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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

\"Combinações de lógicas modais não-normais\" / \"Combinations of non-normal modal logics\"

Rogerio Augusto dos Santos Fajardo 13 August 2004 (has links)
Neste trabalho, estudamos algumas formas de combinar sistemas de Lógica Modal, analisando quando a combinação preserva propriedades como correção, completude e decidibilidade. Estendemos um estudo já realizado sobre combinações de sistemas de Lógica Modal Normal para sistemas de Lógica Modal Não-normal. O principal resultado deste trabalho é a preservação de completude da aplicação externa de um sistema de Lógica Modal Não-normal M em um sistema lógico L. Outro resultado importante é um exemplo de interação forte na combinação independente, ou fusão, de dois sistemas de Lógica Modal Não-normal. / In this work, we study a few ways of combining Modal Logic systems, analysing when the combination preserves properties like soundness, completeness and decidability. We extend a study of the combination of Normal Modal Logic systems to Non-normal Modal Logic systems. The main result of this work is the completeness preservation in the external application of a Non-normal Modal Logic system M to a logic system L. Another important result is an example of strong interations arising in the fusion of two Non-normal Modal Logic system.
42

Contribuição a teoria e pratica da analise modal acustica experimental / A contribution to the theory and practice of experimental acoustic modal analysis

Rossetto, Gustavo Dalben 22 August 2001 (has links)
Orientador: Jose Roberto de França Arruda / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-07-31T18:15:00Z (GMT). No. of bitstreams: 1 Rossetto_GustavoDalben_M.pdf: 4484828 bytes, checksum: b149e9723524115d4c39c2ea81d0c5bc (MD5) Previous issue date: 2001 / Resumo: Neste trabalho uma geometria simples (cavidade retangular) é usada para o estudo da metodologia aplicada na análise modal acústica. Modelos analítico e numérico são desenvolvidos para a comparação com os resultados experimentais. Três tipos de dispositivos de excitação do sistema acústico foram construídos. Um baseado num pistão conectado a um shaker, e outros dois usando um alto-falante do tipo driver. O primeiro atuador usando o driver é similar ao modelo desenvolvido por um projeto europeu, onde um tubo flexível com uma terminação instrumentada com um microfone é usado para a condução da excitação acústica. O segundo atuador baseado no uso do driver também usa um tubo flexível, mas este é instrumentado com dois microfones em sua terminação. O comportamento destes dois últimos atuadores em termos de aceleração de volume (essencial para a análise modal acústica experimental) e de potência ativa (necessária para Análise Estatística de Energia Experimental) sendo injetados no meio são investigados. A análise modal experimental da cavidade retangular é realizada e um método que utiliza a transformada de Fourier espacial multidimensional do campo de pressão medido é proposto para-a construção do campo de deslocamento de partícula para a visualização do modo acústico / Abstract: In the present work, a simple geometry (rectangular shallow cavity) is used to investigate the acoustic modal analysis methodology. Analytical and numerical models are developed for the comparison with the experimental results. Three types of excitation devices were constructed. One based on a shaker-driven piston and the other two using a driver loudspeaker. The first actuator based on a driver loudspeaker is similar to a model developed by an EEC project, where a flexible tube with a socket, instrumented with one microphone, at its termination is used to conduct the sound excitation. The second actuator based on a driver loudspeaker alse uses a flexible tube, but it is instrumented with two microphones in its socket instead of one. The behavior of these last two actuators in terms of volume acceleration (essential in the acoustic modal analysis) and active power (necessary for the Experimental Statistical Energy Analysis) being injected into the medium are investigated. The experimental modal analysis of the rectangular cavity is performed and a method using multi-dimensional spatial Fourier transforms of the array of pressure measurements is proposed for the construction of the partic1e displacement field for acoustic mode shape visualization / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica
43

Kagans modala personism - En kritik

Jändel-Holst, Billy January 2020 (has links)
Shelly Kagan argumenterar i sin bok How to count animals, more or less (2019) för att vi kan rangordna djur och människor hierarkiskt efter moralisk status. Han hävdar att vi människor har högre moralisk status än alla djur eftersom vi har mer utvecklade kognitiva kapaciteter än djur och det är just de kognitiva kapaciteterna som är relevanta för moralisk status. Men eftersom dessa kapaciteter kommer i grader hos människor, där vissa människor kan ha så låg grad av dessa kapaciteter att de hamnar på samma nivå som vissa djurs, så skulle detta kunna implicera att dessa människor har samma moraliska status som dessa djur. Kagan menar att detta är kontraintuitivt och argumenterar för att potential till att bli en person och tidigare potential till att bli en person kan höja en människas moraliska status. Syftet med uppsatsen är att undersöka huruvida Kagans argument för denna teori om tidigare potential, som han kallar modal personism, är hållbara. Jag argumenterar för att Kagans förslag har vissa styrkor men att bristen på motivation om varför tidigare potential skulle vara relevant för en individs moraliska status gör teorin öppen för invändningar och kontraintuitiva implikationer.
44

Developing a correlation criterion(spaceMAC) for repeated and pseudo-repeated modes

Vinze, Pranjal Makarand 01 August 2019 (has links)
No description available.
45

A Comparison Of Attentional Reserve Capacity Across Three Sensory Modalities

Brill, John 01 January 2007 (has links)
There are two theoretical approaches to the nature of attentional resources. One proposes a single, flexible pool of cognitive resources; the other poses there are multiple resources. This study was designed to systematically examine whether there is evidence for multiple resource theory using a counting task consisting of visual, auditory, and tactile signals using two experiments. The goal of the first experiment was the validation of a multi-modal secondary loading task. Thirty-two participants performed nine variations of a multi-modal counting task incorporating three modalities and three demand levels. Performance and subjective ratings of workload were measured for each of the nine conditions of the within-subjects design. Significant differences were found on the basis of task demand level, irrespective of modality. Moreover, the perceived workload associated with the tasks differed by task demand level and not by modality. These results suggest the counting task is a valid means of imposing task demands across multiple modalities. The second experiment used the same counting task as a secondary load to a primary visual monitoring task, the system monitoring component of the Multi-Attribute Task Battery (MATB). The experimental conditions consisted of performing the system monitoring task alone as a reference and performing system monitoring combined with visual, auditory, or tactile counting. Thirty-one participants were exposed to all four experimental conditions in a within-subjects design. Performance on the primary and secondary tasks was measured, and subjective workload was assessed for each condition. Participants were instructed to maintain performance on the primary task, irrespective of condition, which they did so effectively. Secondary task performance for the visual-auditory and visual-tactile conditions was significantly better than for the visual-visual dual task condition. Subjective workload ratings were also consistent with the performance measures. These results clearly indicate that there is less interference for cross-modal tasks than for intramodal tasks. These results add evidence to multiple resource theory. Finally, these results have practical implications that include human performance assessment for display and alarm development, assessment of attentional reserve capacity for adaptive automation systems, and training.
46

Full Field Reconstruction Enhanced With Operational Modal Analysis and Compressed Sensing for General Dynamic Loading

Fu, Gen 09 June 2021 (has links)
In most applications, the structure components have to be tested under different loading conditions before being placed in operation. A reliable and low cost measuring technique is desirable. However, most currently employed measuring approaches can only provide the structural response at several discrete locations. The accuracy of the measurements varies with the location and orientation of the sensors. Practically, it is not possible to place sensors at all the critical locations for different excitations. Therefore, an approach that derives the full field response using a limited set of measured data is desirable. In contrast to experimental full field measurement techniques, the expansion approach involves analytically expanding the limited measurements to all the degrees of freedom of the structure. Among all the analytical methods, the modal expansion method is computationally efficient and thus more suitable for real time expansion of measured data. In this method, the full-field response is approximated by the linear combination of mode shapes. In previous studies, the modal expansion method is limited by errors from mode aliasing, inaccuracy of the calculated mode shapes and the noise in measurements. In order to overcome these limitations, the modal expansion method is enhanced by mode selection and error compensation in this study. First, the key parameters used in modal expansion method were analyzed using a cantilever beam model and a method for optimal placement of sensors was developed. A mode selection method and error compensation method based on operation modal analysis and adaptive compressed sensing techniques were then developed to reduce the effects of mode aliasing, mode shape inaccuracy and measurement noise. The developed approach was further tested virtually using a numerical model of rotor 67. The numerical model was created using a two-way coupled fluid structure interaction technique. By developing these methods, the enhanced modal expansion approach can provide full field response for structures under different load conditions. Compared to the traditional modal expansion method, it can expand the data with high noise and under general dynamic loading. / Doctor of Philosophy / Accurate knowledge of the strain and stress at critical locations of a given structure is crucial when assessing its integrity. However, currently employed measuring approaches can only provide the structural response at several discrete locations. Practically, it is not possible to place sensors at all the critical locations for different excitations. Therefore, an approach that derives the full field response using a limited set of measured data is desirable. Compared to experimental full field measurement techniques, the expansion approach is focused on analytically expanding the limited measurements to all the degrees of freedom of the structure. Among all the analytical methods, the modal expansion method is computationally efficient and thus more suitable for real-time expansion of measured data. The current modal expansion method is limited by errors from mode aliasing, inaccuracy of the mode shapes, and the noise in measurements. Therefore, an enhanced method is proposed to overcome these shortcomings of the modal expansion. The following objectives are accomplished in this study: 1) Develop a method for optimal placement of sensors for modal expansion; 2) Eliminate the mode aliasing effects by determining the significance of participated modes using operational modal analysis techniques; 3) Compensate for the noise in measurements and computational model by implementing the compressed sensing approach. After accomplishing these goals, the developed approach is able to provide full field response for structures under different load conditions. Compared to the traditional modal expansion method, it can expand the data under dynamic loading; it also shows promise in reducing the effects of noise and errors. The developed approach is numerically tested using fluid-structure interaction model of rotor 67 fan blade.
47

The Interaction of Modality, Aspect and Negation in Persian

Hojatollah Taleghani, Azita January 2006 (has links)
This dissertation investigates the verbal system of Persian and is focused on the interaction of modality, tense, aspect and negation in this language. The dissertation challenges the idea that the syntactic structure maps on to the semantic interpretation or vice-versa.It is argued that modals are raising constructions in some languages (Wurmbrand 1999). Modals in Persian, which do not have subject-raising constructions, show different behavior. First, the root complex modals are generally syntactic control in Wurmbrand's (1998, 2001) proposal. There are just a few gaps with respect to dynamic root modals. Second, all epistemic modals which are either defective auxiliary modals or complex modals take default agreements and are pseudo-raising constructions. Third, the syntactic structures of modals show that there is no one-to-one correspondence between the structural positions and semantic interpretations of modals in Persian except in the auxiliary modal bâyad 'must'.The second contribution of this dissertation is that the class of restructuring verbs varies across languages. German semantic control verbs are instances of restructuring constructions (Wurmbrand 2001) while the only case of restructuring in Persian is the functional restructuring which appears in auxiliary modals such as bâyad 'must' and šâyad 'may' since they are mono-clausal and do not have a CP.This dissertation also investigates the structure of complex verbal forms in Persian. It is argued that Persian future tense is an instance of Serial Verb Constructions. However, progressives which are bi-clausal constructions are Aspectual Complex predicates.In the case of the structural analysis of the interaction of Persian modals and negation, this dissertation shows that the syntactic structure maps on the semantic interpretation or vice-versa. There are just a few gaps with respect to the scope possibilities of particular modals.The final contribution of this dissertation is related to the problem of the word order of NV elements and LV within complex predicates. This research provides three suggestions regarding the clausal complement position in complex predicates, and suggests that the vP remnant movement is the most reasonable one, since it is compatible with the recent trends of syntactic theories and suggested for some other languages (Mahajan 2003).
48

Tableau systems for tense logics : a constraint approach

Reddy, Pamoori Venkateswara January 1995 (has links)
No description available.
49

The use of non-linear vibrations in the health monitoring of reinforced concrete structures

Eccles, Bradley James January 1999 (has links)
No description available.
50

Estimation of rotational degrees of freedom using spline functions

Ng'andu, Alvert Namasamu January 1995 (has links)
No description available.

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