ppxscal/embedding_network huggingface dataset:
Optimization of sequence queries in database systems
Authors: Reza Sadri, Carlo Zaniolo, Amir Zarkesh, Jafar Adibi
Venue: Proceedings of the twentieth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2001)

The need to search for complex and recurring patterns in database sequences is shared by many applications. In this paper, we discuss how to express and support efficiently sophisticated sequential pattern queries in databases. Thus, we first introduce SQL-TS, an extension of SQL, to express these patterns, and then we study how to optimize search queries for this language. We take the optimal text search algorithm of Knuth, Morris and Pratt, and generalize it to handle complex queries on sequences. Our algorithm exploits the inter-dependencies between the elements of a sequential pattern to minimize repeated passes over the same data. Experimental results on typical sequence queries, such as double bottom queries, confirm that substantial speedups are achieved by our new optimization techniques.
Current-Mode Delay Equalizer Design Using Multiple Output OTAs
Authors: B. M. Al-hashimi, F. Dudek, Y. Sun
Venue: Analog Integrated Circuits and Signal Processing (2000)

Two new current-mode allpass sections based on dual-output OTAs (DO-OTAs) and triple-output OTAs (TO-OTAs) and grounded capacitors are described. Techniques to minimize the equalizer active device count and efficiently simulate grounded resistors are proposed. A fifth-order group delay equalizer based on the presented allpass sections is designed and simulated using multiple-output CMOS OTAs. Numerical optimization is used to determine the equalizer order and parameters. SPICE simulation results are given, demonstrating that the equalizer can effectively compensate the delay characteristic of a fourth-order 4 MHz lowpass Chebyshev filter to &le;8 ns ripple over 90% of the filter passband.
Symbolic execution and program testing
Authors: James C. King
Venue: Communications of the ACM (1976)

This paper describes the symbolic execution of programs. Instead of supplying the normal inputs to a program (e.g. numbers) one supplies symbols representing arbitrary values. The execution proceeds as in a normal execution except that values may be symbolic formulas over the input symbols. The difficult, yet interesting issues arise during the symbolic execution of conditional branch type statements. A particular system called EFFIGY which provides symbolic execution for program testing and debugging is also described. It interpretively executes programs written in a simple PL/I style programming language. It includes many standard debugging features, the ability to manage and to prove things about symbolic expressions, a simple program testing manager, and a program verifier. A brief discussion of the relationship between symbolic execution and program proving is also included.
Logic Based Abstractions of Real-Time Systems
Authors: Roberto Barbuti, Nicoletta De Francesco, Antonella Santone, Gigiola Vaglini
Venue: Formal Methods in System Design (2000)

When verifying concurrent systems described by transition systems, state explosion is one of the most serious problems. If quantitative temporal information (expressed by clock ticks) is considered, state explosion is even more serious. We present a notion of abstraction of transition systems, where the abstraction is driven by the formulae of a quantitative temporal logic, called qu-mu-calculus, defined in the paper. The abstraction is based on a notion of bisimulation equivalence, called &lang;&rho;, n&rang;-equivalence, where &rho; is a set of actions and n is a natural number. It is proved that two transition systems are &lang;&rho;, n&rang;-equivalent iff they give the same truth value to all qu-mu-calculus formulae such that the actions occurring in the modal operators are contained in &rho;, and with time constraints whose values are less than or equal to n. We present a non-standard (abstract) semantics for a timed process algebra able to produce reduced transition systems for checking formulae. The abstract semantics, parametric with respect to a set &rho; of actions and a natural number n, produces a reduced transition system &lang;&rho;, n&rang;-equivalent to the standard one. A transformational method is also defined, by means of which it is possible to syntactically transform a program into a smaller one, still preserving &lang;&rho;, n&rang;-equivalence.
PSockets: the case for application-level network striping for data intensive applications using high speed wide area networks
Authors: H. Sivakumar, S. Bailey, R. L. Grossman
Venue: Proceedings of the 2000 ACM/IEEE conference on Supercomputing (CDROM) (2000)

Transmission Control Protocol (TCP) is used by various applications to achieve reliable data transfer. TCP was originally designed for unreliable networks. With the emergence of high-speed wide area networks various improvements have been applied to TCP to reduce latency and achieve improved bandwidth. The improvement is achieved by having system administrators tune the network and can take a considerable amount of time. This paper introduces PSockets (Parallel Sockets), a library that achieves an equivalent performance without manual tuning. The basic idea behind PSockets is to exploit network striping. By network striping we mean striping partitioned data across several open sockets. We describe experimental studies using PSockets over the Abilene network. We show in particular that network striping using PSockets is effective for high performance data intensive computing applications using geographically distributed data.
The application of sequential sampling to simulation: an example inventory model
Authors: W. Earl Sasser, Donald S. Burdick, Daniel A. Graham, Thomas H. Naylor
Venue: Communications of the ACM (1970)

Four different sequential sampling procedures are applied to the analysis of data generated by a computer simulation experiment with a multi-item inventory model. For each procedure the cost of computer time required to achieve given levels of statistical precision is calculated. Also the cost of computer time using comparable fixed sample size methods is calculated. The computer costs of fixed sample size procedures versus sequential sampling procedures are compared.
Permutation of data blocks in a bubble memory
Authors: Gian Carlo Bongiovanni, Fabrizio Luccio
Venue: Communications of the ACM (1979)

A common internal organization of bubble memories consists of a set of (minor) loops, connected through another (major) loop. The problem of obtaining any given permutation of the minor loop contents in minimum time is studied in this paper. A lower bound to the number of steps required by a permutation algorithm is derived, and the class of optimum algorithms is identified.
The status of women and minorities in academic computer science
Authors: Richard G. Montanelli,  Jr., Sandra A. Mamrak
Venue: Communications of the ACM (1976)

The results of a survey concerning women and minority students and faculty in computer science during the years 1971 to 1975 are presented. Analysis of the data indicated that effective affirmative action programs for recruitment into graduate degree programs are needed to enlarge the number of women and minorities qualified for later employment in computer science. Also, possible discrimination in employment of women and minority graduate students was revealed.
Presentation of alphameric characters for information processing
Authors: C. Kerpelman
Venue: Communications of the ACM (1969)

This proposed American National Standard has been accepted for publication by American National Standards Committee X3, Computers and Information Processing. In order that the final version of the proposed standard reflect the largest public consensus, X3 authorized publication of this document to elicit comment and general public reaction, with the understanding that such a working document is an intermediate result in the standardization process and is subject to change, modification, or withdrawal in part or in whole. Comments should be addressed to the X3 Secretary, Business Equipment Manufacturers Association, 235 East 42 Street, New York, NY 10017.&mdash;C.K.
Topic detection and tracking in English and Chinese
Authors: Charles L. Wayne
Venue: Proceedings of the fifth international workshop on on Information retrieval with Asian languages (2000)

Topic Detection and Tracking (TDT) refers to automatic techniques for discovering, threading, and retrieving topically related material in streams of data. Newswire and broadcast news are the canonical sources. In 1999, TDT research was extended from English to Chinese, and carefully annotated multilingual corpora were created. Researchers devised clever approaches to the cross-language challenge, and formal performance evaluations yielded very promising results. This paper outlines the 1999 research tasks, corpora, evaluation procedures, technical approaches, and results. The multilingual, multimedia research and evaluations are continuing in 2000 and 2001 under the DARPA TIDES program.
Computer Systems: Reliable full-duplex file transmission over half-duplex telephone line
Authors: W. C. Lynch
Venue: Communications of the ACM (1968)

A field-proven scheme for achieving reliable duplex transmission over a half-duplex communication line is presented, and to demonstrate the difficulty of the problem, another similar scheme, which is only slightly unreliable, is also presented. A flowchart for the reliable scheme and some interesting examples are given.
Replica Consistency in Lazy Master Replicated Databases
Authors: Esther Pacitti, Pascale Minet, Eric Simon
Venue: Distributed and Parallel Databases (2001)

In a lazy master replicated database, a transaction can commit after updating one replica copy (primary copy) at some master node. After the transaction commits, the updates are propagated towards the other replicas (secondary copies), which are updated in separate refresh transactions. A central problem is the design of algorithms that maintain replica's consistency while at the same time minimizing the performance degradation due to the synchronization of refresh transactions. In this paper, we propose a simple and general refreshment algorithm that solves this problem and we prove its correctness. The principle of the algorithm is to let refresh transactions wait for a certain &ldquo;deliver time&rdquo; before being executed at a node having secondary copies. We then present two main optimizations to this algorithm. One is based on specific properties of the topology of replica distribution across nodes. In particular, we characterize the nodes for which the deliver time can be null. The other improves the refreshment algorithm by using an immediate update propagation strategy.
Parsing of decision tables
Authors: Ned Chapin
Venue: Communications of the ACM (1967)

Reduction in the size of decision tables can be accomplished by several techniques. The techniques considered in this paper are on the parsing of decision tables with regard to horizontal and vertical data structures, job identity, hardware and job priorities, and context relationships. Such parsing rests upon some conventions for the linkage of decision tables.
An application of artificial intelligence to operations research
Authors: Robert Marcus
Venue: Communications of the ACM (1984)

An extension of critical path scheduling to a case where there are alternate methods for completing a project is introduced. Three solution methods are presented including one based on the heuristic search algorithm used in artificial intelligence.
Computational geometry column 39
Authors: Joseph O'Rourke
Venue: ACM SIGACT News (2000)

The resolution of a decades-old open problem is described: polygonal chains cannot lock in the plane.
Software engineering for the Cobol environment
Authors: Michael Evans
Venue: Communications of the ACM (1982)

In a attempt to improve the productivity of their 70 development staff, Skandinaviska Enskilda Banken has built an integrated set of manual and automatic tools for the implementation of Cobol programs. It was possible to use a number of modern programming techniques, including software engineering methods, in a Cobol environment. The project required 31 person-months; the aims, current status, and initial results are reported.
Runtime performance of parallel array assignment: an empirical study
Authors: Lei Wang, James M. Stichnoth, Siddhartha Chatterjee
Venue: Proceedings of the 1996 ACM/IEEE conference on Supercomputing (CDROM) (1996)

Compiling the array assignment statement of High Performance Fortran in the presence of block-cyclic distributions of data arrays is considered difficult, and several algorithms have been published to solve this problem. We present a comprehensive study of the performance of these algorithms. We classify these algorithms into several families and identify several issues of interest in the compilation process, and present experimental performance data for the various algorithms. We demonstrate that block-cyclic distributions can be compiled almost as efficiently as block and cyclic distributions.
Optimized timed hardware software cosimulation without roll-back
Authors: W. Sung, S. Ha
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

An optimized hardware software cosimulation method based on the backplane approach is presented in this paper. To enhance the performance of cosimulation, efforts are focused on reducing control packets between simulators as well as concurrent execution of simulators. Optimized timed cosimulation is achieved without roll-back mechanism to build a general cosimulation backplane environment.
A strategic planning methodology for the computing effort in higher education: an empirical evaluation
Authors: James C. Wetherbe, V. Thomas Dock
Venue: Communications of the ACM (1978)

The findings of a study designed to address the pressing problems associated with the strategic planning of the computing effort in higher education are presented here. A planning methodology was developed and tested through implementation at a university. Two years after the methodology was implemented, the effectiveness of the planning methodology was assessed in terms of the improvement of the delivery of computing services to the major institutional roles of instruction, research, and administration. Two control institutions were employed to contrast the improvements at the test institution. The results of the research indicate the planning methodology significantly enhanced the delivery of computing services.
Dummy feature placement for chemical-mechanical polishing uniformity in a shallow trench isolation process
Authors: Ruiqi Tian, Xiaoping Tang, D. F. Wong
Venue: Proceedings of the 2001 international symposium on Physical design (2001)

Manufacturability of a design that is processed with shallow trench isolation (STI) depends on the uniformity of the chemical-mechanical polishing (CMP) step in STI. The CMP step in STI is a dual-material polish, for which all previous studies on dummy feature placement for single-material polish [3, 11, 1] are not applicable. Based on recent semi-physical models of polish pad bending [5], local polish pad compression [2, 10], and different polish rates for materials present in a dual-material polish [2, 13], this paper derives a time-dependent relation between post-CMP topography and layout pattern density for CMP in STI. Using the dependencies derived, the first formulation of dummy feature placement for CMP in STI is given as a nonlinear programming problem. An iterative approach is proposed to solve the dummy feature placement problem. Computational experience on four layouts from Motorola is given.
XML with data values: typechecking revisited
Authors: Noga Alon, Tova Milo, Frank Neven, Dan Suciu, Victor Vianu
Venue: Proceedings of the twentieth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2001)

We investigate the type checking problem for XML queries: statically verifying that every answer to a query conforms to a given output DTD, for inputs satisfying a given input DTD. This problem had been studied by a subset of the authors in a simplified framework that captured the structure of XML documents but ignored data values. We revisit here the type checking problem in the more realistic case when data values are present in documents and tested by queries. In this extended framework, type checking quickly becomes undecidable. However, it remains decidable for large classes of queries and DTDs of practical interest. The main contribution of the present paper is to trace a fairly tight boundary of decidability for type checking with data values. The complexity of type checking in the decidable cases is also considered.
Predicting Performance of Object Recognition
Authors: Michael Boshra, Bir Bhanu
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2000)

We present a method for predicting fundamental performance of object recognition. We assume that both scene data and model objects are represented by 2D point features and a data/model match is evaluated using a vote-based criterion. The proposed method considers data distortion factors such as uncertainty, occlusion, and clutter, in addition to model similarity. This is unlike previous approaches, which consider only a subset of these factors. Performance is predicted in two stages. In the first stage, the similarity between every pair of model objects is captured by comparing their structures as a function of the relative transformation between them. In the second stage, the similarity information is used along with statistical models of the data-distortion factors to determine an upper bound on the probability of recognition error. This bound is directly used to determine a lower bound on the probability of correct recognition. The validity of the method is experimentally demonstrated using real synthetic aperture radar (SAR) data.
Morphing between polylines
Authors: Alon Efrat, Sariel Har-Peled, Leonidas J. Guibas, T. M. Murali
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

Given two non-intersecting simple polylines in the plane, we study the problem of continuously transforming or morphing one polyline into the other. Our morphing strategies have the desirable property that every intermediate polyline is also simple. We also guarantee that no portion of the polylines to be morphed is stretched or compressed by more than a user-defined parameter during the entire morphing. Our algorithms are based on the morphing width, a new metric we have developed for measuring the similarity between two polylines. We develop an algorithm that computes the morphing width of the two polylines and constructs a corresponding morphing strategy in &Ogr;(n2 log2 n) time using &Ogr;(n2) space, where n is the total number of vertices in the polylines. We describe another algorithm that computes a factor-2 approximation of the morphing width and a corresponding morphing scheme in &Ogr;(n log n) time.
Multiple terminals under user program control in a time-sharing environment
Authors: John S. McGeachie
Venue: Communications of the ACM (1973)

User-written programs on the Dartmouth Time-Sharing System can communicate with many remote terminals simultaneously and can control the interactions between these terminals. Such programs can be written using standard input and output instructions in any language available on the system. This paper describes how this multiple-terminal facility was implemented without requiring any changes in the system executive or in any of the system's compilers or interpreters.
The use of COBOL subroutines in FORTRAN main programs
Authors: Kazuo Tajiri
Venue: Communications of the ACM (1965)

If a problem requires both complicated calculations and edited output printing, then the computing part can be efficiently handled in FORTRAN and the editing part, e.g. punctuation, check protect and floating dollar sign, can be conveniently done in COBOL, in particular by the PICTURE clause. The following programs illustrate the simple technique of combining FORTRAN and COBOL. The main program is written in FORTRAN and the subroutine in COBOL. The programs were run on IBM 7090.
On the Barnes function
Authors: V. S. Adamchik
Venue: Proceedings of the 2001 international symposium on Symbolic and algebraic computation (2001)

The multiple Barnes function, defined as a generalization of the Euler gamma function, is used in many applications of pure and applied mathematics and theoretical physics. This paper presents new integral representations as well as special values of the Barnes function. Moreover, the Barnes function is expressed in a closed form by means of the Hurwitz zeta function. These results can be used for numeric and symbolic computations of the Barnes function.
Better Adaptive Diagnosis of Hypercubes
Authors: Evangelos Kranakis, Andrzej Pelc
Venue: IEEE Transactions on Computers (2000)

We consider the problem of adaptive fault diagnosis in hypercube multiprocessor systems. Processors perform tests on one another and later tests can be scheduled on the basis of previous test results. Fault-free testers correctly identify the fault status of tested processors, while faulty testers can give arbitrary test results. The goal is to identify correctly the status of all processors, assuming that the number of faults does not exceed the hypercube dimension. We propose an adaptive diagnosis algorithm whose efficiency is drastically better than that of any previously known strategies. While the worst-case number of tests for any of them exceeds $2^n \log n$ for an $n{\hbox{-}}{\rm dimensional}$ hypercube, our method uses at most $2^n + 3n/2$ tests in the worst case. We can also modify our algorithm to improve the number of testing rounds. By slightly increasing the number of tests to $2^n + (n+1)^2$ (still a much better performance than $2^n \log n$), we can carry out diagnosis in at most 11 rounds in the worst case (as opposed to over $n$ rounds in the best previously known strategy).
Regular right part grammars and their parsers
Authors: Wilf R. LaLonde
Venue: Communications of the ACM (1977)

This paper introduces an alternative to context-free grammars called regular right part (RRP) grammars, which resemble PASCAL syntax diagrams. Formally, RRP grammars have production right parts, which are nondeterministic finite state machines (FSMs), and, as a special case, regular expression, since these can be converted to FSMs. RRP grammars describe the syntax of programming languages more concisely and more understandably than is possible with CF grammars. Also introduced is a class of parsers, RRP LR(m, k) parsers, which includes the CF LR(k) parsers and provides the same advantages. Informally, an RRP LR(m, k) parser can determine the right end of each handle by considering at most k symbols to the right of the handle and the left end, after the right end has been found, by considering at most m symbols to the left of the handle. A mechanism for determining the left end is required because there is no bound on the length of the handle.