Physics and engineering.
Chair: Amed A. Kishk, University of Mississippi The University of Mississippi, also known as Ole Miss, is a public, coeducational research university located in Oxford, Mississippi. Founded in 1848, the school is composed of the main campus in Oxford and three branch campuses located in Booneville, Tupelo, and Southaven.
Vicechair: T.M. Parchure, US Army Engineers
8:30 Divisional Poster Session A poster session is the juried presentation of research information by representatives of several research teams at a congress or conference with an academic or professional focus. These are particularly prominent at scientific conferences such as medical congresses.
Chair: Atef Z. Elsherbeni, The University of Mississippi, University, MS 38677
APPLICATION OF THE FAST FOURIER TRANSFORM See FFT.
(algorithm) Fast Fourier Transform - (FFT) An algorithm for computing the Fourier transform of a set of discrete data values. Given a finite set of data points, for example a periodic sampling taken from a real-world signal, the FFT expresses the data in terms of FOR PERFORMANCE CHARACTERIZATION OF AN IF-DIGITAL CONVERTER
Andy Harrison, Raytheon Electronic Systems, Forest, MS 39074
In this work, the Fast Fourier Transform (FFT (Fast Fourier Transform) A class of algorithms used in digital signal processing that break down complex signals into elementary components.
FFT - Fast Fourier Transform ) is used to characterize the performance of a TPQ TPQ Threshold Planning Quantity
TPQ Tridimensional Personality Questionnaire
TPQ Terminus Post Quem (archaeology)
TPQ Tepic, Nayarit, Mexico (Airport Code)
TPQ Total Product Quality 47 radar IF-Digital Converter (IFDC IFDC International Fertilizer Development Center
IFDC Improved Field Data Collector
IFDC Interest and Fees During Construction (project finance)
IFDC International File Distribution Cooperative ). The IF to digital converter consists of two channels each of which provides down conversion and filtering of the IF frequency, attenuation Loss of signal power in a transmission.
The reduction in level of a transmitted quantity as a function of a parameter, usually distance. It is applied mainly to acoustic or electromagnetic waves and is expressed as the ratio of power densities. control for gain leveling and radar gain control, and 12-bit A/D conversion See A/D converter. . Features of the FFT-based spectrum include harmonic content, spurious content and noise floor level. These combined effects are reflected in the IFDC's rms signal to noise ratio that can be derived from the FFT magnitude spectrum. Ideally, the frequency spectrum of the output signal would be a single line that represents a pure sine wave A continuous, uniform wave with a constant frequency and amplitude. See wavelength.
A Sine Wave _title>
Sine wave input and is free from distortion generated by the circuitry of the IFDC. Since the FFT assumes that the record repeats with a certain period, sharp discontinuities at the points where the start of one record joins the end of the preceding record cause the spectral components to be spread or smeared. The smearing, called leakage, can be reduced by multiplying the data in the record by a windowing For Northcoast
Where we call someone over and then roll our window up on them. Bassline preference.
For Example: "Hey, Andi." *insert window being rolled up* "HAHAHA. function that weights the points in the center of the record heavily while smoothly suppressing the points near the ends. Many different windowing functions were studied that offer various tradeoffs of amplitude resolution versus frequency resolution.
Lying or occurring in the same plane. Used of points, lines, or figures.
copla·nar WAVEGUIDE waveguide, device that controls the propagation of an electromagnetic wave so that the wave is forced to follow a path defined by the physical structure of the guide. FED BOW-TIE APERTURE ANTENNA
Guiping [Zheng.sup.*], Atef Z. Elsherbeni, and Charles E. Smith Charles E. Smith can refer to:
The coplanar waveguide (CPW (1) (Commercial Processing Workload) An IBM metric for system performance. CPW is designed for business applications that have a significant amount of input/output. ) fed aperture antenna consists of an aperture that is etched from a ground plane having a bow-tie shape and a CPW feed line that protrudes through the aperture. This antenna exhibits characteristics similar to a dipole antenna Meaning "two poles," a dipole antenna is the simplest type of antenna, consisting of an electrically conducting wire or rod one half the length of the maximum desired wavelength. The wire or rod is split at the center with an insulator. . A prototype of the CPW aperture antenna is designed at a central frequency around 10 GHz and the computed input impedance The input impedance, load impedance, or external impedance of a circuit or electronic device is the Thévenin equivalent impedance looking into its input. In audio systems is approximately 50 W similar to the characteristic impedance This article is about impedance in electronics. For characteristic acoustic impedance, see acoustic impedance.
The characteristic impedance or surge impedance of a uniform transmission line, usually written of the feed transmission line. A finite difference A finite difference is a mathematical expression of the form f(x + b) − f(x + a). If a finite difference is divided by b − a, one gets a difference quotient. time domain (FDTD FDTD Finite Difference Time Domain
FDTD From Dusk 'Til Dawn ) simulation is performed using a developed MATLAB (MATrix LABoratory) A programming language for technical computing from The MathWorks, Natick, MA (www.mathworks.com). Used for a wide variety of scientific and engineering calculations, especially for automatic control and signal processing, MATLAB runs on Windows, Mac and program and verification is obtained using the Ansoft High Frequency Structure Simulation (HFSS HFSS High Frequency Structure Simulator
HFSS High Fat, Salt and Sugar (food content)
HFSS High-Frequency Sounder System
HFSS High Frequency Simulator System
HFSS High Frequency Sensor Subsystem ) program. With the approximately matched CPW aperture antenna, the return loss at the designed frequency is less than 20 dB. The gain and the radiation efficiency are also improved by taking advantage of this load matching property. The FDTD simulation results demonstrate that the CPW aperture antenna behaves more like a dipole antenna rather than a microstrip patch antenna A patch antenna is a popular antenna type, which gains its name from the fact that it basically consists of a metal patch suspended over a ground plane. The assembly is usually contained in a plastic radome, which protects the structure from damage (as well as concealing its , specially when the width of the aperture is comparable to a dipole length of 1/2. The characteristics of this bow-tie aperture antenna that include small return losses, appropriate resonant frequencies, matched loading, and moderate gain, indicate that it has many features required to build a phased antenna array Antenna array may refer to:
CHARACTERISTICS OF COPLANARBOW-TIE PATCH ANTENNA
P.L. [Chin.sup.*], Atef Z. Elsherbeni, and Charles E. Smith, The University of Mississippi, University , MS 38677
This paper introduces a new concept of coplanar patch antenna (CPA (Computer Press Association, Landing, NJ) An earlier membership organization founded in 1983 that promoted excellence in computer journalism. Its annual awards honored outstanding examples in print, broadcast and electronic media. The CPA disbanded in 2000. ), which consists of a bow-tie shaped patch surrounded by a closely spaced ground conductor and a coplanar waveguide (CPW) feedline. The solid and wire bow-tie antenna configurations have been used in many applications over the past years because of their broadband characteristics. In this case, the characteristics of small aperture between the bow-tie patch and the surrounding ground plane are similar to that of the dual of a wire type bow-tie antenna. Yet it possesses some features characteristic of a patch antenna. To study the structure, the finite difference time domain (FDTD) technique is employed to design and to simulate this type of CPA and bow-tie patch with operation at 10 GHz with 50 [omega] input impedance. Numerical results for return loss, radiation pattern, and gain are presented, and validated using the Ansoft Nigh nigh
adv. nigh·er, nigh·est
1. Near in time, place, or relationship: Evening draws nigh.
2. Nearly; almost: talked for nigh onto two hours. Frequency Structure Simulation (HFSS) program. Although the patch bow-tie antenna exhibits a somewhat narrow bandw idth for small aperture widths as compared to the solid cone bow-tie antenna, more broadband operation can be obtained with wider aperture widths. In addition, the characteristics of this configuration can be further extended using loading due to the ease in adding impedance-type loads to the aperture/patch and the ground plane. This type of antenna is proposed for use as an element of a phased array antenna specifically designed for transmit/receive (TR) modules for radar systems.
COPLANAR PATCH ANTENNAS WITH ENHANCED BANDWIDTH
Brad N. [Baker.sup.*], AtefZ. Elsherbeni, and Charles E. Smith, University of Mississippi, University, MS 38677
Since the inception of the idea of coplanar patch antennas, their popularity has been growing due to their ease of construction as well as their simple design. One potential problem with coplanar antenna geometries, however, is their relatively limited bandwidth. The coplanar patch antenna, like the microstrip patch antenna from which it was derived, suffers from a narrow bandwidth of approximately 3 percent. In this paper, finite difference time domain (FDTD) analysis was used to parametrically analyze a coplanar patch antenna operating at 10 GHz. The effect of the coplanar slot width on the resonant frequency of the antenna is investigated. Two techniques to broaden the functional bandwidth of the 10 GHz coplanar patch antenna are then investigated. Slots are added to the coplanar patch antenna for the possibility of combining the resonances of the slot and the main patch together to broaden the bandwidth. Parasitic patches were also used experimentally to broaden the bandwidth and to provide a better match to the feeding network. The results of these experiments are analyzed to suggest optimum configurations for wideband coplanar patch antennas.
FINITE ELEMENT ANALYSIS Finite element analysis (FEA) is a computer simulation technique used in engineering analysis. It uses a numerical technique called the finite element method (FEM). There are many finite element software packages, both free and proprietary. OF THE PRESSURE BEHA BEHA Blue Eyed Horse Association VIOR DURING THE PULTRUSION Pultrusion is a continuous process of manufacturing of composite materials with constant cross-section whereby reinforcing fibers are pulled through a resin, possibly followed by a separate preforming system, and into a heated die, where the resin undergoes polymerization. OF COMPOSITES
Tabious [Hayes.sup.*] and Tyrus McCarty, University of Mississippi, University, MS 38677
A common problem associated with the manufacture of composites is the formation of voids in the final product. The voids in the composite adversely affect the strength of the final product. A high pressure rise in the die inlet region can eliminate the voids. The elimination of voids can lead to a better quality final product. The purpose of this research is to determine the effect that various process control parameters Control parameters
In a nonlinear dynamic system, the coefficient of the order parameter; the determinant of the influence of the order parameter on the total system. See: Order Parameter. have on the pressure rise during the pultrusion process. A numerical approach referred to as the finite element See FEA. method is employed in this study. Finite element analysis is used to investigate the effect of the process control parameters of pull speed, fiber diameter, and fiber volume fraction on the pressure rise in the pultrusion die region.
COMPUTER SIMULATION OF EARTH/SATELLITE(S) FOR REMOTE SENSING APPLICATIONS
Edward [Woo.sup*], Atef Z. Elsherbeni, and Charles E. Smith, The University of Mississippi, University, MS 38677
A software package for the simulation of earth/satellites relative positions and land coverage for remote sensing applications is developed. This package provides a visualization tool to help in improving the analysis and design of radar systems and the techniques for collecting data for synthetic aperture radar Synthetic aperture radar (SAR)
Radar, airborne or satellite-borne, that uses special signal processing to produce high-resolution images of the surface of the Earth (or another object) while traversing a considerable flight path. (SAR (Segmentation And Reassembly) The protocol that converts data to cells for transmission over an ATM network. It is the lower part of the ATM Adaption Layer (AAL), which is responsible for the entire operation. See AAL.
SAR - segmentation and reassembly ) systems. This simulation will also allow users to get a better understanding of radar technology, global positioning systems, and basic remote sensing Deriving digital models of an area on the earth. Using special cameras from airplanes or satellites, either the sun's reflections or the earth's temperature is turned into digital maps of the area. principles. Users will be able to input orbital parameters (shape and position) and satellite parameters (number, position, and speed). The distance between the satellites (while moving around the earth) and earth spot coverage area will be computed and displayed to the user in a window with a 3-dimensional dynamic view of the earth/satellites movements. A better understanding of the earth/satellites dynamic relationship will assist in solving many of the technical problems of today's satellites global coverage systems.
Divisional Talks Begin; Engineering Session Chair: Ahmed A. Kishk, University of Mississippi, University, MS 38677
10:00 INVESTIGATION OF THE RF PERFORMANCE OF A HYBRID ACTIVE ARRAY ANTENNA SUBARRAY MODULE
Andy [Harrison.sup.*] and Rick Rollenhagen, Raytheon Electronic Systems, Forest, MS 39074
In this work, the RF performance of a TPQ47 radar hybrid active array antenna subarray module (SAM) is analyzed. Transitions and discontinuities in the RF path were investigated in both time and frequency domains. The SAM provides RF transmit and receive signal paths from the feed network to free space, transmit and receive beam steering Beam steering: Changing the direction of the main lobe of a radiation pattern. In radio systems, beam steering may be accomplished by switching antenna elements or by changing the relative phases of the rf signals driving the elements. control, receive signal amplification and element gain leveling, as well as array temperature reporting. The SAM consists of two microwave integrated circuits Integrated circuits
Miniature electronic circuits produced within and upon a single semiconductor crystal, usually silicon. Integrated circuits range in complexity from simple logic circuits and amplifiers, about 1/20 in. (1. (MIC), two digitally controlled ferrite fer·rite
1. Any of a group of nonmetallic, ceramiclike, usually ferromagnetic compounds of ferric oxide with other oxides, especially such a compound characterized by extremely high electrical resistivity and used in computer memory phase shifters, three microcontrollers, one RF circuit board and associated connectors. All electrical components are mounted on one side of the printed wiring board (PWB (Printed Wiring Board) An alternate term for printed circuit board. See printed circuit board. ) and the RF trace is attached to the opposite side. The RF trace is comprised of six dipole elements. RF transmit and receive functions operate on two, three element in line arrays (3 Pack). In transmit, the SAM receives a single RF input that is split to drive both 3 packs. A ferrite phase shifter provides phase control of the transmit signal for each path. In receive, the SAM provides two RF outputs each fed by a 3 pack. Each receive path is driven by a MIC that provides amplitude and phase control.
10:20 BROADBAND SPATIAL POWER COMBINERS: FULL-WAVE ANALYSIS AND MODELING TECHNIQUES
Milan V. [Lukich.sup.*], Alexander B. Yakovlev, Atef Z. Elsherbeni, and Charles E. Smith, University of Mississippi, University, MS 38677
Spatial power combiners are used for power amplification at microwave and milimeter-wave frequencies from an array of solid-state devices. In contrast to traditional power combining techniques, which utilize waveguide and transmission line junctions, free space spatial power combining enables to achieve increased power output levels and power combining efficiencies. In this paper we present a waveguide-based spatial power combining system for operation at milimeter-wave frequencies. The system consists of several interacting antenna arrays placed at dielectric interfaces of an oversized o·ver·size
1. A size that is larger than usual.
2. An oversize article or object.
adj. o·ver·size also o·ver·sized
Larger in size than usual or necessary. multilayered waveguide. Uniform amplitude and phase excitation to the antennas is provided by a hard-horn with a dielectric sidewall side·wall
1. A wall that forms the side of something.
2. A side surface of an automobile tire, between the edge of the tread and the wheel rim.
Noun 1. loading. Signal collected by antenna arrays is coupled to the amplifier array through a ground plane with slots and the amplified signal is then reradiated into free space through slots of another ground plane. Generalized scattering matrix Scattering matrix
An infinite-dimensional matrix or operator that expresses the state of a scattering system consisting of waves or particles or both in the far future in terms of its state in the remote past; also called the S matrix. approach is adopted to model the entire amplifier system by decomposing it into smaller modules and cascading the modules using these matrices. A method of moments integral equation formulation is presented for the full-wave analysis of multilayered waveguide with embedded antennas. In order to increase frequency band and efficiency of the system and provide operation in multiple band regimes, resonant U-slot patch, microstrip loop, tapered meander meander
Extreme U-bend in a stream, usually occurring in a series, that is caused by flow characteristics of the water. Meanders form in stream-deposited sediments and may stack up upstream of an obstruction, resulting in a gooseneck or extremely bowed meander. line, triangular slot antennas, and their modifications are used. Numerical results for several representative antennas are given to illustrate advantages of their utilization in a power combining system.
10:40 IMPLEMENTATION OF THE ASYMPTOTIC BOUNDARY CONDITION boundary condition
The set of conditions specified for behavior of the solution to a set of differential equations at the boundary of its domain. IN THE FDTD METHOD
Andrew [Simon.sup.*] and Ahmed A. Kishk, University of Mississippi, University, MS 38677
Geometry description in the FDTD method is a somewhat tedious task especially when the geometry contains fine details. If the FDTD code is based on the use of cubic cells, this adds further constraints on the cell size and we may be forced to use excessive number of cells to simulate the required geometry. This will increase the memory requirements and also processing time of the problem. For example, if we have a surface loaded with conducting strips that needs to be modeled in a FDTD code, the description of that will be tedious, as each strip has to be described and paid attention to. As an alternative, we propose the use of the asymptotic boundary condition (ABC ABC
in full American Broadcasting Co.
Major U.S. television network. It began when the expanding national radio network NBC split into the separate Red and Blue networks in 1928. ) as a way to avoid dealing with such a problem. The ABC is an isotropic Refers to properties that do not differ no matter which direction is measured. For example, an isotropic antenna radiates almost the same power in all directions. In practice, antennas cannot be 100% isotropic. averaging type of boundary condition that does not require a detailed description of the strips. This boundary condition can be easily implemented the same way we implement the perfectly conducting surfaces and dielectric materials Dielectric materials
Materials which are electrical insulators or in which an electric field can be sustained with a minimal dissipation of power. Dielectrics are employed as insulation for wires, cables, and electrical equipment, as polarizable media for in the FDTD method. It has to be mentioned th at the ABC is accurate when dealing with conducting strips as long as the number of strips per wavelength is large, typically more than 10 strips per wavelength. However, experimental data has shown that the ABC still holds for certain cases that have as little as 4 strips per wavelength. Another type of structure that can be modeled using the ABC is the corrugated cor·ru·gate
v. cor·ru·gat·ed, cor·ru·gat·ing, cor·ru·gates
To shape into folds or parallel and alternating ridges and grooves.
v.intr. structure where the corrugations can be easily modeled without the need for their detailed description. With the ability to classify the corrugated region as a homogenous homogenous - homogeneous region, we enable the division of cubic cells to be employed fully for the problem at hand. The method of implementing these boundary conditions in the FDTD method will be presented together with some applications.
11:00 ANALYSIS OF TRANSMISSION AND REFLECTION LOSSES FROM A CLASS OF COPLANAR WAVEGUIDE STRUCTURES
Abdelnasser A. [Eldek.sup.*], AtefZ. Elsherbeni, and Charles E. Smith, The University of Mississippi, University, MS 38677
In this paper, several geometries of a class of grounded coplanar waveguide (GCPW GCPW Grant County Public Works
GCPW Grounded Co-Planar Waveguide ) are investigated using the finite difference time domain (FDTD) method, and their losses are computed. A uniform GCPW structure is used as a reference case for the other non-uniform geometries. First, this reference case, four geometries are proposed to study the transmission and loss effect of replacing parts of the dielectric substrate with free space. Afterwards, two new geometries are simulated to study the effect of reducing the feed line width in a limited section (step), and the introduction of a gap in the microstrip feeding line, with and without a bridge that connects the two parts of the microstrip feeding line separated with the gap. The effect of adding a perfect electric conductor (PEC) cap above the microstrip feeding line, and connecting the two side ground planes, is also studied. The conductor attenuation, power losses and the input and output impedances are studied for the proposed geometries. The results sho sho (shō),
n See akashi. w that adding more free space in the substrate improves transmission, decreases power losses and increases both input and output impedances. It is also found that the relative power losses and conductor attenuation are increasing with frequency, while a PEG cap improves the transmission and adding a PEC bridge over a gapped feed line improves both transmission and return loss coefficients.
11:20 ANALYSIS OF DUAL TAPERED MEANDER SLOT MICROSTRIP ANTENNA In telecommunication, there are several types of microstrip antennas (also known as a printed antennas) the most common of which is the microstrip patch antenna or patch antenna.
Cuthbert M. [Allen.sup.*], Atef Z. Elsherbeni, and Charles E. Smith, University of Mississippi, University, MS 38677
The objective of this paper is to examine the performance of a dual tapered meander slot microstrip antenna using the FDTD technique. The antenna is to be designed to work at three pre-determined frequencies in the X-band or over the entire X-band region of frequencies. A computer code is developed to automatically create the antenna geometry for any angle, number of turns, width of slot, and spacing between slots. Such flexibility in geometry parameters is essential to easily analyze different configurations of the antenna. In order to have a complete analysis, certain characteristics of the antenna must be studied. Among these characteristics are the return loss, the input impedance, and the far field pattern. There has been no known work published on such an antenna structure. However, there have been numerous papers written on other forms of spiral or meander line antennas. These antennas have been very useful in broadband applications since they are very much frequency independent. Hence this gives motiv ation for the development of the dual tapered meander slot microstrip antenna. In the analysis of this antenna, the return loss is first computed and comparison made using an independent solution. The antenna is shown to work over a very large portion of the entire X-band.
1:00 ANALYSIS OF MODIFIED MICROSTRIP LOOP ANTENNAS
Matthew J. [Inman.sup.*], Atef Z. Elsherbeni, and Charles E. Smith, The University of Mississippi, University, MS 38677
The characteristics of ordinary loop antennas are well known and documented in the literature. However, this paper intends to explore methods to reduce the physical size of rectangular printed loop antennas by introducing a ground plane into the structure as well as to study its effects on the antenna parameters. With the introduction of the ground plane into the antenna structure, the relationship between the dimensions of the modified loop will also be explored to achieve the design goals. This type of antenna is analyzed using the finite difference time domain (FDTD) technique and is then verified by other numerical simulation packages. Differences in the radiation characteristics obtained from the full (unmodified) loop antennas and the modified antennas are examined. Optimization of bandwidth, gain, directivity, and operational bands are also investigated. By manipulating the dimensions of the modified antenna it is possible to adjust its parameters to achieve maximal operation at a specific frequency ba nd, or in some cases at several different bands concurrently. Reducing the physical size of the antenna allows for more commercial uses in mobile transceiving platforms. Design examples of this type of antennas for radar applications and personal communication devices are presented.
1:20 BANDWIDTH ENCHANCEMENT OF THE DIELECTRIC RESONATOR ANTENNA If the dielectric resonator is placed in an open environment, power is lost in the radiated fields. This fact makes dielectric resonators useful as antenna elements. Dielectric resonator antennas (DRA) offer following attractive features:
Materials exhibiting ferromagnetism. The magnetic properties of all materials make them respond in some way to a magnetic field, but most materials are diamagnetic or paramagnetic and show almost no response.
Swee H. [Ong.sup.*] and Ahmed A. Kishk, University of Mississippi, University, MS 38677
The dielectric resonator antenna has been widely investigated in recent years for its high efficiency and mechanical flexibility. Here, the monopole antenna A monopole antenna is a type of radio antenna formed by replacing one half of a dipole antenna with a ground plane at right-angles to the remaining half. If the ground plane is large enough, the monopole behaves exactly like a dipole, as if its reflection in the ground plane is loaded with a multi layer dielectric material acting as a dielectric resonator A dielectric resonator is an electronic component that exhibits resonance for a narrow range of frequencies, generally in the microwave band. The resonance is similar to that of a circular hollow metallic waveguide, except that the boundary is defined by large change in . The dielectric loading has two significant effects: first, it reduces the size of the antenna and second, it improves the antenna matching bandwidth significantly. Last year, results of this antenna with dielectric loading were presented. This year, homogeneous magnetic materials with small permeability constants are added to the dielectric materials. It is believed that these new materials can be obtained by adding the magnetic materials with the dielectrics, in a powder form, with a specific ratio, to achieve the required permittivity Permittivity
A property of a dielectric medium that determines the forces that electric charges placed in the medium exert on each other. If two charges of q1 and q2 coulombs in free space are separated by a distance r and permeability. It is observed that the radiation patterns of the monopole mon·o·pole
A magnetic monopole.
The minimal region for which lines of force, as from an electric or magnetic field, either all enter or all leave the region. were not affected by the loading. Careful selection of the resonator resonator /res·o·na·tor/ (rez´o-na?ter)
1. an instrument used to intensify sounds.
2. an electric circuit in which oscillations of a certain frequency are set up by oscillations of the same frequency in another material can result in wider bandwidths. Numerical results presenting the effects of different permittivity and permeability on an antenna for a cellular communication system will be shown. Results will show that a significant increase in the bandwidth, reaching 40%, can be obtained. This is achieved by the combination of different materials, including the use of homogeneous magnetic materials, which lowers the resonant frequency as compared with dielectric loading.
1:40 DESIGN, CONSTRUCTION, AND VERIFICATION OF AN AUTOMATED MOVEABLE INDOOR ANECHOIC CHAMBER Noun 1. anechoic chamber - a chamber having very little reverberation
room - an area within a building enclosed by walls and floor and ceiling; "the rooms were very small but they had a nice view" FOR ANTENNA MEASUREMENTS
Brian T. [McDaniel.sup.*], Ahmed A. Kishk, and Charles E. Smith, The University of Mississippi, University, MS 38677
This paper presents the design and construction of a moveable anechoic chamber for use in RF, wireless, and microwave education and research applications. The instrumentation used for anechoic chamber measurements is a system consisting of an Agilent/HP 8530 Microwave Receiver, 8530B Sweep Generator, 8714B S-Parameter Test Set, and a computer-controlled rotator for antenna pattern measurements, designed at The University of Mississippi. This computer-controlled system allows for single frequency measurements as well as swept frequency techniques. The operation of the antenna rotator An Antenna Rotator is device which is used to change the orientation of a directional antenna. Most antenna rotators have two parts, the rotator unit and the controller. The controller is normally placed near the equipment which the antenna is connected to, while the rotator is is automated, using a stepper motor A motor that rotates in small, fixed increments and is used to control the movement of the access arm on a disk drive. Contrast with voice coil.
(hardware) stepper motor , with user selected rotation angles and signal sampling intervals. Furthermore, the measured antenna pattern and antenna position data is acquired using a PC, providing real-time pattern display of raw or processed data and simple data storage. The design of the anechoic chamber is presented which includes necessary parts, setup, calibration methods (for single or swept frequency measurements) a nd the construction is described. The verification of the useable quite zone for measurement is studied, and a detailed presentation of two anechoic chamber figure-of-merit methods (Antenna Pattern Comparison and VSWR VSWR Voltage Standing Wave Ratio
VSWR Vertical Standing Wave Ratio ) is presented, along with examples of collected antenna pattern measurements from the University of Mississippi Indoor Anechoic Chamber. Using these techniques, The University of Mississippi has implemented an efficient way to measure, evaluate and characterize experimental antennas and scattering systems in an anechoic chamber whose electromagnetic properties are known.
2:00 HYDRAULIC SCALE MODELS
T.M. Parchure, US Army Engineer Research and Development Center The Engineer Research and Development Center or ERDC is a United States government funded military base located at Vicksburg, Mississippi. The base was set up after the 1927 flood disaster of the Mississippi River. The base is staffed by the U.S. Army Corps of Engineers. , Vicksburg, MS 39180
Hydraulic scale models have been extensively and successfully used over the past century for solving a variety of engineering problems for which analytical solutions were not available. The objective of scale model study is to physically simulate the relevant natural conditions and to operate the model for predicting the effect of proposed changes. The theory of modeling is based on the similitude criteria. Construction and operation of scale models requires expertise and experience. Two types of models are used: a. geometrically similar, in which the horizontal and vertical scales are the same, and b. vertically exaggerated, in which the two scales are different. Once the two scales are carefully selected, the other scales are fixed by mathematical relationships. Scale models may be two-dimensional or three-dimensional. Almost every hydraulic model needs field data for verification. After a model is verified for a certain set of parameters, it is assumed that it will also behave consistently for a new set of values. Hence they are used as predictive tools. Hydraulic models offer not only qualitative but also quantitative answers to a large number of problems. Numerous examples of past projects reveal that large projects constructed without adequate prediction of their effect have proved to be not only expensive mistakes but have also caused irreversible ecological damage in some cases. Such mistakes can be easily avoided through advance modeling, in which several alternatives and options can be investigated at a fraction of the cost of project. In conclusion, hydraulic models offer a valuable tool in achieving success and economy for engineering projects. Theory of scale modeling and practical examples of problems will be presented.
2:20 THE ACCURACY OF KEYSTROKE key·stroke
A stroke of a key, as on a word processor.
keystroke INTERVAL MEASUREMENTS IN A WINDOWS ENVIRONMENT (1) (upper case "W") Refers to computers running under a Microsoft Windows operating system.
(2) (lower case "w") Also called a "windowing environment," it refers to any software that provides multiple windows on screen such as Windows, Mac, Motif and X Window.
Marcus [Parks.sup.*] and Mark Tew, University of Mississippi, University, MS 38677
Psychological experiments were once held in isolated and controlled environments, but now thousands of researchers in fields such as cognitive psychology cognitive psychology, school of psychology that examines internal mental processes such as problem solving, memory, and language. It had its foundations in the Gestalt psychology of Max Wertheimer, Wolfgang Köhler, and Kurt Koffka, and in the work of Jean are conducting experiments over the web. Timing accuracy is of perennial concern to researchers conducting reaction time studies, especially for those using computers that are not dedicated to attaining millisecond One thousandth of a second. See space/time and ohnosecond.
(unit) millisecond - (ms) One thousandth of a second, one thousand microseconds. A long time for a modern computer. accuracy. The following equipment was used during the research: Desktop computer, lap-top computer, keystroke generator, National Instruments DAQPad, and key interface box. Two programs were also used during this research "Key Interval" and "Digital Waveform." This research was held under the following four environments: Default, Experiment Only, Experiment with web traffic, and Experiment with time killer. These four conditions were tested through an executable file and over the web through a web browser The program that serves as your front end to the Web on the Internet. In order to view a site, you type its address (URL) into the browser's Location field; for example, www.computerlanguage.com, and the home page of that site is downloaded to you. . The results from the executable file were compared to the results of the web delivered file. Next, the web browser's results were compared betw een Internet Explorer and Netscape. Finally, the program was executed through an E-Prime player where these results were compared with the previous results that were executed through an Authorware plug-in. A final conclusion could not be drawn at this point and time in the research. The research in which I participated is an ongoing experiment and much more data will be needed. In conclusion, Authorware and E-Prime were found to be capable of acceptable accuracy in measuring keystroke intervals. This held true in the default environment, experiment only environment, and with light web traffic in the background.
2:40 Divisional Business Meeting
Physics and Engineering Session
Chair: T.M. Parchure, US Army ERDC ERDC Engineer Research and Development Center
ERDC Economic Research and Development Center
ERDC Eleanor Roosevelt Democratic Club (Orange County, California)
ERDC Exploratory Research and Development Center
ERDC Extended Response Data Call , Vicksburg, MS 39180
8:30 EXPLANATION OF THE BIRTH OF THE UNIVERSE
Amin Haque, Alcorn State University Alcorn State University, located near Lorman, Mississippi, United States, is a public land grant university. It was founded in 1871 as the nation's first state-supported higher education institution for blacks. , Alcorn State, MS 39096
The four important observations, namely, expansion of the Universe, cosmic background microwave radiation, formation of light nuclides, and formation of galaxies and large-scale structure, prove that the universe has a starting point. According to the general theory of relativity Noun 1. general theory of relativity - a generalization of special relativity to include gravity (based on the principle of equivalence)
Einstein's general theory of relativity, general relativity, general relativity theory , the universe is expanding because space-time itself expands. Edwin Hubble's observations show a linear relationship between the distance to galaxies and their recessional velocities (redshifts), and the age of the universe is estimated about 1.5 x [10.sup.10] years. The 3 K primordial microwave radiation, predicted by George Gamow using quantum physics, has been discovered and accurately measured recently. The lumps detected in the cosmic microwave radiation, confirm that the primordial lumpiness caused due to slight temperature fluctuations at the very early age, has been carried over into modern times. The galaxies were formed due to fluctuations in matter density. The particle physicists speculate that intensive hot dark matter, consisting of high energy particles like neutrinos, tends to form very large structures. Cold dark matter seems to form smaller structures such as galaxies and clusters of galaxies. Inflation could have increased to large gravitational fields powerful enough to form galaxies and clusters. Using nuclear and sub-nuclear physics, the make up of the universe is: protons, neutrons and electrons 5%, dark matter 30%,"dark energy" 65%. We have reason to believe that physics, cosmology, astronomy, and technology will take us 1.5 x [10.sup.10] years back in time to see the birth of our universe.
8:50 UNDERSTANDING THE FATE OF THE UNIVERSE
Amin Haque, Alcorn State University, Alcorn State, Lorman, MS 39096
According to the inflation theory, and general theory of relativity, the Universe is flat, and expanding with a decelerating rate. In 1998, two international teams of astronomers working independently announced that the distant supernovae are dimmer dim·mer
1. A rheostat or other device used to vary the intensity of an electric light.
a. A parking light on a motor vehicle.
b. A low beam. than they should be in a decelerating universe, indicating that the expansion of the Universe is accelerating. It is believed that the universe is filled with "antigravity an·ti·grav·i·ty
The hypothetical effect of reducing or canceling a gravitational field.
an ," a concept originally proposed by Einstein. This force or "dark energy" dominates over gravity, and causes the universe not only to expand, but also accelerate the expansion. The equations of quantum physics independently suggest that the apparently vacuum space in the universe is filled with a form of energy that would act just like Einstein's antigravity. The dark energy is a function of space, and as the distance between galaxies increases more and more dark energy is created filling the space, becoming stronger than the gravity. The recent detection of the primordial lumpiness in the cosmic background radiation cosmic background radiation
Electromagnetic radiation, mostly in the microwave range, believed to be the highly redshifted residual effect (see redshift) of the explosion billions of years ago from which, according to the big-bang model, the universe was created. confirms that dark energy is real. As the universe will continue to have accelerated expansion, stars will die out, and the universe will become cold and black. Astronomers and physicists caution that the discoveries about dark matter, dark energy, accelerated expansion, and flatness of space-time must be confirmed before accepting them without reservations. We might expect surprises in the future. The cosmological constant, could even change direction to reinforce the gravity. Therefore, a closed universe, and hence a Big Crunch, is possible.
9:10 UNDERSTANDING THE CREATION OF MATTER
Amin Haque, Alcorn State University, Alcorn State, MS 39096
According to the Standard Model, the behavior of the fundamental particles, quarks and leptons--the building blocks of matter--and their interactions can be described through the strong, weak and electromagnetic forces. The basic forces are transmitted between the quarks and leptons by a third family of fundamental particles, called gauge bosons. Each force is carried by a different type of gauge boson. Photons carry the electromagnetic force; gluons Gluons
The hypothetical force particles believed to bind quarks into “elementary” particles. Although theoretical models in which the strong interactions of quarks are mediated by gluons have been successful in predicting, interpreting, and carry the strong force; charged particles, and neutral particles, carry the weak force. (A particle called the graviton Graviton
A theoretically deduced particle postulated as the quantum of the gravitational field. According to Einstein's theory of general relativity, accelerated masses (or other distributions of energy) should emit gravitational waves, just as accelerated , is believed to carry force of gravity.) The quarks, leptons and gauge bosons acquire their masses through the interaction with a member of another new family of fundamental particles, known as Higgs bosons, and it is the strength of this interaction that gives the particles their masses. The experimental results from the large Electron Positron positron: see antiparticle.
Subatomic particle having the same mass as an electron but with an electric charge of +1 (an electron has a charge of −1). It constitutes the antiparticle (see antimatter) of an electron. Collider col`lid´er
n. 1. (Physics) a
It is likely to contain information of a speculative nature and the content may change as the facility approaches completion. , the proton energies will reach ten times greater, and will provide an opportunity to have a glimpse of the early Universe. The interactions of the hadrons will produce the Higgs bosons or it will explain whatever mechanism Nature employs to create matter.
9:30 I FELT LIKE GILBRETH!
David [Loflin.sup.*] and S. Kant Vajpayee, The University of Southern Mississippi, Hattiesburg, MS 39406
Frank and Lillian Gilbreth made significant contributions to-industrial engineering in its infancy. It is interesting to know how Frank applied what can only be called common sense to improve a brick layer's productivity threefold. Even today, the practice of industrial engineering--unlike the other disciplines such as civil engineering, mechanical engineering, or electrical engineering--draws a lot from common sense. Or, shall we say uncommon sense for if it were common sense it could not be engineering. Recently, the first author went through a realization probably similar to that of Frank Gilbreth, while working part-time as a student at a local golf course. What he did as part of his job was simply applying common sense. Later when he began his studies at The University of Southern Mississippi as an industrial engineering technology major, he began to interact with the second author. Slowly he began to learn what industrial engineering is all about. The presentation will describe his feelings of Eureka wh en he realized that the common-sense approach to the task of distributing golf carts had the seeds of industrial engineering. We wonder what Gilbreth, the industrial engineer, might have felt later in his life about the spark generated by his now famous, common-sense-based improvements in the brick laying process. In the present case, the golf carting was completed efficiently, thoroughly, error-free, and in time. And these are the measures for evaluating industrial engineering projects.
9:50 THE ISO (1) See ISO speed.
(2) (International Organization for Standardization, Geneva, Switzerland, www.iso.ch) An organization that sets international standards, founded in 1946. The U.S. member body is ANSI. 9000 BEGAN IT ALL!
S. Kant Vajpayee, The University of Southern Mississippi, Hattiesburg, MS 39406
The world-wide quality revolution began in the 1970s with the culmination of ISO 9000. Following this, and in response to a growing concern for the environment, the ISO developed ISO 14000--a family of environment management standards--in 1996. The structure and the concept behind these two standards are the same; both aim at improvement--the former of the product and service quality, and the latter of the environment. Several sectors of the industry have developed their own standards based on ISO 9000 structures and concepts to suit their specific needs. The Big Three US auto makers established QS 9000 in 1994 as requirements for their 13,000 first-tier suppliers. As a supplement, they also developed TE 9000 for their 50,000 suppliers of production equipment and tooling. The aerospace industry, led by Boeing, has adopted a similar standard called AS 9000. Another important industry impacted by these global standards is telecommunications. Its TL 9000 serves the same purpose as the QS 9000 for the auto indust ry. Other issues in the "pipeline" to undergo a similar impact are occupational health and safety, handling of customer complaints, worker welfare, and personal finance planning. Thus, ISO 9000 has proven to be "revolutionary." The US accepted ISO 9000 rather hesitantly, as obvious from an ex-Ford chiefs statement: "I told people we can either adopt the ISO standard and build on it, or we would spend the rest of our lives telling people why we didn't. We figured it just made sense." But as the wisdom set in, we moved fast and are today one of its strong proponents.
10:30 COMPUTER SIMULATION OF THE THERMAL MANAGEMENT
Nichalos L. [Jeffries.sup.*] and Tyrus McCarty, University of Mississippi, University, MS 38677
The trend in packaging electronic systems has been to reduce the size of devices by placing more functions in smaller packages to increase their performance. This has contributed to higher heat densities, requiring that thermal management be given a high priority in the design cycle in order to maintain system performance and reliability. In this study the analysis involved the thermal management of an electronically packaged system associated with a radar subsystem. A computer simulation of the heat transfer in the radar subsystem was performed to test the effectiveness of several specified design conditions. A computational numerical technique was employed to solve the basic equations that governed the physical processes occurring in the radar subsystem. This study focused on the utilization of heat pipe/heat sink technology for cooling the electronic components associated with this subsystem. The results of this study are vital because they provide several effective ways of insuring that the electronic com ponents are operated in a failure-safe environment.
10:50 ACOUSTICAL INVESTIGATION OF SOIL LAYERS
Wheeler B. [Howard.sup.*], Craig J. Hickey, and James M. Sabatier, University of Mississippi, University, MS 38677
In soils containing a fragipan horizon, the rate of soil erosion and crop yield are directly related to the depth and condition of the fragipan layer. The objective of this study is to develop a technique for delineation of the fragipan horizon through use of acoustic to seismic (a/s) coupling. This method utilizes the seismic energy coupled into soil by an impinging airborne acoustic wave to determine the layer depth and velocities in the soil. A site in North Mississippi with a known fragipan horizon was chosen as the test site for our experiment. Two locations with physical depths to the fragipan of about 30 cm and 1 m were selected. Conventional techniques including the shallow refraction refraction, in physics, deflection of a wave on passing obliquely from one transparent medium into a second medium in which its speed is different, as the passage of a light ray from air into glass. survey and Rayleigh wave survey were utilized to determine the "seismic" depth to the fragipan and the seismic speeds of the soil layers. The data obtained from the a/s coupling survey are compared to the conventional seismic and soil cores to establish the accuracy of the acoustic survey.
11:10 COHERENT BACKSCATTERING FROM COMPLEX LIQUIDS
Letemeskel [Asfaw.sup.*] and Joe Whitehead, University of Southern Mississippi, Hattiesburg, MS 39406
An experimental study of coherent backscattering of light from aqueous suspension of micron sized polystyrene spheres and a bulk sample of nematic The stage between a crystal and a liquid that has a threadlike nature; for example, a liquid crystal. See crystalline and LCD. liquid crystal (NLC NLC National League of Cities
NLC National Library of Canada
NLC National Library of China
NLC Northern Lights College (British Columbia, Canada)
NLC North Lake College (Irving, Texas) ) is presented. Both these materials enhance multiple scattering, which is a universal phenomenon occurring in almost every branch of physics. Coherent backscattering is caused by the constructive interference of two waves traveling in opposite directions. A sharp peak in the intensity in contrast with the background appears within a narrow angular cone in the opposite direction of the incident beam. This peak is called the coherent backscattering cone. The angular width at half maximum of the enhanced backscattering peak depends on the mean free path and the wavelength of the laser light used in the experiment. We found the enhancement ratio for the polystyrene samples very close 2.0 but for NLC it is 1.67, a discrepancy is due to the anisotropic Refers to properties that differ based on the direction that is measured. For example, an anisotropic antenna is a directional antenna; the power level is not the same in all directions. Contrast with isotropic. nature of nematic liquid crystals.
11:30 DEBOND1NG CHARACTERISTICS IN BONDED CONCRETE OVERLAYS
Hak-Chul [Shin.sup.*] and David A. Lange, Jackson State University Jackson State University, often abridged as Jackson State or by its initials JSU is a historically black university located in Jackson, Mississippi founded in 1877. , Jackson, MS 39217, and University of Illinois at Urbana-Champaign Early years: 1867-1880
The Morrill Act of 1862 granted each state in the United States a portion of land on which to establish a major public state university, one which could teach agriculture, mechanic arts, and military training, "without excluding other scientific , IL
To rehabilitate old concrete pavements for a longterm performance with only minor repairing, bonded concrete overlays are considered as a cost-effective strategy. The superior performance of bonded concrete overlays is sometimes damaged by early age surface cracking and/or debonding at the interface between old and new concrete. This early age failure is mainly due to volume changes of the overlay concrete by shrinkage and thermal changes. To understand the early age behavior of bonded concrete overlays, an extensive experimental measurements and numerical analysis were carried out. Laboratory overlay specimens were fabricated to measure opening displacement at the interface. Debonding profiles at the interface were determined by a dye technique. A finite element model was developed to compare debonding behavior due to volume changes. From the experimental measurements and numerical analysis, it was found that bonded concrete overlays with HPC (Handheld PC) A palmtop computer that weighs less than one pound and runs specialized versions of popular applications. Microsoft coined the term for its Windows CE operating system, which is an abbreviated version of Windows. See Pocket PC. mixtures have strong tendency to debonding at the early age. The m ain reason for this tendency is due to high shrinkage gradient in the HPC mixtures and low bond strength at the interface.
11:50 ARE INDUSTRIAL ENGINEERS REAL ENGINEERS IN THE CLASSICAL SENSE?
S. Kant Vajpayee, The University of Southern Mississippi, Hattiesburg, MS 39406
Unlike others such as civil engineers, mechanical engineers, or electrical engineers, industrial engineers are less well known as to what they do. There are two primary reasons for this. First, they are relatively a new breed. Second, they are not real engineers in the classical sense of the term. They are half engineers (professionals dealing with engineering and technical matters) and half managers (professionals focusing on optimally utilizing the resources, including people). Industrial engineers are unique as an interface between technical professionals and the management. The former have limited knowledge of what managers do, and the latter is busy mostly with non-engineering/non-technical functions. If industrial engineers are fortunate, both managers and the other engineers of the company "love" them. On the other hand, where they are not appreciated for what they do, both may attempt to "kick" them around. The adjective industrial truly describes them, because they are found in all types of industrie s--not just manufacturing--from health care to wealth care, from doughnut franchises to defense contractors, from shop floors to space programs. Known earlier as productivity engineers, and then as system engineers, now they are called integrators. They have eagle eyes for the forest rather than the trees. Other engineers, on the other hand, are skilled at focusing on the trees. As technology gets more sophisticated and globalization globalization
Process by which the experience of everyday life, marked by the diffusion of commodities and ideas, is becoming standardized around the world. Factors that have contributed to globalization include increasingly sophisticated communications and transportation continues to make industries more complex, industrial engineers are finding themselves needed more.