• 제목/요약/키워드: Sampling-procedures

검색결과 282건 처리시간 0.022초

한 인구학도의 회고

  • 김택일
    • 한국인구학
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    • 제11권1호
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    • pp.1-13
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    • 1988
  • 여기서는 많은 수의 비관측사례로부터 발생할 수 있는 표본의 편의(bias) 문제를 탐구한다. 이 연구는 본래 일본 후생성이 1989년 실시한 <가족주기와 가구형태에 대한 인구학적 조사> 자료를 이용하여 노인부보와 자녀간 근접성을 분석하는 목적에서 이루어졌다. 그런데 <가족주기와 가구형태에 대한 인구학적 조사>는 노인부모를 대상으로 한 조사가 아니라 전체 가구 일반에 대한 조사이기 때문에 노인부모에 대한 많은 정보를 손상하고 있었다. 또한 본 조사는 가구주를 통하여 가족원에 대한 정보를 획득하는 방식으로 설계되었기 때문에 가족원에 대한 정보가 완전하지 못하였다. 나아가 비관측사례의 유형을 보면 여러 항목들이 동시적으로 관측되지 않고 있었다. 이와 같이 복합적 메커니즘에서 발생한 비관측 사례는 분석의 편의를 초래할 위험이 크다. 우선, 많은 수의 비관측사례로 표준오차를 잘못 추정할 소지가 크다. 더욱이 사례들이 선택적으로 관측되지 않았다면 관측된 자료에 따른 추정을 심각한 편의를 포함할 수 있다. 이와 같이 손상된 자료로부터 발생할 수 있는 추정 편의를 개선하기 위하여 여기서는 두 가지 기법을 활용하였다. 첫째, 관측치와 공변인간의 관계에 기초하여 비관측사례를 추정하는 방법으로 EM 알고리듬을 활용하였다. 둘째, 관찰의 선택성에서 비롯된 추정 편의를 개선하기 위하여 이단계(two stage) 모형을 활용하였다.

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Extreme Value Analysis of Statistically Independent Stochastic Variables

  • Choi, Yongho;Yeon, Seong Mo;Kim, Hyunjoe;Lee, Dongyeon
    • 한국해양공학회지
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    • 제33권3호
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    • pp.222-228
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    • 2019
  • An extreme value analysis (EVA) is essential to obtain a design value for highly nonlinear variables such as long-term environmental data for wind and waves, and slamming or sloshing impact pressures. According to the extreme value theory (EVT), the extreme value distribution is derived by multiplying the initial cumulative distribution functions for independent and identically distributed (IID) random variables. However, in the position mooring of DNVGL, the sampled global maxima of the mooring line tension are assumed to be IID stochastic variables without checking their independence. The ITTC Recommended Procedures and Guidelines for Sloshing Model Tests never deal with the independence of the sampling data. Hence, a design value estimated without the IID check would be under- or over-estimated because of considering observations far away from a Weibull or generalized Pareto distribution (GPD) as outliers. In this study, the IID sampling data are first checked in an EVA. With no IID random variables, an automatic resampling scheme is recommended using the block maxima approach for a generalized extreme value (GEV) distribution and peaks-over-threshold (POT) approach for a GPD. A partial autocorrelation function (PACF) is used to check the IID variables. In this study, only one 5 h sample of sloshing test results was used for a feasibility study of the resampling IID variables approach. Based on this study, the resampling IID variables may reduce the number of outliers, and the statistically more appropriate design value could be achieved with independent samples.

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

  • 이승도
    • 한국엔터테인먼트산업학회논문지
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    • 제14권5호
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    • pp.103-114
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    • 2020
  • 본 연구의 목적은 성인골프참여가 운동몰입을 통한 운동지속에 미치는 영향의 차이 분석하여 지속적으로 골프 운동하도록 제시하는데 주된 목적이 있다. 이러한 연구 목적을 달성하기 위하여 2020년 1월에 경남에 소재한 성인 골프동호인 40~70세 대상을 선정하고 유층집락 무선 표집법(Systematic cluster random sampling)으로 표본 추출을 이용한 설문지로 시행하였다. 첫째, 타당도와 신뢰도를 확보하기 위해 요인분석과 신뢰도 분석을 실시하였다. 둘째, 응답자의 일반적 특성을 알아보기 위해 빈도분석 평균(M)과 표준편차(sd)를 실시하였다. 셋째, 일반적 특성에 따라 운동몰입과 운동지속의 차이를 규명하기 위해 t-test와 One-way ANOVA 분석을 실시하였다. 넷째, 변수들 간의 상관분석 및 다중회귀분석(Multiple Regression Analysis)을 실시하였다. 이와 같은 방법과 절차를 통하여 본 연구에서 얻어진 결과는 다음과 같다. 첫째, 일반적 특성의 운동몰입과 운동지속에 유의한 차이가 없는 것으로 나타났다. 둘째, 운동몰입은 운동지속에 높은 차이가 나타났다. 셋째, 운동몰입은 운동지속에 높은 영향이 미치는 것으로 나타났다.

Effect of motivation to participate in horseback riding on emotional style and subjective well-being

  • Qimeng Zhang;Sunmun Park
    • International Journal of Advanced Culture Technology
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    • 제11권4호
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    • pp.233-243
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    • 2023
  • The purpose of this study is to determine the effect of horseback riding participation motivation on emotional style and subjective well-being. In order to achieve this research objective, adults aged 20 or older participating in equestrian clubs in Seoul, Jeolla-do, and Gyeonggi regions in 2022 were selected as the population. The sampling method used cluster random sampling, and a total of 250 people, 180 males and 120 females, were sampled. The survey tool was modified and supplemented for this study based on a questionnaire whose reliability and validity were verified in previous studies, and all questionnaire questions were structured on a 5-point scale. For data analysis, SPSS Windows 21.0 Version was used to perform statistical processing according to the purpose of analysis. The conclusions obtained in this study through data analysis according to these methods and procedures are as follows. First, the motivation to participate in horseback riding was found to partially affect emotional style. Second, the motivation to participate in horseback riding was found to partially affect subjective well-being. Third, the emotional style of horseback riding participants was found to partially affect subjective well-being. Considering these results, it is possible to satisfy various desires in modern people's lives through leisure sports activities such as horseback riding, which allows them to communicate with nature and living things. In other words, internal motivation factors such as social relationships, satisfaction of needs, and professional development through leisure sports activities are positively or negatively related to emotional regulation, and this has a close impact on satisfaction with one's life and happiness.

환경시료은행의 국제적 동향 및 우리의 대응 (International Trends of Environmental Specimen Bank and Our Response)

  • 김명진;유병호;이석조;이종천;이철우
    • 환경영향평가
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    • 제17권4호
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    • pp.225-233
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    • 2008
  • An Environmental Specimen Bank (ESB) is an archive for samples that can be used to document and assess the quality of the environment in which we live. An ESB program looks at changes in the concentration of human and environmental specimens over long periods of time through retrospective analysis of archived samples of a particular area collected at regular intervals. The idea of ESB was first proposed by German and American scientists in the early 1970s and has been established since 1979 in Germany, USA, and Japan. Korea plans to establish a National Environmental Specimen Bank (NESB) in 2010. The NESB will be able to assess and improve the quality of analytical measurements as well as to compare the past and current environmental quality as a time capsule. The concept and design for the NESB facility was developed and its Standard Operation Procedures (SOPs) are being developed based on an evaluation of ESBs and SOPs of Germany, USA, and Japan. Environmental specimens proposed for banking are based on typical representatives of every level of the food chain from each type of ecosystem that are widely distributed thus enabling comparisons between different sampling areas. Through retrospective analysis of environmental specimens, the NESB will improve the reliability of environmental monitoring, ecological risk assessment, and health impact assessment.

NIR - a Tool for Evaluation of Milling Procedure

  • Gergely, Sziveszter;Handzel, Lidia;Zoltan, Andrea;Salgo, Andras
    • 한국근적외분광분석학회:학술대회논문집
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.1125-1125
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    • 2001
  • Micro-scale test methods are producing small-sample size where the conventional physical and chemical tests can not be used (high standard deviation, uncertain sampling conditions, low repeatability). Different small-scale test methods were developed recently for determination of physico-chemical, functional, rheological properties of wheat or wheat dough using miniaturized instruments with sophisticated sample preparation/handling and mechanics (RVA, 2 g mixograph, micro-Z-arm mixer, small-scale noodle maker, micro-baking method etc.). The small-scale methodologies can be used as basic research tools or as technology supported measurements and can be also essential in the early selection for quality traits in breeding programs. The milling as a sample preparation step is essential procedure providing good quality flour or semolina samples from small amount of grain (5-10 g) in a reproducible and reliable way. The aim of present study was to use NIR as quality control tool, and to evaluate the recently developed and manufactured micro-scale lab mill (FQC-2000) produced by Inter-Labor Co. Ltd., Hungary. The milling characteristics of the new instrument were compared to other laboratory mills and the effects of milling action on the chemical composition of fractions were analysed. The fractions were tested with both chemical and near infrared spectroscopic methods. The micro-scale milling resulted significantly different yields, particle size distributions and different fractions from compositional point of view. The near infrared spectra were sensitive enough to distinguish the fractions obtained by different milling procedures. Quantitative NIR calibration equations were developed and tested in order to measure the chemical composition of characteristic milling fractions. Special qualification procedure the PQS (Polar Qualification System) method was used for detecting the differences between fractions obtained by macro and micro-milling procedures. The results and the limitations of PQS method in this application will be discussed.

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기관지경검사에서 객담세포검사의 암양성률에 대한 연구 (Cytologic examination sputum and bronchial secretion bronchofiberscopic sampling procedures in lung cancer)

  • 김송명
    • Journal of Chest Surgery
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    • 제16권1호
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    • pp.138-145
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    • 1983
  • The value of exfoliative sputum cytology in diagnosis of lung cancer has been accepted with bronchoscopic technique and results has been much improved by foreign investigators, but there was not presented accurate reports for sputum cytologic evaluation in Korea. We tried to find indicators of cytologic tests result in our hospital. During the period between May, 1980 and August, 1982, 400 patients, tested at Department of Thoracic and Cardiovascular Surgery of Kosin Medical College, had diagnostic bronchofiberscopic examination, and the cytologic study of sputum and bronchial secretions were performed. The sputum or bronchial secretion during bronchofiberscopic examination were obtained with various methods and the name of specimen were labeled as I, ASPIRATION SPUTUM, which was collected initially endobronchial sputum as introducing of scope, II, WASHING SPUTUM, which was collected washing bronchial secretion, III, BRUSHING SPUTUM, which was washing solution of brushing instrument and endobronchial sputum after brushing of lesions, IV, POST-SCOPIC SPUTUM, which was expectorated sputum as soon as removing of scopic instrument, V, ALL SPUTUM CYTOLOGY & CELL BLOCK, which was collected all specimen of above procedures. The diagnostic results of bronchofiberscopic examination was disclosed 174 cases [43.5%] of proved lung cancer, 47 cases [11.8%] of suspected lung cancer in grossly, and 179 cases [44.8%] of others finding except cancer. Patient with bronchofiberscopically grossly evidence of lung cancer which were not confirmed histologically or cytologically were excluded from this cytologic study. Histologic and cytologic correlation in proven lung cancer, 174 cases was revealed that number of cytologic positive patients were 45 cases [38.7%] among the 117 cases of proved squamous cell carcinoma, 12 cases [38.7%] among hislogically unknown cancer 34 cases and 6 cases [33.3%] among small cell undifferentiated carcinoma 18 Gases. Total cytologic positive result was presented as 67 cases [38.3%]. The other type of lung cancer, histologically, could not comparison because of small cases. The sequence of positive cytologic result in I-V specimen were disclosed as II, WASHING SPUTUM 57.6%, and V, ALL SPUTUM & CELL BLOCK 41.4%. The I, III & IV result were 28.6%, 22.2% and 26.1% respectively.

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관리도에서 Markov연쇄의 적용: 복습 및 새로운 응용 (Implementation of Markov Chain: Review and New Application)

  • 박창순
    • 응용통계연구
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    • 제24권4호
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    • pp.657-676
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    • 2011
  • 통계적 공정관리절차의 특성은 해석적 해를 얻기가 어려운 경우가 많이 있으나 Markov연쇄를 적용하면 가능한 경우가 많이 있다. 이 논문에서는 공정 통계량이 Markov특성을 따르는 경우, Markov연쇄를 생성하는 방법과 이를 이용한 공정관리 절차의 특성을 도출하는 방법에 대해 설명하고 있다. 관리도의 통계적 설계, 경제적 설계 및 변량 표본 추출비 설계 등의 특성 규명을 위한 Markov연쇄의 적용에 대한 기존의 알려진 방법을 복습하고 또한 새로운 공정관리 분야인 재조정 관리도에의 적용방법에 대한 연구결과도 보여주고 있다. 공정관리의 특성연구에서 해석적 해가 가능한 경우에도 이 과정이 복잡하여 Markov연쇄를 병행 사용하면 특성 규명이 명확해지며, 모의실험보다는 짧은 시간에 더 정밀한 결과를 얻을 수 있어 널리 이용되고 있다.

국가환경시료은행의 표준운영절차 적용 (Application of SOPs (Standard Operating Procedures) in National Environmental Specimen Bank)

  • 김명진;이장호;최태영;한아름;송교홍;이유진;이종천
    • 환경영향평가
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    • 제21권2호
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    • pp.327-338
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    • 2012
  • Environmental specimen banks provide the baselines for the scientists and decision makers to do research using the past and present specimens to expect the possible contaminant implications of the future. Many chemicals that are considered harmless now but not found may be found and pose threats in the future. Collected specimens of animals and plants should be conserved without contamination for future analysis. To ensure the availability of samples for the retrospective analysis, the establishment and maintenance of specimen banks in the developing and developed nations has become absolutely necessary. National Environmental Specimen Bank (NESB) established at National Institute of Environmental Research (NIER) in 2009. For the application of NESB, several activities such as standard operating procedures (SOPs) development have been prepared. This study applied the guidelines for sampling and sample treatment of five environmental specimens which had been prepared from 2007 to 2009. The target species were shoots of red pine and Korean pine, leaves of Mongolian oak, eggs of domestic pigeon and muscles and livers of common carp. The NESB will enhance the quality of environmental assessment and environmental monitoring based on real time and retrospective analysis.

관리도에서 Markov연쇄의 적용: 복습 및 새로운 응용 (Implementation of Markov chain: Review and new application)

  • 박창순
    • 응용통계연구
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    • 제34권4호
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    • pp.537-556
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    • 2021
  • 통계적 공정관리절차의 특성은 해석적 해를 얻기가 어려운 경우가 많이 있으나 Markov연쇄를 적용하면 가능한 경우가 많이 있다. 이 논문에서는 공정 통계량이 Markov특성을 따르는 경우, Markov연쇄를 생성하는 방법과 이를 이용한 공정관리 절차의 특성을 도출하는 방법에 대해 설명하고 있다. 관리도의 통계적 설계, 경제적 설계 및 변량표본 추출비 설계 등의 특성 규명을 위한 Markov연쇄의 적용에 대한 기존의 알려진 방법을 복습하고 또한 새로운 공정관리 분야인 재조정 관리도에의 적용방법에 대한 연구결과도 보여주고 있다. 공정관리의 특성연구에서 해석적 해가 가능한 경우에도 이 과정이 복잡하여 Markov연쇄를 병행 사용하면 특성 규명이 명확해지며, 모의실험보다는 짧은 시간에 더 정밀한 결과를 얻을 수 있어 널리 이용되고 있다.