| M119 Howitzer Saddle Gun Fire Finite Element Analysis |
Dec 2011 |
19 pages |
| Authors:
R Terhune; S McDonald; M Kotliar; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER PICATINNY ARSENAL NJ MUNITIONS ENGINEERING TECHNOLOGY CENTER
|
 | The M119 howitzer is the current fielded 105-mm artillery weapon. It is undergoing upgrades to the fire control system in which they will be adding new components and brackets to the existing system. Finite element analysis (FEA) was performed to determine the stress contours along the side of the saddle (a subsystem of the howitzer) in regions where holes will be added for fire control brackets. The FEA results were ... |
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| Multiadaptive Plan (MAP) IMRT to Accommodate Independent Movement of the Prostate and Pelvic Lymph Nodes |
Dec 2011 |
75 pages |
| Authors:
Ping Xia; CLEVELAND CLINIC FOUNDATION OH
|
| We found that the rotational shifts detected by aligning implanted markers between the planning images and the verification images may not determine the true rotation of the prostate. Ignoring these detected rotational shifts may lead to erroneous errors of localizing the prostate. We found that the prostate rotation can be compensated with corrections made in translational shifts, achieving improved geometric and dosimetric evaluation indices. Furthermore, we found that when the ... |
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| Investigation of an Explicitly Modeled Solid Ocean Floor on a Shallow Water UNDEX Event |
Sep 2011 |
134 pages |
| Authors:
Adam P Walters; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Current practices for modeling the ocean floor in underwater explosion simulations call for application of an inviscid fluid with soil properties. A method for modeling the ocean floor as a Lagrangian solid, vice an Eulerian fluid, was developed in order to determine its effects on underwater explosions in shallow water using the DYSMAS solver. The Lagrangian solid bottom model utilized transmitting boundary segments, exterior nodal forces acting as constraints, and ... |
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| Effects of Contoured Pallets on AMC Mission Efficiency |
JUN 2011 |
64 pages |
| Authors:
James R. Hanford; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| Pallets airlifted on Boeing 747s and MD-11s in fiscal year 2009 were analyzed to determine the effects of redistributing cargo from full cubes to contoured shapes. Specifically, the research analyzed the possibility of structuring pallet build strategies that would ensure that MD-11 missions were not cancelled due to lack of available contour-compatible cargo while other, full-cubed cargo was available. Missions were tracked on these airframes between Dover Air Force Base, ... |
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| Linking the Surf Zone and Inner Shelf: Cross-shore Transportation Mechanisms |
JAN 2011 |
6 pages |
| Authors:
Adrianus Reniers; ROSENSTIEL SCHOOL OF MARINE AND ATMOSPHERIC SCIENCE MIAMI FL
|
| The long-term goals are to understand surf zone processes, in particular cross-shore exchange related to rip current systems through field observations and numerical modeling. Rip currents occur commonly on most beaches and dominate many. It is recognized that beaches with straight and parallel contours are not a stable morphologic configuration, whereas more complex beaches, which support the existence of rip current morphology, are stable and more common. The research objectives ... |
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| A Three-Dimensional Foil Bearing Performance Map Applied to Oil-Free Turbomachinery |
Apr-2009 |
22 pages |
| Authors:
Christopher Dellacorte; Kevin C Radil; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH GLENN RESEARCH CENTER
|
| To effectively apply compliant foil gas bearings to increasingly larger and more challenging turbomachinery, a comprehensive method that compares a foil bearing's capabilities with the application's operating requirements is needed. Extensive laboratory and field experience suggests foil bearing failure is generally due to thermal stress brought on by excessive viscous power loss; therefore a map that graphically relates component and system-level parameters (bearing size, applied loads, and shaft rotational speeds) ... |
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| Analysis of Implicit Modeling of Complex Geometric Environments |
28-Feb-2009 |
29 pages |
| Authors:
Gregory M Nielson; ARIZONA STATE UNIV TEMPE
|
| 1. Developed methods for extracting mathematical surface description of urban/terrain implicitly defined from scattered point cloud data obtained from scanners and other detecting devices 2. Developed methods for parameterizing surfaces representing urban/terrain environments which are implicitly modeled. 3. Developed a custom software environment for simulating scanner output producing point cloud data sets. 4. Developed and analyzed adaptive, implicit mathematical methods for modeling data scanned from complex geometric environment. 5. Developed, ... |
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| Experimental Investigation of High-Pressure Steam-Induced Surge in a Transonic Compressor Stage |
01-Jun-2008 |
65 pages |
| Authors:
Andrew M Hurley; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Operational experience indicates that steam escaping from carrier catapults has the potential to induce stall or surge in the compressors of jet aircraft during takeoff. As the carrier fleet ages and the Navy transitions to the single engine F-35C variant of the Joint Strike Fighter, further investigation of steaminduced surge phenomena is necessary to avert undue risks to pilots and to obviate stall related damage to Navy aircraft. This study ... |
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| An Analysis of Groundwater Flow Patterns in a Constructed Treatment Wetland Cell |
MAR 2008 |
104 pages |
| Authors:
Rebecca S. Corbin; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| This research effort analyzed groundwater flow paths within a treatment wetland constructed to degrade tetrachloroethylene (PCE) in groundwater. The treatment cell is a vertical flow wetland that allows the water to flow from the bottom to the surface breaking down PCE and daughter products. The method of conducting this research included collecting field data of hydraulic head contours nested piezometers and collecting data from sampling wells to determine hydraulic conductivities ... |
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| Comparisons between Measurements in Regions of Laminar Shock Wave Boundary Layer Interaction in Hypersonic Flows with Navier-Stokes and DSMC Solutions |
01 JAN 2006 |
57 pages |
| Authors:
Michael S. Holden; Timothy P. Wadhams; John K. Harvey; Graham V. Candler; AEROTHERMAL AND AERO-OPTICS EVALUATION CENTER BUFFALO NEW YORK
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| Experimental studies were conducted in conjunction with computations in a code validation exercise to examine the ability of DSMC and Navier-Stokes techniques to predict the complex characteristics of regions of shock/shock and shock/ boundary layer interactions in hypervelocity flows. In the experimental program, detailed heat transfer and pressure measurements in laminar regions of shock wave/boundary layer interaction, and shock/shock interaction, over hollow cylinder/flare and double cone configurations in hypersonic flow. ... |
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| Enhancement of Chamber Wall Heat Transfer by Surface Contouring |
18 OCT 2005 |
13 pages |
| Authors:
E. Coy; S. Danczyk; J. Watt; J. Poylio; NORTHROP GRUMMAN SPACE AND MISSILE SYSTEMS CORP REDONDO BEACH CA SPACE TECHNOLOGY
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| The effect of surface features on chamber wall heat transfer has been measured in a sub-scale combustion chamber. Results are reported for five different roughness patterns for conditions of hydrogen/oxygen combustion at mixture ratios of 2-6 and chamber pressures of 100-200 psig. The results include the measured levels of heat flux and Stanton number. The transverse ribs and grooves had the largest effect, resulting in approximately a doubling of the ... |
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| Active Contours for Multispectral Images With Non-Homogeneous Sub-Regions |
16 SEP 2005 |
114 pages |
| Authors:
Wesley E. Snyder; NORTH CAROLINA STATE UNIV AT RALEIGH
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| In this work, we develop a framework for image segmentation which partitions an image based on the statistics of image intensity where the statistical information is represented as a mixture of probability density functions defined in a multi-dimensional image intensity space. Depending on the method to estimate the mixture density functions, three active contour models are proposed: unsupervised multi-dimensional histogram method, half-supervised multivariate Gaussian mixture density method, and supervised multivariate ... |
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| Numerical Simulation of Galvanic Corrosion Caused by Shaft Grounding Systems in Steel Ship Hulls |
07 SEP 2005 |
|
| Authors:
Y. Wang; DEFENCE RESEARCH AND DEVELOPMENT ATLANTIC DARTMOUTH (CANADA)
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 | The shaft grounding systems used on board HMC ships have substantially reduced the shaft-to-hull resistance and, thus, improved the performance of the shipboard impressed current cathodic protection (ICCP) system. Under some circumstances, however, the shaft grounding systems have been left on while the ICCP system was turned off. This led to the accelerated corrosion of the exposed steel ship hull on paint holidays because of the substantial difference of the ... |
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| Effects of Boundary Layer Flow Control Using Plasma Actuator Discharges |
SEP 2005 |
125 pages |
| Authors:
Jeffrey M. Newcamp; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
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| This study addresses the usage and effects of atmospheric plasma discharges on the near wall flow conditions for a Pak-B low-pressure turbine blade. A plasma actuator was built normal to the freestream flow in a low-speed wind tunnel. The test section of the wind tunnel had a contoured upper wall geometry designed to mimic the suction side of a Pak-B turbine blade. A high frequency ac voltage source supplied three ... |
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| Cuspate Shoreline Morphology |
JUN 2005 |
71 pages |
| Authors:
Brandon McWilliams; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Large beach cusps with wavelengths O(200m), sometimes termed mega- cusps, were measured along 18km of the Southern Monterey Bay coastline from October 2004 to April 2005 to investigate the cuspate shoreline response to rip current systems. Monterey Bay is a unique location for the study of rip current systems, which has with well defined rips that are present all year long, a large dune erosional rate, and incident wave energy ... |
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| Contour Tracking Control for the REMUS Autonomous Underwater Vehicle |
JUN 2005 |
83 pages |
| Authors:
Alan R. Van Reet; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| In the interest of enhancing the capabilities of autonomous underwater vehicles used in US Naval Operations, controlling vehicle position to follow depth contours presents exciting potential for navigation. Use of a contour tracking control algorithm in lieu of preprogrammed waypoint navigation offers distinct advantages within new challenges. The difficult nature of this problem lies in the non-trivial connection between the necessary corrective action and the feedback error used in traditional ... |
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| A Comparison of Hazard Prediction and Assessment Capability (HPAC) Software Dose-Rate Contour Plots to a Sample of Local Fallout Data From Test Detonations in the Continental United States, 1945 - 1962 |
MAR 2005 |
91 pages |
| Authors:
Richard W. Chancellor; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
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| A comparison of Hazard Prediction and Assessment Capability (HPAC) software dose-rate contour plots to a sample of local nuclear fallout data from test detonations in the continental United States, 1945 - 1962, is performed. Fallout data from test detonations is obtained from "Compilation of Local Fallout Data from Test Detonations 1945- 1962 Extracted from DASA 1251, Volume I - Continental U.S. Tests." This report contains fallout plots and radiation contours ... |
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| Workshop Report Scenario Generation for Simulation Based Design for a Next Generation Surface Combatant |
MAR 2005 |
|
| Authors:
J. K. De Kraker; TNO Defence Security and Safety The Hague (Netherlands)
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| The Netherlands, Germany and Sweden participate in a trilateral cooperation which investigates the possibilities for improving the insight in the relationship between operational requirements and critical design parameters of naval ships. To analyze those ship requirements that drive the ship design costs a number of activities must be performed. One of these activities, which is the subject of this report, concerns the development of operational scenarios in which the cost-driving ... |
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| Targeting MRS-Defined Dominant Intraprostatic Lesions with Inverse-Planned High Dose Rate Brachytherapy |
FEB 2005 |
58 pages |
| Authors:
Jean Pouliot; I-Chow Hsu; John Kurhanewicz; Sue Noworelski; CALIFORNIA UNIV SAN FRANCISCO
|
| During this first year, we have obtained CHR approval (December 2004) from the three step process (C.U., P.R.C. and C.H.R.) committees at UCSF. Patient enrollment will begin immediately after receiving CHR approval from D.O.D. The accuracy of aligning MRI/MSRI data acquired with different types of endorectal probes to images acquired without a probe was determined. A 94% Average overlap of prostate contours was obtained using rigid endorectal coil. We have ... |
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| Knowledge-Based 3D Segmentation and Reconstruction of Coronary Arteries Using CT Images |
SEP 2004 |
4 pages |
| Authors:
Yan Yang; Allen Tannenbaum; Don Giddens; GEORGIA INST OF TECH ATLANTA DEPT OF BIOMEDICAL ENGINEERING
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| An approach for the 3D segmentation and reconstruction of human left coronary arteries using angio-CT images is presented in this paper. Each voxel in the 3D dataset is assumed to belong to one of the three homogeneous regions: blood, myocardium, and lung. A priori knowledge of the regions is introduced via Bayes rule. Posterior probabilities obtained using Bayes rule are anisotropically smoothed, and the 3D segmentation is obtained via MAP ... |
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| Terrain Texture and 3-D Object Cues in the Control of Heading in Simulated Flight |
Jan-2004 |
4 pages |
| Authors:
William Morgan; Robert Patterson; George A Geri; Shama C Akhtar; Christine M Covas; Byron J Pierce; Brian P Dyre; WASHINGTON STATE UNIV PULLMAN
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| The effects of terrain texture type and the height and density of 3D objects on heading control were studied in two experiments conducted in a high-performance flight simulator. The results suggest an orthogonal-extension principle which relates performance to the number and length of contours that are perpendicular to the ground plane, and also begin to define the stimulus conditions for which the principle is valid. |
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| Vulnerability of Wireless Point-to-Point Systems to Interception |
DEC 2003 |
93 pages |
| Authors:
Melvin L. Pin; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Wireless systems have always been susceptible to interception in both urban outdoor and indoor environments. In point-to-point communication links, the placement of base station antennas is usually determined by an experimental or analytical assessment of the propagation path. Since point-to-point links are typically used to network widely separated areas, antennas used in such situations are likely to be directional, but may still be susceptible to interception by covert entities. In ... |
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| A Direct Method and Convergence Analysis for Some System of Singular Integro-Differential Equations |
2003 |
18 pages |
| Authors:
Lurie Caraus; Zhilin Li; NORTH CAROLINA STATE UNIV AT RALEIGH CENTER FOR RESEARCH IN SCIENTIFIC COMPUTATION
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| A class of singular integro-differential equations in Leheague spaces are studied. There are many applications of the singular integro-differential equations discussed in this paper. An example in modeling the stress distribution of an elastic medium with holes is discussed in the paper. Direct numerical schemes using a collocation method and a mechanical quadrature rule designed for the singular integro-differential equations are proposed for arbitrary smooth closed contours. Convergence analysis of ... |
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| Initiation of Detonation in a Large Tube |
2003 |
5 pages |
| Authors:
Viswanath Katta; Colin Tucker; John Hoke; Fredric Schauer; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
|
| One of the important design criteria in the development of Pulse Detonation Engines (PDEs) is to stabilize detonation in a large-diameter tube in the shortest possible distance. The initial shock train emanating from the ignition source plays an important role in transitioning the deflagration wave into a detonation. To sustain such transition in a large diameter tube. innovative methods and strategies are required. An experimental-numerical investigation is conducted to understand ... |
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| Analysis of Interval Changes on Mammograms for Computer Aided Diagnosis |
MAY 2002 |
47 pages |
| Authors:
Lubomir Hadjiiski; MICHIGAN UNIV ANN ARBOR
|
| A new classification scheme was developed to classify mammographic masses as malignant and benign by using interval change information. The masses on both the current and the prior mammograms were automatically segmented using an active contour method. From each mass, texture morhological and spiculation features, were extracted. Additionally, difference features were obtained by subtracting the prior from the corresponding current features. The feature space consisted of the current, difference and ... |
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| Contour Pick-Up and Registration of Infrared Images of Palm |
25 OCT 2001 |
|
| Authors:
Xiaowei Liu; Zhigang Shang; Guotai Jiang; TONGJI UNIV SHANGHAI (CHINA)
|
| In this thesis an approach of Contour Pick-up and image registration is presented for infrared images of palm. Contour Pick-up is based on Gauss- Laplase kernel and image registration is implemented by their cross-correlation function. In order to use the temperature variety attained from the infrared images for diagnoses of metabolically diseases, man used to get the different time temperature of a certain area artificial point by point. It always ... |
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| PDE and Tensor Based Approach for Parietal Dynamic Tracking in Ultrasound Sequences |
25 OCT 2001 |
|
| Authors:
C. Tilmant; L. Sarry; J. Y. Boire; AUVERGNE UNIV CLERMONT-FERRAND (FRANCE)MEDICAL IMAGING RESEARCH TEAM (ERIM)
|
| A method for pericardial and endocardial edge extraction of the left ventricle (LV) in 2-D short axis echocardiographic sequence is presented. The proposed algorithm consists in two steps: nonlinear anisotropic diffusion filtering and directional geodesic active contours, These steps are based on both PDE and tensors, Tensor formalism gives access to structure orientation of the acoustic density field, This provides a more robust algorithm by using the whole image information, ... |
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| Segmentation of TIBIA Bone in Ultrasound Images Using Active Shape Models |
25 OCT 2001 |
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| Authors:
Ping He; Jun Zheng; WRIGHT STATE UNIV DAYTON OH DEPT OF BIOMEDICAL AND HUMAN FACTORS ENGINEERING
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| This paper describes the use of Active Shape Models to segment the tibia bone in ultrasound images. Using CT images from three volunteers, a training set consisting of 60 tibia contours, each represented by 45 labeled points, is first established. After aligning the contours in the training set, a Point Distribution Model (PDM) is generated that includes a mean shape of tibia and six modes of shape variation that explain ... |
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| An Automated Differential Blood Count System |
25 OCT 2001 |
|
| Authors:
Guclu Ongun; Ugur Halici; Kemal Leblebicioglu; Volkan Atalay; Meral Beksac; MIDDLE EAST TECHNICAL UNIV ANKARA (TURKEY) COMPUTER VISION AND NEURAL NETWORKS RESEARCH CENTER
|
| While the early diagnosis of hematopoietic system disorders is view important in hematology, it is a highly complex and time consuming task. The early diagnosis requires a lot of patients to be followed-up by experts which, in general is in-feasible because of the required number of experts. The differential blood counter (DBC) system that we have developed is an attempt to automate the task performed manually by experts in routine. ... |
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| Catheter Calibration Using Template Matching Line Interpolation Algorithm |
25 OCT 2001 |
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| Authors:
L. Nagy; L. Szilagyi; BUDAPEST UNIV OF TECHNOLOGY AND ECONOMICS (HUNGARY) DEPT OF CONTROL ENGINEERING AND INFORMATION
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| This paper presents a study case of specific angiographic X-ray image processing, such as quantitative cardiac analysis During QCA it is very,' important to get precise and accurate results because these data are used to make a diagnosis or to plan an eventual intervention, The two main requests are influenced by many factors, such as: image resolution, type of the calibration, algorithm used for contour detection, size of the FOV, ... |
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| Contour Extraction in Prostate Ultrasound Images Using the Wavelet Transform and Snakes |
25 OCT 2001 |
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| Authors:
Fangwei Zhao; Christopher J. S. deSilva; WESTERN AUSTRALIA UNIV NEDLANDS
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| It is extremely difficult to locate the contour of the prostate in B- scan ultrasound images automatically by computer because of low resolution and signal noise levels. In this paper we present a semi-automatic prostate contour extraction scheme, which is based on the wavelet transform and active contour models, or snakes. The ultrasound image is first decomposed into edge naps at different resolutions via the wavelet transform. Seed points are ... |
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| Effect of Shallow Water Internal Waves on Ocean Acoustic Striation Patterns |
01 JUN 2001 |
20 pages |
| Authors:
Daniel Rouseff; UNIV OF WASHINGTON SEATTLE APPLIED PHYSICS LAB
|
| Contour plots of underwater acoustic intensity, mapped in range and frequency, often exhibit striations. It has been claimed that a scalar parameter 'beta', defined in terms of the slope of the striations, is invariant to the details of the acoustic waveguide. In shallow water, the canonical value for beta is one. In the present paper, the waveguide invariant is modeled as a distribution rather than a scalar. The effects of ... |
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| Relative Erosivity of Nitramine Gun Propellants with Thermoplastic/Elastomer Binder Systems |
26 APR 2001 |
7 pages |
| Authors:
Charles S. Laveritt; Paul J. Conroy; Andrew W. Johnson; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Current and future gun propellant development programs are necessarily moving toward compositions possessing ever-higher impetus and flame temperature. A common goal is impetus above 1250 J/g, resulting in flame temperature above 3400 K. Propellants showing the most promise are composite in nature, consisting of an energetic solid in an energetic thermoplastic elastomer (ETPE). Oxidizers are typically CL-20 or RDX. Normally, such systems could be expected to provide some gun tube ... |
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| PDE Software for Digital Image Management |
10 APR 2001 |
43 pages |
| Authors:
Jill Goldschneider; Lydia Ng; Vikram Chalana; MATHSOFT INC SEATTLE WA
|
| In Phase I research, we investigated and developed image segmentation and registration algorithms using curvature-based flow-driven nonlinear partial differential equation imaging models and algorithms, including total variation, level-set, and active contour techniques. We implemented the developed algorithms in C and S+, an open and extensible software environment, to allow us to do rapid prototyping and evaluation of the methods. We applied combinations of the methods developed to two applications in ... |
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| Analysis of Cloud-Free Line-of-Sight Probability Calculations |
MAR 2001 |
76 pages |
| Authors:
Joseph J. Golemboski III; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH
|
| Cloud-free line-of-sight probabilities were calculated using two separate methods. The first was a variation of a method developed by the Rand Corporation in 1972. In it, CFLOS probabilities were calculated using empirical data based on five years of photograms taken over Columbia, Missouri and forecasted cloud amounts rather than climatological values. The second was a new approach using the Cloud Scene Simulation Model developed by Phillips Laboratory. Cloud scenes were ... |
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| Device for the Acquisition of Contoured Human Body Surface Vibration Signals |
04 OCT 2000 |
16 pages |
| Authors:
Norma L. Owaley; Andrew J. Hull; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| In accordance with the present invention, a device for acquiring contoured human body surface vibration signals is provided. The device comprises a first component for sensing the displacements of a skin surface as a function of time at multiple points on the human body, with the first component having a plurality of sensing elements, a second component for measuring time average displacements of the skin surface at nominal locations of ... |
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| System for Providing an Estimate of the Location of an Undersea Object |
15 SEP 2000 |
22 pages |
| Authors:
G. C. Carter; Harold J. Teller; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A system is disclosed that provides a sonar operator with the most likely range to a target of interest. The system generates and displays a contour based on ship's parameters, target parameters, environmental data, and operator parameters. The sonar operator can vary many of the parameters in 'what if' scenarios so as to Generate Groups of contours for preselected probabilities of detection. Contours can be used to show the actions ... |
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| Early Scene Analysis: Rapid Procession of Contours, Surfaces and Objectsin Human Vision |
01 SEP 2000 |
8 pages |
| Authors:
Patrick Cavanagh; HARVARD UNIV CAMBRIDGE MA DEPT OF PSYCHOLOGY
|
| Peter Murphy and I have created an image analysis program which labels image discontinuities as either occlusions, shadow, or pigment boundaries. The algorithm relies on regularities in the brightness flow surrounding each different contour type--each of contour has a characteristic form of isophotes in its neighborhood. For example, the isophotes of a surface lie parallel to an occluding boundary on the side of the ... |
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| Depth Perception Applied to Search and Target Acquisition |
MAR 2000 |
11 pages |
| Authors:
Wendell R. Watkins; LeRoy Alaways; ARMY RESEARCH LAB WHITE SANDS MISSILE RANGE NM
|
| A search and target acquisition test was performed under an exchange scientist program with the TNO Human Factors Research Institute at Soesterberg, The Netherlands in September 1995. The test was performed at a military training base using several of the scientists from TNO wearing Dutch forest camouflage uniforms. Sets of wide baseline stereo photos were obtained for targeted and non-targeted scenes at two sites. The targeted and non-targeted scene photos ... |
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| Image Structure Models of Texture and Contour Visibility |
MAR 2000 |
8 pages |
| Authors:
Wilson S. Geisler; Thomas Thornton; Donald P. Gallogly; Jeffrey S. Perry; TEXAS UNIV AT AUSTIN DEPT OF PSYCHOLOGY
|
| The perceptual mechanisms underlying texture and contour grouping/segregation play a dominant role in determining the visibility of targets in complex backgrounds. In most quantitative models of texture segregation the image is initially processed by channels selective along certain fundamental stimulus dimensions such as spatial frequency and orientation. These channels generally contain a nonlinearity, such as full-wave rectification, so that they signal the local contrast energy within the bandpass of the ... |
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| Effects of Load History on Damage Characteristics Near Crack Tips in a Particulate Composite Material |
03 JAN 2000 |
17 pages |
| Authors:
C. T. Liu; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
|
| The damage field in a precracked particulate composite specimen subjected to a complex cyclic loading history was investigated using acoustic imaging techniques. The acoustic imaging data were analyzed to delineate the damage field ahead of the crack tips and to generate contour plots of the damage intensity. The results of these analyses were compared and the effect of the loading history on the damage field is discussed. |
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| Distributed Systems for Problems in Robust Control and Visual Tracking |
2000 |
24 pages |
| Authors:
Allen R. Tannenbaum; GEORGIA INST OF TECH ATLANTA SCHOOL OFELECTRICAL AND COMPUTER ENGINEERING
|
| The objectives of this research grant have been development of new theory and algorithms for the analysis and synthesis of robust controllers for nonlinear and possibly distributed feedback systems. A key application is in controlled active vision, including visual tracking, the control of autonomous vehicles, motion planning, and the utilization of visual information in guidance and control. The PI has been employing methods from differential geometry, geometry-driven flows, computational algebraic ... |
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| Study of Polydispersity of Grafted Poly(dimethylsiloxane) Surfaces Using Single Molecule Atomic Force Microscopy |
2000 |
3 pages |
| Authors:
S. Al-Mawaali; J. Bemis; G. C. Walker; PITTSBURGH UNIV PA DEPT OF CHEMISTRY
|
| Single molecule atomic force microscopy (AFM) was used to study the statistical distribution of contour lengths (polydispersity) of polymer chains grafted to a surface. A poly(dimethylsiloxane) (PDMS) monolayer was grafted on a flat silicon substrate by covalently bonding Cl-terminated PDMS to an OH-silicon surface and characterized using contact angle measurements and ellipsometry, and single molecule AFM. A model for the single chain dynamics is presented. The statistical distributions of the ... |
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| Dealing with Topological Singularities in Volumetric Reconstruction |
2000 |
10 pages |
| Authors:
H. Lopes; L. G. Nonato; S. Pesco; G. Tavares; PONTIFICIA UNIVERSIDADE CATOLICA DO RIODE JANEIRO (BRAZIL) DEPT OF MATHEMATICS
|
| In this work we introduce a new representation for three-dimensional stratified manifolds based on Morse theory. This representation, which we call Handle-Strata, includes a new data structure and a set of operators. Applications of this representation on the volumetric reconstruction from planar sections are presented. |
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| Commanders' Display of Terrain Information: Manipulations of Display Dimensionality and Frame of Reference to Support Battlefield Visualization |
SEP 1999 |
80 pages |
| Authors:
Rachel Banks; Christopher D. Wickens; ILLINOIS UNIV AT URBANA-CHAMPAIGN SAVOYAVIATION RESEARCH LAB
|
| To gain a better understanding of the effects of display dimensionality and frame of reference on battlefield commanders' ability to understand the constraints of battlefield terrain, we constructed three electronic map displays, depicting both flat and mountainous terrain, and studied their effects on making various types of tactical judgments. U.S. Military Academy officers were presented with a two-dimensional (2D) contour display, a three- ... |
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| Pressure Measurements on a Proposed Optical Window Fairing for the AltusII Unmanned Air Vehicle |
SEP 1999 |
84 pages |
| Authors:
Scott C. Ferris; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Low-speed wind tunnel tests were conducted to determine surface pressure measurements on a proposed aerodynamic fairing for the Altus II UAV. These tests were conducted at various angle-of-attack and sideslip positions to determine the effect on the surface pressures for the optical window portion of the fairing. Of particular interests were the pressure contour field located over the optical window region and the total force ... |
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| Registering Oblique Image Pairs Without Camera Models |
24 MAY 1999 |
18 pages |
| Authors:
Robert M. Taylor; JOHNS HOPKINS UNIV LAUREL MD APPLIED PHYSICS LAB
|
| This paper presents automatic electro-optical image registration of images taken from oblique views (large baseline separation). The method uses feature based point correspondence to solve for the projective parameters in an iterative approach. The feature points are solved for by analyzing region contours on segmented images. A simple geometric invariance method is used to match points and remove outliers. A projective transform is applied to previously warped images until the ... |
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| Understanding How Saddle Points Affect the Onset of Vortex Asymmetry |
03 MAR 1999 |
4 pages |
| Authors:
Paul D. Orkwis; CINCINNATI UNIV OH DEPT OF AEROSPACE ENGINEERING AND ENGINEERING MECHANICS
|
| The results of this research provide further evidence that the secondary vortex/saddle point region is critical to the formation of vortex asymmetry in conical Navier-Stokes equation set simulations. In addition, the proper technique for tracking the perturbations is explained. Sample perturbation contour plots are provided. The work continues under support from the University of Cincinnati, exploring perturbation growth rate and propagation. |
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| Sound Intensity Prediction System (SIPS) A Noise Complaint Management Tool For Explosive Operations |
Aug-1998 |
15 pages |
| Authors:
Micheal M Kordich; Dean A Pollet; NAVAL SURFACE WARFARE CENTER DAHLGREN DIV VA
|
| The Sound Intensity Prediction System (SIPS) is a range operations tool for the management of noise complaints. It is an acoustic ray tracing computer code employing weather data to determine the locations of both noise enhancements and reductions from the conduct of explosive operations. SIPS was installed at the Utah Test and Training Range, Hill Air Force Base, Ogden Utah in September 1994. Since then 2,400 tons of ordnance, at ... |
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| Development of Satellite Based Sensor for Improved Measurement and Validation of Ionospheric Parameters |
Jan 1998 |
6 pages |
| Authors:
Suman Ganguly; OFFICE OF NAVAL RESEARCH ARLINGTON VA
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| Having ionospheric electron density distributions as a function of height, latitude, longitude and time under different conditions is essential for scientific, technical and operational purposes. A satellitebased, swept-frequency, HF sounder can obtain electron density profiles on a global scale. We are developing a new-generation HF sounder that employs recent developments in technology, electronics and processing capabilities. It will provide global-scale electron density distributions, contours of fixed densities, maps of f0F2, ... |
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