• 제목/요약/키워드: Disparity measure

검색결과 54건 처리시간 0.026초

소표본에서 차이측도 통계량의 비교연구 (A Monte Carlo Comparison of the Small Sample Behavior of Disparity Measures)

  • 홍종선;정동빈;박용석
    • 응용통계연구
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    • 제16권2호
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    • pp.455-467
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    • 2003
  • 소표본 분할표 자료에서 적합도 검정통계량들의 카이제곱 근사 적용 가능에 대하여 많은 연구가 진행되었다. 소표본에서 세 가지 검정 통계량(피어슨 카이제곱 Χ$^2$, 일반화 가능도비 G$^2$, 그리고 역발산 Ι(2/3) 검정통계량)에 관하여 비교한 Rudas(1986)의 연구를 확장하여, 최근에 제안된 차이측도(BWHD(1/9), BWCS(1/3), NED(4/3) 검정통계량)를 포함시켜 비교 분석하였다. 독립모형의 이차원 분할표, 조건부 독립모형과 한 변수 독립 모형을 따르는 삼차원 분할표에 대한 모의실험을 통하여 생성된 90과 95 백분위수와 이에 대응하는 95% 신뢰구간을 살펴보고 실제 백분위수와 비교하였다. 그 결과 Χ$^2$, Ι(2/3), 그리고 BWHD(1/9) 검정통계량이 유사한 결과를 나타내었고 이 통계량들이 기존에 제안된 검정통계량들보다 적은 표본크기에서도 카이제곱 근사방법에 적용 가능함을 발견하였다.

스테레오 카메라의 양안 시차를 이용한 거리 계측의 고속 연산 알고리즘 (An Efficient Algorithm for 3-D Range Measurement using Disparity of Stereoscopic Camera)

  • 김재한
    • 한국정보통신학회논문지
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    • 제5권6호
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    • pp.1163-1168
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    • 2001
  • 거리 계측 시스템은 물체까지의 거리를 삼차원 좌표계에서 측정하는 장치이다. 군용 장비나 건설, 항해, 검사 조립, 로봇 비전 등에 널리 사용되는 무접촉식 원격 거리 계측(ranging) 시스템은 자동화 응용에 매우 중요하다. 계측 방식은 active와 passive방식으로 구분되는데, active방식은 laser나 microwave, 초음파 등의 time of flight를 이용하거나 레이저 조사(illumination)에 대한 카메라 영상을 해석하는 등의 다양한 방식이 있으나 장치가 복잡하며, passive 방식은 stereo camera의 양안영상을 이용하거나 focus특성을 이용하는 방식 등이 있으나 대부분 연산시간이 많이 요구된다. 본 연구에서는 수동식 스테레오 카메라에서 양안시차를 산출하여 triangulation으로 목표전의 거리를 측정하는 방식에서, 연산 시간이 많이 소요되는 과정을 고속으로 처리하는 새로운 방식을 제안하였다. 즉, 목표점에서의 양안 edge 영상을 구하고, 이 영상의 projection profile을 cross correlation하여, 시차를 고속으로 산출해 거리를 구하는 알고리즘을 제안하였으며, 이 방식의 효율성을 실험 결과를 통하여 보였다.

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회전 평면경 영상의 단일 카메라 투영에 의한 거리 측정 (Depth Estimation Through the Projection of Rotating Mirror Image unto Mono-camera)

  • 김형석;송재홍;한후석
    • 제어로봇시스템학회논문지
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    • 제7권9호
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    • pp.790-797
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    • 2001
  • A simple computer vision technology to measure the middle-ranged depth with a mono camera and a plain mirror is proposed. The proposed system is structured with the rotating mirror in front of the fixed mono camera. In contrast to the previous stereo vision system in which the disparity of the closer object is larger than that of the distant object, the pixel movement caused by the rotating mirror is bigger for the pixels of the distant object in the proposed system. Being inspired by such distinguished feature in the proposed system, the principle of the depth measurement based on the relation of the pixel movement and the distance of object is investigated. Also, the factors to influence the precision of the measurement are analysed. The benefits of the proposed system are low price and less chance of occlusion. The robustness for practical usage is an additional benefit of the proposed vision system.

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변이별 정합 척도 분포를 이용한 선소의 정합 (Segment matching using matching measure distribution over disparities)

  • 강창순;남기곤
    • 전자공학회논문지S
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    • 제34S권3호
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    • pp.74-83
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    • 1997
  • In this paper, a new stereo matching algorithm is proposed which uses th econstrainted optimization technique and the matching measures between the segments extracted from zero-crossing edges. The initial matching measures and average disparities are calculated by the features of segments on the searching window of the left and right images. The matching measure is calculated by applying an exponential function using the differences of slope, overlapped length and intensity. The coherency constraint is that neighbouring image points corresponding to the same object should have nearly the same disparities. The matching measures are iteratively updated by applying the coherency constraint. Simulation results on various images show that the proposed algorithm more acculately extracts the segment disparity.

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중국 농촌 지역의 소득 빈곤과 다차원적 빈곤의 구조 분석 (A Structural Analysis of Income Poverty and Multidimensional Poverty in China's Rural Areas)

  • 서성성;왕효봉;양리리;김중기
    • 한국유기농업학회지
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    • 제29권4호
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    • pp.471-484
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    • 2021
  • The characteristics of poverty can be comprehensively revealed from the two angles of income and multidimensional. This paper compares China's rural income poverty measure with multidimensional poverty index using data from China Family Panel Studies (CFPS) by focusing on the static and dynamic disparities, and analyzes the factors influencing poverty through the Logit model. The results show that there exists a substantial mismatch in who is deemed poor, 60 percent of multidimensional poverty households are not considered poor in terms of income poverty, and 70 percent of income poverty households are not considered poor in terms of multidimensional poverty; There is a high level of disparity between the dynamics of the two measures of poverty. Among those who rose in the income dimension, only about 7 percent also rose in the multidimensional measure from 2016 to 2018.

EEG 생체신호 기반 3D 시각피로 측정방법에 대한 타당화 연구 (Validity examination of the measurement of 3D visual fatigue using EEG)

  • 이형철;문경애
    • 감성과학
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    • 제15권1호
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    • pp.17-28
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    • 2012
  • 최근의 디스플레이 기술은 2차원 디스플레이에 제시된 영상으로부터 3차원 깊이감을 지각하는 것을 가능하게 하였다. 이런은 디스플레이와 콘텐츠 기술의 발전에도 불구하고, 사용자는 실생활에서 경험하지 않는 시각피로의 문제를 경험하는데, 이 문제를 해결하기 위해서는 시각피로를 안정적이고 타당하게 측정하는 것이 필요하다. 본 연구의 목적은 EEG(Electroencephalography)신호에 기반한 시각피로 측정의 프로토콜을 개발하고 타당성을 검증하는 것이었다. ERP(Event related potential) 성분 중에서 시각피로를 반영하는 성분을 찾아내기 위해 2D 조건과 3D 조건에서 탐색적 실험을 수행하였고, 탐색적 실험에서 발견된 ERP 성분이 양안시차의 차이에 따라 상이한 특성을 보이는지 검증하기 위하여 확인적 실험을 수행하였다. 실험결과, Cz와 Pz 영역에서 P3 성분의 정점 강도가 2D 조건보다는 3D 조건에서 감소하였으며, 양안시차가 증가할수록 일관되게 P3 성분의 강도가 통계적으로 유의하게 감소하는 것을 확인하였다. 양안시차가 증가함에 따라서 주관적인 시각피로가 통계적으로 유의하게 증가함을 검증하였는데, 이 실험결과는 Cz와 Pz 영역에서의 P3 성분의 정점 강도가 3D 시각피로에 대한 인덱스로 사용할 수 있음을 시사한다.

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Effects of Human Development Index and Its Components on Colorectal Cancer Incidence and Mortality: a Global Ecological Study

  • Khazaei, Salman;Rezaeian, Shahab;Khazaei, Somayeh;Mansori, Kamyar;Moghaddam, Ali Sanjari;Ayubi, Erfan
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권sup3호
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    • pp.253-256
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    • 2016
  • Geographic disparity for colorectal cancer (CRC) incidence and mortality according to the human development index (HDI) might be expected. This study aimed at quantifying the effect measure of association HDI and its components on the CRC incidence and mortality. In this ecological study, CRC incidence and mortality was obtained from GLOBOCAN, the global cancer project for 172 countries. Data were extracted about HDI 2013 for 169 countries from the World Bank report. Linear regression was constructed to measure effects of HDI and its components on CRC incidence and mortality. A positive trend between increasing HDI of countries and age-standardized rates per 100,000 of CRC incidence and mortality was observed. Among HDI components education was the strongest effect measure of association on CRC incidence and mortality, regression coefficients (95% confidence intervals) being 2.8 (2.4, 3.2) and 0.9 (0.8, 1), respectively. HDI and its components were positively related with CRC incidence and mortality and can be considered as targets for prevention and treatment intervention or tracking geographic disparities.

주관적 건강인식과 건강검진 결과의 비교분석을 통한 건강행위 연구 (A Study of Health Behavior through Comparative Analysis of Self-perceived Health Status and Health Examination Results)

  • 문상식;이시백
    • 보건교육건강증진학회지
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    • 제18권3호
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    • pp.11-36
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    • 2001
  • The purpose of this study is to analyze health behavior by comparing the difference between self-perceived health status and health examination results. The study subjects consist of 7,702 people aged over 20, surveyed by Health Interview survey, Health Examination survey, Dietary Life survey, Health Consciousness and Behavior survey. Data used in the study are drawn from raw data from a 1998 National Health and Nutrition survey. General characteristics variables are sex, age, education level, residential area, marital status, occupation, and living standard while dichotomous variables, ‘not healthy’ and ‘healthy’ are used to measure self-perceived health status. Variables for health examination results are high blood pressure, high cholesterol, diabetes, liver diseases, liver inflammation, kidney diseases, normal weight, regular diet, optimum sleeping time(7-8 hours), regular health examination and health behavior practice group. Major findings of the study are as follows: 1) Analysis of self-perceived health status and health behavior by disease: Variables significantly correlated with high self-perceived health status have strong associations with high health behavior practice, which supports the hypothesis that as one has high self-perceived health status, one is more likely to practice health promoting behavior. The results of analysis of health behavior differences by dividing subjects into two categories, ‘cases of illness’ and ‘cases of no illness’ indicate that drinking, sleeping time, health examination are significant variables (p〈0.001, 0.05) whereas smoking, weight control, regular exercise, regular diet are not significant. 2) Analysis of disparity patterns between self-perceived health status and health examination: The hypothesis that health behaviors would be different according to the disparity pattern between self-perceived health status and health examination is supported as a result of χ2 test. Among Type I : Self-perceived health status is high and actual health status is good (no disease) Type II: Self-perceived health status is high and actual health status is poor(have disease) Type III: Self-perceived health status is low and actual health status is good(no disease) Type IN: Self-perceived health status is low and actual health status is poor(have disease) Type I and Type IV show no disparity, Type I shows the highest health promoting behavior whereas Type IV shows the lowest health promoting behavior. Type II, and III, compared to Type I, practise lower health promoting behavior. Multi-logistics regression analysis was conducted to find out the degree of impact on health behavior. Independent variables are general characteristics, self-perceived health status and health examination result and presence of illness, while the dependent variable is health promoting behavior. The analysis of the impact of self-perceived health status on the health promoting behavior shows that smoking, drinking, weight control, regular exercise, health examination practice, and/or regular diet are significantly correlated to self-perceived health status. High self-perceived health status is inversely related to high health promoting behavior. This finding supports the hypothesis that the higher one perceives one's health, the more likely one is to practice health promoting behavior. On the contrary, the presence of illness has little impact on health promoting behavior. 3) Multiple logistics analysis on how disparity patterns between self-perceived health status and health examination affect health behavior: The results of multiple logistics analysis made on health behavior variables compared to the standard variable are as follows: When analyzed on the standard of Type I, smoking is a significant risk factor for the Type IV. In case of drinking, all the patterns show a high probability of relative risk ratio. With regard to weight control, it is a risk factor for Type II while all the patterns show high probability of not practising when analyzed on the standard of type IV. Type III and IV show high probability of not doing regular exercise while Type IV, shows a high probability of not taking appropriate sleeping time. When analyzed on the standard of type IV, all the patterns show a high probability of not taking health examinations. Type III and IV show a high probability of not having regular meals. As for overall health promoting behavior, Type III and IV show a high relative risk ratio. These two groups have low self-perceived health status. It implies that self-perceived health status has significant impact on health promoting behavior. This is also supported by the fact that Type I with high self-perceived health status and no illness shows a high practice rate of health promoting behavior. Types II and III the groups with high disparity between self-perceived health status and health examination results, show a low practice rate of health promoting behavior when compared to Type I. Type IV, that is the group with low self-perceived health status and actual illness, shows the lowest practice of health promoting behavior. It is highly probable that this type proves to be the poorest health group.

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농촌 노인 생활인프라 접근성의 지역 간 격차 - 생활편익시설을 중심으로 - (Disparity of Access to Neighborhood Facilities for the Elderly in Rural Areas - Focusing on Community Facilities -)

  • 김현중;황정임;최윤지
    • 농촌지도와개발
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    • 제22권2호
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    • pp.159-173
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    • 2015
  • The purpose of this study was to identify the conditions of neighborhood facilities for the elderly, paying special attention to the accelerated aging phenomenon in rural areas of Korea. We contrived a new index to measure spatial accessibility for people aged over 65 years, and we analyzed spatial accessibility by focusing on community facilities: public bath facilities, beauty shops, rural public facilities, markets, big stores, and large-scale retail shops. The most outstanding spatial accessibility among community facilities was found with the rural public facilities thanks to governmental installing adequate facilities in the past, followed by the beauty shops and the public bath facilities. In contrast, spatial accessibility of the markets was in the lowest. Spatial accessibility of community facilities for the elderly exhibited high variability among the rural areas. We confirmed significant inequality of spatial accessibility in all facilities we studied. The areas that had better spatial accessibility diverse combinations of the facilities. The areas that had worse spatial accessibility were, on the whole, consistent with traditional undeveloped regions. In the near future rational planning of facilities will be needed to supply adequate accessibility in targeted areas which currently had low accessibility. In order to improve the spatial accessibility of neighborhood facilities, the most essential factor is to take into account the geographical distribution patterns of rural settlements.

복리환경의 시공간적 변화: 1985년~2005년 전남지역을 사례로 (Spatio-Temporal Changes of Social-wellbeing: A Case Study of JeollaNamdo Region, 1985~2005)

  • 김병선;김영성;정수열
    • 한국지역지리학회지
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    • 제17권2호
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    • pp.204-215
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    • 2011
  • 공공서비스의 지역적 불균등을 분석하는 것은 사회복리지리학에 가장 큰 주제 가운데 하나이다. 이 연구는 1885년~2005년 동안 광주광역시를 포함한 전라남도 지역을 대상으로 연구지역의 객관적인 사회복리 수준의 지역적 변화를 분석하기 위해, 군집 분석기법을 비롯한 다양한 사회복리 수준 측정 방법을 사용하였다. 분석결과 지난 20년 동안 연구지역의 전반적인 사회복리 수준이 향상되었다는 것을 확인할 수 있었다. 하지만 도서지역의 경우 사회복리수준의 발전이 상대적으로 미약한 것으로 나타났다. 따라서 도서지역의 사회복리 수준을 개선하기 위한 정책적 방안이 수립될 필요가 있다.

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