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ABSTRACT: A novel phase retrieval method for hard X-ray in-line phase contrast imaging is presented in this paper, which is based on a parallel hybrid genetic algorithm. Different from the tradition numerical algorithm, our approach is a parallel hybrid intelligent method. Some techniques, such as parallel computing, simulated annealing selection and elitist migration, are all combined together with the genetic algorithm to accelerate the convergence and improve the quality of the final output. The proposed method is validated by numerical simulations on MATLAB platform. Experimental results show that the parallel hybrid GA is a satisfying solution for phase retrieval because of its fast convergence and high speed-up.
Computational Sciences and Optimization (CSO), 2011 Fourth International Joint Conference on; 05/2011
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ABSTRACT: H.264/AVC is a merging popular video coding standard which have new features, variable block size motion estimation (ME)，quarter-pixel prediction accuracy, multi-reference frames for inter prediction, 4x4 integer DCT. A H.264 open source, X264 code set, adopt motion estimation which consists of diamond search, hexagonal search, uneven multi-hexagon search, exhaustive search and hadamard exhaustive search. According to statistic values, the time-consuming of ME operations during HDTV(1920x1080p) encoding is about 60-80 percent within whole H.264 algorithm. Considering the characteristics of FPGAs, flexibility, inherent parallel characteristic and the rapid prototyping, a parallel operation architecture of FPGA-based was designed with a Lattice ECP2M chip. The experiment results which include the time-consuming, the wave forms and the calculation cycles were analyzed with special tools, ispLever 6.1, ModelSim, etc. and the Post-Place & Route layout of a project was shown in the end of this paper. It is concluded that the FPGA chip can deal with HDTV sequences as a co-processor in a video coding system.
2011 Fourth International Conference on Information and Computing. 05/2009; 2:317-320.
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ABSTRACT: The emerging coding standard H.264 is mainly intended for video transmission in many areas. Considering the peculiarity of High-Definition TV (HDTV) encoding, the fast development of parallel technology and high-speed DSPs, the efficient hardware architectures were researched for the algorithm of H.264 encoding. After analyzing the experiment results from different platforms, we discussed the application method and the principle of picture splitting as parallel granularity. The parallel system structure based on multi-DSPs, which has many promising characteristics such as powerful computing capability, broad I/O bandwidth, topology flexibility, and expansibility, adopted frame-level load grain, was designed.
Computer Science and Software Engineering, 2008 International Conference on; 01/2009
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11th International Conference on Computer-Aided Design and Computer Graphics, CAD/Graphics 2009, Huangshan, China, August 19-21, 2009; 01/2009
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ABSTRACT: Generally speaking, it is assumed that the smaller the size of the FDTD (finite difference time domain) cell, the better the result will be. In this communication, we show that the shape of the computational domain can significantly influence the accuracy of the results in the FDTD simulation. Specifically, an improper choice for the domain shape can dramatically degrade the FDTD results even if we use a very fine mesh in the simulation. An electromagnetic interference (EMI) problem is used as an example to demonstrate the proper selection process.
Antennas and Propagation Society International Symposium, 2008. AP-S 2008. IEEE; 08/2008
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ABSTRACT: This paper focus on a general-purpose FDTD-based solver, called general electromagnetic solver (GEMS), designed for modeling and simulating a wide variety of large-scale electromagnetic problems, involving microwave circuits, RF and digital electronic packages, as well as open region radiation and scattering problems. We begin by observing that there is a rapidly growing trend in computational electromagnetics (CEM) that is significantly impacting the computing landscape, namely the use of highly-parallel computers to address large and complex problems.
Electromagnetic Compatibility and 19th International Zurich Symposium on Electromagnetic Compatibility, 2008. APEMC 2008. Asia-Pacific Symposium on; 06/2008
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ABSTRACT: In this communication, we investigate the performance of parallel FDTD code on a Gigabit Ethernet and optical network. It is fact that the optical network is necessary for a large cluster due to its wide bandwidth and small latency. However, for a small cluster, the Gigabit Ethernet will have a better ratio of performance to price. We also investigate the difference between high performance server and regular PC for the parallel FDTD code. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2465–2467, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23661
Microwave and Optical Technology Letters 06/2008; 50(9):2465 - 2467. · 0.62 Impact Factor
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ABSTRACT: Since the input impedance of half wavelength dipole antenna is well known, therefore, a dipole antenna is frequently used to validate the computational electromagnetic method. Though its structure is relatively simple, it is not a simple problem for the most computational electromagnetic methods. In this article, we investigate the input impedance of half wavelength dipole antenna using the FDTD method. Numerical experiments have demonstrated that the FDTD method can be used to accurately calculate its input impedance using uniform mesh, nonuniform mesh, or subgridding. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2335–2337, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23631
Microwave and Optical Technology Letters 06/2008; 50(9):2335 - 2337. · 0.62 Impact Factor
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Wenhua Yu,
Xiaoling Yang,
Yongjun Liu,
Lai-ching Ma,
Tao Sul,
Neng-Tien Huang,
R. Mittra,
R. Maaskant, Yongquan Lu,
Qing Che,
Rul Lu,
Zhiwu Su
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ABSTRACT: Rapid developments in high-performance supercomputers, with upward of 65,536 processors and 32 terabytes of memory, have dramatically changed the landscape in computational electromagnetics. The IBM BlueGene/L supercomputer are examples. They have recently made it possible to solve extremely large problems efficiently. For instance, they have reduced 52 days of simulation on a single Pentium 4 processor to only about 10 minutes on 4000 processors in a BlueGene/L supercomputer. In this article, we investigate the performance of a parallel Finite-Difference Time-Domain (FDTD) code on a large BlueGene/L system. We show that the efficiency of the code is excellent, and can reach up to 90%. The code has been used to simulate a number of electrically large problems, including a 100 * 100 patch antenna array, a 144-element dual- polarized Vivaldi array, a 40-element helical antenna array, and an electronic packaging problem. The results presented serve to demonstrate the efficiency of the parallelization of the code on the BlueGene/L system. In addition, we also introduce the development of the high-performance Beowulf clusters for simulation of electrically large problems.
IEEE Antennas and Propagation Magazine 05/2008; · 0.97 Impact Factor
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ABSTRACT: In this communication, we investigate the efficiency of a parallel BOR-FDTD code on a commonly used Beowulf cluster which is connected via an Ethernet or Myrinet networking system. The efficiency of a parallel BOR-FDTD code is relatively high since it only requires data exchanging between the processors on the subdomain boundary. A satellite reflector antenna is simulated by using the parallel BOR-FDTD code in order to verify the parallel code we developed. Numerical experiments have demonstrated both software design and networking system play an important role in the efficiency of parallel processing. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1398–1401, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI.10.1002/mop.22423
Microwave and Optical Technology Letters 03/2007; 49(6):1398 - 1401. · 0.62 Impact Factor
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CHINA HPC 2007, Proceedings of the Asian Technology Information Program's (ATIP's) Third Workshop on High-Performance Computing in China: "Solution Approaches to Impediments for High Performance Computing", Supercomputing 2007 (SC07), November 11, 2007, Reno, Nevada, USA; 01/2007
