• Korean Journal of Remote Sensing
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• v.21 no.2
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• pp.135-143
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• 2005

RPC(Rational Polynomial Camera) models have become the replacement model of choice for a number of high resolution satellite imagery providers. RPCs(Rational Polynomial Coefficients) provide a compact accurate representation of the ground to image geometry, allowing users to perform full photogrammetric processing of satellite imagery including block adjustment, 3D feature extraction and orthorectification. This paper presents an algorithm for 3D feature extraction using downhill simpler method which requires only function evaluations, not derivatives. The algorithm was implemented as an executable software program and tested using stereo IKONOS images of Seoul city. The results showed that the proposed algorithm was fast and accurate enough to be used as a practical method for the 3D feature extraction from stereo images with RPCs.

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.244-245
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• 2004

• The KSFM Journal of Fluid Machinery
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• v.2 no.1 s.2
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• pp.29-34
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• 1999

To develop the efficient numerical optimization method for the design of an airfoil, an evaluation of various methods coupled with two-dimensional Naviev-Stokes analysis is presented. Simplex method and Hook-Jeeves method we used as direct search methods, and steepest descent method, conjugate gradient method and DFP method are used as indirect search methods and are tested to determine the search direction. To determine the moving distance, the golden section method and cubic interpolation method are tested. The finite volume method is used to discretize two-dimensional Navier-Stokes equations, and SIMPLEC algorithm is used for a velocity-pressure correction method. For the optimal design of two-dimensional airfoil, maximum thickness, maximum ordinate of camber line and chordwise position of maximum ordinate are chosen as design variables, and the ratio of drag coefficient to lift coefficient is selected as an objective function. From the results, it is found that conjugate gradient method and cubic interpolation method are the most efficient for the determination of search direction and the moving distance, respectively.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.5
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• pp.26-35
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• 2003

Propellers operating in a given nonuniform ship wake generate unsteady loads leading to undesirable stern vibration problems. The skew is known to be the most proper and effective geometric parameter to control or reduce the fluctuating forces on the shaft. This paper assumes the skew profile as either a quadratic or a cubic function of the radius and determines the coefficients of the polynomial function by applying the simplex method. The method uses the converted unconstrained algorithm to solve the constrained minimization problem of 6-component shaft excitation forces. The propeller excitation was computed either by applying the two-dimensional gust theory for quick estimation or by the fully three-dimensional unsteady lifting surface theory in time domain for an accurate solution. A sample result demonstrates that the shaft forces can be further reduced through optimization from the original design.

• Industrial Engineering and Management Systems
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• v.8 no.1
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• pp.29-36
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• 2009

We present two local-search based metaheuristics for the multi-source capacitated facility location problem. In such a problem, each customer's demand can be supplied by one or more facilities. The problem is NP-hard and the number of locations in the optimal solution is unknown. To keep the search process effective, the proposed methods adopt the following features: (1) a multi-exchange neighborhood structure, (2) a tabu list that keeps track of recently visited solutions, and (3) a multi-start to enhance the diversified search paths. The transportation simplex method is applied in an efficient manner to obtain the optimal solutions to neighbors of the current solution under the algorithm framework. Two in-and-out selection rules are also proposed in the algorithms with the purpose of finding promising solutions in a short computational time. Our computational results for some of the benchmark instances, as well as some instances generated using a method in the literature, have demonstrated the effectiveness of this approach.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.517-523
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• 2011

A lot of DSM (Demand Side Management) programs have been implemented to promote the effective utilization of resources and the rational development of power industry, and various economic analyses and policy-based studies on DSM have been executed to determine effective subsidy budget. In this paper, a new objective function for deciding an optimal incentive allocation among various programs is presented by introducing the maximization of the total saving power of the programs. For simplicity, the objective function and the constraints is linearized to apply LP(Linear Programming) method. LP program based on Simplex Method was developed by MATLAB. An optimal incentive allocation of 4 DSM programs is presented by the use of the developed MATLAB program.

• The Korean Journal of Nuclear Medicine
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• v.36 no.2
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• pp.102-109
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• 2002

Purpose : In gene therapy, tumor cells expressing the herpes simplex virus thymidine kinase are sensitive to prodrugs. Potential prodrugs IVDU and IVFRU were synthesized and radiolabeled with radioiodine for noninvasive imaging of herpes simplex virus type 1 gene expression. Material and Methods : 5-(2-trimethysilyl) vinyl-2'-deoxyuridine and 5-(2-trimethylsilyl)vinyl-2'-fluoro-2'-deoxyuridine, precursors of 5-(2--iodo)viny l-2'-deoxy uridine(IVDU) and 5-(2-iodo)-2'-vinyl-2'-deoxy-2'-fluororibofuranosyl uracil(IVFRU), were synthesized from reaction of trans-1-trimethylsillyl-2-tri-n-butylstannylethylene with 5-iodo-2'-deoxyuridine and 5-iodo-2'-fluoro-2'-deoxyuridine, respectively, on the condition of Pd catalyst. These precursors were separated from reaction mixture by silica gel column chromatography method. Each precursor was radioiodinated with radioiodine by mixing with ICI oxidizing agent. These radioiodinated compounds were purified with HPLC. Radiohalogen exchange has been shown to be effective for the synthesis of products with lower specific activity. Similarly, carrier-added and high specific activity products have been isolated in respectable radiochemical yields using ICI method. Results : Synthetic yield of precursors, IVDU and IVFRU were 43% and 18%, respectively. Radiochemical purity of both compunds was over 98%. Conclusion : We synthesized precursors of IVDU and IVFRU for monitoring of HSV1-tk gene expression. Radiotracers were radioiodinated with high radiolabeling yield by ICI method.

• Structural Engineering and Mechanics
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• v.32 no.5
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• pp.667-683
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• 2009

FE model-based dynamic analysis has been widely used to predict the dynamic characteristics of civil structures. In a physical point of view, an FE model is unavoidably different from the actual structure as being formulated based on extremely idealized engineering drawings and design data. The conventional model updating methods such as direct method and sensitivity-based parameter estimation are not flexible for model updating of complex and large structures. Thus, it is needed to develop a model updating method applicable to complex structures without restriction. The main objective of this paper is to present the model updating method based on the hybrid genetic algorithm (HGA) by combining the genetic algorithm as global optimization method and modified Nelder-Mead's Simplex method as local optimization method. This FE model updating method using HGA does not need the derivation of derivative function related to parameters and without application of complicated inverse analysis methods. In order to allow its application on diversified and complex structures, a commercial FEA tool is adopted to exploit previously developed element library and analysis algorithms. Moreover, an output-level objective function making use of measurement and analytical results is also presented to update simultaneously the stiffness and mass of the analysis model. The numerical examples demonstrated that the proposed method based on HGA is effective for the updating of the FE model of bridge structures.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.12
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• pp.1527-1536
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• 1999

In this paper, a triply-encoded Hadamard transform imaging spectrometer is proposed by applying the grill spectrometer to the Hadamard transform imaging spectrometer. The proposed system encodes the input radiation triply ; once through the input image mask and twice through the two masks in the grill spectrometer. We use an electro-optical mask in the grill spectrometer which is controlled by a left-cyclic simplex matrix. Then we modeled the system using $D^{-1}$ method. In this paper, the average mean square error associated with a recovered estimate is considered for performance evaluation. The relative performance is compared with those of the other conventional systems.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.577-579
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• 1992

A new algorithm, which combines the Evolution Strategy and the Simplex method, is proposed for the detection of magnetic body utilizing the disturbance of magnetic fields. Although the detection problem of magnetic body which belongs to the inverse problem may have many local minima, the global optimum point was found by introducing the Evolution Strategy. And the convergency rate was enhanced by introducing the Simplex method. Through the numerical examples, the applicability and usefulness of the proposed algorithm are proved.