ppxscal/embedding_network huggingface dataset:
Are crossbars really dead?: the case for optical multiprocessor interconnect systems
Authors: Andreas G. Nowatzyk, Paul R. Prucnal
Venue: ACM SIGARCH Computer Architecture News (1995)

Crossbar switches are rarely considered for large, scalable multiprocessor interconnect systems because they require O(n2) switching elements, are difficult to control efficiently and are hard to implement once their size becomes too large to fit on one integrated circuit. However these problems are technology dependent and a recent innovation in fiber optic devices has led to a new implementation of crossbar switches that does not share these problems while retaining the full advantages of a crossbar switch: low latency, high throughput, complete connectivity and multi-cast capability. Moreover, this new technology has several characteristics that allow a distributed control system which scales linearly in the number of attached nodes.The innovation that led to this research is an optical and-gate that can be used to demultiplex multiple high speed data streams that are carried on one common optical medium. Optical time domain multiplexing can combine the data from many nodes and broadcast the result back to all nodes. This paper discusses OTDM technology only to the extent necessary to understand its characteristics and capabilities. The main contribution lies in the description and analysis of interconnect architectures that utilize OTDM to achieve a level performance that is beyond electronic means. It is expected that cost-reduced OTDM systems will become competitive with the next generation of interconnect systems.
Improving TCP/IP performance over wireless networks
Authors: Hari Balakrishnan, Srinivasan Seshan, Elan Amir, Randy H. Katz
Venue: Proceedings of the 1st annual international conference on Mobile computing and networking (1995)

TCP is a reliable transport protocol tuned to perform well in traditional networks made up of links with low bit-error rates. Networks with higher bit-error rates, such as those with wireless links and mobile hosts, violate many of the assumptions made by TCP, causing degraded end-to-end performance. In tbis paper, we describe the design and implementation of a simple protocol, called the snoop protocol, that improves TCP performance in wireless networks. The protocol modifies network-layer software mainly at a base station and preserves end-to-end TCP semantics. The main idea of the protocol is to cache packets at the base station and perform local retransmissions across the wireless link. We have implemented the snoop protocol on a wireless testbed consisting of IBM ThinkPad laptops and i486 base stations communicating over an AT T Wavelan. Our experiments show that it is significantly more robust at dealing with unreliable wireless links as compared to normal TCP; we have achieved throughput speedups of up to 20 times over regular TCP in our experiments with the protocol.
A Dynamic Coherence Protocol for Distributed Shared Memory Enforcing High Data Availability at Low Costs
Authors: Oliver E. Theel, Brett D. Fleisch
Venue: IEEE Transactions on Parallel and Distributed Systems (1996)

DSM coherence protocols should scale well for large networks. Fault-tolerance in terms of highly available data access and uninterrupted DSM service is needed in large-scale environments that have a greater number of potentially malfunctioning components. We present a new class of dynamic coherence protocols for DSM systems in error-prone networks whose instances offer highly available access to DSM data at low operation costs. The approach is based on the highly scalable Boundary-Restricted (BR) coherence protocol class. The new protocol class, called the Dynamic Boundary-Restricted (DBR) coherence protocol class, maintains read/write frequencies of DSM requests at run-time. This information is used to dynamically adjust the minimum number of cached copies of a single DSM page in order to guarantee a given degree of data availability. The description of the new protocol class is accompanied by an analysis covering a large variety of workloads. This analysis presents the overall savings achieved by using a DBR coherence protocol in comparison to a static BR protocol.
Strategies for enhancing user access and understanding of digital library structure and content
Authors: Robert B. Allen
Venue: ACM SIGWEB Newsletter (1995)

Two library classification system interfaces have been implemented for navigating and searching large collections of document and book records. One interface allows the user to browse book records organized by the Dewey Decimal Classification hierarchy. A Book Shelf display reflects the facet position in the classification hierarchy during browsing, and it dynamically updates to reflect search hits and attribute selections. The other interface provides access to records describing computer science documents classified by the ACM Computing Reviews (CR) system. The CR classification system is a type of faceted classification in which documents can appear at several points in the hierarchy. These two interfaces demonstrate that classification structure can be effectively utilized for organizing digital libraries and, potentially, collections of Internet-wide information services.
Control strategies for complex relational query processing in shared nothing systems
Authors: Lionel Brunie, Harald Kosch
Venue: ACM SIGMOD Record (1996)

In this paper, we present an original and complete methodology for supervising relational query processing in shared nothing systems. A new control mechanism is introduced which allows the detection and the correction of optimizer estimation errors and load imbalance. We especially focus on the management of intraprocessor communication and on the overlapping of communication and computation. Performance evaluations on an hypercube and a grid interconnection machine show the efficiency and the robustness of the proposed methods.
LOT: logic optimization with testability&mdash;new transformations using recursive learning
Authors: Mitrajit Chatterjee, Dhiraj K. Pradhan, Wolfgang Kunz
Venue: Proceedings of the 1995 IEEE/ACM international conference on Computer-aided design (1995)

Abstract: A new approach to optimize multi-level logic circuits is introduced. Given a multi-level circuit, the synthesis method optimizes its area, simultaneously enhancing its random pattern testability. The method is based on structural transformations at the gate level. New transformations involving EX-OR gates derived based on indirect implications by Recursive Learning have been introduced in the synthesis of multi-level circuits. This method is augmented with transformations that specifically enhance random-pattern testability while reducing the area. Testability enhancement is an integral part of our synthesis methodology. Experimental results show that the proposed methodology can not only realize lower area, but also achieves better testability compared to testability enhancement synthesis tools such as tstfx. Specifically for ISCAS-85 benchmark circuits, it was observed that EX-OR gate-based transformations can yield smaller circuits compared to state-of-the-art logic optimization tools like SIS and HANNIBAL.
A framework for event-based software integration
Authors: Daniel J. Barrett, Lori A. Clarke, Peri L. Tarr, Alexander E. Wise
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (1996)

Although event-based software integration is one of the most prevalent approaches to loose integration, no consistent model for describing it exists. As a result, there is no uniform way to discuss event-based integration, compare approaches and implementations, specify new event-based approaches, or match user requirements with the capabilities of event-based integration systems. We attempt to address these shortcomings by specifying a generic framework for event-based integration, the EBI framework, that provides a flexible, object-oriented model for discussing and comparing event-based integration approaches. The EBI framework can model dynamic and static specification, composition, and decomposition and can be instantiated to describe the features of most common event-based integration approaches. We demonstrate how to use the framework as a reference model by comparing and contrasting three well-known integration systems: FIELD, Polylith, and CORBA.
Priority workshops: springboard for user participation in redesign activities
Authors: Kristin Braa
Venue: Proceedings of conference on Organizational computing systems (1995)

This paper presents a technique for system redesign called Priority Workshop. The technique aims at widening the circle of decision makers, avoiding arbitrary decisions, and providing an arena for making priorities transparent to those who are affected. Priority Workshop has been conducted in a software company co-operating with several user organisations. The example presented, indicates that Priority Workshops may be a valuable means for users to influence the redesign process.
Experiences in teaching parallel computing&mdash;five years later
Authors: Nan C. Schaller, Andrew T. Kitchen
Venue: ACM SIGCSE Bulletin (1995)

Since 1990, the Computer Science Department at Rochester Institute of Technology has offered a concentration in parallel computing. This concentration is available both to undergraduates and to students studying for the masters degree.This paper documents our experiences with the selection of hardware and software to support our parallel computing program. We describe our concentration, and we report on the networking established between Rochester Institute of Technology and other colleges and universities, designed to provide support for educators who are attempting to introduce parallel computing into their curricula. Finally, we look at what we might do differently if we were starting today.
Error estimation by series association for neural network systems
Authors: Keehoon Kim, Eric B. Bartlett
Venue: Neural Computation (1995)

Estimation of confidence intervals for neural network outputs is important when the uncertainty of a neural network system must be addressed for safety or reliability. This paper presents a new approach for estimating confidence intervals, which can help users validate neural network outputs. The estimation of confidence intervals, called error estimation by series association, is performed by a supplementary neural network trained to predict the error of the main neural network using input features and the output of the main network. The accuracy of this approach is shown using a simple nonlinear mapping and more complicated, realistic nuclear power plant fault diagnosis problems. The results demonstrate that the approach performs confidence estimation successfully.
A new methodology of data dependence analysis for parallelizing C++
Authors: Zhu Genjiang, Xie Li, Sun Zhongxiu
Venue: ACM SIGPLAN Notices (1995)

This paper details parallelism detection in NUAPC[4], an automatically parallelizing compiler based on C++. Two kinds of parallelism, i.e. the inter- and intra-object parallelism, are introduced in NUAPC. The paper presents the method for seeking these parallelism based on the key structures Conflict Set and Method Reference Vector, and proposes a new theoretical formation for expressing and performing data dependence analysis in object-oriented program paradigm. Data dependence involving inherited data and function members are also discussed.
Applying domain analysis and modeling: an industrial experience
Authors: Robert B. France, Thomas B. Horton
Venue: ACM SIGSOFT Software Engineering Notes (1995)

In this paper we describe our experience in applying domain analysis within a company that develops personal electronic devices. We describe how we tailored the DSSA method to suit our needs and then present the process and representations that we found most useful for this situation. The conclusions and lessons learned are useful because few studies published at this time provide details about applications of domain engineering in commercial development environments.
The effect of data structures on the logical complexity of programs
Authors: Farokh B. Bastani, S. Sitharama Iyengar
Venue: Communications of the ACM (1987)

The logical complexity of a program is a measure of the effort required to understand it. We hypothesize that the logical complexity of a program increases with the increase in the opaqueness of the relationship between the physical data structures used in the program and their corresponding abstract data types. The results of an experiment conducted to investigate this hypothesis are reported. Documentation techniques for making programs easier to understand using complex data structures are discussed. Data structure diagrams, data structure invariants, stepwise transformation of data structures, and formal specification of the mapping between abstract and concrete data structures are illustrated using two nontrivial examples.
Two-level logic minimization for low power
Authors: Sasan Iman, Massoud Pedram
Venue: Proceedings of the 1995 IEEE/ACM international conference on Computer-aided design (1995)

Abstract: We study the problem of two-level logic minimization for low power in static CMOS circuits. We start by defining Power Prime Implicants (PPIs) which identify the set of all implicants that are sufficient and necessary for obtaining a minimum power solution. We then provide an efficient algorithm for generating the set of all PPIs of a function. The set of all PPIs is then used in a minimum covering problem to find the best power solution. The feasibility of generating the set of all PPIs and the increased complexity of solving the minimum covering problem are analyzed by deriving an upper bound on the expected number of PPIs which shows it to be linearly proportional to the number of prime implicants of the function. The results of our experiments are then used to draw conclusions on the effectiveness of low power two-level logic minimization.
Writing across the computer science curriculum
Authors: Harriet J. Fell, Viera K. Proulx, John Casey
Venue: Proceedings of the twenty-seventh SIGCSE technical symposium on Computer science education (1996)

At our university, as at many others across the country, there is a movement to integrate the common core subjects with the disciplinary studies. While in the past writing has been a domain of English departments, the new trend is 'writing across curriculum'. It is clear that effective written and oral communication skills are critical for the successful computer professional.We present suggestions for writing assignments that complement the main themes of computer courses from introductory to advanced levels. While some of these have appeared in the literature, others are new. We report on our experience with these assignments and reflect on how they enhance the computer science curriculum.
Chaos engineering in Japan
Authors: Kazuyuki Aihara, Ryu Katayama
Venue: Communications of the ACM (1995)

Since deterministic chaos is not only a profound concept in science but also a ubiquitous phenomenon in real-world nonlinear systems, extending to a variety of temporal and spatial scales, it can be naturally related to applications in science and technology [4]. In fact, it is not difficult to find the buds of such possible applications in historical papers by Van der Pol and Van der Mark [22], Ulam and von Neumann [21], and Kalman [12], although the term deterministic chaos was not used in those days.
Australia: universities offer diversity in computer graphics curricula
Authors: Marion S. Cottingham
Venue: ACM SIGGRAPH Computer Graphics (1996)

This overview of computer graphics education in Australia offers a few surprises in the diversity demonstrated by university curricula, and the languages and hardware used. Computer graphics is taught as a third year course at most Australian universities, with some universities also offering an additional advanced graphics course at the fourth year level.Most universities include what has evolved into a set of core topics that are common to most graphics courses. Most have also added some extra flavor to their courses by providing some unique topics that, although vaguely related, are not normally considered under the heading of mainstream graphics.Each curriculum generally includes all the expected graphics topics, such as line and curve generation, antialiasing, 2D transformations, 3D transformations and 3D viewing, hidden line and hidden surface algorithms, polygon fill algorithms, clipping, illumination and shading models and solid modeling. A good proportion of universities also include texture mapping, color modeling (e.g., RGB and CIE representations), animation, virtual/synthetic camera modeling, GUI design, splines and Bezier surfaces, fractals, ray tracing and human visual perception. Less commonly offered topics are dithering, radiosity and mathematical models.Approximately half of the courses are centered around device independent graphics standards such as GKS and PHIGS, and the SRGP software package is popular in courses based on the PHIGS standard The core topics in these graphics standards courses include graphical input techniques, graphical display devices for output, coordinate systems (world, virtual, and device), graphics primitives, windows and viewports and metagraphics commands.
Profiling in the ASP codesign environment
Authors: Matthew F. Parkinson, Sri Parameswaran
Venue: Proceedings of the 8th international symposium on System synthesis (1995)

Abstract: Automation of the hardware/software codesign methodology brings with it the need to develop sophisticated high-level profiling tools. This paper presents a profiling tool which uses execution profiling on standard C code to obtain accurate and consistent times at the level of individual compound code sections. This tool is used in the ASP Hardware/Software Codesign project. The results from this tool show that profiling must be performed on dedicated hardware which is as close as possible to the final implementation, as opposed to a workstation.
A hypermedia approach to digital libraries: review of research issues
Authors: V. Balasubramanian
Venue: ACM SIGWEB Newsletter (1995)

Digital libraries can provide users with fast access to large, complex, richly connected, and cross-referenced bodies of information. They can be considered as applications based on the hypermedia paradigm. Hypermedia is hypertext with multimedia. The principle behind hypertext or hypermedia is nodes of information (concepts) associated through links (relationships). It is essentially non-linear organization and presentation of information. Nodes can contain text, graphics, animation, audio, video, and even other applications.
Detection of Multiple Faults in Two-Dimensional ILAs
Authors: Martine Schlag, F. Joel Ferguson
Venue: IEEE Transactions on Computers (1996)

We provide test sets proportional to the sum of the two dimensions of the array for a large class of cells, which allow us to test rows (or columns) of cells of the array independently. Constant length test sets for array multipliers have been found under the single faulty cell model if the array is modified, and otherwise test sets are proportional to the number of cells. We can verify the full adder array of a combinational n×m multiplier in O(n + m) tests under the Multiple Faulty Cell (MFC) model. The entire multiplier, including the AND gates which generate the summands, can be verified after applying the same modifications which make the multiplier C-testable under the single faulty cell model.
Managing IT professionals in a global environment
Authors: Janice M. Burn, Louise C. K. Ma, Eugenia M. W. Ng Tye
Venue: ACM SIGCPR Computer Personnel (1995)

Organizations are facing a world which is becoming increasingly more global and where many are now forced to operate in a cross-cultural environment. For the Multinational company (MNC) this implies the development of corporate personnel policies which can be effected and effective in a multi-cultural environment. This is particularly relevant to Information Technology (IT) personnel who, by the very nature of their job, have to participate in the development of Information Systems (IS) that transcend cultural barriers.The effective deployment of IT staff has long been an issue of concern coupled with the scarcity of IT professionals in many countries. The global nature of IS, however, also implies the formation of multi-cultural project teams where management must take into account the different expectations and motivational patterns of IT staff worldwide. The problem has intensified with the growing utilization of outsourcing as a means of supplying cheaper trained IT staff.This article reports on a cross-cultural study which addresses some of these issues. The study examines the career expectations of IT undergraduates with the perceived reality of the IT profession through the eyes of graduates. Hong Kong based IT professionals are compared at both stages of the study against their United States counterparts. Not only is there a severe mismatch between the expectations and their realization but significant differences exist between the two cultures. These differences relate both to staff development needs and management approaches. This has a number of implications for IT personnel policies and for IT management worldwide.
Encouraging Experimental Results on Learning CNF
Authors: Raymond J. Mooney
Venue: Machine Learning (1995)

This paper presents results comparing three simple inductive learning systems using different representations for concepts, namely: CNF formulae, DNF formulae, and decision trees. The CNF learner performs surprisingly well. Results on five natural data sets indicates that it frequently trains faster and produces more accurate and simpler concepts.
Towards a conceptual framework for object oriented software metrics
Authors: Neville I. Churcher, Martin J. Shepperd
Venue: ACM SIGSOFT Software Engineering Notes (1995)

The development of software metrics for object oriented (OO) languages is receiving increasing attention. We examine the reasons why this is a much more challenging problem than for conventional languages. It seems premature to develop and apply OO metrics while there remains uncertainty not only about the precise definitions of many fundamental quantities and their subsequent impact on derived metrics, but also a lack of qualitative understanding of the structure and behaviour of OO systems. We argue that establishing a standard terminology and data model will help provide a framework for both theoretical and empirical work and increase the chances of early success. One potential benefit is improvement of the ability to perform independent validation of models and metrics. We propose a data model and terminology and illustrate the importance of such definitions by examining the seemingly straightforward concept of the number of methods per class. We discuss the implications of ambiguities in definitions for a suite of metrics which has recently been proposed. Preliminary results from our analysis of industrial systems are presented.
An automatic trace analysis tool generator for Estelle specifications
Authors: S. Alan Ezust, Gregor v. Bochmann
Venue: Proceedings of the conference on Applications, technologies, architectures, and protocols for computer communication (1995)

This paper describes the development of Tango, an automatic generator of backtracking trace analysis tools for single-process specifications written in the formal description language, Estelle. A tool generated by Tango automatically checks the validity of any execution trace against the given specification, and supports a number of checking options. The approach taken was to modify an Estelle-to-C++ compiler. Discussion about nondeterministic specifications, multiple observation points, and on-line trace analysis follow. Trace analyzers for the protocols LAPD and TP0 have been tested and performance results are evaluated. Issues in the analysis of partial traces are also discussed.