• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.1
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• pp.130-136
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• 2009

A lumped parameter model of Li-ion battery in hybrid electric vehicle(HEV) is constructed and system parameters are identified by using recursive least square estimation for different C-rates, SOCs and temperatures. The system characteristics of pole and zero in frequency domain are analyzed with the parameters obtained from different conditions. The parameterized model of Li-ion battery indicates highly dependant of temperatures. The system pole and internal resistance changes 6.6 and 18 times at $-20^{\circ}C$, comparing with those at $25^{\circ}C$, respectively. These results will be utilized on constructing model-based state observer or an on-line identification and an adaptation of the model parameters in battery management systems for hybrid electric vehicle applications.

• Korean Journal of Computational Design and Engineering
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• v.14 no.3
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• pp.186-196
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• 2009

Mass customization (MC) is a business practice that aims to provide customers with customized products and services at near mass production efficiency. To achieve the aim, a number of methods to implementing MC are proposed. However, most of them require changes in entire process of the company, which make companies hesitate to implement MC even if it is essential to survive. In this paper, we proposed alternatives to partially implement MC for quick adaptation of MC. The base line assumption is not to change the production lines. The pros and cons of alternatives are given by qualitative and quantitative evaluation. Especially, by giving radar chart analysis of the quantitative measures, we give insight on the changes in the business performance measures, such as time to market and cost. Proposed alternatives are based on sub-processes such as purchasing raw materials, production process changes and packaging for efficient logistics. In this way, companies are able to provide customized products with small changing of the current manufacturing system. The process and benefit of the proposed strategy is verified by real world cases of a Korean health food company.

• Nuclear Engineering and Technology
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• v.30 no.6
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• pp.581-591
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• 1998

Numerical analysis was peformed for the two-dimensional turbulent natural convection for a long horizontal line with different end temperatures. The turbulent model has been applied a standard k-$\varepsilon$ two equation model of turbulence similar to that the proposed by the Launder and Spalding. The dimensionless governing equations are solved by using SIMPLE (Semi-Implicit Method for Pressure Linked Equations) algorithm which is developed using control volumes and staggered grids. The numerical results are verified by comparison with the operating PWR test data. The analysis focuses on the effects of variation of the heat transfer rates at the pipe surface, the thermal conductivities of the pipe material and the thickness of the pipe wall on the thermal stratification. The results show that the heat transfer rate at the pipe surface is the controlling parameter for mitigating of thermal stratification in the long horizontal pipe. A significant reduction and disappearance of the thermal stratification phenomenon is observed at the Biot number of 4.82$\times$10$^{-1}$ . The results also show that the increment of the thermal conductivity and thickness of the wall weakens a little the thermal stratification and somewhat reduces temperature gradient of y-direction in the pipe wall. These effects are however minor, when compared with those due to the variation of the heat transfer rates at the surface of the pipe wall.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.99-110
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• 2021

This study aims to examine empirically the industry and economic fundamental factors that affect the stock prices of the leading palm oil company in Indonesia. The dynamics of stock price are analyzed using the autoregressive distribution lag (ARDL) model both for symmetric and asymmetric effects. The data used in this study are monthly data for the period from 2008:01 to 2020:03. In the long run, the company stock price moves in line with the competitor company stock price at the current time. The palm oil price has a positive effect on the stock price. Meanwhile, inflation negatively affects the stock price in the short run. The estimated equilibrium correction coefficient indicates a reasonably quick correction of the distortion of the stock price equilibrium in monthly dynamics. However, fundamental factors have asymmetric effects, especially the response of stock price when these factors decrease rather than increase in the short run. Stock prices that are responsive to declines in fundamental performance should be of particular concern to both investors and management in their strategic decision making. The results of this study will contribute to the enrichment of literature related to stock prices from the viewpoint of economic analysis on firm-level data.

• Journal of Distribution Research
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• v.15 no.3
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• pp.35-69
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• 2010

Successful management of distributors is crucial for the success of multi-level marketing (MLM) because MLM sells products and services through distributor networks. The present study examines the impact of the up-line distributors' transformational leadership on down-line distributors' entrepreneurship, market orientation, and performance. The proposed research questions were examined based on a survey of 135 down-line distributors working at the largest domestic MLM company. A mediation mechanism was found that the up-line distributors' transformational leadership increases the down-line distributors' entrepreneurship and market orientation, which in turn influences their performance. Based on the findings, the present study suggests the importance of transformational leadership in MLM. Practical implications for the roles of transformational leadership and its impact on corporate management in specific business areas are also discussed.

• Journal of Electrical Engineering and Technology
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• v.1 no.2
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• pp.161-169
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• 2006

Load representation has a significant impact on power system analysis and control results. In this paper, composite load models are developed based on on-line measurement data from a practical power system. Three types of static-dynamic load models are derived: general ZIP-induction motor model, Exponential-induction motor model and Z-induction motor model. For the dynamic induction motor model, two different third-order induction motor models are studied. The performances in modeling real and reactive power behaviors by composite load models are compared with other dynamic load models in terms of relative mismatch error. In addition, numerical consideration of ill-conditioned parameters is addressed based on trajectory sensitivity. Numerical studies indicate that the developed composite load models can accurately capture the dynamic behaviors of loads during disturbance.

• Journal of Korea Technology Innovation Society
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• v.8 no.3
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• pp.1199-1224
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• 2005

This study analyzes various factors affecting a firm's investments, focusing on both a firm's ownership structure and CEO's incentives. While previous empirical works focus on various financial data in order to test the Schumpeterian Hypotheses, this paper is using various ownership structure data as well as financial data. Empirical results show that the greater a firm's CEO has the company's own stock, the less he spends in R&D investments. The main empirical results of this study is in line with past empirical studies on various markets outside of Korea.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.11
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• pp.1432-1443
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• 2005

The purpose of this study was to identify the relationship among the sub-dimensions of interaction and the relationship between interactions and needs satisfactions in the apparel brand online communities. Subjects of 317 members for 9 selected apparel communities responded the questionnaire in the home-page or in the attached file. The results were as follows: The suggested structural equation model which showed the relationship between the interactions and needs satisfaction in communities were accepted($\chi^2=63.80/df.=48/p=0.06$, GFI=0.97, AGFI=0.95, RMR=0.045, NFI=0.93, AIC=123.80). The interaction of company-consumer hads a positive influence on the interaction of consumers-consumers(H1) and the interaction of consumers-consumers had a positive influence on the interaction of consumers-company(H2). The interaction among community members had a positive influence on the satisfaction of interest needs(H3), transaction needs(H4) and relationship needs(H5) in the community. The relationship needs satisfaction had a positive influence on the interaction of members to the company(H6). Therefore, marketers in apparel company should be fully aware of reciprocal influence among types of interaction when planning marketing programs to promote each type of interaction. Furthermore, they also have to plan marketing activities to manage effective interaction.

• Journal of Information Technology Application
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• v.3 no.2
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• pp.103-132
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• 2001

The internet-based business is considered as a new strategic alternative for small-medium size companies. However, very little research about them has been reported. The objectives of this study are to analyze factors influencing the operation for the sites(we call, 'internet shopping mall') which small-and-medium sized firms have built, and to provide the general directions of the successful internee-based business for the small-and-medium sized firms. This paper reports the case studies in which the internet-based electronic commerce practices of 6 small-and-medium sized firms were examined over a 3 month period. In the meantime, this paper reports their present business condition, system environment, positioning, marketing strategy, forward business expectation, and market barrier. This study also focuses on two environmental dimensions of system development; One dimension is on-line only or off-line widened, and the other is self-built or outsourcing. The results found in this study are as follows: 1. The internet shopping mall broadens the company's activity to new business areas. 2. The degree of system outsourcing of the small-medium size company depends on its IT ability and resource capability 3. The marketing strategies on their internet shopping mall differentiate with their business area and market environment. 4. Each interviewed company has its own success and failure factors, in addition to the general factors. 5. Each interviewed company has a positive response for their internet shopping mall for its future. 6. The lack of capital, technology, and government support is the barrier to the improvement of the internet shopping mall system.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.323-325
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• 2009

In this paper, we present simulation results of Dynamic Matrix Control(DMC) to a boiler steam temperature. In order to control of steam temperature, we choose the input-output variables and generate the step response model by each input variable's step test. After that, the control structure executes on-line control with optimization using step response model. Proposed controller is applied to the APESS(Doosan company's boiler model simulator) and it is observed that the simulation results show satisfactory performance of proposed control.