• Title/Summary/Keyword: systematic cluster sampling

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Development of a Forest Inventory System for the Sustainable Forest Management (지속가능한 산림경영에 적합한 표본조사 방법의 개발)

  • Shin, Man Yong;Han, Won Sung
    • Journal of Korean Society of Forest Science
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    • v.95 no.3
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    • pp.370-377
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    • 2006
  • This study was conducted to develop an efficient method of sampling design appropriate for the sustainable forest management. For this, data were collected in Yangpyung-Gun, Gyunggi Province based on three different sampling designs such as systematic design, systematic cluster design, and stratified cluster design. Based on evaluation statistics, the sampling designs were compared to select a sampling method fitted to sustainable forest management. It was found that the systematical cluster sampling is the most efficient sampling method in terms of feasibility for sustainable forest management. It was also recommended that the sample plots should be made as a cluster of triangle-shape. The clusters should be consisted of a main plot and three sub-plots. And the sub-plots should be arranged with a distance of 50m from the main plot in the center of cluster.

A Comparison of Systematic Sampling Designs for Forest Inventory

  • Yim, Jong Su;Kleinn, Christoph;Kim, Sung Ho;Jeong, Jin-Hyun;Shin, Man Yong
    • Journal of Korean Society of Forest Science
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    • v.98 no.2
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    • pp.133-141
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    • 2009
  • This study was conducted to support for determining an efficient sampling design for forest resources assessments in South Korea with respect to statistical efficiency. For this objective, different systematic sampling designs were simulated and compared based on an artificial forest population that had been built from field sample data and satellite data in Yang-Pyeong County, Korea. Using the k-NN technique, two thematic maps (growing stock and forest cover type per pixel unit) across the test area were generated; field data (n=191) and Landsat ETM+ were used as source data. Four sampling designs (systematic sampling, systematic sampling for post-stratification, systematic cluster sampling, and stratified systematic sampling) were employed as optimum sampling design candidates. In order to compute error variance, the Monte Carlo simulation was used (k=1,000). Then, sampling error and relative efficiency were compared. When the objective of an inventory was to obtain estimations for the entire population, systematic cluster sampling was superior to the other sampling designs. If its objective is to obtain estimations for each sub-population, post-stratification gave a better estimation. In order to successfully perform this procedure, it requires clear definitions of strata of interest per field observation unit for efficient stratification.

A Study on the Stratified Cluster Replicated Systematic Unrelated Question Model (층화 집락 반복계통 무관질문모형에 관한 연구)

  • Lee, Gi-Sung
    • The Korean Journal of Applied Statistics
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    • v.26 no.2
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    • pp.209-222
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    • 2013
  • We apply stratified cluster sampling to a replicated systematic unrelated question model for a large scale survey in which the population is comprised of several strata developed by several clusters and with sensitive parameters. We first present a replicated systematic unrelated question model using an unrelated question model to procure sensitive information from the population of clusters and then develop a suggested model to an unrelated question by a stratified cluster replicated systematic sampling that can be used in large population of strata. We cover the proportional and optimum allocation for the suggested model. Finally, we compare and analyze the efficiency of the suggested model with the replicated systematic unrelated question model.

Efficiency of Variance Estimators for Two-stage PPS Systematic Sampling (2단 크기비례 계통추출법의 분산추정량 효율성 비교)

  • Kim, Young-Won;Kim, Yeny;Han, Hye-Eun;Kwak, Eun-Sun
    • The Korean Journal of Applied Statistics
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    • v.26 no.6
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    • pp.1033-1041
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    • 2013
  • In this paper, we investigate several variance estimators for pps systematic sampling. Unfortunately, there is no unbiased variance estimators for a systematic sample because systematic sampling can be regarded as a random selection of one cluster. This study provides guidance on which variance estimator may be more appropriate than others in several circumstances. We judge the efficiency of variance estimators for systematic sampling based on of their relative biases and relative mean square error. Also, we investigate variance estimation problems for two-stage systematic sampling applied for the Food Raw Material Consumption Survey and the Establishment Labor Force Survey simulation study, in order to consider the popular two-stage pps systematic sample design for establishment and household survey in Korea.

A Study for Time Standard Estimation with Activity Sampling Method (가동샘플링기법에 의한 표준시간추정에 관한 연구)

  • 이근희
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.6 no.9
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    • pp.1-5
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    • 1983
  • This study takes over the application of survey sampling theory to activity sampling and the application of activity sampling to time standard estimation. Cluster, stratified, and multistage sampling are studied in conjunction with random and systematic sampling. Estimation procedures that will maximize the information obtained per cost expended on the study and specification of the procedure to be used to estimate the accuracy of the estimates for the adopted procedure are considered. The use of multiple regression md linear programming to estimate standard element performance time from typical job lot production data is also considered.

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A Study of Urban Employed Wives무 Family Financial Management and Economic Well-Being (도시 취업주부의 가계재무관리행동과 경제복지감)

  • 계선자
    • Journal of Family Resource Management and Policy Review
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    • v.4 no.1
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    • pp.95-111
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    • 2000
  • The family financial management is the important element which has a effect on the improvement of family economic well-being. Thus the study sets up human & material resources and requirement as an input factor, family financial management as an throughput factor, and economic well-being as an output factor, and then identifies if there are some relationships among them by using a systematic approach of family financial management. The questionaires were distributed to 600 employed wives by carrying out cluster sampling and disproportional stratified sampling. The 573 cases of them were used as the mean, ratio, Pearson’s Correration, ANOVA, factors analysis, and Stepwise Regression using the SAS/PC+. The major findings of the study are as follows: 1) A practical application of information as on input variable, appears the fator which has an important effect upon the throughput factor, that is, family financial management. The employed wives should manage a lot of resources in rapidly changing social-economic circustances. So it shows that not only they should take informations open to their daily life and then make practical use of them in managing their family finance, but also they must be capable of judging and accepting reasonable informations in order to gain and manage resources suitable to the characteristics of family finance and family members’need. 2) There was significant relationship between the employed wives’family financial management and family economic well-being, focused on the systematic theory of family financial management. This study provides for the information to develope the program for the employed wives’family financial planning and counseling.

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The Effect of Golf Participation on Exercise Adherence through Exercise Immersion (성인골프참여가 운동몰입을 통한 운동지속에 미치는 영향)

  • Lee, Seung-Do
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.5
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    • pp.103-114
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    • 2020
  • The purpose of this study is to analyze the difference of the effect of adult golf participation on the exercise adherence through the exercise immersion and to suggest the adherence golf exercise. To achieve this purpose, 40~70 age subjects of adult golf club located in Gyeongsangnam-do jinju city were selected in January 2020 and sampled by systematic cluster random sampling. First, factor analysis and reliability analysis were conducted to secure validity and reliability. Second, the frequency analysis average(M) standard deviation(sd) were conducted to investigate the general characteristics of the respondents. Third, t-test and one-way ANOVA analysis were conducted to identify differences between exercise immersion and exercise adherence according to general characteristics. Fourth, correlation analysis and multiple regression analysis were conducted among variables. The results of this study through these methods and procedures are as follows. First, there was no significant difference in the exercise impression and exercise adherence of general characteristics. Second, exercise immersion showed a high difference in exercise adherence. Third, exercise immersion had a high effect on exercise adherence.

A New Statistical Sampling Method for Reducing Computing time of Machine Learning Algorithms (기계학습 알고리즘의 컴퓨팅시간 단축을 위한 새로운 통계적 샘플링 기법)

  • Jun, Sung-Hae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.2
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    • pp.171-177
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    • 2011
  • Accuracy and computing time are considerable issues in machine learning. In general, the computing time for data analysis is increased in proportion to the size of given data. So, we need a sampling approach to reduce the size of training data. But, the accuracy of constructed model is decreased by going down the data size simultaneously. To solve this problem, we propose a new statistical sampling method having similar performance to the total data. We suggest a rule to select optimal sampling techniques according to given data structure. This paper shows a sampling method for reducing computing time with keeping the most of accuracy using cluster sampling, stratified sampling, and systematic sampling. We verify improved performance of proposed method by accuracy and computing time between sample data and total data using objective machine learning data sets.

Prevalence Rate and Factors of Myopia in Preschool Children (서울시 학령전기 아동의 근시 유병률과 관련요인)

  • Kim Shin-Ja
    • Journal of Korean Academy of Nursing
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    • v.35 no.2
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    • pp.390-398
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    • 2005
  • Purpose: This study was aimed at providing basic data for developing a nursing intervention program which enables systematic and correct visual acuity care by discovering out visual acuity conditions, prevalence rate of myopia, and the factors related to myopia with Preschool children. Method: The subjects of this study consisted of 519 children between 3 and 6 years of age from 12 kindergartens in Seoul which were selected through multiple cluster sampling. Myopia was defined as the spherical equivalent (SE) of more than -0.5 diopters (D) in the right eye. The data was analyzed by t-test, 2-test, ANOVA, and logistic regression by using the SAS program. Result: The prevalence rate of myopia was $8.7\%$. the odds ratio of child myopia when one parent had myopia was 2.2 times higher than when neither parent had myopia. The odds ratio of child myopia when reading more than three books per week was 0.27 times higher than reading less than three books. Conclusion: Myopia should be continuously and intensively managed from the age of 3.

The Relationships between Sport for All Participation and Physical and Mental Function affecting the Elderly's Self-perceived Health (노인의 생활체육활동 참가와 신체적, 정신적 기능상태의 관계)

  • Lee, Young-Ik
    • 한국노년학
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    • v.28 no.4
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    • pp.1265-1278
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    • 2008
  • The purpose of this study was to study the Relationships between Sport for All Participation and Physical and Mental Function affecting the Elderly's Self-perceived Health. For accomplishing this purpose of this study, the 308 subjects were selected by the multi-stage stratified cluster sampling method from the Seoul, in the years of 2008. presently. Out of the 360 questionnaires responded to, only 308 were used for data analysis because 52 were responded to incompletely or incorrectly. The survey questionaries were used to collect data. The questionary for physical function state were developed and standardized by kung-hee chung(1993), yang-lae Kim(2005). And mental function state were divided two parts; self-perceived scale and depress scale. The questionary for self-perceived scale were based on MMSE-K(Mini Mental State Examination-Korea). The questionary for Depression were based on Depression Scale developed by Beck(1978), adapted in Korean and standardization by Lee Young-ho & Song Jong-yong(1991), regulated by Jo Gyu-whang(2004). From the analysis of this study, the following conclusions were obtained: First, according to the elderly people's participation in leisure sport activities, it partially affected physical and mental function state. Second, according to the degree of elderly people's participation in leisure sport activities, it partially affected physical and mental function state.