• KIEAE Journal
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• 제7권4호
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• pp.23-30
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• 2007

In Korea, the top priority of the exterior space in the urban commercial street has been put on the road and parking for cars, not on the street for pedestrians, because of the lack of institutional urban planning, the land use of high density, the pursuit of maximum commercial profit, etc. Also, it is true that the form and facade of the street buildings which form the characteristics of the commercial street are regarded as the consumption-stimulating tool and, subsequently, are symbolized for commercial profit. This study starts from the recognition of reality, and, with the perspective of general plan for urban exterior space, tries to improve the environmental design of street space. Also, this study searches the ways to enhance the cultural, art, aesthetic and functional values of a city, as well as the ways to promote commercial activities and to perform commercial symbolism and pedestrian functions. This study aims at exploring the importance of street environmental design and the information of environmental design, so that the problems of current street environment, which generates the disorder and chaos of information, may be solved. Also, this study aims at promoting the continuous development for the future street environmental design and design plan.

• 한국기계가공학회지
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• 제14권4호
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• pp.28-33
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• 2015

In this study, the optimal design for the support and the binding device for the protection of crops for the maximum allowable stress of the shape necessary to minimize volume has been proposed. Optimization of the support and the binding device for the crops should be designed to support businesses in terms of profit, in part to reduce the material, and to profit from the ease and speed of working that part of the farmers. We used CATIA for the mechanical design and the ANSYS program for the structural analysis. Additionally, the optimization was performed by PIAnO with seven design variables for the binding device and three parameters for the support. The weight method using a multi-objective function was also determined by the Pareto optimal solution. The volume of the binding device in the optimum design result was found to be reduced by 16%, from $2.278e-005m^3to1.912e-005m^3$. From the result, we confirmed the effectiveness of the design method proposed as a multi-objective function optimization problem.

• Industrial Engineering and Management Systems
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• 제9권3호
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• pp.227-241
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• 2010

A memory module industry's supply chain usually consists of multiple manufacturing sites and multiple distribution centers. In order to fulfill the variety of demands from downstream customers, production planners need not only to decide the order allocation among multiple manufacturing sites but also to consider memory module industrial characteristics and supply chain constraints, such as multiple material substitution relationships, capacity, and transportation lead time, fluctuation of component purchasing prices and available supply quantities of critical materials (e.g., DRAM, chip), based on human experience. In this research, a directed graph-based supply network planning (DGSNP) model is developed for memory module industry. In addition to multi-site order allocation, the DGSNP model explicitly considers production planning for each manufacturing site, and purchasing planning from each supplier. First, the research formulates the supply network's structure and constraints in a directed-graph form. Then, a proposed genetic algorithm (GA) solves the matrix form which is transformed from the directed-graph model. Finally, the final matrix, with a calculated maximum profit, can be transformed back to a directed-graph based supply network plan as a reference for planners. The results of the illustrative experiments show that the DGSNP model, compared to current memory module industry practices, determines a convincing supply network planning solution, as measured by total profit.

• 한국시뮬레이션학회논문지
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• 제13권1호
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• pp.41-50
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• 2004

The purpose of this paper is to analyse the manager's policy to maximize the profit in a multiple-server queueing facility with a limited queue capacity. We assume that the level of advertizing effects on the arrival rate of customers to the facility. The model without ‘word of mouth effect’ is assumed that the arrival rate is independent on the qualify of service level. We estimate the service quality by the balking rate of customers from system. We extend this to the model with ‘word of mouth effect’. To achieve the maximum profit, the most important factor is the considerably high utilization of facility for both models. Given service rate, we should maintain an effective arrival rate to some extent. To this end, among the available options, an increase of advertizing effort is more desirable than reducing the fee if the service value of customers remains unchanged. We also investigate whether the variability of service time has a significant impact on determining the optimal policy. The cost of service variability is not so expensive as that in a single server model due to the reduced variability of service times in a multiple-server model.

• Journal of Korea Trade
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• 제23권2호
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• pp.46-58
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• 2019

Purpose - This paper analyzes how Research and Development (R&D) cartelization and Research Joint Ventures (RJV) affect firms that engage in Cournot competition in their product market using a model in which the Home and Foreign firm produce differentiated products and export their total output to a third country's market. Design/Methodology - In a two-stage game, research expenditures incurred in the first stage improve product quality and are subject to various degrees of spillovers. We consider four different scenarios. Findings - In a symmetric equilibrium we observe the following: (i) an RJV that cooperates in R&D decision yields the highest R&D expenditure. However, the scenario which yields the lowest expenditure depends on the extent of differentiation between the goods and the degree of spillovers; (ii) RJV cartelization yields the highest product quality, output, and consumer surplus in the third country; however, the lowest is produced by R&D competition if spillovers are strong and by R&D cartelization if spillovers are weak; and (iii) each firm's profit is at its minimum in R&D competition and its maximum in RJV cartelization. Furthermore, if spillovers are strong, the profit of each firm in R&D cartelization is greater than that in RJV competition, and vice versa. Originality/value - By analyzing product innovation in international markets, we can find similarities and differences between process R&D and product R&D in international markets.

• Ocean and Polar Research
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• 제37권2호
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• pp.161-177
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• 2015

This study analyzes the stock assessment of yellow croaker caught mainly by the Korean stow net and gill net fisheries focusing on single species and multiple fisheries. This study standardizes fishing efforts for the two fisheries using the general linear model and uses a surplus production model based on the exponential growth model. The Clarke Yoshimoto Pooley model estimates a maximum sustainable yield(MSY), an allowable biological catch(ABC), fishing efforts for MSY($E_{MSY}$) and for ABC($E_{ABC}$). The bio-economic model is used to estimate the maximum economic yield(MEY) and fishing efforts for MEY($E_{MSY}$). Also, the study employs an economic analysis to estimate the economic interaction between stow net and gill net fisheries. The economic analysis shows the profit accruing to the two fisheries from estimated ABC. Finally, the study compares TACs based on single species and single fishery to TAC based on single species and multiple fisheries. The study proposes that the TAC assessment is necessary for single species and multiple fisheries in order to preserve resources.

• 수산해양교육연구
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• 제27권3호
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• pp.821-832
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• 2015

The aims of this study are to estimate the optimal vessel reduction scales and these direct economic effects of coastal and offshore fisheries in the Republic of Korea. To estimate respectively optimal fishing efforts of individual fishery by species in coastal and offshore fisheries, we adopted appropriate fishing power of each species published by National Fisheries Research and Development Institute and also considered biological and socio-economic factors such as the bycatch rate, the profit rate, the efficiency of resource use, the average age of fishing vessel, the intention of vessel reduction, and the annual changes in vessels by other factors. The direct economic effects of the optimal vessel reduction in coastal and offshore fisheries based on maximum sustainable yield and 2/3 maximum sustainable yield was calculated by a cost-benefit analysis. This study showed that optimal reduction numbers of vessels engaged in coastal and offshore fisheries were 4,431 and 374 vessels and the direct economic effects in coastal and offshore fisheries were about 371.7 and 569.4 billion won and these NPV and BCR were 111.7 billion won and 1.65 and 342.6 billion won and 4.97 respectively.

• 수산해양교육연구
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• 제17권3호
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• pp.340-360
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• 2005

Fishery resource rents(i.e. windfall gains or excess profit), which tend to lead a variety of important economic, social, political problems, have been a fundamental cause of unbalance between fishery resource use and management. Thus, there may exist several sorts of optimal level of resource utilization such as economic maximum sustainable yield, biological maximum sustainable yield, social optimum production, socio-political optimum yield, etc. The fishery resource use level seems to a large extent to be determined by the characteristics of fishermen's rent seeking structure. As well known, fishery resources as common properties have a characteristic of being difficult to establish private property rights. Therefore, their use rights are controlled by the permit and/or the license system. As a result, absolute or differential rents are formed by the changes in institutional arrangements. Rent problems are often transformed into serious socio-political issues when the rent in a given industry is much higher to a socially unacceptable extent than the average of other industries. However, individual fishermen or fishermen's groups tend to behave aggressively to change the existing fishery institutions towards maximizing fishery rents. These rent-seeking behaviors often tend to nullify fishery management schemes. The larger is the relative rent difference between fisheries and other industries, the more aggressive tend to be the rent-seeking behaviors in fisheries.

• 한국산학기술학회논문지
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• 제16권12호
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• pp.8791-8799
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• 2015

본 논문에서는 편도(One-way)카셰어링 시스템을 중심으로 이벤트를 고려한 수익 개선 효과 검증을 나타내었다. 이동거리와 시간을 고려한 수익을 그래프로 나타내어 기존 해외 논문에서 검증되었던 One-way 차량 재배치 카셰어링 시스템과 현재 우리나라에서 시행되는 이벤트를 고려한 One-way 차량 재배치 카셰어링 시스템을 비교 분석하였다. 특히, 이동거리와 이용시간에 따른 최대수익을 다중선형회귀분석방법을 통해 평가하였으며, 최대손해액을 고려한 최대추정손실을 나타내었다. 이를 통해 기업이 고객들에게 다양한 마케팅 전략으로 이벤트를 활용한 할인쿠폰을 제시하여 이용고객 수요를 늘리는데 초점을 두었다. 뿐만 아니라 비선형 회귀분석을 통해 실제 이동거리와 시간에 따른 최대수익을 결정하는 상관관계 분석을 보여주고 있다.

• East Asian mathematical journal
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• 제34권5호
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• pp.683-691
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• 2018

We consider an optimal control problem for an impulsive stage-structured model involving ordinary differential equations with impulsive values of initial conditions in the next year. The main goal is to maximize a profit of the catch of Pacific cod in the South Korea through optimal harvest strategy as a control of adult cod. We established necessary conditions for the optimal harvest control using idea of Pontryagin's maximum principle. The optimal harvest strategy is to numerically solve the equation by using an iterative method with the Runge-Kutta method. Finally, we compare a monthly average of fishing mortality of Pacific cod from 2013 to 2017 with monthly fishing mortality for result obtained optimal harvest strategy.