| Spectral Approaches to Learning Predictive Representations |
Sep 2012 |
177 pages |
| Authors:
Byron Boots; CARNEGIE-MELLON UNIV PITTSBURGH PA SCHOOL OF COMPUTER SCIENCE
|
 | A central problem in artificial intelligence is to choose actions to maximize reward in a partially observable, uncertain environment. To do so, we must obtain an accurate environment model, and then plan to maximize reward. However, for complex domains, specifying a model by hand can be a time-consuming process. This motivates an alternative approach: learning a model directly from observations. Unfortunately, learning algorithms often recover a model that is too ... |
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| Numerical Performance Prediction of a Miniature Ramjet at Mach 4 |
Sep 2012 |
131 pages |
| Authors:
Bingqiang Chen; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Using a 3-D axis-symmetric model, the cold-flow performance of a miniature ramjet in Mach 4 flow was predicted with the computational fluids dynamic (CFD) code from ANSYS-CFX. The nozzle-throat area was varied to increase the backpressure and this pushed the normal shock that was sitting within the inlet, out to the lip of the inlet cowl. Using the eddy dissipation combustion model in ANSYS-CFX, a combustion analysis was performed on ... |
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| Mapping Nuclear Fallout Using the Weather Research & Forecasting (WRF) Model |
Sep 2012 |
105 pages |
| Authors:
Joseph C Schofield; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| There are many models that attempt to predict transport & dispersion (T&D) of particulate matter in the sensible atmosphere. The majority of these existing models are unable to incorporate atmospheric processes such wet deposition through scavenging and cloud condensation nuclei (CCN) formation. To this end, the numerical weather prediction (NWP) model known as the Weather Research & Forecasting with Chemistry (WRF/Chem) Model is studied to determine its suitability as a ... |
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| Survival, Growth and Reproduction of Non-Native Nile Tilapia II: Fundamental Niche Projections and Invasion Potential in the Northern Gulf of Mexico |
27 Jul 2012 |
12 pages |
| Authors:
Michael R Lowe; Wei Wu; Mark S Peterson; Nancy J Brown-Peterson; William T Slack; Pamela J Schofield; ARMY CORPS OF ENGINEERS VICKSBURG MS ENGINEER RESEARCH AND DEVELOPMENT CENTER
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| Understanding the fundamental niche of invasive species facilitates our ability to predict both dispersal patterns and invasion success and therefore provides the basis for better-informed conservation and management policies. Here we focus on Nile tilapia (Oreochromis niloticus Linnaeus, 1758), one of the most widely cultured fish worldwide and a species that has escaped local aquaculture facilities to become established in a coastal-draining river in Mississippi (northern Gulf of Mexico). Using ... |
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| Calibration of a Silver Detector using a PuBe Source |
14 Jun 2012 |
99 pages |
| Authors:
Melanie E Mace; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT/DEPT OF ENGINEERING PHYSICS
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| During the initial design of the Field Reversed Compression and Heating Experiment (FRCHX), magnetohydrodynamic simulations performed by Los Alamos National Laboratory using MACH2 predicted a neutron yield on the order of 1012 neutrons. However, Air Force Research Laboratory (AFRL) measurements indicate a total of 107-108 neutrons are generated from the FRCHX. A PuBe source was used to create a burst of neutrons to calibrate an AFRL silver detector based on ... |
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| Conjugate Gradient Parametric Detection of Multichannel Signals (Preprint) |
May 2012 |
32 pages |
| Authors:
Muralidhar Rangaswamy; Chaoshu Jiang; Hongbin Li; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH SENSORS DIR/ LAYERED SENSING EXPLOITATION DIV
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| The parametric adaptive matched filter (PAMF) detector for space-time adaptive processing (STAP) detection is re-examined in this paper. Originally, the PAMF detector was introduced by using a multichannel autoregressive (AR) parametric model for the disturbance signal in STAP detection. While the parametric approach brings in benefits such as reduced training and computational requirements as compared with fully adaptive STAP detectors, the PAMF detector as a reduced-dimensional solution remains unclear. This ... |
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| Development of Life Prediction Models for High Strength Steel in a Hydrogen Emitting Environment |
May 2012 |
48 pages |
| Authors:
Scott M Grendahl; Franklyn Kellogg; Hoang Nguyen; Matthew Motyka; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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| Solvent substitution for maintenance and overhaul operations of military systems has been a primary environmental concern for many years. Cadmium replacement in these systems has been targeted for decades. Both of these areas have a common obstacle for implementation of any potential alternative. Hydrogen embrittlement of high strength steel is the most predominant unforeseen hurdle since high strength materials show sensitivity to the phenomena and the source of the hydrogen ... |
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| Noise Induced Switching in Delayed Systems |
27 Apr 2012 |
17 pages |
| Authors:
Ira B Schwartz; Thomas W Carr; Lora Billings; Mark Dykman; NAVAL RESEARCH LAB WASHINGTON DC BEAM PHYSICS BRANCH
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| We consider the problem of switching in stochastic systems with delayed feedback. A general variational formation is derived for the switch rate in a stochastic differential delay equation where the noise sources is of general form. The resulting equations of motion and boundary conditions describe the optimal escape path which maximizes the probability of escape. Analyzing the dynamics along the optimal path yields exponents of the distribution in terms of ... |
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| Tier One Performance Screen Initial Operational Test and Evaluation: 2011 Interim Report |
Apr 2012 |
95 pages |
| Authors:
Deirdre J Knapp; Tonia S Heffner; HUMAN RESOURCES RESEARCH ORGANIZATION ALEXANDRIA VA
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| Along with educational, medical, and moral screens, the U.S. Army uses a composite score from the Armed Services Vocational Aptitude Battery (ASVAB), the Armed Forces Qualification Test (AFQT), to select new Soldiers. Although the AFQT is useful for selecting new Soldiers, other personal attributes are important to Soldier performance and retention. Based on the U.S. Army Research Institute's (ARI) investigations, the Army selected one promising measure, the Tailored Adaptive Personality ... |
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| Estimating the Uncertainty and Predictive Capabilities of Three-Dimensional Earth Models (Postprint) |
22 Mar 2012 |
12 pages |
| Authors:
Delaine T Reiter; William L Rodi; Stephen C Myers; WESTON GEOPHYSICAL CORP LEXINGTON MA
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| A maximum likelihood approach to solving the geostatistical estimation problem is being pursued whereby the geostatistical parameters, together with pick-error variances, are simultaneously fit to the second-order statistics of the observed travel-time residuals. The maximum likelihood criterion for the optimal parameter values reduces to a set of coupled, nonlinear equations which, in general, must be solved numerically. The geostatistical estimation problem within a maximum-likelihood framework has been formulated and an ... |
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| Collaborative Research: Advanced Excimer Laser Measurements and LES Modeling of Supersonic Combustion |
27 Feb 2012 |
28 pages |
| Authors:
Robert W Pitz; Suresh Menon; VANDERBILT UNIV NASHVILLE TN - DEPT OF MECHANICAL ENGINEERING
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| Accurate numerical predictions are essential to the design of scramjet combustors, and in order to develop and properly validate these predictions accurate temperature, species concentration, and velocity measurements must be obtained. Large eddy simulation (LES) promises to give improved predictions of turbulent, supersonic combustion relative to CFD RANS models, and therefore, a LES approach employing a subgrid turbulent mixing model was selected to model both reacting and non-reacting flow in ... |
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| Ballistic Flash Characterization of Entry-Side Flash |
Feb 2012 |
77 pages |
| Authors:
David J Peyton; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
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| Aircraft survivability is a broad subject that encompasses many fields and subjects. An important part of aircraft survivability is fire prevention. Flashes created by ballistic impacts are a very real threat to aircraft because they can start fires or cause explosions. In an effort to better protect against these flashes, this study seeks to further the understanding and characterization of them. Recent research on this subject has been greatly helped ... |
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| Isogeometric Collocation for Elastostatics and Explicit Dynamics |
25 Jan 2012 |
37 pages |
| Authors:
F Auricchio; L Beirao da Veiga; T J Hughes; A Reali; G Sangalli; TEXAS UNIV AT AUSTIN INST FOR COMPUTATIONAL ENGINEERING AND SCIENCES
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| We extend the development of collocation methods within the framework of Isogeometric Analysis (IGA) to multi-patch NURBS configurations, various boundary and patch interface conditions, and explicit dynamic analysis. The methods developed are higher-order accurate, stable with no hourglass modes, and efficient in that they require a minimum number of quadrature evaluations. The combination of these attributes has not been obtained previously within standard nite element analysis. |
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| Predicting Mechanical Properties of Metal Matrix Syntactic Foams Reinforced with Ceramic Spheres |
Jan 2012 |
16 pages |
| Authors:
J B Ferguson; J A Santa Maria; B F Schultz; P K Rohatgi; WISCONSIN UNIV-MILWAUKEE DEPT OF MATERIALS ENGINEERING
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| A model is presented that predicts peak stress, minimum stress, average stress, densification strain, and composite density in order to determine the energy absorption per unit volume and energy absorption per unit mass of metal matrix syntactic foams reinforced with hollow ceramic spheres subjected to unconstrained compression testing. Comparison of predictions to experimental data for Al-A206 and Al-A380 matrices of various heat treatments reinforced with Al2O3 spheres of various sizes, ... |
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| Physiologic Systems and Their Responses to Conditions of Heat and Cold |
Jan 2012 |
25 pages |
| Authors:
Robert W Kenefick; Samuel N Cheuvront; Scott J Montain; Robert Carter III; Michael N Sawka; Richard R Gonzalez; Brett R Ely; Daniel S Moran; Amir Hadid; Thomas L Endrusick; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
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| Individuals exercise and work in a wide range of environmental conditions. Depending on environmental conditions and a person's metabolic rate and clothing, exercise can accentuate heat gain or heat loss, causing body temperature to rise or fall. Healthy humans normally regulate body (core) temperatures near 37 deg. C at rest, and with environmental and/or exercise perturbations, body temperatures can fluctuate between 35 deg. C and 41 deg. C without adverse ... |
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| Environmental Fate Model for Ultra-Low-Volume Insecticide Applications Used for Adult Mosquito Management |
Jan 2012 |
10 pages |
| Authors:
Jerome J Schleier III; Robert K Peterson; Kathryn M Irvine; Lucy M Marshall; David K Weaver; Collin J Preftakes; MONTANA STATE UNIV BOZEMAN DEPT OF LAND RESOURCES AND ENVIRONMENTAL SCIENCES
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| One of the more effective ways of managing high densities of adult mosquitoes that vector human and animal pathogens is ultra-low-volume (ULV) aerosol applications of insecticides. The U.S. Environmental Protection Agency uses models that are not validated for ULV insecticide applications and exposure assumptions to perform their human and ecological risk assessments. Currently, there is no validated model that can accurately predict deposition of insecticides applied using ULV technology for ... |
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| Optimal Pulse Shapes for SHPB Tests on Soft Materials |
Dec 2011 |
20 pages |
| Authors:
Mike Scheidler; John Fitzpatrick; Reuben Kraft; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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| For split Hopkinson pressure bar (SHPB) tests on soft materials, the goals of homogeneous deformation and uniform uniaxial stress in the specimen present experimental challenges, particularly at higher strain rates. It has been known for some time that attainment of these conditions is facilitated by reducing the thickness of the specimen or by appropriately shaping the loading pulse. Typically, both methods must be employed. Pulse shapes are often tailored to ... |
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| Validation of Resistance Predictions Using Total Ship Drag (TSD) |
Dec 2011 |
31 pages |
| Authors:
Wesley Wilson; Dane Hendrix; Francis Noblesse; Joe Gorski; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD
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| A robust computational tool has been under development at the Naval Surface Warfare Center, Carderock Division (NSWCCD) over the past several years to rapidly predict the resistance of ships, including high-speed ships and unconventional hull forms. The total ship drag (TSD) program utilizes slender ship theory to predict the wave-making resistance, the ITTC friction line to estimate frictional resistance, and adds several other components based on empirical data. The different ... |
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| Horns as Particle Velocity Amplifiers |
Nov 2011 |
6 pages |
| Authors:
Dimitri M Donskoy; Benjamin A Cray; NAVAL UNDERSEA WARFARE CENTER DIV NEWPORT RI
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| Preliminary measurements and numerical predictions reveal that simple, and relatively small, horns generate remarkable amplification of acoustic particle velocity. For example, below 2 kHz, a 2.5 cm conical horn has a uniform velocity amplification ratio (throat-to-mouth) factor of approximately 3, or, in terms of a decibel level, 9.5 dB. It is shown that the velocity amplification factor depends on the horn's mouth-to-throat ratio as well as, though to a lesser ... |
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| Numerical Weather Prediction and Earth System Prediction to Better Understand Sea Level Rise/Coastal Issues as They Affect Readiness |
Nov 2011 |
25 pages |
| Authors:
Dave McCarren; NAVAL METEOROLOGY AND OCEANOGRAPHY COMMAND STENNIS SPACE CENTER MS
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| The National Unified Operational Prediction Capability (NUOPC) is a joint effort between NOAA and DoD to improve collaboration and accelerate operational numerical weather prediction. The Earth System Prediction Capability (ESPC) expands this collaboration to prediction of the physical earth system, expands required predictive capability to the decadal scale, and expands collaboration to include DOC, DoD, DOE and NASA. Both efforts seek to create partnerships, standardize numerical prediction practices in order ... |
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| Performance of a Dynamic Initialization Scheme in the Coupled Ocean-Atmosphere Mesoscale Prediction System for Tropical Cyclones (COAMPS-TC) |
Oct 2011 |
15 pages |
| Authors:
Eric A Hendricks; Melinda S Peng; Xuyang Ge; Tim Li; NAVAL RESEARCH LAB MONTEREY CA MARINE METEOROLOGY DIV
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| Adynamic initialization scheme for tropical cyclone structure and intensity in numerical prediction systems is described and tested. The procedure involves the removal of the analyzed vortex and, then, insertion of a new vortex that is dynamically initialized to the observed surface pressure into the numerical model initial conditions. This new vortex has the potential to be more balanced, and to have a more realistic boundary layer structure than by adding ... |
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| Expansion of a Direct Simulation-Based Study of Radiance in a Dynamic Ocean |
30 Sep 2011 |
6 pages |
| Authors:
Dick K Yue; Yuming Liu; MASSACHUSETTS INST OF TECH CAMBRIDGE CENTER FOR OCEAN ENGINEERING
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| The ultimate goal is to develop direct simulation/physics-based forward and inverse capabilities for radiance prediction in a dynamic ocean environment. The simulation-based model will include and integrate all of the relevant dynamical processes in the upper ocean surface boundary layer into a physics-based computational prediction capability for the time-dependent radiative transport. |
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| Applications of Synthetic Aperture Radar to Meteorology and Oceanography Command Operations |
30 Sep 2011 |
13 pages |
| Authors:
Todd D Sikora; George S Young; Nathanial S Winstead; MILLERSVILLE UNIV PA
|
| Our long-term goal is to employ near-surface wind speed, derived from synthetic aperture radar (SAR) images of the sea surface, as a marine meteorological research and forecasting tool. That is, we aim to use SAR-derived wind speed (SDWS) images to discover dynamical and morphological characteristics of microscale, mesoscale, and synoptic scale marine meteorological phenomena. We also aim to demonstrate how the fruits of our discovery can be used to aid ... |
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| Optimal Asset Distribution for Environmental Assessment and Forecasting Based on Observations, Adaptive Sampling, and Numerical Prediction |
30 Sep 2011 |
7 pages |
| Authors:
Steven R Ramp; SOLITON OCEAN SERVICES INC CARMEL VALLEY CA
|
| The long-term goal of this research is to enhance our understanding of coastal oceanography by means of applying simple dynamical theories to high-quality observations obtained in the field. The objective of this Multi-University Research Initiative (MURI) grant, subtitled The Adaptive Sampling and Prediction System (ASAP), is to learn how to deploy, direct, and utilize autonomous vehicles [and other mobile sensing platforms] most efficiently to sample the ocean, assimilate the data ... |
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| Surface Wave Dynamics in the Coastal Zone |
30 Sep 2011 |
6 pages |
| Authors:
Gerbrant van Vledder; ALKYON HYDRAULIC CONSULTANCY AND RESEARCH BV EMMELOORD (NETHERLANDS)
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| The proposed work will contribute to the improvement of existing third-generation (3G) wave models as well as to the development of the next generation of numerical wave modeling capability. The results will be applicable in the coastal zone from deep water up to and including the surf zone. Our efforts will focus on analyzing high quality datasets to support further development of the source terms for triad interactions, depth-induced wave ... |
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| KAM Torus Frequency Generation from Two Line Element Sets |
Sep 2011 |
12 pages |
| Authors:
Gregory R Frey; William E Wiesel; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| The Kolmogorov Arnold and Moser (KAM) theorem states that a lightly perturbed Hamiltonian system will have solutions which lie on a torus. Earlier work by the second author has shown that most Earth satellite orbits perturbed by the geopotential lie on KAM tori. The problem then arises as to how to convert the current satellite tracking orbits to KAM tori. A KAM torus is characterized by three frequencies and three ... |
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| Achieving Superior Tropical Cyclone Intensity Forecasts by Improving the Assimilation of High-Resolution Satellite Data into Mesoscale Prediction Models |
Sep 2011 |
20 pages |
| Authors:
Christopher Velden; Sharanya J Majumdar; Jun Li; Hui Liu; James D Doyle; Jeffrey Hawkins; WISCONSIN UNIV-MADISON SPACE SCIENCE AND ENGINEERING CENTER
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| Forecasts of TC intensity change are often lacking in skill due in part to the paucity of conventional observations over the oceans that are assimilated into the operational models. The inability to accurately map the three-dimensional atmosphere and the underlying upper ocean has also constrained our understanding of how intensity fluctuations are governed by internal and environmental processes. Remotely-sensed observations from multiple satellite sources have become more routinely available as ... |
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| Refined Source Terms in WAVEWATCH III with Wave Breaking and Sea Spray Forecasts |
Sep 2011 |
7 pages |
| Authors:
Michael L Banner; Russel P Morison; NEW SOUTH WALES UNIV (AUSTRALIA)
|
| Several U.S. Federal Agencies operate wind wave prediction models for a variety of mission specific purposes. Much of the basic science contained in the physics core of these models is over a decade old, and incorporating recent research advances over the last decade will significantly upgrade the model physics. A major goal is to produce a refined set of source and sink terms for the wind input, dissipation and breaking, ... |
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| Predicting Human Subcutaneous Glucose Concentration in Real Time: A Universal Data-Driven Approach |
Sep 2011 |
5 pages |
| Authors:
Yinghui Lu; Srinivasan Rajaraman; W K Ward; Robert A Vigersky; Jaques Reifman; ARMY MEDICAL RESEARCH AND MATERIEL COMMAND FORT DETRICK MD TELEMEDICINE AND ADVANCED TECH RESEARCH CENTER
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| Continuous glucose monitoring (CGM) devices measure and record a patient?s subcutaneous glucose concentration as frequently as every minute for up to several days. When coupled with data-driven mathematical models CGM data can be used for short-term prediction of glucose concentrations in diabetic patients. In this study, we present a real-time implementation of a previously developed offline data-driven algorithm. The implementation consists of a Kalman filter for real-time filtering of CGM ... |
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| The Evaluation of End-of-Repair/End-of-Maintenance Dates for Electronic Assemblies |
30 Aug 2011 |
19 pages |
| Authors:
Peter Sandborn; Anthony Konoza; III Nelson Raymond; Doug Gerdes; Mike Shamet; MARYLAND UNIV COLLEGE PARK CENTER FOR ADVANCED LIFE CYCLE ENGINEERING (CALCE)
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| Electronic systems consist of multiple cards each containing multiple parts. Many parts become obsolete long before the system support is terminated. How long can legacy systems drawing from existing nonreplenishable inventories of parts and cards be sustained? This project used a stochastic discrete event simulator to track all instances of all parts in the system until repair requests cannot be fulfilled. This provides quantitative (simulation-based) analysis of: 1. The length ... |
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| Software Reliability Prediction for Army Vehicle |
11 AUG 2011 |
4 pages |
| Authors:
Macam S. Dattathreya; Harpreet Singh; ARMY TANK AUTOMOTIVE RESEARCH DEVELOPMENT AND ENGINEERING CENTER WARREN MI
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| Three Dimensional Projection Environment for Molecular Design and Surgical Simulation |
Aug 2011 |
92 pages |
| Authors:
Eric Wickstrom; THOMAS JEFFERSON UNIV PHILADELPHIA PA
|
| We hypothesized in Aim 1 that docking of three-dimensional (3D) projections of potential target binding agents with 3D projections of macromolecular disease targets visualized on a computer with touch and feel feedback will enable identification of optimal agent designs, and culling of suboptimal agent designs, prior to synthesis. We found that direct measurements of cellular uptake of two different EGF fragments, EGF20-31 and EGF32-48, agreed with the computer predictions of ... |
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| Optimizing Strategies for an Observation-Nudging-Based Four-Dimensional Data Assimilation Forecast Approach with WRF-ARW |
Aug 2011 |
19 pages |
| Authors:
Andre Pattantyus; ARMY RESEARCH LAB WHITE SANDS MISSILE RANGE NM COMPUTATIONAL AND INFORMATION SCIENCES DIRECTORATE/BATTLEFIELD ENVIRONMENT DIV
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| The Weather Research and Forecasting model is an open-source numerical weather prediction model with numerous features, such as the four-dimensional data assimilation system, an option to nudge forecasts to observations in order to improve forecast quality and performance. This process can act as a dynamical initialization prior to the forecast period to reduce errors that result from interpolation across the grid. For data void regions, assimilating observations from a temporary ... |
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| Variational Multiscale Stabilization and p-adaptivity of High-Order Spectral Elements for the Convection-Diffusion Equation (Preprint) |
26 JUL 2011 |
46 pages |
| Authors:
S. Marras; J. F. Kelly; F. X. Giraldo; M. Vasquez; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF APPLIED MATHEMATICS
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| One major issue in the accurate solution of convection-dominated problems by means of high-order methods is the ability of the solver to maintain monotonicity. This problem is critical for spectral elements, where Gibbs oscillations may pollute the solution. However, typical filter-based stabilization techniques used with spectral elements are not monotone. In this paper, residual-based stabilization methods originally derived for finite elements are constructed and applied to high-order spectral elements. In ... |
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| The Auditory Hazard Assessment Algorithm for Humans (AHAAH): Hazard Evaluation of Intense Sounds |
Jul 2011 |
26 pages |
| Authors:
G R Price; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Prediction of hazard from intense sounds requires that predictive algorithms match the properties of the ear. The existing damage risk criteria do not and, as a result, perform badly. At the very high levels typical of gunfire, the ear has distinctive properties. The primary loss mechanism is mechanical stress within the cochlea. The conductive path exhibits spectral tuning, middle ear muscle attenuation of transmission, and peak limiting of stapes displacements. ... |
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| Exploration of Questions Regarding Modelling of Crack Growth Behaviour under Practical Combinations of Aircraft Spectra, Stress Levels and Materials |
Jul 2011 |
95 pages |
| Authors:
P Jackson; C Wallbrink; K Walker; D Mongru; W Hu; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION VICTORIA (AUSTRALIA) AIR VEHICLES DIV
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| Qustions regarding the most appropriate crack growth modeling tools in aircraft structural analysis have been asked of the Fatigue Methods and Standards Group within AVD Continuing the Group's previous endeavours along these lines this report commences by stating the questions that will be explored and then individually examining the issues using both experimental data from coupon tests run under typical aircraft spectra and results from various crack growth prediction models. ... |
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| Investigation of Density Perturbations in Molecular Nitrogen Formed by Pulsed Optical Lattices |
JUN 2011 |
9 pages |
| Authors:
Barry Cornella; Trey Quiller; Sergey Gimelshein; Taylor Lilly; Andrew Ketsdever; ENGINEERING RESEARCH AND CONSULTING INC (ERC INC) EDWARDS AFB CA
|
| A complimentary experimental/numerical investigation on the effect of counter-propagating pulsed lasers on molecular nitrogen was conducted. The experiment verified published theoretical predictions of the effect of laser intensity and gas pressure on the magnitude of induced density perturbations in the gas using a coherent Rayleigh-Brillouin scattering technique. The investigation further verified the use of a modified version of the SMILE DSMC code for more robust prediction of the effect of ... |
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| Developing a Predictive Model for Facility Repair Costs on United States Air Force Installations |
JUN 2011 |
64 pages |
| Authors:
Gregory A. Morissette; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH INTEGRATED LOGISTICS SUPPORT (ILS)
|
| The Air Force Civil Engineering community spends significant effort maintaining and repairing their infrastructure and facilities at their installations worldwide. They continually search for ways to better illustrate the impact of funding decisions on future infrastructure and facility conditions. The purpose of this research was to develop a predictive model for determining future facility repair costs. The research analyzed current and past funding levels as a possible predictor of future ... |
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| A Neural-Network Model-Based Engineering Tool for Blast Wall Protection of Structures (Postprint) |
Jun 2011 |
21 pages |
| Authors:
Bryan T Bewick; Ian Flood; Zhen Chen; FLORIDA UNIV GAINESVILLE COLL OF DESIGN CONSTRUCTION & PLANNING / RINKER SCHOOL OF BUILDING CONSTRUCTION
|
| Blast barrier walls have been shown to reduce blast loads on structures, especially in urban environments. Analysis of existing test and simulation data for blast barrier response has revealed that a need still exists to determine the bounds of the problem and produce a fast-running accurate model for the effects of barrier walls on blast wave propagation. Since blast experiments are very time intensive and extremely cost prohibitive, it is ... |
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| Talking about killing: Cell Phones, Collective Action, and Insurgent Violence in Iraq |
31 May 2011 |
63 pages |
| Authors:
Jacob N Shapiro; Nils B Weidmann; HARVARD UNIV CAMBRIDGE MA OFFICE FOR RESEARCH CONTRACTS
|
| Does improved communication as provided by modern cell phone technology affect the production of violence during insurgencies? Theoretical predictions are ambiguous. On the one hand, cell phones are assumed to enhance communication among insurgents, thus making it possible for them to coordinate more effectively. On the other hand, mobile communications can also hamper insurgent activity, by allowing the population to share information with counterinsurgents. This paper makes a first attempt ... |
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| Double-Linear Cumulative-Damage Reliability Method |
MAY 2011 |
15 pages |
| Authors:
Jr. Benton Robert E.; ARMY AVIATION AND MISSILE RESEARCH DEVELOPMENT AND ENG CTR REDSTONE ARSENAL AL ENGINEERING DIRECTORATE
|
| Fatigue reliability calculations during iterations of the design process have been demonstrated as practical using new analytical and numerical methods based on analytical cumulative-damage reliability tools (alpha-functions). Effects of fatigue strength and usage distribution may be studied in the presence of load variation. However, to date, the development of the alpha-functions has been centered on use of the Palmgren-Miner cycle-ratio summation rule for cumulative damage, also known as the Linear ... |
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| Optical Quality, Threshold Target Identification, and Military Target Task Performance After Advanced Keratorefractive Surgery |
May 2011 |
29 pages |
| Authors:
Kraig Bower; HENRY M JACKSON FOUNDATION FOR THE ADVANCEMENT OF MILITARY MEDICINE ROCKVILLE MD
|
| The purpose of the present study is to investigate the effect of advanced refractive surgery on task performance in a military operational setting. In this prospective, randomized treatment trial we will enroll 224 nearsighted soldiers to undergo wavefrontguided (WFG) photorefractive keratectomy (PRK), WFG laser in situ keratomileusis (LASIK), wavefront optimized (WFO) PRK or WFO LASIK (56 in each group). Subjects will undergo extensive clinical and military visual performance testing pre- ... |
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| Multidisciplinary Design Optimization Under Uncertainty: An Information Model Approach (PREPRINT) |
01 MAR 2011 |
39 pages |
| Authors:
James A. Reneke; Margaret M. Wiecek; Georges M. Fadel; Sundeep Samson; CLEMSON UNIV SC DEPT OF MATHEMATICAL SCIENCES
|
| Motivated by needs of concurrent multi-disciplinary design of a multi-purpose vehicle, a modeling and methodological approach to handling tradeoffs is presented. Each component has uncertain elements and a random performance which is influenced by the performance of other components. The components may require different knowledge bases and models with different mathematical structures, time and size scales, calling for higher-level coordination. The theory of reproducing kernel Hilbert spaces provides the mathematical ... |
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| Comparison of Development Test and Evaluation and Overall Program Estimate at Completion |
Mar 2011 |
97 pages |
| Authors:
William R Rosado; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Historically, cost growth regression models analyze aggregate, program-level information. Initiatives by the Office of Secretary of Defense, Cost Assessment and Program Evaluation (OSD CAPE) require direct, centralized reporting of the complete Work Breakdown Structure (WBS) Earned Value (EV) data. Centralized reporting allows access to unfiltered, unaltered, EV data for multiple programs. Using regression, we evaluate if WBS element Development Test and Evaluation (DT&E) EV data is related to program estimate ... |
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| Characterization of Regular Wave, Irregular Wave, and Large-Amplitude Wave Group Kinematics in an Experimental Basin |
FEB 2011 |
82 pages |
| Authors:
Lisa M. Minnick; Christopher C. Bassler; Scott Percival; Lauren W. Hanyok; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD HYDROMECHANICS DIRECTORATE
|
| An experiment was performed to measure and characterize wave kinematics in the Maneuvering and Seakeeping (MASK) basin at the Naval Surface Warfare Center Carderock Division (NSWCCD). The experiment is part of an ongoing effort to improve predictions and measurements of ship motions in waves, including more accurate characterization of the near-field wave environment and its influence on ship motions. The primary objective of this experiment was to measure and characterize ... |
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| Paradigms for Tropical-Cyclone Intensification |
Jan 2011 |
33 pages |
| Authors:
Michael T Montgomery; Roger K Smith; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF METEOROLOGY
|
| We review four paradigms of tropical-cyclone intensification that have emerged over the past five decades, discussing the relationship between them and highlighting their positive aspects and limitations. A major focus is on a new paradigm articulated in a series of recent papers by ourselves and colleagues. Unlike the three previous paradigms, all of which assumed axial symmetry, the new one recognizes the importance of rotating deep convection, which possesses local ... |
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| Simulating Pirate Behavior to Exploit Environmental Information |
Dec 2010 |
7 pages |
| Authors:
Leslie Esher; Stacey Hall; Eva Regnier; Paul J Sanchez; James A Hansen; Dashi Singham; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF OPERATIONS RESEARCH
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| Recent years have seen an upsurge in piracy, particularly off the Horn of Africa. Piracy differs from other asymmetric threats, such as terrorism, in that it is economically motivated. Pirates operating off East Africa have threatened maritime safety and cost commercial shipping billions of dollars paid in ransom. Piracy in this region is conducted from small boats which can only survive for a few days away from their base of ... |
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| Hydrodynamic Forces on Spillway Torque-Tube Gates |
Oct 2010 |
13 pages |
| Authors:
Luis A de Bejar; Richard L Stockstill; ARMY CORPS OF ENGINEERS VICKSBURG MS ENGINEER RESEARCH AND DEVELOPMENT CENTER
|
| The critical hydraulic configuration for a set of torque-tube gates controlling the flow through the navigable portion of a spillway was experimentally identified. In this paper, an analytical model for the upstream pressure field on a typical gate within the set is constructed. The gate rotation from the maximum elevation gate in closed position and the hydraulic torque transmitted by the pressure field to the gate tube are formulated. Mean ... |
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| Application of Earth Sciences Products for use in Next Generation Numerical Aerosol Prediction Models |
30 SEP 2010 |
12 pages |
| Authors:
Jeffrey S. Reid; James R. Campbell; Cynthia A. Curtis; Edward J. Hyer; NAVAL RESEARCH LAB MONTEREY CA
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| The long-term goal of this project is to devise a forward modeling system to characterize and predict clear sky radiation fields through the harvest of a number of preexisting basic research programs funded by Navy and other government agencies (NASA, NOAA, DOE, etc.). With an aerosol radiance forward model, we will be able to combine model aerosol background fields from the NRL Aerosol Analysis and Prediction System (NAAPS) and Coupled ... |
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| Numerical Techniques and Cloud-Scale Processes for High-Resolution Models |
30 SEP 2010 |
11 pages |
| Authors:
Jamed D. Doyle; NAVAL RESEARCH LAB MONTEREY CA
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| The long-term goal of this project is to design and evaluate the components that will comprise a next generation mesoscale atmospheric model within the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS). It is anticipated that in order to meet future Navy requirements, next generation approaches to numerical techniques and physical parameterizations will be needed. The objectives of this project involve the development, testing, and validation of new numerical techniques such as ... |
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MATHEMATICAL PREDICTION
