In this article we compare solutions to elliptic problems having rapidly oscillated conductivity (permeability, etc) coefficient with solutions to corresponding homogenized problems obtained from two-scale extensions of the initial coefficient. The comparison is done numerically on several one and two dimensional test problems with randomly generated coefficients for different intensities of os...

Abstract Recently, multi-carrier code division multiple access (MC-CDMA) has been attracting much attention for the broadband wireless access in the next generation mobile communications systems. In the case of uplink transmissions, the orthogonality among users’ signals is destroyed since each user’s signal goes through different fading channel and hence, the use of frequency-domain pre-equali...

Presented here is a quasi-shrinking rectangle algorithm that computes a complex zero of a polynomial or transcendental function. This method has been implemented using several quasi-random number sequences and the results of several test examples are presented. The performance of this algorithm is based on a ranked comparison of relative error and time complexity versus several pseudo-random nu...

Error correction codes defined over realnumber and complex-number fields have been studied and recognized as useful in many applications. However, most real-number and complex-number codes in literature are quite suspect in their numerical stability. In this paper, we introduce a class of numerically stable real-number and complex-number codes that are based on random generator matrices over re...

Numerical error estimation for time dependent hyperbolic problems is challenging for theoretical and practical reasons. In these systems, error can propagate long distances and produce effects far from the point of generation. In addition, nonlinear interactions of error, as well as discretization nonlinearities can play important roles and must be addressed. In this work, we investigate the us...

In this paper, we address a critical problem in conversation systems: limited input interpretation capabilities. When an interpretation error occurs, users often get stuck and cannot recover due to a lack of guidance from the system. To solve this problem, we present a hybrid natural language query recommendation framework that combines natural language generation with query retrieval. When rec...

Forced convection of heat in a two-dimensional channel, partially filled by a porous insert is considered. This system is assumed under fully developed conditions and constant wall heat flux. Further, the fluid and solid phases can feature internal heat generation (exothermicity) and consumption (endothermicity). Analytical solutions are developed for the solid and fluid temperature fields by a...

We design a custom spectrum sensing network, called RadioHound, capable of tuning from 25 MHz to 6 GHz, which covers nearly all widely-deployed wireless activity. We describe the system hardware and network infrastructure in detail with a view towards driving the cost, size, and power usage of the sensors as low as possible. The system estimates the spatial variation of radio-frequency power fr...

A novel multi-code multicarrier code division multiple access (MC-MC-CDMA) system is proposed and analyzed in a frequency selective fading channel. By allowing each user to tl'ansmit multiple orthogonal codes, the proposed MC-MCCDMA system can support various data rates, as required by next generation standards, and achieve spreading gain in the time domain. Multicarrier CDMA provides robustnes...