ppxscal/embedding_network huggingface dataset:
Evaluating the Impact of Simultaneous Round Participation and Decentralized Decision on the Performance of Consensus
Authors: Livia Sampaio, Michel Hurfin, Francisco Brasileiro, Fabiola Greve
Venue: Proceedings of the 37th Annual IEEE/IFIP International Conference on Dependable Systems and Networks (2007)

Consensus services have been recognized as fundamental building blocks for fault-tolerant distributed systems. Many different protocols to implement such a service have been proposed, however, not a lot of effort has been placed in evaluating their performance. In particular, in the context of round-based consensus protocols for asynchronous systems augmented with failure detectors, there has been some work on evaluating how the QoS of the failure detector impacts the performance of the protocols, as well as on the trade-off between having faster decentralized decision at the expenses of generating more network load. These studies, however, focus on protocols that have no mechanism to deal with an eventual bad QoS provided by the failure detector, and have a decision pattern that is either completely centralized - only one process being able to autonomously decide - or completely decentralized - all processes being able to autonomously decide. This paper reports a thorough evaluation of the performance of a consensus protocol that has two unique features. Firstly, it mitigates the problems due to bad QoS delivered by the failure detector by allowing processes to simultaneously participate in multiple rounds. Secondly, it allows its decision pattern to be configured to have different numbers of processors allowed to autonomously decide. We have measured the decision latency of the protocol to conduct the performance analysis. The results, obtained by means of simulation, highlight the advantages and limitations of the two mechanisms and allow one to understand in a comprehensive framework how the protocol's parameters should be set, such that the best performance is achieved depending on the application's requirements.
QoS-aware mobile service transactions in a wireless environment: Research Articles
Authors: Muhammad Younas, Kuo-Ming Chao, Ping Wang, Chun-Lung Huang
Venue: Concurrency and Computation: Practice Experience (2007)

Mobile computing greatly facilitates the provision of mobile services using portable and handheld devices which are connected through wireless networks. A pre-requisite for the provision of an effective service is to ensure quality of service (QoS) during the concurrent execution of requests and system or network failures. This paper presents a new transaction management approach for the provision of mobile services which is based on advanced transaction models and fuzzy selection criteria. It employs a novel QoS consensus moderation approach in order to select preferred mobile services from among various alternatives, thus providing multiple pathways to the completion of mobile service transactions. Unlike traditional transaction management schemes, the proposed approach takes into account QoS attributes in the commit process of mobile service transactions. The proposed approach is implemented as a prototype tool and evaluated through a number of experiments. Experimental results show that the proposed approach effectively selects mobile services and significantly increases the throughput (i.e. commit rate) of mobile service transactions. Copyright &copy; 2007 John Wiley & Sons, Ltd.
Acoustic adaptation using nonlinear transformations of HMM parameters
Authors: V. Abrash
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 02 (1996)

Speech recognition performance degrades significantly when there is a mismatch between testing and training conditions. Linear transformation-based maximum-likelihood (ML) techniques have been proposed recently to tackle this problem. We extend this approach to use nonlinear transformations. These are implemented by multilayer perceptrons (MLPs) which transform the Gaussian means. We derive a generalized expectation-maximization (GEM) training algorithm to estimate the MLP weights. Some preliminary experimental results on nonnative speaker adaptation are presented.
Large 2-transitive arcs
Authors: A. Montinaro
Venue: Journal of Combinatorial Theory Series A (2007)

The projective planes of order n with a collineation group acting 2-transitively on an arc of length v, with n>v>=n/2, are investigated and several new examples are provided.
A Distributed Efficient Architecture for Wireless Sensor Networks
Authors: Chuan Lin, Yan-Xiang He, Chao Peng, Laurence T. Yang
Venue: Proceedings of the 21st International Conference on Advanced Information Networking and Applications Workshops - Volume 02 (2007)

Sensor networking has emerged as a promising tool for monitoring and actuating the devices of the physical world, employing self-organizing networks of battery-powered wireless sensors that can sense, process, and communicate. Though many specific technical challenges remain and deserve much further study, the primary factor currently limiting progress in sensor networks is not these challenges but is instead the lack of an overall sensor network architecture [1]. In this paper, we characterize the unique design requirements of sensor networks infrastructure, and propose a Cubic and Cross-Layer (CCL) sensor network architecture as a suitable architecture for sensor networks. CCL enables cross-layering using a notification service, adaptability of the protocols to application-specific needs, and a communication abstraction for data-centric communication. In our architecture, we argue that the sensor network has a common abstract-sensor service protocol (SSP), which can provide services rich enough for applications and keep the interface platform-independent. While many aspects of deployed sensor networks will be specific to particular applications, we have begun to identify key building blocks that will enable a wide range of applications.
Practical Routing in Delay-Tolerant Networks
Authors: Evan P. C. Jones Lily Li Jakub K. Schmidtke Paul A. S. Ward
Venue: IEEE Transactions on Mobile Computing (2007)

Delay-tolerant networks (DTNs) have the potential to interconnect devices in regions that current networking technology cannot reach. To realize the DTN vision, routes must be found over multiple unreliable, intermittently-connected hops. In this paper we present a practical routing protocol that uses only observed information about the network. We designed a metric that estimates the average waiting time for each potential next hop. This learned topology information is distributed using a link-state routing protocol, where the link-state packets are "flooded” using epidemic routing. The routing is recomputed each time connections are established, allowing messages to take advantage of unpredictable contacts. A message is forwarded if the topology suggests that the connected node is "closer” to the destination than the current node. We demonstrate through simulation that our protocol provides performance similar to that of schemes that have global knowledge of the network topology, yet without requiring that knowledge. Further, it requires significantly less resources than the alternative, epidemic routing, suggesting that our approach scales better with the number of messages in the network. This performance is achieved with minimal protocol overhead for networks of approximately 100 nodes.
Novel mapping of a linear QR architecture
Authors: G. Lightbody
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 04 (1999)

This paper presents a novel architecture mapping technique which was essential in the design of a QR array which forms the core processor of a single chip adaptive beamforming system. The mapping technique assigns a QR triangular array of 2m/sup 2/+3m+1 cells down onto a linear architecture of m+1 processors. The mapping results in a linear systolic architecture with one hundred percent hardware utilisation, local interconnects and individual processors for boundary and internal cell operations. In addition, this paper highlights the effect latency has on the validity of the linear architecture.
Integrating InfoVis and GeoVis Components
Authors: Mikael Jern, Johan Franzen
Venue: Proceedings of the 11th International Conference Information Visualization (2007)

We introduce our generic "GeoAnalytics" visualization (GAV) component toolkit, based on the principles behind Visual Analytics (VA), for dynamically exploring time-varying, geographically referenced and multivariate attribute data. GAV includes components that supports a mixture of technologies from the three visualization fields; information visualization, geovisualization and scientific visualization. Our research concentrates on improving visual user interfaces (VUI) methods and extends existing visual representation techniques. In this paper, we demonstrate the synergy of integrating a wide range of different methods using multiple-linked views with a rich variety of possible coordination exploration ideas and allowing the user to view the information from different perspectives and try out different scenarios. The effectiveness of our proposed framework is demonstrated in a tailor-made case study assembled from GAV components and explores the supply and use of energy data for controlling the emission of carbon dioxide among 290 Swedish municipality regions during 1990-2004.
Resource allocation in stochastic, finite-capacity, multi-project systems through the cross entropy methodology
Authors: Izack Cohen, Boaz Golany, Avraham Shtub
Venue: Journal of Scheduling (2007)

This paper addresses the problem of resource allocation in a finite-capacity, stochastic (random) and dynamic multi-project system. The system is modeled as a queuing network that is controlled by limiting the number of concurrent projects. We propose a Cross Entropy (CE) based approach to determine near-optimal resource allocations to the entities that execute the projects. The performance of the suggested approach is demonstrated through numerical experiments and compared to that of a heuristic, rough-cut based method.
Ultra Fast Parallel Fault Analysis on Structurally Synthesized BDDs
Authors: Raimund Ubar, Sergei Devadze, Jaan Raik, Artur Jutman
Venue: Proceedings of the 12th IEEE European Test Symposium (2007)

An efficient method of parallel fault simulation for combinational circuits is proposed. The method is based on structurally synthesized BDDs (SSBDD) which represent gate-level circuits at higher, macro level where macros represent subnetworks of gates. Converting gate-level circuits to the macro-level is accompanied with fault collapsing. A parallel fault analysis algorithm for SSBDDs was developed. For the faults at fanout stems a new full Boolean differential based parallel fault analysis method is proposed. The algorithm is equivalent to exact critical path tracing. Because of the parallelism and higher abstraction level modeling the speed of analysis is considerably increased. Experimental data show that by the new method speed-up measured in several times has been achieved compared to the current state-of-the-art commercial tools and other exact critical path tracing methods.
Decomposition-Based Interior Point Methods for Two-Stage Stochastic Semidefinite Programming
Authors: Sanjay Mehrotra, M. Go&uml;khan O&uml;zevin
Venue: SIAM Journal on Optimization (2007)

We introduce two-stage stochastic semidefinite programs with recourse and present an interior point algorithm for solving these problems using Bender&rsquo;s decomposition. This decomposition algorithm and its analysis extend Zhao&rsquo;s results [Math. Program., 90 (2001), pp. 507-536] for stochastic linear programs. The convergence results are proved by showing that the logarithmic barrier associated with the recourse function of two-stage stochastic semidefinite programs with recourse is a strongly self-concordant barrier on the first stage solutions. The short-step variant of the algorithm requires $O(\sqrt{p+Kr} \ln \mu^0/\epsilon)$ Newton iterations to follow the first stage central path from a starting value of the barrier parameter $\mu^0$ to a terminating value &egr;. The long-step variant requires $O((p+Kr) \ln \mu^0/\epsilon)$ damped Newton iterations. The calculation of the gradient and Hessian of the recourse function and the first stage Newton direction decomposes across the second stage scenarios.
Changes in freshman engineers' attitudes-a cross institutional comparison: what makes a difference?
Authors: M. Besterfield-Sacre
Venue: Proceedings of the 26th Annual Frontiers in Education - Volume 01 (1996)

The Freshman Engineering Attitude Instrument, developed at the University of Pittsburgh, was administered to the 1995-96 freshman engineering classes at two campuses at the beginning of the year (the pre-survey). The survey was then repeated later in the first year (the post-survey). This paper discusses the results and demonstrates the potential effectiveness of the survey instrument for evaluating freshman engineering programs. This study serves as a pilot for a larger, more comprehensive national survey.
Developing a department-wide learning assessment program
Authors: T. L. Skvarenina
Venue: Proceedings of the 30th Annual Frontiers in Education - Volume 01 (2000)

During the last several years (to 2000), the North Central Association of Colleges and Schools (NCA) shifted the focus of its accreditation visits from resource-based to outcome-based. Faced with an accreditation visit by NCA in the fall of 1999, Purdue University began developing a university-wide learning assessment program. A council was formed at the university level, with committees in each of the schools within the university. The School of Technology was one of the lenders in developing an assessment program, which was to be expected as it is a teaching-based, rather than research-based school. Most of the faculty were reluctant to have new requirements added to their workload. Thus, it was necessary to work as a team to develop requirements that were acceptable or at least palatable to the faculty. The paper describes how an assessment program was developed in the Department of Electrical Engineering Technology (EET) at Purdue in the hope that it will provide help to others who are starting the process of developing an assessment program. 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
Adaptive filtering for non-Gaussian processes
Authors: P. Kidmose
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 01 (2000)

A new stochastic gradient robust filtering method, based on a non-linear amplitude transformation, is proposed. The method requires no a priori knowledge of the characteristics of the input signals and it is insensitive to the signals distribution and to the stationarity of the signals. A simulation study, applying both synthetic and real-world signals, shows that the proposed method has overall better robustness performance, in terms of modeling error, compared with state-of-the-art robust filtering methods. A remarkable property of the proposed method is that it can handle double-talk in the acoustical echo-cancellation problem. 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
A Fast and Accurate approach for Full Chip Leakage Analysis of Nano-scale circuits considering Intra-die Correlations
Authors: Sarvesh Bhardwaj, Sarma Vrudhula
Venue: Proceedings of the 20th International Conference on VLSI Design held jointly with 6th International Conference: Embedded Systems (2007)

This paper presents an accurate and efficient approach for estimating the full chip leakage in the presence of intra-die variations. We use an accurate model for leakage in which the leakage is exponentially dependent on a quadratic function of the device parameters. The intradie correlations in the device parameters are accounted by representing the parameters in terms of abstract independent random variables using Karhunen-Lo`eve Expansion. The total circuit leakage is computed using an efficient sum operation. Our results on ISCAS89 benchmark circuits show a speed up of up to 500× compared to Monte Carlo analysis, with average percentage difference in mean and variance being less than 1.5%.
Swarm intelligence methods for mobile ad hoc networks
Authors: Chien-Chung Shen
Venue:  (2007)

Mobile ad hoc networks (MANET) consist of mobile nodes that autonomously establish connectivity with each other via multihop wireless communications. Swarm intelligence (SI) refers to complex behaviors that emerge from simple individual behaviors and interactions, and is often observed among social insects such as ants and honeybees. This dissertation addresses three different problems in mobile ad hoc networks by applying the metaphor of swarm intelligence. Specifically, we address the problem of unicast routing, multicast packet delivery, and P2P systems in MANET. Applying SI techniques allows us to converge to good solutions quickly and adapt to the dynamic nature of MANETs without needing global information or centralized control. Our unicast routing protocol, ANSI, is a hybrid protocol which works over networks with both pure MANET nodes and infrastructure nodes (hybrid networks). We show, using simulation studies, that ANSI exhibits better or comparable performance when compared to AODV under a variety of conditions in a number of scenarios, both for UDP and TCP traffic. ANSI also responds faster to link breakages and shows better utilization of the MAC layer by expending lesser network overheads per packet delivered. The performance and characteristics of ANSI also motivates the use of TCP as a legitimate evaluation tool for studying the behavior of MANET unicast routing protocols. Simulation studies show that TCP reveals properties of routing protocols which are not understood when using UDP traffic, and points to the different behavior of MANET routing protocols under different scenarios.Our approach to packet recovery for multicast protocols, PIDIS, allows multicast routing protocols to recover lost packets without membership information and is persistent with packet recovery, while striking a balance between the variability of packet delivery and the aggressiveness of packet recovery. PIDIS maintains information about the next hops which help recover lost packets rather than maintain information about members which help recover lost packets, making the process less sensitive to topological fluctuation. Using simulation studies, we show that PIDIS shows better performance than a competing protocol by taking a different approach to gossip-based packet recovery. Our approach to peer-to-peer (P2P) systems over MANET, BTM, adapts the BitTorrent framework to MANET by introducing features of decentralized behavior, redundant services, and cross-layer interactions. In our simulations, BTM performs better in the MANET context as compared to a straightforward implementation of BitTorrent in MANET. We attribute the favorable observations of BTM to its decentralized, resource-redundant characteristics, which, when interacting with a congestion-aware routing protocol such as ANSI, improves TCP performance, and is able to provide an appropriate medium for content distribution in MANET.
Generalized Statistics Framework for Rate Distortion Theory
Authors: R. C. Venkatesan
Venue: Proceedings of the 2007 Data Compression Conference (2007)

A statistical physics analysis for the variational problem encountered in rate distortion (RD) theory and the information bottleneck (IB) method, derived within the generalized nonextensive statistics framework of Tsallis, is presented [1].
Blind source separation combining frequency-domain ICA and beamforming
Authors: H. Saruwatari
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 05 (2001)

We describe a new method of blind source separation (BSS) on a microphone array combining subband independent component analysis (ICA) and beamforming. The proposed array system consists of the following three sections: (1) subband-ICA-based BSS section with direction-of-arrival (DOA) estimation; (2) null beamforming section based on the estimated DOA information; and (3) integration of (1) and (2) based on the algorithm diversity. Using this technique, we can resolve the low-convergence problem through optimization in ICA. The results of the signal separation experiments reveal that a noise reduction rate (NRR) of about 18 dB is obtained under the nonreverberant condition, and NRR of 8 dB and 6 dB are obtained in the case that the reverberation times are 150 msec and 300 msec. These performances are superior to those of both simple ICA-based BSS and simple beamforming method.
A Fault-Tolerant Parallel Algorithm for Iterative Solution of the Laplace Equation
Authors: Amber Roy-Chowdhury, Prithviraj Banerjee
Venue: Proceedings of the 1993 International Conference on Parallel Processing - Volume 03 (1993)

Algorithm based fault tolerance is an inexpensive method of achieving fault tolerance without requiring any hardware modifications. Algorithm-based schemes have been proposed for a wide variety of numerical applications. However, for a particular class of numerical applications, namely those involving the iterative solution of linear systems, there exist almost no fault-tolerant algorithms in the literature. In this paper, we describe a fault-tolerant version of a parallel algorithm for iteratively solving the Laplace equation over a grid.
Low complexity LDPC code decoders for next generation standards
Authors: T. Brack, M. Alles, T. Lehnigk-Emden, F. Kienle, N. Wehn, N. E. L'Insalata, F. Rossi, M. Rovini, L. Fanucci
Venue: Proceedings of the conference on Design, automation and test in Europe (2007)

This paper presents the design of low complexity LDPC codes decoders for the upcoming WiFi (IEEE 802.11n), WiMax (IEEE802.16e) and DVB-S2 standards. A complete exploration of the design space spanning from the decoding schedules, the node processing approximations up to the top-level decoder architecture is detailed. According to this search state-of-the-art techniques for a low complexity design have been adopted in order to meet feasible high throughput decoder implementations. An analysis of the standardized codes from the decoder-aware point of view is also given, presenting, for each one, the implementation challenges (multi rates-length codes) and bottlenecks related to the complete coverage of the standards. Synthesis results on a present 65nm CMOS technology are provided on a generic decoder architecture.
The old man and the C
Authors: Evan Adams
Venue: Proceedings of the USENIX Summer 1994 Technical Conference on USENIX Summer 1994 Technical Conference - Volume 1 (1994)

"You can't teach an old dog new tricks" goes the old proverb. This is a story about a pack of old dogs (C programmers) and their odyssey of trying to learn new tricks (C++ programming). C++ is a large, complex language which can easily be abused, but also includes many features to help programmers more quickly write higher quality code. The TeamWare group consciously decided which C++ features to use and, just as importantly, which features not to use. We also incrementally adopted those features we chose to use. This resulted in a successful C++ experience.