• Title/Summary/Keyword: Spacial Resolution

Search Result 13, Processing Time 0.023 seconds

A Study on the Evaluation of Interpolation Methods in PIV (PIV에서의 보간기법의 평가에 관한 연구)

  • 최장운;조대한;최민선;이영호
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.20 no.4
    • /
    • pp.90-100
    • /
    • 1996
  • To maintain high spacial accuracy and rapid CPU time in interpolating data from grid to random position or inversely in PIV, proposed many technuques are compared and discussed mainly in terms of interpolating error and computing time. And artificial PIV atmosphere data is furnished by CFD result. First, for interpolation from grid to random position, multiquadric method gives the highest accuracy with the longest CPU time and Taylor series expansion methods give reasonable accuracy with less calculating load. Secondly, the sub-pixel resolution analysis in estimating the coordinates of the maximum correlation coefficients essential in the grey level correlation PIV reveal that 8-neighbours 2nd-order least square interpolation gives utmost accuracy in terms of the real flow conditions.

  • PDF

A Study on the Evaluation of Interpolation Methods in PIV (PIV에서의 보간기법의 평가에 관한 연구)

  • Choi, J.W;Cho, D.H;Choi, M.S;Lee, Y.H
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.20 no.4
    • /
    • pp.412-412
    • /
    • 1996
  • To maintain high spacial accuracy and rapid CPU time in interpolating data from grid to random position or inversely in PIV, proposed many technuques are compared and discussed mainly in terms of interpolating error and computing time. And artificial PIV atmosphere data is furnished by CFD result. First, for interpolation from grid to random position, multiquadric method gives the highest accuracy with the longest CPU time and Taylor series expansion methods give reasonable accuracy with less calculating load. Secondly, the sub-pixel resolution analysis in estimating the coordinates of the maximum correlation coefficients essential in the grey level correlation PIV reveal that 8-neighbours 2nd-order least square interpolation gives utmost accuracy in terms of the real flow conditions.

Bandwidth Allocation for Multiple Two-layer Video Sources of Different Spatial Resolution (서로 다른 공간해상도의 두 계층 영상신호원들을 위한 대역할당 방법)

  • 권순각
    • Journal of Korea Multimedia Society
    • /
    • v.3 no.2
    • /
    • pp.164-173
    • /
    • 2000
  • This paper presents an efficient bandwidth allocation method for multiple source in the two-layer video coding of different spatial resolution. We first investigate the model of bitrate distortion in the MPEG-2 spacial scalable coding,. By using approximated model parameters, than we propose an efficient bitrate control method in order to keep the same distortion level among coders and the constant quality ratio between layers. Simulation results show that the proposed method can satify the user requirement in comparison to the conventional method.

  • PDF

The Study on the Establishment of Rural Community Facility Remodeling and Management Process (농촌마을 공동시설 리모델링 및 관리 프로세스 구축에 관한 연구)

  • Kim, Sang-Bum;Shin, Jae-Sun;Kim, Eun-Ja
    • Journal of the Korean Institute of Rural Architecture
    • /
    • v.17 no.3
    • /
    • pp.63-70
    • /
    • 2015
  • Recently, the rural village development projects are proceeding as enhancement of the rural landscape as the interest toward rural tourism and rural immigrant has increased. However, the projects are solely to support construction of community space and there has been a lack of community facility remodeling in term of both deterioration facilities and abandoned facilities. Thus in this study proposes rural community facility remodeling process to utilize remodeling of rural deterioration facilities and abandoned facilities. For setting rural community remodeling process, this study analysed preceding research data and suggested rural community remodeling process stage ; planning, spacial resolution, remodeling factor analysis, implementation, maintenance control, based on research data. For systematic performed this process, this study regulated role of local resident, expert and local government on remodeling process stage.

A Novel Phase Extraction for the Detection of Time Parameters in Signal

  • Lee Eun-bang
    • Journal of Navigation and Port Research
    • /
    • v.29 no.4
    • /
    • pp.341-347
    • /
    • 2005
  • A unique technique to extract the phase in time domain is proposed in order to measure the time parameters such as speed and depth by transmitting sound and electric waves. In the signal analysis processing, the phase of pulse signal can be transformed and digitalized with local data in real time without the effect of direct current bias and Nyquist limits. This method is sensitive to base frequency of pulse signal with high spacial resolution and is effective to compare two signals which have different forms. It is expected that the phase analysis technique will be applied to the measurement of the speed and depth accurately by ultrasonic pulse signal in water.

Visual Feature Extraction for Image Retrieval using Wavelet Coefficient’s Fuzzy Homogeneity and High Frequency Energy (웨이브릿 계수의 퍼지 동질성과 고주파 에너지를 이용한 영상 검색용 특징벡터 추출)

  • 박원배;류은주;송영준
    • The Journal of the Korea Contents Association
    • /
    • v.4 no.1
    • /
    • pp.18-23
    • /
    • 2004
  • In this paper, we propose a new visual feature extraction method for content-based image retrieval(CBIR) based on wavelet transform which has both spatial-frequency characteristic and multi-resolution characteristic. We extract visual features for each frequency band in wavelet transformation and use them to CBIR. The lowest frequency band involves spacial information of original image. We extract L feature vectors using fuzzy homogeneity in the wavelet domain, which consider both the wavelet coefficients and the spacial information of each coefficient. Also, we extract 3 feature vectors wing the energy values of high frequency bands, and store those to image database. As a query, we retrieve the most similar image from image database according to the 10 largest homograms(normalized fuzzy homogeneity vectors) and 3 energy values. Simulation results show that the proposed method has good accuracy in image retrieval using 90 texture images.

  • PDF

The Relative Position Estimate of the Moving Distributed Sources Using the Doppler Scanning Technique (도플러 스캐닝 기법을 이용한 이동하는 다중 음원의 상대 위치 추적 기법)

  • 노용주;윤종락;전재진
    • The Journal of the Acoustical Society of Korea
    • /
    • v.21 no.5
    • /
    • pp.446-454
    • /
    • 2002
  • This paper presents the Doppler Scanning technique which enables us to detect the relative positions of moving distributed sources using Doppler frequency shift estimate when the moving source consists of distributed sources with different signature frequencies. Doppler frequency shifts of characteristic frequencies of machinery noise sources such as ship's generator and propeller, with tine along CPA (Closest Point of Approach of moving source) are unique, and can be functioned with respect to each source position. Therefore, this technique can be applied to estimate the relative geometrical positions between machinery noise sources. The Extended Kalman Filter (EKF) which has a high frequency resolution with high time resolution, is adopted for improving accuracy of Doppler frequency shift estimate geometric resolution of machinery positions since machinery noise sources show in general low frequency band characteristics with limited spacial distance. The performance of the technique is examined by the numerical simulations and is verified by the experiment using loudspeaker sources on the roof of the car.

Spacial Distribution of PM1.0 Major Compounds from Long Range Transport at the Baegryungdo Super Site: Relationship between PSCF and Cluster Analysis (백령도에서 관측된 장거리 유입 PM1.0의 주성분 공간 분포: PSCF 및 군집분석 관계)

  • Oh, Sea-Ho;Lee, Taehyoung;Park, Taehyun;Ahn, Joon-Young;Park, Jin-Soo;Choi, Jin-Soo;Park, Gyutae;Bae, Min-Suk
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.33 no.4
    • /
    • pp.411-423
    • /
    • 2017
  • The spacial potential source contribution function (PSCF) method was utilized by considering topography and height of back trajectories based on the measurement of organic typo matter (OM), $NO_3{^-}$, $SO{_4}^{2-}$, and $NH_4{^+}$ at the Baegryungdo Super Site ($37^{\circ}57^{\prime}N$, $124^{\circ}37^{\prime}E$, 135 m a.s.l. (above sea level)) for three selected periods (i.e., January~April, May~August, and September~December) in 2013. The PSCF were calculated on the contributions of trans-boundary transport to the hourly mean concentrations using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). The cluster analysis using back trajectories was performed to identify the major airflows to the sampling site. The upper atmosphere in the Tianjin area of China and the lower atmosphere in the western coast area of Korea can be the major source of trans-boundary pollution to the sampling site during January~April resulted from PSCF. The area in Lianyungang-city and Liaoning-sheng, China can be responsibile for the nitrogen related secondary compounds during May~August, and Shandong Peninsula in China is the major source area during September~December. In addition, relationships between the cluster analysis of back trajectories and PSCF were investigated for the statistically significance level for the source areas.

Vision based Fast Hand Motion Recognition Method for an Untouchable User Interface of Smart Devices (스마트 기기의 비 접촉 사용자 인터페이스를 위한 비전 기반 고속 손동작 인식 기법)

  • Park, Jae Byung
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.49 no.9
    • /
    • pp.300-306
    • /
    • 2012
  • In this paper, we propose a vision based hand motion recognition method for an untouchable user interface of smart devices. First, an original color image is converted into a gray scaled image and its spacial resolution is reduced, taking the small memory and low computational power of smart devices into consideration. For robust recognition of hand motions through separation of horizontal and vertical motions, the horizontal principal area (HPA) and the vertical principal area (VPA) are defined respectively. From the difference images of the consecutively obtained images, the center of gravity (CoG) of the significantly changed pixels caused by hand motions is obtained, and the direction of hand motion is detected by defining the least mean squared line for the CoG in time. For verifying the feasibility of the proposed method, the experiments are carried out with a vision system.