ppxscal/embedding_network huggingface dataset:
Formal Linear Algebra Methods Environment (FLAME) Overview
Authors: John A. Gunnels, Robert A. van de Geijn
Venue:  (2000)

Since the advent of high-performance distributed-memory parallel computing, the need for intelligible code has become ever greater. The development and maintenance of libraries for these architectures is simply too complex to be amenable to conventional approaches to coding and attempting to employ traditional methodology has led to the production of an abundance of inefficient, anfractuous code that is difficult to maintain and nigh-impossible to upgrade. Having struggled with these issues for more than a decade, we have arrived at a conclusion that is somewhat surprising to us: the answer is to apply formal methods from Computer Science to the development of high-performance linear algebra libraries. The resulting approach has consistently resulted in aesthetically-pleasing, coherent code that greatly facilitates performance analysis, intelligent modularity, and the enforcement of program correctness via assertions. Since the technique is completely language-independent, it lends itself equally well to a wide spectrum of programming languages (and paradigms) ranging from C and FORTRAN to C++ and Java to graphical programming languages like those used for LabView. In this paper, we illustrate our observations by looking at the development of the Formal Linear Algebra Methods Environment (FLAME) for implementing linear algebra algorithms on sequential architectures. This environment demonstrates that lessons learned in the distributed memory world can guide us toward better approaches to coding even in the sequential world.
WAVE SPREADING EVALUATION OF INTERCONNECT SYSTEMS
Authors: Haifang Liao, Wayne W Dai
Venue:  (1992)

With continual progress in integrated circuit processing, operating speeds and new technologies are emerging. The accurate high frequency analysis is needed to design the high performance system. This paper derives general multiport interconnect constraints and presents a new approach -- Wave Spreading Evaluation (WSE) which uses S-parameters based network techniques to analyze coupled, multiconductor, high speed analog and digital integrated circuit interconnect systems. WSE is based on the spreading process of voltage waves, the input sources are transformed into initial spreading waves. The spreading process is independent of input sources, and every step of wave spreading meets the constraints of KCL and KVL, the convergence condition is always met for passives network. The continual spreading of voltage waves will create accurate results.
Access Control and Signatures via Quorum Secret Sharing
Authors: M. Naor, A. Wool
Venue:  (1995)

We suggest a method of controlling the access to a secure database via quorum systems. A quorum system is a collection of sets (quorums) every two of which have a nonempty intersection. Quorum systems have been used for a number of applications in the area of distributed systems. We propose a separation between access servers which are protected and trustworthy, but may be outdated, and the data servers which may all be compromised. The main paradigm is that only the servers in a complete quorum can collectively grant (or revoke) access permission. The method we suggest ensures that after authorization is revoked, a cheating user Alice will not be able to access the data even if many access servers still consider her authorized, and even if the complete raw database is available to her. The method has a low overhead in terms of communication and computation. It can also be converted into a distributed system for issuing secure signatures.
Storage of fuzzy information in continuous classifying associative memories
Authors: Antonio B. Bailón, Miguel Delgado, Waldo Fajardo
Venue: Enterprise information systems IV (2003)

In this paper, we analyze the use of the Continuous Classifying Associative Memory (CCLAM) to store imprecise information expressed with linguistic terms. Freedom in the choice of the functions which control the operation of the CCLAM equip this memory with the capacity to adapt to different information storage and recovery needs. We begin with the problem of storing linguistic terms by memorizing the patterns formed by the degrees of compatibility with these terms. This will allow the use of CCLAM to compute the firing strength of rules whose antecedent is expressed in linguistic terms. After that, the problem of storing Mamdani and TSK rules is discussed.
DECISIONS IN DIRECT VOLUME RENDERING
Authors: Jane Wilhelms
Venue:  (1991)

There are a great range of possible choices to make in rendering volumetric data. The choices can make a difference in time and space requirements, ease of implementation, and the nature of the final image. Some make an objectifiable difference in image quality, e.g. causing aliasing and incorrect discontinuities and holes. Others cause more subjective variations, and the desired effect is more a matter of personal choice than inaccurate information content. The repercussions of the many choices should be examined before choosing or designing software. What follows is a rather preliminary and subjective discussion of the issues that need to be examined. It certainly isn''t complete, but hopefully will stimulate discussion. Most of the discussion concentrates on direct volume rendering, where approaches are especially flexible. Occasional mention is made of methods that extract features such as isosurfaces to produce geometrical representations.
Task Mapping Model (TMM) Analysis Manual
Authors: Kevin A. Mayo
Venue:  (1993)

This guide presents the task mapping model (TMM), a snythesis/analysis methodology for aiding the interface specialist in designing interfaces with better usability. Briefly, TMM describes necessary knowledge for user task completion, and analyzes if this knowledge is supported by the user or interface. This framework consists of various abstract levels of task decomposition and description. TMM focuses on the mappings users make among domains (during task performance) to provide designers with specific information about task structure and user knowledge requirements. This model allows descriptions of tasks using hierarchical decomposition coupled with abstraction of user knowledge requirements.
A Geometric Interpretation of Hidden Markov Model
Authors: Chee W Loke, Roberto Togneri
Venue:  (1994)

In this paper, we investigate the relationship between speech trajectories and the hidden Markov model. The speech utterances were transformed into speech feature vectors and the trajectories displayed on a two dimensional space. The hidden Markov models were also displayed on a two dimensional space. By visual examination, we think that the states seem to be associated with a distinct phoneme of the utterance. Therefore, the number of states required in the contonuous HMM is related to the number of phonemes in the word to be modelled. In the semi-continuous HMM, it is also possible that the same gaussian probability density function is shared by the same phoneme sound in different semi-continuous HMMs.
Increasing the Computational Potential of the World Wide Web
Authors: S. D. Reilly, J. L. Pfaltz, J. C. French
Venue:  (1996)

For many World Wide Web applications there is a need to provide session semantics so that users have the impression of a continuous interaction. This is true, for example, when one searches a database interactively. Because WWW servers are stateless some extra mechanism is necessary to give the impression of session semantics. This report discusses a strategy for implementing session semantics over a WWW application. Apart from the need to maintain state during interactive sessions, there is also the need to control the application. Under any circumstances this is a tedious activity. This report also discusses a mechanism for modeling a WWW application as a finite state automaton and describes a tool, the Stateful Server Application Tool (SSAT), built to assist in the development of these applications.
The Viterbi Algorithm
Authors: Matthew S. Ryan, Graham R. Nudd
Venue:  (1993)

This paper is a tutorial introduction to the Viterbi Algorithm, this is reinforced by an example use of the Viterbi Algorithm in the area of error correction in communications channels. Some extensions to the basic algorithm are also discussed briefly. Some of the many application areas where the Viterbi Algorithm has been used are considered, including it''s use in communications. target tracking and pattern recognition problems. A proposal for further research into the use of the Viterbi Algorithm in Signature Verification is then presented, and is the area of present research at the moment.
On the Automatic generation of Higher Levels of Description
Authors: Mike Alder, Christopher J.S. deSilva, Yianni Attikiouzel
Venue:  (1990)

Human beings use many levels of description of events and entities. For example, one may specify, in principle, the sequence of hand and arm states that drive a pen over a piece of paper, or may say ''he signed a cheque''. These may be alternative descriptions, of use to dfferent people, eg roboticists and bank managers, of the same event. More fundamentally, in learning to drive a car, for example, one aquires the skills by acquiring a collection of subskills and learning how to sequence them. At the lowest level, one learns the co-ordinated sequence of muscle movements that result in changing gear from fourth to third. At a higher level one learns to turn left. Parallel to the levels of descriptions, there are levels of acquisitons of the skills.
Protocol Specification in Concurrent Systems Software Development
Authors: W. M. Beynon, M. Slade, Y. P. Yung
Venue:  (1990)

A protocol specification technique that relates concurrent system behaviour to agent activity and interaction at a high level of abstraction is described. This exploits a concurrent programming technique based on a synthesis of two new programming paradigms: "agent-oriented" and "definition-based" programming. Application of the method to modelling and simulation activity at a railway station is described. Its potential for concurrent systems software requirements specification is assessed.
A Multi-Scale Algorithm for Drawing Graphs Nicely
Authors: R. Hadany, D. Harel
Venue:  (1999)

We describe a multi-scale approach to the problem of drawing undirected straight-line graphs ``nicely". In contrast to conventional global/dynamic algorithms, we employ increasingly coarser-scale representations of the graph, together with a simple local organization scheme, without imposing formal criteria on the quality of the picture at large. Our algorithm can deal easily with very large graphs; some of our examples contain over 1000 vertices.
Architectural Approaches to Information Survivability
Authors: John C. Knight, Raymond W. Lubinsky, John McHugh, Kevin J. Sullivan
Venue:  (1997)

Many large information systems have evolved to a point where the normal activities of society depend upon their continued operation. Significant concerns have been raised about the possible effects of failure in these systems. In this paper we discuss architectural approaches to improving the survivability of critical information systems and present a candidate architecture. The key features of the architecture are the use of a variety of shell structures (sometimes also known as wrappers) and the use of a network-wide approach to recovery and continued service. We discuss the design, implementation, and verification issues raised by the use of shells in complex distributed systems and introduce three types of shell: protection, enhancement, and correction. Combinations of these shells are used to ensure that the critical information system is protected against a wide variety of hazards ranging from software defects to malicious attacks. The implementation of shells is discussed and it is shown that the desirable characteristic of transparent implementation cannot generally be achieved, and that ensuring the correct operation of the shells is itself a significant issue. A demonstration system being developed for evaluation of the architectural concepts is presented.
Hurwitz Interconnect Delay Evaluation - HIDE: Programmer''s Manual
Authors: Zhanhai Qin, Chung Cheng
Venue:  (2000)

This is a programmer''s manual of HIDE, Hurwitz Interconnect Delay Evaluation package.
Explorations of Shape Space
Authors: F. Cutzu, S. Edelman
Venue:  (1995)

Using a small number of prototypical reference objects to span the internal shape representation space has been suggested as a general approach to the problem of object representation in vision (Edelman, 1995c). We have investigated the ability of human subjects to form the low-dimensional metric shape representation space predicted by this approach. In each of a series of experiments, which involved pairwise similarity judgement, and delayed match to sample, subjects were confronted with several classes of computer-rendered 3D animal-like shapes, arranged in a complex pattern in a common high-dimensional parameter space. We combined response time and error data into a measure of view similarity, and submitted the resulting proximity matrix to non metric multidimensional scaling (MDS). In the two-dimensional MDS solution, views of the same shape were invariably clustered together, and, in each experiment, the relative geometrical arrangement of the view clusters of the different objects reflected the true low-dimensional structure in a parameter space (star, triangle, square, line) that defined the relationships between the stimuli classes. These findings are now used to guide the development of a detailed computational theory of shape vision based on similarity to prototypes.
Using Reflection for Incorporating Fault-Tolerance Techniques into Distributed Applications
Authors: Anh Nguyen-Tuong, Andrew S. Grimshaw
Venue:  (1998)

As part of the Legion metacomputing project, we have developed a reflective model, the Reflective Graph & Event (RGE) model, for incorporating functionality into applications. In this paper we apply the RGE model to the problem of making applications more robust to failure. RGE encourages system developers to express fault-tolerance algorithms in terms of transformations on the data structures that represent computations--messages and methods--hence enabling the construction of generic and reusable fault-tolerance components. We illustrate the expressive power of the RGE by encapsulating the following fault-tolerance techniques into RGE components: two-phase commit distributed checkpointing, passive replication, pessimistic method logging, and forward recovery.
Surface Fitting with Hierarchical Splines
Authors: David R. Forsey, Richard H. Bartels
Venue:  (1995)

We consider the fitting of tensor product parametric spline surfaces to gridded data. The continuity of the surface is provided by the basis chosen. When tensor product splines are used with gridded data, the surface fitting problem decomposes into a sequence of curve fitting processes, making the computations particularly efficient. The use of a hierarchical representation for the surface adds further efficiency by adaptively decomposing the fitting process into subproblems involving only a portion of the data. Hierarchy also provides a means of storing the resulting surface in a compressed format. Our approach is compared to multiresolution analysis and the use of wavelets.
Model Checking with Strong Fairness,
Authors: Y. Kesten, A. Pnueli, L. Raviv, E. Shahar
Venue:  (2001)

In this paper we present a coherent framework for symbolic model checking of linear-time temporal logic (LTL) properties over finite state reactive systems, taking full fairness constraints into consideration. We use the computational model of a fair discrete system (FDS) which takes into account both justice (weak fairness) and compassion (strong fairness). The approach presented here reduces the model checking problem into the question of whether a given FDS is feasible (i.e. has at least one computation). The contribution of the paper is twofold: On the methodological level, it presents a direct self-contained exposition of full LTL symbolic model checking without resorting to reductions to either CTL or automata. On the technical level, it extends previous methods by dealing with compassion at the algorithmic level instead of adding it to the specification, and providing the first symbolic method for checking feasibility of FDS''s (equivalently, symbolically checking for the emptiness of Streett automata), based on the Emerson-Lei fixpoint characterization of both weak and strong fairness. Finally, we extend CTL* with past operators, and show that the basic symbolic feasibility algorithm presented here, can be used to model check an arbitrary CTL* formula over an FDS with full fairness constraints.
Block-Projections Algorithms with Blocks Containing Mutually Orthogonal Rows and Columns
Authors: C. Popa
Venue:  (1997)

In this paper we present an algorithm which, for a given (sparse) matrix, constructs a partition of its set of row-indices,such that each subset of this partition (without the last one obtained) contains indices which correspond to mutually orthogonal rows. We then used such decompositions in some classes of well-known block-projections methods (see [1]-[7] and references there) extended by the author in [8]. Numerical experiments on an inconsistent and rank-deficient least-squares model problem,are described in the last section of the paper. 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
PERFORMANCE OF TCP OVER MULTI-HOP ATM NETWORKS: A COMPARATIVE STUDY OF ATM-LAYER CONGESTION CONTROL SCHEMES
Authors: Lampros Kalampoukas, Anujan Varma
Venue:  (1995)

We study the performance of TCP/IP on a multi-hop ATM network by simulation in an effort to evaluate the effectiveness of various congestion-control schemes at the ATM layer. The congestion control schemes considered are the ATM-Early Packet Discard (ATM-EPD) and link-level flow control. The performance of these schemes are compared against that of an ATM layer with no congestion control, as well as TCP/IP over a datagram network. We compare the schemes in terms of the throughputs obtained by long and short connections, number of retransmissions, end-to-end delays, and fairness in bandwidth allocation between connections with unequal round-trip delays. Our results show that significant unfairness in the amount of bandwidth allocated to connections may result in a large ATM network if no congestion control policies are used at the ATM layer. The ATM-EPD scheme is able to remove some of the unfairness, providing performance close to that of a datagram network, but can still provide unacceptable performance if the buffer sizes in the switches are small. Link-level flow control provided the best performance among the schemes studied.
An Interactive Environment For Tool Selection, Specification and Composition
Authors: James D. Arthur
Venue:  (1986)

This paper describes a high-level, screen oriented programming environment that supports problem solving by tool selection and tool composition. Each tool is a powerful parameterized program that performs a single high-level operation (e.g., sort a file). To solve a given problem, the user first interacts with the system to compose a task overview consisting of a sequence of generic operations. Such sequences are called compositions. Once an overview is established, a second part of the environment interacts with the user to help expand the generic operations into a corresponding sequence of parameterized tool calls. When a composition is expanded to include details such as parameterization and punctuation it is called a script. This script, when executed by the underlying runtime system, computes a solution to the specified user task. The current environment runs under the Unix operating system on a VAX 11/785, and uses a Bitgraph terminal with a 640x720 bitmap display and standard keyboard as the principal interface device. 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
Stochastic Local Search Methods for Dynamic SAT- an Initial Investigation
Authors: Holger H. Hoos, Kevin O''Neill
Venue:  (2000)

We introduce the dynamic SAT problem, a generalisation of the satisfiability problem in propositional logic which allows changes of a problem over time. DynSAT can be seen as a particular form of a dynamic CSP, but considering results and recent success in solving conventional SAT problems, we believe that the conceptual simplicity of SAT will allow us to more easily devise and investigate high-performing algorithms for DynSAT than for dynamic CSPs. In this article, we motivate the DynSAT problem, discuss various formalisations of it, and investigate stochastic local search (SLS) algorithms for solving it. In particular, we apply SLS algorithms which perform well on conventional SAT problems to dynamic problems and we analyse and characterise their performance empirically; this initial investigation indicates that the performance differences between various algorithms of the well-known WalkSAT family of SAT algorithms generally carry over when applied to DynSAT. We also study different generic approaches of solving DynSAT problems using SLS algorithms and investigate their performance differences when applied to different types of DynSAT problems.
Analytical solutions for uniaxial bending design of reinforced concrete T cross sections according to the eurocode 2 standard
Authors: M. Skrinar
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

The paper considers the uniaxial bending analysis of reinforcement concrete T cross sections. Due to a discrete change in the width of the web section caused by the flanges the analysis procedures for T cross sections essentially deviate from the analysis of a rectangular cross section. The paper considers all possible locations of the neutral axis implementing the most detailed design stress-strain relationship for the concrete: the parabola-rectangular diagram. For all five cases that appear according to the position of the neutral axis, the paper presents the development of the analytical expressions for coefficients αR and ka that are necessary for the computation of the required cross section of the reinforcements As1.
Simulation in a Theory of Programmable Machines
Authors: J. L. Baker
Venue:  (1977)

In a theory of machines controlled by programs, automata-theoretic simulation can be presented simply and directly, and can be understood as an aspect of the algebraic structure of such machines. Here the notions of product and homomorphism of devices in such a theory are presented, along with a notion of (computational) reducibility of one device to another. Simulation in the automata-theoretic sense is formally defined, and its validity as a technique for proving reducibility established uniformly. The notions of device, product, homomorphism, and reducibility are then extended to model costs of computation evaluated a posteriori (in the manner of concrete complexity studies), and the validity of simulation as a proof technique established in this extended setting. 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