• 제목/요약/키워드: Sampling variance

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Influence of exercise self efficacy and perceived health status according to the stage of change for exercise behaviors in older adults (운동행동 변화단계에 따른 노인의 운동 자기효능감과 지각된 건강상태 수준 변화)

  • Kim, Woo-Cheol
    • Journal of Digital Convergence
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    • 제13권11호
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    • pp.549-559
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    • 2015
  • The purpose of this study was to verify whether there are any differences in the level of exercise self-efficacy and perceived health status according to the stage of change for exercise behaviors in older adults. The subjects consisted of 231 older adults (91 male, 140 female) by convenience sampling residing in city D. The collected dates were analyzed using one-way ANOVA, Tukey HSD, and simple regression analysis by SPSS WIN 21.0 program. Moreover, all statistical significance level was set at a=.05. The study results were as follows: Analysis of variance showed that exercise self-efficacy showed significant differences according to the stage of change for exercise behaviors, and as a result of the posthoc analysis, it was found that as the stage became higher, their exercise self-efficacy became higher as well. Perceived health status showed significant differences according to the stage of change for exercise behaviors, and as a result of the posthoc analysis, it was found that as the stage became higher, their perceived health status became higher as well. Analysis of variance showed that exercise self-efficacy and perceived health status were significantly associated with the stages of exercise behavior change. This study identified that exercise self-efficacy and perceived health status were significant variables to explain a possible relationship with exercise stages of older adults. This study provides new information to influence the development of the better health promotion and exercise intervention for older adults in the community.

The Influence of Perfectionism and Ego-resiliency on Anxiety by Leisure Activity in Nursing Students (간호대학생의 여가활동에 따른 완벽성과 자아탄력성이 불안에 미치는 영향)

  • Jeon, Hae Ok;Kim, Ji Hye
    • Journal of the Korea Academia-Industrial cooperation Society
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    • 제17권7호
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    • pp.134-143
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    • 2016
  • This study examined the effects of perfectionism and ego-resiliency on the anxiety in two groups of nursing students: leisure activity, and no leisure activity group. A total of 134 undergraduate students were recruited at two universities in A and B cities, Korea using the convenient sampling method. They were asked to complete a self-reported questionnaire for 11 days in October, 2015. The results showed that there were significant differences in the ego-resiliency (t=-3.80, p=.001) and anxiety (t=3.71, p<.001) according to the leisure activity. In the subjects who did not have leisure activities, perfectionism (${\beta}=.71$, p<.001) and ego-resiliency (${\beta}=-.29$, p=.003) were identified as significant predictors of anxiety and this model explained 58.0% of the variance in anxiety (F=34.50, p<.001). In the analysis according to the classification of current leisure activity, Perfectionism (${\beta}=.54$, p=.003) was identified as a significant predictor of anxiety in subjects doing travel watch and pastime amusement, and this model explained 26.0% of the variance in anxiety in nursing students (F=5.66, p=.009). Therefore, providing strategies to control anxiety can not only improve ego-resiliency, but also reduce perfectionism among nursing students. In addition, it is necessary to resolve the disturbance factors of the leisure activity and create an environment that promotes leisure activities in universities.

Application of Indicator Geostatistics for Probabilistic Uncertainty and Risk Analyses of Geochemical Data (지화학 자료의 확률론적 불확실성 및 위험성 분석을 위한 지시자 지구통계학의 응용)

  • Park, No-Wook
    • Journal of the Korean earth science society
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    • 제31권4호
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    • pp.301-312
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    • 2010
  • Geochemical data have been regarded as one of the important environmental variables in the environmental management. Since they are often sampled at sparse locations, it is important not only to predict attribute values at unsampled locations, but also to assess the uncertainty attached to the prediction for further analysis. The main objective of this paper is to exemplify how indicator geostatistics can be effectively applied to geochemical data processing for providing decision-supporting information as well as spatial distribution of the geochemical data. A whole geostatistical analysis framework, which includes probabilistic uncertainty modeling, classification and risk analysis, was illustrated through a case study of cadmium mapping. A conditional cumulative distribution function (ccdf) was first modeled by indicator kriging, and then e-type estimates and conditional variance were computed for spatial distribution of cadmium and quantitative uncertainty measures, respectively. Two different classification criteria such as a probability thresholding and an attribute thresholding were applied to delineate contaminated and safe areas. Finally, additional sampling locations were extracted from the coefficient of variation that accounts for both the conditional variance and the difference between attribute values and thresholding values. It is suggested that the indicator geostatistical framework illustrated in this study be a useful tool for analyzing any environmental variables including geochemical data for decision-making in the presence of uncertainty.

A Study of the Factors Influencing Health Promoting Behavior and Satisfaction of Life in Female College Students (여대생의 건강증진행위와 삶의 만족에 영향을 미치는 요인에 관한 연구)

  • 백경신;최연희
    • Korean Journal of Health Education and Promotion
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    • 제20권2호
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    • pp.127-147
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    • 2003
  • The purpose of this study was to investigate the factors influencing health promoting behavior and satisfaction of life in female undergraduate students, to provide the basic data for health promoting intervention in order to improve satisfaction of life. The subjects of this study were 345 female undergraduate students living in Jecheon city who were selected by convenience sampling. The data was collected through self-reported questionnaires from Oct. 2 to Dec. 20, 2001. Research instruments used in this study were the health promoting lifestyle profile developed by Walker et al(1987), satisfaction of life developed by Pavot and Diener(1993), perceived health status by Lawston et al(1982), self-esteem by Rosenberg(1965), self-efficacy by Becker et al(1993), health locus of control by Wallston et al(1978). The data was analyzed by using descriptive statistics, pearson correlation coefficient, stepwise multiple regression with SPSS/Win program. The results of this study were as follows; 1) The mean score of health promoting behavior was 2.31 point out of 4. Among the sub-levels of health promoting behavior, the order of importance was the following self-actualization(2.76), interpersonal support(2.75), stress management(2.31), nutrition(2.06), health responsibility(1.83), exercise(1.76). The mean score of satisfaction of life was 4.11 point out of 7. 2) The health promoting behavior showed significant positive correlation with perceived health status, self-esteem, self-efficacy, internal health locus of control, powerful others health locus of control. The satisfaction of life showed significant positive correlation with perceived health status, self-esteem, self-efficacy, internal health locus of control, health promoting behavior. 3) In the relationship between general characteristics and health promoting behavior, there was a significant difference in majors(F=8.50, p=.000). In the relationship between general characteristics and satisfaction of life were significant differences in a grades(F=2.67, p=.04) and economic status of parents(F=8.59, p=.000) 4) The most powerful predictor of health promoting behavior was self-efficacy. A combination of self-efficacy, self-esteem and powerful others health locus of control accounted for 34.7% of the variance in health promoting behavior. The most powerful predictor of satisfaction of life was self-esteem. A combination of self-esteem, health promoting behavior, perceived health status, economic status of parents and grade accounted for 34.0% of the variance in satisfaction of life. In conclusion, we need a health promotion program focusing on exercise, health responsibility and nursing strategies enhancing self-efficacy and self-esteem should be developed to promote a healthy lifestyle and satisfaction of life in female college students.

Factor Analysis for Exploratory Research in the Distribution Science Field (유통과학분야에서 탐색적 연구를 위한 요인분석)

  • Yim, Myung-Seong
    • Journal of Distribution Science
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    • 제13권9호
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    • pp.103-112
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    • 2015
  • Purpose - This paper aims to provide a step-by-step approach to factor analytic procedures, such as principal component analysis (PCA) and exploratory factor analysis (EFA), and to offer a guideline for factor analysis. Authors have argued that the results of PCA and EFA are substantially similar. Additionally, they assert that PCA is a more appropriate technique for factor analysis because PCA produces easily interpreted results that are likely to be the basis of better decisions. For these reasons, many researchers have used PCA as a technique instead of EFA. However, these techniques are clearly different. PCA should be used for data reduction. On the other hand, EFA has been tailored to identify any underlying factor structure, a set of measured variables that cause the manifest variables to covary. Thus, it is needed for a guideline and for procedures to use in factor analysis. To date, however, these two techniques have been indiscriminately misused. Research design, data, and methodology - This research conducted a literature review. For this, we summarized the meaningful and consistent arguments and drew up guidelines and suggested procedures for rigorous EFA. Results - PCA can be used instead of common factor analysis when all measured variables have high communality. However, common factor analysis is recommended for EFA. First, researchers should evaluate the sample size and check for sampling adequacy before conducting factor analysis. If these conditions are not satisfied, then the next steps cannot be followed. Sample size must be at least 100 with communality above 0.5 and a minimum subject to item ratio of at least 5:1, with a minimum of five items in EFA. Next, Bartlett's sphericity test and the Kaiser-Mayer-Olkin (KMO) measure should be assessed for sampling adequacy. The chi-square value for Bartlett's test should be significant. In addition, a KMO of more than 0.8 is recommended. The next step is to conduct a factor analysis. The analysis is composed of three stages. The first stage determines a rotation technique. Generally, ML or PAF will suggest to researchers the best results. Selection of one of the two techniques heavily hinges on data normality. ML requires normally distributed data; on the other hand, PAF does not. The second step is associated with determining the number of factors to retain in the EFA. The best way to determine the number of factors to retain is to apply three methods including eigenvalues greater than 1.0, the scree plot test, and the variance extracted. The last step is to select one of two rotation methods: orthogonal or oblique. If the research suggests some variables that are correlated to each other, then the oblique method should be selected for factor rotation because the method assumes all factors are correlated in the research. If not, the orthogonal method is possible for factor rotation. Conclusions - Recommendations are offered for the best factor analytic practice for empirical research.

Efficient Occurrence Monitoring by Yellow Sticky Traps for Major Flying Pests in Strawberry Greenhouses (시설딸기 주요 비행해충의 황색끈끈이트랩 이용 효율적인 발생예찰)

  • Yang, Cheol Jun;Song, Jeong Heub;Yang, Young Taek;Kim, Hyo Jeong;Song, Min A;Jwa, Chang Sook
    • Korean journal of applied entomology
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    • 제56권3호
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    • pp.309-314
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    • 2017
  • Sampling plan using yellow sticky traps for the major strawberry flying pests - western flower thrips Frankliniella occidentalis adults, cotton aphid Aphis gossypii alate and greenhouse whitefly Trialeurodes vaporarium adults was developed to determine the initial occurrence time. The analyzed trap data were obtained from three commercial strawberry greenhouses for the whole growing season (September to May of the following year) during 2013 to 2017 in Jeju province. Three flying pests showed the aggregated distribution patterns resulted from commonly used regression techniques - Taylor's power law and Iwao's patchiness regression. Taylor's power law was better description of mean-variance relationship of the western flower thrips and the cotton aphid than Iwao's patchiness regression, otherwise greenhouse whitefly was better described by Iwao's patchiness regression. There were highly significant correlated among mean density per trap, maximum density and proportion of traps with more than 10 individuals. To estimate 4.0 heads of mean density per trap, the minimum number of traps were required 13 traps for western flower thrips, 11 traps for cotton aphid and 10 traps for greenhouse whitefly. The sequential sampling plans at the fixed precision level 0.25 were developed using parameters of Taylor's power law for western flower thrips and cotton aphid, and of Iwao's patchiness regression for greenhouse whitefly.

The Application of Species Richness Estimators and Species Accumulation Curves to Traditional Ethnobotanical Knowledges in South Korea (남한지역 전통민속식물지식 자료를 활용한 종누적곡선 분석 및 종풍부도 추정 연구)

  • Park, Yuchul;Chang, Kae Sun;Kim, Hui
    • Korean Journal of Plant Resources
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    • 제30권5호
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    • pp.481-488
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    • 2017
  • Under circumstances of rapid disappearing of traditional ethnobotanical knowledge, traditional ethnobotanical knowledge surveys are the major step in documenting useful species with a conservation priority. In the ethnobotanical research, the relevance to the survey intensity, ethnobotanical information and plant species richness is the most important research theme. We made up TEK database in south Korea using metadata which had been published by the Korea National Arboretum. We calculated species richness using species richness estimator like ACE, Chao1, Chao2, ICE, Jack 1, Jack 2, and Bootstrap. Species accumulation curves showed each province sampling efforts appeared to be wide range of variance so that Gangwon province need more sampling efforts, and Chungnam province approached a horizontal asymptote earlier. We found heterogeneous patterns in the rarefaction curves of TEK species between gender for each categories of use (medicinal, food and handicrafts). Comparing with regional floral diversities, it was predicted that more diverse species would be found in some provinces by carrying out additional survey.

Density and Viability of Sclerotia of Rice Sheath Blight Pathogen Overwintering in Field (벼잎집무늬마름병균(病菌) 월동균핵(越冬菌核)의 밀도(密度)와 활성(活性))

  • Kim, Choong-Hoe;Kim, Chang-Kyu
    • Korean journal of applied entomology
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    • 제26권2호
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    • pp.99-106
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    • 1987
  • Three post-harvest fields each in four rice growing areas, Iri, Naju, Jinju and Taegu were randomly selected and surveyed during December 1986 to examine sclerotial density of Rhizoctonia solani overwintering in the field. Surface soil of $0.09m^2$ area was sampled in each field with three replications and sieved to collect sclerotia. Germiability and pathogenicity of collected sclerotia were examined in the laboratory. Number of sclerotia $({\times}10^6)/ha$ in Iri, Naju, Jinju, and Taegu was estimated from the sample as 2.7, 1.2, 0.7 and 0.6, respectively. Based on sample variance with simple random sampling in each area, number of sampling required for estimating average sclerotial density with the precision of 10% apart from a chance of 1 in 20 was calculated to 41, 132, 232, and 395 for Iri, Naju, Jinju and Taegu, respectively. Percentage of germination of sampled sclerotia on potato sucrose agar (PSA) ranged from 42 to 78% depending on the area, and averaged 60%. About 49% of the germinated sclerotia were pathogenic to a rice cultivar Jinheung that was used to test pathogenicity of the sclerotia. Proportion of viable sclerotia that have both germiability and pathogenicity was thus estimated to 0.29 of total sclerotia collected. R. solani cultures obtained from the sclerotia could be distinguished into three groups based on colony morphology on PSA. Size and number of sclerotia formed on PSA differed between group but were not associated with pathogenicity to Jinheung.

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The Effect of the Department Satisfaction of the College Students Majoring in Security on the Career Expectation Consciousness (경호전공대학생의 학과만족이 직업기대의식에 미치는 영향)

  • Kim, Jin-Hwan;Cho, Cheol-Kyu
    • Convergence Security Journal
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    • 제14권1호
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    • pp.59-69
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    • 2014
  • The purpose of this study is to investigate an effect of the department satisfaction of college students majoring in security on the career expectation consciousness, and through this to propose basic data to help college students prepare positive school life and career and increase school life adaptation; doing this, it is to investigate the cause to promote not only their development but also school development. As of 2013, I set up a population targeting female and male college students majoring in security at Y University located in Y City, Gyeonggi Province, K University in G City, North Gyeongsang Province, and H University in C City, South Chungcheong Province and conducted study targeting the total 352 students using the random sampling method. The research tool was questionnaires, which I used by recomposing on the basis of the precedent studies at home and abroad. Regarding data processing, I used SPSS WIN 18.0 and carried out frequency analysis, one-way analysis of duncan variance, post hoc analysis, reliability analysis, factorial analysis, correlation analysis and multiple regression analysis. Through the above research methods and data analysis according to the procedures I drew conclusions as follows: First, the department satisfaction according to demographic characteristics of the college students majoring in security had a partially significant difference. Second, the career expectation according to demographic characteristics of the college students majoring in security had a partially significant difference. Third, the effect of the department satisfaction of the college students majoring in security on the career expectation consciousness was partial.

Influences of Acculturative Stress and Social Support on Subjective Quality of Life among Chinese Students in Korea (중국 유학생의 문화적응스트레스와 사회적 지지가 주관적 삶의 질에 미치는 영향)

  • Lee, Kyu-Eun;Yom, Young-Hee;Chang, Hae-Kyung
    • The Journal of Korean Academic Society of Nursing Education
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    • 제17권3호
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    • pp.514-523
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    • 2011
  • Purpose: The purpose of this study was to identify the factors affecting the subjective quality of life among college students from China. Methods: The research design was a descriptive survey design using convenience sampling. Data was collected by using a self-questionnaire completed by 304 Chinese students located in three cities, namely, Seoul, Gangneung, and Seosan. ANOVA, Pearson correlation coefficients and hierarchical multiple regression with the SPSS Win 12.0 Program were used to analyze the data. Results: The average score on subjective quality of life was $3.59{\pm}0.43$. There were significant differences in the subjective quality of life according to length of stay, type of program, and health status. The subjective quality of life had significant negative correlation with acculturative stress and positive correlation with social support. The explained variance for the subjective quality of life was 51.5%. Variables on health status, guilt feelings, other acculturative stress, and social support significantly predicted the degree on subjective quality of life. Conclusion: Findings on this study provide a comprehensive understanding on the subjective quality of life and related factors for Chinese students in Korea. However, further studies with a larger random sample and more detailed research design is necessary.