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SAE 2005 Noise and Vibration conference and Exhibition

作者： Caprioli, Davide Bertolini, Claudio Gaudino, Ciro Rieter Automotive Management AG United Kingdom

The present work explains an innovative design methodology that allows efficient optimizations of vehicle body panels and treatments towards shorter development time and improved vehicle Noise and Vibration Harshness (NVH) characteristics. This tool named GOLD (Genetic optimization for Lighter Damping), internally developed by Rieter Automotive, can be embedded into vehicle Computer Aided Engineering (CAE) design flow and can be then used in providing design and platform component sharing guidance information before prototype vehicles are available. GOLD is able to detect the optimal design of vehicle panel shape and damping packages with respect to NVH targets, by means of vibro-acoustic simulations. The core of this tool are the Genetic algorithms (GAs) which are heuristic methods which have been already successfully used, in several research fields, to solve search and optimization problems with a very large number of variables. Typical design variables, that can be faced into the optimization loop, include the geometry and the materials configuration of the damping viscoelastic layers, as well as potential structural shape modifications of the body panels, like the application of soap film layouts, embossments and ribs. The whole iteration and FE model generation and updating process is automatically performed and controlled by special operators embedded in the GOLD software. The tool has already proven to provide high improvements when solving damping optimization problems of full vehicle structures, and one of this cases will be presented here. A component level optimization takling at the same time damping and shape design variables is also presented, taking into account weight constraints and performance objective functions. Copyright © 2005 SAE International.

关键词： Damping

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Adaptive parallel ant colony algorithm

Adaptive parallel ant colony algorithm

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1st International conference on Natural Computation (ICNC 2005)

作者： Chen, L Zhang, CF Yangzhou Univ Dept Comp Sci Yangzhou 225009 Peoples R China Nanjing Univ Natl Key Lab Novel Software Tech Nanjing 210093 Peoples R China

ISBN: (纸本)3540283250

An adaptive parallel ant colony optimization is presented by improving the critical factor influencing the performance of the parallel algorithm. We propose two different strategies for information exchange between processors: selection based on sorting and on difference, which make each processor choose another processor to communicate and update the pheromone adaplively. In order to increase the ability of search and avoid early convergence, we also propose a method of adjusting the time interval of information exchange adaptively according to the diversity of the solutions. These techniques are applied to the traveling salesman problem on the massive parallel processors (MPP) Dawn 2000. Experimental results show that our algorithm has high convergence speed, high speedup and efficiency.

关键词： algorithms

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Parameter estimation and output feedback nonlinear model predictive control of an industrial batch polymerization system

Parameter estimation and output feedback nonlinear model pre...

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05AIChE: 2005 AIChE Annual Meeting and Fall Showcase

作者： Nagy, Zoltan K. Franke, Ruediger Mahn, Bernd Allgoewer, F.

Nowadays chemical and related processing industries are faced with the need of increasingly precise control of product properties to meet specific demands. It is recognized that nonlinear model predictive control (NMPC) is an excellent candidate as a key enabling technology for the continued success of the chemical industries. However, NMPC has found successful application in a limited number of mainly academic example cases to date [1]. The main objective of the presented project is to fill the gap between the academic results and the industrial potential of NMPC, and to provide a balanced assessment of the advantages and difficulties related to the implementation of this control strategy in an industrial framework. Of particular interest will be on finite time processes since they play a significant role in the production of most modern high-value added products [2,3], and represent specific control problems. The presentation illustrates the benefits of nonlinear model predictive control for batch processes. The control challenges typical for finite-time processes are highlighted. The application of NMPC for the setpoint tracking and end-point property control of an industrial batch reactor is illustrated, with special emphasis related to challenges in the practical application. An industrially feasible batch NMPC approach is described, which can serve as a generic algorithm for the control of the class of non-isothermal batch processes. A real-time formulation of the NMPC that takes computational delay into account is described. Real-time feasibility of the on-line optimization problem from the NMPC is achieved using an efficient multiple shooting algorithm [4,5,6]. A user friendly software package is presented which can serve for the fast prototyping of NMPC algorithms in a typical industrial environment [7]. A two step approach is proposed to derive the control relevant model used in the NMPC from the complex first principles model. The reduced model is fitted

关键词： Predictive control systems

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Hybrid Evolutionary Optimisation Methods for the Clearance of nonlinear Flight Control Laws

Hybrid Evolutionary Optimisation Methods for the Clearance o...

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IEEE conference on Decision and Control

作者： P.P. Menon D.G. Bates I. Postlethwaite Department of Engineering University of Leicester Leicester UK

The application of two evolutionary optimisation methods, namely differential evolution and genetic algorithms, to the clearance of nonlinear flight control laws for highly augmented aircraft is described. The algorithms are applied to the problem of evaluating a nonlinear handling qualities clearance criterion for a simulation model of a high performance aircraft with a delta canard configuration and a full-authority flight control law. Hybrid versions of both algorithms, incorporating local gradient-based optimisation, are also developed and evaluated. Statistical comparisons of computational complexity and global convergence properties reveal the benefits of hybridisation for both algorithms. The differential evolution approach in particular, when appropriately augmented with local optimisation methods, is shown to have significant potential for improving both the reliability and efficiency of the current industrial flight clearance process.

关键词： optimization methods Aerospace control Stability criteria Aircraft propulsion Military aircraft Aerodynamics Uncertainty Genetic algorithms Computational modeling Aerospace simulation

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BDO-RFQ code and optimization models

BDO-RFQ code and optimization models

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International conference on Physics and Control

作者： D.A. Ovsyannikov A.D. Ovsyannikov I.V. Antropov V.A. Kozynchenko Saint-Petersburg State University Russia

The software complex for step-by-step beam dynamics optimization of charged particles in RFQ structure is developed using MATLAB. The RFQ accelerating structure is one of the most common linear accelerators in the wor... 详细信息

关键词： Mathematical model Acceleration Particle beams Automatic control Control systems MATLAB Linear accelerators Particle beam injection software algorithms software performance

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Design and evaluation of dynamic key message algorithms for cluster computing

Design and evaluation of dynamic key message algorithms for ...

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high-performance Computing in Asia-Pacific Region, 2005. Proceedings. Eighth International conference on

作者： Yang Wang Ming Zhu Zhuang Guo Meng Ding Department of Computing Science University of Alberta Edmonton AB Canada Oracle Corporation Redwood City CA USA

The Key Message (KM) approach prioritizes communications along the critical path to speed up the execution of parallel applications in a cluster environment. In this article, we introduce a family of three dynamic KM algorithms that take into account of the dynamic nature of underlying networks to improve over their predecessor. These three dynamic KM algorithms are: Fixed Critical Path Dynamic KM (FDKM), Centralized Predictor Dynamic KM (CDKM), and Distributed Dynamic KM (DDKM). Our performance study based on simulation showed that in general CDKM performs better and is more stable than FDKM and DDKM under heavy traffic conditions. The performance of DDKM is close to that of CDKM and better than that of FDKM on average. By taking advantages of both FDKM and CDKM, DDKM can be expected to be a promising optimization in a real cluster environment.

关键词： critical path analysis parallel algorithms software performance evaluation workstation clusters centralized predictor dynamic algorithm cluster computing distributed dynamic algorithm dynamic key message algorithms fixed critical path dynamic algorithm p

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Applying resource sharing algorithms to ADL-driven automatic ASIP implementation

Applying resource sharing algorithms to ADL-driven automatic...

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IEEE International conference on Computer Design: VLSI in Computers and Processors, (ICCD)

作者： E.M. Witte A. Chattopadhyay O. Schliebusch D. Kammler R. Leupers G. Ascheid H. Meyr Institute for Integrated Signal Processing Systems RWTH Aachen University Aachen Germany

Presently, architecture description languages (ADLs) are widely used to raise the abstraction level of the design space exploration of application specific instruction-set processors (ASIPs), benefiting from automatically generated software tool suite and RTL implementation. The increase of abstraction level and automated implementation traditionally comes at the cost of low area, delay or power efficiency. The standard synthesis flow starting at RTL abstraction fails to compensate for this loss of performance. Thus, high level optimizations during RTL synthesis from ADLs are obligatory. Currently, ADL-based optimization schemes do not perform resource sharing. In this paper, we present an iterative algorithm for performing resource sharing on the basis of global dataflow graph matching criteria. This ADL-based resource sharing optimization is performed over a RISC and a VLIW architecture and two industrial embedded processors. The results indicate a significant improvement in overall performance. A comparative study with manually written RTL code is presented, too.

关键词： Resource management Application specific processors Architecture description languages Space exploration Application software software tools Costs Delay performance loss Iterative algorithms

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A Parallel Simplex Optimizer and its Application to high-Brightness Storage Ring Design

A Parallel Simplex Optimizer and its Application to High-Bri...

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IEEE conference on Particle Accelerator

作者： H. Shang M. Borland Argonne National Laboratory Argonne IL 60439 USA shang@aps.anl.gov Argonne National Laboratory Argonne IL USA

An efficient parallel Simplex optimizer was developed that can on run Solaris and Linux clusters. It can optimize the result of running essentially any program or script that returns a penalty function value. We have used this optimizer with elegant to optimize the dynamic aperture of storage ring designs. This paper discusses the optimization algorithm and performance, design of penalty functions, optimization results, and applications in storage ring design.

关键词： Design optimization Storage rings Convergence Reflection Linux Apertures Clustering algorithms Algorithm design and analysis nonlinear optics Optical computing

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A low-cost experimental ultra-wideband positioning system

A low-cost experimental ultra-wideband positioning system

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IEEE International conference on Ubiquitous Wireless Broadband (ICUWB)

作者： J. Schroeder S. Galler K. Kyamakya Institute of Communications Engineering (IANT) Location Based Services and Systems Group University of Hannover Hanover Germany

In this paper we report on the architecture and implementation status of a low-cost experimental ultra-wideband (UWB) local positioning system, designed to enable practical evaluations of UWB based positioning concepts. The mobile devices use the avalanche effect of transistors for simple generation of bi-phase pulses and are TDMA multi-user capable. After high-speed analog-to-digital conversion, the receiver is implemented in software and employs direct cross-correlation with maximum detection to localize the mobile unit via A. One direct solution and one nonlinear optimization approach are implemented. First measurement results are presented, showing accuracy in the order of decimeters.

关键词： Ultra wideband technology Oscilloscopes Sampling methods Pulse generation Time division multiple access Analog-digital conversion Costs Computer architecture software algorithms Communications technology

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optimization Of Tube Hydroforming With Consideration Of Manufacturing Effects On Structural performance

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AIP conference Proceedings 2005年第1期778卷 585-590页

作者： David Kirby Subir Roy Ravi Kunju AltairEngineering Inc. 1820 East Big Beaver Road Troy MI 48083‐2031

Tube bending and hydroforming processes depend on a multitude of design parameters including geometry of the part and tools, material properties and other process variables. Design by simulation has traditionally been a trial and error process, where the objective is to find a feasible and cost‐effective process to manufacture a defect‐free product by varying design parameters. This trial and error based design process can become extremely cumbersome as, the number of design variables and the complexity to vary them increases. Consequently, it is important to devise efficient methods that will minimize the tedious human intervention while maintaining a high level of interactivity and flexibility with regards to setting up of the optimization problem. In this study, such an interactive design tool is developed by coupling, nonlinear optimization methods with finite element analysis and morphing technology. The process setup is integrated through a unique software interface that provides complete flexibility in the choice of design variables and objective *** optimal design approach developed in this study is applied to improve the formability of a hydroformed part. The design parameters chosen for the study are tool fillets and the hydroforming pressure. The design space for each shape variable is setup by morphing the initial shape. Following the hydroforming optimization, the manufacturing effects (thickness and plastic strain) are transferred to a component level crash model via a mapping tool. The part’s crash performance including manufacturing effects is evaluated and compared with nominal conditions.

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