nasa scientific and technical aerospace reports phần 5 pptx

2005; 39 pp.; In English; Original contains color illustrations Contracts/Grants: F30602-01-2-0507; DARPA ORDER-K545; Proj-DAML Report No.s: AD-A432974; AFRL-IF-RS-TR-2005-94; No Copyrig

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The MONARCH project is sponsored by DARPA under the Polymorphous Computer Architecture Program MONARCH

is developing a revolutionary chip distinguished from other PCA systems by unifying two radically different architectures into

a single flexible VLSI device MONARCH architecture combines the DIVA PIM architecture, developed by USC/ISI as part

of the DARPA-sponsored Data Intensive Program, and HPPS (High Performance Processing System) developed by Raytheonwith IRAD funds We previously presented the motivation for merging these two architectures (HPEC 2002) We have sincedeveloped the detailed specifications for the micro architecture of the MONARCH chip and also the software environment,run time system and on-chip communication network Furthermore, we have completed the evaluation of several benchmarksand we have shown that the MONARCH architecture is capable of achieving a very high stability factor that allows theMONARCH architecture to process data at near peak throughput speeds

DTIC

Architecture (Computers); Chips; Computer Programs; Supercomputers

20050173494 Hampshire Coll., Amherst, MA USA

Multi-Type Self Adaptive Genetic Programming for Complex Applications

Spector, Lee; Mar 2005; 39 pp.; In English; Original contains color illustrations

Contract(s)/Grant(s): F30602-01-2-0507; DARPA ORDER-K545; Proj-DAML

Report No.(s): AD-A432974; AFRL-IF-RS-TR-2005-94; No Copyright; Avail: Defense Technical Information Center (DTIC)The focus of this project was the development of new forms of genetic and evolutionary computation and their application

to problems in the automatic development and programming of multi-agent systems This report summarizes the project’smethods, assumptions, procedures and results, and also provides links to related publications and software packages that wereproduced during the project

DTIC

Computer Programs; Genetics

20050173502 State Univ of New York, Stony Brook, NY USA

Integrated Environment for Control Software Engineering

Smolka, Scott A.; Stark, Eugene; Cleaveland, Rance; Apr 2005; 6 pp.; In English

Contract(s)/Grant(s): DAAD19-01-1-0003

Report No.(s): AD-A432985; ARO-40026.1-C1; No Copyright; Avail: Defense Technical Information Center (DTIC)Significant scientific progress has been made during the final year of the grant We have continued the development ofPIOAL, the process-algebraic specification language for Probabilistic I/O Automata that forms the basis for our toolintegration effort We have also developed a Monte Carlo model checking algorithm a Hybrid-automaton model of cardiac;and a safety-liveness semantics for UML 2.0 Sequence Diagrams We have moreover pursued the development ofmathematical formalisms for the combined modeling of functional and performance aspects of systems, and for softwarearchitecture specification

DTIC

Computer Programming; Environmental Control; Software Engineering

20050173527 Army Research Lab., Aberdeen Proving Ground, MD USA

Virtual Experiments to Determine Behind-Armor Debris for Survivability Analysis

Prakash, Anand; Dec 2004; 7 pp.; In English; Original contains color illustrations

Report No.(s): AD-A433014; No Copyright; Avail: Defense Technical Information Center (DTIC)

When a projectile perforates the armor of a vehicle, the residual projectile entering the vehicle is accompanied by a muchwider cloud of behind-armor debris (BAD) generated by stress wave interactions BAD plays an important role in theevaluation of survivability of crew and components in a vehicle under fire Survivability and vulnerability analysis codes (e.g.,MUVES) require an input of BAD characteristics of the armor for each threat projectile This data is currently generated byconducting laboratory experiments in a standard set-up in which each threat projectile is fired on the actual armor and the BADpattern is captured on witness plates Conducting survivability analyses of vehicles in the design phase, before the armor isactually built, poses a challenging problem To solve this problem, we have come up with an innovative approach to determineBAD characteristics by conducting virtual experiments of the standard set-up We do this by conducting physics-basedthree-dimensional (3-D) computer simulations with the CTH wave code We obtain BAD characteristics for impacts of kineticenergy rods and shaped charges on metal and ceramics plates, including some yawed rod impacts An additional advantage

of these simulations is that they provide important details of the debris field that are difficult to obtain in laboratory

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experiments The expected impact of this work would be to improve the timeliness, accuracy, and cost of survivability analysesfor Army’s decision makers.

DTIC

Armor; Computerized Simulation; Debris; Kinetic Energy; Military Vehicles; Projectiles; Vulnerability

20050173529 Air Force Research Lab., Rome, NY USA

Amending Moore’s Law for Embedded Applications

Linderman, Richard W.; Sep 2004; 13 pp.; In English; Original contains color illustrations

CONTRIBUTION of Moore’s Law to Improvements of Embedded Systems: * Price/ Performance: Gigaflops/$Maffordability * Memory Capacity: programming simplifications * Steep memory hierarchy: programming inefficiencies andcomplexities * New flexibilities: e.g., reconfigurable hardware * New complexities: software and parallelism * Dramatic newsystem capabilities

DTIC

Computer Programs; Embedding; Exponential Functions

62 COMPUTER SYSTEMS

Includes computer networks and distributed processing systems For information systems see 82 Documentation and Information Science For computer systems applied to specific applications, see the associated category.

20050169863 Lawrence Livermore National Lab., Livermore, CA

SLURM: Simple Linux Utility for Resource Management

Jette, M A.; Yoo, A B.; Grondona, M.; Apr 03, 2003; 22 pp.; In English

Report No.(s): DE2004-15003520; UCRL-JC-147996; No Copyright; Avail: Department of Energy Information Bridge

A new cluster resource management system called Simple Linux Utility Resource Management (SLURM) is developedand presented in this paper SLURM, initially developed for large Linux clusters at the Lawrence Livermore NationalLaboratory (LLNL), is a simple cluster manager that can scale to thousands of processors SLURM is designed to be flexibleand fault-tolerant and can be ported to other clusters of different size and architecture with minimal effort We are certain thatSLURM will benefit both users and system architects by providing them with a simple, robust, and highly scalable paralleljob execution environment for their cluster system

NTIS

Unix (Operating System); Computer Systems Design

20050173138 Naval Postgraduate School, Monterey, CA USA

Evaluation of the Embedded Firewall System

Rumelioglu, Sertac; Mar 2005; 97 pp.; In English; Original contains color illustrations

The performance aspect and security capabilities of the Embedded Firewall (EFW) system are studied in this thesis EFW

is a host-based, centrally controlled firewall system consisting of network interface cards and the Policy Server software Anetwork consisting of EFW clients and a Policy Server is set up in the Advanced Network Laboratory at the NavalPostgraduate School The Smartbits packet generator is used to simulate realistic data transfer environment The evaluation

is performed centered on two main categories: performance analysis and security capability tests TTCP program and a scriptwritten in TCL are used to perform throughput and packet loss tests respectively The penetration and vulnerability tests areconducted in order to analyze the security capabilities of EFW Symantec Personal Firewall is used as a representativeapplication firewall for comparing test results Our study shows that EFW has better performance especially in connectionswith high amounts of encrypted packets and more effective in preventing insider attacks However, current implementation

of EFW has some weaknesses such as not allowing sophisticated rules that application firewalls usually do We recommendthat EFW be used as one of the protection mechanisms in a system based on the defense-in-depth concept that consists ofapplication firewalls, intrusion detection systems and gateway protocols

DTIC

Computer Networks; Security

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20050173168 Massachusetts Univ., Amherst, MA USA

Infrastructure Vulnerability Assessment and Defense

Gao, Lixin; Mar 2005; 27 pp.; In English; Original contains color illustrations

Countermeasures; Vulnerability

20050173331 Mitre Corp., McLean, VA USA

An Alternative Paradigm for Routing in Wireless Ad Hoc Networks

Stine, John A.; Dec 2004; 3 pp.; In English

We propose a new paradigm for routing in ad hoc networks based on the collection and dissemination of node states Thisparadigm assumes nodes have location awareness and can measure the received signal strength of incoming transmissions.Thus, nodes can discover the pathloss in their environment This information along with other information relevant to the node

is combined into a node’s state that is disseminated throughout the network This state information not only supports all nodesdiscovering the network’s topology but provides the very information that makes network management, network engineering,traffic engineering, and spectrum management feasible This contribution of this summary is a brief description of how nodestate routing (NSR) paradigm enables these management and engineering capabilities

DTIC

Networks; Wireless Communication

20050173334 Army War Coll., Carlisle Barracks, PA USA

The Dark Fruit of Globalization: Hostile Use of the Internet

Megill, Todd A.; Mar 2005; 23 pp.; In English; Original contains color illustrations

One of the goals of the current National Security Strategy is to expand world economic activity and prosperity This goalfor economic prosperity is linked to globalization and this information technologies that tie the world’s economics andoccupants together A primary means of communication and information sharing is the Internet The USA (US) is currentlythe world’s largest user and proponent of the Internet The massive sharing of information is crucial for US economicdevelopment and expansion and is in line with the American concept of itself However the Internet as a method of sharinginformation has a dark side The information accessible level of communications linkages and sheer interconnectiveness ofthe World-Wide-Web leaves the US vulnerable to violent non-state actors using the Internet These groups will use the Internetand its architecture to command & control collect information target possibly attack access and disseminate the results of theiractivities with minimal exposure to traditional means of national intelligence collection and detection The architecture isallowing violent non-state actors to attack the US over its own systems and designs This paper will look at this phenomenonthe scope of the problem draw conclusions and make some recommendations

DTIC

Fruits; Internets; Security

20050173349 Telcordia Technologies, Inc., Piscataway, NJ USA

Secure Service Provision for Reliable Server Pooling in MANET

Di Crescenzo, Giovanni; Ge, Renwei; Arce, Gonzalo R.; Dec 2004; 3 pp.; In English; Original contains color illustrationsContract(s)/Grant(s): DAAD19-01-2-0011

The unique characteristics of battlefield mobile ad hoc networks bring severe security challenges to the application ofreliable server pooling (rSerPool) This paper uses a novel threshold signature scheme with the features of ad hoc severselection and dynamic group membership to secure the service provision phase of the rSerPool application in MANET Ourdistributed and survivable threshold signature scheme can tolerate single point of failure and Byzantine attacks Its ad hoc

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server selection increases service availability and decreases service latency Our signature scheme provides essentialauthentication service in rSerPool and can be further used as part of distributed certificate authority in MANET.

DTIC

Client Server Systems; Communication Networks; Reliability; Security; Signatures

20050173350 Army Research Lab., Adelphi, MD USA

Identity-Based Random Key Predistribution for Army MANETs

Carman, D W.; Cirincione, G H.; Dec 2004; 3 pp.; In English; Original contains color illustrations

We address a challenge to developing the Future Force Army tactical networks require cryptographic keys to implementsecurity services such as encryption and authentication, but current pairwise key establishment approaches using interactivepublic key techniques are too time-consuming This paper describes identity-based cryptographic solutions that enable strongsecurity and significantly reduce bandwidth consumption and latency, and provides three main contributions: (a) a description

of how identity-based random key predistribution (IBRKP) can be used as a secure and efficient component within an Armytactical mobile ad hoc network (MANET) key management infrastructure; (b) a description of an attack on IBRKP resultingfrom targeted node compromises as opposed to random node compromises; and (c) a technique that creates grainy pool keysthat increases security against targeted and random node compromise attacks

DTIC

Communication Networks; Cryptography; Identities; Military Operations; Security

20050173354 Maryland Univ., College Park, MD USA

Domain Formation and Maintenance in Large Ad hoc Networks

Chandrashekar, Karthikeyan; Morera, Raquel; McAuley, Anthony; Dec 2004; 3 pp.; In English; Original contains colorillustrations

The stability and performance of domains or clusters in MANETs is determined by the election metrics used to generateand maintain these domains In this paper, we evaluate the performance of the distributed Beacon protocol as the topologychanges and as a function of the election metric under various conditions We propose the ‘domain age’ as the primary electionmetric to maintain more stable domains than ‘lowest ID’, yet requires no more information be collected We quantify theincreased stability using OPNET simulations We believe that a combination of domain age, node degree and domain strengthwill provide the Beacon protocol with the ability to maintain good domains in future battlefield networks

DTIC

Communication Networks; Maintenance; Protocol (Computers); Topology

A Case Study of Internet Protocol Telephony (IPT) Implementation at USA Coast Guard Headquarters

Patton, Mark B.; Mar 2005; 205 pp.; In English; Original contains color illustrations

Recent advances in information technology communications have brought about increases to bandwidth and processingspeeds to encourage the growth or Internet protonic Telephony (TPT), a method of transmitting voice conversations over datanetworks Many organizations are replacing portions of their traditional phone systems to gain the benefit of cost savings andenhanced feature sets through the use of IPT The Coast Guard has an interest in exploiting this technology, and has taken itsfirst steps by implementing IPT at Headquarters Support command in Washinton D C This thesis investigates the successfulimplementation practices and security policies of commercial, educationa, and goverment organizations in order to createrecommendations for IPT security policies recommendations for IPT security policies and implementation practices relevant

to the Coast Guard It includes the discussion of the public switched telephone network, an overview of IPT, IPT securityissues, the safeguards available to counter security threata, the tradeoffs (e.g., voice quality, cost) reguired to mitigate securityrisks, and current TPT security policy and implementation guidance It is supported by the study and analyaia of the IPTsystem at Coast Guard Headguarters The Coast Guard gains an understanding ci the advantages, limitations, and securityissues that it will face as it considers further implementation of IPT

DTIC

Coasts; Internets; Protocol (Computers); Telephony; United States

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20050173380 Department of Defense, Arlington, VA USA

Information Technology: DoD FY 2004 Implementation of the Federal Information Security Management Act for Information Technology Training and Awareness

Davis, Sarah; Mitchell, James; Palmer, Kevin A.; Riggins, Liyang; Truex, Kathryn; Williams, Zachary; Dec 2004; 47 pp.; InEnglish

Report No.(s): AD-A432754; IG/DOD-2005-025; No Copyright; Avail: Defense Technical Information Center (DTIC)The overall audit objective was to assess DoD implementation of title III, section 301, ‘Federal Information SecurityManagement Act,’ of the E-Government Act of 2002 (Public Law 107-347) Specifically, we evaluated whether all agencyemployees, including contractors, received IT security training and awareness and whether employees with significant ITsecurity responsibilities were properly trained for their level of responsibility

DTIC

Contractors; Education; Information Management; Information Systems; Management Information Systems; Personnel; Security

20050173468 Army Command and General Staff Coll., Fort Leavenworth, KS USA

Intelligence Collection: Supporting Full Spectrum Dominance and Network Centric Warfare?

Moses, Bruce D.; Jan 2004; 82 pp.; In English

This monograph examines whether the Army’s information collection efforts are supporting the goal of full spectrumdominance and whether these are in harmony with the concepts of network centric warfare Full spectrum dominance andnetwork centric warfare are central themes in Department of Defense and Army transformation literature and both requireinformation collection and an understanding of the role of cognition empowered by networking for success More specifically,

it examines whether Army collection efforts are focusing too heavily on collection for combat operations and leaving it unable

to fully exploit the access to adversary systems during stability operations This study found that the institutional Army is notfully supporting the goal of full spectrum dominance or network centric warfare but is still myopically investing heavily inefforts to defeat the adversary’s conventional capabilities with standoff collection technology and is not creating theorganizational, systems and technical architectures necessary to leverage the power of a fully networked force

DTIC

Communication Networks; Dominance; Intelligence; Military Operations; Spectra; Warfare

63 CYBERNETICS, ARTIFICIAL INTELLIGENCE AND ROBOTICS

Includes feedback and control theory, information theory, machine learning, and expert systems For related information see also 54 Man/System Technology and Life Support.

20050169772 California Univ., Lawrence Berkeley National Lab., Berkeley, CA, USA

Slow Orbit Feedback at the ALS Using Matlab

Portmann, G.; Mar 1999; 12 pp.; In English

Report No.(s): DE2004-7377; LBNL-43030; No Copyright; Avail: Department of Energy Information Bridge

The third generation Advanced Light Source (ALS) produces extremely bright and finely focused photon beams usingundulatory, wigglers, and bend magnets In order to position the photon beams accurately, a slow global orbit feedback systemhas been developed The dominant causes of orbit motion at the ALS are temperature variation and insertion device motion.This type of motion can be removed using slow global orbit feedback with a data rate of a few Hertz The remaining orbitmotion in the ALS is only 1-3 micron rms Slow orbit feedback does not require high computational throughput At the ALS,the global orbit feedback algorithm, based on the singular valued decomposition method, is coded in MATLAB and runs on

a control room workstation Using the MATLAB environment to develop, test, and run the storage ring control algorithms hasproven to be a fast and efficient way to operate the ALS

NTIS

Light Sources; Storage Rings (Particle Accelerators); Algorithms; Feedback Control; Control Simulation

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20050170449 NASA Langley Research Center, Hampton, VA, USA

Real-Time System Verification by Kappa-Induction

Pike, Lee S.; April 2005; 66 pp.; In English

Contract(s)/Grant(s): 23-063-30-RF

Report No.(s): NASA/TM-2005-213751; L-19110; No Copyright; Avail: CASI;A04, Hardcopy

We report the first formal verification of a reintegration protocol for a safety-critical, fault-tolerant, real-time distributedembedded system A reintegration protocol increases system survivability by allowing a node that has suffered a fault to regainstate consistent with the operational nodes The protocol is verified in the Symbolic Analysis Laboratory (SAL), wherebounded model checking and decision procedures are used to verify infinite-state systems by k-induction The protocol andits environment are modeled as synchronizing timeout automata Because k-induction is exponential with respect to k, weoptimize the formal model to reduce the size of k Also, the reintegrator’s event-triggered behavior is conservatively modeled

as time-triggered behavior to further reduce the size of k and to make it invariant to the number of nodes modeled A corollary

is that a clique avoidance property is satisfied

Author

Real Time Operation; Program Verification (Computers); Fault Tolerance

20050170456 NASA Lewis Research Center, Cleveland, OH, USA

EWB: The Environment WorkBench Version 4.0

1995; 2 pp.; In English; No Copyright; Avail: CASI;A01, Hardcopy

The Environment WorkBench EWB is a desktop integrated analysis tool for studying a spacecraft’s interactions with itsenvironment Over 100 environment and analysis models are integrated into the menu-based tool EWB, which was developedfor and under the guidance of the NASA Lewis Research Center, is built atop the Module Integrator and Rule-based IntelligentAnalytic Database (MIRIAD) architecture This allows every module in EWB to communicate information to other modules

in a transparent manner from the user’s point of view It removes the tedious and error-prone steps of entering data by handfrom one model to another EWB runs under UNIX operating systems (SGI and SUN workstations) and under MS Windows(3.x, 95, and NT) operating systems MIRIAD, the unique software that makes up the core of EWB, provides the flexibility

to easily modify old models and incorporate new ones as user needs change The MIRIAD approach separates the computerassisted engineering (CAE) tool into three distinct units: 1) A modern graphical user interface to present information; 2) A datadictionary interpreter to coordinate analysis; and 3) A database for storing system designs and analysis results The userinterface is externally programmable through ASCII data files, which contain the location and type of information to bedisplayed on the screen This approach provides great flexibility in tailoring the look and feel of the code to individual userneeds MIRIADbased applications, such as EWB, have utilities for viewing tabulated parametric study data, XY line plots,contour plots, and three-dimensional plots of contour data and system geometries In addition, a Monte Carlo facility isprovided to allow statistical assessments (including uncertainties) in models or data

Derived from text

Computer Systems Programs; Workstations; Systems Integration; Spacecraft Environments

20050170917 Swedish Defence Research Establishment, Linkoeping, Sweden

Instrusion Analysis in Military Networks File Systems and Logging

Vidstroem, A.; Persson, M.; Karresand, M.; Dec 2004; 40 pp.; In English

Report No.(s): PB2005-103074; FOI-R-1518-SE; No Copyright; Avail: CASI;A03, Hardcopy

This report presents a study of the technical aspects of four file systems, NTFS FAT32, Ext2, and Ext3 Their structure

on disk and organization of data, files, and directories is described at a level enabling further research of the field This reportdoes, however, not describe how writing, changing, and deleting files is done in the respective file system Apart from filesystems the report also covers the basics of logging and different tools for doing system integrity checking The report isconcluded with a chapter presenting suggested future work sprung from the file system and logging studies

NTIS

Intrusion Detection (Computers); Deletion

20050173213 Army Tank-Automotive Research and Development Command, Warren, MI USA

Robots at War - Experiences in Iraq and Afghanistan

Smuda, W J.; Freiburger, L.; Rogan, S.; Gerhart, G.; Dec 2004; 9 pp.; In English; Original contains color illustrationsReport No.(s): AD-A432400; No Copyright; Avail: Defense Technical Information Center (DTIC)

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Recent activities in Iraq and Afghanistan have shown the importance of robotic technology as a force multiplier and a toolfor moving soldiers out of harms way Early user involvement in innovative and aggressive development and acquisitionstrategies are the key to moving robotic and associated technology into the hands of the user This paper updates activityassociated with rapid development of the Omni-Directional Inspection System (ODIS) robot for under vehicle inspection andreports on our field experience with robotics in Iraq and Afghanistan.

DTIC

Afghanistan; Iraq; Robotics; Robots; Warfare

20050173253 Space and Naval Warfare Systems Command, San Diego, CA USA

Supporting the Joint Warfighter by Development, Training, and Fielding of Man-Portable UGVs

Ebert, Kenneth A.; Stratton, Benjamin V.; Jan 2005; 11 pp.; In English; Original contains color illustrations

The Robotic Systems Pool (RSP), sponsored by the Joint Robotics Program (JRP), is an inventory of small roboticsystems, payloads, and components intended to expedite the development and integration of technology into effective.supportable fielded robotic assets The RSP loans systems to multiple users including the military, first- responders, researchorganizations, and academia These users provide feedback in their specific domain, accelerating research and developmentimprovements of robotic systems which in turn allow the joint warfighter to benefit from such changes more quickly thanfrom traditional acquisition cycles Over the past year, RSP assets have been used extensively for pre-deployment operator andfield training of joint Explosive Ordnance Disposal (EOD) teams, and for the training of Navy Reservist repair technicians.These Reservists are part of the Robotic Systems Combat Support Platoon (RSCSP), attached to Space and Naval WarfireSystems Center, San Diego The RSCSP maintains and repairs RSP assets and provides deployable technical support for users

of robotic systems Currently, a small team from the RSCSP is deployed at Camp Victory repairing and maintainingman-portable unmanned ground vehicles (UGVs) used by joint EOD teams in Operation Iraqi Freedom The focus of thispaper is to elaborate on the RSP and RSCSP and their role as invaluable resources for spiral development in the roboticscommunity by gaining first-hand technical feedback from the warfighter and other users

DTIC

Education; Portable Equipment; Robotics

20050173286 Voltage Security, Inc., Palo Alto, CA USA

Voltage Identify Based Encryption (VIBE)

Schertler, Mark J.; Koppula, Prashanth; Mar 2005; 36 pp.; In English; Original contains color illustrations

Contract(s)/Grant(s): FA8750-04-C-0217; DARPA ORDER-8702; Proj-S702

Report No.(s): AD-A432563; AFRL-IF-RS-TR-2005-96; No Copyright; Avail: Defense Technical Information Center (DTIC)Invented by Dr Dan Boneh and Dr Matt Franklin in 2001, Identity-Based Encryption, or IBE, is a breakthrough incryptography that, for the first time, enables users to simply use an identity, such as an email address, to secure businesscommunications This replaces the digital certificates that a traditional X.509 based public key infrastructure (PKI) relies on.Moreover, unlike existing security solutions, secure communication based on IBE technology can be conducted online as wall

as offline, from anywhere in the world, without the complexity of certificates, Certificate Revocation Lists (CRLs) and othercostly infrastructure IBE is transparent to end users, easy to deploy and manage, and can scale to millions of users on theinternet Contract FA8750-04-C-0217 was awarded to Voltage Security, Inc., to demonstrate the effectiveness of thetechnology developed to implement the Boneh-Franklin IBE This contract provided for the necessary hardware and softwareneeded to demonstrate the Voltage technology, as well as necessary supporting services needed to implement the technology.DTIC

Cryptography; Electric Potential; Identities

20050173307 Massachusetts Inst of Tech., Lexington, MA USA

Self-Organizing Networks (SONets) with Application to Target Tracking

Sinno, Dana; Mar 2004; 5 pp.; In English; Original contains color illustrations

The growing interest in large arrays of deployable sensors is not only the result of recent advances in technology that makecheap expendable sensors readily available, but is also due to the limitations of current large expensive assets in someapplications of timely importance such as urban warfare and complex terrain surveillance Large distributed arrays ofdeployable configurable sensors cooperating to achieve system-level goals may provide the solution for such problems

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whether acting as independent networks or as agents gathering localized information to aid large assets The primary challenge

of dynamic allocation of network assets (DANA) is the cost of computation and communication of global optimization andreal-time configuration of individual sensors Scaling of network size generally yields an exponential increase in optimizationcomputation and a prohibitive need for communication bandwidth for scheduling of individual sensors making suchapproaches of limited real-time use This paper presents the novel methodology of Self-Organizing Networks (SONets) wheresmall sensors with local decision capabilities and overall system performance knowledge yield an emergent behavior aimed

at maximizing system information in a communication-constrained architecture while eliminating (or reducing) the need forsensors to be actively scheduled Preliminary results demonstrate promising performance in a multi-target/ multi-sensorenvironment The SONets methodology is based on sensors making local decisions on which mode to operate in including datacollection broadcast, etc based on perceived value of expected return and thresholding with the capability of adaptivelyself-organizing Sensors update learning indices (adaptive weights) based on expected return and observation of overall systemknowledge The result is an emergent behavior that may be supervised and altered through general broadcasts from acentralized unit

DTIC

Targets; Tracking (Position)

20050173329 ElanTech, Inc., Greenbelt, MD USA

Focused Knowledge for the Battlefield

Emmerman, Philip J.; Allen, Swati D.; Dec 2004; 6 pp.; In English; Original contains color illustrations

The USA Army is in the midst of a major transformation The Future Force must be highly mobile, agile, and lethal toensure its dominance in the future battlefield This dominance is reliant on the ability to see and understand first (situationalawareness) Persistent and pervasive sensing and processing, coupled with greatly increased speed of information flow,information assimilation, and decisive action, at and between all levels of our force, are necessary to fulfill this requirement.The USA Army is most vulnerable in urban terrain This highly constrained, complex environment presents a significantchallenge to US forces, particularly dismounted infantry and military intelligence because opposing force activity is readilymasked or obscured by background noise (commerce, schools, religious activity etc.) This paper proposes an intelligentinteraction between the digitized dismounted units and military intelligence, for the significant benefit to both

DTIC

Intelligence; Personnel; Pulse Communication; Situational Awareness; Warfare

20050173414 Redlands Univ., CA USA

Sustaining the Army Training Mission by Re-Thinking Decision Support Systems: Shifting from Decision-Making Individuals to Sense-Making Agents

Ekbia, Hamid R.; Dec 2004; 10 pp.; In English; Original contains color illustrations

Decision Support Systems (DSS), as computerized systems that implement and support complex decision processes, haveevolved significantly during the last four decades However, this evolution has been dominantly bottom-up and technology-driven, with new emerging technologies supporting the traditional concept of decision making as a basically rational process

In an effort to reconceptualize decision making, this paper follows a top-down approach, starting with a new conceptualframework and then exploring the technologies and tools that can support it To this end, the paper proposes four majorconceptual shifts: a pragmatic shift from problems in the mind to problematic situations in the world, a constructive shift frompassive decision making to active sense making, a normative shift from accuracy and certainty to plausibility and transparency,and a technical shift in our understanding of technology as enabler to technology as transformer of human activity These shiftsare in harmony with current theoretical trends in DSS and related disciplines, e.g., the growing emphasis on multipleperspectives in DSS, on multi-agent systems in Artificial Intelligence, on distributed cognition in psychology, and on sensemaking in organization science By focusing our attention on the collective, distributed, and constructive character ofcognition, the framework that results from these shifts provides a useful way of thinking about DSS Furthermore, ideas fromscience and technology studies portray a tightly interwoven picture of technologies and their social and organizational context,which is very different from the traditional view of technologies as mere tools Brought to the realm of DSS, this calls for afresh look at the relationship between information technologies and decision-making processes

DTIC

Decision Making; Decision Support Systems; Education

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20050173438 Carnegie-Mellon Univ., Pittsburgh, PA USA

Robust Path Planning With Imperfect Maps

Ferguson, Dave; Stentz, Anthony; Dec 2004; 8 pp.; In English; Original contains color illustrations

We describe an efficient method for path planning in environments for which prior maps are plagued with uncertainty Ourapproach processes the map to determine key areas whose uncertainty is crucial to the planning task It then incorporates theuncertainty associated with these areas using the recently developed PAO* algorithm to produce a fast, robust solution to theoriginal planning task We present results from a simulated outdoor navigation scenario

DTIC

Algorithms; Autonomous Navigation; Planning; Trajectory Planning

20050173446 Carnegie-Mellon Univ., Pittsburgh, PA USA

Market-Based Complex Task Allocation for Multirobot Teams

Zlot, Robert; Stentz, Anthony; Dec 2004; 9 pp.; In English; Original contains color illustrations

In order for a team of autonomous robots to perform a complex mission effectively, an efficient assignment of tasks torobots must be determined Existing multirobot task allocation algorithms treat tasks as simple, indivisible entities However,when dealing with complex tasks, the structure and semantics of the tasks can be exploited to produce more efficient teamplans by giving individual robots the ability to come up with new ways to perform a task, or by allowing multiple robots tocooperate by sharing the subcomponents of a task, or both In this paper we detail a method for efficiently allocating a set ofcomplex tasks to a robot team The advantages of explicitly modeling complex tasks during the allocation process isdemonstrated by a comparison of our approach with existing task allocation algorithms in an area reconnaissance scenario

An implementation on a team of outdoor robots further validates our approach

DTIC

Allocations; Robots

20050173449 Michigan Univ., Ann Arbor, MI USA

Computational Neuromechanics: Programming Work in Biological Systems *AND* RHex: The CNM Hexapod

Koditschek, Daniel E.; Jan 2004; 9 pp.; In English

Contract(s)/Grant(s): N00014-98-1-0747; N66001-00-C-8026

Report No.(s): AD-A432902; PG-C080469; No Copyright; Avail: CASI;A02, Hardcopy

Most legged animals whose running has been studied exhibit mass center trajectories closely resembling those of apogo-stick Over the course of our five year DARPA/ONR/SPAWAR sponsored project in Computational Neuromechanics andits application to robotics, we have begun to answer the questions, how, why, and when, in a mathematically rigorous andbiologically testable manner Addressing these simple questions has simultaneously helped advance animal motion science aswell as accelerated progress in the design and control of useful legged robots

DTIC

Animals; Computer Programming; Locomotion; Motion; Robotics

20050173459 Army Tank-Automotive Research and Development Command, Warren, MI USA

Dynamic Waypoint Navigation Using Voronoi Classifier Methods

Overholt, J.; Hudas, G.; Fiorani, G.; Skalny, M.; Tucker, A.; Dec 2004; 7 pp.; In English; Original contains color illustrationsReport No.(s): AD-A432915; No Copyright; Avail: Defense Technical Information Center (DTIC)

This paper details the development of a dynamic waypoint navigation method which introduces and utilizes Voronoiclassifiers as the control mechanism for an autonomous mobile robot A Voronoi diagram may be generated by any finite set

of points in a plane For mobile robot control each point in the plane represents a Voronoi classifier The classifiers are used

to generate Voronoi regions As a robot comes into a Voronoi region the classifier will act as a control input; providing a newwaypoint for the vehicle to follow The robot moves towards the new waypoint unless interrupted by an obstacle or wall Therobot will get a new waypoint from the classifier in the robot’s current Voronoi region This process continues until the robothas terminated at a desired position (goal) or runs out of power

DTIC

Autonomous Navigation; Classifications; Classifiers; Control; Navigation; Robots

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64 NUMERICAL ANALYSIS

Includes iteration, differential and difference equations, and numerical approximation.

20050169579 Naples Univ., Italy

A Kirchhoff Scattering Model for fBm Surfaces

Franceschetti, Giorgio; Iodice, Antonio; Migliaccio, Maurizio; Riccio, Daniele; IEEE Antennas and Propagation SocietyInternational Symposium, Volume 1; [1999], pp 518-521; In English; See also 20050169565; Copyright; Avail: OtherSources

In this paper a Kirchhoff-based model is employed to determine the scattering from natural surfaces Natural (rough)surfaces are described by means of the fractional Brownian motion (fBm) model since this has been demonstrated to beparticularly suitable The theoretical model is presented and illustrated also by means of comparisons with classical ones.Author

Brownian Movements; Mathematical Models; Scattering; Kirchhoff Law of Radiation

20050169582 Illinois Univ., Urbana, IL, USA

Error Analysis for the Truncation of Multipole Expansion of Vector Green’s Functions

Song, J M.; Chew, W C.; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999], pp 628-631;

In English; See also 20050169565

Contract(s)/Grant(s): N00014-95-1-0872; NSF ESC-93-02145; F49620-96-1-0025; Copyright; Avail: Other SourcesThe recent advent of fast algorithms in computational electromagnetics has permitted the solution of integral equationswith an unprecedented number of unknowns This is the consequence of the development of the fast multipole algorithms(FMA) and the multilevel fast multipole algorithms (MLFMA) Such algorithms allow a matrix-vector multiplication to beperformed in O(N log N) operations or less for many scattering problems Moreover, the memory requirements of thesemethods are O(N log N), or almost matrix free Using the fast matrix-vector multiplications in an iterative solver, problemsfor integral equations involving millions of unknowns have been solved recently One of most important mathematicalformulas in FMA is the addition theorem In the numerical implementation of the addition theorem, the infinite series should

be truncated The error analysis for the truncation error in the scalar Green’s functions has been done by many researchers

In this paper, the error analysis for the truncation error in the multipole expansion of vector Green’s functions is given.Author

Error Analysis; Truncation Errors; Multipoles; Expansion; Vectors (Mathematics); Green’s Functions

20050169594 Al-Azhar Univ., Cairo, Egypt

A Modified 3D Fourth Order FDTD Algorithm M3d(24) for Improving Phase Accuracy with Low Resolution

El-Raouf, Hany E.; El-Diwani, Esam A.; Ammar, El-Hadi; El-Hefnawi, Fatma M.; IEEE Antennas and Propagation SocietyInternational Symposium, Volume 1; [1999], pp 196-199; In English; See also 20050169565; Copyright; Avail: OtherSources

A second order in time fourth order in space modified finite difference time domain algorithm for 3D electromagneticproblems is presented The algorithm enables the numerical phase error to be minimized, so that it leads to high accuracy withlow resolution grids Good results for long distance propagation in the case of radiation from time harmonic elementary dipoleshow the advantage of this method with low resolution compared to the previous finite difference time domain methods.Derived from text

Time Domain Analysis; Finite Difference Time Domain Method; Finite Difference Theory; Phase Error; Algorithms

20050169603 Manitoba Univ., Winnipeg, Manitoba, Canada

A Comparative Study of Wavelet Matrix Transformations for the Solution of Integral Equations

Quan, W.; Ciric, I R.; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999], pp 328-331; InEnglish; See also 20050169565; Copyright; Avail: Other Sources

Application of wavelets for the solution of electromagnetic field integral equations yields sparse matrix equations whichcan be solved efficiently by using sparse matrix techniques The implementation of orthogonal wavelets with infinite supportwidth, such as the Battle-Lemari6 wavelets and the Meyer wavelets, requires a truncation operation which is associated with

a certain solution error [1] In contrast, the Daubechies orthogonal wavelets (DOW) which are compactly supported can beused without any truncation The efficiency of the DOW for the solution of integral equations was analyzed in [2] for the

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scattering by conducting cylinders The resulting sparse matrix equations were solved by using the conjugate gradient (CG)method with storage space required only for the nonzero entries of the sparse matrix The semi-orthogonal wavelets (SOW)were also applied to the solution of integral equations [3] and their performance was compared with that of the Battle-Lemari_orthogonal wavelets in [4], where the matrix entries had been evaluated by numerical integrations The SOW were alsocompared with the DOW in [5], where a matrix transformation was implemented to reduce the computational effort necessary

to perform numerical integrations It has been reported that the use of the SOW yields more highly sparse matrices and a bettersolution accuracy when a direct solver is adopted than the use of orthogonal wavelets [4], [5] However, the efficiency of theiterative solution methods for the sparse matrix equations obtained by using the SOW has not been investigated

Derived from text

Wavelet Analysis; Iterative Solution; Integral Equations; Electromagnetic Fields

20050169604 Politecnico di Turin, Turin, Italy

Multilevel, Multiresolution Integral Equation Analysis of Printed Antennas

Pirinoli, P.; Vecchi, G.; Garino, M Sereno; Matekovits, L.; Orefice, M.; IEEE Antennas and Propagation Society InternationalSymposium, Volume 1; [1999], pp 352-355; In English; See also 20050169565; Copyright; Avail: Other Sources

In this work, a new approach is presented for the Integral Equation analysis of printed structures, based on the definition

of multiresolution vector functions with properties similar to those of the scalar wavelets; in particular, they both posses spatialand spectral resolution The resulting MoM impedance matrix shows strongly improved features, and especially a goodconditioning, that makes the matrix stable against sparsification and the use of iterative methods convenient for the solution

of the linear system Numerical results for a recess-fed patch and an array of monolithically fed rectangular patches arepresented

Derived from text

Iterative Solution; Wavelet Analysis; Linear Systems; Integral Equations; Spectral Resolution

20050169605 Manitoba Univ., Winnipeg, Manitoba, Canada

On the Semi-Orthogonal Wavelet Matrix Transform Approach for the Solution of Integral Equations

Quan, W.; Ciric, I R.; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999], pp 360-363; InEnglish; See also 20050169565; Copyright; Avail: Other Sources

The application of wavelets for the solution of integral equations for field problems has been recently investigated by anumber of researchers The classical method of moments (MoM) leads to dense matrix equations, whose numerical solution

is expensive for large matrix orders The main reason for using wavelets is that it yields sparse MoM matrices Wavelets havebeen implemented for the solution of integral equations in two ways One is to employ them directly both as basis functionsand as weighting functions in the MoM, with the entries of resulting matrices being evaluated numerically Consequently, alarge amount of computational work is required to perform numerical integrations The computational cost is substantiallyreduced by implementing wavelet matrix transformations In this approach, the MoM matrix equation is first obtained by usingsome local basis functions and weighting functions, and then a matrix transformation is applied, with the transform matricesconstructed by using wavelets In general, the transformed matrices are highly sparse after thresholding

Derived from text

Matrices (Mathematics); Orthogonality; Wavelet Analysis

20050169615 Naples Univ., Italy

Strategies to Apply the Kirchhoff Approximation in Electromagnetic Scattering from Gaussian Surfaces: A Comparison

Franceschetti, Giorgio; Migliaccio, Maurizio; Riccio, Daniele; IEEE Antennas and Propagation Society InternationalSymposium, Volume 1; [1999], pp 514-517; In English; See also 20050169565; Copyright; Avail: Other Sources

A comparison between the classical approach and a new general one to verify the applicability of the KirchhoffApproximation (KA) in electromagnetic scattering from random surfaces is presented The analysis is conducted under thetheoretical, numerical and operative viewpoints Particular emphasis is posed to the small surface slope regime

Author

Electromagnetic Scattering; Autocorrelation; Slopes; Functions (Mathematics)

20050169626 Middle East Technical Univ., Ankara, Turkey

Multilevel FMA for the Discrete Dipole Approximation

Koc, S.; Chew, W C.; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999], pp 640-643; InEnglish; See also 20050169565; Copyright; Avail: Other Sources

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The ‘Discrete Dipole Approximation’ (DDA) developed by Purcell and Pennyparker is a powerful and quite generalmethod to calculate the scattering from arbitrary particles and has been applied to a variety of problems such as calculations

of the scattering from graphite grains and porous dust particles In the DDA, a continuum target is replaced by an array ofpoint dipoles which interact with each other and a consistent solution is sought Direct inversion of the matrix is not feasiblefor most problems due to the huge number of unknowns and iterative solutions become inevitable Iterative solutions requireO(N2) operations per matrix-vector multiplication as compared to O(N3) operations for the direct inversion Even iterativemethods can exhaust the computer resources as the scatterer size increases and it becomes necessary to exploit the specialstructure of the coefficient matrix in order to decrease the problem complexity One approach is to use the FFT method whichresults in O(N log N) complexity for relatively uniform distribution of dipoles For nonuniform distributions, the complexity

is more like O(N2) In this work, the multilevel Fast Multipole Algorithm (MLFMA), is used The FMA was successfully usedfor different problems, and the complexity of MLFMA is O(N) for densely packed particles, and O(N log N) for sparse and/ornonuniform distribution of particles, for any prescribed degree of accuracy This is clearly an improvement over the FFTmethod

Author

Algorithms; Discrete Functions; Dipoles; Approximation; Computation; Scattering; Graphite; Grains

20050169627 University of Electronics Science and Technology of China, Sichuan, China

Efficient Solution of 3-D Vector Electromagnetic Scattering by FMM with Partly Approximate Iteration

Jun, Hu; Zaiping, Nie; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999], pp 656-659; InEnglish; See also 20050169565; Copyright; Avail: Other Sources

Recently the research about efficient integral equation method (IEM) for solving scattering from complex object,especially from complex conductive object with large electrical size (such as airplane, missile, tank car et al.), is attendedextensively Fast multiple method (FMM) developed by V Rokhlin is an efficient method to expedite matrix-vectormultiplication in the iterative method It reduces the complexity of matrix vector multiplication to O(N(sup 1.5)), N is thenumber of unknown A multilevel method of FMM has also been developed by J.M Song etc., attaining the complexity ofO(N log N)

Derived from text

Effectiveness; Three Dimensional Models; Vectors (Mathematics); Iteration; Scattering; Approximation

20050169663 Washington State Univ., Pullman, WA, USA

Inhomogeneous Waves and Faster-than-Light Propagation in the Yee FDTD Grid

Schneider, John B.; Kruhlak, Robert J.; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999],

pp 184-187; In English; See also 20050169565; Copyright; Avail: Other Sources

The numerical dispersion relation governing the propagation of homogeneous plane waves in the Yee finite-differencetime-domain (FDTD) grid is well known [1] In this paper we present the dispersion relation governing inhomogeneous planewaves and show that the homogeneous dispersion relation is a special case of this more general relation It is found that, unlike

in the physical world, constant amplitude planes are not necessarily orthogonal to constant phase planes for inhomogeneousplane waves in lossless materials However, the inhomogeneous dispersion relation does converge to the exact one in the limit

as the discretization goes to zero Additionally, we show that, for very coarsely resolved fields, homogeneous waves willexperience exponential decay as they propagate and they may propagate faster than the speed of light Bounds are establishedfor the speed of propagation within the grid, as well as the highest frequency and the shortest wavelength that can be coupledinto the grid

Derived from text

Finite Difference Time Domain Method; Wave Dispersion; Plane Waves; Finite Difference Theory

20050169664 Illinois Univ at Urbana-Champaign, Urbana, IL, USA

Analysis of the FDTD Method via the Discrete Oscillator

Schutt-Aine, Jose E.; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999], pp 188-191; InEnglish; See also 20050169565; Copyright; Avail: Other Sources

The analysis of the FDTD method is usually performed by assuming an e(sup j(omega)t) time dependence for the fieldquantities as the response due to a steady-state monochromatic wave excitation This continuous dependence, when combinedwith the discrete nature of the Yee grid leads to solution errors and dispersion relations that do not describe accurately thepropagation properties in the grid for all frequencies [1] In this work, the discrete oscillator is introduced and used to study

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the numerical properties of the FDTD method Formulas are derived for the propagation characteristics in the one- andtwo-dimensional cases.

Derived from text

Computational Grids; Finite Difference Theory; Finite Difference Time Domain Method; Oscillators; Wave Dispersion

20050169667 Fujitsu Ltd., Chiba, Japan

A New FDTD Algorithm Free from the CFL Condition Restraint for a 2D-TE Wave

Namiki, Takefumi; Ito, Koichi; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999],

In this paper, a new finite-difference time-domain algorithm, which is based on an alternating direction implicit method,

is proposed in order to eliminate the Courant-Friedrich-Levy condition restraint It is shown that the new algorithm is quitestable numerically even when the CFL condition is not satisfied Therefore, if the cell size in the computational domain islocally much smaller than the wavelength, this new algorithm is more efficient than conventional FDTD schemes in terms ofcomputer resources such as central processing unit (CPU) time

Derived from text

Algorithms; Alternating Direction Implicit Methods; Finite Difference Time Domain Method; Finite Difference Theory; Constraints

20050169670 Tel-Aviv Univ., Ramat-Aviv, Tel-Aviv, Israel

The Time Domain Discrete Green’s Function as a Boundary Condition for Three Dimensional Waveguide Problems

Holtzman, R.; Kastner, R.; Heyman, E.; Ziolkowski, R W.; IEEE Antennas and Propagation Society International Symposium,Volume 1; [1999], pp 172-175; In English; See also 20050169565; Copyright; Avail: Other Sources

With the advent of newly-introduced Absorbing Boundary Conditions (ABC’s) for mesh truncation in the context of theFinite-Difference-Time-Domain (FDTD) computations, it has been recognized that the boundaries of the computationaldomain can be defined in close proximity to scatterers, and yet produce very small reflections The most successful methodscan be categorized under the two following titles: (a) approximations to the continuous one way wave equation at the boundarye.g the Engquist-Majda-Mur conditions, and (b) the use of artificial or physical absorbing materials near the boundary, such

as the PML The ABC’s, applied at the boundaries of the computational domain, are initially formulated in the continuousworld, and then discretized for use in the FDTD scheme It is now recognized that typically more than 10 PML layers must

be employed for sufficiently accurate results This extra computational region imposes additional burden on the computationalresources, compared with simpler methods that only require a small stencil close to the boundary

Author

Finite Difference Time Domain Method; Absorbents; Boundary Conditions; Green’s Functions; Three Dimensional Models; Waveguides

20050169671 Idaho Univ., Moscow, ID, USA

The Design of High-Order, Leap-Frog Integrators for Maxwell’s Equations

Young, Jeffrey L.; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999], pp 176-179; InEnglish; See also 20050169565

Contract(s)/Grant(s): F49620-96-1-0469; Copyright; Avail: Other Sources

In this paper, we address issues related to high-order integrator development and propose an extended leap-frogmethodology that can achieve temporal accuracy to any even order desired Such an integrator is compatible with eitherexplicit spatial differencing or with compact differencing; in this paper we will consider the former To limit the discussion,only the fourth-order and eighth-order integrators are presented The chief attributes of these integrators are that thecomputational memory requirements are small and the algorithmic complexity is not increased, with respect to the classicalFDTD method To validate many of the theoretical claims made herein, numerous studies on the rectangular waveguide areconsidered These studies clearly demonstrate the effect of accuracy on data quality

Author

Integrators; Accuracy; Finite Difference Time Domain Method; Maxwell Equation

20050169672 Helsinki Univ Central Hospital, Helsinki, Finland

On the FEM Treatment of Wedge Singularities in Waveguide Problems

Juntunen, Jaakko S.; Tsiboukis, T D.; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999],

pp 464-467; In English; See also 20050169565

Contract(s)/Grant(s): EU-ERBFMBICT-983462; Copyright; Avail: Other Sources

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In modern micro- and millimeter wave technology, there exist many different devices based on microstrip lines Theseinclude coplanar waveguides, patch antennas, filters, power dividers, directional couplers etc In this work, a simple andcomputationally advantageous extension to a standard 2D polynomial finite element basis is introduced to cope with wedgesingularities in uniform cylindrical structures To enhance the computation, variable-order elements are used For thepropagation mode analysis, the longitudinal components of the fields behave have as r(sup 1/2) in the most singular case.Unfortunately, polynomials can poorly approximate these fields close to the singularity, especially in the sense of H(sup 1)norm It will be shown, that the error of the eigenmodes in just H(sup 1)-norm is critical A modification of the finite elementbasis is presented to incorporate the singular behavior Modifications of the finite-difference time-domain (FDTD) method arealso presented for the same purpose The field is assumed to be expanded into asymptotic series The elements touching thewedge tip are modified to have the correct asymptotic form in the radial coordinate In this case the angular variation is notasymptotically accurate Unfortunately, no quantitative results are given to evaluate the impact of the modification The presentextension is constructed such that a few additional basis functions are joined into a high-order hierarchic polynomial basis.The extension has the correct asymptotic form in both radial and angular coordinates.

Derived from text

Finite Element Method; Singularity (Mathematics); Waveguides; Wedges

20050169674 Compaq Computer Corp., Maynard, MA, USA

Absorbing Boundary Conditions for Convex Object-Conformable Boundaries

Ramahi, Omar M.; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999], pp 472-475; InEnglish; See also 20050169565; Copyright; Avail: Other Sources

Absorbing Boundary Conditions (ABCs) are essential elements for solving open region radiation or scattering problemsbecause they allow limiting the computational domain to a finite size Several ABCs were developed for outer boundaries thatform canonical shapes Most practical radiation or scattering problems have geometrical shapes that do not conform to a box,circle or sphere Hence, when using any of these shapes as outer boundaries for mesh termination, the white space around thescatterer might be unnecessarily large resulting in costly simulation in terms of both memory and run time To address thisproblem, ABCs were developed that can be applied to boundaries that conform, as close as practicable, to the radiatinggeometry In all of these previous ABC constructions, the outer boundary had to be positioned few wavelengths from thenearest surface of the structure to obtain practical levels of accuracy In a total departure from‘the philosophy employed earlier,Kreigsman et al applied the BT operator directly on the surface of the scatterer, while assuming that the origin of waves is

at the center of the osculating circle at each outer boundary node The result of the application of Kreigsman et al was notvery satisfactory because it was only possible to apply only second-order BT operators The novelty, however, of using localscattering centers in the work of Kreigsman et al lead others to extend the concept of the local scattering center to outerboundaries that are positioned at a distance from the structure’s surface

Derived from text

Boundary Conditions; Convexity; Operators (Mathematics)

20050169678 Syracuse Univ., NY, USA

Two-dimensional Adaptive Multiscale Moment Method for Analysis of Scattering from a Perfectly Conducting Plate

Su, Chaowei; Sarkar, Tapan K.; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999],

Two-dimensional adaptive multiscale moment method(AMMM) is presented for discussing the scattering fi’om the thin,perfectly conducting plates The EFIE is directly discretized based on the tensor product of the triangular basis by Galerkinmethod We present the formula of the linear equations for the two-dimensional multiscale basis From one scale to anotherscale, the initial guess can be predicted according to the properties of the multiscale technique AMMM can reduceautomatically the size of the linear equation so as to improve the efficiency of the conventional moment method Severalnumerical results are presented, which demonstrate that AMMM is a useful method to analyze the scattering problems fromperfectly conducting plates

Author

Method of Moments; Linear Equations; Scattering; Galerkin Method

Finite Element Implementation of Bayliss-Turkel Boundary Operators in the Three-Dimensional Vector Wave Equation

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The finite element solution of the vector Helmholtz equation is more difficult than that of the scalar one Absorbingboundary conditions (ABCs) that were developed earlier for the vector wave equation were complex In factGamma themmerical implementations of second-order ABCs were the only that were reported in the literature because ABCs of orderthree or higher were immensely difficult to implement in a finite element numerical code Second-order operators were found

to yield satisfactory solutions only when the outer boundary was positioned one or more wavelengths away from thescattererGamma thus increasing the computational cost substantially Absorptive materialF on the other handF sub as theperfectly matched layer (PML)Gamma promises perfect matching in the analytic domain onlyGamma and the performancewhen incorporated into a discrete system might not be very satisfactory The development of PML for three-dimensionalspherical coordinates has recently been reported In this workGamma we develop a series of simple operators for the finiteelement solution of the three-dimensional vector wave equation Unlike the methodologies adopted earlierGammanamelyGamma that of developing operators by manipulating the vector fieldGamma and this obtaining boundary conditionsthat involve the vector field itselfGamma we develop operators that can be applied on the scalar field components of the vectorfield

Derived from text

Finite Element Method; Wave Equations; Three Dimensional Models; Operators (Mathematics); Boundary Conditions; Vectors (Mathematics)

Frequency-Domain Complementary Operators for Finite Elements Simulation

This paper presented the development of frequency-domain complementary operators The application requires twoindependent solutions of the problem Despite this, however, computer memory and execution time can be saved bypositioning the outer mesh-truncating boundary closer to the conductor than what would be required when using othertechniques

Derived from text

Finite Element Method; Frequency Domain Analysis; Simulation; Operators (Mathematics); Approximation

20050169698 National Taiwan Univ., Taipei, Taiwan, Province of China

Minimum and Maximum Time-Localized Complex-Valued Wavelets for Scattering Problems

Leou, Jeng-Long; Huang, Jiunn-Ming; Jeng, Shyb-Kang; Li, Hsueh-Jyh; IEEE Antennas and Propagation SocietyInternational Symposium, Volume 1; [1999], pp 368-371; In English; See also 20050169565; Copyright; Avail: OtherSources

Publications on numerical methods of electromagnetic filed problems have shown a marked preference for real-valuedwavelets This is probably because the original wavelets, which were widely used for signal/image processing, were primarilyreal valued Among these commonly used wavelets, especially, real-valued Daubechies wavelets are concerned mostfrequently owing to their finite support and orthogonality properties Nevertheless, it does not mean that they are the onlychoice to solve the problem They are just one genus of wavelets within the Daubechies family Various genus of wavelets can

be constructed, real-valued or complex-valued, by means of adjusting the selection strategy of zeros in the Daubechiespolynomial As is generally recognized, in real-valued wavelet family, symmetric or antisymmetric, compactly supported andorthogonal scaling functions and wavelets are not available except for Haar wavelets One of the properties mentioned abovemust be released if the other two properties are required In the meantime, orthogonality and finite support wavelets are mostpreferred and lead to asymmetric real-valued wavelets However, this is not to say symmetric property is not important forsolving electromagnetic problems The purpose here is to explore a little further into the symmetric or antisymmetric waveletswith compact supports and orthogonal behavior Since there are many wavelets genus can be obtained, either real-valued orcomplex-valued, we need a reasonable criterion to choose the most suitable basis for the application at hand In this paper,

a new selection criterion based on the time-localization measure of scaling functions and wavelets is proposed to investigatethe relationship between the localization of wavelets and the sparsity of the resultant MoM matrix equation

Derived from text

Numerical Analysis; Scattering; Wavelet Analysis; Electromagnetism

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20050169700 Texas Univ., Austin, TX, USA

Efficient Representation of Electromagnetic Integral Equations Using Pre-defined Wavelet Packet Basis

Deng, Hai; Ling, Hao; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999], pp 336-339; InEnglish; See also 20050169565

Contract(s)/Grant(s): F49620-96-10025; Copyright; Avail: Other Sources

Wavelet-like basis has been widely applied to sparsify moment matrix for the fast solution of electromagnetic integralequations [1-3] It has been found that the application of wavelet basis functions in electrodynamic problems can result in avery sparse moment matrix, but the number of above-threshold elements in the transformed matrix still grows nearly asO(N(sup 2)) [3] As a result, the computational complexity of solving electromagnetic integral equations is not reduced usingthe conventional wavelet basis More recently there is research to adaptively choose the best wavelet packet basis for themaximum sparsification of the transformed moment matrix [4,5] It was reported that the above threshold elements grows atthe rate of O(N(sup 1.4)) in the adaptive wavelet packet transformed moment matrix However, the adaptive packet methodrequires additional computational cost to fred the best transform basis, and the basis found may deviate from the optimumwhen the problem size is large In this work we define a class of pre-designed wavelet packet bases for the efficientrepresentation of moment equations The new basis is designed from the wavelet packet decomposition tree that grows alongthe free-space wave number 1% Simulation results show that the non-zero elements in the transformed matrix grow at a rate

of about O(N(sup 1.3) for small problem sizes, and the rate tends to O(NlogN) for large problem sizes

Derived from text

Integral Equations; Method of Moments; Wavelet Analysis; Matrices (Mathematics)

20050169702 Hewlett-Packard Labs., Palo Alto, CA, USA

Optimal Grouping of Basis Functions

Baharav, Zachi; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999], pp 340-343; InEnglish; See also 20050169565; Copyright; Avail: Other Sources

The Method of Moments (MoM) is widely used for the solution of scattering problems, but one of its greatest limitations

is the resulting large and dense impedance matrix This imposes constraints both in terms of storage and solution-complexity

of the impedance matrix Most of the methods to relieve these constraints are concerned with rendering the matrix sparse, orotherwise exploit its structure An approach relevant to this paper is that of using special basis functions such that the resultingimpedance matrix will have only small number of dominant terms Thresholding the matrix will lead to a sparse matrix, withyet almost no degradation in the result An example is the use of wavelets as basis functions In the category of selectingspecial basis functions also falls the Impedance Matrix Localization (IML) method of Canning In the IML one performs abasis-transformation in order to transform the impedance matrix into one with only a few dominant terms, and then performs

a threshold operation to arrive at a sparse matrix A different point of view was recently suggested in the Impedance MatrixCompression (IMC) method In the IMC one seeks to use basis functions such that the resulting solution vector is sparse This,

in turn, enables the use of a much smaller (in dimensions) impedance matrix, which is much easier to solve than the originalimpedance matrix In this work we will look into the question of which basis functions should be used for the IMC, in order

to have the most possible sparse solution vector We will start by formulating more precisely the problem at hand, and willthen proceed to description of possible solutions and numerical examples

Author

Scattering; Matrix Methods; Wavelet Analysis

20050169704 Chiba Univ., Chiba, Japan

Wavelet Matrix Transform Approach for the Solution of Electromagnetic Integral Equations

Guan, Ning; Yashiro, Kenichiro; Ohkawa, Sumio; IEEE Antennas and Propagation Society International Symposium, Volume1; [1999], pp 364-367; In English; See also 20050169565; Copyright; Avail: Other Sources

A large class of electromagnetic problems can be formulated by integral equations with their relevant Green’s functions

as integral kernel Conventional method of moments (MoM), when applied directly to the integral equations, leads to densematrix equations which require a computation cost of O(N3) with N unknowns Recently, a wavelet matrix transform approachhas been used to reduce the original equations to sparse ones and hence dramatically reduce the computing time Z Xiang and

Y Lu have proposed a construction method for orthonormal or non-orthonormal wavelet matrices and compared the effect ofusing the cardinal spline wavelet bases with that of using Daubechies’ wavelet bases in the wavelet matrix transform approach,where the advantages of using the former bases have been demonstrated from matrix compression rate and accuracy point ofview However, the computation cost was not discussed there R L Wagner and W C Chew have studied not only thesparsification of matrices but also the cost of matrix-vector multiplication (MVM) which was reported as O(N2) W L Golik

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has applied a discrete wavelet packet and saved the cost of the MVM to O(N(sup p)) with p less than 2 However, the realrun-time of solving the resulting sparse matrix equations was not concerned with in these papers In addition, the number ofvanishing moments of the vavelet was fixed at 8 This value should be optimized from the computation cost consideration.Derived from text

Wavelet Analysis; Matrices (Mathematics); Method of Moments; Multiplication

20050169705 National Taiwan Univ of Science and Technology, Taipei, Taiwan, Province of China

Simulations and Measurements for Indoor Wave Propagation through Periodic Structures

Yang, Chang-Fa; Wu, Boau-Cheng; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999],

Scattering properties of periodic structures have been studied by many investigators for analyzing antennas, selected surfaces, absorber designs, wave propagation etc [1-3] Particularly, a periodic method for material bodies [1] hasbeen applied in [3] to evaluate the scattering from a concrete block wall, which is modeled as a periodically-distributedmaterial structure for determining the effects of periodicity in wireless communications On the other hand, ray-tracingtechniques have been employed to evaluate the reflections, transmissions and diffractions from electrically-large bodies forindoor/outdoor wave propagation [4-6] In this paper, a hybrid approach, combining the ray-tracing method shown in [6] andthe periodic moment method (PMM) for material objects reported in [2], is developed to study the indoor wave propagation,penetrations, and also the scattering due to periodic structures in buildings The PMM is applied to evaluate the specular andgrating transmission and reflection coefficients of the periodic structures Those data are then used in the ray-tracing program

frequency-to find specular and grating ray tubes for each ray tube illuminating one of the periodic structures Those excited ray tubesare continuously traced to determined their contributions to receiving antennas Measurements and simulations for wavespropagating inside a staircase will be compared and discussed, where the stairs are modeled as singly-periodic wedges havingmaterial properties similar to those of the reinforced concrete (RC) wall

Derived from text

Composite Materials; Method of Moments; Periodic Variations; Wave Propagation; Buildings; Scattering

20050169706 Universidad Politecnica de Valencia, Valencia, Spain

Efficient Waveguide Mode Computation Using Wavelet-Like Basis Functions

Cogollos, S.; Vidal, A.; Esteban, H.; Boria, V E.; IEEE Antennas and Propagation Society International Symposium, Volume1; [1999], pp 356-359; In English; See also 20050169565; Copyright; Avail: Other Sources

Wave theory is becoming a very useful tool to characterize electromagnetic structures due to the excellent properties ofwavelet families for the accurate representation of functions and operators Up to now, wavelet theory has been appliedsuccessfully to electromagnetic integral equations solved through Moment Methods However, in this paper, the computation

of the modal behavior of rectangular waveguides strongly perturbed by axial cylindrical conducting objects is taken via theNystrom method, which is an elegant and simple procedure for solving integral equations In order to improve the efficiency,wavelet-like bases are used to expand the unknown electric current Therefore, memory requirements and computational costsare reduced dramatically

Author

Method of Moments; Wavelet Analysis; Rectangular Waveguides; Electric Current; Integral Equations

20050169714 Michigan Univ., Ann Arbor, MI, USA

Numerical Simulation of Scattering from Rough Surfaces Using a Fast Far-Field Iterative Physical Optics Approach

Zahn, Daniel; Sarabandi, Kamal; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999],

The application of a fast far-field iterative Physical Optics (FIPO) method in conjunction with a Monte Carlo simulationfor characterizing the bistatic scattering coefficient of random rough surfaces is examined in this paper The FIPO methodoffers decreased memory and computation time restrictions compared to the standard n,merical methods such as the Method

of Moments (MoM), and decreased computation time compared to an exact iterative PO method Results from the FIPOmethod are compared to the standard electric field integral equation (EFIE), the magnetic field integral equation (MFIE), acomplete iterative PO (IPO), as well as the existing theoretical solutions for rough surfaces It is demonstrated that memoryrequirements and computation time is significantly decreased while providing fairly accurate results for surfaces withmoderate to low tins slope

Author

Numerical Analysis; Scattering; Surface Roughness; Far Fields; Method of Moments

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20050169717 City Univ of Hong Kong, Kowloon, Hong Kong

Integral Equation Formulation for Iterative Calculation of Scattering from Lossy Rough Surfaces

Li, S.Q.; Chan, C H.; Tsang, L.; Li, Q.; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999],

pp 526-529; In English; See also 20050169565

Contract(s)/Grant(s): N00014-96-1-0075; Copyright; Avail: Other Sources

Iterative solution of rough-surface scattering problems has several advantages over traditional solution using matrixfactorization Iterative procedures are O(N(sup 2)) versus O(N(sup 3)) for factorization, where N is the number of unknowns

to be found, so iteration can be much more efficient computationally for large systems Moreover, the matrix interactionelements can be recalculated as needed in an iterative approach, eliminating the need to store the entire interaction matrix(which can exceed the memory capabilities of the computer system for the largest problems) Earlier the use of iterativetechniques to find the scattering from perfectly conducting surfaces was examined It was shown that recently introducediterative schemes are mathematically equivalent to existing stationary approaches whose convergence properties dependstrongly on the conditioning of the interaction matrix, and that non-stationary approaches can be more robust Here theapplication of iterative routines to finite-conductivity surfaces is considered In particular, an integral equation formulation thatyields rapid convergence for horizontally polarized scattering from one-dimensionally rough surfaces without loss of accuracy

is examined

Derived from text

Integral Equations; Surface Roughness; Iterative Solution; Magnetic Fields; Lossy Media; Scattering

20050169723 Motorola, Inc., Arlington Heights, IL, USA

Numerical Study of Reflection and Transmission Coefficients for Different Inhomogeneous Walls

Stratis, Glafkos; Demetriou, Demetrakis; IEEE Antennas and Propagation Society International Symposium, Volume 1;[1999], pp 590-592; In English; See also 20050169565; Copyright; Avail: Other Sources

Analytical expressions such as Fresnel reflection and transmission coefficients have been extensively used in most of theray-tracing simulation tools for the last few years Although these tools predict the field accurately for simple homogeneouswall structures, it is difficult, if not impossible, to extend such an analysis to find reflection and transmission coefficients forwalls composed of dielectric and imperfectly conducting materials In the past we demonstrated the successful application ofthe finite difference time domain (FDTD) method to numerically obtain reflection and transmission coefficients for purehomogeneous layered wails We also compared measurements with the FDTD method for a certain type of inhomogeneouswall [2] with satisfactory results In this paper we further extend the FDTD approach to analyze the transmitted and reflectedfields from 2-D inhomogeneous walls which represent practical wall structures, in order to identify the importance of thevarious paran_ters such as thickness, permittivity, and presence or absence of metallic rebars

Author

Computerized Simulation; Reflectance; Finite Difference Time Domain Method; Dielectrics; Ray Tracing

20050169729 Universidad Politecnica de Catalunya, Barcelona, Spain

Iterative Network Models to Predict the Performance of Sierpinski Fractal Antennas and Networks

Borja, C.; Puente, C.; IEEE Antennas and Propagation Society International Symposium, Volume 1; [1999], pp 652-655; InEnglish; See also 20050169565; Copyright; Avail: Other Sources

Two simple, fast numerical models to predict the input parameters of antennas and networks whose topologies are that

of the Sierpinski Gasket and Carpet fractal shapes, are introduced These models are based on the same recursive principleused to generate fractal structures

Author

Mathematical Models; Iterative Networks; Performance Prediction; Fractals

20050170460 Stanford Univ., Stanford, CA, USA

Statistical Methodology for Yield Enhancement via Baseline Reduction

Fridgeirsdottir, Kristin; Akella, Ram; Li, Mien; McNally, Peter; Mittal, Sanjiv; 1998 IEEE/SEMI Advanced SemiconductorManufacturing Conference And Workshop; [1998], pp 77-81; In English; See also 20050170458; Copyright; Avail: OtherSources

In this paper we introduce a DOE-Regression based methodology to identify which tools, in a segment of a fab linebetween two inspection stations, are defect generating The approach estimates how much the yield could increase by repairingeach of the tools Furthermore, the tools can be ordered for repair according to this potential yield increase The estimate of

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the yield increase includes an evaluation of the power of the statistical test performed to identify the defect generating tools,

as well as the kill ratio By identifying the problem prone tools and repairing them in the order given by the estimated yieldincrease the baseline of the process can be lowered in an effective manner and the yield increased

Author

Statistical Analysis; Yield; Statistical Tests; Inspection; Identifying; Defects

20050170467 California Univ., Berkeley, CA, USA

How to Simultaneously Reduce alpha and beta Error with SPC? A Multivariate Process Control Approach

Nasongkhin, Ruj; Shanthikumar, J George; Nurani, Raman K.; McIntyre, Mike; 1998 IEEE/SEMI Advanced SemiconductorManufacturing Conference And Workshop; [1998], pp 13-18; In English; See also 20050170458; Copyright; Avail: OtherSources

We describe the multivariate statistical process control approach which uses a weighted average metric as a metric plotted

on a control chart We show that the optimal weighted coefficient is a function of mean-shift vector and covariance matrix ofmetrics of interest The control chart constructed by this optimal weighted average metric will have the highest signal to noiseratio and the lowest alpha and beta errors The numerical example using the actual data from a fab is also provided.Author

Multivariate Statistical Analysis; Matrices (Mathematics); Errors

20050170491 Motorola, Inc., Chandler, AZ, USA

Yield Analysis and Data Management Using Yield Manager (trademark)

Lee, Fourmun; Smith, Shawn; 1998 IEEE/SEMI Advanced Semiconductor Manufacturing Conference And Workshop; [1998],

A yield management system (YMS) is an essential component in the tool set of a modem wafer fab The YMS providesthe tools to analyze and manage the immense volume of process and electrical test data generated by process metrology, in-lineinspection monitoring, and electrical test operations The intent of the system is to provide fab personnel with near-real timeaccess to all data required to support the wafer manufacturing process Typical yield enhancement (YE) activities within thesemiconductor manufacturing process include in-line defect reduction, yield excursion control, failure analysis, and baselineyield analysis Each of the above mentioned YE activities typically focus on a specific data type and/or a specific set ofanalysis techniques to achieve the desired result of increasing yield Providing a solution which integrates various data typesand analysis techniques with a common client/server interface is key to achieving the level of YE support needed to establishworld class semiconductor manufacturing yields This paper describes our experiences with using the Knights TechnologyYield Manager(TM) (Knights YM)as a fabwide data integration and analysis tool The Knights YM system is designed around

a client-server architecture, with separate servers to service database management and data analysis tasks The systemprovides: (1) a single interface for extracting multiple types of data generated during device fabrication and testing, and (2)tools to visualize, analyze, and correlate the data All database and analysis functions can be accessed remotely via anyterminal, workstation, or desktop PC which support x-terminal functions At Motorola, the Knights YM system is being used

to facilitate the collection, management, and analysis of fab data Examples of how the Knights YM system is being used toimprove analysis capability, productivity, and response time are presented as case studies

Author

Yield; Data Management; Data Base Management Systems; Wafers

20050173164 Schafer Corp., Arlington, VA USA

Genetic Algorithm-Based System Design and Photonics-Based Receiver Technologies Program SETA Support

Cestaro, Ronald; Howard, Jack; Mar 2005; 7 pp.; In English

Contract(s)/Grant(s): MDA972-01-D-0002-0018; ARPA ORDER-Q383

Report No.(s): AD-A432273; LRS-05-0404; No Copyright; Avail: CASI;A02, Hardcopy

This is the final report for the Schafer Corporation Genetic Algorithm-Based System Design and Photonics-BasedReceiver Technologies Program support under delivery order No 0018 covering the period of August 2003 through December

2003 This report covers the work accomplished by Team Schafer (Schafer Corporation and Booz Allen Hamilton) TeamSchafer supported DARPA with programmatic, technical, and financial assistance support

DTIC

Algorithms; Genetic Algorithms; Photonics; Receivers; Systems Engineering

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20050173203 Maryland Univ., College Park, MD USA

An Efficient and Robust Human Classification Algorithm

Ran, Yang; Weiss, Isaac; Zheng, Qinfen; Davis, Larry S.; Dec 2004; 8 pp.; In English; Original contains color illustrationsReport No.(s): AD-A432371; No Copyright; Avail: Defense Technical Information Center (DTIC)

This paper describes an object classification algorithm for infrared videos Given a detected and tracked object, the goal

is to analyze the periodic signature of its motion pattern We propose an efficient and robust solution similar to frequencyestimation techniques in speech processing Periodic reference functions are correlated with the video signal In order tocapture the frequency response at a given set of period, we explore a local version of DFT By estimating the periodicity atevery pixel, we obtain the overall response for the object, which helps us to make decision robustly Experimental results forboth infrared and visible videos acquired by ground-based as well as airborne moving sensors are presented

DTIC

Algorithms; Classifications; Frequency Response

20050173204 Florida State Univ., Tallahassee, FL USA

Parity Relation Based Fault Detection, Isolation and Reconfiguration for Autonomous Ground Vehicle Localization Sensors

Lu, Ying; Collins, Emmanuel G., Jr.; Selekwa, Majura F.; Dec 2004; 9 pp.; In English; Original contains color illustrationsReport No.(s): AD-A432374; No Copyright; Avail: Defense Technical Information Center (DTIC)

This paper considers fault detection, isolation and reconfiguration (FDIR) for the localization sensors, including the deadreckoning and external sensors, of an autonomous ground vehicle (AGV) designed for use in highly unstructured outdoorenvironments Ten sensors are considered in this research None of these sensors are identical, but subsets of them do havethe ability to measure or calculate (based on simple algebra) the same kinematical parameters To improve the localizationaccuracy, selected sensor outputs are fused using Kalman filters The fused data and selected sensor measurements are thencombined into a set of linearly independent parity equations, which leads to the generation of a bank of residuals A fault inany one of the ten sensors causes a unique subset of these residuals to grow, which allows the fault to be detected and isolated.This allows a control scheme based on these sensors to reconfigure itself so that only the non-faulty sensors are used forlocalization The effectiveness of this FDIR scheme is demonstrated in the context of a recently developed algorithm formaneuvering an AGV in cluttered environments

DTIC

Autonomy; Fault Detection; Isolation; Parity; Position (Location)

20050173227 Scripps Institution of Oceanography, La Jolla, CA USA

ROMS/TOMS Tangent Linear and Adjoint Models: Testing and Applications

Miller, Arthur J.; Cornuelle, Bruce D.; Jan 2004; 6 pp.; In English; Original contains color illustrations

Contract(s)/Grant(s): N00014-99-1-0045

LONG-TERM GOALS: Our long-term technical goal is to produce a tested tangent linear model (TLM) and adjointmodel (ADM) for ROMS/TOMS (Regional Ocean Modeling System/Terrain-Following Ocean Modeling System) that issuitable for general use by the ROMS/TOMS community and to develop computational platforms based on the TLM andADM for 4D variational data assimilation (4DVar), ensemble forecasting and sensitivity analysis Our long-term scientific goal

is to model and predict the mesoscale circulation and the ecosystem response to physical forcing in the various regions of theworld ocean through state estimation

DTIC

Ocean Models; Oceans; Tangents; Total Ozone Mapping Spectrometer

20050173228 Army Test and Evaluation Command, Aberdeen Proving Ground, MD USA

Standardized UXO Technology Demonstration Site Blind Grid Scoring Record No 213

Overbay, Larry; Archiable, Robert; McClung, Christina; Robitaille, George; Jan 2005; 48 pp.; In English; Original containscolor illustrations

Report No.(s): AD-A432426; ATC-8836; No Copyright; Avail: Defense Technical Information Center (DTIC)

This scoring record documents the efforts of the Naval Research Laboratories (NRL) to detect and discriminate inertunexploded ordnance (UXO) utilizing the YPG Standardized UXO Technology Demonstration Site Blind Grid The scoringrecord was coordinated by Larry Overbay and by the Standardized UXO technology Demonstration Site Site Scoring

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Committee Organizations on the committee include the U.S Army Corps of Engineers, the Environmental SecurityTechnology Certification Program, the Strategic Environmental Research and Development Program, the Institute for DefenseAnalysis, the U.S Army Environmental Center, and the U.S Army Aberdeen Test Center.

DTIC

Ammunition; Discriminant Analysis (Statistics); Scoring; Standardization

20050173270 Defence Science and Technology Organisation, Salisbury, Australia

Approximation of Integrals via Monte Carlo Methods, With an Applications to Calculating Radar Detection Probabilities

Weinberg, Graham V.; Kyprianou, Ross; Mar 2005; 39 pp.; In English; Original contains color illustrations

Report No.(s): AD-A432535; DSTO-TR-1692; DODA-AR-013-341; No Copyright; Avail: Defense Technical InformationCenter (DTIC)

The approximation of definite integrals using Monte Carlo simulations is the focus of the work presented here Thegeneral methodology of estimation by sampling is introduced, and is applied to the approximation of two special functions

of mathematics: the Gamma and Beta functions A significant application, in the context of radar detection theory, is basedupon the work of Shnidman 1998 The latter considers problems associated with the optimal choice of binary integrationparameters We apply the techniques of Monte Carlo simulation to estimate binary integration detection probabilities.DTIC

Integrals; Monte Carlo Method; Probability Theory; Radar Detection; Radar Equipment

20050173271 Defence Science and Technology Organisation, Edinburgh, Australia

Simultaneous Localisation and Map Building Using the Probabilistic Multi-Hypothesis Tracker

Davey, Samuel; Mar 2005; 47 pp.; In English; Original contains color illustrations

Report No.(s): AD-A432536; DSTO-TR-1691; DODA-AR-013-343; No Copyright; Avail: Defense Technical InformationCenter (DTIC)

This report presents an algorithm for efficiently solving the Simultaneous Localisation and Map Building (SLAM)problem The SLAM problem requires both the dynamic estimation of the sensor location and the tracking of features ofinterest in the environment using the sensor measurements The problem is difficult because the unknown sensor and featurelocations are coupled through the sensor measurement It has been shown that under linear Gaussian conditions, a KalmanFilter solution converges to a solution relative to the unknown starting location However, this approach does not scale wellwith the number of features in the scene, and is unfeasible for large maps The algorithm introduced here is based on theProbabilistic Multi-Hypothesis Tracker (PMHT) and exploits a factorisation of the problem to reduce the computationalrequirements of the Kalman Filter approach The new algorithm is demonstrated on a benchmark data set recorded in VictoriaPark

DTIC

Algorithms; Hypotheses; Kalman Filters; Mapping; Position (Location); Radar Maps

20050173287 Eagle Aeronautics, Inc., Newport News, VA USA

Life Analysis Development and Verification Delivery Order 0012: Damage Tolerance Application of Multiple Through Cracks in Plates With and Without Holes

Harter, James A.; Taluk, Deviprasad; Oct 2004; 185 pp.; In English; Original contains color illustrations

DTIC

Cracks; Curve Fitting; Damage; Finite Element Method; Stress Intensity Factors; Tolerances (Mechanics)

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20050173358 Army Armament Research, Development and Engineering Center, Picatinny Arsenal, NJ USA

Auction Algorithm for Weapons/Targets Pairing Application

Bogdanowicz, Zbigniew; Coleman, Norman; Dec 2004; 3 pp.; In English

In this paper we propose and study the performance of optimizing weapons/ targets pairing based on an auction algorithm.The weapons/targets pairing problem can be considered as an assignment optimization problem in mathematics Hence, thereare number of optimal algorithms that can solve it We show that for practical weapons/targets pairing a well-known in theliterature auction algorithm should be considered as a preferred choice

DTIC

Algorithms; Optimization; Targets

20050173418 Army Research Office, Research Triangle Park, NC USA

Heavy-Tailed, Non-Gaussian Nature of Terrain and its Implications for Terrain Modeling by L1 Splines

Lavery, John E.; Fang, Shu-Cherng; Dec 2004; 7 pp.; In English

This paper presents the first step in establishing a link between the heavy-tailed nature of terrain and a new terrainmodeling technique, L1 splines, that is, splines based on minimizing the L1 norm rather than the square of the L2 norm Toestablish this link, we focus on the heavy-tailed nature of the second derivatives that occur in the L1 spline minimizationprinciples For one urban-terrain data set (Baltimore, Maryland) and two natural-terrain data sets (Killeen, Texas), the secondderivatives behave asymptotically rather than like exponential functions Similar results for first derivatives minus firstdifferences are presented The distributions investigated here are not directly related to the spatial frequency spectra that havebeen the topic of most previous investigations of the heavy-tailed nature of terrain The heavy-tailed nature of the frequencyspectra of terrain has not resulted in any major impact on modeling of large terrain datasets (although it has had significantpositive impact on modeling of vehicle-terrain interaction, where the data sets are local and smaller) The investigation of theheavy-tailed nature of the derivatives of terrain will have significant impact by providing the theoretical underpinnings for thecurrent observation that L1 splines provide better terrain modeling than alternative techniques

DTIC

Splines; Statistical Distributions; Terrain

20050173420 Army Research Office, Research Triangle Park, NC USA

Starting Errors in Numerical Approximations to an Equilibrium Dusty Gas Model

Davis, Stephen F.; Dec 2004; 3 pp.; In English

Discontinuous initial data can generate spurious waves in the numerical solution of some systems of hyperbolic partialdifferential equations In this paper we study a particular model of a dusty gas that appears to be especially susceptible to thistype of starting error Using a combination of analysis and numerical computation, we identify the source of the error andpropose remedies The method of analysis should be applicable to other systems

DTIC

Approximation; Dust; Errors; Gases; Numerical Analysis

20050173421 Army High Performance Computing Research Center, Minneapolis, MN USA

Scalable Parallel Approximate Formulations of Multidimensional Spatial Auto-Regression Models for Spatial Data Mining

Shekhar, Shashi; Kazar, Baris M.; Lilja, David J.; Dec 2004; 3 pp.; In English

The spatial auto-regression (SAR) model is a popular spatial data analysis technique which has been used in manyapplications with geo-spatial datasets However, exact solutions for estimating SAR parameters are computationally expensivedue to the need to compute all the eigen-values of a very large matrix Therefore, serial solutions for the SAR model do notscale up to map sizes of interest to the Army Thus, we developed the parallel approximate SAR models which can now beused by the Army to increase the accuracy and usefulness of maps, better analyze the impact of weather on the battlefield,

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make near-future predictions of the locations of enemy units, and increase the lethality of missiles.

DTIC

Data Mining; Information Retrieval

20050173429 Army Aviation and Missile Command, Redstone Arsenal, AL USA

Accelerated Concept Exploration of Future Combat Systems Using Evolutionary Algorithms and Enterprise Software

Griffin, Joseph; Hester, Jeff; Dec 2004; 3 pp.; In English

Army R&D labs have played a crucial role in the evaluation of emerging systems that equipped the war fighter withsuperior lethality The Future Combat System’s (FCS) aggressive acquisition strategy of conventional (armor, munitions,propulsion) and non-conventional (unmanned sensors, robotics) technologies place a greater demand on labs for rapid andaccurate analysis of potential weapon systems A combination of validated engineering analysis codes, EvolutionaryAlgorithms (EA) and Enterprise Commercial Off the Shelf Software (COTS) can greatly accelerate the evaluation of candidatesystems Traditional Modeling and Simulation (M&S) activities are not well suited for today’s acquisition environment Inparticular, they suffer from: premature design commitment, a failure to quickly identify dominant design factors and adapt tochanging design requirements Many of these problems stem from a lack of human engineering concurrency andcommunication A partial solution to this problem is to enable virtual collaboration among a lab’s modeling and simulationcodes Genetic Algorithms (GA), a subset of EA’s, are an ideal catalyst for multidisciplinary concept exploration GA’s mimicthe selection process that occurs among biological species in nature, but to various engineering disciplines they provide anexcellent focal point in determining a weapon system’s optimal configuration based on a set of given mission parameters Theorganizational and cultural impact of setting up this type of virtual cooperation is far reaching and cannot be overstated.Concept exploration engines have been around for a number of years; an outstanding example is the Integrated HypersonicAeromechanics Tool (IHAT) used at Naval Air Command, China Lake to design hypersonic air breathing vehicles in the Mach4-8 regime Likewise, the Aviation and Missile Command has adopted a multidisciplinary approach through its Army MissileCollaborative Design Environment (AMCODE)

DTIC

Accelerated Life Tests; Algorithms; Combat; Forecasting; Technology Assessment; Weapon Systems

20050173465 RD Instruments, San Diego, CA USA

A Bound on Mean-Square Estimation Error Accounting for System Model Mismatch

Xu, Wen; Richmond, Christ D.; Bell, Kristine L.; Baggeroer, Arthur B.; Dec 2004; 16 pp.; In English; Original contains colorillustrations

In typical array processing problems the signal observation is a function of the parameter set to be estimated as well assome background system model assumed known The modeled background could differ from the true one, leading to biasedestimates even at high signal-to-noise ratio (SNR) To analyze this system model mismatch problem, a Ziv-Zakai-type lowerbound on the mean-square error is developed based on the mismatched likelihood ratio test (MLRT) At high SNR, the boundincorporates the increase in mean-square error due to estimation bias; at low SNR, it includes the threshold effect due toestimation ambiguity The kernel of the bound’s evaluation is the error probability associated with the MLRT A closed-formexpression for this error probability is derived under a data model typical of the array problem assuming random signalembedded in random noise, both of which can be spatially correlated and potentially mismatched The development is applied

to plane-wave bearing estimation with array shape mismatch and matched-field source localization with channel parametermismatch Examples demonstrate that the developed bound describes the simulations of the maximum likelihood estimatewell, including the sidelobe-introduced threshold behavior and the bias at high SNR

DTIC

Error Analysis; Errors; Mean Square Values

A Systolic FFT Architecture for Real Time FPGA Systems

Jackson, Preston A.; Chan, Cy P.; Scalera, Jonathan E.; Rader, Charles M.; Vai, M M.; Feb 2005; 25 pp.; In English; Originalcontains color illustrations

Contract(s)/Grant(s): F19628-00-C-0002

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MIT Lincoln Laboratory has recently developed a new systolic FFT architecture for FPGAs This architecture utilizes aparallel design to provide high throughput and excellent numerical accuracy Using this design, an 8192-point real-time FFT,operating at 1.2 billion samples per second and performing 78 Gops with 70 dB of accuracy, fits on a single Xilinx Virtex II8000.

DTIC

Architecture (Computers); Fast Fourier Transformations; Field-Programmable Gate Arrays; Real Time Operation; Systolic Arrays

20050173525 Army Research Lab., Aberdeen Proving Ground, MD USA

A Generalized Method for the Computational Study of the Effect of Hull Bottom Shapes on Mine-Blast Loading from Detonation of an Explosive

Clarke, Jerry; Namburu, Raju; Gupta, Aaron; Dec 2004; 7 pp.; In English; Original contains color illustrations

A generalized method for generating the necessary load curves for the finite element input from CTH has been developed

at ARL by using the Interdisciplinary Computing Environment (ICE) While others have successfully coupled CTH with finiteelement codes in the past, this method accurately represents the finite element model’s geometry on the Eulerian mesh andcan be applied to any code with a pressure vs time element loading capacity An accurate representation of the finite elementmodel is inserted into the CTH mesh even if the model contains shell elements

DTIC

Blast Loads; Detonation; Explosions; Finite Element Method; Hulls (Structures); Mines (Ordnance); Shapes

20050173531 Georgia Inst of Tech., Atlanta, GA USA

The Second Path: The Role of Algorithms in Maintaining Progress in DSP

Richards, Mark A.; Sep 2004; 10 pp.; In English; Original contains color illustrations

Digital Signal Processing is ’ That discipline which has allowed us to replace a circuit previously composed of acapacitor and a resistor with two anti-aliasing filters, an A-to-D and a D-to-A converter, and a general purpose computer (orarray processor) so long as the signal we are interested in does not vary too quickly.’ - Prof Tom Barnwell, Georgia TechDTIC

Algorithms; Digital Systems; Embedding; Exponential Functions; Integrated Circuits; Progress; Signal Processing

65 STATISTICS AND PROBABILITY

Includes data sampling and smoothing; Monte Carlo method; time series analysis; and stochastic processes.

20050170478 INTEL Ireland Ltd., Leixlip, Ireland

Statistical Methods for Measurement Reduction in Semiconductor Manufacturing

Babikian, Richard; Engelhard, Curt; 1998 IEEE/SEMI Advanced Semiconductor Manufacturing Conference And Workshop;[1998], pp 212-215; In English; See also 20050170458; Copyright; Avail: Other Sources

Measurement reduction in wafer fabrication represents a significant opportunity for cost reduction and improvement inoperational efficiency This translates into savings on test wafers, metrology equipment, technician time and throughput time.With ever increasing process complexities and move to 300 mm technology the measurement cost are increasingly becoming

an area of focus to improve manufacturing efficiency At Intel statistical methodologies and management systems wheredeveloped to facilitate the reduction of measurements to reduce measurement costs

Author

Semiconductors (Materials); Manufacturing; Statistical Analysis; Management Systems; Wafers; Fabrication

20050170519 Motorola, Inc., Austin, TX, USA

Matching Automated CD SEMs in Multiple Manufacturing Environments

Allgair, John; Ruehle, Dustin; Miller, John; Elliott, Richard; 1998 IEEE/SEMI Advanced Semiconductor ManufacturingConference And Workshop; [1998], pp 252-258; In English; See also 20050170458; Copyright; Avail: Other SourcesIncreasingly stringent critical dimension design rules for semiconductor manufacturing have driven manufacturers of

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automated CD SEMs to develop systems with improved linewidth measurement repeatability and reproducibility [1].However, in a multiple tool manufacturing environment, the technical performance of CD SEMs is as much a function ofconsistent and tight operational controls as it is a function of the fundamental capability of the system Efficient and strictmethods for the characterization and monitoring of the measurement performance of the systems, and in particular systemmatching, are required to preserve proper operation We describe a practical CD SEM control procedure, using a standard dailymonitor wafer, that tracks the major system components that impact CD SEM performance A statistical analysis of thismonitor data is presented which allows system matching to be verified immediately rather than requiring tests that span severaldays This procedure tracks tool stability, provides a common CD SEM length reference, and enables the seamless use ofmultiple CD SEMs within a single manufacturing environment or between separate manufacturing environments, withoutsignificantly increasing the tool qualification time Critical matching of six automated CD SEMs in two separatemanufacturing environments is demonstrated using this technique on a variety of layers.

Author

Semiconductors (Materials); Statistical Analysis; Wafers; Manufacturing

Developing a Markov Model to be Used as a Force Shaping Tool for the Navy Nurse Corps

Kinstler, Daniel P.; Johnson, Raymond W.; Mar 2005; 133 pp.; In English; Original contains color illustrations

A Markov Model was used to determine the number of nurses the Navy must gain each year in order to maintain desiredend strength Significant characteristics affecting career progression of individuals in the Navy Nurse Corps were identified.The characteristic of primary concern, accession source, was determined to be significant Markov models were created toidentify personnel flow from ENS through LCDR The models end-strength projections for 2006-2009 were then compared

to Nurse Corps targeted end-strengths for this same period Several scenarios were run to minimize overages and underages

in rank distribution Optimization was achieved by changing both the distribution of accession sources and the distribution ofrecruited ranks Optimal distribution of accession source and rank are dependant upon the degree of acceptable deviation fromthese targets As stated above we were not able to acquire this information limiting our ability to accurately forecast optimizeddistribution of accession source or rank The Markov Model demonstrated that the Nurse Corps current business practicesoptimize accessions for two year projections Increasing variation between the current force structure plan and our modelsprojections suggest that greater efficiency could be obtained in the out-years This Markov Model provides a tool forimproving extended forecasts

DTIC

Manpower; Markov Processes; Mathematical Models; Medical Personnel; Navy

20050173220 Army Research Inst of Environmental Medicine, Natick, MA USA

Mathematical Analysis of Extremity Immersion Cooling for Brain Temperature Management

Xu, Xiaojiang; Santee, William; Berglund, Larry; Gonzalez, Richard; Jan 2004; 5 pp.; In English

Report No.(s): AD-A432410; MISC-04-07; No Copyright; Avail: Defense Technical Information Center (DTIC)

Due to low heat conductivity of body tissue, head surface cooling methods for management of the brain temperatureduring medical treatments often have limited utility As blood flow rates and surface-to-volume ratios are generally high inthe extremities, heat exchange between the body and the environment through the extremities is an important path for heatexchange This study examines the effects of cold-water extremity immersion on brain temperature by simulation modeling.The work is based on a six-cylinder thermoregulatory model that predicts human thermoregulatory responses to heat, cold,and water immersion An arteriovenous anastomosis (AVA) response algorithm was added to the base model Arteriovenousanastomoses are assumed to be controlled by a combination of core and skin temperatures Our series of simulation scenariosconsists of resting in a hot environment (40 degrees C, 75% relative humidity) until the brain temperature rises to 39 degrees

C, then continuing the rest for 1 h under one of the following treatments: (A) no cooling; (B) hands immersed in 10 degreesC; (C) feet immersed in 10 degrees C water; (D) hands/feet immersed in 10 degrees C water The simulation results indicatethat within the first 30 min, the hands, feet, or hands/feet immersion cooling resulted in brain temperature drops of 1.7 degrees

C, 2.4 degrees C, and 3.3 degrees C, respectively, which correspond to cooling rates of 0.03 degrees C/min, 0.04 degreesC/min, and 0.05 degrees C/min The predicted values show that extremity immersion cooling is a viable mechanism for simpleand effective control of brain temperature

DTIC

Blood Circulation; Body Temperature; Brain; Cooling; Submerging

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20050173359 NorthWest Research Associates, Inc., Bellevue, WA USA

Turbulence in the Stable Planetary Boundary Layer and Aloft: Modeling and Characterization Using DNS and LES

Werne, Joseph; Nov 2004; 11 pp.; In English; Original contains color illustrations

a successful DoD HPCMO proposal for challenge status for the computer work associated with this project and a successfulDOD Golden Opportunity Capability Applications Projects (CAP) proposal that will provide an additional 1 to 2 million hours

of computer time on newly delivered MPP systems before they are made generally available to DoD users The CAP programbenefits the DoD HPCMO by having new systems rigorously tested by experienced users

DTIC

Boundary Layers; Characterization; Direct Numerical Simulation; Large Eddy Simulation; Planetary Boundary Layer; Turbulence

20050173382 Connecticut Researve Technologies, LLC, Stow, OH USA

Size Effects in Ceramic Materials: Computational Issues Associated with Parameter Estimations

Duffy, Stephen F.; Baker, Eric H.; Apr 2005; 36 pp.; In English; Original contains color illustrations

Contract(s)/Grant(s): DAAD17-02-P-0503; Proj-622618H80

Report No.(s): AD-A432759; ARL-CR-0560; No Copyright; Avail: Defense Technical Information Center (DTIC)

Two test specimen geometries obtained from circumferentially machined, tubular components have been proposed toinvestigate different flaw populations that might be present in a ceramic gun barrel C-ring specimens tested in compressionwill generate maximum tensile stress states at the outer surface of the barrel This stress state will activate critical flaws thatare oriented parallel to the long axis of the tube The sectored flexure bar specimen tested in four-point flexure will activateflaws aligned circumferentially around the tube There is a need to take failure data from these tests and transform theinformation so that material characteristic strengths can be computed for subsequent Weibull analyses conducted on the gunbarrel component In order to compute the material characteristic strengths, the requisite Weibull effective area and/or effectivevolume parameters must be obtained The procedure for numerically computing the Weibull effective area and effectivevolume for C-ring and sectored flexural test specimens is detailed in this article

DTIC

Ceramics; Estimates; Guns (Ordnance); Independent Variables; Parameter Identification

Analysis of the USMC FITREP: Contemporary or Inflexible?

Jobst, Mark; Palmer, Jeffrey; Mar 2005; 278 pp.; In English; Original contains color illustrations

The purpose of this thesis is threefold Firstly, to attempt to provide validity for the two-sided matching process; secondly,analyze FITREP attributes to determine their suitability for a weighted criteria evaluation system and; thirdly, compare theUSMC promotion and assignment process with contemporary human resource management practices Using data from theUSMC Officer Accession Career file (MCCOAC), a logit model is used to estimate the effects of TBS preference and otherofficer characteristics on retention to the seven year mark Findings indicate that there was little difference in the probability

of retention throughout most preference levels except for the bottom sixth Using USMC FITREP data, an ordinary leastsquares model is used to estimate the effects of rank and MOS on FITREP scores across all attributes Multiple comparisontests demonstrated that there are statistical differences at the 0.05 level between the means of the MOSs Additionally,reporting creep is continuing across all attributes Surveys were also conducted The first survey indicated that USMC officersbelieve the FITREP attributes were not all equally important within, and across each MOS - although the USMC assesses them

as such The second survey indicated that the USMC promotion and assignment process can be strengthened through a clearlydefined HRM plan that extends beyond ‘faces’ and ‘places’, and provides very clear links to the organizational strategy Based

on the findings it is recommended that the USMC review its HRM processes and conduct further analyses on the FITREP data

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for: (1) correlation, (2) longitudinal analysis as a predictor for success and, (3) relevance and relationship to MOScharacteristics, position descriptions, and organizational strategy.

DTIC

Least Squares Method; Personnel Management; Tasks

20050173497 Oak Ridge National Lab., TN USA

Advanced Physiological Monitoring of FCS Soldiers

Hively, L M.; Protopopescu, V A.; Dec 2004; 9 pp.; In English; Original contains color illustrations

We quantify dynamical change in nonlinear time-serial data via dissimilarity measures between statistical distributionfunctions These new measures are superior to traditional nonlinear measures and give robust and timely forewarning ofnormal-to-abnormal transitions in physiological regimes These novel measures also provide rapid quantitative assessment ofphysiological change such as alertness, soldier readiness and bioagent exposure

DTIC

Military Personnel; Nonlinearity; Physiology

The Capon-MVDR Algorithm Threshold Region Performance Prediction and Its Probability of Resolution

Richmond, Christ D.; Dec 2004; 60 pp.; In English; Original contains color illustrations

The Capon-MVDR algorithm exhibits a threshold effect in mean-squared error (MSE) performance 1 Below a specificthreshold signal-to-noise ratio (SNR) the MSE of signal parameter estimates derived from the Capon algorithm rises rapidly.Prediction of this threshold SNR point is clearly of practical significance for system design and performance Via an adaptation

of an interval error-based method referred to herein as the method of interval errors (MIE) 2, 3 the Capon threshold regionMSE performance is accurately predicted The exact pairwise error probabilities for the Capon (and Bartlett) algorithm derivedherein are given by simple finite sums involving no numerical integration and include finite sample effects for an arbitrarycolored data covariance Combining these probabilities with the large sample MSE predictions of Vaidyanathan and Buckley

4 MIE provides accurate prediction of the threshold SNRs for an arbitrary number of well-separated sources circumventingthe need for numerous Monte Carlo simulations A new two-point measure of the Capon probability of resolution is aserendipitous by-product of this analysis that predicts the SNRs required for closely spaced sources to be mutually resolvable

by the Capon algorithm These results represent very valuable design and analysis tools for any system employing theCapon-MVDR algorithm Potential to characterize performance in the presence of mismatch is briefly considered

DTIC

Algorithms; Monte Carlo Method; Performance Prediction; Prediction Analysis Techniques; Probability Theory

20050173550 Air Force Research Lab., Hanscom AFB, MA USA

Grazing Angle Proton Scattering: Effects on Chandra and XMM-Newton X-Ray Telescopes

Dichter, Bronislaw K.; Woolf, Stanley; Dec 2003; 5 pp.; In English

Report No.(s): AD-A433053; AFRL-VS-HA-TR-2004-1137; No Copyright; Avail: CASI;A01, Hardcopy

A proton scattering process resulted in damage to one of the Chandra X-ray telescope’s focal plane detectors In thisprocess, incident protons were transmitted, by scattering off the telescope mirrors, to the focal plane We identify the protonpopulation responsible for the damage and, using a proper grazing angle formalism, we show that the standard calculations

of grazing angle scattering will significantly under predict the expected proton flux at the focal plane

DTIC

Detectors; Grazing; Proton Scattering; Protons; Radiation Damage; Telescopes; X Ray Telescopes

66 SYSTEMS ANALYSIS AND OPERATIONS RESEARCH

Includes mathematical modeling of systems; network analysis; mathematical programming; decision theory; and game theory.

20050172128 NASA Kennedy Space Center, Cocoa Beach, FL, USA

Space Shuttle Operations and Infrastructure: A Systems Analysis of Design Root Causes and Effects

McCleskey, Carey M.; Apr 2005; 264 pp.; In English

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This NASA Technical Publication explores and documents the nature of Space Shuttle operations and its supportinginfrastructure and addresses fundamental questions often asked of the Space Shuttle program why does it take so long toturnaround the Space Shuttle for flight and why does it cost so much? Further, the report provides an overview of the cause-andeffect relationships between generic flight and ground system design characteristics and resulting operations by using actualcumulative maintenance task times as a relative measure of direct work content In addition, this NASA TP provides anoverview of how the Space Shuttle program’s operational infrastructure extends and accumulates from these designcharacteristics Finally, and most important, the report derives a set of generic needs from which designers can revolutionizespace travel from the inside out by developing and maturing more operable and supportable systems.

Author

Space Shuttles; Systems Engineering; Spacecraft Design; Systems Analysis

20050173190 Defence Research and Development Canada, Valcartier, Quebec Canada

OASIS: Opening-Up Architectures Of Software-Intensive Systems

Lizotte, M.; Rilling, J.; Dec 2004; 3 pp.; In English

Opening-up architectures of software-intensive systems includes, as a key element, reverse engineering software, up to

a simple component level This paper introduces the Oasis project, which aims at decreasing comprehension time of existingsystems to be used in a system-of-systems The problem to be addressed and the vision are presented and current tooldeficiencies are described

DTIC

Reverse Engineering; Software Development Tools; Software Engineering

20050173223 Army Communications-Electronics Command, Fort Monmouth, NJ USA

Analysis of Decision Theoretic Modulation Classification Methods for Digital Communication Signals

Su, Wei; Kosinski, John A.; Dec 2004; 3 pp.; In English

Automated modulation classification is a fundamental requirement for electronic support measures Existing automatedclassifiers use a variety of different modulation recognition techniques This paper reviews the category of decision-theoreticapproaches and discusses the relationships between decision-theoretic methods and other statistical modulation classificationmethods

DTIC

Classifications; Decision Theory; Modulation; Pulse Communication

Underwater Acoustic Networks: Evaluation of the Impact of Media Access Control on Latency, in a Delay Constrained Network

DOS Santos Coelho, Jose; Mar 2005; 187 pp.; In English; Original contains color illustrations

This thesis presents an evaluation of the performance, in terms of throughput and latency, of two Media Access Control(MAC) mechanisms in Underwater Acoustic Networks (UANs), using a model designed in the COTS simulation tool OPNET10.5 The carrier sense multiple access with collision avoidance is the predominant approach for implementing the MACmechanism in UANs However, the underwater acoustic environment is characterized by extreme propagation delays andlimited bandwidth, which suggests that an Aloha-like scheme may merit consideration The performance of these two schemeswas compared with respect to two topologies: tree and grid The results showed that an Aloha-like scheme that does notsegment messages outperforms the contention-based scheme under all load conditions, in terms of both throughput andlatency, for the two topologies This thesis is the first to establish that Aloha-like MAC mechanisms can be more than a limitedalternative for lightly loaded networks; more specifically, they can be the preferred choice for an environment with largepropagation delays

DTIC

Access Control; Networks; Underwater Acoustics

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Power Variable Training STAP

Griesbach, Jacob D.; Krich, Steven I.; Pulsone, Nicholas B.; Rader, Charles M.; Mar 2004; 31 pp.; In English; Originalcontains color illustrations

For GMTI radar processing space-time adaptive processing (STAP) is a standard technique to mitigate clutter whilepreserving moving targets STAP relies on an accurately estimated covariance matrix which is traditionally computed fromlocalized training around the range gate under test This presentation suggests a new approach to covariance training Powervariable training combines phase-selective covariance training which restricts range gate training to the most powerful rangegates that lie on the clutter ridge and a new technique that scales the covariance matrix power to prevent over-nulling Thenew algorithm exhibits improved minimum detectable velocity (MDV) and fewer false alarms from clutter discretes as well

as increased performance with extended-range targets The proposed technique is demonstrated and compared to localizedtraining on Tuxedo data

DTIC

Adaptation; Clutter; Education

20050173322 Princeton Univ., NJ USA

Multiuser MIMO Systems

Poor, H V.; Mar 2004; 27 pp.; In English; Original contains color illustrations

Communication systems with multiple antennas at both transmitter and receiver (i.e MIMO systems) have shownconsiderable promise in providing high-rate high-quality wireless links This talk will discuss implications of using MIMOsystems in multiple-access networks The main focus of the talk will be on receiver signal processing for such systems and

in particular on multiuser detection and related issues Complexity reduction techniques that use turbo processing or adaptiveimplementations will also be described Finally some related issues concerning the spectral efficiencies of such systems will

be discussed

DTIC

Communication Networks; MIMO (Control Systems); Multiple Access; Signal Processing; Telecommunication

20050173351 Alphatech, Inc., Burlington, MA USA

Root Locus Properties of Adaptive Beamforming and Capon Estimation for Uniform Linear Arrays

Steinhardt, Allan; Dec 2004; 8 pp.; In English; Original contains color illustrations

In this paper we explore properties of the zeroes of the transfer function (Z transform) of the weight vector arising inadaptive beamforming and direction of arrival estimation (Capon) using sample matrix inversion Our analysis sheds insights

on properties of diagonal loading, as well as high-resolution properties of Capon’s estimate The analysis also provides hints

at how to extend these properties to nonuniform array manifolds Specifically we prove the following theorem Root locustheorem for ULAs: Let w be the clairvoyant weight vector of dimension N for a length N uniform linear array (ULA), given

by w = R(exp-1)v, where v is the steering vector to the target, and R is the (ensemble) covariance matrix Then all N-1 zeroes

of the Z transform of w lie on the unit circle (Note, since the sample matrix yields an unbiased estimator, the root locus forthe adaptive beamformer has mean root loci on the unit circle as well) We then discuss three applications of this theorem:(I) Diagonal loading: We show that the roots of the weight vector follow a trajectory (root locus) from the quiescent pattern

to the interference angles as the interference-to-noise ratio grows Diagonal loading can then be viewed as a regularizationprocess that relaxes the root loci along this trajectory (II) Capon: The spectrum dynamic range is maximized when the zeroesare all on the unit circle; therefore, our result provides an alternative insight into the high-resolution properties of Caponestimation (III) Non-ULA extensions: We find in our proof that the root locus behavior results from symmetry properties ofthe MVDR objective function This suggests guidelines for successful approaches to generalizing Capon estimation anddiagonal loading to non-ULA settings

DTIC

Adaptation; Beamforming; Linear Arrays; Loci

Tiêu đề	Nasa Scientific and Technical Aerospace Reports Phần 5
Trường học	Hampshire College
Chuyên ngành	Computer Science
Thể loại	Report theo Đề tài, Báo cáo khoa học
Năm xuất bản	2005
Thành phố	Amherst, MA

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