ppxscal/embedding_network huggingface dataset:
Limited area numerical weather forecasting on a massively parallel computer
Authors: Lex Wolters, Gerard Cats, Nils Gustafsson
Venue: Proceedings of the 8th international conference on Supercomputing (1994)

A data-parallel implementation on a SIMD platform of an operational numerical weather forecast model is presented. The performances of two popular numerical techniques within these models are discussed, namely finite difference (gridpoint) methods and spectral methods. In this paper in particular the performance achieved for a full production run is investigated. Also the price/performance ratios of several compute platforms for this forecast model are shown.
Shastra: Multimedia Collaborative Design Environment
Authors: Vinod Anupam, Chandrajit L. Bajaj
Venue: IEEE MultiMedia (1994)

A distributed environment that supports multimedia interfaces, Shastra strengthens collaboration in scientific and engineering design. Implemented on a desktop system, it provides an infrastructure for user- and application-level cooperation. We describe the Shastra architecture and tools, then walk through a scenario that shows how it enhances collaborative problem solving.
Area requirements (abstract)
Authors: Giuseppe Di Battista
Venue: ACM SIGACT News (1993)

A compound diagraph is a directed graph with both inclusion and adjacency edges and is widely used in diverse fields. In this talk, first, a heuristic method for automatically drawing a compound digraph is presented. Then, several graphic interface techniques which facilitate the method in organizing ideas such as direct manipulation, animation, incremental editing, fish-eyes (focusing, abridgements), and utilization of curves are discussed. Finally, it is emphasized that interface issues are important as well as algorithmic aspects of graph drawing. (Joint work with K. Misue.)
Shade: a fast instruction-set simulator for execution profiling
Authors: Bob Cmelik, David Keppel
Venue: Proceedings of the 1994 ACM SIGMETRICS conference on Measurement and modeling of computer systems (1994)

Tracing tools are used widely to help analyze, design, and tune both hardware and software systems. This paper describes a tool called Shade which combines efficient instruction-set simulation with a flexible, extensible trace generation capability. Efficiency is achieved by dynamically compiling and caching code to simulate and trace the application program. The user may control the extent of tracing in a variety of ways; arbitrarily detailed application state information may be collected during the simulation, but tracing less translates directly into greater efficiency. Current Shade implementations run on SPARC systems and simulate the SPARC (Versions 8 and 9) and MIPS I instruction sets. This paper describes the capabilities, design, implementation, and performance of Shade, and discusses instruction set emulation in general.
Data flow equations for explicitly parallel programs
Authors: Dirk Grunwald, Harini Srinivasan
Venue: ACM SIGPLAN Notices (1993)

We present a solution to the reaching definitions problem for programs with explicit lexically specified parallel constructs, such as cobegin/coend or parallel_sections, both with and without explicit synchronization operations, such as Post, Wait or Advance. The reaching definitions information for sequential programs is used to solve many standard optimization problems. In parallel programs, this information can also be used to explicitly direct communication and data ownership. Although work has been done on analyzing parallel programs to detect data races, little work has been done on optimizing such programs. We show how the memory consistency model specified by an explicitly parallel programming language can influence the complexity of the reaching definitions problem. By selecting the &ldquo;weakest&rdquo; memory consistency semantics, we can efficiently solve the reaching definitions problem for correct programs.
Lambda, the ultimate label or a simple optimizing compiler for Scheme
Authors: William D. Clinger, Lars Thomas Hansen
Venue: Proceedings of the 1994 ACM conference on LISP and functional programming (1994)

Optimizing compilers for higher-order languages need not be terribly complex. The problems created by non-local, non-global variables can be eliminated by allocating all such variables in the heap. Lambda lifting makes this practical by eliminating all non-local variables except for those that would have to be allocated in the heap anyway. The eliminated non-local variables become local variables that can be allocated in registers. Since calls to known procedures are just gotos that pass arguments, lifted lambda expressions are just assembly language labels that have been augmented by a list of symbolic names for the registers that are live at that label.
Evaluating performance of prefetching second level caches
Authors: Robert B. Smith, James K. Archibald, Brent E. Nelson
Venue: ACM SIGMETRICS Performance Evaluation Review (1993)

Due to the increasing disparity between processor and main memory system cycle times, many computer systems are now incorporating two levels fo cache memory. Several studies have been done on the design and performance of second level caches, including [3] and [20]. It certainly can and has been shown that the addition of a second level of cache enhances the performance of many systems.
Towards a guide to social action for computer professionals
Authors: Jeff Johnson, Evelyn Pine
Venue: ACM SIGCHI Bulletin (1993)

The Rodney King video, trial, verdict, and subsequent riots jolted Americans in many ways besides showing us acts of violence committed by police and citizens. It also made the inequities of American society painfully clear, and provided a clea r response to Langston Hughes' question: "What happens to a dream deferred?" Answer : it explodes. This caused many people to rethink how they are conducting their lives, and how we are conducting our neighborhoods, our cities, our states, and our nation.
Procedural implementation of algebraic specification
Authors: Huimin Lin
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1993)

An implementation of an algebraic specification in an imperative programming language consists of a representation type, together with an invariant and an equivalence relation over it, and a procedure for each operator in the specification. A formal technique is developed to check the correctness of an implementation with respect to its specification. Here &ldquo;correctness&rdquo; means that the implementation satisfies the axioms and preserves the behavior of the specification. Within legal representing value space, a correct implementation behaves like a desirable model of the specification. A notion of implementation refinement is also proposed, and it is shown that the correctness relation between implementations and specifications is preserved by implementation refinement. In the extreme case the procedures in an implementation may be pre-post-condition pairs. Such abstract implementations can be refined into executable code by refining the abstract procedures in it. In this way a formal link between the algebraic and the pre- post-condition specification techniques is established.
Original Contribution: Efficient information transfer and anti-Hebbian neural networks
Authors: Mark D. Plumbley
Venue: Neural Networks (1993)

We attempt to maximise mutual information in a neural network where the output signal is corrupted by noise in the transmission process to the next stage. We assume that the average power available for transmission is limited and that the transmission noise is uncorrelated equal-variance Gaussian noise. Using the Lagrange multiplier technique, we construct a utility function that should be maximised to achieve our optimum. This optimum will be achieved when the output signal components are also uncorrelated and of equal variance. For a linear network with lateral inhibitory connections, using an anti-Hebbian algorithm with modified self-inhibitory connections we guarantee to increase our utility function over time and converge to the required optimum, although not by steepest ascent. For a network with inhibitory interneurons, a combined Hebbian/anti-Hebbian algorithm will similarly increase the utility function over time to find the optimum. This network with interneurons suggests that negative feedback may be used in a perceptual system to optimise forward transmission of information.
From CSP Models to Markov Models
Authors: Erling Vagn Sørensen, Jens Nordahl, Niels Herman Hansen
Venue: IEEE Transactions on Software Engineering (1993)

It is shown how a probabilistic dependability model of a safety-critical system can be derived from a trace-based functional model of the system. The functional model is a communicating sequential process (CSP) that includes command, failure, and repair events. The dependability model is a time homogeneous Markov process with transitions determined by these events. The method applies to deterministic systems that can be described in terms of a finite number of states and in which all event occurrences are stochastic with exponential time distribution. The derivation is carried out in two steps. An algorithmic determination is made of a finite automaton from the specification of the CSP process. The automaton is transformed into a Markov process. The Markov model for this system is used to determine the waiting time to terminal failure. The theory is applied to a larger and more realistic example: a gas burner system operating in the on-off mode. For this system, the waiting time to terminal failure is calculated, and the number of failures per year in a large population of identical, independently operated systems is estimated.
Tentative prune-and-search for computing Voronoi vertices
Authors: David Kirkpatrick, Jack Snoeyink
Venue: Proceedings of the ninth annual symposium on Computational geometry (1993)

This paper gives optimal logarithmic-time algorithms for two problems related to computing vertices of Voronoi diagrams in the plane: 1) given a convex polygon, compute the largest homothet of a given triangle that can be inscribed in the polygon and 2) given three disjoint convex polygons, compute the points that are equidistant from all three. These algorithms are based on a prune-and-search technique that may make tentative discards that are later revoked or certified. In three dimensions, a general strategy using hierarchical data structures leads to poly-logarithmic algorithms for related problems.
A Survey of Glove-based Input
Authors: David J. Sturman, David Zeltzer
Venue: IEEE Computer Graphics and Applications (1994)

Clumsy intermediary devices constrain our interaction with computers and their applications. Glove-based input devices let us apply our manual dexterity to the task. We provide a basis for understanding the field by describing key hand-tracking technologies and applications using glove-based input. The bulk of development in glove-based input has taken place very recently, and not all of it is easily accessible in the literature. We present a cross-section of the field to date. Hand-tracking devices may use the following technologies: position tracking, optical tracking, marker systems, silhouette analysis, magnetic tracking or acoustic tracking. Actual glove technologies on the market include: Sayre glove, MIT LED glove, Digital Data Entry Glove, DataGlove, Dexterous HandMaster, Power Glove, CyberGlove and Space Glove. Various applications of glove technologies include projects into the pursuit of natural interfaces, systems for understanding signed languages, teleoperation and robotic control, computer-based puppetry, and musical performance.
Towards practical &ldquo;proven secure&rdquo; authenticated key distribution
Authors: Yvo Desmedt, Mike Burmester
Venue: Proceedings of the 1st ACM conference on Computer and communications security (1993)

Secure key distribution is a critical component in secure communications. Finding 'proven secure' practical key distribution systems is one of the major goals in cryptography. The Diffie-Hellman variants, a family of key distribution systems, achieve some of the objectives of this goal. In particular, the 'non-paradoxical' system (by Matsumoto-Takashima-Imai and Yacobi) is claimed to be secure against a known-key attack. In this paper we show that the argument used to prove this is flawed, and we explain how it can be fixed.
Finding $k$ Disjoint Paths in a Directed Planar Graph
Authors: Alexander Schrijver
Venue: SIAM Journal on Computing (1994)

It is shown that, for each fixed $k$, the problem of finding $k$ pairwise vertex-disjoint directed paths between given pairs of terminals in a directed planar graph is solvable in polynomial time.
A probabilistic relational model for the integration of IR and databases
Authors: Norbert Fuhr
Venue: Proceedings of the 16th annual international ACM SIGIR conference on Research and development in information retrieval (1993)

In this paper, a probabilistic relational model is presented which combines relational algebra with probabilistic retrieval. Based on certain independence assumptions, the operators of the relational algebra are redefined such that the probabilistic algebra is a generalization of the standard relational algebra. Furthermore, a special join operator implementing probabilistic retrieval is proposed. When applied to typical document databases, queries can not only ask for documents, but for any kind of object in the database. In addition, an implicit ranking of these objects is provided in case the query relates to probabilistic indexing or uses the probabilistic join operator. The proposed algebra is intended as a standard interface to combined database and IR systems, as a basis for implementing user-friendly interfaces.
Physical database design: a decision support model
Authors: Israel Spiegler, David Widder
Venue: ACM SIGMIS Database (1993)

Methods and techniques are available for helping the system development effort at the analysis and logical design stages. Yet, once the system has been defined, the designer is left with many decisions that will affect the construction, operation and maintenance stages. This article proposes a conceptual model to support the database designer at the physical design stage. The model incorporates database design methodology with decision support system (DSS) methods. A prototype version of the model is described, together with an analysis of a case study. Such a model may be integrated into a CASE methodology to encompass the entire information system development cycle.
Security protocol for Frame Relay
Authors: Panagiotis Katsavos, Vijay Varadharajan
Venue: ACM SIGCOMM Computer Communication Review (1993)

This paper considers the protection of traffic using the Frame Relay service. First, we briefly describe the structure and functionality of the Frame Relay interface. Differences between the PTTs and the private vendor community with respect to Frame Relay interface are outlined. Then, we consider why the existing security protocols are inadequate in protecting the Frame Relay traffic effectively. This leads to the proposal of a new security sublayer (SFRC) which provides Secure Frame Relay Connections. Initially, we discuss the choice behind the placement of the SFRC sublayer within the Frame Relay interface. Then, we present the security services provided by the SFRC sublayer, the structure of the protocol data unit it employs for secure transfer of data and the types of MIB objects controlling its functionality. Finally, we suggest some supplementary security services not directly supported by the SFRC entities for future consideration.
Orchestrating interactions among parallel computations
Authors: Susan L. Graham, Steven Lucco, Oliver Sharp
Venue: Proceedings of the ACM SIGPLAN 1993 conference on Programming language design and implementation (1993)

Many parallel programs contain multiple sub-computations, each with distinct communication and load balancing requirements. The traditional approach to compiling such programs is to impose a processor synchronization barrier between sub-computations, optimizing each as a separate entity. This paper develops a methodology for managing the interactions among sub-computations, avoiding strict synchronization where concurrent or pipelined relationships are possible. Our approach to compiling parallel programs has two components: symbolic data access analysis and adaptive runtime support. We summarize the data access behavior of sub-computations (such as loop nests) and split them to expose concurrency and pipelining opportunities. The split transformation has been incorporated into an extended FORTRAN compiler, which outputs a FORTRAN 77 program augmented with calls to library routines written in C and a coarse-grained dataflow graph summarizing the exposed parallelism. The compiler encodes symbolic information, including loop bounds and communication requirements, for an adaptive runtime system, which uses runtime information to improve the scheduling efficiency of irregular sub-computations. The runtime system incorporates algorithms that allocate processing resources to concurrently executing sub-computations and choose communication granularity. We have demonstrated that these dynamic techniques substantially improve performance on a range of production applications including climate modeling and x-ray tomography, expecially when large numbers of processors are available.
A consensus glossary of temporal database concepts
Authors: Curtis Dyreson, Fabio Grandi, Wolfgang Käfer, Nick Kline, Nikos Lorentzos, Yannis Mitsopoulos, Angelo Montanari, Daniel Nonen, Elisa Peressi, Barbara Pernici, John F. Roddick, Nandlal L. Sarda, Maria Rita Scalas, Arie Segev, Richard Thomas Snodgrass, Mike D. Soo, Abdullah Tansel, Paolo Tiberio, Gio Wiederhold
Venue: ACM SIGMOD Record (1994)

This document contains definitions of a wide range of concepts specific to and widely used within temporal databases. In addition to providing definitions, the document also includes separate explanations of many of the defined concepts. Two sets of criteria are included. First, all included concepts were required to satisfy four relevance criteria, and, second, the naming of the concepts was resolved using a set of evaluation criteria. The concepts are grouped into three categories: concepts of general database interest, of temporal database interest, and of specialized interest. This document is a digest of a full version of the glossary1. In addition to the material included here, the full version includes substantial discussions of the naming of the concepts.The consensus effort that lead to this glossary was initiated in Early 1992. Earlier status documents appeared in March 1993 and December 1992 and included terms proposed after an initial glossary appeared in SIGMOD Record in September 1992. The present glossary subsumes all the previous documents. It was most recently discussed at the "ARPA/NSF International Workshop on an Infrastructure for Temporal Databases," in Arlington, TX, June 1993, and is recommended by a significant part of the temporal database community. The glossary meets a need for creating a higher degree of consensus on the definition and naming of temporal database concepts.
A simpler analysis of algorithm 65 (find)
Authors: Rajeev Raman
Venue: ACM SIGACT News (1994)

We present a simpler analysis of the expected number of comparisons made by Hoare's selection algorithm (Comm. ACM4 (1961), pp. 321--322).
A multi-level solution algorithm for steady-state Markov chains
Authors: Graham Horton, Scott T. Leutenegger
Venue: Proceedings of the 1994 ACM SIGMETRICS conference on Measurement and modeling of computer systems (1994)

A new iterative algorithm, the multi-level algorithm, for the numerical solution of steady state Markov chains is presented. The method utilizes a set of recursively coarsened representations of the original system to achieve accelerated convergence. It is motivated by multigrid methods, which are widely used for fast solution of partial differential equations. Initial results of numerical experiments are reported, showing significant reductions in computation time, often an order of magnitude or more, relative to the Gauss-Seidel and optimal SOR algorithms for a variety of test problems. It is shown how the well-known iterative aggregation-disaggregation algorithm of Takahashi can be interpreted as a special case of the new method.
An execution/sleep scheduling policy for serving an additional job in priority queueing systems
Authors: Kin K. Leung
Venue: Journal of the ACM (JACM) (1993)

In a priority-based computer system, besides the regular jobs, an additional job (refereed to as job A) is invoked infrequently but requires a significant amount of CPU time. To avoid CPU hogging, job A receives (up to) a fixed amount of CPU time whenever it is served. When the time expires, job A immediately relinquishes the CPU and puts itself to sleep for a period of time. By doing so, jobs with low priority may be processed in a timely manner. When the sleep time is over, job A is awakened and waits to resume service according to its priority. Then, the whole process is repeated until job A service is completed. In this paper, such an execution/sleep (ES) scheduling policy is analyzed for serving job A in a nonpreemptive priority queuing system. The Laplace Transforms are derived for: (i) the conditional response time of job A and (ii) the response time for jobs with priorities higher and lower than job A. This work is motivated by the ES policy in a switching system in which job A is invoked in response to the failure of signaling links. The proposed model is applicable to other real-time computer systems, and the modeling techniques can be applied or generalized to analyzing other scheduling policies in which timers are involved.
Friend21 project
Authors: Hirotada Ueda
Venue: ACM SIGCHI Bulletin (1993)

The FRIEND21 project was initiated by the Ministry of International Trade and Industry. FRIEND21 is an acronym for Future Personalized Information Environment Development. The goal of this project is to develop the next-generation human interface architecture for the computing machinery of the 21st century. The research and development period of this project is six years. In October 1988, P.I.E. (Institute for Personalized Information Environment) was authorized to handle the project to its conclusion at the end of March 1994.
Specification languages and their implementations
Authors: Ludo Cuypers
Venue: Proceedings of the 1993 ACM conference on Computer science (1993)

This paper describes some historical software engineering backgrounds leading to specification languages. These specification languages have high promises for the future. One of the main problems is the derivation of implementations. We propose a methodology to translate Lotos specifications into implementations. The principles behind the framework and its concepts are introduced using a simple example. Finally, we explain how implementation techniques proposed by other authors can be integrated in our framework.
HCI and the inadequacies of direct manipulation systems
Authors: Bill Buxton
Venue: ACM SIGCHI Bulletin (1993)

The Direct Manipulation (DM) style of user interface made popular by the Macintosh is becoming a de facto standard. Rather than being taken as a point of departure, it appears to be taken more as a standard to achieve. Using the specification of scope as an example, DM interfaces are shown to be deficient in supporting a transaction fundamental to word processing, information retrieval and CAD. This essay is a plea for designers to break out of the complacency that surrounds the DM approach. It also calls into question the methodologies of HCI for the very limited degree to which they have challenged the DM approach and their paucity of ideas for generating strong new alternatives.