ppxscal/embedding_network huggingface dataset:
Pathwise Optimum Policies for ATM Cell Scheduling and Rejection
Authors: Erol Gelenbe, Sridhar Seshadri
Venue:  (1994)

This paper addresses the following questions related to buffer management schemes for high speed integrated services networks: ($i$) given the pattern of cell arrivals from different classes of traffic, can buffer control significantly influence the effect of cell loss, and ($ii$) what are the ``best'''' policies for selecting cells for transmission from buffers in the network nodes as well as for rejecting cells when the buffers are full. The basic approach to answering these questions is to impute a cost of losing cells which may vary between classes of applications and to minimize this cost over the finite or infinite time horizons. The policies we derive are best in the sense that they minimize the cost function at each (deterministic) instant of time during the system''s operation (pathwise optimum). We then illustrate via simulations how these optimal rules would perform in realistic conditions in a sequence of cascaded buffers. The simulations are conducted using a CM-5 MIMD parallel computer so as to obtain rapid results.
Variable Metric Methods for Minimizing a Class of Nondifferentiable Functions
Authors: Shih Han
Venue:  (1977)

We develop a class of methods for minimizing a nondifferentiable function which is the maximum of a finite number of smooth functions. The methods proceed by solving iteratively qquadratic programming problems to generate search directions. For efficiency the matrices in the quadratic programming problems are suggested to be updated in a variable metric way. By doing so, the methods possess many attractive features of variable metric methods and can be viewed as their natural extension to the nondifferentiable case. To avoid the difficulties of an exact line search, a practical stepsize procedure is also introduced. Under mild asumptions the resulting method converge globally.
Gis2web and its inter-application communications issues
Authors: Xiannong Meng, R. H. Fowler, E. R. Rieken
Venue: Proceedings of the 6th International Conference on Computer Communications and Networks (1997)

Gis2web is a system intended to bridge the gap between GIS software and datasets and the WWW. The system operates by periodically accessing distributed datasets of GIS information and creating a common repository of WWW accessible information on a gis2web server. In this way gis2web users are provided seamless access to different datasets which may be of quite different forms. This paper discusses the architecture and communications issues of gis2web.
Uniform Self-Stabilizing Orientation of Unicyclic networks under Read/Write Atomicity
Authors: James Hoover, Piotr Rudnicki
Venue:  (1996)

A distributed system is self-stabilizing if its behavior is correct regardless of its initial state. A ring is a distributed system in which all processors are connected in a cycle and each processor communicates directly with only its two neighbors. A ring is oriented when all processors have a consistent notion of their left and right neighbors. A ring is uniform when all processors run the same program and have no distinguishing attributes, such as processor IDs. A well-known self-stabilizing uniform protocol for ring orientation is that of [Israeli, Jalfon]. For a ring of size n, this protocol will stabilize in expected O(n^2) processor activations. This assumes that processors are scheduled by a distributed demon---one in which the communication registers between processors can be atomically updated (a read followed by a write), and the processors have the ability to make random choices. This paper generalizes the notion of orienting a ring to that of orienting a unicyclic network, that is, a ring with trees attached. We present a very simple protocol for the self-stabilizing orientation of such unicyclic networks. It has the same expected O(n^2) processor activation performance as the Israeli and Jalfon protocol for rings. But ours works under the more general scheduling assumption of a read/write demon---one in which a read or write of a communication register is atomic, but an update (a read followed by a write) is not. We similarly assume the ability to make random choices. A subresult of our protocol is a uniform self-stabilizing algorithm for the two processor token-passing problem under the read/write demon. Our protocol is uniform in the sense that all processors of the same degree are identical. In addition, observations of the behavior of the protocol on an edge yield no information about the degree of the processors at the ends of the edge.
Interoperability issues in sharing electronic healthcare records-the Synapses approach
Authors: J. Grimson, E. Felton, G. Stephens, W. Grimson, D. Berry
Venue: Proceedings of the Third IEEE International Conference on Engineering of Complex Computer Systems (1997)

This paper describes the approach to information sharing being adopted by Synapses, a pan-European project funded under the EU Health Telematics Programme. The emphasis in Synapses is on developing standards to enable sharing, in whole or in part, of electronic healthcare records between distributed healthcare providers and institutions. The current technological solutions available for data sharing, including federated database systems, gateways, data warehousing, messaging and the web are insufficient on their own to meet the needs of Synapses. Thus in Synapses several different, but complementary technologies are merged in an open, distributed object-oriented environment. Furthermore, in order to safeguard the legal, ethical and clinical integrity of the record, it is essential not only to preserve the meaning of the data being transferred, but also its context and structure. Synapses solves this problem by defining a standard architecture for the federated electronic healthcare record.
Operational Semantics of Constraint Logic Programming over Finite Domains
Authors: Pascal Van Hentenryck, Yves Deville
Venue:  (1990)

Although constraint logic programming (CLP) theory [7] is an elegant generalization of LP theory, it has some difficulties in capturing some operational aspects of actual CLP languages. A difficulty comes from the intentional incompleteness of some constraint-solvers. Some constraints are simply delayed until they can be decided by the constraint-solver. Others are approximated, providing an active pruning of the search space without being actually decided by the constraint-solver. This paper presents an extension of the {\em ask \& tell} framework in order to give a simple and precise operational semantics to (a class of) CLP languages with an incomplete constraint-solver. The basic idea is to identify a subset of the constraints (the basic constraints) for which there exists an efficient and complete constraint-solver. Non-basic constraints are handled through two new combinators, relaxed ask and relaxed tell, that are in fact relaxations of the standard ask and tell. The extended framework is instantiated to CLP on finite domains, say CLP(F). Arc-consistency is shown to be an efficient and complete constraint-solver for basic constraints. We also present how non-basic constraints can be approximated in CLP(F). The resulting semantics precisely describes the operational semantics of the language, enables the programmer to reason easily about the correctness and efficiency of his programs, and clarifies the links of CLP(F) with the CLP and {\em ask \& tell} theories. It is believed that this approach can be used as well to endow other CLP languages such as BNR-Prolog, CLP($SIGMA ^ * $), and parts of Trilogy with a precise operational semantics.
The Operator Gap
Authors: Robert L. Constable
Venue:  (1969)

This paper continues investigations pertaining to recursive bounds on computing resources (such as time or memory) and the amount by which these bounds must be increased if new computations are to occur within the new bound. The paper proves that no recursive operator can increase every recursive bound enough to reach new computations. In other words, given any general recursive operator F[], there is an arbitrarily large recursive t() such that between bound t() and bound F[t()]() there is a gap in which no new computation runs. This demonstrates that the gap phenomenon first discovered by Borodin for composition is a deeply intrinsic property of computational complexity measures. Moreover, the Operator Gap Theorem proved here is shown to be the strongest possible gap theorem for general recursive operators. The proof involves a priority argument but is sufficiently self-contained that it can easily be read by a wide audience. The paper also discusses interesting connections between the Operator Gap Theorem and McCreight & Meyer''s important result that every complexity class can be named by a function from a measured set.
Model Fermion Monte Carlo with Antithetical Pairs
Authors: Zhiping Liu, Shiwei Zhang, M. H. Kalos
Venue:  (1994)

We consider certain model systems within which we seek solutions of the Schrodinger equation that are antisymmetric on inversion in the origin. We find geometrical constructions that define sequences of correlated random walks for which the overlap with the antisymmetrical test functions are asymptotically constant. The emphasis here is on problems in two dimensions, but the methods generalize to many dimensions and to certain other model problems.
Deriving Mode Invariants from SCR Specifications
Authors: Zhenyi Jin
Venue: Proceedings of the 2nd IEEE International Conference on Engineering of Complex Computer Systems (1996)

This paper introduces a formal analysis method to derive modeclass invariants from Software Cost Reduction (SCR) specifications. SCR specifications can be used to specify event-driven systems. Mode invariants in SCR specifications are used to capture safety features that must be ensured during software development. This new method derives mode invariants from well-defined, consistent SCR specifications by transforming an SCR mode transition table into one matrix and two vectors to describe the conditions before and after a mode transition occurs, an algorithm then derives single mode invariants. A case study of a cruise control system shows that the algorithm is capable of determining the same mode invariants that were proved via model checking in earlier investigations.
Cooperation in an unpredictable environment
Authors: Anders Eriksson, Kristian Lindgren
Venue: Proceedings of the eighth international conference on Artificial life (2002)

A framework for studying the evolution of cooperative behaviour in a random environment, using evolution of finite state strategies, is presented. The interaction between agents is modelled by a repeated game with random observable payoffs. The agents are thus faced with a more complex situation, compared to the Prisoner's Dilemma that has been widely used for investigating the conditions for cooperation in evolving populations (Matsuo 1985; Axelrod 1987; Miller 1989; Lindgren 1992; Ikegami 1994; Lindgren & Nordahl 1994; Lindgren 1997). Still, there are robust cooperating strategies that usually evolve in a population of agents. In the cooperative mode, these strategies selects an action that allows for maximizing the payoff sum of both players in each round, regardless of the own payoff. Two such players maximize the expected total long-term pay-off. If the opponent deviates from this scheme, the strategy invokes a punishment action, which aims to lower the opponent's score for the rest of the (possibly infinitely) repeated game. The introduction of mistakes to the game actually pushes evolution towards more cooperative strategies even though the game becomes more difficult.
Learn Microsoft Visual Basic .NET in a Weekend
Authors: Lloyd Work, Jay Miller
Venue:  (2002)

:In the matter of a weekend, readers will learn not only the syntax of this language, but also how to create windows and web-based applications, web services, simple database applications, and much, much more. Learn Microsoft Visual Basic .NET In a Weekend includes valuable examples, exercises, and sample applications, which utilize many things learned in the book and also serve as an integrated assessment tool. Plus, you can quickly access examples and applications referenced in the book with navigational software provided on the companion Web site.
Prioritizing Scenario Evolution
Authors: Frank Moisiadis
Venue: Proceedings of the 4th International Conference on Requirements Engineering (ICRE'00) (2000)

Use cases are currently used in requirement elicitation and analysis. They describe in natural language the complete functionality of a proposed system. In most projects, the amount of detail put into eliciting and documenting a use case is usually dependent on the time and resources available. Seldom is there enough time to fully expand all the scenarios in the use cases. Thus, only a small number of the scenarios are ever fully expanded.This paper delves into the process of expanding the scenarios of use cases. The transition from use cases to OO modeling elements requires functionally decomposed use cases. Discovering possible scenarios reveals the system facilities that are needed. They also guide the discovery of all the relevant classes and objects, and expose the range of possible system interactions in the solution domain. Thus, it is important to discover and expand the most important scenarios in the use cases.Each scenario of the high-level use cases can be ranked by applying various measures from the use case model, from the stakeholders' goals, and from applying concepts and formulas from Social Network Analysis. Once the most important scenarios are detected, the elaboration of a use case can be properly directed and controlled.The technique used for ranking scenarios has been applied to the case study of developing a meeting scheduler system for JRCASE, Macquarie University. The findings as well as observations on reusability and dependencies in the use case model are presented and analyzed.
Transient Solution of Acyclic Markov Chains
Authors: Raymond Marie, Andrew Riebman, S K Trivedi
Venue:  (1984)

Continuous time Markov chains are commonly used in system reliability modeling. Increasing system complexity and non-Markovian behavior can drastically increase the size of a Markov model''s state space. Special approximation techniques and numerical methods have been introduced to reduce the resources needed to solve Markov chain models. In this paper we discuss a method for automatically deriving exact transient solutions of Markov chains. The solutions derived are symbolic in $t$. Our approach can also provide solutions that are symbolic in other parameters. We extend our method to include parametric sensitivity analysis of the transient solution, and to provide cumulative measures of Markov chain behavior. We present three examples, one to show the use of our method in evaluating approximate solution techniques, one showing parametric sensitivity analysis of a large Markov model, and one demonstrating the computation of cumulative measures for an acyclic Markov reward processes.
Integration Mechanisms in the FIELD Environment
Authors: Steven P. Reiss
Venue:  (1988)

Selective broadcasting is a mechanism that allows a wide variety of programming tools to be combined in an integrated environment. It follows the UNIX philosophy of allowing independent tools to cooperate easily though simple conventions while at the same time providing the functionality necessary to a complex programming environment. It is combined with an annotation editor that allows consistent, multi-function access to source files in the FIELD programming environment. FIELD demonstrates the power and capabilities of these mechanisms. It is currently being used for both instruction and research at Brown University.
Testing of Concurrent Programs after Specification Changes
Authors: In Sang Chung, Hyeon Soo Kim, Hyun Seop Bae, Yong Rae Kwon, Dong Gil Lee
Venue: Proceedings of the IEEE International Conference on Software Maintenance (1999)

This paper describes a specification-based regression testing technique that can be applied for revalidating concurrent programs after specification changes. This kind of regression testing technique requires sequencing constraints which specify the precedence relations among synchronization events. In our method, the sequencing constraints are extracted automatically from Message Sequence Charts (MSCs) that are considered to be partial and non deterministic specifications. We show how to identify the sequencing constraints affected by the modifications of a specification rather than creating new sequencing constraints from scratch to reduce the cost of regression testing. We also describe how to determine whether the affected sequencing constraints are satisfied by the program being tested.
Investigations in Model Elimination Based Theorem Proving
Authors: L O Astrachan
Venue:  (1992)

Automated reasoning systems, also called automatic theorem provers, have been a focus of study since computer science expanded to include the study of symbolic computation in the 1950''s. More recently, the so-called ``logic programming'''' language Prolog has been the focus of much study that has generated very efficient implementations of a language once noted for its expressive power, but now noted for its performance as well. The joining of Prolog technology with an early system of inference called Model Elimination led to the development of theorem proving systems with a very high rate of inference. This dissertation focuses on the study of automated reasoning based on Model Elimination. A theorem proving architecture and system called {\small \sl METEOR} is described and is implemented that is the foundation of a reasoning system that runs on sequential computers, NUMA shared-memory MIMD computers, and in a message-passing distributed computing environment; this reasoning system has the highest rate of inference in the world. As is well-known, brute-force is sometimes useful but must be augmented by intelligent search in many situations. We augment the search mechanism using two methods called {\em caching} and {\em lemmaizing} which lead to performance gains of more than an order of magnitude and which permit proofs to be found heretofore unobtainable by provers based on Model Elimination and by any general purpose theorem prover. We also develop different depth measures used in iterative deepening search and classes of theorems useful in the analytic study of these measures that show that no measure is uniformly superior to the other. {\small \sl METEOR} demonstrates that the high inference rate associated with Model Elimination theorem proving can be combined with redundancy reducing mechanisms and large inference steps in the form of lemmas in a powerful automated reasoning system.
An Agent-based Petri Net Model with Application to Seller/Buyer Design in Electronic Commerce
Authors: Haiping Xu, Sol M. Shatz
Venue: Proceedings of the Fifth International Symposium on Autonomous Decentralized Systems (2001)

Agents are becoming one of the most important topics in distributed and autonomous decentralized systems (ADS), and there are increasing attempts to use agent technologies to develop software systems in electronic commerce. Such systems are complex and there is a pressing need for system modeling techniques to support reliable, maintainable and extensible design. G-Nets are a type of Petri net defined to support modeling of a system as a set of independent and loosely-coupled modules. In this paper, we first introduce an extension of G-Net, agent-based G-Net, as a generic model for agent design. Then new communication mechanisms are introduced to support asynchronous message passing among agents. To illustrate our formal modeling technique is effective for agent modeling in electronic commerce, a price-negotiation protocol example between buyers and sellers is provided. Finally, by analyzing an ordinary Petri net reduced from our agent-based G-Net models, we conclude that our agent-based G-Net models are L3-live, concurrent and effective for agent communications.
The Complexity of Kleene Algebra with Tests
Authors: Ernie Cohen, Dexter Kozen, Frederick Smith
Venue:  (1996)

Kleene algebras with tests provide a natural framework for equational specification and verification. Kleene algebras with tests and related systems have been used successfully in basic safety analysis, source-to-source program transformation, and concurrency control. The equational theory of Kleene algebras with tests has been shown to be decidable in at most exponential time by an efficient reduction to Propositional Dynamic Logic. In this paper we prove that the theory is PSPACE-complete.
Local convexity preserving rational cubic spline curves
Authors: M. Sarfraz, M. Hussain, Z. Habib
Venue: Proceedings of the IEEE Conference on Information Visualisation (1997)

A scheme for generating plane curves which interpolates given data is described. A curve is obtained by patching together rational cubics and straight-line segments which, in general, is C/sup 1/ continuous. It is a local scheme which controls the shape of the curve and preserves the shape of the data by being local convexity-preserving. A particular scheme is suggested which selects the tangent vectors required at each interpolation point for generating a curve. An algorithm is presented which constructs a curve by interpolating the given data points. This scheme provides a visually pleasant display of the curve's presentation. An extra feature of this curve scheme is that it allows subsequent interactive alteration of the shape of the default curve by changing the shape control parameters and the shape-preserving parameters associated with each curve segment. Thus, this feature is useful for further enhancing the user satisfaction, if desired.
Comprehension with[in] Virtual Environment Visualisations
Authors: Claire Knight, Malcolm Munro
Venue: Proceedings of the 7th International Workshop on Program Comprehension (1999)

For many years basic visualisation, based around simple boxes and lines, has been done in an attempt to be able to ease some of the cognitive overload caused by program comprehension. The problems with such visualisations is that they can very easily become incomprehensible by trying to force large amounts of information into a small space, relying solely on two dimensions for the representations. Three-dimensional visualisations are one approach that is being considered to combat these problems, although there are also many different issues that must be considered for these sorts of visualisations. Especially when those visualisations are of intangible software systems. A solution is to use virtual environments as a base for these three-dimensional visualisations, which allows a sense of context to be maintained and also promotes collaboration between the people trying to comprehend the code.
Incorporating Fault Tolerance in Analog-to-Digital Converters (ADCs)
Venue: Proceedings of the 3rd International Symposium on Quality Electronic Design (2002)

The reliability of ADCs used in highly critical systems can be increased by applying a two-step procedure starting with sensitivity analysis followed by redesign. The sensitivity analysis is used to identify the most sensitive blocks which could then be redesigned for better reliability by incorporating fault tolerance. This paper illustrates the steps involved in incorporating fault tolerance in an ADC. Two redesign techniques to improve the reliability of a circuit are presented. Novel selective node resizing algorithms for increased tolerance against alpha-particle induced transients are discussed.
A calculational proof of Andrews''s challenge
Authors: David Gries
Venue:  (1996)

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