• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.298-299
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• 2011

The impacts of EV charging demands on power system such as increased peak demands may be developed by means of modeling a stochastic distribution of charging and a demand dispatch calculation. Optimization processes are proposed to determine optimal demand distribution portions so that charging costs and demands can be managed optimally. There are two optimization methods which have different effects on the outcome. These focus either on the Electric vehicle customer side (cost optimization) or the System Operator side (Load-weighted optimization).

• 한국가스학회지
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• 제10권4호
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• pp.11-16
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• 2006

본 논문에서는 현재 국제에너지기구에서 국가 에너지시스템분석에 공식적으로 사용되고 있는 시장분배모형(MARKAL: MARKet ALlocation) 모형을 이용하여 국내 발전부문의 온실가스 배출감축 잠재량평가를 위한 분석을 실시하였다. 모형 운영에 필요한 입력자료를 구축하고 4개의 시나리오를 설계하여 2040년까지의 발전기술의 구성, 특히 가스발전의 온실가스 감축에 대한 역할을 다양하게 분석하였다.

• 한국항행학회논문지
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• 제11권1호
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• pp.79-86
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• 2007

정보기술의 급격한 발전과 함께 정보보호 분야에서 다양하고 복잡한 제품 및 서비스가 등장하게 되었다. 본 연구에서는 다양하고 복잡한 네트워크 보안성과 보안성능부분에 초점을 맞추어 네트워크 보안성을 평가하기 위해 필요한 평가 시스템들을 추출하고 이들 각각을 평가할 수 있는 체크리스트와 각 시스템들이 네트워크 보안성에 얼마만큼 기여하는지를 결정하여 네트워크 보안성을 평가할 수 있는 방법을 제시하였다. 또한 네트워크 보안성능을 평가할 수 있는 평가 모델과 테스트 시에 필요한 테스트 시나리오를 제시하였다.

• Journal of information and communication convergence engineering
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• 제12권3호
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• pp.193-197
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• 2014

Edges are a robust feature for object detection. In this paper, we present an edge-based background modeling method for the detection of moving objects. The edges in the image frames were mapped using robust Canny edge detector. Two edge maps were created and combined to calculate the ultimate moving-edge map. By selecting all the edge pixels of the current frame above the defined threshold of the ultimate moving edges, a temporary background-edge map was created. If the frequencies of the temporary background edge pixels for several frames were above the threshold, then those edge pixels were treated as background edge pixels. We conducted a performance comparison with previous works. The existing edge-based moving-object detection algorithms pose some difficulty due to the changes in background motion, object shape, illumination variation, and noises. The result of the performance evaluation shows that the proposed algorithm can detect moving objects efficiently in real-world scenarios.

• Journal of Power Electronics
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• 제10권5호
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• pp.563-571
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• 2010

A model of an advanced aircraft electric power system is developed and studied under variable-speed constant-frequency (VSCF) operation. The frequency of the generator's output voltage is varied from 400-Hz to 800-Hz for different loading scenarios. Power conversions are obtained using 12-pulse power converters. To reduce the harmonic contents of the generator output waveforms, two high-pass passive filters are designed and installed one at a time at the generator terminals. The performance of the two passive filters is compared according to their losses and effectiveness. The power quality characteristics of the studied VSCF aircraft electric power system are presented and the effectiveness of the proposed filter is demonstrated through compliance with the newly published aircraft electrical standards MIL-STD-704F.

• International Journal of Automotive Technology
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• 제5권3호
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• pp.173-180
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• 2004

An intensive study was conducted for the crash worthy structural design of the recently developed Korean High Speed Train (KHST). Two main design concepts were set up to protect both crews and passengers from serious injury in heavy collision accidents, and to reduce damage to the train itself in light collision accidents. A collision against a movable 15-ton rigid obstacle at 110 kph was selected from train accident investigations as the accident scenario for the heavy collisions. A train-to-train collision at the relative velocity of 16 kph was used for the light collision. The crashworthiness behaviors of KHST were numerically evaluated using FEM. Analysis results using 1-D collision dynamics model of the full rake consist and 3-D shell element model of the front end structure showed good crashworthy responses in a viewpoint of structural design. Occupant analyses and sled tests demonstrated that KHST performed well enough to protect occupants under the considered accident scenarios. Finally our numerical approaches were evaluated by a real scale collision test.

• Structural Engineering and Mechanics
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• 제40권3호
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• pp.297-313
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• 2011

As bridge conditions in the United States continue to deteriorate, rapid bridge replacement procedures are needed. Decked precast prestressed concrete (DPPC) girders are used for rapid bridge construction because the bridge deck is precast with the girders eliminating the need for a cast-in-place slab. One of the concerns with using DPPC girders as a bridge construction option is the durability of the longitudinal joints between girders. The objectives of this paper were to propose a method to use a spring element modeling procedure for representing welded steel connector assemblies between adjacent girders in DPPC girder bridges, perform a preliminary study of bridge performance under multiple loading scenarios and bridge configurations, and discuss model flexibility for accommodating future field data for model verification. The spring elements have potential to represent the contribution of joint grout materials by altering the spring stiffness.

• Earthquakes and Structures
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• 제12권1호
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• pp.47-54
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• 2017

Introduction of robustness index in the structure is done in three ways: deterministic robustness index, probabilistic robustness index, and risk-based robustness index. In past decades, there have been numerous researches to evaluate robustness index in both deterministic and probabilistic ways. In this research, by using a risk analysis, a risk-based robustness index has been defined for the structure. By creating scenarios in accordance with uncertainty parameters of critical and unexpected gas blast accident, a new method has been suggested for evaluating risk-based robustness index. Finally, a numerical example for the evaluation of risk-based robustness index of a four-storey reinforced concrete moment frame, designed and built based on Eurocode 8 code, has been presented with results showing a lower risk of robustness.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.769-771
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• 2005

Interconnection of electric power systems, as an alternative for energy cooperation under regional economic bloc, has been under extensive debate before progressing the restructure in electric power industry and rapidly expanded in many regions after 1990s. Especially, since northeast asia has strong supplementation in resource, load shape, fuel mix etc., electric power system interconnection in this region may bring considerable economic benefits. In this paper, we evaluate economic benefits from CO2 emission abatement and effectiveness on the fuel mix in Korea by the interconnection in northeast asia. For this analysis, we evaluate effects of CO2 emission abatement under various system interconnection scenarios and compare the results of fuel mix in Korean electric power system with and without transacted electricity via interstate electric power system in northeast asia.

• 한국철도학회논문집
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• 제10권2호
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• pp.131-136
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• 2007

In this paper, the methodology to predict the number of deaths and possible fire propagation scenarios will be described in case of fire on a train in a tunnel. We use a probabilistic analysis method for the evaluation of possibility for each scenario and the deaths tolls are calculated with the help of the passenger evacuation simulation program. The resulting safety of passengers is displayed on a F/N graph, which could be used in part as a guideline to predict the safety level of the tunnel in fire.