• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.134-137
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• 2003

Both browsing and retrieval with search engines are major operations that establish the interaction between users and the Web. Although both operations are usually combined to locate information from the Web, recent growth of the Web has overtaken the potential of this conventional interaction. This paper proposes the concept of Retrieve, Browse, and Analyze (RBA)-based interactions, as the improvement of the conventional Retrieve and Browse (RB)-based interaction. The prototype interface based on RBA-based interaction is also presented.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.57-62
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• 1998

This paper presents an auto tuning method of PID controller based on the application of fuzzy logic. The proposed method combined the principles of PID control with fuzzy control, which cam considerably improve the performance index of PID controller. Simulation results show that higher performance and accuracy of overall system for desired value is achieved with our manner when compared to widely-used conventional tuning method.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.3
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• pp.275-280
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• 1999

This paper presents a disturbance accommodating sliding mode control for a quarter-car active suspension using an electro-hydraulic actuator. The electro-hydraulic actuator model is nonlinear and uncertain. The hardware constrains on the actuator prevent high gain in a sliding mode control, which deteriorates the force tracking performance. DAC(Disturbance Accommodating Control) is combined with the sliding mode control to improve the tracking performance. DAC observer estimates the pressure due to the actuator uncertainty. The additional control is designed to compensate the estimated pressure. Simulation results show the improved tracking performance with the Proposed control methods.

• Transactions on Control, Automation and Systems Engineering
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• v.2 no.3
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• pp.196-200
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• 2000

A neural controller for process control is proposed that combines a conventional multi-loop PID controller with a neural network. The concept of target signal based on feedback error is used fur on-line learning of the neural network. This controller is applied to distillation column control to illustrate its effectiveness. The result shows that the proposed neural controller can cope well with disturbance, strong interactions, time delays without any prior knowledge of the process.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.102.1-102
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• 2002

In this paper, we propose Self-organizing neurofuzzy networks(SONFN) and discuss their comprehensive design methodology. The proposed SONFN is generated from the mutually combined structure of both neurofuzzy networks (NFN) and polynomial neural networks(PNN) for model identification of complex and nonlinear systems. NFN contributes to the formation of the premise part of the SONFN. The consequence part of the SONFN is designed using PNN. The parameters of the membership functions, learning rates and momentum coefficients are adjusted with the use of genetic optimization. We discuss two kinds of SONFN architectures and propose a comprehensive learning algorithm. It is shown that this network...

• Asia pacific journal of information systems
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• v.3 no.1
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• pp.155-189
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• 1993

Empirical studies have shown that the performance of decision tree induction usually improves when the trees are pruned. Whether these results hold in general and to what extent pruning improves the accuracy of a concept have not been investigated theoretically. This paper provides a theoretical study of pruning. We focus on a particular type of pruning and determine a bound on the error due to pruning. This is combined with PAC (Probably Approximately Correct) Learning theory to determine a sample size sufficient to guarantee a probabilistic bound on the concept error. We also discuss additional pruning rules and give an analysis for the pruning error.

• Transactions on Control, Automation and Systems Engineering
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• v.2 no.2
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• pp.136-139
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• 2000

A neural controller for process control is proposed that combines a conventional multi-loop PID controller with a neural network. The concept of target signal based on feedback error is used for on-line learning of the neural network. This controller is applied to distillation column control to illustrate its effectiveness. The result shows that the proposed neural controller can cope well with disturbance, strong interactions, time delays without any prior knowledge of the process.

• CDE review
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• v.4 no.2
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• pp.36-41
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• 1998

To survive in the intensive world wide automotive market, more and more automotive companies are investing their resources into concurrent engineering systems (CE) based on the combined CAD/CAM/CAE/ PDM technology. The main objectives of CE in automotive companies are the quality improvement of products and the reduction of cost and time to market. Remarkable effects are appearing from some of these companies. As shown in this paper, these successful automotive companies have been focusing on establishing the new process and methodology in applying CE into their car development process.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2007.02a
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• pp.58-60
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• 2007

The availability of Information Technology in geological and engineering geological fields is rapidly increasing in Korea. Especially GIS-based hazard mapping is the most distinctive part to predict a possibility of landslide occurrence. Integrated expert system for tunnel construction is also practically used to manage investigated or designed data and to predict un-known underground geological condition. Computer-based field data acquisition tools are also one of the typical part using information technology including GIS combined with mobile phone in Geological field.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.34
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• pp.9-14
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• 1995

A cost minimization model for designing AS/RS (Automated Storage/Retrieval Systtems) has been developed under the S/R (Storage/Retrieval) machine throughput rate and total storage capacity requirements. The objective function includes S/R machine cost storage rack cost, and interface conveyor cost. Since the model is a nonlinear integer programming problem which is very hard to solve with large problem size, the model is simplified using previous research results to be solved exactly and a simultion procedure is combined to verify that throughput rate requirements are satisfied.