University of Minnesota

About: University of Minnesota is a education organization based out in Minneapolis, Minnesota, United States. It is known for research contribution in the topics: Population & Transplantation. The organization has 117432 authors who have published 257986 publications receiving 11944239 citations. The organization is also known as: University of Minnesota, Twin Cities & University of Minnesota-Twin Cities.

Enthalpy-porosity technique for modeling convection-diffusion phase change: application to the melting of a pure metal

Abstract: The melting of pure gallium in a rectangular cavity has been numerically investigated using the enthalpy-porosity approach for modeling combined convection-diffusion phase change. The major advantage of this technique is that it allows a fixed-grid solution of the coupled momentum and energy equations to be undertaken without resorting to variable transformations. In this work, a two-dimensional dynamic model is used and the influence of laminar natural-convection flow on the melting process is considered. Excellent agreement exists between the numerical predictions and experimental results available in the literature. The enthalpy-porosity approach has been found to converge rapidly, and is capable of producing accurate results for both the position and morphology of the melt front at different times with relatively modest computational requirements. These results may be taken to be a sound validation of this technique for modeling isothermal phase changes in metallurgical systems.

Wireless multicarrier communications

Abstract: Relying on basic tools such as eigensignals of linear time-invariant systems, linear and circular block convolution, and fast Fourier transforms (FFTs), this article develops a systematic discrete-time framework and designs novel systems for single- and multiuser wireless multicarrier communications-a field rich in signal processing challenges that holds great potential in various applications including audio/video broadcasting, cable television, modem design, multimedia services, mobile local area networks, and future-generation wideband cellular systems. Wireless multicarrier (MC) communication systems utilize multiple complex exponentials as information-bearing carriers. MC transmissions thus retain their shape and orthogonality when propagating through linear time-dispersive media, precisely as eigensignals do when they pass through linear time-invariant (LTI) systems.

Knowledge Sharing in Organizations: A Conceptual Framework

Abstract: Knowledge is now being seen as the most important strategic resource in organizations, and the management of this knowledge is considered critical to organizational success. If organizations have to capitalize on the knowledge they possess, they have to understand how knowledge is created, shared, and used within the organization. Knowledge exists and is shared at different levels in organizations. This article examines knowledge sharing at the most basic level; namely, between individuals in organizations. Based on a review of existing literature in this area, this article presents a model that identifies factors that most significantly influence knowledge sharing at this level.

Personality and transformational and transactional leadership: a meta-analysis.

Abstract: This study was a meta-analysis of the relationship between personality and ratings of transformational and transactional leadership behaviors. Using the 5-factor model of personality as an organizing framework, the authors accumulated 384 correlations from 26 independent studies. Personality traits were related to 3 dimensions of transformational leadership—idealized influence–inspirational motivation (charisma), intellectual stimulation, and individualized consideration—and 3 dimensions of transactional leadership— contingent reward, management by exception–active, and passive leadership. Extraversion was the strongest and most consistent correlate of transformational leadership. Although results provided some support for the dispositional basis of transformational leadership— especially with respect to the charisma dimension— generally, weak associations suggested the importance of future research to focus on both narrower personality traits and nondispositional determinants of transformational and transactional leadership. A recent PsycINFO search revealed that 1,738 of the 15,000 articles (12%) published since 1990 on the topic of leadership included the keywords personality and leadership. Clearly, scholars have a strong and continuing interest in the dispositional bases of leadership behavior. Indeed, a meta-analysis by Lord, DeVader, and Alliger (1986) reported some associations between personality traits and perceptions of leadership. A more recent meta-analysis (Judge, Bono, Ilies, & Gerhardt, 2002) further advanced this literature, providing evidence that some traits were consistently associated with leadership emergence and effectiveness. Although these meta-analyses made an important contribution to our knowledge of the link between personality and leadership, they do not address the relationship between personality and transformational, transactional, and charismatic leadership. Given the volume of recent research attention focused on these types of leadership, it is important to understand the dispositional bases of transformational and transactional leadership. The purpose of this article was to extend what is known about the association between personality and leadership by focusing directly on the relationship between personality and the eight dimensions of transformational and transactional leadership. These leadership dimensions have been found to be valid predictors of follower job performance and satisfaction (see Fuller, Patterson, Hester, & Stringer, 1996; Lowe, Kroeck, & Sivasubramaniam, 1996). Thus, understanding the personality traits associated with transformational and charismatic leadership has important implications for the selection, training, and development of such leaders. For example, if charisma is linked to stable traits of the individual, organizations may wish to select leaders with these traits. Barling, Weber, and Kelloway (1996) demonstrated that some transformational leadership behaviors can be trained. Thus, an understanding of the role of personality can aid in determining which individuals might gain the most from such training and how training approaches might differ on the basis of trainee personality (i.e., aptitude by treatment interaction).