ppxscal/embedding_network huggingface dataset:
Low contention linearizable counting
Authors: Maurice Herlihy, Nir Shavit, Orli Waarts
Venue: Proceedings of the 32nd annual symposium on Foundations of computer science (1991)

The linearizable counting problem requires asynchronous concurrent processes to assign themselves successive values so that the order of the values assigned reflects the real-time order in which they were requested. It is shown that the problem can be solved without funneling all processes through a common memory location. Two new constructions for linearizable counting networks, data structures that solve the linearizable counting problem, are given. The first construction is nonblocking: some process takes a value after O(n) network gates have been traversed. The second construction is wait-free: it guarantees that each process takes a value after it traverses O(wn) gates, where w is a parameter affecting contention. It is shown that in any nonblocking or wait-free linearizable counting network, processes must traverse an average of Omega (n) gates, and so the constructions are close to optimal. A simpler and more efficient network is constructed by giving up the robustness requirements and allowing processes to wait for one another.
A new way to design causally and totally ordered multicast protocols
Authors: G. Florin C. Toinard
Venue: ACM SIGOPS Operating Systems Review (1992)

Multicast protocols must often provide a given property on the order in which messages are delivered. This delivery order may be consistent with local dependences between messages or with causal dependences. A local delivery is defined according to the emitting order observed at the same process source. A causal delivery is defined according to the causal relations observed between different emitting events. If an arbitrary delivery order is applied (when there are no particular dependences) the multicast is said to be totally ordered. In this paper we study totally and causally ordered multicast protocols i.e. multicast protocols that guarantee a total order conforming with the causal dependences. We propose a new method that begins to build a total order to obtain a causal and total multicast, when all current methods propose to build first a causal order then a total order (developed using the services of this causal layer).This new approach results from a formal study of ordering properties. In the first main result we show that a broadcast that guarantees a local and total order also provides a causal broadcast. Then we show that a multicast protocol that guarantees a local and a total order with additional constraints is also a causal and total multicast. This result makes no assumption about structure of overlapping groups. We finally develop the scheme of a multicast protocol using a centralized server of order. This solution is efficient in terms of messages and delay for a small number of sites. It allows all types of messages (unicast, multicast, broadcast) to mix while getting a causal and total ordering.
Asynchronous transfer of control and interrupt handling
Authors: Thomas J. Quiggle
Venue: Proceedings of the fourth international workshop on Real-time Ada issues (1990)

This is a summary of the discussions on two requirement areas: Asynchronous Transfer of Control Interrupt Handling
Continuous queries over append-only databases
Authors: Douglas Terry, David Goldberg, David Nichols, Brian Oki
Venue: Proceedings of the 1992 ACM SIGMOD international conference on Management of data (1992)

In a database to which data is continually added, users may wish to issue a permanent query and be notified whenever data matches the query. If such continuous queries examine only single records, this can be implemented by examining each record as it arrives. This is very efficient because only the incoming record needs to be scanned. This simple approach does not work for queries involving joins or time. The Tapestry system allows users to issue such queries over a database of mail and bulletin board messages. The user issues a static query, such as &ldquo;show me all messages that have been replied to by Jones,&rdquo; as though the database were fixed and unchanging. Tapestry converts the query into an incremental query that efficiently finds new matches to the original query as new messages are added to the database. This paper describes the techniques used in Tapestry, which do not depend on triggers and thus be implemented on any commercial database that supports SQL. Although Tapestry is designed for filtering mail and news messages, its techniques are applicable to any append-only database.
The impact of communication locality on large-scale multiprocessor performance
Authors: Kirk L. Johnson
Venue: Proceedings of the 19th annual international symposium on Computer architecture (1992)

As multiprocessor sizes scale and computer architects turn to interconnection networks with non-uniform communication latencies, the lure of exploiting communication locality to increase performance become inevitable. Models that accurately quantify locality effects provide invaluable insight into the importance of exploiting locality as machine sizes and features change. This paper presents a framework for modeling the impact of communication locality on system performance. The framework provides a means for combining simple models of application, processor, and network behavior to obtain a combined model that accurately reflects feedback effects between processors and networks. We introduce a model that characterizes application behavior with three parameters that capture computation grain, sensitivity to communication latency, and amount of locality present at execution time. The combined model, we show that exploiting communication locality provides gains which are at most linear in the factor by which average communication distance is reduced when the number of outstanding communication transactions per processor is bounded. The combined model is also used to obtain rough upper bounds on the performance improvement from exploiting locality to minimize communication distance.
On-line learning of rectangles
Authors: Zhixiang Chen, Wolfgang Maass
Venue: Proceedings of the fifth annual workshop on Computational learning theory (1992)

This paper solves the following open problem: Is there an algorithm for on-line learning of rectangles i=1d ai, ai+1,&hellip;,bi} over a discrete domain {1,&hellip;,n}d whose error bound is polylogarithmic in the size nd of the domain (i.e. polynomial in d and log n )? We give a positive solution by introducing a new design technique that appears to be of some interest on its own. The new learning algorithm for rectangles consists of 2d separate search strategies that search for the parameters a1,b1,&hellip;,ad,bd of the target rectangle. A learning algorithm with this type of modular design ends to fail because of the well known &ldquo;credit assignment problem&rdquo;: Which of the 2d local search strategies should be &ldquo;blamed&rdquo; when the global algorithm makes an error? We overcome this difficulty by employing local search strategies (&ldquo;error tolerant binary search&rdquo;) that are able to tolerate certain types of wrong credit assignments. Section 4 contains another application of this design technique: an algorithm for learning the union of two rectangles in the plane.
Interface design as a prosthesis for an individual with a brain injury
Authors: Elliot Cole, Parto Dehdashti
Venue: ACM SIGCHI Bulletin (1990)

This is a case study demonstrating how interface design was applied to make personal productivity software accessible and appropriate for an individual with learning disabilities from a head injury. Substantial customization was required, and nine months of data are presented.
Concentrated regular data streams on grids: sorting and routing near to the bisection bound
Authors: Manfred Kunde
Venue: Proceedings of the 32nd annual symposium on Foundations of computer science (1991)

Sorting and routing on r-dimensional n*. . .*n grids of processors is studied. Deterministic algorithms are presented for h-h problems, h>or=1, where each processor initially and finally contains h elements. It is shown that the classical 1-1 sorting can be solved with (2r-1.5)n+o(n) transport steps, i.e. in about 2.5n steps for r=2. The general h-h sorting problem, h>or=4r-4 can be solved within a number of transport steps that asymptotically differs by a factor of at most 3 from the trivial bisection bound. Furthermore, the bisection bound is asymptotically tight for sequences of h permutation routing problems, h=4cr, c>or=1, and for so-called offline routing.
Optimal Task Assignment in Linear Array Networks
Authors: Cheol-Hoon Lee, Dongmyun Lee, Myunghwan Kim
Venue: IEEE Transactions on Computers (1992)

The problem of assigning tasks to the processors of a distributed computing system such that the sum of execution and communication costs is minimized is discussed. This problem is known to be NP-complete in the general case, and thus intractable for systems with a large number of processors. H.S. Stone's (1977) network flow approach for a two-processor system is extended to the case for a linear array of any number of processors. The task assignment problem for a linear array network is first transformed into the two-terminal network flow problem, and then solved by applying the Goldberg-Tarjan (1987) network flow algorithm in time no worse than O(n/sup 2/m/sup 3/ log n), where n and m are the number of processors and the number of tasks, respectively.
Simulating BPP using a general weak random source
Authors: David Zuckerman
Venue: Proceedings of the 32nd annual symposium on Foundations of computer science (1991)

It is shown how to simulate BPP and approximation algorithms in polynomial time using the output from a delta -source. A delta -source is a weak random source that is asked only once for R bits, and must output an R-bit string according to some distribution that places probability no more than 2/sup - delta R/ on any particular string. Also given are two applications: one to show the difficulty of approximating the size of the maximum clique, and the other to the problem of implicit O(1) probe search.
Iterative design of an interface for easy 3-D direct manipulation
Authors: Stephanie Houde
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1992)

Although computer tools for 3-D design applications are now widely available for use on personal computers, they are unnecessarily difficult to use. Conventions for establishing and manipulating views of 3-D objects require engineering-oriented dialogues that are foreign to most users. This paper describes the iterative design and testing of a new mechanism for moving 3-D objects with a mouse-controlled cursor in a space planning application prototype. Emphasis was placed on developing a design which would make 3-D interaction more intuitive by preserving users' experiences with moving objects in the real, physical world. Results of an informal user test of the current interface prototype are presented and implications for the development of a more general direct manipulation mechanism are discussed.
A deductive database architecture based on partial evaluation
Authors: Li Lei, G.-H. Moll, J. Kouloumdjian
Venue: ACM SIGMOD Record (1990)

The implementation of a logic programming language for database management systems is a possible way to build a knowledge base management system. It allows to re-use the know-how in the fields: of inference engines, of data management. However, the strategy of each component is very different. SLD resolution leads to a one tuple at a time access to facts, opposed to the set oriented approach of databases. To face this problem, a new strategy, has been designed to keep the advantages of each part avoiding the drawbacks. The kernel of the system is a Partial Evaluator, designed as a metaprogram, which allows to bridge the impedance mismatch gap.
Hackers: computer heroes or electronic highwaymen?
Authors: Richard C. Hollinger
Venue: ACM SIGCAS Computers and Society (1991)

In his book, Hackers: Heroes of the Computer Revolution (Doubleday, 1984), Steven Levy documents the linguistic evolution of the word "hacker." He argues that among computer aficionados the term has been long used to express respect and admiration for another's superior computer programming expertise. In the last ten years (particularly among members of the law enforcement community), however, the concept has taken on an extremely negative connotation and is regularly used to refer to electronic vandals and computer criminals. Yet, recent surveys of computer crime victims indicate that the typical computer criminal is an employee, not an outsider trying to "hack" into the system. In trying to explain this paradox, comparisons are made with earlier historical periods when highwaymen and train robbers were also viewed by law enforcement as criminals but considered by their peers as folk heroes. These modern day "electronic highwaymen" are innovative deviants who prey on the inherent vulnerabilities of our pioneering (and sometimes unpopular) communication and information corporations. The social construction of "hackers" as the principal focus of computer criminalization is explained by examining the specific characteristics of the victims, offenses, offenders, and law enforcement agencies within the scope of the larger computer and information technology revolution.
Efficient exponentiation in finite fields (extended abstract)
Authors: Joachim von zur Gathen
Venue: Proceedings of the 32nd annual symposium on Foundations of computer science (1991)

Optimal sequential and parallel algorithms for exponentiation in a finite field extension are presented, assuming that a normal basis over the ground field is given.
Simultaneous scheduling and allocation for cost constrained optimal architectural synthesis
Authors: Catherine H. Gebotys, Mohamed I. Elmasry
Venue: Proceedings of the 28th ACM/IEEE Design Automation Conference (1991)

An integer programming (IP) model, which simultaneously schedules and allocates functional units, registers, and busses, is presented for synthesizing cost-constrained globally optimal architectures. This research is important for industry by providing optimal schedules which minimize interconnect costs and interface to analog and asynchronous processes, since these are seen as key to synthesizing high performance architectures. A partially structured tight IP formulation of the architectural synthesis problem provides globally optimal schedules for peicewise linear cost functions, using branch and bound, in execution times faster than previous research. This research breaks new ground by 1. simultaneously scheduling and allocating hardware resources including interconnect, 2. support for asynchronous and analog interfaces, and 3. guaranteeing globally optimal solutions in practical execution times.
A New Parameterization of Digital Straight Lines
Authors: M. Lindenbaum, J. Koplowitz
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1991)

A 1:1 correspondence is established between digital straight lines which start at a fixed point and a simple set of quadruples of integer parameters. Such a representation by parameters is useful for enumeration, First, the authors show a 1:1 correspondence between point pairs in a planar set of points and the linear dichotomies of this set. Then, from the equivalence between digital lines and linear dichotomies of points on the digitization grid, they prove a 1:1 and 'onto' correspondence between digital straight lines starting at a fixed point and a well-defined set of pairs of grid points. It follows that four parameters uniquely represent any given digital line with a fixed starting point. An O(N) algorithm is given for determining the parameters from the digital line, as well as O(log N) algorithms for transforming between these parameters and the parameters suggested by L. Dorst and A.W.M. Smeulders (1984).
Data Flow Representation of Iterative Algorithms for Systolic Arrays
Authors: Chein-Wei Jen, Ding-Ming Kwai
Venue: IEEE Transactions on Computers (1992)

An algebraic representation is proposed for regular iterative algorithms that can be described as bundles of data flows with different wavefronts. A form corresponding to a geometric representation such as a dependence graph is obtained by modeling data flows with a generating function of a power series. The main attributes of systolic algorithms and arrays are revealed by a unique dataflow representation. This provides the ability to pipeline two or more systolic arrays solving different subproblems without intermediate buffering. An example is given to show a case in which the technique can be used.
Gray Level Thresholding in Badly Illuminated Images
Authors: J. R. Parker
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1991)

The thresholding method involves first locating objects in an image by using the intensity gradient, then noting the levels that correspond to the objects in various areas of the image, and finally using these levels as initial guesses at a threshold. This method is capable of thresholding images that have been produced in the context of variable illumination. The thresholding method, called the local intensity gradient (LIG) method, was implemented in C using a Sun4 host running UNIX. The LIG method was compared against iterative selection (IS), gray level histograms (GLHs) and two correlation based algorithms on a dozen sample images under three different illumination effects. Overall, the LIG method, while it takes significantly longer, properly thresholds a larger set of images than does any other method examined over the sample images tested.
Concise reference manual for the Series macro package
Authors: Richard C. Waters
Venue: ACM SIGPLAN Lisp Pointers (1989)

Series expressions are transformed into loops by pipelining them---the computation is converted from a form where entire series are computed one after the other to a form where the series are incrementally computed in parallel. In the resulting loop, each individual element is computed just once, used, and then discarded before the next element is computed. For this pipelining to be possible, four restrictions have to be satisfied. Before looking at these restrictions, it is useful to consider a related issue.
Designing laboratory modules for novices in an undergraduate AI course track: artificial intelligence
Authors: Robert M. Aiken, Dean Allemang, Thomas Wehrle
Venue: ACM SIGCSE Bulletin (1992)

A current joint project between three institutions in Switzerland has as its goal to create Artificial Intelligence (AI) software in teaching principles of AI at the University level. The modules of this project, the Portable AI Lab (PAIL), illustrate basic concepts of Artificial Intelligence in a uniform and self-contained manner. This paper discusses the design considerations that were adopted in order to make the presentation of this material easier for novice students.
Scientific visualization of performance data: evaluation of DV-Draw
Authors: Blaine Gaither
Venue: ACM SIGMETRICS Performance Evaluation Review (1990)

This report discusses the attributes of the DV-Draw package from the VI Corporation of Amherst, Massachusetts. DV-Draw is a scientific visualization package which is part of a larger package called DataViews. The requirements for visualization software in performance evaluation are identified. The results of applying DV-Draw to animate the output of an architectural model were successful.
Design and analysis of buffered crossbars and banyans with cut-through switching
Authors: Ted Szymanski, Chien Fang
Venue: Proceedings of the 1990 ACM/IEEE conference on Supercomputing (1990)

The design and approximate analyses of discrete time buffered crossbar and banyans with cut-through switching are presented. The crossbar switches can contain either (1) input FIFO queueing, (2) input &ldquo;bypass&rdquo; queueing where the FIFO discipline is relaxed, (3) a novel scheme called &ldquo;restricted output queueing&rdquo; where the number of simultaneous arrivals to an output queue is upper bounded, or (4) a novel combination of input FIFO and restricted output queueing. An analysis for the delay distribution of a packet leaving the network is presented. It is shown that restricted output queueing (or combined input and restricted output queueing) can rival the performance of pure output queueing, while requiring far less hardware; typically, limiting the number of simultaneous arrivals to an output queue to 2 or 3 is sufficient to ensure near optimal performance. It is shown that for light to moderate loads, cut-through switching offers significant improvement since most buffers are empty and cut-through occurs often. A comparison indicates that cut-through switching offers larger performance improvements when newer pin-limited GaAs Integrated circuits are used, rather than conventional CMOS or ECL, due to the similarity to bit-serial transmission in the newer and faster ICs with fewer pins.
Artificial neural networks: an emerging new technique
Authors: Youngohc Yoon, Lynn Peterson
Venue: ACM SIGMIS Database (1992)

The artificial neural network is at the heart of an emerging technique, which many academicians and practitioners are using very productively due to its high performance in addressing complex problems. Although the ANN has not yet reached its full potential, the technique has demonstrated the capability of enhancing performance in a broad range of problems. This article presents an overview of the artificial neural network, a taxonomy of its learning paradigm, and its application areas.
A contingency approach to the application software generations
Authors: Roger Clarke
Venue: ACM SIGMIS Database (1991)

The current environment in which software development is undertaken includes a mix a languages at varying levels of abstraction. The goal of this paper is threefold. First, the range of application software technologies is reviewed from a historical perspective. Second, a model based on levels of abstraction summarizes the key differences between these technologies. Third, a contingency model is proposed to guide the selection of the appropriate level of abstraction.It is argued that the selection of the appropriate level of abstraction should be based on economic criteria mediated by political factors. The level should be chosen not once for the entire application, but for each component within an application. The search should be commenced at the level of abstraction at which the requirements are stated, and the highest level of abstraction chosen at which the particular component can, in the given environments of development and use, be practically implemented.To support this contingency approach, an application development product must comprise a family of compatible languages and tools, such that developers have the freedom to choose at which level of abstraction they will express their solutions, problems, domain-models or domain empirical data.
An Object-Based Taxonomy for Distributed Computing Systems
Authors: Bruce E. Martin, Claus H. Pedersen, James Bedford-Roberts
Venue: Computer (1991)

A hierarchy of questions and answers about the features of distributed computing systems (DCSs) leads to an overall system description that facilitates system comparisons. The taxonomy uses terminology from an object-based model of DCSs and emphasizes the runtime services the DCS provides to applications. It is based on the division of DCS issues into three distinct categories: threads object properties and separation. The threads subtree explores the creation, the number, and the control of threads in the DCS. The object properties subtree explores DCS features that are defined for objects in isolation. The separation subtree explores issues that arise because there are many objects in the DCS. To describe a specific DCS, a taxonomy user traces paths through the hierarchy.