• Proceedings of the Plant Resources Society of Korea Conference
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• 2001.11b
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• pp.67-67
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• 2001

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.3937-3954
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• 2014

With the increasing electricity consumption and the wide application of renewable energy sources, energy auction attracts a lot of attention due to its economic benefits. Many schemes have been proposed to support energy auction in smart grid. However, few of them can achieve range query, ranked search and personalized search. In this paper, we propose an efficient multi-keyword range query (EMRQ) scheme, which can support range query, ranked search and personalized search simultaneously. Based on the homomorphic Paillier cryptosystem, we use two super-increasing sequences to aggregate multidimensional keywords. The first one is used to aggregate one buyer's or seller's multidimensional keywords to an aggregated number. The second one is used to create a summary number by aggregating the aggregated numbers of all sellers. As a result, the comparison between the keywords of all sellers and those of one buyer can be achieved with only one calculation. Security analysis demonstrates that EMRQ can achieve confidentiality of keywords, authentication, data integrity and query privacy. Extensive experiments show that EMRQ is more efficient compared with the scheme in [3] in terms of computation and communication overhead.

• The Journal of Fisheries Business Administration
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• v.23 no.2
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• pp.101-128
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• 1992

How to distribute fisheries catches from producer to consumer is very important for everybody joined fisheries marketing channels (FMC), because most people are influenced their revenue and expenditure through marketing channels. Many institutions in Korea after 1960's have tried to develop the rationalization of FMC, but they have not gotten the satisfactory results in general in spite of a lot fruits. Comparing with general manufacturing industry, the fisheries industry has some specializations in the marketing channels. It makes them unique structure included wholesale market system similiar to fresh (perishable) food market with expertised technology. Wholesale market collects, distributes the fisheries catches and evaluates in by auction or bidding without consideration of producer's opinion. It is very necessary institution to make a decision to equatible price for fresh food and to play an important role for marketing effectiveness with minimum total transation and with massed reserve among institutions. But it has two weak points to increase the marketing cost and to make products bad fresh (perishable). Therefore, both Producer and consumer want to find the direct channels not to pass through wholesale market and to get more profit. I wanted to explain what problems of traditional FMC are and why the direct channel is necessary as follows in this paper. Chapter II : The types and specialization of FMC Chapter III : The structure and problem of fisheries wholesale market channel Chapter IV Marketing cost of FMC and direct channel I suggested when the direct channel in FMC is designed, new planner must carry out marketing functions which are performanced by wholesaler, middle man and the joined members of auction at wholesale market. In view of consumption area, these functions are : (1) the finding of production partner to make a business ; (2) communication of information ; (3) collecting ; (4) distribution ; (5) selecting and grading ; (6) evaluating ; (7) financing and payment ; (8) organization, in view of consumption area. The government must support also the group or individual of new direct channels to succeed it with (1) furnishing of market information (2) supplying of land and facility (3) financing (4) feed-back of dierct channels totally (5) making an opportunity of communication between producer and consumer. I want to emphasize again wholesale market is necessary and important institution for equatible price of fresh food in spite of the its weak points. At the same time. the direct channels are necessary to reduce the marketing cost and to keep better fresh food.

• Journal of Electrical Engineering and Technology
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• v.6 no.4
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• pp.493-504
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• 2011

The present paper presents a genetic algorithm (GA) to maximize social welfare and perform congestion management by optimally placing and sizing one Thyristor-Controlled Series Capacitor (TCSC) device in a double-sided auction market. Simulation results, with line flow constraints before and after the compensation, are compared through the Sequential Quadratic Programming SQP method, and are used to analyze the effect of TCSC on the congestion levels of modified IEEE 14-bus and 30-bus test systems. Quadratic, smooth and nonsmooth (with sine components due to valve point loading effect) generator cost curves, and quadratic smooth consumer benefit functions are considered. The main aims of the present study are the inclusion of customer benefit in the social welfare maximization and congestion management objective function, the consideration of nonsmooth generator characteristics, and the optimal locating and sizing of the TCSC using real code-based GA to guarantee fast convergence to the best solution.

• KIEE International Transactions on Power Engineering
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• v.5A no.1
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• pp.85-92
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• 2005

In this paper, Nash equilibriums of generation markets are investigated using a game theory application for simplified competitive electricity markets. We analyze the characteristics of equilibrium states in N-company spot markets modeled by uniform pricing auctions and propose a new method for obtaining Nash equilibriums of the auction. We assume that spot markets are operated as uniform pricing auctions and that each generation company submits its bids into the auction in the form of a seal-bid. Depending on the bids of generation companies, market demands are allocated to each company accordingly. The uniform pricing auction in this analysis can be formulated as a non-cooperative and static game in which generation companies correspond to players of the game. The coefficient of the bidding function of company-n is the strategy of player-n (company-n) and the payoff of player-n is defined as its profit from the uniform price auction. The solution of this game can be obtained using the concept of the non-cooperative equilibrium originating from the Nash idea. Based on the so called residual demand curve, we can derive the best response function of each generation company in the uniform pricing auction with N companies, analytically. Finally, we present an efficient means to obtain all the possible equilibrium set pairs and to examine their feasibilities as Nash equilibriums. A simple numerical example with three generation companies is demonstrated to illustrate the basic idea of the proposed methodology. From this, we can see the applicability of the proposed method to the real-world problem, even though further future analysis is required.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.461-469
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• 2019

The aim of this study was to analyze the contribution of carcass traits (backfat thickness, eye muscle area, carcass weight and marbling score) and the season at slaughter to the price (auction and market) using squared semi-partial correlation. The season at slaughter (summer expressed as season_2, autumn as season_3, and winter as season_4) were added into the estimation as dummy variables, and spring was set as a default variable. In this study, the carcass grades of 22,298 Hanwoo steers slaughtered from 2012 to 2017 were used to performmultiple regression analysis. The rankings of the contribution of the carcass traits and the seasons at slaughter to the auction prices were in the order of marbling score (68.63%), season_4 (11.88%), backfat thickness (10.45%), eye muscle area (6.11%), season_3 (2.19%), season_2 (0.45%) and carcass weight (0.28%). (R-square of the regression = 0.4101). The rankings of the contribution to the total prices were in the order of carcass weight (51.74%), marbling score (32.12%), season_4 (6.04%), backfat thickness (5.54%), eye muscle area (3.22%), season_3 (1.14%), and season_2 (0.19%). (R-Square of the regression = 0.6486). As a result, season_3 and season_4 had a negative effect on the auction price and total price. Because of seasonal event such as Korean Thanksgiving Day and Korean New Year's Day on season_3 and season_4, much supply was needed to meet the high demand. Thus, the seasonal effect at slaughter could be another factor to be cosideredin when considering of slaughter or breeding.

• The KIPS Transactions:PartB
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• v.8B no.6
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• pp.601-608
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• 2001

The automated assignment of multiple tasks to executing agents is a key problem in the area of multi-agent systems. In many domains, significant savings can be achieved by reallocating tasks among agents with different costs for handling tasks. The automation of task reallocation among self-interested agents requires that the individual agents use a common negotiation protocol that prescribes how they have to interact in order to come to an agreement on "who does what". In this paper, we introduce the multi-agent Traveling Salesman Problem(TSP) as an example of task reallocation problem, and suggest the Vickery auction as an interagent negotiation protocol for solving this problem. In general, auction-based protocols show several advantageous features: they are easily implementable, they enforce an efficient assignment process, and they guarantce an agreement even in scenarios in which the agents possess only very little domain-specific Knowledge. Furthermore Vickrey auctions have the additional advantage that each interested agent bids only once and that the dominant strategy is to bid one′s true valuation. In order to apply this market-based protocol into task reallocation among self-interested agents, we define the profit of each agent, the goal of negotiation, tasks to be traded out through auctions, the bidding strategy, and the sequence of auctions. Through several experiments with sample multi-agent TSPs, we show that the task allocation can improve monotonically at each step and then finally an optimal task allocation can be found with this protocol.

• The Journal of Information Systems
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• v.14 no.2
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• pp.55-74
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• 2005

In order to purchase a product cheaper, a lot of customers have been trying to search one or more marketplaces. Ever since the commercial use of the Internet, several types of marketplaces have been operating successfully on the Internet. Some of them are online shopping malls, auction markets, and group-buying markets. They have the price settlement mechanisms of their own. Online shopping malls where many stores are located support a customer to purchase the product that matches his/her requests such as price, function, design, and so forth. In online auction market, a customer can buy the product by making bids sequentially and competitively until a final price is reached. In online group-buying market, a customer can purchase the product by aggregating the orders from several buyers so that cheaper prices can be negotiated. The cheaper customers could purchase the same product item, the more satisfied they would be. However, it is very difficult for the customer to determine the marketplace to purchase, considering different kinds of marketplaces at the same time. Even though the purchasing price is cheapest in one marketplace, it is very difficult for customers to convince it the cheapest for all marketplaces. Therefore, rules and methods have been developed for purchase decision making in multiple marketplaces to reach the optimal purchase decision as a whole. They can maximize customer's utility and resolve the conflicts with other marketplaces through multi-agent negotiation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.39-51
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• 2002

Online exchange is a cost-effective approach to trade goods and information among multiple sellers and buyers. Shipping industry includes lots of global entities such as shippers, liners, ship owners and shipping agents. Marine insurance companies and ship repairers and many other groups are also supporting the industry. However, international shipping exchanges are located on few cities in the world. Its our motivation that a shipping market can be online so that market participants do the dealing while sitting where they are with more efficient manner, preferable price and larger pool of candidates of trading partners. This paper presents Korean governmental project of building a cyber shipping exchange. The exchange covers ship sale and purchase, charter, insurance, freight futures, repairs, supplying of ships oil and database service. The workflows of each business were analyzed and designed to fit for online environment. The project includes design of trading mechanism, online documents, data flow, data storage and security. Online match making and trading mechanisms such as auction, reverse auction, bid are used. The whole trading process involves multiple organizations and business processes. So, this Paper focuses on how each organization would play their roles so that users can complete transactions with integrated and transparent view. The online exchange selves also as maritime portal site that links to other sites for cooperation vertically or horizontally, and serves database and information in global perspective. This paper also issues and discusses the justification of an online shipping exchange

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.11a
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• pp.437-452
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• 2006

Previous research on two-sided markets has, for the most part, concentrated on indirect network externalities between buyers and sellers. This paper considers direct competition effect among sellers and among buyers as well as indirect network externalities. We develop an analytic model of C2C e-marketplaces and examine whether a monopolistic incumbent could successfully deter new entry into its market. We find that the effect of the number of sellers or buyers on the price of goods depends on whether sellers have decided to sell the goods using an auction or fixed pricing rule and on the characteristics of the goods. We argue that when the effect of the number of sellers on the price of goods is significantly larger than that of buyers, there is a high possibility of entry. In particular, we show that entry becomes more difficult to deter as fixed-price format is adopted more frequently or the proportion of collectables is relatively low.