822 research outputs found

    Developing Artificial Intelligence Agents for a Turn-Based Imperfect Information Game

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    Artificial intelligence (AI) is often employed to play games, whether to entertain human opponents, devise and test strategies, or obtain other analytical data. Games with hidden information require specific approaches by the player. As a result, the AI must be equipped with methods of operating without certain important pieces of information while being aware of the resulting potential dangers. The computer game GNaT was designed as a testbed for AI strategies dealing specifically with imperfect information. Its development and functionality are described, and the results of testing several strategies through AI agents are discussed

    The Codling Moth and Its Control

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    PDF pages: 1

    Structural Analysis and Performance-Based Validation of a Composite Wing Spar

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    Electric-motor powered aircraft possess the ability to operate with efficient energy delivery, but lack the operational range of internal combustion engine powered aircraft. This range limitation requires the use of high aspect ratio, thin-chord wings to minimize aerodynamic drag losses, which results in highly loaded composite spar structures. High aspect ratio wings are required to increase mission durations for a NASA-developed experimental multi-rotor electric powered aircraft denoted as the Scalable Convergent Electric Propulsion Technology and Operations Research (SCEPTOR) or X-57. This paper examines the structural performance of the composite main wing spars to validate spar strength using ply-based laminate finite element methods. Geometric scaling of a main spar test-section was initially proposed for proof-testing but sacrificed stability. Ply-based structures modeling with local structural features was implemented as a risk-reduction methodology. Ply-based modeling was selected to augment the conventional building block approach to reduce risk, and leverage a performance-based approval processes encouraged in Federal Aviation Administration (FAA) design guidance. Therefore, ply-based laminate modeling of the full-scale main spar and forward spar shear-web attachments were subsequently undertaken to determine load path complexity with predicted flight loads. Ply-based modeling included stress concentrations and interlaminate behavior at interface locations that can be obscured in traditional finite element sizing models. Analysis of the wing spar laminate ply-based models compared with bearing test coupon performance was used to reduce future wing assembly proof-testing burden and facilitate performance-based flight hardware safety for the X-57 experimental aircraft

    Reaction Pathways Initiated by One-electron Oxidation of Guanine: Reaction Pathways Leading to Stable End Products

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    8-hydroxyguanine (8-oxoG) is one of the most important products resulting from the oxidation of guanine in DNA. 8-oxoG is known as a biomarker of oxidative stress such as lung cancer. 2,5-diamino-4H-imidazol-4-one (Iz) and its hydrolysis product 2,2-diamino-4-[(2-deoxy-ÎČ-D-erythro-pentofuranosyl)-amino]-2,5-dihydrooxazol-5-one (Oz) are also important products of oxidation of guanine in DNA. Recently, novel types of dimer intermediates related to 8-oxoG and Iz have been identified in our research lab. Using high performance liquid chromatography (HPLC), LC-MS, and NMR coupled with educated hypotheses, it is possible to identify the products, X1 and X2, resulting from the oxidation of guanine and decipher the mechanisms leading to the products. Gaining a better understanding of these mechanisms could potentially lead to more effective medical treatment of conditions resulting from oxidative stress. X1 and X2 were isolated in large amounts from deoxyguanosine (dGuo) via photochemical oxidation. Subsequent testing included a comparison of the effects of different pH values as well as determination of the lifetimes for the X2 product during hydrolysis and reactions with amines. It was shown from the results that X1 undergoes further oxidation to produce X2

    THE ANTITHESIS OF ‘BUSINESS AS USUAL’: YOUTH, CLASS, AND VOLUNTEER ORGANIZATIONS IN DAR ES SALAAM, TANZANIA

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    Youth in Tanzania make up the majority of the current growing population and therefore are increasingly a focus of local and international development concern, specifically as the rates of urban growth and unemployment are also increasing. This research builds upon existing anthropological literature, which largely addresses contemporary and urban African youths as “problems” in dire need of governmental intervention and international solutions. Through explorations of the ways in which Tanzanian youth are actively and creatively working to improve their own futures, utilizing their own agency to create opportunities, and solving their own problems in the absence of successful external intercessions, this research eschews these negative stereotypes and offers insights into how innovation and creativity are shaping the lives of Tanzanian youth and their communities during the increasing and prolonged period of youthhood known as “waithood.” Utilizing ethnographic data collected during eight months of fieldwork in Dar es Salaam, Tanzania, and methodologies of participant observation, surveys, and approximately 35 semi-structured interviews, this research contributes insights into the changing definition of youth and youthhood, the contemporary trend of youth navigating un/underemployment through avenues of volunteerism, and how local, youth-run NGOs and organizations are developing and utilizing unique methods of organizing to address issues relevant to their own productivity and futures. Drawing from literature on youth studies, organization studies, social organization, labor, and class, the data collected points to the ways in which volunteering for these youths in Dar es Salaam is shifting from a social based enterprise to a professionalization of non-profit work, leading to a market for volunteering. This market, however, looks different when exploring class differences related to reasons for participating in voluntary labor, varying from required professionalization experiences in order to earn skills to obtain employment, to actually filling in for formal employment for those for which it is not available. Additionally, this research examines the proliferation of innovative methodologies utilized specifically by youth-run NGOs and organizations, focusing on technologically advanced methods, such as 3D animation, and sports and games. The two organizations presented as case studies demonstrate how each method allows these organizations to conduct the work that many other groups are simultaneously involved in, but in such a way that purports to increase effectiveness, sustainability, and creativity. Overall, this research lends a voice to the increasing, and dynamic, involvement of Tanzanian youth as leaders in their own futures, in a country where the government and civil sector loudly call for change in the media and in engagements with international governments, but does not follow this with action. I argue that the period of “waithood” for youth in Africa is increasing in length, leading to the need to develop alternative livelihood practices. The youth involved in this research represent the growing nature of the agency of young people, particularly in urban areas like contemporary Dar es Salaam, to challenge the identity of youth and to take up the reins and be proactive in ensuring their own, and their fellow youth community members’, success. By literally changing the way in which volunteering is typically viewed in the Minority World, and exploring new avenues of innovation, these young people are role models for the burgeoning global youth population

    Codling moth biology and control investigations

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    Mode of access: Internet

    Friedel-Crafts alkylation of benzene with a superacid catalyst

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    Long-chain alkylbenzenes are industrially synthesized precursors to commercial surfactants such as laundry detergent. The currently used catalysts in the processes of their synthesis are corrosive and harmful to the environment. These problems can be avoided utilizing heterogeneous highly acidic catalysts. Solid catalysts do not corrode equipment and are relatively simple to remove from the post-reaction mixture. Phosphotungstic acid (PTA) supported on silica gel could be a possible catalyst due to its high acidity with an estimated pKa ≈ -13. The catalyst PTA-SiO2 was prepared via the sol-gel method to covalently embed it in a silica support. The catalyst was granulated with γ-alumina for use in a fixed bed flow reactor during the alkylation of benzene with long chain alkenes. The isomerization of 1-octene, 1-decene, and 1-octadecene as well as the conversion of 1-decene in the alkylation of benzene were studied under varying conditions. During these reactions, the catalyst demonstrated good catalytic activity at temperatures above 200 °C with an optimal temperature of 250 °C. Of all three alkenes, 1-octadecene showed the highest conversion into respective isomers. The alkylation of benzene with 1-decene experiments showed decreasing of flow rate and increasing the ratio of benzene to 1-decene lead to higher conversions of 1-decene. Characterization of the catalyst after the reaction showed little changes in porosity and particle size. No leaching of PTA was observed. However, carbon deposits were found on the catalyst that requires regeneration before next use in catalysis
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