• Title/Summary/Keyword: Change points

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Intersections of a polyhedral surface with parallel planes using characteristics points (특성점의 성질을 이용한 다면체 곡면과 평행한 평면들과의 교선)

  • 전차수;김영일
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1995.04a
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    • pp.603-616
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    • 1995
  • Presented in this paper is an algorithm to obtain the intersections of a polyhedral surface composed of triangle facets with a series of parallel planes for extracting machining information from the surface. The change of the topology of the intersection curves is caused by characteristic points of the surface when sectioning the surface with parallel planes. The characteristic points are internal maximum, internal minimum, internal saddle, boundary maximum, boundary minimum, boundary max-saddle, and boundary min-saddle points. The starting points of the intersects are found efficiently and robustly using the characteristic points. The characteristic points as well as the intersection contours can be used to evaluate the machining information for process planning, and to generate NC tool path in CAD/CAM system.

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Feature Matching Algorithm Robust To Viewpoint Change (시점 변화에 강인한 특징점 정합 기법)

  • Jung, Hyun-jo;Yoo, Ji-sang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.12
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    • pp.2363-2371
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    • 2015
  • In this paper, we propose a new feature matching algorithm which is robust to the viewpoint change by using the FAST(Features from Accelerated Segment Test) feature detector and the SIFT(Scale Invariant Feature Transform) feature descriptor. The original FAST algorithm unnecessarily results in many feature points along the edges in the image. To solve this problem, we apply the principal curvatures for refining it. We use the SIFT descriptor to describe the extracted feature points and calculate the homography matrix through the RANSAC(RANdom SAmple Consensus) with the matching pairs obtained from the two different viewpoint images. To make feature matching robust to the viewpoint change, we classify the matching pairs by calculating the Euclidean distance between the transformed coordinates by the homography transformation with feature points in the reference image and the coordinates of the feature points in the different viewpoint image. Through the experimental results, it is shown that the proposed algorithm has better performance than the conventional feature matching algorithms even though it has much less computational load.

Job Satisfaction of Children Foodservice Employees at Daycare Centers (어린이 급식소 조리종사자의 직무만족도 조사 -100인 미만의 어린이 급식소를 중심으로-)

  • Shin, Hyewon;Choi, Juhee;Lee, Younghwa;Cho, Wookyoun
    • Journal of the Korean Dietetic Association
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    • v.21 no.3
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    • pp.241-252
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    • 2015
  • The research was conducted by center for children's foodservice management in Hanam-si. In order to improve job satisfaction, a survey was carried out by working conditions and job satisfaction in children foodservice employees working at child daycare centers registered from January to April. Ninety-five surveys out of 120 were collected, and 76 surveys were analyzed. Job satisfaction consisted of four elements, working environment, welfare, human relationships, and job-itself, analyzed by general characteristics. Pearson's correlation was carried out between job satisfaction and intention to change job by Likert 5 scales using SPSS statistic program. The percentages of child daycare centers owned by civilians was 52.6%, high school education level was 65.8%, permanent workers was 68.4%, and less than 1 year of foodservice was 34.2%. Average scores of job satisfaction were as follows: working environment scored 20.6 out of 25 points, welfare scored 10.3 out of 15 points, human relationships scored 17.5 out of 20 points, and job-itself scored 13.2 out of 15 points. The lowest job satisfaction average was 'I get paid fairly regarding the working hours and the amount of work' with a score of 3.6 points. Job satisfaction based on facility type, age, education level, and working period did not show significant differences, whereas hired status, numbers of foodservice children, and intention to change jobs showed significant differences. Hired status showed significant differences with welfare satisfaction (P<0.05). Numbers of children showed a significant difference with welfare and human relationship satisfaction (P<0.01, P<0.05). Intention to change job showed a significant difference with four elements of job satisfaction (P<0.05, P<0.01, P<0.01). In conclusion, to improve job satisfaction of children foodservice employees, working conditions and welfare satisfaction should be increased.

A NONPARAMETRIC CHANGE-POINT ESTIMATOR USING WINDOW IN MEAN CHANGE MODEL

  • Kim, Jae-Hee;Jang, Hee-Yoon
    • Journal of applied mathematics & informatics
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    • v.7 no.2
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    • pp.653-664
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    • 2000
  • The problem of inference about the unknown change-point with a change in mean is considered. We suggest a nonparametric change-point estimator using window and prove its consistency when the errors are from the distribution with the mean zero and the common variance. a comparison study is done by simulation on the mean, the variance, and the proportion of matching the true change-points.

A Study on Change-Points in System Reliability

  • Kwang Mo Jeong
    • Communications for Statistical Applications and Methods
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    • v.1 no.1
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    • pp.10-19
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    • 1994
  • We study the change-point problem in the context of system reliability models. The maximum likelihood estimators are obtained based on the Jelinski and Moranda model. To find the approximate distribution of the change-point estimator, we suggest of parametric bootstrap method in which the estimators are substituted in the assumed model. Through an example we illustrate the proposed method.

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Analysis of Meridian Energy and its Change Pattern with Time using Measurement of Skin-Capacitance on Source Points (체표 캐패시턴스 측정 방식을 이용한 체표 경락.경혈 에너지 변화 분석)

  • Kim, Soo-Byung;Kwon, Sun-Min;Myoung, Hyoun-Seok;Lee, Kyoung-Joung;Kang, Hee-Jung;Yim, Yun-Kyoung;Lee, Yong-Heum
    • Korean Journal of Acupuncture
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    • v.26 no.3
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    • pp.1-11
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    • 2009
  • Objectives : The object of this study is to investigate the balance/imbalance of skin capacitances between left and right meridians, and to analyze the change patterns of electric energy on meridians with the lapse of time. Method : Electric potential was measured on five source points (LU9, PC7, HT7, LI4, SI4) bilaterally for 4 hours. The energy balance/imbalance between left and right was investigated, and the change patterns with time were analyzed. Results and Conclusions : The amplitude of meridian energy on five source points and the energy balance/imbalance between left and right were varied in each individual. When a source point showed a balanced meridian energy bilaterally, the change patterns of meridian energy with time were similar between left and right. While, when it showed an imbalanced energy between left and right, the change patterns of meridian energy were also different between left and right. Through this study, we proposed a new diagnostic method of meridian energy.

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Gamut Mapping Using Variable Anchor Points for Continuous Color Reproduction between Devices (장치간 연속 색 재현을 위한 가변 닻점 방식의 색역 사상)

  • 이채수;윤태진;한찬호
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2001.05a
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    • pp.300-310
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    • 2001
  • In this paper, new gamut-mapping algorithm (GMA) that utilizes variable anchor points (center of gravity on the luminance axis) is proposed. The proposed algorithm increases luminance range, which is reduced from conventional gamut mapping toward an anchor point. In this process, this algorithm utilizes multiple anchor points with constant slopes to both reduce a sudden color change on the gamut boundary of the printer and to maintain a uniform color change during the mapping process. Accordingly, the proposed algorithm can reproduce high quality images with low-cost color devices.

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Bayesian Multiple Change-Point for Small Data (소량자료를 위한 베이지안 다중 변환점 모형)

  • Cheon, Soo-Young;Yu, Wenxing
    • Communications for Statistical Applications and Methods
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    • v.19 no.2
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    • pp.237-246
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    • 2012
  • Bayesian methods have been recently used to identify multiple change-points. However, the studies for small data are limited. This paper suggests the Bayesian noncentral t distribution change-point model for small data, and applies the Metropolis-Hastings-within-Gibbs Sampling algorithm to the proposed model. Numerical results of simulation and real data show the performance of the new model in terms of the quality of the resulting estimation of the numbers and positions of change-points for small data.

Effects of Microcurrent Electrical Neuromuscular Stimulation of Auricular and Somatic Acupuncture Points on Experimental Pressure Threshold (외이경혈 미세전류신경근 자극과 체성경혈 미세전류신경근 자극이 압통역치에 미치는 효과)

  • Ko, Hyun-Chul;Cho, Won-Ho;Han, Seung-Soo
    • Physical Therapy Korea
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    • v.4 no.2
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    • pp.36-50
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    • 1997
  • The purpose of this study was to compare the effects of high intensity, high frequency microcurrent electrical neuromuscular stimulation(MENS) of auricular and somatic acupuncture points and low intensity, low frequency microcurrent electrical neuromuscular stimulation(MENS) of auricular and somatic acupuncture points on experimental pressure threshold at the elbow according to the time. Fifty healthy adults, aged 19 to 26 years, were assigned randomly to one of five groups: 1) the high intensity, high frequency somatic group(n=10) received MENS to somatic acupuncture points, 2) the high intensity, high frequency auricular group(n=10) received MENS to auricular acupuncture points, 3) the low intensity, low frequency somatic group(n=10) received MENS to somatic acupuncture points, 4) the low intensity, low frequency somatic group(n=10) receive MENS to somatic acupuncture points, and 5) the placebo group(n=10) received placebo treatment and served as controls. Pressure threshold was measured before, after, 5 minutes, 10 minutes and 15 minutes. Pressure threshold has increased significantly(p<.05) in the high intensity, high frequency auricular group following treatment after 5 minutes, with no statistically significant differences in pressure threshold change scores among five groups, Only the high intensity, high frequency auricular group demonstrated statistically significant change score in pressure threshold following treatment after, 5 minutes, 10 minutes and 15 minutes after compared to the placebo group. The results indicated that MENS applied to the high intensity, high frequency auricular group increases pressure threshold.

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A Probabilistic Estimation of Changing Points of Seoul Rainfall Using BH Bayesian Analysis (BH 베이지안 분석을 통한 서울지점 강우자료의 확률적 변화시점 추정)

  • Hwang, Seok-Hwan;Kim, Joong-Hoon;Yoo, Chul-Sang;Jung, Sung-Won
    • Journal of Korea Water Resources Association
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    • v.43 no.7
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    • pp.645-655
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    • 2010
  • In this study, occurrences of relative probabilistic changing points between Chukwooki rainfall data (CWK) and modern rain gage data (MRG) were analyzed using Barry and Hartigan (BH) Bayesian changing points estimation method which estimated the changing points by calculation of change probabilities at each point. Since any natural phenomenon cannot be simulated identically and perfectly, a statistical method which can not consider the sequential order has its limitation on prediction of a specific time of occurrence. In this respect, Homogeneity analysis between CWK and MRG was performed through the occurrence investigation of relative probabilistic changing points for four rainfall characteristics of data sets using BH bayesian model which estimate the change point by calculating the relative probabilities in each data points. The results show that statistical characteristics of CWK are not different significantly from MRG, even though considered that there may be little quantitative difference CWK and MRG caused from limitation of measurement accuracy of CWK.