ppxscal/embedding_network huggingface dataset:
Verifying sequential equivalence using ATPG techniques
Authors: Shi-Yu Huang, Kwang-Ting Cheng, Kuang-Chien Chen
Venue: ACM Transactions on Design Automation of Electronic Systems (TODAES) (2001)

In this paper we address the problem of verifying the equivalence of two sequential circuits. State-of-the-art sequential optimization techniques such as retiming and sequential redundancy removal can handle designs with up to hundreds or even thousands of flip-flops. However, the BDD-based approaches for verifying sequential equivalence can easily run into memory explosion for such designs. In an attempt to handle larger circuits, we modify test pattern-generation techniques for verification. The suggested approach utilizes the popular efficient backward-justification technique used in most sequential ATPG programs. We present several techniques to enhance the efficiency of this approach by (1) identifying equivalent flip-flop pairs using an induction-based algorithm, and (2) generalizing the idea of exploring the structural similarity between circuits to perform verification in stages. This ATPG-based framework is suitable for verifying circuits either with or without a reset state. In order to extend this approach to verify retimed circuits, we introduce a delay-compensation-based algorithm for preprocessing the circuits. The experimental results of verifying the correctness of circuits after sequential redundancy removal and retiming with up to several hundred flip-flops are presented.
Metadata for smart multimedia learning objects
Authors: Abdulmotaleb El Saddik, Amir Ghavam, Stephan Fischer, Ralf Steinmetz
Venue: Proceedings of the Australasian conference on Computing education (2000)

The application of educational metadata is nowadays often limited to the description of static resources (text or image) in order to support the retrieval process. The usage of metadata is done in a static way with respect to the (static) content and cannot influence multimedia content itself. An adequate description of dynamic multimedia content, for example animations, is also difficult. In this paper we propose dynamic educational metadata as an extension of IEEE's Learning Objects Metadata (LOM) to describe multimedia content. These metadata can be used to customize the behavior of the multimedia object according to the user's needs. The term customization is normally used in the context of component software technology and applied in our context to denote changes and/or modifications to a multimedia learning object. These changes are necessary to match the learning goals of a user and to reuse dynamic multimedia content in a different context.
A bypass scheme for core-based system fault testing
Authors: M. Nourani, C. Papachristou
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

We present a global design for test methodology for testing a core-based system in its entirety. This is achieved by introducing a "bypass" mode for each core by which the data can be transferred from a core input port to the output port without interfering the core circuitry itself. The interconnections are thoroughly tested since they are used to propagate test data (patterns or signatures) in the system. The system is modeled as a directed weighted graph in which the core accessibility is solved as a shortest path problem.Fault Detection for Linear Analog Circuits Using Current Injection83590987abs.htm J. Velasco-Medina , Th. Calin, M. NicolaidisReliable Integrated Systems Group, TIMA/INPGA new test technique for linear analog circuits which employs current injection as input test stimulus is described. Our investigations have shown that current transitions resulting from a current injected on internal test points are significantly different for the fault free and faulty circuits. This can be used for fault detection purposes. In fact, the current injection as test input stimulus represents a powerfull alternative to the test approaches based on conventional voltage input stimulus. The new approach allows to improve the testability of various faults, which are difficult to detect or are untestable when using voltage-based test stimulus. In addition the technique has significant advantages for BIST testing purposes. The technique is illustrated by means of a modern opamp circuit and by considering catastrophic and gate-oxide-short (GOS) faults. RAM-Based FPGA's: A Test Approach for the Configurable Logic83590082abs.htm M. Renovell, J. M. PortalLIRMM-UM2J. FiguerasUPC DiagonalY. ZorianLogic Vision Inc.This paper proposes a methodology for testing the configurable logic of RAM-based FPGAs taking into account the configurability of such flexible devices. The methodology is illustrated using the XILINX 4000 family. On this example of FPGA, we obtain only 8 basic Test Configurations to fully test the whole matrix of CLBs. In the proposed Test Configurations, all the CLBs have exactly the same configuration forming a set of one-dimensional iterative arrays. The iterative arrays present a C-testability property in such a way that the number of Test Configurations 8 is fixed and independent of the FPGA size.
Polymorphic panelists
Authors: Byron Weber Becker, Richard Rasala, Joseph Bergin, Christine Shannon, Eugene Wallingford
Venue: ACM SIGCSE Bulletin (2001)

Polymorphism is an important object-oriented programming concept in which objects from two or more different classes respond to the same set of messages. For instance, HourlyEmployee, SalariedEmployee, and ContractEmployee all respond to the message calculatePay(). Instances of each class "do the right thing" to calculate their pay even though the methods to do so may be quite different. But the payroll program using these classes doesn't care - it can ask each object for the amount owed without caring what kind of employee it represents or how the amount is calculated.The panelists are all instances of subclasses of Professor which will respond to the following queries. Since each of the subclasses implement these queries differently, the answers will usually be different as well! bull; polymorphPreconditions(): The object (professor) specifies the information students must know before polymorphism is introduced in their class. bull; polymorphPresentation(): The object (professor) describes how polymorphism is introduced in their class. bull; polymorphStudentUsage(): The object (professor) describes how their students use polymorphism later in the course. bull; answerQuestions(): The object (professor) responds to any questions about their approach.
A locally-organized parser for spoken input
Authors: Perry Lowell Miller
Venue: Communications of the ACM (1974)

This paper describes LPARS, a locally-organized parsing system, designed for use in a continuous speech recognizer. LPARS processes a string of phonemes which contains ambiguity and error. The system is locally-organized in the sense that it builds local parse structures from reliable word candidates recognized anywhere in an input utterance. These local structures are used as &ldquo;islands of reliability&rdquo; to guide the search for more highly garbledwords which might complete the utterance.
Teachers as simulation programmers: minimalist learning and reuse
Authors: Mary Beth Rosson, Cheryl D. Seals
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2001)

Five public school teachers were observed during two self-study sessions where they learned to use Visual AgenTalk (VAT). The first session emphasized the basic visual programming skills, while the second introduced ways to reuse existing simulations. Two versions of the reuse tutorial were developed, one offering a concrete example world for reuse, and the second an abstract world. During their learning and reuse sessions, the teachers thought out loud as they worked, enabling a detailed analysis of their goals, reactions, problems, and successes. After each session, the teachers also completed user reaction questionnaires. Although all teachers succeeded in learning the basics of VAT, they varied considerably in their reuse of the example simulations. It appears that the simplified components of the abstract world supported reuse to a greater degree than those of the concrete example world.
Making scientific computations reproducible
Authors: Matthias Schwab, Martin Karrenbach, Jon Claerbout
Venue: Computing in Science and Engineering (2000)

To verify a research paper's computational results, readers typically have to recreate them from scratch. ReDoc is a simple software filing system for authors that lets readers easily reproduce computational results using standardized rules and commands.
On the equivalent bandwidth of self-similar sources
Authors: Nelson L. S. Fonseca, Gilberto S. Mayor, Cesar A. V. Neto
Venue: ACM Transactions on Modeling and Computer Simulation (TOMACS) (2000)

This article presents a method for the computation of the equivalent bandwidth of an aggregate of heterogeneous self-similar sources, as well as the time scales of interest for queueing systems fed by a fractal Brownian motion (fBm) process. Moreover, the fractal leaky bucket, a novel policing mechanism capable of accurately monitoring self-similar sources, is introduced.
Some theorems to aid in solving the file allocation problem
Authors: Enrique Grapa, Geneva G. Belford
Venue: Communications of the ACM (1977)

The file allocation problem &mdash; i.e. the problem of finding the optimal set of network sites at which to locate copies of a file &mdash; is known to be, in general, polynomial complete. Heuristics and other aids to finding optimal, or near-optimal, solutions are therefore much needed. In this paper we present three theorems which can be applied a priori to indicate that certain sites should (or should not) be included in an optimal allocation.
Experiences with Parallel N-Body Simulation
Authors: Pangfeng Liu, Sandeep N. Bhatt
Venue: IEEE Transactions on Parallel and Distributed Systems (2000)

This paper describes our experiences developing high-performance code for astrophysical N-body simulations. Recent N-body methods are based on an adaptive tree structure. The tree must be built and maintained across physically distributed memory; moreover, the communication requirements are irregular and adaptive. Together with the need to balance the computational work-load among processors, these issues pose interesting challenges and tradeoffs for high-performance implementation. Our implementation was guided by the need to keep solutions simple and general. We use a technique for implicitly representing a dynamic global tree across multiple processors which substantially reduces the programming complexity as well as the performance overheads of distributed memory architectures. The contributions include methods to vectorize the computation and minimize communication time which are theoretically and experimentally justified. The code has been tested by varying the number and distribution of bodies on different configurations of the Connection Machine CM-5. The overall performance on instances with 10 million bodies is typically over 48 percent of the peak machine rate, which compares favorably with other approaches.
A multiprogramming environment for online data acquistion and analysis
Authors: Peter C. Lockemann, W. Dale Knutsen
Venue: Communications of the ACM (1967)

An experimental system for acquisition and analysis of large bodies of data derived from scientific experiments is described. Its architecture and implementation is largely based on certain objectives and characteristics of a general data analysis scheme. Early applications have been oriented towards the investigation of data obtained in biological research. Some of the problems encountered by the chosen approach are discussed.
Reasoning about code mobility with mobile UNITY
Authors: Gian Pietro Picco, Gruia-Catalin Roman, Peter J. McCann
Venue: ACM Transactions on Software Engineering and Methodology (TOSEM) (2001)

Advancements in network technology have led to the emergence of new computing paradigms that challenge established programming practices by employing weak forms of consistency and dynamic forms of binding. Code mobility, for instance, allows for invocation-time binding between a code fragment and the location where it executes. Similarly, mobile computing allows hosts (and the software they execute) to alter their physical location. Despite apparent similarities, the two paradigms are distinct in their treatment of location and movement. This paper seeks to uncover a common foundation for the two paradigms by exploring the manner in which stereotypical forms of code mobility can be expressed in a programming notation developed for mobile computing. Several solutions to a distributed simulation problem are used to illustrate the modeling strategy and the ability to construct assertional-style proofs for programs that employ code mobility.
A first step towards flexible local feedback for ad hoc retrieval
Authors: Tetsuya Sakai, Masahiro Kajiura, Kazuo Sumita
Venue: Proceedings of the fifth international workshop on on Information retrieval with Asian languages (2000)

Local feedback for ad hoc retrieval typically hurts performance for about one-third of the search requests while improving the average performance. Our objective is to make it more reliable by estimating the optimal number of assumed-relevant documents and the optimal number of expansion terms for each request. We examine some simple optimization methods based on: the number of case particles in the request; the number of initial search terms; the highest document score in the initial ranked output; and the document score curves. Unfortunately, our first results using the BMIR-J2 and IREX Japanese test collections are negative. We are currently exploring some modified strategies for solving the optimization problems.
ICA Mixture Models for Unsupervised Classification of Non-Gaussian Classes and Automatic Context Switching in Blind Signal Separation
Authors: Te-Won Lee, Michael S. Lewicki, Terrence J. Sejnowski
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2000)

An unsupervised classification algorithm is derived by modeling observed data as a mixture of several mutually exclusive classes that are each described by linear combinations of independent, non-Gaussian densities. The algorithm estimates the density of each class and is able to model class distributions with non-Gaussian structure. The new algorithm can improve classification accuracy compared with standard Gaussian mixture models. When applied to blind source separation in nonstationary environments, the method can switch automatically between classes, which correspond to contexts with different mixing properties. The algorithm can learn efficient codes for images containing both natural scenes and text. This method shows promise for modeling non-Gaussian structure in high-dimensional data and has many potential applications.
Numerical analysis in a Ph.D. computer science program
Authors: Seymour V. Parter
Venue: Communications of the ACM (1969)

Numerical Analysis is the study of methods and procedures used to obtain&ldquo;approximate solutions&rdquo; to mathematical problems. Much of the emphasis is on scientific calculation. The difficulties of education in such a broad area center around the question of background and emphasis. The Numerical Analysis program in the Computer Science Department should emphasize an awareness of the problems of computer implementation and experimental procedures. Nevertheless, there is a need for a solid background in applied mathematics.
Quicksilver: a quasi-static compiler for Java
Authors: Mauricio Serrano, Rajesh Bordawekar, Sam Midkiff, Manish Gupta
Venue: Proceedings of the 15th ACM SIGPLAN conference on Object-oriented programming, systems, languages, and applications (2000)

This paper presents the design and implementation of the Quicksilver1 quasi-static compiler for Java. Quasi-static compilation is a new approach that combines the benefits of static and dynamic compilation, while maintaining compliance with the Java standard, including support of its dynamic features. A quasi-static compiler relies on the generation and reuse of persistent code images to reduce the overhead of compilation during program execution, and to provide identical, testable and reliable binaries over different program executions. At runtime, the quasi-static compiler adapts pre-compiled binaries to the current JVM instance, and uses dynamic compilation of the code when necessary to support dynamic Java features. Our system allows interprocedural program optimizations to be performed while maintaining binary compatibility. Experimental data obtained using a preliminary implementation of a quasi-static compiler in the Jalape ntilde;o JVM clearly demonstrates the benefits of our approach: we achieve a runtime compilation cost comparable to that of baseline (fast, non-optimizing) compilation, and deliver the runtime program performance of the highest optimization level supported by the Jalape ntilde;o optimizing compiler. For the SPECjvm98 benchmark suite, we obtain a factor of 104 to 158 reduction in the runtime compilation overhead relative to the Jalape ntilde;o optimizing compiler. Relative to the better of the baseline and the optimizing Jalape ntilde;o compilers, the overall performance (taking into account both runtime compilation and execution costs) is increased by 9.2% to 91.4% for the SPECjvm98 benchmarks with size 100, and by 54% to 356% for the (shorter running) SPECjvm98 benchmarks with size 10.
Differential Analog Data Path DC Offset Calibration Methods
Authors: Takeo Yasuda, Hajime Andoh
Venue: Analog Integrated Circuits and Signal Processing (2000)

DC offset causes performance degradation in signal processing systems especially for high-speed applications. A new offset cancellation method that relaxes the requirement for the offset of the circuit components in the differential analog data path to about 10 times larger is introduced. This method moves the adjusting target from analog-to-digital converter (ADC) to its input buffer and adjusts DC level of ADC input to its center before the final offset cancellation. It eliminates post-production adjustment such as fuse trimming, which increases the cost and TAT in manufacturing and testing. Execution and simulation times are shortened down to 1/9 for less settling time in buffer and with improved logic. An automatic quick offset calibration circuit is implemented in a small silicon space in a high-speed hard disk drive (HDD) channel with 0.25-&mu;m four-layer metal CMOS process. The measured data show this method works effectively in this system.
Using high-speed WANs and network data caches to enable remote and distributed visualization
Authors: Wes Bethel, Brian Tierney, Jason lee, Dan Gunter, Stephen Lau
Venue: Proceedings of the 2000 ACM/IEEE conference on Supercomputing (CDROM) (2000)

Visapult is a prototype application and framework for remote visualization of large scientific datasets. We approach the technical challenges of tera-scale visualization with a unique architecture which employs high speed WANs and network data caches for data staging and transmission. This architecture allows for the use of available cache and compute resources at arbitrary locations on the network. High data throughput rates and network utilization are achieved by parallelizing I/O at each stage in the application, and by pipelining the visualization process. On the desktop, the graphics interactivity is effectively decoupled from the latency inherent in network applications. We present a detailed performance analysis of the application, and improvements resulting from field-test analysis conducted as part of the DOE Combustion Corridor project.
Domain-specific languages: an annotated bibliography
Authors: Arie van Deursen, Paul Klint, Joost Visser
Venue: ACM SIGPLAN Notices (2000)

We survey the literature available on the topic of domain-specific languages as used for the construction and maintenance of software systems. We list a selection of 75 key publications in the area, and provide a summary for each of the papers. Moreover, we discuss terminology, risks and benefits, example domain-specific languages, design methodologies, and implementation techniques.
Computation of Jn(x) by numerical integration
Authors: A. H. Stroud, J. P. Kohli
Venue: Communications of the ACM (1969)

It is shown to be practical to compute Jn(x) by numerical integration of its integral representation using the trapezoidal rule. The error in this approximation was studied empirically.
An encoding method for multifield sorting and indexing
Authors: Michael W. Blasgen, Richard G. Casey, Kapali P. Eswaran
Venue: Communications of the ACM (1977)

Sequences of character strings with an order relation imposed between sequences are considered. An encoding scheme is described which produces a single, order-preserving string from a sequence of strings. The original sequence can be recovered from the encoded string, and one sequence of strings precedes another if and only if the encoding of the first precedes the encoding of the second. The strings may be variable length, without a maximum length restriction, and no symbols need be reserved for control purposes. Hence any symbol may occur in any string. The scheme is useful for multifield sorting, multifield indexing, and other applications where ordering on more than one field is important.
Mobility prediction and routing in ad hoc wireless networks
Authors: William Su Sung-Ju Lee Mario Gerla
Venue: International Journal of Network Management (2001)

By exploiting non-random behaviors for the mobility patterns that mobile users exhibit, we can predict the future state of network topology and perform route reconstruction proactively in a timely manner. Moreover, by using the predicted information on the network topology, we can eliminate transmissions of control packets otherwise needed to reconstruct the route and thus reduce overhead. In this paper, we propose various schemes to improve routing protocol performances by using mobility prediction. We then evaluate the effectiveness of using mobility prediction via simulation. Copyright &copy; 2001 John Wiley Sons, Ltd.
A moment of perfect clarity II: consequences of sparse sets hard for NP with respect to weak reductions
Authors: Christian Glaßer Lane A. Hemaspaandra
Venue: ACM SIGACT News (2000)

This issue's column, Part II of the article started in the preceding issue, is about progress on the question of whether NP has sparse hard sets with respect to weak reductions.Upcoming Complexity Theory Column articles include A. Werschulz on information-based complexity; J. Castro, R. Gavald agrave;, and D. Guijarro on what complexity theorists can learn from learning theory; S. Ravi Kumar and D. Sivakumar on a to-be-announced topic; M. Holzer and P. McKenzie on alternating stack machines; and R. Paturi on the complexity of k-SAT.
Coding the Lehmer pseudo-random number generator
Authors: W. H. Payne, J. R. Rabung, T. P. Bogyo
Venue: Communications of the ACM (1969)

An algorithm and coding technique is presented for quick evaluation of the Lehmer pseudo-random number generator modulo 2 ** 31 - 1, a prime Mersenne number which produces 2 ** 31 - 2 numbers, on a p-bit (greater than 31) computer. The computation method is extendible to limited problems in modular arithmetic. Prime factorization for 2 ** 61 - 2 and a primitive root for 2 ** 61 - 1, the next largest prime Mersenne number, are given for possible construction of a pseudo-random number generator of increased cycle length.