ppxscal/embedding_network huggingface dataset:
Algebraic geometrical methods for hierarchical learning machines
Authors: Sumio Watanabe
Venue: Neural Networks (2001)

Hierarchical learning machines such as layered perceptrons, radial basis functions, Gaussian mixtures are non-identifiable learning machines, whose Fisher information matrices are not positive definite. This fact shows that conventional statistical asymptotic theory cannot be applied to neural network learning theory, for example either the Bayesian a posteriori probability distribution does not converge to the Gaussian distribution, or the generalization error is not in proportion to the number of parameters. The purpose of this paper is to overcome this problem and to clarify the relation between the learning curve of a hierarchical learning machine and the algebraic geometrical structure of the parameter space. We establish an algorithm to calculate the Bayesian stochastic complexity based on blowing-up technology in algebraic geometry and prove that the Bayesian generalization error of a hierarchical learning machine is smaller than that of a regular statistical model, even if the true distribution is not contained in the parametric model.
Indexing Valid Time Databases via B+-Trees
Authors: Mario A. Nascimento, Margaret H. Dunham
Venue: IEEE Transactions on Knowledge and Data Engineering (1999)

We present an approach, named MAP21, which uses standard $\rm B^+$-trees to provide efficient indexing of valid time ranges. The MAP21 approach is based on mapping one dimensional ranges to one dimensional points where the lexicographical order among the ranges is preserved. The proposed approach may employ more than one tree, each indexing a disjoint subset of the indexed data. When compared to the Time Index and the $\rm R^*$-tree we show that MAP21's performance is comparable to or better than those, depending on the type of query. In terms of storage, MAP21's structure was less than 10 percent larger than the $\rm R^*$-tree's and much smaller than the Time Index's. The main contribution of this paper though, is to show that standard $\rm B^+$-trees, available in virtually any DBMS, can be used to provide an efficient temporal index.
Hypercube Algorithms on Mesh Connected Multicomputers
Authors: Luis Díaz de Cerio, Miguel Valero-García, Antonio González
Venue: IEEE Transactions on Parallel and Distributed Systems (2002)

A new methodology named CALMANT (CC-cube Algorithms on Meshes and Tori) for mapping a kind of algorithms that we call CC-cube algorithm onto multicomputers with hypercube, mesh, or torus interconnection topology is proposed. This methodology is suitable when the initial problem can be expressed as a set of processes that communicate through a hypercube topology (a CC-cube algorithm). There are many important algorithms that fit into the CC-cube type. CALMANT is based on three different techniques: a) the standard embedding to assign the processes of the algorithm to the nodes of the mesh multicomputer; b) the communication pipelining technique to increase the level of communication parallelism inherent in the CC-cube algorithms; and c) optimal message-scheduling algorithms proposed in this work in order to avoid conflicts and minimizing in this way the communication time. Although CALMANT is proposed for multicomputers with different interconnection network topologies, this paper only focuses on the particular case of meshes.
Generalized FDTD-ADI: an unconditionally stable full-wave Maxwell's equations solver for VLSI interconnect modeling
Authors: Charlie C. P. Chen, Tae-Woo Lee, Narayanan Murugesan, Susan C. Hagness
Venue: Proceedings of the 2000 IEEE/ACM international conference on Computer-aided design (2000)

The finite-difference time-domain (FDTD) method of solving the full-wave Maxwell's equations has been recently extended to provide accurate and numerically stable operation for time steps exceeding the Courant limit. The elimination of an upper bound on the size of the time step was achieved using an alternating-implicit direction (ADI) time-stepping scheme. This greatly increases the computational efficiency of the FDTD method for classes of problems where the cell size of the three-dimensional space lattice is constrained to be much smaller than the shortest wavelength in the source spectrum. One such class of problems is the analysis of high-speed VLSI interconnects where full-wave methods are often needed for the accurate analysis of parasitic electromagnetic wave phenomena. In this paper, we present an enhanced FDTD-ADI formulation which permits the modeling of realistic lossy materials such as semiconductor substrates and metal conductors as well as artificial lossy materials needed for perfectly matched layer (PML) absorbing boundary conditions. Simulations using our generalized FDTD-ADI formulation are presented to demonstrate the accuracy and extent to which the computational burden is reduced by the ADI scheme.
Identification and testing of modes in beliefs
Authors: Ernan Haruvy
Venue: Journal of Mathematical Psychology (2002)

Characterizing diversity in beliefs is of paramount importance in empirical research on human behavior. In game theory, the focus is on the hypothesis formation. We present a data set with ideal properties for characterizing such diversity. The data consist of hypotheses on the empirical distribution of opponent choices. Using nonparametric techniques, we identify modes in the data corresponding to subpopulations of behavioral types and find the statistical significance of these modes in the underlying population distribution.
Low-energy off-chip SDRAM memory systems for embedded applications
Authors: Hojun Shim, Yongsoo Joo, Yongseok Choi, Hyung Gyu Lee, Naehyuck Chang
Venue: ACM Transactions on Embedded Computing Systems (TECS) (2003)

Memory systems are dominant energy consumers, and thus many energy reduction techniques for memory buses and devices have been proposed. For practical energy reduction practices, we have to take into account the interaction between a processor and cache memories together with application programs. Furthermore, energy characterization of memory systems must be accurate enough to justify various techniques. In this article, we build an in-house energy simulator for memory systems that is accelerated by special hardware support while maintaining accuracy. We explore energy behavior of memory systems for various values of the processor and memory clock frequencies and cache configuration. Each experiment is performed with 24M instruction steps of real application programs to guarantee accuracy.The simulator is based on precise energy characterization of memory systems including buses, bus drivers, and memory devices by a cycle-accurate energy measurement technique. We characterize energy consumption of each component by an energy state machine whose states and transitions are associated with the dynamic and static energy costs, respectively. Our approach easily characterizes the energy consumption of complex SDRAMs. We divide and quantify energy components of main memory systems for high-level reduction. The energy simulator enables us to devise practical energy reduction schemes by providing the actual amount of reduction out of the total energy consumption in main memory systems. We introduce several practical energy reduction techniques for SDRAM memory systems and demonstrate energy reduction ratio over the SDRAM memory systems with commercial SDRAM controller chipsets. We classify the SDRAM memory systems into high-performance and mid-performance classes and achieve suitable system configurations for each class. For instance, a typical high-performance 32-bit, 64 MB SDRAM memory system consumes 19.6 mJ, 33.8 mJ, 35.4 mJ, and 37.0 mJ for 24M instructions of an MP3 decoder, a JPEG compressor, a JPEG decompressor, and an MPEG4 decoder, respectively. Our reduction scheme saves 12.7 mJ, 15.1 mJ, 15.5 mJ, and 14.8 mJ, and the reduction ratios are 64.8&percnt;, 44.6&percnt;, 43.8&percnt;, and 40.1&percnt;, respectively, without compromising execution speed.
SDAARC: An Extended Cache-Only Memory Architecture
Authors: Frank Eschmann, Bernd Klauer, Ronald Moore, Klaus Waldschmidt
Venue: IEEE Micro (2002)

An established data distribution paradigm--extended to include automatic distribution of instruction sequences--might help overcome the traditional difficulties associated with parallel programming.
Rational Functions with Prescribed Global and Local Minimizers
Authors: Arnold Neumaier
Venue: Journal of Global Optimization (2003)

A family of multivariate rational functions is constructed. It has strong local minimizers with prescribed function values at prescribed positions. While there might be additional local minima, such minima cannot be global. A second family of multivariate rational functions is given, having prescribed global minimizers and prescribed interpolating data.
In the News
Venue: IEEE Software (1996)

No abstract availalble. 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
Communication Optimization for Affine Recurrence Equations Using Broadcast and Locality
Authors: Vincent Loechner, Catherine Mongenet
Venue: International Journal of Parallel Programming (2000)

This paper deals with communication optimization which is a crucial issue in automatic parallelization. From a system of parameterized affine recurrence equations we propose a heuristic that determines a set of efficient space-time transformations. It focuses on distant communications removal using broadcast&mdash;including anticipated broadcast, and locality enforcement.
A Tutorial on Built-In Self-Test, Part 2: Applications
Authors: Vishwani D. Agrawal, Charles R. Kime, Kewal K. Saluja
Venue: IEEE Design Test (1993)

For pt.1 see ibid., vol.10, no.1, p.73-82 (1993). The hardware structures and tools used to implement built-in self-test (BIST) pattern generation and response analysis concepts are reviewed. The authors describe testing approaches for general and structured logic, including ROMs, RAMs, and PLAs. They illustrate BIST techniques with real-world examples.
Development of a kinetic model for coke formation in pyrolysis of naphtha
Authors: J. Towfighi, A. Niaei, S. Hosseini
Venue: Iranian Journal of Science and Technology (2002)

Coke formed on the internal skin of the reactor tube, limits the on-stream time of cracking furnaces. On the basis of the plant output information and insight in the mechanisms for coke formation in pyrolysis reactors, a mathematical model describing the coke formation has been derived. It consists of four reactions for coke production, assuming that the sources of coke formation are ethylene, propylene, butadiene and aromatics. The coking model was combined with two other models, the kinetic model for the pyrolysis of naphtha and a reactor model. The combination of these models allows accurate prediction of the run length of the reactor with a limitation value of 1100 °C for tube wall temperature. In this model, ethylene, propylene butadiene and aromatics have been postulated as the coke precursors, 30,10,10 and 50 percent, respectively.
Automating the Design of SOCs Using Cores
Authors: Reinaldo A. Bergamaschi, Subhrajit Bhattacharya, Ronoldo Wagner, Colleen Fellenz, Michael Muhlada, William R. Lee, Foster White, Jean-Marc Daveau
Venue: IEEE Design Test (2001)

Assembling a system on a chip using IP blocks is an error-prone, labor-intensive, and time-consuming process. Emerging high-level tools can help by automating many of the design tasks.
High-Pressure Steam Engines and Computer Software
Authors: Nancy G. Leveson
Venue: Computer (1994)

The introduction of computers into the control of potentially dangerous devices has led to a growing awareness of the possible contribution of software to serious accidents. The number of computer-related accidents so far has been small due to the restraint shown in introducing computers into safety-critical control loops. However, as the economic and technological benefits of using computers become more widely accepted, their use is increasing dramatically. We need to ensure that computers are introduced into safety-critical systems in the most responsible way possible and at a speed that does not expose people to undue risk. Risk induced by technological innovation existed long before computers; this is not the first time that humans have come up with an extremely useful new technology that is potentially dangerous. Studying parallels in the early development of high-pressure steam engines and of software engineering can help.
Dielectric Lens Antennas for Wireless Broadband Communications
Authors: Carlos Fernandes, Veselin Brankovic, Sven Zimmermann, Miguel Filipe, Luís Anunciada
Venue: Wireless Personal Communications: An International Journal (1999)

Dielectric lens antennas are proposed for wireless broadband communication systems in the mm-wave range. Two lens antenna configurations for base station applications are presented and evaluated in terms of radiation characteristics, feeding system, input reflection loss, bandwidth and fabrication tolerances. The system requirements to provide optimum power distribution over the cell and good control of the cell boundaries are achieved. These lens antennas are designed for circular symmetric cell coverage and use a circular waveguide as the feed targeting typical applications at 60 GHz and 40 GHz range. The same concept is applicable for non- symmetrical cells with other feeds. Simulations are performed using Geometrical and Physical Optics codes as well as Finite Elements codes. Theoretical results are verified by measurements, showing good agreement.
Charge sheet model of a polysilicon thin-film transistor
Authors: Simrata Bindra, Subhasis Haldar, R. S. Gupta
Venue: Microelectronic Engineering (2002)

A simple analytical model for the current-voltage characteristics of a poly-Si thin-film transistor (TFT) using charge sheet analysis has been developed. An effective doping due to the presence of trap levels at grain boundaries and the effect of diffusion current is considered. The model also takes into account the charge sharing factor, necessary to explain the characteristics of a short channel device. The results so obtained for both long- and short-channel lengths were compared with the experimental data and good agreement was found. The transconductance and the drain conductance were also evaluated.
On the Location Error of Curved Edges in Low-Pass Filtered 2-D and 3-D Images
Authors: P. W. Verbeek, L. J. van Vliet
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1994)

The authors study the location error of curved edges in two- and three-dimensional images after analog and digital low-pass filtering. The zero crossing of a second derivative filter is a well-known edge localization criterion. The second derivative in gradient direction (SDGD) produces a predictable bias in edge location towards the centers of curvature while the linear Laplace filter produces a shift in the opposite direction. Their sum called PLUS (PLUS=Laplace+SDGD) leads to an edge detector that finds curved edges one order more accurately than its constituents. This argument holds irrespective of the dimension. The influence of commonly used low-pass filters (such as the PSF originating from diffraction limited optics using incoherent light (2-D), the Gaussian filter with variable cutoff point (D-D), and the isotropic uniform filter (D-D)) is studied.
Growing and Pruning Neural Tree Networks
Authors: A. Sakar, R. J. Mammone
Venue: IEEE Transactions on Computers (1993)

A pattern classification method called neural tree networks (NTNs) is presented. The NTN consists of neural networks connected in a tree architecture. The neural networks are used to recursively partition the feature space into subregions. Each terminal subregion is assigned a class label which depends on the training data routed to it by the neural networks. The NTN is grown by a learning algorithm, as opposed to multilayer perceptrons (MLPs), where the architecture must be specified before learning can begin. A heuristic learning algorithm based on minimizing the L1 norm of the error is used to grow the NTN. It is shown that this method has better performance in terms of minimizing the number of classification errors than the squared error minimization method used in backpropagation. An optimal pruning algorithm is given to enhance the generalization of the NTN. Simulation results are presented on Boolean function learning tasks and a speaker independent vowel recognition task. The NTN compares favorably to both neural networks and decision trees.
Issues in Emerging 4G Wireless Networks
Authors: Upkar Varshney, Radhika Jain
Venue: Computer (2001)

4G wireless networks support global roaming across multiple wireless and mobile networks.
Strategies for Low-Cost Test
Authors: Rohit Kapur, R. Chandramouli, T. W. Williams
Venue: IEEE Design Test (2001)

More collaboration between EDA, semiconductor, and ATE industry segments can improve the manufacturing test environment. These improvements can dramatically reduce the cost of test and lead to a new generation of DFT-aware ATE and ATE-aware DTE.
A Pseudospectral Multi-Domain Method for the Incompressible Navier&ndash;Stokes Equations
Authors: P. Droll, M. Schäfer
Venue: Journal of Scientific Computing (2002)

A pseudospectral method for the solution of incompressible flow problems based on an iterative solver involving an implicit treatment of linearized convective terms is presented. The method is designed for moderately complex geometries by means of a multi-domain approach. Key components are a Chebyshev collocation discretization, a special pressure-correction scheme and a restarted GMRES method with a preconditioner derived from a fast direct solver. The performance of the method with respect to the multi-domain functionality is investigated and compared to finite-volume approaches.
Speech enhancement using fourth-order cumulants and optimum filters in the subband domain
Authors: Elias Nemer, Rafik Goubran, Samy Mahmoud
Venue: Speech Communication (2002)

A new method for speech enhancement using time-domain optimum filters and fourth-order cumulants (FOC) is proposed based on newly established properties of the FOC of speech signals. In the exploratory part of the paper, the analytical expression of the FOC of subbanded speech is derived assuming a sinusoidal model and up to two harmonics per band. Important properties about this cumulant are revealed and actual speech data is used to verify the derivations and the underlying model. In the application part of the work, speech enhancement is formulated as an estimation problem and the expression for the time-domain causal optimum filters is derived for a pth order system. The key idea is to use the FOC of the noisy speech to estimate the parameters required for the enhancement filters, namely the second-order statistics of the speech and noise. It is shown that the kurtosis and the diagonal slice of the FOC may be used to estimate such parameters as the SNR, the speech autocorrelation and the probability of speech presence in a given band. Subjective listening and examination of the spectrograms show that the resulting algorithm is effective on typical noises encountered in mobile telephony. Compared to the TIA-IS127 standard for noise reduction, it results in overall more noise reduction and better speech preservation in Gaussian, street and fan noise. Its effectiveness diminishes however in harmonic and impulsive types such as office and car engine, where discrimination between speech and noise based on FOC becomes more difficult.
Deciding to Correct Distributed Query Processing
Authors: P. Bodorik, J. S. Riordan, J. S. Pyra
Venue: IEEE Transactions on Knowledge and Data Engineering (1992)

Most algorithms for determining query processing strategies in distributed databases are static in nature; that is, the strategy is completely determined on the basis of a priori estimates of the size of intermediate results, and it remains unchanged throughout its execution. The static approach may be far from optimal because it denies the opportunity to reschedule operations if size estimates are found to be inaccurate. Adaptive query execution may be used to alleviate this problem. A low overhead delay method is proposed to decide when to correct a strategy. Sampling is used to estimate the size of relations, and alternative heuristic strategies prepared in a background mode are used to decide when to correct. Evaluation using a model of a distributed database indicates that the heuristic strategies are near optimal. Moreover, it also suggests that it is usually correct to abort creation of an intermediate relation which is much larger than predicted.
Software Architectures for Reducing Priority Inversionand Non-determinism in Real-time Object Request Brokers
Authors: Douglas C. Schmidt, Sumedh Mungee, Sergio Flores-Gaitan, Aniruddha Gokhale
Venue: Real-Time Systems (2001)

There is increasing demand to extend Object Request Broker (ORB) middleware to support distributed applications with stringent real-time requirements. However, conventional ORB implementations, such as CORBA ORBs, exhibit substantial priority inversion and non-determinism, which makes them unsuitable for applications with deterministic real-time requirements. This paper provides two contributions to the study and design of real-time ORB middleware. First, it illustrates empirically why conventional ORBs do not yet support real-time quality of service. Second, it evaluates connection and concurrency software architectures to identify strategies that reduce priority inversion and non-determinism in real-time CORBA ORBs. The results presented in this paper demonstrate the feasibility of using standard OO middleware like CORBA to support certain types of real-time applications over the Internet.
Intelligent dialog overcomes speech technology limitations: the SENECa example
Authors: Wolfgang Minker, Udo Haiber, Paul Heisterkamp, Sven Scheible
Venue: Proceedings of the 8th international conference on Intelligent user interfaces (2003)

We present a primarily speech-based user interface to a wide range of entertainment, navigation and communication applications for use in vehicles. The multimodal dialog en ables the system to uniquely identify one of 79,000 place name variants using an active vocabulary of only 3,000 words at any given time. Low confidence in speech recog nition and word-level ambiguities are compensated for in flexible clarification dialogs with the user. The underlying dialog concept was developed in the framework of the EU-project SENECa. Some recent evalua tion results of the SENECa system demonstrator are discussed in the paper