ppxscal/embedding_network huggingface dataset:
Language support for changeable large real time systems
Authors: Ivar Jacobson
Venue: ACM SIGPLAN Notices (1986)

A set of concepts for modeling large real time systems is discussed informally. The concepts support the design of centralized as well as distributed systems. They are object oriented in that they correspond to entities of the 'real world', and they are 'change oriented' in that they support not only the first development stage of a system but also its continuous change and evolution. In particularly, the concepts give a promising solution to 'on the fly' changes of existing, active entities.
A model for evaluating demand assignment protocols with arbitrary workloads
Authors: Z Koren, I Chlamtac, A Ganz
Venue: ACM SIGCOMM Computer Communication Review (1986)

Demand assignment protocols have been implemented in a large number of operational LANs. However, the analytic models for protocol evaluation currently capture only a limited range of LAN operational circumstances. In this paper we present an analytic tool for evaluating fair and prioritized demand assignment protocols with a relatively general workload model. We consider arbitrary and station dependent message size distributions and arrival rates. This allows the modeling of LANs with heterogeneous workloads, thus permitting a larger correspondence between the modeled system and the real life network.
Hierarchical design based on a calculus of nets
Authors: B. Becker, G. Hotz, R. Kolla, P. Molitor, H.-G. Osthof
Venue: Proceedings of the 24th ACM/IEEE Design Automation Conference (1987)

We present an algebraic approach to hierarchical design of integrated circuits. This approach is based on a &ldquo;calculus of nets&rdquo; which includes topological as well as behavioural aspects of integrated circuits. We have developed a hierarchical design system called CADIC which is build around this calculus in much the same way as e.g. Algol is build around numerics. An example for the design of a family of fast adders will demonstrate the power of this calculus. Finally we will give a summary outline on the structure of procedures which automatically transform the design into lower design levels.
The Design of the Saguaro Distributed Operating System
Authors: Gregory R. Andrews, Richard D. Schlichting
Venue: IEEE Transactions on Software Engineering (1987)

This paper describes the design of the Saguaro operating system for computers connected by a local-area network. Systems constructed on such an architecture have the potential advantages of concurrency and robustness. In Saguaro, these advantages are made available to the user through several mechanisms. One is channels, an interprocess communication and synchronization facility that allows the input and output of different commands to be connected to form general graphs of communicating processes. Two additional mechanisms are provided to support semitransparent file replication and access: reproduction sets and metafiles. A reproduction set is a collection of files that the system attempts to keep identical on a "best effort" basis. A metafile is a special file that contains symbolic pathnames of other files; when a metafile is opened, the system selects an available constituent file and opens it instead. The advantages of concurrency and robustness are also realized at the system level by the use of pools of server processes and decentralized allocation protocols. Saguaro also makes extensive use of a type system to describe user data such as files and to specify the types of arguments to commands and procedures. This enables the system to assist in type checking and leads to a user interface in which command-specific templates are available to facilitate command invocation.
Mainframe and microcomputer-based business graphics: end user computing comparisons and trends
Authors: John Lehman, Douglas Vogel
Venue: Proceedings of the twenty-first annual conference on Computer personnel research (1985)

This paper compares use of mainframe-based, microcomputer-based, and mixed computer-based business graphics in 200 organizations. It compares organizational, and technological environment, motivation for selection and use, functional area use, end users, organizational responsibility and support, application profiles, impediments to increased use, and forecasts for the future. It presents profiles of typical end users for both mainframe and micro computer groups with organizational environments and culture. In so doing, it provides empirical evidence for differing strategies of MIS involvement in the development of business graphics.
Multi-thread input
Authors: P P Tanner
Venue: ACM SIGGRAPH Computer Graphics (1987)

Implementors of interactive computer workstations have tended to shy away from making several devices simultaneously available to a user of their systems. The principal reason for this reluctance has been the difficulty faced by an application program in analyzing the several streams of input that such a configuration would present. Recently systems have been developed that support such multi-thread input. This paper discusses the requirements of multi-thread input and gives examples of how the requirements are being met by the experimental systems.
The role of champions in successful applications
Authors: Peter G. Cook
Venue: ACM SIGOIS Bulletin (1988)

A structure to understand the reasons for computer success or failure is reported. It is represented as a matrix, where rows relate to the elements of a successful application, and the column structure is derived from diffusion theory as it relates to technology transfer.The rows are the result of a number of years of implementation efforts and observation of the efforts of others. It asserts that to be successful, a computer application must have:A real needGood hardwareAdequate softwareA receptive environmentA championThe columns derive from diffusion theory, particularly the work of Everett Rogers. It categorizes user environments into four categories:InnovatorEarly adopterMajorityLate AdopterObservations are made about each of the cells of the resulting matrix.
Experiences in using Ada with DBMS applications
Authors: M McNickle, A Reedy
Venue: ACM SIGAda Ada Letters (1987)

This paper presents an overview of work performed between July, 1984 and February, 1986. A prototype effort consisting of the redesign and reimplementation of COBOL programs into Ada has been completed successfully. The redesign and reimplementation of a DBMS applications system under full military life cycle standards is still underway. An important feature of this work is that it demonstrates a transition path for large CODASYL database systems away from COBOL and into Ada. The more important lessons learned and recommendations for future work are summarized. This work was partially funded by U. S. Navy SPAWARSYSCOM under contracts N00039-81-C-0119 and N68786-85-C3010.
A comparison of techniques for the specification of external system behavior
Authors: Alan M. Davis
Venue: Communications of the ACM (1988)

The elimination of ambiguity, inconsistency, and incompleteness in a Software Requirements Specification (SRS) document is inherently difficult, due to the use of natural language. The focus here is a survey of available techniques designed to reduce these negatives in the documentation of a software product's external behavior.
A necessary condition for a doubly recursive rule to be equivalent to a linear recursive rule
Authors: Weining Zhang, C. T. Yu
Venue: ACM SIGMOD Record (1987)

Nonlinear recursive queries are usually less efficient in processing than linear recursive queries. It is therefore of interest to transform non-linear recursive queries into linear ones. We obtain a necessary and sufficient condition for a doubly recursive rule of a certain type to be logically equivalent to a single linear recursive rule obtained in a specific way.
A Generalized Theory for System Level Diagnosis
Authors: A. K. Somani, V. K. Agarwal, D. Avis
Venue: IEEE Transactions on Computers (1987)

System-level diagnosis appears to be a viable alternative to circuit-level testing in complex multiprocessor systems. A completely new generalization of the characterization problem in the system-level diagnosis area is developed in this paper. This generalized characterization theorem provides necessary and sufficient conditions for any fault-pattern of any size to be uniquely diagnosable, under the symmetric, and asymmetric invalidation models with or without the intermittent faults. Moreover, it is also shown that the well known t-characterization theorems under these models can be derived as special cases. In addition to the generalization provided by these results, it is hoped that these results will also have a great impact on the diagnosis of faulty units in uniform structures based on the system-level diagnosis concepts and would be particularly useful in the diagnosis of WSI-oriented multiprocessor systems.
An experimental multi-media bridging system
Authors: E. J. Addeo, A. B. Dayao, A. D. Gelman, V. F. Massa
Venue: Proceedings of the ACM SIGOIS and IEEECS TC-OA 1988 conference on Office information systems (1988)

The prototype system, which is described in this paper and called the Multi-Media Bridge, is designed to test service concepts and evolving technologies that make possible the deployment of multi-media group communications in future broadband networks. It incorporates such features as extended quality audio, full-motion video, graphics and data multi-point communications capability. The Bridge could serve as either a separate vendor entity or as an integral part of a network-based complex. The multi-shelf architecture of the experimental system allows a variety of technical problems and issues to be autonomously addressed. The shelves, designated Audio, Video, Graphics, and Data, are functionally integrated by a distributed control capability. A graphics user interface was developed which can be realized on any PC or workstation that supports the MIT X-Windowing system. It provides users with the flexibility to dynamically invoke each medium at any time and control various modes of media integration.
Rearrangeability of multistage shuffle/exchange networks
Authors: A. Varma, C. S. Raghavendra
Venue: Proceedings of the 14th annual international symposium on Computer architecture (1987)

In this paper we study the rearrangeability of multistage shuffle/exchange networks. Although a theoretical lower bound of (2 log2N - 1) stages for rearrangeability of a network with N = 2n inputs and outputs has been known, the sufficiency of (2 log2N - 1) stages has neither been proved nor disproved. The best known upper bound for rearrangeability is (3 log2N - 3) stages. We prove that, if (2 log2R - 1) shuffle/exchange stages are sufficient for rearrangeability of a network with R = 2' inputs and outputs, then, for any N > R, 3 log2N - (r + 1) stages are sufficient for a network with N inputs and outputs. This result is established by setting some of the middle stages of the network to realize a fixed permutation and showing the reduced network to be topologically equivalent to a member of the Benes class of rearrangeable networks. We first characterize equivalence to Benes networks in set-theoretic terms and use this to prove equivalence of the reduced shuffle/exchange network to the Benes network. From the known result that 5 stages are sufficient for rearrangeability when N = 8, we obtain an upper bound of (3 log2N - 4) stages for rearrangeability when N &ge; 8. Further, any increase in the network size R for which the rearrangeability of (2 log2R - 1) stages could be shown, results in a corresponding improvement in the upper bound for all N &ge; R. In addition, due to the one-to-one correspondence that exists between the switches in the reduced shuffle/exchange network and those in the Benes network, the former network can be controlled by the well-known looping algorithm.
Fifteen years ACM
Authors: Franz L. Alt
Venue: Communications of the ACM (1987)

The development years of ACM, as recounted in 1962 by founding member and former president Franz L. Alt, depicts the players and progress of an organization committed to sharing computing knowledge and skills.
A formal view integration method
Authors: Joachim Biskup, Bernhard Convent
Venue: ACM SIGMOD Record (1986)

The design of an appropriate conceptual database scheme is one of the most difficult tasks in usual database applications. Especially, the design of a common global database scheme for many different user groups requires a great amount of effort and skill, because the desired scheme should fit a great variety of requirements and expectations. Here, view integration is a natural method that should help to manage the complexity of such a design problem. For each user group the requirements and expectations are separately collected and specified as views, that are subsequently integrated into a global scheme supporting all those different views. In this paper, we carefully develop a formal model, clarifying many notions and concepts, related to the view integration method. This formal model serves as a theoretical basis of our integration approach that uses equivalence preserving, local scheme transformations as the main integration operations.
Ambiguities in Incremental Line Rastering
Authors: Jack Bresemham
Venue: IEEE Computer Graphics and Applications (1987)

In implmenting rater grahic algorithms, it is impotant to toroughly understand behavior and implicit defaults inherent in each algorithm. Design choices must balance performance with respect to drawing speed, circult count, code space, picture fidelity, system complexity, and system consistency. For example, "close" may sound appealing when describing the match of the rastered representation to a geometirc line. An implementation, however, must quantily an error metric¿such as minimum normal distance between candidate raster grid points and the geometric line¿and resolve "ties" in which two candidate grid points have an equal error metric. Equal error metric ambiguity can permit algorithimic selection of raster points for a line from (X0, Y0) to (X1, Y1) to differ from points selected rastering the same line back from (X1, Y1) to (X0, Y0). Modilying a rastering algorithm to provide an exactly reversibie path, though, will cause problems when lines are rastered in a context of approximating a circle with a polygon. Only by fully understanding any algorithm can designers determine whether such pel-level anomalies are worth the code space or circuit count necessary to provide explicit user resolution, or whether a fixed default must suffice. This article discusses implementation considerations relevant to selecting and customizing incremental line-drawing algorithms to cope with such anomalies as equal error metric instances, perturbation effects of clipping, interesections in raster space, EXOR interpretations for polylines, reversibility, and fractional endpoint rounding.
Efficient algorithms for automatic construction and compactification of parsing
Authors: D. J. Rosenkrantz, H. B. Hunt
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1987)

Several computational problems about grammars are studied. Efficient algorithms are presented for the problems of (1) determining, for a given semantic grammar, if there exists a related parsing grammar in some specified grammar class, and (2) finding such a related parsing grammar when one exists. The two grammars are to be related by mergers of nonterminals and/or terminals. Efficient algorithms are presented for most of the grammar classes used in compilers. We also study the problem of (3) determining which terminals of a grammar are good candidates for merger into common lexical tokens of the corresponding parsing grammar.
Interactive State-Space Analysis of Concurrent Systems
Authors: E. Timothy Morgan, Rami R. Razouk
Venue: IEEE Transactions on Software Engineering (1987)

The introduction of concurrency into programs has added to the complexity of the software design process. This is most evident in the design of communications protocols where concurrency is inherent to the behavior of the system. The complexity exhibited by such software systems makes more evident the need for computer-aided tools for automatically analyzing behavior.
Independent general principles for constructing responsive software systems
Authors: Connie U. Smith
Venue: ACM Transactions on Computer Systems (TOCS) (1986)

Three general principles are presented that can be applied in early software life cycle stages for the definition of software requirements and designs with acceptable performance. They are genuine high-level considerations for meeting responsiveness goals without sacrificing understandability and maintainability, and without increasing development time and cost. The principles are derived from the interrelationships of two performance models: a queueing network based on computer system model and an execution graph software model. The performance effect of each of the principles is quantified using the models. Examples are given that illustrate how they can be applied to software systems.
Bubble reflections
Authors: C. T. Zahn
Venue: ACM SIGCSE Bulletin (1987)

A published version of Bubblesort is analyzed via correctness arguments and the failure of these arguments leads to the discovery of a subtle bug. A simple change produces a correct version and a not-so-trivial proof of termination completes the total correctness demonstration for the revised algorithm. Several important lessons are extracted from this experience.
Security problems on inference control for SUM, MAX, and MIN queries
Authors: Francis Chin
Venue: Journal of the ACM (JACM) (1986)

The basic inference problem is defined as follows: For a finite set X = {xi,  , xn}, we wish to infer properties of elements of X on the basis of sets of "queries" regarding subsets of X. By restricting these queries to statistical queries, the statistical database (SDB) security problem is obtained. The security problem for the SDB is to limit the use of the SDB so that only statistical information is available and no sequence of queries is sufficient to infer protected information about any individual. When such information is obtained the SDB is said to be compromised. In this paper, two applications concerning the security of the SDB are considered: On-line application. The queries are answered one by one in sequence and it is necessary to determine whether the SDB is compromised if a new query is answered. Off-line application. All queries are available at the same time and it is necessary to determine the maximum subset of queries to be answered without compromising the SDB. The complexity of these two applications, when the set of queries consists of (a) a single type of SUM query, (b) a single type of MAX/MIN query, (c) mixed types of MAX and MIN queries, (d) mixed types of SUM and MAX/MIN queries, and (e) mixed types of SUM, MAX, and MIN queries, is studied. Efficient algorithms are designed for some of these situations while others are shown to be NP-hard.
On learning Boolean functions
Authors: B. K. Natarajan
Venue: Proceedings of the nineteenth annual ACM symposium on Theory of computing (1987)

This paper deals with the learnability of Boolean functions. An intuitively appealing notion of dimensionality is developed and used to identify the most general class of Boolean function families that are learnable from polynomially many positive examples with one-sided error. It is then argued that although bounded DNF expressions lie outside this class, they must have efficient learning algorithms as they are well suited for expressing many human concepts. A framework that permits efficient learning of bounded DNF functions is identified.
One-way functions and pseudorandom generators
Authors: L A Levin
Venue: Proceedings of the seventeenth annual ACM symposium on Theory of computing (1985)

One-way are those functions which are easy to compute, but hard to invert on a non-negligible fraction of instances. The existence of such functions with some additional assumptions was shown to be sufficient for generating perfect pseudorandom strings |Blum, Micali 82|, |Yao 82|, |Goldreich, Goldwasser, Micali 84|. Below, among a few other observations, a weaker assumption about one-way functions is suggested, which is not only sufficient, but also necessary for the existence of pseudorandom generators. The main theorem can be understood without reading the sections 3-6.
Quilt: a collaborative tool for cooperative writing
Authors: Robert S. Fish, Robert E. Kraut, Mary D. P. Leland
Venue: Proceedings of the ACM SIGOIS and IEEECS TC-OA 1988 conference on Office information systems (1988)

Quilt is a computer-based tool for collaborative writing, which provides annotation, messaging, computer conferencing, and notification facilities to support communication and information sharing among the collaborators on a document. In addition, extensible sets of social roles and communication types are used to provide views of a document tailored to individual collaborators or to other users of the document based upon their position in a permission hierarchy. This paper describes the rationale for and design of Quilt.
An Analysis of Some Problems in Managing Virtual Memory Systems with Fast Secondary Storage Devices
Authors: Stephen J. Hartley
Venue: IEEE Transactions on Software Engineering (1988)

Some of the problems that are expected to be encountered in managing virtual memory systems using the newer-technology secondary storage devices are address. The difficulties that two proposed policies have in choosing the most economical program localities of reference to assign to primary memory are analyzed. K. Koh's (1981) criterion for examining the cyclic locality interval (CLI) hierarchy of a program and choosing the least-cost pathway is examined. Koh's criterion is designed for the case of a CLI containing a single inner CLI. The decision to descend the hierarchy is based on the cycle time of the outer CLI. If the outer CLI has two or more inner CLIs, it is possible for Koh's criterion to indicate that it is more economical to descend to one of the inner CLIs without that actually being the case. Choosing which CLI to descend to requires knowledge of its duration, and this is not generally available to the memory management system. An attempt to use Koh's criterion with the loop structure of a program in order to reduce space-time execution cost was not successful.
Information systems for organizational productivity
Authors: Gib Akin, David Hopelain
Venue: ACM SIGCPR Computer Personnel (1986)

No matter what the reason for designing an information system in a particular way or acquiring a sysrtem with particular features, there is always a broader rationale which justifies the introduction of new automated information into the workplace. Inevitably, an executive, manager, or user has decided that the organization will be more productive - that is, its ability to get its work done will be enhanced by making new information available to the organization.
Laws of programming
Authors: C. A. R. Hoare, I. J. Hayes, He Jifeng, C. C. Morgan, A. W. Roscoe, J. W. Sanders, I. H. Sorensen, J. M. Spivey, B. A. Sufrin
Venue: Communications of the ACM (1987)

A complete set of algebraic laws is given for Dijkstra's nondeterministic sequential programming language. Iteration and recursion are explained in terms of Scott's domain theory as fixed points of continuous functionals. A calculus analogous to weakest preconditions is suggested as an aid to deriving programs from their specifications.