• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.2
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• pp.67-75
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• 2001

This paper presents a fast and effective methodology for service restoration in large-scale distribution systems. The service restoration problem is formulated as a constrained optimization problem and requires the fast computation time and superior solution because the more unfaulted out-of-service area should be restored as soon as possible. The proposed methodology is designed to consider the fast computation time and priority service restoration by dijkstra algorithm and fuzzy theory in large-scale distribution systems. Simulation results demonstrate the validity and effectiveness of the proposed on a 26-bus and 140-bus system.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.11
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• pp.528-536
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• 2001

This paper proposes a method of solving a unit commitment problem using parallel tabu search(PTS) approach. Tabu search is a heuristic optimization method that has the tabu list to control the search process. To improve the searching ability of a global solution, we used a method of exchanging solutions among connected processors as a diversification strategy, and to reduce the computation time, a new evaluating method was proposed which evaluates only a changed par. To show the usefulness of the proposed method, we simulated for 10 units system and 110 units system. Numerical results show improvements in the generation costs and the computation time compared with other conventional methods.

• Broadcasting and Media Magazine
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• v.7 no.3
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• pp.75-82
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• 2002

In this report, the complexity analysis of the JVT(Joint Video Team) codec, which has jointly developed the next video coding standard, is performed. Three types of configurations in terms of coding efficiency are set and the analysis of the memory band width and computation time for each configuration is performed. ATOMIUM complexity analysis tool is used for both the memory access statistics and computation time calculation of JVT codec. Also the complexity of each video coding tool in the encoder and decoder is shown in relative complexity.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.132-134
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• 2007

The conventional method used low pass filter for computing resistive leakage current from total leakage current. Therefore, it takes long time for computation. In this paper, a new algorithm is proposed to reduce the computation time. In the theory, the resistive leakage current is computed exactly from the signals during only a half period of power voltage. The suggested method uses integrator and sample-hold circuit and it is confirmed to be able to measure the resistive leakage current from total leakage current by simulation.

• Journal of the Korea Computer Industry Society
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• v.3 no.12
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• pp.1669-1678
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• 2002

Symmetry region searching can extract face region without a prior information in an image by using symmetric. However, this method requires a plenty of the computation time because the mask size to process symmetry region searching must be larger than the size of object such as eye, nose and mouth in face. In this paper, we proposed symmetric by using symmetry region searching in the reduced image to reduce computation time of symmetry region searching. It was applied to this method in an original image. To extract exact face region, we also experimented face region searching by using domain division in extraction legion.

• Journal of Korea Multimedia Society
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• v.20 no.10
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• pp.1655-1661
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• 2017

A high-speed directional interpolation algorithm based on the pattern of a $2{\times}2$ pixel block is proposed in this paper. The basic concept of the proposed algorithm is started from UDWT(un-decimated discrete wavelet transform), but there are no transform operations. In order to detect the direction of the edge, 4-pixel differences of two pairs in the $2{\times}2$ block are compared. The $2{\times}2$ block patterns are grouped into total 8 classes, and thereafter the directional interpolation is executed according to the type of the pattern. Since the calculation of the proposed algorithm is very simple and needs a few additions on integer data type, the computation time is almost same as that of bilinear interpolation algorithm. However, experimental results show that the output quality of the proposed one is better than those of the conventional interpolation ones in the objective quality and the computation time.

• The Journal of the Acoustical Society of Korea
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• v.19 no.7
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• pp.85-89
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• 2000

In this paper, by extending the previously developed self- and mutual-radiation impedance calculation method for a regular-square vibrating surface by using numerical series, we proposed a method to obtain the self-radiation impedance of a rectangular transducer with an arbitrary integer ratio of the length to width. The proposed method exhibits high accuracy and a short computation time. After investigating the accuracy and computation time as the number of elements changes, we have calculated the self-radiation impedance of several rectangular transducers, and compared the results with those in the literature.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.4
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• pp.265-276
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• 2004

Genetic Algorithm(GA), that is shown stable performance to find an optimal solution, has been used as a method of solving large-scaled optimization problems with complex constraints in various applications. Since it takes so much time to execute a long computation process for iterative evolution and adaptation. In this paper, a hardware-based adaptive GA was proposed to reduce the serious computation time of the evolutionary process and to improve the accuracy of convergence to optimal solution. The proposed GA, based on steady-state model among continuos generation model, performs an adaptive mutation process with consideration of the evolution flow and the population diversity. The drawback of the GA, premature convergence, was solved by the proposed adaptation. The Performance improvement of convergence accuracy for some kinds of problem and condition reached to 5-100% with equivalent convergence speed to high-speed algorithm. The proposed adaptive GAP(Genetic Algorithm Processor) was implemented on FPGA device Xilinx XCV2000E of EHW board for face recognition.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.1
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• pp.52-58
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• 2000

Signal propagation in nonlinear optical fiber is analyzed numerically by using SS-FEM (Split-Step Finite Element Method). By adopting cubic element function in FEM, soliton equation of which exact solution was well known, has been solved. Also, accuracy of numerical results and computing times are compared with those of Fourier method, and we have found that solution obtained from using FEM was very relatively accurate. Especially, to reduce CPU time in matrix computation in each step, the matrix imposed by the boundary condition is approximated as a sparse matrix. As a result, computation time was shortened even with the same or better accuracy when compared to those of the conventional FEM and Fourier method.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.10a
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• pp.158-161
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• 2000

An inverse finite element approach is employed for more capability to design the optimum blank shape from the desired final shape with small amount of computation time and effort. For multi-stage deep-drawing processes, numerical analysis is extremely difficult to carry out due to its complexities and convergence problem as well as tremendous computation time. In this paper, multi-stage finite element inverse analysis is applied to multi-stage rectangular cup drawing processes to calculate intermediate blank shapes and strain distributions in each stages. Finite element patches are used to describe arbitrary intermediate sliding constraint surfaces.