ppxscal/embedding_network huggingface dataset:
Computation of algebraic properties of elementary particle reactions using a digital computer
Authors: A. C. Hearn
Venue: Communications of the ACM (1966)

A large number of calculations in high-energy elementary particle physics involve the manipulation of complicated algebraic expressions containing both tensor and noncommutative matrix quantities. Many of these calculations take several months to complete, although the operations involved follow straightforward rules. In this paper a program is described, which has been developed in LISP for solving such problems. The manner in which these problems are encountered is outlined, and their representation in the computer discussed. At present, about six months of human work takes less than fifteen minutes on an IBM 7090. Limitations of the present system and future plans are also outlined.
Programming analysis of variance by sequences of operators and isomorphic mappings
Authors: K. C. Peng
Venue: Communications of the ACM (1964)

A special operator calculus developed by Hartley in 1956 together with a new mapping scheme has been found to be efficient in programming analysis of variance for multifactor experiments. The operator calculus and the mapping scheme are described in detail.
Self-Timed Carry-Lookahead Adders
Authors: Fu-Chiung Cheng, Stephen H. Unger, Michael Theobald
Venue: IEEE Transactions on Computers (2000)

Integer addition is one of the most important operations in digital computer systems because the performance of processors is significantly influenced by the speed of their adders. This paper proposes a self-timed carry-lookahead adder in which the logic complexity is a linear function of $n$, the number of inputs, and the average computation time is proportional to the logarithm of the logarithm of $n$. To the best of our knowledge, our adder has the best area-time efficiency which is $\Theta(n\log\log n)$. An economic implementation of this adder in CMOS technology is also presented. SPICE simulation results show that, based on random inputs, our 32-bit self-timed carry-lookahead adder is 2.39 and 1.42 times faster than its synchronous counterpart and self-timed ripple-carry adder, respectively; and, based on statistical data gathered from a 32-bit ARM simulator, it is 1.99 and 1.83 times faster than its synchronous counterpart and self-timed ripple-carry adder, respectively.
A note on multiple precision arithmetic
Authors: Albert G. Cox, H. A. Luther
Venue: Communications of the ACM (1961)

Since computers have means to detect overflow on addition or subtraction, this can be used in a multiple precision addition-subtraction subroutine to obviate a sign analysis. Consider all integers in the computer to be expressed &ldquo;radix t&rdquo;, that is, in the form a = a0 + a1t + &middot;&middot;&middot; + antn where ai are of like sign and have magnitudes less than t. t is a positive integer determined by the word length of the computer. Consider the expression c = a &plusmn; b = (a0 &plusmn; b0) + (a1 &plusmn; b1)t + &middot;&middot;&middot; + (an &plusmn; bn)tn. Here ai &plusmn; bi may exceed the storage capacity of one word or may have a sign different from c.
A semi-iterative process for evaluating arctangents
Authors: Wen-Hwa Chu, Donald R. Saathoff
Venue: Communications of the ACM (1963)

The technique of obtaining arctangents by inverse interpolation [1] is a relatively long process not suitable for a subroutine. The Taylor series expansion for arguments less than unity converges rather slowly for those near unity. The method of small increments of the argument [2] is again inconvenient for a subroutine. A more rapid series expansion in terms of Chebyshev polynomial [3] is given in terms of a new argument, which is less than 0.1989. This method requires the storage of &pgr;, &radic;2 - 1 and seven coefficients and is perhaps widely used. However, for multiple precision not only the coefficients have to be evaluated to the precision desired, but more must be used. Therefore the following alternative method may prove to be convenient and efficient.
Programming languages, natural languages, and mathematics
Authors: Peter Naur
Venue: Communications of the ACM (1975)

Some social aspects of pro gramming are illuminated through analogies with similar aspects of mathematics and natural languages. The split between pure and applied mathematics is found similarly in programming. The development of natural languages toward flexionless, word-order based language types speaks for programming language design based on general, abstract constructs. By analogy with incidents of the history of artificial, auxiliary languages it is suggested that Fortran and Cobol will remain dominant for a long time to come. The most promising avenues for further work of wide influence are seen to be high quality program literature (i.e. programs) of general utility and studies of questions related to program style.
Convergence Acceleration for Hyperbolic Systems Using Semicirculant Approximations
Authors: Henrik Brandén, Sverker Holmgren
Venue: Journal of Scientific Computing (1999)

The iterative solution of systems of equations arising from systems of hyperbolic, time-independent partial differential equations (PDEs) is studied. The PDEs are discretized using a finite volume or finite difference approximation on a structured grid. A convergence acceleration technique where a semicirculant approximation of the spatial difference operator is employed as preconditioner is considered. The spectrum of the preconditioned coefficient matrix is analyzed for a model problem. It is shown that, asymptotically, the time step for the forward Euler method could be chosen as a constant, which is independent of the number of grid points and the artificial viscosity parameter. By linearizing the Euler equations around an approximate solution, a system of linear PDEs with variable coefficients is formed. When utilizing the semicirculant (SC) preconditioner for this problem, which has properties very similar to the full nonlinear equations, numerical experiments show that the favorable convergence properties hold also here. We compare the results for the SC method to those of a multigrid (MG) scheme. The number of iterations and the arithmetic complexities are considered, and it is clear that the SC method is more efficient for the problems studied. Also, the MG scheme is sensitive to the amount of artificial dissipation added, while the SC method is not.
Optimizing object queries using an effective calculus
Authors: Leonidas Fegaras, David Maier
Venue: ACM Transactions on Database Systems (TODS) (2000)

Object-oriented databases (OODBs) provide powerful data abstractions and modeling facilities, but they generally lack a suitable framework for query processing and optimization. The development of an effective query optimizer is one of the key factors for OODB systems to successfully compete with relational systems, as well as to meet the performance requirements of many nontraditional applications. We propose an effective framework with a solid theoretical basis for optimizing OODB query languages. Our calculus, called the monoid comprehension calculus, captures most features of ODMG OQL, and is a good basis for expressing various optimization algorithms concisely. This article concentrates on query unnesting (also known as query decorrelation), an optimization that, even though it improves performance considerably, is not treated properly (if at all) by most OODB systems. Our framework generalizes many unnesting techniques proposed recently in the literature, and is capable of removing any form of query nesting using a very simple and efficient algorithm. The simplicity of our method is due to the use of the monoid comprehension calculus as an intermediate form for OODB queries. The monoid comprehension calculus treats operations over multiple collection types, aggregates, and quantifiers in a similar way, resulting in a uniform method of unnesting queries, regardless of their type of nesting.
Policy based agent management using conversation patterns
Authors: Christos Stergiou, Geert Arys
Venue: Proceedings of the fifth international conference on Autonomous agents (2001)

In this paper we provide a framework for building management services for software agents using conversation patterns. These patterns classify agent interaction, using the principles of Object Oriented software design patterns, encapsulating pure communication requirements and responsibilities. Role theory and reusable policy specifications regulate the way agents participate, providing a rich source of information for conversation management. The methodology promotes platform independence and fits the needs of a modular, distributed environment. So, management services use the plug- and- play concept. We also introduce the concept of co- operation patterns, which are built upon conversation patterns, but also describe the social relationships between agents based on beliefs, desires and intentions.
Constructing Planar Cuttings in Theory and Practice
Authors: Sariel Har-Peled
Venue: SIAM Journal on Computing (2000)

We present several variants of a new randomized incremental algorithm for computing a cutting in an arrangement of n lines in the plane. The algorithms produce cuttings whose expected size is O(r2), and the expected running time of the algorithms is O(nr). Both bounds are asymptotically optimal for nondegenerate arrangements. The algorithms are also simple to implement, and we present empirical results showing that they perform well in practice. We also present another efficient algorithm (with slightly worse time bound) that generates small cuttings whose size is guaranteed to be close to the best known upper bound of J. Matou{s}ek [Discrete Comput. Geom., 20 (1998), pp. 427--448].
IRM: integrated region matching for image retrieval
Authors: Jia Li, James Z. Wang, Gio Wiederhold
Venue: Proceedings of the eighth ACM international conference on Multimedia (2000)

Content-based image retrieval using region segmentation has been an active research area. We present IRM (Integrated Region Matching), a novel similarity measure for region-based image similarity comparison. The targeted image retrieval systems represent an image by a set of regions, roughly corresponding to objects, which are characterized by features reflecting color, texture, shape, and location properties. The IRM measure for evaluating overall similarity between images incorporates properties of all the regions in the images by a region-matching scheme. Compared with retrieval based on individual regions, the overall similarity approach reduces the influence of inaccurate segmentation, helps to clarify the semantics of a particular region, and enables a simple querying interface for region-based image retrieval systems. The IRM has been implemented as a part of our experimental SIMPLIcity image retrieval system. The application to a database of about 200,000 general-purpose images shows exceptional robustness to image alterations such as intensity variation, sharpness variation, color distortions, shape distortions, cropping, shifting, and rotation. Compared with several existing systems, our system in general achieves more accurate retrieval at higher speed.
An inexpensive braille terminal device
Authors: Gary B. Anderson, David W. Rogers
Venue: Communications of the ACM (1968)

The active use of time-shared facilities for blind programmers requires a braille terminal system. Details are given for the construction of a brailler from a model 33 teletype by modifying the print head and increasing the resiliency of the platen. A description of the programming needed to drive the brailler is presented.
Table Lookup Techniques
Authors: C. E. Price
Venue: ACM Computing Surveys (CSUR) (1971)

Consideration is given to the basic methodology for table searching in computer programming. Only static tables are treated, but references are made to techniques for handling dynamic tables. Methods described are: sequential search, merge search, binary search, estimated entry, and direct entry. The rationale of key transformation is discussed, with some consideration of methods of &ldquo;hash addressing.&rdquo; A general guide to technique selection is given in conclusion.
The Complexity of the A B C Problem
Authors: Jin-yi Cai, Richard J. Lipton, Yechezkel Zalcstein
Venue: SIAM Journal on Computing (2000)

We present a deterministic polynomial-time algorithm for the A B C problem, which is the membership problem for 2-generated commutative linear semigroups over an algebraic number field. We also obtain a polynomial-time algorithm for the (easier) membership problem for 2-generated abelian linear groups. Furthermore, we provide a polynomial-sized encoding for the set of all solutions.
Planning buffer locations by network flows
Authors: X. Tang, D. F. Wong
Venue: Proceedings of the 2000 international conference on Computer-aided design (2001)

The problem of planning the locations of large number of buffers is of utmost importance in deep submicron VLSI design. Recently, Cong et al in p1] proposed an algorithm to directly address this problem. Given a placement of circuit blocks, a key step in [1] is to use the free space between the circuit blocks for inserting as many buffers as possible. This step is very important because if all buffers can be inserted into existing spaces, no expansion of chip area would be needed. An effective greedy heuristic was used in [1] for this step. In this paper, we give a polynomial-time optimal algorithm for solving the problem of inserting maximum number of buffers into the free space between the circuit blocks. In the case where the "costs" of placing a buffer at different locations are different, we can guarantee to insert maximum number of buffers with minimum total cost. Our algorithm is based on efficient min-cost network-flow computations.
Combining Global Code and Data Compaction
Authors: Bjorn De Sutter, Bruno De Bus, Koen De Bosschere, Saumya Debray
Venue: ACM SIGPLAN Notices (2001)

Computers are increasingly being incorporated in devices with a limited amount of available memory. As a result research is increasingly focusing on the automated reduction of program size. Existing literature focuses on either data or code compaction or on highly language dependent techniques. This paper shows how combined code and data compaction can be achieved using a link-time code compaction system that reasons about the use of both code and data addresses. The analyses proposed rely only on fundamental properties of linked code and are therefore generally applicable. The combined code and data compaction is implemented in SQUEEZE, a link-time program compaction system, and evaluated on SPEC2000, MediaBench and C++ programs, resulting in total binary program size reductions of 23.6%-46.6%. This compaction involves no speed trade-off, as the compacted programs are on average about 8% faster.
Fast implementations of secret-key block ciphers using mixed inner- and outer-round pipelining
Authors: Pawel Chodowiec, Po Khuon, Kris Gaj
Venue: Proceedings of the 2001 ACM/SIGDA ninth international symposium on Field programmable gate arrays (2001)

The new design methodology for secret-key block ciphers, based on introducing an optimum number of pipeline stages inside of a cipher round is presented and evaluated. This methodology is applied to five well-known modern ciphers, Triple DES, Rijndael, RC6, Serpent, and Twofish, with the goal to first obtain the architecture with the optimum throughput to area ratio, and then the architecture with the highest possible throughput. All ciphers are modeled in VHDL, and implemented using Xilinx Virtex FPGA devices. It is demonstrated that all investigated ciphers can operate with similar maximum clock frequencies, in the range from 95 to 131 MHz, limited only by the delay of a single CLB layer and delays of interconnects. Rijndael, RC6, Twofish, and Serpent achieve throughputs in the range from 12.1 Gbit/s to 16.8 Gbit/s; and Triple DES achieves the throughput of 7.5 Gbit/s. Because of the optimum speed to cost ratio, the proposed architecture seems to be very well suited for practical implementations of secret-key block ciphers using both FPGAs and custom ASICs. We also show that using this architecture for comparing hardware performance of secret-key block ciphers, such as AES candidates, operating in non-feedback cipher modes, leads to the more prudent and fairer analysis than comparisons based on other types of pipelined architectures.
Approximation for minimum triangulation of convex polyhedra
Authors: F. Y. L. Chin, S. P. Y. Fung, C. A. Wang
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

The minimum triangulation of a convex polyhedron is a triangulation that contains the minimum number of tetrahedra over all its possible triangulations. Since finding the minimum triangulation of convex polyhedra was recently shown to be NP-hard, it becomes significant to find algorithms that give good approximation. In this paper, we give a new triangulation algorithm with an improved approximation ratio 2 - &OHgr;(1/&radic;n). We also show that this is best possible for algorithms that only consider the combinatorial structure of the polyhedra.
Automatic data structure selection: an example and overview
Authors: James R. Low
Venue: Communications of the ACM (1978)

The use of several levels of abstraction has proved to be very helpful in constructing and maintaining programs. When programs are designed with abstract data types such as sets and lists, programmer time can be saved by automating the process of filling in low-level implementation details. In the past, programming systems have provided only a single general purpose implementation for an abstract type. Thus the programs produced using abstract types were often inefficient in space or time. In this paper a system for automatically choosing efficient implementations for abstract types from a library of implementations is discussed. This process is discussed in detail for an example program. General issues in data structure selection are also reviewed.
Distributed cognition: toward a new foundation for human-computer interaction research
Authors: James Hollan, Edwin Hutchins, David Kirsh
Venue: ACM Transactions on Computer-Human Interaction (TOCHI) (2000)

We are quickly passing through the historical moment when people work in front of a single computer, dominated by a small CRT and focused on tasks involving only local information. Networked computers are becoming ubiquitous and are playing increasingly significant roles in our lives and in the basic infrastructures of science, business, and social interaction. For human-computer interaction to advance in the new millennium we need to better understand the emerging dynamic of interaction in which the focus task is no longer confined to the desktop but reaches into a complex networked world of information and computer-mediated interactions. We think the theory of distributed cognition has a special role to play in understanding interactions between people and technologies, for its focus has always been on whole environments: what we really do in them and how we coordinate our activity in them. Distributed cognition provides a radical reorientation of how to think about designing and supporting human-computer interaction. As a theory it is specifically tailored to understanding interactions among people and technologies. In this article we propose distributed cognition as a new foundation for human-computer interaction, sketch an integrated research framework, and use selections from our earlier work to suggest how this framework can provide new opportunities in the design of digital work materials.
The score-distributional threshold optimization for adaptive binary classification tasks
Authors: Avi Arampatzis, André van Hameran
Venue: Proceedings of the 24th annual international ACM SIGIR conference on Research and development in information retrieval (2001)

The thresholding of document scores has proved critical for the effectiveness of classification tasks. We review the most important approaches to thresholding, and introduce thescore-distributional (S-D) threshold optimizationmethod. The method is based on score distributions and is capable of optimizing any effectiveness measure defined in terms of the traditional contingency table.As a byproduct, we provide a model forscore distributions, and demonstrate its high accuracy in describing empirical data. The estimation method can be performed incrementally, a highly desirable feature for adaptive environments. Our work in modeling score distributions is useful beyond threshold optimization problems. It directly applies to other retrieval environments that make use of score distributions,e.g., distributed retrieval, or topic detection and tracking.The most accurate version of S-D thresholding --- although incremental --- can be computationally heavy. Therefore, we also investigate more practical solutions. We suggest practical approximations and discuss adaptivity, threshold initialization, and incrementality issues. The practical version of S-D thresholding has been tested in the context of the TREC-9 Filtering Track and found to be very effective [2].
Addressing an array Yi in k-dimensions by Fortran for analysis of variance
Authors: M. J. Garber
Venue: Communications of the ACM (1963)

In analysis of variance and covariance of data in factorial designs, multidimensional arrays are the rule rather than the exception. The 1620 FORTRAN language is severely limited in its DIMENSION statements in that subscripting may be done for a maximum of only three dimensions. In the technique described, a one-dimensional ordered array may be entered into storage and without additional identification treated as multidimensional. The conceptual technique illustrated below for summation may be expanded to handle any number of factors and is limited only by the storage capacity of the computer.
Generation of optimal code for expressions via factorization
Authors: Melvin A. Breuer
Venue: Communications of the ACM (1969)

Given a set of expressions which are to be compiled, methods are presented for increasing the efficiency of the object code produced by first factoring the expressions, i.e. finding a set of subexpressions each of which occurs in two or more other expressions or subexpressions. Once all the factors have been ascertained, a sequencing procedure is applied which orders the factors and expressions such that all information is computed in the correct sequence and factors need be retained in memory a minimal amount of time. An assignment algorithm is then executed in order to minimize the total number of temporary storage cells required to hold the results of evaluating the factors. In order to make these techniques computationally feasible, heuristic procedures are applied, and hence global optimal results are not necessarily generated. The factorization algorithms are also applicable to the problem of factoring Boolean switching expressions and of factoring polynomials encountered in symbol manipulating systems.
Cellular automata as a built in self test structure
Authors: Biplab K. Sikdar, Debesh K. Das, Vamsi Boppana, Cliff Yang, Sobhan Mukherjee, P. Pal Chaudhuri
Venue: Proceedings of the 2001 Asia and South Pacific Design Automation Conference (2001)

This paper presents an efficient BIST solution for VLSI circuit testing based on GF(2p) CA (Cellular automata on an extended Galois Field). The novel architecture of GF(2p)) CA permits the BIST structure to be highly customized to the circuit under test (CUT). A methodology has been proposed to optimize the design of GF(2p) CA structure to maximize the fault coverage in a given CUT. In addition, an innovative scheme based on logic folding is presented to reduce the BIST overhead and make it more effective for large circuits.