Local fractional variational iteration and decomposition methods for wave equation on cantor sets within local fractional operators

We perform a comparison between the fractional iteration and decomposition methods applied to the wave equation on Cantor set. The operators are taken in the local sense. The results illustrate the significant features of the two methods which are both very effective and straightforward for solving the differential equations with local fractional derivative.

Previsão de curto prazo do consumo de energia elétrica

Dissertação para a obtenção do grau de Mestre em Engenharia Electrotécnica - Ramo de Energia

Simulação de processos de adsorção recorrendo ao Aspen Chromatography

As operações de separação por adsorção têm vindo a ganhar importância nos últimos anos, especialmente com o desenvolvimento de técnicas de simulação de leitos móveis em colunas, tal como a cromatografia de Leito Móvel Simulado (Simulated Moving Bed, SMB). Esta tecnologia foi desenvolvida no início dos anos 60 como método alternativo ao processo de Leito Móvel Verdadeiro (True Moving Bed, TMB), de modo a resolver vários dos problemas associados ao movimento da fase sólida, usuais nestes métodos de separação cromatográficos de contracorrente. A tecnologia de SMB tem sido amplamente utilizada em escala industrial principalmente nas indústrias petroquímica e de transformação de açúcares e, mais recentemente, na indústria farmacêutica e de química fina. Nas últimas décadas, o crescente interesse na tecnologia de SMB, fruto do alto rendimento e eficiente consumo de solvente, levou à formulação de diferentes modos de operação, ditos não convencionais, que conseguem unidades mais flexíveis, capazes de aumentar o desempenho de separação e alargar ainda mais a gama de aplicação da tecnologia. Um dos exemplos mais estudados e implementados é o caso do processo Varicol, no qual se procede a um movimento assíncrono de portas. Neste âmbito, o presente trabalho foca-se na simulação, análise e avaliação da tecnologia de SMB para dois casos de separação distintos: a separação de uma mistura de frutose-glucose e a separação de uma mistura racémica de pindolol. Para ambos os casos foram considerados e comparados dois modos de operação da unidade de SMB: o modo convencional e o modo Varicol. Desta forma, foi realizada a implementação e simulação de ambos os casos de separação no simulador de processos Aspen Chromatography, mediante a utilização de duas unidades de SMB distintas (SMB convencional e SMB Varicol). Para a separação da mistura frutose-glucose, no quediz respeito à modelização da unidade de SMB convencional, foram utilizadas duas abordagens: a de um leito móvel verdadeiro (modelo TMB) e a de um leito móvel simulado real (modelo SMB). Para a separação da mistura racémica de pindolol foi considerada apenas a modelização pelo modelo SMB. No caso da separação da mistura frutose-glucose, procedeu-se ainda à otimização de ambas as unidades de SMB convencional e Varicol, com o intuito do aumento das suas produtividades. A otimização foi realizada mediante a aplicação de um procedimento de planeamento experimental, onde as experiências foram planeadas, conduzidas e posteriormente analisadas através da análise de variância (ANOVA). A análise estatística permitiu selecionar os níveis dos fatores de controlo de modo a obter melhores resultados para ambas as unidades de SMB.

Teacher placement report: investigation: action research project investigating methods for promoting creativity in double bass students attending a portuguese music school

The investigation which employed the action research method (qualitative analysis)was divided into four fases. In phases 1-3 the participants were six double bass students at Nossa Senhora do Cabo Music School. Pilot exercises in creativity were followed by broader and more ambitious projects. In phase 4 the techniques were tested and amplified during a summer course for twelve double bass students at Santa Cecilia College.

Análise crítica do Regulamento Geral dos Sistemas Públicos e Prediais de Distribuição de Água e de Drenagem de Águas Residuais

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Hidráulica

Metaheuristic approach to the Holt-Winters optimal short term load forecast

Electricity short-term load forecast is very important for the operation of power systems. In this work a classical exponential smoothing model, the Holt-Winters with double seasonality was used to test for accurate predictions applied to the Portuguese demand time series. Some metaheuristic algorithms for the optimal selection of the smoothing parameters of the Holt-Winters forecast function were used and the results after testing in the time series showed little differences among methods, so the use of the simple local search algorithms is recommended as they are easier to implement.

Metaheuristhic approach to the Holt-Winters optimal short term load forecast

Electricity short-term load forecast is very important for the operation of power systems. In this work a classical exponential smoothing model, the Holt-Winters with double seasonality was used to test for accurate predictions applied to the Portuguese demand time series. Some metaheuristic algorithms for the optimal selection of the smoothing parameters of the Holt-Winters forecast function were used and the results after testing in the time series showed little differences among methods, so the use of the simple local search algorithms is recommended as they are easier to implement.

Using a prioritized MAC protocol to execute the database operation join in networked embedded computer systems

Database query languages on relations (for example SQL) make it possible to join two relations. This operation is very common in desktop/server database systems but unfortunately query processing systems in networked embedded computer systems currently do not support this operation; specifically, the query processing systems TAG, TinyDB, Cougar do not support this. We show how a prioritized medium access control (MAC) protocol can be used to efficiently execute the database operation join for networked embedded computer systems where all computer nodes are in a single broadcast domain.

Gestão de um projecto de uma torre de arrefecimento industrial: estudo de caso

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica

Federalism and health policy: the intergovernmental committees in Brazil

OBJECTIVE To analyze the dynamics of operation of the Bipartite Committees in health care in the Brazilian states.METHODS The research included visits to 24 states, direct observation, document analysis, and performance of semi-structured interviews with state and local leaders. The characterization of each committee was performed between 2007 and 2010, and four dimensions were considered: (i) level of institutionality, classified as advanced, intermediate, or incipient; (ii) agenda of intergovernmental negotiations, classified as diversified/restricted, adapted/not adapted to the reality of each state, and shared/unshared between the state and municipalities; (iii) political processes, considering the character and scope of intergovernmental relations; and (iv) capacity of operation, assessed as high, moderate, or low.RESULTS Ten committees had advanced level of institutionality. The agenda of the negotiations was diversified in all states, and most of them were adapted to the state reality. However, one-third of the committees showed power inequalities between the government levels. Cooperative and interactive intergovernmental relations predominated in 54.0% of the states. The level of institutionality, scope of negotiations, and political processes influenced Bipartite Committees’ ability to formulate policies and coordinate health care at the federal level. Bipartite Committees with a high capacity of operation predominated in the South and Southeast regions, while those with a low capacity of operations predominated in the North and Northeast.CONCLUSIONS The regional differences in operation among Bipartite Interagency Committees suggest the influence of historical-structural variables (socioeconomic development, geographic barriers, characteristics of the health care system) in their capacity of intergovernmental health care management. However, structural problems can be overcome in some states through institutional and political changes. The creation of federal investments, varied by regions and states, is critical in overcoming the structural inequalities that affect political institutions. The operation of Bipartite Committees is a step forward; however, strengthening their ability to coordinate health care is crucial in the regional organization of the health care system in the Brazilian states.

Classification of some penalty methods

Optimization problems arise in science, engineering, economy, etc. and we need to find the best solutions for each reality. The methods used to solve these problems depend on several factors, including the amount and type of accessible information, the available algorithms for solving them, and, obviously, the intrinsic characteristics of the problem. There are many kinds of optimization problems and, consequently, many kinds of methods to solve them. When the involved functions are nonlinear and their derivatives are not known or are very difficult to calculate, these methods are more rare. These kinds of functions are frequently called black box functions. To solve such problems without constraints (unconstrained optimization), we can use direct search methods. These methods do not require any derivatives or approximations of them. But when the problem has constraints (nonlinear programming problems) and, additionally, the constraint functions are black box functions, it is much more difficult to find the most appropriate method. Penalty methods can then be used. They transform the original problem into a sequence of other problems, derived from the initial, all without constraints. Then this sequence of problems (without constraints) can be solved using the methods available for unconstrained optimization. In this chapter, we present a classification of some of the existing penalty methods and describe some of their assumptions and limitations. These methods allow the solving of optimization problems with continuous, discrete, and mixing constraints, without requiring continuity, differentiability, or convexity. Thus, penalty methods can be used as the first step in the resolution of constrained problems, by means of methods that typically are used by unconstrained problems. We also discuss a new class of penalty methods for nonlinear optimization, which adjust the penalty parameter dynamically.

Damage evaluation of drilled carbon/epoxy laminates based on area assessment methods

The characteristics of carbon fibre reinforced laminates had widened their use, from aerospace to domestic appliances. A common characteristic is the need of drilling for assembly purposes. It is known that a drilling process that reduces the drill thrust force can decrease the risk of delamination. In this work, delamination assessment methods based on radiographic data are compared and correlated with mechanical test results (bearing test).

A web-based tool to evaluate the iterative processes of direct search methods

Constrained and unconstrained Nonlinear Optimization Problems often appear in many engineering areas. In some of these cases it is not possible to use derivative based optimization methods because the objective function is not known or it is too complex or the objective function is non-smooth. In these cases derivative based methods cannot be used and Direct Search Methods might be the most suitable optimization methods. An Application Programming Interface (API) including some of these methods was implemented using Java Technology. This API can be accessed either by applications running in the same computer where it is installed or, it can be remotely accessed through a LAN or the Internet, using webservices. From the engineering point of view, the information needed from the API is the solution for the provided problem. On the other hand, from the optimization methods researchers’ point of view, not only the solution for the problem is needed. Also additional information about the iterative process is useful, such as: the number of iterations; the value of the solution at each iteration; the stopping criteria, etc. In this paper are presented the features added to the API to allow users to access to the iterative process data.

Direct-search penalty/barrier methods

In Nonlinear Optimization Penalty and Barrier Methods are normally used to solve Constrained Problems. There are several Penalty/Barrier Methods and they are used in several areas from Engineering to Economy, through Biology, Chemistry, Physics among others. In these areas it often appears Optimization Problems in which the involved functions (objective and constraints) are non-smooth and/or their derivatives are not know. In this work some Penalty/Barrier functions are tested and compared, using in the internal process, Derivative-free, namely Direct Search, methods. This work is a part of a bigger project involving the development of an Application Programming Interface, that implements several Optimization Methods, to be used in applications that need to solve constrained and/or unconstrained Nonlinear Optimization Problems. Besides the use of it in applied mathematics research it is also to be used in engineering software packages.

Handling random errors and biases in methods used for short-term dietary assessment

Epidemiological studies have shown the effect of diet on the incidence of chronic diseases; however, proper planning, designing, and statistical modeling are necessary to obtain precise and accurate food consumption data. Evaluation methods used for short-term assessment of food consumption of a population, such as tracking of food intake over 24h or food diaries, can be affected by random errors or biases inherent to the method. Statistical modeling is used to handle random errors, whereas proper designing and sampling are essential for controlling biases. The present study aimed to analyze potential biases and random errors and determine how they affect the results. We also aimed to identify ways to prevent them and/or to use statistical approaches in epidemiological studies involving dietary assessments.