ppxscal/embedding_network huggingface dataset:
Parameterized programming and software architecture
Authors: J. A. Goguen
Venue: Proceedings of the 4th International Conference on Software Reuse (1996)

The paper discusses an approach to software architecture based on concepts from parameterized programming, particularly its language of "module expressions". A module expression describes the architecture of a system as an interconnection of component modules, and executing the expression actually builds the system. Language features include: modules parameterized by theories, which declare interfaces; a number of module composition operations; views for binding modules to interfaces; and both vertical and horizontal composition. Modules may involve information hiding, theories may declare semantic restrictions with axioms, and views assert behavioral satisfaction of axioms by a module. Some "laws of software composition" are given, showing how various module composition operations are related. We also show how a variety of architectural styles can be supported, and how this approach can be extended to support evolution and traceability. All this is intended to ease the development of large systems, and in particular, to make reuse more effective in practice.
GEMM-Based Level-3 BLAS
Authors: Bo Kagstrom, Charles V Loan
Venue:  (1991)

The Level-3 Basic Linear Algebra Subprograms (BLAS) are designed to perform various matrix multiply and triangular system solving computations. With an optimized Level-3 library, it is possible to design portable high performance codes for LAPACK, a collection of routines for linear equation, least squares, and eigenvalue problems. A drawback of the library, which consists of nine subprograms, is that the development of optimal code is costly and time consuming because it requires assembly level programming/thinking. In this paper, we show that all one really needs is an optimized GEMM, the BLA subprogram for general matrix multiplication. With suitable partitioning, all the other Level-3 BLA subprograms can be defined in terms of GEMM and a neglibible [sic] amount of Level-2 computation.
A Language-Based Approach to Security
Authors: Fred Schneider, Greg Morrisett, Robert Harper
Venue:  (2000)

Language-based security leverages program analysis and program rewriting to enforce security policies. The approach promises efficient enforcement of fine-grained access control policies and depends on a trusted computing base of only modest size. This paper surveys progress and prospects for the area, giving overviews of in-lined reference monitors, certifying compilers, and advances in type theory.
Intelligent Ballistic Control of a Jointed Leg
Authors: P. Israel Doerschuk, W. Simon, F. Kwong, V. Nguyen
Venue: Proceedings of the 1996 IEEE International Joint Symposia on Intelligence and Systems (1996)

In order to perform a wide variety of locomotive tasks, a legged robot should be able to autonomously adjust its stride and properly move its legs so as to fit the current locomotion requirement. We develop an adaptive intelligent system that controls the movement of a jointed leg during a running stride. This paper focuses on the ballistic controller, which controls the movement of the leg from the point of takeoff from the ground to the point of landing. The controller learns from experience to move the leg along a specified series of configurations which provide a smooth transition from takeoff to landing. Learning is on-line, so the controller adapts to the requirements of the leg on the fly. It can handle strides of different sizes and can scale obstacles. Very accurate control is achieved even during the first learning attempt. This work was sponsored by NASA Grant NAG9-695 and a Lamar University Research Enhancement Grant.
Performance Analysis of Traffic Networks Based on Stochastic Timed Petri Net Models
Authors: Jiacun Wang, Chun Jin, Yi Deng
Venue: Proceedings of the 5th International Conference on Engineering of Complex Computer Systems (1999)

A compositional method for modeling and evaluation of performance indices of traffic control systems based on Stochastic Timed Petri Nets (STPN) is presented. We use STPN to specify traffic and traffic control at an intersection and use a random distribution model to model the motion of vehicles in a road segment between any two consecutive intersections. The traffic control system is thus modeled as a composition of individual intersection models and segment distribution models. A technique is presented to incrementally evaluate the system's performance by analyzing intersections separately according to a carefully selected order. The analysis technique conforms to the accepted practice of transportation research. Compared to existing Petri net models of traffic control systems, our technique dramatically reduces the complexity of analysis.
Optimal Allocation of Clients to Replicated Multicast Servers
Authors: Zongming Fei, Mostafa H. Ammar, Ellen W. Zegura
Venue: Proceedings of the Seventh Annual International Conference on Network Protocols (1999)

In this paper we investigate multicast server selection problems. First we give a definition of the static multicast server selection problem, in which we assume a set of static clients and multicast servers and consider how one might produce an optimal allocation of the clients to the servers. We use a transformation method for deriving multicast server selection algorithms from traditional multicast routing algorithms. To investigate the dynamic behavior of client join and leave and the cost incurred during the process, we next define the dynamic multicast server selection problem, in which the clients join and leave the multicast session dynamically.The goal is to produce an optimal allocation of clients to servers with an emphasis on how this allocation behaves over time. We formulate the problem as a Markovian Decision Process (MDP). Our analysis of the problem leads to two heuristics which we use to propose a simple selection algorithm. Our simulation compares the performance of our proposed algorithm with other multicast server selection algorithms.
A Distributed Asynchronous Execution Semantics for Programming the Middleware Machine
Authors: Andrew Berry, Simon Kaplan
Venue: Proceedings of the Fifth International Symposium on Autonomous Decentralized Systems (2001)

Distributed software is traditionally built by connecting a set of software components using a communications abstraction. The interaction semantics provided by the abstraction is predominantly static: any programming of behavior occurs in the components or in local wrappers around those components. While autonomous behavior can be programmed over these abstractions, there is increasing awareness that static interaction models are not sufficient to capture the semantic diversity found in dynamic, evolving distributed systems. This paper presents an asynchronous, distributed and executable semantic model suitable for implementing programmable connector objects. Programs described using the semantic model can be jointly executed by a set of autonomous, distributed participants with no explicit synchronization of execution state. By removing the requirement for explicit synchronization, participants can execute independently with no requirement for centralized mediation, and the asynchrony of the model implicitly allows for potentially high latencies in distributed environments like the Internet. This combination of properties makes the model ideal for E-commerce applications.
A Comparison-Based Diagnosis Algorithm Tolerating Comparator Faults
Authors: Balazs Sallay, Piero Maestrini, Paolo Santi
Venue:  (1999)

A promising application of system-level diagnosis is the testing of VLSI chips during the manufacturing process. A comparison-based diagnosis is easier to implement on the wafer than the PMC-conform one. However, existing comparison models essentially overlook the test invalidation due to the physical faults in the comparators. This paper proposes a comparison-based model and a diagnosis algorithm which takes into account the effects of faults that affect the comparators. In order to deal with faults in the comparators, a preliminary comparator test session is included. This session requires the adjacent units to be able to feed the comparator with all needed patterns independently of each other. As shown in the paper, this requirement can be satisfied at a relatively small wafer design cost. The test session can also be extended to handle the faults in the syndrome collection circuitry. TEL:: +39-50-593462
Tiling Imperfectly-nested Loops
Authors: Nawaaz Ahmed, Nikolay Mateev, Keshav Pingali
Venue:  (1999)

Tiling is one of the more important transformations for enhancing locality of reference in programs. Intuitively, tiling a set of loops achieves the effect of interleaving iterations of these loops. Tiling has been applied only to perfectly-nested loop nests which are loop nests in which all assignment statements are contained in the innermost loop. In practice, most loop nests are imperfectly-nested, so existing techniques have limited utility. In this paper, we propose an approach to tiling imperfectly-nested loop nests. The key idea is to embed the iteration space of every statement in the imperfectly-nested loop nest into a special space called the product space which is tiled to produce the final code. We evaluate the effectiveness of this approach for dense numerical linear algebra benchmarks, relaxation codes, and the tomcatv code from the SPEC benchmarks. No other approach in the literature can tile all these codes automatically.
Real Time Optimization by Extremum Seeking Control
Authors: Kartik B. Ariyur, Miroslav Krstic
Venue:  (2003)

:Extremum seeking is a method of adaptive control outside the classical paradigm or model reference and related schemes. The unique feature of extremum seeking as an optimization tool is that is is an on-line methodology, performed by feedback, and with the ability to achieve rapid convergence. A second distinction between classical adaptive control and extremum seeking is that the latter is not model based. Its non-model based character explains the remarkable popularity of extremum seeking in the last half decade: the recent applications in fluid flow combustion, and biomedical systems are all characterized by complex, unreliable models. Written by authorities in the field and pioneers in adaptive nonlinear control systems, this book presents both significant theoretic value and important practical potential.
A Selective Packet Discard Scheme for Supporting Internet QoS in Congested ATM Switches
Authors: M. Casoni
Venue: Proceedings of the 7th IEEE International Conference on Networks (1999)

Previous papers have described and evaluated the performance of packet discard techniques for maintaining packet integrity during overload in ATM switches but without taking into account different classes of service.In this paper a packet discard scheme is proposed with the goal to provide incoming flows of cells with output link bandwidth depending on the class of service they belong to. Also good performance in terms of throughput and fairness in bandwidth sharing among equal priority flows are considered as the requirements to meet.In the scenarios here considered, the proposed discard scheme is shown to provide very good results and to represent a possible solution for dealing with the most demanding data flows during congestion intervals. Numerical results are reported and discussed for different operating conditions and traffic patterns.
On the ratio of the stability number and the domination number
Authors: Zverovich I. E., Zverovich I. I.
Venue:  (2000)

Let $\alpha(G)$ and $\gamma(G)$ be the stability number and domination number of a graph $G$, respectively. Since $\alpha(G) \ge \gamma(G)$, $\alpha(G)/\gamma(G) \ge 1$. For each $r \ge 1$, we define a graph $G$ to be an {\em $\alpha/\gamma \le r$-perfect graph} if $\alpha(H)/\gamma(H) \le r$ for each induced subgraph $H$ of $G$. We show that the class of all $\alpha/\gamma \le r$-perfect graphs is determined by a unique forbidden induced subgraph. It gives the possibility to approximate $\alpha(G)$ and $\gamma(G)$ in the corresponding classes.
Goppa-like bounds for the generalized Feng--Rao distances
Authors: J. I. Farrán, C. Munuera
Venue: Discrete Applied Mathematics (2003)

We give some general bounds and formulas for the generalized Feng-Rao distances (or generalized order bounds) in an arbitrary numerical semigroup. The obtained results can be regarded as generalizations of well-known facts on the classical Feng-Rao distance (or first order bound), namely its connection with the Goppa distance. These results show that their asymptotical behaviour is essentially the same as in the case of the classical order bound. Explicit computations are given for the second Feng-Rao distance.
Quality Improvement in Switching-System Software
Authors: Takaaki Fukuda, Tetsuyasu Yamada, Tomoharu Yamaguchi
Venue: Proceedings of the IEEE International Conference on Software Maintenance (1999)

This paper describes the effects on switching-system software quality of development and maintenance activities. The effect of the application of object-oriented methods and quantitative quality control methods in the development of switching-system programs is evaluated by comparing the number of errors after shipping to that of earlier systems. Effective approaches to further improving the quality have been developed by analyzing error data obtained during development and maintenance. The main findings are as follows. (1) Although the error density in switching programs, which include call-processing and system-management functions, is the same as that in maintenance programs, errors in the switching programs are more likely to have a serious impact on the system when the errors are not discovered. Thus, quality-control management that takes the potential impact of errors into account will more effectively improve the total software quality. (2) To increase the error-detection rate in each testing phase, the omission of test items must be prevented by managing the correspondence of test items between each testing phase, and by supporting the generation of test items from the system specifications.
An Architecture for Optimal All-to-All Personalized Communication
Authors: Susan Hinrichs, Corey Kosak, David R. O''Hallaron, Thomas M. Stricker, Riichiro Take
Venue:  (1994)

In all-to-all personalized communication (AAPC), every node of a parallel system sends a potentially unique packet to every other node. AAPC is an important primitive operation for modern parallel compilers, since it is used to redistribute data structures during parallel computations. As an extremely dense communication pattern, AAPC causes congestion in many types of networks and therefore executes very poorly on general purpose, asynchronous message passing routers. We present and evaluate a network architecture that executes all-to-all communication optimally on a two-dimensional torus. The router combines optimal partitions of the AAPC step with a self-synchronizing switching mechanism integrated into a conventional wormhole router. Optimality is achieved by routing along shortest paths while fully utilizing all links. A simple hardware addition for synchronized message switching can guarantee optimal AAPC routing in many existing network architectures. The flexible communication agent of the iWarp VLSI component allowed us to implement an efficient prototype for the evaluation of the hardware complexity as well as possible software overheads. The measured performance on an 8 x 8 torus exceeded 2 GigaBytes/sec or 80% of the limit set by the raw speed of the interconnects. We make a quantitative comparison of the AAPC router with a conventional message passing system. The potential gain of such a router for larger parallel programs is illustrated with the example of a two-dimensional Fast Fourier Transform.
Relationship quality: the undervalued dimension of software quality
Authors: Bruce Russell, Sangit Chatterjee
Venue: Communications of the ACM (2003)

Software service firms that want to win more business, generate referrals, and ensure timely payment of their bills manage the quality of their client relationships, not just of the systems they develop.
Enforceable Security Policies
Authors: Fred B. Schneider
Venue:  (1998)

A precise characterization is given for the class of security policies that can be enforced using mechanisms that work by monitoring system execution, and a class of automata is introduced for specifying those security policies. Techniques to enforce security policies specified by such automata are also discussed. READERS NOTE: A substantially revised version of this document is available at http://cs-tr.cs.cornell.edu:80/Dienst/UI/1.0/Display/ncstrl.cornell/TR99-1759
Directed Rectangle-Visibility Graphs have Unbounded Dimension
Authors: K. Romanik
Venue:  (1995)

Visibility representations of graphs map vertices to sets in Euclidean space and express edges as visibility relations between these sets. One visibility representation in the plane that has been studied is one in which the vertices of the graph map to closed isothetic rectangles and the edges are expressed by horizontal or vertical visibility between the rectangles. Two rectangles are only considered to be visible to one another if there is a non-zero width horizontal orvertical band of sight between them. A graph that can be represented in this way is called a rectangle-visibility graph. A rectangle-visibility graph can be directed by directing all edges towards the positive x and y directions, which yields a directed acyclic graph. A directed acyclic graph G has dimension d if d is the minimum integer such that the vertices of G can be ordered by d linear orderings, >_1, ..., >_d, and for vertices u and v there is a directed path from u to v if and only if u >_i v for all 1 >= i >= d. In this note we show that the dimension of the class of directed rectangle-visibility graphs is unbounded. 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
A Parallel Ordering for the Block Jacobi Method on a Hypercube Architecture
Authors: Christian H. Bischof
Venue:  (1986)

Jacobi methods for computing the singular value decomposition are ideally suited for multiprocessor environments since they contain a great deal of inherent parallelism. We give a parallel ordering for the block Jacobi Method that allows us to take full advantage of the nearest-neighbor topology of the hypercube. It is based on recursively embedding smaller rings into the hypercube using a Gray code labelling of processor nodes. This scheme is optimal in that it entails the lowest communication overhead possible. 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
Real-Time Systems: Scheduling, Analysis, and Verification, 1 edition
Authors: Albert M. K. Cheng
Venue:  (2002)

:A complete guide to testing, analyzing, verifying, and monitoring real-time systemsMore and more of our modern-day systems and devices-from toasters and climate-control systems to airplanes and space shuttles-contain embedded systems to control their functions and ensure that their responses are both timely and correct. With safety a requisite factor, performance validation is a critical aspect of real-time systems. Answering the needs of professionals and students alike, Real-Time Systems: Scheduling, Analysis, and Verification provides a substantial, up-to-date overview of the verification and validation process. It describes several approaches to the problem, and examines the advantages and disadvantages of each approach.Designed to be both an introductory text and a handy reference for the practitioner, the book discusses:Symbolic logic, automata, and languages in non-real-time systemsReal-time scheduling and schedulability analysisVerification using timed automata and timed petri netsProcess algebraThe design and analysis of propositional-logic rule-based systemsTiming analysis of predicate-logic rule-based systemsOptimization of rule-based systemsModel checking, real-time logic, and statechartsWith ample illustrations and examples of a variety of industrial and toy applications, Real-Time Systems: Scheduling, Analysis, and Verification serves as a key resource for every professional who works with real-time systems.
Dependability of fault-tolerant systems-explicit modeling of the interactions between hardware and software components
Authors: K. Kanoun, M. Borrel
Venue: Proceedings of the 2nd International Computer Performance and Dependability Symposium (IPDS '96) (1996)

This paper addresses the dependability modeling of hardware and software fault-tolerant systems taking into account explicitly the interactions between the various components. It presents a framework for modeling these interactions based on Generalized Stochastic Petri Nets (GSPNs). The modeling approach is modular: the behavior of each component and each interaction is represented by its own GSPN, while the system model is obtained by composition of these GSPNs. The composition rules are defined and formalized through clear identification of the interfaces between the component and the dependency nets. In addition to modularity, the formalism brings flexibility and re-usability. This approach is applied to a simple, but still representative, example.
Factorizable schemes for the equations of fluid flow
Authors: David Sidilkover
Venue: Applied Numerical Mathematics (2002)

We present an upwind high-resolution factorizable (UHF) discrete scheme for the compressible Euler equations. The scheme approximates equations in their general conservative form and is related to the family of genuinely multidimensional upwind schemes developed previously and demonstrated to have good shockcapturing capabilities. A unique property of this scheme is that in addition to the aforementioned features it is also factorizable, i.e., it allows to distinguish between full-potential and advection factors at the discrete level. The latter property facilitates the construction of optimally efficient multigrid solvers. This is done through a relaxation procedure that utilizes the factorizability property.
Fixed Points in Spectral Complexity
Authors: Sean W. Smith, Carl Sturtivant
Venue:  (1992)

Spectral analysis has emerged as an exciting tool in complexity research. In some cases, the functions in a complexity class can be characterized by specifying a simple property of their Fourier spectra--even though their truth tables do not display such simple properties. In this paper, we demonstrate a fundamental limitation of this tool: if a class of functions contains parity and is closed under some simple composition rules, then we can take the set of Fourier spectra of a subset of the class, close it under some simple projections, and obtain everything in the original class. Indeed, we can demonstrate this property for a general family of transforms, of which the parity-based Fourier transform is only one. If a class contains the basis function of such a transform, then no reduction in complexity is obtained when we shift from truth tables to spectra.