ppxscal/embedding_network huggingface dataset:
VIBDaST: a virtual interactive book as a data structures teaching aid
Authors: Dimitrios Theotokis, George Gyftodimos, Panagiotis Georgiadis, George Philokyprou
Venue: Proceedings of the 2nd conference on Integrating technology into computer science education (1997)

Internet based teaching is well established under various contexts. WWW based virtual interactive books are used for this purpose. Using WWW browsers students can study such books locally or remotely. Enhanced by JavaTM applets, such books provide an interactive as well as a traditional approach to learning. Examples and exercises implemented as applets cater for both observation and exploration. Such a book, addressing the topic of data structures, is being developed as a teaching aid for a first year Computer Science students. Theory is presented in a hyperlinked textual form thus realising cross references, while examples and exercises are visualised as interactive JavaTM applets.
Frequency-domain compatibility in digital filter BIST
Authors: Laurence Goodby, Alex Orailoğlu
Venue: Proceedings of the 34th annual Design Automation Conference (1997)

We examine frequency-domain issues in the design and selectionof on-chip test generators for built-in self-test (BIST) of high-performancedigital filters. Test-generator/circuit compatibility isidentified as a significant factor in testing large filters. A fault-injectionexperiment is used to show that when an incompatible testgenerator is used, high fault coverage (over 99%) does not guaranteethat all serious faults will be detected. The frequency-domaincharacteristics of some basic test generation schemes are examined,and guidelines for test generator selection are proposed. Analyticaltechniques for identifying frequency-related testability problemsare discussed, and several test generation schemes are evaluated byfault simulating them against lowpass, bandpass, and highpass filters.A mixed test generation scheme is shown to reduce the numberof untested faults by a factor of two to three over a standard linear-feedbackshift-register (LFSR) based test scheme, at little added cost.
Minimizing the Application Execution Time Through Scheduling of Subtasks and Communication Traffic in a Heterogeneous Computing System
Authors: Min Tan, Howard Jay Siegel, John K. Antonio, Yan Alexander Li
Venue: IEEE Transactions on Parallel and Distributed Systems (1997)

In a heterogeneous computing (HC) environment consisting of different types of machines, an application program is decomposed into subtasks, each of which is computationally homogeneous. The goal is to execute subtasks on the machines in such a way that the total program execution time is minimized. A mathematical framework is presented that models the matching of subtasks to machines, scheduling of subtasks' computation, scheduling of intermachine communication steps, and selection of sources of shared data items for intermachine communication (data relocation). The goal of this work is to generate a provably optimal scheme for communicating shared data among subtasks as an enhancement to any given matching and scheduling. Initially, it is assumed that at any instant in time, only one machine is being used for program execution and only one subtask is being executed. Based on this assumption, a polynomial algorithm is introduced to optimize scheduling and data relocation with respect to any given matching of subtasks to machines. The data relocation scheme is then extended to reduce intermachine data communication time in an HC environment with a given matching and scheduling of subtasks' computation where: 1) multiple subtasks' computations can be performed concurrently on different machines; 2) subtask computation stteps can be overlapped with other subtasks' communication steps for intermachine data transfers; and 3) machines in the HC suite are interconnected by a shared-bus type of network.
Simulation model of space station operations in the space debris environment
Authors: Mark M. Mekaru, Brian M. Waechter
Venue: Proceedings of the 17th conference on Winter simulation (1985)

A discrete event simulation model was developed to analyze the effect of space debris on the Space Station operations. The space environment model includes elements contributing debris (e.g., launches) and the dynamics of the elements (e.g., explosions and decay). The model simulates the Space Station operations and interaction with the debris environment. The resulting data describe the number of Space Station encounters with debris as a function of the buffer zone. These results are translated to fuel requirements for avoidance maneuvers. Sensitivity analysis results caused by varying the initial conditions, system dynamics and operations philosophy are discussed.
Asymptotic Optimization of a Nonlinear Hybrid System Governed by a Markov Decision Process
Authors: Eitan Altman, Vladimir Gaitsgory
Venue: SIAM Journal on Control and Optimization (1997)

We consider in this paper a continuous time stochastic hybrid control system with finite time horizon. The objective is to minimize a nonlinear function of the state trajectory. The state evolves according to a nonlinear dynamics. The parameters of the dynamics of the system may change at discrete times $l\epsilon$, $l=0,1,...$, according to a controlled Markov chain which has finite state and action spaces. Under the assumption that $\epsilon$ is a small parameter, we justify an averaging procedure allowing us to establish that our problem can be approximated by the solution of some deterministic optimal control problem.
Near-optimal intraprocedural branch alignment
Authors: Cliff Young, David S. Johnson, Michael D. Smith, David R. Karger
Venue: ACM SIGPLAN Notices (1997)

Branch alignment reorders the basic blocks of a program to minimize pipeline penalties due to control-transfer instructions. Prior work in branch alignment has produced useful heuristic methods. We present a branch alignment algorithm that usually achieves the minimum possible pipeline penalty and on our benchmarks averages within 0.3% of a provable optimum. We compare the control penalties and running times of our algorithm to an older, greedy approach and observe that both the greedy method and our method are close to the lower bound on control penalties, suggesting that greedy is good enough. Surprisingly, in actual execution our method produces programs that run noticeably faster than the greedy method. We also report results from training and testing on different data sets, validating that our results can be achieved in real-world usage. Training and testing on different data sets slightly reduced the benefits from both branch alignment algorithms, but the ranking of the algorithms does not change, and the bulk of the benefits remain.
Effective whole-program analysis in the presence of pointers
Authors: Darren C. Atkinson, William G. Griswold
Venue: Proceedings of the 6th ACM SIGSOFT international symposium on Foundations of software engineering (1998)

Understanding large software systems is difficult. Traditionally, automated tools are used to assist program understanding. However, the representations constructed by these tools often require prohibitive time and space. Demand-driven techniques can be used to reduce these requirements. However, the use of pointers in modern languages introduces additional problems that do not integrate well with these techniques. We present new techniques for effectively coping with pointers in large software systems written in the C programming language and use our techniques to implement a program slicing tool.First, we use a fast, flow-insensitive, points-to analysis before traditional data-flow analysis. Second, we allow the user to parameterize the points-to analysis so that the resulting program slices more closely match the actual program behavior. Such information cannot easily be obtained by the tool or might otherwise be deemed unsafe. Finally, we present data-flow equations for dealing with pointers to local variables in recursive programs. These equations allow the user to select an arbitrary amount of calling context in order to better trade performance for precision.To validate our techniques, we present empirical results using our program slicer on large programs. The results indicate that cost-effective analysis of large programs with pointers is feasible using our techniques.
Automatic Differentiation and Interval Arithmetic for Estimation of Disequilibrium Models
Authors: Max E. Jerrell
Venue: Computational Economics (1997)

Nonlinear estimation problems have a unknown number of stationary points. Interval arithmetic is a promising method that eliminates all but the global optimum. Automatic differentiation provides users with a convenient method of computing the gradient and Hessian of nonlinear functions. These two can be combined to provide an efficient and convenient global optimization process.
Communications controller prototype
Authors: Donna D. Gregorio
Venue: Proceedings of the 17th conference on Winter simulation (1985)

A United States military battle simulation center, consisting of a number of rooms containing computer equipment, functions as a training facility for force commanders. The computer equipment is used to conduct simulated air/land battle engagements, and each room is designed to simulate a representative Air Force or Army operations center. Because communication within the facility are current state of the art, they have been designed deliberately to be nearly error-free. The communications controller prototype simulates wartime communication failures by confronting the participants with an information exchange capability approximating that which would be experienced in wartime with regard to both the availability and the quality of the communications. The prototype intercepts a message about to be transmitted between two users over the LAN, loses, garbles, and/or delays the message, and then sends it to the receiver if it is not lost. This paper describes the following: a. Need for a communications controller b. Prototype communications controller used for demonstration purposes c. Ideas for an upgraded communications controller The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Specification matching of software components
Authors: Amy Moormann Zaremski, Jeannette M. Wing
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (1997)

Specification matching is a way to compare two software components, based on descriptions of the component's behaviors. In the context of software reuse and library retrieval, it can help determine whether one component can be substituted for another or how one can be modified to fit the requirements of the other. In the context of object-oriented programming, it can help determine when one type is a behavioral subtype of another. We use formal specifications to describe the behavior of software components and, hence, to determine whether two components match. We give precise definitions of not just exact match, but, more relevantly, various flavors of relaxed match. These definitions capture the notions of generalization, specialization, and substitutability of software components. Since our formal specifications are pre- and postconditions written as predicates in first-order logic, we rely on theorem proving to determine match and mismatch. We give examples from our implementation of specification matching using the Larch Prover.
Linear-time subtransitive control flow analysis
Authors: Nevin Heintze, David McAllester
Venue: Proceedings of the ACM SIGPLAN 1997 conference on Programming language design and implementation (1997)

We present a linear-time algorithm for bounded-type programs that builds a directed graph whose transitive closure gives exactly the results of the standard (cubic-time) Control-Flow Analysis (CFA) algorithm. Our algorithm can be used to list all functions calls from all call sites in (optimal) quadratic time. More importantly, it can be used to give linear-time algorithms for CFA-consuming applications such as: bull; effects analysis: find the side-effecting expressions in a program. bull; k-limited CFA: for each call-site, list the functions if there are only a few of them ( le; k) and otherwise output "many". bull; called-once analysis: identify all functions called from only one call-site.
Disjunctive datalog
Authors: Thomas Eiter, Georg Gottlob, Heikki Mannila
Venue: ACM Transactions on Database Systems (TODS) (1997)

We consider disjunctive Datalog, a powerful database query language based on disjunctive logic programming. Briefly, disjunctive Datalog is a variant of Datalog where disjunctions may appear in the rule heads; advanced versions also allow for negation in the bodies which can be handled according to a semantics for negation in disjunctive logic programming. In particular, we investigate three different semantics for disjunctive Datalog: the minimal model semantics the perfect model semantics, and the stable model semantics. For each of these semantics, the expressive power and complexity are studied. We show that the possibility variants of these semantics express the same set of queries. In fact, they precisely capture the complexity class P2 . Thus, unless the Polynomial Hierarchy collapses, disjunctive Datalog is more expressive that normal logic programming with negation. These results are not only of theoretical interest; we demonstrate that problems relevant in practice such as computing the optimal tour value in the Traveling Salesman Problem and eigenvector computations can be handled in disjunctive Datalog, but not Datalog with negation (unless the Polynomial Hierarchy collapses). In addition, we study modularity properties of disjunctive Datalog and investigate syntactic restrictions of the formalisms.
Rational Functions and Association Scheme Parameters
Authors: Douglas A. Leonard
Venue: Journal of Algebraic Combinatorics: An International Journal (1997)

The parameters of metric, cometric, symmetric association schemes with q \not= \pm 1 (the same as the parameters of the underlying orthogonal polynomials) can be given in general by evaluating a single rational function of degree (4, 4) in the complex variable q^j. But in all known examples, save the simple n-gons, these reduce to polynomials of degree at most 2 in q^j with q an integer. One reason this occurs is that the rational function can have singularities at points which would determine some of the parameters. This paper deals with the case in which not all of the singularities are removable, thus giving some reason why then -gons might naturally be the only exceptions to schemes with parameters being polynomials of degree at most 2 inq^j , except possibly for schemes of very small diameter.
Statistical issues in simulation
Authors: W. David Kelton
Venue: Proceedings of the 28th conference on Winter simulation (1996)

This paper describes, in general terms, methods to help design the runs for simulation models and in terpreting their output. Statistical methods are described for several different purposes, and related problems like comparison, variance reduction, sensitivity estimation, metamodeling, and optimization are mentioned. The main point is to call attention to the challenges and opportunities in using simulation models carefully and effectively.
A practical approach to reinforcing concepts in introductory operating systems
Authors: Thomas D. Wagner, Eugene K. Ressler
Venue: ACM SIGCSE Bulletin (1997)

The challenge of including both theory and practical experience to reinforce the concepts of theory in Introductory Operating Systems is discussed. The traditional approaches to answering this challenge are presented. A practical approach that uses straightforward programming problems rather than problems that involve modification of an existing operating system is described. Examples of the types of problems used are presented and experience with the proposed approach is described.
Comparison of two stationary stochastic processes using standardized time series
Authors: Bor-Chung Chen, Robert G. Sargent
Venue: Proceedings of the 17th conference on Winter simulation (1985)

References to confidence interval estimations for the difference between the means and for the ratio of the variances of two independent strictly stationary phimixing processes using standardized time series are given. Results of a limited empirical investigation on one set of the estimators for the difference between the two means are presented after they are briefly discussed. These estimators performed well in this investigation.
Classification of Extremal Double Circulant Formally Self-DualEven Codes
Authors: T. Aaron Gulliver, Masaaki Harada
Venue: Designs, Codes and Cryptography (1997)

Formally self-dual even codes have recently been studied. Double circulant even codes are a family of such codes and almost all known extremal formally self-dual even codes are of this form. In this paper, we classify all extremal double circulant formally self-dual even codes which are not self-dual. We also investigate the existence of near-extremal formally self-dual even codes.
The Impact of Discharge Decisions on Health Care Quality
Authors: Emre Berk, Kamran Moinzadeh
Venue: Management Science (1998)

In this paper, we present a normative study that describes the impact of discharging decisions in the face of resource shortages. We develop a model that represents the dynamics of a healthcare unit. Then, to capture the essence of discharge decisions, we consider discharge policies that incorporate both the occupancy level of the unit and the status of patients measured by their stage of recovery and the time they have spent in that stage. We believe that our model can be used as an aid to physicians and administrators to better assess discharge and/or capacity decisions. In addition, we investigate the impact of discharge decisions on the measures that represent the quality of care at a facility such as average hospital stays, system accessibility, and average complication risk of discharged patients. Our findings illustrate that inclusion of early discharge option improves system accessibility significantly and does not jeopardize care equity among patients. Furthermore, introduction of early discharge option has more pronounced effects on increasing care unit capacity than addition of open beds with no early discharges.
TransIT - investing SME co-operation across borders in Europe
Authors: Oliver Stiemerling, Volker Wulf, Armin B. Cremers, Clive Bancroft, Christine Buelens, Gert Boulliard, Martin Maidhof, Ralph Peters, Francis Fricker, Charles Durand
Venue: ACM SIGGROUP Bulletin (1998)

TRANSIT investigates the current challenges and potential of computer supported transnational cooperation of small and medium size engineering firms in Europe. The project is an international initiative supported by the European Social Fund's ADAPT program and involves Universities and private companies in the UK, Belgium, and Germany. The partners from each country are in turn involved in national ADAPT projects which benefit from the experiences made on the transnational level. The project started in January 98 and will end in December 99. In this article we describe the TRANSIT approach to the investigation of transnational SME-cooperation and present findings to date.
A Stable Penalty Method for the Compressible Navier--Stokes Equations: II. One-Dimensional Domain Decomposition Schemes
Authors: J. S. Hesthaven
Venue: SIAM Journal on Scientific Computing (1997)

This paper presents asymptotically stable schemes for patching of nonoverlapping subdomains when approximating the compressible Navier--Stokes equations given on conservation form. The scheme is a natural extension of a previously proposed scheme for enforcing open boundary conditions and as a result the patching of subdomains is local in space. The scheme is studied in detail for Burgers's equation and developed for the compressible Navier--Stokes equations in general curvilinear coordinates.The versatility of the proposed scheme for the compressible Navier--Stokes equations is illustrated for quasi-one-dimensional transonic nozzle flows and for flows around an infinitely long circular cylinder.
Interval-based Clock Synchronization
Authors: Ulrich Schmid, Klaus Schossmaier
Venue: Real-Time Systems (1997)

In this paper, we develop and analyze a simple interval-based algorithm suitable for fault-tolerant external clock synchronization. Unlike usual internal synchronization approaches, our convergence function-based algorithm provides approximately synchronized clocks maintaining both precision and accuracy w.r.t. external time. This is accomplished by means of a time representation relying on intervals that capture external time, providing accuracy information encoded in interval lengths. The algorithm, which is generic w.r.t. the convergence function and relies on either instantaneous correction or continuous amortization for clock adjustment, is analyzed by utilizing a novel, interval-based framework for establishing worst-case precision and accuracy bounds subject to a fairly detailed system model. Apart from individual clock rate and transmission delay bounds, our system model incorporates non-standard features like clock granularity and broadcast latencies as well. Relying on a suitable notion of internal global time, our analysis unifies treatment of precision and accuracy, ending up in striking conceptual beauty and expressive power.
A General Method for Deflection Worm Routing on Meshes Based on Packet Routing Algorithms
Authors: Alan Roberts, Antonios Symvonis
Venue: IEEE Transactions on Parallel and Distributed Systems (1997)

In this paper, we consider the deflection worm routing problem on n×n meshes. In deflection routing, a message cannot be queued and it is always moving until it reaches its destination. In worm routing, the message is considered to be a worm, a sequence of k flits which, during the routing, follow the head of the worm, which knows the destination address. We show how to derive a deflection worm routing algorithm from a packet routing algorithm which uses queues of size O(f(N)) (N is the side-length of the mesh in which the packet routing algorithm is applied). Our result generalizes the method of Newman and Schuster in which only packet routing algorithms with a maximum queue of four packets can be used.
Performance of Multistage Bus Networks for a Distributed Shared Memory Multiprocessor
Authors: Laxmi N. Bhuyan, Ravi R. Iyer, Tahsin Askar, Ashwini K. Nanda, Mohan Kumar
Venue: IEEE Transactions on Parallel and Distributed Systems (1997)

A Multistage Bus Network (MBN) is proposed in this paper to overcome some of the shortcomings of the conventional multistage interconnection networks (MINs), single bus, and hierarchical bus interconnection networks. The MBN consists of multiple stages of buses connected in a manner similar to the MINs and has the same bandwidth at each stage. A switch in an MBN is similar to that in a MIN switch except that there is a single bus connection instead of a crossbar. MBNs support bidirectional routing and there exists a number of paths between any source and destination pair. In this paper, we develop self routing techniques for the various paths, present an algorithm to route a request along the path with minimum distance, and analyze the probabilities of a packet taking different routes. Further, we derive a performance analysis of a synchronous packet-switched MBN in a distributed shared memory environment and compare the results with those of an equivalent bidirectional MIN (BMIN). Finally, we present the execution time of various applications on the MBN and the BMIN through an execution-driven simulation. We show that the MBN provides similar performance to a BMIN while offering simplicity in hardware and more fault-tolerance than a conventional MIN.