ppxscal/embedding_network huggingface dataset:
Model abstraction for formal verification
Authors: Y.-W. Hsieh, S. P. Levitan
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

As the complexity of circuit designs grows, designers look toward formal verification to achieve better test coverage for validating complex designs. However, this approach is inherently computationally intensive, and hence, only small designs can be verified using this method. To achieve better performance, model abstraction is necessary. Model abstraction reduces the number of states necessary to perform formal verification while maintaining the functionality of the original model with respect to the specifications to be verified. As a result, model abstraction enables large designs to be formally verified. In this paper, we describe three methods for model abstraction based on semantics extraction from user models to improve the performance of formal verification tools.
Advanced database concepts for undergraduates: experience with teaching a second course
Authors: Susan D. Urban, Suzanne W. Dietrich
Venue: ACM SIGCSE Bulletin (2001)

This paper describes the development of a second database course for undergraduates, preparing students for the advanced database concepts they will experience in industry. Assuming an introductory course on relational database systems as a prerequisite, the topics addressed in the course include object-oriented data modeling, object-oriented database systems, object-relational database systems, Web access to databases, and professionalism and ethics. We present our experience with teaching the course, elaborating on the topics and assignments. We also present feedback from students and industry partners as well as our own assessment of future course refinements.
On &ldquo;shapes&rdquo; of colors for content-based image retrieval
Authors: Renato O. Stehling, Mario A. Nascimento, Alexandre X. Falcão
Venue: Proceedings of the 2000 ACM workshops on Multimedia (2000)

Color is a commonly used feature for realizing content-based image retrieval (CBIR). Towards this goal, this paper presents a new approach for CBIR which is based on well known and widely used color histograms. Contrasting to previous approaches, such as using a single color histogram for the whole image, or local color histograms for a fixed number of image cells, the one we propose (named Color Shape) uses a variable number of histograms, depending only on the actual number of colors present in the image. Our experiments using a large set of heterogeneous images and pre-defined query/answer sets show that the Color Shape approach offers good retrieval quality with relatively low space overhead, outperforming previous approaches.
Simulating complex systems without adjustable parameters
Authors: Michele Parrinello
Venue: Computing in Science and Engineering (2000)

The author reviews the principles on which molecular dynamics is based. He also illustrates how in combination with modern density functional theory for the electronic structures it provides a powerful tool for studying complex chemical processes without adjustable parameters.
Construction of a Chinese-English WordNet and its application to CLIR
Authors: Hsin-Hsi Chen, Chi-Ching Lin
Venue: Proceedings of the fifth international workshop on on Information retrieval with Asian languages (2000)

This paper integrates five linguistic resources, including Cilin, a Chinese-English dictionary, ASBC corpus, SemCor, and WordNet, to construct a Chinese-English WordNet. The result is employed in Chinese-English information retrieval. Under TREC-6 text collection, TREC topics 301-350, and Smart information retrieval system, the model for CLIR achieves 69.23% of monolingual information retrieval. It also gains 10.02% increase relative to a model that resolves translation ambiguity and target polysemy together using a Chinese-English dictionary.
CHAMP&mdash;character manipulation procedures
Authors: Edward F. Storm
Venue: Communications of the ACM (1968)

A new programming language facility for symbol manipulation is described. String procedures may be declared and called in a standard ALGOL context. ALGOL procedures can in turn be called by string procedures so that numeric and symbolic processes may conveniently be programmed together. Concatenation and a variant of SNOBOL's pattern matching make up a set of primitive commands. These are assembled together into conditional expressions which are to be used to provide alternative computational patterns. Arrays of strings are processed using quantifiers. The class of things which may be assigned to an identifier can be restricted by a procedure expressed in the notation. The language facilities have been implemented in the ALGOL compiler for the Burroughs B5500.
Low-latency communication on the IBM RISC system/6000 SP
Authors: Chi-Chao Chang, Grzegorz Czajkowski, Chris Hawblitzel, Thorsten von Eicken
Venue: Proceedings of the 1996 ACM/IEEE conference on Supercomputing (CDROM) (1996)

The IBM SP is one of the most powerful commercial MPPs, yet, in spite of its fast processors and high network bandwidth, the SP's communication latency is inferior to older machines such as the TMC CM-5 or Meiko CS-2. This paper investigates the use of Active Messages (AM) communication primitives as an alternative to the standard message passing in order to reduce communication overheads and to offer a good building block for higher layers of software. The first part of this paper describes an implementation of Active Messages (SP AM) which is layered directly on top of the SP's network adapter (TB2). With comparable bandwidth, SP AM's low overhead yields a round-trip latency that is 40% lower than IBM MPL's. The second part of the paper demonstrates the power of AM as a communication substrate by layering Split-C as well as MPI over it. Split-C benchmarks are used to compare the SP to other MPPs and show that low message overhead and high throughput compensate for SP's high network latency. The MPI implementation is based on the freely available MPICH version and achieves performance equivalent to IBM's MPI-F on the NAS benchmarks.
A real-time 64-monosyllable recognition LSI with learning mechanism
Authors: Kazuhiro Nakamura, Qiang Zhu, Shinji Maruoka, Takashi Horiyama, Shinji Kimura, Katsumasa Watanabe
Venue: Proceedings of the 2001 Asia and South Pacific Design Automation Conference (2001)

In the paper, a real-time 64-mono-syllable recognition LSI is presented. The LSI accepts 11.6 msec speech frame and outputs a 6-bit symbol-code for each frame by the end of the next frame with the pipelining manner. The recognition method is based on the Hidden Markov Model and is speaker-independent. An on-chip learning mechanism has also been designed, but the circuit is off-chip at present implementation because of the restriction of LSI area. The LSI is fabricated by VDEC Rohm with 0.6 um process on a 4.5 mm x 4.5 mm chip.
Evaluation of the streams-C C-to-FPGA compiler: an applications perspective
Authors: Jan Frigo, Maya Gokhale, Dominique Lavenier
Venue: Proceedings of the 2001 ACM/SIGDA ninth international symposium on Field programmable gate arrays (2001)

The Streams-C compiler ([5]) synthesizes hardware circuits for reconfigurable FPGA-based computers from parallel C programs. The Streams-C language consists of a small number of libraries and intrinsic functions added to a synthesizable subset of C, and supports a communicating process programming model. The processes may be either software or hardware processes, and the compiler manages communication among the processes transparently to the programmer. For the hardware processes, the compiler generates Register-Transfer-Level (RTL) VHDL, targeting multiple FPGAs with dedicated memories. For the software processes, a multi-threaded software program is generated.The Streams-C language and compiler offer a very high level of expressivity for reconfigurable computing application development, particularly for stream-processing applications. We find this is reflected in productivity, for a factor of up to 10 times improvement in time to produce a program. However, use of the tool in the ``real world'' is predicated on performance: only if such a compiler can deliver performance comparable to hand-coded performance will it be used in practice.This paper presents an application study of the Streams-C compiler. Four applications have been written in Streams-C and compiled to the AMC Wildforce board containing Xilinx 4036's. Those same applications have been hand-coded in a combination of RTL and structural VHDL. We compare performance of the generated code with the hand-optimized code. Our study shows that the compiler-generated designs are 1.37--4 times the area and $1/2$--1 times the clock frequency of the hand designs. We find that the compiler, based on the SUIF infrastructure, can be greatly improved through various standard compiler optimizations that are not currently being exploited. Thus we are currently re-writing a public domain version of Streams-C to better optimize and target the Virtex chip.
Maintaining approximate extent measures of moving points
Authors: Pankaj K. Agarwal, Sariel Hal-Peled
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

We present approximation algorithms for maintaining various descriptors of the extent of moving points in Rd. We first describe a data structure for maintaining the smallest orthogonal rectangle containing the point set. We then use this data structure to maintain the approximate diameter, smallest enclosing disk, width, and smallest area or perimeter bounding rectangle of a set of moving points in R2 so that the number of events is only a constant. This contrasts with &OHgr;(n2) events that data structures for the maintenance of those exact properties have to handle.
Bugs in the programs
Authors: Richard D. Pethia
Venue: ACM SIGSOFT Software Engineering Notes (2000)

Security on the Internet is receiving increasing attention as more and more organizations are becoming dependent on the network. The use of the Internet for electronic commerce, government operations, research activities, and entertainment has now reached the point that attacks against the network and the systems connected to it have become major news items. While the press highlights a few high-profile incidents, the actual number of attacks is much higher. The CERT Coordination Center works with the Internet community to deal with incidents and responded to over 8,000 incidents in 1999. The incident projection for year 2000 is 17,000 to 20,000. At the same time, the amount of damage resulting from the incidents is also increasing. While the press often focuses on cases of web site graffiti, more serious cases of financial fraud, extortion, and debilitating denial of service attacks are being reported at increasing rates.
Weak Approximations and Extrapolations of Stochastic Differential Equations with Jumps
Authors: X. Q. Liu, C. W. Li
Venue: SIAM Journal on Numerical Analysis (2000)

Numerical discretization schemes are developed to approximate functionals of stochastic differential equations with jumps, and the convergence is shown to have an appropriate order. For the Euler scheme and the second order weak scheme, the leading coefficient of their global errors are determined by the stochastic Taylor expansion. Based on the error expression, the extrapolation technique can be applied to get a higher order convergence. Numerical examples are provided to compare various weak schemes and extrapolations.
Evaluation by highly relevant documents
Authors: Ellen M. Voorhees
Venue: Proceedings of the 24th annual international ACM SIGIR conference on Research and development in information retrieval (2001)

Given the size of the web, the search engine industry has argued that engines should be evaluated by their ability to retrieve highly relevant pages rather than all possible relevant pages. To explore the role highly relevant documents play in retrieval system evaluation, assessors for the \mbox{TREC-9} web track used a three-point relevance scale and also selected best pages for each topic. The relative effectiveness of runs evaluated by different relevant document sets differed, confirming the hypothesis that different retrieval techniques work better for retrieving highly relevant documents. Yet evaluating by highly relevant documents can be unstable since there are relatively few highly relevant documents. TREC assessors frequently disagreed in their selection of the best page, and subsequent evaluation by best page across different assessors varied widely. The discounted cumulative gain measure introduced by J\"{a}rvelin and Kek\"{a}l\"{a}inen increases evaluation stability by incorporating all relevance judgments while still giving precedence to highly relevant documents.
Computer science: a conceptual framework for curriculum planning
Authors: Saul Amarel
Venue: Communications of the ACM (1971)

Two views of computer science are considered: a global view which attempts to capture broad characteristics of the field and its relationships to other fields, and a local view which focuses on the inner structure of the field. This structure is presented in terms of the kinds of knowledge, problems, and activities that exist within the discipline, as well as the relations between them. An approach to curriculum planning in computer science is presented which is guided by the structure of the field, by the fact that change is an important feature of the situation, and by the expectation that computer science will continue to increase its working contacts with other disciplines.
An efficient algorithm for fast parasitic extraction and passive order reduction of 3D interconnect models
Authors: N. Marques, M. Kamon, J. White, L. M. Silveira
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

As VLSI circuit speeds have increased, the need for accurate three-dimensional interconnect models has become essential to accurate chip and system design. In this paper, we describe an integral equation approach to modeling the impedance of interconnect structures accounting for both the charge accumulation on the surface of conductors and the current traveling along conductors. Unlike previous methods, our approach is based on a modified nodal analysis formulation and can be used directly to generate guaranteed passive low order interconnect models for efficient inclusion in a standard circuit simulator
Optimal Order Preconditioning of Finite Difference Matrices
Authors: Yvan Notay
Venue: SIAM Journal on Scientific Computing (1999)

A new multilevel preconditioner is proposed for the iterative solution of linear systems whose coefficient matrix is a symmetric M-matrix arising from the discretization of a second-order elliptic PDE. It is based on a recursive block incomplete factorization of the matrix partitioned in a two-by-two block form, in which the submatrix related to the fine grid nodes is approximated by a modified incomplete (MILU) factorization and the Schur complement computed from a diagonal approximation of the same submatrix. A general algebraic analysis proves optimal order convergence under mild assumptions related to the quality of the approximations of the Schur complement on the one hand and of the fine grid submatrix on the other hand. This analysis does not require a red-black ordering of the fine grid nodes, nor a transformation of the matrices in hierarchical form.Considering more specifically 5 point finite difference approximations of two-dimensional problems, we prove that the spectrum of the preconditioned system is contained in the interval [0.46, 3], independently of possible (large) jumps or anisotropy in the PDE coefficients, as long as the latter are piecewise constant on the coarsest mesh. Numerical results illustrate the efficiency and the robustness of the proposed method.
A theorem-proving language for experimentation
Authors: L. Henschen, Ross Overbeck, L. Wos
Venue: Communications of the ACM (1974)

Because of the large number of strategies and inference rules presently under consideration in automated theorem proving, there is a need for developing a language especially oriented toward automated theorem proving. This paper discusses some of the features and instructions of this language. The use of this language permits easy extension of automated theorem-proving programs to include new strategies and/or new inference rules. Such extendability will permit general experimentation with the various alternative systems.
An Adaptive Contour Closure Algorithm and Its Experimental Evaluation
Authors: Xiaoyi Jiang
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2000)

The potential of edge-based complete image segmentation into regions has not gained the due attention in the literature thus far. The present paper attempts to explore this potential by proposing an adaptive grouping algorithm to solve the contour closure problem that is the key to a successful edge-based complete image segmentation. The effectiveness of the proposed algorithm will be extensively tested in the range image domain and compared to several region-based segmentation methods within a rigorous comparison framework. On three range image databases of varying quality acquired by different range scanners, it will be shown that the proposed approach is able to achieve very appealing performance with respect to both segmentation quality and computation time.
Geometric Camera Calibration Using Circular Control Points
Authors: Janne Heikkilä
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2000)

Modern CCD cameras are usually capable of a spatial accuracy greater than 1/50 of the pixel size. However, such accuracy is not easily attained due to various error sources that can affect the image formation process. Current calibration methods typically assume that the observations are unbiased, the only error is the zero-mean independent and identically distributed random noise in the observed image coordinates, and the camera model completely explains the mapping between the 3D coordinates and the image coordinates. In general, these conditions are not met, causing the calibration results to be less accurate than expected. In this paper, a calibration procedure for precise 3D computer vision applications is described. It introduces bias correction for circular control points and a nonrecursive method for reversing the distortion model. The accuracy analysis is presented and the error sources that can reduce the theoretical accuracy are discussed. The tests with synthetic images indicate improvements in the calibration results in limited error conditions. In real images, the suppression of external error sources becomes a prerequisite for successful calibration.
Performance of hybrid message-passing and shared-memory parallelism for discrete element modeling
Authors: D. S. Henty
Venue: Proceedings of the 2000 ACM/IEEE conference on Supercomputing (CDROM) (2000)

The current trend in HPC hardware is towards clusters of shared-memory (SMP) compute nodes. For applications developers the major question is how best to program these SMP clusters. To address this we study an algorithm from Discrete Element Modeling, parallelized using both the message-passing and shared-memory models simultaneously (&ldquo;hybrid&rdquo; parallelization). The natural load-balancing methods are different in the two parallel models, the shared-memory method being in principle more efficient for very load-imbalanced problems. It is therefore possible that hybrid parallelism will be beneficial on SMP clusters. We benchmark MPI and OpenMP implementations of the algorithm on MPP, SMP and cluster architectures, and evaluate the effectiveness of hybrid parallelism. Although we observe cases where OpenMP is more efficient than MPI on a single SMP node, we conclude that our current OpenMP implementation is not yet efficient enough for hybrid parallelism to outperform pure message-passing on an SMP cluster.
Classifying properties: an alternative to the safety-liveness classification
Authors: Gleb Naumovich, Lori A. Clarke
Venue: ACM SIGSOFT Software Engineering Notes (2000)

Traditionally, verification properties have been classified as safety or liveness properties. While this taxonomy has an attractive simplicity and is useful for identifying the appropriate analysis algorithm for checking a property, determining whether a property is safety, liveness, or neither can require significant mathematical insight on the part of the analyst. In this paper, we present an alternative property taxonomy. We argue that this taxonomy is a more natural classification of the kinds of questions that analysts want to ask. Moreover, most classes in our taxonomy have a known, direct mapping to the safety-liveness classification, and thus the appropriate analysis algorithm can be automatically determined.
Performing Permutations on Interconnection Networks by Regularly Changing Switch States
Authors: Wei Kuang Lai
Venue: IEEE Transactions on Parallel and Distributed Systems (2000)

In this paper, we present an algorithm for performing permutations of messages on multistage interconnection networks. Permutations of messages are needed in many parallel algorithms. The proposed algorithm is feasible for any networks that can connect each input to each output using a set of $N$ nonblocking connections, where $N$ is the number of ports on the network. Messages are segmented into $N$ submessages that are sent independently in each time step. For any permutation, the settings of switches are changed with fixed patterns. Partitioning of the network into independent subnetworks is also supported, each capable of simultaneously routing a different permutation.
Experiences when migrating from structured analysis to object-oriented modelling
Authors: Roger Box, Michael Whitelaw
Venue: Proceedings of the Australasian conference on Computing education (2000)

Students' learning difficulties in object-oriented technology are examined from the perspective of Constructivist Learning Theory. It is shown that more abstract types of learning are required by the student for object-oriented technology than for structured technology. An introductory subject in object-oriented modelling of user applications is described which uses object diagrams and concept maps to assist students to learn to perform abstractions.
Derive: a tool that automatically reverse-engineers instruction encodings
Authors: Dawson R. Engler, Wilson C. Hsieh
Venue: ACM SIGPLAN Notices (2000)

Many binary tools, such as disassemblers, dynamic code generation systems, and executable code rewriters, need to understand how machine instructions are encoded. Unfortunately, specifying such encodings is tedious and error-prone. Users must typically specify thousands of details of instruction layout, such as opcode and field locations values, legal operands, and jump offset encodings. We have built a tool called DERIVE that extracts these details from existing software: the system assembler. Users need only provide the assembly syntax for the instructions for which they want encodings. DERIVE automatically reverse-engineers instruction encoding knowledge from the assembler by feeding it permutations of instructions and doing equation solving on the output. DERIVE is robust and general. It derives instruction encodings for SPARC, MIPS, Alpha, PowerPC, ARM, and x86. In the last case, it handles variable-sized instructions, large instructions, instruction encodings determined by operand size, and other CISC features. DERIVE is also remarkably simple: it is a factor of 6 smaller than equivalent, more traditional systems. Finally, its declarative specifications eliminate the mis-specification errors that plague previous approaches, such as illegal registers used as operands or incorrect field offsets and sizes. This paper discusses our current DERIVE prototype, explains how it computes instruction encodings, and also discusses the more general implications of the ability to extract functionality from installed software.