ppxscal/embedding_network huggingface dataset:
Software fault isolation in wide area networks
Authors: Dinesh Gambhir, Ivan Frish, Micheal Post
Venue: Proceedings of the 1992 ACM annual conference on Communications (1992)

The problem of real-time detection and isolation of errors in distributed software systems operating in a wide-area networked environment is considered. The approach presented combines the results of static software analysis with dynamic event-driven monitoring. Static software analysis is used to generate a model of the distributed system. The model describes all possible executions of the processes composing the distributed system. The event-driven monitoring algorithm upon detecting an erroneous event uses the model to isolate the distributed software process states causing the fault. Because this approach does not require the use of the network for fault isolation, it is ideal for use in the low-bandwidth, high-latency communications environments characterizing wide-area networks.
A theory of specialization constraints for complex objects
Authors: G. E. Weddell, N. Coburn
Venue: Proceedings of the third international conference on database theory on Database theory (1990)

Most semantic data models and object-oriented data models allow entity and object classes to be organized according to a generalization taxonomy. In addition, range restrictions (or property typing) may be specified not only on properties associated with a given class, but also on properties inherited from superclasses. In this paper, we consider a more general form of specialization constraint in which range restrictions are associated with property value paths, instead of with the properties themselves. One consequence is that the constraints enable a form of molecular abstraction, in which the internals of more complicated objects can be defined in terms of a collection of more primitive types. Sound and complete axiomatizations are given for two models: one not assuming a most specialized class rule (MSC), and another satisfying MSC together with an additional almost lower semilattice condition. Efficient decision procedures for both cases are also presented.
Macsyma computation of local minimal realization of dynamical systems of which generating power series are finite
Authors: Nour Eddine Oussous
Venue: Journal of Symbolic Computation (1991)

We present here a package of Macsyma programs, allowing the manipulation of words, and noncommutative power series over some finite alphabet. On the basis of the works of M.Fliess and C.Reutenauer, concerning local realization of nonlinear dynamical systems, we present an algorithm allowing the computation of the local and minimal realization of finite generating power series. We describe that algorithm in the computer algebra system Macsyma.
Portholes: supporting awareness in a distributed work group
Authors: Paul Dourish, Sara Bly
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (1992)

We are investigating ways in which media space technologies can support distributed work groups through access to information that supports general awareness. Awareness involves knowing who is &ldquo;around&rdquo;, what activities are occurring, who is talking with whom; it provides a view of one another in the daily work environments. Awareness may lead to informal interactions, spontaneous connections, and the development of shared cultures&mdash;all important aspects of maintaining working relationships which are denied to groups distributed across multiple sites. The Portholes project, at Rank Xerox EuroPARC in Cambridge, England, and Xerox PARC in Palo Alto, California, demonstrates that awareness can be supported across distance. A data network provides a shared database of image information that is regularly updated and available at all sites. Initial experiences of the system in use at EuroPARC and PARC suggest that Portholes both supports shared awareness and helps to build a &ldquo;sense of community&rdquo;.
Gigabit Network Testbeds
Venue: Computer (1990)

A description is given of five testbeds developed to examine gigabit applications and network technologies: Aurora, Blanca, Casa, Nectar, and Vistanet. Aurora is an experimental wide-area network testbed whose main objective is to explore and evaluate technologies for phase three of the proposed gigabit National Research and Education Network. The goals of the Blanca network research program are to develop technologies supporting gigabit/second networks, to develop programming tools supporting advanced network-based applications, and to explore the relationships between network technology paradigms and application requirements. The intent of the Casa testbed is to demonstrate that distributed supercomputing using wide-area high-speed networks can provide new levels of computational resources for leading-edge scientific problems. For the Nectar testbed project, a gigabit/second or higher experimental network will be developed to connect a variety of high-performance hosts. The Vistanet research project is intended to help determine whether networks based on emerging public-network standards will satisfy the goals of the National Research and Education Network and to provide information on specifications for those standards.
Integrating an array processor into a &ldquo;hands on&rdquo; computer science curriculum
Authors: Bruce P. Hillam
Venue: ACM SIGCSE Bulletin (1990)

Problems in acquiring an array processor by a public university are discussed, including lessons learned, present uses, and future plans to develop courses in computational science.
The design and implementation of hierarchical software systems with reusable components
Authors: Don Batory, Sean O'Malley
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (1992)

We present a domain-independent model of hierarchical software system design and construction that is based on interchangeable software components and large-scale reuse. The model unifies the conceptualizations of two independent projects, Genesis and Avoca, that are successful examples of software component/building-block technologies and domain modeling. Building-block technologies exploit large-scale reuse, rely on open architecture software, and elevate the granularity of programming to the subsystem level. Domain modeling formalizes the similarities and differences among systems of a domain. We believe our model is a blueprint for achieving software component technologies in many domains.
On the number of Eularian orientations of a graph
Authors: Milena Mihail, Peter Winkler
Venue: Proceedings of the third annual ACM-SIAM symposium on Discrete algorithms (1992)

We give efficient randomized schemes to sample and approximately count Eulerian orientations of any Eulerian graph. Eulerian orientations are natural flow-like structures, and Welsh has pointed out that computing their number (i)corresponds to evaluating the Tutte polynomial at the point (0, &ndash;2) [8,19] and (ii) is equivalent to evaluating &ldquo;ice-type partition functions&rdquo; in statistical physics [20]. Our algorithms are based on a reduction to sampling and approximately counting perfect matchings for a class of graphs for which the methods of Broder [3, 10] and others [4, 6] apply. A crucial step of the reduction is the &ldquo;Monotonicity Lemma&rdquo; (Lemma 3.3) which is of independent combinatorial interest. Roughly speaking, the Monotonicity Lemma establishes the intuitive fact that &ldquo;increasing the number of constraints applied on a flow problem can only decrease the number of solutions&rdquo;. In turn, the proof of the lemma involves a new decomposition technique which decouples problematically overlapping structures (a recurrent obstacle in handling large combinatorial populations) and allows detailed enumeration arguments. As a byproduct, (i) we exhibit a class of graphs for which perfect and near-perfect matchings are polynomially related, and hence the permanent can be approximated, for reasons other than &ldquo;short augmenting paths&rdquo; (previously the only known approach); and (ii) we obtain a further direct sampling scheme for Eulerian orientations which is faster than the one suggested by the reduction to perfect matchings. Finally, with respect to our approximate counting algorithm, we give the complementary hardness result, namely, that counting exactly Eulerian orientations is #P-complete, and provide some connections with Eulerian tours.
Information exchanges patterns in a computer-supported cooperative work environment
Authors: Gary J. Cook, Cheryl L. Dunn, Severin V. Grabski
Venue: ACM SIGCHI Bulletin (1991)

Software for supporting cooperative work, or groupware, is an approach for increasing project team productivity by changing the way team members work and communicate with each other. Since groupware use can be influenced by various individual, team, and organizational factors, empirical research is needed to "... study the flow of members' interaction to discover the impact the technology is having on the nature of the group's cognitions, actions, and feelings, and the relationship between these attributes of information exchange and decision outcomes (DeSanctis and Gallupe, 1987, p. 603)." The objective of this study is to examine patterns of computer-supported information exchange in a cooperative work environment. The environment requires colleagues to work together to complete a project within a specified time frame. The patterns of information exchange observed should provide insight into what aspects of groupware are perceived as helpful by users, and provide directions for further research.
Formula: A Programming Language for Expressive Computer Music
Authors: David P. Anderson, Ron Kuivila
Venue: Computer (1991)

An overview is given of Formula (an abbreviation for Forth Music Language), a language for controlling synthesizers that can model the expressiveness of a human performance. Formula supports algorithmic composition, interactive performance, and programmed interpretation of traditional scores. It uses concurrent processes that share a single address space and are scheduled by the runtime system. Note-playing processes compute sequences of pitches and play these pitches as notes or chords. Auxiliary processes are attached to note-playing processes or groups to supply note parameters such as volume, duration, and articulation. Input-handling processes execute when input arrives from a particular device. Two representative Formula programs are described.
Design of a text formatter with AUTO STAR
Authors: M. Zhu
Venue: ACM SIGAda Ada Letters (1990)

The formal development of a prototyping text formatter with the aid of AUTO STAR (AUTOmati c Specification To Ada Realization) has been introduced. This experiment shows that a large software system can be developed with a formal approach in a very easy and fast way.
A framework for dynamic graph drawing
Authors: R. F. Cohen, G. Di Battista, R. Tamassia, I. G. Tollis, P. Bertolazzi
Venue: Proceedings of the eighth annual symposium on Computational geometry (1992)

In this paper we give a model for dynamic graph algorithms, based on performing queries and updates on an implicit representation of the drawing. We present dynamic algorithms for drawing planar graphs that use a variety of drawing standards (such as polyline, straight-line, orthogonal, grid, upward, and visibility drawings), and address aesthetic criteria that are important for readability, such as the display of planarity, symmetry, and reachability. Also, we provide techniques that are especially tailored for important subclasses of planar graphs such as trees and series-parallel digraphs. Our dynamic drawing algorithms have the important property of performing &ldquo;smooth updates&rdquo; of the drawing. Of special geometric interest is the possibility of performing point-location and window queries on the implicit representation of the drawing.
Developing and integrating ProDAG in the Arcadia environment
Authors: Debra J. Richardson, T. Owen O'Malley, Cynthia Tittle Moore, Stephanie Leif Aha
Venue: ACM SIGSOFT Software Engineering Notes (1992)

ProDAG is an analysis toolset that provides an application programmatic interface for program dependence analysis. Program dependences are syntactic relationships between program statements. The ProDAG interface provides a uniform set of operations for creating and accessing several pre-defined dependence relations, which are represented as graphs, as well as a standard mechanism for developing new dependence graphs. ProDAG is one analysis toolset in Arcadia, ProDAG was developed in the Arcadia environment and has been integrated with the language processing, oject management, and process definition components of the Arcadia architecture, and further integration with the user interface development system and the measurement and evaluation components are underway. This paper describes the design, implementation and integration of proDAG within Arcadia.
An accidental translator from Smalltalk to ANSI C
Authors: C. Nash, W. Haebich
Venue: ACM SIGPLAN OOPS Messenger (1991)

Smalltalk's great advantage over all of its competitors is the sophistication of its environment and the elegance of its implementation of the Object-Oriented paradigm. One of its disadvantages is that Smalltalk applications cannot be separated from the Smalltalk environment. The completeness of the environment as opposed to its insularity, appear to represent a natural trade-off. This paper describes an initially limited attempt to resolve the trade-off, for the purposes of a particular application, which subsequently grew in scope.
A Theory of Photometric Stereo for a Class of Diffuse Non-Lambertian Surfaces
Authors: Hemant D. Tagare, Rui J. P. deFigueiredo
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1991)

A theory of photometric stereo is proposed for a large class of non-Lambertian reflectance maps. The authors review the different reflectance maps proposed in the literature for modeling reflection from real-world surfaces. From this, they obtain a mathematical class of reflectance maps to which the maps belong. They show that three lights can be sufficient for a unique inversion of the photometric stereo equation for the entire class of reflectance maps. They also obtain a constraint on the positions of light sources for obtaining this solution. They investigate the sufficiency of three light sources to estimate the surface normal and the illuminant strength. The issue of completeness of reconstruction is addressed. They show that if k lights are sufficient for a unique inversion, 2k lights are necessary for a complete inversion.
Inheritance in natural language processing
Authors: Walter Daelemans, Koenraad De Smedt, Gerald Gazdar
Venue: Computational Linguistics (1992)

In this introduction to the special issues, we begin by outlining a concrete example that indicates some of the motivations leading to the widespread use of inheritance networks in computational linguistics. This example allows us to illustrate some of the formal choices that have to be made by those who seek network solutions to natural language processing (NLP) problems. We provide some pointers into the extensive body of AI knowledge representation publications that have been concerned with the theory of inheritance over the last dozen years or so. We go on to identify the three rather separate traditions that have led to the current work in NLP. We then provide a fairly comprehensive literature survey of the use that computational linguists have made of inheritance networks over the last two decades, organized by reference to levels of linguistic description. In the course of this survey, we draw the reader's attention to each of the papers in these issues of Computational Linguistics and set them in the context of related work.
On Ada packages, types and task types
Authors: Albert Llamosí
Venue: ACM SIGAda Ada Letters (1992)

Two important uses of Ada packages are analyzed. Namely, for defining abstract data types and for defining task subsystems. Their advantages are only summarized, since they are well known, but the advantages and drawbacks of alternative ways of achieving such purposes are discussed and a uniform style of use is sustained, as well as the need for a specific notation for compound task types.
The documentation and evaluation of team-oriented database projects
Authors: D. V. Pigford
Venue: Proceedings of the twenty-third SIGCSE technical symposium on Computer science education (1992)

This paper focuses on documentation and evaluation techniques for monitoring and assessing team oriented database projects in a senior level database course in computer science. Instead of effecting documentation as the last phase in traditional software development, the documentation procedures are implemented as nine separate staggered deliverables during the project development. These deliverables are revised and organized into a final documentation binder. Evaluation techniques are monitored through four distinct phases: Project Plan, Ongoing Documentation, Progress Report, and Project Presentation (Demonstration).
Safe fusion of functional expressions
Authors: Wei-Ngan Chin
Venue: ACM SIGPLAN Lisp Pointers (1992)

Large functional programs are often constructed by decomposing each big task into smaller tasks which can be performed by simpler functions. This hierarchical style of developing programs has been found to improve programmers' productivity because smaller functions are easier to construct and reuse. However, programs written in this way tend to be less efficient. Unnecessary intermediate data structures may be created. More function invocations may be required. To reduce such performance penalties, Wadler proposed a transformation algorithm, called deforestation, which could automatically fuse certain composed expressions together in order to eliminate intermediate tree-like data structures. However, his technique is only applicable to a subset of first-order expressions. This paper will generalise the deforestation technique to make it applicable to all first-order and higher-order functional programs. Our generalisation is made possible by the adoption of a model for safe fusion which views each function as a producer and its parameters as consumers. Through this model, static program properties are proposed to classify producers and consumers as either safe or unsafe. This classification is used to identify sub-terms that can be safely fused/eliminated. We present the generalised transformation algorithm as a set of syntax-directed rewrite rules, illustrate it with examples, and provide an outline of its termination proof.
Analysis of the paging behavior of UNIX
Authors: Jeffrey C. Becker, Arvin Park
Venue: ACM SIGMETRICS Performance Evaluation Review (1991)

We analyze the paging behavior of several different versions of UNIX by recording traces of paging activity over time and writing programs to analyze the traces. We recorded periodic totals of paging events instead of individual paging events themselves. Our analysis shows that paging activity accounts for between 15% and 21% of all disk block accesses. Average paging system traffic is very low. The paging system is idle most of the time and paging activity occurs in large periodic bursts. Despite the fact that it is often overlooked, swap related paging accounts for a significant portion of all paging activity (between 24% and 71%). Furthermore, the behavior of swap-related paging differs greatly from the well-studied behavior of demand paging. The ratio of pages read to pages written (which varies between 0.85 and 1.9) is lower than typical read to write ratios for file system accesses. Paging activity is loosely correlated with load average or number of users.
Redesign of an A.S. degree in computer science to meet emerging national standards
Authors: William C. Harris, Leon P. Johnson
Venue: ACM SIGCSE Bulletin (1992)

The state of science and technical education is at a crucial juncture in our nation. In order to address this issue, the Division of Natural Sciences and Mathematics felt the need to incorporate recent technological developments into its Computer Science program. A conceptual framework for the revision and the resulting A.S. degree in Computer Science Program with a Telecommunications option are presented.
A program integration algorithm that accommodates semantics-preserving transformations
Authors: Wuu Yang, Susan Horwitz, Thomas Reps
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (1992)

Given a program Base and two variants, A and B, each created by modifying separate copies of Base, the goal of program integration is to determine whether the modifications interfere, and if they do not, to create an integrated program that includes both sets of changes as well as the portions of Base preserved in both variants. Text-based integration techniques, such as the one used by the Unix diff3 utility, are obviously unsatisfactory because one has no guarantees about how the execution behavior of the integrated program relates to the behaviors of Base, A, and B. The first program-integration algorithm to provide such guarantees was developed by Horwitz et al.[13]. However, a limitation of that algorithm is that it incorporates no notion of semantics-preserving transformations. This limitation causes the algorithm to be overly conservative in its definition of interference. For example, if one variant changes the way a computation is performed (without changing the values computed) while the other variant adds code that uses the result of the computation, the algorithm would classify those changes as interfering. This paper describes a new integration algorithm that is able to accommodate semantics-preserving transformations.
A parallel algorithm for the minimum spanning tree on an SIMD machine
Authors: Francis Suraweera, Prabir Bhattacharya
Venue: Proceedings of the 1992 ACM annual conference on Communications (1992)

A parallel algorithm for constructing a minimum spanning tree of a connected, weighted, undirected graph in O(log m) time using O(m + ) processors is presented for an SIMD machine where m and n denote the number of edges and vertices respectively.
A theorem on random polynomials and some consequences in average complexity
Authors: F. Cucker, M. -F. Roy
Venue: Journal of Symbolic Computation (1990)

Real polynomials have very often very few real roots, and when algorithms depend on the number of real roots of polynomials rather than on their degrees, this fact has consequences on average complexity of algorithms. In this paper we recall some classical results on the average number of real roots (which is in O(log n) where n is the degree of the polynomial for many natural random distributions) and use them to get estimates on the average complexity of various algorithms characterizing real algebraic numbers.
Programming for events
Authors: David S. Eastwood
Venue: ACM SIGAPL APL Quote Quad (1991)

Modern windowing user interfaces offer both a challenge and an opportunity to the APL programmer. This paper discusses some of the factors that need to be taken into account when designing APL applications in a windowing environment. In such an environment the application programmer needs to design the application to react to events which occur in the environment rather than design the application to take over the environment, especially when a number of independent applications are being run simultaneously. Some of the typical techniques required to produce a windowing application are discussed and applications examples are quoted using APL.68000 on the Apple Mac.
Designing Storage Efficient Decision Trees
Authors: O. J. Murphy, R. L. McCraw
Venue: IEEE Transactions on Computers (1991)

The problem of designing storage-efficient decision trees from decision tables is examined. It is shown that for most cases, the construction of the storage optimal decision tree is an NP-complete problem, and therefore a heuristic approach to the problem is necessary. A systematic procedure analogous to the information-theoretic heuristic is developed. The algorithm has low computational complexity and performs well experimentally.