• Title/Summary/Keyword: Judgment Method

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Study on the Multi-measuring Method for Evaluation of Internal Leak of Power Plant Valve (발전용 밸브누설 평가를 위한 다중계측 연구)

  • Lee, S.G.;Park, S.K.;Park, J.H.;Kim, K.H.;Kim, Y.B.
    • Journal of Power System Engineering
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    • v.11 no.3
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    • pp.35-40
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    • 2007
  • Leak would happen because of the damage of high temperature and high-pressure valve in nuclear power plant. condition based prevention maintenance is essential by using the suitable method based on local condition. Energy loss prevention can prevent from an accurate test, Local actually and ability. The methods of test for high energy fluid leak at present are analysis of ${\Delta}T$, AE(Acoustic Emission) analysis, and thermal image. The result for test of secondary system in nuclear power plant Unit reveals that the AE occurred clearly in leakage situation, but thermal image didn't occur. It is identified that leak is occurred when the orifice located front and back of valve operates. It shows that making a impatient judgment by using the single method if it is leakage is containing uncertainty. So we think that using the Multi-Measuring method is more sound judgment than single-measuring method.

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Study on searching method of human errors accidents for case study of disaster database (재해 데이터베이스의 사례연구를 위한 휴먼에러 재해 검색방법에 관한 연구)

  • 한우섭
    • Journal of the Society of Disaster Information
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    • v.1 no.1
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    • pp.121-136
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    • 2005
  • Most human-error case of accident database is written by various description and expression because accident database is produced by two or more person. And extracted information by searching of database varies in researcher's judgment criteria and the capability. Furthermore, much time and effort are required to examine manually information related to the human error from each accident case. Accordingly, it is difficult to explore objectively the accidents relevant to the human-error from the accident data base which is accumulated enormously. In this study, to solve these problems, it was developed an searchig method which is not influenced by researcher's judgment criteria and capability. For this, human-error keywords were extracted from a Japanese-English dictionary to examine objectively the accident case related to human-error in data base. This searching method by the human-error keywords can be applicable in most accident databases, although a database will be accumulated in future. Also, using the searching technique of this research, knowledge obtained by searching result can be compared with other research's results by the same method. Although the number of accident case increasese, searching results from database have the objectivity because it is not necessary to modify the based searching method or change the human-error keywords. However, as subject of future investigation, it would be necessary that the extension and investigation on human-error keywords improve and the technique to enhance searching accuracy would be modified.

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Method for High-visibility of Online Monitoring and Fault Diagnosis System for Industrial Motor using PVA (PVA를 이용한 산업용 모터 고장진단 모니터링 시스템의 가시성을 높이는 방법)

  • Goh, Yeong-Jin;Kang, In-Won
    • Journal of the Korea Safety Management & Science
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    • v.22 no.1
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    • pp.15-21
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    • 2020
  • Industrial Motors diagnostic equipment is highly dependent on the automation system, so if there are defects in the automation equipment, it can only rely on the operator's intuitive judgment.To help with intuitive judgment, Park's Vactor Approach(PVA) represents the current signal as a pattern of circles, so it can tell if a fault occurs when the circle is distorted. However, the failure to judge the degree of distortion of the circle pattern is the basis of the fault, so it will face difficulties. In this paper, in order to compare the faults of PVA, the period of d-axis current of PVA pulsation was mastered, so that two phase differences occurred in the same signal source. Through experiments, it is confirmed that this is a 90 degree cross formation of PVA, which is convenient for judging from the vision that there is no fault, thus helping the operator to make intuitive judgment.

Study on the Standards for Acknowledgement of Cerebral and Cardiovascular Diseases due to Occupational Cases (업무상 뇌.심혈관질환의 인정기준에 관한 고찰)

  • Choi, Soon-Young;Rim, Hwa-Young
    • Journal of the Korea Safety Management & Science
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    • v.12 no.3
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    • pp.61-72
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    • 2010
  • Judgment of cerebral and cardiovascular diseases arising out of duty follows the legal judgment method for the purpose of investigation of medical causes based on the Industrial Accident Compensation Insurance Act, with the characteristics of the occurrence as personal factors etc. act as risk factors while work-related ones as triggers, in the case of disease due to occupational cases, as whether it arose out of duty must be judged including even the individual's personal risk factors, there are limitations securing fairness even with existing laws, regulations and guidelines. This study was carried out to suggest basic data for the preparation of standardized guidances for diseases arising out of duty by reviewing the standards for the acknowledgment of cerebral and cardiovascular diseases due to occupational cases, and it has a significance in that it suggests target diseases that may be judged as cerebral and cardiovascular diseases, legal criteria for the acknowledgment and standards for the judgment of cerebral and cardiovascular diseases arising out of duty.

A Structural Model on the Nursing Competencies of Nursing Simulation Learners (간호시뮬레이션 학습자의 간호역량에 관한 구조모형)

  • Park, Soo Jin;Ji, Eun Sun
    • Journal of Korean Academy of Nursing
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    • v.48 no.5
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    • pp.588-600
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    • 2018
  • Purpose: The purpose of this study was to test a model of nursing competencies of nursing simulation learners. The conceptual model was based on the theory of Jeffries's simulaton theory. Methods: Data collection was conducted in October 2017 for 310 students from two nursing universities in Kyungbuk area for 20 days. Data analysis methods were covariance structure analysis using SPSS 21.0 and AMOS 22.0 statistical programs. Results: The hypothetical model was a good fit for the data. The model fit indices were comparative fit index=.97, normed fit index=.94, Tucker-Lewis Index=.97, root mean square error of approximation=.44, and standardized root mean square residual=.04. Teacher factors were directly related to simulation design characteristics, and it was confirmed that the curriculum, classroom operation and teaching method of the instructors were important factors. Learner factors were found to have a direct effect on nursing competence, self-confidence, and clinical performance that belong to nursing capacity. In particular, the results of this study indicate that the simulation design characteristics have a partial mediating effect on learner factors and clinical performance, and a complete mediating effect on learner factors and clinical judgment ability. Conclusion: In order to improve the learner's clinical performance and clinical judgment ability, it is necessary to conduct practical training through nursing simulation besides preparing the learner and the educator.

Leakage Monitoring of Control Valves for Nuclear Power Plants Using Multi-measuring (Multi-measuring기법을 이용한 원전 제어밸브의 누설진단)

  • Kim, Sung-Young;Kim, Young-Bum;Kim, Bong-Ho;Lee, Sang-Guk
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.3458-3463
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    • 2007
  • Leakage would happen because of the damage of high temperature and high-pressure valve in nuclear power plant. condition based prevention maintenance is essential by using the suitable method based on local condition. Energy loss prevention can prevent from an accurate test, Local actually and ability. The methods of test for high energy fluid leakage at present are analysis of ${\Delta}$T, AE(Acoustic Emission) analysis, and thermal image. The result for test of AC (Main steam) system in YNG 2 Unit reveals that the AE occurred clearly in leakage situation, but thermal image didn't occur. It is identified that leakage is occurred when the orifice located front and back of valve operates. It shows that making a impatient judgment by using the single method if it is leakage is containing uncertainty. So I think that using the Multi-Measuring method is more sound judgment than Single-Measuring method.

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A Comparative Study on Learning Outcomes according to the Integration Sequences of S-PBL in Nursing Students: Randomized Crossover Design (S-PBL의 연계순서에 따른 간호대학생의 학습성과 비교: 무작위 교차설계)

  • Yun, So Young;Choi, Ja Yun
    • Journal of Korean Academy of Nursing
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    • v.49 no.1
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    • pp.92-103
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    • 2019
  • Purpose: This study aimed to compare the effects of simulation integrated with problem based learning (S-PBL) according to the sequences of problem-based learning (PBL) and high fidelity simulation training (HFS) on knowledge, clinical performance, clinical judgment, self-confidence, and satisfaction in fourth-grade nursing students. Methods: In this randomized crossover design study, four S-PBLs on medical-surgical nursing were applied alternatively to two randomly-assigned groups of 26 senior nursing students for 8 weeks. The collected data were analyzed using an independent t-test. Results: The method of administering PBL prior to HFS led to significantly higher scores on knowledge (t=2.28, p=.025) as compared to the method of administering HFS prior to PBL. However, the latter method led to significantly higher scores on clinical performance (t=-6.49, p<.001) and clinical judgment (t=-4.71, p<.001) as compared to the method of administering PBL prior to HFS. There were no differences in the effect of the two methods on self-confidence (t=1.53, p=.128) and satisfaction (t=1.28, p=.202). Conclusion: The integration sequences of S-PBL was associated with different learning outcomes. Therefore, when implementing S-PBL, it is necessary to consider the educational goal to executes an appropriate sequence of integration.

An Improved Multilevel Fuzzy Comprehensive Evaluation to Analyse on Engineering Project Risk

  • LI, Xin;LI, Mufeng;HAN, Xia
    • The Journal of Economics, Marketing and Management
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    • v.10 no.5
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    • pp.1-6
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    • 2022
  • Purpose: To overcome the question that depends too much on expert's subjective judgment in traditional risk identification, this paper structure the multilevel generalized fuzzy comprehensive evaluation mathematics model of the risk identification of project, to research the risk identification of the project. Research design, data and methodology: This paper constructs the multilevel generalized fuzzy comprehensive evaluation mathematics model. Through iterative algorithm of AHP analysis, make sure the important degree of the sub project in risk analysis, then combine expert's subjective judgment with objective quantitative analysis, and distinguish the risk through identification models. Meanwhile, the concrete method of multilevel generalized fuzzy comprehensive evaluation is probed. Using the index weights to analyse project risks is discussed in detail. Results: The improved fuzzy comprehensive evaluation algorithm is proposed in the paper, at first the method of fuzzy sets core is used to optimize the fuzzy relation matrix. It improves the capability of the algorithm. Then, the method of entropy weight is used to establish weight vectors. This makes the computation process fair and open. And thereby, the uncertainty of the evaluation result brought by the subjectivity can be avoided effectively and the evaluation result becomes more objective and more reasonable. Conclusions: In this paper, we use an improved fuzzy comprehensive evaluation method to evaluate a railroad engineering project risk. It can give a more reliable result for a reference of decision making.

Maritime Officers' Strategies for Collision Avoidance in Crossing Situations

  • Hong, Seung Kweon
    • Journal of the Ergonomics Society of Korea
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    • v.36 no.5
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    • pp.525-533
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    • 2017
  • Objective: The aim of this study is to investigate maritime officers' strategies to avoid the ship collision in crossing situations. Background: In a situation where there is a risk of collision between two ships, maritime officers can change the direction and speed of the own-ship to avoid the collision. They have four options to select; adjusting the speed only, the direction only, both the speed and direction at the same time and no action. Research questions were whether the strategy they are using differs according to the shipboard experience of maritime officers and the representation method of ARPA (automatic radar plotting aid) - radar graphic information. Method: Participants were 12. Six of them had more than 3 years of onboard experience, while the others were 4th grade students at Korea Maritime and Ocean University. For each participant, 32 ship encounter situations were provided with ARPA-radar information. 16 situations were presented by the north-up display and 16 situations were presented by the track-up display. Participants were asked to decide how to move the own-ship to avoid the ship collision for each case. Results: Most participants attempted to avoid the collision by adjusting the direction of the ship, representing an average of 22.4 times in 32 judgment trials (about 70%). Participants who did not have experience on board were more likely to control speed and direction at the same time than participants with onboard experience. Participants with onboard experience were more likely to control the direction of the ship only. On the other hand, although the same ARPA Information was provided to the participants, the participants in many cases made different judgments depending on the method of information representation; track-up display and north-up display. It was only 25% that the participants made the same judgment under the same collision situations. Participants with onboard experience did make the same judgment more than participants with no onboard experience. Conclusion: In marine collision situations, maritime officers tend to avoid collisions by adjusting only the direction of their ships, and this tendency is more pronounced among maritime officers with onboard experience. The effect of the method of information representation on their judgment was not significant. Application: The results of this research might help to train maritime officers for safe navigation and to design a collision avoidance support system.

Selection of Evaluation Metrics for Grading Autonomous Driving Car Judgment Abilities Based on Driving Simulator (드라이빙 시뮬레이터 기반 자율주행차 판단능력 등급화를 위한 평가지표 선정)

  • Oh, Min Jong;Jin, Eun Ju;Han, Mi Seon;Park, Je Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.44 no.1
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    • pp.63-73
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    • 2024
  • Autonomous vehicles at Levels 3 to 5, currently under global research and development, seek to replace the driver's perception, judgment, and control processes with various sensors integrated into the vehicle. This integration enables artificial intelligence to autonomously perform the majority of driving tasks. However, autonomous vehicles currently obtain temporary driving permits, allowing them to operate on roads if they meet minimum criteria for autonomous judgment abilities set by individual countries. When autonomous vehicles become more widespread in the future, it is anticipated that buyers may not have high confidence in the ability of these vehicles to avoid hazardous situations due to the limitations of temporary driving permits. In this study, we propose a method for grading the judgment abilities of autonomous vehicles based on a driving simulator experiment comparing and evaluating drivers' abilities to avoid hazardous situations. The goal is to derive evaluation criteria that allow for grading based on specific scenarios and to propose a framework for grading autonomous vehicles. Thirty adults (25 males and 5 females) participated in the driving simulator experiment. The analysis of the experimental results involved K-means cluster analysis and independent sample t-tests, confirming the possibility of classifying the judgment abilities of autonomous vehicles and the statistical significance of such classifications. Enhancing confidence in the risk-avoidance capabilities of autonomous vehicles in future hazardous situations could be a significant contribution of this research.