• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.5
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• pp.87-92
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• 1985

A simple method to derive EID function which is necessary to compensate for the pro-ximity effect in electron-beam lithography is presented. Using optimization techniques, parameters of EID function is derived and well agreed with experimental valuta.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05b
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• pp.78-81
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• 2004

막을 이용한 기체분리의 경우 높은 투과도와 높은 선택도를 얻는 것은 매우 중요하면서도 어려운 일이다. 일반적으로 투과도가 높아지면 선택도가 낮아지고 선택도가 높아지면 투과도가 낮아지는 거동을 보인다. 이 두 가지의 특성을 적절히 조절하여 최적화하기 위하여 막은 기계적 강도를 높이기 위한 다공성의 지지층과 실질적인 분리가 일어나는 얇은 선택 층으로 구성된 복합막의 형태로 제조된다.(중략)

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.1
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• pp.157-163
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• 1998

A neural network structure able to perform the operations of analogue and binary addition is proposed. The network employs Hopfield' model of a neuron with the connection elements specified on the basis of an analysis of the energy function. Simulation using NMOS neurons has shown convergence predominantly to the correct global minima.

• The korean journal of orthodontics
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• v.41 no.1
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• pp.25-35
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• 2011

Objective: The purpose of this study was to optimize the thread pattern of orthodontic microimplants. Methods: In search of an optimal thread for orthodontic microimplants, an objective function stability quotient (SQ) was built and solved which will help increase the stability and torsional strength of microimplants while reducing the bone damage during insertion. Selecting the AbsoAnchor SH1312-7 microimplant (Dentos Inc., Daegu, Korea) as a control, and using the thread height (h) and pitch (p) as design parameters, new thread designs with optimal combination of hand p combination were developed. Design soundness of the new threads were examined through insertion strain analyses using 3D finite element simulation, torque test, and clinical test. Results: Solving the function SQ, four new models with optimized thread designs were developed (h200p6, h225p7, h250p8, and h275p8). Finite element analysis has shown that these new designs may cause less bone damage during insertion. The torsional strength of two models h200p6 and h225p7 were significantly higher than the control. On the other hand, clinical test of models h200p6 and h250p8 had similar success rates when compared to the control. Conclusion: Overall, the new thread designs exhibited better performance than the control which indicated that the optimization methodology may be a useful tool when designing orthodontic microimplant threads.

• Journal of Korea Water Resources Association
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• v.36 no.2
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• pp.161-172
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• 2003

This study has evaluated the stream gauge network with the main emphasis on if the current stream gauge network can catch the runoff characteristics of the basin. As the evaluation of the stream gauge network in this study does not consider a special purpose of a stream gauge, nor the effect from a hydraulic structure, it becomes an optimization of current stream gauge network under the condition that each stream gauge measures the natural runoff volume. This study has been applied to the Nam-Han River Basin for the optimization of total 31 stream gauge stations using the entropy concept. Summarizing the results are as follows. (1) The unit hydrograph representing the basin response from rainfall can be transferred into a probability density function for the application of the entropy concept to optimize the stream gauge network. (2) Accurate derivation of unit hydrographs representing stream gauge sites was found the most important part for the evaluation of stream gauge network, which was assured in this research by comparing the measured and derived unit hydrographs. (3) The Nam-Han River Basin was found to need at least 28 stream gauge stations, which was derived by considering both the shape of the unit hydrograph and the runoff volume. If considering only the shape of the unit hydrograph, the number of stream gauges required decreases to 23.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.4
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• pp.243-248
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• 2022

Weight optimization was performed for a rotorcraft shaft system using one-dimensional Euler-Bernoulli beam elements. Torsion, shaft support stiffness such as bearings, flange mass are all considered. To guarantee structural dynamic stability, eigenvalue analysis was performed to avoid critical speed and tooth mesh excitation form the gearbox. The weight optimization was performed by adjusting the thickness and radius while the length of the shaft was fixed, and the optimization process was divided into two stages. In the first, the weight is optimized with the torsional strength constraint. In the second, the difference between the primary mode of shaft and the critical speed is maximized so that the primary mode of the shaft can avoid the critical speed while the constraint on the torsional strength of the shaft is satisfied according to the standard for shaft system stability (AMC P 706-201, 1974). The proposed method was verified by comparing the results of the optimal design using the given one-dimensional beam elements with the stress results of the 3D finite element and the actual manufactured shaft.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.5
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• pp.8-17
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• 2002

This paper considers the problems of robust decentralized control for uncertain discrete-time large-scale systems with delays in interconnections and state feedback gain perturbations. Based on the Lyapunov method, the state feedback control design for robust stability is given in terms of solutions to a linear matrix inequality (LMI), and the measure of non-fragility in controller is presented. The solutions of the LMI can be easily obtained using efficient convex optimization techniques. A numerical example is included to illustrate the design procedures.

• Journal of Korea Multimedia Society
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• v.12 no.3
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• pp.436-444
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• 2009

As the interest in sensor networks has been increased recently, researches have been performed in many areas using sensor networks. In this paper, we propose and implement a lecture room control system based on a sensor network. It is possible to give an efficient lecture by collecting lecturers' lecture history information through the sensor network and controlling a PC, a beam projector, lights, etc. in a lecture room appropriately using the information. We construct a sensor network and perform experiments so that the proposed lecture room control system performs efficiently. Through the experiments, we obtained the optimal message generation period of the sensor node in a lecture room and the optimal number of sensor nodes deployed in a lecture room to communicate without any trouble between sensor nodes.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.3
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• pp.103-111
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• 1996

A generalized slope deflection method has already been developed by the authors from the existing one, and applied to the 3-dimensional structural analysis of tankers idealized as frame models to verify the effectiveness of the method from the analysis viewpoint. In this study, a minimum hull weight design program of tankers is developed to verify the effectiveness of the method from the design viewpoint by the combination of generalized slope deflection method and optimization method considering discrete design variables. By this program, it is possible to determine the scantling of each member of actual tankers that give minimum weight under given constraints. Also, a considerable weight saving has been found compared with existing ship.

• Polymer(Korea)
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• v.32 no.1
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• pp.19-25
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• 2008

The purpose of this study was improving the rheology properties of dentifrice by finding optimum binders polymer system which consists of carboxymethylcellulose (CMC), carbomer, and Mg/Al silicate. Response surface methodology (RSM) was employed to investigate the correlation between polymers and rheological properties of dentifrice and to optimize responses. Rheological properties were measured with oscillatory rheometer. As a result, it was identified that gel strength and yield stress were dependent on contents of CMC and carbomer and CMC caused long stringiness of dentifrice. And springness of dentifrice was dependent on contents of CMC and Mg/Al silicate. Optimum components proportion of polymers and silicate were obtained by responses optimization process. According to determined optimum components proportion, it was possible to observe a dentifrice with improved rheological properties.