ppxscal/embedding_network huggingface dataset:
Sequentially t-Diagnosable Systems: A Characterization and Its applications
Authors: Jie Xu, Shi-ze Huang
Venue: IEEE Transactions on Computers (1995)

In the system-level fault diagnosis area, the fundamental problem of characterizing sequentially $t$-diagnosable systems in the PMC model has remained open for more than two decades. We resolve this problem by providing a complete characterization of such systems. Our solution to the characterization problem leads to the correct identification of optimal sequentially $t$-diagnosable $D_{\delta,k}$ systems. Given a set of $n$ units where $n = 2t + 1$, an optimal $D_{\delta,k}$ system can be constructed with just $n(\lfloor(t + 2)/3\rfloor)$ tests, rather than $n(\lfloor t/2\rfloor + 1)$ tests¿a previously misjudged bound. An efficient algorithm for identifying the set of faulty units in a sequentially $t$-diagnosable $D_{\delta,k}$ system is given along the line of the proposed characterization, which is linear with respect to the number of tests in the system.Index Terms¿Consistent fault sets, $D_{\delta,k}$ systems, fault diagnosis, PMC model, sequentially diagnosable systems, syndrome, test assignment.
METU interoperable database system
Authors: A. Dogac, C. Dengi, E. Kilic, G. Ozhan, F. Ozcan, S. Nural, C. Evrendilek, U. Halici, B. Arpinar, P. Koksal, N. Kesim, S. Mancuhan
Venue: ACM SIGMOD Record (1995)

METU INteroperable Database System (MIND) is a multidatabase system that aims at achieving interoperability among heterogeneous, federated DBMSs. MIND architecture if based on OMG distributed object management model. It is implemented on top of a CORBA compliant ORB, namely, ObjectBroker. MIND provides users a single ODMG-93 compliant common data model, and a single global query language based on SQL. This makes it possible to incorporate both relational and object oriented databases into the system. Currently Oracle 7, Sybase and METU OODBMS (MOOD) have been incorporated into MIND. The main components of MIND are a global query processor, a global transaction manager, a schema integrator, interfaces to supported database systems and a user graphical interface.In MIND all local databases are encapsulated in a generic database object with a well defined single interface. This approach hides the differences between local databases from the rest of the system. The integration of export schemas is currently performed manually by using an object definition language (ODL) which is based on OMG's interface definition language. The DBA builds the integrated schema as a view over export schemas. the functionalities of ODL allow selection and restructuring of schema elements from existing local schemas.MIND global query optimizer aims at maximizing the parallel execution of the intersite joins of the global subqueries. Through MIND global transaction manager, the serializable execution of the global transactions are provided.
Regression analysis with fuzzy knowledge representation
Authors: Inna N. Louneva, Sergei M. Obraztsov, Alexander L. Shimkevich
Venue: ACM SIGAPL APL Quote Quad (1995)

An algorithm for fuzzy non-linear estimation and an APL implementation of this algorithm are discussed. The algorithm is based on using probability distributions for experimental data. The parameters of the distributions are given as linguistic variables by an expert.
Communication optimizations for parallel computing using data access information
Authors: Martin C. Rinard
Venue: Proceedings of the 1995 ACM/IEEE conference on Supercomputing (CDROM) (1995)

Given the large communication overheads characteristic of modern parallel machines, optimizations that eliminate, hide or parallelize communication may improve the performance of parallel computations. This paper describes our experience automatically applying communication optimizations in the context of Jade, a portable, implicitly parallel programming language designed for exploiting task-level concurrency. Jade programmers start with a program written in a standard serial, imperative language, then use Jade constructs to declare how parts of the program access data. The Jade implementation uses this data access information to automatically extract the concurrency and apply communication optimizations. Jade implementations exist for both shared memory and message passing machines; each Jade implementation applies communication optimizations appropriate for the machine on which it runs. We present performance results for several Jade applications running on both a shared memory machine (the Stanford DASH machine) and a message passing machine (the Intel iPSC/860). We use these results to characterize the overall performance impact of the communication optimizations. For our application set replicating data for concurrent read access and improving the locality of the computation by placing tasks close to the data that they access are the most important optimizations. Broadcasting widely accessed data has a significant performance impact on one application; other optimizations such as concurrently fetching remote data and overlapping computation with communication have no effect.
Algorithm 740: Fortran subroutines to compute improved incomplete Cholesky factorizations
Authors: Mark T. Jones, Paul E. Plassmann
Venue: ACM Transactions on Mathematical Software (TOMS) (1995)

Efficient and reliable code to compute incomplete Cholesky factors of sparse matrices for use as preconditioners in a conjugate gradient algorithm is described. This code implements two recently developed, improved incomplete factorization algorithms. An efficient implementation of the standard incomplete Cholesky factorization is also included.
Epsilon-Maximum Principle of Pontryagin Type and Perturbation Analysis of Convex Optimal Control Problems
Authors: Mohammed Moussaoui, Alberto Seeger
Venue: SIAM Journal on Control and Optimization (1996)

In this paper we study the first-order behaviour of the optimal-value function associated with a convex parametric problem of optimal control. A formula for the subdifferential of the optimal-value function is derived without assuming the existence of optimal solutions to the unperturbed problem. The so-called epsilon-maximum principle is a key ingredient in the writing of our main sensitivity result.
An effective hash-based algorithm for mining association rules
Authors: Jong Soo Park, Ming-Syan Chen, Philip S. Yu
Venue: Proceedings of the 1995 ACM SIGMOD international conference on Management of data (1995)

In this paper, we examine the issue of mining association rules among items in a large database of sales transactions. The mining of association rules can be mapped into the problem of discovering large itemsets where a large itemset is a group of items which appear in a sufficient number of transactions. The problem of discovering large itemsets can be solved by constructing a candidate set of itemsets first and then, identifying, within this candidate set, those itemsets that meet the large itemset requirement. Generally this is done iteratively for each large k-itemset in increasing order of k where a large k-itemset is a large itemset with k items. To determine large itemsets from a huge number of candidate large itemsets in early iterations is usually the dominating factor for the overall data mining performance. To address this issue, we propose an effective hash-based algorithm for the candidate set generation. Explicitly, the number of candidate 2-itemsets generated by the proposed algorithm is, in orders of magnitude, smaller than that by previous methods, thus resolving the performance bottleneck. Note that the generation of smaller candidate sets enables us to effectively trim the transaction database size at a much earlier stage of the iterations, thereby reducing the computational cost for later iterations significantly. Extensive simulation study is conducted to evaluate performance of the proposed algorithm.
IDA: user interface design assistance
Authors: Harald Reiterer
Venue: ACM SIGCHI Bulletin (1995)

This summary reports first results of the GMD project "User Interface Design Assistance (IDA)". The objective of this project is to develop computer based design aid tools for human factors based user interface design. The design aid tools are integrated in a user interface management system (UIMS) to support the designers during the development process.
Security in a networked environment
Authors: Cleopas O. Angaye
Venue: ACM SIGAPP Applied Computing Review (1995)

Networking allows multiple users to share data, information, software, and hardware. In addition, a network can centralize the management of a large base of connected processing units often configured to provide one location for coordinating security, backup and control. Security is the means to limit damage to data and to prevent user access to unauthorized information. The question of maintaining adequate security provisions across heterogenous platforms presents new security challenges for the network administrator. Computer crimes are on the rise. These crimes range from eavesdropping confidential information to physicial damage of equipments that information is stored. Some reasons of the increase in computer crimes include that there are more computers in use, there are more networks, and PCs can now access larger mainframe databases.
A Subexponential Algorithm for Abstract Optimization Problems
Authors: Bernd Gartner
Venue: SIAM Journal on Computing (1995)

An abstract optimization problem (AOP) is a triple $(H, The algorithm is applied to the problem of finding the distance between two $n$-vertex (or $n$-facet) convex polyhedra in $d$-space, and to the computation of the smallest ball containing $n$ points in $d$-space; for both problems we give the first subexponential bounds in the arithmetic model of computation.
A concurrency analysis tool suite for Ada programs: rationale, design, and preliminary experience
Authors: Michal Young, Richard N. Taylor, David L. Levine, Kari A. Nies, Debra Brodbeck
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (1995)

Cats (Concurrency Analysis Tool Suite) is designed to satisfy several criteria: it must analyze implementation-level Ada source code and check user-specified conditions associated with program source code; it must be modularized in a fashion that supports flexible composition with other tool components, including integration with a variety of testing and analysis techniques; and its performance and capacity must be sufficient for analysis of real application programs. Meeting these objectives together is significantly more difficult than meeting any of them alone. We describe the design and rationale of Cats and report experience with an implementation. The issues addressed here are primarily practical concerns for modularizing and integrating tools for analysis of actual source programs. We also report successful application of Cats to major subsystems of a (nontoy) highly concurrent user interface system.
Pattern Properties and Spectral Inequalities in Max Algebra
Authors: R. B. Bapat, David P. Stanford, P. vanden Driessche
Venue: SIAM Journal on Matrix Analysis and Applications (1995)

The max algebra consists of the set of real numbers, along with negative infinity, equipped with two binary operations, maximization and addition. This algebra is useful in describing certain conventionally nonlinear systems in a linear fashion. Properties of eigenvalues and eigenvectors over the max algebra that depend solely on the pattern of finite and infinite entries in the matrix are studied. Inequalities for the maximal eigenvalue of a matrix over the max algebra, motivated by those for the Perron root of a nonnegative matrix, are proved.
On the Reliability of Electronic Payment Systems
Authors: Ross J. Anderson, S. Johann Bezuidenhoudt
Venue: IEEE Transactions on Software Engineering (1996)

One of the problems facing the builders of the 'Information Superhighway' is how to charge for services. The high costs of billing systems suggest that prepayment mechanisms could play a large part in the solution. Yet how does one go about making an electronic prepayment system (or indeed any kind of payment system) robust? We describe some recent systems engineering experience which may be relevant_the successful introduction of cryptology to protect prepayment electricity meters from token fraud. These meters are used by a number of utilities from Scotland to South Africa, and they present some interesting reliability challenges.
Computing on Anonymous Networks: Part II-Decision and Membership Problems
Authors: Masafumi Yamashita, Tsunehiko Kameda
Venue: IEEE Transactions on Parallel and Distributed Systems (1996)

In anonymous networks, the processors do not have identity numbers. In Part I of this paper, we characterized the classes of networks on which some representative distributed computation problems are solvable under different conditions. A new graph property called symmetricity played a central role in our analysis of anonymous networks. In Part II, we turn our attention to the computational complexity issues. We first discuss the complexity of determining the symmetricity of a given graph, and then that of testing membership in each of the 16 classes of anonymous networks defined in Part I. It turns out that, depending on the class, the complexity varies from P-time to NP-complete or co-NP-complete.
Selecting the best system in steady-state simulations using batch means
Authors: Marvin K. Nakayama
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Suppose that we want to compare k different systems, where /spl mu//sub i/ denotes the steady state mean performance of system i. Our goal is to use simulation to pick the "best" system (i.e., the one with the largest or smallest steady state mean). To do this, we present some two stage procedures based on the method of batch means. Our procedures also construct multiple comparisons with the best (MCB) confidence intervals for /spl mu//sub i/-max/sub j/spl ne/i//spl mu//sub j/, i=1,...,k. Under the assumption of an indifference zone of (absolute or relative) width /spl delta/, we can show that asymptotically (as /spl delta//spl rarr/0 with the size of the batches proportional to 1//spl delta//sup 2/), the joint probability of correctly selecting the best system and of the MCB confidence intervals simultaneously containing /spl mu//sub i/-max/sub j/spl ne/i//spl mu//sub j/, i=1,...,k, is at least 1-/spl alpha/, where /spl alpha/ is prespecified by the user.
New Tight Bounds on Uniquely Represented Dictionaries
Authors: Arne Andersson, Thomas Ottmann
Venue: SIAM Journal on Computing (1995)

We present a solution to the dictionary problem where each subset of size $n$ of an ordered universe is represented by a unique structure, containing a (unique) binary search tree. The structure permits the execution of search, insert, and delete operations in $O(n^{1/3})$ time in the worst case. We also give a general lower bound, stating that for any unique representation of a set in a graph of bounded outdegree, one of the operations search or update must require a cost of $\Omega(n^{1/3})$. Therefore, our result sheds new light on previously claimed lower bounds for unique representation of dictionaries.
Experiments with Oval: a radically tailorable tool for cooperative work
Authors: Thomas W. Malone, Kum-Yew Lai, Christopher Fry
Venue: ACM Transactions on Information Systems (TOIS) (1995)

This article describes a series of tests of the generality of a &ldquo;radically tailorable&rdquo; tool for cooperative work. Users of this system can create applications by combining and modifying four kinds of building blocks: objects, views, agents, and links. We found that user-level tailoring of these primitives can provide most of the functionality found in well-known cooperative work systems such as gIBIS, Coordinator, Lotus Notes, and Information Lens. These primitives, therefore, appear to provide an elementary &ldquo;tailoring language&rdquo; out of which a wide variety of integrated information management and collaboration applications can be constructed by end users.
Workflow management systems: ensuring organizational flexibility by possibilities of adaptation and negotiation
Authors: Thomas Herrmann
Venue: Proceedings of conference on Organizational computing systems (1995)

Characteristics of workflow management systems must be adaptable by the users themselves according to the dynamism of organizational structures and of the conditions of cooperative task performance. In the case of those systems, adaptations which are initiated by individuals also affect other users in most cases. Therefore, a process of negotiation is required. A design principle called negotiability should be introduced. It helps users affected by adaptations to comment on them or to reject, accept or modify them. Supposing that the configuration of workflow management systems leads to a fixing of organizational structures by technical means, adaptation based on negotiability can be used to make those structures more flexible.
The Algebraic Riccati Equation and Inequality for Systems with Uncontrollable Modes on the Imaginary Axis
Authors: Carsten W. Scherer
Venue: SIAM Journal on Matrix Analysis and Applications (1995)

If $({\cal A,B})$ is stabilizable, one pretty well knows algebraic conditions for the solvability and for the existence of largest solutions of the algebraic Riccati equation and inequality $$ {\cal A}*{\cal X}+{\cal XA}-{\cal XBB}*{\cal X}+{\cal Q}=0 {\rm and} {\cal A}*{\cal X}+{\cal XA}-{\cal XBB}*{\cal X}+{\cal Q} \ge 0, $$ which leads to immediate existence results for positive definite solutions. In this paper we work out how far these properties may be generalized if $({\cal A,B})$ could have uncontrollable modes on the imaginary axis. Since the relations of the equation and inequality are not as tight any more, we provide separate conditions for the existence of Hermitian or positive definite solutions and give a detailed discussion how to verify them. As auxiliary steps we discuss various new aspects for the corresponding Lyapunov equation/inequality and a complete solvability test for the quadratic equation $$ X*RX + SX + (SX)* + T = 0 $$ with Hermitian $R$ and $T$. Finally, we briefly point out the consequences of our results for the general state-feedback $H_\infty$-control problem at optimality.
A monotonic superclass linearization for Dylan
Authors: Kim Barrett, Bob Cassels, Paul Haahr, David A. Moon, Keith Playford, P. Tucker Withington
Venue: Proceedings of the 11th ACM SIGPLAN conference on Object-oriented programming, systems, languages, and applications (1996)

Object-oriented languages with multiple inheritance and automatic conflict resolution typically use a linearization of superclasses to determine which version of a property to inherit when several superclasses provide definitions. Recent work has defined several desirable characteristics for linearizations, the most important being monotonicity, which prohibits inherited properties from skipping over direct superclasses. Combined with Dylan's sealing mechanism, a monotonic linearization enables some compile-time method selection that would otherwise be impossible in the absence of a closed-world assumption.The Dylan linearization is monotonic, easily described, strictly observes local precedence order, and produces the same ordering as CLOS when that is monotonic. We present an implementation based on merging and a survey of class heterarchies from several large programs, analyzing where commonly used linearizations differ.
Technical Note: Bias and the Quantification of Stability
Authors: Peter Turney
Venue: Machine Learning (1995)

Research on bias in machine learning algorithms has generally been concerned with the impact of bias on predictive accuracy. We believe that there are other factors that should also play a role in the evaluation of bias. One such factor is the stability of the algorithm&semi; in other words, the repeatability of the results. If we obtain two sets of data from the same phenomenon, with the same underlying probability distribution, then we would like our learning algorithm to induce approximately the same concepts from both sets of data. This paper introduces a method for quantifying stability, based on a measure of the agreement between concepts. We also discuss the relationships among stability, predictive accuracy, and bias.
Talisman: fast and accurate multicomputer simulation
Authors: Robert C. Bedichek
Venue: Proceedings of the 1995 ACM SIGMETRICS joint international conference on Measurement and modeling of computer systems (1995)

Talisman is a simulator that models the execution semantics and timing of a multicomputer. Talisman is unique in combining high semantic accuracy, high timing accuracy, portability, and good performance. This good performance allows users to run significant programs on large simulated multicomputers. The combination of high accuracy and good performance yields an ideal tool for evaluating architectural trade-offs. Talisman models the semantics of virtual memory, a circuit-switched internode interconnect, I/O devices, and instruction execution in both user and supervisor modes. It also models the timing of processor pipelines, caches, local memory buses, and a circuit-switched interconnect. Talisman executes the same program binary images as a hardware prototype at a cost of about 100 host instructions per simulated instruction. On a suite of accuracy benchmarks run on the hardware and the simulator, Talisman and the prototype differ in reported running times by only a few percent.
Nearly Optimal Algorithms For Canonical Matrix Forms
Authors: Mark Giesbrecht
Venue: SIAM Journal on Computing (1995)

A Las-Vegas-type probabilistic algorithm is presented for finding the Frobenius canonical form of an $n\times n$ matrix $T$ over any field $\KK$. The algorithm requires $\softO(\MM(n))=\MM(n)\cdot(\log n)^{O(1)}$ operations in $\KK$, where $O(\MM(n))$ operations in $\KK$ are sufficient to multiply two $n\times n$ matrices over $\KK$. This nearly matches the lower bound of $\Omega(\MM(n))$ operations in $\KK$ for this problem, and improves on the $O(n^4)$ operations in $\KK$ required by the previously best known algorithms.A fast parallel implementation of the algorithm is also demonstrated for the Frobenius form, which is processor-efficient on a PRAM. As an application we give an algorithm to evaluate a polynomial $g\in\KK[x]$ at $T$ which requires only $\softO(\MM(n))$ operations in $\KK$ when $\deg g\leq n^2$. Other applications include sequential and parallel algorithms for computing the minimal and characteristic polynomials of a matrix, the rational Jordan form of a matrix (for testing whether two matrices are similar), and for matrix powering which are substantially faster than those previously known.
A unified representation for numerical and qualitative simulations
Authors: Daniel Berleant
Venue: ACM SIGAPP Applied Computing Review (1995)

Models fall naturally into two main categories, those of discrete systems and those of continuous systems. Our model-based reasoning work deals with continuous systems, augmented to provide for the possibility that one continuous system model transitions to another, as when a threshold event occurs such as a thermostat turning on.One aspect of model-based reasoning is simulation. A model is defined and its behavior(s) inferred through qualitative or numerical simulation. The simulated trajectories then facilitate tasks that one expects model-based reasoning to aid in, such as prediction, monitoring, diagnosis, and design.Here we describe an approach to representing simulation trajectories that results in descriptions of system behavior that contain both qualitative and quantitative information about trajectories closely integrated together. Those descriptions are supported by an internal, representation methodology that also closely integrates qualitative and quantitative information. The internal representation methodology supports quantitative inferences about the trajectories, and an example trace of such inferencing is provided.