• 제목/요약/키워드: Hierarchical data

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Exploring Twitter Follower-Networks of Startup Companies Employing Social Network Analysis and Cluster Analysis (소셜네트워크 분석과 클러스터 분석 방법을 활용한 스타트업 회사의 트위터 팔로워 네트워크에 대한 탐색적 연구)

  • Yu, Seunghee
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.14 no.4
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    • pp.199-209
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    • 2019
  • The importance of business strategy for successful social media engagement has quickly increased as more businesses engage in social media. The importance is even greater for startup companies because startup companies are genuinely new to business, and they need to increase their presence in the market, and quickly access future customers. The objective of this paper lies in exploring key indicators of social media engagements by selected startup companies. The key indicators include two aspects of social media usages by the companies: i) overall social media activities, and ii) properties of network structure of the information flow platform provided by social media service. To better assess and evaluate the key indicators of social media usages by startup companies, the indicators will be compared with those of selected large established companies. Twitter is selected as a social media service for the analysis of this paper, and using Twitter REST API, data regarding the key indicators of overall Twitter activities and the Twitter follower-network of each company in the sample are collected. Then, the data are analyzed using social network analysis and hierarchical clustering analysis to examine the characteristics of the follower-network structures and to compare the characteristics between startup companies and established companies. The results show that most indicators are significantly different across startup companies and established companies. One key interesting finding is that the startup companies have proportionally more influencers in their follower-networks than the established companies have. Another interesting finding is that the follower-networks of startup companies in the sample have higher modularity and higher transitivity, suggesting that the startup companies tend to have a proportionally larger number of communities of users in their follower-networks, and the users in the networks are more tightly connected and cohesive internally. The key business implication for the future social media engagement efforts by startup companies in general is that startup companies may need to focus on getting more attention from influencers and promoting more cohesive communities in their follower-networks to appreciate the potential benefits of social media in the early stage of business of startup companies.

Study on the snack menu pattern, food diversity and satisfaction of parent provided by Center for Children's Foodservice Management in Jeonbuk area (전북지역 어린이급식관리지원센터에서 제공하는 어린이집 간식메뉴의 유형, 식품 다양성 및 학부모 만족도 연구)

  • Sym, Eun-Byul;Rho, Jeong-Ok
    • Journal of Nutrition and Health
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    • v.52 no.5
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    • pp.501-513
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    • 2019
  • Purpose: This study examined the menu pattern, food diversity, and satisfaction of parents with the snack menus of childcare centers provided by the Center for Children's Foodservice Management (CCFM) in Jeonbuk area. Methods: Data from 2,432 snack menus (1,321 for morning snacks and 1,111 for afternoon snacks) of March, June, September, and December 2017 from 13 CCFM in Jeonbuk area were analyzed. In addition, the participants for the survey were 247 parents in Jeonju and Kunsan. The data were analyzed using a t-test, ${\chi}^2$-test, and hierarchical regression analysis with SPSS v. 24.0. Results: Differences in the menu pattern and food diversity were observed between morning and afternoon snack menus. The majority of snack menus (61.6%) were one menu item. The percentage of 'G' (20.0%) was highest in the food group patterns. The morning snacks served mainly porridge, raw fruits, and milk, and the afternoon snacks served mainly flour-based foods, juices, and milk. The awareness level of parents about the snack menus of daycare centers was $4.09{\pm}0.82$, and its overall satisfaction was $4.06{\pm}0.69$. In the snack-quality attribute analysis, the hygiene of foods was the most important factor, and parents judged that they were doing well. Regression analysis showed that the hygiene of personnel was the most influential variable on the overall satisfaction, followed by balance with the main meal and the portion size. Conclusion: Therefore, it is important to establish snack menu guidelines considering the eating behaviors of the children and to strengthen hygiene for the increasing the satisfaction of various stakeholders in daycare centers.

Design and Implementation of Transmission Scheduler for Terrestrial UHD Contents (지상파 UHD 콘텐츠 전송 스케줄러 설계 및 구현)

  • Paik, Jong-Ho;Seo, Minjae;Yu, Kyung-A
    • Journal of Broadcast Engineering
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    • v.24 no.1
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    • pp.118-131
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    • 2019
  • In order to provide 8K UHD contents of terrestrial broadcasting with a large capacity, the terrestrial broadcasting system has various problems such as limited bandwidth and so on. To solve these problems, UHD contents transmission technology has been actively studied, and an 8K UHD broadcasting system using terrestrial broadcasting network and communication network has been proposed. The proposed technique is to solve the limited bandwidth problem of terrestrial broadcasting network by segmenting 8K UHD contents and transmitting them to heterogeneous networks through hierarchical separation. Through the terrestrial broadcasting network, the base layer corresponding to FHD and the additional enhancement layer data for 4K UHD are transmitted, and the additional enhancement layer data corresponding to 8K UHD is transmitted through the communication network. When 8K UHD contents are provided in such a way, user can receive up to 4K UHD broadcasting by terrestrial channels, and also can receive up to 8K UHD additional communication networks. However, in order to transmit the 4K UHD contents within the allocated bit rate of the domestic terrestrial UHD broadcasting, the compression rate is increased, so a certain level of image deterioration occurs inevitably. Due to the nature of UHD contents, video quality should be considered as a top priority over other factors, so that video quality should be guaranteed even within a limited bit rate. This requires packet scheduling of content generators in the broadcasting system. Since the multiplexer sends out the packets received from the content generator in order, it is very important to make the transmission time and the transmission rate of the process from the content generator to the multiplexer constant and accurate. Therefore, we propose a variable transmission scheduler between the content generator and the multiplexer to guarantee the image quality of a certain level of UHD contents in this paper.

A Study on the Intention to Use the Loan Service of the Mobile-Based Financial Platform (모바일 기반 금융플랫폼의 대출서비스 사용의도에 관한 연구)

  • Lee, Sangho;Cho, Kwangmoon
    • Journal of Internet of Things and Convergence
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    • v.8 no.3
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    • pp.1-10
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    • 2022
  • The purpose of this study was to investigate how the characteristics of mobile-based financial platforms have an impact on the intention to use loan service users. In addition, it was attempted to investigate whether usefulness and ease of use had a mediating effect in the relationship between each characteristic of the mobile financial platform on the intention to use the loan service. Data collection was conducted from March 1 to April 30, 2022, and 200 people participated in the study. Analysis methods were frequency analysis, exploratory factor analysis, reliability analysis, correlation analysis, hierarchical multiple regression analysis, and three-step mediation regression analysis. The research results are as follows. First, the influence of user factors, technical factors, and environmental factors of a financial platform on the intention to use a mobile loan service was found to be ubiquity in user factors, reliability in technical factors, and facilitation conditions in environmental factors. Second, in the relationship between convenience and intention to use user factors, usefulness had a completely mediating effect. Third, in the relationship between reliability of technical factors and intention to use, usefulness showed a partial mediating effect. Fourth, in the relationship between the social impact of environmental factors and facilitation conditions and intention to use, the usefulness showed a partial mediating effect. Fifth, ease of use showed a completely mediating effect in the relationship between convenience and intention of use of user factors. Sixth, in the relationship between reliability of technical factors and intention to use, ease of use showed a partial mediating effect. Seventh, in the relationship between the social impact of environmental factors and intention to use, ease of use showed a partial mediating effect, and in the relationship between facilitation conditions and intention to use, ease of use showed a fully mediating effect. Through this study, we tried to present basic data on the determinants of the user's acceptable intention to use the mobile loan service.

The Effects of Self-Efficacy and Social Support on the Quality of Life of the Elderly with Depression (자기효능감과 사회적 지원이 우울증 노인의 삶의 질에 미치는 영향에 관한 연구)

  • Kang, Sun-Kyung
    • 한국노년학
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    • v.29 no.2
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    • pp.629-643
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    • 2009
  • The purpose of this study is, by using the demographic variables, to identify self-efficacy, social support, and quality of life of the elderly with depression and to assess the impacts of these factors upon their quality of life. By analyzing the factors which have an impact upon the life quality of the elderly with depression, this study aims to provide important information which help understand them, and to find out what kind of care is necessary for their happy and satisfactory life. The study took purposive sampling and survey of 215 people among the elderly with depression who were under care of the outpatient clinics, day hospitals, and mental health clinics located in Seoul and Kyunggi Province, Korea. This study was conducted from November 10th to 20th, 2008 and the data were collected using the questionnaires of self-efficacy, social support, and quality of life scales. Using a SPSS/WIN 15.0 program, the analysis of the data showed the following results. First, among the demographic characteristics, the elderly with depression who were male, had spouse, higher education, no public assistance, shorter period of depression, and were healthy turned out to have higher self-efficacy. In terms of social support, the participants who had higher education, no public assistance, and were healthy turned out to have more social support. Further, in terms of quality of life, the variables of spouse, public assistance, period of depression, and health condition were statistically significant. Second, as a result of hierarchical regression, it appeared that the elderly with depression, who had higher self-efficacy, more social support, spouse, good health, no public assistance, and shorter period of depression, turned out to have higher quality of life. Based on the study findings, the implications of social work practice, policy, and future research were discussed.

A study on OHIP-14 and EQ-5D of residents in some rural areas (일부 농촌지역 주민들의 OHIP-14와 EQ-5D에 관한 연구)

  • Lee, Eun-Gyeong;Park, Jeong-Hee;Park, Jeong-Ran;Park, Jae-Yong
    • Journal of Korean society of Dental Hygiene
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    • v.11 no.2
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    • pp.197-211
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    • 2011
  • Objectives : OHIP-14 and EQ-5D were used, targeting the residents of farming communities to identify the elements that influence oral cavity's health and quality of life due to health and to identify the importance of oral cavity's health in order to increase health of adults' oral cavity and quality of life via improved health. Methods : This research was conducted from July 17th, 2010 to August 16th, 2010 targeting 600 residents in Goryeong-gun, Gyeongsangbuk-do, aging over 40. The data has been analyzed using Mann-Whitney U test, Kruskal-Wallis test and hierarchical multiple regression through SPSS Win Program 18.0 version. Results : 1. OHIP-14 and EQ-5D based on general characteristics showed lower oral health-related quality of life and health-related quality of life on the following cases: women (p=0.004, p<0.001), older (p<0.001, p<0.001), lower scholastic ability (p<0.001, p<0.001), lower average of average spending money (p<0.001, p<0.001), higher number of chronic disease (p<0.001, p<0.001), less drinking (p=0.012, p=0.008), lower perceived oral health and health status (p<0.001, p<0.001) and non smoking showed only EQ-5D (p<0.001). 2. OHIP-14 and EQ-5D based on oral health behavior showed lower oral health-related quality of life and health-related quality of life on the following cases: no periodic oral check-up (p<0.001, p<0.001), less experience of oral health education (p<0.001, p<0.001), horizontal tooth-brushing method(p<0.001, p<0.001) and lower frequency of tooth-brushing showed only OHIP-14 (p=0.042). OHIP-14 and EQ-5D based on oral health status and subjective oral symptom showed lower oral health-related quality of life and health-related quality of life on following cases: number of existing tooth less than 20 (p<0.001, p<0.001), the number of missing teeth more than 9 (p<0.001, p=0.044), DMFT (Decay, Missing, Filling Teeth) index more than 18 (p<0.001, p<0.001), wears denture (p<0.001, p<0.001), edentulous (p<0.001, p=0.002), have xerostomia (p<0.001, p<0.001) and have chewing discomfort (p<0.001, p<0.001). 3. Factors affecting OHIP-14 were gender, age, perceived oral health status, perceived health status, number of existing teeth, dental status, xerostomia and chewing discomfort, and the of reliability (how well it explains) the final model was 48.7%. EQ-5D showed relevance on gender, age, presence of chronic disease, perceived health status, xerostomia, chewing discomfort and oral health-related quality of life, and the reliability of the final model was 42.9%. Conclusions : In order to improve the quality of life of ruralists, oral health needs to be improved or remained by increasing the rate of possession of the existing teeth and preventing the loss of teeth. In order to do so, improvement of accessibility of dental clinic, change of direction from treatment-centered to prevention-centered health care system, development of oral health education program and various oral health care policies which would vitalize continuous oral health care system are considered to be necessary.

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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Development of Traffic Volume Estimation System in Main and Branch Roads to Estimate Greenhouse Gas Emissions in Road Transportation Category (도로수송부문 온실가스 배출량 산정을 위한 간선 및 지선도로상의 교통량 추정시스템 개발)

  • Kim, Ki-Dong;Lee, Tae-Jung;Jung, Won-Seok;Kim, Dong-Sool
    • Journal of Korean Society for Atmospheric Environment
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    • v.28 no.3
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    • pp.233-248
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    • 2012
  • The national emission from energy sector accounted for 84.7% of all domestic emissions in 2007. Of the energy-use emissions, the emission from mobile source as one of key categories accounted for 19.4% and further the road transport emission occupied the most dominant portion in the category. The road transport emissions can be estimated on the basis of either the fuel consumed (Tier 1) or the distance travelled by the vehicle types and road types (higher Tiers). The latter approach must be suitable for simultaneously estimating $CO_2$, $CH_4$, and $N_2O$ emissions in local administrative districts. The objective of this study was to estimate 31 municipal GHG emissions from road transportation in Gyeonggi Province, Korea. In 2008, the municipalities were consisted of 2,014 towns expressed as Dong and Ri, the smallest administrative district unit. Since mobile sources are moving across other city and province borders, the emission estimated by fuel sold is in fact impossible to ensure consistency between neighbouring cities and provinces. On the other hand, the emission estimated by distance travelled is also impossible to acquire key activity data such as traffic volume, vehicle type and model, and road type in small towns. To solve the problem, we applied a hierarchical cluster analysis to separate town-by-town road patterns (clusters) based on a priori activity information including traffic volume, population, area, and branch road length obtained from small 151 towns. After identifying 10 road patterns, a rule building expert system was developed by visual basic application (VBA) to assort various unknown road patterns into one of 10 known patterns. The expert system was self-verified with original reference information and then objects in each homogeneous pattern were used to regress traffic volume based on the variables of population, area, and branch road length. The program was then applied to assign all the unknown towns into a known pattern and to automatically estimate traffic volumes by regression equations for each town. Further VKT (vehicle kilometer travelled) for each vehicle type in each town was calculated to be mapped by GIS (geological information system) and road transport emission on the corresponding road section was estimated by multiplying emission factors for each vehicle type. Finally all emissions from local branch roads in Gyeonggi Province could be estimated by summing up emissions from 1,902 towns where road information was registered. As a result of the study, the GHG average emission rate by the branch road transport was 6,101 kilotons of $CO_2$ equivalent per year (kt-$CO_2$ Eq/yr) and the total emissions from both main and branch roads was 24,152 kt-$CO_2$ Eq/yr in Gyeonggi Province. The ratio of branch roads emission to the total was 0.28 in 2008.

Relationship Between Job Stress and Turnover Intention Among Nurses in University Hospitals (대학병원 간호사들의 직무스트레스와 이직의도와의 관련성)

  • Shin, Hyun-Ran;Cho, Young-Chae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.8
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    • pp.3958-3970
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    • 2013
  • This study was carried out to grasp the job stress and intention to change their jobs of nurses at general hospitals by their socio-demographic, job-related and health-related behavior characteristics and especially to investigate their relationship to the job stress and intention to change their jobs. The subjects were 355 nurses working at three university hospitals located in Daejeon City, and data were collected by a survey using self-administered questionnaires structured from April 1 to May 31, 2012. As a results, the average point of the nurses' intention to change jobs by the causes for job stress was significantly higher in the boss group with low support than in that with high support while it was higher in colleague group with low support than in that with high support. To look into the correlation between the points of intention to change their jobs and the causes for job stress, their intention to change their jobs showed a significant negative correlation to the boss's support and colleagues' support while there was no significant relationship with job demands and job autonomy. As a result of hierarchical multiple regression, age, drinking coffee, department, job satisfaction, the boss's support and colleagues' support were selected as significant related variables affecting the nurses' intention to change their jobs and these variables' descriptive power was 29.4%. Viewed from the above results, it is suggested that the nurses' job stress and intention to change their jobs has a significant relationship with various variables such as socio-demographic, health-related behavior and job-related characteristics. In addition, there were a significant positive correlation between the causes for the job stress cause and intention to change their jobs, and among the causes for the job stress, support by their boss or colleagues turned out to be those affecting their intention to change their jobs. Thus, it is considered that it is necessary to minimize the nurses' job stress and at the same time to seek for specific measures for preventing their turnover.

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.