Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. Bing Kwan, Florida State University, College of Engineering, Dept. of Electrical and Computer Engineering. Title and description from dissertation home page (viewed June 16, 2004). Includes bibliographical references.

No description available.

We present data structures and algorithms for sets and some generalizations thereof (fuzzy sets, multisets, and fuzzy multisets) available for R through the sets package. Fuzzy (multi-)sets are based on dynamically bound fuzzy logic families. Further extensions include user-definable iterators and matching functions. (author´s abstract) / Series: Research Report Series / Department of Statistics and Mathematics

Univ., Habil.-Schr.--Stuttgart, 2005. / Literaturverz. S. [245] - 252.

Thesis (M.Sc. (Mathematics)) - Rhodes University, 2009.

Made available in DSpace on 2014-06-11T19:27:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-08-31Bitstream added on 2014-06-13T19:35:07Z : No. of bitstreams: 1 maesta_mf_me_ilha.pdf: 873415 bytes, checksum: 880fe18acc29b2008480d8e368970b8d (MD5) / Asas adaptativas são estruturas capazes de alterar sua forma para permitir uma maior controlabilidade da aeronave em manobras. Aeronaves com capacidade de se adaptar prometem uma distinta vantagem em relação às aeronaves convencionais, por serem capazes de voar em diferentes tipos de missões e realizar manobras extremas. O objetivo principal deste trabalho é ilustrar uma aplicação de controle angular ativo em asas adaptativas utilizando ligas de memória de forma. No modelo de asa proposto, deseja-se estabelecer uma forma para o perfil aerodinâmico a partir da determinação de um ângulo entre duas seções da asa. Este ângulo é atingido pelo efeito de memória de forma da liga através da passagem de uma corrente elétrica. A função da corrente elétrica é alterar a temperatura dos atuadores através do efeito Joule, modificando a forma da liga. Este material é capaz de converter energia térmica em energia mecânica, e uma vez deformado permanentemente, o material pode retornar a sua condição original de forma através de seu aquecimento. Devido à presença de efeitos não lineares principalmente no modelo matemático da liga, este trabalho propõe a aplicação de um sistema de controle angular baseado na lógica nebulosa do tipo Mandani. Dentre as principais vantagens do controlador nebuloso utilizado, destaca-se: a não necessidade do conhecimento detalhado do modelo a ser controlado. A metodologia de controle nebuloso apresentada revelou-se bastante eficiente no caso estudado, permitindo ao sistema atingir características satisfatórias de amortecimento e estabilidade. Através de ensaios experimentais, o desempenho do controlador nebuloso é comparado com um controlador liga-desliga aplicado em um protótipo de aerofólio construído / Morphing wings are structures that can alter its shape to allow greater controllability of aircraft maneuvers. Aircraft with a capacity for adapting can have great advantage over conventional aircraft, in order to fly in different types of missions and perform extreme maneuvers. The main objective of this work is to illustrate an application of angular active control in morphing wings using shape memory alloys. In the proposed wing model, one wants to establish the shape of the airfoil based on the determination of an angle between two sections of the wing. This angle is obtained by the effect of the shape memory of the alloy by passing an electric current. The function of the electric current is to change the temperature of the wire through the Joule effect, changing the shape of the alloy. This material can change thermal energy into mechanical energy and once permanently deformed, the material can return to its original shape by heating. Due to the presence of nonlinear effects, especially in the mathematical model of the alloy, this work proposes the application of a control system based on fuzzy logic. Among the main advantages of fuzzy controller used, it stands out: the not need detailed knowledge of the model to be controlled. The fuzzy control methodology presented proved to be very efficient in the case studied, allowing the system to achieve satisfactory characteristics of cushioning and stability. Through experimental tests, the performance of the fuzzy controller is compared with an on-off controller applied in a built aerofoil prototype

Orientador: Vicente Lopes Junior / Coorientador: Gustavo Luiz Manhães de Abreu / Banca: Samuel da Silva / Banca: Carlos Marqui Junior / Resumo: Asas adaptativas são estruturas capazes de alterar sua forma para permitir uma maior controlabilidade da aeronave em manobras. Aeronaves com capacidade de se adaptar prometem uma distinta vantagem em relação às aeronaves convencionais, por serem capazes de voar em diferentes tipos de missões e realizar manobras extremas. O objetivo principal deste trabalho é ilustrar uma aplicação de controle angular ativo em asas adaptativas utilizando ligas de memória de forma. No modelo de asa proposto, deseja-se estabelecer uma forma para o perfil aerodinâmico a partir da determinação de um ângulo entre duas seções da asa. Este ângulo é atingido pelo efeito de memória de forma da liga através da passagem de uma corrente elétrica. A função da corrente elétrica é alterar a temperatura dos atuadores através do efeito Joule, modificando a forma da liga. Este material é capaz de converter energia térmica em energia mecânica, e uma vez deformado permanentemente, o material pode retornar a sua condição original de forma através de seu aquecimento. Devido à presença de efeitos não lineares principalmente no modelo matemático da liga, este trabalho propõe a aplicação de um sistema de controle angular baseado na lógica nebulosa do tipo Mandani. Dentre as principais vantagens do controlador nebuloso utilizado, destaca-se: a não necessidade do conhecimento detalhado do modelo a ser controlado. A metodologia de controle nebuloso apresentada revelou-se bastante eficiente no caso estudado, permitindo ao sistema atingir características satisfatórias de amortecimento e estabilidade. Através de ensaios experimentais, o desempenho do controlador nebuloso é comparado com um controlador liga-desliga aplicado em um protótipo de aerofólio construído / Abstract: Morphing wings are structures that can alter its shape to allow greater controllability of aircraft maneuvers. Aircraft with a capacity for adapting can have great advantage over conventional aircraft, in order to fly in different types of missions and perform extreme maneuvers. The main objective of this work is to illustrate an application of angular active control in morphing wings using shape memory alloys. In the proposed wing model, one wants to establish the shape of the airfoil based on the determination of an angle between two sections of the wing. This angle is obtained by the effect of the shape memory of the alloy by passing an electric current. The function of the electric current is to change the temperature of the wire through the Joule effect, changing the shape of the alloy. This material can change thermal energy into mechanical energy and once permanently deformed, the material can return to its original shape by heating. Due to the presence of nonlinear effects, especially in the mathematical model of the alloy, this work proposes the application of a control system based on fuzzy logic. Among the main advantages of fuzzy controller used, it stands out: the not need detailed knowledge of the model to be controlled. The fuzzy control methodology presented proved to be very efficient in the case studied, allowing the system to achieve satisfactory characteristics of cushioning and stability. Through experimental tests, the performance of the fuzzy controller is compared with an on-off controller applied in a built aerofoil prototype / Mestre

Various established and emerging applications of RFID technology have been and are being implemented by companies in different parts of the world. However, RFID technology is susceptible to a variety of security and privacy concerns, as it is prone to attacks such as eavesdropping, denial of service, tag cloning and user tracking. This is mainly because RFID tags, specifically low-cost tags, have low computational capability to support complex cryptographic algorithms. Tag cloning is a key problem to be considered since it leads to severe economic losses. One of the possible approaches to address tag cloning is using an intrusion detection system. Intrusion detection systems in RFID networks, on top of the existing lightweight cryptographic algorithms, provide an additional layer of protection where other security mechanisms may fail. This thesis presents an intrusion detection mechanism that detects anomalies caused by one or more cloned RFID tags in the system. We make use of a Hybrid Fuzzy Genetics-Based Machine Learning algorithm to design an intrusion detection model from RFID system-generated event logs. For the purpose of training and evaluation of our proposed approach, part of the RFID system-generated dataset provided by the University of Tasmania’s School of Computing and Information Systems was used, in addition to simulated datasets. The results of our experiments show that the model can achieve high detection rates and low false positive rates when identifying anomalies caused by one or more cloned tags. In addition, the model yields linguistically interpretable rules that can be used to support decision making during the detection of anomaly caused by the cloned tags.

Thesis (Ph. D.)--Florida State University, 2006. / Advisor: Ladislav J. Kohout, Florida State University, College of Arts and Sciences, Dept. of Computer Science. Title and description from dissertation home page (viewed Sept. 20, 2006). Document formatted into pages; contains xiii, 103 pages. Includes bibliographical references.

This thesis reviews Quality Function Deployment (QFD) and its relation with the Total Quality Management philosophy. In particular the thesis focuses on the inherent drawbacks of QFD and it investigates potential techniques and methods that could be integrated with QFD to overcome some of its problems. Fuzzy Logic/Fuzzy Sets and the Taguchi Method are identified as techniques and methods to be incorporated within the QFD process to provide a more consistent, quantitative and rigorous method to analyse subjective data in the QFD charts. Two approaches are developed that integrate Fuzzy Logic and Fuzzy Set theory with QFD to identify and rectify inconsistencies in the input data in the QFD charts. Another approach that integrates the Taguchi Method and QFD is further developed to set more precise technical target values in the QFD chart. Case studies are used to illustrate the results of the developed Fuzzy-QFD and the QFD-Taguchi approaches. The synergistic approaches take into account nteractions between requirements, which are not utilised in the traditional QFD charts. In addition, it was found that the resulting data in the QFD charts are sensitive to the interaction in the correlation matrices, therefore another method is also proposed to detect inconsistencies in the correlation matrices by utilising an inference mechanism and multi-valued logic theory. An integrated systems approach to QFD is eventually developed that forms a synergy between QFD, Fuzzy Logic/Fuzzy sets and the Taguchi Method. This results in a superior approach that combines the inherent benefits of each of the individual approaches. The integrated systems approach to QFD is a generic approach that can be used for other case studies provided that in addition to the relationship matrix and customer importance ratings, the correlation matrices and benchmarking data are readily available. As a result of this research, the subjectivity and ill-defined data in the QFD process have been partially resolved by the application of Fuzzy Logic/Fuzzy sets. The QFD analysis has been made more rigorous by integrating it to more quantitative techniques (Fuzzy Logic/Fuzzy sets) and method (Taguchi Method). It has been identified that demands are dependent on each other in the QFD charts and how including these dependencies in the problem can change the results. This problem has been addressed by considering interactions between the demands in the Fuzzy-QFD and QFD-Taguchi approaches developed. These interactions between demands have been identified and dealt with in the developed approaches, such that they no longer provide sub-optimal solutions.