• Journal of the Korea Society of Computer and Information
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• v.27 no.3
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• pp.173-182
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• 2022

In this paper, we propose a machine learning model that can prevent fraudulent transactions in advance and interpret them using the XAI approach. For the experiment, we collected a real data set of 12,258 mobile phone sales posts from Joonggonara, a major domestic online C2C resale trading platform. Characteristics of the text corresponding to the post body were extracted using Doc2vec, dimensionality was reduced through PCA, and various derived variables were created based on previous research. To mitigate the data imbalance problem in the preprocessing stage, a complex sampling method that combines oversampling and undersampling was applied. Then, various machine learning models were built to detect fraudulent postings. As a result of the analysis, LightGBM showed the best performance compared to other machine learning models. And as a result of SHAP, if the price is unreasonably low compared to the market price and if there is no indication of the transaction area, there was a high probability that it was a fraudulent post. Also, high price, no safe transaction, the more the courier transaction, and the higher the ratio of 0 in the price also led to fraud.

• Journal of Distribution Science
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• v.15 no.1
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• pp.95-104
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• 2017

Purpose - This study focuses on long-term orientation that can lead long-term partnership. A long-term orientation needs a trust and relation commitment between company. So in this study, the researcher conducts a dependent variable as a justice recognition and brand asset value to research model to find out casual relationship among quoted factors. Research design, data, and methodology - The focus of this study was employees who work in a liquor distribution company to figure out factors that effect on long-term relationship in b2b transaction. The development of the research model is based on the literature of the preceding research analysis of justice recognition, brand asset value, trust, relation commitment and long-term orientation. This study have constructs that defined operationally by previous studies, research model design that to figuring casual relationships among the quoted factors. From 2016 Sep. 1st to Oct. 30th, a questionnaire survey was conducted targeting employees who work in liquor distribution company. 176 survey data were used for empirical analysis to prove the research hypotheses. Results - The main results of this study's empirical methodology were as follows. First, procedural justice and interactive justice has a positive significant effect on trust and relation commitment. Also brand image, brand awareness and perceived quality has a positive significant effect on trust and relation commitment. Second, trust and relation commitment has a positive significant effect on long-term orientation. Every hypothesis adopted as the researcher designed for empirical study. Conclusions - Based on empirical results, this study confirmed that trust and relation commitment has empirical relationship with long-term orientation. Based on the analysis, the researcher provided managerial implication by setting 2 way path for making long-term orientation with business company. First path is procedural justice to relation commitment. It contains that procedural justice recognised while business transaction execution, consideration intension and relation development will happen in b2b. Second path is perceived quality to trust. It contains that the perceived quality recognised while business transaction execution, trust will increase rapidly. So when a business company wants to make a partnership, they have to consider procedural justice and perceived quality to make a long-term relationship.

• Journal of Fashion Business
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• v.8 no.4
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• pp.94-103
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• 2004

The purpose of this study was to make activated electronic business transaction of clothes. The subject used for this study was 19 - 24 aged 149 college women who most likely buying products through internet. By compare the 149 women's body shape with 3D model, 149 women could be judged their body shape objectively. We showed the average 3D model by the measurement of 19 - 24aged women's body shape. 19 - 24aged women are big customer of internet shopping mall. By understanding of the difference between real somatotype and perceptual somatotype, we can reduce the disadvantage such as returning clothes. Also, imaginary fitting model can be used for internet shopping mall, animation work, fashion show, and advertisement work. Therefore, we can expect the worth of this study to do.

• Korean Management Science Review
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• v.17 no.3
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• pp.97-118
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• 2000

This paper proposes an evaluation model for internet shopping mall business by defining its characteristics and evaluation criteria. We analyzed the characteristics of internet shopping mall business environments and classified the business into four major categories. We derived the evaluation criteria which can evaluated all categories comprehensively. The proposed criteria are cost, netizen, technology, transaction, and marketing, each of which gives a significant impact on the business profitability. Based on these criteria, a quantitative evaluation method was developed. We also proposed a penta-classification scheme which can be used to identify the overall characteristics shape of each internet shopping mall business site. An actual application of our evaluation model was illustrated in order to show that our proposed model may be used in the real business sites.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.896-898
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• 2005

게임이론에서의 기본적인 Cournot Model과 같은 형태는 실제 전력 시장에서의 복잡성을 모두 반영하지는 못한다. Pool 기반 전력시장에서의 송전과 가격 결정은 명백하게 전송 제약뿐만 아니라 ancillary service의 상호간의 최적화도 고려되어야하기 때문이다. 이 논문은 다중재화의 상호간 최적화를 다루는 다중시장의 Cournot Model을 확장시킨 모델의 해석과 사례연구를 논한다. 사례연구로는 제주도 전력 시장의 형태를 적용시켜 2개 발전사업자가 2개의 상품을 가지고 경쟁할 때의 최적화를 MATLAB을 이용하여 구현해본다.

• Industrial Engineering and Management Systems
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• v.16 no.1
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• pp.118-128
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• 2017

Uncertain factors in finical markets make the prediction of future returns and risk of asset much difficult. In this paper, a model,assuming the admissible errors on expected returns and risks of assets, assisted in the multiperiod mean variance portfolio selection problem is built. The model considers transaction costs, upper bound on borrowing risk-free asset constraints, cardinality constraints and threshold constraints. Cardinality constraints limit the number of assets to be held in an efficient portfolio. At the same time, threshold constraints limit the amount of capital to be invested in each stock and prevent very small investments in any stock. Because of these limitations, the proposed model is a mix integer dynamic optimization problem with path dependence. The forward dynamic programming method is designed to obtain the optimal portfolio strategy. Finally, to evaluate the model, our result of a meaning example is compared to the terminal wealth under different constraints.

• Journal of Korea Technology Innovation Society
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• v.3 no.1
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• pp.139-153
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• 2000

The aim of this paper is to provide a new model to evaluate the quantitative value of technology(nonfinancial benefits). This new model is based on the technology stock(technology level) ac-quired in R&D process. The model can explain the quantitative relation between the technology stock(level) and the market value of technology as considering the R&D expenditure to acquire technologies above a certain level(>70%) in comparison with the advanced country and the cost to prevent the technology obsolescence. The value of non-destructive testing technology which is one of the electric power technology is measured quantitatively as a case study.

• Korean Management Science Review
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• v.33 no.3
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• pp.65-87
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• 2016

Being the FinTech technologies rapidly developed, the non face-to-face private loan market is also growing dramatically. While the real-world interests in this market are keen, the empirical studies on the issue are few compared to its prospective impact on credit loan market. This paper suggests a credit scoring model for the non face-to-face private loan employing the ratings approach (the absolute measurement method) of AHP. Analyzing a sample of data consisting of 460,000 transaction records over an 8-year period in the United States, we develop a scoring model for the non face-to-face private loan screening, and validate the model for the practical usage. Conducting sensitivity analysis, we suggest customized cut-off points for the loan execution to suit each individual loan institution's need.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.2B no.4
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• pp.168-173
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• 2002

A new identification algorithm for the Preisach model is presented. The algorithm treats the identification procedure of the Preisach model as an inverse problem where the independent variables are parameters of the distribution function and the objective function is constructed using only the initial magnetization curve or only tile major loop of the hysteresis curve as well as the whole reversal curves. To parameterize the distribution function, the Bezier spline and Gaussian function are used for the coercive and interaction fields axes, respectively. The presented algorithm is applied to the ferrite permanent magnets, and the distribution functions are correctly found from the major loop of the hysteresis curve or the initial magnetization curve.

• International journal of advanced smart convergence
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• v.10 no.4
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• pp.198-205
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• 2021

With the development of blockchain technology, the scope of blockchain applications has expanded rapidly. Blockchain decentralization allows transaction participants to make transparent and safe transactions without a third trust agency. A distributed ledger-based system enables transparent and trusted business for anonymous users. For this reason, many companies apply blockchain to various fields such as logistics, electronic voting, and real estate. Despite this interest, there are still not enough case studies confirming the potential of blockchain as a concrete business model. Therefore, it is necessary to study how blockchain technology can change the existing business model and connect it to a new business model. In this paper, we propose blockchain-based business models and workflow types in various fields such as healthcare, logistics, and energy. We also present application cases. We expect to help companies apply blockchain to their business.