ppxscal/embedding_network huggingface dataset:
Elastic flexural-torsional buckling and postbuckling of arches subjected to a central concentrated load
Authors: Y. L. Pi, M. A. Bradford
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

This paper investigates the elastic buckling and postbuckling behaviour of arches that are subjected to a central concentrated load, using a finite element model developed by authors. Comparisons with existing experimental and analytical results demonstrate that the model is effective and efficient in terms of accuracy, the number of elements needed for convergence, and the ability to perform a postbuckling analysis. It is found that under a central concentrated load, the elastic buckling and postbuckling behaviour of a simply supported arch is similar to that of an arch in unform bending or in uniform axial compression. The slenderness of a simply supported arch has almost no effect on its buckling behaviour. However, the slenderness of all but very stocky pin-ended arches has significant effects on their buckling behaviour. For shallow pinended arches, the elastic flexural-torsional buckling load is reduced significantly by the large axial compression developed in the arch prior to buckling. As the included angle increases, the buckling load of the pin-ended arch decreases significantly until a minimum value of the buckling load is reached, and then increases. The increase of the buckling load stops at a certain value of the included angle, and thereafter the buckling load steadily decreases with the increase of the included angle. For stocky pin-ended arches, the buckling load decreases steadily with the increase of the included angle. The slenderness of deep pin-ended arches has a very small effect on their buckling behaviour. There is a substantial postbuckling response for shallow pin-ended arches, due to relaxation of the axial compression after buckling. The slenderness of fixed arches has a significant effect on their buckling behaviour. The large axial compression developed in shallow fixed arches reduces the elastic flexural-torsional buckling loads significantly. Shallow fixed arches also have a substantial postbuckling response due to the relaxation of the axial compression and the moment redistribution in the postbuckling range. For slender fixed arches with moderate or large included angles, four inflexion points can be developed in their deformed profile, which reduces their effective length and leads to a significant increase of their flexural-torsional buckling load. After buckling, a redistribution of bending moment takes place which increases the moments at the supports and decreases the moment at mid-span, thereby increasing the postbuckling strengths. For stocky fixed arches, however, only two inflexion points can be developed in their deformed profile prior to buckling and the buckling load decreases slightly as the included angle increases.
CENSUS: COLLECTING HOST INFORMATION ON A WIDE-AREA NETWORK (B.A. Thesis)
Authors: Nitin K. Ganatra
Venue:  (1992)

The exponential growth of the Internet presents new problems in recording global network information. The Domain Name System provided a way to cope with the enormous growth rates by distributing network information among all domains. This distribution accomplished its goal of eliminating the need for a central database, but at the same time eliminated the source of centralized network information. Such information is useful in applications dealing with resource discovery on the Internet and in studies of the network topography. Census is a program to traverse the Internet domain tree and collect information by recursively querying name servers for host information and other sub-domains. During the development of the Census program (about 6 months), the host population of the Internet has grown in size by 30 percent, and has showed no sign of abating. 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
Whole Page Performance
Authors: Leeann Bent, Geoffrey M. Voelker
Venue:  (2002)

This paper explores the user-perceived Web performance of downloading entire pages, and how various common Web enhancements impact overall page performance. We use Medusa, a non-caching forwarding proxy, to collect user traces and replay them under various configurations of HTTP request optimizations. These optimizations include parallel and persistent connections, DNS caching, and the use of CDNs. We then use Medusa to characterize whole-page performance and measure the impact of request optimizations on downloading entire Web pages. We find that the most effective optimization is parallel connections. Other optimizations provide incremental benefits due to limited opportunity for use or due to limited benefit of the optimization itself. When there is more opportunity for use, we find that optimizations in the former case provide substantial benefit.
What if There Were Desktop Access to the Computer Science Literature?
Authors: Dennis J. Brueni, Edward A. Fox, Lenwood S. Heath, Deborah Hix, Lucy T Nowell, William C. Wake
Venue:  (1992)

What if there was an electronic computer science library? Consider the possibilities of having your favorite publications available within finger''s reach. Consider project Envision, an ongoing effort to build a user-centered database from the computer science literature. This paper describes our first year progress, stressing the motivation underlying project Envision, user-centered development, and overall design.
On the Structural Simplicity of Machines and Languages
Authors: Y. Moscowitz, E. Shapiro
Venue:  (1993)

We employ an algebraic method for comparing the structural simplicity of families of abstract machines. We associate with each family of machines a first-order structure that includes machines as objects, composition operations, which construct larger machines from smaller ones, as functions, and a set of semantic relations. We then compare families of machines by studying the existence of homomorphisms between the associated structures. Given families of machines L, L? if there is a homomorphism of S into S?, but not vice versa.
Justification and Applications of the Set Conceptual Model
Authors: Paul C. Gilmore
Venue:  (1987)

In an earlier paper, the SET conceptual model was described. along with the domain graph method of table design. In this paper a justification for the method is provided, and a simple condition shown to be sufficient for the satisfaction of the degree constraints of a set schema. The basis for the consistency of the model is also described. Applications of the SET model to the full range of data processing are suggested, as well as to the problems raised by incomplete information.
The JONES Microprocessor: User''s Manual
Authors: David Mayhew
Venue:  (1987)

This technical report is no longer available.
Collapse load of optimally designed unbraced flexibly connected steel frames
Authors: E. S. Kameshki
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

In this paper a genetic algorithm based optimum design method is developed for unbraced steel frames with semi-rigid beam-to-column connections including the geometric non-linearity. Followed by presentation of collapse load computation of the optimally designed steel frames carrying out second order plastic hinge analysis. The effect of non-linearity arising from the connection flexibility is accounted for by representing the non-linear moment-rotation behaviour using the standardization functions of the Frye-Morris polynomials. Two design examples are presented to show the effect of geometric nonlinearly and connection flexibility on the optimum design of unbraced steel frames and their collapse loads.
The Complexity of Some Polynomial Network Consistency Algorithms for Constraint Satisfaction Problems
Authors: Alan K. Mackworth, E. C. Freuder
Venue:  (1982)

Constraint satisfaction problems play a central role in artificial intelligence. A class of network consistency algorithms for eliminating local inconsistencies in such problems has previously been described. In this paper we analyze the time complexity of several node, arc and path consistency algorithms. Arc consistency is achievable in time linear in the number of binary constraints. The Waltz filtering algorithm is a special case of the arc consistency algorithm. In that computational vision application the constraint graph is planar and so the complexity is linear in the number of variables.
Zernike or Orthogonal Fourier-Mellon Moments for Representing and Recognising Printed Digits
Authors: Patrick C Hew, Michael D Alder
Venue:  (1998)

We recognise printed digits in greyscale images by Zernike or Orthogonal Fourier-Mellon moments. We consider image preprocessing for calculation, the selection of appropriate moments for recognition, the validity of Gaussian models for classification, and resistance to noise.
Program Confuguration for Massively Parallel Computers
Authors: Jurgen W. Meyer
Venue:  (1992)

Many heuristics have been created to solve the mapping problem. This contribution presents an integration of a set of mapping heuristics into a program development system, such that mapping becomes an automatic step of program generation. This is achieved by designing a flexible interface to mapping heuristics and by introducing a new method of generating the process graph using runtime-monitoring. The system serves as a basis for development, analysis and comparison of mapping heuristics as well as as program development tool with selectable mapping heuristics for program configuration. It is implemented on a flexible transputer based parallel computer, which is able to emulate a large variety of problems for mapping heuristics. Runtime monitoring of configured programs allows a detailed evaluation of mapping heuristics. 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
Efficient Dynamic Range Searching using Data Replication
Authors: K. V. R Kanth, Ambuj K. Singh
Venue:  (1997)

Given the lower bound of $\Omega(n^{(d-1)/d})$ for range query time complexity on $n$ $d$-dimensional point data, we investigate whether little replication can improve the query and update times significantly. We propose linear-space index structures that minimize the query and update times; the query time we achieve is $O(n^{\epsilon})$ for any $\epsilon <0$, and, the update time is $O(\log n)$.
SORTING AND SEARCHING WITH A FAULTY COMPARISON ORACLE
Authors: Philip M. Long
Venue:  (1992)

We study sorting and searching using a comparison oracle that ``lies.'''' First, we prove that an algorithm of Rivest, Meyer, Kleitman, Winklmann and Spencer for searching in an n-element list using a comparison oracle that lies E times requires at most O(log n + E) comparisons, improving the best previously known bound of log n + E log log n + O(E log E). A lower bound, easily obtained from their results, establishes that the number of comparisons used by their algorithm is within a constant factor of optimal. We apply their search algorithm to obtain an algorithm for sorting an n element list with E lies that requires at most O(n log n + En) comparisons, improving on the algorithm of Lakshmanan, Ravikumar and Ganesan, which required at most O(n log n + En + E^2) comparisons. A lower bound proved by Lakshmanan, Ravikumar and Ganesan establishes that the number of comparisons used by our sorting algorithm is optimal to within a constant factor.
A parallel computer as a NOC region
Authors: Martti Forsell
Venue: Networks on chip (2003)

A network on chip (NOC) scheme relying on reuse of existing intellectual property blocks and a unified communication solution has been proposed for solving architectural and design productivity problems of future systems on chips. A NOC consists of a set of heterogeneous computing and storage resources that are connected to each other via a standardized communication network. A heterogeneous structure is suitable for application specific computing, but not for high-speed general purpose computing that is increasingly used in devices that will be powered by NOCs. General purpose functionality can, however, be provided by dedicating the whole chip or a special area on a heterogeneous NOC, called region, for a homogeneous general purpose computing engine. Unfortunately the architectures proposed for NOCs and on-chip parallel computers feature poor performance and portability, or are difficult to program in general purpose computing due to limited communication bandwidth, inability to eliminate delays caused by the latency of the network, high communication overheads, and poor models of parallel computing. In this chapter we will discuss the problems and solutions of implementing an efficient single chip general purpose parallel computing engine. We will also describe our ECLIPSE architecture that can be used either as a truly scalable, high-speed, single chip parallel computer or as a NOC region responsible of general-purpose computation.
Epidemic Quorums for Managing Replicated Data
Authors: J. Holliday, R. Steinke, D. Agrawal, A. E Abbadi
Venue:  (1999)

In the epidemic model an update is initiated on a single site, and is propagated to other sites in a lazy manner. When combined with version vectors and event logs, this propagation mechanism delivers updates in causal order despite communication failures. We integrate quorums into the epidemic model to processes transactions on replicated data. Causal order helps establish the global serialization order on transactions. Our approach enforces serializability by aborting transactions that may cause inconsistency. In the absence of conflict a transaction can commit as soon as it is known to a quorum of sites. In the presence of conflict, sites vote and a transaction can commit as soon as a quorum of sites vote for it. We present a detailed simulation study of a distributed replicated database and demonstrate the performance improvements.
A NOVEL DIMENSION REDUCTION TECHNIQUE FOR 3D CAPACITANCE EXTRACTION OF VLSI INTERCONNECTS
Authors: Wei Hong, Weikai Sun, Wayne W Dai
Venue:  (1995)

In this paper, a new method named Dimension Reduction Technique (DRT) is presented for capacitance extraction of 3D multilayer and multiconductor interconnects. In this technique, a complex 3D problem is decomposed to a series of simpler 2D problems. Therefore, it results in dramatical savings in computing time and memory usage. Compared to FASTCAP, a field solver based on BEM with multipole acceleration and developed from MIT, DRT is generally an order of magnitude faster with significantly less memory usage. Based on this technique, accurate close-form formulae or data base can be generated efficiently for calculating the capacitances of some typical 3D structures of VLSI interconnect.
Data coherence protocols: the home update protocol
Authors: C. Williams, P. F. Reynolds,  Jr., B. R. de Supinski
Venue:  (2000)

We describe a class of directory coherence protocols called delta coherence protocols that use network guarantees to support a new and highly concurrent approach to maintain a consistent shared memory. Delta coherence protocols are more concurrent than other coherence protocols in that they allow processes to pipeline memory accesses without violating sequential consistency; support multiple concurrent readers and writers to the same cache block; and allow processes to access multiple shared variables atomically without invalidating copies held by other processes or otherwise obtaining exclusive access to the referenced variables. Delta protocols include both update and invalidate protocols. In this paper we describe the simplest, most basic delta protocol, an update protocol called the home update protocol. Delta protocols are based on isotach network guarantees. An isotach network maintains a logical time system that allows each process to predict and control the logical time at which its messages are received. We prove the home update protocol is correct using logical time to reason about the order in which requests are executed.
A Spline Least Squares Method for Numerical Estimation in Differential Equations
Authors: James M. Varah
Venue:  (1980)

In this paper, we describe a straightforward least squares approach to the problem of finding numerical values for parameters occurring in differential equations, so that the solution best fits some observed data. The method consists of first fitting the given data by least squares using cubic spline functions with knots chosen interactively, and then finding the parameters by least squares solution of the differential equation sampled at a set of points. We illustrate the method by three problems from chemical and biological modelling.
ON-LINE PREDICTION AND CONVERSION STRATEGIES
Authors: N. Cesa-Bianchi, Y. Freund, D. P. Helmbold, M. Warmuth
Venue:  (1994)

We study the problem of deterministically predicting boolean values by combining the boolean predictions of several experts. Previous on-line algorithms for this problem predict with the weighted majority of the experts'' predictions. These algorithms give each expert an exponential weight beta^m where beta is a constant in [0,1) and m is the number of mistakes made by the expert in the past. We show that it is better to use sums of binomials as weights. In particular, we present a deterministic algorithm using binomial weights that has a better worst case mistake bound than the best deterministic algorithm using exponential weights. The binomial weights naturally arise from a version space argument. We also show how both exponential and binomial weighting schemes can be used to make prediction algorithms robust against noise.
Binary Component Adaptation
Authors: Ralph Keller, Urs Holzle
Venue:  (1997)

Binary component adaptation (BCA) allows components to be adapted and evolved in binary form and on-the-fly (during program loading). BCA rewrites component binaries before (or while) they are loaded, requires no source code access and guarantees release-to-release compatibility. That is, an adaptation is guaranteed to be compatible with a new binary release of the component as long as the new release itself is compatible with clients compiled using the earlier release. We describe our implementation of BCA for Java and demonstrate its usefulness by showing how it can solve a number of important integration and evolution problems. Even though our current implementation was designed for easy integration with Sun''s JDK 1.1 VM rather than for ultimate speed, measurements show that the load-time overhead introduced by BCA is small, in the range of one or two seconds. With its flexibility, relative simple implementation, and low overhead, binary component adaptation could significantly improve the reusability of Java components.
More on Nonregular PDL: Expressive Power, Finite Models, Fibonacci Programs
Authors: D. Harel, E. Singerman
Venue:  (1994)

We continue research on enriching propositional dynamic logic (PDL) with nonregular programs. Previous work indicates that the general problem of characterizing those extensions for which PDL becomes undecidable is probably very hard. Concsquently, in this paper we aim lower, addressing the related issues of expressive power and the finite model property. We also settle the decidability question for a nontrivial special case. Specifically, (i) the expressive power of any nonregular extension of PDL is hown to be stronger than that of regular PDL; (ii) a general condition is formulated that is sufficient for a one-letter nonregular extension to violate the finite model property, and is shown to hold in several cases, such as polynomials, sums of primes, factorial numbers, and linear recurrences; (iii) building on a technique of Paterson and Harel, the validity problem for PDL enriched with the Fibonacci-like sequence 1,4,5,9,14,... is shown to be P1>sub<1>/sub<-complete.
The Approximation of Implicates and Explanations
Authors: Alex Kean
Venue:  (1990)

This paper studies the continuum between implicates and minimal implicates; and the continuum between explanations and minimally consistent explanations. The study is based on the approximation of the set of these objects. A general definition for approximated minimal implicates, called selective implicates, is presented. Three specific instances of selective implicates: query-based, ATMS and length-based are studied. Using the set of query-based minimal implicates, explanations are generated and the properties of these explanations are studied. The goal of these studies is to extract computationally feasible properties in order to achieve tractable abduction. The setting is the compiled approach using minimal implicates in Clause Management Systems.
The Twelve Dimensional Space Ship
Authors: Mike Alder, Roberto Togneri
Venue:  (1990)

This is a popularised version of some work done on Projection Pursuit, the Kohonen Process and the Speech Space, covered in the paper "Dimension of the Speech Space". The intention is to make the ideas comprehensible to a wider audience, at least in a general way. The aims are frankly pedagogical: we feel that not enough is being done to explain to the wider community, particularly schoolchildren, either the kind of work Universities do or the spirit which motivates it.
Compositional Model Checking of Partially Ordered State Spaces
Authors: Scott Hazelhurst
Venue:  (1996)

Symbolic trajectory evaluation (STE) --- a model checking technique based on partial order representations of state spaces --- has been shown to be an effective model checking technique for large circuit models. However, the temporal logic that it supports is restricted, and as with all verification techniques has significant performance limitations. The demand for verifying larger circuits, and the need for greater expressiveness requires that both these problems be examined. The thesis develops a suitable logical framework for model checking partially ordered state spaces: the temporal logic \TL\ and its associated satisfaction relations, based on the quaternary logic $\Q$. \TL\ is appropriate for expressing the truth of propositions about partially ordered state spaces, and has suitable technical properties that allow STE to support a richer temporal logic. Using this framework, verification conditions called \emph{assertions} are defined, a generalised version of STE is developed, and three STE-based algorithms are proposed for investigation. Advantages of this style of proof include: models of time are incorporated; circuits can be described at a low level; and correctness properties are expressed at a relatively high level. A primary contribution of the thesis is the development of a compositional theory for \TL\ assertions. This compositional theory is supported by the partial order representation of state space. To show the practical use of the compositional theory, two prototype verification systems were constructed, integrating theorem proving and STE. Data is manipulated efficiently by using binary decision diagrams as well as symbolic data representation methods. Simple heuristics and a flexible interface reduce the human cost of verification. Experiments were undertaken using these prototypes, including verifying two circuits from the IFIP WG 10.5 Benchmark suite. These experiments showed that the generalised STE algorithms were effective, and that through the use of the compositional theory it is possible to verify very large circuits completely, including detailed timing properties.