ppxscal/embedding_network huggingface dataset:
An experimental study of an opportunistic index
Authors: Paolo Ferragina, Giovanni Manzini
Venue: Proceedings of the twelfth annual ACM-SIAM symposium on Discrete algorithms (2001)

The size of electronic data is currently growing at a faster rate than computer memory and disk storage capacities. For this reason compression appears always as an attractive choice, if not mandatory. However space overhead is not the only resource to be optimized when managing large data collections; in fact data turn out to be useful only when properly indexed to support search operations that efficiently extract the user-requested information. Approaches to combine compression and indexing techniques are nowadays receiving more and more attention. A first step towards the design of a compressed full-text index achieving guaranteed performance in the worst case has been recently done in [10]. This index combines the compression algorithm proposed by Burrows and Wheeler [5] with the suffix array data structure [16]. The index is opportunistic in that it takes advantage of the compressibility of the input data by decreasing the space occupancy at no significant asymptotic slowdown in the query performance. In this paper we present an implementation of this index and perform an extensive set of experiments on various text collections. The experiments show that our index is compact (its space occupancy is close to the one achieved by the best known compressors), it is fast in counting the number of pattern occurrences, and the cost of their retrieval is reasonable when they are few (i.e., in case of a selective query). In addition, our experiments show that the FM-index is flexible in that it is possible to trade space occupancy for search time by choosing the amount of auxiliary information stored into it.
Analysis of boolean program models for time-shared, paged environments
Authors: Thomas C. Lowe
Venue: Communications of the ACM (1969)

Directed graphs or their associated matrices are frequently used to represent the logical structure of sequences of computer instructions. Such techniques are used and, in addition, data references are represented in a nondirected model. The complete structural specification of a program is represented by a combined model. A transformation of the combined model yields a new model in which additional timing information is also contained. Analysis of these models prior to execution yields information valuable in determining segmentation of instructions and data for a time-shared environment, as well as for initial page loading; during execution, the analysis may be used for &ldquo;look ahead&rdquo; control of page turning.
Cobol under control
Authors: Henry F. Ledgard, William C. Cave
Venue: Communications of the ACM (1976)

A sample set of Cobol programming standards is offered. These standards constrain code to be developed in a &ldquo;structured&rdquo; form for both data and control structures. They do not require syntax beyond the existing Cobol language and in fact utilize a typical limited subset of the 1974 ANS Cobol standard. These standards have proved extremely valuable in practice and have reduced the cost and time to produce and maintain large software systems that have been deployed in live multiple customer environments.
Oracle SQL: the essential reference
Authors: David C. Kreines
Venue:  (2000)

Everything Oracle developers and DBAs need to know about standard SQL (Structured Query Language) and Oracle's extensions to it is in this single, concise reference volume. Quick-reference chapters investigate basic SQL elements, Data Definition Language (DDL) and Data Manipulation Language (DML), SQL functions, PL/SQL, SQL*Plus, and Oracle SQL optimization and tuning. The book covers Oracle8i, release 8.1.6.
The use of normal multiplication tables for information storage and retrieval
Authors: Dalia Motzkin
Venue: Communications of the ACM (1979)

This paper describes a method for the organization and retrieval of attribute based information systems, using the normal multiplication table as a directory for the information system. Algorithms for the organization and retrieval of information are described. This method is particularly suitable for queries requesting a group of information items, all of which possess a particular set of attributes (and possibly some other attributes as well). Several examples are given; the results with respect to the number of disk accesses and disk space are compared to other common approaches. Algorithms evaluating the appropriateness of the above approach to a given information system are described. For a certain class of information systems, the normal multiplication table method yields far more rapid retrieval with a more economical space requirement than conventional systems. Moreover this method incorporates an improved modification of the inverted file technique.
Consistency and locking for distributing updates to web servers using a file system
Authors: Randal C. Burns Darrell D. E. Long
Venue: ACM SIGMETRICS Performance Evaluation Review (2000)

Distributed file systems are often used to replicate a Web site's content among its many servers. However, for content that needs to be dynamically updated and distributed to many servers, file system locking protocols exhibit high latency and heavy network usage. Poor performance arises because the Web-serving workload differs from the assumed workload. To address the shortcomings of file systems, we introduce the publish consistency model well suited to the Web-serving workload and implement it in the producer-consumerlocking protocol. A comparison of this protocol against other file system protocols by simulation shows that producer-consumer locking removes almost all latency due to protocol overhead and significantly reduces network load.
Efficiency by Incrementalization: An Introduction
Authors: Yanhong A. Liu
Venue: Higher-Order and Symbolic Computation (2000)

Incremental computation takes advantage of repeated computations on inputs that differ slightly from one another, computing each output efficiently by exploiting the previous output. This paper gives an overview of a general and systematic approach to incrementalization: given a program f and an operation &oplus;, the approach yields an incremental program that computes f(x &oplus; y) efficiently by using the result of f(x), the intermediate results of f(x), and auxiliary information of f(x) that can be inexpensively maintained.Since every non-trivial computation proceeds by iteration or recursion, the approach can be used for achieving efficient computation by computing each iteration incrementally using an appropriate incremental program. This approach has applications in interactive systems, optimizing compilers, transformational programming, and many other areas, where problems were previously solved in less general and systematic ways. This paper also describes the design and implementation of CACHET, a prototype system for incrementalization.
A cell and macrocell compiler for GaAs VLSI full-custom design
Authors: J. A. Montiel-Nelson, V. de Armas, R. Sarmiento, A. Núnez
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

A Gallium Arsenide automated layout generation system (OLYMPO) for SSI, MSI and LSI circuits used in GaAs VLSI design has been developed. We introduce a full-custom layout style, called RN-based cell model, that it is suited to generate low self-inductance circuit layouts of cells and macrocells. The cell compiler can be used as a cell library builder and it is embedded in a random logic macrocell and an iterative logic array generator. Experimental results demonstrate that OLYMPO generates complex and compact layouts and the synthesis process can be interactively used at the system design level.
JOME, a software component for interactive and distributed mathematics
Authors: Laurent Dirat
Venue: ACM SIGSAM Bulletin (2000)

JOME (Java OpenMath Editor) is a self-contained software component written in Java (as a Java Bean), dedicated to the visualisation and manipulation of mathematical formul aelig;. Conceptually based on the well-known Model-View-Controller (MVC) design pattern, JOME naturally consists of three different entities: the Model, the View and the Controller, each itself a Java Bean. Thus, it is easy to add different kinds of representations (instances of the View component) of a formula (the Model), and to provide different of ways editing it (instances of the Controller component). Moreover, JOME uses OpenMath, a platform-independent standard for the representation of semantically rich mathematical objects, enabling in a meaningful way the exchange of mathematical objects between various software tools. These two characteristics make JOME a useful component for interactive and distributed mathematics.
A nonrecursive method of syntax specification
Authors: John W. Carr,  III, Jerome Welland
Venue: Communications of the ACM (1966)

The use of the Kleene regular expression notation for describing algebraic language syntax, in particular of ALGOL, is described in this paper. A FORTRAN II computer program for carrying out the elimination algorithm of Gorn, similar to Gaussian elimination for linear systems of algebraic equations, is described. This was applied to numerous smaller languages, including some sublanguages of ALGOL. A hand calculation result of the application of the algorithm to all of ALGOL is given, thus expressing the Revised ALGOL 1960 syntax in completely nonrecursive terms, as far as its context-free portion is concerned. This description in many ways is far more intuitively understood than the previous recursive description, it is suggested. The paper also includes results of the machine program, which does not include a simplification algorithm.
An Experimental Comparison of Three Methods for Constructing Ensembles of Decision Trees: Bagging, Boosting, and Randomization
Authors: Thomas G. Dietterich
Venue: Machine Learning (2000)

Bagging and boosting are methods that generate a diverse ensemble of classifiers by manipulating the training data given to a &ldquo;base&rdquo; learning algorithm. Breiman has pointed out that they rely for their effectiveness on the instability of the base learning algorithm. An alternative approach to generating an ensemble is to randomize the internal decisions made by the base algorithm. This general approach has been studied previously by Ali and Pazzani and by Dietterich and Kong. This paper compares the effectiveness of randomization, bagging, and boosting for improving the performance of the decision-tree algorithm C4.5. The experiments show that in situations with little or no classification noise, randomization is competitive with (and perhaps slightly superior to) bagging but not as accurate as boosting. In situations with substantial classification noise, bagging is much better than boosting, and sometimes better than randomization.
Machinery in the new factories: interaction and technology in a bank's telephone call centre
Authors: John Bowers, David Martin
Venue: Proceedings of the 2000 ACM conference on Computer supported cooperative work (2000)

This paper presents analyses of calls to a bank's telephone call centre documenting the way calls are opened, closed, and how financial services are actioned. Throughout, how the social interaction between caller and operator is interleaved with the human-computer interaction between operator and the bank's accounts database is attended to. We show participants varying in their orientation to each other and to providing and receiving database information, and how these matters are influenced by the recent introduction of more active, intelligent technology. Implications for design of interactive technology in such settings and for the study of organisations in CSCW are offered.
Xilinx Improves Its Semiconductor Supply Chain Using Product and Process Postponement
Authors: Alexander O. Brown, Hau L. Lee, Raja Petrakian
Venue: Interfaces (2000)

The semiconductor firm Xilinx uses two different postponement strategies: product postponement and process postponement. In product postponement, the products are designed so that the product's specific functionality is not set until after the customer receives it. Xilinx designed its products to be programmable, allowing customers to fully configure the function of the integrated circuit using software. In process postponement, a generic part is created in the initial stages of the manufacturing process. In the later stages, this generic part is customized to create the finished product. Xilinx manufactures a small number of generic parts and holds them in inventory. The use of these generic parts allows Xilinx to hold less inventory in those finished products that it builds to stock. And for some finished products, Xilinx can perform the customization steps quickly enough to allow it to build to order.
Informative art: using amplified artworks as information displays
Authors: Johan Redström, Tobias Skog, Lars Hallnäs
Venue: Proceedings of DARE 2000 on Designing augmented reality environments (2000)

Informative art is computer augmented, or amplified, works of art that not only are aesthetical objects but also information displays, in as much as they dynamically reflect information about their environment. Informative art can be seen as a kind of slow technology, i.e. a technology that promotes moments of concentration and reflection. Our aim is to present the design space of informative art. We do so by discussing its properties and possibilities in relation to work on information visualisation, novel information display strategies, as well as art. A number of examples based on different kinds of mapping relations between information and the properties of the composition of an artwork are described.
The parallel execution of DO loops
Authors: Leslie Lamport
Venue: Communications of the ACM (1974)

Methods are developed for the parallel execution of different iterations of a DO loop. Both asynchronous multiprocessor computers and array computers are considered. Practical application to the design of compilers for such computers is discussed.
Formalization and Analysis of a Solution to the PCI 2.1 Bus Transaction Ordering Problem
Authors: Abdel Mokkedem, Ravi M. Hosabettu, Michael D. Jones, Ganesh C. Gopalakrishnan
Venue: Formal Methods in System Design (2000)

The transaction ordering problem of the original PCI 2.1 standard bus specification violates the desired correctness property of maintaining the so called &lsquo;Producer/Consumer&rsquo; relationship between writers and readers of data. This violation stems mainly from the so called completion stealing problem, first identified and solved by Corella et al. [4], and supported by a formal paper and pencil argument. In this paper, we develop a flexible graph theory library in PVS for modeling computer bus structures, formalize the PCI 2.1 protocol containing the solution of [4] in it, and mechanically prove the absence of completion stealing. Next, we define the Producer/Consumer property in PVS and sketch its mechanical proof. Noting the complexity of this proof effort (unfinished as yet), we explore a combination of theorem proving and model-checking in which the model used for model-checking is made tractable by exploiting the formal theorems established during theorem-proving as well as several intuitively justified assumptions. The theorem-proving infrastructure we have built for modeling CPU interconnect structures is highly reusable. Our work is one example of a natural division of labor between theorem-proving and model-checking in tackling system-level verification problems under realistic time budgets.
Approximation and Limit Results for Nonlinear Filters Over an Infinite Time Interval: Part II, Random Sampling Algorithms
Authors: Amarjit Budhiraja, Harold J. Kushner
Venue: SIAM Journal on Control and Optimization (2000)

The paper is concerned with approximations to nonlinear filtering problems that are of interest over a very long time interval. Since the optimal filter can rarely be constructed, one needs to compute with numerically feasible approximations. The signal model can be a jump-diffusion, reflected or not. The observations can be taken either in discrete or continuous time. The cost of interest is the pathwise error per unit time over a long time interval. In a previous paper of the authors [A. Budhiraja and H. J. Kushner, SIAM J. Control Optim., 37 (1999), pp. 1946--1979], it was shown, under quite reasonable conditions on the approximating filter and on the signal and noise processes that as time, bandwidth, process and filter approximation, etc. go to their limit in any way at all, the limit of the pathwise average costs per unit time is just what one would get if the approximating processes were replaced by their ideal values and the optimal filter was used. When suitable approximating filters cannot be readily constructed due to excessive computational requirements or to problems associated with a high signal dimension, approximations based on random sampling methods (or, perhaps, combinations of sampling and analytical methods) become attractive, and are the subject of a great deal of attention. The work of the previous paper is extended to a wide class of such algorithms. Under quite broad conditions, covering virtually all the cases considered to date, it is shown that the pathwise average errors converge to the same limit that would be obtained if the optimal filter was used, as time goes to infinity and the approximation parameter goes to its limit in any way at all. All the extensions (e.g., wide bandwidth observation or system driving noise) in [A. Budhiraja and H. J. Kushner, SIAM J. Control Optim., 37 (1999), pp. 1946--1979] hold for our random sampling algorithms as well.
sTeam: structuring information in team-distributed knowledge management in cooperative learning environments
Venue: Journal on Educational Resources in Computing (JERIC) (2001)

Learning is a socially embedded design process. But most of todays hypermedia systems fail to properly support the design-related and the social aspects of learning. Authoring and Web-publishing systems aim to support the authors design processes. Consequently, the activities of learners are confined to selecting and reading. Based on some fundamental reflections on the role of technology in learning processes, we conclude that top priority must be given to the construction of infrastructures that support cooperative learning processes if we are to properly harness the technologys potential. We present a learner-centered, wholly Web-based approach for structuring information in teams (sTeam). In sTeam the key concept is virtual space. It draws cooperation and communication together, while at the same time embodying the common external memory of a (virtual) learning group. Hence, the focus is not on interactive systems for individual access of knowledge bases, but on the cooperative management and structuring of distributed knowledge bases.
Performance Metrics for Embedded Parallel Pipelines
Authors: Martin Fleury, Andrew C. Downton, Adrian F. Clark
Venue: IEEE Transactions on Parallel and Distributed Systems (2000)

A statistical approach to performance prediction is applied to a system development methodology for pipelines comprised of independent parallel stages. The methodology is aimed at distributed memory machines employing medium-grained parallelization. The target applications are continuous-flow embedded systems. The use of order statistics on this type of system is compared to previous practical usage which appears largely confined to traditional Non-Uniform Memory Access (NUMA) machines for loop parallelization. A range of suitable performance metrics which give upper bounds or estimates for task durations are discussed. The metrics have a practical role when included in prediction equations in checking fidelity to an application performance specification. An empirical study applies the mathematical findings to the performance of a multicomputer for a synchronous pipeline stage. The results of a simulation are given for larger numbers of processors. In a further simulation, the results are extended to take account of waiting-time distributions while data are buffered between stages of an asynchronous pipeline. Order statistics are also employed to estimate the degradation due to an output ordering constraint. Practical illustrations in the image communication and vision application domains are included.
A video-based augmented reality golf simulator
Authors: Alok Govil, Suya You, Ulrich Neumann
Venue: Proceedings of the eighth ACM international conference on Multimedia (2000)

Recent advances in augmented reality technology (AR) have opened a tremendous scope of applications. We describe a use of the technology in virtual golf gaming that exemplifies how the technology can be made to suit the specific needs of distinct applications. Various challenges involved challenges involved, proposed solutions, and the results obtained are described.
Automated revsion of GIS databases
Authors: Volker Walter, Dieter Fritsch
Venue: Proceedings of the 8th ACM international symposium on Advances in geographic information systems (2000)

Digital spatial data are underlying strong temporal changes. The typical approach of updating these changes is to check the data manually for their correctness by superimposing them on up-to-date orthophotos. The update cycles of large data sets are in the range of several years. At present shorter update cycles are unrealizable for two reasons. The manual inspection of the data is very cost- and time-consuming and aerial photographs for large areas are very often not available in the needed time intervals. However, a decisive turn can be seen in data availability. With new satellite systems, it will be possible to provide up-to-date high resolution orthophotos in short time periods and high quality in the near future. At September 24th, 1999, the optical high resolution satellite IKONOS, developed by the company Space Imaging (http://www.spaceimaging.com), was brought successfully into orbit. Further systems as for example Quickbird of the company EarthWatch, OrbView 3 and 4 of the company ORBIMAGE or EROS A and B of the company West Indian Space will follow shortly (see also [9, 10]). The data which will be delivered from these new satellite systems will close the gap between existing medium resolution satellite data (as for example Spot, Landsat or IRS-1C) and very high resolution data from airborne systems. In near future users will be able to select images from several providers to use them for their mapping tasks. In order to eliminate the still existing bottle-neck of manual updating of GIS data, the Institute of Photogrammetry (ifp), University of Stuttgart developed a software package which is presented in this article.
Education: Expenditures, sources of funds, and utilization of digital computers for research and instruction in higher education: 1964-65 with projections for 1968-69
Authors: John W. Hamblen
Venue: Communications of the ACM (1968)

The Southern Regional Education Board published a complete report on a survey it conducted to determine the funding and characterize the utilization of computers used for research and instruction in institutions of higher education in the United States. The sampling survey is described and the estimates for this total population are presented.
Extending Ada's real-time systems annex with the POSIX scheduling services
Authors: Mario Aldea Rivas, Michael González Harbour
Venue: Proceedings of the 10th international workshop on Real-time Ada workshop (2001)

In this paper we propose extending the scheduling model of the Ada 95 Real-Time Systems Annex with the services specified in the Real-Time POSIX standard. These services include a round robin within priorities scheduling policy, a sporadic server scheduling policy, and execution time clocks and timers. With these services the Ada Real-Time Annex will enable addressing a larger number of application requirements.