• Proceedings of the KIEE Conference
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• summer
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• pp.1412-1414
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• 2004

Railway takes an important role of transporting massive passenger and freight. Accidents which occur related to trains have a risk of serious loss of lives, so those accidents need to be controlled urgently. Therefore moving picture transmission system is required which transmits exact information of moving picture of accident status to CTC and also communication line is also required with it. By using WTB line as a wayside transmission line, railway telephones, fax and train service information are provided to local offices. As transmission line improving project, optical cabling work is being processed by phases. Therefore optical fiber line is more effective way for a communicating way between stations than coaxial transmission line. This paper consider's connecting method when optical fibers is used for moving picture data transmission of train accidents and its problems.

• Journal of the Korean Professional Engineers Association
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• v.44 no.5
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• pp.31-35
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• 2011

The WHO/International Agency for Research on Cancer(IARC) has classified radiofrequency electromagnetic fields as possibly carcinogenic to humans(Group 2B), based on an increased risk for glioma, a malignant type of brain cancer, associated with wireless phone use on 31, May 2011. It takes 10 years after announcing the electric magnetic as possibly carcinogenic to humans(Group 2B) and 14 years after starting research project. It is too late as mentioned, too weak in terms of the same class to 'pickles & coffee' and too little in terms of using words 'more studies required'. The guidelines on human exposure to electromagnetic fields have been developed to provide guidance to identify the safety of exposure to electromagnetic fields. On the recent recommendations of safety guidelines, there has been discussion on possible chronic effects of electromagnetic fields with much lower or no threshold. This paper riviews the global trends of safety guidelines and has suggested the new guidelines for protecting the human health, wildlife and insects.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.299-301
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• 2005

The urban transit system is operated by driverless and automatic.In driverless and automatic system, the system function is accomplished exactly to obtain the safety and reliability of system and the system is designed to minimize risk. In order to design the system, the functional analysis is performed. Recently functional analysis is performed by design toolwhich is used and verified by aerospace, military, etc. Generally, the design tool is used to perform functional analysis in urban transit system development project. The design toolassist the system engineer to analysis the function of system in basic design. Therefore, In this paper, it is performed the functional analysis to satisfy the system requirement of urban transit system and to confirm the operation of system using design tool.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1663-1665
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• 2005

The urban transit system is operated by driverless and automatic. In driverless and automatic system, the system function is accomplished exactly to obtain the safety and reliability of system and the system is designed to minimize risk. In order to design the system, the functional analysis is performed. Recently functional analysis is performed by design tool which is used and verified by aerospace, military, etc. Generally, the design tool is used to perform functional analysis in urban transit system development project. The design toolassist the system engineer to analysis the function of system in basic design. Therefore, in this paper, it is performed the functional analysis to satisfy the system requirement of urban transit system and to confirm the operation of system using design tool.

• Communications for Statistical Applications and Methods
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• v.27 no.2
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• pp.201-210
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• 2020

Baseline-category logit random effects models have been used to analyze longitudinal nominal data. The models account for subject-specific variations using random effects. However, the random effects covariance matrix in the models needs to explain subject-specific variations as well as serial correlations for nominal outcomes. In order to satisfy them, the covariance matrix must be heterogeneous and high-dimensional. However, it is difficult to estimate the random effects covariance matrix due to its high dimensionality and positive-definiteness. In this paper, we exploit the modified Cholesky decomposition to estimate the high-dimensional heterogeneous random effects covariance matrix. Bayesian methodology is proposed to estimate parameters of interest. The proposed methods are illustrated with real data from the McKinney Homeless Research Project.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.424-429
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• 2013

The trolley carrying the pod moves along by the airfield runway. The pod through the trolley are subjected to vibration arising from the ground state, the precision optical components in the pod can have a significant impact. The road tests were conducted by using the measurement pod to remove the risk for the project. The measurement pod was composed with the ACRA, sensors, battery. The accelerometers were attached to get the acceleration through the road condition. The PSD envelop was calculated by FFT from the acceleration. The driving safety was proven through comparing the measurement data and MIL-STD-810G specification.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.292-295
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• 2006

2005년 말 현재, 국내의 상업운전 중인 풍력발전기는 93.5MW(KPX 2005)에 불과하여 민간의 풍력에너지 개발 참여를 위한 사업타당성 조사에서 상업운전에 이르는 풍력발전단지 개발절차에 대한 사례 연구가 미비하다. 최근 신재생에너지 보급을 위한 정부의 강력한 의지와 맞물려 민간의 대규모 풍력발전단지 개발 계획이 속속 진행되고 있는 여건에서, 국내 최초의 대단위 상업용 풍력발전단지인 영덕풍력발전의 개발 및 운영사례를 통해 국내 풍력발전단지 개발 시 고려사항과 발생 가능한 문제점 및 해결방안을 제시한다.

• Journal of Information Technology Services
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• v.4 no.2
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• pp.23-32
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• 2005

Information system audit of Korea is different from that of the United States of America, Japan and so on. Information system audit improves the quality of information system. Information system audit of Korea carried out administrative branches. Recently Public sides required ordinary audit frequently. The reason is that the risk of information system project has increased. Examined closely relation between audit quality and audit style such as ordinary audit, fixed period audit, residence audit, and responsibility audit. And, wished to examine closely relation between audit quality and customer satisfaction. As research result, being effect factor that audit style keeps in mind in audit quality, also, audit quality in audit satisfaction, and was proved that exert effect that ordinary audit, report to the responsibility audit or sense of responsibility state keeps in mind in audit satisfaction.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.891-894
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• 2015

IT 프로젝트의 규모와 불확실성이 급변하고 있기 때문에 프로젝트를 계획된 비용과 납기 내에 성공적으로 종료하기가 어려워졌다. 이에 프로젝트 성공 가능성을 높이기 위한 방안으로 리스크 기반의 테스트 전략을 도입하여 적용하는 프로젝트 사례가 증가 하고 있다. 본 연구의 목적은 차세대 규모의 프로젝트를 수행할 때 리스크 기반의 테스트 전략을 어떻게 적용해야 하는지 사례를 통하여 구체적인 적용방안을 제시하고자 한다. 본 연구에서는 크게 두 가지 측면에서 시사점이 존재한다. 첫째, 차세대 규모의 프로젝트를 수행하기위해 전사적 차원에서 테스트 활동 방안을 제시하였다는 점이고, 둘째, 리스크 기반 테스트 전략을 프로젝트 라이프 사이클에 따라 적용한 사례를 통하여 구제적인 방안을 제시하였다는 점이다.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.265-269
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• 2017

Because of abrupt changes for velocity in water, transient flow is occurred in practical life. To reduce and avoid the high or low pressure of pipe network system, various surge protection facilities are used to prevent the risk in pipe network system. Especially, we focused on study not only preventing positive and negative pressure but also selecting adequate equipment for high pressurized pipelines. Several critical cases were considered by undertaking a steady state hydraulic study and transient dynamic simulation and we suggested that the surge vessel of various surge protection system was recommended to control high and low pressures on pipeline system in perspective.