• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.1
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• pp.62-68
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• 2009

Two new generation gap models with modified parent-centric recombination(PCX) operator are proposed. First, the self-adaptation generation gap(SGG) model is a control method that keeps a replaced probability of parents by offspring to a certain level which obtains better performance. Second, virtual cluster generation gap(VCGG) is provided to extend distances among parents using clustering, which causes it to diversify individuals. In this model, distances among parents can be controlled by size of clusters. To demonstrate the effectiveness of our two proposed approaches, experiments for three standard test problems are executed and compared to most competing current approaches, CMA-ES and Generalized Generation Gap(G3) with PCX. It is shown two proposed methods are superior to consistently other approaches in the study.

• Industrial Engineering and Management Systems
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• v.8 no.1
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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.

• Journal of Information Technology Services
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• v.9 no.4
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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.

• IE interfaces
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• v.20 no.2
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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.

• Proceedings of the KIPE Conference
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• 2003.07b
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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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• v.10 no.4
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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.

• Journal of Embryo Transfer
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• v.10 no.1
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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.

• Land and Housing Review
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• v.11 no.1
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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.

• Journal of the Korea Society of Computer and Information
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• v.25 no.11
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• pp.245-253
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• 2020

This study is a longitudinal analysis of the life satisfaction of Generation X and Generation Y, with different historical backgrounds, growth backgrounds, values, and lifestyles, using data from the Korean Welfare Panel(KOWEPS). The research data is from the KOWEPS 1st year(2006) to 14th year(2019), out of 27,301 people, who conducted life satisfaction from the latest 12th to 14th year, and the responses were properly answered data from 3 years of 2,492 were used. As a result of the study, the higher the life satisfaction of both Generation X and Generation Y, the more the life satisfaction slowly increases at a slower rate as time passes. In addition, in terms of life satisfaction and rate of change, the initial value of life satisfaction was higher as the living satisfaction increased in both Generation X and Generation Y, but in the case of Generation X, the higher living satisfaction, the lower the rate of change in life satisfaction for 3 years by .327, in the case of Generation Y, the rate of change in life satisfaction was not affected. Finally, in the model of this study, a partial mediation of health condition was established between living satisfaction and life satisfaction tendency. Living satisfaction was analyzed to have a direct effect on life satisfaction and at the same time indirectly with a health condition as a parameter.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.3
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• pp.11-17
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• 2011

In this paper, we propose method of the social scenario generation that maximize public`s participation taking advantage of a Social Network Service technology to overcome limit of scenario generation formed in existent analog space. The method is novel because digital technology was used only in storytelling, and never used in improving the quality of information introducing in scenario generation. Existent scenario generation was apt to lean in subjective thinking of individual and when handle story of professional field, there was difficulty because it was writer individual`s generation. Entrance on the stage of digital scenario generation programs was standardized form of scenario, but This limitation did not still solve. Therefore, whatever make scenario in digital space, scenario generation is still depending on only writer individual`s ideas. By method that overcome this limit, we propose social scenario generation that use SNS that writer can accommodate opinions of many people and relevant informations up to date.