ppxscal/embedding_network huggingface dataset:
Stochastic decomposition and approximation of stock index return volatility
Authors: E. Capobianco
Venue:  (2001)

We show that decomposing a class of signals with overcomplete dictionaries of functions and combining multiresolution and independent component analysis allow for feature detection in complex non-stationary high frequency time series. Computational learning techniques are then designed through the Matching Pursuit algorithm, whose performance is monitored so to extract relevant information about the structure of the volatility function. We refer to wavelet and cosine packet dictionaries due to the fact that with intra-daily time series some features of the underlying stochastic processes may remain undetected when standard volatility models are applied to the observed data. Independent component analysis results are particularly encouraging and suggest a better compromise between time and frequency resolutions, and thus a more efficient and accurate Matching Pursuit performance. 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
The XML benchmark project
Authors: A. R. Schmidt, Florian Waas, Martin L. Kersten, D. Florescu, I. Manolescu, M. J. Carey, R. Busse
Venue:  (2001)

With standardization efforts of a query language for XML documents drawing to a close, researchers and users increasingly focus their attention on the database technology that has to deliver on the new challenges that the sheer amount of XML documents produced by applications pose to data management: validation, performance evaluation and optimization of XML query processors are the upcoming issues. Following a long tradition in database research, the XML Store Benchmark Project provides a framework to assess an XML database''s abilities to cope with a broad spectrum of different queries, typically posed in real-world application scenarios. The benchmark is intended to help both implementors and users to compare XML databases independent of their own, specific application scenario. To this end, the benchmark offers a set queries each of which is intended to challenge a particular primitive of the query processor or storage engine. The overall workload we propose consists of a scalable document database and a concise, yet comprehensive set of queries, which covers the major aspects of query processing. The queries'' challenges range from stressing the textual character of the document to data analysis queries, but include also typical ad-hoc queries. We complement our research with results obtained from running the benchmark on our XML database platform. They are intended to give a first baseline, illustrating the state of the art.
Capturing agent autonomy in roles and XML
Authors: Gerhard Weiß, Michael Rovatsos, Matthias Nickles
Venue: Proceedings of the second international joint conference on Autonomous agents and multiagent systems (2003)

A key question in the field of agent-oriented software engineering is how the kind and extent of autonomy owned by computational agents can be appropriately captured. As long as this question is not answered convincingly, it is very unlikely that agent-oriented software (having "autonomy" as a real property rather than just a catchy label) gets broadly accepted in industry and commerce. In particular, in order to be of practical value an answer to this question has to come in form of concrete techniques which enable developers of agent-oriented software to precisely capture the scope of behavioral freedom and self-control they want to concede to a computational agent. This paper describes two such techniques. First, a formal schema called RNS for specifying the boundaries of autonomous agent behavior. This schema is conceptually grounded in sociological role theory, and employs the concepts of role, norm and sanction to capture agent autonomy. What makes RNS particularly valuable and distinct from related autonomy specification approaches is, among other things, its strong expressiveness and high precision. Second, a software tool called XRNS which enables developers to easily generate RNS-based autonomy specifications in XML format. Encoded in XML, these specifications are easily accessible to all stakeholders in an agent-oriented software under development, and can be even processed directly by XML enabled computational agents.
Storage Systems: Not Just a Bunch of Disks Anymore
Venue: Queue (2003)

The concept of a storage device has changed dramatically from the first magnetic disk drive introduced by the IBM RAMAC in 1956 to today’s server rooms with detached and fully networked storage servers. Storage has expanded in both large and small directions—up to mulit-terabyte server appliances and down to multi-gigabyte MP3 players that fit in a pocket. All use the same underlying technology—the rotating magnetic disk drive—but they quickly diverge from there.
Convergence of a Substructuring Method with Lagrange Multipliers
Authors: Jan Mandel, Radek Tezaur
Venue:  (1994)

We analyze the convergence of a substructing iterative method with Lagrange multipliers, propose recently by Farhat and Roux. The method decomposes finite element discretization of an elliptic boundary value problem into Neumann problems on the subdomains plus a coarse problem for the subdomain nullspace components. For linear conforming elements and preconditioning by the Dirichlet problems on the subdomains, we prove the asymptotic bound on the condition number C(1+log(H/h))^\alpha, \alpha=2 or 3, where h is the characteristic element size, H subdomain size, and C is independent of the number of subdomains.
Quadratic finite element methods for unilateral contact problems
Authors: Patrick Hild, Patrick Laborde
Venue: Applied Numerical Mathematics (2002)

The present paper is concerned with the frictionless unilateral contact problem between two elastic bodies in a bidimensional context. We consider a mixed formulation in which the unknowns are the displacement field and the contact pressure. We introduce a finite element method using quadratic elements and continuous piecewise quadratic multipliers on the contact zone. The discrete unilateral non-interpenetration condition is either an exact non-interpenetration condition or only a nodal condition. In both cases, we study the convergence of the finite element solutions and a priori error estimates are given. Finally, we perform the numerical comparison of the quadratic approach with linear finite elements.
Coding to relax laser linewidth requirements for multichannel CPFSK coherent optical communications
Authors: Jyh-Horng Wu, Jingshown Wu, Yang-Han Lee
Venue: Proceedings of the IEEE Symposium on Computers and Communications (ISCC'95) (1995)

A study of the multichannel coherent CPFSK communication system employing Reed-Solomon codes is reported. The crosstalk between adjacent channels, the impact of the laser phase noise, and selection of the optimum code rate are investigated. By applying a suitable coding scheme, the laser linewidth can be greatly relaxed, and the receiver sensitivity will be remarkably improved. A 100 Mbit/s system is used to verify the coding benefit. The results show that the impact of the laser linewidth can be largely alleviated by applying a (255, 223) Reed-Solomon code. When the linewidth is fixed (/spl Delta//spl nu/T=2%), this code can improve the receiver sensitivity by more than 15 dB.
Models for Computational Steering
Authors: J. Vetter, K. Schwan
Venue: Proceedings of the 3rd International Conference on Configurable Distributed Systems (1996)

This paper describes a conceptual model for computational program steering. By exploiting previous results attained in program monitoring, debugging, and configuration, the abstractions and mechanisms derived from this model are shown suitable for both algorithmic and human interactive steering. A characterization of existing systems for computational steering using the model's abstractions demonstrate such generality. The model is illustrated through its use for steering a large-scale scientific code. Mechanisms for computational steering derived from the model are presented that include sensors, probes, and actuators.
An $0(n \log^3 n)$ Algorithm for the Real Root and Symmetric Tridiagonal Eigenvalue Problems
Authors: H J Reif
Venue:  (1994)

Given a univariate complex polynomial $f(x)$ of degree $n$ with rational coefficients expressed as a ratio of two integers $> 2^m$, the {\em root problem} is to find all the roots of $f(x)$ up to specified precision $2^{-\mu}$. In this paper we assume the arithmetic model for computation. We give an algorithm for the {\em real root problem}: where all the roots of the polynomial are real. Our real root algorithm has time cost of $O(n \log^2n(\log n+\log b)),$ where $b = m+\mu$. Our arithmetic time cost is thus $O(n \log^3n)$ even in the case of high precision $b \le n^{O(1)}$. This is within a small polylog factor of optimality, thus (perhaps surprisingly) upper bounding the arithmetic complexity of the real root problem to nearly the same as basic arithmetic operations on polynomials. The {\em symmetric tridiagonal} problem is given a $n \times n$ symmetric tridiagona matrix, with $3n$ nonzero rational entries each expressed as a ratio of two integers $> 2^m$, find all the eigenvalues up to specified precision $2^{-\mu}$. Using known efficient reductions from the symmetric tridiagonal eigenvalue problem to the real root problem, we also get an $O(n \log^2n(\log n+\log b))$ arithmetic time bound for the symmetric tridiagonal eigenvalue problem. We require only $\pi = O(n(b+n))$ bits of precision to carry out our computations. The Boolean complexity of our algorithms are a multiplicative factor of $M(\pi)$ more, where $M(\pi) = O(\pi (\log \pi)\log\log \pi)$ is the bit complexity for multiplication of integers of length $\pi.$ 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
Nonoverlapping Local Alignments, Weighted Independent Sets of Axis Parallel Rectangles
Authors: Vineet Bafna, Babu Narayanan, R. Ravi
Venue:  (1995)

We consider the following problem motivated by an application in computational molecular biology. We are given a set of weighted axis-parallel rectangles such that for any pair of rectangles and either axis, the projection of one rectangle does not enclose that of the other. Define a pair to be independent if their projections in both axes are disjoint. The problem is to find a maximum-weight independent subset of rectangles. We show that the problem is NP-hard even in the uniform case when all the weights are the same. We analyze the performance of a natural local- improvement heuristic for the general problem and prove a performance ration of 3.25. We extend the heuristic to the problem of finding a maximum-weight independent set in (d+1)-claw free graphs, and show a tight performance ration of (d - 1 + (1/d)). A performance ratio of d/2 was known for the heuristic when applied to the uniform case. Our contributions are proving the hardness of the problem and providing a tight analysis of the local-improvement algorithm for the general weighted case.
Client--Access Protocols for Replicated Services
Authors: Christos Karamanolis, Jeff Magee
Venue: Proceedings of the Third IEEE International Conference on Engineering of Complex Computer Systems (1997)

The paper addresses the problem of client--service interaction in the case of replicated service provision. Existing systems that follow the State Machine approach concentrate on the synchronization of the server replicas and do not consider the problem of client interaction with the server group. Client interaction is analyzed and a number of access protocols are proposed to meet a range of client requirements. The paper demonstrates that protocols for the ``open'' group model---clients external to the group of servers---satisfy the requirements of the State Machine approach, even when replication is transparent to the clients. Experimental performance results indicate that the ``open'' model is clearly desirable when the service is used by a large, dynamic set of clients.
From System F to Typed Assembly Language (Extended Version)
Authors: Greg Morrisett, David Walker, Karl Crary, Neal Glew
Venue:  (1997)

We motivate the design of a statically typed assembly language (TAL) and present a type-preserving translation from System F to TAL. The TAL we present is based on a conventional RISC assembly language, but its static type system provides support for enforcing high-level language abstractions, such as closures, tuples, and objects, as well as user-defined abstract data types. The type system ensures that well-typed programs cannot violate these abstractions. In addition, the typing constructs place almost no restrictions on low-level optimizations such as register allocation, instruction selection, or instruction scheduling. Our translation to TAL is specified as a sequence of type-preserving transformations, including CPS and closure conversion phases; type-correct source programs are mapped to type-correct assembly language. A key contribution is an approach to polymorphic closure conversion that is considerably simpler than previous work. The compiler and typed assembly language provide a fully automatic way to produce proof carrying code, suitable for use in systems where untrusted and potentially malicious code must be checked for safety before execution.
A model of biological differentiation in adaptiogenesis to the environment
Authors: Takamasa Sawada, Atsuko Mutoh, Shohei Kato, Hidenori Itoh
Venue: Proceedings of the eighth international conference on Artificial life (2002)

In this paper, we propose a model of biological differentiation based on physical features and behavioral strategies in order to probe the mysteries of biological differentiation. We, then, implement the model, and perform the Alife simulations of birds' evolution in an artificial ecology. The ecology consists of two islands, and the atmospheric temperature in each of the islands fluctuates periodically. As a result of the simulations, we have observed that birds, adapting themselves to a change of temperature in their habitat, branch off in two types of biology: migratory bird and resident bird.
Estimating Circuit Fault-Tolerance by Means of Transient-Fault Injection in VHDL
Authors: Fabian Vargas, Alexandre Amory, Raoul Velazco
Venue: Proceedings of the 6th IEEE International On-Line Testing Workshop (IOLTW) (2000)

We present hereafter a new approach to estimate the reliability of complex circuits used in harmful environments like radiation. This goal can be attained in an early stage of the design process. Usually, this step is performed in laboratory, by means of radiation facilities (particle accelerators). In our case, we estimate the expected tolerance of the complex circuit with respect to SEU during the VHDL specification step. By doing so, the early-estimated reliability level is used to balance the design process into a trade-off between maximum area overhead due to the insertion of redundancy and the minimum reliability required for a given application. This approach is being automated through the development of a CAD tool.
New Developments in Structural Complexity Theory
Authors: Juris Hartmanis
Venue:  (1988)

This paper discusses the scope and goals of structural complexity theory, describes some working hypothesis of this field and summarizes (some) recent development.
Impact of JIT/JVM Optimizations on Java Application Performance
Authors: K. Shiv, R. Iyer, C. Newburn, J. Dahlstedt, M. Lagergren, O. Lindholm
Venue: Proceedings of the Seventh Workshop on Interaction between Compilers and Computer Architectures (2003)

With the promise of machine independence and efficientportability, JAVA has gained widespread popularityin the industry. Along with this promise comes theneed for designing an efficient runtime environment thatcan provide high-end performance for Java-based applications.In other words, the performance of Java applicationsdepends heavily on the design and optimization ofthe Java Virtual Machine (JVM). In this paper, we start byevaluating the performance of a Java server application(SPECjbb2000TM) on an Intel platform running a rudimentaryJVM. We present a measurement-based methodologyfor identifying areas of potential improvement and subsequentlyevaluating the effect of JVM optimizations andother platform optimizations. The compiler optimizationspresented and discussed in this paper include peephole optimizationsand Java specific optimizations. In addition, wealso study the effect of optimizing the garbage collectionmechanism and the effect of improved locking strategies.The identification and analysis of these optimizations areguided by the detailed knowledge of the micro-architectureand the use of performance measurement and profiling tools(EMON and VTune) on Intel platforms.
An Implementable Dynamic Automatic Self-Stabilizing Protocol
Authors: Olivier Flauzac, Vincent Villain
Venue: Proceedings of the 1997 International Symposium on Parallel Architectures, Algorithms and Networks (1997)

The notion of self-stabilization was first introduced by Dijkstra : it is the property for a system to eventually recover by itself a legitimate state after any perturbation modifying the memory state. This paper proposes a dynamic automatic self-stabilizing protocol. This algorithm runs in the fully asynchronous message-passing model in which messages can also be corrupted. The principle of the algorithm is to compute regularly a global state and if necessary to generate a global reset. When the system is stabilized, the message complexity is O(max(D *m,n^2)) where D is the degree of the communication graph, m the number of links and n the number of processes. This complexity allows a possible implementation.
Algorithm-based fault detection in prime factor FFT networks
Authors: J. M. Tahir, S. S. Dlay, R. N. G. Naguib, O. R. Hinton
Venue: Proceedings of the IEEE Symposium on Computers and Communications (ISCC'95) (1995)

A concurrent error detection (CED) scheme has been proposed by Jou and Abraham (1988)for a radix-2 FFT network. The method uses a coding scheme to ensure that all the modelled faults are detectable. The same method has been applied to the prime factor algorithm (PFA) FFT network. The results show that the CED scheme is applicable to multi-factor PFA networks and it is efficient, only, for large N. Since the PFA is a minimum multiplication algorithm, it is logical to adopt a minimum multiplication CED scheme. For this purpose, a suitable CED scheme has been developed such that the data coding is no longer needed which results in less hardware and time overheads. The new scheme provides a stage-by-stage error detection without causing time delay and additional roundoff noise. The hardware overhead is substantially reduced with improved error detection performance since the scheme needs to consider the roundoff error of only one stage instead of the entire FFT network.
Meta-information for multimedia elearning
Authors: Ralf Steinmetz, Cornelia Seeberg
Venue: Computer Science in Perspective: Essays Dedicated to Thomas Ottmann (2003)

The generation of multimedia learning objects are expansive and time consuming. Only by reusing them in many contexts, the effort becomes worth while. Reusing requires a flexible layout. Therefore content and format should be separated. Means for searching relevant learning object are of highest importance. Metainformation has to be added to the learning object. Metadata and especially learning metadata are a powerful instrument. Complemented by an ontology and relations between the learning object, the learning material become findable. For supporting the authors, tools like a metadata editor are necessary.
On the non-minimal codewords in binary Reed--Muller codes
Authors: Yuri Borissov, Nickolai Manev, Svetla Nikova
Venue: Discrete Applied Mathematics (2003)

First, we compute the number of non-minimal codewords of weight 2dmin in the binary Reed-Muller code RM(r,m). Second, we prove that all codewords of weight greater than 2m - 2m-r+1 in binary RM(r,m), are non-minimal.
Integrating Agents and Objects to Develop Distributed AI Systems
Authors: A. Poggi
Venue: Proceedings of the 8th International Conference on Tools with Artificial Intelligence (1996)

This paper presents a language for the development of multi-agent systems that allows a user to write programs with a small effort thanks to a predefined agent model and a set of specialized primitives for agent management. Moreover; the user can develop agent parts at a low level taking advantage of all the potentialities of C++, Common Lisp and Java object-oriented languages, and reusing a large part of the C, C++, Lisp, Common Lisp and Java software available on the internet. 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
Computational Geometry On The OTIS-Mesh Optoelectronic Computer
Authors: Chih-fang Wang, Sartaj Sahni
Venue: Proceedings of the 2002 International Conference on Parallel Processing (2002)

We develop efficient algorithms for problems in computational geometry ¿convex hull, smallest enclosing box, ECDF, two-set dominance, maximal points, all-nearest neighbor, and closest-pair¿ on the OTIS-Mesh optoelectronic computer. We also demonstrate the algorithms for computing convex hull and prefix sum with condition on a multi-dimensional mesh, which are used to compute convex hull and ECDF respectively. We show that all these problems can be solved in 0(\sqrt {N}) time even with N2 inputs.
The Assertion Table System for the PL/CV2 Program Verifier
Authors: Dean B. Krafft
Venue:  (1978)

A system to implement the block structured storage of PL/CV2 assertions is described. The system allows certain simple logical deductions to be performed automatically. These include deductions involving propositional reasoning, associativity and commutativity of arithmetic operators, and reasoning about equality. The implementation is described at a conceptual level.
Structural Complexity Column: Some Observations About Relativization of Space Bounded Computations
Authors: Juris Hartmanis
Venue:  (1988)

NO AVAILABLE
Inference and Estimation of a Long-Range Trigram Model
Authors: Stephen D Pietra, Vincent D Pietra, John Gillett, John Lafferty, Harry Printz, Lubos Ures
Venue:  (1994)

We describe an implementation of a simple probabilistic link grammar. This probabilistic language model extends trigrams by allowing a word to be predicted not only from the two immediately preceeding words, but potentially from any preceeding pair of adjacent words that lie within the same sentence. In this way, the trigram model can skip over less informative words to make its predictions. The underlying "grammar" is nothing more than a list of pairs of words that can be linked together with one or more intervening words; this word-pair grammar is automatically inferred from a corpus of training text. We present a novel technique for indexing the model parameters that allows us to avoid all sorting in the M-step of the training algorithm. This results in significant savings in computation time, and is applicable to the training of a general probabilistic link grammar. Results of preliminary experiments carried out for this class of models are presented.