Hardware synthesis for asynchronous communications mechanisms

Asynchronous data communication mechanisms (ACMs) have been extensively studied as data connectors between independently timed concurrent processes. In this work an automatic method for synthesis of re-reading ACMs is introduced. This method is is oriented to the generation of hardware artifacts. The behavior of re-reading ACMs is formally defined and the correctness properties are discussed. Then it is shown how to generate the ACMs specifications and how they can be translated into a proper hardware implementation. Verilog has been used as the target language to describe the hardware being synthesized.Peer ReviewedPostprint (published version

A compositional method for the synthesis of asynchronous communication mechanisms

Asynchronous data communication mechanisms (ACMs) have been extensively studied as data connectors between independently timed concurrent processes. In previous work, an automatic ACM synthesis method based on the generation of the reachability graph and the theory of regions was proposed. In this paper, we propose a new synthesis method based on the composition of Petri net modules, avoiding the exploration of the reachability graph. The behavior of ACMs is formally defined and correctness properties are specified in CTL. Model checking is used to verify the correctness of the Petri net models. The algorithms to generate the Petri net models are presented. Finally, a method to automatically generate C++ source code from the Petri net model is described.Peer ReviewedPostprint (author's final draft

Automating synthesis of asynchronous communication mechanisms

Asynchronous data communication mechanisms (ACMs) have been extensively studied as data connectors between independently timed processes in digital systems. In previous work, systematic ACM synthesis methods have been proposed. In this paper, we advance this work by developing algorithms and software tools which automate the major part of the ACM synthesis process. Firstly, an interleaving specification is constructed in the form of a state graph, and secondly, a Petri net model of an "ACM-type" is derived using the notion of an ACM-region. The method is applied to a number of "standard" writing and reading policies of ACMs with shared memory and unidirectional control variables.Peer ReviewedPostprint (published version

Issues in the Probability Elicitation Process of Expert-Based Bayesian Networks

A major challenge in constructing a Bayesian network (BN) is defining the node probability tables (NPT), which can be learned from data or elicited from domain experts. In practice, it is common not to have enough data for learning, and elicitation from experts is the only option. However, the complexity of defining NPT grows exponentially, making their elicitation process costly and error-prone. In this research, we conducted an exploratory study through a literature review that identified the main issues related to the task of probability elicitation and solutions to construct large-scale NPT while reducing the exposure to these issues. In this chapter, we present in detail three semiautomatic methods that reduce the burden for experts. We discuss the benefits and drawbacks of these methods, and present directions on how to improve them

Efeitos da Leitura em Mídia Digital sobre Velocidade de Leitura e Compreensão Textual

Este artigo tem por objetivo observar os efeitos de diferentes estratégias de leitura digital em comparação à leitura em papel, considerando as perspectivas de velocidade de leitura e compreensão textual. Esse tipo de estudo se faz importante pois cada vez mais texto é apresentado de forma digital e muitos cursos de educação à distância apoiam-se fortemente nesse tipo de leitura. Projetou-se um experimento com estudantes da área de informática no intuito de comparar quatro diferentes estratégias de leitura, três delas digitais. Apenas uma das estratégias digitais obteve resultados de compreensão equivalentes aos da leitura em papel. Nenhuma estratégia digital obteve performance melhor do que a de leitura em papel em termos de velocidade de leitura

Análise da variação do limiar para o algoritmo de aprendizado semissupervisionado flexcon-c / Threshold variation analysis for flexcon-c semisupervised learning algorithm

Algoritmos de aprendizado semissupervisionado são capazes de treinar classificadores a partir de uma pequena parcela de objetos inicialmente rotulados. A confiabilidade do processo de classificação depende de vários fatores que incluem o tipo de classificador utilizado e um conjunto de parâmetros que os customiza. Um dos fatores mais importantes é um limiar que determina quais instâncias são incluídas por iteração, permitindo rotular apenas instâncias classificadas com alto valor de confiança. Este artigo analisa diferentes valores para o fator de variação do algoritmo FlexCon-C e mede o impacto dessa alteração na sua acurácia. Os resultados consideram trinta diferentes bases de dados, quatro classificadores e cinco diferentes percentuais de dados pré-rotulados

Continuous Learning of the Structure of Bayesian Networks: A Mapping Study

Bayesian networks can be built based on knowledge, data, or both. Independent of the source of information used to build the model, inaccuracies might occur or the application domain might change. Therefore, there is a need to continuously improve the model during its usage. As new data are collected, algorithms to continuously incorporate the updated knowledge can play an essential role in this process. In regard to the continuous learning of the Bayesian network’s structure, the current solutions are based on its structural refinement or adaptation. Recent researchers aim to reduce complexity and memory usage, allowing to solve complex and large-scale practical problems. This study aims to identify and evaluate solutions for the continuous learning of the Bayesian network’s structures, as well as to outline related future research directions. Our attention remains on the structures because the accurate parameters are completely useless if the structure is not representative

ARMSUSP: um aplicativo computacional para cálculo da armadura de suspensão em apoios indiretos

A usual situation in concrete structures designs is the indirect support, especially the crossing of two beams, where there are a support and a supported beam. The Brazilian code for the design of concrete structures NBR 6118: 2014, in this case, establishes a single guiding paragraph, theoretically correct, but with no detail that assists the engineer to plan the hanger reinforcement. In this respect, the omission of the NBR 6118 contrasts with several international codes, which set many requirements. For example, the definition of the reinforcement lengths, reduction factors, among others. The objective of this paper is to discuss the indirect support on beams and present the ARMSUSP software application to provide assistance in this reinforcement design, which incorporates several criteria. The review presented helps to understand a seemingly simple theme, often neglected by designers and not specifically defined by some codes. Finally, some examples of calculation are presented, comparing the code requirements and the parameters adopted in some Brazilian softwares of structural design.Uma situação usual nos projetos de estruturas de concreto é a dos apoios indiretos, notadamente o encontro de duas vigas, onde há uma viga apoio e uma viga apoiada. A norma brasileira de projeto de estruturas de concreto, NBR 6118:2014, para este caso, estabelece um único parágrafo de orientação, o qual, embora teoricamente correto, não apresenta qualquer detalhe que auxilie o engenheiro no projeto da armadura de suspensão. Neste aspecto, a omissão da NBR 6118 contrasta com diversas normas internacionais, que estabelecem vários requisitos; por exemplo, a definição dos comprimentos dos trechos de armação e de fatores de redução, dentre outros. O objetivo deste artigo é discorrer sobre o apoio indireto em vigas e apresentar o aplicativo ARMSUSP para o auxílio no cálculo desta armadura, o qual incorpora diversos critérios, e está disponível a todos que o desejem. Destaca-se a revisão bibliográfica apresentada para auxiliar a compreensão de um tema aparentemente simples, mas muitas vezes negligenciado pelos projetistas e nem sempre bem formulado nos documentos normativos. Por último, são feitos exemplos de cálculo, comparando as prescrições de várias normas e os parâmetros adotados em alguns programas computacionais brasileiros de projeto de estruturas