• 제어로봇시스템학회:학술대회논문집
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• 1987.10a
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• pp.812-816
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• 1987

A quadratic regulator problem for a class of nonlinear system, in which a small parameter multiplies the control cost, is considered. In the analysis of the problem, we utilize the method of multiple time-scale decomposition which has been devised for analyzing complex linear cheap control problems. In so doing, we extend the class of nonlinear systems, considerably, for which the minimum cost becomes zero as the small parameter goes to zero.

• Journal of the Korean Data and Information Science Society
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• v.22 no.3
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• pp.549-553
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• 2011

In this paper, we deal with the problem of deciding the length of data for estimating the parameters in geometric Brownian motion. As an approach to this problem, we consider the change point test and introduce simple test statistic based on the cumulative sum of squares test (cusum test). A real data analysis is performed for illustration.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.32.5-32
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• 2001

There has been many teleoperation systems handling the micro object. However, the stability problem for these systems has not been mentioned yet. Historically, Lawrence[1] proposed the Transparency-Optimized Architecture and passivity theorem for stability analysis of bilateral teleoperation. He claimed that unless the task(or environment) impedance contains significance inertial behavior, Passivity condition for Transparency-optimized architecture is not satisfied. In this paper we propose one method which satisfies passivity condition for the micro-teleoperation system handling a insignificant inertial object and is based on the structure of Lawrence and Hashtrudi-Zaad[2] and velocity-force scaling.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.76.3-76
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• 2001

In this paper, an adaptive disturbance compensation technique is used in a tracking problem, under which the tracking reference is unknown. Based on a simple disturbance observer that effectively estimates the low frequency components of disturbance, the feedforward compensation is applied in addition to the conventional feedback control. Under the proposed compensation method, sensitivity analysis is given to illustrate the effectiveness. Finally, the proposed method is applied to the tracking problem in an optical storage system.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.69.3-69
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• 2002

The reliability of system is to become a important concern in developed industry. The controller based on the reliability is so important position. A reliable system is for system protection and human life by fault detection and control action against the transient condition of system. The aerospace system , nuclear reactor and chemical reactor are representative of a reliable system. This paper presents analysis of reliable system reliability, formal problem statement of optimal redundancy based on the reliability for a reliable system. And the problem is optimized by genetic algorithm. The genetic algorithms is useful algorithm in case of...

• Journal of applied mathematics & informatics
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• v.6 no.3
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• pp.727-734
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• 1999

Let G be a connected graph of n vertices. The problem of finding a depth-first spanning tree of G is to find a connected subgraph of G with the n vertices and n-1 edges by depth-first-search. in this paper we propose an O(n) time algorithm to solve this problem on permutation graphs.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.405-408
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• 2000

The objective of this paper is to develop a model to integrate process planning and resource planning through analysis of the machine tool selection and operations sequencing problem. The model is formulated as a travelling salesman problem with precedence relations. To solve our model, we also propose an efficient genetic algorithm based on topological sort concept.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.184-188
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• 2001

Severe vibration was detected during test operation in motor frame of the Turbo Chiller (300RT). To identify the vibration problem, vibration measurement and modal test were carried out. From the test results, it is concluded that the severe vibration occurred due to the resonance between the motor frame horizontal mode and the motor excitation frequency. Therefore the horizontal mode of the frame could be controlled by the sensitivity analysis results for the length of the supporting plate.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.04a
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• pp.141-145
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• 2000

A systematic method to find the optimal blank shape for sheet forming is proposed by coupling the numerical simulation technique. A weighted parameter was introduced in order to simplify the multi-variable optimization problem to a single-variable problem. The proposed method has been applied to the blank design of drawing processes to obtain the near-net shape within the required error bound after forming, Excellent results have been obtained between the numerical results and the target contour shapes. Through the investigation the proposed systematic method for optimal blank design is found to be effective in the practical forming processes

• Journal of Industrial Technology
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• v.15
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• pp.103-111
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• 1995

In this paper we evaluate the performance of the cached RAID5 which uses the parity cache and the data cache to overcome the small write problem. From the result of the simulation study we show that the cached RAID5 provides performance improvement with reasonable cache size.