Bessel Integrals and Fundamental Solutions for a Generalized Tricomi Operator

Partial Fourier transforms are used to find explicit formulas for two remarkable fundamental solutions for a generalized Tricomi operator. These fundamental solutions reflect clearly the mixed type of the operator. In order to prove these results, we establish explicit formulas for Fourier transforms of some type of Bessel functions

Modeling formalisms for dynamic structure systems

We present a new concept for a system network to represent systems that are able to undergo structural change. Change in structure is defined in general terms, and includes the addition and deletion of systems and the modification of the relations among components. The structure of a system network is stored in the network executive. Any change in structure-related information is mapped into modifications in the network structure.Based on these concepts, we derive three new system specifications that provide a shorthand notation to specify classes of dynamic structure systems. These new formalisms are: dynamic structure discrete time system, dynamic structure differential equation specified systems, and dynamic structure discrete event system specification. We demonstrate that these formalisms are closed under coupling, making hierarchical model construction possible. formalisms are described using set theoretic notation and general systems theory concepts

piHyFlow Operational Semantics

Simulation models have been described using different perspectives, or worldviews. In the process interaction world view (PI), every entity is modeled by a sequence of actions describing its life cycle, offering a comprehensive model that groups the events involving each entity. In this paper we describe piHyFlow, a formalism for representing hybrid models using a set of communicating processes. This set is dynamic, enabling processes to be created and destroyed at runtime. Processes are encapsulated into piHyFlow base models and communicate through shared memory. piHyFlow, however, can guarantee modularity by enforcing that models can only communicate by input and output interfaces. piHyFlow extends current PI approaches by providing support for HyFlow concepts of sampling and dense (continuous) outputs, in addition to the more traditional event-based communication. In this paper we present piHyFlow operational semantics using the concepts of simulator and component

Representing Tactics for Fault Recovery: A Reconfigurable, Modular, and Hierarchical Approach

We show the advantages of modular and hierarchical design in obtaining fault-tolerant software. Modularity enables the identification of faulty software units simplifying key operations, like software removal and replacement. We describe three approaches to repair faulty software based on replication, namely, Passive Replication, N-Version Replication, and Active Replication, based on modular components. We show that the key construct to represent these tactics is the ability to make ad hoc changes in software topologies. We consider hierarchical mobility as a useful operation to introduce new software units for replacing faulty ones. For illustration purposes, we use connecton, a hierarchical, modular, and self-modifying software specification formalism, and its implementation in the Desmos framework

Identifying argumentative acts within the classroom amongst engineering students

Students’ arguments surrounding a scientific topic are analyzed. This analysis comes from research developed in the classroom where dialogic interaction was promoted. The purpose of this study has not only been to identify argumentative elements used by students during the sessions but principally to the process of discussion. Three different ways have been proposed for this analysis: speech acts, acts of argumentative process and acts of learning process, with the intention of establishing relationships between them

Gestão de RCD - resíduos de construção e demolição, na obra de ampliação do Aeroporto Francisco Sá Carneiro

A primeira, parte deste artigo consiste numa contextualização da problemática da gestão de RCD – Resíduos de Construção e Demolição, que inclui dados sobre produção de resíduos na UE – União Europeia e em Portugal, sobre a composição de RCD, os sectores de actividade económica geradores de RCD, uma menção à legislação portuguesa sobre gestão de resíduos, em geral e específica de RCD, e onde são formuladas linhas orientadoras para uma boa gestão de RCD. A segunda parte versa a gestão de RCD na obra de ampliação do Aeroporto Francisco Sá Carneiro (AFSC), Porto, Portugal (“estudo de caso”), no período temporal de Janeiro de 2004 a Janeiro de 2005. Segundo o constante no processo de AIA – Avaliação de Impacte Ambiental da obra, faz-se uma classificação das fracções dos RCD, de acordo com a LER – Lista Europeia de Resíduos, são apresentadas quantidades médias mensais para a geração dessas fracções de RCD, assim como são apresentados valores mensais para vários índices de desempenho de gestão ambiental de RCD. Conclui-se que a metodologia adoptada pelo consórcio da obra de ampliação do AFSC para a gestão de RCD, assim como os indicadores de desempenho, constituem um bom exemplo. The first part of this paper makes a context on the issue of the environmental management of RCD – Residues of Construction and Demolition. It includes data of the production of residues in the EU – European Union and in Portugal, of the composition of RCD, lists the economic activity sectors that generate RCD, comments on the Portuguese legislation about residues management, in general and specific of RCD, and some guidelines for a good management of RCD are proposed. The second part concerns the management of RCD in the building construction works for the expansion of the Francisco Sá Carneiro Airport (AFSC), in Oporto, Portugal, in the time period from January 2004 to January 2005. Following the process of EIA – Environmental Impact Assessment of the building project, a classification of RCD fractions is presented according to EWC – European Waste Catalogue, as well as average monthly amounts for the production of RCD fractions and monthly values for several indices that assess the level of the environmental management of RCD. As a conclusion, the case-study presented here may be taken as a good example of the environmental management of RCD

Children ́s literature and education for democracy: A pedagogical intervention in the 4th grade of a Portuguese Elementary School

Este artigo relata uma intervenção pedagógica levada a cabo junto de alunos do 4º ano de escolaridade do Ensino Básico, em Portugal, com dois objetivos: (1) desenvolver competências literácitas, especificamente ao nível da leitura e compreensão leitora; e (2) construir o conhecimento histórico, recorrendo a obras de literatura infanto-juvenil que recriam eventos históricos. O referencial teórico baseou-se quer no conceito de Content Area Literacy (MOSS, 2005; BROZO, 2010), quer no Programa de Leitura Fundamentado na Literatura (YOOP; YOOP, 2006).This paper documents a pedagogical intervention conducted with Portuguese students in the 4th grade of an Elementary School, which had two goals: (1) to develop literacy competences, mainly reading and reading comprehension; (2) to construct historical knowledge through children’s literature books which show historical events. The theoretical mainframe is based on Content Area Literacy (MOSS, 2005; BROZO, 2010) and on Literature Based Reading Activities (YOOP; YOOP, 2006).CIEC - Centro de Investigação em Estudos da Criança, IE, UMinho (UI 317 da FCT

Análise do fenómeno da naturbanização ao nível de PDM: aplicação a Terras de Bouro

Dissertação de Mestrado em Engenharia MunicipalEste documento analisa mudanças no processo da urbanização, as quais se evidenciaram nas duas últimas décadas, gerando dois novos fenómenos: Contraurbanização e Naturbanização. Estes dois conceitos de movimentos da população foram assim apelidados, em estudos desenvolvidos em Inglaterra por Berry Champion (counterurbanization) e em Espanha por Maria José Prados (naturbanization). O primeiro é descrito como o movimento das populações das cidades para áreas da periferia e o segundo, como o movimento de pessoas de áreas urbanas para áreas rurais de grande valor e riqueza paisagística envolventes a Parques Naturais e Nacionais. Ambos os movimentos ocorrem em sociedades industrializadas maduras. Estes conceitos pemitem explicar como a mudança de atitudes e de mentalidades perante as novas preocupações com factores ambientais, tem levado a população a procurar espaços de maior qualidade de vida, nomeadamente, na envolvência e no interior do Parque Nacional da Peneda-Gerês. De facto, depois de uma concentração inicial da população em centros urbanos em detrimento dos espaços rurais, tem-se assistido a um retorno das populações a essas áreas, evidenciando-se indícios destes novos fenómenos. Este comportamento diferenciado de habitar o território é avaliado através do processo de revisão de um Plano Director Municipal e dos inquéritos de Audiência Prévia onde as pessoas expressam a vontade de mudança do uso do solo e, com isso, a modificação pretendida e a consequente pressão sobre o território. Demonstra-se também o carácter importante das relações entre grandes pólos urbano e os territórios rurais adjacentes como catalizador destes fenómenos. Propõem-se, agora, novos desafios à sociedade portuguesa que ainda se encontra em fase de amadurecimento das suas políticas de ordenamento territorial perante o factor do esvaziamento das áreas rurais, factor predominante nestas duas últimas décadas. No entanto, encontram-se já novos sinais de mudança que se vão evidenciando, embora de forma ténue, acarretando como tal novas implicações no uso urbano do território de elevado valor paisagístico.This document analyses changes in the process of urbanisation, observed in the last two decades, generating two new phenomena: Counterurbanization and Naturbanization. These two new concepts of population movements have been named counterubanization, in studies developed in England by Berry Champion and Naturbanization in research developed in Spain by Maria José Prados. The first is described as the movement of the populations of the cities to peripheral areas and the second as the movement of people from urban areas to rural areas of great landscape value and richness that evolved to Natural and National Parks. Both movements occurred in industrialized societies. These concepts, allow the explanation how the changes of attitudes and of mentalities fostered with worries about environmental factors, have induced the population to find new places with better quality of life, especially in natural protected areas as inside the National Park of Peneda Gerês. In fact, after one initial concentration of the population in urban centres in detract of rural places, a new trend is evidenced by the return of population to these areas. This different pattern of behaviour is evaluated through the analyses of data compiled under the revision process of a Municipal Plan, where the people expressed their will to shift the land use attributed to their plots among other requests. This phenomenon has been framed by the two mentioned concepts of counterurbanization and naturbanization and it was confirmed that proximity to major urban centres and to main roads acts as a catalyst for these phenomena. New challenges are proposed to the Portuguese society in the present days, a society that needs to mature its land-use policies in face of the human desertification of last two decades in the rural areas and corresponding implications. Nevertheless, some new evidences, albeit of small intensity can be located in territories of high landscape value