| Fellowship in Solid State |
AUG 88 |
8 pages |
| Authors:
A. J. Sievers; CORNELL UNIV ITHACA NY LAB OF ATOMIC AND SOLID STATE PHYSICS
|
 | Experiments have demonstrated the feasibility of solid state lasers based on vibrational transitions, and point toward the possibility of new high power and tunable sources in the infrared. The great importance of V-V transfer processes in this solid state context, however, has shown that further advances will strongly depend on the understanding of the vibrational energy transfer phenomena. Other research led to the development of a new solid state high ... |
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| Instruction Sets for Parallel Random Access Machines |
AUG 88 |
172 pages |
| Authors:
Jerry L. Trahan; ILLINOIS UNIV AT URBANA COLL OF ENGINEERING
|
| An important model of parallel computation is the Parallel Random Access Machine (PRAM), which comprises multiple processors that execute instructions synchronously and share a common memory. Formalized by Fortune and Wyllie (1978) and Goldschlager (1982), the PRAM is a much more natural model of parallel computation than older models such as combinational circuits and alternating Turing machines (Ruzzo, 1981) because the PRAM abstracts the salient features of a modern multiprocessor ... |
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| Robust Recognition of Loud and Lombard speech in the Fighter Cockpit Environment |
AUG 88 |
433 pages |
| Authors:
Bill J. Stanton Jr; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| There are a number of challenges associated with incorporating speech recognition technology into the fighter cockpit. One of the major problems is the wide range of variability in the pilot's voice. That can result from changing levels of stress and workload. Increasing the training set to include abnormal speech is not an attractive option because of the innumerable conditions that would have to be represented and the inordinate amount of ... |
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| Dynamic Order Quantity: An Alternative to Economic Order Quantity |
AUG 88 |
96 pages |
| Authors:
Douglas W. Brown; James H. Perry; Inta A. Silina; LOGISTICS MANAGEMENT INST BETHESDA MD
|
| Overpricing by DoD vendors and the Competition in Contracting Act forced the Military Services and the Defense Logistics Agency (DLA) to reexamine their basic inventory management and procurement methods for spares and repair parts. To take advantage of price reductions associated with purchasing larger quantities and to offset growing procurement workload and administrative leadtimes, they increased their minimum order quantities from 3-months supply to 12-months' supply. That policy shift brought ... |
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| An Infrared Spectroelectrochemical Investigation of the Ion Pairing Reactions of the Anions and Dianions of TCNE (Tetracyanoethylene) and TCNQ (tetracyanoquinodimethane) |
15 JUL 88 |
20 pages |
| Authors:
S. B. Khoo; J. K. Foley; C. Korzeniewski; S. Pons; C. Marcott; UTAH UNIV SALT LAKE CITY DEPT OF CHEMISTRY
|
| The infrared spectra of the dianions of tetracyanoethylene (TCNE) and tetracyanoquinodimethane (TCNQ), generated electrochemically in acetonitrile, are dependent upon the supporting electrolyte. In particular, the C-N triple bond stretching wavenumbers are higher in the presence of alkali metal salts than in the presence of tetraalkylammonium salts, and the magnitude of the shift is correlated with a positive shift in the half-wave potential of the second reduction wave. The shifts in ... |
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| Spectroscopy, Structure and Proton Dynamics of 2-Hydroxypyridine and Its Clusters with Water and Ammonia |
12 JUL 88 |
43 pages |
| Authors:
M. R. Nimlos; D. F. Kelley; E. R. Bernstein; COLORADO STATE UNIV FORT COLLINS DEPT OF CHEMISTRY
|
| The two tautomeric forms of 2 hydroxypyridine (2-HP) have been studied in a supersonic jet expansion. Time-of-flight mass spectroscopy (TOFMS) and emission spectroscopy of the lactim and lactam tautomers have been studied and are reported here. The lactim spectrum is similar to an earlier TOFMS spectrum and has its origin at 36,136/cm. Evidence of mixing of the npi and pi electronic states is seen in the lactim spectrum. The mixing ... |
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| Parallel Distributed Processing: Implications for Cognition and Development |
11 JUL 88 |
42 pages |
| Authors:
James L. McClelland; CARNEGIE-MELLON UNIV PITTSBURGH PA ARTIFICIAL INTELLIGENCE AND PSYCHOLOGY PRO JECT
|
| This paper provides a brief overview of the connectionist or parallel distributed processing framework for modeling cognitive processes, and considers the application of the connectionist framework to problems of cognitive development. Several aspects of cognitive development might result from the process of learning as it occurs in multi-layer networks. This learning process has the characteristic that it reduces the discrepancy between expected and observed events. As it does this, representations ... |
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| The Photophysical Behavior of Ester-Substituted Aminocoumarins: A New Twist |
06 JUL 88 |
16 pages |
| Authors:
Gary B. Schuster; J. A. Van Gompel; ILLINOIS UNIV AT URBANA DEPT OF CHEMISTRY
|
| The fluorescent behavior of two amino-substituted coumarin esters was examined in solvents of different polarity. Coumarin 3, a simple ester derivative, behaves conventionally. Its fluorescence emission shifts to lower energy as the solvent polarity increases and the efficiency of the emission is essentially unaffected by solvent change. This behavior is characteristic of a rotation-inhibited intramolecular charge transfer (ICT) state. Coumarin 4, substituted with an alpha-keto ester function at the 3-position, ... |
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| Nonlinear Real-Time Optical Signal Processing |
01 JUL 88 |
125 pages |
| Authors:
A. A. Sawchuk; B. K. Jenkins; UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES IMAGE PROCESSING INST
|
| During the period 1 July 1987 - 30 June 1988, the research under Grant AFOSR-84-0181 has been concerned with binary parallel optical computing architectures with particular attention to cellular logic and symbolic substitution for pattern recognition and numerical operations. Our approach has been to experimentally implement binary optical cellular logic processors and interconnection arrays; define an instruction set and software suited to optical systems; and to study generalizations of optical ... |
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| Excited State Energetics and Dynamics of Large Molecules, Complexes and Clusters |
JUL 88 |
112 pages |
| Authors:
J. Jortner; TEL-AVIV UNIV (ISRAEL)
|
| New techniques for spectroscopy in supersonic expansions and in the development of specific supersonic sources were developed, including vacuum ultraviolet absorption spectroscopy in supersonic expansions, development of conical nozzles for supersonic jets and pulse extraction mass spectrometer. Research included studies of energetics of rydberg states of jet-cooled molecules, rydberg states of anthracene, intramolecular relaxation of rydberg states and interference effects between extravalence and intravalence molecular excitations. The rotational state dependence ... |
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| Fatigue Crack Growth of 5456-H116 Aluminum and HSLA-80 Weldments |
JUL 88 |
31 pages |
| Authors:
L. R. Link; DAVID TAYLOR RESEARCH CENTER BETHESDA MD SHIP MATERIALS ENGINEERING DEPT
|
| Fatigue crack growth rate experiments were performed on 4W-type compact tension specimens of baseplate and weldments of 5556-H116 A1 and of baseplate and HAZ of HSLA-80 steel. Stress ratios for the tests were 0.1 for both materials with the A1 weld also being tested at R=0.5. Crack opening levels were determined for both the weld and baseplate in the aluminum material and for the A710 material in the as-welded and ... |
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| Condensation Nuclei in the Mirnyy Region |
24 JUN 88 |
12 pages |
| Authors:
A. I. Voskresenskiy; FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH
|
| The number of condensation nuclei near the coast of Antarctica is extremely low and is closely tied to wind direction. In the presence of the effluent wind, the mean concentration of atmospheric condensation nuclei in the ground layer is around 60/cc, with a maximum value of 410/cc. No nuclei at all were detected in some samples. When the sea wind encroaches on the shore, the mean number of condensation nuclei ... |
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| Stimulated Raman Scattering in Micrometer-Sized Droplets: Time-Resolved Measurements |
JUN 88 |
3 pages |
| Authors:
A. Biswas; P. Chylek; R. L. Armstrong; H. Latifi; E. Creegan; NEW MEXICO STATE UNIV LAS CRUCES DEPT OF PHYSICS
|
| Time resolved measurements of elastic scattering and stimulated Raman scattering (SRS) in micrometer sized water and carbon tetrachloride droplets irradiated with a pulsed, frequency doubled Nd:YAG laser (pulse width 8 nsec, lambda = 532 nm, peak intensity approx. 1 GW sq.cm.) are reported. Elastic scattering of light is instantaneous within our measurement error, estimated to be < + or - 3 nsec. On the other hand, the first Stokes shift ... |
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| Role of Retinocortical Processing in Spatial Vision |
JUN 88 |
21 pages |
| Authors:
Donald H. Kelly; SRI INTERNATIONAL MENLO PARK CA
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| Several important image-processing functions have been proposed for the geometric distortion known as cortical (or more precisely, retinocortical) magnification. This spatial distortion can convert the radial velocities projected on the retina by egocentric motion into uniform, rectilinear motion at the cortex. It can also convert changes of size and orientation in retinal coordinates into mere translation at the cortex. (In both cases, an image-like property is converted into ... |
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| Direct and Indirect Scaling of Membership Functions of Probability Phrases |
JUN 88 |
57 pages |
| Authors:
Amnon Rapoport; Thomas S. Wallsten; James A. Cox; NORTH CAROLINA UNIV AT CHAPEL HILL PSYCHOMETRIC LAB
|
| A crucial issue in the empirical measurement of membership functions is whether the degree of fuzziness is invariant under different scaling procedures. In this paper a direct and an indirect procedure, magnitude estimation and graded pair-comparison, are compared in the context of establishing member ship functions for probability phrases such as probable, rather likely, very unlikely, and so forth. Analyses at the level of individual respondents indicate that (a) membership ... |
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| Total Dose Response of Silicon-on-Insulator (SOI) Metal-Oxide- Semiconductor Field-Effect Transistor's (MOSFET's) |
JUN 88 |
80 pages |
| Authors:
Mark C. Biwer; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| Total dose response of both NMOS and PMOS FET's fabricated on SIMOX and ZMR substrates was studied. Two types of back channel leakage currents were identified for the SIMOX devices. A back channel leakage due to MOSFET action uses the substrate bias as the gate bias. The other component is due to soft reverse characteristics of the body-drain junction. The back channel leakage due to MOSFET action varies with the ... |
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| A Comparative Study of Dialkylboron Chlorides and Triflates for the Enolization of Ketones. The Controlled Stereospecific Synthesis of Either (E)- or (Z)-Enol Borinates |
12 MAY 88 |
11 pages |
| Authors:
Herbert C. Brown; Bakthan Singaram; Raman K. Bakshi; Paul K. Pandiarajan; Raj K. Dhar; PURDUE UNIV LAFAYETTE IN
|
| The ready synthesis and ease of handling of dialkylboron chlorides, R2BC1, as compared to the corresponding triflates, R1BOTf, give the chlorides a significant advantage as reagents to achieve the conversion of ketones into enol borinates quantitatively. A systematic study, in the case of two representative ketones, propiophenone and diethyl ketone, of the effect of the steric requirement of the R group (R2 = 9-BBN vs. Chx2), the amine, Et3N vs. ... |
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| Time Periodic Control of a Multi-Blade Helicopter |
MAY 88 |
|
| Authors:
Stephen G. Webb; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
 | The flap-lag equations of motion of an isolated rotor blade and those for a rigid helicopter containing four blades free to flap and lag are derived. Control techniques are developed which stabilize both systems for a variety of flight conditions. Floquet theory is used to investigate the stability of a rotor blade's flap-lag motion. A modal control technique, based on Floquet theory, is used to eliminate the blade's instabilities using ... |
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| Use of Depletion Edge Translation for High-Speed Modulation and Switching of Lightwaves |
MAY 88 |
|
| Authors:
L. A. Coldren; J. G. Mendoza; T. R. Hausken; K. W. Lee; R. J. Simes; CALIFORNIA UNIV SANTA BARBARA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| The main objective continues to be the achievement of large index shifts at low voltages for applications in modulators and switches for optical processing, the device area of application has shifted from the in-plane guided wave modulator vehicle to a surface-normal modulator configuration more appropriate for spatial light modulator arrays, optical logic gates and reconfigurable optical interconnection. However, in the course of building up the surface-normal effort in the early ... |
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| Relating Sensitivity and Criterion Effects to the Internal Mechanisms of Visual Spatial Attention |
30 APR 88 |
18 pages |
| Authors:
Gordon L. Shulman; Michael I. Posner; WASHINGTON UNIV ST LOUIS MO DEPT OF NEUROLOGY
|
| A recent paper by Muller and Findlay (1987) raises the important issue of how to relate the parameters d' and beta to the internal mechanisms that process visual stimuli. This commentary considers the widely held view that d' changes reflect a variety of mechanisms leading to perception, but that beta changes reflect a single high level decision mechanism that is postperceptual and under conscious control. In a complex highly parallel, ... |
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| A Model for Visual Attention |
01 APR 88 |
|
| Authors:
Adam Reeves; NORTHEASTERN UNIV BOSTON MA
|
| Research has been undertaken on visual attention and short term visual memory (VSTM). One set of experiments has concerned the role that depth information might play in retrieval from VSTM, using an iconic memory paradigm. Another set concerns development of the attention gating model, using the attention shift RSVP paradigm. Finally, we are studying some effects of attention and visual imagery on visual acuity. |
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| SDI (Strategic Defense Initiative) Where Do We Go from Here |
30 MAR 88 |
|
| Authors:
Robert R. Dierker; ARMY WAR COLL CARLISLE BARRACKS PA
|
| President Reagan's announcement five years ago of his vision for a Strategic Defense Initiative (SDI) has had strong implications for the United States nuclear strategy. Implementation of any or all parts of a strategic defense system would constitute a shift away from the offense-dominant strategy that the U.S. has espoused for over forty years. Effecting a shift in U.S. nuclear strategy while maintaining stability between the superpowers is an extremely ... |
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| Further Discussion of the Dynamical Processes That Contribute to the Spectrum of Mesoscale Atmospheric Motions |
23 MAR 88 |
|
| Authors:
K. S. Gage; G. D. Nastrom; CONTROL DATA CORP MINNEAPOLIS MN METEOROLOGY RESEARCH CENTER
|
| In recent years much progress has been made in determining the spectrum of mesoscale atmospheric motions. The frequency spectra of vertical and horizontal velocities have been determined in the free atmosphere by means of the nearly continuous measurement of radial velocity by wind-profiling Doppler radar. In addition, wind measurements by commercial aircraft collected during the NASA Global Atmospheric Sampling Program (GASP) have been analyzed to yield wavenumber spectra in the ... |
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| Rapid Detection of Enveloped Viruses |
12 MAR 88 |
|
| Authors:
Doris J. Bucher; MOUNT SINAI MEDICAL CENTER OF THE CITY OF NEW YORK NEW YORK
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| M-protein of influenza virus is a type-specific antigen and the most invariant protein of the virus. A rapid virus detection system based on M- protein detection would detect all type A influenza viruses and be independent of antigenic shift and drift. To provide a source of highly specific antibodies to M-protein for viral detection, a panel of 18 hybridoma lines secreting monoclonal antibodies reactive with M-protein of type A influenza ... |
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| JFET/SOS (Junction Field-Effect Transistor/Silicon-on-Sapphire) Devices: Gamma-Radiation-Induced Effects |
01 MAR 88 |
|
| Authors:
Linda F. Halle; Thomas C. Zietlow; Charles E. Barnes; AEROSPACE CORP EL SEGUNDO CA ELECTRONICS RESEARCH LAB
|
| Enhancement and depletion mode JFETs have been fabricated on silicon- on-sapphire substrates. When these devices are irradiated under bias with a 60Co source, their drain currents increase, and their threshold voltages shift in such a way that the devices become more difficult to pinch off. These effects can be explained by positive charge trapping at the silicon/sapphire interface. Gate to drain leakage currents also increase, and can be traced to ... |
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| Functional Assessment of Laser Irradiation |
MAR 88 |
|
| Authors:
David O. Robbins; OHIO WESLEYAN UNIV DELAWARE DEPT OF PSYCHOLOGY
|
| Exposure of the retina to intense spots of coherent light produces immediate changes in the ability of the animal to perform a visual discrimination task. Relatively large shifts in visual acuity occur during laser irradiation and recovery is somewhat rapid following termination of relatively low-energy, long duration exposures. With more intense energies, recovery is slower and permanent shifts in postexposure spectral sensitivity often accompany these types of exposure conditions. Keywords: ... |
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| Medicare: Potential Effects of Shifting the Home Health Benefit from Part A to Part B |
MAR 88 |
|
| Authors:
GENERAL ACCOUNTING OFFICE WASHINGTON DC HUMAN RESOURCES DIV
|
| Medicare, authorized by title XVIII of the Social Security Act, is a health insurance program that helps almost all Americans age 65 or over and some disabled persons pay for needed health services. Medicare consists of two parts: Part A, Hospital Insurance for the Aged and Disabled, covers inpatient hospital services, skilled nursing facility services after a hospitalization, hospice services, and home health services. Part A is financed primarily by ... |
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| Solvent Relaxation in Thermal Electron-Transfer Reactions: Some Comparisons with Real-Time Measurements of Solvation Dynamics |
17 FEB 88 |
|
| Authors:
George E. McManis; Michael J. Weaver; PURDUE UNIV LAFAYETTE IN DEPT OF CHEMISTRY
|
| The role of solvent dielectric relaxation on the barrier-crossing dynamics for outersphere electron transfer (ET), as evaluated from the solvent- dependent kinetics of metallocene self-exchange reactions, is compared with recent real-time measurements of polar solvation dynamics obtained from time- dependent fluorescence Stokes shifts (TDFS) for suitable charge-transfer excited states. While the solvent-dependent kinetics obtained in some aprotic media are consistent with the TDFS measurements, the barrier-crossing dynamics in several associated ... |
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| The Effect of Torch Pressure on Analyte Response in a 27 MHz Inductively Coupled Plasma |
04 FEB 88 |
4 pages |
| Authors:
Thomas R. Smith; M. B. Denton; ARIZONA UNIV TUCSON DEPT OF CHEMISTRY
|
| Recent studies employing an inductively coupled argon plasma system equipped with a torch capable of operating at pressures between 100 torr and 3000 torr will be described. Results from these studies indicate two major areas of research where non-atmospheric pressure torch conditions can be utilized. The first of these areas is the elucidation of excitation and energy transfer mechanisms within the plasma. The effect of pressure on energy transfer mechanisms, ... |
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| Acetylcholinesterase Inhibition and Information Processing in the Auditory Cortex |
01 FEB 88 |
|
| Authors:
Norman M. Weinberger; CALIFORNIA UNIV IRVINE CENTER FOR THE NEUROBIOLOGY OF LEARNING AND MEMOR
|
| Foundational characterization of cholinergic alteration of information processing was accomplished in the auditory cortex of unanesthetized cat by micropressure and iontophoresis during controlled pure tone stimulation. Discharges of single neurons for both single tones and frequency tuning functions were altered by muscarinic agonists, antagonists, and cholinesterase blockers in highly selective and specific ways. Agonist effects were systematically shifted by agonist and anticholinesterases, with soman tuning shifts shifts being uniquely permanent. ... |
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| Two-Dimensional Polyacrylamide Gel Electrophoresis of Human Serum: A case Report of Suspected Chemical Agent Exposure |
FEB 88 |
|
| Authors:
Michael A. Deaton; Peter Schmid; Gregory P. Jones; Charles A. Barba; David Jack; LETTERMAN ARMY INST OF RESEARCH PRESIDIO OF SAN FRANCISCO CA
|
| Serum was obtained from a patient who was suspected of having been exposed to mustard agent, Cl(CH2)2S(CH2)2Cl. Samples were collected approximately 30 days after the incident and were subjected to two-dimensional polyacrylamide gel electrophoresis. Serum proteins thus separated were then stained consecutively with Coomassie blue and silver. Compared to a sample of normal serum, no fewer than 5 of the patient's serum proteins displayed differences in isoelectric point as determined ... |
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| Event-Related and Steady Potential Changes in the Brain Related to Workload during Tracking, |
FEB 1988 |
|
| Authors:
W. C. McCallum; R. Cooper; P. V. Pocock; BURDEN NEUROLOGICAL INST BRISTOL (UNITED KINGDOM)
|
| In two experiments ERP's and slow potential changes have been recorded from normal subjects performing a visual tracking task in which the level of difficulty was systematically varied. In the second experiment a secondary discrimination task was added to increase the level of operator load and to probe the allocation of cerebral processing resources. The most notable feature to emerge was a protracted slow potential shift, associated with the primary ... |
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| Significance of the Local Electrode Potential within Pits, Crevices and Cracks |
FEB 88 |
|
| Authors:
Howard W. Pickering; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF MATERIALS SCIENCE AND ENGINEE RING
|
| This paper begins with a review of the experimental measurements of the electrode potential within pits, crevices and cracks for several commercially important alloy systems. Then, recent results for crevicing are reviewed. They give further insight into the relationship of the important parameters within the cavity: IR drop, Flade or passivation potential and solution composition, namely that stable crevice corrosion occurs when the electrode potential in the crevice is less ... |
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| On the Accuracy of Marine Gravity Measurements |
10 JAN 88 |
|
| Authors:
Pal Wessel; Anthony B. Watts; COLUMBIA UNIV NEW YORK
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| The accuracy of Lamont-Doherty Geological Observatory's global marine gravity data bank is assessed by examining the crossover errors (COEs) at intersecting ship tracks. More than 63,000 COEs were found, having a standard deviation of 22.43 mGal(mGal=10.00001 m/s-sq). The COEs are used to find and remove linear drifts and DC shifts present in the data set. This adjustment reduces the standard deviation to 13.96 mGal. COEs generally decrease with latitude, which ... |
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| Development and Experimental Verification of a Two-Dimensional Numerical Model of Piezoelectrically Induced Threshold Voltage Shifts in GaAs MESFETs |
JAN 88 |
|
| Authors:
Jean-Claude Ramirez; Patrick J. McNally; Lisa S. Cooper; James J. Rosenberg; L. B. Freund; BROWN UNIV PROVIDENCE RI DIV OF ENGINEERING
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| The results of a combined experimental and analytical investigation of the effects of mechanical stress on DC electrical parameters, particularly threshold voltage, in MESFETs are reported. The theoretical aspect of this study involves a two-dimensional finite element simulation of the same device structure on which measurements were made. In contrast with an approximate analytical calculation reported in the literature in which the stress concentrations which occur at the gate edges ... |
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| Further Studies of Seismic Variability at the Shagan River Test Site |
JAN 88 |
81 pages |
| Authors:
Brian W. Barker; John R. Murphy; S-CUBED LA JOLLA CA
|
| Large samples of teleseismic P wave data recorded from Shagan River underground explosions have been systematically analyzed in an attempt to develop a better quantitative understanding of the sources of m sub b variability observed for these explosions. Results indicate that large differences in station-corrected m sub b residuals between explosions in close proximity are associated with changes in the near-source proximity are associated with changes in the near-source P ... |
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| Coherence Effects in Optical Physics with Special Reference to Spectroscopy |
JAN 88 |
|
| Authors:
Emil Wolf; ROCHESTER UNIV NY DEPT OF PHYSICS AND ASTRONOMY
|
| Results are reported of investigation in the area of light propagation and spectroscopy from sources of arbitrary states of coherence. The research undertaken has completely clarified the foundations of the radiometric model. It was demonstrated conclusively that spatial coherence properties of a source influence the nature of the spectrum of the emitted radiation. A number of results were derived relating to effects of a random medium on the state of ... |
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| Longitudinal Spatial Inhomogeneities in Intrinsic Optical Bistability due to Induced Absorption |
JAN 1988 |
10 pages |
| Authors:
Charles M. Bowden; C. C. Sung; J. W. Haus; J. M. Cook; ARMY MISSILE COMMAND REDSTONE ARSENAL AL RESEARCH DIRECTORATE
|
| Longitudinal spatial effects in the nonlinear medium are analyzed in a model for mirrorless optical bistability due to induced absorption that treats heat conduction, electromagnetic field propagation, and temperature-dependent absorption. We consider two specific cases: the temperature-induced shift of the absorption peak of bound I2 excitons in CdS single crystals and the temperature-induced shrinkage of the band gap in GaAs/GaA1As quantum-well material. For both cases it is shown that the ... |
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| The Analysis of Current-Mirror MOSFETs for Use in Radiation Environments |
88 |
|
| Authors:
Marino J. Martinez; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| Experiments were conducted on current-mirror MOSFETs to examine their suitability for use in radiation environments. These devices, which allow low loss load current sensing (defined by a current-ratio n'), are an important element of many power integrated circuits (PICs). Total-dose testing demonstrated that the current ratio was virtually unaffected for many operating conditions. In all cases, changes were largest when sense resistance was largest and minimal when sense voltage was ... |
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| A Search for Wave Induced Particle Precipitation from Lightning and Transmitter Sources |
88 |
120 pages |
| Authors:
Jon E. Lundberg; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| Wave induced particle precipitation is introduced and examined for whistlers whose sources are within the plasmapause. The possible correlation between lightning strokes that carry positive charge to the ground and the observed 'Trimpi' events is discussed, sudden phase and/or amplitude shifts of a received VLF signal with gradual return to predisturbed values. The thunderstorm charging mechanisms that lead to the observed charge distribution and the advection of the positively charged ... |
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| Imaging of Ocean Waves by SAR |
88 |
42 pages |
| Authors:
R. L. Schult; F. S. Henyey; J. A. Wright; LA JOLLA INST CA CENTER FOR THE STUDY OF NONLINEAR DYNAMICS
|
| A model is presented for Synthetic Aperture Radar imaging of the ocean surface. The model attempts to avoid making assumptions about the relative importance of various imaging mechanisms. The model is applied to three issues, the focus setting, the asymmetry in the images obtained with obtained with opposite airplane flight directions, and the azimuthal image shift of features on range directed waves. The focus setting depends on a combination of ... |
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| An Investigation of Soviet Capabilities in Extended Range Arctic Ice Forecasting |
DEC 87 |
|
| Authors:
SCIENCE APPLICATIONS INTERNATIONAL CORP MONTEREY CA
|
| Recent trends in Soviet ice forecasting include: 1) rapid development in the use of satellite infrared, microwave, and side looking radar data relative to ice conditions in the last few years; 2) the continued emphasis on empirical or empirical/dynamic mixed models emphasizing application to regional problems; and 3) an arctic atmospheric circulation pattern change and a concomitant spatial shift of ice conditions within the Alaskan to Siberian sector that were ... |
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| Components of an Atmospheric Lidar System |
30 NOV 87 |
|
| Authors:
David Rees; UNIVERSITY COLL LONDON (ENGLAND) DEPT OF PHYSICS AND ASTRONOMY
|
| A wavelength meter and a doppler interferometric detector were developed to use with a lidar for measurements of atmospheric temperature and wind. These high spectral resolution instruments are used to measure the laser output line width and the backscatter wavelength shift. The sodium resonance lines are used to measure atmospheric structure properties in the 80 to 110 km altitude range. In this region, meteoric debris enters the earths upper atmosphere ... |
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| Visual Attention Effects on Discrimination of Line Orientation and Line Arrangement |
NOV 87 |
|
| Authors:
MaryLou Cheal; Don Lyon; David C. Hubbard; DAYTON UNIV OH RESEARCH INST
|
| The distinction between visual processes that require focused attention and those that use more diffuse or global attention is largely based on studies of visual search and texture segregation. It has been inferred from these studies that stimuli differing in the orientation of their component line segments can be distinguished without focal attention, whereas stimuli that differ only in the arrangement discrimination. In the first of the present experiments, while ... |
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| How Quickly Can Attention Affect Form Perception? |
NOV 87 |
|
| Authors:
Don R. Lyon; DAYTON UNIV OH RESEARCH INST
|
| It is possible to attend to different locations in the visual field without changing fixation. Recently, some researchers have suggested that sequenced of such internal attention shifts may be a necessary part of perception. This seems to require that attention be shifted very rapidly, since a complex scene can often be seen with only brief presentation. The present experiments trace the time course of the effects of internal attention shifts ... |
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| Coupling of Vibrational Modes of Adsorbates: Application to Field Induced Shifts for CO and CN on Cu(100) |
NOV 87 |
|
| Authors:
P. S. Bagus; C. J. Nelin; K. Hermann; M. R. Philpott; IBM ALMADEN RESEARCH CENTER SAN JOSE CA
|
| We have studied the coupling of the metal-ligand and the intra- molecular ligand stretching vibrations for CO and CN chemisorbed on Cu(100) using potential energy surfaces obtained with ab initio cluster model wave functions. When there is no applied electric field, approximate internal coordinate modes for these vibrations and the fully coupled normal modes give essentially the same results, showing that their coupling is small. In the presence of an ... |
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| Simulation of Infrared Spectra |
20 OCT 87 |
|
| Authors:
C. H. Douglass; R. T. Loda; H. H. Nelson; NAVAL RESEARCH LAB WASHINGTON DC
|
| Programs have been developed to simulate absorption and emission spectra of atmospheric and combustion product species. The programs use tabulated constants of the molecules have been included. The calculated emission and absorption spectra can be compared to experimental spectra and can be used to predict spectral shifts due to isotopic substitution. Results for a variety of materials and conditions are presented. Keywords: Spectral simulation, Emission spectra, Absorption spectra. |
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| Study of the Vibrational Modes of Subsurface Oxygen on Al (111) Using Diode Laser Infrared Reflection-Absorption Spectroscopy |
15 OCT 87 |
|
| Authors:
V. M. Bermudez; R. L. Rubinovitz; J. E. Butler; NAVAL RESEARCH LAB WASHINGTON DC
|
| Infrared reflection absorption spectroscopy (IRRAS), using polarization modulation and tunable diode laser excitation, has been applied to the study of the vibrational modes of subsurface oxygen on A1 (111). The dependence of the spectra on O2 exposure and on annealing has been investigated at a resolution of about 10-20/cm (1.2-2.5 meV) and correlated with Auger data. The absorption band (780-920/cm) consists of overlapping bands at about 835 and 862/cm associated, ... |
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| The Organization of Permutation Architectures with Bussed Interconnections |
14 OCT 87 |
31 pages |
| Authors:
Joe Kilian; Shlomo Kipnis; Charles E. Leiserson; MASSACHUSETTS INST OF TECH CAMBRIDGE MICROSYSTEMS RESEARCH CENTER
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| This paper explores the problem of efficiently permuting data stored in VLSI chips in accordance with a predetermined set of permutations. By connecting chips with shared bus interconnections, as opposed to point-to-point interconnections, the number of pins per chip can often be reduced. For example, for infinitely many n, permutation architectures are exhibited with Sq. rt. n pins per chip that can realize any of the n cyclic shifts on ... |
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| Performance of Data Compression Codes in Channels with Errors |
OCT 87 |
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| Authors:
SAIC COMSYSTEMS SAN DIEGO CA
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| Huffman codes, comma-free codes, and block codes with shift indicators are important candidate message compression codes for improving the efficiency of communications systems. This study was undertaken to determine if these codes could be used to increase the thruput of the fixed very low frequency (FVLF) communication system. This applications involves the use of compression codes in a channel with errors. Keywords include: Comma-free codes, and Block codes. |
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Reports by Keyword(s)
SHIFTING
