• Title/Summary/Keyword: Self-diagnostics

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Bearing Fault Diagnostics in a Gearbox (기어박스에서의 베어링 결함 진단)

  • Kim, Heung-Sup;Lee, Sang-Kwon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.611-616
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    • 2002
  • Bearing diagnostics is difficult in a gearbox because bearing signals are masked by the strong gear signals. Self adaptive noise cancellation(SANC) is useful technique to seperate bearing signals from gear signals. While gear signals are correlated with a long correlation length, bearing signals are not correlated with a short length. SANC seperates two components on the basis of correlation length. Then we can find defect frequency component in the envelope spectrum of the bearing signals.

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Bearing Falut Diagnostics in a Gearbox (기어 박스에서의 베어링 결함 진단)

  • Kim, Heung-Sup;Lee, Sang-Kwon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.362.2-362
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    • 2002
  • Bearing diagnostics is difficult in a gearbox because bearing signals are masked by the strong gear signals. Self adaptive noise cancellation(SANC) Is useful technique to seperate bearing signals from gear signals. While gear signals are correlated with a long correlation length, bearing signals are not correlated with a short length. SANC seperates two components on the basis of correlation length. (omitted)

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A Study on Development of Fault diagnosis system for PLC self-diagnostics and its external devices (PLC 자체 고장진단과 그의 외부 소자의 고장 진단 시스템 개발에 관한 연구)

  • Bur, Yone-Gi;Blen, Zeung-Nam
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.1189-1192
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    • 1996
  • In this paper, a fault diagnosis method is proposed for self-diagnostics of PLC(Programmable Logic Controller), process controller in industrial fields, and diagnosis of its external devices such as sensors and actuators. The aim of this research is proposition of systematic method of fault diagnosis of PLC control system and development of its equipment. A PLC fault diagnosis algorithm consists of self-diagnostics given by PLC makers, Inpuot/Output tracking method by analyzing sequence PLC programs, searching method of past fault cases in database using an expert system, and diagnosis of PLC units such as CPU, DI, and DO board. Finally usability of PLC fault diagnostic system is verified by testing a MELSEC PLC.

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The Fault Tolerant Evaluation Model due to the Periodic Automatic Fault Detection Function of the Safety-critical I&C Systems in the Nuclear Power Plants (원전 안전필수 계측제어시스템의 주기적 자동고장검출기능에 따른 고장허용 평가모델)

  • Hur, Seop;Kim, Dong-Hoon;Choi, Jong-Gyun;Kim, Chang-Hwoi;Lee, Dong-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.7
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    • pp.994-1002
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    • 2013
  • This study suggests a generalized availability and safety evaluation model to evaluate the influences to the system's fault tolerant capabilities depending on automatic fault detection function such as the automatic periodic testings. The conventional evaluation model of automatic fault detection function deals only with the self diagnostics, and supposes that the fault detection coverage of self diagnostics is always constant. But all of the fault detection methods could be degraded. For example, the periodic surveillance test has the potential human errors or test equipment errors, the self diagnostics has the potential degradation of built-in logics, and the automatic periodic testing has the potential degradation of automatic test facilities. The suggested evaluation models have incorporated the loss or erroneous behaviors of the automatic fault detection methods. The availability and the safety of each module of the safety grade platform have been evaluated as they were applied the automatic periodic test methodology and the fault tolerant evaluation models. The availability and safety of the safety grade platform were improved when applied the automatic periodic testing. Especially the fault tolerant capability of the processor module with a weak self-diagnostics and the process parameter input modules were dramatically improved compared to the conventional cases. In addition, as a result of the safety evaluation of the digital reactor protection system, the system safety of the digital parts was improved about 4 times compared to the conventional cases.

A Study on the Relationships between Edema Index of Body Composition and Pathologic Patterns (체성분 분석의 부종지수와 변증설문과의 상관성 연구)

  • Lee, Ju-Ho;Yoo, Seung-Yeon;Lee, Jin-Moo;Park, Young-Jae;Park, Young-Bae
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.16 no.1
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    • pp.27-34
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    • 2012
  • Objectives The purpose of this study was to find out whether if there is correlation between the pattern differentiation questionnaire and edema index of body composition analysis. Methods The authors obtained results of pattern differentiation Questionnaires and body composition analysis tests from 195 female patients who visited the Oriental gynecology department in Kyung Hee university Oriental medicine hospital at Gang-dong. The authors conducted correlation analysis between indicators of Body composition analysis and each part of the pattern differentiation Questionnaire. Pearson correlation analysis was performed on SPSS version 13.0 for windows. Results There was negative correlation between the Phlegm Questionnaire and right arm ECF, left arm ECF, and left arm ECW of the Body composition index. There was no correlation between Yin-deficiency Questionnaire and Body composition index. There was no correlation between Heat pattern Questionnaire and Body composition index. There was positive correlation between the Cold pattern Questionnaire and right leg ECF, and right leg ECW of the body composition index. There was no correlation between degree of edema self-awareness and Body composition index. Conclusions The result showed that each Questionnaire score has different correlation or even no correlation with Body composition index and degree of edema self-awareness. Further studies are needed for a better understanding and interpretation of the relationship between edema index on Body composition analysis and Questionnaires.

About the Meditation and Self-discipline in Korean Medicine through "Donguibogam(東醫寶鑑)" (동의보감(東醫寶鑑)의 명상 수행(修行)에 대한 고찰)

  • Lee, Jeong-Won;Kim, Gyeong-Cheol;Lee, Hai-Woong
    • Journal of Korean Medical classics
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    • v.25 no.3
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    • pp.149-158
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    • 2012
  • Objectives : In modern meditation, psychologic therapy and happy life have been in the main status. The aim of this study is to search about the value of modern meditation systematically and to summarize the contents on the meditation in "Donguibogam(東醫寶鑑)". Methods : We investigated the meditation-related materials in "Donguibogam(東醫寶鑑)", and discussed them in comparison with the other contents found in "Huangdi's Internal Classic(黃帝內經)" and some scriptures on meditation and self-discipline. Results : The mind-body concept in Korean Medicine takes meditation and self-discipline into main consideration. Meditation and self-discipline mean the endless pursuing the nature of mind and body, thus leading to self-practice about the true meaning of life. "Donguibogam(東醫寶鑑)" includes the views on the meditation and self-discipline from the various angles based on Confucianism, Buddhism and Taoism. Conclusions : Meditation and self-discipline rooted in East Asian tradition are good ways to reach the true nature of mind-body system of universe and to help people seek happiness in their lives.

Abnormal Vibration Diagnostics Algorithm of Rotating Machinery Using Self-Organizing Feature Map nad Learing Vector Quantization (자기조직화특징지도와 학습벡터양자화를 이용한 회전기계의 이상진동진단 알고리듬)

  • 양보석;서상윤;임동수;이수종
    • Journal of KSNVE
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    • v.10 no.2
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    • pp.331-337
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    • 2000
  • The necessity of diagnosis of the rotating machinery which is widely used in the industry is increasing. Many research has been conducted to manipulate field vibration signal data for diagnosing the fault of designated machinery. As the pattern recognition tool of that signal, neural network which use usually back-propagation algorithm was used in the diagnosis of rotating machinery. In this paper, self-organizing feature map(SOFM) which is unsupervised learning algorithm is used in the abnormal defect diagnosis of rotating machinery and then learning vector quantization(LVQ) which is supervised learning algorithm is used to improve the quality of the classifier decision regions.

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Critical Thinking Disposition, Professional Self-Concept and Clinical Competence in Nursing Students (일개 대학 간호대학생의 비판적 사고성향, 전문직 자아개념과 임상수행 능력에 관한 연구)

  • Park, Narae;Jeon, Yourim;Jang, Eunsu;Kim, Yunyoung
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.20 no.1
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    • pp.27-36
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    • 2016
  • Objectives The purpose of this study was to revealed the association among the clinical performance, self-concept of the nursing profession and critical thinking disposition of nursing students. Methods The subjects were recruited from the university nursing students who was experienced Grade 3 and Grade 4 students. The general characteristics of the subjects were presented with the frequency and percentage. Differences in clinical performance, professional nursing self-concept and critical thinking disposition were analyzed by t-test, ANOVA according to the degree of general characteristics. A significant positive correlation were analyzed from $Scheff{\acute{e}}$ test. Multiple regression analysis was used to reveal the effective indexes for Clinical Competence of the subjects. The suitable significance was 0.05 Results Total 318(23 males and 295 females) participants were joined in this study. Critical thinking disposition of the nursing students was significantly different in the university satisfaction, academic record, major satisfaction, satisfaction of clinical practice, relationships with colleagues practice, satisfaction amount of practice(p<0.001). Clinical competence of nursing students was positively associated with critical thinking disposition, professional self-concept and professional self-concept was positively associated with critical thinking disposition. Critical thinking disposition and professional self-concept was significant (F=83.081, p<.001). The higher clinical competence was (${\beta}=.168$, p=.001), the higher professional self-concept was(${\beta}=.051$, p<.001). The explanation power of critical thinking disposition and professional self-concept was 34.5% in clinical competence. Conclusions There is significantly positive correlation among critical thinking disposition, professional self-concept, and clinical performance in the nursing students.

The Effect of the Fault Tolerant Capability due to Degradation of the Self-diagnostics Function in the Safety Critical System for Nuclear Power Plants (원자력발전소 안전필수시스템 고장허용능력에 대한 자가진단기능 저하 영향 분석)

  • Hur, Seop;Hwang, In-Koo;Lee, Dong-Young;Choi, Heon-Ho;Kim, Yang-Mo;Lee, Sang-Jeong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.8
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    • pp.1456-1463
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    • 2010
  • The safety critical systems in nuclear power plants should be designed to have a high level of fault tolerant capability because those systems are used for protection or mitigation of the postulated accidents of nuclear reactor. Due to increasing of the system complexity of the digital based system in nuclear fields, the reliability of the digital based systems without an auto-test or a self-diagnostic feature is generally lower than those of analog system. To overcome this problem, additional redundant architectures in each redundant channel and self-diagnostic features are commonly integrated into the digital safety systems. The self diagnostic function is a key factor for increasing fault tolerant capabilities in the digital based safety system. This paper presents an availability and safety evaluation model to analyze the effect to the system's fault tolerant capabilities depending on self-diagnostic features when the loss or erroneous behaviors of self-diagnostic function are expected to occur. The analysis result of the proposed model on the several modules of a safety platform shows that the improvement effect on unavailability of each module has generally become smaller than the result of usage of conventional models and the unavailability itself has changed significantly depending on the characteristics of failures or errors of self-diagnostic function.

The Effects of the Seven Emotions on Self-awareness Quality of Life (칠정상이 자각적 삶의 질 수준에 미치는 영향)

  • Cho, Shin-Woong;Oh, Hwan-Sup;Kim, Min-Yong;Park, Young-Bae;Park, Young-Jae
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.15 no.1
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    • pp.87-94
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    • 2011
  • Objectives: The purpose of our study was to verify whether the Seven Emotions evaluated by Guibi-Tang questionnaire (GTQ) were predictive of self-awareness level of one's quality of life (QOL). Methods: Eighty volunteers participated in this study and completed the GTQ. In addition, the volunteers were asked to answer one's self-awareness of the QOL using numerical scale. Factor analysis was conducted for extraction of GTQ factors. Structural Equation Model (SEM) was conducted to verify path structure. Results: The estimates of the four factors on the level of one's QOL demonstrated that Chest Factor (=-0.330) showed the highest level of correlation followed by the seven emotions (=-0.213); Deficient fire (=0.141); and Qi Deficiency (=-0.023). Model fit is $X^2$=34.740 (df=36), GFI=0.931, AGFI=0.873, NFI=0.867, RFI=0.797, IFI=0.975, TLI=1.006, CFI=1.009, RMSEA=0.000. Therefore, considering these values, SEM could be accepted as a workable model. Conclusions: Our study results suggest that According to SEM, The Seven Emotions evaluated by GTQ are predictable for self-awareness of one's QOL.