• Proceedings of the KSEEG Conference
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• 2001.04a
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• pp.271-274
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• 2001

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05b
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• pp.1493-1496
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• 2003

본 논문에서는 하이브리드 SC/MRC 다이버시티 방식을 DS/CDMA 시스템에 적용하였을 경우, 다중경로 페이딩 채널환경에서 페이딩 지수와 다이버시티의 브랜치 수가 시스템의 BER성능에 미치는 영향을 MRC 다이버시티 방식과 비교 분석하였다. 또한, 브랜치 수는 2, 3, 4인 경우를 고려하였으며, 브랜치 수에 따른 각 다이버시티 방식을 적용하였다. 실제 통신 환경이 열악한 경우 시스템의 복잡도를 줄이면서도 비슷한 성능을 얻을 수 있는 방법으로 각 브랜치 수에 수신되는 강도가 센 몇몇 신호를 가진 경로를 선택하는 하이브리드 SC/MRC 다이버시티 방식이 MRC 다이버시티방식을 대신할 수 있는 방식임을 입증하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.4
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• pp.699-705
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• 2001

It is considered DPSK modulation and the channel is modeled as multipath Nakagami fading type which has been recently taken as a general model in the communication environments in this paper. Most paper assumed that Nakagami fading index(m) of each branch of Rake receiver was fixed the same value in recent years. However, Nakagami fading index(m) of each branch of Rake receiver takes several value through communication environments. In this case, the branch ,which takes a small Nakagami fading index(m), exclude. So we can improve performance. We are considered phase error and analyzed wideband DS/CDMA cellular system. When nakagami fading index(m) takes voluntary value, we analyze BER of wideband DS/CDMA cellular system. Finally, When the branch, which takes a small Nakagami fading index(m), exclude, we analyze BER of wideband DS/CDMA cellular system.

• Information Systems Review
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• v.13 no.3
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• pp.27-46
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• 2011

Many business managers claim that treasury management is their leading concern. Managing cash flows is the center of treasury management. However, in reality, companies has experienced the difficulty in monitoring and controling this flow initiated by business transactions. To resolve this problem, Webcash Inc. developed an innovative systems called Branch Solution. Branch Solution stands in between banking systems and a company's ERP system to connect them. This system provides the company with an ability to control the financial flow in accordance with the physical flow of materials. Due to this solution many companies accomplish a high efficiency and visibility in their cash management. This study analyses a treasury management case from the perspective of supply-chain processes integration.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.7A
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• pp.477-484
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• 2003

In this paper, we compared and analyzed the influence of the fading index and the number of branch of diversity in the Nakagami-m fading channel environment when the MRC diversity and the hybrid SC/MRC are applied to the DS/CDMA system. We considered that the number of branches were 2,3, and 4, respectively and applied an individual diversity type according to the number of branches, when nakagami fading index(m) were 1 and 2. We found that when the Nakagami fading index m is small, that is to say, when fading is inferior, the application of a hybrid SC/MRC diversity Rake receiver is efficient; however, when the fading environment is good, the application of the MRC diversity Rake receiver is efficient. As a result, we verified that when the actual communication environment is inferior, the hybrid SC/MRC diversity that selects a strong signal to be received on an individual number of branches could replace the MRC diversity, as a method to achieve a similar performance by reducing the complexity of the system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.6
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• pp.1510-1521
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• 1996

This paper presents acquisition algorithm and an improved detection technique for the DS/CDMA (direction sequence code division multiple access) RAKE receiver in multipath fading channel. The DS/CDMA systems use the RAKE receiver, an accurate code acquisition is required for the RAKE branches. The algorithmis able to findthe pseudonoise (PN) code delay estimates for the RAKE branches in a multipath fading channel. In this paper a numerical method and computer simulation simulation have been developed for the acquisition system. The detection probability and mean acquisition time are investigated asa performance measure of the system using the Monte Carlo method. And also in order to analyze the effect of the acquisition on the RAKE receiver this paper bring out the effect of integration time, doppler frequency, processing gain and the number of users on the acquired code phase.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.6B
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• pp.1108-1112
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• 1999

In this paper, we propose an efficient ABR multicast algorithm for ATM networks. In ABR multicast algorithim, the feedback consolidation is necessary to avoid excessive backward resource management (BRM) cells and to aggregate the information from BRM cells received from each branch. The proposed scheme is shown to achieve fast transient response to the congestion status on a branch as well as effectively eliminate the consolidation noise through system simulation.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.206-207
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• 2006

본 논문에서는 브랜치 교환(Branch Exchange) 방법을 이용하여 배전 계통을 재구성하는 문제에 대하여 연구하였다. 최적 재구성 문제는 선로 절체에 따라 달라지는 모든 가능한 계통 구성들에 대해 선로손실, 전압조건을 계산하고 이들 중 최적인 구성을 찾아내는 것이다. 하지만 빠른 시간 내에 이에 대한 해를 찾기란 대단히 어렵다. 그 이유는, 계통내에 수많은 연계개폐기와 구분개폐기들이 존재하고 이들로서 방사상의 운전조건을 만족해야 하기 때문이다. 따라서 본 연구에서는 시간적으로 가장 유리한 특성을 갖는 브랜치 교환법을 이용하여 시스템 전체 손실이 감소하고 방사상운전조건과 전압의 제약조건을 만족하도록 최적화하는 방안을 구현하고자 한다.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.24-26
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• 2006

본 논문에서는 브랜치 교환(Branch Exchange) 방법을 이용하여 배전 계통을 재구성하는 문제에 대하여 연구하였다. 최적 재구성 문제는 선로 절체에 따라 달라지는 모든 가능한 계통 구성들에 대해 선로손실, 전압조건을 계산하고 이들 중 최적인 구성을 찾아내는 것이다. 하지만 빠른시간 내에 이에 대한 해를 찾기란 대단히 어렵다. 그 이유는, 계통내에 수많은 연계개폐기와 구분개폐기들이 존재하고 이들로서 방사상의 운전조건을 만족해야 하기 때문이다. 따라서 본 연구에서는 시간적으로 가장 유리한 특성을 갖는 브랜치 교환법을 이용하여 시스템 전체 손실이 감소하고 방사상 운전조건과 전압의 제약조건을 만족하도록 최적화하는 방안을 구현하고자 한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.10
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• pp.1030-1035
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• 2003

In this paper, we compare the performance of IS-OFDM(interference suppressing orthogonal frequency division multiplexing) system with that of the conventional OFDM system. Each parallel branch symbol of IS-OFDM is multiplied by the orthogonal sequence and distributed into all sub-carriers. Then, each sub-carrier transmits information composed of the symbol components of all parallel branches in the given frame. The structure of IS-OFDM shows the frequency diversity characteristic. Therefore, IS-OFDM can be robust to the narrowband interference. BER performances are found in the narrow-band interference and a harmonic noise channels. When JSR(Jamming to signal ratio) increases from -10 dB to +10 dB in the constant interference bandwidth, IS-OFDM outperforms the conventional OFDM and the BER difference between IS-OFDM and OFDM is reduced as JSR increases. Also, the similar properly can be shown when interference bandwidth increases at the constant JSR. In the harmonic noise channel, we can find the good performance of IS-OFDM when the h-rate(harmonic noise bandwidth to signal bandwidth ratio) increases from 0.01 to 0.8. So, simulation results show that the IS-OFDM is more robust to the interference than the conventional OFDM.