ppxscal/embedding_network huggingface dataset:
A Circular Graph - Counterexample to the Duchet Kernel Conjecture
Authors: A. Apartsin, E. Ferapontova, V. Gurvich
Venue:  (1996)

We construct a directed graph G such that a) G is strongly connected, b) G has the circular symmetry, c) G is not a directed odd cycle, d) G has no kernel but e) after removing any edge from G the obtained graph has a kernel .
Cylindric process algebras with conditionals give substitutionless pCRL
Authors: S. P. Luttik
Venue:  (1999)

Theories that are designed to reason about processes and the information they exchange usually also include a construction to quantify over this information. We mention the input prefix mechanism of, e.g., the $\pi$-calculus and the operation $\gsum{}$ for alternative quantification over data of \mcrl. These constructions are implemented as binders, and hence imply a relatively complicated notion of substitution that takes the binding of these operations into account. As a consequence, the defining axioms of such constructions are not suitable for purely equational reasoning, or, to put it differently, proof systems for process theories that contain binders are not algebraic. In this paper, we shall define the variety of cylindric process algebras with conditionals, and we prove that, for data with built-in equality and built-in Skolem functions, it is an algebraic semantics of a subsystem of \mcrl{}. Thus we obtain a proof system for a class of process algebras with data and alternative quantification from which the complicated notion of substitution is eliminated.
Defect-Oriented Analysis of Memory BIST Tests
Authors: Alvin Jee
Venue: Proceedings of the Proceedings of The Eighth IEEE International On-Line Testing Workshop (IOLTW'02) (2002)

This paper describes defect-oriented analysis of 4 BIST tests that are used to test a commercial 6-port embedded SRAM. We will examine the realistic fault and defect coverages of these memory BIST tests. We also uncover the subtle effect that addressing order has on the coverage that a test can provide. In addition, we will show that the coverage that a test provides can vary from row to row depending on the addressing scheme.
Test functions for three-dimensionalcontrol-volume mixed finite element methods on irregular grids
Authors: R. L. Naff, Thomas F. Russell, J. Wilson
Venue:  (2000)

Numerical methods based on unstructured grids, with irregular cells, usually require discrete shape functions to approximate the distribution of quantities across cells. For control-volume mixed finite element methods, vector shape functions are used to approximate the distribution of velocities across cells and vector test functions are used to minimize the error associated with the numerical approximation scheme. For a logically cubic mesh, the lowest-order shape functions are chosen in a natural way to conserve intercell fluxes that vary linearly in logical space. Vector test functions, while somewhat restricted by the mapping into the logical reference cube, appear to accept a wider class of possibilities. Ideally, an error minimization procedure to select the test function from an acceptable class of candidates would be the best procedure. Lacking such a procedure, we first investigate the effect of possible test functions on the pressure distribution over the control volume; we look for test functions which allow for the elimination of intermediate pressures on cell faces. From these results, we select three forms for the test function for use in a control-volume mixed method code and subject them to an error analysis for different forms of grid irregularity; errors are reported in terms of the discrete L2 norm of the velocity error. Of these three forms, one appears to produce optimal results for most forms of grid irregularity.
Fault Contribution Trees for Product Families
Authors: Dingding Lu, Robyn R. Lutz
Venue: Proceedings of the 13th International Symposium on Software Reliability Engineering (2002)

Software Fault Tree Analysis (SFTA) provides structured way to reason about the safety or reliability of software system. As such, SFTA is widely used in mission-criticalapplications to investigate contributing causes possible hazards or failures. In this paper we propose approach similar to SFTA for product families. Thecontribution of the paper is to define a top-down, tree-basedanalysis technique, the Fault Contribution TreeAnalysis (FCTA), that operates on the results of a product-familydomain analysis and to describe a method by whichthe FCTA of a product family can serve as a reusable assetthe building of new members of the family. Specifically,we describe both the construction of the fault contributiontree for a product family (domain engineering) and thereuse of the appropriately pruned fault contribution treefor the analysis of a new member of the product family(application engineering). The paper describes severalchallenges to this approach, including evolution of product family, handling of subfamilies, and distinguishingthe limits of safe reuse of the FCTA, and suggests partialsolutions to these issues as well as directions for futurework. The paper illustrates the techniques with examplesfrom applications to two product families.
A slicing-based approach for locating type errors
Authors: T. B. Dinesh, Frank Tip
Venue:  (1998)

The effectiveness of a type checking tool strongly depends on the accuracy of the positional information that is associated with type errors. We present an approach where the location associated with an error message e is defined as a slice P_e of the program P being type checked. We show that this approach yields highly accurate positional information: P_e is a program that contains precisely those program constructs in P that caused error e. Semantically, we have the interesting property that type checking P_e is guaranteed to produce the same error e. Our approach is completely language-independent, and has been implemented for a significant subset of Pascal.
Visualization of Economic Input-Output Data
Authors: James H. Garrett Jr.
Venue: Proceedings of the 1999 International Conference on Information Visualisation (1999)

In this paper, visual techniques used to present economic input-output data are described. These techniques were created because the size of the data matrices and the screen limitations complicate data navigation. These techniques allow users to ask questions about detailed and global information. The techniques were designed based on the user tasks.The graphic techniques are combined with direct manipulation techniques to improve the ease and efficiency with which users interact with the system. The software prototype uses I992 US economic data.
Integrity Constraints in Deductive Databases: an overview
Authors: Patrizia Asirelli, Paola Inverardi, Giuseppe Plagenza
Venue:  (1996)

This paper contains a critical review of the most well known integrity constraints checking algorithms that can be found in the literature for logic based (deductive) databases. Some criterion are xed in order to be able to give a sistematic insite into this area; The approaches are then brie y described and compared according to the xed criterion. EMAIL:: asirelli@iei.pi.cnr.it
Issues in Analyzing the Behavior of Event Dispatching Systems
Authors: Giovanni Bricconi, Emma Tracanella, Elisabetta Di Nitto
Venue: Proceedings of the 10th International Workshop on Software Specification and Design (2000)

A good architecture is a necessary condition to guarantee that the expected levels of performance, availability, fault tolerance, and scalability are achieved by the implemented system. While in the software architecture domain several approaches focus on checking static characteristics of software systems, a general approach to performance analysis, independent from a specific application domain, is still missing. In this paper we focus on the analysis of performances of an event-based middleware with two objectives in mind: first, to determine the design alternative that provides the best performances; second, to experience with statistical analysis and simulation tools in order to understand their applicability to the evaluation of software architectures.
Revisiting Strategies for Ordering Class Integration Testing in the Presence of Dependency Cycles
Authors: Lionel C. Briand, Yvan Labiche, Yihong Wang
Venue: Proceedings of the 12th International Symposium on Software Reliability Engineering (2001)

The issue of ordering class integration in the context of integration testing has been discussed by a number of researchers.More specifically, strategies have been proposed to generate a test order while minimizing stubbing.Recent papers have addressed the problem of deriving an integration order in the presence of dependency cycles in the class diagram.Suchdependencies represent a practical problem as they make any topological ordering of classes impossible.This paper proposes a strategy that integrates two existing methods aimed at ¿breaking¿ cycles so as to allow a topological order of classes.The first one was proposed by Tai et al and is based on assigning a higher-level order according to aggregation and inheritance relationships and a lower-level order according to associations.The second one was proposed by Le Traon et al and is based on identifying strongly connected components in the dependency graph.Among other things, the former approach may result into unnecessary stubbing whereas the latter may lead to breaking cycles by ¿removing¿ aggregation or inheritance dependencies, thus leading to complexstubbing.We propose here an approach that combines some of the principles of both approaches and addresses some of their shortcomings.All approaches (principles,benefits,drawbacks) are thoroughly compared by the means of a case study, based on a real system written in Java.
Automatic Construction of CSP Programs from Sequential Non-Deterministic Programs
Authors: Abha Moitra
Venue:  (1984)

In this paper we describe a systematic method for transforming a sequential program, written in a guarded command language, into a distributed program, written in CSP. The variables of the sequential program are first partitioned into $n$ disjoint sets, and then the program is transformed into a CSP program of $n$ communicating processes. The two versions of the program are shown to be strongly equivalent, in the sense that they exhibit the properties of reaching the same final states and of either aborting, terminating, or running forever. We also discuss the conditions under which, when compared to the execution of the original sequential program, a speed-up in the execution of the resulting distributed program can be achieved.
Multi-parent recombination to overcome premature convergence in genetic algorithms
Authors: Agoston E. Eiben, Cees H.M. Kemenade
Venue:  (1995)

Recent research shows that enlarging the arity of recombination operators in a Genetic Algorithm lowers the probability of premature convergence. This results in more robust genetic function optimizers. In this paper we try to give an explanation why these multi-parent operators are better. In particular, we discuss two operators: the uniform scanning crossover and the diagonal crossover operator. First we show that these operators are better than the standard ones by testing them on an extensive test-suite of function optimization problems. Second, we explain the empirical results by first looking at the influence that the operators have on the evolution of populations, and then by using a new kind of description we are able to explain the convergence curves and rates of success as obtained in the experiments.
Degradation identification and model parameter estimation in discontinuity-adaptive visual reconstruction
Authors: Anna Tonazzini, Luigi Bedini
Venue:  (2001)

This paper describes our recent experiences and progress towards an efficient solution of the highly ill-posed and computationally demanding problem of blind and unsupervised visual reconstruction. Our case study is image restoration, i.e. deblurring and denoising. The methodology employed makes reference to edge-preserving regularization. This is formulated both in a fully Bayesian framework, using a MRF image model with explicit, and possibly geometrically constrained, line processes, and in a deterministic framework, where the line process is addressed in an implicit manner, by using a particular MRF model which allows for self-interactions of the line and an adaptive variation of the model parameters. These MRF models have been proven to be efficient in modeling the local regularity properties of most real scenes, as well as the local regularity of object boundaries and intensity discontinuities. In both cases, our approach to this problem attempts to effectively exploit the correlation between intensities and lines, and is based on the assumption that the line process alone, when correctly recovered and located, can retain a good deal of information about both the hyperparameters that best model the whole image and the degradation features. We show that these approaches offer a way to improve both the quality of the reconstructed image, and also the estimates of the degradation and model parameters, and significantly reduce the computational burden of the estimation processes. EMAIL:: tonazzini@iei.pi.cnr.it
Sams Teach Yourself Macromedia Flash MX in 24 Hours, 2 edition
Authors: Phillip Kerman
Venue:  (2003)

:Since its introduction in 1996, Macromedia Flash has become the standard for delivering high impact, vector-based graphics to the Web. Flash is deceptively simple at first, yet has great depth and flexibility.Sams Teach Yourself Macromedia Flash 5 in 24 Hours offers a clearly written, well-organized introduction to this powerful product, and gives the beginner an overview of the entire package, without becoming too overwhelming.A new version of Flash is expected to be released in the 1st quarter of 2002. It will have user interface improvements, several new features, and extensive improvements to existing features.
Towards Fast Volume Visualization on the WWW
Authors: J. Y. Shi
Venue: Proceedings of the 1999 International Conference on Information Visualisation (1999)

The steady growth of the Internet has dramatically changed the way information is shared, and modern users expect near real-time delivery, high quality images together with in-depth navigation and exploration of 3D models. Multiresolution is a promising approach for fast distributed volume visualisation employing Levels-of-Detail. We review multiresolution algorithms and visualisation systems on the WWW. Our discussion is based on experience gained in the development of the IAEVA-II project funded by the European Commission. A new method for rapid data classification/rendering of multiresolution volumes, based on shear-warp factorisation, is described. We can change classification functions and data resolution during rendering without significant reduction in interactivity. A method for constructing multiresolution transfer functions for determining opacity is also investigated. Finally, future trends in developing www visualisation systems are discussed.
Resampling methods for variable selection in robust regression
Authors: James W. Wisnowski, James R. Simpson, Douglas C. Montgomery, George C. Runger
Venue: Computational Statistics Data Analysis (2003)

With the inundation of large data sets requiring analysis and empirical model building, outliers have become commonplace. Fortunately, several standard statistical software packages have allowed practitioners to use robust regression estimators to easily fit data sets that are contaminated with outliers. However, little guidance is available for selecting the best subset of the predictor variables when using these robust estimators. We initially consider cross-validation and bootstrap resampling methods that have performed well for least-squares variable selection. It turns out that these variable selection methods cannot be directly applied to contaminated data sets using a robust estimation scheme. The prediction errors, inflated by the outliers, are not reliable measures of how well the robust model fits the data.As a result, new resampling variable selection methods are proposed by introducing alternative estimates of prediction error in the contaminated model. We demonstrate that, although robust estimation and resampling variable selection are computationally complex procedures, we can combine both techniques for superior results using modest computational resources. Monte Carlo simulation is used to evaluate the proposed variable selection procedures against alternatives through a designed experiment approach. The experiment factors include percentage of outliers, outlier geometry, bootstrap sample size, number of bootstrap samples, and cross-validation assessment size. The results are summarized and recommendations for use are provided.
A Practical Method For The Estimation Of Software Reliability Growth In The Early Stage Of Testing
Authors: M. Xie, G. Y. Hong, C. Wohlin
Venue: Proceedings of the Eighth International Symposium on Software Reliability Engineering (1997)

The traditional approach of reliability prediction using software reliability growth models requires a large number of failures which might not be available at the beginning of the testing. The commonly used maximum likelihood estimates may not even exist or converge to a reasonable value. In this paper, an approach of making use of information from similar projects in order to obtain an early estimation of one model parameter for a current project is studied. As most of the two-parameter reliability growth models contains one parameter related to the number of faults in the software and a reliability growth rate parameter related to the testing efficiency, information from a similar project can used to estimate the reliability growth rate parameter and the limited failure data from initial testing is used to estimate the other parameter. Our case study shows that this approach is very easy to use as the estimation does not require a numerical algorithm and it always exists. It is also very stable and when the maximum likelihood estimates exist and are reasonable, our approach gives values very close to that, and the approximate confidence interval is overlapping for most cases.
Scalable Message Stability Detection Protocols
Authors: Katherine Guo
Venue:  (1998)

In group communication, in order to deliver multicast messages reliably in a group, it is common practice for each member to maintain copies of all messages it sends and receives in a buffer for potential local retransmission. The storage of these messages is costly and buffers may grow out of bound. A form of garbage collection is needed to address this issue. Garbage collection occurs once a process learns that a message in its buffer has been received by every process in the group. The message is declared {\it stable} and is released from the buffer. An important part of garbage collection is message stability detection. This dissertation presents the result of an investigation into message stability detection protocols. A number of message stability detection protocols used in popular reliable multicast protocols are studied with a focus on their performance in large scale settings. This dissertation proposes a new gossip-style protocol with improved scalability and fault tolerance. This dissertation also shows that by adding a hierarchical structure to the set of basic protocols, their performance can be significantly improved when the number of participants is large.
Experiences With Monitoring OSPF on a Regional Service Provider Network
Authors: David Watson, Farnam Jahanian, Craig Labovitz
Venue: Proceedings of the 23rd International Conference on Distributed Computing Systems (2003)

This paper presents the results from a detailed, experimentalstudy of OSPF, an intra-domain routing protocol,running on a mid-size regional Internet service provider.Using multiple, distributed probes running custom monitoringtools, we collected continuous protocol informationfor a full year. We use this data to analyze the health ofthe network including the amount, source, duration and periodicityof routing instability. We found that informationfrom external routing protocols produces significant levelsof instability within OSPF. We also examine the evolutionof the routing topology over time, showing that short termchanges are incremental and that the long term trend showsconstant change. Finally, we present a set of detailed investigationsinto several large scale anomalies. These anomaliesdemonstrate the significant impact external routing protocolshave on OSPF. In addition, they highlight the need fornew network management tools that can incorporate informationfrom routing protocols.
Oracle Performance Troubleshooting: With Dictionary Internals SQL and Tuning Scripts
Authors: Robin Schumacher
Venue:  (2003)

:If you're a DBA who's looking for real world Oracle tuning techniques, Oracle scripts, and advice on how to get to the heart of critical Oracle performance problems, then you've come to the right place. Written by one the world's top DBAs and Oracle internals experts, Robin Schumacher focuses his incredible knowledge of the Oracle data dictionary into a superb book that show how to quickly troubleshoot and correct Oracle performance problems. As a Vice President at Embarcadero Technologies, Robin Schumacher has written the internals for some of the world's most powerful Oracle performance software and now he shows you how to use the most recent advancements in Oracle8i and 9i to make your Oracle database run as fast as possible.
An Estimate of the Variance of Estimators for Lead Time and Screening Benefit in Randomised Cancer Screening Trials
Authors: K. Kafadar, P. C. Prorok, P. J. Smith
Venue:  (1996)

Variance estimators are derived for estimators of the average lead time and leverage benefit time due to screening in a randomized screening trial via influence functions. The influence functions demonstrate that these estimators are asymptotically equivalent to the mean difference, between the study and control case groups, in the survival times. For estimating benefit time, the survival time is measured since time of diagnosis. Asymptotic variances of these estimators can be calculated in a straightforward manner from the influence functions, and these variances can be estimated from actual trial data. The performance of the variance estimates is assessed via a simulated screening trial. The situation involving censored data is also discussed.
A Proof of the Church-Rosser Theorem and its Representation in a Logical Framework
Authors: Frank Pfenning
Venue:  (1992)

We give a detailed, informal proof of the Church-Rosser property for the untyped lambda-calculus and show its representation in LF. The proof is due to Tait and Martin-Lof and is based on the notion of parallel reduction. The representation employs higher-order abstract syntax and the judgments-as-types principle and takes advantage of term reconstruction as it is provided in the Elf implementation of LF. Proofs of meta-theorems are represented as higher-level judgments which relate sequences of reductions and conversions.