• 자원환경지질
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• 제27권2호
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• pp.209-212
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• 1994

Cheju Island was formed by volcanic activity probably related to the inferred geodynamics in the early Quaternary times. Paleostress analysis, in spite of a few fault slip data collected near Sanbangsan trachyte dome (dated 0.87 Ma) represents an extentional tectonic event with the direction ENE-WSW. Joint anayses in the vicinity of Seahwa reveal three extensional tectonic events of directions NW-SE, NE-SW and ENE-WSW. Especially the extensional event with the direction ENE-WSW affected the whole Cheju area during the most recent time.

• 한국전자통신학회논문지
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• 제2권3호
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• pp.185-190
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• 2007

해저케이블 장애의 가장 큰 원인은 어로 활동으로써 약 70%가 어선의 닻으로 인해 발생되며, 수심 200m 이내 지역에서 가장 많이 발생 하고 있다. 이는 어선으로 부터 해저케이블 보호를 위한 보호규정마련과 천해부에서 케이블 건설 기준이 마련되어야 함을 알 수 있다. 본고에서는 해저 이용자간 구조물 설치를 위한 방안을 제시하고 관련법을 마련토록 제언하였으며, 해저케이블 포설사업자들이 일반적으로 설치하던 천해부에서 해저케이블 매설 기법을 보완 발전시켜 정부차원의 관련 기술기준을 마련하고자 한다.

• Journal of Information Processing Systems
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• 제6권2호
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• pp.235-252
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• 2010

Regression testing is a very costly process performed primarily as a software maintenance activity. It is the process of retesting the modified parts of the software and ensuring that no new errors have been introduced into previously tested source code due to these modifications. A regression test selection technique selects an appropriate number of test cases from a test suite that might expose a fault in the modified program. In this paper, we propose both a regression test selection and prioritization technique. We implemented our regression test selection technique and demonstrated in two case studies that our technique is effective regarding selecting and prioritizing test cases. The results show that our technique may significantly reduce the number of test cases and thus the cost and resources for performing regression testing on modified software.

• 응용통계연구
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• 제23권3호
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• pp.573-584
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• 2010

This paper considers the differences in the software execution environments in the testing phase and the operational phase to determine the optimal release time and warranty period of software systems. We formulate equations for the total expected software cost until the end of the software life cycle based on the NHPP. In addition, we derive the optimal release time that minimizes the total expected software cost for an imperfect debugging software reliability model. Finally, we analyze the sensitivity of the optimal testing and maintenance design related to variation of the cost model parameters based on the fault data observed in the actual testing process, and discuss the quantitative properties of the proposed model.

• 한국초전도ㆍ저온공학회논문지
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• 제19권2호
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• pp.1-8
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• 2017

Recently, Research and development activity of HTS (High Temperature Superconducting) power application is very progressive worldwide. Especially, HTS cable system and HTSFCL (HTS Fault current limiter) system are proceeding to practical stages. In such system and equipment, cryogenic cooling system, which makes HTS equipment cooled lower than critical temperature, is one of crucial components. In this article, cryogenic cooling system for HTS application, mainly cable, is reviewed. Cryogenic cooling system can be categorized into conduction cooling system and immersion cooling system. In practical HTS power application area, immersion cooling system with sub-cooled liquid nitrogen is preferred. The immersion cooling system is besides grouped into open cycle system and closed cycle system. Turbo-Brayton refrigerator is a key component for closed cycle system. Those two cooling systems are focused in this article. And, each design and component of the cooling system is explained.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1465-1467
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• 1999

An Algorithm is devised to discriminate power distribution faults from other activites utilizing the arc activity and changes in the loading. This scheme intends to determine the cause of the transients and identify them. the discrimination algorithm was tested using recorded event data.

• 한국철도학회논문집
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• 제9권4호
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• pp.412-418
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• 2006

In this paper we deal with the APARP theory which has been applied for UK railway system and risk assessment method which has been using in the domestic railway system for the safety demonstration. Both techniques are applied to the ATP wayside equipment for interface. Also, fur the applications of each techniques a analysis of the safety activity and a possibility of the application of ALARP theory are evaluated. Finally, we generate requirements of the safety demonstration for the future domestic railway system by way of the analysis of some assumptions and requirement data which can be applied to the risk assessment of ALARP.

• 전기학회논문지
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• 제58권10호
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• pp.2000-2004
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• 2009

In general, for the condition monitoring of a power transformer using the UHF PD measuring technique, detection of any partial discharge, identifying the defect in the transformer and locating the insulation defect are necessary. In this paper one of the most frequent detects which can result in turn to turn fault in power transformer was examined for identifying the defect. In order to model the defect, as a discharge source, a partial discharge cell was used for experimental activity. Magnitude of electromagnetic wave signals and corresponding amount of apparent discharge were measured simultaneously against phase of applied voltage to the discharge cell. Frequency range and phase resolved partial discharge signals were measured and analyzed. The results will be contributed to build the defect database of power transformer and to decrease the occurrence of transformer faults.

• 한국항행학회논문지
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• 제19권5호
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• pp.370-378
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• 2015

데이터획득/처리장치는 수리온의 2차양산 항공기에 최초 적용하기 위해 개발한 항공기 구성품으로서 엔진, 동력전달, 유압 등 항공기의 주요 계통의 정보를 처리, 타 계통 및 조종사에게 제공한다. 그러나 항공기 생산시험비행 중 해당 구성품과 관련된 여러 결함이 발생하였으며, 장비의 중요성을 고려할 때 긴급하고 확실한 개선이 요구되었다. 본 논문에서는 항공기에서 발생한 결함을 유형별로 분석하고 그 결과를 바탕으로 동작회로와 소프트웨어 전반에 걸쳐 원인분석 및 개선형상을 검증한 결과를 기술하였다. 특히 결함주입기법 기반의 항공기 연동시험을 통해 구성품 장비단위 뿐 아니라 체계단위에서 효과적으로 개선형상을 검증하였으며 이를 통해 수리온 비행안전성 및 품질 신뢰성을 크게 향상시킬 수 있었다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제26권11호
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• pp.1282-1287
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• 1999

통신 프로그램은 고도의 신뢰성과 기능성, 확장성, 그리고 유지 보수성이 필요하다. 프로그램 테스트의 결과와 McCabe의 Complexity를 측정한 데이타를 가지고 회귀모델을 만들고 그 신뢰성을 분석함으로서 프로그램의 결함과 복잡도의 관련성을 평가한다.본 연구에서 사용한 통신 프로그램은 500개 블록이 59가지 기능을 수행하는 교환 기능 중에서 복잡도가 너무 많아서 통계 처리의 bias가 될 블록을 제외하고 394 블록을 선정하여 SAS에 의해서 통계 분석을 하고 회귀 분석 모델을 설계하였다. t 분포에 의하여 방정식의 유의성 수준을 검증하고 프로그램의 결함수에 가장 큰 영향을 주고 있는 복잡도가 McCabe의 복잡도와 설계 복잡도 임을 밝혀냈다. 이 연구 결과에 의해서 설계 정보 및 유지 보수 정보를 얻을 수 있다. Abstract Switching software requires high reliability, functionality, extendability and maintainability. For doing, software quality model based on MaCabe's complexity measure is investigated. It is experimentally shown using regression analysis the program fault density depends on the complexity and size of the function unit. The software should be verified and tested if it satisfies its requirements with automated analysis tools. In this paper we propose the regression model with the test data.The sample program for the regression model consists of more than 500 blocks, where each block compose of 10 files, which has 59 functions of switching activity.Among them we choose 394 blocks and analyzed for 59 functions by testing tools and SAS package. We developed Regression Analysis Model and evaluated significant of the equation based on McCabe's cyclomatic complexity, block design complexity, design complexity, and integration complexity.The results of our experimental study are that number of fault are under the influence of McCabe's complexity number and design complexity.