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NASA Network Resource and Training Site
by NASA Technical Reports Server (NTRS)
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NASA's Jet Propulsion Laboratory has developed a computer model for planning future health care needs in the Los Angeles area. The model integrates demographic health and other data to provide rational projections of hospital bed and physician specialty requirements.
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, HEALTH, HOSPITALS, PHYSICIANS
An investigation into the application of an observer based sliding mode controller for robust control of a highly unstable aircraft and methods of compensating for actuator dynamics is performed. After a brief overview of some reconfigurable controllers, sliding mode control (SMC) is selected because of its invariance properties and lack of need for parameter identification. SMC is reviewed and issues with parasitic dynamics, which cause system instability, are addressed. Utilizing sliding...
Topics: NASA Technical Reports Server (NTRS), AIRCRAFT CONTROL, AIRCRAFT STABILITY, ACTUATORS, COMPUTERIZED...
Although perhaps not so dramatic or newsworthy as chemical, biologic, radiologic, nuclear, or explosive attacks, intentionally set fires are identified security threats to federal buildings accessible to the public. The Department of Homeland Security Interagency Security Committee in 2010 adopted building construction standards that purport to give facility safety committees and building designers guidance on developing permanent countermeasures to 31 diverse threat scenarios described in the...
Topics: DTIC Archive, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *BUILDINGS, ATTACK, COMPUTERIZED SIMULATION,...
The feasibility is evaluated of an evolutionary development for use of a single-axis gimbal star tracker from prior two-axis gimbal star tracker based system applications. Detailed evaluation of the star tracker gimbal encoder is considered. A brief system description is given including the aspects of tracker evolution and encoder evaluation. System analysis includes evaluation of star availability and mounting constraints for the geosynchronous orbit application, and a covariance simulation...
Topics: NASA Technical Reports Server (NTRS), ATTITUDE INDICATORS, GIMBALS, STAR TRACKERS, COMPUTER...
Defense Technical Information Archive
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The purpose of this Idea Development award is to evaluate the additive benefits of automated feedback and eye tracking to standard (human-directed training) of driving skills for those who are diagnosed with high functioning autism and have a learner s permit. The goal for year 1, which began when funding arrived on Sept 30, 2012, was to secure and operationalize the software to provide automated feedback, and to recruit and train 20 drivers, 10 receiving standard training and 10 receiving...
Topics: DTIC Archive, VIRGINIA UNIV CHARLOTTESVILLE, *AUTOMATION, *COMPUTERIZED SIMULATION, *DEVELOPMENTAL...
Some of the processes involved in the nucleation and growth of thin films were simulated by means of a digital computer. The simulation results were used to study the nucleation and growth kinetics resulting from the various processes. Kinetic results obtained for impingement, surface migration, impingement combined with surface migration, and with reevaporation are presented. A substantial fraction of the clusters may form directly upon impingement. Surface migration results in a decrease in...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, NUCLEATION, THIN FILMS, CRYSTAL...
Defense Technical Information Archive
by Defense Technical Information Center
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This briefing discusses the ins and outs of planning the Connections '09 conference.
Topics: DTIC Archive, VERIDIAN ENGINEERING DAYTON OH, *PLANNING, *SYMPOSIA, COMPUTER GAMES, COMPUTERIZED...
Defense Technical Information Archive
by Defense Technical Information Center
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The theory of oscillator analysis in the immittance domain is presented. This theory enables the computer simulation of the steady state oscillator. The simulation makes practical the calculation of the oscillator total steady state performance, including noise. Some oscillator applications of the PC program, BPT, created for the simulation, are listed.
Topics: DTIC Archive, PARZEN (BENJAMIN) SAN DIEGO CA, *OSCILLATORS, PERFORMANCE(ENGINEERING), STEADY STATE,...
Defense Technical Information Archive
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The purpose of this Idea Development award is to evaluate the additive benefits of automated feedback and eye tracking to standard (human-directed training) of driving skills for those who are diagnosed with high functioning autism and have a learner s permit. The goal for year 2, which began when funding arrived on Sept 30, 2013, was to examine the effects of eye-tracking feedback on training. This was accomplished by integrating the eye-tracking component with the standard training. To date...
Topics: DTIC Archive, IOWA UNIV IOWA CITY, *EYE MOVEMENTS, *TRACKING, *VIRTUAL REALITY, COMPUTERIZED...
Defense Technical Information Archive
by Defense Technical Information Center
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Topics: DTIC Archive, Stout, P., CFD RESEARCH CORP HUNTSVILLE AL, *COMPUTER AIDED DESIGN, *QUANTUM...
Defense Technical Information Archive
by Defense Technical Information Center
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We investigate the effect of magnetic reconnection between open and closed fields, often referred to as interchange reconnection, on the dynamics and topology of coronal hole boundaries. The most important and most prevalent three-dimensional topology of the interchange process is that of a small-scale bipolar magnetic field interacting with a large-scale background field. We determine the evolution of such a magnetic topology by numerical solution of the fully three-dimensional MHD equations...
Topics: DTIC Archive, NAVAL RESEARCH LAB WASHINGTON DC, *MAGNETOHYDRODYNAMICS, NUMERICAL ANALYSIS, BIPOLAR...
The logistics of orbital vehicle servicing computer specifications was developed and a number of alternatives to improve utilization of the space shuttle and the tug were investigated. Preliminary results indicate that space servicing offers a potential for reducing future operational and program costs over ground refurbishment of satellites. A computer code which could be developed to simulate space servicing is presented.
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, LOGISTICS, SPACE SHUTTLES, SPACE...
Current system simulations are mature, difficult to modify, and poorly documented. Probabilistic life prediction techniques for space applications are in their early application stage. Many parts of the full system, variable fidelity simulation, have been demonstrated individually or technology is available from aeronautical applications. A 20% reduction in time to design with improvements in performance and risk reduction is anticipated. GRC software development will proceed with similar...
Topics: NASA Technical Reports Server (NTRS), PREDICTION ANALYSIS TECHNIQUES, COMPUTERIZED SIMULATION,...
NASA engineers use simulation software to detect and prevent interference between different radio frequency (RF) systems on a rocket and satellite before launch. To speed up the process, Kennedy Space Center awarded SBIR funding to Champaign, Illinois-based Delcross Technologies LLC, which added a drag-and-drop feature to its commercial simulation software, resulting in less time spent preparing for the analysis.
Topics: NASA Technical Reports Server (NTRS), ARTIFICIAL SATELLITES, LAUNCHING, RADIO FREQUENCIES,...
Defense Technical Information Archive
by Defense Technical Information Center
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This document describes subroutines (link source library listings) pertaining to interactive Visual Simulation of Communications systems.
Topics: DTIC Archive, LINKNET ROLLING HILLS ESTATES CA, *COMPUTERIZED SIMULATION, *SUBROUTINES, VISION,...
NASA Network Resource and Training Site
by NASA Technical Reports Server (NTRS)
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Topics: NASA Technical Reports Server (NTRS), SUPERCOMPUTERS, NASA PROGRAMS, COMPUTERIZED SIMULATION,...
Differential Evolution is a simple, fast, and robust evolutionary algorithm that has proven effective in determining the global optimum for several difficult single-objective optimization problems. In this paper, the Differential Evolution algorithm is extended to multiobjective optimization problems by using a Pareto-based approach. The algorithm performs well when applied to several test optimization problems from the literature.
Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, OPTIMIZATION, COMPUTERIZED SIMULATION, Madavan,...
During the final year of this investigation we have finished several event studies that we considered necessary for the development of a tail magnetopause model and for the calibration of our simulation code. We have not reached the ultimate goal of the project, i.e., the development of an analytical tail magnetopause model. In the course of the investigation we have learned that such a model would be much more complex than we had anticipated. However, the investigations that we conducted...
Topics: NASA Technical Reports Server (NTRS), MAGNETOPAUSE, COMPUTERIZED SIMULATION, MODELS, MATHEMATICAL...
The design, fabrication, testing, and evaluation of components for a modularized engineering prototype of a unified system for detection of life on Mars is summarized.
Topics: NASA Technical Reports Server (NTRS), EXTRATERRESTRIAL LIFE, MARS (PLANET), BIOLOGY, COMPUTERIZED...
Defense Technical Information Archive
by Defense Technical Information Center
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There is an enormous range of computational models and simulations for addressing a variety of analysis and design issues in complex systems. This report addresses systems where behavioral and social phenomena are significant elements of system performance. The report begins with an overview of the state of the art for multi-level modeling of such socio-technical systems. It then reports on an interview study of how four non-defense industries address computational modeling of complex...
Topics: DTIC Archive, SYSTEMS ENGINEERING RESEARCH CENTER HOBOKEN NJ, *SYSTEMS ENGINEERING, COMPUTERIZED...
Defense Technical Information Archive
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Half-symmetric model is used in AutoDyn to simulate Depth of Penetration (DoP) experiments on aluminum targets with ceramic facing with and without a gap between tiles. Impacts from a .30cal AP M2 projectile are modeled using SPH elements. Model validation runs were conducted based on the DoP experiments described in reference - ARL-TR-2219, 2000. Boundary conditions were modified in order to achieve better data agreement. Further analysis will be conducted to determine the effect of material...
Topics: DTIC Archive, DELAWARE UNIV NEWARK, *ARMOR, ALUMINUM, CERAMIC MATERIALS, COMPUTERIZED SIMULATION,...
Defense Technical Information Archive
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Modern air vehicles face increasing internal heat loads that must be appropriately understood in design and managed in operation. This paper examines one solution to creating more efficient and effective thermal management systems (TMSs): vapor cycle systems (VCSs). VCSs are increasingly being investigated by aerospace government and industry as a means to provide much greater efficiency in moving thermal energy from one physical location to another. In this work, we develop the Air Force...
Topics: DTIC Archive, ILLINOIS UNIV AT URBANA-CHAMPAIGN, *COOLING AND VENTILATING EQUIPMENT, AIRCRAFT,...
This paper describes an algorithm for detecting the occurrence of events, which signify discontinuities in the first derivative of the state variables, while simulating a set of non-smooth differential equations. Such combined-discrete continuous systems arise in many contexts and are often referred to as hybrid systems, switched systems, or non-smooth systems. In all cases the state events are triggered at simulated times which generate states corresponding to the zeros of some algebraic event...
Topics: DTIC Archive, NAVAL ACADEMY ANNAPOLIS MD, *COMPUTERIZED SIMULATION, *HYBRID SYSTEMS, ALGORITHMS,...
Defense Technical Information Archive
by Defense Technical Information Center
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The goal of this project is to enhance the flexibility and computational efficiency of the ESME Workbench and to work with NUWC-Newport to merge the NEMO and ESME approaches into the One Navy Model. The One Navy Model is intended to serve as the standard simulation system for use in predicting impacts of anthropogenic sound sources on marine life for environmental compliance purposes. Two versions of the One Navy Model will be created. The first version will designed for use by the US Navy and...
Topics: DTIC Archive, BOSTON UNIV BIOMEDICAL ENGINEERING, *OCEAN MODELS, ALGORITHMS, MARINE BIOLOGY,...
A frequency sub-band based adaptive spectral subtraction algorithm is developed to remove noise from noise-corrupted speech signals. A single microphone is used to obtain both the noise-corrupted speech and the estimate of the statistics of the noise. The statistics of the noise are estimated during time frames that do not contain speech. These statistics are used to determine if future time frames contain speech. During speech time frames, the algorithm determines which frequency sub-bands...
Topics: NASA Technical Reports Server (NTRS), NOISE REDUCTION, SIGNAL PROCESSING, COMPUTERIZED SIMULATION,...
NASA Network Resource and Training Site
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Being "lost" is an exemplar of imperfect Situation Awareness/Situation Understanding (SA/SU) -- information/knowledge that is uncertain, incomplete, and/or just wrong. Being "lost" may be a geo-spatial condition - not knowing/being wrong about where to go or how to get there. More broadly, being "lost" can serve as a metaphor for uncertainty and/or inaccuracy - not knowing/being wrong about how one fits into a larger world view, what one wants to do, or how to do...
Topics: NASA Technical Reports Server (NTRS), SITUATIONAL AWARENESS, COMPUTERIZED SIMULATION, VIRTUAL...
Defense Technical Information Archive
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This study was part of an ongoing effort to evaluate plans for increasing air traffic capacity in the Dallas/Fort Worth (D/FW) area. The objective was to evaluate the traffic handling ability of controllers during Instrument Meteorological Conditions (IMC) for D/FW's proposed quadruple parallel approach airport configuration using a real-time air traffic control (ATC) simulation. Both dual and quadruple simultaneous parallel Instrument Landing System (ILS) approaches were simulated with...
Topics: DTIC Archive, Fischer, T, CTA INC MCLEAN VA, *AIR TRAFFIC CONTROL SYSTEMS, AIRPORTS, COMPUTERIZED...
The Applied Meteorology Unit (AMU) evaluated the Regional Atmospheric Modeling System (RAMS) contained within the Eastern Range Dispersion Assessment System (ERDAS). ERDAS provides emergency response guidance for Cape Canaveral Air Force Station and Kennedy Space Center operations in the event of an accidental hazardous material release or aborted vehicle launch. The RAMS prognostic data are available to ERDAS for display and are used to initialize the 45th Space Wing/Range Safety dispersion...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC MODELS, WEATHER FORECASTING, COMPUTERIZED...
Defense Technical Information Archive
by Defense Technical Information Center
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SMITE sought to develop a wargame to assist the examination of the applicability of new technology and TTPs and secondarily provide a modifiable tool useful for training, educating and assisting American and allied planners committed to COIN/CT & AT/FP efforts (hereafter referred to simply as COIN). SMITE assessed various hypotheses on how to measure progress in COIN operations; incorporating the most influential measures into planning support tools in new ways based on new ideas and...
Topics: DTIC Archive, AIR FORCE RESEARCH LAB ROME NY INFORMATION DIRECTORATE, *WAR GAMES, PEACEKEEPING,...
The products of this contractual effort have been a computerized M712 155mm Projectile (Copperhead) program Independent Cost Estimate (ICE) model (delivered separately), an operating personal computer system and an in-house capability to develop and use this and similar cost estimating models. This model was constructed using the contractor's computer which was not the same as the one later purchased for the Army. There was, however, considerable compatibility between the two so that updating...
Topics: DTIC Archive, DYNATREND INC WOBURN MA, *COST ESTIMATES, *COST MODELS, *ROCKET ASSISTED PROJECTILES,...
In prior work (Yoginath and Perumalla, 2011; Yoginath, Perumalla and Henz, 2012), the motivation challenges and issues were articulated in favor of virtual time ordering of Virtual Machines (VMs) in network simulations hosted on multi-core machines. Two major components in the overall virtualization challenge are (1) virtual timeline establishment and scheduling of VMs, and (2) virtualization of inter-VM communication. Here, we extend prior work by presenting scaling results for the first...
Topics: DTIC Archive, OAK RIDGE NATIONAL LAB TN, *COMPUTER NETWORKS, *COMPUTERIZED SIMULATION, *VIRTUAL...
Defense Technical Information Archive
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Simulation flocking has been introduced as a method for generating simulation input from multivariate dependent time series for sensitivity and risk analysis. It can be applied to data for which a parametric model is not readily available or imposes too many restrictions on the possible inputs. This method uses techniques from agent-based modeling to generate a flock of boids that follow the data. In this paper, we apply simulation flocking to a border crossing scenario to determine if...
Topics: DTIC Archive, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *COMPUTERIZED SIMULATION, ALGORITHMS, INPUT,...
Defense Technical Information Archive
by Defense Technical Information Center
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This note discusses a microcomputer-based software package that contains a collection of generalized computer programs assembled to enable the user to perform complete longshore sediment transport processes and shoreline evolution assessments. This software package was developed at the Coastal Engineering Research Center (CERC) to facilitate the technology transfer of recently developed coastal engineering tools throughout the Corps.
Topics: DTIC Archive, COASTAL ENGINEERING RESEARCH CENTER VICKSBURG MS, *SEDIMENT TRANSPORT, *SOFTWARE...
Defense Technical Information Archive
by Defense Technical Information Center
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Increased emphasis on simulation-based acquisition and network-centric warfare within the objective force has posed key challenges within the embedded ground vehicle community. While simulation-based acquisition enables a faster time to field through increased concurrency, tighter decision cycles, more efficient and effective testing; the ultimate goal of rapidly transitioning outputs from the simulation phase of a program to the vehicle design and integration phase is minimally met in today's...
Topics: DTIC Archive, DCS CORP ALEXANDRIA VA, *COMBAT VEHICLES, *COMPUTERIZED SIMULATION, HIGH LEVEL...
Defense Technical Information Archive
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In 1992 we began the development of a ground vehicle simulation software architecture that was specifically designed for evolvability. This architecture along with its supporting development processes and standards was reused throughout the 1990's on a variety of Army programs. We have now taken this software architecture, which was designed for stationary simulation in crewstations in a laboratory environment and reused it to add embedded simulation capabilities to fielded ground vehicles. The...
Topics: DTIC Archive, WASHINGTON UNIV BOTHELL, *COMPUTERIZED SIMULATION, *SOFTWARE ENGINEERING, LESSONS...
Defense Technical Information Archive
by Defense Technical Information Center
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We present a review of our study of interactions of plasma particles (atoms, molecules) with hydrogenated amorphous carbon surfaces typical of plasma-facing divertor tiles and deposited layers in magnetic-fusion reactors. Our computer simulations of these processes are based on classical molecular dynamics simulations, using the best currently available multibody bond-order hydrocarbon potentials. Our research in this field has been focused on the chemical sputtering of carbon surfaces at low...
Topics: DTIC Archive, CLEMSON UNIV SC, *MOLECULAR DYNAMICS, REPRINTS, ATOMS, CARBON, EROSION, PARTICLES,...
The focal point of this thesis is the overall process of diffusion and adoption of technological innovations (computer-supported training simulations) within the military domain. The goal was to capture the positive and negative trends that appear to be the most significant toward the adoption process. The approach selected in this thesis was to execute a user study and collect a set of data points concerned with the users overall demographics, attitudes, expectations, knowledge,...
Topics: DTIC Archive, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *COMPUTERIZED SIMULATION, DATA BASES,...
The Comprehensive Approach to security, including military support to civilian authorities in stabilization and reconstruction operations, is central for the improvement of defense and force planning. More and more the foresight activities support to planning are based on generation and analysis of scenarios (authors have been participated in recent EU and NATO projects like: FORESEC, ESRIF, SAFE, using ideas and tools, presented in the paper). The proposed methodological approach encompasses a...
Topics: DTIC Archive, BULGARIAN ACADEMY OF SCIENCES SOFIA, *MILITARY PLANNING, COMPUTERIZED SIMULATION,...
NASA Network Resource and Training Site
by NASA Technical Reports Server (NTRS)
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Topics on the slide include:quality, test coverage, functional criticality, exposure, criticality, and risk index.
Topics: NASA Technical Reports Server (NTRS), MODELS, RISK, COMPUTER PROGRAMS, COMPUTERIZED SIMULATION,...
Defense Technical Information Archive
by Defense Technical Information Center
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This paper presents a framework to address new data management challenges introduced by data-intensive pervasive computing environments. These challenges include a spatio-temporal variation of data and data source availability lack of a global catalog and schema and no guarantee of reconnection among peers due to the serendipitous nature of the environment. An important aspect of our solution is to treat devices as semi-autonomous peers guided in their interactions by profiles and context. The...
Topics: DTIC Archive, Perich, Filip, MARYLAND UNIV BALTIMORE, *DATA MANAGEMENT, COMPUTERIZED SIMULATION,...
Agenda: *Background *CMIST Overview -Architecture -Concept of Operations *PMESII IDE -Model Representation -Model Integration -Model Execution *Commander's IDE -Model Authoring -Model Debugging -Model Visualization *Experimental Results *Future Work *Conclusions
Topics: DTIC Archive, Melhuish, James, BAE SYSTEMS ADVANCED INFORMATION TECHNOLOGIES INC BURLINGTON MA,...
Defense Technical Information Archive
by Defense Technical Information Center
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Breast cancer will affect approximately 12.5% of the women in the United States, and currently mammographic screening is considered the best way to reduce mortality from this disease through early detection. There is much controversy concerning the most appropriate screening parameters such as starting age, the screening interval, and the stopping age. Long term multi-center clinical trials are the traditional approach to evaluating the efficacy of a medical test such as mammography, however...
Topics: DTIC Archive, Boone, John M, CALIFORNIA UNIV DAVIS, *BREAST CANCER, *MAMMOGRAPHY, COMPUTERIZED...
Defense Technical Information Archive
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Adaptive maximum likelihood sequence estimation (AMLSE) has been shown to be an effective mitigation technique for high data rate links against the deleterious effects of intersymbol interference resulting from rapidly time-varying and frequency selective fading channels. It was demonstrated that significant performance improvements can be obtained through the use of AMLSE receiver demodulation in comparison to conventional (non-delay spread specialized) receivers and even decision feedback...
Topics: DTIC Archive, Ibaraki,R, ESL INC SUNNYVALE CA, *NUCLEAR EXPLOSIONS, *COMMUNICATION SATELLITES,...
Defense Technical Information Archive
by Defense Technical Information Center
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The purpose of this document is to provide a definition for the Simulation, Test, and Evaluation Process (STEP), a description of the process and of the underlying STEP concept, and guidelines for Program Managers, Test & Evaluation Master Plan (TEMP) writers and reviewers, and other users on the application of STEP to an acquisition program.
Topics: DTIC Archive, AIR DEFENCE COMMAND OTTAWA (ONTARIO), *COMPUTER PROGRAMS, *ACQUISITION, *PLANNING...
Defense Technical Information Archive
by Defense Technical Information Center
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Topics: DTIC Archive, CONSTRUCTION ENGINEERING RESEARCH LAB (ARMY) CHAMPAIGN IL, *COMPUTER PROGRAM...
This report presents the technical objectives of OCI's activities during Phase 2, our findings and project activities, results from our activities and recommendations for further development, including plans for Phase 2.5 and Phase 3. The overall objective of this phase was to demonstrate the suitability for commercialization of the OpenDDS product for use in the simulation laboratory as middleware for the distribution of simulation data. We identified the use of a toolkit during software...
Topics: DTIC Archive, OBJECT COMPUTING INC (OCI) SAINT LOUIS MO, *MIDDLEWARE, COMPUTERIZED SIMULATION, REAL...
Defense Technical Information Archive
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This paper describes a multi-resolution, distributed design and simulation software for rapid prototyping and analysis of complex systems using a Co-simulation approach. The current focus of this work is on the modeling of the engine cooling system in the Ford Escape Hybrid SUV vehicle. In that particular vehicle the cooling system consists of three coupled subsystems: a) engine cooling; b) electronic transaxle cooling; and battery cooling. This paper discusses two aspects of this work: a) high...
Topics: DTIC Archive, COMPUTATIONAL SCIENCES LLC MADISON AL, *COOLING, COMPUTERIZED SIMULATION, ENGINES,...
A self-consistent computer code for particle simulations which could treat both Landau and cyclotron interactions is discussed.
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, ELECTRIC FIELDS, PARTICLE...
Defense Technical Information Archive
by Defense Technical Information Center
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The focus of critical U.S. programs on Homeland Security and Homeland Defense applications, and on the brown water navies of potential adversaries elicits a need for understanding and visualizing the near-shore land and maritime environments. The goal of this project is to develop a windows application that will provide a near real-time visual depiction of wave, wind, or other environmental elements' impact on the littoral environment that can be used as an aid to decision makers in their...
Topics: DTIC Archive, SONALYSTS INC WATERFORD CT, *COMPUTERIZED SIMULATION, *LITTORAL ZONES, COMPUTER...
The United States Army and the United States Marine Corps currently use Combat XXI as their premier computer simulation for estimating the effects of the introduction of changes to unit composition and equipment on the battlefield. It is a time consuming model to produce and run, in that it represents very detailed and intricate interactions. Another similar, but less detailed computer simulation is the Dynamic Allocation of Fires and Sensors (DAFS). Instead of modeling the explicit...
Topics: DTIC Archive, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *ALLOCATIONS, *COMPUTERIZED SIMULATION,...
The scientific and technical objectives of our research in this project include: * Directly capture the generation and evolution of Langmuir cells in simulations; quantify the statistics of Langmuir turbulence. * Investigate the onset of wave breaking; quantify wave breaking intensity and model the resultant injection of turbulence to upper-ocean; study wave breaking effect on Langmuir cells. * Develop physics based wind force modeling for oceanic flows; investigate the impact of spatial and...
Topics: DTIC Archive, MINNESOTA UNIV MINNEAPOLIS DEPT OF MECHANICAL ENGINEERING, *OCEAN WAVES, COMPUTERIZED...
Defense Technical Information Archive
by Defense Technical Information Center
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The long-term goal of this research is to develop an efficient, robust hydrodynamic model that is capable of three-dimensional (3D), prognostic baroclinic simulations on a parallel computing platform. Our approach is to modify an existing model ADCIRC (ADvanced 3D CIRCulation model [1]), which is the product of over 20 years of research and development by scientists and engineers at six different institutions. Among other military and civilian applications, ADCIRC is currently one of a suite of...
Topics: DTIC Archive, OKLAHOMA UNIV NORMAN, *OCEAN MODELS, COMPUTERIZED SIMULATION, HYDRODYNAMICS, NAVAL...
NASA Network Resource and Training Site
by NASA Technical Reports Server (NTRS)
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The Coastal Center and the NASA Biomedical Team are working together to adapt a suspension device that simulates weightlessness. Attempts to approximate weightlessness have led astronauts underwater and into harnesses that suspend all or part of their weight. One such device, built at Langley Research Center, is being transferred to rehabilitation work. It can help a person walk and re-learn muscular coordination following a stroke. Hospitals could use it to lift handicapped persons.
Topics: NASA Technical Reports Server (NTRS), GRAVITATION, COMPUTERIZED SIMULATION, MECHANICAL DEVICES,...
A catalog is presented of subsystem and environment math models used or planned for space shuttle simulations. The purpose is to facilitate sharing of similar math models between shuttle simulations. It provides information on mach model requirements, formulations, schedules, and contact persons for further information.
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, MATHEMATICAL MODELS, SPACE SHUTTLES,...
The computerized design, methods for generation, simulation of meshing, and enhanced stress analysis of modified involute helical gears is presented. The approaches proposed for modification of conventional involute helical gears are based on conjugation of double-crowned pinion with a conventional helical involute gear. Double-crowning of the pinion means deviation of cross-profile from an involute one and deviation in longitudinal direction from a helicoid surface. Using the method developed,...
Topics: NASA Technical Reports Server (NTRS), COMPUTER AIDED DESIGN, GEARS, STRESS ANALYSIS, COMPUTERIZED...
Defense Technical Information Archive
by Defense Technical Information Center
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This is the final report for the activities conducted at the University of Maryland during participation in the Collaborative Center in Multidisciplinary Sciences (CCMS) project. In this work, the investigators have primarily explored the suitability of computational tools to predict desirable micro-air-vehicle (MAV) designs. The use of computationally expensive high-fidelity tools such as direct numerical simulation is compared to that of moderate fidelity tools, such as the inexpensive...
Topics: DTIC Archive, MARYLAND UNIV COLLEGE PARK, *DRONES, AIRCRAFT DESIGN, COMPUTERIZED SIMULATION
Flight simulators can be designed to train pilots or assess their flight performance. Low-Fidelity simulators maximize the initial learning rate of novice pilots and minimize initial costs; whereas, expensive, high-fidelity simulators predict the realworld in-flight performance of expert pilots (Fink & Shriver, 1978 Hays & Singer 1989; Kinkade & Wheaton. 1972). Although intuitively appealing and intellectually convenient to generalize concepts of learning and assessment, what holds...
Topics: NASA Technical Reports Server (NTRS), FLIGHT SIMULATORS, EDUCATION, AERONAUTICS, COMPUTERIZED...
Defense Technical Information Archive
by Defense Technical Information Center
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This paper highlights some of the key human factors issues that we found in OneSAF, and how we chose to remedy them in our own system design. The goal is to provide guidelines for application human interface design standards so that future tools developed for the Department of Defense allow the operator to perform more effectively.
Topics: DTIC Archive, Rowe, Steve, CYBERNET SYSTEMS CORP ANN ARBOR MI, *MAN COMPUTER INTERFACE,...
NASA Network Resource and Training Site
by NASA Technical Reports Server (NTRS)
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In 1984, researchers from Ames Research Center came together to develop advanced human interfaces for NASA s teleoperations that would come to be known as "virtual reality." The basis of the work theorized that if the sensory interfaces met a certain threshold and sufficiently supported each other, then the operator would feel present in the remote/synthetic environment, rather than present in their physical location. Twenty years later, this prolific research continues to pay...
Topics: NASA Technical Reports Server (NTRS), HEARING, TELEOPERATORS, COMPUTERIZED SIMULATION, VIRTUAL...
Defense Technical Information Archive
by Defense Technical Information Center
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One of the primary results of this study is that wave group statistics observed in the ocean at depths greater than 10 m for a large range of wave conditions are consistent with linear theory. Wave group prediction models that do not include the effect of correlations between waves separated by several intervening waves underpredict the number of sequential large waves. On the other hand, a model that includes correlations of waves separated by as many as six intervening waves predicts...
Topics: DTIC Archive, Elgar, Steve, WASHINGTON STATE UNIV PULLMAN, *OCEAN SURFACE, MATHEMATICAL MODELS,...
Fundamental research was performed in support of the development of a new generation of wave prediction capability, which is call SNOW (simulation of nonlinear ocean wavefield), for the evolution of large-scale realistic ocean surface and internal wavefields using direct phase-resolved simulations. Large-scale phase-resolved SNOW simulations of nonlinear wavefield evolutions are obtained and used to quantify and understand nonlinear ocean wave statistics and rogue wave kinematics/dynamics and...
Topics: DTIC Archive, MASSACHUSETTS INST OF TECH CAMBRIDGE, *OCEAN WAVES, COMPUTERIZED SIMULATION, OCEAN...
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Simulations with the TRAK ray-tracing code have shown that grid-focused diodes might be a simple alternative to gas/plasma cell focusing for moderate-energy radiography machines. Multi-grid focusing has advantages over single grid focusing, especially in circumventing neutralization from gases evolved from the heated target. The practical technology for grid focusing was established many years ago in an extensive series of experiments.
Topics: DTIC Archive, LOS ALAMOS NATIONAL LAB NM, *ELECTRON BEAMS, *RADIOGRAPHY, COMPUTERIZED SIMULATION,...
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Half-symmetric model is used in AutoDyn to simulate Depth of Penetration (DoP) experiments on SiC tile with and without a gap supported by solid aluminum. Impacts of a .30cal AP M2 projectile over an impact velocity range 700 m/s to 1000 m/s are modeled using SPH elements. Model validation runs with monolithic SiC tiles are conducted based on the DoP experiments described in reference - ARL-TR-2219, 2000. Tile gap is found to increase the DoP as compared to monolithic tiles. The next step will...
Topics: DTIC Archive, DELAWARE UNIV NEWARK, *ARMOR, ALUMINUM, CERAMIC MATERIALS, COMPUTERIZED SIMULATION,...
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Aside the capital investment and without the ability to otherwise simulate, motion capture is the preferred method by which to model human movements in a digital environment. However, these capture sessions are almost universally conducted in stationary environments. While this may be adequate for modeling many industrial applications of digital modeling, many other jobs require operators to perform tasks while being exposed to a moving environment (e.g. postal drivers, flight attendants, and...
Topics: DTIC Archive, MICHIGAN UNIV ANN ARBOR, *COMPUTERIZED SIMULATION, *HUMANS, *MOTION, KINEMATICS,...
To determine how dilution of microbial communities affects the diversity of the diluted assemblage a series of numerical simulations were conducted that determined the theoretical change in diversity, richness, and evenness of the community with serial dilution. The results of the simulation suggested that the effects are non linear with a high degree of dependence on the initial evenness of the community being diluted. A series of incubation experiments using a range of dilutions of raw sewage...
Topics: NASA Technical Reports Server (NTRS), DILUTION, MICROORGANISMS, COMPUTERIZED SIMULATION,...
TRACOR has been assigned the task of performing computer evaluations of transducer element design submittals for the C/P Array Program as directed by the NEL Transducer Division. This report contains the results of the first iteration of the Iterative Design Activity teams from the various participating vendors. Certain properties for each of the transducer element designs are presented in graphical form using identical format and scaling for ease of comparison and evaluation of the various...
Topics: DTIC Archive, TRACOR INC AUSTIN TX, *SONAR TRANSDUCERS, *ELECTROACOUSTIC TRANSDUCERS, PLANAR...
Long-term Goals: The overarching goals of this project are to understand the role of sea ice-albedo feedback on sea ice predictability, to improve how sea ice-albedo is modeled and how sea ice predictions are initialized, and then to evaluate how these improvements influence inherent sea ice predictability. Objectives: The sources of errors in a model forecast are from initial conditions and the model itself. Both can be evaluated with observations and potentially improved. We will use...
Topics: DTIC Archive, WASHINGTON UNIV SEATTLE DEPT OF ATMOSPHERIC SCIENCES, *SEA ICE, ALBEDO, COMPUTERIZED...
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This document summarizes the activities of the Goddard Earth Sciences and Technology Center (GEST), a consortium of scientists and engineers led by the University of Maryland, Baltimore County (UMBC), during the contract reporting period. Topics covered include: new programs, eligibility and selection criteria, Goddard Coastal Research Graduate Fellowship Program and staffing changes.
Topics: NASA Technical Reports Server (NTRS), STUDENTS, EDUCATION, UNIVERSITIES, EARTH SCIENCES,...
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This paper describes the Persistent Simulation Environment (PSE), which combines object-oriented simulation with a persistent object repository and domain-dependent object prefetching facilities. The goals of PSE are threefold: (1) to augment a contemporary object-oriented programming language with discrete event and process-based simulation facilities equaling those found in simulation languages such as Simscript and Simula; (2) to tightly couple an object-oriented simulation language with a...
Topics: DTIC Archive, RAND NATIONAL DEFENSE RESEARCH INST SANTA MONICA CA, *COMPUTERIZED SIMULATION,...
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"Elizabeth," a computerized beauty analysis system marketed by Elizabeth Arden, is based upon an ARAC data base search of technologies measuring skin profiles. * "Elizabeth" is no longer commercially available.
Topics: NASA Technical Reports Server (NTRS), COMPUTER TECHNIQUES, DIAGNOSIS, SKIN (ANATOMY), DATA BASES,...
Land surface models (LSMs) play a critical role in the simulation of climate, for they determine the character of a large fraction of the atmosphere's lower boundary. The LSM partitions the net radiative energy at the land surface into sensible heat, latent heat, and energy storage, and it partitions incident precipitation water into evaporation, runoff, and water storage. Numerous modeling experiments and the existing (though very scant) observational evidence suggest that variations in these...
Topics: NASA Technical Reports Server (NTRS), PARAMETERIZATION, COMPUTERIZED SIMULATION, DRAINAGE,...
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This report summarizes the work and results achieved under SERDP project MM-1514 entitled, Active Tensor Magnetic Gradiometer System. The objective of the project was to prove the concept of an active tensor magnetic gradiometer system (ATMGS) using physics-based models and systems-based real-world simulations. Positive outcomes of this feasibility study were identified as: (1) a conceptual design at a functional system block diagram level, containing specific engineering design and operational...
Topics: DTIC Archive, GEOLOGICAL SURVEY RESTON VA, *ALGORITHMS, *GRADIOMETERS, *TENSORS, COMPUTERIZED...
In 2013, Naval Air Systems Command (NAVAIR) at the Naval Air Station, Patuxent River, Maryland initiated a research task (RT-48) to assess the technical feasibility of creating/leveraging a more holistic Model-Based Systems Engineering (MBSE) approach to support Mission-based Analysis and Engineering in order to achieve a 25% reduction in development time from that of the traditional large-scale weapon systems. The research need included the evaluation of emerging system design through computer...
Topics: DTIC Archive, SYSTEMS ENGINEERING RESEARCH CENTER HOBOKEN NJ, *SYSTEMS ENGINEERING, COMPUTERIZED...
During the investigation we have finalized the event studies that are necessary for the development of the magnetopause model and for the calibration of our simulation code.
Topics: NASA Technical Reports Server (NTRS), MAGNETOPAUSE, COMPUTERIZED SIMULATION, MODELS, CALIBRATING,...
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This is a report of my activities as a NASA Fellow during the summer of 2003 at the NASA Kennedy Space Center (KSC). The core of these activities is the assigned project: the Virtual Test Bed (VTB) from the Spaceport Engineering and Technology Directorate. The VTB Project has its foundations in the NASA Ames Research Center (ARC) Intelligent Launch & Range Operations program (ILRO). The objective of the VTB project is to develop a unique collaborative computing environment where simulation...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, SYSTEMS SIMULATION, LAUNCHING BASES,...
This report describes the method of developing an E-Prime computer simulation of an interactive Human Rights Violation (HRV) negotiation. An HRV negotiation script was originally developed under the PWGSC Contract No. W7711-007893/001/TOR Callup No. 7893-12. The HRV negotiation script was designed based on a training scenario developed by the Canadian Forces (CF) for use at the Peace Support Training Centre (PSTC) at Canadian Forces Base (CFB) Kingston. The computer simulation developed in this...
Topics: DTIC Archive, HUMANSYSTEMS INC GUELPH (ONTARIO), *COMPUTERIZED SIMULATION, CANADA, NEGOTIATIONS,...
Defense Technical Information Archive
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The DOD is becoming critically dependent on combat models (including simulations and war games)-even more dependent than in the past. There is considerable activity to improve model interoperability and capabilities for distributed war gaming. In contrast to this interest in model-related technology, there has been far too little interest in the substance of the models and the validity of the lessons learned from using them. In our view, the DOD does not appreciate that in many cases the models...
Topics: DTIC Archive, Davis, Paul K, DEFENSE ADVANCED RESEARCH PROJECTS AGENCY ARLINGTON VA, *COMPUTERIZED...
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This thesis has dealt with various approaches to modelling 2-D data fields using state-space formulations. Computer simulation of these models has been carried out to generate simulated 2-D data which could then be used for various other signal processing operations. An interesting development that has resulted from this study is that of adaptation of the 1-D SSPACK software package for simulating 2-D linear systems as well as using one of the above state-variable models. (Author)
Topics: DTIC Archive, Theofilou,Evangelos, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *SIGNAL PROCESSING,...
Human behavioral models are computer programs that emulate humans performing tasks and executing missions. Human cognitive models are behavioral models with a focus on cognitive tasks involving planning, problem solving, and learning among other things. A quarter century of research in Artificial Intelligence, Cognitive Science, Computer Human Interaction, and Computer Simulation has generated a rich collection of competing theories and tools for developing cognitive models. While the field of...
Topics: DTIC Archive, ARMY TANK AUTOMOTIVE RESEARCH DEVELOPMENT AND ENGINEERING CENTER WARREN MI,...
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An aerodynamic bicycle wheel developed by two DuPont engineers and a California company incorporates research into NASA airfoils. Computer modeling was accomplished with MSC/NASTRAN. Each of the three spokes in the wheel is, in effect, an airfoil, maximizing aerodynamic efficiency for racing.
Topics: NASA Technical Reports Server (NTRS), WHEELS, AERODYNAMIC CHARACTERISTICS, RECREATION, COMPUTER...
The long-term goals are to provide accurate and detailed predictions of nearshore hydrodynamics and bathymetric evolution using an advanced process-based model (Delft3D). Observations of dense remotely sensed and sparse in situ data will be assimilated to continuously improve model performance, and where the data are uncertain or absent, the model will be used to fill in the gaps and construct a more complete estimate of current or near-future conditions. The objectives of the proposed study...
Topics: DTIC Archive, DELFT UNIV OF TECHNOLOGY (NETHERLANDS), *INSHORE AREAS, *BATHYMETRY, *HYDRODYNAMICS,...
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Wicab, Inc. has developed novel technology which allows information from external devices to be sensed by humans via neuro-stimulation of the tongue. This report summarizes a multi-year effort to empirically measure the electro-stimulation properties of the tongue, including spatial and temporal discrimination, contrast sensitivity, and stimulation optimization approaches.
Topics: DTIC Archive, WICAB INC MIDDLETON WI, *VESTIBULAR APPARATUS, INTERFACES, TONGUE, NEUROMUSCULAR...
The Kennedy Space Center (KSC) Electrostatics and Surface Physics Laboratory is participating in an Innovative Partnership Program (IPP) project with an industry partner to modify a commercial off-the-shelf simulation software product to treat the electrodynamics of particulate systems. Discrete element modeling (DEM) is a numerical technique that can track the dynamics of particle systems. This technique, which was introduced in 1979 for analysis of rock mechanics, was recently refined to...
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, ELECTROSTATICS, CHARGED PARTICLES,...
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This technical note provides step-by-step instructions for using a computerized tutorial to help set up, execute, and calibrate the Wetland Water Budget Model, and to help manipulate the model's output using a post-processing program.
Topics: DTIC Archive, ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS, *ECONOMIC ANALYSIS,...
This report documents a case study at East Pass, Florida, to assess the concepts and performance of the Diagnostic Modeling System (DMS), which is presently under development. The DMS is intended to give the capability to identify, categorize, and evaluate navigation channel sediment-deposition hot spots, from which the system can be applied to identify corrective actions and perform the appropriate analysis. The level of corrective measures are expected to be within existing project...
Topics: DTIC Archive, Gosselin, Mark S., TAYLOR ENGINEERING JACKSONVILLE FL, *DREDGING, COMPUTERIZED...
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Previous studies have shown that satellite servicing is cost effective; however, all of these studies were of different formats, dollar year, learning rates, availability, etc. Threfore, it was difficult to correlate any useful trends from these studies. The reviewed study was initiated to correlate the economic data into a common data base, using a common set of assumptions. A selected set of existed funded programs was then analyzed to provide an independent analysis of the servicing options...
Topics: NASA Technical Reports Server (NTRS), DATA BASES, ECONOMICS, SPACECRAFT MAINTENANCE, COMPUTERIZED...
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The present article describes research in progress which is developing a simple, replicable methodology aimed at identifying the regularities and specificity of human behavior in conflict escalation and de-escalation processes. These research efforts will ultimately be used to study conflict dynamics across cultures. The experimental data collected through this methodology, together with case-studies, and aggregated, time-series macro data are key for identifying relevant parameters, systems'...
Topics: DTIC Archive, WARSAW UNIV POLAND, *PREDICTIONS, *CONFLICT, *CROSS CULTURE(SOCIOLOGY), BEHAVIORAL...
The Short-Term Aggregate Inventory Projection Model (SAM) is one component of the Enlisted Force Management System (EFMS). SAM makes monthly projections (for the rest of the current fiscal year) of the aggregate force (the total enlisted force across all specialties). SAM can be used to analyze the total size, grade composition, and budget cost of the enlisted force during a fiscal year. It supports planning of management actions to achieve user- specified end-of-year force levels (known as end...
Topics: DTIC Archive, Brauner, Marygail K, RAND CORP SANTA MONICA CA, *MODELS, *ENLISTED PERSONNEL,...
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The Common Simulation Framework (CSF) facilitates live, virtual, and constructive (LVC) simulation of a complete missile deployment system. It includes some support for real-time operation but not enough to allow hardware-in-the-loop (HWIL) testing. This project added realtime monitoring capabilities to CSF and demonstrated its use for a HWIL simulation. The demonstration involved driving a motion simulator table at the Redstone Technical Test Center in Huntsville, AL. The project successfully...
Topics: DTIC Archive, OHIO SUPERCOMPUTER CENTER COLUMBUS, *SOFTWARE ENGINEERING, MONITORING, SYMPOSIA,...
Its time: a) To bring planetary scientists, deflection system investigators and vehicle designers together on the characterization/mitigation problem. b) To develop a comprehensive trade space of options. c) To trade options under a common set of assumptions and see what comparisons on effectiveness can be made. d) To explore the synergy that can be had with proposed scientific and exploration architectures while interest in NEO's are at an all time high.
Topics: NASA Technical Reports Server (NTRS), DESIGN ANALYSIS, COMPUTERIZED SIMULATION, IDENTIFYING,...
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This briefing presents the idea that to boost our success in war, we should think about starting our strategy and modeling and simulation (M&S) at the end of the war rather than at the beginning. What is a desirable outcome? Wars take place in systems that must change appropriately. How do you want the systems to change? By starting at the end, the M&S community can help policy makers make smart war decisions.
Topics: DTIC Archive, VENTURIST INC MONTGOMERY AL, *WAR GAMES, *COMPUTERIZED SIMULATION, TIME, GOAL...
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To better equip the groundwater community with accessible, useable, and practical models for evaluating matrix diffusion effects, the Environmental Security Technology Certification Program (ESTCP) of the U.S. Department of Defense (DoD) has funded the development of this Matrix Diffusion Toolkit. Based on the Microsoft Excel(registered trademark) platform, the Toolkit is an easy-to-use, comprehensive, free software tool that can assist site personnel to effectively and efficiently estimate...
Topics: DTIC Archive, GSI ENVIRONMENTAL INC HOUSTON TX, *GROUND WATER, COMPUTERIZED SIMULATION,...
This slide presentation reviews the internship assignment of the author and his work on the GFSSP among other assignments.
Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, FLUID FLOW, COMPUTER PROGRAMS,...
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The GENEralized model for SImulating Shoreline change (GENESIS) is a system of numerical models developed to aid in the evaluation of shore protection design alternatives. These evaluations are accomplished through simulation of the nearshore wave climate and long-term shoreline change.
Topics: DTIC Archive, COASTAL ENGINEERING RESEARCH CENTER VICKSBURG MS, *COMPUTERIZED SIMULATION, *SHORES,...
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Topics: DTIC Archive, CONSTRUCTION ENGINEERING RESEARCH LAB (ARMY) CHAMPAIGN IL, *COMPUTER PROGRAM...
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A theoretical study and computer analysis of the cathode spot of a unipolar arc was conducted. The underlying theories of plasma physics, space charge effects, and electron emission needed for an understanding of cathode phenomena are presented. Two models of unipolar arcing are reviewed and an analysis of the cathode spot is begun. A stationary model of the cathode spot is formulated with a system of equations that is not closed. A method of solution. using the Steenbeck Minimum Principle, is...
Topics: DTIC Archive, Curtiss, Dwayne H, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *CATHODES, *ELECTRIC ARCS,...
The authors use the method of probability weighted moments to derive estimators of the parameters and quantiles of the generalized extreme-value distribution. They investigate the properties of these estimators in large samples, via asymptotic theory, and in small and moderate samples, via computer simulation. Probability weighted moment estimators have low variance and no severe bias, and compare favourably with estimators obtained by the methods of maximum likelihood or sextiles. The method...
Topics: DTIC Archive, Hosking,J R M, WISCONSIN UNIV-MADISON MATHEMATICS RESEARCH CENTER, *Numerical methods...
Throughout its rich history, NASA has invested heavily in sophisticated simulation capabilities. These capabilities reside in NASA facilities across the country - and with partners around the world. NASA s Exploration Systems Mission Directorate (ESMD) has the opportunity to leverage these considerable investments to resolve technical questions relating to its missions. The distributed nature of the assets, both in terms of geography and organization, present challenges to their combined and...
Topics: NASA Technical Reports Server (NTRS), SPACE EXPLORATION, SYSTEMS SIMULATION, GEOGRAPHY,...
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In order to clarify the control mechanism of a stomatognathic system, we developed a two-dimensional dynamic jaw model capable of performing an unloaded open-close movement. To simulate an open-close movement, we created a position feedback control scheme by providing a desired movement. Our numerical results verified that the proposed model could be applied to mandibular movement control analysis.
Topics: DTIC Archive, Itoh, Ken-ichi, NIIGATA UNIV (JAPAN) FACULTY OF ENGINEERING, *COMPUTERIZED...
Over three million Americans and 20 million people worldwide suffer from some form of heart failure. Mechanical heart assist devices are being used as a temporary support to sick ventricle and valves as a bridge-to-transplant or bridge-to-recovery. This viewgraph presentation gives an overview of the development of NASA-DeBakey Ventricular Assist Device (VAD) using numerical aerospace simulation technology.
Topics: NASA Technical Reports Server (NTRS), HEART, MECHANICAL DEVICES, COMPUTERIZED SIMULATION,...