• 제목/요약/키워드: Change points

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

  • 전차수;김영일
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
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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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시점 변화에 강인한 특징점 정합 기법 (Feature Matching Algorithm Robust To Viewpoint Change)

  • 정현조;유지상
    • 한국통신학회논문지
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    • 제40권12호
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    • pp.2363-2371
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    • 2015
  • 본 논문에서는 FAST(Features from Accelerated Segment Test) 특징점 검출기와 SIFT(Scale Invariant Feature Transform) 특징점 서술자(descriptor)를 사용하여 시점 변화에 강인한 특징점 정합 기법을 제안한다. 기존의 FAST 기법은 영상의 에지 부분을 따라서 불필요하게 특징점을 많이 추출하게 되는데 이러한 단점을 주곡률(principal curvatures)을 적용하여 개선한다. 추출된 특징점을 SIFT 서술자를 통해 기술하고 시점이 다른 두 영상으부터 구해진 정합쌍에 RANSAC(RANdom SAmple Consensus) 기법을 통하여 호모그래피(homography)를 계산한다. 시점 변화에 강인한 특징점 정합을 위해서 기준 영상의 특징점들을 호모그래피 변환을 통해 변경된 좌표와 시점이 다른 영상의 특징점 좌표간의 유클리디언(Euclidean) 거리를 통해 정합쌍을 분류한다. 같은 물체나 장소에 대해 시점이 변화된 여러 영상에 대한 실험을 통해서 제안하는 정합 기법이 적은 계산량으로 기존의 특징점 정합 기법보다 우수한 성능을 보여주는 것을 확인하였다.

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

  • 신혜원;최주희;이영화;조우균
    • 대한영양사협회학술지
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    • 제21권3호
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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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    • 제7권2호
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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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    • 제1권1호
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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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체표 캐패시턴스 측정 방식을 이용한 체표 경락.경혈 에너지 변화 분석 (Analysis of Meridian Energy and its Change Pattern with Time using Measurement of Skin-Capacitance on Source Points)

  • 김수병;권선민;명현석;이경중;강희정;임윤경;이용흠
    • Korean Journal of Acupuncture
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    • 제26권3호
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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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장치간 연속 색 재현을 위한 가변 닻점 방식의 색역 사상 (Gamut Mapping Using Variable Anchor Points for Continuous Color Reproduction between Devices)

  • 이채수;윤태진;한찬호
    • 한국산업정보학회:학술대회논문집
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    • 한국산업정보학회 2001년도 춘계학술대회논문집:21세기 신지식정보의 창출
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    • pp.300-310
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    • 2001
  • 본 논문에서는 가변하는 닻점을 이용하는 새로운 색역 사상 방법을 제안한다. 제안된 방법은 기존의 닻점을 사용하는 색역 사상에서 발생하는 휘도 범위의 축소를 가변하는 닻점을 이용하여 보상하여 준다. 또한 이과정에서 연속 계조 칼라를 재현하기 위하여 색역을 여러 영역으로 구분하여 각각의 영역에서 다른 닻점을 사용하는 다중 닻점 방식을 제안한다. 따라서 본 논문에서는 저가의 칼라 출력장치에서 고화질의 칼라를 재현할 수 있게 한다.

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

  • 전수영
    • Communications for Statistical Applications and Methods
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    • 제19권2호
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    • pp.237-246
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    • 2012
  • 다중 변환점(multiple change-point) 추론에 있어 소량자료에 관한 연구는 많지 않다. 본 논문에서는 소량 자료의 다중 변환점 추정을 위해 베이지안 비중심(noncentral) t 분포 변환점 모형을 제안하고, 제안된 모형 추론을 위해 메트로폴리스-해스팅스를 포함한 깁스 샘플링(Metropolis-Hastings-Within-Gibbs sampling) 알고리즘을 이용하였다. 모의실험 및 태풍 발생 수의 실증 분석결과는 제안된 모형과 알고리즘의 우수성을 보여 준다.

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

  • 고현철;조원호;한승수
    • 한국전문물리치료학회지
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    • 제4권2호
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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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BH 베이지안 분석을 통한 서울지점 강우자료의 확률적 변화시점 추정 (A Probabilistic Estimation of Changing Points of Seoul Rainfall Using BH Bayesian Analysis)

  • 황석환;김중훈;유철상;정성원
    • 한국수자원학회논문집
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    • 제43권7호
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    • pp.645-655
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    • 2010
  • 본 논문에서는 각각의 시점에서의 변화확률을 산정하여 변화시점을 추정하는 Barry and Hartigan (BH)의 베이지안 변화시점 추정방법(Bayesian changing points estimation method)을 이용하여 측우기 관측자료계열(CWK)과 근대우량계 관측자료계열(MRG)간의 변화에 대한 상대확률적 절점의 발생여부를 분석하였다. 어떠한 자연 현상도 완전히 동일하게 재현되지 않기때문에 시간적인 순서를 고려하지못하는 통계적 방법은 구체적인발생시간을 예측하기 어렵다는 점에서 자료의 변화량 파악은 가능하나 변화시점을 명확히 추정하는데 한계가 있다. 이러한 배경에서, 본 논문에서는 각 시점에서의 변화확률을 산정하여 변화시점을 추정하는 BH 베이지안 방법을 적용하여 CWK와 MRG의 각 강우특성별로 상대확률적인 변화시점 분석을 통하여 CWK와 MRG 간의 동질성 분석을 실시하였다. 분석 결과, CWK의 정성적인(본질적인) 통계적 특성은 MRG와 큰 차이가 없는 것으로 나타났다. 다만, 관측정밀도의 한계로 인한 정량적인 차이가 존재하는 것으로 분석되었다.