• Title/Summary/Keyword: Grey-level

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A Comparative Analysis for Projection Models of the Physician Demand and Supply Among 5 Countries (주요 국가 의사인력 수급 추계방법론 비교분석)

  • Seo, Kyung Hwa;Lee, Sun Hee
    • Health Policy and Management
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    • v.27 no.1
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    • pp.18-29
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    • 2017
  • Background: In Korea, the problem of physician workforce imbalances has been a debated issue for a long time. This study aimed to draw key lessons and policy implications to Korea by analyzing projection models of physician demand/supply among five countries. Methods: We adopted theoretical framework and analyzed detail indicators used in projection models of demand/supply comparatively among countries. A systematic literature search was conducted using PubMed and Google Scholar with key search terms and it was complimented with hand searching of grey literature in Korean or English. Results: As a results, Korea has been used a supply-based traditional approach without taking various variables or environmental factors influencing on demand/supply into consideration. The projection models of USA and Netherlands which considered the diversity of variables and political issues is the most closest integrated approach. Based on the consensus of stakeholder, the evolved integrated forecasting approach which best suits our nation is needed to minimize a wasteful debate related to physician demand/supply. Also it is necessary to establish the national level statistics indices and database about physician workforce. In addition, physician workforce planning will be discussed periodically. Conclusion: We expect that this study will pave the way to seek reasonable and developmental strategies of physician workforce planning.

PIV Measurement of Airflow in a Vertical Channel With Square Heat Source (정방형 발열체를 갖는 수직채널 내부의 공기유동 관한 PIV계측)

  • Bae, S.T.;Kim, D.K.;Kim, S.P.;Cho, D.H.;Lee, Y.H.
    • Solar Energy
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    • v.17 no.3
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    • pp.35-41
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    • 1997
  • An experimental study was carried out in a vertical channel with square heat source by visualization equipment with laser apparatus. The image processing system consists of one commercial image board slit into a personal computer and 2-dimensional sheet light by Argon-Ion Laser with cylindrical lens and flow picture recording system. Instant simultaneous velocity vectors at whole field were measured by 2-D PIV system which adopted two-frame grey-level cross correlation algorithm. Heat source was uniform heat flux(5W). The obtained results show various flow patterns such as the kinetic energy distribution and the turbulent kinetic energy distribution.

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EVALUATION OF SPEED AND ACCURACY FOR COMPARISON OF TEXTURE CLASSIFICATION IMPLEMENTATION ON EMBEDDED PLATFORM

  • Tou, Jing Yi;Khoo, Kenny Kuan Yew;Tay, Yong Haur;Lau, Phooi Yee
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.89-93
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    • 2009
  • Embedded systems are becoming more popular as many embedded platforms have become more affordable. It offers a compact solution for many different problems including computer vision applications. Texture classification can be used to solve various problems, and implementing it in embedded platforms will help in deploying these applications into the market. This paper proposes to deploy the texture classification algorithms onto the embedded computer vision (ECV) platform. Two algorithms are compared; grey level co-occurrence matrices (GLCM) and Gabor filters. Experimental results show that raw GLCM on MATLAB could achieves 50ms, being the fastest algorithm on the PC platform. Classification speed achieved on PC and ECV platform, in C, is 43ms and 3708ms respectively. Raw GLCM could achieve only 90.86% accuracy compared to the combination feature (GLCM and Gabor filters) at 91.06% accuracy. Overall, evaluating all results in terms of classification speed and accuracy, raw GLCM is more suitable to be implemented onto the ECV platform.

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A Study on Ventilation Characteristics of LNG Carrier Hood room by PIV and CFD (PIV와 CFD에 의한 LNG선박의 Hood room 환기특성에 관한 연구)

  • Cho, D.H.;Kim, D.C.;Kim, M.E.;Lee, Y.H.
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.673-679
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    • 2000
  • LNG Carriers are currently known as sole commercial means of shipping natural gas on the sea. They are designed to proven dangerous explosion for shipping a lot of gas over long distance. In this study. In this study, a scaled model chamber was made to investigate ventilation characteristics of the hood room in LNG carrier. Experimental study was performed in model using visualization equipments with laser apparatus and image intensifier CCD camera gated by an AOM controller Twelve different kinds of measuring area were selected as experimental condition. Instant simultaneous velocity vectors at whole field were measured by using 2-D PIV system which software adopts two-frame grey-level cross correlation algorithm. To look into stagnation area of hood room for LNG carrier, a three-dimensional numerical simulation with standard ${\kappa}-{\varepsilon}$ model was carried out by using PHOENICS for three kinds of Reynolds number, $6.5{\times}10^3$, $9.7{\times}10^3\;and\;1.29{\times}10^4$, based on the cavity inlet velocity and cavity height. The flow pattern showed the large scale counter-clockwise forced-vortex rotated at center area, small eddies at each corner and stagnation area located at left-back upper side of model.

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PIV Analysis of Flow around a Submerged Pitch Damping Foil (몰수형 피치댐핑포일 주위 유동의 PIV 해석)

  • Gim, Ok-Sok;Lee, Gyoung-Woo
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.5
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    • pp.410-415
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    • 2012
  • An experimental study is carried out to investigate the near-wake characteristics of a NACA 0018 foil with a flat plate. Two-frame grey-level cross correlation PIV method is used to measure the local flow characteristic around a pitch damping foil to control the vertical motion of high speed crafts in a circulating water channel. The analysis also includes angles of attack 10 and 20 degrees respectively. Reynolds number $Re{\fallingdotseq}3.5{\times}10^4$ based on the chord length(C=100mm) of NACA0018 has been applied during the whole experiments. The distance between the foil and the flat plate is D/C=0.5, 1.0 and 1.5 respectively. The channel effect according as the distance between the foil and the flat plate has a close relation with the velocity distributions around the foil. In the wake of 20-degree of attack, the complex turbulent flow and a thick boundary layer are formed due to the processes of vortex generation and dissipation.

The Obstacle Avoidance Algorithm of Mobile Robot using Line Histogram Intensity (Line Histogram Intensity를 이용한 이동로봇의 장애물 회피 알고리즘)

  • 류한성;최중경;구본민;박무열;윤경섭;윤석영
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.331-334
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    • 2002
  • In this paper, we present two types of vision algorithm that mobile robot has CCD camera. for obstacle avoidance. This is simple algorithm that compare with grey level from input images. Also, The mobile robot depend on image processing and move command from PC host. we has been studied self controlled mobile robot system with CCD camera. This system consists of digital signal processor, step motor, RF module and CCD camera. we used wireless RF module for movable command transmitting between robot and host PC. This robot go straight until recognize obstacle from input image that preprocessed by edge detection, converting, thresholding. And it could avoid the obstacle when recognize obstacle by line histogram intensity. Host PC measurement wave from various line histogram each 20 Pixel. This histogram Is ( x , y ) value of pixel. For example, first line histogram intensity wave from ( 0, 0 ) to ( 0, 197 ) and last wave from ( 280, 0 ) to ( 280, 197 ). So we find uniform wave region and nonuniform wave region. The period of uniform wave is obstacle region. we guess that algorithm is very useful about moving robot for obstacle avoidance.

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Contrast Image Enhancement Using Multi-Histogram Equalization

  • Phanthuna, Nattapong;cheevasuwit, Fusak
    • International Journal of Advanced Culture Technology
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    • v.3 no.2
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    • pp.161-170
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    • 2015
  • Mean separated histogram equalization in order to preserve the original mean brightness has been proposed. To provide the minimum mean brightness error after the histogram modification, the input image's histogram is successively divided by the factor of 2 until the mean brightness error is satisfied the defined threshold. Then each divided group or sub-histogram will be independently equalized based on the proportional input mean. To provide the overall minimum mean brightness error, each group will be controlled by adding some certain pixels from the adjacent grey level of the next group for giving its mean near by the corresponding the divided mean. However, it still exists some little error which will be put into the next adjacent group. By successive dividing the original histogram, we found that the absolute mean brightness error is gradually decreased when the number of group is increased. Therefore, the error threshold is assigned in order to automatically dividing the original histogram for obtaining the desired absolute mean brightness error (AMBE). This process will be applied to the color image by treating each color independently.

Real-time Human Detection under Omni-dir ectional Camera based on CNN with Unified Detection and AGMM for Visual Surveillance

  • Nguyen, Thanh Binh;Nguyen, Van Tuan;Chung, Sun-Tae;Cho, Seongwon
    • Journal of Korea Multimedia Society
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    • v.19 no.8
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    • pp.1345-1360
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    • 2016
  • In this paper, we propose a new real-time human detection under omni-directional cameras for visual surveillance purpose, based on CNN with unified detection and AGMM. Compared to CNN-based state-of-the-art object detection methods. YOLO model-based object detection method boasts of very fast object detection, but with less accuracy. The proposed method adapts the unified detecting CNN of YOLO model so as to be intensified by the additional foreground contextual information obtained from pre-stage AGMM. Increased computational time incurred by additional AGMM processing is compensated by speed-up gain obtained from utilizing 2-D input data consisting of grey-level image data and foreground context information instead of 3-D color input data. Through various experiments, it is shown that the proposed method performs better with respect to accuracy and more robust to environment changes than YOLO model-based human detection method, but with the similar processing speeds to that of YOLO model-based one. Thus, it can be successfully employed for embedded surveillance application.

Humpback Whale Assisted Hybrid Maximum Power Point Tracking Algorithm for Partially Shaded Solar Photovoltaic Systems

  • Premkumar, Manoharan;Sumithira, Rameshkumar
    • Journal of Power Electronics
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    • v.18 no.6
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    • pp.1805-1818
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    • 2018
  • This paper proposes a novel hybrid maximum power point tracking (MPPT) algorithm combining a Whale Optimization Algorithm (WOA) and the conventional Perturb & Observation (P&O) to track/extract the highest amount of power from a solar photovoltaic (SPV) system working under partial shading conditions (PSCs). The proposed hybrid algorithm is based on a WOA which predicts the initial global peak (GP) and is followed by P&O in the final stage to achieve a quicker convergence to a GP. Thus, this hybrid algorithm overcomes the computational burden encountered in a standalone WOA, grey wolf optimization (GWO) and hybrid GWO reported in the literature. The conventional algorithm searches for the maximum power point (MPP) in the predicted region by the WOA. The proposed MPPT technique is modelled and simulated using MATLAB/Simulink for simulating an environment to check its effectiveness in accurately tracking the MPP during the GP region. This hybrid algorithm is compared with a standalone WOA, GWO and hybrid GWO. From the simulating results, it is shown that the proposed algorithm offers high tracking performance and that it increases the output power level of a SPV system under partial shading. The algorithm also verified experimentally on various PSCs.

A Study on Micro-calcification Detection in Digital Mammography (디지털 맘모그래피에서 미소석회화 검출을 위한 연구)

  • Whi-Vin Oh;Young-Jae Kim;Kwang-gi Kim;Hyung-Seok Choi;Young-Wook Seo;Young-Ho Cho
    • Annual Conference of KIPS
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    • 2008.11a
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    • pp.112-113
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    • 2008
  • 유방암은 유럽과 미국을 비롯해 전 세계적으로 증가하고 있으며 최근 우리나라에서도 가장 급속하게 늘고 있는 여성암중에 하나이다. 본 연구에서는 먼저 grey level co-occurrence matrix(GLCM)을 적용하여 유방영역을 분할한 후, median filter 를 적용하여 잡음을 제거하였다. 전처리 수행 후, 2차미분 행렬을 이용할여 미소석회화 부분을 강조한 후, 가우시안 정규분포도를 적용하여 미소석회화 후보군을 검출하였다. 검출된 후보군은 8 개의 feature 들을 적용하여 미소석회화를 최종 결정하였다. 본 연구를 통해서 조기 유방암 진단을 위한 발전된 미소석회화 검출 방법을 제안하였다.