One significant difficulty associated with the implementation of multiple-input multiple-output (MIMO) technology is that communication node mobility leads to a time-varying channel which can limit the achievable system throughput [1]. This paper quantifies the degradation in channel capacity resulting from channel temporal variation using novel information theoretic metrics, and demonstrates t...

In this paper we suggest a cylindrical array, which utilizes signal cancellation and sparse element spacing. The array has narrow beamwidth and low sidelobe level. The beamwidth is about 12° for a 35 element array having -20 dB sidelobe level. Omnidirectional coverage area is obtained by a combination of commutation and phasing. The array has less elements and smaller size than a respective arr...

This study aims at presenting a numerical model for predicting grout flow and penetration length into the jointed rock mass using Universal Distinct Element Code (UDEC). The numerical model is validated using practical data and analytical method for grouting process. Input data for the modeling, including geomechanical parameters along with grout properties, were obtained from a case study. The...

this study aims at presenting a numerical model for predicting grout flow and penetration length into the jointed rock mass using universal distinct element code (udec). the numerical model is validated using practical data and analytical method for grouting process. input data for the modeling, including geomechanical parameters along with grout properties, were obtained from a case study. the...

A combined air and ground simulation of terminal-area arrival operations was conducted at NASA Ames Research Center to evaluate Distributed Air Ground Traffic Management (DAG-TM) project Concept Element 11 (CE 11): Terminal Arrival: SelfSpacing for Merging and In-trail Separation. The simulation was the final DAG-TM study conducted at NASA Ames with funding from the NASA Airspace Systems Progra...

The proposed wideband shorted planar inverted cone antenna (SPICA) has been described as a two element antenna array in this paper. The two element array by this antenna with proper phase of excitation and spacing between the elements provide superdirective array characteristic. This array gives peak endfire directivity from 3.502 dBi to 10.3 dBi and radiation efficiency above 98% in the operat...

A novel method of measuring the relative headmedium spacing based on a measurement in the servo sectors is developed and simulated using a read back signal model. The spacing measurement is tested experimentally on a spin stand where the flying height is varied using the resistance heater element in a thermal flying height control slider. In addition, voltage step response measurements were obt...

The suitable use of an array antenna at the base station of a wireless communications system can result in improvement in the signal-to-interference ratio (SIR). In general, the SIR is a function of the direction of arrival of the desired signal and depends on the configuration of the array, the number of elements, and their spacing. In this paper, we consider a uniform linear array antenna and...

We examine how the wavenumber influences the compression in a wavelet boundary element method for the Helmholtz equation. We show that for wavelets with high vanishing moments the number of nonzeros in the resulting compressed matrix is approximately proportional to the square of the wavenumber. When the wavenumber is fixed, the wavelet boundary element method has optimal complexity with respec...

This paper investigates the effect of micropile installation into saturated sandy soil by means of finite element method. The obtained results from numerical modeling are compared with the received data from the site. The validation of software has been done by simulating standard penetration test. The effect of some changes in spacing (3m, 1.6m and 0.8m) and injection pressure (1cm, 2.5cm, 5cm...