| Accelerated Decay of Radioisotopes |
Jan 2013 |
22 pages |
| Authors:
Joseph W Schumer; B V Weber; J C Zier; J P Apruzese; J Seely; NAVAL RESEARCH LAB WASHINGTON DC
|
 | Radioisotopes have energy densities up tole9 J/g, whereas chemical-bonds typically store energies less than 1e4 J/g. Energy density is only a necessary condition for usefulness as an energetic material. Detailed here is the final report of a search for novel mechanisms for the rapid and controllable release of nuclear energy within radioisotopes. In particular, the focus of this work was to theoretically, numerically, and experimentally quantify the cross-sections or nuclear ... |
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| Design and Performance of Ka-Band Fiber-Optic Delay Lines |
28 Dec 2012 |
67 pages |
| Authors:
Vincent J Urick; Joseph M Singley; Christopher E Sunderman; John F Diehl; Keith J Williams; NAVAL RESEARCH LAB WASHINGTON DC
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| The principles of fiber-optic delay lines (FODLs) are summarized and an example design is provided. The performance of two packaged FODLs is detailed including four-port S Parameters, noise figure, single-sideband phase noise, single-sideband amplitude noise, compression dynamic range and spurious-free dynamic range (SFDR). |
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| Combining Nondeterministic Separation and Chemical Interactions for Concentration of Nanoparticles |
17 Dec 2012 |
23 pages |
| Authors:
Anthony P Malanoski; Brandy J White; Jeffrey S Erickson; NAVAL RESEARCH LAB WASHINGTON DC
|
| This report summarizes the results of studies conducted to evaluate the potential utility of separation techniques based on Brownian motion. Two generations of ratchet devices and four different chemical functionalities were evaluated. The devices were used to alter concentration profiles for polystyrene nanoparticles in aqueous solutions. Key paramaters such as feature size, flow rate, and particle concentration were considered. The study demonstrated that nondeterministic separation has potential for application to ... |
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| Quantum Control of a Spin Qubit Coupled to a Photonic Crystal Cavity |
Dec 2012 |
26 pages |
| Authors:
Samuel G Carter; Timothy M Sweeney; Mijin Kim; Chul S Kim; Dmitry Solenov; Sophia E Economou; Thomas L Reinecke; Lily Yang; Allan S Bracker; Daniel Gammon; NAVAL RESEARCH LAB WASHINGTON DC
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| A key ingredient for a quantum network is an interface between stationary quantum bits and photons, which act as flying qubits for interactions and communication. Photonic crystal architectures are promising platforms for enhancing the coupling of light to solid state qubits. Quantum dots can be integrated into a photonic crystal, with optical transitions coupling to photons and spin states forming a long-lived quantum memory. Many researchers have now succeeded in ... |
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| Formaldehyde Five-Day Passive Chemical Dosimeter Badge Validation Study |
30 Nov 2012 |
29 pages |
| Authors:
Kevin J Johnson; Janet M Hughes; NAVAL RESEARCH LAB WASHINGTON DC
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| The utility of commercially available chemical dosimeter badges to adequately sample low-concentration formaldehyde vapor aboard Navy submarines was evaluated. In this work, badges were exposed to formaldehyde vapor at two approximate concentrations: 6 ppb and 2.5 ppb (13% and 6% of the Navy 90-day exposure limit, respectively) and for durations of 30, 60, 90, and 120 hours. Certified permeation tubes were used to generate formaldehyde vapor, which was then validated ... |
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| A Bio-Inspired Polymeric Gradient Refractive Index (GRIN) Human Eye Lens |
19 Nov 2012 |
10 pages |
| Authors:
Shanzuo Ji; Michael Ponting; Richard S Lepkowicz; Armand Rosenberg; Richard Flynn; Guy Beadie; Eric Baer; NAVAL RESEARCH LAB WASHINGTON DC
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| A synthetic polymeric lens was designed and fabricated based on a bio-inspired, Age=5 human eye lens design by utilizing a nanolayered polymer film-based technique. The internal refractive index distribution of an anterior and posterior GRIN lens were characterized and confirmed against design by microATR-FTIR. 3D surface topography of the fabricated aspheric anterior and posterior lenses was measured by placido-cone topography and exhibited confirmation of the desired aspheric surface shape. Furthermore, ... |
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| Restoring Turbulence-Degraded Underwater Images |
19 Nov 2012 |
4 pages |
| Authors:
Andrey Kanaev; Weilin Hou; NAVAL RESEARCH LAB WASHINGTON DC
|
| Underwater imaging is essential for a variety of scientific and military applications, such as optical communications, situational awareness, diver visibility, and mine detection. Unfortunately underwater imaging is severely impaired by scattering and optical turbulence associated with refraction index fluctuations. Because of the similarities between underwater and atmospheric image degradation, approaches taken to solve the underwater image restoration problem originate in atmospheric turbulence compensation algorithms. However, applying unmodified atmospheric techniques to ... |
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| Performance Loss of Lithium Ion Polymer Batteries Subjected to Overcharge and Overdischarge Abuse |
16 Nov 2012 |
25 pages |
| Authors:
Corey T Love; A'Dia Gaskins; NAVAL RESEARCH LAB WASHINGTON DC
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| Lithium-ion-polymer (LiPo) batteries are rechargeable energy storage devices which power a variety of unmanned ground and aerial vehicles throughout the Department of Defense. Thin form factor make LiPo cells ideal for assembling in large strands or stacks to make high voltage and high energy batteries. However, faulty connections between cells or improper cell balancing during routine charge/discharge can lead to overcharge or overdischarge of an individual cell, thus reducing performance ... |
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| Beacon Beams for Deep Turbulence High Energy Laser Beam Directors |
02 Nov 2012 |
13 pages |
| Authors:
Phillip Sprangle; Antonio Ting; Joseph Penano; Bahman Hafizi; V Markov; A Khizhnyak; C Davis; L DeSandre; NAVAL RESEARCH LAB WASHINGTON DC
|
| The objective of this report is to outline a new type of beam director for deep turbulence propagation of high energy lasers (HELs). The proposed beam director is based on a new and innovative approach employing a Brillouin enhanced four-wave mixing mechanism for generating a tight (small spot size) beacon beam on a remote target. This mechanism results in amplification and complete conjugation (phase and amplitude) of the beacon beam ... |
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| Maritime Threat Detection using Plan Recognition |
Nov 2012 |
8 pages |
| Authors:
Bryan Auslander; Kalyan M Gupta; David W Aha; NAVAL RESEARCH LAB WASHINGTON DC
|
| Existing algorithms for maritime threat detection employ a variety of normalcy models that are probabilistic and/or rule-based. Unfortunately, they can be limited in their ability to model the subtlety and complexity of multiple vessel types and their spatio-temporal events, yet their representation is needed to accurately detect anomalies in maritime scenarios. To address these limitations, we apply plan recognition algorithms for maritime anomaly detection. In particular, we examine hierarchical task ... |
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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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| Flat-Top Sector Beams Using Only Array Element Phase Weighting: A Metaheuristic Optimization Approach |
10 Oct 2012 |
53 pages |
| Authors:
Irwin D Olin; NAVAL RESEARCH LAB WASHINGTON DC
|
| The development of wide flat-top sector main beams by control of only the excitation phase of phased array elements is described. Pattern parameters are determined by an optimization approach using Visual Basic macros that control the repetitive application of Microsoft Excel's Solver spreadsheet add-in. By only controlling element phases with maximum equal amplitude signals, maximum integrated beam power is achieved. The basic common structure is a linear array of equally ... |
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| Naval Research Laboratory Overview |
Oct 2012 |
24 pages |
| Authors:
Dino Ferrari; NAVAL RESEARCH LAB WASHINGTON DC
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| A Versatile Impactor-Inspired Sample Chamber with a Virtual Pin-Grid Array for Sensor Performance Evaluation |
28 Sep 2012 |
1 pages |
| Authors:
Christopher R Field; Susan L Rose-Pehrsson; Cy R Tamanaha; Michael P Malito; NAVAL RESEARCH LAB WASHINGTON DC
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| An impactor-inspired sample chamber was constructed and assembled to evaluate sensor performance during exposure to trace analytes, such as explosives and chemical warfare agents. A flexible, virtual pin-grid array (PGA) was created with a series of hardware and software to make electrical connections without need to create prototype, expensive circuits. The sample chamber and Virtual-PGA electronics were characterized and tested using a thermal imager and a custom temperature and relative ... |
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| Development of Periodically Oriented Gallium Nitride for Non-linear Optics |
01 Sep 2012 |
7 pages |
| Authors:
Jennifer Hite; Mark Twigg; Michael Mastro; Jr Freitas Jaime; Jerry Meyer; Igor Vurgaftman; Shawn O'Connor; Nicholas Condon; Fritz Kub; Steven Bowman; NAVAL RESEARCH LAB WASHINGTON DC
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| Methods for growing periodically alternating polarities of GaN on GaN substrates have been developed. The resulting periodically oriented samples demonstrate feasibility of using this method to produce structures of utility in optical parametric generation. |
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| Radial Photonic Crystals for Microwave Operation |
Sep 2012 |
4 pages |
| Authors:
A Diaz-Rubio; J Carbonell; D Torrent; F Cervera; M A Kirleis; A Pique; J Sanchez-Dehesa; NAVAL RESEARCH LAB WASHINGTON DC
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| We analyze the properties of electromagnetic metamaterials with anisotropic constitutive parameters. Particularly, we analyze the so-called Radial Photonic Crystals, which are radially periodic structures verifying the Bloch theorem. This type of crystals can be designed and implemented in acoustics as well as in electromagnetism by using anisotropic metamaterials. They were originally proposed in acoustics, but similar functionalities are here proven in the electromagnetic domain together, for the first time, with ... |
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| Search and Determine Integrated Environment (SADIE) for Space Situational Awareness |
Sep 2012 |
12 pages |
| Authors:
Chris A Sabol; Alan Segerman; Aaron Hoskins; Bryan Little; Jr Schumacher Paul W; Shannon Coffey; NAVAL RESEARCH LAB WASHINGTON DC
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| A new high performance computing software applications package called the Search and Determine Integrated Environment (SADIE) is being jointly developed and refined by the Air Force and Naval Research Laboratories (AFRL and NRL) to automatically resolve uncorrelated tracks (UCTs) and build a more complete space object catalog for improved Space Situational Awareness (SSA). The motivation for SADIE is to respond to very challenging needs identified by and guidance received from ... |
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| Imaging Geostationary Satellites with a Common-Mount Interferometer: Image Quality and Fringe Tracking |
Sep 2012 |
10 pages |
| Authors:
Anders M Jorgensen; H R Schmitt; D Mozurkewich; J T Armstrong; R L Hindsley; E K Baines; NAVAL RESEARCH LAB WASHINGTON DC
|
| Imaging geostationary satellites is difficult because they are both too large and too small. They are too small to resolve with existing ground-based single telescopes, and they are too large (and too faint) to resolve with existing ground-based interferometers. Earth-rotation synthesis also does not work with geostationary satellites. We have designed a common-mount telescopes which we believe is the right instrument for geostationary satellite imaging, and described it previously in ... |
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| The Probabilities of Unique Events |
30 Aug 2012 |
35 pages |
| Authors:
Sangeet S Khemlani; Max Lotstein; Phil Johnson-Laird; NAVAL RESEARCH LAB WASHINGTON DC
|
| Many theorists argue that the probabilities of unique events, even real possibilities such as President Obama's re-election, are meaningless. As a consequence, psychologists have seldom investigated them. We propose a new theory (implemented in a computer program) in which such estimates depend on an intuitive non-numerical system capable only of simple procedures, and a deliberative system that maps intuitions into numbers. The theory predicts that estimates of the probabilities of ... |
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| TACSAT-4 Early Flight Operations Including Lessons From Integration, Test, and Launch Processing |
Aug 2012 |
14 pages |
| Authors:
Tim Duffey; Mike Hurley; Bill Raynor; Trevor Specht; Ken Weldy; Eric Bradley; Chris Amend; Eric Rossland; Jim Barnds; Keith Akins; NAVAL RESEARCH LAB WASHINGTON DC
|
| TacSat-4 is an experimental Ultra High Frequency (UHF) communications satellite that launched on a Minotaur IV+ from Kodiak, Alaska on September 27, 2011. The spacecraft and ground capabilities are briefly described for context. The integration, testing, launch processing, early flight operations, and initial end user results are then discussed. Unique approaches and lessons learned are highlighted. For example, the launch powered off approach used to test new Operationally Responsive Space ... |
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| Coherent Integration in Optical Interferometry |
Jul 2012 |
9 pages |
| Authors:
A M Jorgensen; H R Schmitt; G T van Belle; D Mozurkewich; D Hutter; J T Armstrong; E K Baines; S Restaino; T Hall; NAVAL RESEARCH LAB WASHINGTON DC
|
| Optical Interferometry has long been limited by low SNR making it nearly impossible to measure the small visibilities required to make resolved images. Although the SNR exists in the raw data, much SNR is lost in the conventional squared-visibility processing. In modern interferometers fringes are recorded simultaneously at many wavelengths and baselines. This makes phase-referencing possible, which is the key to coherent integration, which in turns can greatly improve the ... |
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| Effect of Chaos on Relativistic Quantum Tunneling |
Jun 2012 |
8 pages |
| Authors:
Xuan Ni; Liang Huang; Ying-Cheng Lai; Louis M Pecora; NAVAL RESEARCH LAB WASHINGTON DC
|
| We solve the Dirac equation in two spatial dimensions in the setting of resonant tunneling, where the system consists of two symmetric cavities connected by a finite potential barrier. The shape of the cavities can be chosen to yield both regular and chaotic dynamics in the classical limit. We find that certain pointer states about classical periodic orbits can exist,which suppress quantum tunneling, and the effect becomes less severe as ... |
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| Randomly Distributed Delayed Communication and Coherent Swarm Patterns |
May 2012 |
7 pages |
| Authors:
Brandon Lindley; Luis Mier-y-Teran-Romero; Ira B Schwartz; NAVAL RESEARCH LAB WASHINGTON DC
|
| Previously we showed how delay communication between globally coupled self-propelled agents causes new spatio-temporal patterns to arise when the delay coupling is fixed among all agents [1]. In this paper, we show how discrete randomly distributed delays affect the dynamical patterns. In particular, we investigate how the standard deviation of the time delay distribution affects the stability of the different patterns as well as the switching probability between coherent states. ... |
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| An Improved Empirical Model for Radar Sea Clutter Reflectivity |
27 Apr 2012 |
46 pages |
| Authors:
Vilhelm Gregers-Hansen Rashmi; NAVAL RESEARCH LAB WASHINGTON DC
|
| The most fundamental characteristic of sea clutter, as used in radar performance evaluation, is its apparent reflectivity, used here as a reminder that any measurement of sea clutter reflectivity includes the effects of propagation and shadowing close to the sea surface. Sea clutter reflectivity depends on many factors including sea state, wind velocity, grazing angle, polarization and radar frequency. A comprehensive tabulation of measurements from approximately 60 sources is included ... |
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| All-optical, Three-axis Fiber Laser Magnetometer |
16 Apr 2012 |
33 pages |
| Authors:
Geoffrey A Cranch; Gary A Miller; Clay K Kirkendall; NAVAL RESEARCH LAB WASHINGTON DC
|
| This report describes the development of an undersea fiber-optic magnetometer, suitable for remote deployment as a moving target detection system. A comprehensive overview of the operating principle and performance of this sensor system is given. The magnetic field sensor utilizes the Lorentzian force acting on a current carrying bridge in the presence of a magnetic field, which drives its oscillation measured with a fiber laser strain sensor. The undersea node ... |
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| Practical Implications of Pole Series Convergence and the Early-time in Transient Backscatter |
16 Apr 2012 |
13 pages |
| Authors:
Sun K Hong; Walter S Wall; Tim D Andreadis; W A Davis; NAVAL RESEARCH LAB WASHINGTON DC
|
| Here we consider the convergence of the singularity expansion method (SEM) pole series representation of the transient backscatter in terms of the stability in the estimated poles from the time domain response. Using a numerically simulated backscattered response of a thin wire, the temporal progression of the estimated pole series is examined by iteratively estimating them (using the Matrix Pencil Method) at different time-window locations. The results show a good ... |
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| Heave and Pitch Dynamics of Shallow Draft Surface Vehicles |
10 Apr 2012 |
26 pages |
| Authors:
Roger S Cortesi; Owen Thorp; George Piper; NAVAL RESEARCH LAB WASHINGTON DC
|
| This project's objective is to develop a model of the heave and pitch dynamics for a shallow draft surface vehicle. The model developed uses a novel approach of representing the ship dynamics in the frequency domain. The model is based on theoretical first-principles involving highly nonlinear equations that depend on the water wave frequency. Compared to time domain modeling and simulation approaches, the frequency domain model provides greater insight to ... |
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| Mariana Islands-Hyperspectral Airborne Remote Environmental Sensing Experiment 2010 |
09 Apr 2012 |
|
| Authors:
Charles M Bachmann; Marcos J Montes; Robert A Fusina; Rong-Rong Li; Deric Gray; Daniel Korwan; Carl Gross; Christopher Jones; Krista Lee; Jon Wende; NAVAL RESEARCH LAB WASHINGTON DC
|
 | This report describes the data collected during one of a series of Naval Research Laboratory (NRL) remote sensing and calibration and validation (Cal/Val) campaigns, providing data and information for the development of models of coast types and their associated environmental factors. Models allow rapid processing of hyperspectral imagery (HSI), generating shallow water bathymetric charts and trafficability maps. Cal/Val data collected during the Mariana Islands Hyperspectral Airborne Remote Environmental Sensing 2010 ... |
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| Quantification of Noise Sources in EMI Surveys |
09 Apr 2012 |
64 pages |
| Authors:
Glenn R Harbaugh; Daniel A Steinhurst; Mark J Howard; Bruce J Barrow; Jonathan T Miller; Thomas H Bell; NAVAL RESEARCH LAB WASHINGTON DC
|
| A series of field measurements were made under carefully controlled conditions at our home facility at the Army Research Laboratory Blossom Point Facility between July and September 2006. The magnitudes and effects of several types of background and noise sources on the data collected with several commonly used EMI sensors were measured. These noise sources included ground response/geology, inherent sensor noise, external noise sources, motion-induced noise, and position uncertainty. By ... |
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| Talisman-Saber 2009 Remote Sensing Experiment |
30 Mar 2012 |
173 pages |
| Authors:
Charles M Bachmann; Robert A Fusina; Marcos J Montes; Rong-Rong Li; Carl Gross; C R Nichols; John C Fry; Chris Parrish; Jon Sellars; Stephen White; NAVAL RESEARCH LAB WASHINGTON DC
|
| This report describes the data collected during one of a series of NRL remote sensing and calibration and validation (Cal/Val) campaigns, providing data and information for the development of models of coast types and their associated environmental factors for use in rapidly processing hyperspectral imagery (HSI) and generating shallow water bathymetric charts and trafficability maps. This report documents data that was collected during a remote sensing campaign that was conducted ... |
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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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| Hawaii-Hyperspectral Airborne Remote Environmental Sensing (HIHARES'09) Experiment |
15 Mar 2012 |
117 pages |
| Authors:
Charles M Bachmann; Robert A Fusina; Marcos J Montes; Rong-Rong Li; C R Nichols; John C Fry; Patrick Woodward; Eric Hallenborg; Chris Parrish; Jon Sellars; NAVAL RESEARCH LAB WASHINGTON DC
|
| This report describes data collected during one of a series of NRL remote sensing and calibration and validation (Cal/Val) campaigns, undertaken to develop models of coastal environments for use in rapidly processing hyperspectral imagery (HSI) and generating shallow water bathymetric charts and trafficability maps. This report describes data collected during the Hawaii-Hyperspectral Airborne Remote Environmental Sensing (HIHARES'09) experiment conducted at Marine Corps Base Hawaii and Marine Corps Training Area-Bellows from ... |
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| Polarization Characteristics of Coherent Waves |
12 Mar 2012 |
76 pages |
| Authors:
Irwin D Olin; NAVAL RESEARCH LAB WASHINGTON DC
|
| Coherent polarized waves, propagating toward and receding from an observer, together with their representation in terms of orthogonal linearly and circularly polarized component pairs are described in some detail. Appropriate matrix formulation facilitates their bases interchange and enables a better understanding of their characteristics, especially in connection with radar or communications related subjects. Component parameters in terms of Poincar?phere locations are described and readily characterize measurable relationships among different polarizations. ... |
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| THz Detection Of Small Molecule Vapors In The Atmospheric Transmission Windows |
Mar 2012 |
21 pages |
| Authors:
Joseph S Melinger; Yihong Yang; Mahboubeh Mandehgar; D Grischkowsky; NAVAL RESEARCH LAB WASHINGTON DC
|
| Using a low power beam of ultrashort THz pulses that propagate in the ambient laboratory environment we have measured the rotational signatures of small molecule vapors at frequencies within the atmospheric transmission windows. We investigate two types of apparatus. In the first type the THz beam propagates along a 6.7 meter round trip path that is external to the spectrometer, and which contains a long sample tube (5.4 meter round ... |
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| Impact of Signal-to-Noise Ratio in a Hyperspectral Sensor on the Accuracy of Biophysical Parameter Estimation in Case II Waters |
13 Feb 2012 |
23 pages |
| Authors:
Wesley J Moses; Jeffrey H Bowles; Robert L Lucke; Michael R Corson; NAVAL RESEARCH LAB WASHINGTON DC
|
| Errors in the estimated constituent concentrations in optically complex waters due solely to sensor noise in a spaceborne hyperspectral sensor can be as high as 80%. The goal of this work is to elucidate the effect of signal-to-noise ratio (SNR) on the accuracy of retrieved constituent concentrations. Large variations in the magnitude and spectral shape of the reflectances from coastal waters complicate the impact of SNR on the accuracy of ... |
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| Interband Cascade Lasers for Spectroscopy with Very Low Input Power |
30 Jan 2012 |
20 pages |
| Authors:
Charles D Merritt; William W Bewley; Chadwick L Canedy; Chul Soo Kim; Igor Vurgaftman; Joshua Abell; Jerry R Meyer; Mijin Kim; NAVAL RESEARCH LAB WASHINGTON DC
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| Analysis Of The IJCNN 2011 UTL Challenge |
13 Jan 2012 |
13 pages |
| Authors:
Isabelle Guyon; Gideon Dror; Vincent Lemaire; Daniel L Silver; Graham Taylor; David W Aha; NAVAL RESEARCH LAB WASHINGTON DC
|
| We organized a challenge in Unsupervised and Transfer Learning: the UTL challenge. We made available large datasets from various application domains: handwriting recognition, image recognition, video processing, text processing, and ecology. The goal was to learn data representations that capture regularities of an input space for re-use across tasks. The representations were evaluated on supervised learning target tasks unknown to the participants. The first phase of the challenge was dedicated ... |
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| Analysis of the IJCNN 2011 UTL Challenge |
13 Jan 2012 |
13 pages |
| Authors:
Isabelle Guyon; Gideon Dror; Vincent Lemaire; Daniel L Silver; Graham Taylor; David W Aha; NAVAL RESEARCH LAB WASHINGTON DC
|
| We organized a challenge in Unsupervised and Transfer Learning: the UTL challenge. We made available large datasets from various application domains handwriting recognition, image recognition, video processing, text processing, and ecology. The goal was to learn data representations that capture regularities of an input space for re-use across tasks. The representations were evaluated on supervised learning target tasks unknown to the participants. The first phase of the challenge was dedicated ... |
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| Magnetometer Response of Commonly Found Munitions Items and Munitions Surrogates |
12 Jan 2012 |
31 pages |
| Authors:
T H Bell; N Khadr; G R Harbaugh; D A Steinhurst; NAVAL RESEARCH LAB WASHINGTON DC
|
| Target response coefficients for several commonly encountered munitions types and three munitions surrogates were calculated from measurements made using the Naval Research Laboratory Multi-sensor Towed Array Detection System (MTADS) magnetometer array. A best-practice method for making these measurements is presented. Results are presented for four locations in the continental United States: Welcome, MD; Black Hills Army Depot, SD; Hawthorne Army Depot, NV; and a site in Withlacoochee, FL. The minimum-response ... |
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| Exploring the Mechanism of Biomolecule Immobilization on Plasma-Treated Polymer Substrates |
Jan 2012 |
9 pages |
| Authors:
E H Lock; S H North; J Wojciechowski; C R Taitt; S G Walton; NAVAL RESEARCH LAB WASHINGTON DC
|
| An electron beam-generated plasma source developed at NRL was used to modify polystyrene microtitre plates. A combination of complementary surface analytical and biochemical techniques was applied to evaluate the relationship between the biotic and abiotic layers, with particular emphasis on the efficiency of the preparation of polymer surfaces and its effectiveness for bioimmobilization. We conclude that the development of novel interface materials with superior transducing capabilities is dependent on the ... |
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| First-Principles Thermodynamics of Energetic Materials |
Jan 2012 |
6 pages |
| Authors:
Aaron C Landerville; Michael W Conroy; You Lin; Mikalai Budzevich; Carter T White; I I Oleynik; NAVAL RESEARCH LAB WASHINGTON DC
|
| Using density functional theory with empirical van der Waals corrections, cold pressure curves were calculated and combined with the quasi-harmonic approximation to study thermodynamical properties of several energetic molecular solids. Vibration spectra at each compression were calculated and used for including temperature and zero-point energy contributions to the free energy. Equilibrium properties at temperatures of experiments, as well as hydrostatic equations of state, specific heat capacities, and coefficients of thermal ... |
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| Maritime Threat Detection Using Probabilistic Graphical Models |
Jan 2012 |
7 pages |
| Authors:
Bryan Auslander; Kalyan M Gupta; David W Aha; NAVAL RESEARCH LAB WASHINGTON DC
|
| Maritime threat detection is a challenging problem because maritime environments can involve a complex combination of concurrent vessel activities, and only a small fraction of these may be irregular, suspicious, or threatening. Previous work on this task has been limited to analyses of single vessels using simple rule-based models that alert watchstanders when a proximity threshold is breached. We claim that Probabilistic Graphical Models (PGMs) can be used to more ... |
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| Goal-Driven Autonomy for Responding to Unexpected Events in Strategy Simulations |
Jan 2012 |
19 pages |
| Authors:
Matthew Klenk; Matt Molineaux; David W Aha; NAVAL RESEARCH LAB WASHINGTON DC
|
| To operate autonomously in complex environments, an agent must monitor its environment and determine how to respond to new situations. To be considered intelligent, an agent should select actions in pursuit of its goals, and adapt accordingly when its goals need revision. However, most agents assume that their goals are given to them; they cannot recognize when their goals should change. Thus, they have difficulty coping with the complex environments ... |
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| Performance Improvement of Long-Wave Infrared InAs/GaSb Strained-Layer Superlattice Detectors Through Sulfur-Based Passivation |
Jan 2012 |
5 pages |
| Authors:
E A Plis; M N Kutty; S Myers; A Rathi; E H Aifer; I Vurgaftman; S Krishna; NAVAL RESEARCH LAB WASHINGTON DC
|
| We report on effective sulfur-based passivation treatments of type-II InAs/GaSb strained layer superlattice detectors (100% cut-off wavelength is 9.8 microns at 77 K). The electrical behavior of detectors passivated by electrochemical sulfur deposition (ECP) and thioacetamide (TAM) was evaluated for devices of various sizes. ECP passivated detectors with a perimeter-to-area ratio of 1600/cm exhibited superior performance with surface resistivity in excess of 10(exp 4) ohm cm, dark current density of ... |
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| Toward Determining the Comprehensibility of Machine Translations |
Jan 2012 |
8 pages |
| Authors:
Tucker Maney; Linda Sibert; Dennis Perzanowski; Kalyan Gupta; Astrid Schmidt-Nielsen; NAVAL RESEARCH LAB WASHINGTON DC
|
| Economic globalization and the needs of the intelligence community have brought ma-chine translation into the forefront. There are not enough skilled human translators to meet the growing demand for high quality transla-tions or good enough translations that suf-fice only to enable understanding. Much research has been done in creating transla-tion systems to aid human translators and to evaluate the output of these systems. Metrics for the latter have primarily focused ... |
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| Pneumatically Modulated Liquid Delivery System for Nebulizers |
02 Dec 2011 |
27 pages |
| Authors:
Christopher R Field; Duane A Rogers; Susan L Rose-Pehrsson; Alex Terray; Sean J Hart; Adam Lubrano; NAVAL RESEARCH LAB WASHINGTON DC
|
| A liquid delivery system for nebulizers typically used in inductively coupled plasma spectrometry is implemented with active, closed-loop feedback to generate a constant, stable flow rate over extended periods of time. An electronic pressure control unit is coupled with a pressure vessel and flow meter in three separate configurations. The first configuration uses a computer to monitor the flow rate and adjust the pressure based on a PID algorithm. The ... |
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| Enhancement-Mode Antimonide Quantum-Well MOSFETs With High Electron Mobility and Gigahertz Small-Signal Switching Performance |
Dec 2011 |
4 pages |
| Authors:
Ashkar Ali; Himanshu Madan; Ashish Agrawal; Israel Ramirez; Rajiv Misra; J B Boos; Brian R Bennett; Jeff Lindemuth; Suman Datta; NAVAL RESEARCH LAB WASHINGTON DC
|
| This letter demonstrates, for the first time, enhancement-mode (e-mode) antimonide MOSFETs by integrating a composite high- gate stack (3 nm Al2 O3 1 nm GaSb) with an ultrathin InAs0.7 Sb0.3 quantum well (7.5 nm). The MOSFET exhibits record high electron drift mobility of 5200 cm2 /V s at carrier density (Ns ) of 1.8 1012 cm 2 , subthreshold slope of 150 mV/dec, ION /IOFF ratio of 4000 within a ... |
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| Communicating Uncertainty Information Across Conceptual Boundaries |
Dec 2011 |
8 pages |
| Authors:
Paul Hyden; Elias Ioup; Stephen Russell; NAVAL RESEARCH LAB WASHINGTON DC
|
| Information about data collection and modeling risks are frequently locked with information providers rather than shared with downstream information consumers. Information consumers often ingest products automatically. Without protocols to inject uncertainty, the ensemble modeling products common in the modeling discipline cannot accurately account for the input uncertainty inherent to those products. Future work to establish use cases and incorporate practitioner-driven rules and protocols for transmitting tiered uncertainty information between information ... |
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| Characterization of Lasers for Use in Analog Photonic Links |
22 Nov 2011 |
35 pages |
| Authors:
Joseph M Singley; John Diehl; Vincent J Urick; NAVAL RESEARCH LAB WASHINGTON DC
|
| A survey of lasers was conducted to characterize their performance as it relates to analog photonic link applications. The methods used to measure a laser's noise spectrum, linewidth, and optical spectrum are presented along with the results of those measurements. Trade-offs for each of the lasers characterized are discussed as well as their impact on analog photonic link performance. |
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| Microfabricating 3D Structures by Laser Origami |
09 Nov 2011 |
4 pages |
| Authors:
Alberto Pique; Scott Mathews; Andrew Birnbaum; Nicholas Charipar; NAVAL RESEARCH LAB WASHINGTON DC
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| A new technique generates 3D microstructures by controlled out-of-plane folding of 2D patterns through a variety of laser-based digital fabrication processes. |
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