• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.4
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• pp.105-123
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• 2006

Previous research on two-sided markets has, for the most part, concentrated on indirect network externalities between buyers alto 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.

• Journal of Intelligence and Information Systems
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• v.20 no.3
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• pp.93-108
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• 2014

To support business decision making, interests and efforts to analyze and use transaction data in different perspectives are increasing. Such efforts are not only limited to customer management or marketing, but also used for monitoring and detecting fraud transactions. Fraud transactions are evolving into various patterns by taking advantage of information technology. To reflect the evolution of fraud transactions, there are many efforts on fraud detection methods and advanced application systems in order to improve the accuracy and ease of fraud detection. As a case of fraud detection, this study aims to provide effective fraud detection methods for auction exception agricultural products in the largest Korean agricultural wholesale market. Auction exception products policy exists to complement auction-based trades in agricultural wholesale market. That is, most trades on agricultural products are performed by auction; however, specific products are assigned as auction exception products when total volumes of products are relatively small, the number of wholesalers is small, or there are difficulties for wholesalers to purchase the products. However, auction exception products policy makes several problems on fairness and transparency of transaction, which requires help of fraud detection. In this study, to generate fraud detection rules, real huge agricultural products trade transaction data from 2008 to 2010 in the market are analyzed, which increase more than 1 million transactions and 1 billion US dollar in transaction volume. Agricultural transaction data has unique characteristics such as frequent changes in supply volumes and turbulent time-dependent changes in price. Since this was the first trial to identify fraud transactions in this domain, there was no training data set for supervised learning. So, fraud detection rules are generated using outlier detection approach. We assume that outlier transactions have more possibility of fraud transactions than normal transactions. The outlier transactions are identified to compare daily average unit price, weekly average unit price, and quarterly average unit price of product items. Also quarterly averages unit price of product items of the specific wholesalers are used to identify outlier transactions. The reliability of generated fraud detection rules are confirmed by domain experts. To determine whether a transaction is fraudulent or not, normal distribution and normalized Z-value concept are applied. That is, a unit price of a transaction is transformed to Z-value to calculate the occurrence probability when we approximate the distribution of unit prices to normal distribution. The modified Z-value of the unit price in the transaction is used rather than using the original Z-value of it. The reason is that in the case of auction exception agricultural products, Z-values are influenced by outlier fraud transactions themselves because the number of wholesalers is small. The modified Z-values are called Self-Eliminated Z-scores because they are calculated excluding the unit price of the specific transaction which is subject to check whether it is fraud transaction or not. To show the usefulness of the proposed approach, a prototype of fraud transaction detection system is developed using Delphi. The system consists of five main menus and related submenus. First functionalities of the system is to import transaction databases. Next important functions are to set up fraud detection parameters. By changing fraud detection parameters, system users can control the number of potential fraud transactions. Execution functions provide fraud detection results which are found based on fraud detection parameters. The potential fraud transactions can be viewed on screen or exported as files. The study is an initial trial to identify fraud transactions in Auction Exception Agricultural Products. There are still many remained research topics of the issue. First, the scope of analysis data was limited due to the availability of data. It is necessary to include more data on transactions, wholesalers, and producers to detect fraud transactions more accurately. Next, we need to extend the scope of fraud transaction detection to fishery products. Also there are many possibilities to apply different data mining techniques for fraud detection. For example, time series approach is a potential technique to apply the problem. Even though outlier transactions are detected based on unit prices of transactions, however it is possible to derive fraud detection rules based on transaction volumes.

• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.126-131
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• 2007

Most Internet auction studies have focused on examining the determinants of auction success or closing price. However, there has been little previous research which investigates dark-side factors such as overbidding behavior in the Internet C2C transactions. For this reason, this study attempts to find situations with the escalation of commitment to bids using Internet auction systems and also examines whether the bidder's bidding is irrational. Therefore, this study applies escalation of commitment to explain the auction process such as the "going, going, gone period" with competition in Internet C2C auctions. In order to describe the auction process in terms of escalation of commitment, this study proposes psychological sunk costs, completion effect, and self-justification as the key factors of escalation of commitment and also willingness to continue bidding reflecting the decision maker's escalation behavior in terms of persistence perspective as final dependent variable. The results of PLS analysis indicate that a bidder's overbidding behavior is explained by the escalation of commitment.

• Proceedings of the Safety Management and Science Conference
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• 2002.11a
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• pp.295-304
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• 2002

This case describes key development challenges and patterns as experienced by Internet Auction Company, Ltd. from the startup stage through IPO to the sale to eBay. Currently an eBay company, Internet Auction Co. continues to pursue new auction systems and substitute distribution systems for the future with a renewed entrepreneurial spirit. In 1997, Mr Hyuk Oh saw a business opportunity in the Internet allowing two-way communications. At that time, the success stories of eBay and Onsale in the United States were good stimuli to his startup of an auction site. He opened the Website in April 1, 1998 after four months of development efforts. Auction has merit more than other shopping malls. First, it brings about interesting and benefit. Second, it has interactive trade system. Third, customers will trade for reasonable price through direct own will of them. Fourth, Auction's model brings about multitude sale through aggressive sales. Even if Network Marketing has socially negative effect in case of inappropriate use, it is good mood for further business. In case E-Commerce use as useful purpose, it will have competitive priority revenue model.

• Journal of Family Resource Management and Policy Review
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• v.11 no.2
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• pp.133-154
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• 2007

This research investigated consumer's usage of, evaluation on and satisfaction of the Auction Site, with a view to analyze the key factors influencing a commission paid Auction Site. The findings of results from the analysis are summarized as follows. First of all, the consumer group at the age equal to and less than 20 years old showed the highest purchasing frequency, and the consumer group with a household income less than 2,500,000 won showed the highest number of hours on the site. Secondly, the evaluation index showed that consumers think highly of the complaint resolution process, and, especially, the aged consumer group respected the Auction Site's level of confidentiality of transaction and privacy. Thirdly, among consumers' satisfaction, subdivided by types, price satisfaction was the highest followed by quality satisfaction, settlement satisfaction, delivery satisfaction, information satisfaction and AS satisfaction, in that order. Fourthly, in the event consumers used the commission paid Auction Site, the number of times it has been used, evaluations related to information provision and evaluations on confidentiality of transactions and privacy are influential parameters.

• Journal of Convergence for Information Technology
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• v.11 no.2
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• pp.31-40
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• 2021

Blockchain technology is also actively studied in the real estate transaction field, and real estate transactions have various ways. In this paper, we propose a model that simplifies the authentication procedure of auction systems using Ethereum's Ether to solve the problem of offline court auctions. The proposed model is written in Ethereum's Solidity language, the court registers the sale date and the sale date with the DApp browser, and the bidder accesses the address of the individual's wallet created through Metamask's private key. The bidder then selects the desired sale and enters the bid price amount to participate in the auction. The bidder's record of the highest bid price for the sale he wants is written on the Ethereum test network as a smart contract. and creates a block. Finally, smart contracts written on the network are distributed by the court auction manager to all nodes in the blockchain network, and each node in the blockchain network can be viewed and contract verified. As a result of analyzing the smart contracts of the proposed model and the performance of the system, there are fees incurred due to the creation and use of Ether on platforms using Ethereum, and participation. Ether's changes in value affect the price of the sale, resulting in inconsistent fees in smart contracts each time. However, in future work, we issue our own tokens to solve the market volatility problem and commission problem with the value change of Ether, and refine complex court auction systems.

• Journal of Digital Convergence
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• v.19 no.11
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• pp.255-266
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• 2021

Investment demand for factory facilities has increased due to the balloon effect caused by housing price regulation. This study investigated the impact of the real estate market and macroeconomic factors on the bid price ratio of apartment auctions and factory auctions, focusing on the metropolitan area. To this end, we reviewed theories and previous studies on real estate auctions, and examined how macroeconomic variables affect bid price ratio of apartments and factories using the panel vector autoregressive model. It was found that the increase in the apartment bid price ratio increases as the participation in apartment auctions increases. However, as the factory bid price ratio increases, the factory bid price ratio does not increase, it was confirmed that the positive (+) relationship between the successful bid price ratio and the bid price ratioe does not exist, unlike previous studies. Based on the analysis results, it is suggested that the real estate market and macroeconomic factors should be considered for the stable operation of the related relevant auction system. This study has limitations in that it is limited to the metropolitan area. In the future, research that expands the scope of research to the whole country and provinces should be conducted.

• 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.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.3 s.59
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• pp.63-73
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• 2006

Auctions have been traditionally used to find the current price of goods when little is known about their true value. A special auction methodology, called a 'simultaneous multiple round auction', is available to auction radiofrequency spectrum where all lots are simultaneously on of for over multiple rounds of bidding. This type of auction is especially useful when there are lots that are of essentially equal value and substitutable, except that different bidders may prefer different combinations of lots. By using multiple rounds, a bidder has the opportunity to gather information concerning the value of individual lots and can change strategy by shifting the bidding to another preferred combination if one combination becomes too expensive. Information is released in three main ways during an auction: Bidder Status; High Bids; and Bandwidth Value.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.445-446
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• 2022

본 논문은 시세정보를 활용한 적정한 가격으로 경매를 할 수 있는 전자상거래를 연구하였다. 일반적인 전자상거래는 물건의 적정한 가격 정보 없이 등록 및 구매가 진행된다. 하지만 본 연구는 시세 조회를 이용한 가격 비교를 통해 거래가 적합한 금액에 이루어지는지 확인할 수 있도록 가격정보를 제공한다. 경매 시스템은 일반적인 경매방식인 최저가에서 시작해 점점 가격을 올려 최후의 구매자에게 판매하는 영국식 경매와 가장 높은 금액을 제시한 순서대로 구매자들의 순위가 정해지며 1순위가 2순위의 금액에 입찰 단위 금액을 포함해 구매하는 비딩 경매를 함께 사용한다. 또한, 시간이 부족하거나 경매가 어려운 사용자들을 위해 자신이 지불할 수 있는 최고가를 설정하면 시스템이 스스로 입찰을 해주는 예약 입찰을 추가해 사용자들에게 편리함을 제공한다.