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IEEE Annual Joint Conference: INFOCOM, IEEE Computer and Communications Societies

作者： Ye Tian Ratan Dey Yong Liu Keith W. Ross Anhui Key Laboratory of High Performance Computing University of Science and Technology of China Hefei Anhui China Polytechnic Institute of New York University Brooklyn NY USA

ISBN: (纸本)9781467307734;9781467307758

We perform a large-scale topology mapping and geolocation study for China's Internet. To overcome the limited number of Chinese PlanetLab nodes and looking glass servers, we leverage several unique features in China's Internet, including the hierarchical structure of the major ISPs and the abundance of IDCs. Using only 15 vantage points, we design a traceroute scheme that finds significantly more interfaces and links than iPlane with significantly fewer traceroute probes. We then consider the problem of geolocating router interfaces and end hosts in China. We develop a heuristic for clustering the interface topology of a hierarchical ISP, and then apply the heuristic to the major Chinese ISPs. We show that the clustering heuristic can geolocate router interfaces with significantly more detail and accuracy than can the existing geoIP databases in isolation, and the resulting clusters expose the major ISPs' provincial structure. Finally, using the clustering heuristic, we propose a methodology for improving commercial geoIP databases.

关键词： Geology Telecommunications

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Photonic crystals in proton-exchanged LiNbO3 waveguides for photonic applications

Photonic crystals in proton-exchanged LiNbO3 waveguides for ...

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2012 Photonics Global Conference, PGC 2012

作者： Jun, Deng Jia Wei Kumar, Vanga Sudheer Png, Ching Eng Bettiol, Andrew A. Danner, Aaron J. Department of Electrical and Computer Engineering National University of Singapore Singapore 117576 Singapore Institute of High Performance Computing Agency for Science Technology and Research 1 Fusionopolis Way #16-16 Connexis Singapore 138632 Singapore Henan Key Laboratory of Laser and Opto-electric Information Technology Zhengzhou University Henan 450052 China Department of Physics National University of Singapore Singapore 117542 Singapore

ISBN: (纸本)9781467325165

Photonic crystals realized in LiNbO3 have a great potential to reduce the size and increase the functionality of integrated optical devices. In order to accomplish these aims, fabrication know-how must be mastered yet it remains relatively uncharted. In this work we report the fabrication and optical characterization of photonic crystal structures in annealed proton exchanged (APE) LiNbO3 waveguides. In our work, channel waveguides were fabricated by photolithography patterning followed by immersing LiNbO 3 wafers in molten benzoic acid at 235°C for 5 h. The thickness and the composition profiles of the APE waveguides were measured using the secondary ion mass spectroscopy (SIMS) method. The experimental characterization of the photonic crystal waveguides was performed and a photonic stop band with good sharpness can be observed from the transmission spectra. © 2012 IEEE.

关键词： Niobium compounds

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Fast analysis of antennas mounted on platform using hybrid AIM-PO technique

Fast analysis of antennas mounted on platform using hybrid A...

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IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)

作者： Xing Wang Shu-Xi Gong Wei-Jiang Zhao Chao-Fu Wang Temasek Laboratories National University of Singapore Singapore National Key Laboratory of Science and Technology on Antennas and Microwaves Xidian University Xi'an Shaanxi China Department of Electronics and Photonics Institute of High Performance Computing Agency for Science Technology and Research Singapore

A novel hybridization of adaptive integral method (AIM) and physical optics (PO) is presented for fast analysis of antennas in the presence of electrically large conducting platform. A coupled electric field integral equation (EFIE), built in MoM region, is modified to couple the PO contributions into MoM ones. Then the AIM is employed to efficiently solve the coupled EFIE through speeding up all the matrix-vector multiplications with less memory requirement. Numerical examples show the accuracy and efficiency of the proposed technique.

关键词： Moment methods Memory management Microwave antennas Central Processing Unit Integral equations

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Dynamic Ionic Clusters with Flowing Electron Bubbles from Warm to Hot Dense Iron along the Hugoniot Curve

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Physical Review Letters 2012年第17期109卷 175701-175701页

作者： Jiayu Dai Dongdong Kang Zengxiu Zhao Yanqun Wu Jianmin Yuan Department of Physics College of Science National University of Defense Technology Changsha 410073 People’s Republic of China College of Optoelectric Science and Engineering National University of Defense Technology Changsha 410073 People’s Republic of China State Key Laboratory of High Performance Computing National University of Defense Technology Changsha 410073 People’s Republic of China

Complex structures of warm and hot dense matter are essential to understanding the behavior of materials in high energy density processes and provide new features of matter constitutions. Here, around a new unified first-principles determined Hugoniot curve of iron from the normal condensed condition up to 1 Gbar, the novel structures characterized by the ionic clusters with electron bubbles are found using quantum Langevin molecular dynamics. Subsistence of complex clusters can persist in the time scale of 50 fs dynamically with quantum flowing bubbles, which are produced by the interplay of Fermi electron degeneracy, the ionic coupling, and the dynamical nature. With the inclusion of those complicated features in quantum Langevin molecular dynamics, the present equation of states could serve as a first-principles based database in a wide range of temperatures and densities.

关键词： ELECTRONS -- Research IRON ions ENERGY density QUANTUM theory LANGEVIN equations MOLECULAR dynamics

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Photonic crystals in proton-exchanged LiNbO3 waveguides for photonic applications

Photonic crystals in proton-exchanged LiNbO3 waveguides for ...

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IEEE PhotonicsGlobal@Singapore, IPGC

作者： Deng Jun Jia Wei Vanga Sudheer Kumar Ching Eng Png Andrew A. Bettiol Aaron J. Danner Institute of High Performance Computing Agency for Science Technology and Research (ASTAR) Singapore Department of Electrical and Computer Engineering National University of Singapore Singapore Henan Key Laboratory of Laser and O pto-electric Information Technology Zhengzhou University Henan China Department of Physics National University of Singapore Singapore

Photonic crystals realized in LiNbO 3 have a great potential to reduce the size and increase the functionality of integrated optical devices. In order to accomplish these aims, fabrication know-how must be mastered yet it remains relatively uncharted. In this work we report the fabrication and optical characterization of photonic crystal structures in annealed proton exchanged (APE) LiNbO 3 waveguides. In our work, channel waveguides were fabricated by photolithography patterning followed by immersing LiNbO 3 wafers in molten benzoic acid at 235°C for 5 h. The thickness and the composition profiles of the APE waveguides were measured using the secondary ion mass spectroscopy (SIMS) method. The experimental characterization of the photonic crystal waveguides was performed and a photonic stop band with good sharpness can be observed from the transmission spectra.

关键词： Photonics Optical fibers Optical device fabrication Optical imaging Optical polarization

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performance optimization of Top-K queries on GPU

Performance optimization of Top-K queries on GPU

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2011 4th International Symposium on Parallel Architectures, Algorithms and Programming, PAAP 2011

作者： Luo, Tao Sun, Guang-Zhong Chen, Guoliang Key Laboratory on High Performance Computing Anhui Province University of Science and Technology of China Hefei Anhui China

ISBN: (纸本)9780769545752

With the development of web search engines, the concern on real-time performance of Top-k queries has attracted more and more attention. We study implementation of classic algorithm - No Random Access Algorithm - in order to optimize performance of Top-k queries on GPU. We present a novel GPU algorithm by using the features of CUDA's programming model. Experiment results show that an implementation of the algorithm on one GPU runs more than 7000 times faster than a single core implementation on a latest CPU. © 2011 IEEE.

关键词： Graphics processing unit

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Efficient approximate top-κ Query algorithm using cube index

Efficient approximate top-κ Query algorithm using cube inde...

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13th Asia-Pacific Conference on Web technology, APWeb 2011

作者： Chen, Dongqu Sun, Guang-Zhong Gong, Neil Zhenqiang Key Laboratory on High Performance Computing Anhui Province School of Computer Science and Technology University of Science and Technology of China China

ISBN: (纸本)9783642202902

Exact top-k query processing has attracted much attention recently because of its wide use in many research areas. Since missing the truly best answers is inherent and unavoidable due to the user's subjective judgment, and the cost of processing exact top-κ queries is highly expensive for datasets with huge volume, it is intriguing to answer approximate top-κ query instead. In this paper, we first define a novel kind of approximate top-κ query, called μ - approximate top-κ query. Then we introduce an efficient index structure, i.e. cube index, based on which, we propose our novel Cube Index Algorithm (CIA). We analyze the complexity of both constructing cube index and CIA algorithm. Moreover, extensive experiments show that CIA performs much better than the well-known approximate TA θ algorithm [3]. © 2011 Springer-Verlag Berlin Heidelberg.

关键词： Query processing

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Modeling TCP sack steady state performance in lossy networks

Modeling TCP sack steady state performance in lossy networks

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International Conference on Information Networking 2011, ICOIN 2011

作者： Xu, Wei Xu, Yinlong Wu, Xiaohu Ou, Kaiqian School of Computer Science and Technology University of Science and Technology of China Key Laboratory on High Performance Computing Anhui Province Hefei 230026 China

ISBN: (纸本)9781612846613

Modeling TCP performance is an important issue which has attracted research over the past two decades. Most literatures are to measure the steady state throughput of TCP Reno, however, few existing literatures are on modeling the throughput of the other important TCP variant, TCP Selective Acknowledgment (Sack). In this paper, an analytic model for the TCP Sack steady state throughput is proposed as a function of round trip time and packet loss rate. The presented model not only captures the behavior of fast recovery mechanism of Sack which is the main difference with Reno but also takes unsuccessful retransmission timeout in consideration. Those results simulated by ns2 show that our model can capture steady state TCP Sack throughput more accurately than existing TCP Sack model. ©2011 IEEE.

关键词： Throughput

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A hybrid scheme against pollution attack to network coding

A hybrid scheme against pollution attack to network coding

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IEEE International Symposium on Network Coding

作者： Wu, Xiaohu Xu, Yinlong Xiang, Liping Xu, Wei School of Computer Science and Technology University of Science and Technology of China Key Laboratory on High Performance Computing Anhui Province Hefei 230026 China

ISBN: (纸本)9781612841403

Network coding allows intermediate nodes to encode data packets, which increases network throughput and enhances robustness. However, once a node injects corrupted data blocks into a network, the polluted data blocks will propagate quickly with network coding. Based on linear subspace and key pre-distribution, this paper proposes a HYBRID scheme against pollution attacks to network coding. Some typical properties of HYBRID are: (1) all nodes are able to detect polluted data blocks;(2) it prevents tag pollution attacks;(3) It does not need a very large field to implement and is computationally efficient;(4) It does not need a time synchronization of all nodes in a network and the correctness of each data packet can be verified immediately when it arrives at a node. © 2011 IEEE.

关键词： Network coding

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Estimation of BSP network parameters based on MPI-2 one-sided operation

Estimation of BSP network parameters based on MPI-2 one-side...

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2011 4th International Symposium on Parallel Architectures, Algorithms and Programming, PAAP 2011

作者： Zhou, Huan Zheng, Qi-Long Wang, Rui Anhui High Performance Computing Key Laboratory at Hefei USTC Hefei 230027 China College of Computer Science and Technology USTC Hefei 230027 China

ISBN: (纸本)9780769545752

The BSP network parameters are usually measured by one-sided communication functions in BSPlib standard, which can't reflect the communication performance of the message passing parallel machines effectively. Furthermore, the onesided operation is becoming more and more popular with high-performance communication as the release of MPI-2 version. This paper further investigates the implementation of MPI-2 one-sided operation, and proposes a new estimation scheme that using the onesided operation for BSP network parameters g and L, they are measured on the DOWNING 4000A Cluster machine under the condition of different number of processes which adopts the all-to-all total change communication mode. And it validates the correctness and the validity of the MPI program cost analysis, which makes use of the BSP model and a parallel radix-2 FFT algorithm based on the BSP model. The results prove that the new estimation scheme is effective and practical for the DOWNING Cluster machine and other similar message passing parallel machines. © 2011 IEEE.

关键词： Message passing

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