ppxscal/embedding_network huggingface dataset:
A scheduling algorithm for a computer assisted registration system
Authors: W. K. Winters
Venue: Communications of the ACM (1971)

This paper presents the scheduling algorithm used in the Computer Assisted Registration System at the University of Tennessee. Notation is defined and the logic of the algorithm necessary to implement educational policy is described. Results from the first term's implementation are presented.
Optimal Combinatorial Functions Comparing Multiprocess Allocation Performance in Multiprocessor Systems
Authors: HÅkan Lennerstad, Lars Lundberg
Venue: SIAM Journal on Computing (2000)

For the execution of an arbitrary parallel program P, consisting of a set of processes with any executable interprocess dependency structure, we consider two alternative multiprocessors.The first multiprocessor has q processors and allocates parallel programs dynamically; i.e., processes may be reallocated from one processor to another. The second employs cluster allocation with k clusters and u processors in each cluster: here processes may be reallocated within a cluster only. Let Td(P,q) and Tc(P,k,u) be execution times for the parallel program P with optimal allocations. We derive a formula for the program independent performance function $$ G(k,u,q)=\sup_{\mbox{{\footnotesize all parallel programs $P$}}} \:\frac{T_c(P,k,u)}{T_d(P,q)}. $$ Hence, with optimal allocations, the execution of P can never take more than a factor G(k,u,q) longer time with the second multiprocessor than with the first, and there exist programs showing that the bound is sharp.The supremum is taken over all parallel programs consisting of any number of processes. Overhead for synchronization and reallocation is neglected only.We further present a tight bound which exploits a priori knowledge of the class of parallel programs intended for the multiprocessors, thus resulting in a sharper bound. The function g(n,k,u,q) is the above maximum taken over all parallel programs consisting of n processes.The functions G and g can be used in various ways to obtain tight performance bounds, aiding in multiprocessor architecture decisions.
A Crash Course in SDL
Authors: John Hall
Venue: Linux Journal (2001)

An adaptation of a chapter from the author's upcoming book.
A numbering system for combinations
Authors: Gary D. Knott
Venue: Communications of the ACM (1974)

It is often necessary to generate the sequence of combinations of s things chosen from among n things, or to generate a random member of this sequence. Various algorithms have been given for these tasks. Algorithm 94 [1] is a good combination generator, and methods for generating a random combination are discussed in [2, pp. 121-125].
Design patterns and real-time object-oriented modeling (poster session)
Authors: Ross McKegney, Terry Shepard,  Dr.
Venue: Addendum to the 2000 proceedings of the conference on Object-oriented programming, systems, languages, and applications (Addendum) (2000)

Real-time object-oriented modeling tools (e.g. Rational Rose-RT, i-Logix Rhapsody) allow developers to focus on software architecture by abstracting away low-level implementation details. We believe that design patterns can be very beneficial in this context, and present the rationale and concepts behind a proposal for the extension of such a toolset to support them explicitly.
On the Key Equation Over a Commutative Ring
Authors: Graham H. Norton, Ana Salagean-Mandache
Venue: Designs, Codes and Cryptography (2000)

We define alternant codes over a commutative ring R and a corresponding key equation. We show that when the ring is a domain, e.g. the p-adic integers, the error-locator polynomial is the unique monic minimal polynomial (equivalently, the unique shortest linear recurrence) of the finite sequence of syndromes and that it can be obtained by Algorithm MR of Norton.WhenR is a local ring, we show that the syndrome sequence may have more than one (monic) minimal polynomial, but that all the minimal polynomials coincide modulo the maximal ideal ofR . We characterise the set of minimal polynomials when R is a Hensel ring. We also apply these results to decoding alternant codes over a local ring R: it is enough to find any monic minimal polynomial over R and to find its roots in the residue field. This gives a decoding algorithm for alternant codes over a finite chain ring, which generalizes and improves a method of Interlando et. al. for BCH and Reed-Solomon codes over a Galois ring.
The Quickest Transshipment Problem
Authors: Bruce Hoppe, Òva Tardos
Venue: Mathematics of Operations Research (2000)

A dynamic network consists of a graph with capacities and transit times on its edges. The quickest transshipment problem is de2ned by a dynamic network with several sources and sinks; each source has a speci2ed supply and each sink has a specified demand. The problem is to send exactly the right amount of 6ow out of each source and into each sink in the minimum overall time.Variations of the quickest transshipment problem have been studied extensively; the special case of the problem with a single sink is commonly used to model building evacuation. Similar dynamic network flow problems have numerous other applications; in some of these, the capacities are small integers and it is important to find integral flows. There are no polynomial-time algorithms known for most of these problems.In this paper we give the first polynomial-time algorithm for the quickest transshipment problem. Our algorithm provides an integral optimum flow. Previously, the quickest transshipment problem could only be solved efficiently in the special case of a single source and single sink.
A Note on the Existence of Optimal Policies in Total Reward Dynamic Programs with Compact Action Sets
Authors: Rolando Cavazos-Cadena, Eugene A. Feinberg, Raúl Montes-De-Oca
Venue: Mathematics of Operations Research (2000)

This work deals with Markov decision processes (MDPs) with expected total rewards, discrete state spaces, and compact action sets. Within this framework, a question on the existence of optimal stationary policies, formulated by Puterman (1994, p. 326), is considered. The paper concerns the possibility of obtaining an affirmative answer when additional assumptions are imposed on the decision model. Three conditions ensuring the existence ofaverage optimal stationary policies infinite-state MDPs are analyzed, and it is shown that only the so-called structural continuity condition is a natural sufficient assumption under which the existence of total-reward optimal stationary policies can be guaranteed. In particular, this existence result holds for unichain MDPs with finite state space, but an example is provided to show that this general conclusion does not have an extension to the denumerable state space case.
Confidence intervals using orthonormally weighted standardized time series
Authors: Robert D. Foley, David Goldsman
Venue: ACM Transactions on Modeling and Computer Simulation (TOMACS) (1999)

We extend the standardized time series area method for constructing confidence intervals for the mean of a stationary stochastic process. The proposed intervals are based on orthonormally weighted standardized time series area variance estimators. The underlying area estimators possess two important properties: they are first-order unbiased, and they are asymptotically independent of each other. These properties are largely the result of a careful choice of weighting functions, which we explicitly describe. The asymptotic independence of the area estimators yields more degrees of freedom than various predecessors; this, in turn, produces smaller mean and variance of the length of the resulting confidence intervals. We illustrate the efficacy of the new procedure via exact and Monte Carlo examples. We also provide suggestions for efficient implementation of the method.
Translation equations
Authors: Steven Vere
Venue: Communications of the ACM (1970)

Input limited transduction expressions, or translation equations, are used to describe the syntax and left-context sensitive semantics for context-free languages. A formal procedure is given for deriving from a set of translation equations the specifications for a pushdown translator. The translator consists of Mealy form finite-state automata interacting by means of a pushdown stack. Within the framework described, string recognition and parsing may be treated as special cases of the translation problem.
Reducing Parallel Program Simulation Complexity by Static Analysis
Authors: Rocco Aversa, Beniamino Di Martino, Nicola Mazzocca, Umberto Villano
Venue: The Journal of Supercomputing (2000)

In this paper we present a novel approach, based on the integration of static program analysis and simulation techniques, for the performance prediction of message passing programs. PS, a simulator of PVM applications developed in the last years by our research group, is fed with traces collected by executing the parallel program to be analyzed in quasi-concurrent mode on a single workstation. Since this process is typically a non negligible part of the simulation complexity, we have devised a technique based on static analysis and code restructuring for significantly speeding up the trace generation. We show how, by statically analyzing and restructuring the program, it is possible to obtain a simplified code (shrinked code) to be run for collecting a reduced version of the traces.
Relevance based language models
Authors: Victor Lavrenko, W. Bruce Croft
Venue: Proceedings of the 24th annual international ACM SIGIR conference on Research and development in information retrieval (2001)

We explore the relation between classical probabilistic models of information retrieval and the emerging language modeling approaches. It has long been recognized that the primary obstacle to effective performance of classical models is the need to estimate arelevance model: probabilities of words in the relevant class. We propose a novel technique for estimating these probabilities using the query alone. We demonstrate that our technique can produce highly accurate relevance models, addressing important notions of synonymy and polysemy. Our experiments show relevance models outperforming baseline language modeling systems on TREC retrieval and TDT tracking tasks. The main contribution of this work is an effective formal method for estimating a relevance model with no training data.
Journaling with ReisersFS
Authors: Chris Mason
Venue: Linux Journal (2001)

Mason gives a tour through the Reiser File System: its features and construction.
Interconnect tuning strategies for high-performance ICs
Authors: A. B. Kahng, S. Muddu, E. Sarto, R. Sharma
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

Interconnect tuning is an increasingly critical degree of freedom in the physical design of high-performance VLSI systems. By interconnect tuning, we refer to the selection of line thicknesses, widths and spacings in multi-layer interconnect to simultaneously optimize signal distribution, signal performance, signal integrity, and interconnect manufacturability and reliability. This is a key activity in most leading-edge design projects, but has received little attention in the literature. Our work provides the first technology-specific studies of interconnect tuning in the literature. We center on global wiring layers and interconnect tuning issues related to bus routing, repeater insertion, and choice of shielding/spacing rules for signal integrity and performance. We ad-dress four basic questions. (1) How should width and spacing be allocated to maximize performance for a given line pitch? (2) For a given line pitch, what criteria affect the optimal interval at which repeaters should be inserted into global interconnects? (3) Under what circumstances are shield wires the optimum technique for improving interconnect performance? (4) In global interconnect with repeaters, what other interconnect tuning is possible? Our study of question (4) demonstrates a new approach of offsetting repeater placements that can reduce worst-case cross-chip delays by over 30% in current technologies.
An Empirical Study Using Task Assignment Patterns to Improve the Accuracy of Software Effort Estimation
Authors: Randy K. Smith, Joanne E. Hale, Allen S. Parish
Venue: IEEE Transactions on Software Engineering (2001)

In most software development organizations, there is seldom a one-to-one mapping between software developers and development tasks. It is frequently necessary to concurrently assign individuals to multiple tasks and to assign more than one individual to work cooperatively on a single task. A principal goal in making such assignments should be to minimize the effort required to complete each task. But what impact does the manner in which developers are assigned to tasks have on the effort requirements? This paper identifies four task assignment factors: team size, concurrency, intensity, and fragmentation. These four factors are shown to improve the predictive ability of the well-known Intermediate COCOMO cost estimation model. A parsimonious effort estimation model is also derived that utilizes a subset of the task assignment factors and Unadjusted Function Points. For the data examined, this parsimonious model is shown to have goodness of fit and quality of estimation superior to that of the COCOMO model, while utilizing fewer cost factors.
Parametric Timing Analysis
Authors: Emilio Vivancos, Christopher Healy, Frank Mueller, David Whalley
Venue: Proceedings of the ACM SIGPLAN workshop on Languages, compilers and tools for embedded systems (2001)

Embedded systems often have real-time constraints. Traditional timing analysis statically determines the maximum execution time of a task or a program in a real-time system. These systems typically depend on the worst-case execution time of tasks in order to make static scheduling decisions so that tasks can meet their deadlines. Static determination of worst-case execution times imposes numerous restrictions on real-time programs, which include that the maximum number of iterations of each loop must be known statically. These restrictions can significantly limit the class of programs that would be suitable for a real-time embedded system. This paper describes work-in-progress that uses static timing analysis to aid in making dynamic scheduling decisions. For instance, different algorithms with varying levels of accuracy may be selected based on the algorithm's predicted worst-case execution time and the time allotted for the task. We represent the worst-case execution time of a function or a loop as a formula, where the unknown values affecting the execution time are parameterized. This parametric timing analysis produces formulas that can then be quickly evaluated at run-time so dynamic scheduling decisions can be made with little overhead. Benefits of this work include expanding the class of applications that can be used in a real-time system, improving the accuracy of dynamic scheduling decisions, and more effective utilization of system resources.
Implementing Quicksort programs
Authors: Robert Sedgewick
Venue: Communications of the ACM (1978)

This paper is a practical study of how to implement the Quicksort sorting algorithm and its best variants on real computers, including how to apply various code optimization techniques. A detailed implementation combining the most effective improvements to Quicksort is given, along with a discussion of how to implement it in assembly language. Analytic results describing the performance of the programs are summarized. A variety of special situations are considered from a practical standpoint to illustrate Quicksort's wide applicability as an internal sorting method which requires negligible extra storage.
ENSEMBLE: A Communication Layer for Embedded Multi-Processor Systems
Authors: Sidney Cadot, Frits Kuijlman, Koen Langendoen, Kees van Reeuwijk, Henk Sips
Venue: ACM SIGPLAN Notices (2001)

The ENSEMBLE communication library exploits overlapping of message aggregation (computation) and DMA transfers (communication) for embedded multi-processor systems. In contrast to traditional communication libraries, ENSEMBLE operates on n-dimensional data descriptors that can be used to specify often-occurring data access patterns in n-dimentional arrays. This allows ENSEMBLE to setup a three-stage pack-transfer-unpack pipeline, effectively overlapping message aggregation and DMA transfers. ENSEMBLE is used to support Spar/Java, a Java-based language with SPMD annotations. Measurements on a TriMedia-based multi-processor system show that ENSEMBLE increases performance up to 39% for peer-to-peer communication, and up to 34% for all-to-all communication.
Provably good global routing by a new approximation algorithm for multicommodity flow
Authors: C. Albrecht
Venue: Proceedings of the 2000 international conference on Computer-aided design (2001)

We show how that new approximation algorithms by Garg and K&ooul;nemann for the multicommodity flow problem can be modified to solve the linear programming relaxation of the global routing problem. The algorithm presented here also provides a solution of the dual linear problem, thus gives a lower bound on the optimum maximum relative congestion. Our computation results with recent IBM processor chips show that this approach can be used in practice even for large chips and that it is superior on difficult instances where rip-up and reroute algorithms fail. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
New spectral bounds on k-partitioning of graphs
Authors: T.k LÜcking, B. Monien, R. Elsässer
Venue: Proceedings of the thirteenth annual ACM symposium on Parallel algorithms and architectures (2001)

When executing processes on parallel computer systems they encounter as a major bottleneck inter-processor communication. One way to address this problem is to minimize the communication between processes that are mapped to different processors. This translates to the k-partitioning problem of the corresponding process graph, where k is the number of processors. The classical spectral lower bound of &brvbar;V&brvbar &divide; 2k &Sgr; k i =1 &lgr;i for the k-section width of a graph is well-known. We show new relations between the structure and the eigen values of a graph and present a new method to get tighter lower bounds on the k-section width. This method makes use of the level structure defined by the k-section. We define some global expansion property and prove that for graphs with the same k-section width the spectral lower bound increases with this global expansion. We also present examples of graphs for which our new bounds are tight up to a constant factor.
A Fully Discrete BEM-FEM for the Exterior Stokes Problem in the Plane
Authors: Salim Meddahi, Francisco-Javier Sayas
Venue: SIAM Journal on Numerical Analysis (2000)

We reformulate the Johnson--Nedelec approach for the exterior two-dimensional Stokes problem taking advantage of the parameterization of the artificial boundary. The main aim of this paper is the presentation and analysis of a fully discrete numerical method for this problem. This one responds to the needs of having efficient approximate quadratures for the weakly singular boundary integrals. We give a complete error analysis of both the Galerkin and fully discrete Galerkin methods.
Intermediacy Prediction for High Speed Berger Code Checkers
Authors: Cecilia Metra, Jien-Chung Lo
Venue: Journal of Electronic Testing: Theory and Applications (2000)

We present an intermediacy prediction method that can be used to designhigh speed checkers for Berger codes, as well as for any other unordered code. In the proposed method, the received information and check bits are processed simultaneously toward an intermediate result. A two-rail code checker is then used to compare the two versions of such an intermediate result. Recall that, in conventional checkers for unordered codes, the received check bits remain idle until the received information bits are converted to the re-generated check bits. Therefore, our proposed intermediacy prediction method allows a checker's speed improvement. We show the application of our method to two well-Bergercode checker architectural solutions: (1) the threshold function based implementation, and (2) the Berger code partitioning design. We have verified that, as expected, the proposed method can improve the detecting speed of these existing solutions with moderate or minimum increase, and sometimes decrease, in hardware complexity.
Towards approximations which preserve integrals
Authors: Elizabeth L. Mansfield, Peter E. Hydon
Venue: Proceedings of the 2001 international symposium on Symbolic and algebraic computation (2001)

We investigate the algorithmic approximation of ordinary differential equations having a known conservation law, with finite difference schemes which inherit a discrete version of the conservation law. We use the method of moving frames on a multispace due to Olver. We assume that the system of ODEs to be studied has a variational principle and that the conservation law arises from a variational symmetry via Noether's theorem.
Immersive panoramic video
Authors: Ulrich Neumann, Thomas Pintaric, Albert Rizzo
Venue: Proceedings of the eighth ACM international conference on Multimedia (2000)

The acquisition and presentation of high-resolution panoramic video presents a number of technical difficulties. We demonstrate a system that acquires high-resolution (>3Kx480) panoramic images. These images are recorded at 30Hz frame rates and played back for later viewing. During playback users wear a head-mounted display (HMD) and a head-tracking device that allows them to turn their heads freely to observe the desired portions of the panoramic scene. User impressions initially indicate that the experience produces a strong sense of immersion and this new form of media offers new options for creating immersive simulations./par>
Design of a large scale discrete element soil model for high performance computing systems
Authors: Alex R. Carrillo, David A. Horner, John F. Peters, John E. West
Venue: Proceedings of the 1996 ACM/IEEE conference on Supercomputing (CDROM) (1996)

The Discrete Element Model (DEM) is an alternative to the classical continuum mechanics approach for problems with flow-like deformations of solids. DEM is especially well-suited for problems such as soil plowing where the media is subject to large discontinuous deformations. The goal of this project was to develop a large-scale three dimensional DEM soil modeling system capable of handling problems with potentially several million particles. This paper discusses the development of that model and the factors driving it toward a High Performance Computing (HPC) solution. It also discusses how work in progress is making use of heterogeneous HPC environments and high speed networks to produce a real-time user interaction and visualization capability.
The Many Proofs and Applications of Perron's Theorem
Authors: C. R. MacCluer
Venue: SIAM Review (2000)

This paper chronicles the wide dispersal of Perron's 1907 result on positive matrices into many fields of science. The many proofs given during the last 93 years are categorized and critiqued (including Perron's original two proofs), and a more natural proof is presented. This simple-to-understand result of Perron provides a unequaled vehicle for taking students on a tour of many applied areas with some depth.
Basic cycle generation [H]
Authors: Norman E. Gibbs
Venue: Communications of the ACM (1975)

The PL/I procedure BASIC_GENERATOR is an implementation of Paton's algorithm [1] for finding a set of basic (fundamental) cycles of a finite undirected graph from its vertex adjacency matrix.