• 한국압력기기공학회 논문집
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• 제6권2호
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• pp.54-60
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• 2010

Piping failures due to thermal fatigue have been widely reported in normally stagnant non-isolable reactor coolant branch lines. Since the thermal fatigue due to thermal stratification was not considered in the piping fatigue design in old NPPs, it is important to evaluate the effect of thermal stratification on the integrity of branch lines. In this study, geometrical screening criteria for Up-horizontal branch lines in MRP-132 were applied to SI(Safety Injection) lines of KSNP 2-loop and WH 3-loop. Some computational fluid dynamic(CFD) analyses on the Reactor Coolant System(RCS) branch lines were also performed to develop the regulatory guidelines for screening criteria. As a result of applying MRP-132 screening criteria, KSNP 2-loop and WH 3-loop SI lines are determined to need further detailed evaluation. Results of CFD analyses show that both valve isolation and amount of leakage through valve can be used as technical bases for the screening criteria on the thermal fatigue analysis.

• 한국안전학회지
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• 제37권5호
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• pp.1-6
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• 2022

In this study, to confirm the effects of the mixed load of normal and shear forces acting on a fixing bolt, fatigue design criteria were developed by varying the loading angle and conducting tensile and fatigue tests. After evaluating and comparing the test results under different loading angles, the evaluation criteria were selected. These evaluation criteria were then applied to develop the design criteria. An Arcan fixture was designed and manufactured to simultaneously apply a mixed load of normal and shear forces to the fixing bolt of a turntable, and a fatigue test was conducted. S-N diagrams for various loading angles were obtained, and a 1% P-S-N diagram of failure probability was determined using statistical processing techniques. Our results show that failures of the fixing bolt can be prevented using these diagrams as a basis for developing fatigue design criteria.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.240-242
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• 1988

This paper proposes an improved ART (Algebraic Reconstruction technique) algorithm. This algorithm is an iterative one with iteration sequence criteria based on the discrepancy between measurement and pseudo-projection data. The simulation result using the proposed algorithm shows a significant improvement in convergency rate over the conventional ART algorithm.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2010년도 춘계학술대회
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• pp.181-188
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• 2010

The research presents the implementation and improvement strategies of scientific methodologies and techniques in the audit criteria of KS certification. The paper discusses the establishment of management strategy and quality policy by the alignment of BSC or policy deployment, the effective handling methodologies of control plan based on SPC, and the traceability of calibration uncertainty and MSA, etc.

• 한국신뢰성학회지:신뢰성응용연구
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• 제15권1호
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• pp.67-75
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• 2015

Differential pressure sensor for DPF (Diesel Particulate Filter) is the important part of a automobile exhaust system. This device measures the pressure of before DOC and after DPF to determine whether the DPF regenerate. In this paper reliability assessment criteria for DPF differential pressure sensor are established on terms of quality calcification test and lifetime test. The former quality certification test comprises general performance test and environmental test. Items which pass the test undergo lifetime test which guarantees the extent of mean lifetime with certain confidence.

• 한국신뢰성학회지:신뢰성응용연구
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• 제11권1호
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• pp.1-15
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• 2011

Automobile markets are so fierce in the world market that every major manufacturer assure the buyer of the car by give a provocative warranty plan for their cars. For instance Hyundai motor company offer 10 years and 100,000 miles of warranty whichever comes first. But in order for this effort to be successful every critical component such as window switch has to be proven to be reliable in an adverse environment. Therefore, in this article reliability assessment criteria for window switch are established in terms of basic performance test, environment test and life test.

• Journal of Information Technology Applications and Management
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• 제14권1호
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• pp.117-135
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• 2007

Globalization changes in market structures and consumer needs, as well as technology innovations force organizations to adopt new structures and collaborative networks to cope with rapidly changing environments. These Collaborative Networks are based on the Idea of virtual enterprise. A virtual enterprise(VE) is a temporary alliance of globally distributed independent enterprises that share core competencies and computer networks. This paper presents a proposal for a methodology to measure a key factor of success and risk First of all, we chose thirty experts' defines on virtual enterprise, fifteen are academic specialist and other fifteen are from industry. For this study we define twenty two factors determining VE's success and seventeen factors determining VE's risk using by Delphi method. And we built the influence model on virtual enterprise. A research model was established according to preceeding research and consensus on experts then the revised model of key factors on virtual enterprise. This survey was based on the Analytical Hierarchy Process (AHP). AHP is an approach to decision making that involves structuring multiple choice criteria into a hierarchy, the assessing the relative important of these criteria, comparing alternative for each criteria, and determining an overall ranking of the alternatives. A model was constructed as 3 level hierarchy. The hierarches are organizational, strategic, technical criteria. for success model on VE has 22 factors and 17 factors for risk model. They are selected by all 30 experts. 14 copies among 30 copies distributed to carry out on the Analytical Hierarchy Process (AHP). Consistency ratio confirm high validity and reliability of instrument and support theoretical model. The results of this study are summarized as follows. (1) This study presented success on VE influenced strategic criteria, and essential factor is Creating a value. Risk on VE influenced strategic criteria, and essential factor is Outcome/Distribution. (2) Its enable that ranking the criteria influence on VE. These are supported VE management and using guideline of VE.

• 한국의상디자인학회지
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• 제19권2호
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• pp.79-90
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• 2017

The main purpose of the study was to explore effects of selection criteria of collaborating fashion companies on the partnership growth of collaborating artists with those companies. Secondly was to find differences in the selection criteria of collaborating fashion companies and the partnership growth of collaborating artists according to the characteristics of artists including gender, age, frequency and time period of collaboration. The questionnaire was developed by the researchers and was collected from 50 artists with experience in collaboration with fashion companies. The questionnaire was composed of three parts including the selection criteria of fashion companies, partnership growth measured by a Likert-type scale, and characteristics of artists measured by a nominal scale. Data were analyzed by a frequency test, factor analysis, reliability test, regression analysis, and independent sample t-test using SPSS Win 18.0. The results of the study showed that significant effects of the selection criteria of collaborating fashion companies on the partnership growth of collaborating artists with the companies. Also, there were differences in the selection criteria of collaborating fashion companies and the partnership growth of collaborating artists between artist groups according to the characteristics of the artists including gender, age, frequency and time period of collaboration.

• 대한교통학회지
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• 제33권1호
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• pp.29-39
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• 2015

현재 보행자도로의 LOS분석 방법은 한국도로용량편람(2013)의 보행자시설편에서 제공하고 있다. 그러나 용량편람에서 제시하는 보행자도로의 분석방법을 적용하여 LOS를 산출할 경우, 분석지점의 대부분이 A수준으로 산출되어 현실적인 보행자도로의 서비스 수준을 반영하지 못하고 있는 실정이다. 이에 본 연구는, 2009년 조사된 '서울시 유동인구조사' 자료를 바탕으로 현재 도로용량편람에서 제시하는 보행자도로의 MOE를 적용하여 LOS기준의 적정성과 문제점을 파악하고, 보다 개선되어진 LOS기준을 제시하고자 하였다. 이의 개선방안으로 본 연구에서는 표준인체치수의 최신화, 보행점유공간의 여유폭 고려, Fruin과 Hall의 연구에서 제시하는 LOS의 정성적인 정의를 활용하여 새로운 기준을 제시하였다. 새로운 기준의 적용결과 종전의 보행자도로 LOS판단 기준보다 합리적인 결과를 보였으며, 본 연구 결과를 바탕으로 추후 보행자도로에 관한 현실적이고 다양한 계획 설계 시공이 가능할 것으로 판단된다.

• 한국농공학회논문집
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• 제61권3호
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• pp.101-112
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• 2019

This study developed selection criteria of small-scales reservoirs, having under $300,000m^3$ storage capacity, for the Emergency Action Plan(EAP) establishment in order to reduce the disaster risks of the reservoir's failures. Those reservoirs are out of ranges of Korean EAP establishment standard, but have potential risk of disasters as they have often failed by the recent extreme rainfall events and earthquakes, causing economical and life losses. The problem of reservoir aging is also one of the reasons of them. In this study, the developed selection criteria of small reservoirs for EAP establishment are storage capacity, embankment height, reservoir age, heavy rain factor and earthquake factor. These criteria were selected based on the review of the existing EAP establishment guidelines, analysis of the past dam failure cases, and the previous related studies. The quantification of these criteria were conducted for the practical applications in the fields, and applied to 67 previous failures in order to investigate the relation of each criteria with these failures. The earthquake factor found to be the highest relations followed by heavy rain factors, combination of earthquake and heavy rain factors, and reservoir age. The classification was made as observation and review groups for EAP establishments based on overlapping numbers of each criteria. This classifications applied to 354 reservoirs designated as having the potential disaster risk by MOIS, and showed 38.4% of observation and 11.9% of review groups. Anticipatory monitoring and regular inspection should be made by professional facility managers for the observation group, and necessity of EAP establishment should be assessed for the review group based on the downstream status and financial budget.