This paper describes an improved model for multiple building diffraction modeling based on the uniform theory of diffraction (UTD). A well-known problem in conventional uniform theory of diffraction (CUTD) is multiple-edge transition zone diffraction. Here, higher order diffracted fields are used in order to improve the result; hence, we use higher order diffraction coefficients to improve a hy...

in this paper, a new propagation model based on utd for multiple diffraction paths in cellular mobile radio communications in urban environments is proposed. moreover, the most rigorous novel utd-based expressions for multiple diffractions by buildings and excess path losses are d - rived and analyzed. for this purpose, building rows are supposed to have rectangular cross-sections with the same...

i * Corresponding Author, A. Tajvidy is with the Department of Electrical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran (e-mail: [email protected]). ii A. Ghorbani is with the Department of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran (e-mail: [email protected]). iii M. Nasermoghaddasi is with the Department of Electrical Engin...

This paper introduces the study of group work pressure (GWP) in information technology (IT) task groups. We theorize that GWP arises from demands and resources in group work and that high levels of GWP inhibit group performance. To identify the constructs of a new group task demands-resources (GTD-R) model, we solicit subjects’ descriptions of factors associated with high and low pressure group...

The Choice of Plausible Alternatives (COPA) task in SemEval-2012 presents a series of forced-choice questions wherein each question provides a premise and two viable cause or effect scenarios. The correct answer is the cause or effect that is the most plausible. This paper describes the COPACETIC system developed by the University of Texas at Dallas (UTD) for this task. We approach this task by...

A ray tracing model based on the application of the uniform theory of diffraction (UTD) and geometrical optics (GO) for modeling the propagation in the microcellular urban scenarios has been implemented. This model has been used to analyze the behavior of the rms delay spread while turning a corner in two street-corner environmentsregular and chaflane street corners. The study of the environmen...

We present a joint approach for recognizing spatial roles in SemEval-2012 Task 3. Candidate spatial relations, in the form of triples, are heuristically extracted from sentences with high recall. The joint classification of spatial roles is then cast as a binary classification over the candidates. This joint approach allows for a rich feature set based on the complete relation instead of indivi...