• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 E
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• pp.1586-1588
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• 1998

To use the EMTP, in this paper, a arcing horn is simulated by non-linear resistor and inductor element using TACS, a tower by distributed parameter model, and lines as K. C. Lee model. Changing lightning current characteristics, lightning position, and tower footing resistor value, we analysis multi-phase flashover characteristics in 765 kV transmission line.

• 전기학회논문지
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• 제58권10호
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• pp.2064-2070
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• 2009

According to recent researches, apparent power in a non-sinusoidal single phase system can be represented with geometric algebra. In this paper, the geometric algebra is applied to apparent power defined in a multi-line system having transmission lines with frequency-dependency under non-sinusoidal conditions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권5호
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• pp.2509-2528
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• 2019

There are various styles of license plates for different countries and use cases that require style-specific methods. In this paper, we propose and illustrate a multi-style license plate recognition system. The proposed system performs a series of processes for license plate candidates detection, structure classification, character segmentation and character recognition, respectively. Specifically, we introduce a license plate structure classification process to identify its style that precedes character segmentation and recognition processes. We use a K-Nearest Neighbors algorithm with pre-training steps to recognize numbers and characters on multi-style license plates. To show feasibility of our multi-style license plate recognition system, we evaluate our system for multi-style license plates covering single line, double line, different backgrounds and character colors on Korean and the U.S. license plates. For the evaluation of Korean license plate recognition, we used a 50 minutes long input video that contains 138 vehicles of 6 different license plate styles, where each frame of the video is processed through a series of license plate recognition processes. From two experiments results, we show that various LP styles can be recognized under 50 ms processing time and with over 99% accuracy, and can be extended through additional learning and training steps.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.980-992
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• 2024

Steam line break accident (SLB) in the nuclear reactor is one of the representative Non-LOCA accidents in which thermal-hydraulics and neutron kinetics are strongly coupled each other. Thus, the multi-scale and multi-physics approach is applied in this study in order to examine a realistic safety margin. An entire reactor coolant system is modelled by system scale node, whereas sub-channel scale resolution is applied for the region of interest such as the reactor core. Fuel performance code is extended to consider full core pin-wise fuel behaviour. The MARU platform is developed for easy integration of the codes to be coupled. An initial stage of the steam line break accident is simulated on the MARU platform. As cold coolant is injected from the cold leg into the reactor pressure vessel, the power increases due to the moderator feedback. Three-dimensional coolant and fuel behaviour are qualitatively visualized for easy comprehension. Moreover, quantitative investigation is added by focusing on the enhancement of safety margin by means of comparing the minimum departure from nucleate boiling ratio (MDNBR). Three factors contributing to the increase of the MDNBR are proposed: Various geometric parameters, realistic power distribution by neutron kinetics code, Radial coolant mixing including sub-channel physics model.

• 한국정보전자통신기술학회논문지
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• 제9권6호
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• pp.584-590
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• 2016

본 논문에서 제안하는 "도심환경에서 통신 단절 예방을 위한 RRPS(Priority Scheduling and Multi Path Routing Protocol)"에서는 밀집도에 따라 통신의 단절이 빈번하게 일어나는 도심환경의 V2I 및 V2V통신의 단절을 최소화 하기 위하여, RSU의 관리 영역인 Start Line, End Line을 이용하여 End Line에 도달하기 전에 요청 메시지에 대한 우선순위를 적용하여 우선순위가 제일 높은 요청데이터를 먼저 처리할 수 있도록 하는 RRPS(RSU Request Priority Scheduling)알고리즘을 설계를 제안한다. 결과적으로 본 논문에서 제안하는 RRPS는 RSU내에 정보를 요청한 차량의 메시지에 대하여 우선순위 스케줄링을 적용하여 V2I의 처리효율을 향상하고, 통신 단절을 예방하여 전송 성공확률을 향상시키는 효과를 갖는다.

• 산업경영시스템학회지
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• 제40권4호
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• pp.211-220
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• 2017

The application of the theoretical model to real assembly lines has been one of the biggest challenges for researchers and industrial engineers. There should be some realistic approach to achieve the conflicting objectives on real systems. Therefore, in this paper, a model is developed to synchronize a real system (A discrete event simulation model) with a theoretical model (An optimization model). This synchronization will enable the realistic optimization of systems. A job assignment model of the assembly line is formulated for the evaluation of proposed realistic optimization to achieve multiple conflicting objectives. The objectives, fluctuation in cycle time, throughput, labor cost, energy cost, teamwork and deviation in the skill level of operators have been modeled mathematically. To solve the formulated mathematical model, a multi-objective simulation integrated hybrid genetic algorithm (MO-SHGA) is proposed. In MO-SHGA each individual in each population acts as an input scenario of simulation. Also, it is very difficult to assign weights to the objective function in the traditional multi-objective GA because of pareto fronts. Therefore, we have proposed a probabilistic based linearization and multi-objective to single objective conversion method at population evolution phase. The performance of MO-SHGA is evaluated with the standard multi-objective genetic algorithm (MO-GA) with both deterministic and stochastic data settings. A case study of the goalkeeping gloves assembly line is also presented as a numerical example which is solved using MO-SHGA and MO-GA. The proposed research is useful for the development of synchronized human based assembly lines for real time monitoring, optimization, and control.

• 생명과학회지
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• 제12권1호
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• pp.67-76
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• 2002

Agrobacterium(LBA4404/pBI1121)을 이용하여 형질전환된 애기장대 (Arabidopsis thaliana)를 대상으로 T2, T3, F3세대에서의 도입된 외래 유전자의 비활성화 현상을 조사하였다. Kanamaycin저항성 개체들의 GUS유전자 발현을 분석한 결과, T2세대에서 조사된 12계통 중 5계통에서 GUS 비활성 개체가 관찰되었다 (GUS유전자 비활성율 2.3%). Multi copy T-DNA 계통을 조사한 결과, GUS 비활성 정도가 더욱 심해짐이 관찰되었다 (5.8%). T3 세대에서 single copy T-DNA 계통들은 1.3%의 GUS 비활성율을 보인 반면, multi-copy T-DNA 계통에서의 비활성율은 12.6%로 급격히 증가하였다. 유사한 현상이 형질전환 식물체와 정상개체를 교배하여 생산된 F2 계통에서도 관찰되었다 (비활성율 9.9%). 본 실험으로 식물체에 도입된 외래 유전자가 후대에서의 전이과정동안 점진적으로 비활성화되고, 이 현상은 multi copy T-DNA 계통에서 훨씬 심각함이 밝혀졌다.

• 전자공학회논문지
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• 제50권3호
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• pp.16-22
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• 2013

n 개의 균일한 결합선로를 해석하기 위하여 2n-port 어드미턴스 매트릭스의 추출에 기초한 일반적인 특성화 절차가 제시된다. 본 논문에서는 비대칭 다중 결합선로를 해석하기 위하여 시간영역의 유한차분법을 사용하여 정규화 모드 파라미터 접근법의 적용을 제안한다. 주파수 의존적인 정규화 모드 파라미터는 2n-port 어드미턴스 매트릭스로부터 얻어지고, 이로부터 주파수 의존적인 전파상수와 유효 유전율 및 결합선로의 특성임피던스를 계산할 수 있다. 이 기법을 설명하기 위해 몇몇의 실질적인 다중 유전체상의 결합선로 구조들이 모의 실험되었으며, 특히 전도체가 유전체 사이에 내재된 형태의 선로가 해석되었다. 시간영역 유한 차분법을 활용한 결과는 Spectral Domain Method의 모의실험 결과와 비교하였고, 잘 일치함을 보였다. 시간영역의 특성화 절차에 기인한 유한차분법은 얇거나 두꺼운 혼성 구조 뿐 아니라 다층 PCB상의 다중의 전도체 결합 선로 설계를 위한 훌륭한 광대역 모의실험 도구가 됨을 볼 수 있다.

• 전기학회논문지P
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• 제59권2호
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• pp.191-196
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• 2010

The electricity distribution system in Korea is adopting a multi-grounding system. Protection of this distribution system against lightning is performed by installing overhead ground wires over the high voltage wires, and connecting the overhead ground wires to the ground every 200 m. The ground resistance in this system is limited not to exceed $50\Omega$ and overhead ground wire and neutral wire are multiple parallel lines. Although overhead ground wire and neutral wire are installed in different locations on the same pole, this circuit configuration has duplicated functions of providing a return path for unbalanced currents and protecting the distribution system against induced lightning. Therefore, the purpose of this study is to analyze the induced lightning shielding effect according to the neutral wire installation structure of a 22.9kV distribution line in order to present a new 22.9kV distribution line structure model and characteristics. This study calculated induced lightning voltage by performing numerical analysis when an overhead ground wire is present in the multi-grounding type 22.9kV distribution line structure, and calculated the induced lightning shielding effect based on this calculated induced lightning voltage. In addition, this study proposed and analyzed an improved distribution line model allowing the use of both overhead wire and neutral wire to be installed in the current distribution lines. The result of MATLAB simulation using the conditions applied by Yokoyama showed almost no difference between the induced lightning voltage developed in the current line and that developed in the proposed line. This signifies that shielding the induced lightning voltage through overhead wire makes no difference between current and proposed distribution line structures. That is, this study found that the ground resistance of the overhead wire had an effect on the induced lightning voltage, and that the induced lightning shielding effect of overhead wire is small.

• 한국통신학회논문지
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• 제30권6A호
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• pp.510-516
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• 2005

본 논문은 고속 광 이더넷에서 최소 대역폭 특성을 지닌 선로 부호에 의한 전송 성능의 개선 가능성을 제시하고자 선로 부호의 파라미터들을 조사 분석하고, 동일한 광 이더넷에서 최소 대역폭 특성이 있는 선로 부호(MB810)와 기존의 선로 부호(8B/10B)로 각각 부호화된 데이터를 전송하는 시뮬레이션을 수행하였다. 시뮬레이션 환경은 10기가비트 이더넷의 표준에 있는 Serial type LAN PHY 10GBASE-E 물리 계층을 사용한 단일 채널 전송 광 이더넷과 WDM type LAN PHY 10GBASE-LX4 물리계층을 사용한 다중 채널 전송 광 이더넷으로 구현되었다. 또 MB810 선로부호의 최소 대역폭 특성을 확인하고 두 선로부호에 의한 전송 성능을 비교하기 위하여 수신 광 파워에 따른 비트 오율(BER)을 비교하였다.