• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.645-648
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• 2004

In this paper, we drive a theoretical performance of complementary code keying (CCK) codes on additive white Gaussian noise (AWGN) channel. The CCK codes can be demodulated by the optimal maximum likelihood decoding method and sub-optimal correlation magnitude decoding algorithm. We calculate the bit error rate (BER) and symbol or codeword error rate (SER) of the CCK codes using the above mentioned two decoding algorithms. To derive the error performance, we use the weigh distributions and cross-correlation distributions of CCK codes.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.157-160
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• 2000

In order to design a low complexity and high performance SOVA decoder for Turbo Codes, we need to analyze the decoding performance with respect to several important design parameters and find out optimal values for them. Thus, we use a scaling factor of soft output and a update depth as the parameters and analyze their effect on the BER performance of the SOVA decoder. finally, we shows the optimal values of them for maximum decoding performance of SOVA decoder for 3GPP complied Turbo codes.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1996.06a
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• pp.209-212
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• 1996

In this paper, we propose to re-size images using an oblique projection operator instead of the orthogonal one in order to obtain faster, simpler, and more general algorithms. The main advantage is that it becomes perfectly feasible to use higher order models(e.g., splines of degree n 3). We develop the theoretical background and present a simple and practical implementation procedure that uses B-splines. Experiments show that the proposed algorithm consistently outperforms the standard interpolation method and that it essentially provides the same performance as the optimal procedure (least squares solution) with considerably less computations.

• Journal of Korean Institute of Industrial Engineers
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• v.20 no.3
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• pp.55-63
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• 1994

Optional two-part tariffs are in growing use in telecommunication services markets. This paper considers the problem of designing profit-maximizing optional two-part tariffs for heterogeneous user groups. It is shown that, at an optimum, one of usage charges among a set of optional two-part tariffs should be made equal to marginal cost. It is also shown that, if demand curves cross, then one of usage charges at the optimum can be below marginal cost. An example with linear demand functions is given to illustrate the important features of optimal two-part tariffs.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1553-1556
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• 1991

This paper deals with a problem on the selection of alternative tools in a flexible manufacturing system (FMS) where a lot of tools are required to produce a large variety of product items. An approach using branch and bound method is proposed to minimize a total number of tools required through the optimal use of the alternative tools. In this approach, tools are initially divided into tool subgroups based on graph theory for the purpose of the effective search of the optimal solution. A small example is also presented to highlight the effectiveness of the proposed approach.

• 전기의세계
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• v.23 no.3
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• pp.53-59
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• 1974

The purpose of this paper is to use hydraulic sources optimally on the hydro-thermal power coordination in power system of Korea by means of Multiple Dynamic Programming. Four principal hydraulic power plans of Korea; Whachon, Chunchon, Uiam and Chong-pyong which are located on Han river side are treated in this research. For the illustrative purpose, a case study was made on the year round monthy optimal water control under the given load distribution and constraints.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.999-1002
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• 2002

In this research, the mechanism of micro-ECM was investigated with potentiodynamic method and the optimal condition for micro-ECM was selected by voltage-current-time curve with potentiostatic method. From the experimental result. it was confirmed that anodic voltage curve could be used very effectively for determining the optimal condition of micro-ECM, and the micro part which has extremely fine surface could be fabricated by use of micro-ECM with point electrode method.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.303-312
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• 1994

The problem of optimally allocating available communication channels in a cellular mobile system with nonuniform traffic distribution is considered. This problem is to minimize the weighted average blocking probability subject to cochannel interference constraints. We use the concept of pattern to deal with the problem more conveniently. Using Lagrangian relaxation and subgradient optimization techniques, we obtain high-quality solutions with information about their deviations from true optimal solutions. Computational experiments show that our method works very well.

• IE interfaces
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• v.16 no.2
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• pp.195-200
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• 2003

In this paper, the selective use of RTS and CTS frames is considered to analyze the capacity of IEEE 802.11 WLAN (Wireless Local Area Network). The RTS and CTS frames are used to transmit the data frames longer than dot11RTSThreshold according to IEEE 802.11 specification. The analysis of the optimal RTS-CTS threshold is derived to maximize the capacity of IEEE 802.11 WLAN. And, numerical examples are also presented for IEEE 802.11 a and b WLANs.

• Korean Management Science Review
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• v.10 no.2
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• pp.111-120
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• 1993

The most important factors for a product to survive in the market are cost and quality. In recent years, quality proceeds to cost. There are many techniques of use to improve the quality of a product. One of the techniques is applying statistical methods (especially Taguchi method) to real operational conditions for a continuous manufacturing process in P company. There are 91 factors to control in the process. So, we predetermined 7 main effect factors and 6 interactive effect factors by statistical methods and advices of engineers. With these 13 factors, we determined the optimal level of operations for the process.