3,037 research outputs found

    ASME Mini-Baja RC CAR (Steering and suspension systems)

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    The issue that this project is concerned with is how to design and build a drivetrain, steering and suspension systems for an RC car. The systems must be simple and functional. Furthermore, these systems will be designed to fit on a small chassis and not interfere with each other. They also need to be strong and durable enough to propel the car forward and maneuver through various obstacles and be built in a way that is easy to take apart and repair quickly. These design problems were approached using basic mechanical design concepts such as gear kinematics, spur and bevel gear design, static and spring analysis as well as linkage design. These concepts were used to analyze the design and ensure it would function properly. Once the designs were finalized the necessary parts and components were machined, printed, and purchased. The result was a functioning RC car with all the necessary systems in place. These systems also fit well with each other on the chassis and they are relatively simple to assemble and dissemble. Overall the vehicle drives with sufficient power (approximately 20 mph), control (turning radius of under 50”) and meets the requirements set out by the principle investigators Mike Cox and Jason Moore

    Free-Standing Leaping Experiments with a Power-Autonomous, Elastic-Spined Quadruped

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    We document initial experiments with Canid, a freestanding, power-autonomous quadrupedal robot equipped with a parallel actuated elastic spine. Research into robotic bounding and galloping platforms holds scientific and engineering interest because it can both probe biological hypotheses regarding bounding and galloping mammals and also provide the engineering community with a new class of agile, efficient and rapidly-locomoting legged robots. We detail the design features of Canid that promote our goals of agile operation in a relatively cheap, conventionally prototyped, commercial off-the-shelf actuated platform. We introduce new measurement methodology aimed at capturing our robot’s “body energy” during real time operation as a means of quantifying its potential for agile behavior. Finally, we present joint motor, inertial and motion capture data taken from Canid’s initial leaps into highly energetic regimes exhibiting large accelerations that illustrate the use of this measure and suggest its future potential as a platform for developing efficient, stable, hence useful bounding gaits. For more information: Kod*La

    Vertical Greening Systems by Integrated Design Approach in Residential Buildings Towards mitigating Urban Heat Island effect the case study of Tehran, Iran

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    As urbanization grows, the results become more visible. Heat islands are formed due to the loss of green spaces and the consequent disruptive effects of climate change, especially in densely populated urban areas. These phenomena threaten and endanger human health. One solution to compensate for the scarcity of urban green space today is to construct urban green space within the house's walls to provide a suitable and desirable space. Vertical greening systems have recently been recognized and tested by scholars as one of the most effective methods for reducing the harmful impact of heating on the environment. Due to the beauty of this solution, it has also been considered by architectural designers, and today we are witnessing a growing trend of green-covered buildings. In this regard, the number of manufacturing companies is expanding and considering that this solution is in its first steps of growth and there is a need for further study. So, the standard process makes it more functional. This research aims to study the actual process and design of green walls. As a result, at the outset of the journey, the market's current and usable systems should be defined and segmented, followed by analyzing the design and manufacturing process's strengths and limitations. Then, by examining the divisions produced among scientists and companies, the final classification has been presented and analyzed in this study in order to standardize the production process. It should be remembered that businesses from various European, Asian, Australian, and American countries were surveyed to ensure that gaps existed. Based on the current system's flaws, a new Vertical Greening Integrated Approach (VGIS) approach was introduced to make it more popular, economical, and functional. Developing countries like Iran have a significant share in increasing the earth's temperature. However, because of the high price of this nature-based, it is less welcomed and used more as a decorative component in luxury buildings. Therefore, Tehran's study sample, one of the leading centers of pollution and population density and buildings, has been selected. Finally, based on the new approach, the selected green wall simulated on residential building in Tehran. Results show that this strategy's effectiveness was to lower the surface temperature by direct green facade about 10.95 °C and via felt-based living wall 13.95°C

    Fabrication feasibility study of a 20 watt per pound solar cell array Final report, 22 Feb. - Dec. 1965

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    Feasibility of large deployable solar photovoltaic cell array for electric propulsion syste

    X-ray satellite

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    An overview of the second quarter 1985 development of the X-ray satellite project is presented. It is shown that the project is proceeding according to plan and that the projected launch date of September 9, 1987 is on schedule. An overview of the work completed and underway on the systems, subsystems, payload, assembly, ground equipment and interfaces is presented. Problem areas shown include cost increases in the area of focal instrumentation, the star sensor light scattering requirements, and postponements in the data transmission subsystems

    Designing energy-efficient computing systems using equalization and machine learning

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    As technology scaling slows down in the nanometer CMOS regime and mobile computing becomes more ubiquitous, designing energy-efficient hardware for mobile systems is becoming increasingly critical and challenging. Although various approaches like near-threshold computing (NTC), aggressive voltage scaling with shadow latches, etc. have been proposed to get the most out of limited battery life, there is still no “silver bullet” to increasing power-performance demands of the mobile systems. Moreover, given that a mobile system could operate in a variety of environmental conditions, like different temperatures, have varying performance requirements, etc., there is a growing need for designing tunable/reconfigurable systems in order to achieve energy-efficient operation. In this work we propose to address the energy- efficiency problem of mobile systems using two different approaches: circuit tunability and distributed adaptive algorithms. Inspired by the communication systems, we developed feedback equalization based digital logic that changes the threshold of its gates based on the input pattern. We showed that feedback equalization in static complementary CMOS logic enabled up to 20% reduction in energy dissipation while maintaining the performance metrics. We also achieved 30% reduction in energy dissipation for pass-transistor digital logic (PTL) with equalization while maintaining performance. In addition, we proposed a mechanism that leverages feedback equalization techniques to achieve near optimal operation of static complementary CMOS logic blocks over the entire voltage range from near threshold supply voltage to nominal supply voltage. Using energy-delay product (EDP) as a metric we analyzed the use of the feedback equalizer as part of various sequential computational blocks. Our analysis shows that for near-threshold voltage operation, when equalization was used, we can improve the operating frequency by up to 30%, while the energy increase was less than 15%, with an overall EDP reduction of ≈10%. We also observe an EDP reduction of close to 5% across entire above-threshold voltage range. On the distributed adaptive algorithm front, we explored energy-efficient hardware implementation of machine learning algorithms. We proposed an adaptive classifier that leverages the wide variability in data complexity to enable energy-efficient data classification operations for mobile systems. Our approach takes advantage of varying classification hardness across data to dynamically allocate resources and improve energy efficiency. On average, our adaptive classifier is ≈100× more energy efficient but has ≈1% higher error rate than a complex radial basis function classifier and is ≈10× less energy efficient but has ≈40% lower error rate than a simple linear classifier across a wide range of classification data sets. We also developed a field of groves (FoG) implementation of random forests (RF) that achieves an accuracy comparable to Convolutional Neural Networks (CNN) and Support Vector Machines (SVM) under tight energy budgets. The FoG architecture takes advantage of the fact that in random forests a small portion of the weak classifiers (decision trees) might be sufficient to achieve high statistical performance. By dividing the random forest into smaller forests (Groves), and conditionally executing the rest of the forest, FoG is able to achieve much higher energy efficiency levels for comparable error rates. We also take advantage of the distributed nature of the FoG to achieve high level of parallelism. Our evaluation shows that at maximum achievable accuracies FoG consumes ≈1.48×, ≈24×, ≈2.5×, and ≈34.7× lower energy per classification compared to conventional RF, SVM-RBF , Multi-Layer Perceptron Network (MLP), and CNN, respectively. FoG is 6.5× less energy efficient than SVM-LR, but achieves 18% higher accuracy on average across all considered datasets

    Overview of the PALM model system 6.0

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    In this paper, we describe the PALM model system 6.0. PALM (formerly an abbreviation for Parallelized Largeeddy Simulation Model and now an independent name) is a Fortran-based code and has been applied for studying a variety of atmospheric and oceanic boundary layers for about 20 years. The model is optimized for use on massively parallel computer architectures. This is a follow-up paper to the PALM 4.0 model description in Maronga et al. (2015). During the last years, PALM has been significantly improved and now offers a variety of new components. In particular, much effort was made to enhance the model with components needed for applications in urban environments, like fully interactive land surface and radiation schemes, chemistry, and an indoor model. This paper serves as an overview paper of the PALM 6.0 model system and we describe its current model core. The individual components for urban applications, case studies, validation runs, and issues with suitable input data are presented and discussed in a series of companion papers in this special issue
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