• ETRI Journal
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• v.42 no.3
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• pp.366-375
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• 2020

The network traffic prediction of a smart substation is key in strengthening its system security protection. To improve the performance of its traffic prediction, in this paper, we propose an improved gravitational search algorithm (IGSA), then introduce the IGSA into a wavelet neural network (WNN), iteratively optimize the initial connection weighting, scalability factor, and shift factor, and establish a smart substation network traffic prediction model based on the IGSA-WNN. A comparative analysis of the experimental results shows that the performance of the IGSA-WNN-based prediction model further improves the convergence velocity and prediction accuracy, and that the proposed model solves the deficiency issues of the original WNN, such as slow convergence velocity and ease of falling into a locally optimal solution; thus, it is a better smart substation network traffic prediction model.

• Proceedings of the Korean Society for the Gifted Conference
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• 2005.05a
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• pp.173-180
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• 2005

The purpose of this study was to identify common and domain-specific cognitive characteristics of gifted students based on a hierarchical structural model of human abilities. This study is based on the premise that abilities identified by tests can appear as observable characteristics in test or school situations. Abilities proposed by major models of intelligence were reviewed in terms of their power to explain cognitive characteristics of gifted students. However, due to the lack of their explanatory power and disagreement on common and domain-specific cognitive abilities, a new hierarchical structural model was conceptualized in a unique way based on interrelationships between abilities proposed by the models. The newly established model hypothesizes a cognitive mechanism that accounts for how domain-specific knowledge is formed, as well as which abilities are common and domain-specific, how they are related functionally, and how they account for common and domain-specific cognitive characteristics of gifted students. The cognitive mechanism has important implications for our understanding of the chronically controversial concepts, 'intelligence' and 'knowledge.' Clearer definitions of what intelligence is (g or multiple), what knowledge is, and how knowledge develops ('genetic or environmental,' 'rationalistic or empiricist') may result from this model.

• Structural Engineering and Mechanics
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• v.57 no.3
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• pp.389-402
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• 2016

Based on the traditional mechanical model of thin-walled straight beam, the paper makes analysis and research on the pre-twisted thin-walled beam finite element numerical model. Firstly, based on the geometric deformation differential relationship, the Saint-Venant warping strain of pre-twisted thin-walled beam is deduced. According to the traditional thin-walled straight beam finite element mechanical model, the finite element stiffness matrix considering the Saint-Venant warping deformations is established. At the same time, the paper establishes the element stiffness matrix of the pre-twisted thin-walled beam based on the classic Vlasov Theory. Finally, by calculating the pre-twisted beam with elliptical section and I cross section and contrasting three-dimensional solid finite element using ANSYS, the comparison analysis results show that pre-twisted thin-walled beam element stiffness matrix has good accuracy.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.502-506
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• 1992

In this study, we proposed the fuzzy modeling method and designed a model-based logic controller for Activated and Sludge Process(A.S.P.) in sewage treatment. The identification of the structure of fuzzy implications is carreid out by use of fuzzy c-means clustering algorithm. And to identify the parameters of fuzzy implications, we used the complex and the least square method. To tune the premise parameters automatically the complex method is implemented. The model-based fuzzy controller is designed by rules generated from the identified A.S.P. fuzzy model. The feasibility of the proposed approach is evaluated through the identification of the fuzzy model to describe an input-output relation of the A.S.P.. The performance of identified model-based fuzzy controller is evaluated through the computer simulations.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1027-1031
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• 1990

In this paper, we propose a model-based method of estimating the velocity of a moving object from a series of images. The proposed method utilizes Kalman filtering technique. Assuming that the motion is described by an affine transformation, we construct a discrete-time state variable model of the motion based on the dynamic motion imagery modeling technique proposed by Schalkoff. Using this state variable model, we derive a Kalman filter algorithm. Some simulation results are presented to show that the proposed Kalman filter algorithm is superior to a simple least square method without a model.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.3
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• pp.102-113
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• 2010

In this research, we proposed a quality evaluation standard model which is suitable for the internet shopping mall based on the Malcolm Baldrige National Quality Award model. A 7-Point Likert Scale was used based on the seven categories within the 2008 Malcolm Baldrige Criteria : Leadership, Strategic Planning, Customer and Market Focus, Measurement Analysis and Knowledge Management, Workforce Focus, Process Management, and Result. Furthermore, we analysed the validity and causal relationship among the factors within the model. The goal of this research is to find a rational standard to evaluate internet shopping malls nationwide and help the structuring and the operation of these malls. The results may be used not only as a tool to evaluate internet shopping mall sites but also as a guideline to improve the quality of a internet shopping mall site that is under development.

• Journal of Engineering Education Research
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• v.15 no.3
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• pp.40-46
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• 2012

This paper deals with an example of the engineering education through the SE-based development of an underwater-robot kit model. It has a purpose of establishing the example of a SE-based development by undergraduate through executing the requirement and functional analysis, hardware and software design, manufacturing, test and evaluation for developing the model. In addition, it also has a purpose of establishing the basis of the development of an optimized underwater-robot kit through understanding the weight and buoyancy characteristics and the actuation and propulsion characteristics of the developed model.

• Journal of Power System Engineering
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• v.19 no.3
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• pp.42-47
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• 2015

This paper studies on the design of a servo controller for an antilock brake system(ABS) based on the car tire model. First, a nonlinear differential equation of the car tire is constructed and its linearization model is obtained by Taylor's series. Second, a servo controller based on the mathematical model is analytically designed to obtain the maximum brake force, where the tire velocity and the slip ratio of car tire are respectively controlled to the given command values. Third, it is theoretically shown that the proposed control algorithm has good usefulness in ABS.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.329-335
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• 2004

An, FE-based, on-line model is presented for the rapid and precise prediction of roll thermal profile in hot strip rolling. The validity of the model is demonstrated through comparison with FE-based off-line model which was verified by measurements. Also demonstrated is its capability of reflecting the effect of diverse process variables.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.4
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• pp.356-362
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• 2002

In this paper, well-known Takagi-Sugeno fuzzy model is used as the nonlinear plant model and uncertainty is assumed to be included in the model structure with known bounds. Based on the fuzzy models, a numerical robust stability analysis for the fuzzy feedback linearization regulator is presented using Linear Matrix Inequalities (LMI) Theory. For these structured uncertainty, the closed system can be cast into Lur'e system by simple transformation. From the LMI stability condition for Lur'e system, we can derive the robust stability condition for the fuzzy feedback linearization regulator based on Takagi-Sugeno fuzzy model. The effectiveness of the proposed analysis is illustrated by a simple example.