• 유통과학연구
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• 제14권11호
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• pp.61-73
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• 2016

Purpose - Marketing scholars have developed various types of mathematical models for describing marketing phenomenon, because there is no single model comprehensive enough to incorporate all the relevant marketing phenomena. This study tries to summarize the behavioral foundations and the mathematical derivations of the most widely used marketing models and discusses their strategic implications. This study selected four representative marketing models: multinomial logit(MNL) model, elimination-by-aspects(EBA) model, Hauser and Shugan model and Bass diffusion model. Especially, this study focuses on Hauser and Shugan(1983)'s Defender model and discusses the model's behavioral foundation and its implications. Research design, data, and methodology - Of the four selected model, the multinomial logit model is selected as the basic normative model and the other three models are described as descriptive models in contrast. Starting the discussion from the multinomial logit model, this study explains what important strategic variables are incorporated in each of the four models. The IIA(independence of irrelevant alternatives) axiom and Luce choice model is also discussed in relation to the multinomial logit model. The concept of 'efficient frontier' is discussed in relation to Hauser and Shugan's model. Graphs and tables are used to represent the key implications. No empirical study is included. Results - The analyses of the mathematical marketing models are shown to be very useful in understanding the essence of positioning strategy. The multinomial logit model implies the importance of increasing utility or consumer preference level. The EBA model implies the importance of lowering the inter-brand similarity and dominating the competitors. Hauser and Shugan model implies the importance of considering customer heterogeneity distribution in selecting the target market. Conclusions - It is shown that the concepts of 'efficient frontier' is useful in understanding the effectiveness of positioning strategy. Market positioning can be understood as occupying some place on the efficient frontier. The important strategic implications can be summarized as follows: Always try to increase customer preference by providing what they value, and differentiate from competing alternatives as much as possible. The best positioning strategy is to dominate all the competitors and the worst is to be dominated by the competitors.

• Journal of Information Processing Systems
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• 제15권5호
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• pp.1218-1230
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• 2019

This study proposes a novel video traffic flow detection method based on machine vision technology. The three-frame difference method, which is one kind of a motion evaluation method, is used to establish initial background image, and then a statistical scoring strategy is chosen to update background image in real time. Finally, the background difference method is used for detecting the moving objects. Meanwhile, a simple but effective shadow elimination method is introduced to improve the accuracy of the detection for moving objects. Furthermore, the study also proposes a vehicle matching and tracking strategy by combining characteristics, such as vehicle's location information, color information and fractal dimension information. Experimental results show that this detection method could quickly and effectively detect various traffic flow parameters, laying a solid foundation for enhancing the degree of automation for traffic management.

• 대한수학교육학회지:수학교육학연구
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• 제17권2호
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• pp.91-109
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• 2007

이 논문은 이원일차연립방정식과 관련하여 초등수학과 중등수학의 연결성 문제를 분석한 것이다. 초등학교 수학 교과서와 중학교 수학 교과서에서 이원일차연립방정식 문장제가 다루어지는 방식을 연결성 측면에서 분석하고, 연결성을 강화하는 접근법을 제안하였다. 교과서 분석 결과 이원일차연립방정식 문장제에 대한 초등학교 수학 교과서와 중학교 수학 교과서의 접근법이 서로 연결되어 있지 않았다. 이에 이 논문에서는 이원일차연립방정식 문장제 해결에 그림그리기 전략을 도입하여 초등수학과 중등수학의 연결성을 강화하는 방안을 한 초등 6학년 아동의 사례를 통해 제시하였다.

• Journal of Power Electronics
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• 제16권3호
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• pp.946-959
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• 2016

A novel Virtual Space Vector (VSV) modulation strategy for complete control of potential neutral point (NP) issues is proposed in this paper. The neutral point potential balancing problems of multi-level converters, which include elimination of low frequency oscillations and self-balancing for NP dc unbalance, are investigated first. Then a set of improved virtual space vectors with dynamic adjustment factors are introduced and a multi-objective optimization algorithm which aims to optimize these adjustment factors is presented in this paper. The improved virtual space vectors and the multi-objective optimization algorithm constitute the novel Virtual Space Vector modulation. The proposed novel Virtual Space Vector modulation can simultaneously recover NP dc unbalance and eliminate low frequency oscillations of the neutral point. Experiment results show that the proposed strategy has excellent performance, and that both of the neutral point potential issues can be solved.

• Journal of Power Electronics
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• 제19권3호
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• pp.727-743
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• 2019

This paper presents a pulse-width modulation strategy to eliminate the common mode voltage (CMV) with reduced CMV spikes in multilevel inverters since a high CMV magnitude and its fast variations dv/dt result in bearing failure of motors, overvoltage at motor terminals, and electromagnetic interference (EMI). The proposed method only utilizes the zero CMV states in a space vector diagram and it is implemented by a carrier-based pulse-width modulation (CBPWM) method. This method is generalized for odd number levels of inverters including neutral-point-clamped (NPC) and cascaded H-bridge inverters. Then it is extended to the over-modulation mode. The over-modulation mode is implemented by using the two-limit trajectory principle to maintain linear control and to avoid look-up tables. Even though the CMV is eliminated, CMV spikes that can cause EMI and bearing current problems still exist due to the deadtime effect. As a result, the deadtime effect is analyzed. By taking the deadtime effect into consideration, the proposed method is capable of reducing CMV spikes. Simulation and experimental results verify the effectiveness of the proposed strategy.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권1호
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• pp.80-96
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• 2022

Nowadays, artificial intelligence promotes the rapid development of skin cancer detection technology, and the federated skin cancer detection model (FSDM) and dual generative adversarial network model (DGANM) solves the fragmentation and privacy of data to a certain extent. To overcome the problem that the many-objective evolutionary algorithm (MaOEA) cannot guarantee the convergence and diversity of the population when solving the above models, a many-objective evolutionary algorithm based on integrated strategy (MaOEA-IS) is proposed. First, the idea of federated learning is introduced into population mutation, the new parents are generated through sub-populations employs different mating selection operators. Then, the distance between each solution to the ideal point (SID) and the Achievement Scalarizing Function (ASF) value of each solution are considered comprehensively for environment selection, meanwhile, the elimination mechanism is used to carry out the select offspring operation. Eventually, the FSDM and DGANM are solved through MaOEA-IS. The experimental results show that the MaOEA-IS has better convergence and diversity, and it has superior performance in solving the FSDM and DGANM. The proposed MaOEA-IS provides more reasonable solutions scheme for many scholars of skin cancer detection and promotes the progress of intelligent medicine.

• Journal of Power Electronics
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• 제14권2호
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• pp.315-323
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• 2014

An optimized space vector pulse width modulation (SVPWM) method with common mode voltage elimination and neutral point potential balancing is proposed for an open-end winding induction motor. The motor is fed from both of the ends with two neutral point clamped (NPC) three-level inverters. In order to eliminate the common mode voltage of the motor ends and balance the neutral point potential of the DC link, only zero common mode voltage vectors are used and a balancing control factor is gained from calculation in the strategy. In order to improve the harmonic characteristics of the output voltages and currents, the balancing control factor is regulated properly and the theoretical analysis is provided. Simulation and experimental results show that by adopting the proposed method, the common mode voltage can be completely eliminated, the neutral point potential can be accurately balanced and the harmonic performance for the output voltages and currents can be effectively improved.

• KIEAE Journal
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• 제11권2호
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• pp.105-111
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• 2011

Aims of this study is to investigate the daylighting control strategy of venetian blind system was performed as a function of ratio of shading height to window and slat angles in the preliminary stage of the parametric study. Floor-to-ceiling window walls of living spaces are used widely in apartment buildings since the Korean government has legally allowed elimination of the balcony area. Enlarging living area by balcony elimination, the larger glass area of window is exposed to the direct sunlight. As a common sunlight controlling device, blind system can be used in all orientations and all latitudes and it may obstruct, absorb, reflect and transmit solar radiation to building by proper adjusting. However, blind system can produce discomfort in occupant and less energy efficiency, if it has not been controlled optimally. The simulation model was based on the unit module of typical living space with balcony elimination. The room dimension was $6.0m(w){\times}6.9m(d){\times}2.7m(h)$ with floor to ceiling height of 2.5m. The blind system was simulated at five slat angles (horizontal, $30^{\circ}$, $45^{\circ}$ upward and downward tilted) and the four ratio of shading height to window (fully closed, partly opened, no-blind) using the Desktop RADIANCE 2.0 program. The series of simulation results indicates that the advantages of available daylight and outside of view can be improved by proper adjusting blind system.

• Journal of Power Electronics
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• 제15권4호
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• pp.1105-1118
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• 2015

Battery energy storage devices (ESDs) have become more and more commonplace to maintain the stability of islanded power systems. Considering the limitation in inverter capacity and the requirement of flexibility in the ESD, the droop control was implemented in paralleled ESDs for higher capacity and autonomous operation. Under the conventional droop control, state-of-charge (SoC) errors between paralleled ESDs is inevitable in the discharging operation. Thus, some ESDs cease operation earlier than expected. This paper proposes an adaptive accelerating parameter to improve the performance of the SoC error eliminating droop controller under the constraints of a microgrid. The SoC of a battery ESD is employed in the active power droop coefficient, which could eliminate the SoC error during the discharging process. In addition, to expedite the process of SoC error elimination, an adaptive accelerating parameter is dedicated to weaken the adverse effect of the constraints due to the requirement of the system running. Moreover, the stability and feasibility of the proposed control strategy are confirmed by small-signal analysis. The effectiveness of the control scheme is validated by simulation and experiment results.

• 경영과학
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• 제33권2호
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• pp.11-28
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• 2016

This study empirically investigated the relationships among external factors (i.e., the imitation, compulsory and normative pressures, and governmental regulation), proactive environmental strategy, the adoption of green-supply chain management (GSCM) techniques, green corporation with suppliers, environmental performance, and organizational performance. To empirically demonstrate the relationships, 78 sample firms' data were collected from Korean manufacturing firms that are listed on the Korean stock market. The results of this study showed that a proactive environmental strategy mainly and positively influences the adoption of GSCM, and the introduction of a proactive environmental strategy is significantly and positively affected by governmental regulation. It was also found that governmental regulation has an indirect impact on the adoption of GSCM through the introduction of a proactive environmental strategy. Thus, it is asserted that governmental regulation, in Korean manufacturing firms, is the unique external factor on the adoption of a proactive environmental strategy, which facilitates the use of GSCM techniques. According to the results, it was observed that GSCM positively influences the levels of green corporation, and both GSCM and green corporation have positive effects on the improvement of environmental performance. Hence, it is suggested that the implementation of GSCM inevitably brings high degrees of green collaboration with suppliers. Finally, it was found that environmental performance has a significant and positive impact on the organizational performance of a firm. This result implies that high degrees of environmental performance, which bring both the efficient usage of materials and energy and the elimination of wastes, can lead to the increase of organizational performance.