| Validation of the Voice of America Coverage Analysis Program (VOACAP) |
Feb 2013 |
40 pages |
| Authors:
Peter S Guest; Arlene A Guest; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
 | This is the final report of the COMNAVMETOCCOM Independent Model Review Panel (CIMREP) for the Voice of America Coverage Analysis Program (VOACAP), version 05.0119W, as modified by the Space and Naval Warfare Systems Center Pacific (SSC-Pacific), Atmospheric Propagation Branch (5528). VOACAP is a tool for predicting the performance of High Frequency (HF) radio communication systems. The authors evaluated VOACAP for possible inclusion in the Oceanography and Atmospheric Master Library (OAML) ... |
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| Terahertz Reflection Spectroscopy for Identification of Explosive Devices |
09 Dec 2012 |
18 pages |
| Authors:
Eric I Thorsos; WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
|
| The research conducted under this project was a joint effort between Applied Physics Laboratory, University of Washington (APL-UW), and Portland State University (PSU). The focus at APL-UW was on 1) developing an experimental setup for variable source and detector angles and variable linear polarization, and then implementing it on a commercial THz spectroscopic system at PSU, 2) expanding the current THz time domain spectroscopic system at APL-UW to cover broader ... |
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| Evaluation of JSAF EM Propagation Prediction Methods for Navy Continuous Training Environment/Fleet Synthetic Training Results and Recommendations: Part 1 - Evaluation of Current JSAF EM Propagation Modeling |
Dec 2012 |
33 pages |
| Authors:
Peter S Guest; Paul A Frederickson; Tom Murphree; Arlene A Guest; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| The EM propagation model currently used in JSAF is FFACTR which is a part of the Engineers Refractive Index Prediction System (EREPS) Tactical Decision Aid (TDA) developed by what is now SPAWARS SSC San Diego in 1988. This model is no longer supported by SPAWARS or any other group and has been replaced; it is obsolete. This model is able to represent some realistic features including: (1) decrease in signal ... |
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| Resonant Terahertz Absorption Using Metamaterial Structures |
Dec 2012 |
77 pages |
| Authors:
Allan T Phillips; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The Sensor Research Lab at the Naval Postgraduate School is developing a real-time THz imaging camera. Vital to its design is the metamaterial absorbing layer (metafilm) within each pixel that allows for THz absorption. While there are numerous applications in the THz region, sensors and sources for THz energy have much room for improvement. The use of metamaterial technology for the purpose of a THz sensor has the potential to ... |
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| Review of Electromagnetic Frequency (EMF) Safety Program for Homestead ARB, FL |
28 Nov 2012 |
20 pages |
| Authors:
Zahid Sulaiman; Samuel Ortiz; Michael Ames; SCHOOL OF AEROSPACE MEDICINE WRIGHT PATTERSON AFB OH OCCUPATIONAL AND ENVIRONMENTAL HEALTH DEPT
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| A review of the electromagnetic frequency (EMF) safety program at Homestead ARB was conducted. Additionally, a survey of two previously unassessed emitters was performed. USAFSAM personnel identified and corrected deficiencies in the existing base EMF safety program and provided training to BE personnel on the management of the program in accordance with Air Force Occupational Safety and Health Standard 48-9, Electro-magnetic Frequency (EMF) Radiation Occupational Health Program. |
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| A Fundamental Study of Heat Transfer Phenomenon in Periodic Structures |
09 Nov 2012 |
23 pages |
| Authors:
Tribikram Kundu; ARIZONA UNIV TUCSON
|
| Ever increasing demand from structures makes them to work more in adverse environments. For example, engine components in high performance, high speed new aircrafts are being exposed to much higher temperatures than those in old aircrafts, in different control devices the continuous trend to pack more transistors on a single chip have resulted in an unprecedented level of power dissipation, and therefore higher temperatures at the chip level. Thermal phenomena ... |
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| Microwave Power Transmission Using Electromagnetic Coupling of Open-Ring Resonators |
01 Nov 2012 |
24 pages |
| Authors:
Yasuo Ohno; TOKUSHIMA UNIV (JAPAN)
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| Experimental results on 60GHz band signal transmission through ECOR (Electromagnetic Coupling of Open-Ring Resonators) are shown. Through sapphire substrate, 60-70GHz band signal are transmitted with 58.9% transmission efficiency and 7.4GHz bandwidth. However, the transmission band was shifted about 10GHz higher frequency. The reason is under investigation. ECOR technology is extended to lower frequencies for non-contact power transmission. The technology will benefit to power connectors for equipment modules where the problems ... |
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| Dielectric Response at THz Frequencies of Fe Water Complexes and Their Interaction with O3 Calculated by Density Functional Theory |
24 Oct 2012 |
69 pages |
| Authors:
L Huang; Samuel G Lambrakos; A Shabaev; L Massa; C Yapijakis; NAVAL RESEARCH LAB WASHINGTON DC
|
| The need for better monitoring of water quality and levels of water contamination implies a need for determining the dielectric response properties of water contaminants with respect to electromagnetic wave excitation. In addition to monitoring contaminants, there is an associated need for monitoring chemical processes whose purpose is deactivation or assistance in the removal of water contaminants. Two naturally occurring water contaminants, which are the result of decaying vegetation, are ... |
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| Dielectric Response at THz Frequencies of Mg Water Complexes Interacting with O3 Calculated by Density Functional Theory |
24 Oct 2012 |
67 pages |
| Authors:
L Huang; Samuel G Lambrakos; A Shabaev; L Massa; C Yapijakis; NAVAL RESEARCH LAB WASHINGTON DC CENTER FOR COMPUTATIONAL MATERIALS SCIENCE
|
| The need for better monitoring of water quality and levels of water contamination implies a need for determining the dielectric response properties of water contaminants with respect to electromagnetic wave excitation. In addition to monitoring contaminants, there is an associated need for monitoring chemical processes whose purpose is deactivation or assistance in the removal of water contaminants. Two naturally occurring water contaminants, which are the result of decaying vegetation, are ... |
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| A Scalable Distributed Syntactic, Semantic, and Lexical Language Model |
Sep 2012 |
43 pages |
| Authors:
Ming Tan; Wenli Zhou; Lei Zheng; Shaojun Wang; WRIGHT STATE UNIV DAYTON OH DEPT OF COMPUTER SCIENCE
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| This paper presents an attempt at building a large scale distributed composite language model that is formed by seamlessly integrating an n-gram model, a structured language model, and probabilistic latent semantic analysis under a directed Markov random field paradigm to simultaneously account for local word lexical information, mid-range sentence syntactic structure, and long-span document semantic content. The composite language model has been trained by performing a convergent N-best list approximate ... |
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| Beaming Electricity via Relay Satellites in Support of Deployed Combat Forces |
Sep 2012 |
79 pages |
| Authors:
Thomas R Essenpreis; NAVAL POSTGRADUATE SCHOOL MONTEREY CA SPACE SYSTEMS ACADEMIC GROUP
|
| The logistics required to supply military forces based in remote hostile territory can be onerous. A major component of those supplies is the fuel required to operate generators that provide electrical power. This research sought to determine the feasibility of a space-based system using wireless power transfer technology to relay power to a remote base from a location with a commercial grid. The two wireless power transfer methods examined in ... |
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| Design and Performance Evaluation of a 200 deg C Interleaved Boost Converter (Preprint) |
Sep 2012 |
22 pages |
| Authors:
James D Scofield; Seana A McNeal; Brett A Jordan; Hiroyuki Kosai; Biswajit Ray; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH AEROSPACE SYSTEMS DIR
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| Recent advances in SiC power semiconductor technology and resulting availability of SiC Schottky rectifiers and controlled devices (BJTs, JFETs, and MOSFETs) make it possible to design and implement power converters capable of operating at 200oC. The design, prototype development, operation, and testing of a 74 kHz, 2 kW, 100 V/270 V inversely-coupled, interleaved, dc-dc boost converter over the 20oC to 200oC temperature range is presented in this paper. The advantages ... |
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| Universal Zero Specular Reflection Curves for MetaMaterials |
Sep 2012 |
84 pages |
| Authors:
Choon B Ting; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Materials are generally classified in terms of their constitutive parameters, the complex permittivity and permeability epsilon in the frequency domain. These parameters are used to determine the response of materials to electromagnetic (EM) radiation. Materials found in nature have positive real parts for both epsilon and mu. In recent years, researchers have shown that a new class of materials called metamaterials (MTMs), characterized by inclusions of various shapes and materials ... |
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| Low Frequency Plasma Turbulence as a Source of Clutter in Surveillance and Communication |
Sep 2012 |
22 pages |
| Authors:
V Sotnikov; T Kim; E Mishin; W Amatucci; G Ganguli; E Tejero; T A Mehlhorn; I Paraschiv; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH
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| Presence of plasma turbulence can strongly influence propagation properties of electromagnetic signals used for surveillance and communication. In particular, we are interested in the generation of low frequency plasma turbulence in the form of coherent vortex structures coexisting with short scale density irregularities and of lower hybrid turbulence. Lower-hybrid type density irregularities are excited by plasma flows with velocity shear, whereas interchange or flute type oscillations in magnetized plasma are ... |
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| Munitions Classification With Portable Advanced Electromagnetic Sensors, Demonstration at the former Camp Beale, CA, Summer 2011 |
Jul 2012 |
47 pages |
| Authors:
Herbert Nelson; Anne Andrews; ENVIRONMENTAL SECURITY TECHNOLOGY CERTIFICATION PROGRAM OFFICE (DOD) ARLINGTON VA
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| Classification using portable advanced electromagnetic sensors, designed to operate in areas where terrain and vegetation preclude the use of vehicle-borne sensors, was demonstrated at the former Camp Beale, CA in 2011. The TEMTADS 2x2, Man-Portable Vector (MPV) and portable Berkeley UXO Discriminator (BUD) were used to successfully classify all of the targets of interest by all analysts. There was some variation among analysts in the percent of clutter rejected. All ... |
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| Design, Fabrication and Testing of Tunable RF Meta-atoms |
14 Jun 2012 |
198 pages |
| Authors:
Derrick Langley; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| Metamaterials are engineered structures designed to alter the propagation of electromagnetic waves incident upon the structure. The focus of this research was the effect of metamaterials on electromagnetic signals at radio frequencies. RF meta-atoms were investigated to further develop the theory, modeling, design and fabrication of metamaterials. Comparing the analytic modeling and experimental testing, the results provide a deeper understanding into metamaterials which could lead to applications for beam steering, ... |
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| Deep Horizontal Atmospheric Turbulence Modeling and Simulation with a Liquid Crystal Spatial Light Modulator |
Jun 2012 |
7 pages |
| Authors:
Peter Jacquemin; Bautista Fernandez; Christopher C Wilcox; Ty Martinez; Brij Agrawal; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| We investigate the performance of a Liquid Crystal (LC) Spatial Light Modulator (SLM) as an optical device for generating high intensity atmospheric turbulence in the laboratory. The experimental setup represents long range horizontal beam propagation at a low altitude where the conditions of atmospheric turbulence can be most severe. WaveProp is a software package written by the Optical Sciences Company (tOSC) which is used for simulating electro-magnetic field propagation through ... |
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| Passive Millimeter-Wave Imaging with Extended Depth of Field and Sparse Data |
May 2012 |
5 pages |
| Authors:
Vishal M Patel; Joseph N Mait; MARYLAND UNIV COLLEGE PARK CENTER FOR AUTOMATION RESEARCH
|
| In this paper, we introduce a new millimeter wave imaging modality with extended depth-of-field that provides diffraction limited images based on a significant reduction in scan-time. The technique uses a cubic phase element in the pupil of the system and a nonlinear recovery algorithm to produce images that are insensitive to object distance. We present experimental results that validate system performance and demonstrate a greater than four-fold increase in depth-of-field ... |
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| Acceptance Angle of a Plasma Channel |
09 Apr 2012 |
10 pages |
| Authors:
Daniel F Gordon; Bahman Hafizi; NAVAL RESEARCH LAB WASHINGTON DC BEAM PHYSICS BRANCH
|
| Plasma channels are useful as guiding structures for high intensity electromagnetic radiation. A finite radius plasma channel ceases to act as a guiding structure if the f-number of the focusing used to couple radiation into the channel is too small. Expressions are derived for the critical f-number needed to achieve guiding in a finite radius plasma channel. This is done using both a ray tracing analysis, and an eigenmode expansion ... |
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| Joint Electromagnetic Spectrum Management Operations |
20 Mar 2012 |
103 pages |
| Authors:
JOINT CHIEFS OF STAFF WASHINGTON DC
|
| Military operations are complicated by increasingly complex demands on the electromagnetic spectrum (EMS). All modern forces depend on the EMS. The EMS is a physical medium through which joint forces conduct operations. The importance of the EMS and its relationship to the operational capabilities is the key focus of joint electromagnetic spectrum management operations (JEMSMO). The EMS is a highly regulated and saturated natural resource. The EMS includes the full ... |
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| Terahertz Spectra of Water Complexes of Beta-HMX Calculated by Density Functional Theory |
16 Mar 2012 |
29 pages |
| Authors:
L Huang; Samuel G Lambrakos; N Bernstein; V Jacobs; A Shabaev; L Massa; NAVAL RESEARCH LAB WASHINGTON DC
|
| The need for better detection of explosive devices has imposed a necessity for determining the dielectric response properties of energetic materials with respect to electromagnetic wave excitation. Among the range of different frequencies for electromagnetic excitation, the THz frequency range is of particular interest because of its nondestructive nature. The present study is based on significant progress in density functional theory (DFT), and associated software technology, which is sufficiently mature ... |
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| ALLTEM System User's Manual, Munitions Management Projects, ALLTEM Multi-Axis Electromagnetic Induction System Demonstration and Validation, Version 1.0 |
05 Mar 2012 |
196 pages |
| Authors:
Theodore H Asch; ENVIRONMENTAL SECURITY TECHNOLOGY CERTIFICATION PROGRAM OFFICE (DOD) ARLINGTON VA
|
| An advanced multi-axis electromagnetic induction system, ALLTEM, has been specifically designed and developed for detection and discrimination of unexploded ordnance (UXO) by the U.S. Geological Survey. This document is a combined user s manual for operating the ALLTEM including data acquisition with navigation, data pre-processing in a customized LabView interface, and finally data processing from within Geosoft Oasis Montaj. This ALLTEM software manual is a supplement to the on-line tutorials ... |
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| One-Pot Synthesis of Conducting Graphene Polymer Composites and Its Strain Sensing Application (Preprint) |
Mar 2012 |
7 pages |
| Authors:
Varrla Eswaraiah; Krishnan Balasubramaniam; Sundara Ramaprabhu; INDIAN INST OF TECHNOLOGY CHENNAI (INDIA)
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| In-situ reduction of graphite oxide in polymer powder has been implemented using focused solar electromagnetic radiation. Graphene has proved that it can act as alternative filler in nanocomposites due to its high electronic transport properties and its use in advanced polymer composites for EMI shielding applications. With an applied load, strain measured and corresponding change in resistance of the reduced graphite oxide-polymer composites has been observed. The morphological, structural, electrical, ... |
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| Near-Field Propagation of Sub-Nanosecond Electric Pulses into Amorphous Masses |
01 Feb 2012 |
52 pages |
| Authors:
Shu Xiao; Karl H Schoenbach; OLD DOMINION UNIV NORFOLK VA FRANK REIDY RESEARCH CENTER FOR BIOELECTRICS
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| The project, Near-Field Propagation of Sub-Nanosecond Electric Pulses into Amorphous Masses , deals with the propagation of subnanosecond pulsed radiation in the near field region and its use in probing inhomogeneities in dielectrics. It also explores the possibility of changing the physical structure of lossy dielectrics by using very intense pulses. A subnanosecond high voltage pulse generator was constructed, which is able to deliver 150 ps (FWHM) pulses with 100 ... |
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| Coupling Issues Associated with Electro-Magnetic Vulnerability (EMV) Testing of Vehicles Over Ground |
Jan 2012 |
17 pages |
| Authors:
T H Shumpert; M L Waller; S H Wong; R W Scharstein; REDSTONE TEST CENTER REDSTONE ARSENAL AL
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| Electromagnetic Vulnerability (EMV) testing of ground vehicles and helicopters is (by necessity) performed in the immediate presence of ground surfaces (natural earth, asphalt, concrete, ship decks, and other finitely conducting grounds). The impact of the nature of these grounds on the EM coupling to the various vehicles being tested is the focus of this work. As one approach to addressing these issues quantitatively, personnel at Redstone Test Center Electromagnetic Environmental ... |
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| Plasmon Lasers: Coherent Light Source at Molecular Scales |
Jan 2012 |
22 pages |
| Authors:
Ren-Min Ma; Rupert F Oulton; Volker J Sorger; Xiang Zhang; CALIFORNIA UNIV BERKELEY NANOSCALE SCIENCE AND ENGINEERING CENTER
|
| Plasmon lasers are a new class of coherent optical frequency electromagnetic wave amplifiers that deliver intense coherent and directional surface plasmons well below the diffraction barrier. The strongly confined electric fields in plasmon lasers can enhance significantly light-matter interactions and bring fundamentally new capabilities to bio-sensing, data storage photolithography and optical communications. |
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| Conceptual Design of Future Undersea Unmanned Vehicle (UUV) System for Mine Disposal |
Jan 2012 |
13 pages |
| Authors:
Kwang S Song; Peter C Chu; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| A conceptual design is proposed for an effective mine countermeasure (MCM) system, which consists of 3- unmanned underwater vehicles (UUVs) and 10-20 small charged deliverable vehicles. New underwater optical communication systems are introduced to improve onboard mine reconnaissance and decision making with the key technologies focused on system and communication efficiency, capability of data processing, and cost effectiveness of MCM systems. The proposed UUV MCM system is cost effective due ... |
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| Recent Advances in Transformation Optics |
Jan 2012 |
17 pages |
| Authors:
Yongmin Liu; Xiang Zhang; CALIFORNIA UNIV BERKELEY NANOSCALE SCIENCE AND ENGINEERING CENTER
|
| Within the past a few years, transformation optics has emerged as a new research area, since it provides a general methodology and design tool for manipulating electromagnetic waves in a prescribed manner. Using transformation optics, researchers have demonstrated a host of striking phenomena and devices; many of which were only thought possible in science fiction. In this paper, we review the most recent advances in transformation optics. We focus on ... |
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| Effects of Meandering on Dipole Antenna Resonant Frequency |
Jan 2012 |
8 pages |
| Authors:
Olusola O Olaode; W D Palmer; William T Joines; DUKE UNIV DURHAM NC
|
| In low-frequency applications, antenna designers find that it is beneficial to adjust the resonant frequency while preferably maintaining the physical size as a means of improving the antenna?s radiation resistance, which in turn improves the radiation efficiency. The closer the resonant frequency is to the frequency of operation, the more efficient the antenna is. Addition of bends is one such technique for increasing the electrical size of a dipole antenna ... |
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| Fundamental Studies of Electronic Properties of Materials and Devices for High Power, Compact Terahertz Vacuum Electron Devices |
23 Dec 2011 |
6 pages |
| Authors:
John H Booske; WISCONSIN UNIV MADISON
|
| The results of this investigation have yielded two major new research capabilities and several important advances in physical understanding of materials and devices at high (THz-regime) frequencies. A quasi-optical cavity THz measurement system was developed with a record-high Q and resolution capable of measuring differences in surface conductivity less than 10% at frequencies between 300- 1000 GHz. A multi physics computational model (EMC, FDTD, MD) was developed for electron transport ... |
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| Constructing a Climatology of Whistler Wave Energy from Lightning in Low Earth Orbit |
16 Dec 2011 |
48 pages |
| Authors:
Jonah J Colman; AIR FORCE RESEARCH LAB KIRTLAND AFB NM SPACE VEHICLES DIRECTORATE
|
| Starting from OTD/LIS lightning data representing 1995-2005, a climatology is constructed with 1 deg x 1 deg latitude-longitude spatial resolution, averaged into 2 hour bins for each month of the year. Assuming a linear relationship between optical flash rate and VLF power flux, and that the VLF amplitude drops off as one over distance, a proxy for VLF power is developed. A typical lightning spectrum is then applied and the ... |
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| Exploitation of Unintentional Information Leakage from Integrated Circuits |
Dec 2011 |
220 pages |
| Authors:
William E Cobb; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
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| Unintentional electromagnetic emissions are used to recognize or verify the identity of a unique integrated circuit (IC) based on fabrication process-induced variations in a manner analogous to biometric human identification. The effectiveness of the technique is demonstrated through an extensive empirical study, with results presented indicating correct device identification success rates of greater than 99:5%, and average verification equal error rates (EERs) of less than 0:05% for 40 near-identical devices. ... |
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| Properties and Applications of Lossy Metamaterials |
Dec 2011 |
97 pages |
| Authors:
Christos Doumenis; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The complex permittivity ( ) and permeability ( ) of a material determines the response of the material to electromagnetic radiation. In many cases, the real part of and are both positive for materials that can be found in nature. Metamaterials (MTMs) are engineered media that are designed to have either a negative permittivity or a negative permeability or both. Negative permittivity and permeability cause electromagnetic waves travelling through this ... |
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| Investigation of an Electromagnetic Induction Sensor |
Dec 2011 |
143 pages |
| Authors:
Jr Scott Waymond R; GEORGIA TECH APPLIED RESEARCH CORP ATLANTA GA
|
| In recent years, advanced EMI sensors that use a broad range of frequencies long with advanced signal processing have been shown to be capable of discrimination between buried land mines and many types of buried metal clutter. For these EMI sensors to be effective, they must be able to accurately, repeatably, and quickly measure the response of a buried target. This is difficult because the sensor must operate with bandwidths ... |
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| Demonstration Report, Munitions Management Projects, ESTCP Project MR-200809, ALLTEM Multi-Axis Electromagnetic Induction System Demonstration and Validation, Aberdeen Proving Ground Standardized UXO Technology Demonstration Site, Version 1.0 |
17 Nov 2011 |
291 pages |
| Authors:
Theodore H Asch; GEOLOGICAL SURVEY WASHINGTON DC
|
| An advanced multi-axis electromagnetic induction system, ALLTEM, has been specifically designed for detection and discrimination of unexploded ordnance (UXO). This work has been funded by ESTCP (Project MM-0809). ALLTEM uses a continuous trianglewave excitation that measures the target step response rather than the more common impulse response. Ferrous and non-ferrous metal objects have opposite polarities. The system multiplexes through all three orthogonal (Hx, Hy, and Hz axes) transmitting loops and ... |
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| Plasma Metamaterials for Arbitrary Complex-Amplitude Wave Filters |
07 Oct 2011 |
13 pages |
| Authors:
OSAMU SAKAI; KYOTO UNIV (JAPAN)
|
| In this project, we investigated arbitrary complex functions for electromagnetic waves by using a plasma array reinforced by metallic components and changing a pattern of series switches, external power for plasma generation, and pressure of discharge gases. In Section II., we describe the theoretical part of this project, where plasma metamaterials were predicted for the purpose of potential complex wave filters for the first time. In Section III, we show ... |
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| Numerical Simulations of Cloaking Problems using a DPG Method |
Oct 2011 |
21 pages |
| Authors:
L Demkowicz; Jichun Li; TEXAS UNIV AT AUSTIN INST FOR COMPUTATIONAL ENGINEERING AND SCIENCES
|
| The paper reviews the construction of cloaks for 2D acoustic or electromagnetic waves using the Piola transform, and shows how the transform leads to the construction of a quasi-optimal test norm for the Discontinuous Petrov-Galerkin (DPG) method with optimal test functions for this class of problems. Numerical experiments for cylindrical and square cloaks illustrate the discussed concepts and show that the DPG method is effective in cloak simulations. |
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| Optimizing Refractivity from Clutter (RFC) for Surface-Based Ducts |
30 Sep 2011 |
11 pages |
| Authors:
Amalia E Barrios; Nathan Fuhrer; Peter Gerstoft; Caglar Yardim; Ali Karimian; SPACE AND NAVAL WARFARE SYSTEMS COMMAND SAN DIEGO CA
|
| Develop electromagnetic propagation models, and refractivity inversion algorithms, that perform equally well over land and sea and in the presence of anomalous propagation conditions for both surface and airborne emitters, for use in operational or engineering propagation assessment systems. |
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| Efficient Terahertz Emission from InAs Nanowires |
16 Sep 2011 |
8 pages |
| Authors:
Denis V Seletskiy; Michael P Hasselbeck; Jeffrey G Cederberg; Aaron Katzenmeyer; Maria E Toimil-Molares; Francois Leonard; A A Talin; Mansoor Sheik-Bahae; NEW MEXICO UNIV ALBUQUERQUE DEPT OF PHYSICS AND ASTRONOMY
|
| We observe intense pulses of far-infrared electromagnetic radiation emitted from arrays of InAs nanowires. The terahertz radiation power efficiency of these structures is 15 times higher than a planar InAs substrate. This is explained by the preferential orientation of coherent plasma motion to the wire surface, which overcomes radiation trapping by total-internal reflection.We present evidence that this radiation originates from a low-energy acoustic surface plasmon mode of the nanowire. This ... |
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| Optical Readout System for Bi-Material Terahertz Sensors |
Sep 2011 |
99 pages |
| Authors:
Elison Montagner; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The objective of this work is to design, assemble, and characterize an optical readout for bi-material MEMs sensor arrays that can be integrated into a THz imaging system. All this effort is a contribution to the goals of the research conducted by the Naval Postgraduate School Sensor Research Laboratory on designing and fabricating THz-optimized bi-material MEMs sensor arrays for THz imaging. Basic concepts of THz radiation and detection are presented. ... |
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| Programming Models for Heterogeneous Multicore Systems |
08 Aug 2011 |
9 pages |
| Authors:
Jesus J Labarta; BARCELONA SUPERCOMPUTING CENTER BARCELONA (SPAIN)
|
| This report results from a contract tasking BSC as follows. The objective of this grant was to study a programming model and performance analysis tools to productively exploit the parallelism in multicore systems. The work is based on the StarSs programming model proposal by BSC and the performance analysis tools also developed at BSC, The focus was on three areas: 1) Intelligent analysis techniques in performance data analysis, 2) Locality ... |
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| Performance Analysis of Adaptive Probabilistic Multi-Hypothesis Tracking With the Metron Data Sets |
08 Jul 2011 |
6 pages |
| Authors:
Christian G Hempel; Tod Luginbuhl; NAVAL UNDERSEA WARFARE CENTER DIV NEWPORT RI
|
| The Probabilistic Multi-hypothesis Tracking (PMHT) algorithm [1] is a batch type multi-target tracking algorithm based on the Expectation-Maximization (EM) method [2]. Unlike other popular batch methods (e.g., Multi-Hypothesis Tracking, MHT) the computational burden of PMHT grows linearly in the size of the batch, the number of clutter detections, and the number of targets tracked. this is achieved by employing the independent assignment model for assigning measurements to tracks which gives ... |
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| Ground State Resonance Structure of Molecular Clusters of beta-HMX Calculated by Density Functional Theory for THz Frequencies |
21 JUN 2011 |
41 pages |
| Authors:
L. Huang; A. Shabaev; S. G. Lambrakos; L. Massa; NAVAL RESEARCH LAB WASHINGTON DC CENTER FOR COMPUTATIONAL MATERIALS SCIENCE
|
| We present calculations of ground state resonance structure associated with molecular clusters of HMX using density functional theory (DFT), which is for the construction of parameterized dielectric response functions for excitation by electromagnetic waves at compatible frequencies. These dielectric functions provide for different types of analyses concerning the dielectric response of explosives. In particular, these dielectric response functions provide quantitative initial estimates of spectral response features for subsequent adjustment with ... |
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| Ballistic Protection |
14 JUN 2011 |
21 pages |
| Authors:
Jeffrey A. Koshko; ARMY TANK AUTOMOTIVE RESEARCH DEVELOPMENT AND ENGINEERING CENTER WARREN MI
|
| Further mature and develop weight / space trades to reduce cost of the threshold CVAD armor for GCV Develop GCV objective threat armor system while meeting platform weight, space and cost goals Advance electro-magnetic armor systems maturity Develop smart armor with embedded, real-time health monitoring capability. |
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| Combinational Circuit Obfuscation Through Power Signature Manipulation |
JUN 2011 |
128 pages |
| Authors:
Hyunchul Ko; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Today's military systems are composed of hardware and software systems, many of which are critical technologies, and must be protected to ensure our adversaries cannot gain any information from a various analysis attacks. Side Channel Analysis (SCA) attacks allow an attacker to gain the significant information from the measured signatures leaked by side-channels such as power consumption, and electro-magnetic emission. In this research the focus on detecting, characterizing, and manipulating ... |
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| Large-Scale Coherent Flow Structures in a Natural Braided Reach Section of a Gravel-Bed River |
JUN 2011 |
67 pages |
| Authors:
William F. Ashley; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Stream-wise length scales of coherent flow structures were examined to test the hypothesized 2 to 6 times the depth scale in relatively deeper (~1 m) and faster (~1.5 m/s) flows in a braided reach of the Kootenai River, Idaho. Velocities were measured using a custom Acoustic Doppler Current Profiler, an array of six electromagnetic current meters, and an Acoustic Doppler Velocimeter in a variety of river depths (0.6 1.7 m) ... |
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| An EM System With Dramatic Multi-Axis Transmitter and Tensor Gradiometer Receiver |
Jun 2011 |
|
| Authors:
David C George; D D Snyder; G AND G SCIENCES INC GRAND JUNCTION CO
|
 | The objective of the work was to demonstrate that sensor pairs could be used to adequately approximate the spatial gradients of the vector dB/dt field and to test if the use of sensor differences improved or degraded the quality of data compared to conventional measurements. An array of four, small, three-component sensors was shown to be useful to approximate the spatial gradient tensor when the target was not exceedingly c ... |
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| Method for Enabling the Electronic Propagation Mode Transition of an Electromagnetic Interface System |
31 May 2011 |
16 pages |
| Authors:
Donald H Steinbrecher; NAVAL UNDERSEA WARFARE CENTER DIV NEWPORT RI
|
| A propagating mode transition system provides a transition from a free-space-propagating electromagnetic energy field, which is partitioned by an array of elongate elements, to a transverse electromagnetic-mode propagating energy field in a transmission line. Electrically-conductive pads are disposed on a substrate with the pads being arranged in spaced-apart fashion. Each pad is substantially covered by and electrically coupled to one of the elongate elements at a base thereof such that ... |
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| Study on Active Terahertz Metamaterials |
01 APR 2011 |
5 pages |
| Authors:
Taiichi Otsuji; TOHOKU UNIV SENDAI (JAPAN) RESEARCH INST OF ELECTRICAL COMMUNICATION
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| In this program the grantee investigated THz radiation sources and modulators formed by active metamaterials made with the grantee's original interdigitated grating gate (DGG) structures on HEMT device layers. The principle of operation is the two-dimensional plasmons which are confined into artificial dimensions of metamaterial structure in a HEMT and are electrically or optoelectronically excited to seed the electromagnetic radiation. |
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| Shallow Water Marine UXO Detection Survey, United States Marine Corps Base, Camp Lejeune, North Carolina |
APR 2011 |
46 pages |
| Authors:
Paula Bond; Raye Lahti; AMEC EARTH AND ENVIRONMENTAL INC KNOXVILLE TN
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| The underwater unexploded ordnance (UXO) towed array (UUTA) electromagnetic system designed by 3Dgeophysics.com (3Dg) utilizes modified and improved Geonics, Ltd. electromagnetic (EM)61 metal detection technology. The UUTA system includes a 2.0 m (6.56 ft) wide (two receiver coil) non-contact bottom-skimming sensor platform, a down rigging tow bar, and a hydrofoil control surface mounted on a 6.7 m (22 ft) ThunderJet boat. The system was designed to be used with a ... |
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Reports by Keyword(s)
ELECTROMAGNETIC RADIATION
