• 한국ITS학회:학술대회논문집
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• 2004.11a
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• pp.338-342
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• 2004

• Journal of the Korean Mathematical Society
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• v.39 no.5
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• pp.745-764
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• 2002

In this paper we Study a time-optimal model of pursuit in which the players move on a plane with bounded velocities. This game is supposed to be a nonzero-sum group pursuit game. The main point of the work is to construct and compare cooperative and non-cooperative solutions in the game and make a conclusion about cooperation possibility in differential pursuit games. We consider all possible cooperations of the players in the game. For that purpose for every game $\Gamma(x_0,y_0,z_0)$ we construct the corresponding game in characteristic function form $\Gamma_v(x_0,y_0,z_0)$. We show that in this game there exists the nonempty core for any initial positions of the players. The core can take four various forms depending on initial positions of the players. We study how the core changes when the game is proceeding. For the original agreement (an imputation from the original core) to remain in force at each current instant t it is necessary for the core to be time-consistent. Nonemptiness of the core in any current subgame constructing along a cooperative trajectory and its time-consistency are shown. Finally, we discuss advantages and disadvantages of choosing this or that imputation from the core.

• Journal of Distribution Research
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• v.2 no.1
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• pp.143-174
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• 1997

The model applied in this paper is based on the theory of economic order quantity (EOQ). EOQ model is introduced to explain the improvement of the transaction efficiency through the cooperative purchase. We examine explicitly how horizontal cooperation affects vertical transactions. A result of the analysis is that a seller can prefer transacting with a cooperative rather than with each buyer separately, even if he reduces the selling price of the product. Without increasing the demand for the product, this result is that dealing with a cooperative, rather than separately with each buyer, decreases the transaction cost for the seller-buyers system, the cost reduction more than off-setting the effect of price decrease on the sellers profit. For a coopative consisting of any number of buyers, Pareto efficient ordering policies that maximize the joint cost saving for the seller-buyers system are identified. We then discuss the conditions under which a cooperative under consideration can be modified to increase efficiency gain. Next, we relax the assumption that all buyers participate in a single cooperative and examine the issue of how many cooperatives, each consisting of a subset of the buyers, should be formed to maximize the total cost saving for the seller-buyers system. Finally, the issue of shapley value to divide the cooperatives gain among its members is discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2B
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• pp.269-278
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• 2010

In the clustering protocol, lifetime of the cluster members radically decrease because frequency interference between clusters make every cluster member consume a lot of energy to maintain or increase its transmission rate. In this paper, we analyze the frequency interference among the clusters with the game theory which deals with resource bargaining problems between players, and present a rational power allocation strategy. Both the cases that each cluster tries to selfishly occupy and cooperatively share the resource are analyzed in terms of non-cooperative and cooperative games. In simulation, we compare the cooperative game with non-cooperative game in terms of the node lifetime.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.11
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• pp.4483-4501
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• 2015

In this paper, we investigate a security transmission scheme at the physical layer for cooperative wireless relay networks in the presence of a passive eavesdropper. While the security scheme has been previously investigated with perfect channel state information(CSI) in the presence of a passive eavesdropper, this paper focuses on researching the robust cooperative relay beamforming mechanism for wireless relay networks which makes use of artificial noise (AN) to confuse the eavesdropper and increase its uncertainty about the source message. The transmit power used for AN is maximized to degrade the signal-to-interference-plus-noise-ratio (SINR) level at the eavesdropper, while satisfying the individual power constraint of each relay node and worst-case SINR constraint at the desired receiver under a bounded spherical region for the norm of the CSI error vector from the relays to the destination. Cooperative beamforming weight vector in the security scheme can be obtained by using S-Procedure and rank relaxation techniques. The benefit of the proposed scheme is showed in simulation results.

• The Journal of Fisheries Business Administration
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• v.26 no.1
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• pp.79-104
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• 1995

Dividend Policy involves the decision to pay out earnings versus retaining them for reinvestment in the firm, and dividend policy decisions can have either favorable or unfavorable effects on the attainment of firm's objective. This paper is to examine the present status of dividend policy of the Pusan Cooperative Fish Market, and to suggest the optimal dividend policy decisions appropriate for achieving its objective, which is to promote the fishermen's benefits and protect the interest of consumers. There are two types of dividend that the Pusan Cooperative Fish Market pays to the equity owners : (1) dividend on capital and (2) equalized patronage dividend. During'90s, while the rate of dividend on capital ranged from 1.7% to 2.8%, that of equalized patronage dividend ranged from 13.9% to 22.9%. Therefore, the rate of total dividend on capital including revolving funds has been about 20%, which turns out to be much higher than those of companies listed in the stock market. According to the current dividend data, the Pusan Cooperative Fish Market focuses on the equalized patronage dividend and the dividen on capital is the secondary type of dividend. In addition, the interesting feature of equalized patronage dividend is that it is supposed to be reinvested into capital by the Articles of the Fish Market, as soon as the Fish Market pays it to its members. Finally, this paper suggests the rational dividend policy of the Fish Market that is able to help its objective to be achidved more efficiently. The overall direction of the rational dividend policy can be summarized as follows ; (1) The level of cash dividend on capital should be increased enough to reflect the market interest rate. (2) The subsidy of working capital to some member fisheries cooperatives as quasi- dividend should be cut off steadily. (3) The equalized patronage dividend should be replaced by the original patronage dividend whose level is determined by the volume of each member's purchase. (4) In the long-term, it is necessary to improve the system of revolving funds in the way that revoloving funds could serve to complement equity capital for only a fixed time, after which they ard repaid to the members.

• Journal of Acupuncture Research
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• v.33 no.4
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• pp.109-119
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• 2016

Objectives : The aim of this study is to give a statistical basis for the characteristics of patients who received cooperative medical care after being referred from Western medical departments to the Department of Acupuncture and Moxibustion in a Korean medical hospital. Methods : The request records were searched for cooperative medical treatment at the Department of Acupuncture and Moxibustion in a Korean medical hospital between September 1st, 2011 and August 31, 2016, based on the Order Communication system(OCS). The records were reviewed and retrospectively analyzed according to the patient's general characteristics, the chief diagnosis code based on the 7th Korean standard classification of diseases(KCD-7) before and after the cooperative medical care in the Department of Acupuncture and Moxibustion, and the actual treatment measures which patients received as a result of the cooperative medical care. Results : Among the 2702 records, 1549 patients were included in the analysis. The male to female ratio was 1 : 1.17. Sexagenarians formed the highest age group and the number of patients whose age was over 50 was 1176(75.92 %). The surgery department requested the cooperative care from the department of Acupuncture and Moxibustion for the highest number of patients, 1194(77.08 %). When analysing specific medical departments, Neurosurgery, General Surgery, Neurology, Otorhinolaryngology, and Physical medicine and rehabilitation followed. The frequency of chief diagnosis code used before the cooperative medical care was in the order of I, C, G, S, and M code, from highest to lowest. The order of the codes after the cooperative medical care was the same. Acupuncture treatment was the most frequently-used measure after the cooperative medical care. Following were infrared, moxibustion, transfer, herbal acupuncture, cupping, electroacupuncture, and so on. Conclusion : This study provides a statistical basis for the demands placed on the Department of Acupunture and Moxibustion for cooperative medical care with the Western medical department. Based on the present condition of cooperative medical care, more preparation and effort is required for its activation.

• Korean Management Science Review
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• v.17 no.3
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• pp.73-95
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• 2000

In Korea, the distribution channel for agricultural products is notorious for its complexity and ineffectiveness. In this sense, the Agricultural Cooperative has tried to clarify the distribution channel and reduce its length. However, there still exist much room for improvements. The Internet shopping mall specific for agricultural product, therefore, is drawing much attention because it can reduce the length of distribution channel drastically and improve effectiveness from the distribution perspective. To test the validity of such Internet-driven shopping mall, we gathered questionnaire data from the Internet based Hannaro Shopping Mall which is run directly by the Agricultural Cooperative. We performed experiments respectively for the two groups of operating personnel and consumers. Experimental results showed that several important factors can be identified which are significant statistically and deemed to have meaningful relationship with performance variables. Our results also showed that the Internet shopping mall has a great potential for improving the effectiveness of the distribution channel of the agricultural products.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3024-3026
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• 1999

This paper presents a cooperative action controller of a multi-agent system. To achieve an object, i.e. win a game, it is necessary that a robot has its own roles, actions and work with each other. The presented incorporated action controller consists of the role selection, action selection and execution layer. In the first layer, a fuzzy logic controller is used. Each robot selects its own action and makes its own path trajectory in the second layer. In the third layer, each robot performs their own action based on the velocity information which is sent from main computer. Finally, simulation shows that each robot selects proper roles and incorporates actions by the proposed controller.

• 한국ITS학회:학술대회논문집
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• 2010.05a
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• pp.33-36
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• 2010