• Title/Summary/Keyword: proportional sampling

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기관패널 표집설계를 통한 훈련 교·강사 실태조사 방안 연구 (A Study on the Survey of Vocational Training Teachers and Instructors through Institutional Panel Sampling Design)

  • 정혜경;정일찬;이진구
    • 실천공학교육논문지
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    • 제13권2호
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    • pp.393-403
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    • 2021
  • 본 연구의 목적은 훈련 교·강사를 모집단으로 데이터 기반 의사결정을 위한 토대를 마련하고자 직업훈련기관 수준에서의 패널조사 표집설계 방안을 제시하여 지속적이고 체계적인 훈련 교·강사 실태조사의 기초를 제공하는데 있다. 이에 본 연구에서는 체계적인 조사 설계를 위한 요소인 목표 모집단과 표본추출틀을 제안하였으며, 전문가 자문과 실증 자료 분석을 토대로 데이터의 대표성, 자료 수집의 효율성 및 지속가능성 등을 종합적으로 고려하여 표본추출단위, 외층변인과 내층변인을 고려한 표본추출방법 등을 제시하였다. 연구 결과 패널의 단위를 직업훈련기관으로 하여 패널로 선정된 기관과 그 기관에 소속된 훈련 교·강사가 설문조사에 참여할 수 있도록 2단계 층화 비례 표집 방안을 마련하였으며, 이를 바탕으로 패널조사 표본 설계 방안에 대한 시사점을 제시하였다.

A Study on the Body Proportion and Proportional Dimension Standards for Chinese Women - Focusing on the analysis of the high-frequence group -

  • Kim, Eun-Hee;Sohn, Hee-Soon
    • 패션비즈니스
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    • 제10권6호
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    • pp.91-109
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    • 2006
  • This study aims at strengthening the national competitiveness of Korea's clothing industry as it provides substantial information on the human body proportion and proportional dimension standards for Chinese women and improves the fitness of clothing, considering human proportion in the production of clothing products for export to China. This study selected by simple random sampling Chinese women in Beijing and Shanghai, China, whose age is between 19-50 from June 23 to August 7, 2004. The stature of the average Chinese woman belonging to the High Frequency group is 7.09 times as long as the length of the head. We developed the body proportional dimension standards with the same proportion with High-Frequence group. The basic size of proportional dimension standards for Chinese women has the stature of 159cm, (chest circumference)/2 of 42.8cm.

The Selection of Strategies for Variance Estimation under πPS Sampling Schemes

  • Kim Sun-Woong
    • Communications for Statistical Applications and Methods
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    • 제13권1호
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    • pp.61-72
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    • 2006
  • When using the well-known variance estimator of Sen (1953) and Yates and Grundy (1953) in inclusion probability proportional to size sampling, we often encounter the problems due to the calculation of the joint probabilities. Sarndal (1996) and Knottnerus (2003) proposed alternative strategies for variance estimation to avoid those problems in the traditional method. We discuss some of practical issues that arise when they are used. Also, we describe the traditional strategy using a sampling procedure available in a statistical software. It would be one of the attractive choices for design-based variance estimation.

포함확률비례추출에서 회귀계수 최소제곱추정량의 근사분산 (Approximate Variance of Least Square Estimators for Regression Coefficient under Inclusion Probability Proportional to Size Sampling)

  • 김규성
    • Communications for Statistical Applications and Methods
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    • 제19권1호
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    • pp.23-32
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    • 2012
  • 본 논문은 유한모집단에서 회귀계수추정량의 근사편향과 근사분산을 다루고 있다. 유한모집단에서 고정크기 포함확률비례표본을 추출하고 이 표본에서 조사된 데이터에 기초하여 회귀계수를 일반최소제곱추정량과 가중최소제곱추정량으로 추정할 때 두 추정량의 편향, 분산 그리고 평균제곱오차의 근사식을 유도하였다. 그리고 두 추정량의 효율을 비교하기 위하여 두 추정량의 분산을 비교하는 필요충분조건을 제시하였다. 또한 수치적인 비교를 위하여 간단한 예제를 소개하였다.

잣 수확의 기계화 연구(II) -잣나무 가지의 전단 특성- (Mechanization of Pine Cone Harvest(II) -Shearing Characteristics of Shoots of Korean Pine Trees-)

  • 강화석;김상헌;이재선
    • Journal of Biosystems Engineering
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    • 제19권1호
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    • pp.17-21
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    • 1994
  • This reasearch was performed to provide the fundamental intonation for the mechanization of Korean pine cone harvest when the shoot shearing method is adopted. Shear force and stress of pine cone shoots were measured and analyzed for this purpose. Samples are selected along their harvesting time and tested in 17 levels of shoot diameter from 10 to 26mm with 1mm increment. 1) Shear force-deformation characteristics showed that shoot reached its rupture point after 2 to 4 of bio-yield points. It was supposed that these multiple bio-yield points were caused by the discrete compression of wood parts which are composed of water, nutrient, resin, etc. 2) Required shear force to shear shoot was proportional to the square of shoot diamter, however, shear force for shoots of early harvesting time(Aug. 31) was proportional to the shoot diameter. Variance of shear force was increased as the harvesting time was delayed. Shear forces were distributed from 468N(Aug. 31, 12mm dia) to 4153N(Aug. 31, 26mm dia) disregarding the sampling date. 3) The average shear stresses by sampling dates were 744,822, and 883N/m2, respectively, and for the earlier shoot samples shear stress was quite smaller than the others. Shear stress was proportional to shoot diameter squared, and the effect of shoot diameter on the shear stress was decreased as harvesting time was delayed.

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A Proportional Odds Mixed - Effects Model for Ordinal Data

  • Choi, Jae-Sung
    • Journal of the Korean Data and Information Science Society
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    • 제18권2호
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    • pp.471-479
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    • 2007
  • This paper discusses about how to build up mixed-effects model for analysing ordinal response data by using cumulative logits. Random factors are assumed to be coming from the designed sampling scheme for choosing observational units. Since the observed responses of individuals are ordinal, a proportional odds model with two random effects is suggested. Estimation procedure for the unknown parameters in a suggested model is also discussed by an illustrated example.

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2001년 국민건강.영양조사 표본설계 (A Sampling Design for the 2001 National Health.Nutrition Survey)

  • 류제복;이계오;김영원
    • 응용통계연구
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    • 제14권2호
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    • pp.289-304
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    • 2001
  • 2001년에 실시할 $\ulcorner$국민건강.영양조사$\lrcorner$를 위한 새로운 표본설계를 하였다. 본 표본설계에서는 표본의 대표성을 높이기 위해서 기존의 표본가구수는 유지하면서 표본조사구를 증가시키고 새로운 지역 층화변수를 추가로 도입하였다. 또한 추정량의 추정오차 공식을 유도하여 추정의 신뢰성을 측정할 수 있도록 설계하였다.

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Internet Poll System

  • Kim, Yon-Hyong;Oh, Min-Gweon
    • Communications for Statistical Applications and Methods
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    • 제7권3호
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    • pp.927-935
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    • 2000
  • In this paper we propose a poll system n the internet. This system expects to increase the confidence of the internet poll results by sampling theory(proportional allocation). This system provides a cross-tale and result of hypothesis test which plays an important role for decision making. These results do offer a few statistical packages(such as SAS, SPSS) in the world wide web.

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Optimal Allocations in Two-Stage Cluster Sampling

  • Koh, Bong-Sung
    • Communications for Statistical Applications and Methods
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    • 제6권3호
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    • pp.749-754
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    • 1999
  • The cost is known to be proportional to the size of sample. We consider a cost function of the form Cost=c1np+c2npmq where c1, c2 p, and q are all positive constants. This cost function is to be used in finding an optimal allocation in two-stage cluster sampling. The optimal allocations of n and m gives the properties of uniqueness under some conditions and of monotonicity with p>0 when q=1.

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멀티 라인 레이저 비전 센서를 이용한 고속 3차원 계측 및 모델링에 관한 연구 (Development of multi-line laser vision sensor and welding application)

  • 성기은;이세헌
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 춘계학술대회 논문집
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    • pp.169-172
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    • 2002
  • A vision sensor measure range data using laser light source. This sensor generally use patterned laser which shaped single line. But this vision sensor cannot satisfy new trend which feeds foster and more precise processing. The sensor's sampling rate increases as reduced image processing time. However, the sampling rate can not over 30fps, because a camera has mechanical sampling limit. If we use multi line laser pattern, we will measure multi range data in one image. In the case of using same sampling rate camera, number of 2D range data profile in one second is directly proportional to laser line's number. For example, the vision sensor using 5 laser lines can sample 150 profiles per second in best condition.

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