• Title/Summary/Keyword: 수변

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Harmonic Analysis Method for Power Quality Problems (전기품질 분석을 위한 고조파 해석 기법)

  • 사근하;이의용;설용태
    • Proceedings of the KAIS Fall Conference
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    • 2001.11a
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    • pp.147-149
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    • 2001
  • 본 논문에서는 산업용 전력시스템의 전기품질을 평가하기 위한 고조파 해석기법을 제시하였다. 먼저 수변전계통의 전압강하, 고조파, 고장전류 등을 PTW Tool을 이용해서 시뮬레이션 하였으며, 실제 계통에서의 운전중 고조파 현상을 실측치와 비교 분석함으로써 기존 시뮬레이션 기법의 정확성을 검증하였다.

The Study on the Design and Implementation of SHF band Downconverter of Digital Satellite Communication (디지털위성중계기용 SHF 대역 하향주파수 변환장치 설계 및 구현에 대한 연구)

  • Kim, Ki-Jung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.12 no.3
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    • pp.427-432
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    • 2017
  • This study describes the design and implementation of SHF band Downconverter Digital Satellite Communication. The SHF band Downconverter unit consists of PLDRO and Frequency converter. In Frequency converter, microstrip BPF and LPF designed through the pre EM simulation are implemented to minimize the unwanted spurious in Frequency converter. Through the pre-simulation analysis of space environment, the possibility of and minimized about the malfunction of equipment and we designed a reliable SHF band Downconverter through simulation for a TID according to the vibration generated during the launch and space radiation environment, and compared pre-simulation of main performance results to test results about main performances of SHF band Downconverter after production.

The Investigation of Residential Area Changes by the Provision of Urban Linear Parks - Case Studies of the Regenerated Street Parks and the Uncovered Stream Parks in Seoul - (선형공원 조성에 의한 주변 주거지의 변화 분석 - 서울시 재생 가로공원과 복원하천 수변공원 사례 연구 -)

  • Lee, Ju-Eun;Yang, Woo-Hyun
    • Journal of the Korean housing association
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    • v.27 no.6
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    • pp.45-55
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    • 2016
  • This study focused on the changes of residential area around the linear park. The goal of this study is to determine the value of linear park at the view of residents and discover the interaction between the linear park and the residential area around it. To investigate this goal, the researcher chose case sites, the regenerated linear park and the uncovered stream park. This study analyzed the site around the linear parks with four points of view, the organization of urban Fabric, architecture, the economic value of the site and the behavior of residents. This research adopted several research methodologies like aerial photograph analysis, road-view analysis, paper research, and field study, observation, and expert interview to approach as both quantitative and qualitative analysis. With that variation characteristic, the researcher determines the influence of linear park through the residential area around them. As the result, linear park gives positive effects of running sustainable residential area around them and acting as the pivot for the residential area. Also for the future, designers must consider this interactive relation between the linear park and residential area with the wide point of view.

Studies on the Ecological Management and Stream Environment in Dorim Stream for Establishing Eco-wetland Parks (도림천 수변지역 조성을 위한 생태적 관리방안 및 하천환경 관리방안에 관한 연구)

  • Lee, Sang-Don;Kim, Seok-Chul
    • Journal of Wetlands Research
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    • v.10 no.3
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    • pp.133-139
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    • 2008
  • Urban streams are degrading functional role due to development and pollution. This study chose the representative stream of Do-rim and identified flora and fauna. The ecological survey aimed at identifying indicator of urban streams for measuring urban healthiness and we discussed the possibility of wetland conservation area. From the beginning of Dorim stream to An-yang mixture we were successfully identified 113 species of plants, 9 of mammals, 23 of birds, 4 of amphibians, 2 of reptiles and 2 of fish species. Terrestrial insects were 71 species. The wetland vegetation is quite various and we suggested 4 different vegetation zones (aquatic vegetation zone, emergent zone, riparian-meadow zone, riparian-woodland zone) depending on distance from the flowing water stream and vegetation characteristics for urban stream management.

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A Study of Analysis of Present Condition and Users' Behavior on Waterfront in Local City -focusing on Nam river, Taewha river, Gumho river- (지방도시 수변공간 이용자 행태 및 현황분석에 관한 연구 -남강, 태화강, 금호강을 중심으로-)

  • Kang, Seok-Jin
    • Journal of the Korean Institute of Rural Architecture
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    • v.16 no.1
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    • pp.53-61
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    • 2014
  • The purpose of this study is to analyze present condition and users' behavior on waterfront in local city. To analyze the current physical statues and behavioral issues, 3 cities including Jinju city(Nam river), Ulsan city(Taewha river), and Dae-gu city(Gumho river) has chosen as research areas, the questionnaire and field survey were conducted in research areas focusing on post occupancy evaluation. In this study, it was found that main behaviors of waterfront were rest and exercise and overall satisfactions of waterfront were related to the decision-making for revisitation. However, unsatisfactory physical factors of waterfront were the position and number of facilities related to the behaviors such as rest, exercise, and bicycle riding. Especially, most unsatisfactory factor was the inadequate lighting in respect of intensity of illumination and position although much people had been used each waterfronts at nighttime. In conclusion it was thought that it was necessary to reinforce the program related to culture and leisure such as public performance and to establish infrastructure related to life-time sport and various outdoor exercise for waterfront activation.

용담댐 건설로 인한 금강 상류의 하천환경변화 분석 I - 수문변화분석 -

  • 정승권;정동양
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.966-970
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    • 2004
  • 전북권에 일정량의 생${\cdot}$공용수를 제공한다는 배경아래 금강수계 최상류에 건설된 용담 다목적댐으로 인해 금강 상류로의 자연 유입량이 인위적으로 감소되었고, 이에 따른 하천수변환경의 변화가 발생하게 되었다. 따라서 본 연구에서는 댐 건설전 자연유출로 인한 금강 상류구간의 수문변화와 댐 건설로 인한 인위적인 유입유량 감소로 인해 발생되는 수문변화를 비교 분석함으로써 용담댐 건설 및 부족한 용수 공급량으로 인한 수질 및 수변${\cdot}$수중생태계 분야의 문제점 제시를 위한 기초자료를 제공하고자 한다. 이를 위해 1차원 수문 모의를 수행하였으며 이에 금강 상류의 하천횡단자료 445개를 직접 구축하였다. 또한 과거 12년간의 강우 자료를 바탕으로 강우량 편중정도에 따라 평균 강우량을 갈수기, 평수기, 홍수기로 구분하여 산정하였다. 이를 바탕으로 각 지류유입량을 산정하기 위하여 소유역별 평균 유출량을 산정하였다. 이러한 과정을 통해 댐건설전 자연유출량과 댐 건설 후 하천유지목적으로 방류되는 용담댐 방류량 $5.4m^3/s$, 그리고 추가적으로 금강수환경 조사연구용역과 관련하여 용수배분팀(전병호, 2002)에서 제시한 적정 용담댐 방류량 $9.1m^3/s$이 금강수계에 미치는 수문학적 영향을 분석하였다. 용담댐 건설전${\cdot}$ 후의 대청호 유입량을 비교한 결과 갈수기때는 $9.46\%$, 평수기때는 $3.32\%$, 홍수기때는 $33.73\%$의 감소율을 보이고 있다.

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Stimulated Brillouin scattering using a source with a few axial modes and an optical fiber ring resonator (수개의 종모드를 갖는 광원에 의한 고리형광섬유공진기에서의 유도브릴루앙산란)

  • 이현재;윤병호;이동호;전영윤;김향균
    • Korean Journal of Optics and Photonics
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    • v.6 no.4
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    • pp.324-330
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    • 1995
  • Stimulated Brillouin scattering theory is described in an optical fiber. Frequency change with an optical heterodyne method is analyzed between reference signal of a source and stimulated Brillouin scattering signal in an optical fiber. By coupling a source with a few axial modes and an optical fiber ring resonator, Brillouin scattering is studied with a spectrum analyzer. Using reference beating signal of a source, we have reduced the Brillouin beating frequency from 13 GHz range to below GHz. Experimentally, we can see the Brillouin beating frequency from 13 GHz range to below GHz with a dispersion shifted fiber (1.32 GHz), Ti-doped fiber (900 MHz) and single mode optical fiber (870 MHz). MHz).

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