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IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Naiyang Guan Long Lan Dacheng Tao Zhigang Luo Xuejun Yang Science and Technology on Parallel and Distributed Processing Laboratory School of Computer Science National University of Defense Technology Changsha Hunan 410073 China Centre for Quantum Computation and Intelligent Systems FEIT University of Technology Sydney Sydney NSW 2007 Australia State Key Laboratory of High Performance Computing National University of Defense Technology Changsha Hunan 410073 China

ISBN: (纸本)9781479928941

Regarding the non-negativity property of the magnitude spectrogram of speech signals, nonnegative matrix factorization (NMF) has obtained promising performance for speech separation by independently learning a dictionary on the speech signals of each known speaker. However, traditional NM-F fails to represent the mixture signals accurately because the dictionaries for speakers are learned in the absence of mixture signals. In this paper, we propose a new transductive NMF algorithm (TNMF) to jointly learn a dictionary on both speech signals of each speaker and the mixture signals to be separated. Since TNMF learns a more descriptive dictionary by encoding the mixture signals than that learned by NMF, it significantly boosts the separation performance. Experiments results on a popular TIMIT dataset show that the proposed TNMF-based methods outperform traditional NMF-based methods for separating the monophonic mixtures of speech signals of known speakers.

关键词： Speech Dictionaries as Topic Loudspeakers NMF protocol signals mixtures factorization HIGH-PERFORMANCE

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Balancing CPU-GPU Collaborative High-Order CFD Simulations on the Tianhe-1A Supercomputer

Balancing CPU-GPU Collaborative High-Order CFD Simulations o...

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International Symposium on parallel and distributed Processing (IPDPS)

作者： Chuanfu Xu Lilun Zhang Xiaogang Deng Jianbin Fang Guangxue Wang Wei Cao Yonggang Che Yongxian Wang Wei Liu College of Computer Science National University of Defense Technology Changsha P.R. China parallel and Distributed Systems Group Delft University of Technology Delft The Netherlands State Key Laboratory of Aerodynamics Mianyang P.R. China National University of Defense Technology Changsha Hunan CN

ISBN: (纸本)9781479938018

HOSTA is an in-house high-order CFD software that can simulate complex flows with complex geometries. Large scale high-order CFD simulations using HOSTA require massive HPC resources, thus motivating us to port it onto modern GPU accelerated supercomputers like Tianhe-1A. To achieve a greater speedup and fully tap the potential of Tianhe-1A, we collaborate CPU and GPU for HOSTA instead of using a naive GPU-only approach. We present multiple novel techniques to balance the loads between the store-poor GPU and the store-rich CPU, and overlap the collaborative computation and communication as far as possible. Taking CPU and GPU load balance into account, we improve the maximum simulation problem size per Tianhe-1A node for HOSTA by 2.3X, meanwhile the collaborative approach can improve the performance by around 45% compared to the GPU-only approach. Scalability tests show that HOSTA can achieve a parallel efficiency of above 60% on 1024 Tianhe-1A nodes. With our method, we have successfully simulated China's large civil airplane configuration C919 containing 150M grid cells. To our best knowledge, this is the first paper that reports a CPUGPU collaborative high-order accurate aerodynamic simulation result with such a complex grid geometry.

关键词： Graphics processing units Kernel Collaboration Computational fluid dynamics Computational modeling Memory management Performance evaluation

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Efficiently indexing sparse wide tablesin cloud computing

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Information Technology Journal 2013年第20期12卷 5415-5423页

作者： Huang, Bin Peng, Yuxing Department of Computer Huaihua University 418008 Huaihua China School of Computer Science Wuhan University 430072 Wuhan China National Laboratory of Parallel and Distributed Processing National University of Defense Technology 410073 Changsha China

For its perception of unlimited resources and infinite scalability, Cloud Computing has emerged as a pervasive paradigm for hosting? data-centric applications in large computing infrastructures. The data produced by these applications are essentially sparse and wide and may change schema frequently, traditional relational data model is inappropriate for their data management. A new data model, called Sparse Wide Table, was introduced for this task. Unfortunately, we have to face many challenges in building the secondary index for Sparse Wide Table in cloud, as the distributed and column-oriented storage which eliminates a number of NULLs. In this study, we present a three-level index scheme for efficient data processing in the Cloud. Our approach can be summarized as follows. First, we build an index for each column by which the records can be rebuilt easily. Second, we build a bitmap index for each storage node which only indexes the data residing on the node. Third, we organize the storage nodes as a structured overlay and each node maintains a portion of the global index for the all different data. The global index is a bitmap index to indicate the node each data resides in. Finally, based on the three-level index scheme, some query algorithms are implemented. We conduct extensive experiments on a LAN and the results demonstrate that our indexing scheme is dynamic, efficient and scalable. © 2013 Asian Network for Scientific Information.

关键词： Cloud computing

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A distributed algorithm for SI transactions serializability in cloud computing

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Information Technology Journal 2013年第24期12卷 8435-8445页

作者： Huang, Bin Peng, Yuxing Peng, Xiaoning School of Computer Science Wuhan University Wuhan 430072 China Department of Computer Huaihua University Huaihua 418008 China National Laboratory of Parallel and Distributed Processing National University of Defense Technology Changsha 410073 China

There are well known anomalies permitted by snapshot isolation that can lead to violations of data consistency by interleaving transactions that individually maintain consistency. Until now, there are some ways to prevent these anomalies only in single computer and there are not the corresponding solving methods in cloud computing. This paper describes our PDCC algorithm to detect cycles in a snapshot isolation dependency graph and abort transactions to break the cycle in cloud computing. The algorithm ensures serializable executions for SI transactions in cloud computing. Based on the transaction concurrency control of Percolator, we have implemented our algorithm in an open source cloud database system (HBase) and our performance study shows that PDCC throughput and scalability are good. © 2013 Asian Network for Scientific Information.

关键词： Cloud computing

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Effective top-down active learning for hierarchical text classification

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17th Pacific-Asia Conference on Knowledge Discovery and Data Mining, PAKDD 2013

作者： Li, Xiao Ling, Charles X. Wang, Huaimin Department of Computer Science University of Western Ontario Canada National Laboratory for Parallel and Distributed Processing National University of Defense Technology China

ISBN: (纸本)9783642374555

Hierarchical text classification is an important task in many real-world applications. To build an accurate hierarchical classification system with many categories, usually a very large number of documents must be labeled and provided. This can be very costly. Active learning has been shown to effectively reduce the labeling effort in traditional (flat) text classification, but few works have been done in hierarchical text classification due to several challenges. A major challenge is to reduce the so-called out-of-domain queries. Previous state-of-the-art approaches tackle this challenge by simultaneously forming the unlabeled pools on all the categories regardless of the inherited hierarchical dependence of classifiers. In this paper, we propose a novel top-down hierarchical active learning framework, and effective strategies to tackle this and other challenges. With extensive experiments on eight real-world hierarchical text datasets, we demonstrate that our strategies are highly effective, and they outperform the state-of-the-art hierarchical active learning methods by reducing 20% to 40% queries. © Springer-Verlag 2013.

关键词： Text processing

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Supporting environmental modelling with Taverna workflows, web services and desktop grid technology 7

Supporting environmental modelling with Taverna workflows, w...

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7th International Congress on Environmental Modelling and Software, iEMSs 2014

作者： Horváth, Ferenc Ittzés, Péter Ittzés, Dóra Barcza, Zoltán Dobor, Laura Hidy, Dóra Marosi, Attila Hardisty, Alex Institute of Ecology and Botany Centre for Ecological Research Hungarian Academy of Sciences Alkotmány u. 2-4. Vácrátót2163 Hungary Department of Meteorology Eötvös Loránd University Pázmány sétány 1/A Budapest1117 Hungary Institute of Botany and Ecophysiology Szent Istvan University Páter K. u.1. Gödöllo2100 Hungary Laboratory of Parallel and Distributed Systems Institute for Computer Science and Control Hungarian Academy of Sciences P.O. Box 63 Budapest1518 Hungary School of Computer Science and Informatics Cardiff University Queen's Buildings 5 The Parade Roath CardiffCF24 3AA United Kingdom

Ecosystem functioning, climate change, and multiple interactions among biogeochemical cycles, climate system, site conditions and land use options are leading-edge topics in recent environmental modelling. Terrestrial ecosystem models are widely used to support carbon sequestration and ecosystem studies under various ecological circumstances. Our team uses the Biome-BGC model (Numerical Terradynamic Simulation Group, University of Montana), and develops an improved model version of it, called Biome-BGC MuSo. Both the original and the improved model estimate the ecosystem scale storage and fluxes of energy, carbon, nitrogen and water, controlled by various physical and biological processes on a daily time-scale. Web services were also developed and integrated with parallel processing desktop grid technology. Taverna workflow management system was used to build up and carry out elaborated workflows like seamless data flow to model simulation, Monte Carlo experiment, model sensitivity analysis, model-data fusion, estimation of ecosystem service indicators or extensive spatial modelling. Straightforward management of complex data analysis tasks, organized into appropriately documented, shared and reusable scientific workflows enables researchers to carry out detailed and scientifically challenging 'in silico' experiments and applications that could open new directions in ecosystem research and in a broader sense it supports progress in environmental modelling. The workflow approach built upon these web services allows even the most complicated computations to be initiated without the need of programming skills and deep understanding of model structure and initialization. The developments enable a wider array of scientists to perform ecosystem scale simulations, and to perform analyses not previously possible due to high complexity and computational demand.

关键词： Web services

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Opportunities and pitfalls of multi-core scaling using hardware transaction memory 13

Opportunities and pitfalls of multi-core scaling using hardw...

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4th Asia-Pacific Workshop on systems, APSys 2013

作者： Wang, Zhaoguo Qian, Hao Chen, Haibo Li, Jinyang School of Computer Science Fudan University China Institute of Parallel and Distributed Systems Shanghai Jiao Tong University China Department of Computer Science New York University United States

ISBN: (纸本)9781450323161

Hardware transactional memory, which holds the promise to simplify and scale up multicore synchronization, has recently become available in main stream processors in the form of Intel's restricted transactional memory (RTM). Will RTM be a panacea for multicore scaling? This paper tries to shed some light on this question by studying the performance scalability of a concurrent skip list using competing synchronization techniques, including fine-grained locking, lock-free and RTM (using both Intel's RTM emulator and a real RTM machine). Our experience suggests that RTM indeed simplifies the implementation, however, a lot of care must be taken to get good performance. Specifically, to avoid excessive aborts due to RTM capacity miss or conflicts, programmers should move memory allocation/deallocation out of RTM region, tuning fallback functions, and use compiler optimization. Copyright 2013 ACM.

关键词： Storage allocation (computer)

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On Mobilizing Processes of Cyber Movement Organizations

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IFAC Proceedings Volumes 2014年第3期47卷 9853-9857页

作者： Tao Wang Zhong Liu Kainan Cui Jie Zhang Fei-Yue Wang C.L. Philip Chen College of Information System and Management National University of Defense Technology Changsha 410073 China The State Key Laboratory of Management and Control for Complex Systems Chinese Academy of Sciences Beijing 100190 China The Research Center for Computational Experiments and Parallel Systems Technology National University of Defense Technology Changsha 410073 China Department of Computer and Information Science Science and Technology University of Macau Macau China

—Cyber Movement Organization (CMO) is a special kind of social movement organization on the Web. In this paper, we propose a model to simulate the mobilizing process of CMO, which consists of the individual unit, organization unit, and the mobilizing mechanisms. The mobilizing mechanisms has three sub-mechanisms: the participation mechanism, the choice mechanism, and the inviting mechanism. A dataset of more than two million “human flesh search” related microblogs is used to validate the model. Empirical results show that our model can capture the key features of the real-world mobilizing process.

关键词： Cyber Movement Organizations (CMO) Social Network Analysis Human Flesh Search (HFS) Simulation Social Movement Organizations Resource Mobilization

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Maximum lifetime broadcast in mobile sensor networks 1

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12th International Conference on Ad-hoc, Mobile and Wireless Networks, ADHOC-NOW 2013

作者： Nunes, Bruno Barboza, Frederico Assis, Flávio LaSiD - Distributed Systems Laboratory DCC - Department of Computer Science UFBA - Federal University of Bahia Salvador Bahia Brazil

ISBN: (数字)9783642392474

ISBN: (纸本)9783642392467

In this paper we investigate the Maximum Lifetime Broadcast (MLB) problem, i.e. the problem of extending network lifetime when a series of broadcast operations is executed, in sensor networks with mobile nodes. For this problem, we present two localized algorithms (nodes use only 2-hop information), namely LPrim and LMCP, which are based on trees with minimum highest cost edges and shortest paths trees, respectively. The algorithms were evaluated through simulations under three distinct mobility models and compared against common broadcasting techniques (broadcasting based on a Connected Dominating Set and Flooding). According to our experiments, LPrim outperformed alternative solutions in terms of the number of successfully executed broadcasts (network lifetime) and in terms of the energy consumed by broadcast. © 2013 Springer-Verlag.

关键词： Sensor nodes

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Flexible triangular formation keeping of marine robotic vehicles using range measurements 1

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IFAC Proceedings Volumes 2014年第3期47卷 5145-5150页

作者： Francisco Rego Jorge M. Soares António Pascoal A. Pedro Aguiar Colin Jones Laboratory of Robotics and Systems in Engineering and Science Instituto Superior Técnico University of Lisbon Lisbon Portugal Department of Electrical and Computer Engineering Faculty of Engineering University of Porto Porto Portugal Institute of Mechanical Engineering School of Engineering École Polytechnique Fédérale de Lausanne Lausanne Switzerland Distributed Intelligent Systems and Algorithms Laboratory School of Architecture Civil and Environmental Engineering École Polytechnique Fédérale de Lausanne Lausanne Switzerland National Institute of Oceanography Dona Paula Goa India

This paper addresses the problem of keeping an autonomous marine vehicle in a moving triangular formation by regulating its position with respect to two leader vehicles. The follower vehicle has no prior knowledge of the path described by the leaders but has access to their heading angle and is able to measure inter-vehicle ranges. It is assumed that the distance between the leaders is constant and known. A control strategy is adopted that generates speed and heading commands so as to drive suitably defined along track and cross track errors to zero. The commands are used as input to local inner loops for yaw and speed control. The paper describes the algorithms derived for range-based control and assesses their performance in simulations using realistic models of the vehicles involved. Tests with three autonomous marine vehicles equipped with acoustic modems and ranging devices allow for the evaluation of the performance of the algorithms in a real-world situation.

关键词： Autonomous Vehicles Marine systems Control Laws Formation Control Station Keeping Triangular Formations

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