ppxscal/embedding_network huggingface dataset:
Improved subject access, browsing and scanning mechanisms in modern on-line IR
Authors: Peter Ingwersen, Irene Wormell
Venue: Proceedings of the 9th annual international ACM SIGIR conference on Research and development in information retrieval (1986)

Focusing on communication, the paper analyses and proposes practical solutions to key problems in online IR, in particular concerned with ill defined and &ldquo;muddled&rdquo; information requirements, concept interpretation in searching and text representation. The need for development of new additional browsing and scanning feedback devices, based on existing methods to support searchers is emphasised. The paper points to economically feasible indexing methods fitting the potentials of current information technology and adaptable to in-house information environments: the SAP (Subject Access Project) principles. Focusing display mechanisms and the term frequency analysis feature Zoom are discussed and suggested combined into a flexible database front-end. The design principles are outlined and demonstrated in a worked example.
Smart Substrate MCMs
Authors: Anne E. Gattiker, Wojciech Maly
Venue: Journal of Electronic Testing: Theory and Applications (1997)

This paper presents a cost-based assessment of the effectiveness of Smart Substrate MCM Systems. A Smart Substrate MCM System is one in which the substrate contains active circuitry for carrying out testing functions. The feasibility of using this approach is investigated. The Smart Substrate strategy is compared to an alternative approach based on the assumption that system components are perfect (&ldquo;Known Good Die (KGD)&rdquo; approach). The obtained results identify the domain of applicability of Smart substrate MCMs and point to limitations of the KGD approach.
Simulation of manufacturing systems
Authors: Averill M. Law
Venue: Proceedings of the 17th conference on Winter simulation (1985)

Simulation is the most widely used technique for designing and analyzing manufacturing systems. However, there is an unfortunate impression that simulation is just a complicated exercise in computer programming. Consequently, many &ldquo;studies&rdquo; have been composed of heuristic model building, coding, and a single run of the program to produce the &ldquo;answers.&rdquo; This attitude, which neglects the important issues of how to build a valid model and how to draw correct statistical inferences from a properly coded model, has led to erroneous conclusions being drawn from many simulation studies. In this tutorial, we discuss how simulation can be used in a manufacturing context and also the steps in a sound simulation study. In particular, the following topics will be discussed: Manufacturing issues which can be investigated using simulation, Manufacturing measures of performance which can be estimated using simulation, Techniques for building valid and credible models of manufacturing systems, Simulation languages for manufacturing modeling, Statistics aspects of manufacturing simulation, Common pitfalls in simulation modeling. 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
Enhanced Cell-Centered Finite Differences for Elliptic Equations on General Geometry
Authors: Todd Arobogast, Clint N. Dawson, Philip T. Keenan, Mary F. Wheeler, Ivan Yotov
Venue: SIAM Journal on Scientific Computing (1998)

We present an expanded mixed finite element method for solving second-order elliptic partial differential equations on geometrically general domains. For the lowest-order Raviart--Thomas approximating spaces, we use quadrature rules to reduce the method to cell-centered finite differences, possibly enhanced with some face-centered pressures. This substantially reduces the computational complexity of the problem to a symmetric, positive definite system for essentially only as many unknowns as elements. Our new method handles general shape elements (triangles, quadrilaterals, and hexahedra) and full tensor coefficients, while the standard mixed formulation reduces to finite differences only in special cases with rectangular elements. As in other mixed methods, we maintain the local approximation of the divergence (i.e., local mass conservation). In contrast, Galerkin finite element methods facilitate general element shapes at the cost of achieving only global mass conservation. Our method is shown to be as accurate as the standard mixed method for a large class of smooth meshes. On nonsmooth meshes or with nonsmooth coefficients one can add Lagrange multiplier pressure unknowns on certain element edges or faces. This enhanced cell-centered procedure recovers full accuracy, with little additional cost if the coefficients or mesh geometry are piecewise smooth. Theoretical error estimates and numerical examples are given, illustrating the accuracy and efficiency of the methods.
Proving concurrent constraint programs correct
Authors: Frank S. De Boer, Maurizio Gabbrielli, Elena Marchiori, Catuscia Palamidessi
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1997)

We introduce a simple compositional proof system for proving (partial) correctness of concurrent constraint programs (CCP). The proof system is based on a denotational approximation of the strongest postcondition semantics of CCP programs. The proof system is proved to be correct for full CCP and complete for the class of programs in which the denotational semantics characterizes exactly the strongest postcondition. This class includes the so-called confluent CCP, a special case of which is constraint logic programming with dynamic scheduling.
A 3.3 V Current-Controlled &radic; -Domain Oscillator
Authors: J. Mulder, W. A. Serdijn, A. C. van der Woerd, A. H. M. van Roermund
Venue: Analog Integrated Circuits and Signal Processing (1998)

In this paper, the strong inversion MOS analog of the recently proposed class of log-domain filters, or translinear filters, is proposed.The dynamic &radic; -domain principle, or dynamic voltage-translinear principle, exploits the quadratic law, describing the MOS transistor in the strong inversion region, both to perform an expanding V-I conversion of the capacitor voltages and to implement multiplications and square roots of currents based on the voltage-translinear principle.The presented theory is applied to the design of a current-controlled two-integrator oscillator. Experiment results of a pure CMOS test IC show the feasibility of the &radic; -domain principle. The realized oscillator has a THD of &minus;42 dB and is linearly frequency tunable across 1.3 decades.
Decomposition of tautologies into regular formulas and strong completeness of connection-graph resolution
Authors: W. Bibel, E. Eder
Venue: Journal of the ACM (JACM) (1997)

This paper addresses and answers a fundamental question about resolution. Informally, what is gained with respect to the search for a proof by performing a single resolution step? It is first shown that any unsatisfiable formula may be decomposed into regular formulas provable in linear time (by resolution). A relevant resolution step strictly reduces at least one of the formulas in the decomposition while an irrelevant one does not contribute to the proof in any way. the relevance of this insight into the nature of resolution and of the unsatisfiability problem for the development of proof strategies and for complexity considerations are briefly discussed.The decomposition also provides a technique for establishing completeness proofs for refinements of resolution. As a first application, connection-graph resolution is shown to be strongly complete. This settles a problem that remained open for two decades despite many proff attempts. The result is relevant for theorem proving because without strong completeness a connection graph resolution prover might run into an infinite loop even on the ground level.
Microarchitecture support for improving the performance of load target prediction
Authors: Chung-Ho Chen, Akida Wu
Venue: Proceedings of the 30th annual ACM/IEEE international symposium on Microarchitecture (1997)

Presents a load target prediction scheme that mitigates the impact of load latency for modern microprocessors. The scheme uses a cache-like buffer to provide the base address, offset and operand size at the instruction fetching stage of a pipeline so that a load target address can be computed earlier at the decode stage. With the dynamic use of a load stride, the scheme has achieved a prediction rate that is 15% higher than a previously proposed approach. By providing a 128-entry direct-mapped load-prediction buffer, two adders and two forwarding paths, for a 4-fetch processor the scheme provides an average speedup of 10% to 32% in performance improvement as the data cache latency increases from 2 cycles to 4 cycles. A bit-array design that supports multiple-cast writes and eliminates the associative logic commonly used in base register caching is developed for the prediction scheme.
Device-circuit optimization for minimal energy and power consumption in CMOS random logic networks
Authors: Pankaj Pant, Vivek De, Abhijit Chatterjee
Venue: Proceedings of the 34th annual Design Automation Conference (1997)

We demonstrate a new approach minimizing the total ofthe static and the dynamic power dissipation components in aCMOS logic network required to operate at a specified clockfrequency using joint optimization of both device and circuitdesigns for a specific logic schematic and activity profile.We present a new approach to designing ultra low-powerCMOS logic circuits by joint optimization of supply voltage,threshold voltage and device widths for a specified speedconstraints.The static (leakage) and dynamic (switching)energy components are considered and an efficient heuristicis developed that delivers over an order of magnitude savingsin power over conventional optimization methods.
A Systematic Approach to the Petri Net Based Specificationof Concurrent Systems
Authors: Antonino Mazzeo, Nicola Mazzocca, Stefano Russo, Valeria Vittorini
Venue: Real-Time Systems (1997)

We describe an approach to the specification of concurrent systems which enables a Petri net model of a system to be built up in a systematic way starting from a trace-based CSP specification. This method enables the separate specification of the behavior of each component (process) and their interactions in terms of the feasible sequences of events in which they can be involved. A set of rules is then applied to transform the trace-based specifications into a complete Petri net that is analyzed and/or executed to validate system behavior. The domain transformation procedure is fully automatable. The specification of a safety-critical railway control system is used as a case study.
Computing a Factor of a Polynomial by Means of Multishift LR Algorithms
Authors: Luca Gemignani
Venue: SIAM Journal on Matrix Analysis and Applications (1998)

In this paper we deal with the numerical approximation of a factor of a polynomial. Our approach is based on the relations between matrix transforms and functional iterations. We show that a generalized LR algorithm applied to an $n\times n$ Hessenberg matrix A may be viewed in a polynomial setting as an iterative method for the computation of a single factor of arbitrary degree k n of the characteristic polynomial of A. In its basic form our method is linearly convergent under very mild assumptions. The convergence rate can be improved by considering the technique of shifting; the local convergence of our method complemented with a suitable shift strategy is typically quadratic. One iteration of the resulting algorithm can be performed at the overall cost of O(k4 + nk3) arithmetical operations and n k2log p/p parallel steps with order-pk2 processors; therefore, it appears to have nice computational features in the typical case where k is a prespecified integer of modest size with respect to n. Moreover, it can be arranged to produce highly efficient parallel algorithms because of its possibility of extensive vectorization. Finally, we confirm its effectiveness by means of numerical experiments which are reported and discussed.
Sensitivity analysis of a large-scale transportation simulation using design of experiments and factor analysis
Authors: Glenn G. Rousseau, Kenneth W. Bauer,  Jr.
Venue: Proceedings of the 28th conference on Winter simulation (1996)

This paper describes how design of experiments and factor analysis were used to conduct sensitivity analysis on multivariate output from a large scale transportation simulation model. Specifically, this research focused on the sensitivity of airlift system performance to changes or errors in a list of transportation requirements. The general approach included perturbing a time-phased list of transportation requirements according to an experimental design and using a simulation model to estimate the airlift system performance response. We used factor analysis to reduce the dimensionality of the multivariate output data and to generate sensitivity plots, which proved to be valuable graphical tools for sensitivity analysis. Additionally, we identified how factor analysis can be used as a verification and validation tool for large stochastic simulation models.
Computing 3SLS Solutions of Simultaneous Equation Models with a Possible Singular Variance&ndash;Convariance Matrix
Authors: Erricos J. Kontoghiorghes, Elias Dinenis
Venue: Computational Economics (1997)

Algorithms for computing the three-stage least squares (3SLS) estimator usually require the disturbance convariance matrix to be non-singular. However, the solution of a reformulated simultaneous equation model (SEM) results into the redundancy of this condition. Having as a basic tool the QR decomposition, the 3SLS estimator, its dispersion matrix and methods for estimating the singular disturbance covariance matrix and derived. Expressions revealing linear combinations between the observations which become redundant have also been presented. Algorithms for computing the 3SLS estimator after the SEM have been modified by deleting or adding new observations or variables are found not to be very efficient, due to the necessity of removing the endogeneity of the new data or by re-estimating the disturbance covariance matrix. Three methods have been described for solving SEMs subject to separable linear equalities constraints. The first method considers the constraints as additional precise observations while the other two methods reparameterized the constraints to solve reduced unconstrained SEMs. Method for computing the main matrix factorizations illustrate the basic principles to be adopted for solving SEMs on serial or parallel computers.
Security functions for a file repository
Authors: Arne Helme, Tage Stabell-Kulø
Venue: ACM SIGOPS Operating Systems Review (1997)

When personal machines are incorporated into distributed systems a new mixture of threats is exposed. The security effort in the MobyDick project is aimed at understanding how privacy can be protected in this new environment. Our claim is that a two-step process for authentication and authorisation is required, but also sufficient. The research vehicle is a distributed file repository.
A compacting incremental collector and its performance in a production quality compiler
Authors: Martin Larose, Marc Feeley
Venue: ACM SIGPLAN Notices (1999)

We present a new near-real-time compacting collector and its implementation in a production quality Scheme compiler (Gambit-C). Our goal is to use this system as a base for an implementation of Erlang for writing soft real-time telecommunication applications. We start with a description of Gambit-C's memory organisation and its blocking collector. The design and integration of the incremental collector within Gambit-C are then explained. Finally we measure the performance of the incremental collector and compare it to the original blocking collector. We found that the overhead of the incremental collector is high (a factor of 1.3 to 8.1, with a median of 2.24) but nevertheless the collection pauses are compatible with typical soft real-time requirements (we get an average pause of 2.9 milliseconds and a maximum pause of 15 milliseconds on a 133Mhz DEC Alpha 21064).
Stirling Numbers for Complex Arguments
Authors: Bruce Richmond, Donatella Merlini
Venue: SIAM Journal on Discrete Mathematics (1997)

We define the Stirling numbers for complex values and obtain extensions of certain identities involving these numbers. We also show that the generalization is a natural one for proving unimodality and monotonicity results for these numbers. The definition is based on the Cauchy integral formula and can be used for many other combinatorial numbers.
Design and code reuse based on fuzzy classification of components
Authors: E. Damiani, M. G. Fugini
Venue: ACM SIGAPP Applied Computing Review (1996)

A bottleneck in software reuse is the classification schema and retrieval method of components. Particularly when large repositories of components are available, classification and retrieval for reuse should be flexible to allow the selection also of components which, although not perfectly matching requirements, are adaptable with a limited effort. This paper presents a fuzzy classification model for a repository storing descriptors of components. These descriptors include fuzzy-weighted keyword pairs describing components functionalities extracted from code and its design documentation. A mechanism for semi-automatic extraction of keywords, and for automatic assignement of fuzzy weights to keyword pairs based on text retrieval algorithms is provided.
Operators for program control
Authors: Edward V. Eusebi
Venue: ACM SIGAPL APL Quote Quad (1985)

Structured programming constructs such as if-then-else and do-while have traditionally been used to give a natural flow to programs written in one of the ALGOL-like languages. Languages with a functional basis, such as APL and LISP, provide (and are characterized by) alternative means of controlling the flow of expression. These include function modularity, the application of functions across data structures, the use of data structures to control program flow, and the mapping of operations across data and across other operations. In APL2, the use of these methods has been enhanced by the generalization of APL data structures, the addition of the primitive operator Each(&Prime;), and the ability to define operators. This paper will examine ways in which these features may be used to give a non-procedural look to APL2 functions.
Efficient data consistency in HLA/DIS++
Authors: Sudhir Srinivasan
Venue: Proceedings of the 28th conference on Winter simulation (1996)

Simulation exercises based on the DIS paradigm are faced with a severe scalability limitation due to the use of time out updates or "heartbeat" messages for maintaining consistency despite message loss. Since they carry information that is redundant and useless in most cases, these messages represent a waste of network bandwidth and computational resources. This paper presents an elegant solution that eliminates heartbeats without compromising consistency. Rather than using additional schemes and software components as others have done, the solution proposed here consists of careful use of reliable and unreliable communications based on a key insight into the communication properties of DIS-based simulations. Not only does our solution eliminate heartbeats, it also minimizes additional resource consumption by using reliable communications minimally. Finally, due to its simplicity, it can be easily incorporated into HLA-compliant simulations.
Rational parametrizations of nonsingular real cubic surfaces
Authors: Chandrajit L. Bajaj, Robert L. Holt
Venue: ACM Transactions on Graphics (TOG) (1998)

Real cubic algebraic surfaces may be described by either implicit or parametric equations. One particularly useful representation is the rational parametrization, where the three spatial coordinates are given by rational functions of two parameters. These parametrizations take on different forms for different classes of cubic surfaces. Classification of real cubic algebraic surfaces into five families for the nonsingular case is based on the configuration of 27 lines on them. We provide a method of extracting all these lines by constructing and solving a polynomial of degree 27. Simple roots of this polynomial correspond to real lines on the surface, and real skew lines are used to form rational parametrizations for three of these families. Complex conjugate skew lines are used to parametrize surfaces from the fourth family. The parametrizations for these four families involve quotients of polynomials of degree no higher than four. Each of these parametrizations covers the whole surface except for a few points, lines, or conic sections. The parametrization for the fifth family, as noted previously in the literature, requires a square root. We also analyze the image of the derived rational parametrization for both real and complex parameter values, together with &ldquo;base&rdquo; points where the parametrizations are ill-defined.
On the characterization of VBR MPEG streams
Authors: Marwan Krunz, Satish K. Tripathi
Venue: Proceedings of the 1997 ACM SIGMETRICS international conference on Measurement and modeling of computer systems (1997)

We present a comprehensive model for variable-bit-rate MPEG video streams. This model captures the bit-rate variations at multiple time scales. Long-term variations are captured by incorporating scene changes, which are most noticeable in the fluctuations of I frames. The size of an I frame is modeled by the sum of two random components: a scene-related component and an AR(2) component that accounts for the fluctuations within a scene. Two random processes of i.i.d. rvs are used to model the sizes of P and B frames, respectively. The complete model is then obtained by intermixing the three sub-models according to a given GOP pattern. It is shown that the composite model exhibits long-range dependence (LRD) in the sense that its autocorrelation function is non-summable. The LRD behavior is caused by the repetitive GOP pattern which induces periodic cross-correlations between different types of frames. Using standard statistical methods, we successfully fit our model to several empirical video traces. We then study the queueing performance for video traffic at a statistical multiplexer. The results show that the model is sufficiently accurate in predicting the queueing performance for real video streams.
On Coset Weight Distributions of the 3-Error-Correcting BCH-Codes
Authors: Pascale Charpin, Victor Zinoviev
Venue: SIAM Journal on Discrete Mathematics (1997)

We study the coset weight distributions of the 3-error-correcting binary narrow-sense BCH-codes and of their extensions, whose lengths are, respectively, 2m-1 and 2m, m odd. We prove that all weight distributions are known as soon as those of the cosets of minimum weight 4 of the extended code are known. We point out that properties of the cosets which are orphans yield interesting properties on the other cosets. We describe the classes of cosets which are equivalent under the affine permutations. At the end we produce significant numerical results, proving that the number of distinct weight distributions of cosets increases with the length of the codes.