• 전기학회논문지
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• 제59권8호
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• pp.1423-1428
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• 2010

The results of off-line and on-line diagnostic tests performed on the stator winding of an air-cooled gas turbine(G/T) generator are reported in this paper. Off-line diagnostic tests included measurements of the ac current, dissipation factor(tan${\delta}$), and partial discharge(PD). Six epoxy-mica capacitors were installed in the three phases of G/T generator for performing on-line diagnostic testing with the turbine generator analyzer(TGA). The TGA showed that the normalized quantity number(NQN) and the PD magnitude($Q_m$) were high in phase A of the stator winding. Internal discharges were generated in phases B and C, and slot discharge occurred in phase A. According to the trend analyses of the NQN and $Q_m$ values available for insulation condition assessment for G/T generator stator windings, it was concluded that phases B and C were in good condition, whereas phase A has been significantly deteriorated.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제24권1호
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• pp.17-23
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• 2018

본 논문은 인지기능장애를 동반한 환자를 검사하고, 재활치료와 인지기능 평가를 하는데 사용될 수 있는 전자펜 기반의 시스템을 제안하고 있다. 제안된 시스템은 기존에 병원에서 널리 사용 중인 종이와 펜을 활용한 라인추종시험(Line tracing test; LTT)을 그대로 응용함으로써, 환자와 치료사가 거부감 없이 새로운 시스템을 적용할 수 있도록 하였다. 개발된 시스템의 정확성과 효과를 검증하기 위하여 성인 남녀 20명을 대상으로 시험한 결과, 전자펜을 활용한 측정치와 사람이 직접 측정한 측정치 간의 신뢰도가 0.90으로, 효과크기는 0.38로 평가되었으며 이는 전자펜을 활용한 검사 결과를 충분히 신뢰할 수 있음을 의미한다. 이와같이 신뢰성을 유지하는 반면, 검사 결과를 산출하는 시간에 있어서 사람이 직접 산출하는 경우 평균 48.2초가 소요되는데 반하여 전자펜을 기반으로 하는 방식의 경우 실시간으로 평가 결과가 기록되며 검사 종료 후 즉시(1초이내) 결과가 산출되기 때문에 시간 효율이 높음을 확인할 수 있다. 제안된 시스템은 파킨슨병, 심장마비 등으로 인한 뇌손상 환자의 인지기능장애 검사에 활용될 수 있다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1077-1092
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• 2007

The structural analysis model for estimate of load carrying capacity of railway bridge on service line is important to determine safety of bridges in service, we need to take response of bridge exactly, applying analysis model similar to the real railway bridge most. Track structure which is to distribute loads and decrease vibrations occurred from running train is constructed on the railway bridges. And it is important factor which should be considered to understand exact dynamic and static responses of bridge. But track structure is currently classified as a none structural members in the structural analysis model for estimating load carrying capacity of railway bridge and not considered in analysis model. That's the reason it is difficult to understand exact behavior of bridges. Therefore, the major objective of this study is to develop an analytical track-bridge model which is similar to real railway bridges considering track structure for safety assessment of railway bridge on service line to be effectively done.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.28-30
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• 2003

Probabilistic Load Flow(PLF) solution based on the method of moments is used for security assessment of bus voltages in power systems. Bus voltages, line currents, line admittances, generated real and reactive power, and bus loads are treated as complex random variables. These complex random variables are known in terms of probability density functions(PDF). Also, expressions for the convolutions of complex random variables in terms of moments and cumulants have been derived. Proposed PLF solution using the method of moments is fast, because the process of convolution of various complex random variables is performed in moment and cumulant domain. Therefore, the method is applied to security assessment of power systems in this paper. Finally, system operator also can be used information of security assessment to improve reliability of power systems.

• 제어로봇시스템학회논문지
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• 제20권6호
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• pp.647-650
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• 2014

Assessment and rehabilitation of patients with unilateral visual neglect has been one of the fields that require assistive technology. Paper-and-pencil tests, including the LBT (Line Bisection Test), have been one of the most commonly used visual neglect assessment methods used in a clinical setting. The key motivation of this study was to establish a computer-based real-time assessment system for the hemi-neglect patients without altering the conventional paper-and-pencil based user tools. A digital penbased assessment and rehabilitation system, the ePen System, could eliminate the manual assessment time while maintaining measurement accuracy. As a result, the proposed system may assist rehabilitation specialists to assess and diagnose patients with unilateral visual neglect. This system can be applied to a range assessment and rehabilitation modalities based on a pen and paper. It can also be applied to various patients such as those with Parkinson's disease, stroke sufferers, or those who have experienced different forms of brain lesions.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.331-340
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• 2009

This study is objected by suggesting rationalization method of management and maintenance cost for railway investment assessment. The estimate of rational benefit and cost are a work of vital importance to decide railway investment as preliminary feasibility investigation is institutionally reinforced since January 2007. In particular, railway management and maintenance cost have to be applied to realistic and detail cost as railway investment assessment guide. For example, types of railway, construction of new line, improvement of conventional line, double tracking, railway electrification. However, railway investment assessment is inconsistency because of estimating the railway management and maintenance cost using existing unrealistic management and maintenance cost. Therefore, this study is performed parametric analysis effecting on the railway management and maintenance cost considered new technique, enhanced facilities and improved standard. Also, it suggests the itemized standard management and maintenance cost. Finally, it will be helped to establish the base of railway investment through the rationalization method of management and maintenance cost.

• 대한전기학회논문지:전력기술부문A
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• 제49권6호
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• pp.253-258
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• 2000

This paper presents an application of Kohonen neural networks to assess the dynamic security of power systems. The dynamic security assessment(DSA) is an important factor in power system operation, but conventional techniques have not achieved the desired speed and accuracy. The critical clearing time(CCT) is an attribute which provides significant information about the quality of the post-fault system behaviour. The function of Kohonen networks is a mapping of the pre-fault system conditions into the neurons based on the CCTs. The power flow on each line is used as the input data, and an activated output neuron has information of the CCT of each contingency. The trajectory of the activated neurons during load changes can be used in on-line DSA efficiently. The applicability of the proposed method is demonstrated using a 9-bus example.

• 한국안전학회지
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• 제26권3호
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• pp.8-14
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• 2011

The live-line works are very dangerous because of direct contacts with the distribution line or neighboring contacts. So the purpose of this study is to identify the risk factor by accident occurrence form and accident case analysis, and to suggest the quantified risk index by risk occurrence frequency and risk strength analysis. And the risk index assessment is researched by accident cases analysis on work type. Accident cases of transmission distribution line are researched based on data of the Ministry of Employment and Labor in the last ten-year period (2000~2009). In results of this paper, high risk isn't always a priority of safety measures. Risk occurrence frequency and risk strength have to be considered according to detail work types, work methods and conditions of field work. And safety management measures must be planned according to risk occurrence frequency and risk strength.

• 한국산업안전학회:학술대회논문집
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• 한국안전학회 1997년도 추계 학술논문발표회 논문집
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• pp.117-122
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• 1997

This paper presents a study on the fuzzy based approach for the safety assessment of human body under ELF electric and magnetic(EM) field considering power system states. The analysis of ELF EM field based on quasi-static method is introduced. UP to the present, the analysis of ELF EM field has been conducted with the consideration of one transmission line, or a power line model only In this paper, however, the power system is included to model the expected and/or unexpected uncertainty caused by the load fluctuation and parameter changes and the states are classified into two types, normal state resulting from normal operation and emergency state from outages. In order to analyze the uncertainty in the normal state, the Monte Carlo Simulation, a statistic approach was introduced and line current and bus voltage distribution are calculated by a contingency analysis method, in the emergency state. To access the safety of human body, the approach based on fuzzy linguistic variable is adopted to overcome the shortcomings of the assessment by a crisp set concept. In order to validate the usefulness of the approach suggested herein, the case study using a sample system with 765(kV) was done. The results are presented and discussed.

• 정보처리학회논문지D
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• 제13D권1호
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• pp.51-60
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• 2006

제품 계열 공학(Product Line Engineering, PLE)은 도메인에서 멤버들이 갖는 공통 휘처를 재사용 가능한 핵심 자산으로 만들고, 만들어진 핵심 자산을 이용해서 애플리케이션을 개발하는 방법론이다. PLE는 핵심 자산을 개발해서 재사용하므로, 개발비용을 감소시키며 자산의 재사용성을 증가시킬 수 있다. 지금까지 여러 개의 PLE 방법론이 소개되었으나, 표준화된 PLE 방법론이 존재하지 않기 때문에, 방법론이 제시하는 프로세스나 산출물 등에서 차이가 크며, 산업계에서는 PLE 방법론을 채택하는데 어려움이 있다. 이에 프로세스의 선택과 효율적인 활용을 위해서 기존의 여러 방법론을 비교 분석하는 작업이 요구된다. 본 논문에서는 FAST, SEI SPL, PuLSE, Bosch의 제품 계열 프로세스, FOPLE, ESAPS, KobrA/PoLITe, Alexandria COPA, QADA 방법론 등 대표적인 PLE 방법론을 프로세스, 산출물, 적용 지침 측면 별로 비교 기준을 나누고, 비교 기준에 따라서 비교 평가를 수행한다. 또한 방법론간 공통성이 큰 항목과 적은 항목을 확인해서, PLE 방법론이 포함해야 하는 요소와 각 방법론이 개선해야 하는 사항을 확인한다. 본 논문은 적절한 프로세스를 선택 또는 재정의하는 과정에서 활용할 수 있을 뿐만 아니라, 향후 PLE 개발 방범론의 표준을 정의하는 과정에서 기반이 될 수 있을 것이다.