• 한국수학교육학회지시리즈A:수학교육
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• 제50권1호
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• pp.103-118
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• 2011

The study examined whether the relation between mathematics self-efficacy and mathematics achievement was partially mediated by the learning strategies, using latent growth model analyses. It was also examined the auto-regressive, cross-lagged (ARCL) panel model for testing the stability and change in the relation of mathematics self-efficacy and learning strategy over time. The study analyzed the first-year to the third-year data of the Korean Educational Longitudinal Survey (KELS). The result of ARCL panel model analysis showed that earlier mathematics self-efficacy could predict later learning strategy use. There were linear trends in mathematics self-efficacy, learning strategy, and mathematics achievement. Specifically, mathematics achievement was increased over the three time points, whereas mathematics self-efficacy and learning strategies were significantly decreased. In the analyses of latent growth models, the mediating effects of learning strategies were overall supported. That is, both of initial status and change rate of rehearsal strategy partially mediated the relation of mathematics self-efficacy and mathematics achievement. However, in elaboration and meta-cognitive strategies, only the initial status of each variable showed the indirect relationship.

• 경영과학
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• 제29권1호
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• pp.57-71
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• 2012

In this paper, we deal with a sector investment strategy by implementing the black-litterman model that incorporates expert evaluation and sector rotation momentum. Expert evaluation analyzes the relative performance of the industry sector compared with the market, while sector rotation momentum reflects the price impact of significant sector anomaly. In addition, we consider the portfolio impact of sector cardinality and weight constraints within the context of mean-variance portfolio optimization. Finally, we demonstrate the empirical viability of the proposed sector investment strategy with KOSPI 200 data.

• 대한교통학회지
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• 제27권3호
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• pp.103-109
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• 2009

항공교통시스템에서 핵심적 역할을 하는 항공사의 운영비 중 유류비용은 가장 큰부분을 차지한다. 따라서 많은 항공사들은 유류비 절감을 위한 많은 노력을 기울이고 있는 실정이다. 이 중 체계적인 항공기 급유계획 전략은 많은 비용절감 효과로 인하여 근래에 많은 주목을 받고 있다. 항공기 급유계획은 항공유의 급유비용이 각 운항공항 별로 상이할 때, 총 유류비를 최소화할 수 있도록 각 항공기의 운항공항에서 최적 급유량을 도출하는 계획이다. 본 연구에서는 항공기 급유계획에 관한 수리모형을 제시한다. 제시된 모형은 각 운항공항의 급유비용과 항공기 경로정보가 알려져 있을 때 각 운항공항에서 총비용을 최소로하는 정확한 급유량을 계산하는 최적화 모형이다. 실험결과, 제안된 모형은 직관적 형태의 발견적 기법보다 효과적인 비용절감이 이루어짐을 확인하였고, 향후 항공사를 비롯한 대형 운송시스템에서 유류관리 전략으로 중요한 역할을 할 것이라 기대된다.

• 한국IT서비스학회지
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• 제2권1호
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• pp.51-73
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• 2003

The success of 2002 Korea Japan Worldcup became a good opportunity to give the message of revival to the people of Korea. With the effect of it, the national brand image has risen. Nevertheless, in order to maximize the chance of time, the most necessary thing that need to be done is to find the strategic counterproposal of the Post Worldcup. Especially, to find the more active plan in the respect of economy. In this research, we have studied the IT industry(especially SI industry) of the economy in order to look into the strategic counterproposal to get the development effect after the Worldcup. We mainly analyzed the SI industry in the respect of economy, because it is not only a high-value added industry of the integration of knowledge and technology but also a high-tech industry which has a spreading effect on the related industries. To implement the analysis of SI industry, derive and verify the strategy, and get the activating plan, we studied with 4 stages. Firstly, analyze the exterior environment and the interior strength with the Competitive Strategy Model(Specially, 7 Force Model & Value Chain Model). Secondly, get the strategy with SWOT analysis. Thirdly, verify the Strategy with interview and survey. Fourthly, classify the SI industry activation plan into 5 kinds after Worldcup through panel discussion and seminar with the data which we got through interview and survey.

• Journal of Mechanical Science and Technology
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• 제15권11호
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• pp.1482-1489
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• 2001

Thermally-induced errors originating from machine tool errors have received significant attention recently because high speed and precise machining is now the principal trend in manufacturing proce sses using CNC machine tools. Since the thermal error model is generally a function of temperature, the thermal error compensation system contains temperature sensors with the same number of temperature variables. The minimization of the number of variables in the thermal error model can affect the economical efficiency and the possibility of unexpected sensor fault in a error compensation system. This paper presents a thermal error model with minimum number of variables using a fuzzy logic strategy. The proposed method using a fuzzy logic strategy does not require any information about the characteristics of the plant contrary to numerical analysis techniques, but the developed thermal error model guarantees good prediction performance. The proposed modeling method can also be applied to any type of CNC machine tool if a combination of the possible input variables is determined because the error model parameters are only calculated mathematically-based on the number of temperature variables.

• Journal of Information Technology Applications and Management
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• 제19권3호
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• pp.49-68
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• 2012

M&A (Merger and Acquisitions) is a standard corporate strategy frequently used by companies seeking to secure new growth engines and gain a solid foothold in their markets in order to become more globally competitive. To achieve the original goals of M&A, the two involved parties need to invest significant time and resources in integrating all aspects of the companies. A well-planned post-merger integration of information technology (IT PMI) by the two M&A parties is considered a crucial and difficult process because IT provides a fundamental infrastructure for integration. Considering various internal and external factors, the two parties normally formulate an IT PMI strategy. The many IT PMI strategies can be categorized into four major types: Renewal, Takeover, Standardization, and Synchronization. This study aims to develop a decision making model to help merger company and IT managers select the proper IT PMI strategy. More specifically, we identify key determinants that need to be considered when selecting a proper IT PMI strategy. The relative importance of each determinant is defined by analytic hierarchy process (AHP) analysis. Finally, this study evaluates each IT integration strategy under the identified determinants.

• 한국정보시스템학회지:정보시스템연구
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• 제20권1호
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• pp.127-146
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• 2011

Coping with the rapid change of competition in retail industry, retail firms have dreamed various differentiation strategy to obtain their added value and their life. And they have considered CRM strategy that can differentiate with other retail firms in order to develop some new differentiation factors. So we searched new factors that is best for "T store" and found CRM strategy such as the optimization for product portfolio considering private-brand products and the optimization for product display for customer demands. This study is meaningful in that it has suggested a new CRM strategy model, which can manage new various differentiation factors of a retail firms considering its core competence. We verified and altered retail firm's business model using system dynamics. By simulation results, CRM strategy need long time to obtain visible and satisfactory performance of "T store".

• Journal of Information Technology Applications and Management
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• 제21권4호
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• pp.173-186
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• 2014

This study outlines possible risk factors in the SCM of a company and correlates risk assessment, the strategy of risk management, and the supply chain performance. The data is surveyed from an international Korean company and is analyzed by the structure equation model of actual proof. The research model verifies the correlation between the risk assessment, the strategy of risk management, and the supply chain performance as dependent variables after the risk factors of the SCM are defined as independent variables. The research shows that there are consecutive links among the risk factors of the SCM, the risk assessment, and the strategy of risk management. The strategy of risk management was conclusively determined to have an effect on supply chain performance. Therefore, improving the supply chain performance of a company requires the constructive process for risk management based on a correlation between risk assessment and the strategy of risk management.

• 경영과학
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• 제30권3호
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• pp.1-16
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• 2013

In this paper, we deal with an enhanced index fund strategy by implementing the exchange trade funds (ETFs) within the context of the Black-Litterman approach. The KOSPI200 index ETF is used to build risk-controlled portfolio that tracks the benchmark index, while the proposed Black-Litterman model mitigates estimation errors in incorporating both active investment views and equilibrium views. First, we construct a Black-Litterman model portfolio with the active market perspective based on the momentum strategy. Then, we update the portfolio with the KOSPI200 index ETF by using the equilibrium return ratio and weighted averages, while devising optimization modeling for improving the information ratio (IR) of the portfolio. Finally, we demonstrate the empirical viability of the proposed enhanced index strategies with KOSPI 200 data.

• Asian Journal of Business Environment
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• 제4권4호
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• pp.5-11
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• 2014

Purpose - The paper aims to study strategic enterprise resource initiative formation processes. It analyzes the process of managing the strategic resource initiative and discusses its implementation mechanism. A research model for enterprises' strategic development is proposed, which suggests a geometric interpretation for estimating a company's long-term development. Research design, data, and methodology - The analysis employs theoretical studies of modern researchers. The main models used to determine the optimal alternative business strategy are graphic interpretation and mathematical modeling. Results - The hypotheses testing demonstrates the definition of a company's strategic resource initiative and explains the-mechanism or design of its formation. The study presents a geometric prism-refraction model of practice using a strategic resource initiative. Conclusions - An enterprise's strategy could return to its initial state in case of its unexpected deviation as a result of passing through the nodal points. The proposed model allows us to evaluate business performance, its surrounding environment, and the resource management strategy, to determine the necessary scope of strategy changes necessary to bring it back to the original state.