Background : We assessed direct effects of neighborhood-level characteristics and interactive effects of neighborhood-level characteristics and individual socioeconomic position on adult smoking and drinking, after consideration of individual-level characteristics in Taiwan.

This study suggests a multivariate-structural approach combining factor analysis and cluster analysis that could be used to examine neighborhood effects on an individual's health. Data were from the Taiwan Social Change Survey conducted in 1990, 1995, and 2000. In total, 5,784 women and men aged over 20 years living in 428 neighborhoods were interviewed. Participants' addresses were geocoded with census data for measuring neighborhood-level characteristics. The factor analysis was applied to identify neighborhood dimensions, which were used as entities in the cluster analysis to generate a neighborhood typology. The factor analysis generated three neighborhood dimensions: neighborhood education, age structure, and neighborhood family structure and employment. The cluster analysis generated six types of neighborhoods with combinations of the three neighborhood dimensions. Multilevel binomial regression models were used to assess the effects of neighborhoods on an individual's health. The results showed that the biggest health differences were between two neighborhood types: (1) the highest concentration of inhabitants younger than 15 years, a moderate education level, and a moderate level of single-parent families and (2) the highest educational level, a median level of single-parent families, and a median level of elderly concentrations. Individuals living in the first type had significantly higher chances of having functional limitations and poor self-rated health than the individuals in the second neighborhood type. Our study suggests that the multivariate-structural approach improves neighborhood measurements by addressing neighborhood diversity and examining how an individual's health varies in different neighborhood contexts.

A proton exchange membrane of poly (vinylidene fluoride) grafted onto poly (2-acrylamido-2-methylpropane sulfonic acid) (PVDF-g-PAMPS) was prepared as follows: acrylamido-2-methylpropane sulfonic acid (AMPS) was first added to a N-Methyl pyrrolidone (NMP) solution containing poly (vinylidene fluoride) (PVDF) that was modified with plain sodium silicate. Ammonium persulfate was then added as an evocating agent and PAMPS was directly grafted onto the PVDF that was modified with plain sodium silicate. The influences of AMPS contents on the proton conductivity and mechanical properties were studied. The results showed that AMPS is easily grafted into PVDF modified by Plain sodium silicate (Na4SiO4) and mechanical properties were improved, with increasing of the content of 2-acrylamido-2-methylpropane sulfonic acid, the proton conductivity of PVDF-g-PAMPS membranes was increased.

The implicit parametric method was briefly discussed in this paper. An implicit parametric 3D solid model and a finite element (FE) model of a body-in-white (BIW) were built up by this method. Low order natural vibration frequencies and modes, bending and torsional stiffness of the BIW were analyzed by FE calculation. A good agreement was acquired by comparing the prediction results with the test values. Results indicated that the implicit parametric model of the BIW established could be used for design and development of the BIW in concept design stage of the BIW.

The three-dimensional time domain parabolic equation (3D-TDPE) is derived to simulate the EM pulse propagation in straight, curved tunnels. Then the finite differential (FD) method is applied to accurately and flexibly describe the fine structures in the tunnel, such as cars. By using the alternating direction implicit (ADI) scheme to the spatial unknowns, the TDPE can be solved line by line in each transverse plane at any time step. More specifically, the computational efficiency can be improved significantly since a three-dimensional problem is changed into several one-dimensional problems. Moreover, both the Dirichlet and Neumann boundary conditions are used to estimate the transmission loss in tunnels. The rigorous numerical method, finite difference time domain (FDTD), is applied to verify the accuracy and efficiency of the proposed method. Numerical results are given to demonstrate that the proposed 3D-ADI-TDPE method can be used as an efficient tool to predict EM pulse propagation in tunnels including fine barriers.INDEX TERMS Time domain parabolic equation, electromagnetic pulse propagating, alternating direction implicit, finite differential method.