ppxscal/embedding_network huggingface dataset:
Knowledge Discovery in Deductive Databases with Large Deduction Results: The First Step
Authors: Chien-Le Goh, Masahiko Tsukamoto, Shojiro Nishio
Venue: IEEE Transactions on Knowledge and Data Engineering (1996)

Deductive databases have the ability to deduce new facts from a set of facts using a set of rules. They are also useful in the integration of artificial intelligence and database. However, when recursive rules are involved, the amount of deduced facts can become too large to be practically stored, viewed or analyzed. This seriously hinders the usefulness of deductive databases. In order to overcome this problem, we propose four methods to discover characteristic rules from large amount of deduction results without actually having to store all the deduction results. This paper presents the first step in the application of knowledge discovery techniques to deductive databases with large deduction results.
Local Search Techniques for Constrained Portfolio SelectionProblems
Authors: Andrea Schaerf
Venue: Computational Economics (2002)

We consider the problem of selecting a portfolio of assets that provides the investor a suitable balance of expected return and risk. With respect to the seminal mean-variance model of Markowitz, we consider additional constraints on the cardinality of the portfolio and on the quantity of individual shares. Such constraints better capture the real-world trading system, but make the problem more difficult to be solved with exact methods. We explore the use of local search techniques, mainly tabu search, for the portfolio selection problem. We compare the combine previous work on portfolio selection that makes use of the local search approach and we propose new algorithms that combine different neighborhood relations. In addition, we show how the use of randomization and of a simple form of adaptiveness simplifies the setting of a large number of critical parameters. Finally, we show how our techniques perform on public benchmarks.
RASSP: Changing the Paradigm of Electronic-System Design
Authors: James H. M. Malley
Venue: IEEE Design Test (1996)

RASSP is a DoD program to develop a process that meets four ambitious goals. Over the four year life of this ARPA/Tri-Service project, the cost and development time of producing military embedded digital signal processors is to be reduced by a factor of four (4X). At the same time the program is to provide for at least a 4X lowering of life cycle costs for the development of signal processors. A team consisting of Sanders, Motorola, Hughes Aircraft Company, and ISX has been working for two years towards meeting these objectives. This article summarizes the technical approach that is being used and provides measures, using real systems developments, of progress that has been made. 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
An Auto-Adaptive Multidomain Spectral Technique for Linear Stability Analysis: Application to Viscous Compressible Flows
Authors: Eric Serre, Serge Gauthier
Venue: Journal of Scientific Computing (2002)

An auto-adaptive multidomain pseudo-spectral technique is considered in order to solve the linear stability problem of viscous compressible flows. Both the locations of the interfaces and the parameters of the mappings in each subdomain are adapted by minimizing the H2&omega;-norm of the calculated solution. Such method provides automatically&mdash;this is the key point&mdash;the best polynomial interpolation of the basic state the stability of which is studied. It turns out that the whole procedure is needed to obtain reliable results. The method is first validated against results available in the literature (both viscous incompressible and inviscid compressible Rayleigh&ndash;Taylor configurations). The efficiency of the numerical method is illustrated with results on the linear stability of the compressible viscous diffusive Rayleigh&ndash;Taylor flow where no analytical or numerical results are available. New results showing the influence of stratification, viscosity, diffusity between species and thermal diffusivity are presented.
The m-calculus: a higher-order distributed process calculus
Authors: Alan Schmitt, Jean-Bernard Stefani
Venue: ACM SIGPLAN Notices (2003)

This paper presents a new distributed process calculus, called the M-calculus, that can be understood as a higher-order version of the Distributed Join calculus with programmable localities. The calculus retains the implementable character of the Distributed Join calculus while overcoming several important limitations: insufficient control over communication and mobility, absence of dynamic binding, and limited locality semantics. The calculus is equipped with a polymorphic type system that guarantees the unicity of locality names, even in presence of higher-order communications -- a crucial property for the determinacy of message routing in the calculus.
Optimum Time Diversity and BCH Codes for DS SS-CDMA CellularMobile Channels
Authors: Adel Ahmed Ali
Venue: Wireless Personal Communications: An International Journal (1999)

This paper presents the results of optimum diversity and coding of a cellular radio system using spread-spectrum code division multiple-access (SS-CDMA) and binary phase-shift-keying modulation (BPSK). The base-to-mobile link is considered with the mobile at the boundary between cells. Hence, the received signal is subject to Rayleigh or log-normal fading, as well as to interference from neighbouring cells.First, the probability of error for the fading-interference channel is approximated as a simple, closed-form expression, with one-parameter which signifies the degree of channel fading and interference. It is shown that the approximation is quite satisfactory for a wide range of channel fading and interference. Beside avoiding numerical integration, the use of such simplification offers more insight into the nature of the channel.The use of error-correcting codes to enable increasing the system capacity is then investigated. Since employment of either SS or forward-error correction (FEC) techniques results in bandwidth expansion for a communication system using a fixed alphabet size, there exists a trade-off between how much processing gain and how much coding gain the system should employ such that the bit-error rate is minimum. Two types of coding are analysed, viz. repetitive coding and binary BCH codes. For the repetitive code, Chernoff upper-bound is used to approximate the bit-error rate (BER) and the optimum diversity is then found by a simple minimisation.To find the optimum trade-off between code rate k/n and correction capability t of BCH (n,k,t) codes, the first term of the series representing the BER is used as an estimate of the probability of error. Such approximation is shown to yield a nearly exact estimate of the optimum coding parameters, which minimise the BER. Although exact analysis can be used, the present approach yields a general solution, and optimum design parameters can be related to channel conditions. The essence of the results is as follows: (i) fading and interference channel is approximated as a one parameter family; (ii) optimum diversity increases and processing gain decreases, almost linearly, with the increase of interference and fading severity; (iii) optimum BCH code rate is 0.3 over a wide range of fading and interference conditions, and (iv) optimising coding gain and processing gain can provide substantial increase in system capacity.
A comparison of three programming models for adaptive applications on the origin2000
Authors: Hongzhang Shan, Jaswinder Pal Singh, Leonid Oliker, Rupak Biswas
Venue: Journal of Parallel and Distributed Computing (2002)

Adaptive applications have computational workloads and communication patterns that change unpredictably at runtime, requiring dynamic load balancing to achieve scalable performance on parallel machines. Efficient parallel implementations of such adaptive applications is therefore a challenging task. In this paper, we compare the performance of and the programming effort required for two major classes of adaptive applications under three leading parallel programming models on an SGI Origin2000 system, a machine that supports all three models efficiently. Results indicate that the three models deliver comparable performance; however, the implementations differ significantly beyond merely using explicit messages versus implicit loads/stores even though the basic parallel algorithms are similar. Compared with the message-passing (using MPI) and SHMEM programming models, the cache-coherent shared address space (CC-SAS) model provides substantial ease of programming at both the conceptual and program orchestration levels, often accompanied by performance gains. However, CC-SAS currently has portability limitations and may suffer from poor spatial locality of physically distributed shared data on large numbers of processors.
Why is Combinational ATPG Efficiently Solvable for Practical VLSI Circuits?
Authors: Mukul R. Prasad, Philip Chong, Kurt Keutzer
Venue: Journal of Electronic Testing: Theory and Applications (2001)

Empirical observation shows that practically encountered instances of combinational ATPG are efficiently solvable. However, it has been known for more than two decades that ATPG is an NP-complete problem (Ibarra and Sahni, IEEE Transactions on Computers, Vol. C-24, No. 3, pp. 242&ndash;249, March 1975). This work is one of the first attempts to reconcile these seemingly disparate results. We introduce the concept of cut-width of a circuit and characterize the complexity of ATPG in terms of this property. We introduce the class of log-bounded width circuits and prove that combinational ATPG is efficiently solvable on members of this class. The class of of log-bounded width circuits is shown to strictly subsume the class of k-bounded circuits introduced by Fujiwara (International Symposium on Fault-Tolerant Computing, June 1988, pp. 64&ndash;69). We provide empirical evidence which indicates that an interestingly large class of practical circuits is expected to have log-bounded width, which ensures efficient solution of ATPG on them.
Supporting project awareness on the WWW with the iScent framework
Authors: Kenneth M. Anderson, Niels Olof Bouvin
Venue: ACM SIGGROUP Bulletin (2000)

Supporting project awareness in the context of large-scale software development is difficult. One problem is identifying appropriate abstractions and techniques that support the insertion of project awareness mechanisms into a software development environment with minimal impact. An additional problem is scaling project awareness mechanisms to handle the demands of large software development projects. The Web is increasingly being used to support software engineering and, as such, becomes an additional target for project awareness mechanisms with its own unique challenges. To maintain awareness of information evolving on an Internet scale, and to address the problems and challenges mentioned above, we present a framework to support awareness and intersubjectivity among software team members through the use of automatically collected, hypermedia-enabled event trails. The concepts, techniques, and tools of event notification and open hypermedia are used to support a new project awareness framework. A distinction of this framework is the presence of mechanisms that explicitly support intersubjectivity among team members and the use of event trails as a new abstraction for providing project awareness information.
On large sets of disjoint Kirkman triple systems
Authors: Jian-guo Lei
Venue: Discrete Mathematics (2002)

In this paper, we introduce LR(u) designs and use these designs together with large sets of Kirkman triple systems (LKTS) and transitive KTS (TKTS) of order υ to construct an LKTS(uυ). Our main result is that there exists an LKTS(υ) for υ ∈ {3nm(2 . 13k + 1)t; n ≥ 1, k ≥ 1, t = 0,1, m ∈ {1, 5, 11, 17, 25, 35, 43}}.
Software System Engineering: A Tutorial
Authors: Richard H. Thayer
Venue: Computer (2002)

Software, the dominant technology in many technical systems, often provides the cohesiveness and data control that enable a complex system to solve problems. Yet the vast majority of large software systems do not meet their projected schedule or estimated cost, nor do they completely fulfill the system acquirer's expectations.The application of system engineering principles to software development produces activities, tasks, and procedures called software system engineering, or SwSE-a distinct and powerful tool for managing the technical development of large software projects. This tutorial integrates the definitions and processes from the IEEE software engineering standards into the SwSE process.
Environment classifiers
Authors: Walid Taha, Michael Florentin Nielsen
Venue: ACM SIGPLAN Notices (2003)

This paper proposes and develops the basic theory for a new approach to typing multi-stage languages based a notion of environment classifiers. This approach involves explicit but lightweight tracking -- at type-checking time -- of the origination environment for future-stage computations. Classification is less restrictive than the previously proposed notions of closedness, and allows for both a more expressive typing of the "run" construct and for a unifying account of typed multi-stage programmin.The proposed approach to typing requires making cross-stage persistence (CSP) explicit in the language. At the same time, it offers concrete new insights into the notion of levels and in turn into CSP itself. Type safety is established in the simply-typed setting. As a first step toward introducing classifiers to the Hindley-Milner setting, we propose an approach to integrating the two, and prove type preservation in this setting.
New Approach to Requirements Trade-Off Analysis for Complex Systems
Authors: Jonathan Lee, Jong-Yih Kuo
Venue: IEEE Transactions on Knowledge and Data Engineering (1998)

In this paper, we propose a faceted requirement classification scheme for analyzing heterogeneous requirements. The representation of vague requirements is based on Zadeh's canonical form in test-score semantics and an extension of the notion of soft conditions. The trade-off among vague requirements is analyzed by identifying the relationship between requirements, which could be either conflicting, irrelevant, cooperative, counterbalance, or independent. Parameterized aggregation operators, fuzzy and/or, are selected to combine individual requirements. An extended hierarchical aggregation structure is proposed to establish a four-level requirements hierarchy to facilitate requirements and criticalities aggregation through the fuzzy and/or. A compromise overall requirement can be obtained through the aggregation of individual requirements based on the requirements hierarchy. The proposed approach provides a framework for formally analyzing and modeling conflicts between requirements, and for users to better understand relationships among their requirements.
Hazards, Critical Races, and Metastability
Authors: Stephen H. Unger
Venue: IEEE Transactions on Computers (1995)

The various modes of failure of asynchronous sequential logic circuits due to timing problems are considered.These are hazards, critical races and metastable states. It is shown that there is a mechanism common to all forms of hazards and to metastable states. A similar mechanism, with added complications, is shown to characterize critical races. Means for defeating various types of hazards and critical races through the use of one-sided delay constraints are introduced. A method is described for determining from a flow table situations in which metastable states may be entered. A circuit technique is presented for extending a previously known technique for defeating metastability problems in self-timed systems. It is shown that the use of simulation for verifying the correctness of a circuit with given bounds on the branch delays cannot be relied upon to expose all timing problems. An example is presented that refutes a plausible conjecture that replacing pure delays with inertial delays can never introduce, but only eliminate glitches.
Load Balanced and Optimal Disk Allocation Strategy for Partial Match Queries on Multidimensional Files
Authors: Sajal K. Das, Cristina M. Pinotti
Venue: IEEE Transactions on Parallel and Distributed Systems (2002)

A multidimensional file is one whose data are characterized by several attributes, each specified in a given domain. A partial match query on a multidimensional file extracts all data whose attributes match the values of one or more attributes specified in the query. The disk allocation problem of a multidimensional file \big. F\bigr. on a database system with multiple disks accessible in parallel is the problem of distributing \big. F\bigr. among the disks such that the data qualifying for each partial match query are distributed as evenly as possible among the disks of the system. We propose an optimal solution to this problem for multidimensional files with pairwise prime domains based on a large and flexible class of maximum distance separable codes, namely, the redundant residue codes. We also introduce a new family of residue codes, called the redundant nonpairwise prime residue codes, to deal with files whose attribute domains are nonpairwise prime.
An empirical comparison of B-trees, compact B-trees and multiway trees
Authors: David M. Arnow, Aaron M. Tenenbaum
Venue: Proceedings of the 1984 ACM SIGMOD international conference on Management of data (1984)

It is well-known that the B-tree data structure yields excellent worst-case search costs and for that reason is widely employed in the organization of external files and in the implementation of data bases. In this paper, we examine general B-trees empirically and compare them with a less restrictive structure, the general multiway tree, and a more restrictive structure, the compact B-tree. We compare search costs, insertion costs, and space costs of these three structures for both small and large orders and indicate their relative utility for large and small data sets. Although there are cases when general multiway trees are more effective than B-trees, this is not the case for most practical situations. Compact B-trees are also shown to degrade rapidly in the presence of insertions and are therefore only useful for static data sets.
A half-quadratic block-coordinate descent method for spectral estimation
Authors: Philippe Ciuciu, Jérôme Idier
Venue: Signal Processing (2002)

In short-time spectral estimation, Sacchi et al. (IEEE Trans. Signal Process. 46(1)(1998) 31) and Ciuciu et al. (IEEE Trans. Signal Process. 49 (2001) 2202) derived new nonlinear spectral estimators defined as minimizers of penalized criteria. The first contributors have introduced separable penalizations for line spectra (LS) recovering, whereas the latter have proposed circular Gibbs-Markov functions for smooth spectra (SS) restoration, and combined both contributions for estimation of "mixed" spectra (MS), i.e., frequency peaks superimposed on a homogeneous background (Ciuciu et al., 2001). Sacchi et al. resorted to the iteratively reweighted least squares (IRLS) algorithm for the minimization stage. Here, we show that IRLS is a block-coordinate descent (BCD) method performing the minimization of a half-quadratic(HQ) energy. The latter, derived from the Geman and Reynolds construction, has the same minimizer as the initial criterion but depends on more variables. After proving that such a construction is not available for Gibbs-Markov penalizations, we extend the pioneering work of Geman and Yang (IEEE Trans. Image Process. 4(7) (1995) 932) that leads to a suitable HQ energy for any kind of penalization encountered in Ciuciu et al. (2001). The BCD algorithm used for minimizing such HQ criteria is actually an original residual steepest descent (RSD) procedure (IEEE Trans. Acoust. Speech Signal Process. ASSP-33(1) (1985) 174) and thus converges in any convex case. A comparison between RSD, IRLS when available, and a pseudo-conjugate gradient algorithm is addressed in any case.
On certain spaces of lattice diagram determinants
Authors: Jean-Christophe Aval
Venue: Discrete Mathematics (2002)

The aim of this work is to study some lattice diagram determinants ΔL(X, Y) as defined in (Adv. Math. 142 (1999) 244) and to extend results of Aval et al. (J. Combin. Theory Ser. A, to appear). We recall that ML denotes the space of all partial derivatives of ΔL. In this paper, we want to study the space Mki,j(X,Y) which is defined as the sum of ML spaces where the lattice diagrams L are obtained by removing k cells from a given partition, these cells being in the "shadow" of a given cell (i,j) in a fixed Ferrers diagram. We obtain an upper bound for the dimension of the resulting space Mi,jk(X, Y), that we conjecture to be optimal. This dimension is a multiple of n! and thus we obtain a generalization of the n! conjecture. Moreover, these upper bounds associated to nice properties of some special symmetric differential operators (the "shift" operators) allow us to construct explicit bases in the case of one set of variables, i.e. for the subspace Mi,jk(X) consisting of elements of 0 Y-degree.
Parallel Mining of Association Rules
Authors: Rakesh Agrawal, John C. Shafer
Venue: IEEE Transactions on Knowledge and Data Engineering (1996)

We consider the problem of mining association rules on a shared-nothing multiprocessor. We present three algorithms that explore a spectrum of trade-offs between computation, communication, memory usage, synchronization, and the use of problem-specific information. The best algorithm exhibits near perfect scaleup behavior, yet requires only minimal overhead compared to the current best serial algorithm.
Computer Science Research in India
Authors: Krithi Ramamritham
Venue: Computer (1997)

The computer industry plays an increasingly important role in India's economy. However, for a number of reasons, many researchers are not doing high-quality work. Computer science research in India takes place at academic, government-sponsored, and industry-sponsored institutions. These major institutions can conduct effective research because they have sufficient funding, high-quality programs, good equipment, and an effective infrastructure. This is not the case at India's many other institutions. Many local observers say that Indian computer scientists make advances in existing areas of research but rarely do cutting-edge work. This occurs, in part, because many Indian computer scientists receive little direction and have few co-workers in their fields, which means they work in relative isolation.
On large complete arcs: odd case
Authors: M. Giulietti, F. Pambianco, F. Torres, E. Ughi
Venue: Discrete Mathematics (2002)

An approach to the computations of upper bounds on the size of large complete arcs is presented. In particular, we obtain geometrical properties of irreducible envelopes associated with a second largest complete arc provided that the order of the underlying field is large enough.