• 제목/요약/키워드: By Variables

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퍼지-랜덤 변수를 이용한 DES 모델링을 통한 실시간 전력 시스템의 성능 및 신뢰도 평가 (Evaluation of the Performance and Reliability of a Real-time Power System Described by a DES Model using Fuzzy-Random Variables)

  • 민병조;이석주;김학배
    • 대한전기학회논문지:시스템및제어부문D
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    • 제49권7호
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    • pp.363-369
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    • 2000
  • To flexibly evaluate performance and reliability of an electric power system in the aspect of the real-time system which is intrinsically characterized by stringent timing constraints fails catastrophically if its control input is not updated by its digital controller computer within a certain time limit called the hard deadline, we propose fuzzy-random variables and build a discrete event model embedded with fuzzy-random variables. Also, we adapt fuzzy-variables to a path-space approach, which derives the upper and lower bounds of reliability by using a semi-Markov model that explicitly contains the deadline information. Consequently, we propose certain formulas of state automata properly transformed by fuzzy-random variables, and present numerical examples applying the formulas as well.

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사회-환경적 변인과 인지적 변인이 청소년의 우울에 미치는 영향의 경로분석 (Depression in Adolescence : Path Analysis of the Effects of Socio-Environmental Variables and Cognitive Variables)

  • 김선하;김춘경
    • 아동학회지
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    • 제27권6호
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    • pp.249-261
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    • 2006
  • This study investigated the influence of socio-environmental variables and cognitive variables on adolescent depression. Subjects were 494 middle and high school students of Deagu. The instrument was a self-report questionnaire; data were analyzed by t-test, stepwise multiple regression and path analysis. Among Socio-environmental variables, social support variables had a stronger effect on depression than stress. Among cognitive variables, automatic thought had a stronger effect on depression than cognitive distortion and socio-environmental variables. In path analysis, social support had a direct effect on cognitive distortion and automatic thought. Automatic thought served as a mediater of the relation between social support and depression. Although adolescent stress resulted in high depression, its effect on depression varied with the level of perceived social support.

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노인전문병원 근무자들의 직무만족도 결정요인 (Determinants of Job Satisfaction among Workers at Elderly Care Hospitals)

  • 서영준;오지영
    • 한국병원경영학회지
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    • 제13권2호
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    • pp.64-85
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    • 2008
  • This study purports to investigate the determinant of job satisfaction among workers working at Long-term care hospitals. The independent variables contain three groups of determinants: organizational characteristics variables(job autonomy, job variety, distributive justice, role conflict, supervisor support, job suitability, job significance, job security, organizational support, job growth, promotional opportunity), environmental variables(job opportunity), and psychological variables (met expectation, job efficacy, positive affectivity, and negative affectivity). The sample used in this study consisted of 250 workers from 4 Long-term care hospitals nationwide. Data were collected with self-administered questionnaires and analyzed using multiple regression analysis. The results of the study are as follows: 1) the following variables, listed in order of size, have significant effects on job satisfaction: negative affectivity(-), job significance(+), job growth(+), age(+), positive affectivity(+), organizational support(+), job opportunity(-). 2) the variance of job satisfaction explained by the variables used in the study are 53.8%. When demographic variables added to Model I, job satisfaction explained by variables are 55.4%. 3) the results of this study indicate that three variables of negative affectivity, job significance, job growth are especially important for improving the level of job satisfaction among workers at Long-term care hospitals.

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Application of Principal Component Analysis Prior to Cluster Analysis in the Concept of Informative Variables

  • Chae, Seong-San
    • Communications for Statistical Applications and Methods
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    • 제10권3호
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    • pp.1057-1068
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    • 2003
  • Results of using principal component analysis prior to cluster analysis are compared with results from applying agglomerative clustering algorithm alone. The retrieval ability of the agglomerative clustering algorithm is improved by using principal components prior to cluster analysis in some situations. On the other hand, the loss in retrieval ability for the agglomerative clustering algorithms decreases, as the number of informative variables increases, where the informative variables are the variables that have distinct information(or, necessary information) compared to other variables.

ON THE COMPLETE CONVERGENCE FOR WEIGHTED SUMS OF NEGATIVELY SUPERADDITIVE DEPENDENT RANDOM VARIABLES

  • SEO, HYE-YOUNG;SHII, DA-LI;BAEK, JONG-IL
    • Journal of applied mathematics & informatics
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    • 제37권3_4호
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    • pp.207-217
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    • 2019
  • We are presented of several basic properties for negatively superadditive dependent(NSD) random variables. By using this concept we are obtained complete convergence for maximum partial sums of rowwise NSD random variables. These results obtained in this paper generalize a corresponding ones for independent random variables and negatively associated random variables.

청소년의 학교생활 부적응에 영향을 미치는 가족관련 변인 (Family-Related Variables Affecting Adolescents′ School Life Maladjustment)

  • 류경희
    • 대한가정학회지
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    • 제41권12호
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    • pp.147-168
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    • 2003
  • The researcher worked with 1001 middle and high school students so as to inquire into family-related variables affecting adolescents' school life maladjustment, relying on average, standard deviation and hierarchical regression. The following are the major findings. 1) The research shows that to look into school life maladjustment on the basis of analysis models including family environment variables and family relationship variables in addition to family background variables offers more explanatory power. 2) Of all the variables, parent relationship variables turned out to have the greatest influences on maladjustment to teacher relationship and teaming activity areas among the subordinate areas of school life maladjustment. 3) Of all the variables, family's physical variables have the greatest influence on maladjustment to regulation-keeping relationship and opposite sex relationship among the subordinate areas of school life maladjustment. 4) Of all the variables, sibling relationship variables have the greatest influence on maladjustment to friendship among the subordinate areas of school life maladjustment. 5) Parent relationship variables have the greatest influence on total school life maladjustment followed by family physical environment, structural environment, the number of family members, cultural environment and residential variables in the right order.

퍼지-랜덤 변수를 이용한 실시간 제어 시스템의 성능 및 신뢰도 평가기법 연구 (Evaluation of the Performance and Reliability of a Real-Time System Using Fuzzy-Random Variables)

  • 민병조;이석주;김학배
    • 제어로봇시스템학회논문지
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    • 제6권6호
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    • pp.433-440
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    • 2000
  • To flexibly evaluate performance and reliability of a real-time system which is intrinsically characterized by stringent timing constraints to generate correct responses, we propose fuzzyrandom variables and build a discrete event model embedded with fuzzy-random variables. Also, we adapt fuzzy-variables to a path-space approach, which derives the upper and lower bounds of reliability by using a semi-Markov model that explicitly contains the deadline information. Consequently, we propose certain formulas of state automata properly transformed by fuzzy-random variables, and present numerical examples applying the formulas to RTP(Rapid Thermal Process) to show that a complex system can be properly evaluated based on this model by computer simulation.

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가족기업 창업으로의 전환결정요인에 관한 연구 (A study on transformation factors to family business establishment - focussing on pre-wage earner group -)

  • 정순희;송지영
    • 가족자원경영과 정책
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    • 제5권2호
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    • pp.13-27
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    • 2001
  • The purpose of this study was to analyze which factor, influenced their change from pre-wage group to family business group. The subject of study classified by wage earner group and family business group. Independent variables effected by transform to family business group are classified by personal variables and workable variables. The major findings of this study are as followings: Sex, age, marriage of personal variables and pre-work time, pre-wage, wholesale - retail business, restaurant business and person service business of pre-industry of work variables had significant effect on transform to family business. Especially, Marriage group and low pre-wage income group significant effected on transfer to family business. By this, personal to transfer to family business can conjugate information of search and choice decision and can be used as a valuable data for future family business study.

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고등학교 전정의 공간 Image와 시각적 선호도 조사에 관한 연구 (A Study on the Spatial Image and Visual Preference for Front Gardens of High School)

  • 진희성;서주환
    • 한국조경학회지
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    • 제13권2호
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    • pp.37-70
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    • 1985
  • The purpose of this study is to present objective basic data for environmental design by the quantitative analysis of visual quality emboded in physical environment. For this, as for the front garden of high schools, the spatial image was measured by the S.D. Scale Method, Factor Analysis was proceeded by the principal component analysis and the visual preference was investigated by the Paired Comparision Method. The scale values of plain and unpleasant road surface and external appearance of buildings, which are related to emotions of simpleness fell from straightness and stability, were found to be high. But, except for the road surface of Kyunggi High School, scale values of variables explaining the variation of the quality of materials, level of floor and rythm were generally low. For all green spaces, scale values of variables explaining the degree of pleasantness was found to be generally high. And, those explaining tidiness and characteristics of green spaces were not in the same tendency. But, the green spaces of Youngdong High school can be considered to the space with plenty of visual absorption uniqueness were high. As for the correlation between variables, variables for green spaces(12 and 26) and those for overall view of front garden( 1 and 4) revealed high positive correlation. Also, "order - disorder" and "convenient- incovenient" included in road surface variable can be regarded to have the same meaning since the correlation coefficient between them is very high, 0.7045. Image variables including road surface, external appearance of buildings, green spaces and overall view of front garden showed 91.21~61.08% of total variance. Thus, the remains can be considered to be the error valiance or specific variance. In Fctor I, II and III, main components explaining the road surface image of front gardens are order, hardness, texture, color, gradient and rythm. As for the external appearance of b wilding, variables of color, hardness, stability, peculiality and shape revealed high values of factor load. For all variables, communality was drastically high and ellen values and common variance were found to be very high in Factor I. As for the front gardens, variables explaining volume and peculiarity were found to be the main components of Factor I. In Factor II and III, variables of factor load were tidiness, pleasantness.

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유행선도력에 관한 연구 II - 유행선도력에 따른 집단들의 특성 - (A Study on Fashion Leadership II - The Characteristics among the Groups Divided according to Their Fashion Leadership -)

  • 이화연;이은영
    • 한국의류학회지
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    • 제13권1호
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    • pp.67-77
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    • 1989
  • The purposes of the study were to compare the characteristics among five segments of the population (innovative communicators, innovators, opinion leaders, followers, indifferents) which were divided according to their fashion opinion leadersship and innovativeness. Thirty-one variables (thirteen fashion-related variables, five social variables, nine psychological variables, four demographic variables) were included in the analysis (analysis of variance, chi-square test). Data were obtained from 446 women living in Seoul area by self-administered questionnaire. The results of the study were as follows: there were significant differences among groups in most of fashion-related variables (fashion interest and clothing importance, four dimensions of clothing values, marketer-dominated and neutral information sources) and psychological variables (eight self-image variables) and in some of social and demographic variables (social activity, social stratum, education).

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