ppxscal/embedding_network huggingface dataset:
Modified fuzzy c-mean in medical image segmentation
Authors: N. A. Mohamed
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 06 (1999)

This paper describes the application of fuzzy set theory in medical imaging, namely the segmentation of brain images. We propose a fully automatic technique to obtain image clusters. A modified fuzzy c-mean (FCM) classification algorithm is used to provide a fuzzy partition. Our new method, inspired from the Markov random field (MRF), is less sensitive to noise as it filters the image while clustering it, and the filter parameters are enhanced in each iteration by the clustering process. We applied the new method on a noisy CT scan and on a single channel MRI scan. We recommend using a methodology of over segmentation to the textured MRI scan and a user guided-interface to obtain the final clusters. One of the applications of this technique is TBI recovery prediction in which it is important to consider the partial volume. It is shown that the system stabilizes after a number of iterations with the membership value of the region contours reflecting the partial volume value. The final stage of the process is devoted to decision making or the defuzzification process.
Note: An upper bound for Hilbert cubes
Authors: Csaba Sándor
Venue: Journal of Combinatorial Theory Series A (2007)

In this note we give a new upper bound for the largest size of subset of {1,2,...,n} not containing a k-cube.
An FFT for the 2-sphere and applications
Authors: J. Astola
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 03 (1996)

A fast algorithm for the computation of spherical harmonic expansions of bandlimited functions on the 2-sphere is described. The algorithm also provides for an efficient inverse transform (synthesis) as well and consequently fast convolution on the 2-sphere is also possible. We discuss applications to image processing and medical imaging as well as aspects of our working implementation.
Using clock changes in multi-path applications
Authors: B. Lacaze
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 06 (2000)

This paper studies an alternative to the Watterson (1970) model for multi-path channels. The new model is based on the introduction of random delays. This model is shown to well-represent different kinds of spectra. An application is presented in the case of backscattering from sea surface at small grazing angles of incidence. This clock change-based model allows one to well-describe the physical phenomenon.
A Self-Aware Clock for Pervasive Computing Systems
Authors: Andrea Bondavalli, Andrea Ceccarelli, Lorenzo Falai
Venue: Proceedings of the 15th Euromicro International Conference on Parallel, Distributed and Network-Based Processing (2007)

The paper addresses the challenges and opportunities of instrumenting pervasive computing systems with a logical clock, aware of the quality of synchronization with respect to a time reference. Pervasive computing systems are i) mobile, ii) dynamic and iii) composed of a large number of distributed components; in systems with these characteristics the availability of a "smart" clock that is i) capable to use different mechanisms for the synchronization with the global distributed time reference and ii) aware of the current quality of synchronization with such time reference, can be very useful in order to build dependable middleware services and applications.
Embedded joint source-channel coding of speech using symbol puncturing of trellis codes
Authors: A. Bernard
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 05 (1999)

This paper presents an embedded joint source-channel coding scheme of speech. The source coder is an embedded variable bit rate perceptually based sub-band coder producing bits with different error sensitivities. The channel encoder is a rate compatible punctured trellis code (RCPT) which permits rate variability and unequal error protection by puncturing symbols. Furthermore, RCPT code design naturally incorporates large constellations, allowing high information rate per symbol. The embedded speech coder and the rate compatible puncturing of symbols provide the embeddibility of the joint coding scheme. The coder is robust to acoustic noise and produces good quality speech for a wide range of channel conditions (AWGN or fading), allowing digital transmission of speech with analog-like graceful degradation.
Modelling Latency-Insensitive Systems in CSP
Authors: Hemangee K. Kapoor
Venue: Proceedings of the Seventh International Conference on Application of Concurrency to System Design (2007)

With the advance in semiconductor technology we are able to pack more and more devices on a single chip [5]. However, the threat comes from the long interconnect wires [6] whose delays dominate in deep-submicron (DSM) CMOS. To handle the increased latency due the long interconnects, we require the IP cores to be latency-insensitive (LI). Design and validation of LI design is studied in [1, 2, 11]. Generalised latency-insensitive systems, design of connecting FIFOs and other communication protocols appear in [3, 4, 8, 10].
MUSIC-Type Electromagnetic Imaging of a Collection of Small Three-Dimensional Inclusions
Authors: Habib Ammari, Ekaterina Iakovleva, Dominique Lesselier, Gae&uml;le Perrusson
Venue: SIAM Journal on Scientific Computing (2007)

In this paper we consider the localization of a collection of small, three-dimensional bounded homogeneous inclusions via time-harmonic electromagnetic means, typically using arrays of electric or magnetic dipole transmitters and receivers with given polarization(s) at some distance from the collection, possibly also lying in the far field. The inclusions, somewhat apart or closely spaced, are buried within a homogeneous medium, and are of arbitrary contrast of permittivity, conductivity, and permeability vis-a&grave;-vis this embedding medium. The problem is formulated as an inverse scattering problem for the full Maxwell equations and it involves a robust asymptotic modeling of the multistatic response matrix. No specific application is studied at this stage, but characterization of obstacles in subsoils, nondestructive evaluation of man-made structures, and medical imaging are primary fields of application envisaged. The proposed approach uses a MUSIC (multiple signal classification)-type algorithm, and it yields fast numbering, accurate localization, and estimates of the electromagnetic and geometric parameters (polarization tensors) of the inclusions. The mathematical machinery is detailed first, some specific attention being given to triaxial ellipsoidal inclusions and degenerate spherical shapes (for the latter known results are retrieved). Then, the viability of this algorithm&mdash;which would be easily extended to planarly layered environments by introduction of their Green&rsquo;s functions&mdash;is documented by a variety of numerical results from synthetic, noiseless, and severely noisy field data.
Distributed power-management techniques for wireless network video systems
Authors: Nicholas H. Zamora, Jung-Chun Kao, Radu Marculescu
Venue: Proceedings of the conference on Design, automation and test in Europe (2007)

Wireless sensor networks operating on limited energy resources need to be power efficient to extend the system lifetime. This is especially challenging for video sensor networks due to the large volumes of data they need to process in short periods of time. Towards this end, this paper proposes two coordinated power management policies for video sensor networks. These policies are scalable as the system grows and flexible to video parameters and network characteristics. In addition to simulation results, our prototype demonstrates the feasibility of implementing these policies. Finally, the analytical framework we provide gives an upper bound for the achievable sleep fraction and insight into how adjusting select parameters will affect the performance of the power management policies.
Shared virtual environment (SVE): a framework for developing social games
Authors: M. Carmen Juan, Mariano Alcañiz, Luciano Gamberini, Irene Zaragoza, F. Martino
Venue: Proceedings of the international conference on Advances in computer entertainment technology (2007)

The communication channels are changing. More and more, face to face communication is being replaced by computer mediated communication. Using mediated communication, the non-verbal communication cues that are available in face to face communication are not. PASION is a European project where mediated communication is augmented. In this paper we present the Shared Virtual Environment (SVE), the framework to be used for the development of two types of applications (social gaming and collaborative work) where augmentation will be studied. The first version of SVE has been used for the development of the first version of a pervasive game for treasure hunting, Bluenet.
A Class of VeCa Distributions for the Statistical Modeling of Fast Fading
Authors: Saralees Nadarajah, Samuel Kotz
Venue: Wireless Personal Communications: An International Journal (2007)

Vellis and Capsalis [Wireless Personal Communication, Vol. 15 pp. 207---219, 2000] pioneered the concept of VeCa distribution to study the statistical behavior of the received signal when a user is present near the transmitting handset antenna. In this note, we derive a comprehensive class of formulas for the VeCa distribution to help better statistical modeling of fast fading in the presence of a user. The corresponding estimation procedures are also derived by the method of moments.
Signal compression by piecewise linear non-interpolating approximation
Authors: R. Nygaard
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 03 (1999)

We present a signal compression scheme based on coding linear segments approximating the signal. Although the approach is useful for many types of signals, we focus in this paper on compression of electrocardiogram (EGG) signals. The ECG signal compression has traditionally been tackled by heuristic approaches. However, it has been demonstrated that exact optimization algorithms outclass these heuristic approaches by a wide margin with respect to the reconstruction error. The exact optimization algorithm extracts signal samples from the original signal by formulating the sample selection problem as a graph theory problem. Thus known optimization theory can be applied in order to yield optimal compression. This paper generalizes the exact optimization scheme by removing the interpolation restriction when applying piecewise linear approximation. This guarantees a lower reconstruction error with respect to the number of extracted signal samples. The method shows superior performance compared to traditional ECG compression methods.
The professor and the media laboratory: a case study in Web-based course creation
Authors: B. V. Koen
Venue: Proceedings of the Frontiers in Education Conference, 2001. 31st Annual - Volume 02 (2001)

One thing is certain: modern engineering education will move towards more Web-based distance learning in the future. Can we realistically expect the average professor who contemplates participating in this development to be an expert in his or her technical specialty, in modern educational theory, in distance learning technology, and in effective strategies for media presentation? To create professional quality instructional materials a critical partnership must emerge between the modern professor and a media support infrastructure. This article presents a case study of a successful partnership in the creation of a Personalized System of Instruction (PSI or Keller Plan) course for delivery over the Web with the aid of the Faculty Innovation Center (FIC) of the College of Engineering at The University of Texas at Austin. This paper describes the course objectives, the chosen pedagogical strategy, and the crucial issues that emerged along with specific examples.
Refractivity estimation from radar clutter by sequential importance sampling with a Markov model for microwave propagation
Authors: S. Vasudevan
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2001. on IEEE International Conference - Volume 05 (2001)

This paper addresses the problem of estimating range-varying parameters of the height-dependent index of refraction over the sea surface in order to predict ducted microwave propagation loss. Refractivity estimation is performed using a Markov model for microwave radar clutter returns from the sea surface. Specifically, the parabolic approximation for numerical solution of the wave equation is used to formulate the problem within a nonlinear recursive Bayesian state estimation framework. Solution for the conditional expectation of range-varying refractivity, given log-amplitude clutter versus range data, is achieved using a sequential importance sampling technique. Simulation results are presented which demonstrate the ability of this approach to synoptically estimate range-varying refractivity parameters by "through-the-sensor" remote sensing.
Iterative nonlinear MMSE multiuser detection
Authors: S. Gollamudi
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 05 (1999)

This paper introduces the notion of nonlinear MMSE multiuser detection and shows that MMSE signal estimates followed by single user detectors yield MAP (or minimum probability of error) decisions for CDMA signals. Iterative solutions are proposed for nonlinear MMSE estimation. If interferers' codes are assumed to be known by the signal estimators for each user, the MMSE solution is shown to be a fixed point which is reached in one iteration, but is computationally intractable. If interferers' codes are not assumed to be known, the resulting iterative multiuser detector (called random-code NMIC) is shown to be of the same order of complexity as a conventional multistage interference canceler. Furthermore, the nonlinear MMSE solution is shown to be a fixed point of the random-code NMIC. Particular solutions are presented for the cases of BPSK and M-ary orthogonal spread spectrum systems.
SQTL: A Preliminary Proposal for a Temporal-to-Temporal Query Language
Authors: Nicole Bidoit, Matthieu Objois
Venue: Proceedings of the 14th International Symposium on Temporal Representation and Reasoning (2007)

A temporal database can be represented as a finite sequence of relational instances. Queries over such temporal instances usually map the input sequences to relation instances. Motivated by emerging applications, we are investigating a new type of queries over temporal instances, called t2t queries (temporal-to- temporal queries). The issue is to develop languages able to define mappings from temporal instances to temporal instances. The paper proposes and investigates two types of t2t query languages: point wise languages and SQTL languages.
A Formal Approach to Aspect-Oriented Modular Reconfigurable Computing
Authors: Phan Cong-Vinh, Jonathan P. Bowen
Venue: Proceedings of the First Joint IEEE/IFIP Symposium on Theoretical Aspects of Software Engineering (2007)

For aspect-oriented modular reconfigurable computing, we specify a notion of "aspect" in the context of modular reconfigurable computing systems. In our formal approach, an aspect is determined as a coalgebraic transformation on modular reconfigurable computing systems. Then, based on this fundamental concept of aspect, inheritance and superimposition properties of aspects are studied. Specifically, the inheritance property is shown to be a bisimulation relation and the superimposition property is determined in the context of coalgebraic reconfiguration. Moreover, we also justify that our approach is sufficiently expressive to combine aspect-orientation and modular reconfigurable computing.
Cognitive modelling using a logic-based algebra
Authors: L. Flax
Venue: Proceedings of the Fourth IEEE International Conference on Cognitive Informatics (2005)

We give an approach to cognitive modelling which allows for richer expression than the one based simply on the firing of sets of neurons. The object language of the approach is first-order logic augmented by operations of an algebra, PSEN. Some operations useful for this kind of modelling are postulated combination, comparison and inhibition of sets of sentences. It is shown how these operations can be realised using PSEN. 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
Searching for remotely homologous sequences in protein databases with hybrid psi-blast
Authors: Mario Lauria
Venue:  (2006)

Sequence alignment is one of the fundamental techniques used in molecular biology. It has been widely used in many biological applications, such as protein classification, gene finding, homology modeling, structure and function prediction, phylogenetic analysis and database annotation. In high sensitivity sequence homology database searches, progressive sequence model refinement by means of iterative searches is an effective method and is currently employed in many popular tools such as PSI-BLAST and SAM. Recently, a novel alignment algorithm has been proposed that offers features expected to improve the sensitivity of such iterative approaches, specifically a well-characterized theory of its statistics even in the presence of position-specific gap costs. We have demonstrated that the new hybrid alignment algorithm is ready to be used as the alignment core of PSI-BLAST. We also evaluated the accuracy of two proposed approaches to edge effect correction in short sequence alignment statistics that turns out to be one of the crucial issues in developing a hybrid-alignment based version of PSI-BLAST. In addition, we have exploited other benefits of the hybrid alignment. We show that incorporating information about the suboptimal alignments, otherwise ignored in PSI-BLAST, already improves the sensitivity of PSI-BLAST. In one experiment, we have found a set of sequences on which our tool disagrees with the classification given by SCOP. Careful examination points to a possible misclassification in SCOP. Cross-referencing with two other methods of protein structure classification, CATH and DALI, supports this view, indicating that the enriched information from suboptimal alignments is valuable for detecting more weakly related sequences. Finally, we have integrated position-specific gap penalties in PSI-BLAST, which is intensionally left out due to a theoretical limitation of its underlying Smith-Waterman score statistics. We also investigated several strategies to adjust the position-based gap costs derived from the forward-backward algorithm. The results show that the degree of conservedness calculated as a localized relative entropy from the position-specific substitution matrix is the most effective. Such enhancements further improve the sensitivity of PSI-BLAST for remote homology detection in database searches.
Concatenated sequences for inter-base station synchronization in WCDMA TDD mode
Authors: Y. K. Khit, T. T. Jhung
Venue: Proceedings of the The 8th International Conference on Communication Systems - Volume 01 (2002)

In order to prevent inter-slot interference and to enhance system capacity in wideband code division multiple access (WCDMA) time division duplex (TDD) mode, synchronization between the base stations are necessary. The easiest way of achieving synchronization is using the global positioning system (GPS). However the use of the GPS would increase the costs of base-stations, as special radio receivers are required to detect the time reference signals. An alternative solution that is proposed by 3GPP is to synchronize the base stations via an air-interface using inter-cell synchronization codes since this would reduce the costs of base stations as only simple hardware is required. We summarize the proposed synchronization codes by 3GPP using concatenated extended complementary (CEC) sequences with multiple code offsets. This is followed by the presentation of a new form of concatenated sequence which has relatively better cross correlation properties than the proposed sequences. Problems and shortcomings regarding the use of this new form of sequences are also addressed.
A generalized VQ method for combined compression and estimation
Authors: A. Rao
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 04 (1996)

In vector quantization, one approximates an input random vector, Y, by choosing from a finite set of values known as the codebook. We consider a more general problem where one may not have direct access to Y but only to some statistically related random vector X. We observe X and would like to generate an approximation to Y from a codebook of candidate vectors. This operation, called generalized vector quantization (GVQ), is essentially that of quantized estimation. An important special case of GVQ is the problem of noisy source coding wherein a quantized approximation of a vector, Y, is obtained from observation of its noise-corrupted version, X. The optimal GVQ encoder has high complexity. We overcome the complexity barrier by optimizing a structurally-constrained encoder. This challenging optimization task is solved via a probabilistic approach, based on deterministic annealing, which overcomes problems of shallow local minima that trap simpler descent methods. We demonstrate the successful application of our method to the coding of noisy sources.
A 6Kbps to 85Kbps scalable audio coder
Authors: T. S. Verma
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 02 (2000)

Scalable audio coding is important in network environments, such as the Internet, where bandwidth is not guaranteed, packet loss is common, and client connection data rates are heterogeneous. Signal models provide a general framework for attacking a wide range of challenges in the unicast delivery of real-time audio over packet switched networks. The specific signal model in this work generates a parametric representation for general wide-band audio signals. The model consists of three complementary components: sines, transients, and noise. Because the human hearing system ultimately judges the validity of a model for audio signals, psychoacoustic principles are explicitly considered in the three part model. Once analyzed, the parameters are quantized, compressed and packed into a single 85Kbps bit-stream. From this bit-stream, bit-streams at several bit-rates between 6Kbps and 85Kbps may be readily extracted. The audio coder offers a wide range of scalability while the audio quality of the coding scheme gracefully degrades from perceptually lossless to low-quality.
A Remote Hands-on Exercise Environment for an Asia-Wide Real-Time Workshop
Authors: Achmad Basuki, Achmad H. Thamrin, Keiko Okawa, Jun Murai
Venue: Proceedings of the 2007 International Symposium on Applications and the Internet Workshops (2007)

This paper discusses the problems of conducting a real-time workshop, where the instructors and the participants are located in different places, and the participants should perform hands-on lab exercises using computers that are located in another place. To address this problem, we implemented a remote hands-on exercise environment using virtual machines and a low-bandwidth remote console access. In this environment, the instructors can monitor each participant's exercise progress thus they can give specific feedbacks to the participants. We evaluated this environment using a real-time online workshop. We found that it was easy to setup, and participants had a good user-experience using this environment.