| 5-Volt Low Level Serial Transceiver. |
28 JUN 1994 |
|
| Authors:
Trung H. Tran; DEPARTMENT OF THE NAVY WASHINGTON DC
|
 | A transceiver has a transmitter portion using active comparators coupled to a single low level positive bias source to enable low powered drain transmit and receive conversion of TTL input signals to LLS (low level serial) data output signals for a coaxial data transmission cable. The transceiver also provides a constant impedance for a coaxial or triaxial transmission cable during active transmission periods, standby periods and power-off periods to provide ... |
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| Skin Blood Flow and Bioelectrical Impedance |
14 JUN 94 |
20 pages |
| Authors:
Marcie B. Beckett; James A. Hodgdon; Wanda Woods; Brian W. Appleton; NAVAL HEALTH RESEARCH CENTER SAN DIEGO CA
|
 | This study was performed to determine the effect of changes in skin blood flow (SBF) on bioelectrical resistance (RES). Twenty-three men had their left hand repeatedly immersed (1 min) and removed from water (3 min) for a total of 12 min in order to manipulate SBF in the contralateral (right) limbs where RES electrodes were located. Tests were completed at three water temperatures (5, 15, and 350C) in constant ambient ... |
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| The Social Construction of Race and Gender: Black Women Officers in the U.S. Navy |
JUN 94 |
70 pages |
| Authors:
Kathleen B. Daniels; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis explores the impact of life histories on the attitudes and experiences of Black women officers. In-depth, personal interviews with fifteen women officers, concentrating heavily on life histories, were the major source of data. Literature and studies concentrating on military Black women are few and limited in scope. This thesis attempts to unveil the importance of understanding the experiences of Black female officers. This thesis includes an examination of ... |
|
| Machine Learning: A Comparative Study of Pattern Theory and C4.5 |
JUN 94 |
129 pages |
| Authors:
Jeffery A. Goldman; AIR FORCE MATERIEL COMMAND WRIGHT-PATTERSON AFB OH
|
| The Machine Learning field has identified several different inductive bias classes with Occam's Razor being held as an accepted paradigm. C4.5, an extension of ID3, is one of the leaders in this class of learning systems with which other systems measure their ability. A completely different approach, yet still a method in the class of Occam biased learning mechanisms, is Pattern Theory. This approach seeks to recognize patterns in a ... |
|
| The Social Construction of Gender in the U.S. Navy |
JUN 94 |
151 pages |
| Authors:
Douglas S. Borrebach; Norman G. Fitzpatrick; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis explores the social construction of masculinity in the U. S. Navy and its implication for the successful integration of women. Semi- structured, in-depth interviews of 40 Naval Academy graduates were the major source of data. The literature explores the construction of masculinity and how the identity of men is developed through social interaction. Constant comparative analysis of qualitative data yielded 15 major themes. The themes display various ways ... |
|
| An Atomically-Resolved STM Study of the Thermal Decomposition of Disilane on Si(001) |
27 MAY 94 |
77 pages |
| Authors:
Y. Wang; J. Bronikowski; R. J. Hamers; WISCONSIN UNIV-MADISON DEPT OF CHEMISTRY
|
| Scanning Tunneling Microscopy (STM) has been used to study the adsorption and thermal dissociation of disilane (Si2H6) on the Si(OO1) surface. At low coverage, disilane adsorbs dissociatively to produce adsorbed SiH3 groups which are randomly distributed on the surface. STM images show that these SiH3 groups spontaneously dissociate into SiH2 and H within several minutes of adsorption at room temperature, and images depicting individual dissociation events have been obtained. Thermal ... |
|
| Direct Dimer-by-Dimer Identification of Clean and Monohydride Dimers on the Si(001) Surface by Scanning Tunneling Microscopy |
27 MAY 94 |
28 pages |
| Authors:
Y. Wang; M. Bronikowski; R. J. Hamers; WISCONSIN UNIV-MADISON DEPT OF CHEMISTRY
|
| Atomic resolution images of clean Si(001)-(2x1) and the mono-hydride phase, Si(001)-(2xl)H were investigated using scanning tunneling microscopy at various sample-tip bias voltages. At a sample-tip bias of -1.9 V, each dimer of the monohydride phase show two protrusions 3.3 A apart separated by a minimum 0. 11 A deep for a sample bias of -1.9 Volt, while clean dimers show a single protrusion per unit cell. Monohydride dimers appear lower ... |
|
| Can Computers Penetrate the Fog of War? |
16 MAY 94 |
31 pages |
| Authors:
Kevin B. Leahy; NAVAL WAR COLL NEWPORT RI DEPT OF OPERATIONS
|
| Computerized Systems are playing an increasingly important role in our Command and Control process. These systems promise to process large quantities of battlefield data, aid in operational decision making through sophisticated display and artificial intelligence, and provide the operational commander nearly absolute control over his forces. Will these capabilities remove the ambiguity and uncertainty from the battlefield? Will they penetrate the fog of war? Information overload, reinforcement of human decision ... |
|
| Multi-Method Planning |
APR 94 |
156 pages |
| Authors:
Soowon Lee; UNIVERSITY OF SOUTHERN CALIFORNIA MARINA DEL REY INFORMATION SCIENCES INST
|
| The ability to find a low execution-cost plan efficiently over a wide domain of applicability is the core of domain-independent planning systems. The approach investigated here to building such a planning system begins with two hypotheses: (1) no single method will satisfy both sufficiency and efficiency for all situations: and (2) multi-method planning can out-perform single-method planning in terms of sufficiency and efficiency. To evaluate these hypotheses, a set of ... |
|
| Development of Si Light Emitting Technology Based on Si Quantum Wires |
31 MAR 94 |
29 pages |
| Authors:
Dim-Lee Kwong; TEXAS UNIV AT AUSTIN
|
| The objectives of this program are four folds. (1) Process development: develop new techniques to fabricate luminescent PS, control the luminescence spectra, and process PS with minimal damage to the luminescent properties. To that end, we have developed a novel approach to produce luminescent PS without an external electrical bias by stain etching Si in HF- HNO3-based solution. In addition, we have utilized dry oxidation to efficiently control the PL ... |
|
| Maximum-Likelihood Network Magnitude Estimates of Low-Yield Underground Nuclear Explosions |
31 MAR 94 |
105 pages |
| Authors:
Rong-Song Jih; Richard R. Baumstark; TELEDYNE GEOTECH ALEXANDRIA VA ALEXANDRIA LABS
|
| This final report covers the analysis performed under Task 3 of this contract, using the raw station magnitudes collected under Task One. 35,211 station Mb values from 6 major nuclear test sites have been fed into the GLM (general Linear Model) inversion to determine jointly the event sizes, the station corrections, and the specific path correction for each source-station pair. The simultaneously-inferred path and station corrections are related to known ... |
|
| Electron Cyclotron Resonance Plasma Oxidation Studies of InP |
15 MAR 94 |
29 pages |
| Authors:
Y. Z. Hu; J. Joseph; E. A. Irene; NORTH CAROLINA UNIV AT CHAPEL HILL DEPT OF CHEMISTRY
|
| Electron cyclotron resonance plasma oxidation of InP was studied using both spectroscopic and single wavelength ellipsometry employed during the oxidation process. A two layer oxide was observed with the outer layer being In rich and the inner layer P rich as-confirmed from x-ray photoelectron spectroscopy and etch rate studies. Optical models and oxidation kinetics are analyzed. From positive substrate bias effects on oxidation rates, negative ion oxidant species were identified ... |
|
| Control of the Residual Sub-Electronic Charge on a Mesoscopic Conductor by Means of a Scanning Tunneling Microscope Tip |
07 MAR 94 |
5 pages |
| Authors:
E. L. Wolf; POLYTECHNIC UNIV BROOKLYN NY DEPT OF PHYSICS
|
|
| Policies, Practices, and the Effect of Gender Discrimination on the Integration of Women Officers in the Department of the Navy |
MAR 94 |
151 pages |
| Authors:
Mary A. Margosian; Judith M. Vendrzyk; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis explores the impact of gender discrimination and institutional bias on the integration of women officers in the Department of the Navy. Semi-structured, in-depth personal interviews with 61 women Navy and Marine Corps officers were the major source of data. This thesis includes an examination of the phenomenon by which gendering processes occurs within society, organizations, and the military; a historical review of women's roles in the military and ... |
|
| Growth, Characterization and Device Development in Monocrystalline Diamond Films |
MAR 94 |
24 pages |
| Authors:
R. F. Davis; J. T. Glass; R. J. Nemanich; L. Bergman; M. T. McClure; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| Micro- and macro-photoluminescence techniques were employed in this research to investigate the role of nitrogen-doping on the optical spectra of chemical vapor deposited diamond films and to determine whether the origin of the broadband luminescence is due to vibronic interaction of the nitrogen centers. The temperature behavior of the broadband PL and of the 1.681 eV silicon related optical center were analyzed. The intensity of the broadband was found to ... |
|
| Field Emitter Array RF Amplifier Development Project. Phase 1, Option 1 |
25 FEB 94 |
6 pages |
| Authors:
W. D. Palmer; Gary E. McGuire; MICROELECTRONICS CENTER OF NORTH CAROLINA RESEARCH TRIANGLE PARK
|
| We have demonstrated anode current modulation at 1 GHz as reported in the special technical report of 31 JAN 94. 80 microns A peak of anode current modulated at 1 GHz was observed with only 2.02 V peak RF modulation on the gate electrode at a DC gate bias voltage of 118 V and DC anode emission current of 1. 8 mA. The bias current is about 2 microns A ... |
|
| Center for Seismic Studies Final Technical Report, October 1992 through October 1993 |
07 FEB 94 |
97 pages |
| Authors:
Anne Henson; Hans Israelsson; SCIENCE APPLICATIONS INTERNATIONAL CORP ARLINGTON VA
|
| A 1992 study by Suteau-Henson where azimuth bias and scatter were systematically measured for regional phases of events recorded at ARCESS is extended here by mapping the observed bias and scatter around ARCESS. In another study, the optimization of polarization analysis at IMS/IRIS stations in the Former Soviet Union is addressed. Also in this report, a procedure to stack waveforms recorded by a network of seismic stations for detection of ... |
|
| Algorithms and Structures for Real-Time Signal Processing. Revised |
04 FEB 94 |
4 pages |
| Authors:
Clifford T. Mullis; COLORADO UNIV AT BOULDER
|
| The study of digital signal processing is to a large extent the study of algorithms, but there is a natural classification into algorithms for design and algorithms for actual processing. our research has been mainly concerned with the latter classification and has addressed structural constraints which arise because of resource limits and/or a desire for efficiency. This has led in a number of problems to some algebraic decomposition of algorithms ... |
|
| Field Emitter Array RF Amplifier Development Project. Phase 1. Option 1 |
FEB 94 |
33 pages |
| Authors:
Gary McGuire; W. Devereux; MICROELECTRONICS CENTER OF NORTH CAROLINA RESEARCH TRIANGLE PARK ELECTRONIC T ECHNOLOGIES DIV
|
| Modulation of anode current at 1 GHz was observed on two different devices. The devices tested were 1,197-tip arrays of 4 micrometer column emitters. Net signal gain of 0.84 dB was recorded at a bias current of 172 micro-A. As more devices are tested, it is expected that increased RF gain will be observed. An identical array was tested at lower frequencies (1 - 50 MHz). Extrapolating from the gain ... |
|
| Electrostrictive Ceramics for Underwater Transducer Applications |
FEB 1994 |
10 pages |
| Authors:
Kurt M. Rittenmyer; NAVAL RESEARCH LAB ORLANDO FL UNDERWATER SOUND REFERENCE DETACHMENT
|
| The electromechanical properties of two electrostrictive materials designed for use in underwater acoustic applications are determined as functions of temperature and electric field. The materials are 0.859Pb(Mgl/3Nb2/3)O3-0 . 141 PbTiO3 doped with 2.5% SrTiO3 or BaTiO3. Dielectric properties are determined as functions of temperature and electric field. The equivalent piezoelectric coefficients were found as functions of temperature to be equal to or superior to the lead zirconate-titanate ceramics at very ... |
|
| Field Emitter Array RF Amplifier Development Project Phase One, Cathode Technology Development |
31 JAN 94 |
5 pages |
| Authors:
W. D. Palmer; Gary E. McGuire; MICROELECTRONICS CENTER OF NORTH CAROLINA RESEARCH TRIANGLE PARK
|
| MCNC has duplicated and improved upon test results documented in the Special Technical Report dated 17 JAN 94. Tables detailing the measured 1 GHz modulation of the field emitter array anode current are included, as is a printout of an oscilloscope screen displaying our best results. A net power gain at 1 GHz of +7.74 dB was observed with 161.9 micro A of modulated anode current at a DC bias ... |
|
| MDA AEL Error Analysis |
JAN 94 |
91 pages |
| Authors:
E. D. Wolin; D. E. Ensberg; S. Escher; J. Murray; W. S. Hodges; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
|
| The following report summarizes the types and effects of errors in navigating the tripod array deployed in the Northwest Atlantic in July 1991. We argue that the overall root mean squared error (RMSE) in navigating array element positions is less than 2 m (one and two leg data) and 4 m (three leg data). (AN) |
|
| The Criteria-Based Content Analysis and Its Utility in Distinguishing Between Truthful and Fabricated Criminal Allegations: A Critical Review |
94 |
75 pages |
| Authors:
C. L. Ruby; John C. Brigham; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| This review examined the utility of the Criteria-Based Content Analysis as a method to distinguish truthful from fabricated criminal allegations. It appears that the U.S. justice system would accept the CBCA as a viable method for, truth detection if empirical support could be obtained. Although the research results demonstrate some utility, the studies have either not been experimental in nature and fall prey to selection bias, or have fallen short ... |
|
| Split Recursive Least Squares: Algorithms, Architectures, and Applications |
1994 |
33 pages |
| Authors:
An-Yeu Wu; K. J. Liu; MARYLAND UNIV COLLEGE PARK INST FOR SYSTEMS RESEARCH
|
| In this paper, a new computationally efficient algorithm for recursive least-squares (RLS) filtering is presented. The proposed Split RLS algorithm can perform the approximated RLS with 0(N) complexity for signals having no special data structure to be exploited, while avoiding the high computational complexity (0(N2)) required in the conventional RLS algorithms. Our performance analysis shows that the estimation bias will be small when the input data are less correlated. We ... |
|
| DLTS and Dynamic Transconductance Analysis of Deep-Submicron Fully- Depleted SOI MOSFET's |
31 DEC 93 |
49 pages |
| Authors:
Dimitris E. Ioannou; GEORGE MASON UNIV FAIRFAX VA
|
| An experimental study of the degradation mechanisms in hot-carrier stressed partially- and fully-depleted SOI(SIMOX) nMOSFET's has been carried out as a function of device (drain) design and fabrication technology, in an effort to develop hot-electron resistant devices that are suitable for space and satellite applications. A multitude of experimental techniques were used for this purpose, including the newly developed sequential front/back channel stressing measurement tech which makes use of the ... |
|
| Antenna Erector for a Towed Buoyant Cable. |
21 DEC 1993 |
|
| Authors:
Stuart C. Dickinson; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| An apparatus is provided for erecting and stowing a communications antenna from an underwater buoyant cable. In its stowed position, the antenna is approximately parallel to the cable. In its erected position, the antenna is approximately perpendicular to the cable. A hinge, spring biased to maintain the antenna in its stowed position, is connected to the cable and to one end of the antenna. A shape memory alloy actuator is ... |
|
| Low Level Serial Transceiver. |
21 DEC 1993 |
|
| Authors:
Trung H. Tran; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A transceiver has a transmitter portion using serially coupled FETs coupled to low level positive and negative bias sources to enable a low power drain conversion of TTL input signals to low level serial data output signals for a coaxial data transmission cable and vice versa The transceiver also provides a constant 50 ohm impedance for the coaxial or triaxial transmission cable during active transmission periods, stand-by periods and power-off ... |
|
| Carrier Collection and Scattering in Quantum Well and Superlattice Devices |
16 DEC 93 |
93 pages |
| Authors:
Robert M. Kolbas; NORTH CAROLINA STATE UNIV AT RALEIGH
|
| The objective of this experimental program is to define the regimes in which scattering and carrier collection dominate the performance of quantum well and superlattice devices. The program consists of five thrusts: (1) materials growth; (2) carrier collection experiments; (3) utilization of ultra- thin monolayer thick quantum wells; (4) the understanding, control and utilization of dissipative mechanisms for new device concepts, and; (5) the demonstration of devices. The results obtained ... |
|
| LADAR Detection Statistics in the Presence of Pointing Errors |
15 DEC 1993 |
69 pages |
| Authors:
Hal T. Yura; AEROSPACE CORP EL SEGUNDO CA TECHNOLOGY OPERATIONS
|
| The probability of detection of optically rough targets by pulsed LADAR systems that employ direct detection is considered here. It is assumed that the LADAR operates under conditions of both unintentional pointing off-set bias (i.e., bore-sight error) and jitter. Under these conditions, the probability of detection of targets in both the near and far field of the collecting aperture (i.e., for resolved, partially resolved, and unresolved targets) and for both ... |
|
| Array Element Gain and Phase Estimation in the Presence of Interference |
DEC 93 |
|
| Authors:
Eric K. Hung; DEFENCE RESEARCH ESTABLISHMENT OTTAWA (ONTARIO)
|
| Presented is a method to estimate the element gains and phases of a sensor array when interfering signals, including specular multipath, are present. A movable calibration source is used. The element gains are derived from the relative output powers at the array elements. The element phases are obtained by transforming the array snapshots to make the source direction appear fixed and then maximizing a function constructed with the transformed snapshots. ... |
|
| An Analysis of the Effects of Military Service on Retirees' Civilian Earnings |
DEC 93 |
97 pages |
| Authors:
Tsung-Ying Wang; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis analyzes differences in earnings between U.S. military retired veterans and non-retired veterans with similar demographic characteristics. Using data from the 1987 National Survey of Veterans (SOVIII) Files, the analysis first examines the frequency distribution of the explanatory variables. It then employs Heckman's two stage regression technique to correct for the selectivity bias that distorts the estimates obtained using Ordinary Least Squares. A log-earnings model is specified based on ... |
|
| Interface Properties of Wide Bandgap Semiconductor Structures |
DEC 93 |
212 pages |
| Authors:
Robert F. Davis; Salah Bedair; Jerry Bernholc; Jeffrey T. Glass; R. J. Nemanich; NORTH CAROLINA STATE UNIV AT RALEIGH
|
| Ab initio molecular dynamics calculations have shown that the lxl:2H and the 2xl:H surfaces of diamond(C)(100) have a (-) electron affinity(EA); the clean (100) surface has a (+) EA. This is in agreement with experiment. Biased nucleation of C on Beta-SiC(100) and Si(100) has been achieved but not on Cu(100). C nucleation densities on Hf, Ti, Ta, Ni and W were directly related to the carbide heat of formation. The ... |
|
| Atomic Layer Epitaxy of Group IV Materials: Surface Processes, Thin Films, Devices and their Characterization |
DEC 93 |
34 pages |
| Authors:
Robert F. Davis; Salah Bedair; Nadina El-Masry; Jeffrey T. Glass; NORTH CAROLINA STATE UNIV AT RALEIGH
|
| Atomic layer epitaxy of monocrystalline Beta-SiC on Si(100) and alpha (6H)-SiC(0001) substrates has been accomplished at 850 deg C by alternating the supplies of Si2H6, C2H4 and atomic hydrogen and without the use of a carbonizing step. Conformal deposition of SiC has been demonstrated within trenches etched into Si(100) wafers. P-type films have also been achieved using A1 as a dopant. Devices including HBTs with Beta-SiC emitters have been designed. ... |
|
| Detection of Low-Intensity Magnetic Fields with a Magnetostrictive Fiber Optic Sensor |
DEC 93 |
|
| Authors:
Laura L. Picon; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
| This thesis presents the fabrication, evaluation, and performance results of a magnetostrictive fiber optic sensor. The sensor was fabricated using a Mach-Zehnder interferometric arrangement. Four classes of sensing arms were fabricate as: ribbons, cylinders, sandwiches, and sputter coated sheaths. The four classes of sensing arms were evaluated using MetglasTM, nickel, and a combination of MetglasTM and nickel. Optimization techniques were applied to the sensor to maximize its sensitivity. These techniques ... |
|
| Growth, Characterization and Device Development in Monocrystalline Diamond Films |
DEC 93 |
66 pages |
| Authors:
Robert F. Davis; Jeffrey T. Glass; R. J. Nemanich; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| Biased enhanced nucleation of diamond on Beta-SiC(100) and Si(100) has been achieved but not on Cu(100). Carbide formation is an apparent attribute to the nucleation. The refractory metals of Hf, Ti, Ta, Ni and W were thus explored as substrates. Diamond nucleation density was found to be directly related to the carbide heat of formation without scratching these substrates. TEM of highly oriented diamond films on Si(100) showed dislocations at ... |
|
| Statistical Study of Soviet Nuclear Explosions: Data, Results, and Software Tools |
05 NOV 93 |
87 pages |
| Authors:
Rong-Song Jih; Robert A. Wagner; Robert H. Shumway; TELEDYNE GEOTECH ALEXANDRIA VA ALEXANDRIA LABS
|
| This final report summarizes our efforts in analyzing Soviet underground nuclear tests, with emphases on our updated results and the statistical software developed. 28,875 carefully measured station magnitudes were fed into a maximum-likelihood inversion scheme which simultaneously determines the event size and the station correction, as well as the specific path correction for each source-station pair. The simultaneously-inferred path and station corrections are related to known geological/geophysical features. Applying these ... |
|
| Laboratory Evaluation of the Standard Elektrik Lorenz (SEL) Fibre-Optic Rate Gyroscope |
NOV 93 |
|
| Authors:
M. F. Vinnins; L. D. Gallop; DEFENCE RESEARCH ESTABLISHMENT OTTAWA (ONTARIO)
|
| A fibre-optic rate-sensing gyroscope (FOG) manufactured by Standard Elektrick Lorenz (SEL) was loaned to DREO for evaluation. The SEL FOG, model PMIDE, was designed for a drift rate of 10 to 100 deg/hr and consists of two units; a fibre-optic sensor and a support electronics unit. Laboratory tests were carried out in the DREO Inertial Navigation Laboratory and consisted of bias drift and scale factor over +/ 400 deg/sec as ... |
|
| Growth, Characterization and Device Development in Monocrystalline Diamond Films |
31 OCT 93 |
154 pages |
| Authors:
Robert F. Davis; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| The effects of hydrogen on cluster binding energy and resulting growth mode during chemical vapor deposition of diamond, the process parameters and the effect of substrates during bias enhanced nucleation, the growth of textured diamond films, the characterization of these films using transmission electron microscopy, Raman spectroscopy and photo-luminescence comprise the growth and thin film characterization research conducted during this grant. Additional work included determination of the surface properties including ... |
|
| Improvements to the Automated Real-Time Tidal Elevation System |
OCT 93 |
114 pages |
| Authors:
Leon E. Borgman; Andrew W. Garcia; Todd L. Walton; COASTAL ENGINEERING RESEARCH CENTER VICKSBURG MS
|
| Two statistical techniques for making rapid, short-term predictions of the harmonically determined tidal residual are presented. The techniques are applied to an Automated Real-Time Tidal Elevation System (ARTTES) to improve short-term tide prediction. The techniques investigated are conventionally called 'Kriging' and autoregression. The autoregressive method is based on the Yule-Walker equations for stationary time series. Evaluations using both synthetic and prototype data indicate that although Kriging has a slightly larger ... |
|
| Correlation Function Estimator Performance in Non-Gaussian Spherically Invariant Random Processes |
OCT 93 |
32 pages |
| Authors:
James H. Michels; ROME LAB GRIFFISS AFB NY
|
| In this report, analytic expressions are developed for the variance, error variance and bias of the time-averaged correlation function estimator for stationary, discrete, non-Gaussian complex processes. The expressions derived here pertain to the general class of non-Gaussian processes known as Spherically Invariant Random Processes (SIRP's) Specific results are shown for K-distributed processes which form a special case of the SIRP's. Furthermore, these equations are derived for the general case of ... |
|
| Bias in Reporting Location |
30 SEP 93 |
11 pages |
| Authors:
Janellen Huttenlocher; Larry V. Hedges; CHICAGO UNIV IL DEPT OF PSYCHOLOGY
|
| The overall purpose of the research done under the Air Force Grant was to test a model of bias in the judgment of spatial location. The model holds that the representation of locations is not itself biased, but that it is the process of estimation that leads to bias. The process we argue is one of combining category and fine grain information about location (e.g., for any item in a ... |
|
| Analysis of Radiation Damaged and Annealed Gallium Arsenide and Indium Phosphide Solar Cells Using Deep Level Transient Spectroscopy |
SEP 93 |
|
| Authors:
Joseph A. Bruening; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Power loss in spacecraft solar cells due to radiation damage was investigated. The mechanisms behind the degradation and based on deep-level defects in the crystalline lattice structure of the solar cell. Through a process known as Deep Transient Spectroscopy (DLTS), a correlation can be made between damage/recovery and trap energy of the cell. Gallium (GaAs/Ge) and Indium Phosphide (InP) solar cells were subjected to 1 MeV electron irradiation, to fluences ... |
|
| Acoustic Intensity Measurements in the Presence of Low Mach Number Flow |
SEP 93 |
110 pages |
| Authors:
Toby McNeal; G. C. Lauchle; PENNSYLVANIA STATE UNIV UNIVERSITY PARK APPLIED RESEARCH LAB
|
| Acoustic intensity is an important analysis tool since it provides wave propagation directionality along with absolute magnitude, and it can be measured in the near or far field of a source. Acoustic intensity measurements acquired in the presence of a mean flow are susceptible to errors due to the effects of the flow noise on the sensor. To determine if this error could be accurately quantified, intensity measurements were acquired, ... |
|
| A Study of Line of Bearing Errors |
SEP 93 |
32 pages |
| Authors:
Andrew A. Thompson III; Gary L. Durfee; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Many systems use Line-of-Bearing (LOB) information to locate distant objects. The errors in location due to noisy LOB measurements are the focus of this report. A central assumption for these systems is that the LOB location errors are adequately modeled by bivariate Gaussian distributions. These systems typically use weighted averages to estimate a target's location. A discussion in Thompson and Durfee (1992) illustrates that these location errors are not necessarily ... |
|
| Global and Regional Comparative Performance of Linear and Nonlinear Satellite Multichannel Sea Surface Temperature Algorithms |
SEP 93 |
36 pages |
| Authors:
Douglas A. May; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
|
| This report summarizes investigations conducted at the Naval Research Laboratory on the accuracy of advanced very high resolution radiometer (AVHRR) satellite sea surface temperature (SST) retrieval techniques. Investigations focused on linear and nonlinear AVHRR atmospheric correction algorithms and their comparative performance relative to global drifting buoy in situ SST observations. Satellite retrievals were matched to drifting buoy SSTs within 2 hours and 10 km from January to December 1990. Emphasis ... |
|
| Interinjection-Locked Quasioptical Power Combiners and Phased Arrays |
16 AUG 93 |
16 pages |
| Authors:
Karl D. Stephen; MASSACHUSETTS UNIV AMHERST DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Monolithic integration of microwave and millimeter-wave circuits means new techniques for using high-frequency devices in monolithic circuits must be developed. This report describes a series of several studies that address this need. A biasing technique for negative-resistance devices using a low-impedance lossy transmission line was found to be very useful in the design of planar oscillator circuits. This technique can be applied to monolithic circuits. Mutual impedance between elements in ... |
|
| Electrostrictive Response of Elastomeric Polymers |
AUG 93 |
14 pages |
| Authors:
Jerry I. Scheinbeim; Brian A. Newman; Z. Y. Ma; J. W. Lee; RUTGERS - THE STATE UNIV PISCATAWAY NJ DEPT OF MECHANICS AND MATERIALS SCIENC E
|
| It is well known that the electrostrictive response of all materials is small at low applied electric fields. However, the electrostrictive strains (S) are related to the square of the applied field (E). It therefore appeared reasonable to assume that for a soft polymeric material, a large thickness response, d sub T(d sub T = partial derivative of S/partial derivative of E), might be obtained by application of sufficiently high ... |
|
| A Finite Element Scheme for Shock Capturing |
AUG 93 |
63 pages |
| Authors:
R. C. Berger; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS HYDRAULICS LAB
|
| The representation of hydraulic jumps or shocks in compressible fluids is a difficult task for numerical models. These models require more smoothness than the analytic solution contains. For this reason these models are plagued with oscillations. The most widespread method is to smear the solution in the vicinity of the shock, giving up 0(1) errors, but restricting the error to the neighborhood of the jump or shock. This technique is ... |
|
| Human-Machine Interfaces |
31 JUL 93 |
26 pages |
| Authors:
Nathaniel Durlach; MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS
|
| The normal human auditory system suffers from many deficiencies in its ability to localize sound sources in space. Not only is it generally poor at determining the elevation and distance of a sound source, but in certain cases it is relatively poor at determining the azimuth of the source. The research discussed in this report is concerned with the development and evaluation of systems that result in improved localization, i.e., ... |
|
| Field Emitter Array Memory Device. |
27 JUL 1993 |
|
| Authors:
Henry F. Gray; DEPARTMENT OF THE NAVY WASHINGTON DC
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| A field emitter array memory device having two or more collector electrodes, an extraction electrode, at least one deflector electrode, and at least one electron field emitter is disclosed. The field emitter array memory circuit has bias voltages for collector electrodes, for the at least one deflector electrode and for the extraction electrode. In a preferred embodiment of the invention, first and second input signal voltages selectively applied to first ... |
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