298 research outputs found

    Biomechanics of the Upper Extremity in Response to Dynamic Impact Loading Indicative of a Forward Fall: An Experimental and Numerical Investigation.

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    The distal radius is one of the most common fracture sites in humans, often resulting from a forward fall with more than 60 % of all fractures to the wrist requiring some form of surgical intervention. Although there is a general consensus regarding the risk factors for distal radius fractures resulting from forward falling, prevention of these injuries requires a more thorough understanding of the injury mechanisms. Therefore the overall purpose of this dissertation was to assess the response of the upper extremity to impact loading to improve the understanding of distal radius fracture mechanisms and the effectiveness of joint kinematic strategies for reducing the impact effects. Three main studies were conducted that utilized in vivo, in vitro and numerical techniques. In vitro impact testing of the distal radius revealed that fracture will occur at a mean (SD) resultant impact force and velocity of 2142.1(1228.7) N and 3.4 (0.7) m/s, respectively. Based on the failure data, multi-variate injury criteria models were produced, highlighting the dynamic and multidirectional nature of distal radius fractures The in vitro investigation was also used to develop and validate a finite element model of the distal radius. Dynamic impacts were simulated in LS-DYNA and the resulting z-axis force validation metrics (0.23-0.54) suggest that this is a valid model. A comparison of the experimental fracture patterns to those predicted numerically (i.e. von-Mises stress criteria) shows the finite element model is capable of accurately predicting bone failure

    DRONE DELIVERY OF CBNRECy – DEW WEAPONS Emerging Threats of Mini-Weapons of Mass Destruction and Disruption (WMDD)

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    Drone Delivery of CBNRECy – DEW Weapons: Emerging Threats of Mini-Weapons of Mass Destruction and Disruption (WMDD) is our sixth textbook in a series covering the world of UASs and UUVs. Our textbook takes on a whole new purview for UAS / CUAS/ UUV (drones) – how they can be used to deploy Weapons of Mass Destruction and Deception against CBRNE and civilian targets of opportunity. We are concerned with the future use of these inexpensive devices and their availability to maleficent actors. Our work suggests that UASs in air and underwater UUVs will be the future of military and civilian terrorist operations. UAS / UUVs can deliver a huge punch for a low investment and minimize human casualties.https://newprairiepress.org/ebooks/1046/thumbnail.jp

    Aeronautical Engineering: A continuing bibliography with indexes

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    This bibliography lists 512 reports, articles and other documents introduced into the NASA scientific and technical information system in April 1982

    Emergency first response to a crisis event a multi-agent simulation approach

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    Homeland Security Presidential Directive #8 led to the establishment of the National Exercise Program and the Top Officials exercise series to test and evaluate first response agency integration and effectiveness. The last TOPOFF exercise cost $16M and involved over 10,000 people, but did not effectively leverage simulation techniques to make efficient use of resources. This research adapts an existing organizational learning process, integrating low- and high resolution simulation to provide decision support. This process led to the development of a multi-agent simulation methodology for emergency first response, specifically applied to analyze a notional vehicle bomb attack during a festival in the Baltimore Inner Harbor. This simulation demonstrates the potential benefits of low resolution simulation, using efficient experimental design and high-performance computing. Combined, these two ideas result in examining a 48-dimensional response surface and using over 156 CPU centuries of computer time. All experiments were completed in less than three weeks. The analysis of this data set provided insight into several areas, including the importance of standing operating procedures in the early moments of a crisis. Analysis showed that effective procedures may even be more important than the effectiveness of communications devices early in a first response operation.http://archive.org/details/emergencyfirstre109452800Outstanding ThesisUS Army (USA) author.Approved for public release; distribution is unlimited.Approved for public release; distribution is unlimited

    Computing fast search heuristics for physics-based mobile robot motion planning

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    Mobile robots are increasingly being employed to assist responders in search and rescue missions. Robots have to navigate in dangerous areas such as collapsed buildings and hazardous sites, which can be inaccessible to humans. Tele-operating the robots can be stressing for the human operators, which are also overloaded with mission tasks and coordination overhead, so it is important to provide the robot with some degree of autonomy, to lighten up the task for the human operator and also to ensure robot safety. Moving robots around requires reasoning, including interpretation of the environment, spatial reasoning, planning of actions (motion), and execution. This is particularly challenging when the environment is unstructured, and the terrain is \textit{harsh}, i.e. not flat and cluttered with obstacles. Approaches reducing the problem to a 2D path planning problem fall short, and many of those who reason about the problem in 3D don't do it in a complete and exhaustive manner. The approach proposed in this thesis is to use rigid body simulation to obtain a more truthful model of the reality, i.e. of the interaction between the robot and the environment. Such a simulation obeys the laws of physics, takes into account the geometry of the environment, the geometry of the robot, and any dynamic constraints that may be in place. The physics-based motion planning approach by itself is also highly intractable due to the computational load required to perform state propagation combined with the exponential blowup of planning; additionally, there are more technical limitations that disallow us to use things such as state sampling or state steering, which are known to be effective in solving the problem in simpler domains. The proposed solution to this problem is to compute heuristics that can bias the search towards the goal, so as to quickly converge towards the solution. With such a model, the search space is a rich space, which can only contain states which are physically reachable by the robot, and also tells us enough information about the safety of the robot itself. The overall result is that by using this framework the robot engineer has a simpler job of encoding the \textit{domain knowledge} which now consists only of providing the robot geometric model plus any constraints

    Fifth Annual Workshop on Space Operations Applications and Research (SOAR 1991), volume 2

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    Papers given at the Space Operations and Applications Symposium, host by the NASA Johnson Space Center on July 9-11, 1991 are given. The technical areas covered included intelligent systems, automation and robotics, human factors and life sciences, and environmental interactions

    Strategic Latency Unleashed: The Role of Technology in a Revisionist Global Order and the Implications for Special Operations Forces

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    The article of record may be found at https://cgsr.llnl.govThis work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory in part under Contract W-7405-Eng-48 and in part under Contract DE-AC52-07NA27344. The views and opinions of the author expressed herein do not necessarily state or reflect those of the United States government or Lawrence Livermore National Security, LLC. ISBN-978-1-952565-07-6 LCCN-2021901137 LLNL-BOOK-818513 TID-59693This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory in part under Contract W-7405-Eng-48 and in part under Contract DE-AC52-07NA27344. The views and opinions of the author expressed herein do not necessarily state or reflect those of the United States government or Lawrence Livermore National Security, LLC. ISBN-978-1-952565-07-6 LCCN-2021901137 LLNL-BOOK-818513 TID-5969

    Air Force Institute of Technology Research Report 2018

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    This Research Report presents the FY18 research statistics and contributions of the Graduate School of Engineering and Management (EN) at AFIT. AFIT research interests and faculty expertise cover a broad spectrum of technical areas related to USAF needs, as reflected by the range of topics addressed in the faculty and student publications listed in this report. In most cases, the research work reported herein is directly sponsored by one or more USAF or DOD agencies. AFIT welcomes the opportunity to conduct research on additional topics of interest to the USAF, DOD, and other federal organizations when adequate manpower and financial resources are available and/or provided by a sponsor. In addition, AFIT provides research collaboration and technology transfer benefits to the public through Cooperative Research and Development Agreements (CRADAs). Interested individuals may discuss ideas for new research collaborations, potential CRADAs, or research proposals with individual faculty using the contact information in this document

    Organic over-the-horizon targeting for the 2025 surface fleet

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    Please note that this activity was not conducted in accordance with Federal, DOD, and Navy Human Research Protection RegulationsAdversarial advances in the proliferation of anti-access/area-denial (A2/AD) techniques requires an innovative approach to the design of a maritime system of systems capable of detecting, classifying, and engaging targets in support of organic over-the-horizon (OTH) tactical offensive operations in the 2025–2030 timeframe. Using a systems engineering approach, this study considers manned and unmanned systems in an effort to develop an organic OTH targeting capability for U.S. Navy surface force structures of the future. Key attributes of this study include overall system requirements, limitations, operating area considerations, and issues of interoperability and compatibility. Multiple alternative system architectures are considered and analyzed for feasibility. The candidate architectures include such systems as unmanned aerial vehicles (UAVs), as well as prepositioned undersea and low-observable surface sensor and communication networks. These unmanned systems are expected to operate with high levels of autonomy and should be designed to provide or enhance surface warfare OTH targeting capabilities using emerging extended-range surface-to-surface weapons. This report presents the progress and results of the SEA-21A capstone project with the recommendation that the U.S. Navy explore the use of modestly-sized, network-centric UAVs to enhance the U.S. Navy’s ability to conduct surface-based OTH tactical offensive operations by 2025.http://archive.org/details/organicovertheho1094545933Approved for public release; distribution is unlimited

    Virtual Reality Games for Motor Rehabilitation

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    This paper presents a fuzzy logic based method to track user satisfaction without the need for devices to monitor users physiological conditions. User satisfaction is the key to any product’s acceptance; computer applications and video games provide a unique opportunity to provide a tailored environment for each user to better suit their needs. We have implemented a non-adaptive fuzzy logic model of emotion, based on the emotional component of the Fuzzy Logic Adaptive Model of Emotion (FLAME) proposed by El-Nasr, to estimate player emotion in UnrealTournament 2004. In this paper we describe the implementation of this system and present the results of one of several play tests. Our research contradicts the current literature that suggests physiological measurements are needed. We show that it is possible to use a software only method to estimate user emotion
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