• 한국지능시스템학회논문지
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• 제19권1호
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• pp.62-68
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• 2009

수정된 PCX(parent-centric recombination) 연산자와 결합한 두 가지 새로운 세대차 모델이 제안된다. 첫째, 자가적응 세대차 모델(SGG, self-adaptation generation gap)은 자손에 의한 부모의 대치 확률을 일정한 수준으로 유지하는 제어 방식이다. 둘째, 가상 클러스터 세대차(VCGG, virtual cluster generation gap)는 클러스터링을 통해 부모간의 거리를 조정해 주며, 이로 인해 개체들이 다양화 될 수 있다. 이 모델에서 부모간의 거리는 클러스터의 크기로 조절된다. 제안된 두 가지 접근법의 효용성을 입증하기 위해서 3 가지 표준적인 문제에 대한 실험이 수행되었다. 가장 최근의 경쟁력 있는 접근법인 CMA-ES와 G3-PCX와 비교한 결과, 제안된 두 기법 모두 기존의 접근법들 보다 우수함을 보여준다.

• Industrial Engineering and Management Systems
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• 제8권1호
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• pp.22-28
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• 2009

We consider facility layout problems, where mn facility units are assigned into mn cells. These cells are arranged into a rectangular pattern with m rows and n columns. In order to solve this cell type facility layout problem, many approximation algorithms with improved local search methods were studied because it was quite difficult to find exact optimum of such problem in case of large size problem. In this paper, new algorithms based on Simulated Annealing (SA) method with two neighborhood generation methods are proposed. The new neighborhood generation method adopts the exchanging operation of facility units in accordance with adjacent preference. For evaluating the performance of the neighborhood generation method, three algorithms, previous SA algorithm with random 2-opt neighborhood generation method, the SA-based algorithm with the new neighborhood generation method (SA1) and the SA-based algorithm with probabilistic selection of random 2-opt and the new neighborhood generation method (SA2), are developed and compared by experiment of solving same example problem. In case of numeric examples with problem type 1 (the optimum layout is given), SA1 algorithm could find excellent layout than other algorithms. However, in case of problem type 2 (random-prepared and optimum-unknown problem), SA2 was excellent more than other algorithms.

• 한국IT서비스학회지
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• 제9권4호
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• pp.243-259
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• 2010

It is expected that the next generation mobile communication system will be a service-driven developed system capable to realize the human-centric mobile convergence services. and it is different from the technology-driven development approach of the second and the third generation mobile communication systems. As a preliminary research work on such service-driven system development approach for the next generation mobile communication system. we developed the scenario based service analysis process (2SAP) framework to derive core service technologies and functionalities. In this paper. we propose the next generation mobile convergence service business model creation methodology based on research results of the 2SAP framework. To achieve this goal, we first establish a service model contains several components such as infrastructures. operations. and provision of services that are indispensible for providing next generation mobile services. Then, the next generation mobile services and its corresponding business models can be created by adding service and value flows to the developed service model after defining necessary components of business model including actors, their relationships, and roles.

• 산업공학
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• 제20권2호
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• pp.186-194
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• 2007

Recent deregulation of Korean electricity industry has made each power generation company pay more attention to maximizing its own profit instead of minimizing the overall system operation cost while guaranteeing system security. Electricity power generation problem is typically defined as the problem of determining both the on and off status and the power generation level of each generator under the given fuel constraints, which has been known as Profit-Based Unit Commitment (PBUC) problem. To solve the PBUC problem, the previous research mostly focused on devising Lagrangian Relaxation (LR) based heuristic algorithms due to the complexity of the problem and the nonlinearity of constraints and objectives. However, these heuristic approaches have been reported as less practical in real world applications since the computational run time is usually quite high and it may take a while to implement the devised heuristic algorithms as software applications. Especially when considering long-term planning problem which spans at least one year, the complexity becomes higher. Therefore, this paper proposes an explicit column generation algorithm using power generation patterns and the proposed algorithm is successfully applied to a Korean power generation company. The proposed scheme has a robust structure so that it is expected to extend general PBUC problems.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.981-986
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• 2003

Recently, a fuel cell is remarkable for new generation system. The fuel cell generation system converts the chemical energy of a fuel directly into electrical energy. The fuel cell generation is characterized by low voltage and high current. For connecting to utility, it needs both a step up converter and an inverter. The step up converter makes DC link and the inverter changes D.C to A.C. In this paper, full bridge converter and the single phase inverter are designed and installed for fuel cell. Simulation and experiment verify that fuel cell generation system could be applied for the distributed generation.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1460-1470
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• 2015

This paper presents an approach to solve the long-term generation expansion planning problem of the restructured electricity industry using an agent-based environment. The proposed model simulates the generation investment decisions taken by a particular agent (i.e. a generating company) in a market environment taking into account its competitors’ strategic investment. The investment decision of a particular company is modeled taking into account that such company has imperfect foresight on the future system development hence electricity prices. The delay in the construction of new plants is also explicitly modeled, in order to compute accurately the yearly revenues of each agent. On top of a conventional energy market, several capacity incentive mechanisms including capacity payment and capacity market are simulated, so as to assess their impact on the investment promotion for generation expansion. Results provide insight on the investment cycles as well as dynamic system behavior of long-term generation expansion planning in a competitive electricity industry.

• 한국수정란이식학회지
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• 제10권1호
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• pp.73-82
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• 1995

large scale production of cloned embryos requires the technology of multiple generation nuclear transplantation(NT) using NT embryos as the subsequent donor nuclei. The purposes of this study were producing the second generation cloned rabbit embryos, and also to determine the electrofusion rate and in vitro developmental potential comparatively in the cloned embryos of the first and second NT generation. The embryos of 16-cell stage were collected from the mated does by flushing oviducts with Dulbecco's phosphate buffered saline(D-PBS) containing 10% fetal calf serum(FCS) at 47 hours after hCG injection In the first generation NT, the nuclear donor embryos were synchronized in the phase of Gi /S transition of 32-cell stage. The first generation NT embryos which were developed to 8-cell were synchronized in Gi /S transition phase of the following 16-cell stage and used as donor nuclei for second generation Synchronization of the cell cycle of blastomeres was induced, first, using an inhibitor of microtuble polymerization, colcemid for 10 hours to arrest blastomeres in M phase, and secondly, using a DNA synthesis inhibitor, aphidicolin for 1.5 to 2 hours to arrest them in Gi /S transition boundary. The recipient cytoplasms were obtained by removing the nucleus and the first polar body from the oocytes collected at 14 hours after hCG injection. The separated donor blastomeres were injected into the enucleated recipient oocytes by micromanipulation and were electrofused by electrical stimulation of three pulses for 60 $\mu$sec at 1.25 kV /cm in 0.28 M rnannitol solution The fused oocytes were co-cultured with a monolayer of rabbit oviductal epithelial cells in M-199 solution containing 10% FCS for 120 hours at 39$^{\circ}C$ in a 5% $CO_2$ incubator. Following in vitro culture of the first and second generation cloned embryos to blastocyst stage, they were stained with Hoechst 33342 dye for counting the number of blastomeres by fluorescence microscopy. The results obtained were summarized as follows: 1. The electrofusion rate was found to be similar as 79.4 and 91.5% in the first and second generation NT rabbit embryos, respectively. 2. The in vitro developmental potential to blastocyst stage of the second generation NT embryos (23.3%) was found significantly(p<0.05) lower, compared with that of the first generation NT embryos (56.8%). 3. The mean blastomeres counts of embryos developed to blastosyst stage following in vitro culture for 120 hours and also their daily cell cycles during the culture period were decreased significantly (p<0.05) to 104.3 cells and 1.33 cylces in the second NT generation, compoared with 210.4 cells and 1.54 cycles in the first NT generation, respectively.

• 토지주택연구
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• 제11권1호
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• pp.21-38
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• 2020

This study examined the population movement of the young generation in accordance with the characteristics of housing market focusing on the housing problem of youth issues. Targeting 64 local governments in the seoul metropolitan area, the temporal range was decided as 2015. Setting up the rising population in 19-34 as a dependent variable, supposing that each age group shows different characteristics, it was divided into age groups in 19~34, 19~29, and 25~34. The population movement of the young generation in accordance with the characteristics of housing market was considered through the multiple regression analysis. In the results, the population movement of the young generation was influenced by the change in detached multi-family housing and the rate of housing supply. The increase of detached multi-family housing promoted the population inflow of the young generation while the population movement of the young generation was disturbed by the rising rate of housing supply. Also, when the local characteristics are not controlled, the young generation hesitates to enter the region where relatively high rent should be paid while the new housing supply focusing on apartment is hard to be selected by the young generation for residence because of the size and price. The population movement of the young generation looked quite different in each age group. The population inflow of the young generation in 19~29 was influenced when there were many officetels and non-apartments on top of detached multi-family housing. On the contrary, the population movement of the young generation in 25~34 was significantly influenced by the increase of the whole size of completed apartment area. Even though it was not the research subject of this study, among control variables, the financial independence and daily average number of get-on/off had effects on the movement of the young generation. It means that the housing type preferred by college students and social novices is different from the housing type preferred by the group with experiences in marriage and childbirth within the same young generation. Thus, it would be necessary to divide the purposes of policies for each subject when executing the youth housing policies.

• 한국컴퓨터정보학회논문지
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• 제25권11호
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• pp.245-253
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• 2020

본 연구는 한국복지패널(KOWEPS) 자료를 활용하여 역사적 배경, 성장배경, 가치관, 라이프 스타일 등이 서로 다른 X세대와 Y세대의 삶의 만족도를 종단적으로 분석하는 연구이다. 연구 자료는 한국복지패널의 1차 년도(2006년)부터 14차 년도(2019년) 까지 이루어진 27,301명 중에서 삶의 만족도를 실시한 최근 12차 년도부터 14차 년도까지 응답이 제대로 이루어진 2,492명의 3개년도 자료를 활용하였다. 연구 결과 X세대와 Y세대 모두 삶의 만족도가 높은 세대일수록 시간이 경과 함에 따라 느린 속도로 삶의 만족도가 천천히 증가한다는 것이다. 또한 X세대와 Y세대 모두 생활 만족도가 높을수록 삶의 만족도 초기값은 높게 나타났으나, X세대의 경우 생활 만족도가 높을수록 3년 동안 삶의 만족도 변화율은 .327이 낮아지고, Y세대의 경우에는 삶의 만족도 변화율에 영향을 미치지 않았다. 최종적으로 본 연구의 모형은 생활 만족도와 삶의 만족도 경향성 사이에서 건강 상태의 부분 매개가 성립하여 생활 만족도는 삶의 만족도에 직접적으로 영향을 미치고 동시에 건강 상태를 매개변수로 하여 간접적으로 영향을 미치는 것으로 분석되었다.

• 전자공학회논문지CI
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• 제48권3호
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• pp.11-17
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• 2011

본 논문에서는 기존의 아날로그 공간에서 이루어지는 시나리오 생성의 한계를 극복하기 위해 Social Network Service 기술을 이용하여 대중의 참여를 극대화시킨 소셜 시나리오 생성 방법을 제안한다. 소셜 시나리오 생성 방법은 시나리오의 표현 기술에만 쓰이던 디지털 기술을 시나리오 생성에 도입하여 정보의 질까지 향상시킬 수 있다는 점에서 큰 의미가 있다. 기존의 시나리오 생성은 작가 개인의 창작이었기 때문에 전문분야의 이야기를 다룰 때 어려움이 있었고, 개인의 주관적인 생각에 치우치기 쉬웠다. 디지털 시나리오 작성 프로그램들의 등장은 시나리오의 형식을 정형화시켰으나 여전히 이 한계점은 해결하지 못했다. 때문에 디지털 공간에서 시나리오를 작성한다 하더라도 여전히 시나리오 생성은 작가 개인의 생각에만 의지하고 있다. 이러한 한계를 극복하는 방법으로 작가가 많은 사람들의 의견과 관련 정보 중에서 가장 최신의 정보들을 수용할 수 있는 SNS를 이용한 소셜 시나리오 생성 방법을 제안한다.