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Fast time-domain edge-diffraction calculations for interactive acoustic simulations

Eurasip Journal on Advances in Signal Processing 2007年 2007卷

作者： Calamia, Paul T. Svensson, U. Peter Program in Architectural Acoustics School of Architecture Rensselaer Polytechnic Institute Troy NY 12180 United States Department of Computer Science Princeton University Princeton NJ 08544 United States Acoustics Research Centre Department of Electronics and Telecommunications Norwegian University of Science and Technology NO-7491 Trondheim Norway

The inclusion of edge diffraction has long been recognized as an improvement to geometrical-acoustics (GA)modeling techniques, particularly for acoustic simulations of complex environments that are represented as collections of finite-sized planar surfaces. One particular benefit of combining edge diffraction with GA components is that the resulting total sound field is continuous when an acoustic source or receiver crosses a specular-zone or shadow-zone boundary, despite the discontinuity experienced by the associated GA *** interactive acoustic simulations which include only GA components, such discontinuities may be heard as clicks or other undesirable audible artifacts, and thus diffraction calculations are important for high perceptual quality as well as physical realism. While exact diffraction calculations are difficult to compute at interactive rates, approximate calculations are possible and sufficient for situations in which the ultimate goal is a perceptually plausible simulation rather than a numerically exact one. In this paper, we describe an edge-subdivision strategy that allows for fast time-domain edge-diffraction calculations with relatively low error when compared with results from a more numerically accurate solution. The tradeoff between computation time and accuracy can be controlled with a number of parameters, allowing the user to choose the speed that is necessary and the error that is tolerable for a specific modeling scenario.

关键词： Edge detection

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A schematic-based design model for microphone and circuit integration

A schematic-based design model for microphone and circuit in...

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International Microsystems, Packaging, Assembly and Circuits technology (IMPACT)

作者： Jen-Yi Chen Shu-Sheng Lee Peter Chang Chun-Hsun Chu Tamal Mukherjee Gary K. Fedder Microsystems Technology Center Industrial Technology and Research Institute Taiwan Department of Systems and Naval Architecture Engineering National Taiwan Ocean University Taiwan Department of Electrical and Computer Engineering USA Carnegie Mellon University Pittsburgh PA USA The Robotics Institute Case Western Reserve University USA

The transistor-level elements for condenser microphone design have been implemented in an IC design environment. Arbitrary diaphragm shapes can be composed and simulated by using our basic elements. The sensitivity and frequency response are obtained by co-simulation with the microphone and the readout circuit using Cadence/Spectre reg simulator. The new model is capable of dealing with the multi-field coupling effects including acoustical, mechanical and electrostatic behavior. Comparing to the ANSYS static simulation by using shell63 elements, our design model gives matched results based on the same mesh condition. Both the finite element analysis and theoretical calculated natural frequency agree with the nodal simulation results. Co-simulation enables trade-off analysis between the acousto-electro-mechanical and electronic design parameters. Furthermore, this platform provides a unified design interface between mechanical and electrical engineers, which is critical for top-down design of monolithic microsystems.

关键词： Microphones Circuit simulation Shape Frequency response Coupling circuits Electrostatics Finite element methods Analytical models Acoustical engineering Design engineering

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Critical path analysis of the TRIPS architecture

Critical path analysis of the TRIPS architecture

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ISPASS 2006: IEEE International Symposium on Performance Analysis of Systems and Software, 2006

作者： Nagarajan, Ramadass Xia, Chen McDonald, Robert G. Burger, Doug Keckler, Stephen W. Computer Architecture and Technology Laboratory Department of Computer Sciences University of Texas Austin

ISBN: (纸本)1424401860

Fast, accurate, and effective performance analysis is essential for the design of modern processor architectures and improving application performance. Recent trends toward highly concurrent processors make this goal increasingly difficult. Conventional techniques, based on simulators and performance monitors, are ill-equipped to analyze how a plethora of concurrent events interact and how they affect performance. Prior research has shown the utility of critical path analysis in solving this problem [5,18]. This analysis abstracts the execution of a program with a dependence graph. With simple manipulations on the graph, designers can gain insights into the bottlenecks of a design. This paper extends critical path analysis to understand the performance of a next-generation, high-ILP architecture. The TRIPS architecture introduces new features not present in conventional superscalar architectures. We show how dependence constraints introduced by these features, specifically the execution model and operand communication links, can be modeled with a dependence graph. We describe a new algorithm that tracks critical path information at a fine-grained level and yet can deliver an order of magnitude (30x) improvement in performance over previously proposed techniques [5, 18]. Finally, we provide a breakdown of the critical path for a select set of benchmarks and show an example where we use this information to improve the performance of a heavily-hand-optimized program by as much as 11%. © 2006 IEEE.

关键词： Critical path analysis

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Evaluation of parallel EDAs to create chemical calibration models

Evaluation of parallel EDAs to create chemical calibration m...

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e-Science 2006 - 2nd IEEE International Conference on e-Science and Grid Computing

作者： Mendiburu, A. Miguel-Alonso, J. Lozano, J.A. Department of Computer Architecture and Technology Department of Computer Science and Artificial Intelligence University of the Basque Country Gipuzkoa Spain

ISBN: (纸本)0769527345

Estimation of Distribution Algorithms (EDAs) are a set of optimization techniques that have been successfully applied to different kinds of problems. In this paper, we deal with the creation of multivariate calibration models in quantitative chemistry. For this purpose, we use parallel implementations of two EDAs (EBNABIC and UMDA), using different approaches to create a calibration model using data obtained from controlled reactions. Once the calibration model has been trained, it can be used to predict initial concentrations for some species taking part in new reactions. The results show that these new approaches are able to obtain good-quality calibration models. Moreover, the use of parallel algorithms allows researchers to complete experiments faster and to study a wider set of alternative solutions. © 2006 IEEE.

关键词： Parallel algorithms

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Waters network's potential to transform environmental engineering education

Waters network's potential to transform environmental engine...

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114th Annual ASEE Conference and Exposition, 2007

作者： Eschenbach, Elizabeth Montgomery, Jami Johnson, James Brus, Chris Carlson, Patricia Giammar, Dan Grauer, Bette Hotaling, Liesl Oguntimein, Gbekeloluwa Safferman, Steven Wentling, Tim Humboldt State University United States Department of Environmental Resources Engineering Humboldt State University United States WATERS Network - CLEANER Project Office Network Howard University United States Department of Environmental Engineering College of Engineering Architecture and Computer Sciences Howard University United States American Academy of Environmental Engineers United States University of Iowa United States Program University of Iowa United States Rose-Hulman Institute of Technology United States Department of Rhetoric Rose-Hulman Institute of Technology United States National Research Council U. S. Air Force United States NASA's Classroom of the Future Wheeling WV United States Washington University United States Department of Energy Environmental and Chemical Engineering Washington University St. Louis United States Environmental Studies Program Center for Materials Innovation United States McPherson High School United States McPherson High School McPherson KS United States Stevens Institute of Technology United States Stevens Institute of Technology United States Morgan State University United States Michigan State University United States Biosystems and Agricultural Engineering Department Michigan State University United States University of Dayton United States Education Planning Committee National Center for Supercomputing Applications United States Department of Information Science Graduate School of Library and Information Science National Center for Supercomputing Applications University or Illinois United States Knowledge and Learning Systems Group NCSA United States

The WATERS Network (WATer and Environmental Research Systems Network) will be an integrated real-time distributed observing system which will enable academic and government scientists, engineers, educators, and practitioners to advance effective management of our nation's water resources by understanding human interactions with water and the natural and built environment. WATERS will provide easily accessible real time environmental data as well as analysis tools to engineers, scientists, educators, K- graduate students and policymakers so they can better understand how water quantity, quality and related components of the hydrologic cycle are impacted by natural and human influences. The WATERS strategic plan will be completed by July 2007 and requires constituent input. This paper describes the draft Conceptual Design and the Education Plan of WATERS Network. This paper will highlight the potential impact of WATERS on undergraduate and graduate environmental engineering education in order to elicit input from the environmental engineering education community on how WATERS Network could better meet the future needs of undergraduate and graduate students and educators. More information can be found at ***. © American Society for Engineering Education, 2007.

关键词： Water resources

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High-performance computing in remotely sensed hyperspectral imaging: The pixel purity index algorithm as a case study 20

High-performance computing in remotely sensed hyperspectral ...

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20th IEEE International Parallel and Distributed Processing Symposium, IPDPS 2006

作者： Plaza, Antonio Valencia, David Plaza, Javier Computer Architecture and Technology Section Computer Science Department University of Extremadura Avda. de la Universidad s/n E-10071 Caceres Spain

ISBN: (纸本)1424400546

The incorporation of last-generation sensors to airborne and satellite platforms is currently producing a nearly continual stream of high-dimensional data, and this explosion in the amount of collected information has rapidly created new processing challenges. For instance, hyperspectral imaging is a new technique in remote sensing that generates hundreds of spectral bands at different wavelength channels for the same area on the surface of the Earth. The price paid for such a wealth of spectral information available from latest-generation sensors is the enormous amounts of data that they generate. In recent years, several efforts have been directed towards the incorporation of high-performance computing (HPC) models in remote sensing missions. This paper explores three HPC-based paradigms for efficient information extraction from remote sensing data using the Pixel Purity Index (PPI) algorithm (available from the popular Kodak's Research Systems ENVI software) as a case study for algorithm optimization. The three considered approaches are: 1) Commodity cluster-based parallel computing;2) Distributed computing using heterogeneous networks of workstations;and 3) FPGA-based hardware implementations. Combined, these parts deliver an excellent snapshot of the state-of-the-art in those areas, and offer a thoughtful perspective on the potential and emerging challenges of adapting HPC models to remote sensing problems. © 2006 IEEE.

关键词： Sensors

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Parallel morphological processing of hyperspectral image data on heterogeneous networks of computers 20

Parallel morphological processing of hyperspectral image dat...

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20th IEEE International Parallel and Distributed Processing Symposium, IPDPS 2006

作者： Plaza, Antonio J. Computer Architecture and Technology Section Computer Science Department University of Extremadura Avda. de la Universidad s/n E-10071 Caceres Spain

ISBN: (纸本)1424400546

Recent advances in space and computer technologies are revolutionizing the way remotely sensed data is collected, managed and interpreted. The development of efficient techniques for transforming the massive amount of collected data into scientific understanding is critical for space-based Earth science and planetary exploration. Although most currently available parallel processing strategies for hyperspectral image analysis assume homogeneity in the computing platform, heterogeneous networks of computers represent a very promising cost-effective solution expected to play a major role in the design of high-performance computing platforms for many on-going and planned remote sensing missions. This paper explores techniques for mapping morphological hyperspectral analysis algorithms, characterized by their scalability and sub-pixel accuracy, onto heterogeneous parallel computers. Important aspects in algorithm design are illustrated by using both homogeneous and heterogeneous parallel computing facilities available at NASA 's Goddard Space Flight Center and University of Maryland. Experiments reveal that heterogeneous networks of workstations represent a source of computational power that is both accessible and applicable in many remote sensing studies. © 2006 IEEE.

关键词： Parallel processing systems

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Self-adaptive robot control using fuzzy logic

Self-adaptive robot control using fuzzy logic

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International Workshop on Advanced Motion Control (AMC)

作者： I. Rojas H. Pomares J. Gonzalez L.J. Herrera A. Guillen O. Valenzuela Department of Computer Architecture and Computer Technology University of Granada Spain

This paper presents a new methodology to achieve real time self tuning and self learning in fuzzy controllers, with application to motion control of a trailer for reaching an aiming point and obstacle-avoidance. The advantage of this approach is that it only requires qualitative information about the plant to be controlled, in terms of the monotony presented by the output with respect to the control signal and the delay of the plant. Also, starting with a non-optimum controller, the system is able to self-adapt its behaviour in order to reduce the error. Thus, it is capable of controlling highly non-linear systems, in a pseudo-optimum way, even when these are time variable, for example, the dynamic of the robot or trailer change (i.e.: different mass, different environments, different dynamics of the system). Control is achieved by means of two auxiliary systems: the first one is responsible for adapting the consequences of the main controller to minimize the error arising at the plant output, while the second auxiliary system compiles real input/output data obtained from the plant. The methodology has been successfully applied to a real robot with different dynamics and in different environments, showing its ability to tune its +behaviour

关键词： Robot control Fuzzy logic Control systems Motion control Error correction Nonlinear dynamical systems Fuzzy control Delay Weight control Nonlinear control systems

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Soft-computing techniques for the development of adaptive helicopter flight controller

Soft-computing techniques for the development of adaptive he...

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International Workshop on Advanced Motion Control (AMC)

作者： I. Rojas H. Pomares J. Gonzalez L.J. Herrera A. Guillen F. Rojas Department of Computer Architecture and Computer Technology University of Granada Spain

In this paper we design an on-line controller which is able to modify and adapt the rule base of the system with just only qualitative knowledge about the plant to be controlled. Since flying a helicopter is an extremely difficult task, the fuzzy logic controller was necessarily quite complex. In fact, the control tasks were distributed over four individual control units, each of which had its own rules and associated membership functions. Because the fuzzy logic controller was large, and because the rules implemented in the individual control units were not necessarily those a human pilot would use, an efficient technique for writing the rules was required. A genetic algorithm was used to discover rules that provided for effective control of the helicopter. Our study is focused on the module responsible for controlling the helicopter's altitude. For the simulations performed by the adaptive controller, we modify, in a dynamic way, the value of the mass of the helicopter. This would correspond, in real life, to an increase or decrease, for example, in the number of passengers, discharge of water in a fire, etc. On the basis of the nominal value of the helicopter's mass, various simulations are performed to modify the latter parameter within a 15% range. Faced with such a situation, the values of the consequences of the rules responsible for controlling the helicopter's altitude must vary, as otherwise it would not be possible to maintain a zero difference between the desired altitude and that measured by the sensors. Finally, due to the speed requirement, the controller is implemented in FPGA

关键词： Programmable control Adaptive control Helicopters Control systems Fuzzy logic Distributed control Humans Genetic algorithms Weight control Fires

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Heart rate variability before fainting under the graded load of artificial gravity

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Autonomic Neuroscience 2007年第1-2期137卷 106-106页

作者： Yutaka Yoshida Kiyoko Yokoyama Hiroki Takada Satoshi Iwase Graduate School Business Administration and Computer Science Aichi Institute of Technology Toyota 470-0392 Japan School of Design and Architecture Nagoya City University Nagoya 464-0083 Japan Department of Radiological Technology Gifu University of Medical Science Gifu 501-3892 Japan School of Medicine Aichi Medical University Aichi 480-1195 Japan

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