ppxscal/embedding_network huggingface dataset:
Evaluation of the Cluster Structure on the PIM/C Parallel Inference Machine
Authors: Toshiaki Tarui, Machiko Asaie, Noriyasu Ido, Takayuki Nakagawa, Mamoru Sugie
Venue: Proceedings of the 1994 International Conference on Parallel Processing - Volume 02 (1994)

The characteristics of a cluster-structure parallel computer are analyzed and evaluated on the PIM/c parallel inference machine, which consists of eight-processor shared-memory clusters communicating through a processor connected to a network. To avoid communication bottlenecks, the maximum number of processors in a cluster is limited by the ratio of communication operations to program-execution operations. Since this ratio can be as high as 30% on the PIM/c, the network receiving operations should be distributed to processors in the same cluster.
Negotiating Agreements Using Policies in Ubiquitous Computing Scenarios
Authors: V. Ramakrishna, Kevin Eustice, Peter Reiher
Venue: Proceedings of the IEEE International Conference on Service-Oriented Computing and Applications (2007)

The emerging ubiquitous computing vision is characterized by decentralized and ad hoc interoperation among devices and networks for access to services. Interacting devices or groups have highly heterogeneous resources and security and privacy concerns, and invariably belong to different security or administrative domains. Flexible and automated mechanisms are needed to achieve effective cross-domain interoperation that leads to a service or resource sharing agreement. We describe how policies representing system state, requirements and intent can be used to negotiate agreements between mutually unknown and untrusted systems that differ widely in their characteristics. Our negotiation protocol uses a small number of message types, which we have found to be sufficient for supporting a wide variety of application scenarios that occur on the Web, and that will likely be important in the ubiquitous computing environments of the future.
Exponential sinusoidal modeling of transitional speech segments
Authors: J. Jensen
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 01 (1999)

A generalized sinusoidal model for speech signal processing is studied. The main feature of the model is that the amplitude of each sinusoidal component is allowed to vary exponentially with time. We propose to use the model in transitional speech segments such as speech onsets and voiced/unvoiced transitions. Computer simulations with natural speech signals indicate substantial better modeling performance in both transitional and voiced regions compared with the traditional constant-amplitude sinusoidal model.
Shift invariant properties of the dual-tree complex wavelet transform
Authors: N. Kingsbury
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 03 (1999)

We discuss the shift invariant properties of a new implementation of the discrete wavelet transform, which employs a dual-tree of wavelet filters to obtain the real and imaginary parts of complex wavelet coefficients. This introduces limited redundancy (2/sup m/:1 for m-dimensional signals) and allows the transform to provide approximate shift invariance and directionally selective filters (properties lacking in the traditional wavelet transform) while preserving the usual properties of perfect reconstruction and computational efficiency with good well-balanced frequency responses.
Towards robustness to fast speech in ASR
Authors: N. Mirghafori, E. Fosler, N. Morgan
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 01 (1996)

Psychoacoustic studies show that human listeners are sensitive to speaking rate variations. Automatic speech recognition (ASR) systems are even more affected by the changes in rate, as double to quadruple word recognition error rates of average speakers have been observed for fast speakers on many ASR systems. In our earlier work (see Proceedings of EUROSPEECH95, p.491-4, 1995), we studied the causes of higher error and concluded that both the acoustic-phonetic and the phonological differences are sources of higher word error rates. In this work, we have studied various measures for quantifying rate of speech (ROS) and used simple methods for estimating the speaking rate of a novel utterance using ASR technology. We have also implemented mechanisms that make our ASR system more robust to fast speech. Using our ROS estimator to identify fast sentences in the test set, our rate-dependent system has 24.5% fewer errors on the fastest sentences and 6.2% fewer errors on all sentences of the WSJ93 evaluation set relative to the baseline HMM/MLP system.
Structural Conditions for Model-checking of Parameterized Networks
Authors: Siamak Nazari, John Thistle
Venue: Proceedings of the Seventh International Conference on Application of Concurrency to System Design (2007)

Sufficient conditions are given for effective model-checking of parameterized ring networks of isomorphic finite-state processes. Unlike others appearing in the literature, the present sufficient conditions do not restrict the mechanism whereby processes interact with one another, but rather the structure of the processes themselves. The results provide "cutoffs" for systems of "piecewise recognizable" processes, and show that all ring networks based on a given piecewise recognizable template fall into a finite number of weak trace equivalence classes. This result is then extended to three other finer equivalence relations: complete trace equivalence, weak failure equivalence and weak possible-futures equivalence. The paper also formalizes a notion of processes whose actions affect only a bounded number of other processes, using the property of "shuffled processes"; if a ring segment is a shuffled process, then all ring networks fall into a finite number of "weak bisimilarity" classes. It is also shown that each of the above equivalence relations preserve a subset of "observable modal logic" formulas.
A multipath interference cancellation technique for WCDMA downlink receivers: Research Articles
Authors: Derong Liu, Hossein Zare
Venue: International Journal of Communication Systems (2007)

In this paper, we present a simple interference cancellation technique for the downlink of wideband code-division multiple-access (WCDMA) systems in multipath environment. With the same knowledge required by a RAKE receiver, the present method acts as an equalizer and cancels the interfering multipath signals from the received signal to retrieve the orthogonality property of the received signal. The present receiver has a simple structure and it has significant performance gain against the RAKE receiver. In addition, the noise enhancement is negligible when there is a line of sight path or the channel power delay profile has an exponential decaying form. Copyright &copy; 2006 John Wiley & Sons, Ltd.
The AT&T AST OpenSource software collection
Authors: Glenn S. Fowler, David G. Korn, Stephen S. North, Kiem-Phong Vo
Venue: Proceedings of the annual conference on USENIX Annual Technical Conference (2000)

This paper introduces a large collection of reusable software components that AT&T is making available in an OpenSource form. This software has been widely used around the world and includes well-known components such as KornShell, Nmake, Graphviz, Sfio, Vmalloc and Cdt.
ICT, educational technology and educational instruments. Will what has worked work again elsewhere in the future?
Authors: Georges-Louis Baron, Eric Bruillard
Venue: Education and Information Technologies (2007)

Computers in education have been around for more than 30 years. They have been the vector not only of diverse forms of educational technology, but also of many new kinds of learning activities using software instruments. With the gradual trivialization of computer systems, the initially rather positive expectations about computers in education have progressively turned into more skeptical attitudes about the use of ICT. What is really working with computers in education? Was the investment worth the outcomes? The number of scientific studies focusing on these issues is huge. Most of their results have been obtained either by very focused experiments on some educational technology, generally involving a limited number of students, or by surveys, taking into account large numbers of learners but with little control about the kind of activities that were actually organized. Overall, hardly any conclusive results about possible causal implications of using ICT in learning have been obtained and there is no evidence about the stability of existing results over time. This paper, particularly taking into account the French experience, draws attention on the specific case of software instruments. These instruments do not exactly aim at performing more efficiently existing activities, but lead to invent new learning activities better in line with constructivist views. It suggests that, besides studies about what works, more research is in order about how it works and contends that what will work in the future is linked to the capability of the teaching profession and their allies to collectively build and discuss new interrogations and solutions to pedagogical problems, which will sustain and regulate the many discoveries of innovators.
Simulation of IPA gradients in hybrid network systems
Authors: Benjamin Melamed, Shuo Pan, Yorai Wardi
Venue: Computers Mathematics with Applications (2007)

Infinitesimal perturbation analysis (IPA) provides formulas for random gradients (derivatives) of performance measures with respect to parameters of interest, computed from sample paths of stochastic systems. In practice, IPA derivatives may be computed either from simulation runs or from empirical field data (when the formulas are nonparametric). Nonparametric IPA derivatives in fluid-flow queues have been recently derived for the loss volume and time average of buffer occupancy, with respect to buffer size, and arrival-rate or service-rate parameters. Additionally, these IPA derivatives have been shown to be unbiased in the sense that their expectation and differentiation operators commute, while their traditional discrete counterparts have long been known to be generally biased. Recent work has further shown how to map the computation of IPA derivatives from a fluid-flow queue to a compatible discrete counterpart without an appreciable loss of accuracy in performance measures. Thus, this work holds the promise of potential applications of IPA derivatives to gradient-based optimization of objective functions involving performance metrics parameterized by settable parameters in a queueing network context. This paper is an empirical study of IPA derivatives of individual queues within queueing systems which model telecommunications networks and some of their protocols. As a testbed, we used HNS (Hybrid Network Simulator) - a hybrid Java simulator of queueing networks with traffic streams subject to several telecommunications protocols. More specifically, the hybrid feature of HNS admits models with mixtures of discrete (packet) flows and continuous (fluid) flows, and collects detailed statistics and IPA derivatives for all flow types. The paper outlines the mapping of IPA derivatives from the fluid domain to the packet domain as implemented in HNS, and studies the accuracy of IPA derivatives in compatible fluid and packet queueing models, as well as the stabilization of their values in time. Our experimental results lend empirical support to the contention that IPA derivatives can be accurately computed from discrete versions by adopting a fluid-flow view. Furthermore, the long-run values of various IPA derivatives are empirically shown to stabilize quite fast. Finally, the results provide the basis and motivation for IPA applications to the optimization of telecommunications network design and to potential new open-loop protocols that take advantage of IPA information.
Rationale and assessment of a fully asynchronous model for distance training
Authors: F. Ramos
Venue: Proceedings of the 30th Annual Frontiers in Education - Volume 02 (2000)

In April 1999, the University of Aveiro launched a Web based distance training programme, supported on a fully asynchronous model, that introduced at innovative approach to training in Portugal. In this model a mixed approach is adopted as far as the use of technologies is concerned: for the course materials a very conventional approach is used (off-the-shelf books and paper versions of most of other documentation) but communication among participants (students, professors and staff) is based on the Internet. This model has several advantages when compared with other more conventional and, also, more sophisticated (as far as the use of technology is concerned) distance education models, and has provided a very good trade-off between effectiveness and flexibility. The paper presents and discusses the rationale beyond the model adopted, identifies its main characteristics and presents the results and conclusions achieved up to now, one year after being used in a distance training programme on interactive multimedia and Internet technologies already followed by more than 250 students. 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
Revisit of View-Oriented Parallel Programming
Authors: Z. Huang, W. Chen
Venue: Proceedings of the Seventh IEEE International Symposium on Cluster Computing and the Grid (2007)

Traditional parallel programming styles have many problems which hinder the development of parallel applications. The message passing style can be too complex for many programmers. While shared memory based parallel programming is relatively easy, it requires programmers to guarantee there is no data race in programs by using mutually exclusive locks. Data race conditions are generally difficult to debug and difficult to prevent as well. The View-Oriented Parallel Programming (VOPP) is a novel shared-memory-based programming style. It removes the burden of guaranteeing data race free from the programmers. With the VOPP approach, shared data objects in a parallel program are divided into views according to the memory access pattern of the parallel algorithm. Data race is not an issue in VOPP, since mutual exclusion is automatically done by the underlying system when a view is accessed. The programmer only needs to synchronize the access of views using synchronization primitives like barriers. By removing data races of view access, VOPP makes it easier to code and less difficult to debug programs. It provides potential performance advantages on multi-core systems as well as cluster computers. It will also provide useful information for efficient implementation of transactional memory.
Non-Euclidian geographic routing in wireless networks
Authors: Niklas Carlsson, Derek L. Eager
Venue: Ad Hoc Networks (2007)

Greedy geographic routing is attractive for large multi-hop wireless networks because of its simple and distributed operation. However, it may easily result in dead ends or hotspots when routing in a network with obstacles (regions without sufficient connectivity to forward messages). In this paper, we propose a distributed routing algorithm that combines greedy geographic routing with two non-Euclidian distance metrics, chosen so as to provide load balanced routing around obstacles and hotspots. The first metric, Local Shortest Path, is used to achieve high probability of progress, while the second metric, Weighted Distance Gain, is used to select a desirable node among those that provide progress. The proposed Load Balanced Local Shortest Path (LBLSP) routing algorithm provides loop freedom, guarantees delivery when a path exists, is able to efficiently route around obstacles, and provides good load balancing.
Minimum variance unbiased estimation of frequency offset in OFDM systems, a blind synchronization approach
Authors: N. Lashkarian
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 05 (2000)

We present a novel blind synchronization method for carrier frequency offset estimation of orthogonal frequency division modulation (OFDM) systems. The proposed approach exploits the properties of cyclic prefix subset to reveal the synchronization parameters in the likelihood function of the received vector. Using Neyman-Fisher factorization theorem, the sufficient statistic for estimation of carrier frequency offset is identified. The resulting statistic, when applied to the Rao-Blackwell-Lehmann-Scheffe (RBLS) theorem, results in a robust minimum variance unbiased (MVU) estimate of the synchronization parameter. Statistical and closed loop performance of the estimator is analyzed and assessed by simulation for an OFDM system.
Localization of a distributed source which is "partially coherent"-modeling and Cramer-Rao bounds
Authors: R. Raich
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 05 (1999)

The problem of using antenna array measurements to estimate the bearing of a mobile communications user surrounded by local scatterers is considered. The concept of "partial coherence" is introduced to account for the temporal as well as spatial correlation effects often encountered in mobile radio propagation channels. A simple, intuitive parametric model for temporal channel correlation is presented. The result is an overall spatio-temporal channel model which is more realistic than formerly proposed models (which assume either full or zero temporal channel correlation). Thus, previously posed bearing estimation problems for a "distributed" or "scattered" source are generalized to a joint spatio-temporal parameter estimation problem. A study of the associated Cramer-Rao Bound for the case of known transmitted signal of constant modulus indicates that the inherent accuracy limitations associated with this generalized problem lie somewhere between the cases of zero and full temporal correlation and become more severe as temporal channel correlation increases.
Non-fractional parallelism in LDPC decoder implementations
Authors: John Dielissen, Andries Hekstra
Venue: Proceedings of the conference on Design, automation and test in Europe (2007)

Because of its excellent bit-error-rate performance, the Low-Density Parity-Check (LDPC) decoding algorithm is gaining increased attention in communication standards and literature. Also the new Chinese Digital Video Broadcast standard (CDVB-T) uses LDPC codes. This standard uses a large prime number as the parallelism factor, leading to high area cost. In this paper we present a new method to allow fractional dividers to be used. The method depends on the property that consecutive sub-circulants have one memory row in common. Several techniques are shown for assuring this property, or solving memory conflicts, making the method more generally applicable. In fact, the proposed technique is a first step towards a general purpose LDPC processor. For the CDVB-T decoder implementation the method leads to a factor 3 improvement in area.
Modeling Orienting Behavior and Its Disorders with “Ecological” Neural Networks
Authors: Andrea Di Ferdinando, Domenico Parisi, Paolo Bartolomeo
Venue: Journal of Cognitive Neuroscience (2007)

Computational modeling is a useful tool for spelling out hypotheses in cognitive neuroscience and testing their predictions in artificial systems. Here we describe a series of simulations involving neural networks that learned to perform their task by self-organizing their internal connections. The networks controlled artificial agents with an orienting eye and an arm. Agents saw objects with various shapes and locations and learned to press a key appropriate to their shape. The results showed the following: (1) Despite being able to see the entire visual scene without moving their eye, agents learned to orient their eye toward a peripherally presented object. (2) Neural networks whose hidden layers were previously partitioned into units dedicated to eye orienting and units dedicated to arm movements learned the identification task faster and more accurately than did nonmodular networks. (3) Nonetheless, even nonmodular networks developed a similar functional segregation through self-organization of their hidden layer. (4) After partial disconnection of the hidden layer from the input layer, the lesioned agents continued to respond accurately to single stimuli, wherever they occurred, but on double simultaneous stimulation they oriented toward and responded only to the right-sided stimulus, thus simulating extinction/neglect. These results stress the generality of the advantages provided by orienting processes. Hard-wired modularity, reminiscent of the distinct cortical visual streams in the primate brain, provided further evolutionary advantages. Finally, disconnection is likely to be a mechanism of primary importance in the pathogenesis of neglect and extinction symptoms, consistent with recent evidence from animal studies and brain-damaged patients.
Good educational experiments are not necessarily good change processes
Authors: J. Froyd
Venue: Proceedings of the 30th Annual Frontiers in Education - Volume 01 (2000)

Design, problem solving, and scientific discovery are examples of important processes for which engineers and scientists have developed exemplary process models, i.e., a set of widely accepted procedures by which these functions may best be accomplished. However, undergraduate curriculum transformation in engineering, that is, systemic change in pedagogy, content, and/or course structure, lacks a widely recognized process model. In other words, engineering faculty members do not widely and explicitly agree upon a set of assumptions and flow diagrams for initiating, sustaining and integrating curriculum improvement. The two-loop model that is described in conjunction with the EC2000 criterion (http://www.abet.org/eac/two_loops.htm) provides a flow diagram that integrates assessment, evaluation and feedback processes. However the two-loop model does not provide a set of assumptions and flow diagrams for quantum actual change or improvement. To initiate discussion of models for the curriculum change process, referred to as change models, this paper examines three change models and advocates the organizational change model.
Using groupware for international collaborative learning
Authors: T. Clear
Venue: Proceedings of the 30th Annual Frontiers in Education - Volume 01 (2000)

The paper reports the lessons learned from a two year collaborative learning trial between students at Auckland University of Technology (AUT) and Uppsala University. The trials took place using a combination of email and a custom developed Lotus Notes/sup TM/ database. The first trial involved a case study in which students performed different roles in designing a software solution for an Auckland based nailcare distributor. The second trial built upon the knowledge base of the earlier trial, and required students to evaluate and rank the previous design proposals. A theoretical model developed from the group support systems literature guided some of the changes in the second trial. The software, the collaboration process and the evaluation methods evolved over the course of these trials. The challenges of creating global student communities within a short collaboration window in existing courses of study are discussed. Further extensions to this research are proposed and some general recommendations are made.