Characteristic Functions for Ergodic Tuples

Gohm, Rolf; Dey, S., 'Characteristic function for ergodic tuples', Integral Equations and Operator Theory 58(1) pp.43-63 RAE2008

Information sets and partial permutation decoding for codes from finite geometries

Mavron, Vassili; McDonough, T.P.; Key, J.D., (2006) 'Information sets and partial permutation decoding for codes from finite geometries', Finite Fields and their applications 12(2) pp.232-247 RAE2008

Síndrome de Burnout em farmacêuticos

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas

O prazer associado ao consumo de alimentos e factores influenciadores

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas

A influência dos principais factores de risco cardiovascular nos AVCs e consequente perturbação da linguagem adquirida

Trabalho de Projeto apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Terapêutica da Fala, área de especialização em Linguagem no Adulto

Diagnóstico sobre el potencial de la artesanía como actividad económica productiva para desarrollar con mujeres desplazadas o jefes de hogar y artesanos, en Barrancabermeja, Santander.

140 hojas : ilustraciones, fotografías color.

Behind, Between, and Beyond Anthropomorphic Models

The plurality of models of ultimate reality is a central problem for religious philosophy. This essay sketches what is involved in mounting comparative inquiries across the plurality of models. In order to illustrate what advance would look like in such a comparative inquiry, an argument is presented to show that highly anthropomorphic models of ultimate reality are inferior to a number of competitors. This paper was delivered as a keynote address during the APA Pacific 2007 Mini-Conference on Models of God.

Sleep Patterns in Elementary School Children (Grades 2-5) and Adolescents (Grade 10)

Background: To date, there is limited research examining sleep patterns in elementary school children. Previous researchers focused on parental responses rather than student responses to determine factors that affect sleep. The presented study surveyed sleep patterns and examined external factors affecting total sleep time among elementary school children and adolescents. Methods: Students in grades 2-5 (n=885) and grade 10 (n=190) enrolled in a public school system in the Northeast, completed a district administered survey that included questions on sleep duration and hygiene. Results. Average reported sleep duration decreased with increasing grade level. Children in grades 2-5 woke up earlier (31.7-72.4%) and on their own in comparison to adolescents in grade 10 (6.8%). Significantly shorter sleep durations were associated with having a television (grades 2, 4, 5, p< 0.01) or a cell phone in the room (grades 3, 4; p < 0.05), playing on the computer or video games (grades 3, 4, p<.001) before going to bed. In contrast, students in grade 2, 3, & 4 who reported reading a book before going to bed slept on average 21 minutes more per night (p=.029, .007, .009, respectively). For tenth graders, only consumption of energy drinks led to significant reduction in sleep duration (p<.0001). Conclusion. Sleep is a fundamental aspect in maintaining a healthy and adequate life style. Understanding sleep patterns will assist parents, health care providers, and educators in promoting quality sleep hygiene in school-aged children.

Using Warp to Control Network Contention in Mermera

Parallel computing on a network of workstations can saturate the communication network, leading to excessive message delays and consequently poor application performance. We examine empirically the consequences of integrating a flow control protocol, called Warp control [Par93], into Mermera, a software shared memory system that supports parallel computing on distributed systems [HS93]. For an asynchronous iterative program that solves a system of linear equations, our measurements show that Warp succeeds in stabilizing the network's behavior even under high levels of contention. As a result, the application achieves a higher effective communication throughput, and a reduced completion time. In some cases, however, Warp control does not achieve the performance attainable by fixed size buffering when using a statically optimal buffer size. Our use of Warp to regulate the allocation of network bandwidth emphasizes the possibility for integrating it with the allocation of other resources, such as CPU cycles and disk bandwidth, so as to optimize overall system throughput, and enable fully-shared execution of parallel programs.

Timeliness via Speculation for Real-Time Databases

Various concurrency control algorithms differ in the time when conflicts are detected, and in the way they are resolved. In that respect, the Pessimistic and Optimistic Concurrency Control (PCC and OCC) alternatives represent two extremes. PCC locking protocols detect conflicts as soon as they occur and resolve them using blocking. OCC protocols detect conflicts at transaction commit time and resolve them using rollbacks (restarts). For real-time databases, blockages and rollbacks are hazards that increase the likelihood of transactions missing their deadlines. We propose a Speculative Concurrency Control (SCC) technique that minimizes the impact of blockages and rollbacks. SCC relies on the use of added system resources to speculate on potential serialization orders and to ensure that if such serialization orders materialize, the hazards of blockages and roll-backs are minimized. We present a number of SCC-based algorithms that differ in the level of speculation they introduce, and the amount of system resources (mainly memory) they require. We show the performance gains (in terms of number of satisfied timing constraints) to be expected when a representative SCC algorithm (SCC-2S) is adopted.

The Specialized Mappings Architecture

A probabilistic, nonlinear supervised learning model is proposed: the Specialized Mappings Architecture (SMA). The SMA employs a set of several forward mapping functions that are estimated automatically from training data. Each specialized function maps certain domains of the input space (e.g., image features) onto the output space (e.g., articulated body parameters). The SMA can model ambiguous, one-to-many mappings that may yield multiple valid output hypotheses. Once learned, the mapping functions generate a set of output hypotheses for a given input via a statistical inference procedure. The SMA inference procedure incorporates an inverse mapping or feedback function in evaluating the likelihood of each of the hypothesis. Possible feedback functions include computer graphics rendering routines that can generate images for given hypotheses. The SMA employs a variant of the Expectation-Maximization algorithm for simultaneous learning of the specialized domains along with the mapping functions, and approximate strategies for inference. The framework is demonstrated in a computer vision system that can estimate the articulated pose parameters of a human’s body or hands, given silhouettes from a single image. The accuracy and stability of the SMA are also tested using synthetic images of human bodies and hands, where ground truth is known.

StaXML: Static Typing of XML Document Fragments for Imperative Web Scripting Languages

We present a type system, StaXML, which employs the stacked type syntax to represent essential aspects of the potential roles of XML fragments to the structure of complete XML documents. The simplest application of this system is to enforce well-formedness upon the construction of XML documents without requiring the use of templates or balanced "gap plugging" operators; this allows it to be applied to programs written according to common imperative web scripting idioms, particularly the echoing of unbalanced XML fragments to an output buffer. The system can be extended to verify particular XML applications such as XHTML and identifying individual XML tags constructed from their lexical components. We also present StaXML for PHP, a prototype precompiler for the PHP4 scripting language which infers StaXML types for expressions without assistance from the programmer.

Addendum to "New Notions of Reduction and Non-Semantic Proofs of β-Strong Normalization in Typed λ-Calculi"

This is an addendum to our technical report BUCS TR-94-014 of December 19, 1994. It clarifies some statements, adds information on some related research, includes a comparison with research be de Groote, and fixes two minor mistakes in a proof.

Dynamic Server Selection using Bandwidth Probing in Wide-Area Networks

Replication is a commonly proposed solution to problems of scale associated with distributed services. However, when a service is replicated, each client must be assigned a server. Prior work has generally assumed that assignment to be static. In contrast, we propose dynamic server selection, and show that it enables application-level congestion avoidance. To make dynamic server selection practical, we demonstrate the use of three tools. In addition to direct measurements of round-trip latency, we introduce and validate two new tools: bprobe, which estimates the maximum possible bandwidth along a given path; and cprobe, which estimates the current congestion along a path. Using these tools we demonstrate dynamic server selection and compare it to previous static approaches. We show that dynamic server selection consistently outperforms static policies by as much as 50%. Furthermore, we demonstrate the importance of each of our tools in performing dynamic server selection.

Real-Time Mutable Broadcast Disks

There is an increased interest in using broadcast disks to support mobile access to real-time databases. However, previous work has only considered the design of real-time immutable broadcast disks, the contents of which do not change over time. This paper considers the design of programs for real-time mutable broadcast disks - broadcast disks whose contents are occasionally updated. Recent scheduling-theoretic results relating to pinwheel scheduling and pfair scheduling are used to design algorithms for the efficient generation of real-time mutable broadcast disk programs.