• 제목/요약/키워드: Blind channel estimation

검색결과 63건 처리시간 0.019초

음선 역전파 기반의 선박 위치 추정 (Ray backpropagation-based ship localization)

  • 조성일;변기훈;변성훈;김재수
    • 한국음향학회지
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    • 제37권4호
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    • pp.196-205
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    • 2018
  • 본 논문은 선박소음 데이터에 음선 역전파 기법을 적용하여 수동 선박 위치 추정 알고리듬을 제시한다. 기존의 방법 [S. H. Abadi, D. Rouseff and D. R. Dowling, J. Acoust. Soc. Am. 131, 2599-2610 (2012)]은 음선 기반 블라인드 디컨벌루션 및 음선 역전파 기법을 활용하여 배열의 기울기가 없는 근거리 환경에서 음원의 위치를 추정하였다. 하지만 위 방법은 배열의 기울기에 따른 위치 추정 오차가 크게 발생한다는 단점이 존재한다. 이를 극복하기 위해 본 논문에서는 음선 기반 블라인드 디컨벌루션 및 음선 역전파 기법을 사용하되, 배열의 기울기를 보정하여 음원의 위치를 추정할 수 있는 알고리듬을 제안한다. 제안된 알고리듬의 성능은 SAVEX15(Shallow-water Acoustic Variability EXperiment in 2015)해상 실험의 선박소음 데이터를 이용하여 검증하였다.

웨이블릿 변환과 적응적 변이 추정을 이용한 스테레오 영상 블라인드 워터마킹 (Stereo Image Blind Watermarking Scheme based-on Discrete Wavelet Transform and adaptive Disparity Estimation)

  • 고정환;김성일;김은수
    • 한국통신학회논문지
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    • 제31권2C호
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    • pp.130-138
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    • 2006
  • 본 논문에서는 웨이블릿 변환과 적응적 변이 추정 알고리즘을 이용한 새로운 스테레오 입체영상 블라인드 워터마킹 기법을 제시하였다. 즉, 좌, 우 스테레오 영상 중 우 영상에 이산 웨이블릿 변환을 이용하여 워터마크 영상을 삽입하고 워터마킹된 우영상과 좌 영상으로부터 변이정보를 추출한 다음 추춘된 변이정보는 좌영상과 함께 채널을 통해 전송된다. 그리고, 수신단에서는 전송되어온 변이정보와 좌 영상으로부터 적응적 정합 기법을 이용하여 워터마킹된 우 영상을 복원하게 되며, 최종적인 워터마크 추출과정에서는 복원된 우 영상으로부터 원 영상을 사용하지 않고 워터마크 영상을 추출하는 블라인드 방식을 사용하였다. CCETT의 'Manege'와 실제로 획득한 영상 'Friends', 그리고 영문 알파벳 '3DRC'를 스테레오 및 워터마크 영상으로 사용한 실험결과, 복원 영상으로부터 추출된 워터마크 영상에 대한 PSNR 측정의 경우, 2.64dB, 3.03dB가 향상되었으며 본 논문에서 제안한 알고리즘의 성능 분석을 위한 다양한 공격 실험에서도 강건한 실험결과를 얻을 수 있었으며, 이를 통해 본 논문에서 새로이 제안한 적응적 변이추정 기반의 스테레오 입체영상 워터마킹 기법의 실질적 응용 가능성을 제시하였다.

설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제27권7호
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    • pp.380-394
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    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.