4,890 research outputs found

    A case study of technology transfer: Cardiology

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    Research advancements in cardiology instrumentation and techniques are summarized. Emphasis is placed upon the following techniques: (1) development of electrodes which show good skin compatibility and wearer comfort; (2) contourography - a real time display system for showing the results of EKGs; (3) detection of arteriosclerosis by digital computer processing of X-ray photos; (4) automated, noninvasive systems for blood pressure measurement; (5) ultrasonoscope - a noninvasive device for use in diagnosis of aortic, mitral, and tricuspid valve disease; and (6) rechargable cardiac pacemakers. The formation of a biomedical applications team which is an interdisciplinary team to bridge the gap between the developers and users of technology is described

    Configurable Strategies for Work-stealing

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    Work-stealing systems are typically oblivious to the nature of the tasks they are scheduling. For instance, they do not know or take into account how long a task will take to execute or how many subtasks it will spawn. Moreover, the actual task execution order is typically determined by the underlying task storage data structure, and cannot be changed. There are thus possibilities for optimizing task parallel executions by providing information on specific tasks and their preferred execution order to the scheduling system. We introduce scheduling strategies to enable applications to dynamically provide hints to the task-scheduling system on the nature of specific tasks. Scheduling strategies can be used to independently control both local task execution order as well as steal order. In contrast to conventional scheduling policies that are normally global in scope, strategies allow the scheduler to apply optimizations on individual tasks. This flexibility greatly improves composability as it allows the scheduler to apply different, specific scheduling choices for different parts of applications simultaneously. We present a number of benchmarks that highlight diverse, beneficial effects that can be achieved with scheduling strategies. Some benchmarks (branch-and-bound, single-source shortest path) show that prioritization of tasks can reduce the total amount of work compared to standard work-stealing execution order. For other benchmarks (triangle strip generation) qualitatively better results can be achieved in shorter time. Other optimizations, such as dynamic merging of tasks or stealing of half the work, instead of half the tasks, are also shown to improve performance. Composability is demonstrated by examples that combine different strategies, both within the same kernel (prefix sum) as well as when scheduling multiple kernels (prefix sum and unbalanced tree search)

    Perceptually optimized real-time computer graphics

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    Perceptual optimization, the application of human visual perception models to remove imperceptible components in a graphics system, has been proven effective in achieving significant computational speedup. Previous implementations of this technique have focused on spatial level of detail reduction, which typically results in noticeable degradation of image quality. This thesis introduces refresh rate modulation (RRM), a novel perceptual optimization technique that produces better performance enhancement while more effectively preserving image quality and resolving static scene elements in full detail. In order to demonstrate the effectiveness of this technique, a graphics framework has been developed that interfaces with eye tracking hardware to take advantage of user fixation data in real-time. Central to the framework is a high-performance GPGPU ray-tracing engine written in OpenCL. RRM reduces the frequency with which pixels outside of the foveal region are updated by the ray-tracer. A persistent pixel buffer is maintained such that peripheral data from previous frames provides context for the foveal image in the current frame. Traditional optimization techniques have also been incorporated into the ray-tracer for improved performance. Applying the RRM technique to the ray-tracing engine results in a speedup of 2.27 (252 fps vs. 111 fps at 1080p) for the classic Whitted scene with reflection and transmission enabled. A speedup of 3.41 (140 fps vs. 41 fps at 1080p) is observed for a high-polygon scene that depicts the Stanford Bunny. A small pilot study indicates that RRM achieves these results with minimal impact to perceived image quality. A secondary investigation is conducted regarding the performance benefits of increasing physics engine error tolerance for bounding volume hierarchy based collision detection when the scene elements involved are in the user\u27s periphery. The open-source Bullet Physics Library was used to add accurate collision detection to the full resolution ray-tracing engine. For a scene with a static high-polygon model and 50 moving spheres, a speedup of 1.8 was observed for physics calculations. The development and integration of this subsystem demonstrates the extensibility of the graphics framework

    Accelerator Design for the CHESS-U Upgrade

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    During the summer and fall of 2018 the Cornell High Energy Synchrotron Source (CHESS) is undergoing an upgrade to increase high-energy flux for x-ray users. The upgrade requires replacing one-sixth of the Cornell Electron Storage Ring (CESR), inverting the polarity of half of the CHESS beam lines, and switching to single-beam on-axis operation. The new sextant is comprised of six double-bend achromats (DBAs) with combined-function dipole-quadrupoles. Although the DBA design is widely utilized and well understood, the constraints for the CESR modifications make the CHESS-U lattice unique. This paper describes the design objectives, constraints, and implementation for the CESR accelerator upgrade for CHESS-U

    Computer-controlled autonomous model car: A mechatronics project

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    Mechatronics is a synthesis of mechanical engineering and electronic engineering, and computer engineering, distinct areas that overlap in the design of systems. It represents the interdisciplinary nature of design and development of today\u27s products.;The current research focuses on the design, construction and testing of a computer controlled autonomous model car which can exhibit intelligent behavior such as timed course execution, obstacle detection, and response to sensor inputs. The car is intended as a mechatronics design project that will be integrated into an existing one-semester mechanical engineering undergraduate instrumentation course.;The car was designed around a microprocessor board (Tern Analog Drive) controlled by a 16-bit microcontroller (Tern V104) and equipped with several sensor channels. Two stepper motors were used to propel and guide the car. Photocells were used to detect the path. The control program was written in Turbo C.;The car was tested on a path of reflective white tape about 2 inches wide. The path consists of a 36-inch straight portion followed by a 17-inch radius of curvature curved portion, and completed by a 6-inch straight section with an obstacle at the end. The autonomous car successfully traversed the path and stopped when it detected the obstacle.;It was concluded that a successful mechatronic design project could be developed around the construction and testing of an autonomous car

    Telescience Testbed Pilot Program

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    The Telescience Testbed Pilot Program is developing initial recommendations for requirements and design approaches for the information systems of the Space Station era. During this quarter, drafting of the final reports of the various participants was initiated. Several drafts are included in this report as the University technical reports

    Mobile and web tools for participative learning

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    Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, para a obtenção do grau de Mestre em Engenharia InformáticaThe combination of different media formats has been a crucial aspect on teaching and learning processes. The recent developments of multimedia technologies over the Internet and using mobile devices can improve the communication between professors and students, and allow students to study anywhere and anytime, allowing each student progress at its own pace. The usage of these new platforms and the increase of multimedia sharing applied to educational environments allow a more participative learning, and make the study of interfaces a relevant aspect of existing multimedia learning systems. The work done in this dissertation explores interfaces and tools for participative learning,using multimedia educational systems over Internet broadband and mobile devices. In this work, aWeb-based learning system was developed, which enables to store, transmit, search and share the contents of courses captured in video and its extension to support Tablet PCs. The Web system, developed as part of the VideoStore project, explores video interfaces and video annotations, which encourage the participative work. The usage of Tablet PCs, through the mEmLearn project, has the aim to encourage the participative work, allowing the students to augment the course materials and to share them with other students or instructors

    NASA/JPL Aircraft SAR Workshop Proceedings

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    Speaker-supplied summaries of the talks given at the NASA/JPL Aircraft SAR Workshop on February 4 and 5, 1985, are provided. These talks dealt mostly with composite quadpolarization imagery from a geologic or ecologic prespective. An overview and summary of the system characteristics of the L-band synthetic aperture radar (SAR) flown on the NASA CV-990 aircraft are included as supplementary information. Other topics ranging from phase imagery and interferometric techniques classifications of specific areas, and the potentials and limitations of SAR imagery in various applications are discussed
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