ppxscal/embedding_network huggingface dataset:
Design and Implementation of a VBR Continuous Media File Server
Authors: Dwight Makaroff, Gerald Neufeld, Norman Hutchinson
Venue: IEEE Transactions on Software Engineering (2001)

This paper describes the design and implementation of a file server for variable bit rate continuous media. We address the problem of building a server where each stream may have a different bit rate and, more importantly, where the bit rate within a single stream may vary considerably. Such a server has been implemented within a high-speed network environment. The server is designed to be used in a heterogeneous environment and is linearly scalable. A significant aspect of the design of the system is the detailed consideration of the variable bit-rate profile of each data stream in performing admission control for the disk and for the network. This paper describes the system model, the user interface design, implementation details, and performance results based on initial experience with the server.
Temporal Coupling Verification in Time Series Databases
Authors: Chang-Shing Perng, D. Stott Parker
Venue: Journal of Intelligent Information Systems (2000)

Time series are often generated by continuous sampling or measurement of natural or social phenomena. In many cases, events cannot be represented by individual records, but instead must be represented by time series segments (temporal intervals). A consequence of this segment-based approach is that the analysis of events is reduced to analysis of occurrences of time series patterns that match segments representing the events.A major obstacle on the path toward event analysis is the lack of query languages for expressing interesting time series patterns. We have introduced SQL/LPP (Perng and Parker, 1999). Which provides fairly strong expressive power for time series pattern queries, and are now able to attack the problem of specifying queries that analyze temporal coupling, i.e., temporal relationships obeyed by occurrences of two or more patterns.In this paper, we propose SQL/LPP+, a temporal coupling verification language for time series databases. Based on the pattern definition language of SQL/LPP (Perng and Parker, 1999), SQL/LPP+ enables users to specify a query that looks for occurrences of a cascade of multiple patterns using one or more of Allen's temporal relationships (Allen, 1983) and obtain desired aggregates or meta-aggregates of the composition. Issues of pattern composition control are also discussed.
A new approach to fragment assembly in DNA sequencing
Authors: Pavel A. Pevzner, Haixu Tang, Michael S. Waterman
Venue: Proceedings of the fifth annual international conference on Computational biology (2001)

For the last twenty years fragment assembly in DNA sequencing followed the &ldquo;overlap - layout - consensus&rdquo; paradigm that is used in all currently available assembly tools. Although this approach proved to be useful in assembling clones, it faces difficulties in genomic shotgun assembly: the existing algorithms make assembly errors and are often unable to resolve repeats even in prokaryotic genomes. Biologists are well-aware of these errors and are forced to carry additional experiments to verify the assembled contigs. We abandon the classical &ldquo;overlap - layout - consensus&rdquo; approach in favor of a new Eulerian Superpath approach that, for the first time, resolves the problem of repeats in fragment assembly. Our main result is the reduction of the fragment assembly to a variation of the classical Eulerian path problem. This reduction opens new possibilities for repeat resolution and allows one to generate error-free solutions of the large-scale fragment assembly problems. The major improvement of EULER over other algorithms is that it resolves all repeats except long perfect repeats that are theoretically impossible to resolve without additional experiments.
Finding approximate shape regularities in reverse engineered solid models bounded by simple surfaces
Authors: Frank Langbein, Bruce I. Mills, A. Dave Marshall, Ralph R. Martin
Venue: Proceedings of the sixth ACM symposium on Solid modeling and applications (2001)

Current reverse engineering systems are able to generate simple valid boundary representation (B-rep) models from 3D range data. Such models suffer from various inaccuracies caused by noise in the input data and algorithms. The quality of reverse engineered geometric models can potentially be improved by finding candidate shape regularities in such an initial model, and imposing a suitable subset of them on the model by using constraints, in a postprocessing step called beautification. Finding such candidate regularities is a necessary first step, and is discussed in this paper. Algorithms for analysis are presented which use feature objects to describe properties of faces, edges and vertices, and small groups of these elements in a B-rep model with only planar, spherical, cylindrical, conical and toroidal faces. The methods seek similarities between feature objects, e.g. axes which are parallel, for each property type. For each group of similar feature objects they also try to find a special feature object which might represent the group, e.g. an integer value which approximates the radius of similar cylinders. The feature objects used represent shape parameters, directions, axes and positions present in the model. Experiments show that the regularities found by these algorithms include the desired regularities. Although other spurious regularities which must be discarded in subsequent beautification steps are also produced, their number can be reduced by appropriate choice of tolerance values.
Joining policies in a multipriority multiclass batch computer system
Authors: Jair M. Babad, Mario M. Modiano
Venue: Communications of the ACM (1976)

Consider a multipriority batch computer system which users from several different classes may join, with toll, service, and waiting charges. Such a system is formulated here as a semi-Markov decision process, in which the aim of arriving users is to minimize their expected loss. The optimal joining policy of arriving users who may join the system at some of its queues is a control limit policy, with a single control number for any possible queue and the user's class; a newly arriving user will join a queue that is not filled up to the control number corresponding to this queue and the user's class. In this paper control numbers, as well as lower and upper bounds for the control numbers and the capacities of the system's queues, are derived.
A Mathematical Model and Scheduling Heuristics for Satisfying Prioritized Data Requests in an Oversubscribed Communication Network
Authors: Mitchell D. Theys, Min Tan, Noah B. Beck, H. J. Siegel, Michael Jurczyk
Venue: IEEE Transactions on Parallel and Distributed Systems (2000)

Providing up-to-date input to users' applications is an important data management problem for a distributed computing environment, where each data storage location and intermediate node may have specific data available, storage limitations, and communication links available. Sites in the network request data items and each request has an associated deadline and priority. In a military situation, the data staging problem involves positioning data for facilitating a faster access time when it is needed by programs that will aid in decision making. This work concentrates on solving a basic version of the data staging problem in which all parameter values for the communication system and the data request information represent the best known information collected so far and stay fixed throughout the scheduling process. The network is assumed to be oversubscribed and not all requests for data items can be satisfied. A mathematical model for the basic data staging problem is introduced. Then, three multiple-source shortest-path algorithm-based heuristics for finding a near-optimal schedule of the communication steps for staging the data are presented. Each heuristic can be used with each of four cost criteria developed. Thus, 12 implementations are examined. In addition, two different weightings for the relative importance of different priority levels are considered. The performance of the proposed heuristics are evaluated and compared by simulations. The proposed heuristics are shown to perform well with respect to upper and lower bounds. Furthermore, the heuristics and a complex cost criterion allow more highest priority messages to be received than a simple-cost-based heuristic that schedules all highest priority messages first.
Inadequacy of computable loop invariants
Authors: Andreas Blass, Yuri Gurevich
Venue: ACM Transactions on Computational Logic (TOCL) (2001)

Hoare logic is a widely recommended verification tool. There is, however, a problem of finding easily checkable loop invariants; it is known that decidable assertions do not suffice to verify while programs, even when the pre- and postconditions are decidable. We show here a stronger result: decidable invariants do not suffice to verify single-loop programs. We also show that this problem arises even in extremely simple contexts. Let N be the structure consisting of the set of natural numbers together with the functions S(x)=x+1,D(x)=2(x)=***x/2***. There is a single-loop program *** using only three variables x,y,z such that the asserted program x=y=z=0 *** false is partially correct on N but any loop invariant I(x,y,z) for this asserted program is undecidable.
Fractional-Step Dimensionality Reduction
Authors: Rohit Lotlikar, Ravi Kothari
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2000)

Linear projections for dimensionality reduction, computed using linear discriminant analysis (LDA), are commonly based on optimization of certain separability criteria in the output space. The resulting optimization problem is linear, but these separability criteria are not directly related to the classification accuracy in the output space. Consequently, a trial and error procedure has to be invoked, experimenting with different separability criteria that differ in the weighting function used and selecting the one that performed best on the training set. Often, even the best weighting function among the trial choices results in poor classification of data in the subspace. In this short paper, we introduce the concept of fractional dimensionality and develop an incremental procedure, called the fractional-step LDA (F-LDA) to reduce the dimensionality in fractional steps. The F-LDA algorithm is more robust to the selection of weighting function and for any given weighting function, it finds a subspace in which the classification accuracy is higher than that obtained using LDA.
Adaptive Fuzzy Morphological Filtering of Impulse Noisein Images
Authors: Jinsung Oh, Luis F. Chaparro
Venue: Multidimensional Systems and Signal Processing (2000)

In this paper we first introduce a neural network implementation for fuzzy morphological operators, and by means of a training method and differentiable equivalent representations for the operators we then derive efficient adaptation algorithms to optimize the structuring elements. Thus we are able to design fuzzy morphological filters for processing multi-level or binary images. The convergence behavior of basic structuring elements and its significance for other structuring elements of different shape is discussed. Besides the filter design, the localized structuring elements obtained from the training method give a structural characterization of the image which is useful in many applications. The performance of the fuzzy morphological filters in removing impulse noise in multi-level and binary images is illustrated and compared with existing procedures.
Contention resolution with constant expected delay
Authors: Leslie Ann Goldberg, Philip D. Mackenzie, Mike Paterson, Aravind Srinivasan
Venue: Journal of the ACM (JACM) (2000)

We study contention resolution in a multiple-access channel such as the Ethernet channel. In the model that we consider, n users generate messages for the channel according to a probability distribution. Raghavan and Upfal have given a protocol in which the expected delay (time to get serviced) of every message is O(log n) when messages are generated according to a Bernoulli distribution with generation rate up to about 1/10. Our main results are the following protocols: (a) one in which the expected average message delay is O(1) when messages are generated according to a Bernoulli distribution with a generation rate smaller than 1/e, and (b) one in which the expected delay of any message is O(1) for an analogous model in which users are synchronized (i.e., they agree about the time), there are potentially an infinite number of users, and messages are generated according to a Poisson distribution with generation rate up to 1/e. (Each message constitutes a new user.)To achieve (a), we first show how to simulate (b) using n synchronized users, and then show how to build the synchronization into the protocol.
On the use of self-similar processes in network simulation
Authors: José C. López-Ardao, Cándido López-García, Andrés Suárez-González, Manuel Fernández-Veiga, Raúl Rodríguez-Rubio
Venue: ACM Transactions on Modeling and Computer Simulation (TOMACS) (2000)

Several recent traffic measurement studies have convincingly shown the presence of self-similarity in modern high-speed networks, involving a very important revolution in the stochastic modeling of traffic. Thus the use of self-similar processes has opened new problems and research fields in network performance analysis, mainly in simulation studies, where the efficient synthetic generation of sample paths (traces) corresponding to self-similar traffic is one of the main topics. In this article, we justify the selection of interarrival time instead of counting processes for modeling arrivals. Also, we discuss the advantages and drawbacks of the most important self-similar processes when applied to traffic modeling in simulation studies, proposing the use of models based in F-ARIMA, mainly due to their flexibility to capture both long- and short-range correlations. However, F-ARIMA processes have been little used in simulation studies, mainly because the synthetic generation methods available in the literature are very inefficient compared with those for FGN. In order to solve this problem, we propose a new method that can generate high-quality traces corresponding to a F-ARIMA(p, d, q) process. A comparison with existing methods shows that the new method is significantly more efficient, and even slightly better than the best method for FGN.
Evolving Multilayer Perceptrons
Authors: P. A. Castillo, J. Carpio, J. J. Merelo, A. Prieto, V. Rivas, G. Romero
Venue: Neural Processing Letters (2000)

This paper proposes a new version of a method (G-Prop, genetic backpropagation) that attempts to solve the problem of finding appropriate initial weights and learning parameters for a single hidden layer Multilayer Perceptron (MLP) by combining an evolutionary algorithm (EA) and backpropagation (BP). The EA selects the MLP initial weights, the learning rate and changes the number of neurons in the hidden layer through the application of specific genetic operators, one of which is BP training. The EA works on the initial weights and structure of the MLP, which is then trained using QuickProp; thus G-Prop combines the advantages of the global search performed by the EA over the MLP parameter space and the local search of the BP algorithm. The application of the G-Prop algorithm to several real-world and benchmark problems shows that MLPs evolved using G-Prop are smaller and achieve a higher level of generalization than other perceptron training algorithms, such as QuickPropagation or RPROP, and other evolutive algorithms. It also shows some improvement over previous versions of the algorithm.
Systematic generation of Hamiltonian circuits
Authors: S. M. Roberts, Benito Flores
Venue: Communications of the ACM (1966)

For a combinatorial matrix which may specify both directed and nondirected arcs, the paper describes a computer program which generates systematically and exhaustively all the Hamiltonian circuits. Specific application is made to the &ldquo;traveling salesman&rdquo; problem.
Will database researchers have any role in data security? (panel session)
Authors: Arnon Rosenthal, Klaus Dittrich, Jim Donahue, Bill Maimone
Venue: Proceedings of the 2001 ACM SIGMOD international conference on Management of data (2001)

Data security issues today go far beyond the traditional questions of grant/revoke in an RDBMS. We will discuss what the new research agenda should be.
Scheduling meetings with a computer
Authors: Claire K. Schultz, Alan Brooks, Phyllis Schwartz
Venue: Communications of the ACM (1964)

Computer scheduling of papers as it was developed for the 1960 meeting of the Federation of American Societies for Experimental Biology (FASEB) is described. The FASEB meeting is the largest scientific meeting held in the United States each year. The technique developed for FASEB can be applied to schedule any meeting with parallel sessions.
A system level memory power optimization technique using multiple supply and threshold voltages
Authors: Tohru Ishihara, Kunihiro Asada
Venue: Proceedings of the 2001 Asia and South Pacific Design Automation Conference (2001)

A system level approach for a memory power reduction is proposed in this paper. The basic idea is allocating frequently executed object codes into a small subprogram memory and optimizing supply voltage and threshold voltage of the subprogram memory. Since large scale memory contains a lot of direct paths from power supply to round, power dissipation caused by subthreshold leakage current is more serious than dynamic power dissipation. Our approach optimizes the size of subprogram memory, supply voltage, and threshold voltage so as to minimize memory power dissipation including static power dissipation caused by leakage current. A heuristic algorithm which determines code allocation, supply voltage, and threshold voltage simultaneously so as to minimize power dissipation of memories is proposed as well. Our experiments with some benchmark programs demonstrate significant energy reductions up to 80% over a program memory which does not employ our approach.
A correction to Brelaz's modification of Brown's coloring algorithm
Authors: Jürgen Peemöller
Venue: Communications of the ACM (1983)

Brelaz's modification of Brown's exact coloring algorithm contains two errors as demonstrated in two examples. A correct version of the algorithm and a proof of the exactness are given. Finally, Brown's look-ahead rule is built into this algorithm.
Trajectory computation in a problem-oriented language
Authors: Clarice MacDonald
Venue: Communications of the ACM (1962)

A new problem-oriented language, XYZ, is being used on an experimental basis for trajectory computation. In the experiment, XYZ is compared with FORTRAN to determine the relative advantages of the two systems for use in flight simulation work. The comparison is concerned with the steps of: problem definition, program design, coding, checkout, and production.
EASY - a system for computer-aided examination of analog circuits
Authors: G. Dröge, M. Thole, E.-H. Horneber
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

The EASY analog design system includes a qualitative analysis tool for examination of the principal aptitude of a chosen circuit structure, as well as a symbolic analysis component. It allows the deduction of compact but sufficiently accurate design equations. These tools support the first steps of the design process and give insight in the behavior of the analog circuit.
Summarizing Similarities and Differences Among Related Documents
Authors: Inderjeet Mani, Eric Bloedorn
Venue: Information Retrieval (1999)

In many modern information retrieval applications, a common problem which arises is the existence of multiple documents covering similar information, as in the case of multiple news stories about an event or a sequence of events. A particular challenge for text summarization is to be able to summarize the similarities and differences in information content among these documents. The approach described here exploits the results of recent progress in information extraction to represent salient units of text and their relationships. By exploiting meaningful relations between units based on an analysis of text cohesion and the context in which the comparison is desired, the summarizer can pinpoint similarities and differences, and align text segments. In evaluation experiments, these techniques for exploiting cohesion relations result in summaries which (i) help users more quickly complete a retrieval task (ii) result in improved alignment accuracy over baselines, and (iii) improve identification of topic-relevant similarities and differences.
Status of information systems accreditation
Authors: John T. Gorgone, Doris K. Lidtke, David Feinstein
Venue: ACM SIGCSE Bulletin (2001)

Accreditation standards have been developed for BS programs in Information Systems and have been widely reviewed. The standards drew heavily on the existing computer science accreditation standard and recent curriculum efforts in information systems. The effort was facilitated by support from the National Science Foundation (NSFDUE 9812278). Recently CSAB approved the process to accredit IS programs and that accreditation will begin in Fall 2002.
Turing the tables: introducing software engineering concepts in a user interface design course
Authors: Julie Barnes, Laura Leventhal
Venue: ACM SIGCSE Bulletin (2001)

The most recent report of the Computing Curricula 2001 (CC2001) suggests that updated curricula must reflect the broadening nature of our discipline. Two areas that are included in the strawman draft of CC2001 are software engineering (SE) and human-computer interaction (HC). While the first inclination might be to incorporate these minimal HC concepts in a traditional SE course, we propose a different approach. This paper outlines a project oriented HC course in which we are able to emphasize SE in the context of HC concepts. We include an overview of course content that illustrates our approach.
Effective parameterization of architectural registers for register allocation algorithms
Authors: Y. N. Srikant, D. V. Ravindra
Venue: ACM SIGPLAN Notices (2000)

Code Selection in translation has been effectively abstracted out in terms of tree rewriting or pattern matching based approaches. However, modelling register files in an architecture independent way is a problem which is bypassed in most available algorithms. Architectural parameterization is frequently just code selector generation while architectural registers and operand constraints are handled in a machine-specific way. To partially address this issue, we present an abstraction for register allocation and assignment in non-uniform register file architectures in terms of bipartite graph matching.
Divide-and-correct methods for multiple precision division
Authors: Marvin L. Stein
Venue: Communications of the ACM (1964)

A division problem is defined and notation to relate it to the problem of multiple precision operation in a digital computer is introduced. A basic divide-and-correct method for multiple precision division is formulated and its known properties briefly reviewed. Of particular interest is the fact that the method produces at each step a set of precisely three estimates for the desired result, one of which is exact.