• Title/Summary/Keyword: Human errors

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Estimation of Sensitivity Axis Offset of an Accelerometer for Accurate Measurement of the 6 DOF Human Head Motion (인체 머리부 6 자유도 운동 측정의 신뢰성 향상을 위한 가속도계 감도축의 옵셋(offset) 추정)

  • Lee, Jeung-Hoon;Kim, Kwang-Joon;Jang, Han-Kee
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.9
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    • pp.905-912
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    • 2008
  • Notion sickness is well known to be caused by long time exposure to the very low frequency motion in the multiple axes of human body Since the vestibular system for the perception of low frequency motion is located in the head, accurate measurement of 6 degree of freedom head motion is of great importance. In this study, the measurement system consisting of a safety helmet and 9 translational accelerometers was constructed for the estimation of 3 translational and 3 rotational motions of human head. Since estimation errors of 3 rotational components can be significantly magnified even by small offset of the sensitivity axis from the geometric center of an accelerometer, accurate measurement of sensitivity axis must be preceded. The method for accurate estimation of the offset was proposed, and the effect of offset on the estimation of angular acceleration was investigated.

A Study on the Operator Performance According to the Drastic Change of Illumination Level and Lighting Environment of Control Room in Nuclear Power Plants

  • Shin, Kwang Hyeon;Lee, Yong Hee
    • Journal of the Ergonomics Society of Korea
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    • v.32 no.1
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    • pp.37-45
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    • 2013
  • Objective: This study describes the change of operator performance in drastic change of illumination level, and proposes an alternative method to cope with it. Background: The control standard of illumination for nuclear power plants(NPPs) is based on the set of limit criteria for maintaining a specific illumination level. However, there is a possibility to cause human errors according to the psychological and physiological influences to operators in the situation of drastic change of illumination such as SBO(Station Black Out), so a basic study is necessary to review the current approach. Method: We assessed the visual fatigue, subjective work load and task performance according to the three illumination situations(Normal Illumination, Emergency Illumination, and Drastic Change of Illumination). Result: Research finding shows that there are not significant differences in task performance between normal illumination (1,000lx level) and emergency illumination (100lx level), only if beyond the dark adaptation limit. However, subjective work load on mental demand and visual fatigue show a potential challenge to visual performance in drastic change of illumination. Conclusion/Application: Several trials can complement this challenge in NPPs by applying 3-way communication, enhancing readability of procedures, and managing the visual factors affecting the operators' performance through a Visual Environment Management Program including visual health aspects, etc.

An Analysis of Human Errors in Gun Powder Jobs. (화약류작업에서 인적오류에 대한 분석)

  • 이정훈;안명석;김종현
    • Explosives and Blasting
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    • v.22 no.3
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    • pp.97-101
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    • 2004
  • The using of Gun powders are getting grower than power due to the road opening, tunnel digging, the highest building, the pound digging on the construction industry, it also happen blasting accident as well, and it become society issue more than more. In this study, The check list far the human cause of the most rate among the blasting accident was developed in availing of accident investigation chart for the analysis of the blasting accident of already developed and FTA technique analysis with the analysis systematically of blasting accident. And then, Analysis for the application was carried out in construction cite, availing of the check list. As results, The most error has broken out at charge work, an uncomfortable processes, among the blasting work. Thus, It is a matter for consideration with improvement work.

Development of Simple Articulated Human Models using Superquadrics for Dynamic Analysis

  • Lee, Hyun-Min;Kim, Jay-Jung;Chae, Je-Wook
    • Journal of the Ergonomics Society of Korea
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    • v.30 no.6
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    • pp.715-725
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    • 2011
  • Objective: This study is aimed at developing Articulated Human Models(AHM) using superquadrics to improve the geometric accuracy of the body shape. Background: The previous work presents the AHM with geometrical simplification such as ellipsoids to improve analysis efficiency. However, because of the simplicity, their physical properties such as a center of mass and moment of inertia are computed with errors compared to their actual values. Method: This paper introduces a three steps method to present the AHM with superquadrics. First, a 3D whole body scan data are divided into 17 body segments according to body joints. Second, superquadric fitting is employed to minimize the Euclidean distance between body segments and superquadrics. Finally, Fee-Form Deformation is used to improve accuracy over superquadric fitting. Results: Our computational experiment shows that the superquadric models give better accuracy of dynamic analysis than that of ellipsoid ones. Conclusion: We generate the AHM composed of 17 superquadrics and 16 joints using superquadric fitting. Application: The AHM using superquadrics can be used as the base model for dynamics and ergonomics applications with better accuracy because it presents the human motion effectively.

Effects of the Training Transfer Management on the Workers in Nuclear Power Plants

  • Kim, Seonsu;Luo, Meiling;Lee, Yong-Hee
    • Journal of the Ergonomics Society of Korea
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    • v.33 no.1
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    • pp.49-58
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    • 2014
  • Objective: The aim of this study is to enhance the efficiency of education and training through application and management of 'Transfer of Training' in nuclear power plants. Background: Despite the sophistication and standardization of job-related skills and techniques of workers, accidents/incidents keep taking place due to human errors and unsafe actions and behaviors, which translates into the necessity to review and examine the effectiveness and influence of education and training on the workers of nuclear power plants. Method/Results: This study drew the factors of 'Transfer of Training' through a review on the preceding studies and document research. In addition, through expert examination, this study explored the expected effects and possibility of application when managing the influencing factors of 'Transfer of Training' in nuclear power plants. And lastly, management priority order for nuclear power plants was drawn through an AHP analysis. Conclusion: Among the 'Transfer of Training' factors, the training design factor was the most important. In addition, the design of the training and transfer and goal setting showed a high degree of importance among the influencing factors. Application: The management of 'Transfer of Training' in nuclear power plants enhances the capability of workers and improves the operational integrity of nuclear power plants.

Dynamic discrmination of sensory evaluation capability using a paired-comparison method (일대비교에 의한 관능평가능력의 동작판별)

  • 김정만;이상도
    • Journal of the Ergonomics Society of Korea
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    • v.12 no.2
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    • pp.85-91
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    • 1993
  • Data obtained for sensory evaluation have a wide dispersion and fuzziness since human sensory organs are used as a means of measuring sensation instead of measuring instruments. Such dispersion and fuzziness are caused by all kinds of time error and have a great influence on the sensory evaluation, but most of previous papers not consider time errors. In this study, the comparative judgement capability of the evaluator was discriminated by means of the eigen- structure analysis on the premise that evaluation values of sensory evaluators obtained by a paired-comparison become different by the order of sample presentation.

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Developing an RFID Application Solution for Detecting Human Errors in Filling Prescriptions (처방약 조제 오류방지를 위한 RFID 응용솔루션 개발)

  • Hong, Min-Sun;Rim, Suk-Chul
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2005.05a
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    • pp.100-105
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    • 2005
  • 최근들어 RFID기술은 향후 바코드를 대체할 자동인식기술로 주목받고 있으며, 특히 유통물류분야의 응용이 기대되고 있다. 그러나 비용을 고려할 때 RF tag를 단품마다 적용하기에는 앞으로도 상당한 기간이 필요할 것으로 보인다. 오히려 인간의 생명과 안전을 다루는 의료분야에서 RFID를 사용하여 인간의 실수를 방지하는 응용시스템은 비용이 정당화되는 유용한 적용사례가 될 수 있다. 본 연구에서는 병원이나 약국의 처방약 조제과정에서의 인간의 오류를 방지할수 있는 RFID 응용시스템을 소개하고, 그 구조 및 개발사례를 소개한다.

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Scoring Methods for Improvement of Speech Recognizer Detecting Mispronunciation of Foreign Language (외국어 발화오류 검출 음성인식기의 성능 개선을 위한 스코어링 기법)

  • Kang Hyo-Won;Kwon Chul-Hong
    • MALSORI
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    • no.49
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    • pp.95-105
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    • 2004
  • An automatic pronunciation correction system provides learners with correction guidelines for each mispronunciation. For this purpose we develope a speech recognizer which automatically classifies pronunciation errors when Koreans speak a foreign language. In order to develope the methods for automatic assessment of pronunciation quality, we propose a language model based score as a machine score in the speech recognizer. Experimental results show that the language model based score had higher correlation with human scores than that obtained using the conventional log-likelihood based score.

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Pronunciation Network Construction of Speech Recognizer for Mispronunciation Detection of Foreign Language (한국인의 외국어 발화오류 검출을 위한 음성인식기의 발음 네트워크 구성)

  • Lee Sang-Pil;Kwon Chul-Hong
    • MALSORI
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    • no.49
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    • pp.123-134
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    • 2004
  • An automatic pronunciation correction system provides learners with correction guidelines for each mispronunciation. In this paper we propose an HMM based speech recognizer which automatically classifies pronunciation errors when Koreans speak Japanese. We also propose two pronunciation networks for automatic detection of mispronunciation. In this paper, we evaluated performances of the networks by computing the correlation between the human ratings and the machine scores obtained from the speech recognizer.

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Image Coding of Visually Weighted t Discrete Cosine Transform (시각 하중 이산여현변환 영상부호화)

  • 이문호;박주용
    • Journal of the Korean Professional Engineers Association
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    • v.22 no.2
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    • pp.19-25
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    • 1989
  • Utilizing a cosine transform in image compression has several recognized performance benefits, resulting in the ability to attain large compression ratio with small quality loss. Also, various models incorporating Human Visual System (HVS) to Discrete Cosine Trans-form (DCT) scheme are considered. Using the exact frequency components of DCT basis function, the optimum modulation transfer function (MTF) is obtained analytically. The errors at a block boundary which is important factor in transform coder are criteria for error measurement. The HVS weight coding results in perceptually higher quality images compared with the unweighted scheme.

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