| Linear Algebraic Modeling of Power Flow in the HMP500-3 Transmission |
Aug 2012 |
11 pages |
| Authors:
Matthew G McGough; ARMY TANK AUTOMOTIVE RESEARCH DEVELOPMENT AND ENGINEERING CENTER WARREN MI
|
 | The HMPT500-3 is a split torque path hydrostatic / mechanical continuously variable transmission used in the Bradley Fighting Vehicle. Power transmission and steering is accomplished through the interaction of six planetary gear sets and two variable displacement hydrostatic pump / motor units (HSUs). Power flow in the HMPT500-3 is extremely complex, with numerous feedback paths within the planetary gear train. Without a clearly defined power flow path from gear set ... |
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| Linear Algebraic Modeling of Power Flow in the HMP500-3 Transmission |
Aug 2012 |
17 pages |
| Authors:
Matthew G McGough; ARMY TANK AUTOMOTIVE RESEARCH DEVELOPMENT AND ENGINEERING CENTER WARREN MI
|
| These charts use linear algebra to describe the transmission of a tracked vehicle. |
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| Analysis and Modeling of Small Crack Detection in Pressurized Fuselages for Structural Health Monitoring Applications (Preprint) |
Jul 2012 |
14 pages |
| Authors:
J L Blackshire; F Ospina; S R Soni; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
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| This effort explores the evolution and characterization of structural cracks in aircraft fuselage structures in which the loads are varying. During flight, an aircraft fuselage skin and structure are subjected to varied cyclic loads, which can cause embedded cracks and other damage features to change their characteristics due to loading effects. The current research uses finite element modeling and experimental techniques to characterize the behavior of cracks under different static ... |
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| Effects of Processing and Powder Size on Microstructure and Reactivity in Arrested Reactive Milled Al + Ni |
May 2012 |
19 pages |
| Authors:
Eric B Herbold; Jennifer L Jordan; N N Thadhani; AIR FORCE RESEARCH LAB EGLIN AFB FL MUNITIONS DIRECTORATE
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| Ball-milling Al-metal powders can result in self-sustaining high-temperature synthesis in intermetallic-forming systems. Here, Al and Ni powders with similar composition are used to investigate how microstructural differences affect the measured time to reaction (TTR) between powders of different sizes processed under milling conditions specified by statistically designed experiments. Linear statistical models predicting the TTR and the change in temperature (DT) are built from these experimental results. The time required to ... |
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| LITHO1.0: An Updated Crust and Lithosphere Model of the Earth (Postprint) |
22 Mar 2012 |
12 pages |
| Authors:
T G Masters; Zhitu Ma; Gabi Laske; Michael E Pasyanos; CALIFORNIA UNIV SAN DIEGO LA JOLLA
|
| The compilation of extremely large global datasets of group velocity for Rayleigh and Love waves from 10mHz to 40mHz have completed using a cluster analysis technique. The method has been extended to measure phase velocity to complement the group velocity with global data sets of longer period phase data that help to constrain deep lithosphere properties. To model these data, a starting model for the crust at a nominal resolution ... |
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| Automating Nearshore Bathymetry Extraction from Wave Motion in Satellite Optical Imagery |
Mar 2012 |
117 pages |
| Authors:
Steven Mancini; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Nearshore depths for Waimanalo Beach, HI, are extracted from optical imagery, taken by the WorldView-2 satellite on 31 March 2011, by means of automated wave kinematics bathymetry (WKB). Two sets of three sequential images taken at intervals of about 10 seconds are used for the analyses herein. Water depths are calculated using a computer program that registers the images, estimates the currents, and then uses the linear dispersion relationship for ... |
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| Toward an Integrated Framwork for Data-Efficient Parametric Adaptive Detection |
27 Feb 2012 |
47 pages |
| Authors:
Hongbin Li; STEVENS INST OF TECHNOLOGY HOBOKEN NJ
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| The conjugate-gradient (CG) algorithm is investigated for reduced-rank STAP detection. A family of CG matched filter (CG-MF) is developed by using the k-th iteration of the CG in solving the Wiener-Hopf equation. The performance the CG-MF detectors is examined for two cases. The first involves an arbitrary covariance matrix. It is shown that each CG-MF detector 1) yields the highest output SINR and smallest MSE among all linear solutions in ... |
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| Robust Computation of Linear Models, or How to Find a Needle in a Haystack |
17 Feb 2012 |
46 pages |
| Authors:
Gilad Lerman; Michael McCoy; Joel A Tropp; Teng Zhang; CALIFORNIA INST OF TECH PASADENA DEPT OF COMPUTING AND MATHEMATICAL SCIENCES
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| Consider a dataset of vector-valued observations that consists of a modest number of noisy inliers, which are explained well by a low-dimensional subspace, along with a large number of outliers, which have no linear structure. This work describes a convex optimization problem, called reaper, that can reliably t a low-dimensional model to this type of data. The paper provides an efficient algorithm for solving the reaper problem, and it documents ... |
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| Testing Properties of Boolean Functions |
Jan 2012 |
165 pages |
| Authors:
Eric Blais; CARNEGIE-MELLON UNIV PITTSBURGH PA SCHOOL OF COMPUTER SCIENCE
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| Given oracle access to some boolean function f, how many queries do we need to test whether f is linear? Or monotone? Or whether its output is completely determined by a small number of the input variables? This thesis studies these and related questions in the framework of property testing introduced by Rubinfeld and Sudan ('96). The results of this thesis are grouped into three main lines of research. I. ... |
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| Coastal Bathymetry Using Satellite Observation in Support of Intelligence Preparation of the Environment |
Sep 2011 |
75 pages |
| Authors:
II Myrick Kenneth B; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Subaqueous beach profiles are obtained for littoral regions near Camp Pendleton, CA, using observations of wave motion. Imagery was acquired from WorldView2 Satellite on 24 March 2010. Two sequential images taken 10 seconds apart are used for the analyses herein. Water depths were calculated using linear dispersion relationship for surface gravity waves. Depth profiles were established from shoreline out to 1 kilometer offshore and depths of up to 15 meters. ... |
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| User-based Software Tool for S-Parameter Conversion and Manipulation |
Sep 2011 |
22 pages |
| Authors:
Scott Trocchia; Tony Ivanov; Robert Proie; ARMY RESEARCH LAB ADELPHI MD
|
| S-parameters fully characterize the linear behavior of an arbitrary number of ports. We aim to characterize various field-effect transistors (FETs), each having a certain gate width and geometry, from their S-parameters. We extract the data from the vector network analyzer in real-time and perform a series of calculations and conversions on the initial S-parameters. Using a software tool written in C++ that interfaces with the vector network analyzer (VNA), the ... |
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| Limits to Maximum Absorption Length in Waveguide Photodiodes |
13 Apr 2011 |
12 pages |
| Authors:
Shannon M Madison; Jonathan Klamkin; Douglas C Oakley; Antonio Napoleone; Jason J Plant; Paul W Juodawlkis; MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
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| The maximum photocurrent, power dissipation, and Iinearity of waveguide photodiodes are limited by the length over which the input optical power is absorbed. This absorption length is determined by the absorption coefficient of the absorbing layer material (a0), the optical confinement factor (r), and the excess optical loss (ai). In this work, we analyze the fundamental limits to maximizing the absorption length and demonstrate a new waveguide photodiode structure that ... |
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| Impact of Snow Removal Operations on Thermoplastic Pavement Markings |
MAR 2011 |
82 pages |
| Authors:
Monica L. Monfette; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
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| This pilot study explored the effect snow removal operations have on thermoplastic pavement markings. Including snow removal as a separate independent variable is unique because much of the previous research performed on pavement marking degradation mentioned snow removal as a direct cause in a marking degrading more rapidly; however, it is mentioned as an afterthought and a suggestion to be considered in future research. This pilot study looked at 10 ... |
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| AlGaN/GaN High Electron Mobility Transistor Degradation Under On- and Off-State Stress |
Jan 2011 |
6 pages |
| Authors:
E A Douglas; C Y Chang; D J Cheney; B P Gila; C F Lo; Liu Lu; R Holzworth; P Whiting; K Jones; G D Via; FLORIDA UNIV GAINESVILLE DEPT OF MATERIALS SCIENCE AND ENGINEERING
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| AlGaN/GaN High Electron Mobility Transistors (HEMTs) with various gate lengths have been stepstressed under both on- and off-state conditions. On-state, high power stress tests were performed on 0.17 lm gate length HEMTs and a single 5 lm spaced TLM pattern. Significant degradation of the submicron HEMTs as compared to the excellent stability of the TLM patterns under the same stress conditions reveal that the Schottky contact is the source of ... |
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| New Material System for 3rd Generation IR Applications |
DEC 2010 |
24 pages |
| Authors:
Gregory Brill; Yuanping Chen; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| Much progress has been made in developing high quality mercury cadmium telluride (HgCdTe)/silicon (Si) for large area long wavelength infrared (LWIR) focal plane array (FPA) applications. However, even with all the material advances made to date, there is no guarantee that this technology will be mature enough to meet FPA specifications for a fielded system. With this in mind, the U.S. Army Research Laboratory (ARL) has begun investigating mercury cadmium ... |
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| A Unified Approach to Joint Regional/Teleseismic Calibration and Event Location with a 3D Earth Model |
Sep 2010 |
12 pages |
| Authors:
William L Rodi; Delaine T Reiter; Stephen C Myers; Nathan A Simmons; MASSACHUSETTS INST OF TECH CAMBRIDGE
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| This project is investigating the problem of locating seismic events from combined data sets of regional and teleseismic arrival times, based on the use of a unified 3D model of the Earth's velocity structure to predict travel times for both types of data. Inherent to this problem is the joint tomographic calibration of the Earth model with both regional and teleseismic ground-truth data. The goal of the unified approach is ... |
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| Intertemporal Reasoning and Cross-Cultural Decision Making |
30 Jul 2010 |
10 pages |
| Authors:
Donald G MacGregor; Joseph R Godfrey; MACGREGOR BATES INC COTTAGE GROVE OR
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| Elements of economic theory are examined to understand the Euro-American cultural assumptions encoded in their formulation. The research develops a framework by which to understand how Euro-American beliefs relevant to economic theory might be understood or misunderstood in other cultures, with the goal of facilitating inter-cultural dialog. The framework is constructed using an approach based on decomposing key economic concept into their component elements and relating those elements to research ... |
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| Planning in Dynamic Environments: Extending HTNs with Nonlinear Continuous Effects |
Jan 2010 |
7 pages |
| Authors:
Matt Molineaux; Matthew Klenk; David W Aha; KNEXUS RESEARCH CORP SPRINGFIELD VA
|
| Planning in dynamic continuous environments requires reasoning about nonlinear continuous effects, which previous Hierarchical Task Network (HTN) planners do not support. In this paper, we extend an existing HTN planner with a new state projection algorithm. To our knowledge, this is the first HTN planner that can reason about nonlinear continuous effects. We use a wait action to instruct this planner to consider continuous effects in a given state. We ... |
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| Biokinetics and Biodynamics of Nanomaterial Interactions |
30 Sep 2009 |
63 pages |
| Authors:
Nancy A Monteiro-Riviere; Jim E Riviere; Xin-Rui Xia; NORTH CAROLINA STATE UNIV AT RALEIGH
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| A requirement to assess toxicity of nanomaterials is to assess their interactions with available viability assays. Single-walled carbon nanotubes (SWCNT), fullerenes (C60), carbon black (CB), nC60, and quantum dots (QD) were studied in vitro to determine their toxicity in a number of cell types. The classical dye-based assays such as MTT and neutral red (NR) that determine cell viability produced invalid results with some NM (nanomaterials) due to NM/dye interactions ... |
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| Predicting Electron Transport Using Simulated Axial Waves in a Radial-Axial Hybrid Hall Thruster Model |
Sep-2009 |
12 pages |
| Authors:
Michelle K Scharfe; Mark A Cappelli; Eduardo Fernandez; ENGINEERING RESEARCH AND CONSULTING INC (ERC INC) EDWARDS AFB CA
|
| Axial waves predicted by a two-dimensional hybrid numerical model have been used to estimate electron cross field transport due to tilted waves with azimuthal components. Since the radial-axial hybrid simulation cannot model these tilted waves directly, the predicted axial waves are assumed to couple symmetrically into two counter-propagating axial-azimuthal waves. A linearized two-dimensional dispersion relation is solved to obtain the azimuthal component of wavenumber consistent with the frequency and axial ... |
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| Finite Deformations and Internal Forces in Elastic-Plastic Crystals: Interpretations From Nonlinear Elasticity and Anharmonic Lattice Statics |
Sep-2009 |
22 pages |
| Authors:
J D Clayton; D J Bammann; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Large deformation kinematics and internal forces arising from defects in crystalline solids are addressed by a nonlinear kinematic description and multiscale averaging concepts. An element of crystalline material with spatially uniform properties and containing defects such as dislocation lines and loops is considered. The average deformation gradient for this element is decomposed multiplicatively into terms accounting for effects of dislocation flux, recoverable elastic stretch and rotation, and residual elastic deformation ... |
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| Automated Instantaneous Performance Assessment for Marine-Squad Urban-Terrain Training |
Jun-2009 |
48 pages |
| Authors:
Neil C Rowe; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Urban operations (MOUT) are a key component of U.S. Marine training, yet assessment of performance during the later and more integrative training exercises is difficult because events happen quickly and walls impede full view. We are building a performance assessment system called BASE-IT that will collect data on positions, orientations, postures, and activities of Marines during training using a network of cameras. BASE-IT will automatically summarize performance over exercises and ... |
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| Detached-Eddy Simulation of Flow Non-Linearity of Fluid-Structural Interactions Using High Order Schemes |
May-2009 |
199 pages |
| Authors:
Gecheng Zha; Baoyuan Wang; MIAMI UNIV CORAL GABLES FL DEPT OF MECHANICAL ENGINEERING
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| The objective of this research is to develop an efficient and accurate methodology to resolve flow non-linearity of fluid-structural interaction. To achieve this purpose, a numerical strategy to apply the detached-eddy simulation (DES) with a fully coupled fluid-structural interaction model is established for the first time. The following novel numerical algorithms are also created: a general sub-domain boundary mapping procedure for parallel computation to reduce wall clock simulation time, an ... |
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| A Priori Design of Optimal Electro-Optic Materials for Laser Eye Protection |
Dec-2008 |
9 pages |
| Authors:
J Andzelm; M Davis; A Chafin; G Lindsay; Weitao Yang; D N Beratan; C Rinderspacher; T M Pritchett; J Dougherty; A Rawlett; P J Reynolds; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
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| The task of protecting soldier eyesight and battlefield optical sensors from potentially damaging effects of high-intensity light has stimulated interest in electro-optic (EO) materials such as EO chromophores inserted into polymeric material. A priori design of optimal EO chromophores of Army relevance requires the capability to calculate accurately both the linear absorption properties (in effect, the color) and non-linear optical (NLO) properties of EO chromophores. Here we discuss two major ... |
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| Test Operations Procedure (TOP) 2-1-007 Dynamic Displacement Measurement |
18-Sep-2008 |
21 pages |
| Authors:
ABERDEEN TEST CENTER MD BALLISTICS INSTRUMENTATION DIVISION
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| This Test Operations Procedure (TOP) describes the selection, setup and operation of the various instrumentation used for measurement of dynamic displacement events, as a part of vehicle live fire vulnerability testing. |
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| Nonlinear Dynamic Response Optimization Using the Equivalent Static Loads for a Joined-Wing |
01-Sep-2008 |
49 pages |
| Authors:
Gyung-Jin Park; HANYANG UNIV GYEONGGI-DO (SOUTH KOREA) DEPT OF MECHANICAL ENGINEERING
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| The joined-wing airplane proposed by Wolkovich in 1986 is defined as an airplane that incorporates tandem wings arranged to form diamond shapes in both top and front views. The joined-wing can lead to increased aerodynamic performances as well as reduction of the structural weight. However, the joined-wing has high geometric nonlinearity under the gust load. The gust load acts as a dynamic load. In previous researches, linear dynamic response optimization ... |
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| Terminal Control of a Variable-Stability Slender Reentry Vehicle |
02 JUN 2008 |
137 pages |
| Authors:
Matthew T. Karmondy; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF AERONAUTICS AND ASTRONAUTICS
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| Various terminal control schemes are applied to a proposed slender reentry vehicle, controlled by two separately-articulating flaps. The flap deflections are summarized as symmetric and asymmetric flap deflections; the former manipulates the drag, lift-curve slope, and static margin; the latter controls the vehicle trim characteristics. The control problem is interesting because the static margin can be actively controlled from statically stable in pitch to statically unstable in pitch. Deflection limits ... |
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| An Efficient Method for Calculating Surface Temperature and Heat Flux Based on Embedded Temperature Sensors (Preprint) |
09-May-2008 |
11 pages |
| Authors:
Edward B Coy; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| Approximate analytical solutions have been obtained for surface temperature and heat flux for the case of two embedded temperature sensors. The solutions have been verified and the range of validity has been established using several methods including comparisons with an exact analytical solution for a linear problem and numerical calculations for a non-linear problem. The performance of the model is presented in both the frequency domain and the time domain. ... |
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| A Nonlinear Approach to Strategy Formulation |
01-Mar-2008 |
35 pages |
| Authors:
Gary B James; ARMY WAR COLL CARLISLE BARRACKS PA
|
| The United States Army War College educates strategic leaders who function as national security professionals who develop and implement national policy and strategy, as well as oversee the resources of the state Therefore, graduates must understand how policy and strategy are formulated The Army War College has developed a strategy formulation model to educate the Army's future security leaders This model is a linear process, with internal and external forces ... |
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| An Authorization Logic with Explicit Time |
02 FEB 2008 |
96 pages |
| Authors:
Henry DeYoung; Deepak Garg; Frank Pfenning; CARNEGIE-MELLON UNIV PITTSBURGH PA SCHOOL OF COMPUTER SCIENCE
|
| We present an authorization logic that permits reasoning with explicit time. Following a proof-theoretic approach, we study the meta-theory of the logic, including cut elimination. We also demonstrate formal connections to proof-carrying authorization's existing approach for handling time and comment on the enforceability of our logic in the same framework. Finally, we illustrate including those with complex interactions between time, authorization, and mutable state. |
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| 4DVAR Assimilation of ADCP Data with the Navy Coastal Ocean Model using the Cycling Representer Method |
30 JAN 2008 |
14 pages |
| Authors:
Scott R. Smith; Hans E. Ngodock; Gregg A. Jacobs; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| 40-variational assimilation (4DVAR) is used to combine ADCP velocity observations with the Navy Coastal Ocean model (NCOM) to obtain an optimal solution that minimizes a cost function containing the weighted squared errors of velocity measurements, initial conditions, boundary conditions, and model dynamics. However, in order to converge to the global minimum of this cost function,the ocean model (and its adjoint) must be linear. Ocean models, especially those that are designed ... |
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| A Constraint Generation Approach to Learning Stable Linear Dynamical Systems |
JAN 2008 |
17 pages |
| Authors:
Sajid M. Siddiqi; Byron Boots; Geoffrey J. Gordon; CARNEGIE-MELLON UNIV PITTSBURGH PA SCHOOL OF COMPUTER SCIENCE
|
| Stability is a desirable characteristic for linear dynamical systems, but it is often ignored by algorithms that learn these systems from data. We propose a novel method for learning stable linear dynamical systems: we formulate an approximation of the problem as a convex program, start with a solution to a relaxed version of the program, and incrementally add constraints to improve stability. Rather than continuing to generate constraints until we ... |
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| Square-Shaped Metal Screens in the Infrared to Terahertz Spectral Region: Resonance Frequency, Band Gap, and Bandpass Filter Characteristics |
Jan-2008 |
8 pages |
| Authors:
O Sternberg; K D Moller; D Sliwinski; Y -L Mathis; M Bornefeld; J F Federici; A Bandyopadhyay; Y Hor; K P Stewart; H Grebel; NEW JERSEY INST OF TECH NEWARK DEPT OF ELECTRICAL ENGINEERING
|
| Resonance frequency of freestanding, square-shaped thick metal screens have been studied here in the wavelength range of infrared (IR) to mm (20 to 0.2 THz). It was found that their peak transmission has a linear relationship to the screen's pitch. An experimental spectral feature, unaccounted for in typical simulations with plane parallel incident beams, was observed in the transmittance envelope for measurements in focused beams. In the past, this spectral ... |
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| Localized Surface Plasmon Resonance of Metal Nanodot Nanowire Arrays Studied by Far-Field and Near-Field Optical |
05 SEP 2007 |
8 pages |
| Authors:
Heh-Nan Lin; NATIONAL TSING HUA UNIV HSINCHU (TAIWAN) DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| A combination of AFM nanomachining and lift-off process based on the one-layer approach is a convenient method for the fabrication of metal nanostructures. For an obtained Au nanodot array with an average diameter of 72 nm, the resonance peak in the LSPR scattering spectrum is located at 548 nm and consistent with simulated spectrum from Mie theory. For the Au nanowire arrays, the LSPR scattering spectra are composed of two ... |
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| Geospace Plasma Dynamics: Final Report (2002-2007) |
14 AUG 2007 |
30 pages |
| Authors:
Bamandas Basu; John R. Jasperse; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| Radar measurements of backscatter from plumes extending above the bottom side spread-F layer correlated well with observations of equatorial plasma bubbles in quiet conditions with lower correlation between scintillation and observations of plasma bubbles. DMSP satellites and the ROCSAT-1 satellite showed significantly fewer occurrences of plasma bubbles than expected near the west coast of South America and an east-west chain of GPS receivers confirms a steep longitudinal gradient in EPB ... |
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| A New Class of Analysis-Based Fast Transforms |
06 AUG 2007 |
59 pages |
| Authors:
Michael O'Neil; Vladimir Rokhlin; YALE UNIV NEW HAVEN CT DEPT OF COMPUTER SCIENCE
|
| We introduce a new approach to the rapid numerical application to arbitrary vectors of certain types of linear operators. Inter alia, our scheme is applicable to many classical integral transforms, and to the expansions associated with most families of classical special functions; among the latter are Bessel functions, Legendre, Hermite, and Laguerre polynomials, Spherical Harmonics, Prolate Spheroidal Wave functions, and a number of others. In all these cases, the CPU ... |
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| B and F Projection Methods for Nearly Incompressible Linear and Nonlinear Elasticity and Plasticity using Higher-order NURBS Elements |
AUG 2007 |
62 pages |
| Authors:
T. Elguedj; Y. Bazilevs; V. M. Calo; T. J. Hughes; TEXAS UNIV AT AUSTIN
|
| This paper presents projection methods to treat the incompressibility constraint in small and large deformation elasticity and plasticity within the framework of Isogeometric Analysis. After reviewing some fundamentals of isogeometric analysis we investigate the use of higher-order Non-Uniform Rational B-Splines "NURBS" within the B projection method. The higher-continuity property of such functions is explored in nearly incompressible applications and shown to produce accurate and robust results. A new nonlinear F ... |
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| Statistics of Amplitude and Fluid Velocity of Large and Rare Waves in the Ocean |
Jun-2007 |
|
| Authors:
Il H Suh; MASSACHUSETTS INST OF TECH CAMBRIDGE
|
 | The understanding of large and rare waves in the ocean is becoming more important as these rare events are turning into more common observances. In order to design a marine structure or vehicle to withstand such a potentially devastating phenomenon, the designer must have knowledge of extreme waves with return periods of 50 and 100 years. Based on satellite radar altimeter data, researchers have successfully predicted extreme significant wave heights ... |
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| Sequential MCMC Estimation of Nonlinear Instantaneous Frequency |
APR 2007 |
5 pages |
| Authors:
Y. Li; D. Simon; A. Papandreou-Suppappola; D. Morrell; R. L. Murray; ARIZONA STATE UNIV TEMPE DEPT OF ELECTRICAL ENGINEERING
|
| Instantaneous frequency (IF) estimation of signals with nonlinear phase is challenging, especially for online processing. In this paper, we propose IF estimation using sequential Bayesian techniques, by combining the particle filtering method with the Markov chain Monte Carlo (MCMC) method. Using this approach, a nonlinear IF of unknown closed form is approximated as a linear combination of the IFs of non-overlapping waveforms with polynomial phase. Simultaneously applying parameter estimation and ... |
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| Tightly-Coupled Image-Aided Inertial Navigation Using the Unscented Kalman Filter |
2007 |
12 pages |
| Authors:
S. Ebcin; M. Veth; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| Accurate navigation information "position, velocity, and attitude" can be determined using optical measurements from imaging sensors combined with an inertial navigation system. This can be accomplished by tracking the locations of stationary optical features in multiple images and using the resulting geometry to estimate and remove inertial errors. In previous research efforts, we have demonstrated the effectiveness of fusing imaging and inertial sensors using an extended Kalman filter "EKF" algorithm. ... |
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| Adaptation for Regularization Operators in Learning Theory |
10 SEP 2006 |
22 pages |
| Authors:
Andrea Caponnetto; Yuan Yao; MASSACHUSETTS INST OF TECH CAMBRIDGE COMPUTER SCIENCE AND ARTIFICIAL INTELLIGENCE LAB
|
| We consider learning algorithms induced by regularization methods in the regression setting. We show that previously obtained error bounds for these algorithms using a-priori choices of the regularization parameter, can be attained using a suitable a-posteriori choice based on validation. In particular, these results prove adaptation of the rate of convergence of the estimators to the minimax rate induced by the effective dimension of the problem. We also show universal ... |
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| Predicting Sediment Transport Dynamics in Ephemeral Channels: A Review of Literature |
SEP 2006 |
9 pages |
| Authors:
Stephen H. Scott; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
|
| The goal of this Coastal and Hydraulics Engineering Technical Note (CHETN) is to evaluate state-of-the-art research efforts concerning predicting sediment transport in desert ephemeral channels. The present day methods used to predict sediment transport were primarily formulated for application to perennial flow channels. Additionally, in the development of sediment transport relationships it is assumed that the sediment and water mixture is Newtonian, i.e., a linear relationship exists between the shear ... |
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| Data-Based Control of a Free-Free Beam in the Presence of Uncertainty |
SEP 2006 |
9 pages |
| Authors:
Tannen S. VanZwieten; Gregory M. Bower; Seth L. Lacy; WYOMING UNIV LARAMIE COLL OF ENGINEERING
|
| Linear control development is typically based on deterministic models that approximate the system under consideration. This approach neglects uncertainty in the system response. System uncertainty can arise from a number of sources including disturbances, noise, unmodeled dynamics, and nonlinearity. This may result in a reduction in performance or even instability in the closed loop system. The goal of this research is to account for measured uncertainty in control design. Our ... |
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| Efficient Multiple Hypothesis Track Processing of Boost-Phase Ballistic Missiles Using IMPULSE -Generated Threat Models |
SEP 2006 |
109 pages |
| Authors:
Bert Rakdham; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| In this thesis, a multiple hypotheses tracking (MHT) algorithm is developed to successfully track multiple ballistic missiles within the boost phase. The success of previous work on the MHT algorithm and its application in other scientific fields enables this study to realize an efficient form of the algorithm and examine its feasibility in tracking multiple crossing ballistic missiles even though various accelerations due to staging are present. A framework is ... |
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| Mission Support for the Communications/Navigation Outage Forecast Satellite |
30 AUG 2006 |
11 pages |
| Authors:
D. L. Hysell; CORNELL UNIV ITHACA NY DEPT OF EARTH AND ATMOSPHERIC SCIENCES
|
| This is a project to provide mission support for the Communication/Navigation Outage Forecast System (C/NOFS) under BAA VS-O3-O1 during its first four years of operation. Cornell is required to support the mission with ground-based radar observations of background ionospheric parameters and of Equatorial Spread F (ESF) events from the Jicamarca Radio Observatory near Lima, Peru. In the pre-launch period for C/NOFS, Cornell and Jicamarca contributed to the project by measuring ... |
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| Combined Nonlinear Effects in Two-Photon Absorption Chromophores at High Intensities (Postprint) |
AUG 2006 |
18 pages |
| Authors:
Richard L. Sutherland; Daniel G. McLean; Mark C. Brant; Joy E. Rogers; Paul A. Fleitz; Augustine M. Urbas; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH SURVIVABILITY AND SENSOR MATERIALS DIV/HARDENED MATERIALS
|
| Large two-photon and excited state absorption have been reported in donor-acceptor-substituted π-conjugated molecules. We have performed detailed nonlinear absorption and photophysical measurements on a system of AFX chromophores and calculate the nonlinear transmission based on an effective three-level model. A numerical model that includes far wing linear absorption has been developed and compared with an analytical three-photon absorption model. The models are in accordance and yield excellent agreement with experimental ... |
|
| Intelligence and Accidents: A Multilevel Model |
06 MAY 2006 |
14 pages |
| Authors:
R. R. Vickers; A. Villasenor; NAVAL HEALTH RESEARCH CENTER SAN DIEGO CA
|
| Intelligence reduces the risk of accidents. Prior tests of this reasonable hypothesis have produced associations that are too weak to be of much theoretical or practical importance. However, intelligence is most valuable when complex patterns of information must be processed. In an occupational setting, intelligence may have a strong effect on accident rates only when work involves a complex set of hazards. The study hypothesis was that the association of ... |
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| Axial vs Transverse Bunching in Sheet Beam TWTs |
APR 2006 |
2 pages |
| Authors:
Jr. Antonsen Thomas M.; Simon J. Cooke; Baruch Levush; Yuri N. Pchelnikov; SCIENCE APPLICATIONS INTERNATIONAL CORP MCLEAN VA
|
| We describe the linear theory for interaction between a sheet electron beam and a traveling wave, including space-charge effects, for both axial and transverse bunching. |
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| Modeling of Viscoelastic Shear: A Nonlinear Stick-Slip Formulation |
20 FEB 2006 |
23 pages |
| Authors:
H. T. Banks; Negash G. Medhin; Gabriella A. Pinter; NORTH CAROLINA STATE UNIV AT RALEIGH CENTER FOR RESEARCH IN SCIENTIFIC COMPUTATION
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| We present a class of nonlinear dynamic viscoeleastic models for materials subjected to shear stress. The model equations are based on a continuum variation of a reputation model in which chemically cross-linked (CC) systems of molecules act as constraint boxes per unit volume for physically constrained (PC) systems of molecules. Results from validating the model with dynamic shear experiments are given and a stability analysis for the corresponding linearized systems ... |
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| Dynamic Fracture in Brittle Materials |
FEB 2006 |
10 pages |
| Authors:
Jay R. Walton; TEXAS A AND M UNIV COLLEGE STATION DEPT OF MATHEMATICS
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| The primary objective of this project were the formulation and analysis of canonical boundary value problems modeling dynamic fracture in brittle materials. The following issues concerning dynamic fracture in brittle were studied: unsteady, dynamic, mode I crack growth in linear elastic material; dynamic crack growth in functionally graded elastic bodies; dynamic, steady-state, generalized plane strain crack growth in anisotropic linear viscoelastic material; dynamic, transient, mode III crack growth in linear ... |
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Reports by Keyword(s)
LINEARITY
