• Journal of Forest and Environmental Science
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• v.13 no.1
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• pp.81-89
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• 1997

Urban river needs continuous observation for the river conservation because river surrounding environment sensitivly is changed by human activity. In order to grasp the effect of human activity against Taebaek river in Chunchon city, this research analysed the channel shape change, fluctuation volume and bias degree over five times, for June, 1993 to June, 1996. The results were as follows : 1. The change of channel shape on each surveying time mainly occurred in June, 1996 and maximum deposition. $1,247m^3$ occurred on 19~20 section, maximum scouring, $340m^3$ occurred on 6~7 section, 2. When comparing with June, 1993, increased deposition volume of channelbed was about $4,600m^3$ in June, 1996, 3. The bias degree of channel mainly occurred in June, 1996 of surveying times and at 6, 7, 15, 16, 17, 18, 19, 20 line of surveying lines.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1021-1025
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• 2010

댐과 저수지는 수자원의 이용, 발전, 홍수제어, 그리고 다양한 산업활동을 지원하기 위하여 건설되었다. 그러나 대부분의 댐의 운용에 있어 하류 하천에서 생활하는 생물에 대한 영향은 거의 고려되지 않고 있다. 특히 댐 발전방류와 같이 급격한 유량의 증대와 감소는 하류 하천에서 생활하는 생물의 서식처에 직접적인 영향을 미치고 있으며, 이러한 영향은 생물이 활용할 수 있는 서식처의 제한 요소로 작용한다. 본 연구에서는 2차원 수리모형을 활용하여 댐 방류에 따른 피라미의 물리서식처 변화 양상을 모의 하였다. 대상구간은 발전 방류가 빈번히 발생하는 달천의 괴산댐 하류하천으로 선정하였으며, 목표종은 대상구간에서 우점하는 피라미로 설정하였다. 모의 결과 대상구간의 최적 생태유량은 $9m^3/sec$ 정도로 산정되었으며, 발전 방류로 인하여 댐 하류하천의 물리서식처 규모는 감소하는 것으로 분석되었다. 본 연구는 댐 발전방류에 의한 물리서식처를 분석함으로써, 댐 하류 하천에서 생활하는 생물을 고려하여 댐 운용 계획을 수립하는데 활용될 수 있을 것으로 기대된다.

• Journal of Korea Multimedia Society
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• v.4 no.1
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• pp.46-55
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• 2001

In this paper, a new voice activity detection method estimating SNR of enhanced speech with extended spectral subtraction (ESS) is proposed. Voice activity detection is performed by putting an second Wiener filter behind an Wiener filter used in the ESS to estimate speech and noise power of output signal of first Wiener filter. The proposed voice activity detection method does not require many computational loads and performs well under severe input SNR. Boll's spectral substraction algorithm with proposed voice activity detection was compared to ESS under several noise environment having different time-frequency distributions. During speech and non-speech activity, performance of Boll's spectral substraction algorithm with proposed voice activity detection is superior to that of ESS.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.2
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• pp.45-58
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• 2015

The aim of this study is to find out major accumulation zones through field survey and moving route tracking trials on floating debris of Nakdong River. It also identified composition and accumulated amount of the floating debris by sample survey for accumulation zones. As a result, total 5 accumulation zones were selected from the midstream and downstream of the Nakdong River. There was a large amount of floating debris, including vegetation debris, in the accumulation zones. And two accumulation zones located in the downstream region, it is much more likely to flow into the ocean along river. From the sample survey on the major accumulation zones, more than $40{\ell}$ of floating debris were collected including vegetation and artificial debris. As a result of composition analysis for artificial debris, plastic(49%) and styrofoam(36%) were the majority in number. The present study is expected to help to plan an efficient pre-collecting activity and to reduce floating debris flowing into the ocean from the Nakdong River.

• TTA Journal
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• s.110
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• pp.137-139
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• 2007

ITU의 표준화 추진시 관련된 IPR 이슈를 처리하기 위하여, ITU-T IPR 애드혹 회의가 지난 2월 20과 21일 양일간 스위스 제네바에서 개최되었다. 이번 회의에서는 지난 2년여 간 추진되어 오던 ISO, IEC, ITU 등 3개 국제표준화기구의 공통 특허정책을 최종 채택함으로써, 3개 국제표준화기구간에 조화로운 IPR 정책을 추진하는 발판이 마련되었다. 본 원고는 금번 회의결과를 간단히 소개함으로써 ITU 활동에 도움을 주고자 한다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2019.10a
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• pp.176-176
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• 2019

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1674-1682
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• 2007

This paper presents an criterion of revenue and cost allotment on the basis of the activity based costing system for a loss-making railroad lines, and presents some ways for effective cost reductions focused on expensive resources and consumption

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.557-566
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• 2009

This study was to investigate gender differences in muscle activities on tibialis anterior muscle, gastrocnemius and vastus medialis obliqus and outside and prime mover, antagonist and assistance mover during golf drive swing by electromyography. Ten healthy professional golfers (KPGA(n)=5, KLPGA(n)=5) volunteered in this experiment. All statistical analyses were performed using SPSS. Statistical differences were assess using t-test (p<.05). The conclusion of this study was as following. Muscle dislocation of differences, according to gender, was the highest in case of males in right side of gastrocnemius with the section from the address to the backswing of top and was the highest in case of females in tibialis anterior muscle. Results also show that prime mover was left side of low muscle in case of male with all the sections and situations and is right side low muscle in case of female. These results were significant differences. In case of males, it was though that primer mover was left side of tibialis anterior muscle with moving weight from backswing of top till the address section. In case of females, primer movers were right side of vastus medialis obliqus and tibialis anterior muscle with pushing action form the right knee to the left knee. Therefore, if they try to do the training be able to development right side of vastus medialis obliqus and tibialis anterior muscle in case of females and left side of vastus medialis obliqus and tibialis anterior muscle in case of males, it is consider that golfers' distance and direction will get better.

• Electronics and Telecommunications Trends
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• v.31 no.5
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• pp.80-89
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• 2016

현재 이동통신 분야에서는 5세대(5th Generation: 5G) 이동통신 표준화 작업이 한창 진행 중이며, 그 표준화 현황을 살펴보기 위하여 대표적인 국제 표준화 단체인 ITU-R에서의 활동 및 3GPP에서의 활동을 살펴보고자 한다. 최근 ITU-R WP 5D에서는 IMT-2020으로 명명되는 5세대 이동통신 비전 문서를 토대로 기술 요구사항 및 평가 기준 마련을 위한 작업이 수행되고 있으며, 3GPP의 TSG SA, RAN 및 하위 WG에서는 관련 상위 레벨 요구사항 정립 및 무선 구간에서의 기술적인 SI 논의가 수행되고 있다. 본고에서는 위 두 표준화 활동을 위주로 5G 이동통신에 대한 현황을 기술한다.

• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.121-129
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• 2011

This paper presents the methods to acquire the Safety Certificate from Independent Safety Assessment based on the IEC or EN standard which is commonly applied to railway system for Automatic Train Protection (ATP) system in accordance with ERTMS/ETCS Level 1 system. This also shows approach methods and relative activities for project lifecycle to accomplish and ensure the system requirements of ATP system, RAMS and system quality activities. These kind of activities for quality assurance of ATP system to obtain Safety Certificate could improve the quality of domestic railway system based on On-Board system of ERTMS/ETCS Level 1 and also contribute to the growth of railway business.