67,173 research outputs found

    An overview of the program to place advanced automation and robotics on the Space Station

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    The preliminary design phase of the Space Station has uncovered a large number of potential uses of automation and robotics, most of which deal with the assembly and operation of the Station. If NASA were to vigorously push automation and robotics concepts in the design, the Station crew would probably be free to spend a substantial portion of time on payload activities. However, at this point NASA has taken a conservative attitude toward automation and robotics. For example, the belief is that robotics should evolve through telerobotics and that uses of artificial intelligence should be initially used in an advisory capacity. This conservativeness is in part due to the new and untested nature of automation and robotics; but, it is also due to emphases plased on designing the Station to the so-called upfront cost without thoroughly understanding the life cycle cost. Presumably automation and robotics has a tendency to increase the initial cost of the Space Station but could substantially reduce the life cycle cost. To insure that NASA will include some form of robotic capability, Congress directed to set aside funding. While this stimulates the development of robotics, it does not necessarily stimulate uses of artificial intelligence. However, since the initial development costs of some forms of artificial intelligence, such as expert systems, are in general lower than they are for robotics one is likely to see several expert systems being used on the Station

    Using the DNA Testing of Arrestees to Reevaluate Fourth Amendment Doctrine

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    With the advent of DNA testing, numerous issues have arisen with regard to obtaining and using evidence developed from such testing. As courts have come to regard DNA testing as a reliable method for linking some people to crimes and for exonerating others, these issues are especially significant. The federal government and most states have enacted statutes that permit or direct the testing of those convicted of at least certain crimes. Courts have almost universally approved such testing, rejecting arguments that obtaining and using such evidence violates the Fourth Amendment. More recently governments have enacted laws permitting or directing the taking of DNA samples from those arrested, but not yet convicted, for certain serious crimes. Courts had been far more divided about the constitutionality of DNA testing for arrestees than they were for the comparable testing of those already convicted of crimes. Given the division in the holdings among both state and federal courts and the increasing importance of DNA evidence in criminal investigations, it was hardly surprising that the Supreme Court agreed to hear a case regarding the constitutionality of a Maryland statute allowing for such testing. Section II of this article will provide a brief description of the science of DNA testing as it is used in the criminal justice system. Section III will discuss the Supreme Court\u27s decision in Maryland v. King. Section IV will address the argument of the opponents of the DNA testing of arrestees - that it violates the presumption of innocence. The chief focus of the article will appear in Sections V and VI, which will respond to the arguments posed by those who claim such testing violates the Fourth Amendment. Section V will address the balancing test for such searches and seizures long employed by the Supreme Court. Section VI describes and critiques the use of the primary purpose test as an important factor in determining whether the Fourth Amendment has been violated. This test looks to whether the primary purpose of the government\u27s search or seizure was something other than to ferret out ordinary criminal wrongdoing, and only in such situations excuses the absence of individualized suspicion

    Sciunits: Reusable Research Objects

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    Science is conducted collaboratively, often requiring knowledge sharing about computational experiments. When experiments include only datasets, they can be shared using Uniform Resource Identifiers (URIs) or Digital Object Identifiers (DOIs). An experiment, however, seldom includes only datasets, but more often includes software, its past execution, provenance, and associated documentation. The Research Object has recently emerged as a comprehensive and systematic method for aggregation and identification of diverse elements of computational experiments. While a necessary method, mere aggregation is not sufficient for the sharing of computational experiments. Other users must be able to easily recompute on these shared research objects. In this paper, we present the sciunit, a reusable research object in which aggregated content is recomputable. We describe a Git-like client that efficiently creates, stores, and repeats sciunits. We show through analysis that sciunits repeat computational experiments with minimal storage and processing overhead. Finally, we provide an overview of sharing and reproducible cyberinfrastructure based on sciunits gaining adoption in the domain of geosciences

    The Hardcore Scorecard: Defining, Quantifying and Understanding “Hardcore” Video Game Culture

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    ABSTRACT The goal of the current study is to further conceptualize and define the term “hardcore” as it relates to video game culture. Past research indicates that members of cultural subdivisions favor their own group versus others due to perceived commonalities (Durkheim, 1915; Tajfel, 1970). In gaming culture, the subdivisions of “hardcore” and “casual” games/gamers have become especially salient in recent years. However, the definition of what constitutes “hardcore” and “casual” is inconsistent (Adams, 2000; Alexandre, 2012; Jacobs & Ip, 2003; Juul, 2010; Kim, 2001; Kuittinen, Kultima, Niemelä & Paavilainen, 2007; Wallace & Robbins, 2006). Therefore, it is beneficial to better understand these terms considering the implications: less audience infighting, more accurately tailored game design/marketing, and less ambiguous/sensationalist gaming journalism/media. A sample of 109 undergraduate students from a large university (19,000 undergraduates) in an upstate New York city (metropolitan population of 1.1 million) completed an online survey, reporting their perceptions of hardcore gaming. Values were then attributed to certain video game criteria based on the survey results and applied to popular games. The sum of these values produced a hardcore index for the “scorecard.” To assess the scorecard’s validity, correlations were run between our final values and an independently collected hardcore percentage publicly available on the Wii’s Nintendo Channel (327,818.45 average respondents per game). Results suggest hardcore gaming is perceived as a harsh subculture consisting of long play times, challenging play, anti-social behavior, and content not suitable for children. The index produced by the resulting “hardcore scorecard” was significantly correlated (r = .765, p \u3c .01) with the independently collected data on the Nintendo Channel. Thus, the current research provides tools the gaming industry (users, developers, journalists) can use to their advantage by better understanding and defining the term “hardcore,” as well as a valuable blueprint for future research to continue refining and improving

    The Theory of Theft: An Inspection Game Model of the Stolen Base Play in Baseball

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    This paper applies the theory of equilibrium in mixed strategies in an inspection game model to describe the strategic interaction in the stolen base play in baseball. A parsimonious simultaneous-move game model offers predictions about how the observable conduct of the teams on offense and defense responds as the characteristics of the players involved change. The theory organizes observations from play-by-play data from Major League Baseball, where highly-motivated, experienced professionals interact in an environment where private information is not significant.mixed strategy, Markov equilibrium, baseball

    Vacuum Infusion Process Development for Conformal Ablative Thermal Protection System Materials

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    Conformal ablators are low density composite materials comprised of a flexible carbon felt based fibrous substrate and a high surface area phenolic matrix. These materials are fabricated to near net shape by molding the substrate, placing in a rigid matched mold and infusing with liquid resin through a vacuum assisted process. The open mold process, originally developed for older rigid substrate ablators, such as PICA, wastes a substantial amount of resin. In this work, a vacuum infusion process a type of liquid composite molding where resin is directly injected into a closed mold under vacuum is advanced for conformal ablators. The process reduces waste over the state-of-the-art technique. Small, flat samples of Conformal Phenolic Impregnated Carbon Ablator are infused using the new approach and subjected to a range of curing configurations and conditions. Resulting materials are inspected for quality and compared to material produced using the standard process. Lessons learned inform subsequent plans for process scale up

    Autonomous 3D Exploration of Large Structures Using an UAV Equipped with a 2D LIDAR

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    This paper addressed the challenge of exploring large, unknown, and unstructured industrial environments with an unmanned aerial vehicle (UAV). The resulting system combined well-known components and techniques with a new manoeuvre to use a low-cost 2D laser to measure a 3D structure. Our approach combined frontier-based exploration, the Lazy Theta* path planner, and a flyby sampling manoeuvre to create a 3D map of large scenarios. One of the novelties of our system is that all the algorithms relied on the multi-resolution of the octomap for the world representation. We used a Hardware-in-the-Loop (HitL) simulation environment to collect accurate measurements of the capability of the open-source system to run online and on-board the UAV in real-time. Our approach is compared to different reference heuristics under this simulation environment showing better performance in regards to the amount of explored space. With the proposed approach, the UAV is able to explore 93% of the search space under 30 min, generating a path without repetition that adjusts to the occupied space covering indoor locations, irregular structures, and suspended obstaclesUnión Europea Marie Sklodowska-Curie 64215Unión Europea MULTIDRONE (H2020-ICT-731667)Uniión Europea HYFLIERS (H2020-ICT-779411

    A unique high heat flux facility for testing hypersonic engine components

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    A major concern in advancing the state-of-the-art technologies for hypersonic vehicles is the development of an aeropropulsion system capable of withstanding high thermal loads expected during hypersonic flights. Consequently, there is a need for experimental facilities capable of providing a high heat flux environment for testing compound concepts and verifying analyses. A hydrogen/oxygen rocket engine was developed to provide a high enthalpy/high heat flux environment for component evaluation. This Hot Gas Facility is capable of providing heat fluxes ranging from 200 (on flat surfaces) up to 8000 Btu per sq ft per sec (at a leading edge stagnation point). Gas temperatures up to 5500 R can be attained as well as Reynolds numbers up to 360,000 per ft. Test articles such as cowl leading edges, transpiration-cooled seals, fuel injectors, and cooled panel concepts can be evaluated with gaseous hydrogen as coolant. This facility and its configuration and test capabilities are discussed. Results from flow characterization experiments are also shown and their implications considered
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