• Journal of Korea Society of Industrial Information Systems
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• v.27 no.6
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• pp.105-114
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• 2022

We examine berth allocation problems in tidal bulk ports with an objective of minimizing the demurrage and dispatch associated berthing cost. In the proposed optimization model inventory (or stock) level constraints are considered so as to satisfy the service level requirements in bulk terminals. It is shown that the mathematical programming formulation of this research provides improved schedule resolution and solution accuracy. We also show that the conventional big-M method of standard resource allocation models can be exempted in tidal bulk ports, and thus the computational efficiency can be significantly improved.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.207-216
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• 2014

Purpose : We present a method to reduce this gap and complete the treatment plan, to be made by the re-optimization is performed in the same conditions as the initial treatment plan different from Monaco treatment planning system. Materials and Methods : The optimization is carried in two steps when performing the inverse calculation for volumetric modulated radiation therapy or intensity modulated radiation therapy in Monaco treatment planning system. This study was the first plan with a complete optimization in two steps by performing all of the treatment plan, without changing the optimized condition from Step 1 to Step 2, a typical sequential optimization performed. At this time, the experiment was carried out with a pencil beam and Monte Carlo algorithm is applied In step 2. We compared initial plan and re-optimized plan with the same optimized conditions. And then evaluated the planning dose by measurement. When performing a re-optimization for the initial treatment plan, the second plan applied the step optimization. Results : When the common optimization again carried out in the same conditions in the initial treatment plan was completed, the result is not the same. From a comparison of the treatment planning system, similar to the dose-volume the histogram showed a similar trend, but exhibit different values that do not satisfy the conditions best optimized dose, dose homogeneity and dose limits. Also showed more than 20% different in comparison dosimetry. If different dose algorithms, this measure is not the same out. Conclusion : The process of performing a number of trial and error, and you get to the ultimate goal of treatment planning optimization process. If carried out to optimize the completion of the initial trust only the treatment plan, we could be made of another treatment plan. The similar treatment plan could not satisfy to optimization results. When you perform re-optimization process, you will need to apply the step optimized conditions, making sure the dose distribution through the optimization process.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.8
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• pp.635-640
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• 2006

An optimizer has been applied for the optimal design of pipe diameters in the pipe flow network problems. Pipe network flow analysis, which is developed separately, is performed within the interface for the optimization algorithm. A pipe network is chosen for the test, and optimizer GenOpt is applied with Holder-Mead-O'Niell's simplex algorithm after solving the network flow problem by the Newton-Raphson method. As a result, optimally do-signed pipe diameters are successfully obtained which minimize the total design cost. Design cost of pipe flow network can be considered as the sum of pipe installation cost and pump operation cost. In this study, a practical and efficient solution method for the pipe network optimization is presented. Test system is solved for the demonstration of the present optimization technique.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.2
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• pp.117-124
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• 2011

Valve springs with non-circular cross-section are widely used in automotive engines. Because of the reduced height, the oval cross-section provides some merits in its install height and stress distribution. This paper introduces a new method to generate optimal shape of the non-circular cross-section. For given width and height, arbitrary shape of the cross-section are described using the Hermite spline curves. Cross-section area and maximum stress level are chosen as performance indices, and nonlinear optimization problems are formulated with inequality constraints. Compared to a production spring wire, cross-section area can be reduced about 2.4 [%] without increasing maximum stress level. In addition, the other approach gives an optimum cross-section which reduces maximum stress level of 2.0 [%] without increasing cross-section area.

• Journal of the Korea Computer Industry Society
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• v.4 no.12
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• pp.937-942
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• 2003

Component development of EJB base is activated newly been using widely object oriented analysis and design method recently. Usually, case that use permanent data that use database in EJB base bean creation is much. Separated DBMS connection that various DBMS is applied been subordinate to each entity bean used in the environment in this paper applying DAO pattern, and is normalized object oriented design and analysis because using UML and standardization so that can create done class optimized modelling do.

• 전자공학회논문지 IE
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• v.49 no.2
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• pp.40-45
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• 2012

In this paper, cooling system of power transformers is proposed for temperature optimized control. We predict the peak temperature of power transformer coils using load factors and construct a cooling system using weighting function. For the optimized temperature control for power transformer, a correlation function based on the load factor of a load current and the each temperatures for winding coils, for air and for oil is presented to predict the winding-coil peak temperature. Also, the results controlled by applying the power transformer is presented.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.699-704
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• 2000

The present paper deals with a multiobjective optimization method based on the co-evolutionary genetic strategy. The co-evolutionary strategy carries out the multiobjective optimization in such way that it optimizes individual objective function as compared with each generation's value while there are more than two genetic evolutions at the same time. In this study, the designs that are out of the given constraint map compared with other objective function value are excepted by the penalty. The proposed multiobjective genetic algorithms are distinguished from other optimization methods because it seeks for the optimized value through the simultaneous search without the help of the single-objective values which have to be obtained in advance of the multiobjective designs. The proposed strategy easily applied to well-developed genetic algorithms since it doesn't need any further formulation for the multiobjective optimization. The paper describes the co-evolutionary strategy and compares design results on the simple structural optimization problem.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.208-208
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• 2012

알루미늄이 도핑된 p+후면 에미터 구조를 갖는 n-type 결정질 실리콘 태양전지를 제작하였다. 기판으로는 n-type Cz 실리콘 웨이퍼가 사용되었으며 크기, 두께 및 비저항은 각각 6"x 6", $200{\mu}m$, $3{\sim}5{\Omega}cm$이었다. 실험을 통하여 에너지 변환 효율 17.5%를 얻었다. 모든 공정은 p-type 실리콘 상용 태양전지 제작에 쓰이는 것과 동일하게 적용하였다. 또한 PC1D 시뮬레이션을 통하여 전면 전계의 두께 및 피크 농도, 기판의 소수 운송자 수명, 후면 에미터의 도핑 농도, 실리콘 기판의 두께를 변수로 하여 후면 에미터 구조의 n-type 실리콘 태양전지의 최적화 작업을 실시하였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2010.07a
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• pp.257-260
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• 2010

통신 기술과 모바일 기술의 발달로 인해, 이 두 기술을 융합된 모바일IPTV가 탄생하였다. 하지만, 모바일IPTV는 기존의 IPTV와는 달리 방대한 종류의 디바이스와 그에 따른 제공하는 비디오 포맷과 같은 제약들이 존재한다. 하지만 기존의 서비스는 다양한 이기종의 모바일 장치의 특성을 고려하지 않고 서비스 제공자가 모든 사용자에게 같은 서비스를 제공하기 때문에 사용자는 콘텐츠의 포맷이나 용량으로 인하여 장치에 알맞은 컨텐츠를 받지 못할 경우가 있으며 혹은 신속하게 서비스를 제공받지 못할 경우가 있다. 위와 같은 문제를 해결하기 위해서, 본 논문에서는 CC/PP(Composite Capabilities / Preference Profile)를 이용하여 이기종의 모바일IPTV 장치들의 규격 및 특성을 분석하고, 이를 통해 다양한 기종의 모바일IPTV 사용자들에게 장치의 특성에 맞는 맞춤형 서비스를 최적화하여 제공할 수 있는 시스템을 제안한다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.53-53
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• 2011

도금 시뮬레이션 기법은 도금 용액 개발에서부터 도금설비 제작, 공정 최적화 및 trouble shooting에 이르기까지 도금 산업 전반에서 응용이 될 수 있다. 현재 우리나라에서는 도금 시뮬레이션을 연구하는 연구자나 적용하여 사용하는 도금 업체는 매우 드물다. 본 발표에서는 도금 시뮬레이션 기법에 대한 이론과 절차 등을 설명하고 시뮬레이션 기법을 적용하여 공정 최적화나 도금 두께 균일화를 이룬 몇 가지 사례에 대하여 소개하고자 하였다.