• 제목/요약/키워드: map-reduce

검색결과 849건 처리시간 0.031초

FPGA 에 대한 지연시간 최적화 알고리듬 (Delay optimization algorithm on FPGAs)

  • 허창우;김남우
    • 한국정보통신학회논문지
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    • 제10권7호
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    • pp.1259-1265
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    • 2006
  • 본 논문에서는 고속 FPGA 설계를 위한 논리 수준의 조합회로 합성 알고리듬을 제안한다. 제안된 알고리듬은 회로의 지연시간을 줄이기 위해 critical path를 분할한다. 그리고 분할된 회로를 동시에 수행하는 구조를 갖는 회로를 생성한다. 본 커널 선택 알고리듬은 SUN UNIX 환경에서 C 언어로 구현되었다. 제안된 커널 선택 알고리듬은 기존의 FlowMap 지연시간 최적화 알고리듬과 결과를 비교하였다. 제안된 지연시간 최적화 알고리듬이 기존 알고리듬 에 비해 지연시간이 평균 33.3 % 감소된 회로를 생성함을 보였다.

An Improved Saliency Detection for Different Light Conditions

  • Ren, Yongfeng;Zhou, Jingbo;Wang, Zhijian;Yan, Yunyang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권3호
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    • pp.1155-1172
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    • 2015
  • In this paper, we propose a novel saliency detection framework based on illumination invariant features to improve the accuracy of the saliency detection under the different light conditions. The proposed algorithm is divided into three steps. First, we extract the illuminant invariant features to reduce the effect of the illumination based on the local sensitive histograms. Second, a preliminary saliency map is obtained in the CIE Lab color space. Last, we use the region growing method to fuse the illuminant invariant features and the preliminary saliency map into a new framework. In addition, we integrate the information of spatial distinctness since the saliency objects are usually compact. The experiments on the benchmark dataset show that the proposed saliency detection framework outperforms the state-of-the-art algorithms in terms of different illuminants in the images.

토크맵을 이용한 칼럼형 전기식 동력조향 시스템의 제어로직 (Control Logic Using Torque Map for a Column-Type Electric Power Steering System)

  • 김지훈;송재복
    • 한국자동차공학회논문집
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    • 제8권4호
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    • pp.186-193
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    • 2000
  • EPS(Electric Power Steering) systems have many advantages over traditional hydraulic power steering systems in space efficiency engine efficiency and environmental compatibility. In this paper an EPS system control logic using a torque map is proposed. The main function of the EPS system is to reduce the steering torque exerted by a driver by assist of an electric motor. Vehcile speed steering torque and steering wheel angle are measured and fed back to the EPS control system where appropriate assist torque is generated to assist the operator's steering effort. Another capability of the EPS system for easy adaptation to different steering feels via simple tuning is demonstrated by the experiments. It will be also verified that the EPS system can also improve damping and return performance of the steering wheel by control of the assist motor.

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토폴로지 정보가 없는 CAD 곡면의 꺾인 모서리 탐색 (Convex Sharp Edge Detection of CAD Surfaces without Topology)

  • 박정환;이정근
    • 한국정밀공학회지
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    • 제17권2호
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    • pp.73-79
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    • 2000
  • The part-surface of mold or stamping-dies consists of a compound surface which consists of lots of composite surfaces, and may have various types of feature shapes including convex sharp edge (CSE). Those CSE features should be considered with care in machining the surface, which necessitates extraction of CSE curves on a compound surface. This work can be done rather easily for a solid model which has a complete topology information. In case of the compound surface without topology information, however, such CSE curves must be gathered through some geometrical calculations paying much computation time. In the paper, extracting CSE curves by the construction of a CSE region-map which can reduce time, and detecting various common edge types are presented.

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Efficient Indoor Location Estimation using Multidimensional Indexes in Wireless Networks

  • Jun, Bong-Gi
    • International Journal of Contents
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    • 제5권2호
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    • pp.59-63
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    • 2009
  • Since it is hard to use GPS for tracking mobile user in indoor environments, much research has focused on techniques using existing wireless local area network infrastructure. Signal strength received at a fixed location is not constant, so fingerprinting approach which use pattern matching is popular. But this approach has to pay additional costs to determine user location. This paper proposes a new approach to find user's location efficiently using an index scheme. After analyzing characteristics of RF signals, the paper suggests the data processing method how the signal strength values for each of the access points are recorded in a radio map. To reduce computational cost during the location determination phase, multidimensional indexes for radio map with the important information which is the order of the strongest access points are used.

한 대의 카메라와 Fiducial 마커를 이용한 SLAM (Indoor Single Camera SLAM using Fiducial Markers)

  • 임현;양지혁;이영삼;김진걸
    • 제어로봇시스템학회논문지
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    • 제15권4호
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    • pp.353-364
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    • 2009
  • In this paper, a SLAM (Simultaneous Localization and Mapping) method using a single camera and planar fiducial markers is proposed. Fiducial markers are planar patterns that are mounted on the ceiling or wall. Each fiducial marker has a unique hi-tonal identification pattern with square outlines. It can be printed on paper to reduce cost or it can be painted using retro-reflective paint in order to make invisible and prevent undesirable visual effects. Existing localization methods using artificial landmarks have the disadvantage that landmark locations must be known a priori. In contrast, the proposed method can build a map and estimate robot location even if landmark locations are not known a priori. Hence, it reduces installation time and setup cost. The proposed method works good even when only one fiducial marker is seen at a scene. We perform computer simulation to evaluate proposed method.

Development of TFT-LCD panel with reduced driver ICs

  • Kim, Sung-Man;Lee, Jong-Hyuk;Lee, Hong-Woo;Lee, Jong-Hwan;Choi, Kwang-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.352-354
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    • 2008
  • A 15.4" WXGA TFT-LCD, featuring integrated a-Si:H gate driver circuits and reduced data driver ICs, has been developed. To reduce number of data lines into 1/2 of conventional structure, the pixel array has been re-mapped with re-organized data signal. Unintended artificial effects such as flicker were removed by adopting the novel pixel array having a 'zigzag' map. To minimize the power consumption, a column inversion method was incorporated in the zigzag pixel array (Fig.1) without modifying the polarity map of conventional dot inversion method.

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다해상도 영역에서 신뢰확산 알고리즘을 사용한 고속의 스테레오 정합 알고리즘에 관한 연구 (A Study on Fast Stereo Matching Algorithm using Belief Propagation in Multi-resolution Domain)

  • 장선봉;지인호
    • 한국인터넷방송통신학회논문지
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    • 제8권4호
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    • pp.67-73
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    • 2008
  • 마코브 랜덤 필드로 모델링한 마코브 네트워크에서 신뢰확산 알고리즘은 각각의 화소에 대응하는 노드들 사이의 메시지 이동에 의해 동작한다. 신뢰확산 알고리즘은 정확한 결과를 얻기 위해 많은 수의 반복 연산을 요구하게 된다. 본 논문에서는 다해상도 영역에서 신뢰확산 알고리즘을 적용한 스테레오 정합 알고리즘을 제안한다. 웨이브렛 또는 리프팅에 기반한 다해상도 변환은 스테레오 정합 알고리즘에서 탐색 영역을 줄일 수 있는 장점 갖기 때문에 고속의 연산을 통해 변이 영상을 생성할 수 있다.

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물 분사 시스템에 의한 소형 디젤엔진의 NOx 및 그 외 배출물의 특성에 관한 연구 (A Study on the Characteristics of NOx and another Emisson by Water Injection System for a Light-Duty Diesel Engine)

  • 최재성;남정길
    • Journal of Advanced Marine Engineering and Technology
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    • 제29권6호
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    • pp.628-636
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    • 2005
  • In this paper. the effects of a WI(Water Injection) in the intake pipe for a 4-cylinder Dl(Direct Injection) diesel engine are investigated experimentally, The WI system was controlled by the duty cycle from the intake manifold's temperature and MAF(Manifold Air Flow) First. effect of EGR on NOx reduction was investigated. Then WI system was applied to reduce NOx As the results. we can make the NOx map and visualize the NOx results by variation of engine speed and engine load It was known that effect of WI system on NOx reduction without the EGR was better than the with EGR base engine except of low load and speed condition.

경계선 및 영역 정보를 이용한 스테레오 정합 (Stereo Matching Based on Edge and Area Information)

  • 한규필;김용석;하경훈;하영호
    • 전자공학회논문지B
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    • 제32B권12호
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    • pp.1591-1602
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    • 1995
  • A hybrid approach which includes edge- and region-based methods is considered. The modified non-linear Laplacian(MNL) filter is used for feature extraction. The matching algorithm has three steps which are edge, signed region, and residual region matching. At first, the edge points are matched using the sign and direction of edges. Then, the disparity is propagated from edge to inside region. A variable window is used to consider the local method which give accurate matched points and area-based method which can obtain full-resolution disparity map. In addition, a new relaxation algorithm for considering matching possibility derived from normalized error and regional continuity constraint is proposed to reduce the mismatched points. By the result of simulation for various images, this algorithm is insensitive to noise and gives full- resolution disparity map.

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