检索结果-内蒙古大学图书馆

proceedings of the 2012 ieee 26th International parallel and distributed processing symposium Workshops, IPDPSW 2012 2012年 2271-2271页

作者： Cirne, Walfredo Desai, Narayan Frachtenberg, Eitan Schwiegelshohn, Uwe Google United States Argonne National Laboratory United States Facebook United States Technische Universität Dortmund Germany

来源：评论

学校读者我要写书评

暂无评论

Towards Cyber-Eco Systems: Networked Sensing, Inference and Control for distributed Ecological Experiments

Towards Cyber-Eco Systems: Networked Sensing, Inference and ...

引用

ieee/ACM International Conference on Green Computing and Communications (GreenCom) / ieee International Conference on Internet of things (ithings) / 5th ieee International Conference on Cyber, Physical and Social Computing (CPSCom)

作者： Flikkema, Paul G. Yamamoto, Kenji R. Boegli, Samuel Porter, Christopher Heinrich, Paul No Arizona Univ Wireless Networks Res Lab Flagstaff AZ 86011 USA Blue Plasma Engn Scottsdale AZ USA No Arizona Univ Merriam Powell Ctr Environm Res Flagstaff AZ 86011 USA

ISBN: (纸本)9780769548654;9781467351461

New applications are motivating and informing the design of sensor/actuator networks, and, more broadly, research in cyber-physical systems (CPS). Our knowledge of many physical systems is uncertain, so that sensing and actuation must be mediated by inference of the structure and parameters of physical-system models. One CPS application domain of growing interest is ecological systems, motivated by the need to understand plant survival and growth as a function of genetics, environment, and climate change. For this effort to be successful, we must be able to infer coupled, data-driven predictive models of plant growth dynamics in response to climate drivers that allow incorporation of uncertainty. We are developing an architecture and implementation for precise fine-scale control of irrigation in an array of geographically-distributed outdoor gardens on an elevational gradient of over 1500 m, allowing design of experiments that combine control of temperature and water availability. this paper describes a system architecture and implementation for this class of cyber-eco systems, including sensor/actuator node design, site-level networking, data assimilation, inference, and distributed control. Among its innovations are a modular, parallel-processing node hardware design allowing real-time processing and heterogeneous nodes, energy-aware hardware/software design, and a networking protocol that builds in trade-offs between energy conservation and latency. throughout, we emphasize the changes in system architecture required as missions evolve from sensing-only to sensing, inference, and control. We also describe our developmental implementation of the architecture and its planned deployment. Future extensions will likely add negative control of precipitation using active rain-out shelters and additional plant-level control of air or soil temperature.

关键词： sensor sensor/actuator cyber-physical systems cyber-eco systems networks ecological systems engineering

来源：评论

学校读者我要写书评

暂无评论

Performance evaluation of an opportunistic distributed power control procedure for wireless multiple access

Performance evaluation of an opportunistic distributed power...

引用

International symposium on Communications Control and Signal processing (ISCCSP)

作者： Romeo Giuliano Franco Mazzenga Marco Petracca Remo Pomposini Dipartimento di Ingegneria dellImpresa University of Roma Tor Vergata Rome Italy Radio Laboratories Laboratori di Radiocomunicazioni Consorzio Università Industria Rome Italy

In wireless ad hoc networks, effective spatial channel reuse can maximize the achievable throughput. To this aim, power-controlled multiple access MAC protocols seems to be a viable solution to allow a greater number of simultaneous transmissions on the same channel. In this paper, we propose an opportunistic distributed algorithm to increase throughput in ad-hoc networks by exploiting the spatial reuse deriving from the implementation of power controlled data transmissions. Performance is evaluated through simulation. Results show that a marked improvement of the aggregate channel utilization can be achieved with respect to the no power control schemes (such as in the typical ieee 802.11 systems) by properly selecting the link margins for fading and interference.

关键词： Interference Power control Receivers Ad hoc networks Data communication Transmitters Wireless communication

来源：评论

学校读者我要写书评

暂无评论

L2 Cache Performance Analysis and Optimizations for processing HDF5 Data on Multi-core Nodes

L2 Cache Performance Analysis and Optimizations for Processi...

引用

International symposium on parallel and distributed processing with Applications, ISPA

作者： Rajdeep Bhowmik Madhusudhan Govindaraju Grid and Cloud Computing Research Laboratory Department of Computer Science SUNY at Binghamton Binghamton NY USA

It is important to design and develop scientific middleware libraries to harness the opportunities presented by emerging multi-core processors that are available on grid and cloud environments. Scientific middleware libraries not adhering or adapting to this programming paradigm can suffer from severe performance limitations while executing on emerging multi-core processors. In this paper, we focus on the utilization of a critical shared resource on chip multiprocessors (CMPs), the L2 cache. the way in which an application schedules and assigns processing work to each thread determines the access pattern of the shared L2 cache, which may result in either enhancing or diminishing the effects of memory latency on a multi-core processor. therefore, while processing scientific datasets such as HDF5, it is essential to conduct fine-grained analysis of cache utilization, to make informed processing and scheduling decisions in multi-threaded programming. In this paper, using the TAU toolkit for performance feedback from dual- and quad-core machines, we analyze and recommend methods for effective scheduling of threads on multi-core nodes to augment the performance of scientific applications processing HDF5 data. We discuss the benefits that can be achieved by using L2 Cache-Affinity and L2 Balanced-Set based scheduling algorithms for improving L2 cache performance and effectively the overall execution time.

关键词： Instruction sets Multicore processing Optimization Processor scheduling Hardware Libraries Middleware

来源：评论

学校读者我要写书评

暂无评论

Concurrent access control using subcarrier signature in heterogeneous MIMO-based WLAN

Concurrent access control using subcarrier signature in hete...

引用

5th International Workshop on Multiple Access Communications, MACOM 2012

作者： Shen, Hu Lv, Shaohe Sun, Yanqiang Dong, Xuan Wang, Xiaodong Zhou, Xingming National Key Laboratory of Parallel and Distributed Processing National University of Defense Technology Changsha 410073 China Institute of Network Information and Security National University of Defense Technology Changsha 410073 China

ISBN: (纸本)9783642349751

In recent WLAN standards (such as ieee 802.11n), MIMO (Multiple Input Multiple Output) is deployed to provide high data transmission rate. It is however challenging to efficiently share the channel resources among different stations/users. In this paper, we study the MAC protocol in heterogeneous MIMO-based WLAN to effectively exploit the capability of concurrent transmission. We propose a novel subcarrier encoding method, which uses frequency signatures to perform the control message exchange between the AP and multiple stations simultaneously. Afterwards, a MAC protocol, HT-MIMO MAC, is presented to support concurrent transmission in both the uplink and downlink directions. HT-MIMO MAC supports link adaptation and is completely compatible with legacy stations. We evaluate the performance of the HT-MIMO MAC protocol and find that it outperforms the existing 802.11 MAC protocol with SU-MIMO and the downlink MU-MIMO MAC protocol in [9] with a remarkable throughput gains up to 86%. © 2012 Springer-Verlag.

关键词： MIMO systems

来源：评论

学校读者我要写书评

暂无评论

distributed Virtual Diskless Checkpointing: A Highly Fault Tolerant Scheme for Virtualized Clusters

Distributed Virtual Diskless Checkpointing: A Highly Fault T...

引用

ieee International symposium on parallel and distributed processing Workshops and Phd Forum (IPDPSW)

作者： Ben Eckart Xubin He Chentao Wu Ferrol Aderholdt Fang Han Stephen Scott Robotics Institute Carnegie Mellon University Pittsburgh PA USA Department of Electrical and Computer Engineering Virginia Commonwealth University Richmond VA USA Department of Computer Science Tennessee Technological University Cookeville TN USA Oak Ridge National Laboratory Oak Ridge TN USA

ISBN: (纸本)9781467309745

Today's high-end computing systems are facing a crisis of high failure rates due to increased numbers of components. Recent studies have shown that traditional fault tolerant techniques incur overheads that more than double execution times on these highly parallel machines. thus, future high-end computing must be able to provide adequate fault tolerance at an acceptable cost or the burdens of fault management will severely affect the viability of such systems. Cluster virtualization offers a potentially unique solution for fault management, but brings significant overhead, especially for I/O. In this paper, we propose a novel diskless check pointing technique on clusters of virtual machines. Our technique splits Virtual Machines into sets of orthogonal RAID systems and distributes parity evenly across the cluster, similar to a RAID-5 configuration, but using VM images as data elements. Our theoretical analysis shows that our technique significantly reduces the overhead associated with check pointing by removing the disk I/O bottleneck.

关键词： Checkpointing Fault tolerant systems Fault tolerance Program processors Hardware Virtual machining Libraries

来源：评论

学校读者我要写书评

暂无评论

Enabling In-situ Execution of Coupled Scientific Workflow on Multi-core Platform

Enabling In-situ Execution of Coupled Scientific Workflow on...

引用

International symposium on parallel and distributed processing (IPDPS)

作者： Fan Zhang Ciprian Docan Manish Parashar Scott Klasky Norbert Podhorszki Hasan Abbasi Center for Autonomic Computing Rutgers University Piscataway NJ USA Oak Ridge National Laboratory Oak Ridge TN USA

ISBN: (纸本)9781467309752

Emerging scientific application workflows are composed of heterogeneous coupled component applications that simulate different aspects of the physical phenomena being modeled, and that interact and exchange significant volumes of data at runtime. With the increasing performance gap between on-chip data sharing and off-chip data transfers in current systems based on multicore processors, moving large volumes of data using communication network fabric can significantly impact performance. As a result, minimizing the amount of inter-application data exchanges that are across compute nodes and use the network is critical to achieving overall application performance and system efficiency. In this paper, we investigate the in-situ execution of the coupled components of a scientific application workflow so as to maximize on-chip exchange of data. Specifically, we present a distributed data sharing and task execution framework that (1) employs data-centric task placement to map computations from the coupled applications onto processor cores so that a large portion of the data exchanges can be performed using the intra-node shared memory, (2) provides a shared space programming abstraction that supplements existing parallel programming models (e.g., message passing) with specialized one-sided asynchronous data access operators and can be used to express coordination and data exchanges between the coupled components. We also present the implementation of the framework and its experimental evaluation on the Jaguar Cray XT5 at Oak Ridge National Laboratory.

关键词： Data models Atmospheric modeling Couplings distributed databases Computational modeling Program processors Servers

来源：评论

学校读者我要写书评

暂无评论

Low-Cost parallel Algorithms for 2:1 Octree Balance

Low-Cost Parallel Algorithms for 2:1 Octree Balance

引用

International symposium on parallel and distributed processing (IPDPS)

作者： Tobin Isaac Carsten Burstedde Omar Ghattas Institute for Computational Engineering and Sciences (ICES) University of Texas Austin USA Institut für Numerische Simulation (INS) Rheinische Friedrich-Wilhelms-Universität Germany Institute for Computational Engineering and Sciences (ICES) Jackson School of Geosciences Department of Mechanical Engineering University of Texas Austin USA

the logical structure of a forest of octrees can be used to create scalable algorithms for parallel adaptive mesh refinement (AMR), which has recently been demonstrated for several petascale applications. Among various frequently used octree-based mesh operations, including refinement, coarsening, partitioning, and enumerating nodes, ensuring a 2:1 size balance between neighboring elements has historically been the most expensive in terms of CPU time and communication volume. the 2:1 balance operation is thus a primary target to optimize. One important component of a parallel balance algorithm is the ability to determine whether any two given octants have a consistent distance/size relation. Based on new logical concepts we propose fast algorithms for making this decision for all types of 2:1 balance conditions in 2D and 3D. Since we are able to achieve this without constructing any parent nodes in the tree that would otherwise need to be sorted and communicated, we can significantly reduce the required memory and communication volume. In addition, we propose a lightweight collective algorithm for reversing the asymmetric communication pattern induced by non-local octant interactions. We have implemented our improvements as part of the opensource “p4est” software. Benchmarking this code with both synthetic and simulation-driven adapted meshes we are able to demonstrate much reduced runtime and excellent weak and strong scalability. On our largest benchmark problem with 5.13 × 10 11 octants the new 2:1 balance algorithm executes in less than 8 seconds on 112,128 CPU cores of the Jaguar Cray XT5 supercomputer.

关键词： Octrees Partitioning algorithms Arrays Vegetation Insulation Educational institutions USA Councils

来源：评论

学校读者我要写书评

暂无评论

Fast and Efficient Graph Traversal Algorithm for CPUs: Maximizing Single-Node Efficiency

Fast and Efficient Graph Traversal Algorithm for CPUs: Maxim...

引用

International symposium on parallel and distributed processing (IPDPS)

作者： Jatin Chhugani Nadathur Satish Changkyu Kim Jason Sewall Pradeep Dubey Parallel Computing Laboratory Intel Corporation USA

Graph-based structures are being increasingly used to model data and relations among data in a number of fields. Graph-based databases are becoming more popular as a means to better represent such data. Graph traversal is a key component in graph algorithms such as reachability and graph matching. Since the scale of data stored and queried in these databases is increasing, it is important to obtain high performing implementations of graph traversal that can efficiently utilize the processing power of modern processors. In this work, we present a scalable Breadth-First Search Traversal algorithm for modern multi-socket, multi-core CPUs. Our algorithm uses lock- and atomic-free operations on a cache-resident structure for arbitrary sized graphs to filter out expensive main memory accesses, and completely and efficiently utilizes all available bandwidth resources. We propose a work distribution approach for multi-socket platforms that ensures load-balancing while keeping cross-socket communication low. We provide a detailed analytical model that accurately projects the performance of our single- and multi-socket traversal algorithms to within 5-10% of obtained performance. Our analytical model serves as a useful tool to analyze performance bottlenecks on modern CPUs. When measured on various synthetic and real-world graphs with a wide range of graph sizes, vertex degrees and graph diameters, our implementation on a dual-socket Intel ® Xeon ® X5570 (Intel microarchitecture code name Nehalem) system achieves 1.5X-13.2X performance speedup over the best reported numbers. We achieve around 1 Billion traversed edges per second on a scale-free R-MAT graph with 64M vertices and 2 Billion edges on a dual-socket Nehalem system. Our optimized algorithm is useful as a building block for efficient multi-node implementations and future exascale systems, thereby allowing them to ride the trend of increasing per-node compute and bandwidth resources.

关键词： Sockets Arrays Bandwidth Instruction sets Partitioning algorithms

来源：评论

学校读者我要写书评

暂无评论

Checkpoint selection in fault recovery based on byzantine fault model 4th

Checkpoint selection in fault recovery based on byzantine fa...

引用

4th International Conference on Computational Intelligence and Communication Networks, CICN 2012

作者： Xu, Xinhai Lin, Yufei National Laboratory for Parallel and Distributed Processing Computer School National University of Defense Technology Changsha Hunan China

ISBN: (纸本)9781467329811

Nowadays, with the growth of the performance, the reliability problem of supercomputers becomes more and more serious. In order to complete an application with small fault recovery overhead, Checkpoint/Restart(C/R) methods are widely used. So far, the mainstream C/R methods are either based on Fail-Stop fault model or making the system(or program) do error detection before storing checkpoints, so they can ensure the correctness of every checkpoint. However, the faults occurring in the systems in real world are more accordant with the Byzantine fault model, and in order to pursue the higher practical performance, neither the system nor the program implements any fault detection mechanism. Consequently, there may be errors in the checkpoints. this paper studies the checkpoint selection problem that which checkpoint should be selected as the object of rolling back after system occurring failure, based on Byzantine fault model. We design a framework of checkpoint selection, and then, based on it, propose three checkpoint selection strategies: conservative strategy, aggressive strategy and statistical strategy. the simulation results show that: the conservative strategy shows its superiority when the error latent period is long, while the aggressive strategy behaves oppositely, the statistical strategy has a stable efficiency, only 50% more overhead compared to the ideal checkpoint selection when the checkpoint period is the half of mean time between faults. © 2012 ieee.

关键词： Fault tolerance

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：