• Journal of the Korean Operations Research and Management Science Society
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• v.13 no.2
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• pp.47-58
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• 1988

The dynamic uncapacitated facility location model is formulated by a mixed integer programming. It has the objective of minimizing total discounted costs for meeting demands specified in different time periods at various demand centers. Costs include those for operation of facilities to demand centers and a fixed cost associated with the capital investment. The problem is decomposed into two simple Lagrangian relaxed subproblems which are coordinated by Lagrangian multipliers. We explored the effect of using the subgradient optimization procedure and a viable solution approach is proposed. Computational results are presented and further research directions are discussed.

• Journal of Chest Surgery
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• v.20 no.3
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• pp.548-551
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• 1987

Thoracoscopy, mediastinoscopy and/or mediastinotomy and explo-thoracotomy were performed and confirmed diagnosis of the 26 cases of the mediastinal tumors, those were admitted and treated at the Department of Thoracic and Cardiovascular surgery, Chonbuk National University Hospital, from June,1976 to September, 1986. We experienced 7 thoracoscopies, 7 mediastinoscopies &/or mediastinotomies, and 12 explo-thoracotomies. The most common histologic type was teratoma and lymphoma [6 cases]. Of the 26 cases of the histologically confirmed mediastinal tumor, 19 were benign tumors and 7 were malignants. 19 cases of benign tumors were surgically resected with good result but one case of the surgically resected malignant thymoma was recurred 4 months later. 6 cases of malignant lymphoma and one case of recurred malignant thymoma were treated with chemo-and radiation therapy. Thoracoscopy and mediastinoscopy with tissue biopsy were simple in procedure and had a tissue diagnosis with obtaining the pathologic tissue in a acceptable complication rate and reduced exploratory thoracotomy.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.10a
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• pp.127-133
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• 2001

Photoelastic isochromatic fringes related to the difference of principal stresses have some bandwidth whose light intensities are not constant and unsymmetrical in experimental image. Hence it is difficult to measure fringe order accurately at a data point by visual observation. In this study, the method of fringe sharpening, which can extract sharpened lines from both full-and half-order fringes by digital image processing, is developed. To test the method, various simple photoelastic fringe patterns are simulated and their image are processed to yield sharpened lines. The method is than applied to general problem such as image of a circular disk compressed by concentrated loads and a cylinder subjected to internal pressure. The procedure is proved to be capable of extracting sharpened lines accurately from photoelastic isochromatic fringes.

• Journal of Institute of Control, Robotics and Systems
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• v.2 no.1
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• pp.14-20
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• 1996

This paper presents a self tuning method of a velocity type PID controller for minimum or non-minimum phase systems with time delays. The velocity type PID control structure is determined in the process of minimizing the variance of the auxilliary output, and self tuning effect is achieved through the recursive least square algorithm at the parameter estimation stage and also through the Robbins-Monro algorithm at the stage of optimizing a design parameter. This method is simple and effective compared with other existing methods[1,2]. Numerical examples are included to illustrate the procedure and to show the performance of the control system.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.7
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• pp.607-612
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• 2002

An automatic design method of behaviors in behavior-based robotics is proposed. With this method, a robot can design its behaviors by itself without aids of human designer. Automating design procedure of behaviors can make the human designer free from somewhat tedious endeavor that requires to predict all possible situations in which the robot will work and to design a suitable behavior for each situation. A simple reinforcement learning strategy is the main frame of this method and the key parameter of the learning process is significant change of reward value. A successful application to mobile robot navigation is reported too.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.6
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• pp.1195-1209
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• 1997

This paper presents a new morphological spatio-temporal segmentation algorithm. The algorithm incorporates luminance and motion information simultaneously, and uses morphological tools such as morphological filtersand watershed algorithm. The procedure toward complete segmentation consists of three steps:joint marker extraction, boundary decision, and motion-based region fusion. First, the joint marker extraction identifies the presence of homogeneours regions in both motion and luminance, where a simple joint marker extraction technique is proposed. Second, the spatio-temporal boundaries are decided by the watershed algorithm. For this purposek, a new joint similarity measure is proposed. Finally, an elimination ofredundant regions is done using motion-based region function. By incorporating spatial and temporal information simultaneously, we can obtain visually meaningful segmentation results. Simulation results demonstratesthe efficiency of the proposed method.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.374-379
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• 1994

This paper deals with the problem of plate separation and anchorage at the ends of steel plates strengthened by EBSP. Test results show that the reinforced concrete beams strengthened by EBSP occurs the premature failure without the beams achieving their full flexural strength at the end of plates. The premature failure is the cause of stress concentrations in the adhesive layer of plate, reinforced concrete incase of lack of plate length. Then a simple, approximate procedure for predicting the shear and normal stress concentrations is investigated by Robert's the ory based on partial interaction theory. The theoretical results are compared, and show close agreement with test results. A method is derived for determining the plate length that prevents the premature anchorage zone failure

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.4
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• pp.185-194
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• 2007

This paper presents a motor selection technique for a manipulator design that is used in a multipurpose dog-horse robot. Since the dynamics of a manipulator and its servo drives are closely related to each other, it requires a repetitive analysis to determine a suitable motor. In order to simplify this procedure, Straete et al. proposed a simple normalization method to separate the load dependent terms and the motor dependent terms. This technique is adopted in this paper for selecting a motor in designing a manipulator.

• ETRI Journal
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• v.33 no.1
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• pp.50-59
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• 2011

In the current very deep submicron technology era, fault tolerant mechanisms perform an essential function to cope with the effects of soft errors. To evaluate the effectiveness of the fault tolerant mechanism, reliability engineers use simulated fault injections using either saboteur modules or mutants in the simulation model. However, the two methods suffer from both inefficiency in the simulation mechanism and difficulties with the experimental setups. To overcome these inefficiencies, we propose the Verilog-based simulated fault injection (VFI) technique. VFI has the following advantages. First, modification of the design model is unnecessary. Second, the fault injection simulation procedure is simple and efficient. Third, various types of fault injection experiments can be performed. To evaluate the effectiveness of the proposed methodology, we developed a VFI environment using the ICARUS Verilog Simulator. From the experimental results, we were able to qualitatively evaluate the reliability of the target simulation models and to assess the effectiveness of the employed fault-tolerance mechanisms.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.90-94
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• 2000

A conventional power supply to drive a microwave oven has ferro-resonant transformer and high voltage capacitor(HVC). Though it is simple transformer is bulky heavy and has low-efficiency. To improve this defect a high frequency switching inverter-type power supply has been investigated an developed. in recent years. But because of it's additional circuit and devices inverter-type power supply is more expensive than conventional one. In this paper The design procedure of a novel HVC embedded high frequency transformer is proposed for down-sizing and cost reduction. Also transformer equivalent circuit model is derived by FEM analysis and parameter measurements. And the operation of proposed HVC embedded transformer is verified by simulation and experimental results.