检索结果-内蒙古大学图书馆

Line recognition algorithm for 3D polygonal model using a parallel computing platform

MULTIMEDIA TOOLS AND APPLICATIONS 2015年第1期74卷 259-270页

作者： Kang, Ji Hun Kang, Shin Jin Kim, SooKyun Korea Univ Dept Comp Sci Educ Seoul South Korea Hongik Univ Sch Games Sejong South Korea Paichai Univ Dept Game Engn Taejon South Korea

Line recognition-based rendering technique has been used effectively for shape transmission of 3D polygon model. Line recognition is defined by multifarious forms and characteristics of lines, and has been a fundamental key point in expressing shape of 3D polygon model in non-photorealistic rendering technique. Line recognition, however, requires a long period of calculation time and thus, various methods have been studied to accelerate the speed of the operation. This paper presents a new method that will accelerate the overall operation compared to the standard CPU-based method of extracting ink line. The new method will enhance the efficiency of the calculation speed by applying the parallel processing technique CUDA (Compute Unified Device Architecture) to the complex processes that consume a lot of time such as implicit surface calculation and feature point extraction. The overall performance will be tested and verified through various types of experiments with 3D polygon model.

关键词： Feature detection Line recognition 3D model parallel computing platform GPGPU

来源：评论

学校读者我要写书评

暂无评论

Toward cost-effective aeroelastic analysis on advanced parallel computing systems

引用

JOURNAL OF AIRCRAFT 1999年第4期36卷 710-715页

作者： Goodwin, SA Weed, RA Sankar, LN Raj, P Lockeed Martin Aeronaut Syst Computat Fluid Dynam Flight Sci Div Marietta GA 30063 USA Mississippi State Univ Natl Sci Fdn Res Ctr Computat Field Simulat Nichols Res Inc Vicksburg MS 39180 USA Georgia Inst Technol Sch Aerosp Engn Atlanta GA 30332 USA

Progress toward the development and validation of a fast, accurate, and cost effective aeroelastic method for several advanced parallel computing platforms is presented. The ENSAERO code, developed at NASA Ames Research Center, was selected for this research effort. To improve the performance, the capabilities of the constituent modules have been enhanced. The relative merits of four parallel computing environments are investigated: SGI workstation cluster, SGI Power Challenge machine, SGI Power Challenge cluster, and the IBM SP2 system. To assess the computational performance of the enhanced ENSAERO code, the results of unsteady Navier-Stokes simulations of the transonic how over a fully flexible aeroelastic arrow-wing body configuration are reported. In addition, to ensure that the modified version of ENSAERO performs to specifications and to evaluate the benefits of the enhancements, unsteady Euler/Navier-Stokes calculations for an AGARD standard aeroelastic configuration are done. To evaluate the level of accuracy of the enhanced system, the ENSAERO results are compared with established computational solutions and experimental data.

关键词： Dynamic Aeroelastic Analysis parallel computing Systems parallel computing platform Freestream Mach Number Navier Stokes Calculations Dynamic Pressure NASA Langley Research Center parallel computing Environment Angle of Attack CFL3D

来源：评论

学校读者我要写书评

暂无评论

Multiscale modeling of solid rocket motors: Computational aerodynamics methods for quasi-steady burning

引用

JOURNAL OF PROPULSION AND POWER 2006年第6期22卷 1382-1388页

作者： Stewart, D. Scott Tang, K. C. Yoo, Sunhee Brewster, Quinn Kuznetsov, Igor R. Univ Illinois Ctr Simulat Adv Rockets Urbana IL 61801 USA

We consider the problem of efficiently computing the stable burnback of a solid rocket motor when the motor is in the quasi-steady burning regime of operation. When the motor is modeled as a cavity, filled with a compressible fluid with injection from the solid-propellant surface, the problem is a standard one in steady computational aerodynamics. For large rockets, the problem of quasi-steady solid rocket motor core flow is analogous to the steady aerodynamic flow past a large aircraft flying at speeds such that compressible flow effects must be included. One can adopt advanced time-integration strategies that have been applied to commercial or military aircraft to solid rocket motor grain burning to compute a series of steady flows as the grain burns back to near completion. The slow regression of the burning solid-propellant surface is analogous to the motion of control surfaces on the aircraft. With straightforward two-timing, multiscale asymptotic analysis we develop a reduced quasi-steady description of the quasi-steady burning that is extensible to three dimensions. We show how to integrate reduced equations for stable quasi-steady motor burning and use the multigrid method as a representative method to obtain the steady flows in the frozen configurations.

关键词： Solid Rocket Motor Solid Propellants Compressible Fluid Rockets Computational Aerodynamics Multigrid Methods parallel computing platform Military Aircraft Control Surfaces Direct Numerical Simulation

来源：评论

学校读者我要写书评

暂无评论

Effect of Plasma-Based Control on Low-Reynolds-Number Flapping Airfoil Performance

引用

AIAA JOURNAL 2012年第1期50卷 131-147页

作者： Rizzetta, Donald P. Visbal, Miguel R. USAF Res Lab Computat Aerophys Branch Wright Patterson AFB OH 45433 USA

Large-eddy simulation is employed to investigate the use of plasma-based flow control for the flapping motion of a wing section at low Reynolds number. The SD7003 airfoil section and imposed oscillatory motion of the investigation are representative of micro air vehicle applications. Dielectric-barrier-discharge plasma actuation is used to modify the transitional flow and improve aerodynamic performance. Solutions are obtained to the Navier-Stokes equations that were augmented by source terms used to represent plasma-induced body forces imparted by the actuator on the fluid. A simple phenomenological model provided the body force resulting from the electric field generated by the plasma. The numerical method is based upon an implicit time-marching scheme with spatial high fidelity, an implicit large-eddy simulation approach, and domain decomposition in order to perform calculations on a parallel computing platform. Solutions are obtained for combined periodic pitching and plunging motion about an 8 mean angle of attack at chord-based Reynolds numbers of 30,000 and 60,000. Baseline simulations without control are compared with cases employing plasma actuation in order to assess effects on performance. Comparison is also made with experimental data, and a grid resolution study is performed for validation purposes. Plasma-based control is able to mitigate, but not completely eliminate, the massive separation that occurs during the unsteady motion. It is shown that plasma actuation can reduce drag by 80% over the flapping cycle and increase the lift-to-drag ratio by a factor of 5.

关键词： Airfoil Sections Aerodynamic Force Coefficients Aerodynamic Efficiency Plasma Actuator Transitional Flow Flapping Frequency Dielectric Barrier Discharge Micro Air Vehicle parallel computing platform Navier Stokes Equations

来源：评论

学校读者我要写书评

暂无评论

Turbomachine blade row interaction predictions with a three-dimensional finite element method

引用

JOURNAL OF PROPULSION AND POWER 2002年第5期18卷 978-989页

作者： Gottfried, DA Fleeter, S Purdue Univ Sch Mech Engn W Lafayette IN 47907 USA

High-cycle fatigue (HCF) is a key issue for the advancement of gas-turbine performance and endurance. Models simulating the cyclic aerodynamic forces experienced by gas-turbine vanes are necessary to make quantitative predictions of HCF during design. Although such models exist, there is an urgent need to compare them with benchmark data to assess their accuracy and reliability. In this study, TAM-ALE3D is utilized to simulate the inlet guide vane (IGV) and rotor blade rows in the Purdue Transonic Compressor at both part-speed and design-speed conditions. Of particular interest is the unsteady flow in the IGV row generated by the part-speed potential field and the design-speed shock system generated by the downstream rotor. To assess the accuracy of the TAM-ALE3D predictions, the 90% span instantaneous IGV vane-to-vane flowfield and vane surface pressures are correlated with appropriate state-of-the-art data.

关键词： Unsteady Turbomachinery Arbitrary Lagrangian Eulerian Aerodynamic Force Static Pressure Rotor Blades Advection Particle Image Velocimetry Conservation of Mass parallel computing platform Hexahedron Element

来源：评论

学校读者我要写书评

暂无评论

AEGIS: Autonomous Entity Global Intelligence System for Urban Air Mobility

AEGIS: Autonomous Entity Global Intelligence System for Urba...

引用

AIAA Aviation Forum

作者： Das, Aditya Marotta, Kristina Idris, Husni NASA Ames Res Ctr Flight Dynam Trajectory & Controls Branch Aviat Syst Div Moffett Field CA 94035 USA NASA Ames Res Ctr Aviat Syst Div Moffett Field CA 94035 USA

ISBN: (数字)9781624105982

ISBN: (纸本)9781624105982

This paper presents a global intelligence system that synthesizes aerial vehicles' real-time physical data, planned actions, and historical behavior into engineered data frames representing the collective state of the airspace and suitable for efficient machine learning consumption. These data frames are then learnt by a deep neural net to build a prediction model that estimates the expected evolution path of the current state, thereby identifying potential future conflicts. This approach lends itself to an automated early warning system that the aerial vehicles can implement onboard with a suitable edge computing module more efficiently and effectively than non-AI methods, and eventually take preventive or corrective measures towards self/collaborative resolution of the issues. Contrary to a centralized early warning system where all vehicles' task-space eventually converges to a global optimum state, the presented distributed global intelligence system brings in a balance between local utility functions of each vehicle and the global operating framework. This contributes to effectively handle the potential massive scaling in urban air mobility in the near future.

关键词： Urban Air Mobility Uncontrolled Airspace Bayesian Optimization parallel computing platform Convolutional Neural Network Unmanned Aircraft System Traffic Alert and Collision Avoidance System Air Traffic Management Airborne Separation Assurance Systems Flight Level

来源：评论

学校读者我要写书评

暂无评论

parallel Chebyshev Picard Method

Parallel Chebyshev Picard Method

引用

AIAA Science and Technology Forum and Exposition (AIAA SciTech)

作者： Atallah, Ahmed M. Younes, Ahmad Bani San Diego State Univ Univ Calif San Diego San Diego CA 92182 USA San Diego State Univ Dept Aerosp Engn San Diego CA 92182 USA

ISBN: (数字)9781624105951

ISBN: (纸本)9781624105951

Novel methods have been developed to perform high precision, long-term orbit propagation with immediate application to efficiently propagating catalogs of Resident Space Objects (RSOs). Such efficient propagation methods allow improved accounting for the uncertainty in the ephemeris of these objects. More fundamentally, it promises to be of broad utility in solving perturbed orbital motion. Latest development of Chebyshev Picard method (CPM) has enabled efficient and accurate results in serial formulations of orbital trajectory propagators;its performance is comparable to other state-of-practice numerical integrators. CPM approximates the force function using the orthogonal Chebyshev polynomials and iterates for the trajectory via Picard iteration. However, one significant advantage of CPM is that it is well suited to parallelization. Therefore, this paper presents a parallel implementation of the CPM method. Used in conjunction with Spherical Harmonics Model (SHM) and orthogonal Finite Element Model (FEM) gravity approximations, the CPM enables truly revolutionary speedups in orbit propagation without accuracy loss. For efficient propagation of eccentric orbits, a new segmentation scheme based on the orbit true anomaly is introduced to enhance the overall performance. We present numerical examples for propagating four Earth orbiting satellites considering both a 200 x 200 spherical harmonic gravity model (SHM) and the equivalent finite element model (FEM) representation to test the performance of the algorithm via parallel and serial computation.

关键词： Finite Element Modeling Earth Resident Space Object Spherical Harmonics True Anomaly Satellites Graphics Processing Unit Orbital Period parallel computing platform Numerical Integration

来源：评论

学校读者我要写书评

暂无评论

A Survey of Clustering Algorithms Based on parallel Mechanism

A Survey of Clustering Algorithms Based on Parallel Mechanis...

引用

2018 International Conference on Computer Modeling, Simulation and Algorithm（CMSA2018）

作者： Xingang Wang Bei Hang University

With the rapid development of the Internet and mobile Internet, the amount of data and information generated by people has dramatically increased. The demand for rapid processing of data by computers has become increasingly urgent. Clustering analysis is one of the most important data processing methods. Existing clustering algorithms have a high time complexity in calculating the center point and a large amount of resource consumption and poor execution efficiency in the serial processing of mass data. Therefore, efficient and accurate parallel clustering algorithms need to be studied. This paper introduced the parallel mechanism and its computing platform, summarized the existing parallel clustering algorithms, classified them according to clustering methods, and discuss the key technologies and platforms proposed in the existing work.

关键词： parallelism mechanism parallel computing platform parallel clustering algorithm

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：