• Title/Summary/Keyword: Disparity measure

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

  • 홍종선;정동빈;박용석
    • The Korean Journal of Applied Statistics
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    • v.16 no.2
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    • pp.455-467
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    • 2003
  • There has been a long debate on the applicability of the chi-square approximation to statistics based on small sample size. Extending comparison results among Pearson chi-square Χ$^2$, generalized likelihood .ratio G$^2$, and the power divergence Ι(2/3) statistics suggested by Rudas(1986), recently developed disparity statistics (BWHD(1/9), BWCS(1/3), NED(4/3)) we compared and analyzed in this paper. By Monte Carlo studies about the independence model of two dimension contingency tables, the conditional model and one variable independence model of three dimensional tables, simulated 90 and 95 percentage points and approximate 95% confidence intervals for the true percentage points are obtained. It is found that the Χ$^2$, Ι(2/3), BWHD(1/9) test statistics have very similar behavior and there seem to be applcable for small sample sizes than others.

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

  • 김재한
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.6
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    • pp.1163-1168
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    • 2001
  • The ranging systems measure range data in three-dimensional coordinate from target surface. These non-contact remote ranging systems is widely used in various automation applications, including military equipment, construction field, navigation, inspection, assembly, and robot vision. The active ranging systems using time of flight technique or light pattern illumination technique are complex and expensive, the passive systems based on stereo or focusing principle are time-consuming. The proposed algorithm, that is based on cross correlation of projection profile of vertical edge, provides advantages of fast and simple operation in the range acquisition. The results of experiment show the effectiveness of the proposed algorithm.

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

  • Kim, Hyeong-Seok;Song, Jae-Hong;Han, Hu-Seok
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.9
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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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Segment matching using matching measure distribution over disparities (변이별 정합 척도 분포를 이용한 선소의 정합)

  • 강창순;남기곤
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.3
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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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A Structural Analysis of Income Poverty and Multidimensional Poverty in China's Rural Areas (중국 농촌 지역의 소득 빈곤과 다차원적 빈곤의 구조 분석)

  • Xu, ShengXing;Wang, Xiaofeng;Yang, Lili;Kim, Jung-Gi
    • Korean Journal of Organic Agriculture
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    • v.29 no.4
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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.

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

  • Li, Hyung-Chul O.;Moon, Kyung-Ae
    • Science of Emotion and Sensibility
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    • v.15 no.1
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    • pp.17-28
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    • 2012
  • Recent development of 3D technologies made it possible that observers perceive 3D depth from two dimensional images. Despite this kind of technological development, when observers watch 3D display they experience 3D visual fatigue that they do not usually experience in real life. It is critical to measure visual fatigue in order to overcome the problem of 3D visual fatigue. The purpose of the present study was to develop a protocol to measure 3D visual fatigue based on an EEG signal and to examine its validity. The first experiment explored the possible ERP components that reflected visual fatigue in 2D and 3D conditions. The second experiment examined whether the feature of the component found in the first experiment was affected by the amount of binocular disparity. Both in Cz and Pz channels, the peak amplitude of P3 component was much lower in 3D rather than in 2D conditions, and it decreased as the amount of binocular disparity increased. The subjective 3D visual fatigue also increased with the amount of binocular disparity. These results imply that the peak amplitude of P3 component at Cz and Pz channels can be used as an index of 3D visual fatigue.

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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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    • v.17 no.sup3
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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.

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

  • 문상식;이시백
    • Korean Journal of Health Education and Promotion
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    • v.18 no.3
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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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Disparity of Access to Neighborhood Facilities for the Elderly in Rural Areas - Focusing on Community Facilities - (농촌 노인 생활인프라 접근성의 지역 간 격차 - 생활편익시설을 중심으로 -)

  • Kim, Hyun-Joong;Hwang, Jeong-Im;Choi, Yoon-Ji
    • Journal of Agricultural Extension & Community Development
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    • v.22 no.2
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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.

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

  • Kim, Byeong-Sun;Kim, Young-Sung;Chung, Su-Yeul
    • Journal of the Korean association of regional geographers
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    • v.17 no.2
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    • pp.204-215
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    • 2011
  • One of the major concerns to improve social-wellbeing is uneven spatial distribution of public service. The paper analyses the changes in the geographic distribution of public service facilities over time. The analysis is with a case study about JeollaNamdo Province including Gwangju Metropolitan City, 1985~2005. It employed eighteen proxies in different fields to measure public service and utilized cluster analyses, and various summary statistics including Schutz's coefficient and regression. The results show that overall social well-being has improved during the two decades and the gap between Gwanju City and the major cities in the JeollaNamdo Province has narrowed. However, the disparity between mainland and island areas still persists, calling our attention to the island areas.

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