• Title/Summary/Keyword: hierarchical control

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Discrimination of the drinking water taste by potentiometric electronic tongue and multivariate analysis (전자혀 및 다변량 분석법을 활용한 먹는물의 구별 방법)

  • Eunju Kim;Tae-Mun Hwang;Jae-Wuk Koo;Jaeyong Song;Hongkyeong Park;Sookhyun Nam
    • Journal of Korean Society of Water and Wastewater
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    • v.37 no.6
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    • pp.425-435
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    • 2023
  • Organoleptic parameters such as color, odor, and flavor influence consumer perception of drinking water quality. This study aims to evaluate the taste of the selected bottled and tap water samples using an electronic tongue (E-tongue) instead of a sensory test. Bottled and tap water's mineral components are related to the overall preference for water taste. Contrary to the sensory test, the potentiometric E-tongue method presented in this study distinguishes taste by measuring the mineral components in water, and the data obtained can be statistically analyzed. Eleven bottled water products from various brands and one tap water from I city in Korea were evaluated. The E-tongue data were statistically analyzed using multivariate statistical tools such as hierarchical clustering analysis (HCA), principal component analysis (PCA), and partial least squares discriminant analysis (PLS-DA). The results show that the E-tongue method can clearly distinguish taste discrimination in drinking water differing in water quality based on the ion-related water quality parameters. The water quality parameters that affect taste discrimination were found to be total dissolved solids (TDS), sodium (Na+), calcium (Ca2+), magnesium (Mg2+), sulfate (SO42-), chloride (Cl-), potassium (K+) and pH. The distance calculation of HCA was used to quantify the differences between 12 different types of drinking water. The proposed E-tongue method is a practical tool to quantitatively evaluate the differences between samples in water quality items related to the ionic components. It can be helpful in quality control of drinking water.

Factors associated with the bone mineral density in Korean adults: Data from the 2010-2011 Korean National Health and Nutrition Examination Survey (KNHANES) V (우리나라 성인남녀의 골밀도 관련요인: 국민건강영양조사 제 5기 1, 2차 년도(2010년, 2011년))

  • Kim, Kyung Sook
    • Journal of agricultural medicine and community health
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    • v.39 no.4
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    • pp.240-255
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    • 2014
  • Objective: The purpose of this study was to identify the correlates of bone mineral density of Korean adults. Methods: This study was based on the data from the 2010-2011 Korean National Health and Nutrition Examination Survey (KNHANES, 2010~2011) V. Among 8,473 subjects of the survey, who were adults 19 years old or over with bone mineral density data, the current study excluded those whose data include a missing study variable or the response of 'I don't know', and finally analyzed the data of 5,986 subjects (2,692 males and 3,294 females). This study employed the following statistical methods of analysis: t-test, analysis of variance (ANOVA), and hierarchical multivariate linear regression analysis. Results: In multivariate analysis, in the case of men, the significant associated factors in bone mineral density were age, education level, body mass index (BMI), waist circumference, total muscle mass, exercise, and weight control; in the case of women, the significant associated factors in bone mineral density were age, education level, economic activity, BMI, total muscle mass, exercise, weight control. fat intake, uptake female hormone, menopause, and age of menarche. Conclusion: For both sexes, the strongest modifiable factor in influencing bone mineral density was total muscle mass. Therefore, to prevent osteoporosis and promote health, active health education and interventions such as regular exercise for total muscle mass increase should be implemented from an early growth period.

Usability index evaluation system for mobile WAP service (무선인터넷 서비스 사용성 지수 평가 체계)

  • Park, Hwan-Su
    • 한국HCI학회:학술대회논문집
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    • 2008.02b
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    • pp.152-157
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    • 2008
  • The customer satisfaction of WAP service greatly relies on the usability of the service due to the limited display size of a mobile phone and limitation in realizing UI (User Interface) for function keys, browser, and OS (operating system) Currently, a number of contents providers develop and deliver varying services, and thus, it is critical to control quality level of UI in consistent standards and manner. This study suggests usability index evaluation system to achieve consistent UI quality control of various WAP services. The system adopts both top-down and bottom-up approaches. The former concerns deriving UI design components and evaluation checklists for the WAP, based on the usability attributes and UI principles. The latter concerns deriving usability-related evaluation checklists from the established UI design features, and then grouping them from the viewpoint of usability principles and attributes. This bidirectional approach has two outstanding advantages: it allows thorough examination of potential elements that can cause usability problems from the standpoint of usability attributes, and also derives specific evaluation elements from the perspective of UI design components that are relevant to the real service environment. The evaluation system constitutes a hierarchical structure by networking usability attributes, UI guideline which indicates usability principles for each attribute, and usability evaluation checklist for each UI component that enables specific evaluation. Especially, each evaluation checklist contains concrete contents and format so that it can be readily marked in O/X. The score is based on the ratio of number of items that received positive answer to the number of total items. This enables a quantitative evaluation of the usability of mobile WAP service. The validity of the proposed evaluation system has been proved through comparative analysis with the real usability problems based on the user test. A software was developed that provides guideline for evaluation objects, criteria and examples for each checklist, and automatically calculates a score. The software was applied to evaluating and improving the real mobile WAP service.

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The Effect of Social Network on Information Sharing in Franchise System (프랜차이즈시스템의 사회연결망 특성이 정보공유에 미치는 영향)

  • Yun, Han-Sung;Bae, Sang-Wook;Noh, Jung-Koo
    • Journal of Distribution Research
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    • v.16 no.2
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    • pp.95-118
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    • 2011
  • The purpose of this study is as follows. First, we investigate empirically the effects of social network properties such as social network density and centrality of a franchisee on its information sharing with various subjects such as the franchisor and other franchisees in the franchise system. Second, we examine exploratively if tie strength between a franchisee and its franchisor plays a moderating role on the relationship between social network properties and information sharing. The study model was established as shown in

    . We gathered 200 data from franchisees in Busan through a questionnaire survey and used 189 data for our purpose. To improve the quality of data, we selected respondents from the franchisees' owners or managers that had contacted often with their franchisor and other franchisees in the franchise system. Our data analysis began with reliability analysis, exploratory and confirmatory factor analysis, on the multi-item measures of social network density, social network centrality, tie strength, information sharing and control variables such as shared goals and ownership to assess the reliability and validity of those measures. The results were shown that the presented values satisfied the general criteria for reliability and validity. We tested our hypotheses using a hierarchical multiple regression analysis in four steps. Model 1 regressed the dependent variable(information sharing) only on control variables(shared goals, ownership). Model 2 added main effect variables(social network density, social network centrality) in Model 1. Model 3 added a moderating variable(tie strength) in Model 2. Finally, Model 4 added interaction terms between the main variables and the moderating variable in Model 3. We used a mean-centering method for the main variables and the moderating variable to minimize the multicollinearity problem due to the interaction terms in Model 4. Two important empirical findings emerge from this study. In other words, the effects of social network properties and tie strength on a franchisee's information sharing depend on subject types such as the franchisor and other franchisees in franchise system. First, social network centrality, tie strength, the interaction between social network density and tie strength and the interaction between social network centrality and tie strength all affect significantly a franchisee's information sharing with its franchisor. By the way, the interaction between social network centrality and tie strength has a negative effect on its information sharing while the interaction of social network density and tie strength has a positive effect on its information sharing. Second, both social network centrality affects significantly and directly a franchisee's information sharing with other franchisees in the franchise system. However, there does not exist the moderating role of tie strength in the second case. Finally, we suggest the implications of our findings and some avenues for future research.

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The Relationship between Entrepreneurial Education and Entrepreneurial Intentions : Focusing on Moderating Effects of Entrepreneurial Orientation and Environmental Factors (창업교육과 창업의지의 관계: 기업가 지향성과 환경적 요인의 조절효과)

  • Lee, Jae-Seok;Lee, Sang-Myung
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.10 no.3
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    • pp.61-74
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    • 2015
  • This study attempts to empirically examine the influence of entrepreneurial education in university on entrepreneurial intentions of undergraduate and graduate students as potential entrepreneur and new moderating factors on the relationship between entrepreneurial education and entrepreneurial intentions. We suggested EO(innovativeness, risk-taking propensity, proactiveness and locus of control) and environmental factors(entrepreneurial family background and resource accessibility) as new moderating factors in the relationship. For this study, the following research questions are raised : First, is there a significant difference in entrepreneurial intentions of enrolled and unenrolled students in entrepreneurial education? Second, does entrepreneurial education affect entrepreneurial intentions positively? Finally, do EO and environmental factors have moderating effects in the relationship between entrepreneurial education and entrepreneurial intentions? In order to test our research model, the current study collected data from 265 undergraduate and graduate students who are majoring in natural sciences or engineering in Seoul National Univ., Hanyang Univ., and KAIST. To investigate our research questions and hypotheses, independent-sample T-test and hierarchical regression analysis were employed. The results of empirical analysis revealed that entrepreneurial education positively related to entrepreneurial intentions and that the relationship between entrepreneurial education and entrepreneurial intentions moderated by EO and environmental factors. First, the result showed the significant difference in entrepreneurial intentions between enrolled and unenrolled students in entrepreneurial education. Entrepreneurial intentions of students who enrolled entrepreneurial education was higher than others. Second, entrepreneurial education affected the entrepreneurial intentions positively. Finally, the moderating effects of innovativeness, risk-taking propensity, proactiveness and entrepreneurial family background among investigated six moderators were significant. entrepreneurial education-entrepreneurial intentions relationship was even stronger under high innovativeness and high proactiveness. But risk-taking propensity and entrepreneurial family background decreased the effect of entrepreneurial education on entrepreneurial intentions.

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Effect of Mediating Variable on the Relationship between Job Stress and Stress Response among Clinical Dental Hygienists (임상치과위생사에서 직무스트레스와 스트레스 반응에 있어 매개요인의 영향)

  • Choi, Ja-Hyeong;Choi, Jun-Seon
    • Journal of dental hygiene science
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    • v.14 no.2
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    • pp.114-122
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    • 2014
  • The purpose of this study was to analyze the effect of mediating variables on the relationship between job stress and stress response. A survey was conducted to 243 clinical dental hygienists from January 15, 2013 to March 20, 2013 and the data were analyzed using t-test, one-way ANOVA, Pearson's correlation analysis, and hierarchical multiple regression analysis. The subjects who worked in poor working environment, had high level of role conflict and overload and aggressive nature showed high stress responsivity (p<0.01). The variable that showed mediation effect on the relationship between job stress and physical discomfort, depression was shown to be personality type (p<0.05). Also, the variable that showed mediation effect on the relationship between job stress and turnover intention was social support (p<0.05). According to the results, personality type and social support were shown to be important parameters when it came to the relationship between job stress and stress response. Therefore, in order to reduce negative outcomes caused by stress, it is suggested to provide an educational opportunity on self-control management while increasing social support from the organizational and structural level. Especially, it is asked to expand the system that provides encouragement and recognition to feel the sense of achievement in the course of their duty execution.

An Empirical Study on Influence of Venture Preparation on Business Performance of Initial Venture Foundation: Focused on The Effect of Controlling The Period of Venture Preparation (창업준비성이 창업초기기업 경영성과에 미치는 영향에 관한 실증연구: 창업준비기간의 조절효과 중심)

  • Oh, jaiwoo;Lee, Donghyung;Kang, Jinkyu
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.10 no.4
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    • pp.67-80
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    • 2015
  • Although recent policies and regulations in Korea strongly advocate and encourage cultivation of venture foundations, studies on venture foundation and success are very limited and often primarily focus on entrepreneurship or individual quality as a venture founder in addition to such studies' validity in question. Therefore, this study primarily focuses on venture preparation process which is subject to venture founder's effort to verify the policy effectiveness in the relationship between venture preparation and business performance. Major goal of this study is to reduce social cost of venture failure by suggesting systematic policy support for venture foundations and analyzing the relationship between following variables: first, venture preparation and financial performance, second, venture preparation and non-financial performance, and third, venture preparation and business performance. 400 initial venture foundations less than 5 years are selected from KISED(Korea Institute Startup & Entrepreneurship Development) trend analysis to carry out statistical analysis using SPSS 18.0. To organize the data features, frequency analysis as well as descriptive statistics are performed to verify the hypothesis. As a result, sub-factors in measurement of venture preparation which are venture education period, venture benefit, and experience of incubating organization are selected as independent variables. Likewise, sub-factors in measurement of business performance which are financial performance and non-financial performance are used as dependent variables. To validate interactive effect, venture preparation period is selected as control variable to perform hierarchical regression analysis. The analysis result verifies that venture benefit has positive influence on financial and non-financial performance while venture education period has positive influence on non-financial influence and experience of incubating organization has negative influence on non-financial performance without influence on financial performance. In addition, interaction of venture preparation period has positive influence solely between venture benefit and non-financial performance. Through this study, appropriate supporting plans depending on the level of venture preparation can be derived to improve business performance of initial venture foundations for policy designer of venture support, and quality rather than quality improvement of venture businesses is possible through investigation of structural issues of individual venture businesses. Ultimately, this study suggests venture founders to determine whether to focus on venture preparation process or to start a venture business.

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The Effect of Chinese Customer Coffee Benefit Sought on Korean Coffee Shop Satisfaction, Attachment, and Loyalty - Based on Mediating Effect of Korean Wave Attitude - (중국소비자의 커피제품 추구편익이 한국 커피전문점 만족도와 애착 및 충성도에 미치는 영향에 관한 연구 - 한류태도 매개효과를 중심으로 -)

  • Lee, Hyung-Ju;Suh, Ji-Youn
    • Culinary science and hospitality research
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    • v.22 no.5
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    • pp.151-166
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    • 2016
  • The purpose of this study is to understand the influence of Chinese customer coffee sought benefits on satisfaction with, and attachment and loyalty to Korean coffee shops. Based on a total of 200 samples obtained for empirical research from 10 Mar. to 25 July, 2015, of self-administrated questionaries completed by patrons in Beijing, Shanghai, Haerbin in China, data were analyzed for frequency, exploratory factor analysis, reliability analysis, correlation analysis, multiple regression and hierarchical multiple regression analysis. The results of this study are summarized as follows. First, it was found that Chinese customer sought pursuits (functional & experimental benefits, symbolic benefit) had an effect on satisfaction of Korea coffee shop. Second, satisfaction influenced Korean coffee shop attachment and loyalty. Third, Korean wave attitude had a mediating effect between satisfaction, attachment and loyalty. From the results, we can conclude following implications: First, by providing atmosphere of South Korea, menu, barista service, we can predict that Korean coffee brands can prevail in competition through active promotions of their brands. Second, Korean coffee brands can make a strategy that includes providing full service from trained South Korean baristas and hosting talk shows between baristas from South Korea. Third, providing the opportunity to visit South Korea for local cafe tours is a good social event. These results will help control marketing strategies in China. Limitations and future research directions are also discussed.

The Effects of Parents-Children Relationship Factors on Gifted Adolescents' Career Maturity : Focusing on Gender, Secondary School Level, and Comparison with Regular Adolescents (영재 청소년의 진로성숙도에 영향을 미치는 부모-자녀관계 요인: 성별 및 학교급, 일반학생과의 비교를 중심으로)

  • Chae, Yoojung;Lee, Hyunjoo
    • Journal of Gifted/Talented Education
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    • v.26 no.4
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    • pp.565-585
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    • 2016
  • This study purpose was to explore whether career maturity and parents-children relationship related factors were differentiated by giftedness, gender and secondary school level (research question 1). In addition, this study focused on the effects of parents-children relationship related factors on career maturity with a comparison on gifted and regular students (research question 2). The sample included 213 gifted middle school and high school students who participated in the Korean gifted education center and 243 regular students. Multivariate analysis of variance was conducted for research question 1, and hierarchical regression analysis was conducted for research question 2. The results of this study showed that (1) gifted students showed a higher level of career maturity, achievement expectation (parents-children relationship), respect (parents-children relationship), discussion and leisure (activity with parents), sharing ordinary life and communication (activity with parents), career support of parents compared to regular students ; (2) Girls showed higher level only in sharing ordinary life and communication compared to boys ; (3) middle school students more highly perceived the parents' achievement expectation and control, respect for parents, activities with parents (discussion and leisure, sharing ordinary life and communication) compared to high school students ; (4) the career support of parents was the strongest predictor of career maturity, and discussion and leisure was also a significant factor predictor of career maturity. Based on these results, it was suggested for parents to support their children's career maturity of both gifted and regular students by increasing frequencies of various activities shared with their children such as discussion and leasure.

Spatial analysis of financial activities in the Korean urban system (한국 금융의 공간적 특색에 관한 연구)

  • Choi, Jae Heon
    • Journal of the Korean Geographical Society
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    • v.28 no.4
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    • pp.321-355
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    • 1993
  • This paper focuses on the geographical pattern of financial activities in the Korean urban system during 1975-1990, based on the assumption that financial activities can reveal control points in Korea's urban economy. In terms of spatial evolution of financial insitutions, different locational characteristics are revealed among different types of financial institutions, implying the role of urban hierarchy. Financial resources are highly concentrated in the capital region, Seoul and Kyonggi Province. Both centralization trends into the large metropolitan cities and relative declines of medium and small cities within the Korean urban system, have been experienced over the study period. Financial activities sustain relatively stable hierarchical structure in the urban hierarchy. Regarding the financial flows, dominant flow zones centered on major metropolitan cities are identified, clearly showing a prominant role of Seoul in financial flows in the entire urban system.

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