Search

In order to explore the geometric characteristics of the dynamic balance positions of balls in any orbit in space, this paper first deduces the dynamic equilibrium equations of an eccentric rotor system with the automatic ball balancer (ABB) skew, mounted with a deflection angle from the perspective of three-dimensional (3D) dynamics. The results obtained are consistent with those derived from the Euler–Lagrange equations. It is exciting that the spatial dynamics method reveals the spatial-geometric characteristics of dynamic balance positioning of the balls when the system is balanced with vibration suppression. Then, through spatial geometric inference, it is proved that the balance positioning of any ball in an arbitrary curved track is characterized. This characteristic indicates that the perpendicular line from any balance position to the rotating spindle of the system must pass through the central axis of curvature of the track at that position. Finally, spatial graphics and numerical analysis are used to verify the theoretical correctness. The characteristics are general rules that can explain the phenomena of the stable equilibrium positions of the balls in previous studies under ideal assumptions. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to explore the ways in which social smoking expectations mediate the relationship between adolescent smoking behaviour and the smoking behaviour of family and peers. Design: Descriptive, cross-sectional survey. Setting: Taiwan, Republic of China. Method: The participants were 921 senior high school students who completed a questionnaire to measure smoking status, family and peer smoking and social smoking expectations. The survey was conducted from November to December in 2009. Structural equation modelling was performed to test a mediation model. Analysis was performed using PRELIS 2 and LISREL 8.7 software. Results: After adjusting for students' gender, age and school type, it is clear that social expectations mediate the relationship between sibling smoking, peer smoking and adolescent smoking. The path coefficients of sibling and peer smoking on social expectations in the mediator model were moderate, ß = 0.15-0.41, p < 0.05, but the coefficient of social expectations on adolescent smoking was strong, ß = 0.95, p < 0.001. The total indirect effects between exogenous latent variables and adolescent smoking were 0.54, indicating a strong association that, in this model, is explained by the mediation of social expectations. Conclusion: Determining the mechanisms that influence adolescent smoking is of scientific interest because knowledge of these mechanisms is a prerequisite for the development of recommendations aimed at prevention. With this knowledge, health professionals can develop smoking-prevention policies and education programmes based on reducing the mediating effect of social smoking expectations on the relationship of family smoking and peer smoking with adolescent smoking.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.addbeh.2006.02.024 Byline: Chih-Ling Huang (a)(b), Hsi-Hui Lin (a), Hsiu-Hung Wang (b) Keywords: Nicotine dependence; Biomarker; Psychometrics Abstract: This study examined the psychometric properties of the Chinese version of the Fagerstrom Test for Nicotine Dependence (FTND). Criterion validity, factorial structure, and construct reliability were conducted using PRELIS 2 and LISREL 8.7 software. Two hundred and forty-five adult smokers were recruited from April to August 2005 in Taiwan. Because some items of the FTND are dichotomous and ordinal, biserial and polyserial correlations between the items and saliva cotinine levels were utilized. Confirmatory factor analyses (CFA) were performed to compare the relative fit of three competing models. Computation of the construct reliability was necessitated by a lack of tau-equivalence. The results demonstrated that the Chinese version has satisfactory validity and reliability. One item, 'Smoke more in the morning,' had low correlations with saliva cotinine. CFA found the items of the Chinese version were best modeled as two correlated factors without a cross-loading. These findings differ from the previous research testing the English version. Studies addressing the specific features of cigarette dependence in different socio-cultural contexts are needed. Author Affiliation: (a) Department of Nursing, Chang Jung University, Taiwan (b) College of Nursing, Kaohsiung Medical University, No. 100 Shih-Chuan 1st Road, San-Ming District, Kaoshiung 807, Taiwan