• 전기학회논문지
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• 제62권9호
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• pp.1343-1347
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• 2013

This paper presents an analysis methods for current collection quality in catenary system by means of video image based monitoring system. Arcing is the sparking at the interface point between pantograph and contact wire when the electric trains have traction current values at speed. Percentage of arcing at maximum line speed is measurable parameters for compliance with the requirements on dynamic behaviour of the interface between pantograph and contact wire in accordance with requirement of IEC and EN standards. The arc detector and video is installed on a train aim at the trailing contact strip according to the travel direction. The arc detector presented and measured verity of value such as the duration and power density of each arc and the video image is measured a image when the arc is occurred in pantograph. In this paper we analysis of video image in accordance with power density of arcing from arc detector and compared with video image and power density of arcing so as to produce quality of arcing from image.

• 한국철도학회논문집
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• 제15권6호
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• pp.572-578
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• 2012

철도차량에서 안정적인 집전성능의 확보는 운영의 질 및 최고속도를 결정하는 중요한 요인이다. 이러한 집전성능을 사전에 예측하기 위하여 과거부터 다양한 방법이 제안되었으며, 결과의 정확도 및 해석 과정의 효율성 향상을 위한 연구들도 동시에 진행되어 왔다. 본 논문에서는 집전성능 해석 프로그램의 해석 효율성을 향상시키는 방법에 대하여 제안한다. 제안된 방법은 가선과 같은 길이 방향 구조물에 대하여 판토그래프가 상호작용을 하는 영역만을 해석 모델의 운동방정식에 포함하는 것을 기본 개념으로 두고 있다. 이와 같은 방법을 적용하기 위한 일반화 과정 및 알고리즘을 소개하고 해석 결과의 타당성, 오차를 최소화하기 위한 방법 및 제안된 방법의 효용성을 검토하고자 한다.

• 품질경영학회지
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• 제45권3호
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• pp.335-347
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• 2017

Purpose: Defense government agencies in the world continuously try to improve operational efficiency in government quality assurance activities. The purpose of this paper is to propose some suggestions to enhance efficiency of government quality assurance (GQA) activities based on the analysis of the current quality assurance methods of advanced foreign agencies such as DCMA and NATO. Methods: In order to propose new directions, reviews and analyses are executed. (1) Former research results in Korea for enhancing GQA are reviewed, and their limitations are addressed. (2) Updated policies and procedures of the US DCMA and NATO are reviewed and their advantages are presented. (3) Current GQA policies and procedures are contrasted with those of US DCMA and NATO. Results: Suggestions for efficient Korean GQA activities are given in several aspects: GQA paradigm shift, clarification of GQA methods, facility-wide GQA, risk management for suppliers, counterfeit mitigation policy, data collection and control. Conclusion: Reviews on the government quality assurance policies and procedures of DTaQ, DCMA, and NATO are executed and compared with each other. The results of this research are expected to be useful guidelines to improve GQA policies and procedures in Korea, making it possible to realize more efficient GQA activities in Korea.

• International Journal of Railway
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• 제5권2호
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• pp.55-64
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• 2012

Subject of the paper is a particular configuration of overhead line, in which noise barrier structure is used as supports of the catenary instead of standard poles. This configuration is foreseen in case the noise barrier position is in conflict with the poles location. If the catenary is supported by the noise barrier, the motion that the latter undergo due to wave pressure associated to train transit is transmitted to the overhead line, so that potentially it influences the interaction between the catenary itself and the pantograph of the passing train. The paper focuses on the influence of such peculiar configuration on the quality of the current collection of high speed pantograph, for single and double current collection. The study has been carried out first with an experimental investigation on the pressure distribution on noise barrier, both in wind tunnel and with in-field tests. Subsequently a numerical analysis of the dynamics of the barrier subjected to the wave pressure due to train transit has been carried out, and the output of such analysis has been used as input data for the simulation of the pantograph-dynamic interaction at different speeds and with front or rear pantograph in operation. Consideration of structural modifications was then highlighted, in order to reduce the influence on the contact loss percentage.

• 전기학회논문지
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• 제60권11호
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• pp.2171-2175
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• 2011

The objective of this paper is to discuss technologies on assessing reliability of arc detectors by composing a system that generates and simulates occurrence of arc caused by loss of contact between pantographs and contact wires in a laboratory condition. In order to establish the arc simulator, a device that generates light having the bandwidth of arcs that occur between carbon-metal. The simulator was designed under conditions of EN 50317 and simulations were conducted using the developed device. According to the results, it was possible to conduct certification tests following regulations of international standards and the precision of the simulator was satisfactory. The proposed arc detector assessment system is expected to enhance precision of current collection quality performance assessment methods at high-speed lines and conventional lines while being referred as fundamental technologies for development of detectors suiting international conditions.

• 한국의료질향상학회지
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• 제2권1호
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• pp.126-135
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• 1995

Background: Korean Hospital Standardization Program(KHSP), as a hospital accreditation program initiated and promoted by Korean Hospital Association since 1981, has played a key role in the hospital quality improvement in structural aspect particularly. Recently, however, KHSP has been critisized by hospitals and health personnels in that it is unpractical to be utilized as an initiative to improve hospital quality. In particular, the section of quality assurance in KHSP, strongly influenced by old version of Hospital Accreditation of Joint Commission in U.S.A., has been required to be fundamentally revised. For design of new criteria in quality assurance section, a survey for evaluation of existing program and collection of opinions for ideal one was conducted. Methods: For a month in 1994, structured questionnaires were administered by mailing to 470 hospital staffs from 200 hospitals, participated in the survey for the 1994 KHSP in each hospital. The total number of respondents was 116. Results: Less than half of the respondents(34.5%) value positively on the impact of current KHSP in general on the quality improvement of their hospitals. Moreover, most responses indicated that KHSP should be reorganized towards more practical and applicable one. Current KHSP criteria for quality activities in hospitals were regarded as a unpractical one which should be basically renewed. For new criteria and standards, most respondents emphasized the importance of applicability of those in real situations. Conclusion: For the KHSP to be effective, new evaluation criteria for quality activities should be more practical and fully accommodated to hospital situations in reality.

• 한국대기환경학회지
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• 제27권3호
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• pp.272-280
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• 2011

A novel particle removal system for air handling unit (AHU) of subway station was evaluated experimentally. The novel system was designed in order to minimize the maintenance cost by applying axial-flow cyclones. The system consists of multiple cyclone units and dust trap. Based on our previous numerical study, it was found to be effective for removal $1\sim10{\mu}m$ sized dust particles. In this study, we manufactured the mock-up model and evaluated the model experimentally. Liquid and solid test particles were generated for evaluating collection efficiency of the system and the pressure drop was monitored. The collection efficiency was varied from 41.2% to 85.9% with increasing the sizes of particle from 1 to $6.5{\mu}m$ by particle count ratio of inlet and outlet. The pressure drop was maintained constant less than $20mmH_2O$. In addition, the collection efficiency was estimated by total mass for solid test particles. It was found that the collection efficiency was 65.7% by particle mass ratio of inlet and outlet. It shows that present system can replace current pre-filters used in subway HVAC system for removing particulate matters with minimal operational cost.

• 한국컴퓨터정보학회논문지
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• 제26권9호
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• pp.133-141
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• 2021

도로 이용자의 교통정보에 대한 수요 증가와 효율적인 도로 이용을 위해 또한, 지능형 교통체계(ITS, Intelligent Transport Systems)의 기본 기술로 교통정보를 수집하여 제공하는 시스템에 대한 개발과 요구가 지속되고 있다. 고속도로에서 가장 많이 사용하는 교통정보 수집 도구로는 차량검지기(VDS)와 단거리무선통신(DSRC)이 있으며, 신뢰성 있는 교통정보의 생성을 위해서는 질 높은 교통데이터 수집 및 가공 기술과 더불어 수집된 자료의 효율적 관리 및 활용이 필요하다. 본 연구에서는 교통정보 수집·제공 기술의 현황을 기술하고, VDS를 통하여 수집되는 교통정보의 현황과 문제점에 대하여 분석한다. 이를 바탕으로 VDS 데이터의 차량정보 계측에 칼만 필터를 활용하여 개선된 수집 알고리즘을 제시하고자 한다. 본 연구의 알고리즘을 활용하면 계측 시 필연적으로 발생하는 노이즈 제거 뿐만 아니라 추정 값의 시간지연(time delay)을 최소로 할 수 있다.

• 한국문헌정보학회지
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• 제50권2호
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• pp.271-287
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• 2016

본 연구는 이용자 중심의 도서관장애인서비스 품질요인을 실증적으로 고찰하고자 하였다. 품질요인의 실증적인 고찰을 위해 기존 도서관서비스의 품질 측정도구와 장애인서비스 기준 및 지침을 분석하여 총 9개의 품질요인을 도출하였으며, 이 요인을 활용하여 설문조사와 사례의 질적 평가가 이루어졌다. 조사 결과, 공공도서관 장애인서비스에서 가장 핵심적이며, 또한 상대적으로 취약한 품질요인은 시설, 장서, 직원 등 기본적인 도서관 자원의 영역으로 나타났다. 또한 도서관장애인서비스 우수사례를 분석한 결과 독서문화프로그램과 정보서비스 품질요인에 강조를 두고 있음이 조사되었다.

• 한국문헌정보학회지
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• 제48권3호
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• pp.27-53
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• 2014

이 연구에서는 그동안 장서개발을 주제로 한 연구가 지속적으로 수행되고 도서관의 자료구입비 확보를 위한 노력이 꾸준히 이루어져오고 있음에도 불구하고, 공공도서관 장서의 개선이 원활하게 이루어지지 않는 이유를 자료구입에 영향을 주는 법제에 초점을 두고 분석해 보았다. 이를 위해 첫째, 공공도서관 장서개발을 지원하는 재정적 토대인 자료구입비를 자체재원, 의존재원, 대안재원으로 나누어 각 항목이 유지되는 법제적 근거를 분석하였으며 둘째, 공공도서관 자료구입과정에서 자료구입비가 형성되는 근거를 분석하였다. 셋째, 도서관장서로 편입되는 자료의 성격을 규정하는 법제를 분석하고 넷째, 자료구입과정에 영향을 주는 법제를 계약형태 결정, 계약방법 결정, 자료납품업체 선정 단계로 나누어 분석하였다. 분석결과를 취합하여 공공도서관에서 자료구입비를 확보하고 구입과정을 효율적으로 개선할 수 있는 법제적 차원에서의 개선방안을 제안하였다.