ppxscal/embedding_network huggingface dataset:
Sparse and irregular sampling in array processing
Authors: S. Holm
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 06 (2000)

Rule-based thinning and element placement methods are first discussed. This includes random arrays, binned random arrays, periodic thinning, element shadowing properties, and fractal arrays. The algorithmic optimization of layouts of 1-D and 2-D sparse arrays is presented and it is empirically derived that the peak sidelobe level for an array with K active elements is proportional to 1/K for a 1-D array and 2/K for a 2-D array. The constant of proportionality depends strongly on the width of the mainlobe relative to that of the full array. With an increase of 50%, the constant is 1.5.
A time continuous model for speech recognition
Authors: S. Euler
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 02 (1996)

In this paper we present a time continuous extension of the hidden Markov model approach in order to obtain a better representation of the continuous nature of the speech process. The discrete state sequence of the hidden Markov model is replaced by a continuous parameter, varying between 0 and 1. For an utterance and a given word model an optimum mapping of the feature vectors to the continuous axis is found and the likelihood is calculated based on this mapping. As a first test of this very general approach we extended the hidden Markov model by first mapping the states onto the new axis. Values between the states are then obtained by interpolation between the states. As alternatives we considered interpolation of either the likelihood values of the state density functions and/or of the parameters of the density functions itself. The approach was tested in a speaker independent isolated word recognition system.
Using Python to Solve Partial Differential Equations
Authors: Kent-Andre Mardal, Ola Skavhaug, Glenn T. Lines, Gunnar A. Staff, Asmund Odegard
Venue: Computing in Science and Engineering (2007)

This article describes two Python modules for solving partial differential equations (PDEs): PyCC is designed as a Matlab-likeenvironment for writing algorithms for solving PDEs, and SyFi creates matrices based on symbolic mathematics, code generation, and thefinite element method.
Reordering buffers for general metric spaces
Authors: Matthias Englert, Harald Räcke, Matthias Westermann
Venue: Proceedings of the thirty-ninth annual ACM symposium on Theory of computing (2007)

In the reordering buffer problem, we are given an input sequence of requests for service each of which corresponds to a point in a metric space. The cost of serving the requests heavily depends on the processing order. Serving a request induces cost corresponding to the distance between itself and the previously served request, measured in the underlying metric space. A reordering buffer with storage capacity k can be used to reorder the input sequence in a restricted fashion so as to construct an output sequence with lower service cost. This simple and universal framework is useful for many applications in computer science and economics, e.g., disk scheduling, rendering in computer graphics, or painting shops in car plants. In this paper, we design online algorithms for the reordering buffer problem. Our main result is a strategy with a polylogarithmic competitive ratio for general metric spaces. Previous work on the reordering buffer problem only considered very restricted metric spaces. We obtain our result by first developing a deterministic algorithm for arbitrary weighted trees with a competitive ratio of O(D · log k), where D denotes the unweighted diameter of the tree, i.e., the maximum number of edges on a path connecting two nodes. Then we show how to improve this competitive ratio to O(log2 k) for metric spaces that are derived from HSTs. Combining this result with the results on probabilistically approximating arbitrary metrics by tree metrics, we obtain a randomized strategy for general metric spaces that achieves a competitive ratio of O(log2 k · log n) in expectation against an oblivious adversary. Here n denotes the number of distinct points in the metric space. Note that the length of the input sequence can be much larger than n.
Computing by Floating Strings
Authors: Giuditta Franco, Maurice Margenstern
Venue: Electronic Notes in Theoretical Computer Science (ENTCS) (2007)

We propose a biologically inspired system which computes on double structures of mobile strings by means of rewriting rules that have a biotechnological implementation, by resembling DNA computations. Its computational universality may be straight deduced from a few formal language theoretical results of one of the authors. Such a DNA-like computational device is naturally described by a membrane system which concludes the paper.
Fine-granularity spatially scalable video coding
Authors: Qi Wang
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 03 (2001)

We propose a novel architecture for spatially scalable video coding, namely, fine-granularity spatially scalable (FGSS) coding. The traditional layered spatially scalable coding provides only coarse scalability in which the bit-stream can be decoded only at a few fixed resolutions, but not something in between. The proposed FGSS scheme provides a fine-granularity property to the spatial scalability. In this scheme, the bit plane technique is combined with spatial scalability, thus a fine granularity increase in the image quality from low-resolution to high-resolution can be obtained. In addition, the proposed scheme provides a flexible embedded bitstream that can be decoded up to any point in the enhancement layer bitstream from low-resolution to high-resolution. This feature further enables efficient video streaming over the Internet where the scalable bitstream, can adapt to the widely fluctuating bandwidth. The FGSS coding scheme extends new functionalities such as multi-resolution, fine granularity, channel adaptation and error-recovery properties to scalable video coding, thus it can satisfy different user clients with a wide range of channel bandwidth and screen resolution.
Certified meshing of families of isosurfaces
Authors: Simon Plantinga, Gert Vegter
Venue: Proceedings of the IEEE International Conference on Shape Modeling and Applications 2007 (2007)

Level sets are isosurfaces of an implicit function F : R3 \3 R, that is the set of points satisfying F(x, y, z) = O. In this paper we introduce an algorithm to move at interactive speed through the different level sets. Furthermore the meshes of the level sets are isotopic to the isosurface itself, as long as the surface stays away from singularities. When the surface moves close to singularities, the algorithm indicates arbitrarily small boxes where the topology is not certified. In this case, the user can decide to decrease the size of the boxes by further refinement. For special classes of functions, such as algebraic surfaces, other methods could be used to determine the topology inside the singular boxes.
Distributed Algorithms for Constructing a Depth-First-Search Tree
Authors: S. A. M. Makki, George Havas
Venue: Proceedings of the 1994 International Conference on Parallel Processing - Volume 03 (1994)

We present more efficient distributed depth-firstsearch algorithms which construct a depth-first-search tree for a communication network. The algorithms require \left| V \right|(1 + r) messages and |V|(l + r) units of time in the worst case, where \left| V \right| is the number of sites in the network, and 0 \leqslant r \le 1 . The value of r depends on the network topology and possibly on the routing chosen. In the best case, when the underlying network has a ring topology, r = 0 and our basic algorithm requires \V\ messages and time units, regardless of routing. We extend this algorithm to achieve the same best case bound for other topologies. The worst case bound, which has r = 1 2/\left| V \right|, applies if the network topology is a tree. The improvement over the best of previous algorithms is achieved by dynamic backtracking, with a minor increase in message length.
Inferring specifications to detect errors in code
Authors: Mana Taghdiri, Daniel Jackson
Venue: Automated Software Engineering (2007)

A new technique is presented to statically check a given procedure against a user-provided property. The method requires no annotations; it automatically infers a context-dependent specification for each procedure call, so that only as much information about a procedure is used as is needed to analyze its caller. Specifications are inferred iteratively. Empty specifications are initially used to over-approximate the effects of all procedure calls; these are later refined in response to spurious counterexamples. When the analysis terminates, any remaining counterexample is guaranteed to be valid. However, since the heap is finitized, the absence of a counterexample does not guarantee the validity of the given property in general.
Steps Toward a Science of Service Systems
Authors: Jim Spohrer, Paul P. Maglio, John Bailey, Daniel Gruhl
Venue: Computer (2007)

The service sector accounts for most of the world's economic activity, but it's the least-studied part of the economy. A servicesystem comprises people and technologies that adaptively compute and adjust to a system's changing value of knowledge. A science ofservice systems could provide theory and practice around service innovation.
Algorithm 869: ODRPACK95: A weighted orthogonal distance regression code with bound constraints
Authors: Jason W. Zwolak, Paul T. Boggs, Layne T. Watson
Venue: ACM Transactions on Mathematical Software (TOMS) (2007)

ODRPACK (TOMS Algorithm 676) has provided a complete package for weighted orthogonal distance regression for many years. The code is complete with user selectable reporting facilities, numerical and analytic derivatives, derivative checking, and many more features. The foundation for the algorithm is a stable and efficient trust region Levenberg-Marquardt minimizer that exploits the structure of the orthogonal distance regression problem. ODRPACK95 was created to extend the functionality and usability of ODRPACK. ODRPACK95 adds bound constraints, uses the newer Fortran 95 language, and simplifies the interface to the user called subroutine.
Non-Uniform Hierarchical Geo-consistency for Multi-baseline Stereo
Authors: Marc-Antoine Drouin, Martin Trudeau, Sebastien Roy
Venue: Proceedings of the Fourth Canadian Conference on Computer and Robot Vision (2007)

We propose a new and flexible hierarchical multibaseline stereo algorithm that features a non-uniform spatial decomposition of the disparity map. The visibility computation and refinement of the disparity map are integrated into a single iterative framework that does not add extra constraints to the cost function. This makes it possible to use a standard efficient stereo matcher during each iteration. The level of refinement is increased automatically where it is needed in order to preserve a good localization of boundaries. While two graph-theoretic stereo matchers are used in our experiments, our framework is general enough to be applied to many others. The validity of our framework is demonstrated using real imagery with ground truth.
Text segmentation in mixed-mode images using classification trees and transform tree-structured vector quantization
Authors: K. O. Perlmutter
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 04 (1996)

Multimedia applications such as educational videos and color facsimile contain images that are rich in both textual and continuous tone data. Because these two types of data have different properties, segmentation of the images into text and continuous tone data can improve compression by allowing different compression parameters or even algorithms to be employed on the different types. We propose and compare algorithms that use classification trees (CLTR) or tree-structured vector quantization (TSVQ) for block-based classification in mixed-mode images. We also examine different types of features that can be used in these classifiers. The results show that using linear transform features with either the CLTR or TSVQ can be effective for accurate text classification. In addition, the results indicate that combining these classifiers with another TSVQ that is designed simultaneously to minimize both compression and classification error can provide better classification than does either system alone.
Silver Bullet Talks with Becky Bace
Authors: Gary McGraw
Venue: IEEE Security and Privacy (2007)

Gary McGraw speaks with Becky Bace. Their conversation ranged widely, from explosives to vulnerability disclosure to venture capital.
Power and thermal challenges for microprocessor architectures
Authors: Glenn Reinman
Venue:  (2006)

Power dissipation has become a critical design constraint for a wide range of electronics design: from high-performance microprocessor architectures to much smaller embedded systems. The demand for more sophisticated and faster computation, along with supply voltage scaling limitations are among the main driving forces behind the power dissipation increase. As a result, optimization techniques that target power and temperature need to be incorporated at every stage of the design process, from the operating system and architecture level, to behavioral synthesis and circuit level. In this thesis we propose and investigate the effectiveness of power and temperature optimization techniques at various abstraction levels targeting microprocessor architectures and embedded systems design flow. We look at circuit level power reduction through effective distribution of the existing slack formulated as a budgeting problem. Our experimental analysis reveals 15% improvement in average power and 18% in maximum power consumption over MCNC benchmark set. For behavioral synthesis we investigate low power scheduling selection. We demonstrate that the decisions made at higher levels of abstraction such as behavioral synthesis have significant impact on the design space of the following stages. Moreover, in some cases the design space restrictions are unintentional and undetected. We propose a metric-based evaluation technique that reduces the on-chip temperatures by 12&deg;C on average for data flow graphs extracted from the MediaBench Suite. At the architecture-level we explore the benefits of hierarchical and factored architectures in reducing the power waste due to sub-optimal processor resource sizes. Our analysis indicates power savings around 20% for such architectures. Furthermore, an additional 13% reduction is also possible through adapting the processor resources to the application phase behavior. By minimizing the sizes of performance enhancing structures on the critical path and utilizing hierarchical extensions to extract the distant ILP, it is possible to improve the microprocessor thermal profile. We observed 86% reduction in the number of cycles over the critical temperature threshold. Using this framework, we propose a reduced-overhead activity migration scheme. As a result of the data buffering in shared structures, thermally-triggered activity migration outperforms other dynamic thermal management techniques such as idealized dynamic frequency scaling and global clock gating. Finally, we investigate operating system level thermal management on a Power4-like architecture. We analyze the effects of thread selection on processor temperature, by utilizing the already existing thread scheduling infrastructure. Scheduling decisions are based on dynamic thermal profiling of threads and temperature readings from on-chip sensors. Our MinTemp scheduling policy yields only 3% cycles above the threshold, with virtually no performance degradation over thermally challenging SPEC2000 benchmark suite.
Generators Bidding Behavior in the NYISO Day-Ahead Wholesale Electricity Market
Authors: Ning Zhang, Timothy Mount, Richard Boisvert
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

Statistical and econometric modeling is used to analyze the dynamics of generators' bidding behavior and resulting market prices in the NYISO day-ahead market during the summer of 2001 at three levels. First, at the generator level, generators' offered capacity is modeled by a two-stage sample selection process. The grouping choices of generators are estimated in the first stage. In the second stage, generators' offered capacity is estimated conditional on their grouping choices. Second, at the group level, we estimate the offer curves of each group. Third, at the total supply level, the aggregate supply curve is simulated by aggregating the offer curves of bidding groups. The estimated market prices based on the simulated supply curve can replicate most volatility of actual market prices. We find that demand conditions affect generators' bidding behavior and thus market prices significantly by applying our model under different demand assumptions.
Atomic Operators for Construction and Manipulation of the Augmented Quad-Edge
Authors: Pawel Boguslawski, Christopher Gold
Venue: Proceedings of the 6th International Conference on Computer Information Systems and Industrial Management Applications (2007)

This work presents the new attitude towards the construction and manipulation of 3D cells complexes, stored in the Augmented Quad-Edge (AQE) data structure. Each cell of a complex is constructed using the usual Quad-Edge structure, and the cells are then linked together by the dual edge that penetrates the face shared by two cells. We developed the new set of atomic operators that allow for a significant improvement of the related storage, construction and navigation algorithms in terms of the computational complexity. The idea is based on simultaneous construction of the both 3D Voronoi Diagram and its dual the Delaunay Triangulation. We expect that the increase of the efficiency related to the simultaneous manipulation of the both duals will allow for many new applications, like the real-time analysis and simulation of the modelled structures.
Reducing the TCP acknowledgment frequency
Authors: Sara Landström, Lars-Åke Larzon
Venue: ACM SIGCOMM Computer Communication Review (2007)

Delayed acknowledgments were introduced to conserve network and host resources. Further reduction of the acknowledgment frequency can be motivated in the same way. However, reducing the dependency on frequent acknowledgments in TCP is difficult because acknowledgments support reliable delivery, loss recovery, clock out new segments, and serve as input when determining an appropriate sending rate. Our results show that in scenarios where there are no obvious advantages of reducing the acknowledgment frequency, performance can be maintained although fewer acknowledgments are sent. Hence, there is a potential for reducing the acknowledgment frequency more than is done through delayed acknowledgments today. Advancements in TCP loss recovery is one of the key reasons that the dependence on frequent acknowledgments has decreased. We propose and evaluate an end-to-end solution, where four acknowledgments per send window are sent. The sender compensates for the reduced acknowledgment frequency using a form of Appropriate Byte Counting. The proposal also includes a modification of fast loss recovery to avoid frequent timeouts.
Electrical Simulation Model of the 2T-FLOTOX Core-Cell for Defect Injection and Faulty Behavior Prediction in eFlash Memories
Authors: O. Ginez, J.-M. Daga, P. Girard, C. Landrault, S. Pravossoudovitch, A. Virazel
Venue: Proceedings of the 12th IEEE European Test Symposium (2007)

The embedded Flash technology can be subject to complex defects creating functional faults. In this paper, we describe the different steps in the electrical modeling of 2T-FLOTOX core-cells for a good understanding of failure mechanisms. First, we present a first order electrical model of 2T-FLOTOX core-cells which is characterized and compared with silicon data measurements based on the ATMEL 0.15ìm eFlash technology. Next, we propose a study of resistive defect injections in eFlash memories to show the relevance of the proposed simulation model. At the end of the paper, a table summarizes the functional fault models for different resistive defect configurations and experimental set-ups. According to these first results and with additional analysis of actual defects presented in [1] we are then able to enhance existing test solutions for eFlash testing.
Process Algebra Specification of Flexible Manufacturing Systems
Authors: M. Carmen Ruiz, Diego Cazorla, Fernando Cuartero, J. Jose Pardo
Venue: Proceedings of the Eighth International Symposium on Symbolic and Numeric Algorithms for Scientific Computing (2006)

Nowadays, the success of the manufacturing industry is largely determined by its ability to respond to the rapidly changing market and customer needs. This has resulted in an increasing deployment of automated manufacturing equipment and systems that provide the agility to cope with these new demands. Flexible Manufacturing Systems (FMS) are the most widely used technology to cover these needs. Of course, these FMS must be studied in a formal frame, but the complexity and the dimension of real FMS has prevented from developing efficient control techniques and several challenges are still left. We face up these challenges and present a language that is able to specify nearly any type of real FMS. We use a timed process algebra called BTC (for Bounded True Concurrency) that we have developed from CSP and which takes into account that the available resources in a system have to be shared by all the processes. It is able to consider heterogeneous resources of any type (preemptable and non-preemptable) which makes it suitable for specifying FMS. We show by means of an example that the specifications obtained suit the real systems quite well and are straightforward. To the best of our knowledge, this is the first attempt to do this with process algebras, and we think that it is a good way, mainly, because we are able to split up the system into subsystems which will be easier analyzed.
Noise suppression using a time-varying, analysis/synthesis gamma chirp filterbank
Authors: T. Irino
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 01 (1999)

Spectral subtraction has been cited most often as a noise suppression method for speech signals in steady background noise, because it is basically a non-parametric method and simple enough to implement for various applications using FFT. It has also been well known, however, that spectral subtraction produces so called "musical noise" in synthetic sounds. Since such musical noise, even at low levels, can often bother humans in speech perception, spectral subtraction has not been very successful in signal processing applications for human listeners. To suppress noise without producing musical noise, an alternative method has been developed using a time-varying, analysis/synthesis gammachirp filterbank; this was initially proposed as an auditory filterbank. The present method achieves about the same SNR improvement as spectral subtraction when using the same information on the non-speech interval. Moreover, the synthetic sounds only contain steady white-like noise at reduced levels when the original noise is white. This method is, therefore, advantageous in various applications for human listeners. 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