2007
2007 Doctorate Thesis: 8
| 23th Doctorate Thesis |
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| Author: |
Evangivaldo Almeida Lima |
| Title: | |
| Supervisor: |
Prof. Dr. Luis Allan Künzle |
| Co-supervisor: |
Prof. Dr. Ricardo Lüders |
| Area: |
Informatics |
| Abstract: |
The objective of this thesis is to establish formal conditions for time Petri nets analysis by interval algebra. The interval algebra is traditionally used as a mathematical tool in the solution of problems related to uncertainty. In fact time Petri nets are characterized by presenting an uncertainty at the moment of its transitions firing. This imprecision is denoted by a firing interval. Thus, in this work the dynamics of the firing intervals throughout the evolution of the net is represented by a linear interval equation, which makes possible the calculation of transition firing intervals without generating the whole space of states to be explored, completely or partially. Also, this interval equation is used to solve a kind of inverse problem to the previous one. That is, given a time specification for a time Petri net to evalue from a state to another one any to compute the possibilities of firings between these two states, in case that it exists. Throughout the development of the approach, other important results have been obtained, such as: reduction methods for time Petri nets baseds interval approximation, reduction of the state space, and an alternative for the construction of the state graph with relative and absolute times. The developed approach was applied to different problems to compute metrics such as: maximum and minimum time separation ocurrence of two transition, the scheduling validation of firing sequence, times of cycles, among others. |
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| Vivo voce exam |
February 2007 |
| Download |
[pdf] Only Portuguese |
| 24th Doctorate Dissertation |
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| Author: |
Andrey Ricardo Pimentel |
| Title: | Uma abordagem para projeto de software orientado a objetos baseado na teoria de projeto axiomático |
| Supervisor: |
Prof. Dr. Paulo Cézar Stadzisz |
| Area: |
Informatics |
| Abstract: |
This thesis presents an approach, that applies the Axiomatic Design Theory to Object-Oriented software design in order to guarantee the quality of the design solution along the development process. The quality of the design is an essential aspect for the construction of a product with quality. The theorethical foundation of the Axiomatic Design Theory and its domain-free nature makes it a powerfull tool to be applied together with Object-Oriented software development metodologies and techniques in order to help on guarantiing the quality of the design solution. The goal of this approach is to propose and integrate methods that allow the use of Axiomatic Design together with an Object-Oriented software development methodology, such as the Unified Process. The proposed approach has 4 stages that are inserted mainly on the elaboration phase of the Unified Process. The proposed design approach establishes ways for applying the Independence Axiom in order to guarantee the quality of the design solution along the design process. Analogies between concepts of Axiomatic Design and Object-Oriented software design are defined. A hierarchical model for the decomposition of functional requirements and design parameters, based on use cases, is defined. A zigzagging process that extends the original zigzagging process, is created to be applied on an iterative and incremental software development life cycle. A framework for the application of the Information Axiom on Object-Oriented software is created. This framework uses software complexity metrics well-established on the literature such as use case points, function poins and the Chidamber and Kemerer metrics suite. A case study is presented where a design solution for an embedded system with time constraints is created. This case study illustrates how the proposed approach can be used to choose the best design solution, at each level of design decomposition, in order to guarantee the quality of the design solution. |
| Keywords: |
Software Engineering, Object-Orientation, Axiomatic Design, Unified Process, Design Quality. |
| Viva voce exam: |
25 May 2007 |
| Download |
[pdf] Only Portuguese |
| 25th Doctorate Dissertation |
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| Author: |
Raul José Fernandes de Oliveira |
| Title: | Simultaneously identification method of two electrical feature modulated by physiological parameters |
| Supervisor: |
Prof. Dr. Paulo José Abatti |
| Abstract: |
This work proposes a biotelemetric method to determine simultaneously two electrical characteristics (modulated by physiological parameters) from a passive injectable RLC microcircuit. Due to the presence of free ions inside the biological tissue, inductive links (loop antennas) must be employed, instead of dipole antennas. As the coil of the sensor presents small dimensions (diameter of about mm) its magnetic coupling to the monitoring device requires special attention. To monitor the sensor, a digital device assembled with a group of coils to maximize the mutual inductance (at a distance of 5 mm) between them was developed, detecting its resonance frequencies and the respective amplitude (through a frequency sweep) in real-time. The electrical response acquired by the detector from the sensor was analytically modeled. The model indicates a time constant to consider for each change of the signal frequencies to prevent errors in the response. From that theoretical model, an equation to determine the total resistance from the RLC circuit was obtained and confirmed by experiments. Then, a method to determine the resonance frequency and the total resistance from remote RLC circuit was proposed. A sensor was developed to verify the accuracy and the limits from this method. A parallel RLC circuit was built inside a silicone rubber tube. When the tube is stretched, a ferrite rod assembled beside the inductor is displaced varying the resonance frequency and, changing the environmental temperature, a NTC varies the quality factor of the circuit. Tests using the proposed method to monitor the sensor were realized. Errors small than 0.57 % in the resonance frequencies and 0.77 % in the temperature were obtained. The measured influence of the temperature variation over frequency determination was less than 0.16 %, indicating that the method is feasible. |
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| Viva voce exam: |
September 2007 |
| Download |
[pdf] Only Portuguese |
| 26th Doctorate Dissertation |
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| Author: |
Ricardo Fernando dos Reis |
| Title: | |
| Supervisor: |
Prof. Dr. Paulo César Borges |
| Area: |
Biomedical Engineering |
| Abstract: |
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| Viva voce date: |
June 2007 |
| Dissertation: |
[pdf] - Only Portuguese |
| 27th Doctorate Thesis |
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| Author: |
Marcelo Kleber Felisberto |
| Title: | |
| Supervisor: |
Prof. Dra. Tania Mezzadri Centeno |
| Co-supervisor: |
Profa. Dra. Lúcia Valéria Ramos de Arruda |
| Area: |
Informatics |
| Abstract: |
This work proposes a new method for the automatic detection of the weld seam in radiographic images of pipeline welded joints. The proposed methodology is based on the optimization of parameters that are used to control and modify the position, size and shape of an image window, in order to enclose the image region that best matches the radiographic representation of a reinforced weld seam. The search for the best matching is managed by a genetic algorithm and uses an image similarity concept that is commonly applied on template matching procedures. The proposed technique solved weld seam detection problems for which no other automatic detection method was successful. The test results achieved an accuracy between 93% and 100%, regarding different tests circumstances, for a total of 478 radiographic images. The images data set included radiograph samples that cover all the recommended radiographic exposure techniques that are recommended, in the ASME V code, for inspection of pipeline welded joints. Meanwhile, a known image segmentation technique was modified and applied to perform the automatic detection of welding defects. For that test series, radiographic patterns from the International Institute of Welding (IIW) were used, including samples of the most popular classes of welding defects. After the used segmentation technique has been properly modified, defect detection samples were achieved for all the tested defect classes. Such results contribute with advancements in the automatic analysis of industrial radiographs and, as a final goal, aim at aggregating quality and efficiency to the radiographic inspection of welded joints. |
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| Viva voce exam: |
22 October 2007 |
| Download |
[pdf] Only Portuguese |
| 28th Doctorate Thesis |
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| Author: |
Ricardo Canute Kamikawachi |
| Title: | |
| Supervisor: |
José Luis Fábris |
| Area: |
Informatics |
| Abstract: |
This work describes the production and characterization of long period gratings (LPG) and etched fiber Bragg gratings as sensors. Both the production and characterization were carried out at the Laser Laboratory of UTFPR and the production and characterization of etched fiber Bragg gratings were carried out at Coherent Optics Laboratory of University of Aveiro, Portugal. Aspects concerning to the production and operation principles are shown. The results obtained from the grating production and characterization, as well as the experimental set-up developed to these goals are presented. The method used to write the gratings was the application of point-to-point electrical arch discharge, resulting in grating periods of 598 and 600 μm operating at the third window transmission around 1.55 μm. The long period gratings and the etched fiber Bragg gratings were characterized as a function of modification on the refractive index of the external surrounding environment, of temperature changes and strain (this last parameter was carried out only for long period gratings), the cross sensitivity also was characterized. The refractive index response of long period grating at two different conditions, one of them for presence of gasoline blend in water environment and another one for vapors of some hydrocarbon in closed container, points to the use of this device for hydrocarbon leakage detection at refineries and gas stations. Long period gratings e results obtained for ethanol agrees with the data find in literature, showing that this is a good technique for this goal. |
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| Viva voce exam: |
25 October 2007 |
| Download |
[pdf] Only Portuguese |
| 29th Doctorate Thesis |
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| Author: |
João Cadamuro Júnior |
| Title: | |
| Supervisor: |
Prof. Dr. Douglas P. B. Renaux |
| Area: |
Informatics |
| Abstract: |
The Dyretiva is a method used for verifying the time constraints of embedded realtime systems. The verification is performed by monitoring the embedded software when it is running in an embedded hardware. The Dyretiva method takes into account the resource constrained nature of embedded systems and the time bounded nature of real-time systems. The method is comprised by a monitoring approach and a fault model. The monitoring approach defines the physical and the logical interfaces used in the observation of the system under test, as well as the strategies used for an optimized trace data collection. The fault model identifies relationships and components of the system under test that are most likely to have time faults. To demonstrate Dyretiva concepts, a set of support tools called SoftScope has been developed. SoftScope is comprised of a source code pre-instrumentation tool, a source code instrumentation tool, a hybrid monitor, a program for controlling the hybrid monitor, programs for filtering and analyzing trace data, and a graphical presentation tool. The Dyretiva method and the SoftScope tool set are an integral part of the work-inprogress PERF project, which is under development in the LIT (Laboratory of Embedded Systems Innovation and Technology), at the UTFPR (Federal Technological University of Paraná State). The objective of the PERF project is to build a complete environment suitable for the development of embedded and real-time systems. |
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| Viva voce exam: |
October 2007 |
| Download |
[pdf] Only Portuguese |
| 30th Doctorate Thesis |
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| Author: |
Ernesto Luis Malta Rodrigues |
| Title: | Inference of Context-free Grammars by using Evolutionary Computing with Application in Bioinformatics |
| Supervisor: |
Prof. Dr. Heitor Silvério Lopes |
| Area: |
Informatics |
| Abstract: |
Grammatical inference deals with the task of learning a classifier that can recognize a particular pattern in a set of examples. In this work, a new grammatical inference model based on a variant of Genetic Programming is proposed. In this approach, an individual is a list of structured trees representing their productions. Ordinary genetic operators are modified so as to bias the search and two new operators are proposed. The first one, called Incremental Learning, is able to recognize, based on examples, which productions are missing. The second, called Expansion is able to provide the diversity necessary to achieve convergence. In a suite of experiments performed, the proposed model successfully inferred six regular grammars and two context-free grammars: parentheses and palindromes with four letters, including the disjunct one. Results achieved were better than those obtained by recently published algorithms. Nowadays, grammatical inference has been applied to problems of recognition of biological sequences of DNA. In this work, two problems of this class were addressed: recognition of promoters and splice junction detection. In the former, the proposed model obtained results better than other published approaches. In the latter, the proposed model showed promising results. The model was extended to support fuzzy grammars, namely the fuzzy fractional grammars. Furthermore, an appropriate method of estimation of the values of the production’s membership function is also proposed. Results obtained in the identification of splice junctions shows the utility of the fuzzy inference model proposed. |
| Keywords: |
Grammatical Inference, Genetic Programming, Fuzzy Grammars, Bioinformatics |
| Data: |
December 2007 |
| Download: |
[pdf] Only Portuguese |
