ppxscal/embedding_network huggingface dataset:
Two issues in reservation establishment
Authors: Scott Shenker, Lee Breslau
Venue: Proceedings of the conference on Applications, technologies, architectures, and protocols for computer communication (1995)

This paper addresses two issues related to resource reservation establishment in packet switched networks offering real-time services. The first issue arises out of the natural tension between the local nature of reservations (i.e., they control the service provided on a particular link) and the end-to-end nature of application service requirements. How do reservation establishment protocols enable applications to receive their desired end-to-end service? We review the current one-pass and two-pass approaches, and then propose a new hybrid approach called one-pass-with-advertising. The second issue in reservation establishment we consider arises from the inevitable heterogeneity in network router capabilities. Some routers and subnets in the Internet will support real-time services and others, such as ethernets, will not. How can a reservation establishment mechanism enable applications to achieve the end-to-end service they desire in the face of this heterogeneity? We propose an approach involving replacement services and advertising to build end-to-end service out of heterogeneous per-link service offerings.
A query language and optimization techniques for unstructured data
Authors: Peter Buneman, Susan Davidson, Gerd Hillebrand, Dan Suciu
Venue: Proceedings of the 1996 ACM SIGMOD international conference on Management of data (1996)

A new kind of data model has recently emerged in which the database is not constrained by a conventional schema. Systems like ACeDB, which has become very popular with biologists, and the recent Tsimmis proposal for data integration organize data in tree-like structures whose components can be used equally well to represent sets and tuples. Such structures allow great flexibility y in data representation.What query language is appropriate for such structures? Here we propose a simple language UnQL for querying data organized as a rooted, edge-labeled graph. In this model, relational data may be represented as fixed-depth trees, and on such trees UnQL is equivalent to the relational algebra. The novelty of UnQL consists in its programming constructs for arbitrarily deep data and for cyclic structures. While strictly more powerful than query languages with path expressions like XSQL, UnQL can still be efficiently evaluated. We describe new optimization techniques for the deep or "vertical" dimension of UnQL queries. Furthermore, we show that known optimization techniques for operators on flat relations apply to the "horizontal" dimension of UnQL.
Technology mapping for field-programmable gate arrays using integer programming
Authors: Amit Chowdhary, John P. Hayes
Venue: Proceedings of the 1995 IEEE/ACM international conference on Computer-aided design (1995)

We show that the FPGA technology mapping problem can be efficiently implemented as a mixed integer linear programming (MILP) problem which generates truly optimal mappings. The MILP approach can handle a wide variety of FPGA logic block architectures. We present a compact MILP formulation for logic blocks based on lookup tables (LUTs) multiplexers. We also show that the MILP formulation can be easily modified to modified to optimize area, delay, or a combination of both. We demonstrate that moderately large benchmark circuits can be mapped in a reasonable time using the MILP approach directly. For larger circuits, we propose a technique of partitioning a circuit prior to mapping, which drastically reduces the computation time with little or no loss in optimality.
Adaptive Fault-Tolerant Deadlock-Free Routing in Meshes and Hypercubes
Authors: Chien-Chun Su, Kang G. Shin
Venue: IEEE Transactions on Computers (1996)

We present an adaptive deadlock-free routing algorithm which decomposes a given network into two virtual interconnection networks, VIN1 and VIN2. VIN1 supports deterministic deadlock-free routing, and VIN2 supports fully-adaptive routing. Whenever a channel in VIN1 or VIN2 is available, it can be used to route a message.Each node is identified to be in one of three states: safe, unsafe, and faulty. The unsafe state is used for deadlock-free routing, and an unsafe node can still send and receive messages. When nodes become faulty/unsafe, some channels in VIN2 around the faulty/unsafe nodes are used as the detours of those channels in VIN1 passing through the faulty/unsafe nodes, i.e., the adaptability in VIN2 is transformed to support fault-tolerant deadlock-free routing. Using information on the state of each node's neighbors, we have developed an adaptive fault-tolerant deadlock-free routing scheme for n-dimensional meshes and hypercubes with only two virtual channels per physical link.In an n-dimensional hypercube, any pattern of faulty nodes can be tolerated as long as the number of faulty nodes is no more than $\lceil\, n/2 \,\rceil$. The maximum number of faulty nodes that can be tolerated is 2n¿1, which occurs when all faulty nodes can be encompassed in an (n¿ 1)-cube. In an n-dimensional mesh, we use a more general fault model, called a disconnected rectangular block. Any arbitrary pattern of faulty nodes can be modeled as a rectangular block after finding both unsafe and disabled nodes (which are then treated as faulty nodes). This concept can also be applied to k-ary n-cubes with four virtual channels, two in VIN1 and the other two in VIN2. Finally, we present simulation results for both hypercubes and 2-dimensional meshes by using various workloads and fault patterns.
Impulse response fault model and fault extraction for functional level analog circuit diagnosis
Authors: Chauchin Su, Shenshung Chiang, Shyh-Jye Jou
Venue: Proceedings of the 1995 IEEE/ACM international conference on Computer-aided design (1995)

In this paper, a functional fault model for analog circuit diagnosis is proposed. A faulty module is modeled as a fault-free module in serial or in parallel with a fault module. To extract such a fault module, we adopt an iterative deconvolution technique to deconvolute the impulse response of the fault module from the faulty response. The test results show that with such a fault model and fault extraction technique the diagnostic resolution is improved significantly due to the separation of the fault and the system function. Moreover, such a fault model allows single-module fault tables to be applied to the diagnosis of a multi-module system.
Educational technology and artificial intelligence: a convenient marriage for interactive instructional systems
Authors: Simon C.-H. Wong
Venue: ACM SIGCUE Outlook (1995)

This paper presents an overview on the evolution of educational technology and its impact on interactive instructional systems design; and the development of artificial intelligence techniques for building intelligent tutoring systems. Furthermore, the new potentialities for interactive instructional systems offered by the marriage of modern educational technology and artificial intelligence models are identified.
A study of integrated prefetching and caching strategies
Authors: Pei Cao, Edward W. Felten, Anna R. Karlin, Kai Li
Venue: Proceedings of the 1995 ACM SIGMETRICS joint international conference on Measurement and modeling of computer systems (1995)

Prefetching and caching are effective techniques for improving the performance of file systems, but they have not been studied in an integrated fashion. This paper proposes four properties that optimal integrated strategies for prefetching and caching must satisfy, and then presents and studies two such integrated strategies, called aggressive and conservative. We prove that the performance of the conservative approach is within a factor of two of optimal and that the performance of the aggressive strategy is a factor significantly less than twice that of the optimal case. We have evaluated these two approaches by trace-driven simulation with a collection of file access traces. Our results show that the two integrated prefetching and caching strategies are indeed close to optimal and that these strategies can reduce the running time of applications by up to 50%.
Synthesis of multiplier-less FIR filters with minimum number of additions
Authors: Mahesh Mehendale, S. D. Sherlekar, G. Venkatesh
Venue: Proceedings of the 1995 IEEE/ACM international conference on Computer-aided design (1995)

Abstract: In this paper we present optimizing transformations to minimize the number of additions+subtractions in both the direct form (/spl Sigma/ A/sub i/X/sub n-i/ based) and its transposed form (Multiple Constant Multiplication based) implementation of FIR filters. These transformations are based on the iterative elimination of 2-bit common subexpressions in the coefficients binary representations. We give detailed description of the algorithms and present results for eight low pass FIR filters with the number of coefficients ranging from 16 to 128. The results show upto 35% reduction in the number of additions+subtractions to implement /spl Sigma/ A/sub i/X/sub n-i/ based FIR filter structures and upto 38% reduction to implement MCM based structures.
SimSelect: a system for simulation software selection
Authors: Vlatka Hlupic, Amardeep Singh Mann
Venue: Proceedings of the 27th conference on Winter simulation (1995)

SimSelect is a system developed for the purpose of providing support for users when selecting simulation software. SimSelect consists of a database which is linked to an interface developed using Visual Basic 3.0. The system queries a database and finds a simulation package suitable to the user, based on requirements which have been specified. It also provides a recommendation of alternative packages suitable to the user, and allows prioritisation of requirements in levels of importance. This paper provides an insight into the development of SimSelect, in addition to the reasoning behind the system.
Integration approaches for CIM
Authors: Moira C. Norrie
Venue: Proceedings of the 1995 ACM SIGMOD international conference on Management of data (1995)

In response to pressures to reduce product lead times, manufacturing companies are increasingly aware of the need for some form of integration along the whole product chain. Engineering tasks must be coordinated and data exchanged between the various specialised tools. An enterprise has two main tracks of information flow, namely technical and managerial, and product data management spans both tracks. On the technical track, applications are highly specialised supporting tasks such as product design (CAD) and the programming of numerically controlled machines (CAM). Generally, the various application systems on the technical track are referred to as CAx systems. CAx systems may not only differ in terms of functionality but also in terms of the amount and type of data managed, the run-time environment and performance characteristics. For complete support of Computer Integrated Manufacturing (CIM), we must be able to integrate existing technical and administrative component application systems. These component systems vary in their data management support and many CAx systems store their data directly in files rather than in a database system. The issues are how to describe the dependencies between these component systems and ensure system-wide data consistency. A particularly difficult problem is that of how to interface existing application systems in such a way that their operation can be monitored and controlled and a global transaction scheme provided. Integration must be achieved in a way that supports system evolution in terms of the introduction and replacement of application systems. This is particularly important given the trend towards the notions of the extended enterprise and virtual factories in which a particular product chain may span several enterprises. Further, emerging legal statutes (especially in relation to environmental factors) are resulting in changes to the requirements for product data management. Enterprise integration must be both flexible and dynamic. The best way of achieving this is to integrate component systems by mans of a control layer which coordinates tasks based on explicit inter-system dependencies amenable to both direct view and update. Product Data Management systems (also known as Engineering Databases) have been developed for the integration of CAx systems by managing product data centrally. One problem with a centralised system controlling access to data is that its availability is critical to the operation of all component systems. In an effort to overcome this, systems are being developed which replicate the metadata and data required for coordination. Alternatively, coordination approaches have been proposed which aim to maximise component subsystem autonomy and increase CIM system flexibility. These systems place less emphasis on data sharing and more emphasis on task coordination. The integration effort is minimised and only that information strictly essential to coordination is managed centrally.
Teaching introductory AI from first principles
Authors: Susan L. Epstein, Virginia Teller
Venue: ACM SIGART Bulletin (1995)

Hunter College teaches introductory AI as a one semester, advanced undergraduate elective that focuses on issues in three areas: state-space search and control, knowledge representation, and Lisp. The search component defines AI methodology and conveys how the computing world views the field; knowledge representation illustrates how AI sees the real world; and Lisp shows how to make AI happen. The history and format of the course as it has evolved over a period of fifteen years is covered, along with a description of the course content today and a rationale for teaching AI from this perspective.
Expected deadlock time in a multiprocessing system
Authors: Kevin J. Compton, Chinya Ravishankar
Venue: Journal of the ACM (JACM) (1995)

We consider multiprocessing systems where processes make independent, Poisson distributed resource requests with mean arrival time 1. We assume that resources are not released. It is shown that the expected deadlock time is never less than 1, no matter how many processes and resources are in the system. Also, the expected number of processes blocked by deadlock time is one-half more than half the number of initially active processes. We obtain expressions for system statistics such as expected deadlock time, expected total processing time, and system efficiency, in terms of Abel sums. We derive asymptotic expressions for these statistics in the case of systems with many processes and the case of systems with a fixed number of processes. In the latter, generalizations of the Ramanujan Q-function arise. we use singularity analysis to obtain asymptotics of coefficients of generalized Q-functions.
Branching time and abstraction in bisimulation semantics
Authors: Rob J. van Glabbeek, W. Peter Weijland
Venue: Journal of the ACM (JACM) (1996)

In comparative concurrency semantics, one usually distinguishes between linear time and branching time semantic equivalences. Milner's notion of observatin equivalence is often mentioned as the standard example of a branching time equivalence. In this paper we investigate whether observation equivalence really does respect the branching structure of processes, and find that in the presence of the unobservable action &tgr; of CCS this is not the case.Therefore, the notion of branching bisimulation equivalence is introduced which strongly preserves the branching structure of processes, in the sense that it preserves computations together with the potentials in all intermediate states that are passed through, even if silent moves are involved. On closed CCS-terms branching bisimulation congruence can be completely axiomatized by the single axion scheme: a.(&tgr;.(y+z)+y)=a.(y+z) (where a ranges over all actions) and the usual loaws for strong congruence.We also establish that for sequential processes observation equivalence is not preserved under refinement of actions, whereas branching bisimulation is.For a large class of processes, it turns out that branching bisimulation and observation equivalence are the same. As far as we know, all protocols that have been verified in the setting of observation equivalence happen to fit in this class, and hence are also valid in the stronger setting of branching bisimulation equivalence.
Linear-time suffix parsing for deterministic languages
Authors: Mark-Jan Nederhof, Eberhard Bertsch
Venue: Journal of the ACM (JACM) (1996)

We present a linear-time algorithm to decide for any fixed deterministic context-free language L and input string w whether wis a suffix of some string in L. In contrast to a previously published technique, the decision procedure may be extended to produce syntactic structures (parses) without an increase in time complexity. We also show how this algorithm may be applied to pocess incorrect input in linear time.
Solution of Vandermonde-like Systems and Confluent Vandermonde-like Systems
Authors: Hao Lu
Venue: SIAM Journal on Matrix Analysis and Applications (1996)

It is shown that the solution of Vandermonde-like systems and the solution of confluent Vandermonde-like systems can be obtained by evaluation of certain polynomials and Hermite evaluation of certain rational functions in terms of a J-match of polynomials, respectively. Based on these results, the existence of an $O(n \log ^{2} n)$ algorithm is shown for both Vandermonde-like systems and confluent Vandermonde-like systems for the case where the polynomials satisfy a three-term recurrence relation.
pHluid: the design of a parallel functional language implementation on workstations
Authors: Cormac Flanagan, Rishiyur S. Nikhil
Venue: ACM SIGPLAN Notices (1996)

This paper describes the distributed memory implementation of a shared memory parallel functional language. The language is Id, an implicitly parallel, mostly functional language that is currently evolving into a dialect of Haskell. The target is a distributed memory machine, because we expect these to be the most widely available parallel platforms in the future. The difficult problem is to bridge the gap between the shared memory language model and the distributed memory machine model. The language model assumes that all data is uniformly accessible, whereas the machine has a severe memory hierarchy: a processor's access to remote memory (using explicit communication) is orders of magnitude slower than its access to local memory. Thus, avoiding communication is crucial for good performance. The Id language, and its general dataflow-inspierd compilation to multithreaded code are described elsewhere. In this paper, we focus on our new parallel runtime system and its features for avoiding communication and for tolerating its latency when necessary: multithreading, scheduling and load balancing; the distributed heap model and distributed coherent cacheing, and parallel garbage collection. We have completed the first implementation, and we present some preliminary performance mearsurements.
Generating gamma variates
Authors: Do Le Minh
Venue: ACM Transactions on Mathematical Software (TOMS) (1988)

An algorithm to generate variates having a gamma distribution with shape parameter greater than one is presented in this paper. This algorithm is faster than Schmeiser and Lal's G4PE, which is the fastest one currently available, yet is equally simple and easy to implement.
Formal specification of reusable interface objects
Authors: P. S. C. Alencar, D. D. Cowan, C. J. P. Lucena, L. C. M. Nova
Venue: ACM SIGSOFT Software Engineering Notes (1995)

In this paper we present a formal approach of a new object-oriented design concept to support reuse-in-the-large called Abstract Data Views (ADVs). The ADV approach was created to specify clearly and formally the separation of interfaces from the application components of a software system. Such an approach should lead to high degree of reuse of designs for both interface and application components. Our specification framework is based on descriptive schemas for both ADVs and ADOs, that are the basic building blocks for the system specification, design, and implemention using the ADV approach. These schemas describe the structural, static, and dynanmic features of each system object, and include the specification of the concurrent operation of system components. Additionally, such schemas can be seen as an underlying structure to support the development of a specification language that describes the interconnection between interface and application components.
Bounding errors introduced by clustering of customers in closed product-form queuing networks
Authors: William C. Cheng, Richard R. Muntz
Venue: Journal of the ACM (JACM) (1996)

Product-form queuing network models have been widely used to model systems with shared resources such as computer systems (both centralized and distributed), communication networks, and flexible manufacturing systems. Closed multichain product-form networks are inherently more difficult to analyze than open networks, due to the effect of normalization. Results in workload characterization for closed networks in the literature are often for networks having special structures and only specific performance measures have been considered.In this article, we drive certain properties (insensitivity of conditional state probability distributions and fractional-linearity of Markov reward functions) for a broad class of closed multichain product-form networks. These properties are derived using the most basic flow balance conditions of product-form networks. Then we show how these basic properties can be applied in obtaining error bounds when similar customers are clustered together to speed up computation.
Issues 94&mdash;public key&mdash;trials and tribulations
Authors: Harvey H. Rubinovitz
Venue: ACM SIGSAC Review (1995)

This document was written based on the introductory talk presented at the special workshop, "Issue 94 - Public Key - Trials and Tribulations" in conjunction with the Tenth Annual Computer Security Applications Conference held in December 1994. This document serves to set the stage for the papers which follow and to provide a catalyst to discussions at the conference. Applications which utilize public key technology to enhance security are just starting to emerge. Some applications are starting to use digital signatures to insure authenticity, integrity, and nonrepudiation between sender and receiver. There are applications which allow users to sign forms of Electronic Data Interchange (EDI) transactions digitally. A number of approaches to secure electronic mail such as privacy-enhanced E-mail (PEM) implementations, Pretty Good Privacy (PGP), and Message Security Protocol (MSP) have been defined. The focus of the workshop was to discuss the implementation, deployment, and management experiences of various applications utilizing Public Key systems. These topics are discussed briefly in this paper and are discussed in more detail in the additional papers which were presented at the special workshop.
Risk-Sensitive Production Planning of Stochastic Manufacturing Systems: A Singular Perturbation Approach
Authors: Qing Zhang
Venue: SIAM Journal on Control and Optimization (1995)

This paper is concerned with robust production planning of a stochastic manufacturing system in which the rate of machine breakdown and repair is much larger than the rate of fluctuation in demand. It is shown that the risk-sensitive production planning problem can be approximated by a limiting problem in which the stochastic machine availability process is replaced by its mean availability. The value function of the limiting problem is shown to be the only viscosity solution to the Isaacs equation associated with a zero-sum, two-player differential game. Near-optimal production plans are constructed from near-optimal controls of the limiting problem. Finally, these results are extended to problems with state constraints.