• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.1181-1187
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• 2012

The depression of the elderly decreases satisfaction in life and is also an important risky factor of their suicide. The subjects of the study were 615 males and 904 females aged above 65 who had the 2008 Korea National Health and Nutrition Examination Survey on the relations between presence of spouses and depression given by the Korea Center for Disease Control and Prevention. Through a chi-square test and a multiple logistic regression, the relations between general characteristics, contraction, health characteristics and depression were analysed. As a result of the multiple logistic regression for which age, family income, subjective health status, presence of activity limitation and stress were revised, the odds ratio of the males without spouses was 2.37(95% CI 1.03-5.45), which indicates that they had more depression than female subjects. However, for the female subjects, there were no relations between presence of spouses and depression.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8A
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• pp.814-819
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• 2006

This paper presents the impacts of Ultra Wide-Band(UWB) system applied in Indoor and Handhold communications using frequency band from 3.1 GHz to 10.6 GHz on Wireless Broad-band(WiBro) system based on Orthogonal Frequency Division Multiplexing(OFDM) using frequency of 2.3 GHz. The Minimum Coupling Loss(MCL) method for the case of single interference and Monte Carlo(MC) simulation for multiple interference considering practical scenario were used to evaluate the interference effects of UWB system on WiBro system. As a result, the minimum separation distance between single interferer and the victim receiver required 34.4 m and above to guarantee the co-existence. Also, the UWB transmitting PSD of around - 81 dBm / MHz below should be required to meet the minimum throughput loss of WiBro mobile station in case of multiple UWB interference.

• Korean Journal of Health Education and Promotion
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• v.9 no.2
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• pp.64-71
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• 1992

The purpose of this study is to investigate the standard weight and the perception of the figure, making girls' high school students the object of scientific study. Furthemore this study will try to find the factor having an effect on the weight through measuring the concern with appearance and health. The study consisted of 658 girls' high school students in Seoul. The data was analyzed by the methods of frequency, percentage, reliability, pearson's correlation coefficient and multiple regression analysis. The results of this study are as follows : 1. The standard size of girls height was 160.95cm, their weight was 52.06kg. 2. 34 percent of the girls tested perceived of themselves of having proper figures. Especially in the case of overweight girls. Only 9.7 percent of girls were satisfied with their figure, the other 83.3 percent were not. 3. 88.4 percent of the girls were concerned with their weight. It was through mass communecation that girls were concerned with wheir weight. 41.2 percent of the girls were concerned with weight much more through mass communication than through any other things. This showed that the effect of mass communication on juveniles was increased. 4. The result of correlation of variable about the concern with appearance(p<0.001), the perception of their figures(p<0.001), the existence of weight controller in friends (p<0.001) and the concern with health(p<0.001) indicated significant positive correlation, on the other hand, the satisfaction of their figures(p<0.001) indicated negative correlation. This showed that the less satisfactory their figures were, the higher their concern about weight was. 5. In order th seize the variable having an effect on the concern with weight, the result of multiple regression analysis was that the concern with appearance (p<0.001), the satisfaction of figure (p<0.001), the concern with health (p<0.05), poket money (p<0.05) and health condition (p<0.05) had a statistically significant effect and the variables also 35.7% out of this model. Concern with appearance had the most important effect of all these variables.

• Journal of Preventive Medicine and Public Health
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• v.41 no.1
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• pp.1-9
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• 2008

Objectives : This study evaluated knowledge structure and its effect factor by analysis of co-author and keyword networks in Korea's preventive medicine sector. Methods : The data was extracted from 873 papers listed in the Journal of Preventive Medicine and Public Health, and was transformed into a co-author and keyword matrix where the existence of a 'link' was judged by impact factors calculated by the weight value of the role and rate of author participation. Research achievement was dependent upon the author's status and networking index, as analyzed by neighborhood degree, multidimensional scaling, correspondence analysis, and multiple regression. Results : Co-author networks developed as randomness network in the center of a few high-productivity researchers. In particular, closeness centrality was more developed than degree centrality. Also, power law distribution was discovered in impact factor and research productivity by college affiliation. In multiple regression, the effect of the author's role was significant in both the impact factor calculated by the participatory rate and the number of listed articles. However, the number of listed articles varied by sex. Conclusions : This study shows that the small world phenomenon exists in co-author and keyword networks in a journal, as in citation networks. However, the differentiation of knowledge structure in the field of preventive medicine was relatively restricted by specialization.

• Journal of Preventive Medicine and Public Health
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• v.46 no.1
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• pp.28-38
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• 2013

Objectives: This study aimed to collect information that will help enhance the social networks and improve the quality of life among elderly people by observing the relationship between their social network and health-related quality of life (HRQoL) and by analyzing social network factors affecting HRQoL. Methods: This study was based on the 2008 Community Health Survey in Yeoncheon County. Three hundred elders were included in the study population. We compared the revised Lubben Social Network Scale (LSNS-R) score and Euro quality of life-5 dimensions health status index by demographic characteristics and chronic disease prevalence. We analyzed the data using multiple regression and tobit regression by setting the HRQoL as the dependent variable and social network and other characteristics as the independent variables. We analyzed social network factors by using factor analysis. Results: The LSNS-R score differed significantly according to age and existence of a spouse. According to the results from the hierarchical multiple regression analysis, the LSNS-R explained 0.10 of the variance and LSNS-R friends factor explained 0.10 of the variance. The tobit regression indicated that the contribution of the LSNS-R family size factor to the regression coefficient of the independent variable that affected the HRQoL was $B_T$=2.96, that of the LSNS-R family frequency factor was $B_T$=3.60, and that of LSNS-R friends factor was $B_T$=5.41. Conclusions: Social networks among elderly people had a significant effect on HRQoL and their networks of friends had a relatively higher effect than those of family members.

• Journal of Korean society of Dental Hygiene
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• v.12 no.4
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• pp.827-837
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• 2012

Objectives : The purpose of this study was to investigate the knowledge, attitudes, and practices of dental health care among the teachers at local children centers. Methods : The author administered a questionnaire with 105 teachers while undergoing his/her teacher's internship at a Local Center for Children's Welfare in Daegu, from Feb 18th to Feb 20th, 2011. The statistical techniques as frequencies and means, t-test, ANOVA, Pearson's Correlation Coefficient and multiple regression with the PASW 18.0 program were used to analyze the data. Results : The knowledge, attitudes, and practice of dental health care was average 19.1 point in knowledge, average 7.8 point in attitudes, average 11.9 point practically high in gender role values. The multiple regression results related each variable to practice of dental health, the practice is significant associated to oral health education, children's dental check-up opportunities, and the higher score attitude of dental health care. Based on the results of this study mentioned so far, the teacher's practices of administering the oral hygiene is deemed to be influenced by the existence of their experiences in the oral hygiene educations, and their attitudes on the subject. Conclusions : t is, therefore, just to provide an education program about dental health care of the children to the teachers on consistent base, in order to assist them to develop an appropriate attitude which would lead to better practices.

• Health Policy and Management
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• v.26 no.4
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• pp.325-332
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• 2016

Background: Workplace violence was recognized to be social problems that might impact the health status and the job satisfaction of employee in hospitals. This study investigated the current status of violence and job stress among hospital employees working at administration and discharging department. Methods: The study subjects were 213 administrative employees working at 20 general hospitals. Data were collected by self-administered questionnaire that included information such as demographics, job-related characteristics, experience of violence, and job stress. The violence was classified as verbal violence, physical threat, and physical violence occurred by patients and caregivers. Analysis of variance, t-tests, correlation analysis, and multiple linear regression analysis were performed to examine the associated factors with job stress. Results: The levels of verbal violence, physical threat, and physical violence were $1.64{\pm}1.08$, $0.54{\pm}0.67$, and $0.04{\pm}0.17$, respectively. The score of job stress was $2.74{\pm}0.50$ and it was associated with age, existence of spouse, drinking frequency, subjective health status, disease history, night-time treatment, and public health administration career in simple analysis. In multiple linear regression analysis, the level of verbal violence experience was significantly associated with job stress (B=0.09, p=0.001). Also physical threats (B=0.18, p<0.001) and physical violence (B=0.48, p=0.008) showed positive association with job stress. Conclusion: This study attempted to examine the association between experience of violence and job stress in administrative employees at medical institutions. Levels of violence showed positive correlation with the job stress. Environment improvement to protect employee from violence and management of employees who experienced workplace violence are needed to reduce the job stress.

• Korean Journal of Social Welfare
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• v.50
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• pp.157-172
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• 2002

Most of existing studies about employment of people with disabilities have regarded the disabled groups as only one group which has different characteristics respectively. In fact, each of the disabled groups have several peculiarities of their own. So government or policy makers must regard the disabled group as different groups which have their own characteristics(example : education level, house income, wage, working hours, satisfaction level for their job, disability type and degree, service year in a firm, etc) for promoting employment of the disabled effectively and keeping their job continuously. In this study, we examine and verify the existence of segmentations in Korea labor market of the disabled according to their different education level & sex by using MDFA(Multiple Discriminant Function Analysis technique) and seek solutions for easing those segmentations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.3
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• pp.1164-1183
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• 2019

The rapid development of cloud computing and high requirements of operators requires strong support from the underlying Data Center Networks. Therefore, the effectiveness of using resources in the data center networks becomes a point of concern for operators and material for research. In this paper, we discuss the online virtual-cluster provision problem for multiple tenants with an aim to decide when and where the virtual cluster should be placed in a data center network. Our objective is maximizing the total revenue for the data center networks under the constraints. In order to solve this problem, this paper divides it into two parts: online multi-tenancy scheduling and virtual cluster placement. The first part aims to determine the scheduling orders for the multiple tenants, and the second part aims to determine the locations of virtual machines. We first approach the problem by using the variational inequality model and discuss the existence of the optimal solution. After that, we prove that provisioning virtual clusters for a multi-tenant data center network that maximizes revenue is NP-hard. Due to the complexity of this problem, an efficient heuristic algorithm OMS (Online Multi-tenancy Scheduling) is proposed to solve the online multi-tenancy scheduling problem. We further explore the virtual cluster placement problem based on the OMS and propose a novel algorithm during the virtual machine placement. We evaluate our algorithms through a series of simulations, and the simulations results demonstrate that OMS can significantly increase the efficiency and total revenue for the data centers.

• The korean journal of orthodontics
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• v.53 no.2
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• pp.89-98
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• 2023

Objective: This study aimed to compare the mechanical and thermal properties in the anterior and posterior segments of new and retrieved specimens of a commercially available multizone superelastic nickel-titanium (NiTi) archwire. Methods: The following groups of 0.016 × 0.022-inch Bioforce NiTi archwires were compared: a) anterior and b) posterior segments of new specimens and c) anterior and d) posterior segments of retrieved specimens. Six specimens were evaluated in each group, by three-point bending and bend and free recovery tests. Bending moduli (Eb) were calculated. Furthermore, the new specimens were evaluated with scanning electron microscopy/energy-dispersive X-ray spectrometry. A multiple linear regression model with a random intercept at the wire level was applied for data analysis. Results: The forces in the posterior segments or new specimens were higher than those recorded in the anterior segments or retrieved specimens, respectively. Accordingly, Eb also varied. Higher austenite start and austenite finish (Af) temperatures were recorded in the anterior segments. No statistically significant differences were found for these temperatures between retrieved and new wires. The mean elemental composition was (weight percentage): Ni, 52.6 ± 0.5; Ti, 47.4 ± 0.5. Conclusions: The existence of multiple force zones was confirmed in new and retrieved Bioforce archwires. The retrieved archwires demonstrated lower forces during the initial stages of deactivation in three-point bending tests, compared with new specimens. The Af temperature of these archwires may lie higher than the regular intraoral temperature. Even at 2 mm deflections, the forces recorded from these archwires may lie beyond biologically safe limits.