• Asia pacific journal of information systems
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• v.12 no.1
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• pp.139-158
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• 2002

As the telecommunication market becomes mature in Korea, severe competition has already begun on the market. While service providers struggled for the last couple of years to acquire as many new customers as possible, nowadays they are making more efforts on retaining the current customers. The churn management by analyzing customers' demographic and transactional data becomes one of the key customer retention strategies which most companies pursue. However, the customer data analysis has still remained at the basic level in the industry, even though it has considerable potential as a tool for understanding customer behavior. This paper develops several churn prediction models using data mining techniques such as logistic regression, decision trees, and neural networks. For model-building, real data were used which were collected from one of the major telecommunication companies in Korea. This paper explores various ways of comparing model performance, while the hit ratio was mainly focused in the previous research. The comparison criteria used in this study include gain ratio, Kolmogorov-Smirnov statistics, distribution of the predicted values, and explanation ability. This paper also suggest some guidance for model selection in applying data mining techniques.

• Journal of Distribution Science
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• v.11 no.7
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• pp.23-30
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• 2013

Purpose - The study attempts to investigate the relationship between inventory management and firm performance using a multi-dimensional aspect of inventory management with respect to lean management practices across countries. Research design, data, and methodology - 1643 manufacturing firms from Japan and the US that SIC ranges from 2000 to 3999 were chosen to conduct the empirical test. This study employs hierarchical OLS regression analysis to examine the impact of control variables, ABI, EBI, and the interaction between ABI and EBI on firm performance. Results - The result indicates that in Japan high level of inventory negatively influences the accounting flows of business, while US manufactures exhibit strong positive impact of ELI on firm performance across accounting and market measures. The results show that the complementarity between the amount and the speed of inventory does exist. Except for Tobin's q, the sign of interaction term coefficient is negative, suggesting that when the amount of inventory increases and it stays longer in a firm, market values, ROS, and ROA suffers. Conclusions - The major finding of this study is that there exist some complementarities between the scope and implication of inventory management for lean strategy across countries, particularly in U.S. and Japanese firms.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.6
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• pp.1112-1121
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• 2001

The purpose of the study was to investigate and make comparison of brand images of men's wear brands and women's wear brands targeting middle-aged people or older people. Thus, the study could be an exploratory study to search apparel niche-market for middle-aged or older consumers. The questionnaire consisted of questions on 28 brand image. The subjects were to evaluate their brand images and rate on 5 point Likert-type scales of 28 adjectives. Most of the subjects were designers or merchandisers who worked for men'wear brands or women's wear brands. The SPSS/WIN Program was used to calculate frequency, t-test, and cluster analysis. The results from the study were as follow : 1) The common images which men's wear brands and women's wear brands strongly pursued were prestigious, luxurious. 2) Each 37 men's wear brands and 36 women's wear brands were clustered into one groups by brand images. The common images included in first clusters of men's wear and woman's wear brands consisted of prestigious. luxurious, formal, comfort, and conservative. This market needs to be more segmented by differentiated brand images.

• Journal of Distribution Research
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• v.15 no.5
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• pp.195-215
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• 2010

Large-scale discount stores, that were in charge of leading role up to recently, reach the limit of growth because of increasing competition, saturation of domestic market, and shortened product life-cycle. As per the limit of domestic market, large-scale discount stores are trying to various global market entry strategy and global marketing strategy like new store entry, takeover of foreign distribution chain, and global sourcing strategy. In the past, global companies of advanced country have been entering to Asian market with leading position. But, as per the rapid growth of Asian economy in the late 1980's, East Asian distribution companies like Japanese company were trying to enter the Asian market. In Asian market, starting with China, that was relatively not advanced in comparison with economic development, not only western advanced countries but also East Asian countries like Japan and Korea are entering actively for overcome their limitations of domestic market. Many of distribution companies experienced success and failure for various reason already. Korean large-scale discount stores are relatively late starters in Asian market. So, this paper purposed to review global market entry strategy of Japanese large-scale discount stores, and find out strategic implications for successful global market entry strategy of Korean large-scale discount stores.

• Journal of Information Technology Applications and Management
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• v.27 no.1
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• pp.125-145
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• 2020

We explore technology ecosystem of smart surgical medical system by analyzing patent data applied for in Korea and Japan. First, a review of trends of patent application by country/technological domain show that there exist a minority of technology domains focused on R&D, which represent their trends have been increasingly active. Also, while a number of Japanese firms mainly consist of the patent market of Japan, in case of the Korean market, a few universities, SMEs, and foreign firms are found to be the main applicants. As a result of the network analysis with the links as the relations of co-patenting, the relationships, which are active of convergence and knowledge spillover among the heterogeneous technology domains within each market, as well as the technology domains, which are the most active in international cooperation among each homogeneous domain, could get derived and visualized in the ecosystem. In addition, the technology domains in each patent market with leading locations, roles, and influence in the network can also be identified through the centrality analysis. In this study, the analysis for technology competitiveness are carried out focusing on patent activity and patent impact. The results denote that across all domains, the Japanese market may possess higher patent activity and patent impact compared to the Korean market. In consequence, we derive the position map for comparison by country and technology domain from a perspective considering comprehensively the multi-dimensional attributes based on the results of both network analysis and technology competitiveness.

• Korean Management Science Review
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• v.25 no.1
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• pp.169-191
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• 2008

In this paper, we examined the difference of the effects of buying factors in two consumer segments divided by the innovative behavior for digital convergence products, and developed relevant managerial implications. As the digital convergence product could be understood as a innovative bundling product, the buying factors of the digital convergence products were clustered in 3 groups : common innovation-bundling factors, innovation factors and bundling factors. Tests for the difference of regression coefficients of the purchasing factors in the two markets show that (1) the early market is affected by both of the common innovation-bundling factors and the innovation factors, while the mainstream market is affected by all of the common innovation-bundling factors. the innovation factors and the bundling factors, (2) the early market is more affected by the technical benefit, while the mainstream market is more affected by the pragmatic benefit, and (3) both of the two markets are affected by the compatibility and the message communicability. The relevant managerial implications for the successive diffusion of the digital convergence products can include (1) in the entire period of the diffusion. enhancing the compatibility between consumer and product concept, performing constant and differentiated marketing communication activities, (2) in the early market of the diffusion, introducing unique innovative product which provides obvious and differential synergy through the convergence, appealing to the technical benefit, and (3) in the mainstream market of the diffusion, improving the qualities and features of individual products for the digital convergence product, appealing to the pragmatic benefit, reducing the complexity of product.

• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.2
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• pp.83-95
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• 2014

In this paper, we develop a portfolio selection model that can be used to invest in markets with margin requirements such as the foreign exchange market. An investment algorithm to implement the proposed portfolio selection model based on objective historical data is also presented. We further conduct empirical analysis on the performance of a hypothetical investment in the foreign exchange market, using the proposed portfolio selection model and investment algorithm. Using 7 currency pairs that recorded the highest trading volume in the foreign exchange market during the most recent 10 years, we compare the performance of 1) the Dollar Index, 2) a 1/N Portfolio which equally allocates capital to all N assets considered for investment, and 3) a hypothetical investment portfolio selected and managed according to the portfolio selection model and investment algorithm proposed in this paper. Performance is compared in terms of accumulated returns and Sharpe ratios for the 10-year period from January 2003 to December 2012. The results show that the hypothetical investment portfolio outperforms both benchmarks, with superior performance especially during the period following financial crisis. Overall, this paper suggests that a mathematical approach for selecting and managing an optimal investment portfolio based on objective data can achieve outstanding performance in the foreign exchange market.

• Journal of the Korea Convergence Society
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• v.8 no.3
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• pp.215-223
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• 2017

The purpose of the present study is to identify the differences of customer preference in online and offline used car business. Conjoint analysis is used for examining the attributes of used car choices. As a result, the order of importance in real used car market is as follows: brand, design, price, model, mileage. Whereas the order of importance in online used car market is as follows: brand, trust, price, web design, accident. Accordingly, the author suggested that customer preferences depend on the path people are approaching and the attributes of preference vary in online and real stores. For example, trust and accident are important attributes in online market in comparison with real market. Used car market is increasing and becoming important. The authorities and practitioners need to understand used car market and establish the related policies.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2008.10a
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• pp.76-94
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• 2008

This paper investigates performance of the Markowitz's portfolio selection model with applications to Korean stock market. We choose Samsung-Group-Funds and KOSPI index for performance comparison with the Markowitz's portfolio selection model. For the most recent one and a half year period between March 2007 and September 2008, KOSPI index almost remains the same with only 0.1% change, Samsung-Group-Funds shows 20.54% return, and Markowitz's model, which is composed of the same 17 Samsung group stocks, reaches 52% return. We perform sensitivity analysis on the duration of financial data and the period of portfolio change in order to maximize the return of portfolio. In conclusion, according to our empirical research results with Samsung-Group-Funds, investment by Markowitz's model, which periodically changes portfolio by using nonlinear programming with only financial data, outperforms investment by the fund manager who possesses rich experiences on stock trading and actively changes portfolio based on minute-by-minute market news and business information.

• Korea Trade Review
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• v.43 no.6
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• pp.51-70
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• 2018

This study is to define the relationship between capital structure and the market share in the global shipping market, estimating the debt-equity ratio. To analyze the impact of the debt-equity ratio on market share, this study collected data from the 100 largest shipping companies from 2010 to 2017. Results identified that global shipping lines moderate their debt-equity rates to 62%, and all of them strategically utilize debt in order to increase market share in global shipping market. In comparison between the group focused on cargo volume and another group focused on freight rates, it is found that the group focused on cargo volume increase their handling cargo volume through increasing the debt rates. Another group used debt rate for reducing the freight rate and enhancing market power. Furthermore, after classifying the samples into high-growth and low-growth companies, this study compared the group focused on cargo volume and another group focused on freight rates. As a result, the low-growth group showed more significant impacts of the debt rate on market share than the high-growth group. The results of this study provide useful insight for future strategic decision making of shipping lines in the global shipping market.