceeded 99% for IMRT per-beam analyses and ranged from 93.9% to 100% for composite plan dose analysis, well above the TG-119 action levels of 90% and 88%, respectively. However, all cases had systematic errors that were detected only by using advanced diagnostic techniques and more sensitive metrics. The systematic errors caused variable but noteworthy impact, including estimated target dose coverage loss of up to 5.5% and local dose deviations up to 31.5%. Types of errors included TPS model settings, algorithm limitations, and modeling and alignment of QA phantoms in the TPS. Most of the errors were

  14. Using Benford’s Law to detect data error and fraud: An examination of companies listed on the Johannesburg Stock Exchange

    Directory of Open Access Journals (Sweden)

    A Saville

    2014-06-01

    Full Text Available Accounting numbers generally obey a mathematical law called Benford’s Law, and this outcome is so unexpected that manipulators of information generally fail to observe the law. Armed with this knowledge, it becomes possible to detect the occurrence of accounting data that are presented fraudulently. However, the law also allows for the possibility of detecting instances where data are presented containing errors. Given this backdrop, this paper uses data drawn from companies listed on the Johannesburg Stock Exchange to test the hypothesis that Benford’s Law can be used to identify false or fraudulent reporting of accounting data. The results support the argument that Benford’s Law can be used effectively to detect accounting error and fraud. Accordingly, the findings are of particular relevance to auditors, shareholders, financial analysts, investment managers, private investors and other users of publicly reported accounting data, such as the revenue services

  15. ON-LINE WEAR DETECTION OF MILLING TOOLS USING A DISPLACEMENT FIBER OPTIC SENSOR

    Directory of Open Access Journals (Sweden)

    E. Castillo-Castañeda

    2003-07-01

    Full Text Available A cost-effective technique for on-line wear monitoring of a milling tool is presented. The tool wear is estimateddirectly from a fiber optic sensor with high resolution and high bandwidth characteristics. This sensor providesa distance measurement between its probe and the tool profile. The contribution of this work is the applicationof this sensor to sense on-line wear of a milling tool. Since the light emitted by this sensor comes from aphotodiode, it does not produce eye damage, this is safer than laser displacement sensors. This techniquesenses the tool wear in real time, while the tool is rotating, with an accuracy less than 1 micron. Experimentalresults are also presented for a four-flank cutting tool rotating at 300 rpm.

  16. Proofreading for word errors.

    Science.gov (United States)

    Pilotti, Maura; Chodorow, Martin; Agpawa, Ian; Krajniak, Marta; Mahamane, Salif

    2012-04-01

    Proofreading (i.e., reading text for the purpose of detecting and correcting typographical errors) is viewed as a component of the activity of revising text and thus is a necessary (albeit not sufficient) procedural step for enhancing the quality of a written product. The purpose of the present research was to test competing accounts of word-error detection which predict factors that may influence reading and proofreading differently. Word errors, which change a word into another word (e.g., from --> form), were selected for examination because they are unlikely to be detected by automatic spell-checking functions. Consequently, their detection still rests mostly in the hands of the human proofreader. Findings highlighted the weaknesses of existing accounts of proofreading and identified factors, such as length and frequency of the error in the English language relative to frequency of the correct word, which might play a key role in detection of word errors.

  17. Online production validation in a HEP environment

    Science.gov (United States)

    Harenberg, T.; Kuhl, T.; Lang, N.; Mättig, P.; Sandhoff, M.; Schwanenberger, C.; Volkmer, F.

    2017-03-01

    In high energy physics (HEP) event simulations, petabytes of data are processed and stored requiring millions of CPU-years. This enormous demand for computing resources is handled by centers distributed worldwide, which form part of the LHC computing grid. The consumption of such an important amount of resources demands for an efficient production of simulation and for the early detection of potential errors. In this article we present a new monitoring framework for grid environments, which polls a measure of data quality during job execution. This online monitoring facilitates the early detection of configuration errors (specially in simulation parameters), and may thus contribute to significant savings in computing resources.

  18. Detecting the Online Image of “Average” Restaurants on TripAdvisor

    OpenAIRE

    Hrvoje Jakopović

    2016-01-01

    Collective intelligence can be interpreted as the actions of individuals that provide collective effects. In online spaces, the more user comments about a matter of discussion, the higher the potential that certain repeated points of view will be used as a story frame. This observation can be a very useful explanation for the value of user comments, reviews and the ratings in the field of public relations. Nowadays, it has become noticeable that many indecisive people who are thinking of buyi...

  19. How do community pharmacies recover from e-prescription errors?

    Science.gov (United States)

    Odukoya, Olufunmilola K; Stone, Jamie A; Chui, Michelle A

    2014-01-01

    The use of e-prescribing is increasing annually, with over 788 million e-prescriptions received in US pharmacies in 2012. Approximately 9% of e-prescriptions have medication errors. To describe the process used by community pharmacy staff to detect, explain, and correct e-prescription errors. The error recovery conceptual framework was employed for data collection and analysis. 13 pharmacists and 14 technicians from five community pharmacies in Wisconsin participated in the study. A combination of data collection methods were utilized, including direct observations, interviews, and focus groups. The transcription and content analysis of recordings were guided by the three-step error recovery model. Most of the e-prescription errors were detected during the entering of information into the pharmacy system. These errors were detected by both pharmacists and technicians using a variety of strategies which included: (1) performing double checks of e-prescription information; (2) printing the e-prescription to paper and confirming the information on the computer screen with information from the paper printout; and (3) using colored pens to highlight important information. Strategies used for explaining errors included: (1) careful review of patient's medication history; (2) pharmacist consultation with patients; (3) consultation with another pharmacy team member; and (4) use of online resources. In order to correct e-prescription errors, participants made educated guesses of the prescriber's intent or contacted the prescriber via telephone or fax. When e-prescription errors were encountered in the community pharmacies, the primary goal of participants was to get the order right for patients by verifying the prescriber's intent. Pharmacists and technicians play an important role in preventing e-prescription errors through the detection of errors and the verification of prescribers' intent. Future studies are needed to examine factors that facilitate or hinder recovery

  20. How do Community Pharmacies Recover from E-prescription Errors?

    Science.gov (United States)

    Odukoya, Olufunmilola K.; Stone, Jamie A.; Chui, Michelle A.

    2014-01-01

    Background The use of e-prescribing is increasing annually, with over 788 million e-prescriptions received in US pharmacies in 2012. Approximately 9% of e-prescriptions have medication errors. Objective To describe the process used by community pharmacy staff to detect, explain, and correct e-prescription errors. Methods The error recovery conceptual framework was employed for data collection and analysis. 13 pharmacists and 14 technicians from five community pharmacies in Wisconsin participated in the study. A combination of data collection methods were utilized, including direct observations, interviews, and focus groups. The transcription and content analysis of recordings were guided by the three-step error recovery model. Results Most of the e-prescription errors were detected during the entering of information into the pharmacy system. These errors were detected by both pharmacists and technicians using a variety of strategies which included: (1) performing double checks of e-prescription information; (2) printing the e-prescription to paper and confirming the information on the computer screen with information from the paper printout; and (3) using colored pens to highlight important information. Strategies used for explaining errors included: (1) careful review of patient’ medication history; (2) pharmacist consultation with patients; (3) consultation with another pharmacy team member; and (4) use of online resources. In order to correct e-prescription errors, participants made educated guesses of the prescriber’s intent or contacted the prescriber via telephone or fax. When e-prescription errors were encountered in the community pharmacies, the primary goal of participants was to get the order right for patients by verifying the prescriber’s intent. Conclusion Pharmacists and technicians play an important role in preventing e-prescription errors through the detection of errors and the verification of prescribers’ intent. Future studies are needed

  1. Impact of habitat-specific GPS positional error on detection of movement scales by first-passage time analysis.

    Science.gov (United States)

    Williams, David M; Dechen Quinn, Amy; Porter, William F

    2012-01-01

    Advances in animal tracking technologies have reduced but not eliminated positional error. While aware of such inherent error, scientists often proceed with analyses that assume exact locations. The results of such analyses then represent one realization in a distribution of possible outcomes. Evaluating results within the context of that distribution can strengthen or weaken our confidence in conclusions drawn from the analysis in question. We evaluated the habitat-specific positional error of stationary GPS collars placed under a range of vegetation conditions that produced a gradient of canopy cover. We explored how variation of positional error in different vegetation cover types affects a researcher's ability to discern scales of movement in analyses of first-passage time for white-tailed deer (Odocoileus virginianus). We placed 11 GPS collars in 4 different vegetative canopy cover types classified as the proportion of cover above the collar (0-25%, 26-50%, 51-75%, and 76-100%). We simulated the effect of positional error on individual movement paths using cover-specific error distributions at each location. The different cover classes did not introduce any directional bias in positional observations (1 m≤mean≤6.51 m, 0.24≤p≤0.47), but the standard deviation of positional error of fixes increased significantly with increasing canopy cover class for the 0-25%, 26-50%, 51-75% classes (SD = 2.18 m, 3.07 m, and 4.61 m, respectively) and then leveled off in the 76-100% cover class (SD = 4.43 m). We then added cover-specific positional errors to individual deer movement paths and conducted first-passage time analyses on the noisy and original paths. First-passage time analyses were robust to habitat-specific error in a forest-agriculture landscape. For deer in a fragmented forest-agriculture environment, and species that move across similar geographic extents, we suggest that first-passage time analysis is robust with regard to positional errors.

  2. Impact of habitat-specific GPS positional error on detection of movement scales by first-passage time analysis.

    Directory of Open Access Journals (Sweden)

    David M Williams

    Full Text Available Advances in animal tracking technologies have reduced but not eliminated positional error. While aware of such inherent error, scientists often proceed with analyses that assume exact locations. The results of such analyses then represent one realization in a distribution of possible outcomes. Evaluating results within the context of that distribution can strengthen or weaken our confidence in conclusions drawn from the analysis in question. We evaluated the habitat-specific positional error of stationary GPS collars placed under a range of vegetation conditions that produced a gradient of canopy cover. We explored how variation of positional error in different vegetation cover types affects a researcher's ability to discern scales of movement in analyses of first-passage time for white-tailed deer (Odocoileus virginianus. We placed 11 GPS collars in 4 different vegetative canopy cover types classified as the proportion of cover above the collar (0-25%, 26-50%, 51-75%, and 76-100%. We simulated the effect of positional error on individual movement paths using cover-specific error distributions at each location. The different cover classes did not introduce any directional bias in positional observations (1 m≤mean≤6.51 m, 0.24≤p≤0.47, but the standard deviation of positional error of fixes increased significantly with increasing canopy cover class for the 0-25%, 26-50%, 51-75% classes (SD = 2.18 m, 3.07 m, and 4.61 m, respectively and then leveled off in the 76-100% cover class (SD = 4.43 m. We then added cover-specific positional errors to individual deer movement paths and conducted first-passage time analyses on the noisy and original paths. First-passage time analyses were robust to habitat-specific error in a forest-agriculture landscape. For deer in a fragmented forest-agriculture environment, and species that move across similar geographic extents, we suggest that first-passage time analysis is robust with regard to

  3. The Multi-Criteria On-Line Modeling and Filter for Random Error of MEMS Groscope%多准则MEMS陀螺随机误差在线建模与实时滤波

    Institute of Scientific and Technical Information of China (English)

    代金华; 张丽杰

    2016-01-01

    As the random error of some MEMS gyroscope had weak correlation,the Multi-criteria curve method was introduced to identify the time-sequence model with a intercept. Using this model,the random error model of the MEMS gyroscope could be established on line without zero mean offline processing. Based on this model,an aug-menting state vector was used to design the Kalman filter which had been used to filter real-timely. The results of the experiment showed that AR(2)model with a intercept could be used as a good MEMS gyroscope random error model. After the on-line modeling and real-time filtering,50% of the standard deviation of the random error had been reduced and the random error of MEMS gyroscope was effectively restrained.%针对随机误差相关性较弱的MEMS陀螺仪,提出采用多准则曲线方法辨识其带有截距项的随机误差时间序列模型.采用该模型可直接对MEMS陀螺仪的实测量数据进行在线建模,而无需零均值化离线处理.基于该模型并采用状态扩增的方法设计卡尔曼滤波器,实现了MEMS陀螺仪随机误差的实时滤波.实验结果表明,针对某MEMS陀螺仪带有截距项的AR(2)模型可以作为其随机误差模型,经过在线建模和实时滤波后,MEMS陀螺仪随机误差的标准差降低了50%,有效抑制了MEMS陀螺仪的随机误差.

  4. Online visual detection system for color deviation%布匹色差在线视觉检测系统

    Institute of Scientific and Technical Information of China (English)

    金守峰

    2012-01-01

    为实时客观地评价布匹表面色差,设计了布匹色差在线视觉检测系统.该系统由光源模块、线阵CCD成像模块和计算机色差计算模块组成,通过彩色线阵CCD连续扫描布匹表面成像,运用CIE1976 Lab 颜色模型完成色差的实时计算,同时给出布匹色差的统计数据.结果表明,采用该方法在线检测布匹色差具有可行性.%An online visual detection system is designed to realize objective and real-time evaluation of color variation. This system consists of light source module, imaging module with charge coupled device(CCD) linear array and calculation module of color variation. Images are obtained by continuous scanning of the fabric surfacG with CCD linear array, the color deviation is calculated in real-line via CIE1976Lab color model, and the statistics are given at the same time. The results show that this method is feasible for online detection of color variation.

  5. Development of a Compton Camera for Online Range Monitoring of Laser-Accelerated Proton Beams via Prompt-Gamma Detection

    Directory of Open Access Journals (Sweden)

    Thirolf P.G.

    2014-03-01

    Full Text Available Presently large efforts are conducted in Munich towards the development of proton beams for bio-medical applications, generated via the technique of particle acceleration from high-power, short-pulse lasers. While so far mostly offline diagnostics tools are used in this context, we aim at developing a reliable and accurate online range monitoring technique, based on the position-sensitive detection of prompt γ rays emitted from nuclear reactions between the proton beam and the biological sample. For this purpose, we develop a Compton camera, designed to be able to track not only the Compton scattering of the primary photon, but also to detect the secondary Compton electron, thus reducing the Compton cone to an arc segment and by this increasing the source reconstruction efficiency. Design specifications and the status of the protype system are discussed.

  6. Rapid on-line detection and grading of wooden breast myopathy in chicken fillets by near-infrared spectroscopy

    Science.gov (United States)

    Veiseth-Kent, Eva; Høst, Vibeke; Løvland, Atle

    2017-01-01

    The main objective of this work was to develop a method for rapid and non-destructive detection and grading of wooden breast (WB) syndrome in chicken breast fillets. Near-infrared (NIR) spectroscopy was chosen as detection method, and an industrial NIR scanner was applied and tested for large scale on-line detection of the syndrome. Two approaches were evaluated for discrimination of WB fillets: 1) Linear discriminant analysis based on NIR spectra only, and 2) a regression model for protein was made based on NIR spectra and the estimated concentrations of protein were used for discrimination. A sample set of 197 fillets was used for training and calibration. A test set was recorded under industrial conditions and contained spectra from 79 fillets. The classification methods obtained 99.5–100% correct classification of the calibration set and 100% correct classification of the test set. The NIR scanner was then installed in a commercial chicken processing plant and could detect incidence rates of WB in large batches of fillets. Examples of incidence are shown for three broiler flocks where a high number of fillets (9063, 6330 and 10483) were effectively measured. Prevalence of WB of 0.1%, 6.6% and 8.5% were estimated for these flocks based on the complete sample volumes. Such an on-line system can be used to alleviate the challenges WB represents to the poultry meat industry. It enables automatic quality sorting of chicken fillets to different product categories. Manual laborious grading can be avoided. Incidences of WB from different farms and flocks can be tracked and information can be used to understand and point out main causes for WB in the chicken production. This knowledge can be used to improve the production procedures and reduce today’s extensive occurrence of WB. PMID:28278170

  7. Suppression (but not reappraisal impairs subsequent error detection: an ERP study of emotion regulation's resource-depleting effect.

    Directory of Open Access Journals (Sweden)

    Yan Wang

    Full Text Available Past event-related potentials (ERPs research shows that, after exerting effortful emotion inhibition, the neural correlates of performance monitoring (e.g. error-related negativity were weakened. An undetermined issue is whether all forms of emotion regulation uniformly impair later performance monitoring. The present study compared the cognitive consequences of two emotion regulation strategies, namely suppression and reappraisal. Participants were instructed to suppress their emotions while watching a sad movie, or to adopt a neutral and objective attitude toward the movie, or to just watch the movie carefully. Then after a mood scale, all participants completed an ostensibly unrelated Stroop task, during which ERPs (i.e. error-related negativity (ERN, post-error positivity (Pe and N450 were obtained. Reappraisal group successfully decreased their sad emotion, relative to the other two groups. Compared with participants in the control group and the reappraisal group, those who suppressed their emotions during the sad movie showed reduced ERN after error commission. Participants in the suppression group also made more errors in incongruent Stroop trials than the other two groups. There were no significant main effects or interactions of group for reaction time, Pe and N450. Results suggest that reappraisal is both more effective and less resource-depleting than suppression.

  8. A radio-high-performance liquid chromatography dual-flow cell gamma-detection system for on-line radiochemical purity and labeling efficiency determination

    DEFF Research Database (Denmark)

    Lindegren, S; Jensen, H; Jacobsson, L

    2014-01-01

    into the well of a NaI(Tl) detector. The radio-HPLC flow was directed from the injector to the reference cell allowing on-line detection of the total injected sample activity prior to entering the HPLC column. The radioactivity eluted from the column was then detected in the analytical cell. In this way...

  9. The Trace Analysis of DEET in Water using an On-line Preconcentration Column and Liquid Chromatography with UV Photodiode Array Detection

    Science.gov (United States)

    A method for the detection of trace levels of N,N-diethyl-m-toluamide (DEET) in water is discussed. The method utilizes an on-line preconcentration column in series with high performance liquid chromatography (HPLC) and UV photodiode array detection. DEET, a common insect repel...

  10. A New On-Line Detecting Apparatus of the Residual Chlorine in Disinfectant for Fresh-Cut Vegetables

    Science.gov (United States)

    Hu, Chao; Su, Shu-Qiang; Li, Bao-Guo; Liu, Meng-Fang

    With the fast development of modern food and beverage industry, fresh-cut vegetables have wider application than before. During the process of sterilization in fresh-cut vegetables, the concentration of chloric disinfectant is usually so high that the common sensor can't be used directly on the product line. In order to solve this problem, we have invented a new detecting apparatus which could detect high concentration of chloric disinfectant directly. In this paper, the working principle, main monitor indicators, application and technical creations of the on-line apparatus have been discussed, and we also carried on the experimental analysis for its performance. The actual demands in factory could be met when the detecting flux is 2L/min, the dilution ratio is 15 and input amount of the disinfectant is 200ml per time, the max of the detecting deviation achieves ±4.8ppm(mg/L). The main detecting range of residual chlorine is 0~300ppm.

  11. 含缺失属性值的问题数据检测与修复%Error data detection and repair in condition of field value missing

    Institute of Scientific and Technical Information of China (English)

    高科; 刁兴春; 曹建军

    2016-01-01

    为更加准确地对问题数据进行检测及修复,针对存在属性值缺失的情况,提出综合利用数据质量规则与 Fellegi‐Holt方法进行数据质量检查的策略。针对不同的检测需求,分别设计以问题数据定位和问题数据修复为目标的检测算法,提出相应算法以解决问题数据的修复以及缺失数据的填充问题。分别利用实例数据与生成数据进行实验,实验结果表明,该方法对问题数据进行检测的召回率和准确率有明显优势,两种检测策略在进行问题数据检测时的效率也有较大差异。%To carry out the detection of error data in the condition of field value missing more exactly ,an error data detection method based on Fellegi‐Holt method and data quality rules was put forward .To meet different requirements ,two algorithms were designed to solve the error data location and repairing problems .Algorithms were also put forward to solve the error data repairing and missing data filling problems .Experiments were conducted with both real‐life and synthetic data to examine the al‐gorithms .The results show that there is a great improvement in the recall and accuracy rate of error data detection ,and the effi‐ciencies of two algorithms differ a lot .

  12. Online Grid Measurement and ENS Detection for PV Inverter Running on Highly Inductive Grid

    DEFF Research Database (Denmark)

    Timbus, Adrian Vasile; Teodorescu, Remus; Blaabjerg, Frede;

    2004-01-01

    Photovoltaic (PV) and other sources of renewable energy are being used increasingly in grid-connected systems, for which stronger power quality requirements are being issued. Continuous grid monitoring should be considered so as to provide safe connections and disconnections from the grid....... This letter gives an overview of the methods used for online grid measurement with PV inverters. Emphasis is placed on a method based on the injection of a noncharacteristic harmonic in the grid. Since this injection is regarded as a disturbance for the grid, different issues, i.e., the influence on total...

  13. Coordinating sentence composition with error correction: A multilevel analysis

    Directory of Open Access Journals (Sweden)

    Van Waes, L.

    2011-01-01

    Full Text Available Error analysis involves detecting and correcting discrepancies between the 'text produced so far' (TPSF and the writer's mental representation of what the text should be. While many factors determine the choice of strategy, cognitive effort is a major contributor to this choice. This research shows how cognitive effort during error analysis affects strategy choice and success as measured by a series of online text production measures. We hypothesize that error correction with speech recognition software differs from error correction with keyboard for two reasons. Speech produces auditory commands and, consequently, different error types. The study reported on here measured the effects of (1 mode of presentation (auditory or visual-tactile, (2 error span, whether the error spans more or less than two characters, and (3 lexicality, whether the text error comprises an existing word. A multilevel analysis was conducted to take into account the hierarchical nature of these data. For each variable (interference reaction time, preparation time, production time, immediacy of error correction, and accuracy of error correction, multilevel regression models are presented. As such, we take into account possible disturbing person characteristics while testing the effect of the different conditions and error types at the sentence level.The results show that writers delay error correction more often when the TPSF is read out aloud first. The auditory property of speech seems to free resources for the primary task of writing, i.e. text production. Moreover, the results show that large errors in the TPSF require more cognitive effort, and are solved with a higher accuracy than small errors. The latter also holds for the correction of small errors that result in non-existing words.

  14. Control charts for identifying systematic errors using control sera to detect antibody to Salmonella in an indirect ELISA

    DEFF Research Database (Denmark)

    Bak, H.; Barfod, Kristen

    2008-01-01

    This study evaluated the preparation of Shewhart's control charts using the concept of rational subgroups for monitoring the Salmonella antibody ELISA used for surveillance of Danish pig herds. Control charts were prepared for a buffer control sample, a negative serum sample and a positive serum ...... charts could reveal systematic analytical errors....

  15. Are luminescent bacteria suitable for online detection and monitoring of toxic compounds in drinking water and its sources?

    Science.gov (United States)

    Woutersen, Marjolijn; Belkin, Shimshon; Brouwer, Bram; van Wezel, Annemarie P; Heringa, Minne B

    2011-05-01

    Biosensors based on luminescent bacteria may be valuable tools to monitor the chemical quality and safety of surface and drinking water. In this review, an overview is presented of the recombinant strains available that harbour the bacterial luciferase genes luxCDABE, and which may be used in an online biosensor for water quality monitoring. Many bacterial strains have been described for the detection of a broad range of toxicity parameters, including DNA damage, protein damage, membrane damage, oxidative stress, organic pollutants, and heavy metals. Most lux strains have sensitivities with detection limits ranging from milligrams per litre to micrograms per litre, usually with higher sensitivities in compound-specific strains. Although the sensitivity of lux strains can be enhanced by various molecular manipulations, most reported detection thresholds are still too high to detect levels of individual contaminants as they occur nowadays in European drinking waters. However, lux strains sensing specific toxic effects have the advantage of being able to respond to mixtures of contaminants inducing the same effect, and thus could be used as a sensor for the sum effect, including the effect of compounds that are as yet not identified by chemical analysis. An evaluation of the suitability of lux strains for monitoring surface and drinking water is therefore provided.

  16. Calibration and errors in the detection of heavy metals in fresh and sea waters by PIXE in the ppb-ppm range

    Science.gov (United States)

    Aprilesi, Giancarlo; Cecchi, Rodolfo; Ghermandi, Grazia; Magnoni, Gaetano; Santangelo, Renato

    1984-04-01

    A methodology for the simultaneous detection of several heavy metals in water samples will be described in detail. Targets are chemically prepared by preconcentration of the metals. Characteristics of the proton beam and X-ray detection are summarized. The concentration is obtained by using an internal standard in the range ppb-ppm. The method has been tested by calibration with samples of known concentration. The subtraction of background and the data processing are discussed. The error in each concentration is evaluated. Values of the sensitivity are quoted. The method has been extended to marine samples.

  17. On-line monitoring of nitrogenase activity in cyanobacteria by sensitive laser photoacoustic detection of ethylene

    NARCIS (Netherlands)

    Zuckermann, H.; Staal, M.J.; Stal, L.J.; Reuss, J.; te Lintel Hekkert, S.; Harren, F.J.M.; Parker, D.H.

    1997-01-01

    A new and extremely sensitive method for measuring nitrogenase activity through acetylene reduction is presented. Ethylene produced by nitrogenase-mediated reduction of acetylene is detected by using laser photoacoustics (LPA). This method possesses a detection limit making it 3 orders of magnitude

  18. Retinopathy online challenge: automatic detection of microaneurysms in digital color fundus photographs.

    NARCIS (Netherlands)

    Niemeijer, M.; Ginneken, B. van; Cree, M.J.; Mizutani, A.; Quellec, G.; Sanchez, C.I.; Zhang, B.; Hornero, R.; Lamard, M.; Muramatsu, C.; Wu, X.; Cazuguel, G.; You, J.; Mayo, A.; Li, Q.; Hatanaka, Y.; Cochener, B.; Roux, C.; Karray, F.; Garcia, M.; Fujita, H.; Abramoff, M.D.

    2010-01-01

    The detection of microaneurysms in digital color fundus photographs is a critical first step in automated screening for diabetic retinopathy (DR), a common complication of diabetes. To accomplish this detection numerous methods have been published in the past but none of these was compared with each

  19. Digital detectives and virtual volunteers: Integrating emergent online communities into disaster response operations.

    Science.gov (United States)

    Griswold, Alisha

    2013-01-01

    The demonstration of altruistic behaviours by disaster survivors, and even those observing emergencies from afar, is well documented. Over the past few decades, government-sponsored crisis planning has evolved to include affiliated volunteer agencies, with a general acknowledgment of the need to plan for unaffiliated or spontaneous volunteers. Just as the understanding of the need for volunteers has grown, so too have the ways in which volunteers are able to donate their time and skills. The popularity of social media networks and online communities provide new ways for the public to get involved in disaster response. Public service agencies should be proactive in investigating these emerging platforms and understanding their impacts during crises. Established methods of integrating on-scene volunteers into post-disaster response operations can be used as templates for creating virtual volunteer programmes.

  20. Oestrus Detection in Dairy Cows from Activity and Lying Data using on-line Individual Models

    DEFF Research Database (Denmark)

    Jónsson, Ragnar Ingi; Blanke, Mogens; Poulsen, Niels Kjølstad

    2011-01-01

    Automated monitoring and detection of oestrus in dairy cows is attractive for reasons of economy in dairy farming. While high performance detection has been shown possible using high-priced progesterone measurements, detection results were less reliable when only low-cost sensor data were available......-line from data to cope with behaviours of individuals. Performance is validated on 18 sequences of data where definite proof of prior oestrus was available in form of subsequent pregnancy. These data were extracted from data sequences from 44 dairy cows over an 8 months period. The results show sensitivity...

  1. Trends of Summer Air Temperatures in the Romanian Carpathians Detected by Using a Serially Correlated Errors Model

    Directory of Open Access Journals (Sweden)

    Adina-Eliza CROITORU

    2014-11-01

    Full Text Available This paper investigates summer temperature trends in the Romanian Carpathian Mountains, for three types of topographies: summit, slope and depression. We used a change-point regression model with serially correlated errors and compared it with a mainstream change-point model with independent errors. Statistical theory ensures that the former model gives a more accurate trend analysis than the latter model. For both models we identified strongly decreasing trends before the change-point and strongly increasing trends afterwards for most summer temperature series. The change-points are more consistent with each other, in the early 80’s, when using the former model. These general results occur for all topography types. A separate multiple regression model reveals that the temperature dynamics in the Romanian Carpathians can be explained by a linear effect of several major atmospheric circulation patterns

  2. Error Detection-Based Model to Assess Educational Outcomes in Crisis Resource Management Training: A Pilot Study.

    Science.gov (United States)

    Bouhabel, Sarah; Kay-Rivest, Emily; Nhan, Carol; Bank, Ilana; Nugus, Peter; Fisher, Rachel; Nguyen, Lily Hp

    2017-06-01

    Otolaryngology-head and neck surgery (OTL-HNS) residents face a variety of difficult, high-stress situations, which may occur early in their training. Since these events occur infrequently, simulation-based learning has become an important part of residents' training and is already well established in fields such as anesthesia and emergency medicine. In the domain of OTL-HNS, it is gradually gaining in popularity. Crisis Resource Management (CRM), a program adapted from the aviation industry, aims to improve outcomes of crisis situations by attempting to mitigate human errors. Some examples of CRM principles include cultivating situational awareness; promoting proper use of available resources; and improving rapid decision making, particularly in high-acuity, low-frequency clinical situations. Our pilot project sought to integrate CRM principles into an airway simulation course for OTL-HNS residents, but most important, it evaluated whether learning objectives were met, through use of a novel error identification model.

  3. High performance liquid chromatography with on-line dual quantum cascade laser detection for the determination of carbohydrates, alcohols and organic acids in wine and grape juice

    Science.gov (United States)

    Kuligowski, J.; Quintás, G.; Lendl, B.

    2010-06-01

    In the present study the simultaneous use of two quantum cascade lasers (QC-lasers) was investigated for the on-line detection in high performance liquid chromatography (HPLC). An optical set-up based on three gold mirrors and a ZnSe beam splitter was used to direct the emitted laser light trough a liquid flow cell with an optical path length of 52 μm onto a mercury-cadmium-telluride (MCT) detector. Using the separation of eight components of wine and grape juice as an example, on-line dual QC-laser detection in HPLC could be shown successfully for the first time.

  4. The application of HPLC with on-line coupled UV/MS-biochemical detection for isolation of an acetylcholinesterase inhibitor from narcissus 'Sir Winston Churchill'.

    Science.gov (United States)

    Ingkaninan, K; Hazekamp, A; de Best, C M; Irth, H; Tjaden, U R; van der Heijden, R; van der Greef, J; Verpoorte, R

    2000-06-01

    An HPLC with on-line coupled UV/MS-biochemical detection method for acetylcholinesterase (AChE) inhibitors in natural sources has been developed. The potential of this method is shown by the isolation of a new AChE inhibitor from the alcoholic extract of Narcissus 'Sir Winston Churchill'. Combining a prefractionation technique using centrifugal partition chromatography with the on-line HPLC-UV/MS-biochemical detection resulted in the isolation of the active compound that was identified as ungiminorine. This alkaloid shows a mild inhibitory effect on AChE.

  5. Online detection of vermicular iron quality%蠕化铁水质量的在线检测

    Institute of Scientific and Technical Information of China (English)

    马建华

    2014-01-01

    蠕化铁水共晶度的测量对蠕铁的生产至关重要,蠕化铁水质量的在线检测主机包括蠕化铁水共晶度的测量,蠕化铁水活性镁含量的测量和蠕化铁水的共晶再辉温度测量。%The measurement of the eutectic degree of vermicular iron is essential to vermicular iron production , and online detection of vermicular iron quality mainly includes measuring of vermicular i-ron , eutectic measurements of molten iron and activity recalescence temperature measurement of ver -micular iron vermicular magnesium .

  6. Thermal-induced changes of kale's antioxidant activity analyzed by HPLC-UV/Vis-online-TEAC detection.

    Science.gov (United States)

    Fiol, Michaela; Weckmüller, Annika; Neugart, Susanne; Schreiner, Monika; Rohn, Sascha; Krumbein, Angelika; Kroh, Lothar W

    2013-06-01

    Generally, boiling of vegetables is assumed leading to lower nutritional values because of leaching effects and activity loss of bioactive compounds. Kale (Brassica oleracea var. sabellica) reveals a great diversity of flavonoids, which have been shown to be good antioxidants. As Brassica vegetables are mainly consumed cooked, the influence of boiling on kale's flavonoids and their antioxidant activity was investigated. Therefore, three kale cultivars were cooked at 100°C for 2 and 4h prior to analysis. The total phenolic content (TPC) and the total antioxidant activity (TEAC assay and EPR spectrometry) of each cultivar were determined and revealed no change, independent of cooking time, although kale samples visually altered. Using the HPLC-UV/Vis-online-TEAC approach, distinct changes in composition and antioxidant activity of the flavonoids were detectable. Thus, it was observable, that the antioxidant activities of the reaction products compensated the "loss" of the antioxidant activity of the original compounds of the uncooked material.

  7. Determination of vitamin K homologues by high-performance liquid chromatography with on-line photoreactor and peroxyoxalate chemiluminescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Sameh [Graduate School of Biomedical Sciences, Course of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521 (Japan); Kishikawa, Naoya [Graduate School of Biomedical Sciences, Course of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521 (Japan); Nakashima, Kenichiro [Graduate School of Biomedical Sciences, Course of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521 (Japan); Kuroda, Naotaka [Graduate School of Biomedical Sciences, Course of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521 (Japan)]. E-mail: n-kuro@nagasaki-u.ac.jp

    2007-05-22

    A sensitive and highly selective high-performance liquid chromatography (HPLC) method was developed for the determination of vitamin K homologues including phylloquinone (PK), menaquinone-4 (MK-4) and menaquinone-7 (MK-7) in human plasma using post-column peroxyoxalate chemiluminescence (PO-CL) detection following on-line ultraviolet (UV) irradiation. The method was based on ultraviolet irradiation (254 nm, 15 W) of vitamin K to produce hydrogen peroxide and a fluorescent product at the same time, which can be determined with PO-CL detection. The separation of vitamin K by HPLC was accomplished isocratically on an ODS column within 35 min. The method involves the use of 2-methyl-3-pentadecyl-1,4-naphthoquinone as an internal standard. The detection limits (signal-to-noise ratio = 3) were 32, 38 and 85 fmol for PK, MK-4 and MK-7, respectively. The recoveries of PK, MK-4 and MK-7 were greater than 82% and the inter- and intra-assay R.S.D. values were 1.9-5.4%. The sensitivity and selectivity of this method were sufficient for clinical and nutritional applications.

  8. On-line detection of heavy metals and brominated flame retardants in technical polymers with laser-induced breakdown spectrometry

    Science.gov (United States)

    Stepputat, Michael; Noll, Reinhard

    2003-10-01

    The use of laser-induced breakdown spectrometry (LIBS) for the analysis of heavy metals and brominated flame retardants in end-of-life waste electric and electronic equipment (EOL-WEEE) pieces is investigated. Single- and double-pulse plasma excitation as well as the influence of detection parameters is studied to yield a parameter field with improved sensitivity and limits of detection. A LIBS analyzer was set up as an on-line measuring unit to detect heavy metals and brominated flame retardants in moving EOL-WEEE pieces in an automatic sorting line. An autofocusing unit with an adjustment range of 50 mm was incorporated to permit measurements of objects that pass by a LIBS analyzer with their surfaces at various distances from it. Tests with EOL-WEEE monitor housings on the conveyor belt of a pilot sorting system successfully demonstrated the capability of the LIBS analyzer to quantify the concentration of hazardous elements in real waste EOL-WEEE pieces.

  9. Tolerance analysis of a micro-optical detection system for on-line monitoring of lubricant oils

    Science.gov (United States)

    Van Overmeire, S.; Ottevaere, H.; Mignani, A. G.; Ciaccheri, L.; Desmet, G.; Thienpont, H.

    2010-10-01

    We present a functional prototype of a micro-optical detection unit for both absorbance and laser-induced fluorescence analysis in fused silica capillaries. Absorbance detection allows concentration measurements ranging from 0.6 µM to 12 mM, whereas fluorescence detection enables concentration measurements from 6 pM up to 0.6 mM. We make use of non-sequential optical ray tracing simulations combined with statistical design methodology to perform a complete tolerance analysis for manufacturability and we demonstrate experimentally that the efficiency of the system is insensitive to reasonable misalignment and fabrication errors of its building blocks. The possibility of using standard fabrication techniques to prototype and replicate this miniaturized plastic detection system, as well as its wide measurement range make it a good candidate for applications where low-cost and portable systems are needed to measure small volumes of liquid samples with low-level concentrations. As an example we demonstrate the use of the system for the optical characterization and differentiation of nanoliter volumes of lubricant oils.

  10. Online Data Quality and Bad Interval Detection for the CUORE Neutrinoless Double Beta Decay Search

    Science.gov (United States)

    Welliver, Bradford; Cuore Collaboration

    2016-09-01

    The Cryogenic Underground Observatory for Rare Events (CUORE) is a large neutrinoless double beta decay (0 νββ) search being installed underground at the Laboratori Nazionali del Gran Sasso (LNGS). 0 νββ searches can address fundamental questions about the nature of the neutrino, such as whether it is a Dirac or MAJORANA fermion, its mass scale, and may provide insight into the observed matter-antimatter asymmetry in the universe. CUORE is the largest array of bolometer instrumented crystals in the world, nineteen times larger than the previous implementation used in CUORE-0, and contains a total of 988 TeO2 crystals with a mass of 741kg and is expected to achieve a sensitivity on the 130Te 0 νββ half-life of T1 / 2 = 9 . 5 x 1025 years (90 % C.L.) after 5 years of operation. The large number of individual crystals in CUORE presents challenges for monitoring data quality and the determination of bad intervals of time in detector operation. We will discuss the work being performed to provide expanded online detector quality monitoring tools as well as the development of automated algorithms to test and identify periods of abnormal behavior across all of the individual detectors.

  11. A scalable architecture for online anomaly detection of WLCG batch jobs

    Science.gov (United States)

    Kuehn, E.; Fischer, M.; Giffels, M.; Jung, C.; Petzold, A.

    2016-10-01

    For data centres it is increasingly important to monitor the network usage, and learn from network usage patterns. Especially configuration issues or misbehaving batch jobs preventing a smooth operation need to be detected as early as possible. At the GridKa data and computing centre we therefore operate a tool BPNetMon for monitoring traffic data and characteristics of WLCG batch jobs and pilots locally on different worker nodes. On the one hand local information itself are not sufficient to detect anomalies for several reasons, e.g. the underlying job distribution on a single worker node might change or there might be a local misconfiguration. On the other hand a centralised anomaly detection approach does not scale regarding network communication as well as computational costs. We therefore propose a scalable architecture based on concepts of a super-peer network.

  12. Online Phase Detection Using Wearable Sensors for Walking with a Robotic Prosthesis

    Directory of Open Access Journals (Sweden)

    Maja Goršič

    2014-02-01

    Full Text Available This paper presents a gait phase detection algorithm for providing feedback in walking with a robotic prosthesis. The algorithm utilizes the output signals of a wearable wireless sensory system incorporating sensorized shoe insoles and inertial measurement units attached to body segments. The principle of detecting transitions between gait phases is based on heuristic threshold rules, dividing a steady-state walking stride into four phases. For the evaluation of the algorithm, experiments with three amputees, walking with the robotic prosthesis and wearable sensors, were performed. Results show a high rate of successful detection for all four phases (the average success rate across all subjects >90%. A comparison of the proposed method to an off-line trained algorithm using hidden Markov models reveals a similar performance achieved without the need for learning dataset acquisition and previous model training.

  13. Detection of copper in water using on-line plasma-excited atomic absorption spectroscopy (AAS).

    Science.gov (United States)

    Porento, Mika; Sutinen, Veijo; Julku, Timo; Oikari, Risto

    2011-06-01

    A measurement method and apparatus was developed to measure continuously toxic metal compounds in industrial water samples. The method was demonstrated by using copper as a sample metal. Water was injected into the sample line and subsequently into a nitrogen plasma jet, in which the samples comprising the metal compound dissolved in water were decomposed. The transmitted monochromatic light was detected and the absorbance caused by copper atoms was measured. The absorbance and metal concentration were used to calculate sensitivity and detection limits for the studied metal. The sensitivity, limit of detection, and quantification for copper were 0.45 ± 0.02, 0.25 ± 0.01, and 0.85 ± 0.04 ppm, respectively.

  14. Ground characterization and roof mapping:Online sensor signal-based change detection

    Institute of Scientific and Technical Information of China (English)

    Bahrampour Soheil; Rostami Jamal; Ray Asok; Naeimipour Ali; Collins Craig

    2015-01-01

    Measurement while drilling systems are becoming an important part of excavation operations for rock characterization and ground support design that require reliable information on rock strength and loca-tion&frequency of joints or voids. This paper focuses on improving rock characterization algorithms for instrumented roof-bolter systems. For this purpose, an improved void detection algorithm is proposed, where the underlying theory is built upon the concept of mean change detection based on the feed pressure signals. In addition, the application of acoustic sensing for void detection is examined and it is shown that the variance of the filtered acoustic signal is correlated to the strength of the material being drilled. The proposed algorithm has been validated on the data collected from full-scale drilling tests in various concrete and rock samples at the J. H. Fletcher facility.

  15. X-ray online detection for laser welding T-joint of Al-Li alloy

    Science.gov (United States)

    Zhan, Xiaohong; Bu, Xing; Qin, Tao; Yu, Haisong; Chen, Jie; Wei, Yanhong

    2017-05-01

    In order to detect weld defects in laser welding T-joint of Al-Li alloy, a real-time X-ray image system is set up for quality inspection. Experiments on real-time radiography procedure of the weldment are conducted by using this system. Twin fillet welding seam radiographic arrangement is designed according to the structural characteristics of the weldment. The critical parameters including magnification times, focal length, tube current and tube voltage are studied to acquire high quality weld images. Through the theoretical and data analysis, optimum parameters are settled and expected digital images are captured, which is conductive to automatic defect detection.

  16. Research on On-line detection system for natural gas pipeline

    Institute of Scientific and Technical Information of China (English)

    Zuo Jianyong; Yan Guozheng; Ding Guoqing; Fu Xiguang; Zhang Yunwei

    2005-01-01

    Four methods for testing the thickness and defect of pipeline are compared and analyzed in this paper. The testing principle of magnetic leakage flux based on electromagnetism is discussed in detail. From the experiments of sensor character, the effects caused by some factors are found, which give some important information for sensor design, and this method is proved reasonable and effective. The mechanical and electrical structures of inspection equipment, as well as its working principle and technical features are introduced. In this paper, control flow and software design are discussed, too. This detection system has been successfully developed. Experiments show that this detection system has high resolution and can be put into practice.

  17. Online phase detection using wearable sensors for walking with a robotic prosthesis

    NARCIS (Netherlands)

    Gorsic, M.; Kamnik, R.; Ambrozic, L.; Vitiello, N.; Lefeber, D.J.; Pasquini, G.; Munih, M.

    2014-01-01

    This paper presents a gait phase detection algorithm for providing feedback in walking with a robotic prosthesis. The algorithm utilizes the output signals of a wearable wireless sensory system incorporating sensorized shoe insoles and inertial measurement units attached to body segments. The princi

  18. Online phase detection using wearable sensors for walking with a robotic prosthesis

    NARCIS (Netherlands)

    Gorsic, M.; Kamnik, R.; Ambrozic, L.; Vitiello, N.; Lefeber, D.J.; Pasquini, G.; Munih, M.

    2014-01-01

    This paper presents a gait phase detection algorithm for providing feedback in walking with a robotic prosthesis. The algorithm utilizes the output signals of a wearable wireless sensory system incorporating sensorized shoe insoles and inertial measurement units attached to body segments. The

  19. Feasibility of the detection of trace elements in particulate matter using online High-Resolution Aerosol Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Salcedo, D.; Laskin, Alexander; Shutthanandan, V.; Jimenez, Jose L.

    2012-08-10

    The feasibility of using an online thermal-desorption electron-ionization high-resolution aerosol mass spectrometer (AMS) for the detection of particulate trace elements was investigated analyzing data from Mexico City obtained during the MILAGRO 2006 field campaign, where relatively high concentrations of trace elements have been reported. This potential application is of interest due to the real-time data provided by the AMS, its high sensitivity and time resolution, and the widespread availability and use of this instrument. High resolution mass spectral analysis, isotopic ratios, and ratios of different ions containing the same elements are used to constrain the chemical identity of the measured ions. The detection of Cu, Zn, As, Se, Sn, and Sb is reported. There was no convincing evidence for the detection of other trace elements commonly reported in PM. The elements detected tend to be those with lower melting and boiling points, as expected given the use of a vaporizer at 600oC in this instrument. Operation of the AMS vaporizer at higher temperatures is likely to improve trace element detection. The detection limit is estimated at approximately 0.3 ng m-3 for 5-min of data averaging. Concentration time series obtained from the AMS data were compared to concentration records determined from offline analysis of particle samples from the same times and locations by ICP (PM2.5) and PIXE (PM1.1 and PM0.3). The degree of correlation and agreement between the three instruments (AMS, ICP, and PIXE) varied depending on the element. The AMS shows promise for real-time detection of some trace elements, although additional work including laboratory calibrations with different chemical forms of these elements are needed to further develop this technique and to understand the differences with the ambient data from the other techniques. The trace elements peaked in the morning as expected for primary sources, and the many detected plumes suggest the presence of multiple

  20. Exploiting Polydopamine Nanospheres to DNA Computing: A Simple, Enzyme-Free and G-Quadruplex-Free DNA Parity Generator/Checker for Error Detection during Data Transmission.

    Science.gov (United States)

    Fan, Daoqing; Wang, Erkang; Dong, Shaojun

    2017-01-18

    Molecular logic devices with various functions play an indispensable role in molecular data transmission/processing. However, during any kinds of data transmission, a constant and unavoidable circumstance is the appearance of bit errors, which have serious effects on the regular logic computation. Fortunately, these errors can be detected via plugging a parity generator (pG) at the transmitting terminal and a parity checker (pC) at the receiving terminal. Herein, taking advantage of the efficient adsorption/quenching ability of polydopamine nanospheres toward fluorophore-labeled single-stranded DNA, we explored this biocompatible nanomaterial to DNA logic computation and constructed the first simple, enzyme-free, and G-quadruplex-free DNA pG/pC for error detection through data transmission. Besides, graphene oxide (GO) was innovatively introduced as the "corrective element" to perform the output-correction function of pC. All the erroneous outputs were corrected to normal conditions completely, ensuring the regular operation of later logic computing. The total operation of this non-G4 pG/pC system (error checking/output-correction) could be completed within 1 h (about (1)/3 of previous G4 platform) in a simpler and more efficient way. Notably, the odd pG/pC with analogous functions was also achieved through negative logic conversion to the fabricated even one. Furthermore, the same system could also perform three-input concatenated logic computation (XOR-INHIBIT), enriching the complexity of PDs-based logic computation.