• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.7
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• pp.92-100
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• 1998

In this paper, we suggest a new identification method for sugeno-type fuzzy model via new data clustering strategy. The suggested algorithm is much simpelr than the original identification strategy adopted in. The algorithm suggested in this paper is somewhat similar to that of [2] and [6], that is the algorithm suggested in this paper consists of two steps: coarse tuning and fine tuning. In this paper, double clustering strategy is proposed for coarse tunign. Finally, the resutls of computer simulation are given to demonstrate the validity of this algorithm.

• Journal of Power Electronics
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• v.16 no.3
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• pp.1036-1045
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• 2016

This paper presents a novel control strategy for passive output filter reduction using an active output filter. The proposed method achieves the dual-function of regulating the output voltage ripple and output voltage variation during load transients. The novel control strategy allows traditional simple voltage controllers to be used, without requiring the expensive current sensors and complex controllers used in conventional approaches. The proposed method is verified with results from a 125-W forward converter.

• Management & Information Systems Review
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• v.5
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• pp.185-209
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• 2000

A review of shows that past research has focused predominately on foreign market entry strategy issues in relatively well-established firms. These studies have either ignored venture firms or have failed to treat these firms separately. Only recently, researchers have broadened their search to include aspects of the foreign market investment of the venture. The purposes of this study are to identify and explain the impact factors such as ownership specific advantage, transaction cost, and location specific advantage on the choice of foreign market entry strategy for venture firms. To find the perceived the foreign market entry strategy and determinant factors, 130 venture CEOs from the computer and communications equipment industries were asked to describe their venture's foreign market entry strategy through 17 questionnaire items on competitive method. Using factor analysis, the six determinant factors were categorized. To test the relationships between the foreign market entry strategy and factors such as ownership specific advantage, transaction cost, and location specific advantage, the data collected by questionnaire from 92 ventures. The main results of this research are as follows. First, the factors of ownership specific advantage have partially significant impact on the foreign market entry strategy of venture firms, Second, the factors of transaction cost have significant impact on their foreign market entry strategy. Third, the factors of location specific advantage have significant impact on their foreign market entry strategy. This study has produced evidence to demonstrate that the foreign market entry strategy profile of venture firms can be distinguished from those of relatively well-established firms. An expanded study would allow for stronger conclusions regarding the relative explanatory power of individual variables in the method. Additional research is also needed to examine other determinant variables connecting foreign market entry strategy.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.60-62
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• 2001

This paper shows the optimal bidding strategy determination method using Nash equilibrium concept by defining bidding strategy vector. This vector is 2-dimension vector whose components are generation amount and generation cost. Thereby we are able to make all possible strategies and their's payoff table. And then we erase dominated strategies one by one so that we obtain Nash equilibrium, the optimal bidding strategy of generation bidding game.

• Knowledge Management Research
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• v.8 no.2
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• pp.1-16
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• 2007

This paper describes the Blue Ocean Strategy and Business TRIZ (Russian Theory of Inventive Problem Solving) Tactics as one method for knowledge creation and innovation. The opening new market avoiding keen competition is very popular recently and is not just prosper, but survival problem. As one new strategy for finding new market, the Blue Ocean Strategy gives the big blueprint for new market, but has no enough tools to make more concrete ideas. In this paper, we suggest using the Strategy Campus and other tools in the Blue Ocean Strategy at initial stage and then, compensating the TRIZ principles to make more concrete ideas for new market as tactics. We applied it to find the new market for conventional newspaper industry and EBS (Education Broadcast System) management innovation in Korea as case studies and got better results comparing to using only the Blue Ocean Strategy.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.305-308
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• 1997

The on-line calculation method is developed to obtain the temperature trajectory that brings the reactants to the desired state in batch styrene polymerization reactor. The temperature trajectory is obtained by applying the moments of the polymer concentration to the 2-step calculation method. The computer simulation is also carried out to verify the superiority of the on-line method to the off-line one. When a temperature disturbance of constant size is introduced, the off-line results shows considerable deviation from the target degree of polymerization. The on-line strategy set up a new trajectory to reach the desired state by using the current state of the reactor. Therefore, the on-line strategy deals with the changes of the system more adequately than the off-line strategy.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.7
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• pp.591-597
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• 2001

In this paper, we propose a method of cooperative control (T-cell modeling) and selection of group behavior strategy (B-cell modeling) based on immune system in distributed autonomous robotic system (DARS). Immune system is living body's self-protection and self-maintenance system. These features can be applied to decision making of optimal swarm behavior in dynamically changing environment. For applying immune system to DARS, a robot is regarded as a B-cell, each environmental condition as an antigen, a behavior strategy as an antibody and control parameter as a T-cell respectively. The executing process of proposed method is as follows. When the environmental condition changes, a robot selects an appropriate behavior strategy. And its behavior strategy is stimulated and suppressed by other robot using communication. Finally much stimulated strategy is adopted as a swarm behavior strategy. This control school is based on clonal selection and idiotopic network hypothesis. And it is used for decision making of optimal swarm strategy. By T-cell modeling, adaptation ability of robot is enhanced in dynamic environments.

• Journal of Soil and Groundwater Environment
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• v.25 no.4
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• pp.87-97
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• 2020

In this study, the applicability of the geostatistical evolution strategy as an inverse analysis method of estimating hydraulic properties of small-scale basin was tested. The geostatistical evolution strategy is a type of data assimilation method that can effectively estimate aquifer hydraulic conductivity by combining a global optimization model of the evolution strategy and a local optimization model of the ensemble Kalman filtering. In the applicability test, the geometry, hydraulic boundary conditions, and the distribution of groundwater monitoring wells of Hanlim-Eup were employed. On the other hand, a synthetic hydraulic conductivity distribution was generated and used as the reference property for ease of estimation quality assessment. In the estimations, two different cases were tested where, in Case I, both groundwater levels and hydraulic conductivity measurements were assumed to be available, and only the groundwater levels were available, in Case II. In both cases, the reference and estimated hydraulic conductivity fields were found to show reasonable similarity, even though the prior information for estimation was not accurate. The ability to estimate hydraulic conductivity without accurate prior information suggests that this method can be used effectively to estimate mathematical properties in real-world cases, many of which little prior information is available for the aquifer conditions.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.3
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• pp.238-248
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• 2016

In this study, an automatic command mode transition strategy of direct power control (DPC) is proposed for permanent magnet synchronous generators (PMSGs) medium-voltage (MV) offshore wind turbines (WTs). Benchmarking against the control methods are performed based on a three-level neutral-point-clamped (NPC) back-to-back type voltage source converter (VSC). The ramping rate criterion of complex power is utilized to select the switching vector in DPC for a three-level NPC converter. With a grid command and an MPPT mode transition strategy, the proposed control method automatically controls the generated output power to satisfy a grid requirement from the hierarchical wind farm controller. The automatic command mode transition strategy of DPC is confirmed through PLECS simulations based on Matlab. The simulation result of the automatic mode transition strategy shows that the proposed control method of VOC and DPC achieves a much shorter transient time of generated output power than the conventional control methods of MPPT and VOC under a step response. The proposed control method helps provide a good dynamic performance for PMSGs MV offshore WTs, thereby generating high quality output power.

• Journal of The Korean Association of Information Education
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• v.21 no.6
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• pp.657-664
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• 2017

This study investigates the effect of play-based software education instruction strategy for improving computational thinking as a method of software education. The play-based instruction strategy is a teaching-learning strategy in which the presented code is navigated through play, and the functions are revised and newly reconstructed. We designed an education program with the play-based instruction strategy and applied the program to elementary students. In order to verify the effectiveness of the research, we examined the competence of computing thinking concept and computing thinking practice. As a result, the computing thinking concept and computational thinking practice were that the proposed teaching-learning model is higher than the direct teaching method.