Consistent Digital Curved Rays and Pseudoline Arrangements

Representing a family of geometric objects in the digital world where each object is represented by a set of pixels is a basic problem in graphics and computational geometry. One important criterion is the consistency, where the intersection pattern of the objects should be consistent with axioms of the Euclidean geometry, e.g., the intersection of two lines should be a single connected component. Previously, the set of linear rays and segments has been considered. In this paper, we extended this theory to families of curved rays going through the origin. We further consider some psudoline arrangements obtained as unions of such families of rays

공중보건사업의 수용과 위험인식 : 인천지역 수돗물 불소농도조정사업의 인식도 조사 사례연구

학위논문 (석사)-- 서울대학교 보건대학원 : 보건학과 보건정책관리학 전공, 2016. 2. 유명순.The scope of public health services is expanding in the complex modern society. Health-related information spread rampantly, especially the issues surrounding health safety and effectiveness. Water fluoridation is one example. Initiated in the United States (U.S.) in 1945, the Korean government also implemented this service and the controversy about its political, moral, ethical, and safety issues still remain elusive in many countries that have taken the measures including the U.S. and South Korea. Many studies have conducted the analysis of health benefit/risk, cost-effectiveness, and awareness of water fluoridation, but much less have been focused on the in-depth investigation into sociological reasons behind the two opposing views. It is important to know how the public perceives water fluoridation and find the effective ways of proper public health communication. Therefore, this study is focused on the risk perception of water fluoridation and its effects on the public in deciding whether to accept or reject the service. The data were collected with an online cross-sectional questionnaire survey on 527 Korean citizens in October, 2015. The participants were residents in the city of Incheon who are 20 to 59 in age. The components of the survey include individual characteristics (knowledge, experience, and worldview), media, outrage factor, trust, risk perception, and the acceptance level of water fluoridation service. Correlation analysis and multiple regression analyses were performed to explore the factors influencing water fluoridation risk perception and the acceptance level of water fluoridation service. The mediating effect of water fluoridation risk perception was validated by hierarchical multiple regression analysis and sobel test. The mean age of the study participants was 40 years, with the proportion of men (51%) and women (49%). The mean water fluoridation risk perception was 4.12 (out of 7 interval scale), 59% (ratio scale), with 0.69 standard deviation (SD). The mean acceptance level of water fluoridation was 4.12 (out of 7 interval scale), 59% (ratio scale), with 1.29 SD. Analysis showed that media, outrage factor, and trust were significantly predictive of water fluoridation risk perception and the service acceptance. Moreover, risk perception of water fluoridation partially mediated the service acceptance. This is the first study in South Korea which attempted to determine the influencing factors of acceptance level of water fluoridation service and its risk perception through the analysis of a survey in the city where controversy exists. The findings suggest that considering the risk perception of the individuals is critical in the process of developing public health services and policies. Also planning health communication strategies are necessary to build an effective public health system.1. Introduction 1 1.1 Background 1 1.2 Study objective 6 2. Literature Review 7 2.1 Issue Description and historical background 7 2.1.1 Water fluoridation controversy 7 2.1.2 History of water fluoridation in South Korea 9 2.2 Key variables 15 2.2.1 Independent variables 15 2.2.2 Mediator variable 22 2.2.3 Dependent variable 26 3. Methods 29 3.1 Data collection 30 3.2 Study design 32 3.3 Main variables 34 4. Study Results 38 4.1 Basic statistical results 38 4.2 Pearson correlation analysis of the study population 41 4.3 Affecting factors of the study population 43 4.4 Mediating effect of risk perception 47 5. Discussion and Conclusion 51 5.1 Risk perception and acceptance of water fluoridation 52 5.2 Implications 55 5.3 Limitations 59 Bibliography 60 Appendix 70 1. Survey questionnaire 70 2. Places implementing water fluoridation in South Korea 80 3. Worldview 83 4. Outrage factors 84 Abstract (Korean) 85Maste

Career Development for Youth with Disabilities in South Korea: The Intersection of Culture, Theory, and Policy

Youth with disabilities face difficulties resulting from attitudinal, environmental, and organizational barriers not only in initially accessing and entering school (World Health Organization [WHO], 2011), but also as they transition from school age youth to working adults.  With a focus on facilitating a better understanding of the issues, challenges, and solutions associated with the design and implementation of career development services for youth with disabilities, this article describes the status quo for students with disabilities in South Korea and then discusses career development services that potentially reduce variation, help facilitate optimal career development, and promote future employment opportunities.  To accomplish this task, we explore the intersection of culture, theory, and policy in the Korean transition service delivery system

Algorithms for computing the optimal image segmentation of nonintersecting union of base monotone regions

info:eu-repo/semantics/publishe

Consistent digital rays

Proceedings of the 24th Symposium on Computational geometry (SoCG’08)info:eu-repo/semantics/publishe

Algorithms for computing the maximum weight region decomposable into elementary shapes

Proceedings of the 20th International Symposium on Algorithms and Computation (ISAAC’09)info:eu-repo/semantics/publishe