• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.162-164
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• 2004

This paper proposes a new classification system combining the adaptive feature weighting algorithm using the genetic algorithm and the modified KNN rule. GA is employed to choose the middle value of weights and weights of features for high performance of the system. The modified KNN rule is proposed to estimate the class of test pattern using adaptive feature space. Experiments with the unconstrained handwritten digit database of Concordia University in Canada are conducted to show the performance of the proposed method.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.159-161
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• 2004

Many motion object detection algorithms rely on the process of background subtraction, an important technique that is used for detecting changes from a model of the background scene. This paper propose a novel method to update the background model image of a visual surveillance system which is not stationary. In order to do this, we use a background model based on statistical qualities of monitored images and another background model that excluded motions. By comparing each changed area computed from the two background model images and current monitored image, the areas that will be updated are decided.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.11 no.3
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• pp.143-148
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• 2011

In this paper, a backstepping design is proposed to achieve stabilization and synchronization for the Lorenz-Stenflo (LS) chaotic system. The proposed method is a recursive Lyapunov-based scheme and provides a systematic procedure to design stabilizing controllers. The proposed controller enables stabilization of the chaotic motion and synchronization of two identical LS chaotic systems using only a single control input. Numerical simulations are presented to validate the proposed method.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.11 no.1
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• pp.65-70
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• 2011

The increased disk rotational velocity to improve the data transfer rate has raised up many serious problems in its servo control system which should control the position and velocity of a spot relative to a rotating disk. This paper proposes gain-scheduling-based track-seek control for single stage actuator of hard disk drives. Gain scheduling is a technique that can extend the validity of the linearization approach to a range of operating points and one of the most popular approaches to nonlinear control design. The proposed method schedules controller gains to improve the transient response and minimize overshoot during the functions of the read/write head positioning servomechanism for the seek control. The validity of the proposed method is demonstrated through stability analysis and simulation results.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.4
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• pp.27-32
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• 2010

This paper presents an investigation into the pinhead forming process with the objective of finding the optimal forming conditions. In order to this, the orbital forming analysis of a heading MIG was carried out using the explicit finite element method. Relationships between temperature by forming of load and stresses, rake angle by forming final shape and stress distribution were investigated through analysises in order to find an efficient solution. As a result, the higher temperature and orbital rake angle were the better forming conditions.

• Proceedings of the KWS Conference
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• v.43
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• pp.61-63
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• 2004

Recently many research works are going on in the field of application of Laser-Arc hybrid welding for superstructures such as shipstructures. However, the study on heat distribution and welding residual stress of hybrid weld by numerical simulation loaves much to be desired. Therefore in this study an optimized welding condition and numerical simulation for hybrid welding by using Previous numerical analysis which was used to calculate the kent source for hybrid welding has been analyzed.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.519-521
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• 1994

In this paper, the welding machine with high-frequency inverter is described, which can save energy more than conventional ones with low efficiency. Although for part of welding machine of special type such as MIG, TIG, products were developed by inverter, but it is poor that applied to ordinary ac arc welding machine. Difference between conventional AC arc welding machine and the proposed welding machine is investigated econimically and constructionally. Untill now, kinds of welding machine and its characteristics were also described. The comparison of the proposed welding machine and the conventional is presented in the way of output control.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1309-1312
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• 1987

Hyperthermia for the treatment of cancer has been introduced for a long time and the biological effect for the use of hyperthermia to malignant tumors has been well established and encouraging clinical results has been observed. Unfortunately, the engineering or technical aspects of hyperthermia for the deep seated tumors has not been satisfactory. We have researched and developed the radiofrequency capacitive hyperthermia system (GHT- RF8). It was composed with 8-9 MHZ RF generator, capacitive electrode, matching system, cooling system, temperature measuring system and control computer. The thermal profile was investigated in agar phantom, animals and in human tumors, which was heated with capacitive RF device.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1170-1173
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• 1987

A network flow control method, input buffer limit technique which can adjusts the transit traffics in a node, is proposed. The transit traffics that occupy node buffers more threshold are decreased. It has better performance than input buffer limit. The proposed flow control is analyzed by queueing model. Numerical results of some example are shown.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1174-1177
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• 1987

The design of flow control protocols for integrared networks with complete voice traffic on the data link level is investigated. The class of admissible flow control policies analyzed maximized the average data link throughput subject to an average system time delay constraints a finite intervals (O,s). In particular, it is shown that the optimum control law is bang-bang (window flow mechanism). The window size L can be analytically derived from maximum tolerated time delay T, the input arrival C of the queueing system, the duration of the time interval S, the initial number of packets in the queue.