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This investigation presents an oval slot edge (OSE) antipodal Vivaldi antenna (AVA), hereinafter referred to as Fern AVA (FAVA), with an optimized radiation pattern. The use of OSE provided improvements in the antenna characteristics, especially regarding a lower-frequency limit reduction, an increase of the main lobe (ML) gain, and sidelobe level (SLL) reduction. Those contrasting characteristics are simultaneously obtained through the class of the Palm Tree antennas. The proposed FAVA at 1.5 GHz shows an improved gain of 6.66 dB, -12.9 dB of SLL, and 0 degrees of main lobe squint (MLS), in contrast with 4.41 dB of gain, -4.5 dB of SLL, and 4 degrees of MLS in the conventional AVA. For the FAVA, the notches in an elliptical shape, in addition to mitigating the SLL, direct the E-fields distributions towards the main lobe, which categorizes it into the same class as the Palm Tree Vivaldi Antenna. To study the performance of the proposed antenna for medical applications of near-field microwave imaging, a conceptual proof was performed, thus obtaining the microwave image of a Child Head Phantom, homogeneous and semi-realistic, being possible to detect a brain tumor.

Artificial neural networks (ANNs) have been used over the last few decades to perform tasks by learning with comparisons. Fitting input-output models, system identification, control, and pattern recognition are some fields for ANN applications. However, problems involving uncertain situations could be challenging for them. The family of paraconsistent logics (PL) is a powerful tool that can deal with uncertainty and contradictory information, so getting attention from researchers for its implications and applications in artificial intelligence. This investigation describes a novel activation function reasoned on the paraconsistent annotated logic by two-value annotations (PAL2v) rules, a variation of PL, allowing the design of a new paraconsistent neural net (PNN), applied in model identification for control (I4C) of a closed-loop rotary inverted pendulum (RIP) system.

The Active Noise Reduction (ANR) is widely used in aircraft, headsets, telecommunications and medicine systems, to reduce or eliminate noise, while maintaining the characteristics of the desired signal. In this article a network of paraconsistent artificial neural cells (PANC) will be presented, based on the paraconsistent annotated logic by 2 values annotations (PAL2v) that allows to operate as ANR. Simulations indicate that the results presented by ANRPAL are better than those obtained by classic filters.

In this work a new type of hybrid PI controller is presented using the Paraconsistent Logic (PL) as the basis for the mathematical and logical treatment of the signals corresponding to the control variables. This control has the conventional actions PI (Proportional and Integral) together with the logical actions structured in the concepts of Paraconsistent Logic. Compared to conventional techniques, this new type of Hybrid PI Controller with Paraconsistent Logic responded well to the various tests performed in the control loop. The tests and the technical validations were done with evidences that prove the efficiency of the paraconsistent concepts.

Apresenta-se neste artigo a construção de uma estrutura microcontrolada com algoritmos baseados em Lógica Paraconsistente Anotada compondo uma rede de análises de sinais com a finalidade de atuar como uma estação de razão em malhas de controle de mistura. A Estação de Razão Paraconsistente foi implementada em uma placa eletrônica open-source Arduino que possui um microControlador ATmega328P. O controle de razão é configurado com dois controladores atuando com ações PID-Proporcional+Integral+Derivativo e vem sendo muito utilizado nas plantas industriais em processos de misturas. Um dos principais problemas neste tipo de controle é que apresentam desequilíbrios entre a comunicação dos controladores quando ocorrem mudanças no ajuste de set point e na variável controlada, ocasionando diferenças percentuais entre as quantidades, o que pode inviabilizar a qualidade do produto final. Portanto, o objetivo da pesquisa foi contribuir para amenizar os efeitos danosos à produção quando são feitas alterações no ponto de ajuste dos controladores. Na estrutura algorítmica proposta utiliza-se algoritmos fundamentados em Logica Paraconsistente (LP) que é uma lógica não clássica capaz de suportar sinais contraditórios, o que faz com que seja vantajosa a sua aplicação em relação a lógica clássica binária. O hardware da Estação de Razão Paraconsistente foi simulado em laboratório e em uma malha de controle experimental apresentando resultados superiores a sistemas de razão que utilizam a lógica convencional.

This article presents the modeling of an antipodal Vivaldi antenna (AVA), Palm Tree Class, with radiating fractal slot edge (FSE), in the form of a Koch Square Fractal (SK), labeled as SK-FSE-AVA. The surface currents of the proposed antenna are analyzed, as well as the return loss, directivity, squint, side lobe level (SLL), and Main Lobe (ML) gain. Improvement on directivity is observed when compared to an AVA, with 8.41 dB of gain in the main lobe at 4 GHz, SLL of 11.70 dB, and the squint of 0.10°. SK-FSE-AVA has 9.23 dB of gain in the main lobe at 4 GHz, SLL of –13.50 dB, and the squint of 0.2°. This antenna could be used in ultra-wideband (UWB) systems for applications on Near-Field Microwave Imaging (NMI). To show the feasibility of this application, a 3D numerical simulation of a model containing lung tissue with a malignant tumor is presented, using the proposed antenna and the respective imaging results.

The Paraconsistent Annotated Logic (PAL) is one type of non-classical logics that, differently than classical logic, allows the processing of contradictory signals in its theoretical structure. The Paraconsistent Artificial Neural Cell (PANcell) is the basic block of a set of algorithms that utilizes the interpretation of the lattice of the Paraconsistent Annotated Logic with annotation of two values (PAL2v). The Paraconsistent Artificial Neural Cell of Learning (LPANcell) is a type of PANcell that uses the output as a feedback to the input of the unfavorable degree of evidence in time. The resulting behavior is to learn any real value within a normalized closed range (interval values [0, 1]). This cell can be used in signal analysis, processing, average estimator and as a filter, called PAL2vFilter. The proposed article presents the results of the analysis of a PAL2vFilter, when using the simplified resulting degree of evidence - uE or the resulting degree of real evidence - uRE (when contradiction effects are extracted) as output.

Analysis of the Raman data to obtain results in discrimination models is usually done with multivariate statistics based on principal component analysis (PCA). In this work, we present a technique based on a non-classical logic called paraconsistent logic (PL). The aim of this work is to use computational procedures capable of generating efficient expert systems to discriminate cutaneous tissue samples obtained by Raman spectroscopy. First, a set of algorithms originating from PL is presented, and then its application in discrimination analyses is described; the discrimination analysis was conducted using a database of skin tissue samples obtained ex vivo by Raman spectroscopy of spectrum range of 400–1800 cm−1 wavelengths. Data processing, pattern creation, and comparisons were performed using the set of paraconsistent algorithms (SPA-PAL2v). The total number of samples was divided into four histopathological groups, with 115 spectra of basal cell carcinoma (BCC), 21 spectra of squamous cell carcinoma (SCC), 57 spectra of actinic keratosis (AK), and 30 normal skin (NO) spectra. An arrangement type was created for this study, and the samples were randomly selected and analyzed, and the NO group was compared with the group of non-melanoma cancer lesions (BCC + SCC) and the AK tumor lesion. Two analyses were performed. The first (SPA-PAL2v) Mode 1 (no cross-validation) achieved 76% of hits, and the second (SPA-PAL2v) Mode 2 (with cross-validation) achieved 75.78% of hits. These results were compared with discrimination using PCA statistical methods (PCA/DA) and presented superior percentages of hits, which proves the robustness of the SPA-PAL2v, confirming its potential for Raman spectrum data analysis.

Doutoramento em Engenharia Informática Esta tese surge no contexto de sistemas e serviços web. O objectivo é propor uma solução para o problema da integração de informação de diversas fontes, numa plataforma web única, personalizável e adaptável ao utilizador. Nos casos de empresas ou organizações que tenham para diferentes tarefas, diferentes sistemas de informação independentes, o problema da integração de informação surge com a necessidade de integração destes numa única interface disponibilizada aos seus utilizadores. A integração de serviços numa mesma interface pressupõe que haja comunicação entre um sistema central (que fornece a interface) e os diversos sistemas existentes (que detêm a totalidade – ou parte – da informação a apresentar). Assim, será necessário garantir a identidade do utilizador a cada um dos serviços apresentados, bem como assegurar que cada utilizador tem à sua disposição de forma centralizada, apenas e só a informação e operações a que realmente tem acesso em cada um dos sistemas. Trata-se de uma plataforma que pretende por um lado, fornecer a informação correcta e orientada ao utilizador e, por outro lado, garantir que a organização que suporta o sistema consegue informar e interagir com os seus utilizadores de forma mais eficaz. O cenário adoptado é a Universidade de Aveiro. Esta pretende disponibilizar uma plataforma electrónica, onde os diferentes interlocutores (alunos, docentes, funcionários, ex-alunos, etc.) possam ter acesso a informação dirigida e orientada aos seus interesses e funções na Universidade. De modo a que cada utilizador seja realmente visto como um utilizador único, serão estudados e comparados serviços de modelação de utilizador e perfis de utilizador. Será proposto um serviço de modelação de utilizador e uma lógica de criação de perfis de utilizador, distintos do existente no estado de arte. Esta lógica conjuga a personalização da interface por parte do utilizador, com a gestão de operações e definição de políticas de segurança por parte da organização, de forma independente relativamente ao sistema de informação subjacente. This thesis’ focus is on web systems and services. Its goal is propose a solution for the multiple information sources integration on a single web platform, customizable and adaptable by the user. In cases where companies and organizations have for different tasks, different information systems, the information integration problem comes with the need of assembly of this disperse information in a single interface for their users. Single interface service integration requires the communication between a central platform system (that supplies the interface) and the spread systems that hold the hole (or part of the) information to present to the users. Therefore, it will be necessary to guarantee the user’s identity to each of the presented services, as well as to ensure that each user will only access the information and functionalities to which he has clearance in those systems. This platform aims at providing on one hand, the proper information for the user, and on the other, guarantee that the organization that supports the system can inform and interact with its users in a more effective manner. The adopted scenario for testing is the Universidade de Aveiro. The university plans on making available an electronic platform where the different users (students, teachers, non-teaching staff, alumnae, etc.) may have access to information directly guided towards their interests and roles at the University. In order to have each user seen as a unique user, user modeling servers and user profiles will be studied and compared. It will be proposed a user modeling server and a user profile approach, both different from the state of the art approaches. This approach encompasses the interface customization by the user with operation management and security policy definition by the organization, in an independent logic from the overall information system.