• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.535-536
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• 2011

This paper studies the validity about a joint operation of neutral wire and overhead grounding wire in combined distribution systems. The overhead grounding wire and neutral wire are currently installed separately and grounded by common. However there is no any ineffectiveness or electrical problem in case of the proposed system, such system can be operated at real distribution system. Therefore this paper describes the suitability of a joint operation through lightning surge analysis on combined distribution systems and analyzes the optimal position of lightning arrester on joint operation of neutral wire and overhead grounding wire. Lightning surge analysis is carried out by EMTP/ATPDraw to obtain the overvoltage of overhead line and underground cable in various conditions such as location and current types of lightning stroke. Over voltage gained by the analysis show that the insulation strength of the joint operation case is not stable compare with the current operation case.

• Korean Chemical Engineering Research
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• 제46권2호
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• pp.383-388
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• 2008

화학공정의 안전하고 효율적인 운전에 관심이 커지면서 공정이상의 원인을 조기에 진단하기 위한 다양한 이상진단방법이 연구되어 왔다. 최근에는 통계적 모델 등 정량적 데이터에 기반한 이상진단방법이 많이 연구되고 있으나, 특정 조업영역에서 얻어진 통계적 모델을 다른 조업영역에 적용하면 오진단이 많아지게 된다. 따라서 공정특성상 다양한 조업영역이 존재하는 화학공정에 데이터기반 방법론을 적용하기에는 어려움이 있어 화학공정의 조업영역 판별법이 요구되고 있다. 이 연구에서는 유클리드 거리(Euclidean distance), FDA(Fisher's discriminant analysis), PCA(principal component analysis)의 통계모델과 이 모델들에 공정변수의 동특성을 반영한 모델을 제안하였다. 6개의 조업모드를 가진 TE(tennessee eastman) 공정에 대한 사례연구를 통해 동특성을 반영한 PCA 모델의 성능이 가장 우수함을 확인하였다.

• Journal of Power Electronics
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• 제19권5호
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• pp.1099-1107
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• 2019

A soft switching converter with wide voltage range operation is investigated in this paper. A series resonant converter is implemented to achieve a high circuit efficiency with soft switching characteristics on power switches and rectifier diodes. To improve the weakness of the narrow voltage range in LLC converters, an alternating current (ac) power switch is used on the primary side to select a half-bridge or full-bridge resonant circuit to implement 4:1 voltage range operation. On the secondary-side, another ac power switch is adopted to select a full-wave rectifier or voltage-doubler rectifier to achiever an additional 2:1 output voltage range. Therefore, the proposed resonant converter has the capacity for 8:1 (320V~40V) wide output voltage operation. A single-stage hybrid resonant converter is employed in the study circuit instead of a two-stage dc converter to achiever wide voltage range operation. As a result, the study converter has better converter efficiency. The theoretical analysis and circuit characteristics are verified by experiments with a prototype circuit.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.537-539
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• 2015

considerate operation is a major issue in the equipment-intensive operation. Identifying an optimal equipment combination is important to achieve low-energy operations. An Earthwork operation planning system, which measures the energy consumption of construction operations by taking into account construction equipments' engineering attributes (e.g., weight, capacity, energy consumption rate, etc.) and operation conditions (e.g., road condition, attributes of materials to be moved, geometric information, etc.), is essential to achieve the low-energy consumption. This study develops an automated computerized system which identifies an optimal earthmoving equipment fleet minimizing the energy consumption. The system imports a standard template of earthmoving operation model and compares numerous scenarios using alternative equipment allocation plans. It finds the fleet that minimizes the energy consumption by enumerating all cases using sensitivity analysis. A case study is presented to verify the validity of the system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 춘계학술대회 논문집
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• pp.63-70
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• 2000

Light Rail is highlighted for its construction cost and operation ＆ maintenance cost in Korea. However, lack of analysis on driverless operation effect causes many disputes. In this paper, using latest driverless operation cost data. analysed cost reduction effect of it, with comparing present KNR's metropolitan subway signal system. It showed there is enough economic appropriateness B/C 1.241 on interest rate 6%, 1.076 on 8% and 0.943 on 10%, though it couldn't include passenger travel time value.

• 한국시뮬레이션학회논문지
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• 제28권4호
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• pp.33-43
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• 2019

Link-16은 미 해군 및 공군, NATO에 합동 상호운용성을 제공하는 데이터링크로 국내 무기체계에서도 운용되고 있다. 현재 Link-16 운용을 위한 시험환경, 전술모의훈련 및 상호운용성 검증 시험은 해외 SW 및 도구를 통해 전적으로 의존하고 있다. 따라서 Link-16 기반의 운용환경시험 도구의 개발이 필요하다. 본 논문에서는 Link-16 해외도구 기능 분석을 통해 Link-16 네트워크 운용성능분석 시뮬레이터를 개발하였다. 또한 연동을 위한 SIMPLE 표준 인터페이스를 구현하였다. Link-16 네트워크 운용성능분석을 위한 기능모델은 사전분석, 실시간 운용분석, 사후분석 기능모델로 구성된다. 각 기능모델에 대한 시험은 해외 SW 및 도구와 SIMPLE 연동을 통해서 수행하였다. Link-16 네트워크 운용성능분석 시뮬레이터를 통해 해외 SW를 대체하게 된다면 우리 군에 맞는 전술훈련 및 네트워크 운용성능분석, 운용(시나리오)검증을 수행할 수 있을 것이다.

• 한국군사과학기술학회지
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• 제17권6호
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• pp.744-750
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• 2014

In this paper, I have measured NCO(Network Centric Operation) Effectiveness of Anti-piracy Operation at the Chunghae Unit. For quantitative analysis, Network Centric Operations Conceptual Framework(U.S Office of Force Transformation) is applied. In accordance with the framework, the Chunghae unit anti-piracy operation scenario is analysed. The scenario is devided with two case(only voice communication and networking). The element of analysis be composed of the organic information, networking, share-ability, and individual information. As a result of analysis, the individual information of first case(only voice) gets 0.59 points. The other side, second case (networking) gets 1 points. This means that NCO has effect on the Chunghae Unit's mission. In addition, I stated the tactics advantage of NCO related a fighting power.

• 대한전기학회논문지
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• 제41권6호
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• pp.615-624
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• 1992

For the operation of the resonant DC link inverters, only limited number of modulation techniques such as the delta modulation and instantaneous current control techniques have been suggested. However, these modulation techniques have some limitations in practical operation. In this paper, the application of conventional inverter modulation techniques is suggested for the control of the resonant DC link inverter. The harmonic analysis results are presented. The results show that these modulation techniques offer good output characteristics similar to conventional inverter PWM techniques for the operation of the resonant DC link inverter. This implies that not only the delta modulation technique and instantaneous current control techniques but also various other modulation techniques can be applied to the operation of the resonant DC link inverter. This also indicates that open loop control as well as closed loop control can be used for the operation of the resonant inverter. The resonant DC link inverter with various modulation strategies is implemented using V-40 microprocessors.

• Journal of Astronomy and Space Sciences
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• 제27권4호
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• pp.393-400
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• 2010

Korea Astronomy and Space Science Institute has been developing one mobile satellite laser ranging system named as accurate ranging system for geodetic observation-mobile (ARGO-M). Preliminary design of ARGO-M operation system (AOS) which is one of the ARGO-M subsystems was completed in 2009. Preliminary design results are applied to the following development phase by performing detailed design with analysis of pre-defined requirements and analysis of the derived specifications. This paper addresses the preliminary design of the whole AOS. The design results in operation and control part which is a key part in the operation system are described in detail. Analysis results of the interface between operation-supporting hardware and the control computer are summarized, which is necessary in defining the requirements for the operation-supporting hardware. Results of this study are expected to be used in the critical design phase to finalize the design process.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1171-1176
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• 2010

Because of global warming, the new environment energy policy was already announced. The role of Green-railways is increasing in the field of railway. The government announced a policy direction of science & technology basic plan. The field of railway transportation proposed various railway transportation policy and plans. In this paper, I presented technical trend analysis for railway policy and railway operation field. Technical trend analysis at home and overseas are classified into railway industry technology, railway transportation system technology, railway operation efficiency technology, railway logistics technology.