• Journal of Power Electronics
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• 제18권6호
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• pp.1855-1865
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• 2018

This paper presents a control strategy for voltage-controlled multi-function distributed generation (DG) combined with an active power filter (APF) and a reactive power compensator. The control strategy is based on droop control. As a result of local nonlinear loads, the voltages of the point of common coupling (PCC) and the currents injecting into the grid by the DG are distorted. The power quality of the PCC voltage can be enhanced by using PCC harmonic compensation. In addition, with the PCC harmonic compensation, the DG offers a low-impedance path for harmonic currents. Therefore, the DG absorbs most of the harmonic currents generated by local loads, and the total harmonic distortion (THD) of the grid connected current is dramatically reduced. Furthermore, by regulating the reactive power of the DG, the magnitude of the PCC voltage can be maintained at its nominal value. The performance of the DG with the proposed control strategy is analyzed by bode diagrams. Finally, simulation and experimental results verify the proposed control strategy.

• Smart Structures and Systems
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• 제5권1호
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• pp.69-79
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• 2009

A non-clipped semi-active stochastic optimal control strategy for nonlinear structural systems with MR dampers is developed based on the stochastic averaging method and stochastic dynamical programming principle. A nonlinear stochastic control structure is first modeled as a semi-actively controlled, stochastically excited and dissipated Hamiltonian system. The control force of an MR damper is separated into passive and semi-active parts. The passive control force components, coupled in structural mode space, are incorporated in the drift coefficients by directly using the stochastic averaging method. Then the stochastic dynamical programming principle is applied to establish a dynamical programming equation, from which the semi-active optimal control law is determined and implementable by MR dampers without clipping in terms of the Bingham model. Under the condition on the control performance function given in section 3, the expressions of nonlinear and linear non-clipped semi-active optimal control force components are obtained as well as the non-clipped semi-active LQG control force, and thus the value function and semi-active nonlinear optimal control force are actually existent according to the developed strategy. An example of the controlled stochastic hysteretic column is given to illustrate the application and effectiveness of the developed semi-active optimal control strategy.

• 한국보육지원학회지
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• 제16권6호
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• pp.155-183
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• 2020

Objective: In this study, we tried to verify the effects of program by constructing an effective maker education program that can cultivate the maker's capabilities through voluntary production activities by utilizing various technologies and tools. Methods: First, prior research on maker education and the station teaching strategy was considered, and interviews and surveys were conducted on prospective early childhood teachers in order to find out the degree of demand for maker education. The final program was finalized through verification of the contents validity. Results: The developed program was applied to a total of 49 prospective early childhood teachers (24 in the experimental group, 25 in the comparative group) attending U College, and it was found to be effective in enhancing convergence talent, education knowledge of early childhood teachers' technology, and self-directed learning skills. Conclusion/Implications: These findings show that the preliminary early childhood teacher maker education program using station teaching strategy has educational value that can be used as an effective teaching method in early childhood education.

• 동아시아경상학회지
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• 제9권1호
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• pp.53-61
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• 2021

Purpose - This study aims to understand the phenomenon called "regional multinational" in the geographical expansion of multinational enterprises and to find some evidence whether globalization of multinational enterprises tends to have a strong home region bias. Research design, data, and methodology - Through an in-depth case analysis, we analyze the series of strategic behaviors Wal-Mart made in South Korea from its entry in 1998 to its withdrawal in 2006. Then, we discuss the plausible causes of this exit, seeking to provide some evidence on the "regional multinational" phenomenon. Result - This study finds some evidence on the regional-based expansion of multinational enterprises. Our case study shows that Wal-Mart in South Korea focused on global standardization strategy and made an exit from the market as they were faced with increasing localization demands. From the perspective of multinational enterprises' globalization strategy, Wal-Mart's exit from the South Korean market can be considered as a strategic exit. Conclusion - The findings of this study suggest that while national responsiveness and localized adaptation are considered as a panacea for penetrating international markets, in reality most multinational enterprises attempt to add value primarily by capitalizing on similarities across markets and remain as regional multinationals.

• Structural Engineering and Mechanics
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• 제85권1호
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• pp.119-133
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• 2023

Impact event is the key factor influencing the operational state of the mechanical equipment. Additionally, nonlinear factors existing in the complex mechanical equipment which are currently attracting more and more attention. Therefore, this paper proposes a novel hybrid-separate identification strategy to solve the force identification problem of the nonlinear structure under impact excitation. The 'hybrid' means that the identification strategy contains both l1-norm (sparse) and l2-norm regularization methods. The 'separate' means that the nonlinear response part only generated by nonlinear force needs to be separated from measured response. First, the state-of-the-art two-step iterative shrinkage/thresholding (TwIST) algorithm and sparse representation with the cubic B-spline function are developed to solve established normalized sparse regularization model to identify the accurate impact force and accurate peak value of the nonlinear force. Then, the identified impact force is substituted into the nonlinear response separation equation to obtain the nonlinear response part. Finally, a reduced transfer equation is established and solved by the classical Tikhonove regularization method to obtain the wave profile (variation trend) of the nonlinear force. Numerical and experimental identification results demonstrate that the novel hybrid-separate strategy can accurately and efficiently obtain the nonlinear force and impact force for the nonlinear structure.

• Journal of Korea Trade
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• 제27권1호
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• pp.159-175
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• 2023

Purpose - This paper empirically investigates the relationship between born global strategy and the accounting- and market- based financial performance of Korean firms. Further, this study identifies the characteristics of born global firms (BGs) in comparison with non-BG counterparts in terms of size, R&D, and liability. Design/methodology - Using a database of listed Korean SMEs in the manufacturing sector from 2010 to 2020, this study applies panel generalized least squares (GLS) estimation and logistic regression techniques. Findings - This study finds that BG strategy is negatively related to the firm's accounting-based financial performance, while it is positively related to the market-based financial performance. This study also finds that BGs have higher sales volume and more total assets compared to their non-BG counterparts. In addition, Korean BGs spend more on R&D, and at the same time have higher liability. Originality/value - BGs, by definition, are firms that are actively penetrating foreign markets from the early stages of their establishment. Previous studies of Korean BGs have tried to identify the determinants of BGs' rapid internationalization and their superior performance. However, most of these studies have utilized either qualitative case- or survey-based analyses with relatively limited numbers of observations. From a different perspective, this study provides more objective evidence by investigating how the BG strategy affects the financial and market performance of firms, and by characterizing BGs in terms of financial data.

• Asia Marketing Journal
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• 제6권3호
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• pp.123-141
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• 2004

국내 아파트 시장에서 래미안을 통해 브랜드 마케팅을 본격적으로 도입한 삼성물산 건설부문은 고객의 추구가치를 마케팅믹스전략에 철저히 반영하는 한편 새로운 브랜드 마케팅전략의 트렌드를 창출하고 주도한 결과, 업계 최고의 파워브랜드 구축과 함께 괄목할 만한 경영성과를 단기간에 이룰 수 있었다. 본 사례는 삼성물산 건설부문이 래미안을 최고의 파워 브랜드로 만들기 위해 기울인 체계적 노력을 브랜드 마케팅전략을 중심으로 소개하고, 주요 성공요인이 무엇인지 알아본 후, 시사점과 함께 향후 래미안의 전략적 과제를 제시하고 있다.

• 한국의류학회지
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• 제24권4호
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• pp.498-509
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• 2000

This study is designed to find out the effects of price on the consumers'perceived quality, value and purchase willingness of clothing in order to get the basic information that is needed in helping clothing manufacturer's strategy for merchandising promotion on price. This study was conducted by means of a questionnaire survey of university students in seoul. SAS program was used for analysis. The conclusions of this study as follow: first, with respect to the price level of clothing, consumers evaluate the perceived quality of high-price case higher than that of low-price case, and evaluate the perceived value and purchase willingness of low-price case higher than those of high-price case. Second, with respect to the brand name level of clothing, consumers evaluate the perceived quality, perceived value and purchase willingness of well-known brand case higher than those of unknown brand can. Third, the interaction between price and brand dosen't appear. Thus from this result we can know that price and brand have the same amount of effect in both single-quo case and multi-que case. Forth, with respect to the price and brand name level of clothing, there exist significant differences in perceived quality, perceived value, and brand name level. Fifth, in the study of the relationship between perceived quality and purchase willingness and the relationship between the perceived value and purchase willingness, perceived value has more effect on purchase willingness than perceived quality.

• 한국경영과학회지
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• 제39권3호
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• pp.63-82
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• 2014

The main objective of this research is to investigate whether the RFM (recency-frequency-monetary value) information of a customer's redemption behavior of loyalty points can improve the prediction of future value of the customer. The conventional measurement of customer value has been primarily based on purchase transactions behavior although a customer's future behavior can be also influenced by other interactions between the customer and the firm such as redemption of rewards in a loyalty program. We theorize why a customer's redemption behavior can influence her future purchases and thereby the customer's total value based on operant learning theory, goal gradient hypothesis, and lock-in effect. Using a dataset from a major book store in Korea spanning three years between 2008 and 2010, we analyze both purchase transactions and redemption records of over 10,000 customers. The results show that the redemption-based RFM information does improve the prediction accuracy of the customer's future purchases. Based on this result, we also propose an improved estimate of customer lifetime value (CLV) by combining purchase transactions and loyalty points redemption data. Managerial implications will be also discussed for firms managing loyalty programs to maximize the total value customers.

• Journal of Information Technology Applications and Management
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• 제19권4호
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• pp.115-135
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• 2012

Currently, smart signage as a new kind of advertisement media has been widely used and has had a significant effect on consumers. In this study, we examine the impact on the attitude towards smart signage advertisement based on the Ducoffe's Web advertisement model. In particular, we investigate how the advertising factors (interaction, informativeness, irritation, and entertainment) as well as the contextual factors (localization, immediacy, and personalization) have effects on the value and attitude towards smart signage advertisement. Furthermore, we examine the moderating effect of individual defensive propensity on the relationship between affecting factors and the advertising value. By analyzing 192 samples from undergraduates, we found that four out of seven factors have significant effects on the value towards smart signage. More specifically, for advertising factors, informativeness and irritation have positive effects on the advertising value. For contextual factors, on the other hand, localization and entertainment have positive effects on the value towards smart signage. Besides, we discovered that the defensive propensity moderate the relationship between localization and the advertising value.