850 research outputs found

    Imagine: Deflateables

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    Pneumatic structures are thoroughly investigated and developed during the 1960s. However, the energy crisis and aesthetic developments impeded the use of these structures as a mainstream construction method. Nowadays, they are typically used in special areas of architecture and design. Deflateables concentrates on the very limited knowledge of vacuum constructions and develops a range of aesthetic, technical and functional design possibilities. However, very few designs that use pressurised constructions have actually been realised, even right down to the present day - despite the fact that this technology offers simple, positive aspects: the air pressure of the earth can be used as a stabilising and form-giving parameter, creating a specific and inspiring shape. In addition, the very nature of this technology provides varying degrees of thermal and acoustic insulation. Of course, there are weak points such as potential leakage and the need for high pressurisation of the construction; but new material technologies and specific structural concepts will bring solutions to such issues. Exploiting the possibilities of extremely light and energetically active constructions, deflateables are one of the promising fields of architectural and design developments. The chance to create structures that can move and react to requests such as user and climate requirements, as well as formative demands, lifts this topic onto the level of a realistic and usable technology for as-yet unknown design possibilities.&nbsp

    Imagine: Deflateables

    Get PDF
    Pneumatic structures are thoroughly investigated and developed during the 1960s. However, the energy crisis and aesthetic developments impeded the use of these structures as a mainstream construction method. Nowadays, they are typically used in special areas of architecture and design. Deflateables concentrates on the very limited knowledge of vacuum constructions and develops a range of aesthetic, technical and functional design possibilities. However, very few designs that use pressurised constructions have actually been realised, even right down to the present day - despite the fact that this technology offers simple, positive aspects: the air pressure of the earth can be used as a stabilising and form-giving parameter, creating a specific and inspiring shape. In addition, the very nature of this technology provides varying degrees of thermal and acoustic insulation. Of course, there are weak points such as potential leakage and the need for high pressurisation of the construction; but new material technologies and specific structural concepts will bring solutions to such issues. Exploiting the possibilities of extremely light and energetically active constructions, deflateables are one of the promising fields of architectural and design developments. The chance to create structures that can move and react to requests such as user and climate requirements, as well as formative demands, lifts this topic onto the level of a realistic and usable technology for as-yet unknown design possibilities.&nbsp

    Advanced Rotorcraft Transmission (ART) program-Boeing helicopters status report

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    The Advanced Rotorcraft Transmission (ART) program is structured to incorporate key emerging material and component technologies into an advanced rotorcraft transmission with the intention of making significant improvements in the state of the art (SOA). Specific objectives of ART are: (1) Reduce transmission weight by 25 pct.; (2) Reduce transmission noise by 10 dB; and (3) Improve transmission life and reliability, while extending Mean Time Between Removal to 5000 hr. Boeing selected a transmission sized for the Tactical Tilt Rotor (TTR) aircraft which meets the Future Air Attack Vehicle (FAVV) requirements. Component development testing will be conducted to evaluate the high risk concepts prior to finalizing the advanced transmission configuration. The results of tradeoff studies and development test which were completed are summarized

    SAGA: Sparse And Geometry-Aware non-negative matrix factorization through non-linear local embedding

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    International audienceThis paper presents a new non-negative matrix factorization technique which (1) allows the decomposition of the original data on multiple latent factors accounting for the geometrical structure of the manifold embedding the data; (2) provides an optimal representation with a controllable level of sparsity; (3) has an overall linear complexity allowing handling in tractable time large and high dimensional datasets. It operates by coding the data with respect to local neighbors with non-linear weights. This locality is obtained as a consequence of the simultaneous sparsity and convexity constraints. Our method is demonstrated over several experiments, including a feature extraction and classification task, where it achieves better performances than the state-of-the-art factorization methods, with a shorter computational time

    JUNO Conceptual Design Report

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    The Jiangmen Underground Neutrino Observatory (JUNO) is proposed to determine the neutrino mass hierarchy using an underground liquid scintillator detector. It is located 53 km away from both Yangjiang and Taishan Nuclear Power Plants in Guangdong, China. The experimental hall, spanning more than 50 meters, is under a granite mountain of over 700 m overburden. Within six years of running, the detection of reactor antineutrinos can resolve the neutrino mass hierarchy at a confidence level of 3-4σ\sigma, and determine neutrino oscillation parameters sin2θ12\sin^2\theta_{12}, Δm212\Delta m^2_{21}, and Δmee2|\Delta m^2_{ee}| to an accuracy of better than 1%. The JUNO detector can be also used to study terrestrial and extra-terrestrial neutrinos and new physics beyond the Standard Model. The central detector contains 20,000 tons liquid scintillator with an acrylic sphere of 35 m in diameter. \sim17,000 508-mm diameter PMTs with high quantum efficiency provide \sim75% optical coverage. The current choice of the liquid scintillator is: linear alkyl benzene (LAB) as the solvent, plus PPO as the scintillation fluor and a wavelength-shifter (Bis-MSB). The number of detected photoelectrons per MeV is larger than 1,100 and the energy resolution is expected to be 3% at 1 MeV. The calibration system is designed to deploy multiple sources to cover the entire energy range of reactor antineutrinos, and to achieve a full-volume position coverage inside the detector. The veto system is used for muon detection, muon induced background study and reduction. It consists of a Water Cherenkov detector and a Top Tracker system. The readout system, the detector control system and the offline system insure efficient and stable data acquisition and processing.Comment: 328 pages, 211 figure

    COILReef™ Wave Energy Dissipation Project

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    Within this Final Design Review (FDR) report, the COILReef™ Senior Project concludes with all updates reflecting results after testing. The COILReef™ is a device ideated by Cal Poly Professor Roger Benham. It aims to provide a removeable, low-cost solution to dissipating ocean wave energy, thereby reducing coastal erosion in sensitive areas. Current permanent solutions cost millions of dollars, take years to construct, and sometimes produce undesirable and unintended effects. The work presented in this document provides the foundational research, testing, and steps taken by the team to evaluate the feasibility of the COILReef™ design as a viable solution to reducing coastal erosion. The team developed an understanding of stakeholder needs/wants and current solutions for preventing coastal erosion through background research. The research also included a patent search and technical research pertaining to the subject. The team defined the problem statement and scope of work that will be assessed which includes various analysis techniques including a boundary diagram, Quality Function Deployment (QFD), Gantt chart, ideation, controlled convergence analysis, and Failure Modes and Effects Analysis (FMEA). A project timeline with key milestones was defined and a plan was created to meet deliverable deadlines throughout the duration of the project. To evaluate the feasibility of the COILReef™, the team executed theoretical simulation using CFD software as well as physical testing of prototypes in a waterpark wave pool as well as in a smallscale wave tank. The prototypes were built with high and low parameters for four design factors as follows: coil diameter, coil spacing, depth of placement, and incident angle of wave impact. The coil diameter was selected based on wave height, with the high parameter being equal to the incoming wave height, and the low parameter being equal to one half of the incoming wave height. The coil spacing dimensions were selected with a high parameter of eight inches, and a low of four inches. These parameters were selected intuitively with enough of a difference between the high and low to obtain a noticeable difference in the results. The high parameter for the depth of placement was at the water’s surface, and the low parameter was at a depth equal to one half of the wavelength where the orbital wave particle motion becomes negligible. Lastly, the incident angle of impact was chosen intuitively so that the coil was parallel to the incoming wave height for the low parameter, and at an angle of 45 degrees to the incoming wave for the high parameter. Based on tests conducted with all combinations of high and low parameters, the data suggested that a significant decrease in wave height was achieved by the prototype placed at the water’s surface parallel to the incoming wave with the diameter equal to the wave height and a coil spacing of four inches. It is the team’s recommendation that these results should be treated as preliminary and corroborated with further testing

    Combining information seeking services into a meta supply chain of facts

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    The World Wide Web has become a vital supplier of information that allows organizations to carry on such tasks as business intelligence, security monitoring, and risk assessments. Having a quick and reliable supply of correct facts from perspective is often mission critical. By following design science guidelines, we have explored ways to recombine facts from multiple sources, each with possibly different levels of responsiveness and accuracy, into one robust supply chain. Inspired by prior research on keyword-based meta-search engines (e.g., metacrawler.com), we have adapted the existing question answering algorithms for the task of analysis and triangulation of facts. We present a first prototype for a meta approach to fact seeking. Our meta engine sends a user's question to several fact seeking services that are publicly available on the Web (e.g., ask.com, brainboost.com, answerbus.com, NSIR, etc.) and analyzes the returned results jointly to identify and present to the user those that are most likely to be factually correct. The results of our evaluation on the standard test sets widely used in prior research support the evidence for the following: 1) the value-added of the meta approach: its performance surpasses the performance of each supplier, 2) the importance of using fact seeking services as suppliers to the meta engine rather than keyword driven search portals, and 3) the resilience of the meta approach: eliminating a single service does not noticeably impact the overall performance. We show that these properties make the meta-approach a more reliable supplier of facts than any of the currently available stand-alone services

    Kinematic alignment of precision robotic elements in factory environments

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    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2002.Includes bibliographical references (p. 85-86).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.In the measurement and instrumentation fields, kinematic couplings have been widely used to create precise and repeatable interfaces on a variety of devices. However, these devices have been limited to low load and clean environments such as in semiconductor manufacturing facilities. While traditional factory environments present less ideal conditions for the implementation of kinematic couplings, the benefits of more repeatable, deterministic interfaces is becoming more necessary as tolerances for products continue to become more stringent. In this thesis, general exact constraint and kinematic coupling design theory is discussed with specific application for use in industrial environments. Factors such as installation and cleanliness are discussed along with traditional design parameters such as Hertzian contact stress and preload. To test out the application of kinematic couplings to detrimental environments, two separate case studies were performed. The first case study consists of a small scale metrology device used to calibrate the home position of the ABB 6400R robot. In this application, a low-load coupling is designed for a less than ideal environment. The second case study applies kinematic coupling theory to the medium scale, high load wrist interface on the same robot. In the latter, two forms of couplings were compared, including the classic ball and groove coupling as a baseline and the three pin coupling as a new, cheap solution. Testing of prototypes of each concept shows potential for inclusion of this technology in future robot models.by Patrick Willoughby.S.M
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