• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 Asia Navigation Conference
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• pp.56-62
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• 2006

This thesis researches on the application of computer, modern communication, GIS, GPS, AIS and World-Wide-Web in the field of navigation-aids information system, and has realized an integrated system consisted of navigation-aids information GIS platform, navigation-aids monitoring system and navigation-aids information distribution system. This system has strong integration capability, and has realized navigation-aids information distribution based on WEBGIS at the first time. It strongly promotes navigation-aids daily management and maintenance, and this system provides technique guarantee fur ships and marine departments to acquire navigation-aids information in time, by rule and line expediently.

• Smart Structures and Systems
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• 제16권1호
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• pp.213-222
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• 2015

Early detection and precise location of leakage is of great importance for life-cycle maintenance and management of municipal pipeline system. In the past few years, acoustic emission (AE) techniques have demonstrated to be an excellent tool for on-line leakage detection. Regarding the multi-mode and frequency dispersion characteristics of AE signals propagating along a pipeline, the direct cross-correlation technique that assumes the constant AE propagation velocity does not perform well in practice for acoustic leak location. This paper presents an improved cross-correlation method based on wavelet transform, with due consideration of the frequency dispersion characteristics of AE wave and the contribution of different mode. Laboratory experiments conducted to simulate pipeline gas leakage and investigate the frequency spectrum signatures of AE leak signals. By comparing with the other methods for leak location identification, the feasibility and superiority of the proposed method are verified.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.604-605
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• 2015

To secure quality of dam construction needs appropriate construction duration. Tight construction schedule may have negative influence on infrastructure quality, work safety and maintenance cost. It is necessary to reflect proper construction duration in the planning phase. There have been standards for estimating construction duration of building and industrial complex development but dam construction have not. In order to estimate construction duration of CFRD, feasible study reports and design reports were analyzed to acquire available information. After that, considering on construction duration methods such as comparison with similar cases, approximate estimating formula, approximate quantity assumption were adapted to Critical Path items. Hence, this study present framework for construction duration estimating of CFRD in the planning phase. This framework can be applied other types of dam along the same line.

• 한국시뮬레이션학회논문지
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• 제19권4호
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• pp.179-188
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• 2010

고객과 시장의 요구에 맞는 제품을 신속하게 개발하고 효율적인 유지 보수를 위해 소프트웨어 프로덕트 라인 공학의 관심이 확산되고 있다. 소프트웨어 프로덕트 라인 공학은 도메인을 분석하여 공통적인 부분과 가변적인 부분을 식별하여 공통적인 부분을 재사용 하면서 가변적인 부분을 선택적으로 적용하여 차별화된 프로덕트 라인을 생성 할 수 있는 재사용 패러다임이다. 이 논문의 목적은 국방 분야에 필요한 유도무기체계의 재사용성을 높이기 위해 소프트웨어 프로덕트 라인 공학을 적용하여 동적 재구성이 가능한 유도무기체계 아키텍처를 설계하고 재구성의 기본 단위인 기본 컴포넌트를 개발하는 것이다. 먼저 SPL을 통해 유도무기체계 아키텍처 설계하고, 이를 토대로 재구성이 가능한 기본 컴포넌트를 정의한다. 그리고 아키텍처와 기본 컴포넌트를 기반으로 물리와 행위 컴포넌트를 구성하여 물리 컴포넌트뿐만 아니라 OneSAF의 행위모델을 기초로 한 행위 컴포넌트에 대한 재구성기를 개발하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.224-226
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• 2001

In this paper, a novel high-voltage motor monitoring system (HVMMS) is proposed. This system monitors the insulation condition of the stator winding by on-line measurements of partial discharge (PD). Sensor, EMC (Epoxy-Mica Coupler) is used for PD measurement PD signals are continuously measured and digitized with a peak-hold A/D converter to build the database of the high-voltage motor's insulation condition. Also, this system can communicate with the central monitoring system via RS-485. This helps more efficient operation and maintenance of the generator.

• Journal of Electrical Engineering and Technology
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• 제6권6호
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• pp.760-768
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• 2011

The performance of transmission lines and its shielding design during a lightning phenomenon are quite essential in the maintenance of a reliable power supply to consumers. The leader progression model, as an advanced approach, has been recently developed to calculate the shielding failure rate (SFR) of transmission lines using geometrical data and physical behavior of upward and downward lightning leaders. However, such method is quite time consuming. In the present paper, an effective method that utilizes artificial neural networks (ANNs) to create a metamodel for calculating the SFR of a transmission line based on shielding angle and height is introduced. The results of investigations on a real case study reveal that, through proper selection of an ANN structure and good training, the ANN prediction is very close to the result of the detailed simulation, whereas the Processing time is by far lower than that of the detailed model.

• 전기학회논문지
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• 제57권10호
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• pp.1720-1725
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• 2008

Because of the continuous increasing of energy consumption, metallic pipelines are widely used to supply services to customers such as gas, oil, water, etc. Most common metallic pipelines are underground and are now frequently being installed in nearby electric power lines. In recent years, buried gas pipeline close to power lines can be subjected to hazardous induction effects, especially during single line to ground faults. because it can cause corrosion and it poses a threat to the safety of workers responsible for maintenance. Accordingly, it is necessary to take into consideration for analysis of induced voltage on gas pipelines in transmission lines. This paper analyzed the induced voltage on the gas pipelines due to the 154kV transmission lines in normal case and in different faulty case conditions using EMTP (Electro-Magnetic Transients Program).

• 조명전기설비학회논문지
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• 제20권8호
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• pp.15-21
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• 2006

본 논문은 인터넷과 데이터베이스를 이용한 온라인/오프라인 통합 야외 조명시설 관리 시스템의 개발하고, 제어함과 조명등을 위한 데이터베이스의 구축에 관하여 연구한 내용이다. 또한 연구 결과물의 효용성을 높이기 위해 기존에 사용하는 양식을 기초로 개발하여 새로운 시스템의 적용 시 적응이 용이하도록 하였다. 따라서 온라인/오프라인 통합 야외 조명시설 관리를 통하여 조명시설 정보의 효과적인 운용이 가능하도록 개발하였으며, 이 시스템을 통하여 인력 및 유지보수비를 줄이는데 기여할 수 있을 것으로 기대된다.

• Structural Monitoring and Maintenance
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• 제5권2호
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• pp.261-272
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• 2018

The commonly used TMD design method in the project assumes the TMD has pure linearity. However, in real engineering TMD will exhibit nonlinear behaviors. Without considering the nonlinearity of TMD, the control effect of the TMD that is designed by the linear design method, may be worse and even enlarge the structural response. In this paper, based on the previous study results of nonlinear TMD, the improved design method for engineering application is proposed. The linear design method and the improved design method are compared. Taking the best parameter obtained by the improved design method is less than or equal to 90% of that obtained by the original design method as the dividing line. The critical nonlinear coefficient, reaching which value the improved design method needs to be used, is given. Finally, numerical simulations on two engineering examples are conducted to proof the results.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권12호
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• pp.602-607
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• 2003

We show three-dimensional distribution of voltages resulted from the leakage current originated from outdoor electrical facilities in a submerged area. In case these facilities are grounded by the neutral line multiple grounding method, the existence of ungrounded electrical facilities can cause a disastrous effect on near-by passengers. In order to investigate this situation, we installed a real-scale test field for the experiment type I (for the leakage current path between a enclosure grounded electrical facility and another enclosure grounded one), and that for the experiment type II (for the leakage current path between a enclosure grounded electrical facility and another ungrounded one). For both cases, we carried out three-dimensional monitoring of the voltage distribution while varying additional conditions such as the exposure of the underground cables and the finishing of cable connection part. The result shows that a disastrous effect on human safety can arise from the leakage current without a pertinent measure for the construction and maintenance of outdoor electrical facilities.