12,821 research outputs found

    Some new nonlinear retarded sum-difference inequalities with applications

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    The main objective of this paper is to establish some new retarded nonlinear sum-difference inequalities with two independent variables, which provide explicit bounds on unknown functions. These inequalities given here can be used as handy tools in the study of boundary value problems in partial difference equations. © 2011 Wang et al; licensee Springer.published_or_final_versio

    The impact of green buildings accreditation on construction and demolition waste minimization: A study of Hong Kong Building Environment Assessment Method using big data.

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    Workshop 8: WS8.12Construction and demolition (C&D) waste often constitutes a prodigious portion of the total municipal solid waste in contributing to the environment degradation. C&D waste minimization, which is a sustainable activity for both environment and material resources, serves as an indispensible element of green building assessment systems worldwide. How green building accreditation impacts on C&D waste minimization is a valid and important research question for green building award applicants, policy-makers and other stakeholders, which was seldom studied using a quantitative approach. Therefore, this paper aims to quantify the waste minimization which existing green building assessment system can be used to achieve by analyzing a big dataset of C&D waste management recorded in 2011, 2012, 2013, 2014 and 2015 in Hong Kong. The waste generation rates are compared between buildings awarded with and without Hong Kong Building Environment Assessment Method (HK-BEAM) prizes to illustrate the impact of HK-BEAM on C&D waste minimization. The research findings will not only present accurately quantified effect on CWM led by green building accreditation, but also provide stakeholders with a reference for making strategies and policies on C&D waste management and green building.preprin

    Finite-temperature Gutzwiller projection for strongly correlated electron systems

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    We generalized the Gutzwiller projectional variational method for the ground state of strongly correlated electron systems to the case of finite temperature. Under the Gutzwiller approximation, we show that this maps to a finite temperature renormalized mean-field theory. As one of the key ingredients in the theory, we obtained an explicit expression of the projection entropy or the entropy change due to the projection. We illustrate the application of the theory to the Anderson impurity problem and the half-filled Hubbard model and compare the theory to more elaborate techniques. We find qualitative agreement. The theory can be applied to a wide variety of Hubbard, t-J, and Anderson impurity models. © 2010 The American Physical Society.published_or_final_versio

    Overestimation of peer smoking prevalence predicts smoking initiation among primary school students in Hong Kong

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    Purpose: To investigate the relationship between perceived prevalence of smoking and smoking initiation among Hong Kong primary second- to fourth-grade-students. Methods: A cohort of 2,171 students was surveyed in 2006 and again in 2008. Students who perceived ever-smoking prevalence in peers as "none" or "some" were considered as correct (reference group), whereas those who perceived it as "half" (overestimation) or "most/all" (gross overestimation) were considered as incorrect. Results: At baseline, overestimation was found to be cross-sectionally associated with ever-smoking (p < .01). At follow-up, 7.2% of never-smoking students with incorrect estimation at baseline had started smoking, which was 79% (95% confidence interval: 3%-213%), greater than that of 3.7% for those with correct estimation. Among the never-smoking students with incorrect estimation, subsequent correct estimation was associated with 70% (95% confidence interval: 47%-83%) lower risk of smoking initiation compared with persistent incorrect estimation. Conclusion: Overestimation of the prevalence of peer smoking predicted smoking initiation among children. Interventions should be carried out to evaluate whether correcting children's overestimation of peer smoking could reduce smoking initiation. © 2011 Society for Adolescent Health and Medicine.postprin

    Secondhand Smoke Exposure and Health Services Use among Adolescent Current Smokers

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    Background:To investigate the associations of secondhand smoke (SHS) exposure with medical consultation and hospitalisation among adolescents in Hong Kong.Methods:A total of 35827 secondary 1 (US grade 7) to secondary 5 students from 85 randomly selected schools completed an anonymous questionnaire on smoking, SHS at home, SHS outside home, medical consultation in the past 14 days, hospitalisation in the past 12 months, and socio-demographic characteristics. Current smoking was defined as any smoking in the past 30 days. SHS exposure was classified as none (reference), 1-4 and 5-7 days/week. Logistic regression yielded adjusted odds ratios (AORs) for medical consultation and hospitalisation in relation to SHS exposure at home and outside home in current smokers. Analyses were also done among never-smokers for comparison.Results:Among all students, 15.9% had medical consultation and 5.2% had been hospitalised. Any SHS exposure at home was associated with AORs (95% CI) for medical consultation and hospitalisation of 1.69 (1.14-2.51) and 2.85 (1.47-5.52) in current smokers, and 1.03 (0.91-1.15) and 1.25 (1.02-1.54) in never-smokers, respectively, (P<0.01 for interaction between smoking status and SHS exposure at home). SHS exposure outside home was generally not associated with medical consultation and hospitalisation in smokers and never-smokers.Conclusions:SHS exposure at home was associated with health services use among adolescent current smokers. Adolescent smokers should be aware of the harm of SHS in addition to that from their own smoking. The evidence helps health care professionals to advise adolescent smokers to avoid SHS exposure and stop smoking. © 2013 Wang et al.published_or_final_versio

    Ethics of Artificial Intelligence Demarcations

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    In this paper we present a set of key demarcations, particularly important when discussing ethical and societal issues of current AI research and applications. Properly distinguishing issues and concerns related to Artificial General Intelligence and weak AI, between symbolic and connectionist AI, AI methods, data and applications are prerequisites for an informed debate. Such demarcations would not only facilitate much-needed discussions on ethics on current AI technologies and research. In addition sufficiently establishing such demarcations would also enhance knowledge-sharing and support rigor in interdisciplinary research between technical and social sciences.Comment: Proceedings of the Norwegian AI Symposium 2019 (NAIS 2019), Trondheim, Norwa

    Independent association between parental smoking and non-authoritative parenting style as reported by Chinese adolescents in Hong Kong

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    Poster Discussion 35. Engaging New Partners: no. PD-1005-20Conference Theme: Tobacco and Non-Communicable DiseasesBACKGROUND: Both parental smoking and non-authoritative parenting style predict adolescent smoking, but the association between the two risk factors was seldom studied. We investigated this association in Chinese parents of adolescents in Hong Kong, where smoking is socially undesirable, especially in females. DESIGN/METHODS: In the Hong Kong Student Obesity Surveillance project 2006/07, 33692 adolescents aged 11-18 (44.9% boys, mean age 14.8, SD 1.9 years) from 42 randomly selected schools reported smoking status (yes vs no) and the level (frequent/sometimes as high; seldom/none as low) of care and control of each parent. Parenting style (dependent variable) was defined as authoritative …published_or_final_versio

    A School-based Survey on Adolescent Alcohol Drinking in Hong Kong

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    Symposium Theme: Translating Health Research into Policy and Practice for Health of the PopulationParallel Session 1 - Population Health & Policy: no. S2INTRODUCTION: The effective control of underage drinking requires a thorough understanding of its risk factors and effects, but little is known about the drinking pattern in Hong Kong adolescents. OBJECTIVES: We investigated the drinking pattern and associated risk factors and problems in Hong Kong secondary school students. METHODS: In a territory-wide survey of 44 randomly selected schools, 21627 Secondary 1 to 6 students (mean age 14.7, SD 1.8; 51.6% boys) provided valid data using an anonymous questionnaire in 2012-13. Data on socio-demographic characteristics, alcohol drinking, peer and co-residents’ drinking, exposure to pro-drinking and anti-drinking messages, parental pro-drinking practices and health outcomes were collected. Descriptive data were weighted by sex, age and grade distribution of students in Hong Kong. Risk factors and problems associated with adolescent drinking were …published_or_final_versio
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