| Minimization of Collateral Damage in Airdrops and Airstrikes |
30 Sep 2012 |
138 pages |
| Authors:
Steven P Dillenburger; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
|
 | Collateral damage presents a signi cant risk during air drops and airstrikes, risking citizens' lives and property, straining the relationship between the United States Air Force and host nations. This dissertation presents a methodology to determine the optimal location for making supply airdrops in order to minimize collateral damage while maintaining a high likelihood of successful recovery. A series of non-linear optimization algorithms is presented along with their relative success ... |
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| Decomposition Methods for Optimized Collision Avoidance with Multiple Threats |
03 May 2011 |
22 pages |
| Authors:
James P Chryssanthacopoulos; Mykel J Kochenderfer; MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
|
| Aircraft collision avoidance systems assist in the resolution of collision threats from nearby aircraft by issuing avoidance maneuvers to pilots. Encounters where more than one aircraft poses a threat, though rare, can be difficult to resolve because a maneuver that might resolve a conflict with one aircraft might induce conflicts with others. Recent efforts to develop robust collision avoidance systems for single-threat encounters have involved modeling the problem as a ... |
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| Modeling and Control of a Tethered Rotorcraft |
30 JUL 2010 |
25 pages |
| Authors:
Nathan Slegers; ALABAMA UNIV IN HUNTSVILLE
|
| A tethered rotorcraft model is developed using a computationally efficient recursive tether model. The recursive rigid-body tether model results in unconstrained ordinary differential equations and maintains much of the simplicity of simple lumped mass tether models while avoiding numerical difficulties associated with using many stiff elastic elements with low mass. Further efficiency is achieved by treating each tether link as a body of revolution and assuming that tether spin is ... |
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| The Lehmer Matrix and Its Recursive Analogue |
Jan 2010 |
14 pages |
| Authors:
Emrah Kilic; Pantelimon Stanica; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF APPLIED MATHEMATICS
|
| This paper considers the Lehmer matrix and its recursive analogue. The determinant of Lehmer matrix is derived explicitly by both its LU and Cholesky factorizations. We further define a generalized Lehmer matrix with (i; j) entries gij = min {ui+1, uj+1} / max {ui+1, uj+1} where un is the nth term of a binary sequence {un}. We derive both the LU and Cholesky factorizations of this analogous matrix and we ... |
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| Signal and Image Processing Algorithms for the U.S. Army Research Laboratory Ultra-wideband (UWB) Synchronous Impulse Reconstruction (SIRE) Radar |
Apr-2009 |
68 pages |
| Authors:
Lam Nguyen; ARMY RESEARCH LAB ADELPHI MD
|
| The U.S. Army Research Laboratory (ARL), as part of a mission and customer-funded exploratory program, has developed a new low-frequency, impulse-based, ultra-wideband (UWB) synthetic aperture radar (SAR), which has been used as a test bed to support proof-of-concept demonstration for detecting concealed targets. The radar is intended to collect and process data at combat pace in an affordable, compact, and lightweight package. To achieve this, the radar is based on ... |
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| Individual Decision-Making in Uncertain and Large-Scale Multi-Agent Environments |
18-Feb-2009 |
14 pages |
| Authors:
Prashant Doshi; Adam Goodie; GEORGIA UNIV RESEARCH FOUNDATION INC ATHENS
|
| Research undertaken in this initial performance period developed: (a) the first set of generally applicable approximation methods for the finitely nested interactive POMDP (I-POMDP) framework, and (b) novel probabilistic graphical models called interactive dynamic influence diagrams (I-DIDs) that generalize the well-known DIDs to multiagent settings. These methods provide approximation techniques for decision making in complex multiagent settings in reduced time and space facilitating scalability. Experiments reveal that the approaches generate ... |
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| A Parameterized Design Framework for Hardware Implementation of Particle Filters |
MAR 2008 |
5 pages |
| Authors:
Sankalita Saha; Neal K. Bambha; Shuvra S. Bhattacharyya; MARYLAND UNIV COLLEGE PARK DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Particle filtering methods provide powerful techniques for solving non-linear state-estimation problems, and are applied to a variety of application areas in signal processing. Because of their vast computational complexity, real-time hardware implementation of particle-filter-based systems is a challenging task. However, many particle filter applications share common characteristics, and the same system design can be reused with appropriate streamlining. To achieve this, a parameterized design framework for particle filters is proposed ... |
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| Applying Automated Theorem Proving to Computer Security |
MAR 2008 |
130 pages |
| Authors:
Kelly McElroy; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH DEPT OF GRADUATE COMPUTER SCIENCE
|
| While more and more data is stored and accessed electronically, better access control methods need to be implemented for computer security. Formal modelling and analysis have been successfully used in certain areas of computer systems, such as verifying the security properties of cryptographic and authentication protocols. However, formal models for computer systems in cyberspace, like networks, have hardly advanced. A highly regarded graduate textbook cites the Take-Grant model created in ... |
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| Checking and Measuring the Architectural Structural Conformance of Object-Oriented Systems |
DEC 2007 |
52 pages |
| Authors:
Marwan Abi-Antoun; Jonathan Aldrich; CARNEGIE-MELLON UNIV PITTSBURGH PA SCHOOL OF COMPUTER SCIENCE
|
| The benefits of architectural analyses are only achieved if one can guarantee that the implementation conforms to the architecture. We propose an approach for checking and measuring the structural conformance of a software system's implementation to its execution architecture. In contrast to existing approaches, our approach uses static analyses, and works with existing Java-like programming languages, existing object-oriented designs and existing integrated development environments. We address the problem with a ... |
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| Stochastic Mapping for Chemical Plume Source Localization With Application to Autonomous Hydrothermal Vent Discovery |
FEB 2007 |
|
| Authors:
Michael V. Jakuba; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
 | This thesis presents a stochastic mapping framework for autonomous robotic chemical plume source localization in environments with multiple sources. Potential applications for robotic chemical plume source localization include pollution and environmental monitoring, chemical plant safety, search and rescue, anti-terrorism, narcotics control, explosive ordinance removal, and hydrothermal vent prospecting. Turbulent flows make the spatial relationship between the detectable manifestation of a chemical plume source, the plume itself, and the location of ... |
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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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| Flight Regime Recognition Analysis for the Army UH-60A IMDS Usage |
DEC 2006 |
127 pages |
| Authors:
Ahmet M. Dere; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Usage Monitoring requires accurate regime recognition. For each regime, there is a usage assigned for each component. For example, the damage accumulated at a component is higher if the aircraft is undergoing a high G maneuver than in level flight. The objective of this research is to establish regime recognition models using classification algorithms. The data used in the analysis are the parametric data collected by the onboard system and ... |
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| Recursive Bayesian Method for Tracking a Magnetic Target with a Gradiometer |
SEP 2006 |
|
| Authors:
Marius Birsan; DEFENCE RESEARCH AND DEVELOPMENT ATLANTIC DARTMOUTH (CANADA)
|
| This report describes a numerical method that may be used to efficiently locate and track magnetic targets with a tensor gradiometer. A target containing ferromagnetic material can be adequately modeled at a distance by an equivalent magnetic dipole. This magnetic target can be observed by means of a magnetic gradiometer that measures a symmetric, traceless gradient tensor as a function of time. Of interest is the inverse problem of the ... |
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| Establishing High Confidence in Code Implementations of Algorithms using Formal Verification of Pseudocode |
16 AUG 2006 |
17 pages |
| Authors:
Myla Archer; Elizabeth I. Leonard; NAVAL RESEARCH LAB WASHINGTON DC
|
| Using a theorem prover to establish that a body of code correctly implements an algorithm is a task seldom undertaken because the effort required tends to be prohibitive. Direct reasoning about code in a particular programming language requires that some version of the language's semantics-e.g., axiomatic, operational, denotational-be used to determine the program correctness assertions to establish with the theorem prover. Any scheme for generating correctness assertions will be language-specific, ... |
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| Visual Performance-Based Image Enhancement Methodology: An Investigation of Contrast Enhancement Algorithms |
MAR 2006 |
14 pages |
| Authors:
GENERAL DYNAMICS ADVANCED INFORMATION SYSTEMS DAYTON OH
|
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| Theory of Multirate Statistical Signal Processing and Applications |
SEP 2005 |
195 pages |
| Authors:
Ryan J. Kuchler; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This dissertation develops basic theory and applications of statistical multirate signal processing. Specific tools and terminology for describing multirate systems in the time and frequency domains are presented. An optimal multirate estimator is derived in both a direct form and recursive form. The Recursive form of the optimal estimator allows calculation of the relative change in performance when input signals are added or removed from the multirate system. The optimal ... |
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| Feasability Study of Variance Reduction in the THUNDER Campaign-Level Model |
MAR 2005 |
201 pages |
| Authors:
Earl M. Bednar; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| As an Air Force Chief of Staff endorsed topic, Air Force Studies and Analyses Agency (AFSAA) requested an effective and efficient way to reduce the variance in analysis results from THUNDER. THUNDER is a large-scale discrete event simulation of campaign-level military operations and is used to examine issues involving the utility and effectiveness of air and space power in a theater-level, joint warfare context. Given the large number of stochastic ... |
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| On the Behavior of ECN/RED Gateways Under a Large Number of TCP Flows: Limit Theorems |
2005 |
39 pages |
| Authors:
Peerapol Tinnakornsrisuphap; Armand M. Makowski; QUALCOMM INC SAN DIEGO CA
|
| We consider a stochastic model of an ECN/RED gateway with competing TCP sources sharing the capacity. As the number of competing flows becomes large, the asymptotic queue behavior at the gateway can be described by a simple recursion and the throughput behavior of individual TCP flows becomes asymptotically independent. In addition, a Central Limit Theorem complement is presented, yielding a more accurate characterization of the asymptotic queue. These results suggest ... |
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| Three-Dimensional Hydrodynamic Model for Prediction of Falling Cylinder Through Water Column |
2005 |
12 pages |
| Authors:
Peter C. Chu; Chenwu Fan; Ashley Evans; Anthony F. Gilles; Peter Fleischer; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF OCEANOGRAPHY
|
| A three dimensional hydrodynamic model based on triple coordinate systems is developed to predict translation and orientation of falling rigid cylinder through the water column: earth-fixed coordinate (E-coordinate), cylinder 5 main-axis following coordinate (M-coordinate), and hydrodynamic force following coordinate (F- coordinate). Use of the triple coordinate systems and the transforms among them leads to the simplification of the dynamical system. The body and buoyancy forces and their moments are easily ... |
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| Multiple Model Particle Filtering For Multi-Target Tracking |
20 DEC 2004 |
33 pages |
| Authors:
Alfred Hero; Chris Kreucher; Keith Kastella; MICHIGAN UNIV ANN ARBOR DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
|
| This paper addresses the problem of tracking multiple moving targets by recursively estimating the joint multitarget probability density (JMPD). Estimation of the JMPD is done in a Bayesian framework and provides a method for tracking multiple targets which allow nonlinear target motion and measurement to state coupling as well as non-Gaussian target-state densities. We utilize an implementation of the JMPD method based on particle filtering (PF) techniques. The details of ... |
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| Recursive Parameter Identification for Estimating and Displaying Maneuvering Vessel Path |
DEC 2003 |
175 pages |
| Authors:
Stephen J. Pullard; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Real-time recursive parameters identification is applied to surface vessel modeling for maneuvering path prediction. An end-to-end system is developed to situational vessel motion identify vessel parameters and estimate future path. Path prediction improves bridge team situational awareness by providing a real-time depiction of future notion over the groin on an electronic chart and display system (ECDIS). The extended least squares (ELS) parameter identification approach allows the system to be installed ... |
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| Rapid Identification and Strain-Typing of Respiratory Pathogens for Epidemic Surveillance |
08 APR 2003 |
13 pages |
| Authors:
David J. Ecker; Rangarajan Sampath; Lawrence B. Blyn; Vivek Samant; Kevin Russell; Nikki Freed; Chris Barrozo; Jianguo Wu; Karl Rudnick; Anjali Desai; NAVAL HEALTH RESEARCH CENTER SAN DIEGO CA
|
| Epidemic respiratory infections are responsible for extensive morbidity and mortality within both military and civilian populations. We describe a methodology to examine respiratory samples that simultaneously identifies broad groups of bacteria. The process uses electrospray ionization mass spectrometry and base composition analysis of broad-range PCK amplification products. The base composition analyses from a small set of broad-range primer pairs are used to "triangulate" the identity of pathogenic organisms present in ... |
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| Adaptive Identification and Control of Hysteresis in Smart Material Actuators |
2003 |
22 pages |
| Authors:
Xiaobo Tan; John S. Baras; MARYLAND UNIV COLLEGE PARK INST FOR SYSTEMS RESEARCH
|
| Hysteresis exhibited by smart materials hinders their wider applicability in actuators and sensors. In this paper methods are studied for recursive identification and adaptive inverse control of smart material actuators, where a Preisach operator with a piecewise uniform density function is used to model the hysteresis. Persistent excitation conditions for parameter convergence are discussed in terms of the input to the Preisach operator. Two classes of recursive identification schemes are ... |
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| Ultra-Wideband Antenna Development |
SEP 2002 |
35 pages |
| Authors:
John C. Riordan; TITAN SYSTEMS CORP SAN LEANDRO CA PULSE SCIENCES DIV
|
| This report summarizes the results of a 1-year effort to investigate electromagnetic dispersion caused by finite electrical conductivity in ultra- wideband antennas. Integral equations are well-suited for antenna calculations, but numerical solutions of dispersive time-domain integral equations are extremely limited. The primary cause of this situation is the computational complexity, which increases by a factor or order N(sub t) (the number of time steps) for dispersive materials. We propose an ... |
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| Enabling-Dynamic Simulators: Stability, Bifurcation and Control Computations for Distributed Parameter Systems |
31 JUL 2002 |
7 pages |
| Authors:
Ioannis G. Kevrekidis; PRINCETON UNIV NJ
|
| We developed methodologies for the bifurcation detection and stability analysis of microscopic timesteppers (LB-based. lattice gas or Monte Carlo) based on the Recursive Projection Method (RPM). We demonstrated RPM-based 'coarse' (macroscopic) bifurcation and stability computations for systems for which only microscopic evolution rules are available (LB. KMC, Brownian Dynamics -BD-). We were able to perform the coarse bifurcation analysis of KMC models of surface reactions, of LB models of multiphase-bubbly ... |
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| Tracking Performance of the RLS Algorithm Applied to an Antenna Array in a Realistic Fading Environment |
May-2002 |
15 pages |
| Authors:
James R Zeidler; Brian C Banister; SPACE AND NAVAL WARFARE SYSTEMS CENTER SAN DIEGO CA
|
| In this paper, frequency domain techniques are used to derive the tracking properties of the recursive least squares (RLS) algorithm applied to an adaptive antenna array in a mobile fading environment, expanding the use of such frequency domain approaches for nonstationary RLS tracking to the interference canceling problem that characterizes the use of antenna arrays in mobile wireless communications. The analysis focuses on the effect of the exponential weighting of ... |
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| Chirp Transform in the Nonlinear Tracking Performance Analysis of the LMS Adaptive Predictors |
Nov-2001 |
6 pages |
| Authors:
James R Zeidler; Jun Han; Walter H Ku; SPACE AND NAVAL WARFARE SYSTEMS CENTER SAN DIEGO CA
|
| A chirp transform is defined for the A-step LMS adaptive predictors for linearly chirped signals embedded in additive white Gaussian noise. By converting the chirped signals to stationary baseband signals, this transform provides a different approach in analyzing the tracking performance of the LMS adaptive predictors. This transform also provides an approach of analyzing the nonlinear effects of the LMS adaptive predictor for nonstationary input signals. It is also shown ... |
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| Comparison of Batch and Kalman Filtering for Radar Tracking |
23 JUL 2001 |
|
| Authors:
Haywood Satz; Thomas H. Kerr; RAYTHEON CO BEDFORD MA
|
| Radar tracking performance was compared among two choices of statistical filtering algorithms for the noisy measurements of exo-atmospheric objects in ballistic motion. Such motion is characteristic of satellites and missiles. Object position and velocity were governed by the nonlinear dynamics of body motion in a central force field, and measurements were modeled as nonlinear observations of those object motions in Cartesian coordinates. The two choices of statistical filtering algorithms were ... |
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| Adaptive Identification of Fluid-Dynamic Systems |
14 JUN 2001 |
13 pages |
| Authors:
Aravind Pillarisetti; III Cattafesta Louis N.; FLORIDA UNIV GAINESVILLE DEPT OF AEROSPACE ENGINEERING MECHANICS AND ENGINEERING SCIENCE
|
| Fluid-dynamic systems are inherently nonlinear and are subject to a combination of coherent and random unsteady disturbances. As a result, accurate low-order dynamic models are difficult to obtain for real-time control of such systems. Therefore, controllers implementing adaptive on-line system identification are ideally suited to flow control problems. Adaptive linear and nonlinear filters for real-time system identification are presented in this paper. The linear models studied are traditional FIR and ... |
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| Survivability: A Markov Process |
01 APR 2001 |
7 pages |
| Authors:
Jack G. Parks; ARMY TANK-AUTOMOTIVE COMMAND WARREN MI
|
| Previous articles In this series have covered the time behavior of force strengths, battle trajectories, and recursive relationships between battle parameters. In this edition, the general solution to the Markov equation is derived and effects of segmented battle are compared with traditional conflict modes. Survivability, lethality, and repair are compared as command options. New graphic techniques are explored to reveal fundamental features of this combat structure. |
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| Generalized Aliasing as a Basis for Program Analysis Tools |
NOV 2000 |
295 pages |
| Authors:
Robert O'Callahan; CARNEGIE-MELLON UNIV PITTSBURGH PA SCHOOL OF COMPUTER SCIENCE
|
| Tools for automatic program analysis promise to improve programmer productivity by searching and summarizing large bodies of code. However, the phenomenon of aliasing different names being used to refer to the same data reduces the effectiveness of simple textual analyses. This dissertation describes the design of a system, Ajax, that addresses this problem by using semantics-based program analysis as the basis for a number of different tools to aid Java ... |
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| A Multivariate Time Series Analysis of U.S. Army Recruiting |
JUN 2000 |
110 pages |
| Authors:
Eric C. Burger; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The United States Army Recruiting Command requires tools to quantify the impact of factors in the recruiting environment, identify differences in the recruiting processes across its five regional subordinate units, and measure the effectiveness of its policies and resource expenditures. This thesis examines recruiting data for the "high-quality" male demographic from July 1992 to September 1997. It uses multivariate time series analysis to predict the number ... |
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| Applying Inductive Program Synthesis to Learning Domain-Dependent Control Knowledge - Transforming Plans into Programs |
JUN 2000 |
125 pages |
| Authors:
Ute Schmid; Fritz Wysotzki; CARNEGIE-MELLON UNIV PITTSBURGH PA SCHOOL OF COMPUTER SCIENCE
|
| The goal of this paper is to demonstrate that inductive program synthesis can be applied to learning domain-dependent control knowledge from planning experience. We represent control rules as recursive program schemes (RPSs). An RPS represents the complete subgoal structure of a given problem domain with arbitrary complexity (e.g., rocket transportation problem with n objects). That is, if an RPS is provided for a planning domain, ... |
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| A Recursive Method for Generating the Gray Code |
2000 |
5 pages |
| Authors:
G. M. Dillard; SPACE AND NAVAL WARFARE SYSTEMS CENTER SAN DIEGO CA
|
| The Gray code is a mapping of the naturally ordered B-bit binary numbers to all ordering in which the binary representations of successive integers differ by exactly one bit. For example, the 4-bit Gray code representations of 7 and 8 are 0100 and 1100, respectively, which differ by one bit. The natural' representations are 0111 and 1000, which differ by three bits. The purpose of this correspondence is to present ... |
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| A Fuzzy Logic Multisensor Association Algorithm: Multiple Emitters, Computational Complexity, and Noisy Data |
15 JUL 1999 |
21 pages |
| Authors:
James F. Smith III; NAVAL RESEARCH LAB WASHINGTON DC
|
| A recursive multisensor association algorithm based on fuzzy logic has been developed. It simultaneously determines fuzzy grades of membership and fuzzy cluster centers. It is capable of associating data from various sensor types. In its simplest form, it makes no assumption about noise statistics as many association algorithms do. The algorithm is capable of performing without operator intervention. It associates data from the same target for multiple sensor types. The ... |
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| Optimizing a Solver of Polymorphism Constraints: SEMI |
JUN 1999 |
|
| Authors:
Robert O'Callahan; CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF COMPUTER SCIENCE
|
| As part of the Ajax system for analyzing Java bytecode programs, I have developed an analysis called SEMI, based on type inference with polymorphic recursion. SEMI has a number of optimizations which significantly decrease the time and space requirements for analyzing large programs. These optimizations exploit the characteristics of Java programs to make analysis tractable. These assumptions, and the optimizations that follow from them, may apply in other domains using ... |
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| A Kalman Filtering Approach to Wideband Scattering Function Estimation and Updating |
MAY 1999 |
139 pages |
| Authors:
Michael J. Roan; PENNSYLVANIA STATE UNIV UNIVERSITY PARK APPLIED RESEARCH LAB
|
| Transmitted signals with high time bandwidth products tend to resolvemultiple reflecting structural elements or highlights on the body that is being illuminated. This thesis develops a Kalman filtering approach to estimating the position and velocity of the multiple highlights on a single body undergoing complex motions. First, a general Kalman filter for direct recursive estimation of the spreading function is derived. Second, an algorithm which tracks peak locations within the ... |
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| Recursive Method for Target Motion Analysis |
02 MAR 1999 |
|
| Authors:
Vincent J. Aidala; Marcus L. Graham; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| The present invention relates to a method or estimating the motion of a target relative to an observer station and a system for performing the method. The method includes the steps of: generating data representative of the motion of the target relative to the observer Station during first, second, and subsequent measurement legs; processing the data to yield smoothed estimate of the bearing, bearing rate, and bearing acceleration of the ... |
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| Formal Verification of Explicitly Parallel Microprocessors |
MAR 1999 |
145 pages |
| Authors:
OREGON GRADUATE INST OF SCIENCE AND TECHNOLOGY PORTLAND PACIFIC SOFTWARE RESEARCH CENTER
|
| This report contains a collection of the following papers: (1) Formal Verification of Explicitly Parallel Microprocessors, (2) Symbolic Simulation of Microprocessor Models using Type Classes in Haskell, (3) The Internet As A medium For Software Engineering Experiments, (4) Top level Refinement in Processor Verification, (5) On embedding a microarchitectural design language within Haskell, (6) Elementary Microarchitecture Algebra, (7) Recursive Function Definition over Coinductive Types, (8) DSL Implementation Using Staging and ... |
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| Transparent and Opaque Interpretations of Datatypes |
NOV 1998 |
8 pages |
| Authors:
Karl Crary; Robert Harper; Perry Cheng; Leaf Petersen; Chris Stone; CARNEGIE-MELLON UNIV PITTSBURGH PA SCHOOL OF COMPUTER SCIENCE
|
| Standard ML employs an opaque (or generative) interpretation of datatype specifications, in which every datatype specification provides a new, abstract type that is different from any other type, including other identically specified datatypes. An alternative interpretation is the transparent one, in which a datatype specification exposes the underlying recursive type implementation of the datatype. It is commonly believed that the transparent interpretation is strictly more permissive than the opaque interpretation; ... |
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| Admissibility of Fixpoint Induction over Partial Types |
OCT 1998 |
29 pages |
| Authors:
Karl Crary; CARNEGIE-MELLON UNIV PITTSBURGH PA SCHOOL OF COMPUTER SCIENCE
|
| Partial types allow the reasoning about partial functions in type theory. The partial functions of main interest are recursively computed functions, which are commonly assigned types using fixpoint induction. However, fixpoint induction is valid only on admissible types. Previous work has shown many types to be admissible, but has not shown any dependent products to be admissible. Disallowing recursion on dependent product types substantially ... |
|
| Global Positioning System (GPS) Receiver Design For Multipaths Mitigation |
AUG 1998 |
274 pages |
| Authors:
El-Sayed Abdel-Salam Gadallah; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH
|
| Multipath effects are a source of error degrading the accuracy of DGPS signal processing. The statistical models of multipath are determined by user location and, in addition are time varying. There is no unified statistical model for the multipath signal. Therefore the solution of the multipath problem using statistical models is difficult. This research introduces a new estimator that can detect the presence of multipath, can ... |
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| Video Summarization by Curve Simplification |
JUL 1998 |
22 pages |
| Authors:
Daniel DeMenthon; Vikrant Kobla; David Doermann; MARYLAND UNIV COLLEGE PARK LANGUAGE AND MEDIA PROCESSING LAB
|
| A video sequence can be represented as a trajectory curve in a high dimensional feature space. This video curve can be analyzed by tools similar to those developed for planar curves. In particular, the classic binary curve splitting algorithm has been found to be a useful tool for video analysis. With a splitting condition that checks the dimensionality of the curve segment being split, the video curve can be recursively ... |
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| Relational Interpretations of Recursive Types in an Operational Setting |
24 APR 1998 |
76 pages |
| Authors:
Lars Birkedal; Robert Harper; CARNEGIE-MELLON UNIV PITTSBURGH PA SCHOOL OF COMPUTER SCIENCE
|
| Relational interpretations of type systems are useful for establishing properties of programming languages. For languages with recursive types it is usually difficult to establish the existence of a relational interpretation. The usual approach is to give a denotational semantics of the language in a domain theoretic model given by an inverse limit construction, and to construct relations over the model by a similar inverse limit construction. However, in passing to ... |
|
| Information Theory Analysis for Data Fusion |
16 JAN 1998 |
45 pages |
| Authors:
Ronald P. S. Mahler; LOCKHEED MARTIN TACTICAL DEFENSE SYSTEMS ST PAUL MN
|
| Complete theoretical development of random set unified data fusion, and place under theoretically solid information theory foundation suitable for publication. Findings: (1) Showed that optimal sensor allocation (redirection of the reallocatable sensors in a sensor suite) can be subsumed within the random set approach to information fusion, via generalization of nonlinear optimal control theory. (2) Showed that random set theory and information theory provides a common basis for performance evaluation ... |
|
| Robust, Nonlinear Feedback Control |
21 NOV 97 |
19 pages |
| Authors:
Dennis S. Bernstein; MICHIGAN UNIV ANN ARBOR
|
| This project has encompassed research in four areas of control theory, namely robust, fixed structure control, identification, adaptive cancellation, and nonlinear control. The robust, fixed structure control techniques have been implemented in a mat lab tool box for control design. The identification techniques include recursive methods with guaranteed convergence for high order linear systems. The adaptive cancellation methods provide disturbance rejection for systems with uncertain or time varying disturbance spectra ... |
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| Finite-Difference Time-Domain Calculations Based on Recursive Convolution Approach for Propagation of Electromagnetic Waves in Nonlinear Dispersive Media |
30 OCT 97 |
30 pages |
| Authors:
S. J. Yakura; Jeff MacGillivray; AIR FORCE RESEARCH LAB KIRTLAND AFB NMDIRECTED ENERGY DIRECTORATE
|
| The piecewise linear recursive convolution (PLRC) approach has been shown to provide much improved accuracy over the usual discrete recursive convolution approach while retaining the efficient use of computer memory storage and fast computational speed for finite-difference time-domain (FDTD) electromagnetic propagation calculations for linear dispersive materials. In this paper, an idea behind the implementation of the PLRC approach is extended to handle nonlinear dispersive media, specifically for the convolution integral ... |
|
| A Fuzzy Logic Multisensor Association Algorithm: Theory and Simulation |
30 SEP 97 |
24 pages |
| Authors:
James F. Smith III; NAVAL RESEARCH LAB WASHINGTON DC SURFACE ELECTRONIC WARFARE SYSTEMS BRANCH
|
| A recursive multisensor association algorithm has been developed based on fuzzy logic. It simultaneously determines fuzzy grades of membership and fuzzy cluster centers. It is capable of associating data from various sensor types and performing without operator intervention. It associates data from the same target for multiple sensor types. The algorithm also provides an estimate of the number of targets present, reduced noise estimates of the quantities being measured, and ... |
|
| New Approximation Techniques for Some Ordering Problems |
25 SEP 97 |
|
| Authors:
Satish Rao; Andrea W. Richa; CARNEGIE-MELLON UNIV PITTSBURGH PA DEPT OF COMPUTER SCIENCE
|
| We describe O(log n) times optimal approximation algorithms for the NP-hard graph optimization problems of minimum linear arrangement, minimum containing interval graph and minimum storage-time product. This improves on the O(log n log log n) approximation bounds provided in a previous paper by Even, Naor, Scheiber and Rao. Our techniques are based on using spreading metrics (as in Even Naor Rao, and Scheiber) to define a cost estimate for a ... |
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| Efficient Security Mechanisms for the Border Gateway Routing Protocol |
22 AUG 1997 |
19 pages |
| Authors:
Bradley R. Smith; J. J. Garcia-Luna-Aceves; CALIFORNIA UNIV SANTA CRUZ DEPT OF COMPUTER ENGINEERING
|
| We analyze the security of the BGP routing protocol and identify a number of vulnerabilities in its design and the corresponding threats. We then present modifications to the protocol that minimize or eliminate the most significant threats. The innovation we introduce is the protection of the second-to-last hop information contained in the AS_PATH attributes by digital signatures, and the use of this predecessor information to verify the path of the ... |
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Reports by Keyword(s)
RECURSIVE FUNCTIONS
