• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.237-238
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• 2008

This paper presents a cognitive radio network where a base station exploits multi-antennas. For the system, a joint power control and user selection greedy algorithm which achieve a significant fraction of sum-capacity at lower complexity cost is proposed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.3
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• pp.452-460
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• 2001

Most of researches of tolerance optimization have used a simple sum of tolerance-cost functions with several constraint equations as an optimization model. However, if there is a machining sequence with more than one processes to complete a part, and machining failure, i.e., out-of-tolerance occurs at one of the intermediate processes, the tolerance-cost of this process should be added by the machining cost of all the previous processes already completed on the part. In this study, an accumulated scrap cost model(ASCM) is proposed considering the scrapped machining cost, and applied to a simple assembly example. The result of tolerance optimization using ASCM is compared with that of using a traditional optimization model to confirm its effectiveness.

• Journal of IKEEE
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• v.11 no.4
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• pp.307-314
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• 2007

In this paper, we propose an image contrast enhancement algorithm for an LCD TV. The proposed algorithm consists of two processes: the image segmentation process and the tone curve control process. The first process uses an automatic threshold technique to decompose an input image into two regions and then utilizes a hierarchical structure for real-time processing. The second process generates a gray level tone curve for contrast enhancement using a weighted sum of average tone curves for two segmented regions. Experimental result shows that the proposed algorithm outperforms the conventional contrast enhancement methods for an LCD TV.

• Journal of the Chungcheong Mathematical Society
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• v.30 no.1
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• pp.77-102
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• 2017

As an analogy of $Poincar{\acute{e}}$ series in the space of modular forms, T. Ono associated a module $M_c/P_c$ for ${\gamma}=[c]{\in}H^1(G,R^{\times})$ where finite group G is acting on a ring R. $M_c/P_c$ is regarded as the 0-dimensional twisted Tate cohomology ${\hat{H}}^0(G,R^+)_{\gamma}$. In the case that G is the Galois group of a Galois extension K of a number field k and R is the ring of integers of K, the vanishing properties of $M_c/P_c$ are related to the ramification of K/k. We generalize this to arbitrary n-dimensional twisted cohomology of the ring of integers and obtain the extended version of theorems. Moreover, some explicit examples on quadratic and biquadratic number fields are given.

• Journal of Oriental Neuropsychiatry
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• v.15 no.2
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• pp.203-210
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• 2004

Objectives: The purpose of this study was to investigate the clinical application of oriental medical therapy(OMT) and psychotherapy to a somatoform disorder patient with chronic pelycalgia and hemiparesis. Methods: We treated the patient with psychotherapy such as relaxation therapy and suggestion. OMT that we used is represented by retention enema therapy. The recovery of the pelycalgia was evaluated by Visual Analogue Scale(VAS). Results: Following the treatment the patient's pelycalgia and hemiparesis was improved. The sum of VAS score was rapidly decreased(from 113 to 28). Conclusion: OMT and psychotherapy have positive effects on the patient with chronic pelycalgia and hemiparesis.

• Communications for Statistical Applications and Methods
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• v.18 no.5
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• pp.667-674
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• 2011

A recent trend in software reliability engineering accounts for the coverage growth behavior during testing. The coverage growth function (representing the coverage growth behavior) has become an essential component of software reliability models. Application of a coverage growth function requires the estimation of the coverage growth function. This paper considers the problem of estimating the coverage growth function. The existing maximum likelihood method is reviewed and corrected. A method of minimizing the sum of squares of the standardized prediction error is proposed for situations where the maximum likelihood method is not applicable.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.8
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• pp.786-792
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• 2009

Topology optimization is to find the optimal material distribution of the specified design domain minimizing the objective function while satisfying the design constraints. Since the genetic algorithm (GA) has its advantage of locating global optimum with high probability, it has been applied to the topology optimization. To guarantee the structural connectivity, the concept of compliance pattern is proposed and to improve the convergence rate, small number of population size and variable probability in genetic operators are incorporated into GA. The rank sum weight method is applied to formulate the fitness function consisting of compliance, volume, connectivity and checkerboard pattern. To substantiate the proposed method design examples in the previous works are compared with respect to the number of function evaluation and objective function value. The comparative study shows that the compliance pattern based GA results in the reduction of computational cost to obtain the reasonable structural topology.

• Bulletin of the Korean Mathematical Society
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• v.33 no.1
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• pp.127-133
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• 1996

Let $\Omega_n$ be the polyhedron of $n \times n$ doubly stochastic matrices, that is, nonnegative matrices whose row and column sums are all equal to 1. The permanent of a $n \times n$ matrix $A = [a_{ij}]$ is defined by $$ per(A) = \sum_{\sigma}^ a_{1\sigma(a)} \cdots a_{n\sigma(n)} $$ where $\sigma$ runs over all permutations of ${1, 2, \ldots, n}$.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.209-210
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• 2012

In this study, the following conclusions are drawn. First, the Inorganic terazzo tile flooring and LCC (Life Cycle Cost) analysis showed that the sum of the total cost of 150,304 won Inorganic flooring, terrazzo tile flooring minerals won 186,202 to 35,898 won, compared to 8.22% analysis of the cost savings that have been appearing. Second, if the color chip has a unique and elegant sentence patterns, beautiful and high-strength bonding and that the crack resistance was investigated.

• Journal of Electrical Engineering and Technology
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• v.5 no.4
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• pp.511-521
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• 2010

This paper presents a new algorithm to determine accurate bus-wise transmission loss allocation utilizing path-integrals dictated by the transaction strategy. For any transaction strategy, the total sum of the allocated transmission losses of all buses is equal to the actual loss given by the AC power-flow calculation considering the distributed slack. In this paper, the bus-wise allocation of the transmission loss is calculated by integrating the differential loss along a path determined by the transaction strategy. The proposed algorithm is also compared with Galiana's method, which is the well-known transmission loss allocation algorithm based on integration. The performance of the proposed algorithm is evaluated by case studies carried out on the WSCC 9-bus, IEEE 14-bus, New England 39-bus, and IEEE 118-bus systems. The simulation results show that the proposed algorithm is fast and accurate with a large step size.