ppxscal/embedding_network huggingface dataset:
EZHPC: Easy Access to High Performance Computing
Authors: Patti Duett, Wes Monceaux, Keith Rappold
Venue: Proceedings of the 2004 Users Group Conference (2004)

EZHPC is a Simple Object Access Protocol (SOAP)-based Web service that represents an Application Programming Interface (API) for securely accessing and manipulating high performance computing (HPC) resources. This service was created to make it "easy" for users who are unfamiliar with the HPC environment but would benefit from the utilization of these resources. It not only promotes HPC resources but also allows for the development of future applications through the reuse of this architecture. The API is exposed to developers as a SOAP-based Web service. Numerous API methodcalls are available, some of which include, but are not limited to, the ability to authenticate users against the HPC Kerberos system, move files to and from the HPC systems, submit and monitor batch jobs, access the Data Management System (DMS), etc. The Web service paradigm was chosen so that any type of user front end could be constructed to interact with the HPC resources. This includes stand alone user applications, Personal Digital Assistant (PDA)-based applications, Web applications, or inclusion in existing applications (ArcInfo, Watershed Modeling System (WMS), Groundwater Modeling System (GMS), Surface-Water Modeling System (SMS), etc. A fully functional client application has been developed to demonstrate the usage of the API. The authors will present a detailed inspection of the EZHPC architecture. The structure, usage, and security implications are described for each component of the system. In addition, the HPC-issued Kerberos user utilities, the Web server components, and the database component will be discussed. The client reference implementation will also be covered. The presentation will conclude with a summary of future enhancements and how these enhancements will expand the functionality of EZHPC, increasing its value to the user community.
Performance evaluation of dynamic load balancing scheme with load prediction mechanism using the load growing acceleration for massively parallel computers
Authors: Atsushi Nunome, Hiroaki Hirata, Haruo Niimi, Kiyoshi Shibayama
Venue: Systems and Computers in Japan (2004)

In this paper, we will propose a new dynamic load balancing scheme in which, based on the load conditions of the whole system of a massively parallel computer, the respective processing elements (PEs) will perform load balancing control in such a way that the loads are balanced as a whole. In the proposed scheme, although each PE exchanges load information with the neighboring PEs, load balancing is performed from a more global viewpoint, not considering only the load conditions of the surroundings of the transfer-origin PE: instead, each PE takes into consideration the load distribution in the whole system and its increasing and decreasing trends. Furthermore, in order to determine how the load quantity of the whole system changes, prediction of the load quantity is performed by using the load variation acceleration. By doing so, the transfer-origin PE is made to appropriately select the transfer destination of the load. Evaluation by simulation demonstrated, a performance enhancement of about 60&percnt; maximum compared to the scheme in which only the load quantities of the neighboring PEs are collected. &copy; 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(11): 69&ndash;79, 2004; Published online in Wiley InterScience (). DOI 10.1002&sol;scj.10212
Design and Implementation of Open MPI over Quadrics/Elan4
Authors: Weikuan Yu, Tim S. Woodall, Rich L. Graham, Dhabaleswar K. Panda
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Papers - Volume 01 (2005)

Open MPI is a project recently initiated to provide a fault-tolerant, multi-network capable implementation of MPI-2, based on experiences gained from FT-MPI, LA-MPI, LAM/MPI, and MVAPICH projects. Its initial communication architecture is layered on top of TCP/IP. In this paper, we have designed and implemented Open MPI point-to-point layer on top of a high-end interconnect, Quadrics/Elan4. The restriction of Quadrics static process model has been overcome to accommodate the requirement of MPI-2 dynamic process management. Quadrics Queued-based Direct Memory Access (QDMA) and Remote Direct Memory Access (RDMA) mechanisms have been integrated to form a low-overhead, high-performance transport layer. Lightweight asynchronous progress is made possible with a combination of Quadrics chained event and QDMA mechanisms. Experimental results indicate that the resulting point-to-point transport layer is able to achieve comparable performance to Quadrics native QDMA operations, from which it is derived. Our implementation provides an MPI-2 compliant message passing library over Quadrics/Elan4 with a performance comparable to MPICH-Quadrics.
Securely Utilizing External Computing Power
Authors: Yu Yu, Jussipekka Leiwo, Benjamin Premkumar
Venue: Proceedings of the International Conference on Information Technology: Coding and Computing (ITCC'05) - Volume I - Volume 01 (2005)

Suppose a weak power device Alice (e.g. a smart card) has some private program p. When carried outside, she may capture some private data x and want to compute p(x) but lacks the resources to do it. This paper presents a solution that allows a semi-honest Bob to execute the program in such an oblivious way that both x and p are computationally hidden and p(x) is disclosed to Bob only if Alice so wishes. We describe a procedure of encrypting a general program as well as explore the information hiding properties. Our solution is generic for most deterministic polynomial-time programs and it provides a programming interface for Alice, a compiler for Carol and a circuit evaluator program for Bob.
Design and Programming of Embedded Multiprocessors: An Interface-Centric Approach
Authors: Pieter van der Wolf, Erwin de Kock, Tomas Henriksson, Wido Kruijtzer, Gerben Essink
Venue: Proceedings of the international conference on Hardware/Software Codesign and System Synthesis: 2004 (2004)

We present design technology for the structured design and programming of embedded multi-processor systems. It comprises a task-level interface that can be used both for developing parallel application models and as a platform interface for implementing applications on multi-processor architectures. Associated mapping technology supports refinement of application models towards implementation. By linking application development and implementation aspects, the technology integrates the specification and design phases in the MPSoC design process. Two design cases demonstrate the efficient implementation of the platform interface on different architectures. Industry-wide standardization of a task-level interface can facilitate reuse of function-specific hardware / software modules across companies.
Generalized multichannel frequency-domain adaptive filtering: efficient realization and application to hands-free speech communication
Authors: Herbert Buchner, Jacob Benesty, Walter Kellermann
Venue: Signal Processing (2005)

In unknown environments where we need to identify, model, or track unknown and time-varying channels, adaptive filtering has been proven to be an effective tool. In this contribution, we focus on multichannel algorithms in the frequency domain that are especially well suited for input signals which are not only auto-correlated but also highly cross-correlated among the channels. These properties are particularly important for applications like multichannel acoustic echo cancellation. Most frequency-domain algorithms, as they are well known from the single-channel case, are derived from existing time-domain algorithms and are based on different heuristic strategies, e.g, for stepsize normalization. Here, we present a new rigorous derivation of a whole class of multichannel adaptive filtering algorithms in the frequency domain based on a recursive least-squares criterion. Then, from the normal equation, we derive a generic adaptive algorithm in the frequency domain. Due to the rigorous approach, the proposed framework inherently takes the coherence between all input signal channels into account. An analysis of this multichannel algorithm shows that the mean-squared error convergence is independent of the input signal statistics (i.e., both auto-correlation and cross-correlation). A useful approximation provides interesting links between some well-known algorithms for the single-channel case and the general multichannel framework. We also give design rules for important parameters to optimize the performance in practice. The computational complexity is kept low by introducing several new techniques, such as a robust recursive Kalman gain computation in the frequency domain and efficient fast Fourier transform (FFT) computation tailored to overlapping data blocks. Simulation results and real-time performance for applications such as multichannel acoustic echo cancellation show the high efficiency of the approach.
A large enterprise content distribution network: design, implementation and operation
Authors: Jacobus E. van der Merwe, Paul Gausman, Chuck D. Cranor, Rustam Akhmarov
Venue: Web content caching and distribution: proceedings of the 8th international workshop (2004)

Content distribution networks (CDNs) are becoming an important resource in enterprise networks. They are being used in applications ranging from broadcasted townhall-style meetings to the distribution of training and educational material. In this paper, we present the design, implementation and operation of a large enterprise CDN and describe some of the lessons we learned from our experiences building such a CDN.
Virtual Private/Overlay Network Design With Traffic Concentration and Shared Protection
Authors: Péter Hegyi, Markosz Maliosz, Ákos Ladányi, Tibor Cinkler
Venue: Journal of Network and Systems Management (2005)

In this paper different algorithms are presented and evaluated for designing Virtual Private/Overlay Network (VPNs/VONs) over any network that supports resource partitioning e.g. ATM (Asynchronous Transfer Mode), MPLS (Multi Protocol Label Switching), or SDH/SONET (Synchronous Digital Hierarchy/Synchronous Optical Networking). All algorithms incorporate protection as well. The VPNs/VONs are formed by full mesh demand sets between VPN/VON endpoints. The service demands of VPNs/VONs are characterized by the bandwidth requirements of node-pairs (pipe-model).We investigated four design modes with three pro-active path based shared protection path algorithms and four heuristics to calculate the pairs of paths. The design mode determines the means of traffic concentration. The protection path algorithms use Dijkstra's shortest path calculation with different edge weights. The demands are routed one-by-one, therefore the order in which they are processed matters.To eliminate this factor we used three heuristics (simulated allocation, simulated annealing, threshold accepting). We present numerical results obtained by simulation regarding the required total amount of capacity, the number of reserved edges, and the average length of paths.
NUMA-Aware Java Heaps for Server Applications
Authors: Mustafa M. Tikir, Jeffery K. Hollingsworth
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Papers - Volume 01 (2005)

We introduce a set of techniques to both measure and optimize memory access locality of Java applications running on cc-NUMA servers.These techniques work at the object level and use information gathered from embedded hardware performance monitors.We propose a new NUMA-aware Java heap layout.In addition, we propose using dynamic object migration during garbage collection to move objects local to the processors accessing them most.Our optimization technique reduced the number of non-local memory accesses in Java workloads generated from actual runs of the SPECjbb2000 benchmark by up to 41%, and also resulted in 40% reduction in workload execution time.
On signaling performance bounds of location management in next generation wireless networks
Authors: Eylem Ekici
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2004)

Next Generation Wireless Networks (NGWN) are proposed to achieve the goal of ubiquitous broadband networking by utilizing multiple wireless access subnetworks serving overlapping areas. Location management schemes play a very important role in NGWN since mobile users roam in coverage areas of these subnetworks simultaneously. The performance of location management schemes directly affect the overall performance of NGWN at large. In this paper, signaling performance bounds achievable by a location management scheme in the wireless portion of NGWN are presented. Assuming complete knowledge about user mobility, call arrival patterns, detailed maps of subnetworks coverage areas, and other NGWN parameters, equations for signaling performance achievable by an idealized location management scheme over the wireless interface has been derived. The performance bounds presented in this paper serve as an upper bound for the performance of any other location management scheme designed for NGWN. These bounds are intended to serve as a benchmark to determine how well a proposed location management scheme operates in NGWN and will help to determine how much room for improvement exists.
Verification of feature-based LTAGS
Authors: Bruce Shtelmakher
Venue: Journal of Computing Sciences in Colleges (2004)

In this paper I discuss two current projects, the conversion of LTAGs (lexicalized tree adjoining grammars) into SQL DDL format, and the verification of feature based LTAGs. This work is part of a larger project that considers verification and validation of language processing systems. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Orthogonal segment stabbing
Authors: Matthew J. Katz, Joseph S. B. Mitchell, Yuval Nir
Venue: Computational Geometry: Theory and Applications (2005)

We study a class of geometric stabbing/covering problems for sets of line segments, rays and lines in the plane. While we demonstrate that the problems on sets of horizontal/vertical line segments are NP-complete, we show that versions involving (parallel) rays or lines are polynomially solvable.
An Experimental Study of Parallel Biconnected Components Algorithms on Symmetric Multiprocessors (SMPs)
Authors: Guojing Cong, David A. Bader
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Papers - Volume 01 (2005)

We present an experimental study of parallel biconnected components algorithms employing several fundamental parallel primitives, e.g., prefix sum, list ranking, sorting, connectivity, spanning tree, and tree computations. Previous experimental studies of these primitives demonstrate reasonable parallel speedups. However, when these algorithms are used as subroutines to solve higher-level problems, there are two factors that hinder fast parallel implementations. One is parallel overhead, i.e., the large constant factors hidden in the asymptotic bounds; the other is the discrepancy among the data structures used in the primitives that brings non-negligible conversion cost. We present various optimization techniques and a new parallel algorithm that significantly improve the performance of finding biconnected components of a graph on symmetric multiprocessors (SMPs). Finding biconnected components has application in fault-tolerant network design, and is also used in graph planarity testing. Our parallel implementation achieves speedups up to 4 using 12 processors on a Sun E4500 for large, sparse graphs, and the source code is freely-available at our web site http://www.ece.unm.edu/~dbader.
Irregular Buffer-Zone Partitioning Reducing Synchronization Cost in SAMR
Authors: Johan Steensland
Venue: Proceedings of the 19th IEEE International Parallel and Distributed Processing Symposium (IPDPS'05) - Workshop 13 - Volume 14 (2005)

Achieving good scalability for large simulations based on structured adaptive mesh refinement is non-trivial. Performance is limited by the partitioner's ability to efficiently use the underlying parallel computerýs resources. Domainbased partitioners serve as a foundation for techniques designed to improve the scalability and they have traditionally been designed on the basis of an independence assumption regarding the computational flow among grid patches at different refinement levels. But this assumption does not hold in practice. Hence the effectiveness of these techniques is significantly impaired. This paper introduces a partitioning method designed on the true premises. The method is tested for four different applications exhibiting different behaviors. The results show that synchronization costs on average can be reduced by 75 percent. The conclusion is that the method is suitable as a foundation in general hierarchical methods designed to improve the scalability of structured adaptive mesh refinement applications.
Using Vanishing Points To Correct Camera Rotation In Images
Authors: Andrew C. Gallagher
Venue: Proceedings of the 2nd Canadian conference on Computer and Robot Vision (2005)

Vanishing points provide valuable information regarding the camera model used to capture an image. To explore the relationship between classes of camera models and the location of vanishing points, typical consumer photographic behavior is considered. Based on these findings, an algorithm is presented that can automatically remove the tilted appearance of an image captured with a camera rotated about the principal axis. The algorithm includes detecting vanishing points in an image, determining if any vanishing points are associated with vertical lines in the scene, computing the angle of rotation, and rotating the image. Results of the algorithm are shown for a set of images. The algorithm performs well and produces pleasing images from original images that contain undesirable levels of tilt.
Mobility assessment for MANETs requiring persistent links
Authors: Sanlin Xu, Kim Blackmore, Haley Jones
Venue: Papers presented at the 2005 workshop on Wireless traffic measurements and modeling (2005)

Mobile ad hoc networks (MANETs) have inherently dynamic topologies. It is important to be able to determine the reliability of the communication paths created under these difficult circumstances. For this purpose, mobility metrics have been proposed in the literature, but most existing research is based on simulation results and empirical analysis. We consider two metrics, link persistence and path persistence, and develop an analytical framework to derive their exact expressions as well as the corresponding link residual time and path residual time, under a random mobility environment. Such exact expressions constitute precise mathematical relationships between the network connectivity and the mobility of mobile nodes. This framework could be used to develop efficient algorithms for medium access control, or to optimize existing network routing protocols.
Minimizing memory requirement of real-time systems with concurrent garbage collector
Authors: Yuqiang Xian, Guangze Xiong
Venue: ACM SIGPLAN Notices (2005)

Garbage collection is a key feature in modern programming languages like Java&trade;. But it also brings some obstacles to real-time issues. Previous work had been put on solving the real-time problems of the garbage collector. Among it there are concurrent collectors that can provide truly real-time guarantees but they rely on a relatively large amount of redundant system memory. This paper concentrates on minimizing the system memory requirement with a new concurrent garbage collector which is based on a deferrable server together with a particular parameter configuration scheme proposed by this paper. The parameter configuration scheme is addressed using two different approaches, that is, the utilization based analysis and exact analysis of the selection of parameters. In this way, the worst-case response time of a garbage collector is minimized, and so is the worst-case system memory requirement, with the schedulability of tasks with hard time constraint not jeopardized. Furthermore, the simulation results demonstrate that, based on the new algorithm, the actual maximum system memory requirement for a given task set also becomes less than that of any previous concurrent collector.
A two level market model for resource allocation optimization in computational grid
Authors: Li ChunLin, Li Layuan
Venue: Proceedings of the 2nd conference on Computing frontiers (2005)

This paper investigates the interactions between agents representing users, services and resources to solve resource allocation optimization in computational grid. In order to reduce the computational complexity, we further decompose the grid resource allocation optimization into subproblems: grid user agent-grid service agent in service market and grid service agent-grid resource agent in resource market. Two-level market converges to its optimal points; a globally optimal point is achieved. Total user benefit of the computational grid is maximized when the equilibrium prices are obtained through the service market level optimization and resource market level optimization. It demonstrates a practical approach to market responsive resource pricing that can benefit grid providers and users alike. The paper presents two-level market grid resource pricing that is an iterative algorithm used to perform optimal resource allocation. The experiment shows that two-level market based resource pricing scheme outperforms one level market scheme in terms of task completion time and resource allocation efficiency
From vocal to multimodal: improving home phone services interaction?
Authors: Marc Mersiol
Venue: Proceedings of the 15th French-speaking conference on human-computer interaction on 15eme Conference Francophone sur l'Interaction Homme-Machine (2003)

This paper presents a study conducted on fifteen users. The latter carry out scenarios using three vocal services. Each service is used in its commercial version and in a version providing added textual information. This information is partially redundant with audio information delivered by the vocal services. The aim of this study is to check to what extent this added information modifies use of these services. The main results show that displaying text is favourably accepted by the users, but does not modify the completion of the scenarios.
Mining Association Rules from the Star Schema on a Parallel NCR Teradata Database System
Authors: Soon M. Chung, Murali Mangamuri
Venue: Proceedings of the International Conference on Information Technology: Coding and Computing (ITCC'05) - Volume I - Volume 01 (2005)

The Star schema is a popular relational database schema for representing multidimensional data in data warehouses. In this paper, we propose an efficient algorithm, named Star-miner, for mining association rules on the joined result of the tables in the Star schema. The proposed algorithm is designed to be implemented directly on a relational database system by using SQL queries. It is based on the unique properties of the Star schema and does not create the join result of the tables in the schema. We implemented and evaluated the Star-miner on a parallel NCR Teradata database system. The performance of Star-miner is more efficient and scalable than other algorithms which mine the association rules from the single joined table.