Social Network Analysis in an Extended Structural Equation Modeling Framework

A primary focus of social network analysis (SNA) is to understand actor attributes from social structures in a network. It is an interdisciplinary research topic of statistics, sociology, graph theories, and computer sciences. Despite its popularity in other fields, SNA is under-utilized in psychological and educational research. This is largely due to the lack of easy-to-use models and user-friendly software. To fill the gap, this dissertation proposes three models for SNA under an extended structural equation modeling (SEM) framework. The first model is a latent space model with a factor structure. In this model, a social network is the outcome variable and the model intends to identify covariates predicting a network. As a generalization of the first model, the second model focuses on social networks with ordinal relations among actors. A Probit regression model is used to study the association of an ordinal social network and covariates. Both models are estimated using a two-stage maximum likelihood (ML) method. The performance of the two-stage ML method is assessed through Monte Carlo simulation studies. Simulation results show that the two-stage ML method can recover both model parameters and standard errors. The third model is a mediation model with a social network as a mediator. In this model, a latent space model is used to extract underlying factors of a social network, which directly participate in the causal process between two variables. To estimate the model, a Bayesian estimation method is used and its performance is evaluated through a simulation study. The usefulness of three models is demonstrated in analyzing a friendship network data set.</p

The influence of the information disseminatioin rate <i>β</i>_<i>I</i> on .

The influence of the information disseminatioin rate βI on .</p

Sensitivity index of each variable to .

Sensitivity index of each variable to .</p

Copper-Catalyzed Construction of Benzo[4,5]imidazo[2,1‑<i>a</i>]isoquinolines Using Calcium Carbide as a Solid Alkyne Source

A method for the synthesis of benzo­[4,5]­imidazo­[2,1-a]­isoquinolines through Sonogashira cross-coupling/nucleophilic addition tandem reactions using calcium carbide as a solid alkyne source, 2-(2-bromophenyl)­benzimidazoles as starting materials, and copper as a catalyst is described. The target products can also be synthesized through one-pot three-component reactions of o-phenylenediamines, o-bromobenzaldehydes, and calcium carbide. Both reaction routes can also be scaled up to gram scale

Sensitivity index of each variable to .

Sensitivity index of each variable to .</p

Sensitivity index of each variable to .

Sensitivity index of each variable to .</p

Sensitivity index of each variable to .

Sensitivity index of each variable to .</p

The influence of epidemic recovery rate <i>μ</i>_<i>E</i> values on .

The influence of epidemic recovery rate μE values on .</p

Sensitivity index of each variable to .

Sensitivity index of each variable to .</p

Fig 1 -

(a) Each individual has the same interaction radius. (b) Each individual has a heterogeneous interaction radius.</p