ppxscal/embedding_network huggingface dataset:
Consistent Initial Condition Calculation for Differential-Algebraic Systems
Authors: Peter N. Brown, Alan C. Hindmarsh, Linda R. Petzold
Venue: SIAM Journal on Scientific Computing (1998)

In this paper we describe a new algorithm for the calculation of consistent initial conditions for a class of systems of differential-algebraic equations which includes semi-explicit index-one systems. We consider initial condition problems of two types---one where the differential variables are specified, and one where the derivative vector is specified. The algorithm requires a minimum of additional information from the user. We outline the implementation in a general-purpose solver DASPK for differential-algebraic equations, and present some numerical experiments which illustrate its effectiveness.
An embedded DRAM architecture for large-scale spatial-lattice computations
Authors: Norman Margolus
Venue: Proceedings of the 27th annual international symposium on Computer architecture (2000)

Spatial-lattice computations with finite-range interactions are an important class of easily parallelized computations. This class includes many simple and direct algorithms for physical simulation, virtual-reality simulation, agent-based modeling, logic simulation, 2D and 3D image processing and rendering, and other volumetric data processing tasks. The range of applicability of such algorithms is completely dependant upon the lattice-sizes and processing speeds that are computationally feasible. Using embedded DRAM and a new technique for organizing SIMD memory and communications we can efficiently utilize 1 Tbit/sec of sustained memory bandwidth in each chip in an indefinitely scalable array of chips. This allows a 10,000-fold speedup per memory chip for these algorithms compared to the CAM-8 lattice gas computer, and is about one million times faster per memory chip for these calculations than a CM-2.
EQL &mdash; the query language you never heard of
Authors: Charles D. Havener
Venue: ACM SIGPLAN Notices (1998)

This paper describes a novel but unknown query language for large parallel database applications. EQL is compiled to C++, the new universal assembly language. Using YACC and CO techniques, EQL is representative of projects students of compiler design might implement in the business world.
Fast Approximate Fourier Transforms for Irregularly Spaced Data
Authors: Antony F. Ware
Venue: SIAM Review (1998)

Several algorithms for efficiently evaluating trigonometric polynomials at irregularly spaced points are presented and analyzed. The algorithms can be viewed as approximate generalizations of the fast Fourier transform (FFT), and they are compared with regard to their accuracy and their computational efficiency.
Models for Audiovisual Fusion in a Noisy-Vowel Recognition Task
Authors: Pascal Teissier, Anne Guerin-Dugue, Jean-Luc Schwartz
Venue: Journal of VLSI Signal Processing Systems (1998)

This paper presents a study of models for audiovisual (AV) fusion in a noisy-vowel recognition task. We progressively elaborate audiovisual models in order to respect the major principle demonstrated by human subjects in speech perception experiments (the &ldquo;synergy&rdquo; principle): audiovisual identification should always be more efficient than auditory-alone or visual-alone identification. We first recall that the efficiency of audiovisual speech recognition systems depends on the level at which they fuse sound and image: four AV architectures are presented, and two are selected for the following of the study. Secondly, we show the importance of providing a contextual input linked to the Signal-to-Noise Ratio (SNR) in the fusion process. Then we propose an original approach using an efficient nonlinear dimension reduction algorithm (&ldquo;curvilinear components analysis&rdquo;) in order to increase the performances of the two AV architectures. Furthermore, we show that this approach allows an easy and efficient estimation of the reliability of the audio sensor in relation to SNR, that this estimation can be used to control the AV fusion process, and that it significantly improves the AV performances. Hence, altogether, nonlinear dimension reduction, context estimation and control of the fusion process enable us to respect the &ldquo;synergy&rdquo; criterion for the two most used architectures.
Reasoning About Analog-Level Implementationsof Digital Systems
Authors: Keith Hanna
Venue: Formal Methods in System Design (2000)

An approach is described for specifying and reasoning about implementations of digital systems that are described at the analog level of abstraction. It is an extension of existing methods that use higher-order logic for reasoning about implementations described in terms of ideal components at the digital level of abstraction. The behaviour of analog components (transistors, etc) are conservatively specified by predicates on the analog voltages and currents at their terminals. A syntactically defined class of specifications is identified that has been found both to be adequately expressive and also to possess computationally tractable decision procedures. The overall approach is illustrated by deriving the conditions for correctness and for compositionality of TTL implementations of logic gates.
The Derivation of Theoretical Ultrasonic Doppler Blood Flow Spectrum
Authors: Nihal Fatma Güler, Saban Ozer
Venue: Journal of Medical Systems (1998)

This paper deals with theoretical aspects of blood flow and the ultrasonic Doppler spectrum. Blood flow in the vessel can be considered as a pipe flow with a circular cross-section. Blood flow is, in general, complex and pulsatile. Navier-Stokes and the continuity equations are the governing equations for the blood flow, and the Navier's equations for the blood vessel. If the flow is pulsatile with a large Womersely number, the velocity profile becomes blunt due to the inertia forces. Since the ultrasonic Doppler flowmeter detects the velocities of blood cells across the vessel, Doppler power spectrum is dependent on the velocity profile. If the velocity profile is blunt, the Doppler power spectrum will be narrow banded. If the flow is sinusoidal, the Womersely number is only a parameter describing the pulsatility. Blood flow waveforms, however, differ from the sinusoidal wave. They consist of a steady flow component and many harmonics with amplitudes and phases. In this study, the influence of the harmonic contents and the Womersely number on velocity profiles and the Doppler power spectrum are examined.
OSI distributed transaction processing commitment optimizations
Authors: Richard Banks, Peter Furniss, Klaus Heien
Venue: ACM SIGCOMM Computer Communication Review (1998)

This paper briefly summarizes the work towards the final version of 'Distributed Transaction Processing' (OSI TP). Several well-known optimizations of the presumed abort protocol are introduced: dynamic flow of READY-messages, a one-phase protocol, a read-only extension. Moreover, some useful extensions such as containment of heuristic decisions and reporting of the completion status of a transaction are presented. The requirements and the functionality are discussed especially from the user's point of view. Finally, the evolving requirements for distributed transaction processing are discussed given the increasing number of applications on the Internet (Electronic Commerce).
Online multicast routing with bandwidth guarantees: a new approach using multicast network flow
Authors: Murali S. Kodialam, T. V. Lakshman, Sudipta Sengupta
Venue: ACM SIGMETRICS Performance Evaluation Review (2000)

This paper presents a new algorithm for on-line routing of bandwidth-guaranteed multicasts where routing requests arrive one-by-one without there being any a priori knowledge of future requests. A multicast routing request consists of a source s, a set of receivers R, and a bandwidth requirement b. This multicast routing problem arises in many contexts. Two applications of interest are routing of point-to-multipoint label-switched paths in Multi-Protocol Label Switched (MPLS) networks, and the provision of bandwidth guaranteed Virtual Private Network (VPN) services under the &ldquo;hose&rdquo; service model [17]. Offline multicast routing algorithms cannot be used since they require a priori knowledge of all multicast requests that are to be routed. Instead, on-line algorithms that handle requests arriving one-by-one and that satisfy as many potential future demands as possible are needed. The newly developed algorithm is an on-line algorithm and is based on the idea that a newly routed multicast must follow a route that does not &ldquo;interfere too much&rdquo; with network paths that may be critical to satisfy future demands. We develop a multicast tree selection heuristic that is based on the idea of deferred loading of certain &ldquo;critical&rdquo; links. These critical links are identified by the algorithm as links that, if heavily loaded, would make it impossible to satisfy future demands between certain ingress-egress pairs. The presented algorithm uses link-state information and some auxilliary capacity information for multicast tree selection and is amenable to distributed implementation. Unlike previous algorithms, the proposed algorithm exploits any available knowledge of the network ingress-egress points of potential future demands even though the demands themselves are unknown and performs very well.
Affine Invariant Texture Segmentation and Shape from Texture by Variational Methods
Authors: Coloma Ballester, Manuel González
Venue: Journal of Mathematical Imaging and Vision (1998)

We address the problem of texture segmentation by using a novel affine invariant model. The introduction of affine invariance as a requirement for texture analysis goes beyond what is known of the human performance and also beyond the psychophysical theories. We propose to compute texture features using affine invariant intrinsic neighborhoods and affine invariant intrinsic orientation matrices. We discuss several possibilities for the definition of the channels and give comparative experimental results where an affine invariant Mumford-Shah type energy functional is used to compute the multichannel affine invariant segmentation. We prove that the method is able to retrieve faithfully the texture regions and to recover the shape from texture information in images where several textures are present. The numerical algorithm is multiscale.
Exact Boundary Controllability of the Korteweg--de Vries Equation
Authors: Bing-Yu Zhang
Venue: SIAM Journal on Control and Optimization (1999)

We consider boundary control of the distributed parameter system described by the Korteweg--de Vries (KdV) equation posed on a finite interval $\alpha \leq x\leq \beta$: \[ \left \{ \begin{array}{l} {u _t + u _x + uu_x + u_{xxx} =0} \\ \\ {u (\alpha , t)=h_1 (t), \qquad u(\beta , t) = h_2 (t), \qquad u _x (\beta , t) = h_3 (t) } {u} \end{array} \right. \qquad (*) \] for $ t\geq 0$. It is shown that by choosing appropriate control inputs ($h_j(t), \ j=1,2,3$), one can always guide the system $(*)$ from a given initial state $\phi \in H^s(\alpha, \beta )$ to a given terminal state $\psi \in H^s(\alpha, \beta )$ in the time period $[0,T]$ so long as $\phi $ and $\psi $ satisfy \[ \| \phi (\cdot ) -w(\cdot , 0)\| _{H^s(\alpha, \beta )}\leq \delta \quad \mbox{and} \quad \| \psi (\cdot ) -w(\cdot , T)\| _{H^s(\alpha, \beta )}\leq \delta \] for some $\delta >0$ independent of $\phi $ and $\psi $, where $s\geq 0$ and $w\equiv w(x,t)$ is a given smooth solution of the KdV equation. This exact boundary controllability is established by considering a related initial value control problem of the KdV equation posed on the whole line $R$. Various recently discovered smoothing properties of the KdV equation have played important roles in our approach.
Debugging distributed programs using controlled re-execution
Authors: Neeraj Mittal, Vijay K. Garg
Venue: Proceedings of the nineteenth annual ACM symposium on Principles of distributed computing (2000)

Distributed programs are hard to write. A distributed debugger equipped with the mechanism to re-execute the traced computation in a controlled fashion can greatly facilitate the detection and localization of bugs. This approach gives rise to a general problem, called predicate control problem, which takes a computation and a safety property specified on the computation, and outputs a controlled computation that maintains the property. We define a class of global predicates, called region predicates, that can be controlled efficiently in a distributed computation. We prove that the synchronization generated by our algorithm is optimal. Further, we introduce the notion of an admissible sequence of events and prove that it is equivalent to the notion of predicate control. We then give an efficient algorithm for the class of disjunctive predicates based on the notion of an admissible sequence.
ADSL and high bandwidth over copper lines
Authors: David J. Greggains
Venue: International Journal of Network Management (1997)

ADSL is a new telecommunications phenomenon. Because it works over the existing copper telephone lines, it will likely become the dominant form of broadband data transmission for at least the next 20 years. &copy; 1997 John Wiley & Sons, Ltd.
A new cell loss recovery method using forward error correction in ATM networks
Authors: Anna H. Hać, Xiaoyang H. Chu
Venue: International Journal of Network Management (1998)

A new method using an FEC technique is proposed to enhance the ability of consecutive cell loss compensation due to buffer overflow in ATM networks. This article summarizes different applications of cell loss recovery, and presents the design of a new coding scheme and the coding&sol;decoding algorithm. &copy; 1998 John Wiley & Sons, Ltd.
Structural gate decomposition for depth-optimal technology mapping in LUT-based FPGA designs
Authors: Jason Cong, Yean-Yow Hwang
Venue: ACM Transactions on Design Automation of Electronic Systems (TODAES) (2000)

In this paper we study structural gate decomposition in general, simple gate networks for depth-optimal technology mapping using K-input Lookup-Tables (K-LUTs). We show that (1) structural gate decomposition in any K-bounded network results in an optimal mapping depth smaller than or equal to that of the original network, regardless of the decomposition method used; and (2) the problem of structural gate decomposition for depth-optimal technology mapping is NP-hard for K-unbounded networks when K&ge;3 and remains NP-hard for K-boundeds networks when K&ge;5. Based on these results, we propose two new structural gate decomposition algorithms, named DOGMA and DOGMA-m, which combine the level-driven node-packing technique (used in FlowMap) and the network flow-based labeling technique (used in Chortle-d) for depth-optimal technology mapping. Experimental results show that (1) among five structural gate decompostion algorithms, DOGMA-m results in the best mapping solutions; and (2) compared with speed_up(an algebraic algorithm) and TOS (a Boolean approach), DOGMA-m completes, decomposition of all tested benchmarks in a short time while speed_up and TOS fail in several cases. However, speed_up results in the smallest depth and area in the following technology mapping steps.
Relating Differential Distribution Tables to Other Propertiesof of Substitution Boxes
Authors: Xian-Mo Zhang, Yuliang Zheng, Hideki Imai
Venue: Designs, Codes and Cryptography (2000)

Due to the success of differential and linear attacks on a large number of encryption algorithms, it is important to investigate relationships among various cryptographic, including differential and linear, characteristics of an S-box (substitution box). After discussing a precise relationship among three tables, namely the difference, auto-correlation and correlation immunity distribution tables, of an S-box, we develop a number of results on various properties of S-boxes. More specifically, we show (1) close connections among three indicators of S-boxes, (2) a tight lower bound on the sum of elements in the leftmost column of its differential distribution table, (3) a non-trivial and tight lower bound on the differential uniformity of an S-box, and (4) two upper bounds on the nonlinearity of S-boxes (one for a general, not necessarily regular, S-box and the other for a regular S-box).
Linking codesign and reuse in embedded systems design
Authors: M. Meerwein, C. Baumgartner, W. Glauert
Venue: Proceedings of the eighth international workshop on Hardware/software codesign (2000)

This paper presents a complete codesign environment for embedded systems which combines automatic partitioning with reuse from a module database. Special emphasis has been put on satisfying the requirements of industrial design practice and on the technical and economic constraints associated with automotive control applications. The object-oriented database architecture allows efficient management of a large number of modules. Experimental results from a real-world example demonstrate the viability and advantages of the presented methodology.
A 2D Invariant System Description for Doubly Periodic 2DSystems
Authors: Nevio Carpanese
Venue: Multidimensional Systems and Signal Processing (1999)

In this paper the well-known 1D lifting isomorphism from periodic systems to invariant ones is extended to 2D case. Controllability and reconstructibility of periodic 2D systems are then defined in terms of invariant associated system. Some examples are presented to illustrate the key feature of periodic controllers weak causality which has no counterpart in the invariant case.
Introduction: Computer Vision Research at NECI
Authors: Ingemar J. Cox
Venue: International Journal of Computer Vision (1999)

This special issue of the International Journal of Computer Vision highlights research on computer vision at the NEC Research Institute. The purpose of this preface is to provide some context to how this work reflects our broader goals and themes of computer vision research at NECI.
On Computing the Exact Euclidean Distance Transform on Rectangular and Hexagonal Grids
Authors: Andrew J. H. Mehnert, Paul T. Jackway
Venue: Journal of Mathematical Imaging and Vision (1999)

In this paper we prove an equivalence relation between the distance transform of a binary image, where the underlying distance is based on a positive definite quadratic form, and the erosion of its characteristic function by an elliptic poweroid structuring element. The algorithms devised by Shih and Mitchell [18] and Huang and Mitchell [7], for calculating the exact Euclidean distance transform (EDT) of a binary digital image manifested on a square grid, are particular cases of this result. The former algorithm uses erosion by a circular cone to calculate the EDT whilst the latter uses erosion by an elliptic paraboloid (which allows for pixel aspect ratio correction) to calculate the square of the EDT. Huang and Mitchell&lsquo;s algorithm [7] is arguably the better of the two because: (i) the structuring element can be decomposed into a sequence of dilations by 3 &times; 3 structuring elements (a similar decomposition is not possible for the circular cone) thus reducing the complexity of the erosion, and (ii) the algorithm only requires integer arithmetic (it produces squared distance). The algorithm is amenable to both hardware implementation using a pipeline architecture and efficient implementation on serial machines. Unfortunately the algorithm does not directly transpose to, nor has a corresponding analogue on, the hexagonal grid (the same is also true for Shih and Mitchell&lsquo;s algorithm [7]). In this paper, however, we show that if the hexagonal grid image is embedded in a rectangular grid then Huang and Mitchell&lsquo;s algorithm [7] can be applied, with aspect ratio correction, to obtain the exact EDT on the hexagonal grid.
An Algorithm for Computing the Distance to Instability
Authors: C. He, G. A. Watson
Venue: SIAM Journal on Matrix Analysis and Applications (1999)

An algorithm is developed for computing the distance to instability of an n &times; n matrix. It is aimed primarily at sparse matrices and can be used for any value of n provided that an eigenvalue problem for a (2n) &times; (2n) Hamiltonian matrix can be solved on the computer being used. The algorithm gives both a lower bound and an upper bound for the distance in guaranteed accuracy. The method is faster than other currently available methods.
Nonclassical Shocks and Kinetic Relations: Finite Difference Schemes
Authors: Brian T. Hayes, Philippe G. LeFloch
Venue: SIAM Journal on Numerical Analysis (1998)

We consider hyperbolic systems of conservation laws that are not genuinely nonlinear. The solutions generated by diffusive-dispersive regularizations may include nonclassical (n.c.) shock waves that do not satisfy the classical Liu entropy criterion. We investigate the numerical approximation of n. c. shocks via conservative difference schemes constrained only by a single entropy inequality.The schemes are designed by comparing their equivalent equations with the continuous model and include discretizations of the diffusive and dispersive terms. Limits of these schemes are characterized via the kinetic relation introduced earlier by the authors. We determine the kinetic function numerically for several examples of systems and schemes. This study demonstrates that the kinetic relation is a suitable tool for the selection of unique n. c. solutions and for the study of their sensitive dependence on the critical parameters: the ratios of diffusion/dispersion and diffusion/mesh size, the shock strength, and the order of discretization of the flux.
Characterization of risky projects based on project managers' evaluation
Authors: Osamu Mizuno, Tohru Kikuno, Yasunari Takagi, Keishi Sakamoto
Venue: Proceedings of the 22nd international conference on Software engineering (2000)

During the process of software development, senior managers often find indications that projects are risky and take appropriate actions to recover them from this dangerous status. If senior managers fail to detect such risks, it is possible that such projects may collapse completely.In this paper, we propose a new scheme for the characterization of risky projects based on an evaluation by the project manager. In order to acquire the relevant data to make such an assessment, we first designed a questionnaire from five viewpoints within the projects: requirements, estimations, team organization, planning capability and project management activities. Each of these viewpoints consisted of a number of concrete questions. We then analyzed the responses to the questionnaires as provided by project managers by applying a logistic regression analysis. That is, we determined the coefficients of the logistic model from a set of the questionnaire responses. The experimental results using actual project data in Company A showed that 27 projects out of 32 were predicted correctly. Thus we would expect that the proposed characterizing scheme is the first step toward predicting which projects are risky at an early phase of the development.
Palette: a paper interface for giving presentations
Authors: Les Nelson, Satoshi Ichimura Elin Rønby Pedersen, Lia Adams
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

The Palette is a digital appliance designed for intuitive control of electronic slide shows. Current interfaces demand too much of our attention to permit effective computer use in situations where we can not give the technology our fullest concentration. The Palette uses index cards that are printed with slide content that is easily identified by both humans and computers. The presenter controls the presentation by directly manipulating the cards. The Palette design is based on our observation of presentations given in a real work setting. Our experiences using the system are described, including new practices (e.g., collaborative presentation, enhanced notetaking) that arise from the affordances of this new approach. This system is an example of a new interaction paradigm called tacit interaction that supports users who can spare very little attention to a computer interface.