• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.312-315
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• 2004

This paper presents a tuning-free conditional integration anti-windup strategy for induction machine with Proportional-Integral (PI) type speed controller. The on/off condition of integral action is determined by the frequency domain analysis of machine torque command without a prior knowledge of set-point changes. There are no tuning parameters to be selected by users for anti-windup scheme. In addition, the dynamic performance of the proposed scheme assures a desired tracking response curve with minimal oscillation and settling time even in the change of operating conditions. This algorithm is useful in many high performance induction machine applications not to allow the oscillation and overshoot of speed/torque responses. The main idea can be extended to general applications such as chemical processes and industrial robots.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.6
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• pp.538-548
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• 2014

This study provides a robust control of a grid-connected three-phase two-level photo voltaic inverter. The introduced control method uses the cascade control strategy to regulate AC-side current and DC-link voltage. A robust controller with integration action is used for the inner-loop AC-side current control, which maximizes the convergence rate using a linear matrix inequality-based optimization design method and eliminates the offset error. The robust controller design method considers the parameter uncertainty set to accommodate parameter mismatch and un-modeled components in the inverter model. An outer-loop proportional-integral controller is used to regulate DC-link voltage with linearization of DC/AC relation. The proposed control strategy is applied to a grid-connected 100 kW photo voltaic inverter.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.200-207
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• 2003

Today we have excellent motor drive system using high frequency carrier PWM control voltage source inverter with vector control strategy. In the other hand, we have met serious problems caused by high frequency switching. PWM Cyclo-converter called Matrix converter is expected as the new strategy possible to improve these problems and add some more convenient features suitable for new drive system with system integration. In this paper, we will introduce the background of this development and features of this converter from our research, additionally introduce remarkable active promotions for this converter as a survey.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.399-405
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• 2004

With the explosive growth of information sources available under various information technology and business environment, it has become increasingly necessary for determining effective marketing strategies and optimizing the logical structure of the CRM data mining system. In this paper, we present an overview of the data mining for strategy focused CRM structure. This includes preprocessing, transaction identification and data integration components. We describe the main part of this paper to the discussion of processes and problems that characterize the mining tools and techniques, identify the CRM data mining, and provide a general architecture of a system to do focused CRM data mining that require further research and development.

• Korean Management Science Review
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• v.23 no.1
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• pp.135-152
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• 2006

Over the last decade, the field of supply chain management (SCM) and e-business has received an enormous amount of attention from practitioners and academicians. However, little has been known about how and to what extent small- to medium-sized enterprises (SMEs) are implementing SCM initiatives and e-business practices. This paper proposes a comprehensive research model and presents the survey results of these practices of SMEs located in Wisconsin and illinois, U.S., In terms of competitive strategy and priority, value chain activity priority, supply chain and e-business integration focus, SCM best practices implementation focus and challenges, and business performance. The analysis reveals several valuable insights into how SMEs should run their businesses in today's volatile, rapidly changing customer economy.

• Korean Journal of Child Studies
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• v.27 no.1
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• pp.95-111
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• 2006

In this study of acculturation strategies and adjustment in Korean-Chinese and Chinese-Korean children, 273 Korean-Chinese and 207 Chinese-Korean were asked about levels of assimilation to the mainstream language and culture, ethnic identity, emotional attitude toward their schools, teachers' support, peers' support, and social distance from the mainstream. Results revealed that separation was the most preferred strategy followed by integration, assimilation, and marginalization for both subject groups. Children categorized by separation strategies reported highest scores in school adjustment variables and lowest scores in social distance. There were some differences between Korean-Chinese and Chinese-Korean children in cultural assimilation, ethnic identity, emotional attitude toward school, and teacher's support. These findings were explained by their immigration history and the uniqueness of each mainstream society.

• Spatial Information Research
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• v.13 no.2 s.33
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• pp.185-194
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• 2005

The purpose of this study is to create address standardization through an Algorithm based on cadastral maps, as well as to establish a method of transforming one information area to all of the domestic areas in relation to the geographic information system. To do this, it analyzed the current level of e-government cadastral data and their integration strategy with addresses of both the administrator and the cadastral data. This study will provide a more efficient method for co-operative work between private sector and public sector. In addition, we can expect that the information strategy of local government will become more active.

• Structural Engineering and Mechanics
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• v.14 no.2
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• pp.223-236
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• 2002

The main objective of the present paper is to address a formal procedure for orthotropic steel plates design. The theme of the proposed approach is to recast the design procedure into a mathematical programming model. The objective function to be optimized is the total weight of the structure. The total weight is function of its layout parameters and structural element design variables. Mean while the proposed approach takes into consideration the strength and rigidity criteria in addition to other dimensional constraints. A nonlinear programming model is developed which consists of a nonlinear objective function and a set of implicit/explicit nonlinear constraints. A transformation method is adopted for minimization strategy, where the primal model constrained problem is transformed into a sequence of unconstrained minimization models. The search strategy is based on the well-known Fletcher/Powell algorithm. The finite element technique is adopted for discretization and analysis strategies. Mindlin theory is selected to simulate the finite element model and a selective reduced integration scheme is exploited to avoid a shear lock problem.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.12
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• pp.629-637
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• 2005

This paper proposes a new anti-windup strategy to suppress integrator windup for PI speed controller and to be implemented on the existing system with minimal modification. When the speed control mode is changed from P controller to PI controller. an appropriate initial value for integrator is assigned. This value restricts overshoot and high settling time. Also, the proposed method guarantees the designed performance independent on operating conditions, i.e. different set-point change and load torque. Simulation and experimental results for PMSM speed controller have shown its superior performance compared with the conditional integration and tracking back calculation.

• Journal of Information Processing Systems
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• v.14 no.3
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• pp.607-620
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• 2018

The problem surrounding methods of implementing the software testing process has come under the spotlight in recent times. However, as compliance with the software testing process does not necessarily bring with it immediate economic benefits, IT companies need to pursue more aggressive efforts to improve the process, and the software industry needs to makes every effort to improve the software testing process by evaluating the Test Maturity Model integration (TMMi). Furthermore, as the software test process is only at the initial level, high-quality software cannot be guaranteed. This paper applies TMMi model to Automobile control software testing process, including test policy and strategy, test planning, test monitoring and control, test design and execution, and test environment goal. The results suggest improvement of the automobile control software testing process based on Test maturity model. As a result, this study suggest IT organization's test process improve method.