ppxscal/embedding_network huggingface dataset:
A National-Scale Authentication Infrastructure
Authors: Randy Butler, Von Welch, Douglas Engert, Ian Foster, Steven Tuecke, John Volmer, Carl Kesselman
Venue: Computer (2000)

Individuals and institutions in science and industry are increasingly forming virtual organizations to pool resources and tackle a common goal. Participants in virtual organizations need to share resources such as data archives, computer cycles, and networks. Any sharing mechanism must be able to authenticate the user's identity and determine if the user is authorized to request the resource.The authors have created and deployed an authentication and authorization infrastructure that meets these requirements: the Grid Security Infrastructure. GSI offers secure single sign-ons and preserves site control over access policies and local security. It provides its own versions of common applications, such as FTP and remote login, and a programming interface for creating secure applications.The authors use this technology to create smaller test-beds for individual scientific collaborations. They are investigating its feasibility for high-energy physics projects. Enhancements to GSI will reduce the cost of establishing a virtual organization security environment, add support for advanced features such as smart cards, and restrict delegation for more fine-grained access control.
Algorithms and Proofs Inheritance in the FOC Language
Authors: Virgile Prevosto, Damien Doligez
Venue: Journal of Automated Reasoning (2003)

In this paper, we present the FOC langugage, dedicated to the development of certified computer algebra libraries (that is sets of programs). These libraries are based on a hierarchy of implementations of mathematical structures. After presenting the core set of features of our language, we describe the static analyses, which reject inconsistent programs. We then show how we translate FOC definitions into OCAML and COQ, our target languages for the computational part and the proof checking, respectively.
The Java Virtual Machine: A Passing Fad?
Authors: Michael Franz
Venue: IEEE Software (1998)

Java's portability and platform independence have made it the language of choice for developing Web-based applications. Yet Java actually consists of three parts: a language, a rich class library, and a distribution standard based on a virtual machine. It is this third link that Franz considers most vulnerable to replacement. He explains why this is likely, drawing on his experience developing an alternative scheme to support software transportability, and given the eventual deployment of dynamic code generators.
Directory Reference Patterns in Hierarchical File Systems
Authors: R. A. Floyd, C. Schlatter Ellis
Venue: IEEE Transactions on Knowledge and Data Engineering (1989)

The authors present a brief description of data on directory reference patterns collected from a 4.2BSD UNIX system. These data are used to examine the importance of the name lookup overhead involved in opening and using files. The analysis shows that paths in the environment are relatively long and that, in the absence of caching, name resolution overhead accounts for over 70% of the disk blocks referenced to open and use files. These results confirm recent conjectures on the high level of directory activity in UNIX file systems. Directory references exhibit strong locality, though, making caches an effective way to decrease directory overhead. Simulations of a least recently used (IRU) whole directory cache show that a cache holding just ten nodes achieves an 85% hit ratio. The implications of these results on the design of both local and distributed file systems are discussed.
Resource Reclaiming in Multiprocessor Real-Time Systems
Authors: C. Shen, K. Ramamritham, J. A. Stankovic
Venue: IEEE Transactions on Parallel and Distributed Systems (1993)

Most real-time scheduling algorithms schedule tasks with regard to their worst casecomputation times. Resources reclaiming refers to the problem of utilizing the resourcesleft unused by a task when it executes in less than its worst case computation time, orwhen a task is deleted from the current schedule. Dynamic resource reclaiming algorithms that are effective, avoid any run time anomalies, and have bounded overhead costs that are independent of the number of tasks in the schedule are presented. Each task is assumed to have a worst case computation time, a deadline, and a set of resourcerequirements. The algorithms utilize the information given in a multiprocessor taskschedule and perform online local optimization. The effectiveness of the algorithms isdemonstrated through simulation studies.
Toward Non Commutative Numerical Analysis: High Order Integration in Time
Authors: Michelle Schatzman
Venue: Journal of Scientific Computing (2002)

We review some methods for high precision time integration: it is not easy to ensure stability, precision and numerical efficiency at the same time. Operator splitting&mdash;when it works&mdash;can be a good way to satisfy all these constraints; in some cases, the order of the splitting schemes can be enhanced by extrapolation; nevertheless, the applicability of splitting is limited due to non commutativity. As an alternative to splitting, we introduce preconditioned Runge&ndash;Kutta (PRK) schemes: the preconditioning is included in the scheme, instead of being put aside for implementation. Examples of PRK schemes are given including the extrapolation of the residual smoothing scheme, and sufficient conditions for stability are described.
Automatic Generation of Visual Programming Environments
Authors: Gennaro Costagliola, Genoveffa Tortora, Sergio Orefice, Andrea De Lucia
Venue: Computer (1995)

The VLCC (Visual Language Compiler-Compiler) system has been developed for the automatic generation of visual programming environments. It supports the implementation of a visual language by assisting the language designer during the definition of the graphical objects, the syntax and the semantics of the language. The final result of the generation process consists of an integrated environment comprising an editor and a compiler for the defined visual language.
Achieving ultra rapid evolution using service-based software
Authors: Keith Bennett, Nicolas Gold
Venue: Proceedings of the 4th International Workshop on Principles of Software Evolution (2001)

There is an urgent industrial need for new approaches to software evolution that will lead to far faster implementation of software changes. Existing software maintenance processes are simply too slow to meet the needs of many businesses. To achieve the levels of functionality, flexibility and time to market of changes and updates required by users, a radical shift is required in the development of software, with a more demand-centric view leading to software which will be delivered as a service, within the framework of an open marketplace. Although there are some signs that this approach is being adopted by industry, it is in a very limited and restricted form. We see ultra rapid evolution, in "internet time" as a grand challenge for software engineering.In this position paper, we describe recent work that has resulted in an innovative demand-led model for the future of software. We describe a service architecture in which services may be bound instantly, just at the time they are needed and then the binding may be disengaged. Such ultra late binding requires that many non-functional attributes of the software are capable of automatic negotiation and resolution. Some of these attributes have been demonstrated through two prototype implementations based on existing and available technology. The aim of the position paper is to contribute to the debate at ESEC by presenting a radical, market based view of software evolution which must take place in "internet time". The key underpinning theoretical idea is ultra-late binding, so that a service is engaged dynamically at the point in time it is needed. Hence, the sub services can evolve between usages.
Quasiparallel planes in finite planar spaces
Authors: Sveva Freni
Venue: Discrete Mathematics (2002)

In this paper, quasiparallelism relation in finite planar spaces is investigated. This shed more light on the classification problem: generalized three-dimensional projective spaces and three-dimensional affine spaces are characterized.
Stability Testing of Two-Dimensional Discrete-Time Systems by a Scattering-Type Stability Table and Its Telepolation
Authors: Yuval Bistritz
Venue: Multidimensional Systems and Signal Processing (2002)

Stability testing of two-dimensional (2-D) discrete-time systems requires decision on whether a 2-D (bivariate) polynomial does not vanish in the closed exterior of the unit bi-circle. The paper reformulates a tabular test advanced by Jury to solve this problem. The 2-D tabular test builds for a real 2-D polynomial of degree (n1, n2) a sequence of n2 matrices or 2-D polynomials (the &lsquo;2-D table&rsquo;). It then examines its last polynomial - a 1-D polynomial of degree 2n1n2 - for no zeros on the unit circle. A count of arithmetic operations for the tabular test is performed. It shows that the test has O(n6) complexity (assuming n1 = n2 = n)- a significant improvement compared to previous tabular tests that used to be of exponential complexity. The analysis also reveals that, even though the testing of the condition on the last polynomial requires O(n4) operations, the count of operations required for the table&rsquo;s construction makes the overall complexity O(n6). Next it is shown that it is possible to telescope the last polynomial of the table by interpolation and circumvent the construction of the 2-D table. The telepolation of the tabular test replaces the table by n1n2 + 1 stability tests of 1-D polynomials of degree n1 or n2 of certain form. The resulting new 2-D stability testing procedure requires a very low O(n4) count of operations. The paper also brings extension for the tabular test and its simplification by telepolation to testing 2-D polynomials with complex valued coefficients.
AI and Expert System Myths, Legends, and Facts
Authors: Mark S. Fox
Venue: IEEE Expert: Intelligent Systems and Their Applications (1990)

The author identifies major causes leading to ineffective application of artificial intelligence (AI). His views are based on personal observations made over ten years of building, deploying, and reviewing AI-based systems. The author attributes most failures to one or both of the following: misconceptions regarding the nature of AI technology, and poor management skills in acquiring, nurturing, and applying that technology. He sets forth core AI concepts and then examines and debunks some common misconceptions about expert systems, their construction, and their maintenance.
Scheduling Algorithms for the Broadcast Delivery of Digital Products
Authors: Joel L. Wolf, Mark S. Squillante, John J. Turek, Philip S. Yu, Jay Sethuraman
Venue: IEEE Transactions on Knowledge and Data Engineering (2001)

We provide scheduling algorithms that attempt to maximize the profits of a broadcast-based electronic delivery service for digital products purchased, for example, at e-commerce sites on the World Wide Web. Examples of such products include multimedia objects such as CDs and DVDs. Other examples include software and, with increasing popularity, electronic books as well. We consider two separate alternatives, depending in part on the sophistication of the set-top box receiving the product at the customer end. The first, more restrictive option, assumes that the atomic unit of transmission of the product is the entire object, which must be transmitted in order from start to finish. We provide a solution based in part on a transportation problem formulation for this so-called noncyclic scheduling problem. The second alternative, which is less restrictive, assumes that the product may be transmitted cyclically in smaller segments, starting from an arbitrary point in the object. Three heuristics are provided for this difficult cyclic scheduling problem. Both scenarios assume that the broadcasts of the same digital product to multiple customers can be ¿batched.¿ We examine the effectiveness of these algorithms via simulation experiments under varying parametric assumptions. Each of the three cyclic scheduling algorithms perform better than the noncyclic algorithm. Moreover, one of the cyclic scheduling algorithms emerges as the clear winner.
A PTAS for single machine scheduling with controllable processing times
Authors: Petra Schuurman, Gerhard J. Woeginger
Venue: Acta Cybernetica (2002)

We deal with a single machine scheduling problem in which each job has a release date, a delivery time and a controllable processing time. The fact that the jobs have a controllable processing time means that it is allowed to compress (a part of) the processing time of the job, in return for compression cost. The objective is to find a schedule that minimizes the total cost, that is, the latest delivery time of any job plus the total compression cost. In this note we discuss how the techniques of Hall and Shmoys [3] and Hall [1] can directly be applied to design a polynomial time approximation scheme for this problem.
On Balancing Sorting on a Linear Array
Authors: Y. C. Lin
Venue: IEEE Transactions on Parallel and Distributed Systems (1993)

A balanced parallel algorithm to sort a sequence of items on a linear array of processors is presented. The length of the sequence may be small to arbitrarily large. For a shortsequence, the output of the sorted sequence begins at the step following the last inputof the whole sequence. For an arbitrarily long sequence, the time complexity is optimalunder realistic hardware conditions. A variation of the algorithm is also introduced. Bothalgorithms require far less local memory than that required by a different approach ofbalanced computation. Any number of balanced processors can be connected to delivermore computing power without increasing the memory size of each processor.
Multilevel Classification of Milling Tool Wear with Confidence Estimation
Authors: Randall K. Fish, Mari Ostendorf, Gary D. Bernard, David A. Castanon
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2003)

An important problem during industrial machining operations is the detection and classification of tool wear. Past research in this area has demonstrated the effectiveness of various feature sets and binary classifiers. Here, the goal is to develop a classifier which makes use of the dynamic characteristics of tool wear in a metal milling application and which replaces the standard binary classification result with two outputs: a prediction of the wear level (quantized) and a gradient measure that is the posterior probability (or confidence) that the tool is worn given the observed feature sequence. The classifier tracks the dynamics of sensor data within a single cutting pass as well as the evolution of wear from sharp to dull. Different alternatives to parameter estimation with sparsely-labeled training data are proposed and evaluated. We achieve high accuracy across changing cutting conditions, even with a limited feature set drawn from a single sensor.
Performance Analysis of an Expanding-Search Algorithm forCoarse Acquisition of DSSS Signals
Authors: J. S. Seybold, G. V. Fountain, M. A. Belkerdid
Venue: Wireless Personal Communications: An International Journal (1997)

For coarse acquisition of Direct Sequence Spread Spectrum (DSSS) signals, a search of the possible code phases is required. In cases such as signal reacquisition, where a priori information is available, the serial search may be abandoned in favor of an expanding search. In this paper, an expanding-search algorithm is presented and compared to the expanding-sweep algorithms which have been treated in the literature. Performance results for the serial-search and the expanding-search algorithms are given. A discussion of the optimality of the serial-search and the expanding-search algorithms is presented. Performance comparisons of the serial search and the expanding search are made for different a priori code phase probability density functions (pdfs) and the results are discussed. A technique for determining when the expanding search is an optimal search algorithm is developed and applied to the performance curves shown previously. The results indicate that the expanding search provides a quantifiable improvement over the serial search when the pdf is somewhat peaked. The results also indicate that in many cases the expanding search may be a more effective search algorithm than the more common expanding sweep.
A Higher-Order Taylor Expansion Approach to Simulation of Stochastic Forward-Looking Models with an Application to a Nonlinear Phillips Curve Model
Authors: Fabrice Collard, Michel Juillard
Venue: Computational Economics (2001)

We propose to apply to the simulation of general nonlinear rational-expectation models a method where the expectation functions are approximated through a higher-order Taylor expansion. This method has been advocated by Judd (1998) and others for the simulation of stochastic optimal-control problems and we extend its application to more general cases. The coefficients for the first-order approximation of the expectation function are obtained using a generalized eigenvalue decomposition as it is usual for the simulation of linear rational-expectation models. Coefficients for higher-order terms in the Taylor expansion are then obtained by solving a succession of linear systems. In addition, we provide a method to reduce a bias in the computation of the stochastic equilibrium of such models. These procedures are made available in DYNARE, a MATLAB and GAUSS based simulation program. This method is then applied to the simulation of a macroeconomic model embodying a nonlinear Phillips curve. We show that in this case a quadratic approximation is sufficient, but different in important ways from the simulation of a linearized version of the model.
Can Nonlinear Compactors Be Better than Linear Ones?
Authors: Michal Kopec
Venue: IEEE Transactions on Computers (1995)

This paper presents a new analytical method for estimating compaction quality, based on the entropy. Maximization of the entropy of the signature results in an increase of compaction quality. The paper studies the influence of the architecture of a compactor on the entropy growth. This approach is suitable for nonlinear compactors, widely known linear feedback shift registers (LFSRs) and the counting compactors, as well. Useful theorems to determine entropy growth during the test have been given and proven. Furthermore, the class of nonlinear compactors based on shift registers named cyclic feedback shift registers (CFSRs), which guarantee the maximal entropy growth and the aliasing probability of 2¿n, is found. It is shown that they are considerably better than the simplest linear compactor (feedback shift register) and in many cases are quite as good as linear compactors (LFSRs) having primitive polynomials. On the opposite side, compactors based on counters are far worse than CFSRs. The family of CFSRs is much greater than the already explored family of LFSRs and some CFSRs require less overhead.
Exchange-Rates Forecasting: A Hybrid Algorithm Based onGenetically Optimized Adaptive Neural Networks
Authors: Andreas S. Andreou, Efstratios F. Georgopoulos, Spiridon D. Likothanassis
Venue: Computational Economics (2002)

The use of neural networks trained by a new hybrid algorithm is employed on forecasting the Greek Foreign Exchange-Rate Market. Four major currencies, namely the U.S. Dollar (USD), the Deutsche Mark (DEM), the French Franc (FF) and the British Pound (GBP), versus the Greek Drachma, were used as experimental data. The proposed algorithm combines genetic algorithms and a training method based on the localized Extended Kalman Filter (EKF), in order to evolve the structure and train Multi-Layered Perceptron (MLP) neural networks. The goal of this effort is to predict, as accurately as possible, exchange-rates future behavior. Simulation results show that the method gives highly successful results, while the diversification of the structure between the four currencies has no effect on the performance.
Tactical Approaches for Alleviating Distance in Global Software Development
Authors: Erran Carmel, Ritu Agarwal
Venue: IEEE Software (2001)

The authors describe three tactical approaches to reducing intensive collaboration, national and organizational cultural differences, and temporal distance.
A Period-Processor-Time-Minimal Schedule for Cubical Mesh Algorithms
Authors: C. Scheiman, P. Cappello
Venue: IEEE Transactions on Parallel and Distributed Systems (1994)

Using a directed acyclic graph (dag) model of algorithms, we investigateprecedence-constrained multiprocessor schedules for the n/spl times/n/spl times/ndirected mesh. This cubical mesh is fundamental, representing the standard algorithm forsquare matrix product, as well as many other algorithms. Its completion requires at least3/sup n/spl minus/2/ multiprocessor steps. Time-minimal multiprocessor schedules thatuse as few processors as possible are called processor-time-minimal. For the cubicalmesh, such a schedule requires at least /spl lsqb/3n/sup 2//4/spl rsqb/ processors.Among such schedules, one with the minimum period (i.e., maximum throughput) isreferred to as a period-processor-time-minimal schedule. The period of anyprocessor-time-minimal schedule for the cubical mesh is at least 3/sup n/2/ steps. Thislower bound is shown to be exact by constructing, for n a multiple of 6, aperiod-processor-time-minimal multiprocessor schedule that can be realized on a systolicarray whose topology is a toroidally connected n/2/spl times/n/2/spl times/3 mesh.
An Authorization Model for a Distributed Hypertext System
Authors: Pierangela Samarati, Elisa Bertino, Sushil Jajodia
Venue: IEEE Transactions on Knowledge and Data Engineering (1996)

Digital libraries support quick and efficient access to a large number of information sources that are distributed but interlinked. As the amount of information to be shared grows, the need to restrict access only to specific users or for specific usage will surely arise. The protection of information in digital libraries, however, is difficult because of the peculiarity of the hypertext paradigm which is generally used to represent information in digital libraries, together with the fact that related data in a hypertext are often distributed at different sites. In this paper, we present an authorization model for distributed hypertext systems. Our model supports authorizations at different granularity levels, takes into consideration different types of data and the relationships among them, and allows administrative privileges to be delegated.
Using spatial data access structures for filtering nearest neighbor queries
Authors: A. Belussi, E. Bertino, B. Catania
Venue: Data Knowledge Engineering (2002)

The detection of the nearest neighbor object to a given point in the reference space (NN query) is a common problem in geographical information systems (GISs). Data structures supporting range queries are not always adequate to support NN queries. For this reason, additional data structures, mainly relying on the use of some kind of tree, have been proposed. The main drawback of such solutions is that at least one tree path has to be analyzed in order to determine the NN object. In this paper, we overcome this problem by considering information on the reference space to improve the search. In particular, we propose a data structure that is obtained by integrating the R+-tree with a regular grid, indexed by using a hashing technique. The resulting data structure combines the advantages of a rectangular decomposition of the space, typical of R+-trees, with a direct access to each portion of the space, typical of hashing. The proposed technique is then compared both theoretically and experimentally with the R--tree.