Individual and structural origins of friendship and social position among professionals.

Friendship affects individual and organizational well-being through direct relations, social positions, and complex network structures. In this study, the authors use longitudinal data from 2 groups of master's of business administration students to increase understanding of how friendship networks develop. The authors propose and test a dynamic model in which attribute similarity facilitates dyadic friendship ties, as well as similar network centrality and social position; early friendship increases later similarity in structural position and centrality; and early structural similarity enhances the likelihood of future friendship. Findings largely supported the model, demonstrating how homophily and early social contacts can jointly shape maturing friendship networks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Extended definition TV over an analog FM satellite channel

The performance of several extended definition TV (EDTV) formats are compared in terms of signal-to-noise ratio (SNR) operation in an analog FM satellite channel. The formats considered are the National Television System Committee (NTSC), extended NTSC (ENTSC), multiplexed analog components (MAC), and extend MAC (EMAC). These formats are compared in terms of SNR above and below the FM threshold. Analytically derived curves which show the luminance and chrominance SNR as a function of horizontal resolution for the above-threshold operation are presented. The effect of group delay on the composite video formats is determined for an actual satellite channel. The below-threshold performances for NTSC and MAC are compared in the luminance channel     

Electron mobility enhancement in strained-Si n-typemetal-oxide-semiconductor field-effect transistors

Enhanced performance is demonstrated in n-type metal-oxide-semiconductor field-effect transistors with channel regions formed by pseudomorphic growth of strained Si on relaxed Si_1-xGe_x. Standard MOS fabrication techniques were utilized, including thermal oxidation of the strained Si. Surface channel devices show low-field mobility enhancements of 80% at room temperature and 12% at 10 K, when compared to control devices fabricated in Czochralski Si. Similar enhancements are observed in the device transconductance. In addition, buried channel devices show peak room temperature mobilities about three times that of control devices