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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.
11

Nulling the motion aftereffect with dynamic random-dot stimuli: limitations and implications.

Keeble, David R.T., Castet, E., Verstraten, F. January 2002 (has links)
No / We used biased random-dot dynamic test stimuli to measure the strength of the motion aftereffect (MAE) to evaluate the usefulness of this technique as a measure of motion adaptation strength. The stimuli consisted of noise dots whose individual directions were random and of signal dots moving in a unique direction. All dots moved at the same speed. For each condition, the nulling percentage (percentage of signal dots needed to perceptually null the MAE) was scaled with respect to the coherence threshold (percentage needed to perceive the coherent motion of signal dots without prior adaptation). The increase of these scaled values with the density of dots in the test stimulus suggests that MAE strength is underestimated when measured with low densities. We show that previous reports of high nulling percentages at slow speeds do not reflect strong MAEs, but are actually due to spatio-temporal aliasing, which dramatically increases coherence thresholds. We further show that MAE strength at slow speed increases with eccentricity. These findings are consistent with the idea that using this dynamic test stimulus preferentially reveals the adaptation of a population of high-speed motion units whose activity is independent of adapted low-speed motion units.
12

Eccentricity Sequence of 2

Ogbonna, Antoine I. January 2010 (has links)
No description available.
13

Impact of Expressive Intensity and Stimulus Location on Emotion Detection

Groh, Brittany Nicole 01 July 2017 (has links)
Previous research demonstrates that the age of an observer, the peripheral location of a face stimulus on a display, and the intensity of the emotion expressed by the face all play a role in emotion perception. Older individuals have more difficulty identifying emotion in faces, especially at lower expressive intensities. The purpose of the current study was to understand how younger and older adults’ abilities to detect emotion in facial stimuli presented in the periphery would be affected by the intensity of the emotional expressions and the distance that the expressions are presented away from the center of the display. The current study presented facial stimuli for a short duration to bypass reactionary attentional influences. More intense fearful and angry expressions were expected to be easier to classify for both younger and older adults than lower intensity expressions, but all expressions were expected to become more difficult to classify when presented further in the periphery. Older adults and younger adults displayed similar emotion detection for typical and extreme intensity angry expressions and for high intensity fearful expressions. However, older adults struggled to detect typical intensity fear, and this deficit grew with the angle of eccentricity from which the stimuli were presented from the center of the display. Possible explanations for these age differences are discussed.
14

Non-invasive detection of air gap eccentricity in synchronous machines using current signature analysis

Thirumarai Chelvan, Ilamparithi 13 December 2012 (has links)
Air gap eccentricity fault is one of the major faults that afflict the life and performance of rotating machines. Eccentricity fault, in the worst case, causes a stator rotor rub. Thus, a condition monitoring scheme to identify eccentricity fault at its initial stage is necessary. The most widely practised air gap monitoring schemes for synchronous machines are expensive and invasive sensors based. This work has focussed on developing an inexpensive, non-invasive, air gap monitoring technique especially for salient pole synchronous machines. Motor current signature analysis has been mostly preferred for the above mentioned purpose. By monitoring the frequency spectrum of the machine’s current, faulty condition can be isolated provided the fault specific frequency components are known beforehand. The research work, therefore, has developed a specific permeance function using binomial series for salient pole machines that can be used to identify eccentricity specific harmonic components in the line current spectrum. Then by performing the magneto-motive force – specific permeance analysis the characteristic frequency components have been predicted. In order to validate the prediction as well as to identify a trend in the variation of these harmonic components with changing levels of eccentricity, mathematical models of a three phase reluctance synchronous machine and a three phase salient pole synchronous machine based on modified winding function approach have been developed. The models have been made to incorporate static, dynamic and mixed eccentricity conditions of varying severity. Also time stepped finite element based models have been simulated in Maxwell-2D to verify the theoretical predictions. With the help of eccentrically cut bushings, experiments were then conducted in the laboratory to corroborate the proposed eccentricity detection scheme. It has been observed that non-idealities such as supply time harmonics, machine constructional asymmetry, supply voltage unbalance etc. negatively impact the diagnostic technique. Consequently, a residual estimation based fault detection scheme has been implemented successfully to distinguish eccentricity fault from healthy condition. Moreover, detection logic have been put forth to discriminate the type of eccentricity and to estimate the severity of the fault. / Graduate
15

Victorian Queer: Marginality and Money in Nineteenth-Century Literature

Choi, Jung Sun 03 October 2013 (has links)
This dissertation examines how Victorians used the word “queer” as associated with senses of “counterfeit” and “eccentricity” in selected Victorian novels. The word was popularly used, by Victorian writers of both genders and in various and diverse circumstances, to mean the unfamiliar, the unconventional, the incomprehensible, and the non-normal. Unlike the contemporary uses of the word, which are oriented toward a relatively particular meaning, the non-normal sexual, Victorian uses of the word had been fluid, unstable, and indeterminate, yet referring to or associating with the non-normal aspects in things and people. Knowing how the Victorians used the word helps us to understand that a concept of marginality can be extended to the extent of tolerating Otherness in marginalized positions and minority identities. Victorian novels including Mary Elizabeth Braddon’s Aurora Floyd (1863), Wilkie Collins’s Hide and Seek (1854), and Charlotte Brontë’s Jane Eyre (1847) demonstrate how the word “queer” is indeterminately used and also represent how queer marginality is appreciated or rejected, and tolerated or discriminated against. As queerness is defined as the status of counterfeitabilty, a counterpart of authenticity, queer subjects are described to provoke a feeling of repulsion and tend to be criminalized or pathologized. On the other hand, as queerness is defined as the status of eccentricity, queer subjects are sympathized and defended in the narrative. Manifestations of eccentricities in queer subjects are occasionally reprimanded, but admired for queer subjects’ uncommon or distinguished individuality. Victorian novels demonstrate that queer marginality can be employed as a self-fashioning identity or social status for any non-normal individual to deal with social pressure of conformity.
16

Investigation of single and multiple faults under varying load conditions using multiple sensor types to improve condition monitoring of induction machines.

Ahmed, Intesar January 2008 (has links)
Condition monitoring involves taking measurements on an induction motor while it is operating in order to detect faults. For this purpose normally a single sensor type, for example current is used to detect broken rotor bar using fault frequency components only under the full-load condition or a limited number of load cases. The correlations among the different types of sensors and their ability to diagnose single and multiple faults over a wide range of loads have not been the focused in previous research. Furthermore, to detect different faults in machines using any fault frequency components, it is important to investigate the variability in its amplitude to other effects apart from fault severity and load. This area has also often been neglected in the literature on condition monitoring. The stator current and axial flux have been widely used as suitable sensors for detecting different faults i.e. broken rotor bar and eccentricity faults in motors. Apart from detecting the broken rotor bar faults in generalized form, the use of instantaneous power signal has often been neglected in the literature condition monitoring. This thesis aims to improve machine condition monitoring and includes accurate and reliable detection of single and multiple faults (faults in the presence of other faults) in induction machines over a wide range of loads of rated output by using current, flux and instantaneous power as the best diagnostic medium. The research presents the following specific tasks: A comprehensive real database from non–invasive sensor measurements, i.e. vibration measurements, axial flux, 3-phase voltage, 3-phase current and speed measurements of induction motor is obtained by using laboratory testing on a large set of identical motors with different single and multiple faults. Means for introducing these faults of varying severity have been developed for this study. The collected data from the studied machines has been analysed using a custom-written analysis programme to detect the severity of different faults in the machines. This helps to improve the accuracy and reliability in detecting of single and multiple faults in motors using fault frequency components from current, axial flux and instantaneous power spectra. This research emphasises the importance of instantaneous power as a medium of detecting different single and multiple faults in induction motor under varying load conditions. This enables the possibility of obtaining accurate and reliable diagnostic medium to detect different faults existing in machines, which is vital in providing a new direction for future studies into condition monitoring. Another feature of this report is to check the variability in healthy motors due to: test repeatability, difference between nominally identical motors, and differences between the phases of the same motor. This has been achieved by conducting extensive series of laboratory tests to examine fault frequency amplitudes versus fault severity, load, and other factors such as test repeatability and machine phases. The information about the variations in the amplitudes of the fault frequency components is used to check the accuracy and reliability of the experimental set-up, which is necessary for the practical application of the results to reliably detect the different faults in the machines reliably. Finally, this study also considers the detection of eccentricity faults using fault frequency amplitudes as a function of average eccentricity, instead of as a function of load under different levels of loading. This has not been reported in previous studies. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1298314 / Thesis (Ph.D.)-- University of Adelaide, School of Electrical and Electronic Engineering, 2008
17

E.T.A. Hoffmann e Machado de Assis: expoentes de uma mesma tradição literária / E.T.A. Hoffmann and Machado de Assis: exponents of the same literary tradition

Silva, Ricardo Gomes da [UNESP] 31 May 2017 (has links)
Submitted by RICARDO GOMES DA SILVA null (rgomesdasilva@gmail.com) on 2017-08-04T03:17:40Z No. of bitstreams: 1 TESE RICARDO_posdefesa.pdf: 2164496 bytes, checksum: 3af5608a2937437d220c8afe32640e15 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-08-04T19:22:00Z (GMT) No. of bitstreams: 1 silva_rg_dr_arafcl.pdf: 2164496 bytes, checksum: 3af5608a2937437d220c8afe32640e15 (MD5) / Made available in DSpace on 2017-08-04T19:22:00Z (GMT). No. of bitstreams: 1 silva_rg_dr_arafcl.pdf: 2164496 bytes, checksum: 3af5608a2937437d220c8afe32640e15 (MD5) Previous issue date: 2017-05-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A presente pesquisa pretende aproximar as obras do escritor brasileiro Machado de Assis (1839-1908) e do alemão E.T.A. Hoffmann (1776-1822) a partir do eixo da excentricidade literária. Como demonstramos no desenvolver da análise comparativa entre suas obras, Machado e Hoffmann buscaram desenvolver um tipo de literatura que fugisse do senso comum literário. Sendo que tal tendência em comum nasce da adesão de ambos à uma longa tradição literária de escritores excêntricos como Luciano de Samósata, Petronio, Seneca, Juvenal, Cervantes, Rabelais, Shakespeare e Sterne. Neste sentido, buscamos abordar e esclarecer como se deu esta tradição para na sequência realizar a análise comparada de elementos recorrentes nas obras de nossos dois escritores tal como o tipo de riso utilizado, a sátira, a relação entre realidade e ficção, a metalinguagem e metaliteratura e fragmentação. Ao final do estudo pudemos chegar à conclusão de que mais do que uma influência geral, a excentricidade literária em Machado de Assis e E.T.A. Hoffmann se configura como um modus operandi responsável por fazer com que suas obras ganhassem relevância no quadro geral da literatura ocidental. / The present research intends to approximate the works of the Brazilian writer Machado de Assis (1839-1908) and the German E.T.A. Hoffmann (1776-1822) from the axis of literary eccentricity. As we demonstrate in the development of the comparative analysis between their works, Machado and Hoffmann look for a type of literature that escapes the literary common sense. As such a common tendency arises from the adherence of both a long literary tradition of eccentric writers such as Lucian of Samosata, Petronius, Seneca, Juvenal, Cervantes, Rabelais, Shakespeare and Sterne. In this sense, we seek to approach and clarify how this tradition has developed with a comparative analysis of recurrent elements in the works of two writers such as the type of laughter used, the satire, the relation between reality and fiction, the metalanguage and metaliterature And the fragmentation. At the end of the study we could reach the conclusion that more then a general influence, the literary eccentricity in Machado de Assis and E.T.A. Hoffmann is configured as a modus operandi responsible for making their works gain relevance in the general framework of Western literature.
18

A Geometric Analysis of Time Varying Electroencephalogram Vectors

Thakkar, Kairavee K. January 2020 (has links)
No description available.
19

An Analysis of one approximation algorithm for graph linearization

Althoubi, Asaad Y. 26 April 2017 (has links)
No description available.
20

Lifting Analysis of Precast Prestressed Concrete Beams

Cojocaru, Razvan 31 May 2012 (has links)
Motivated by Robert Mast's original papers on lifting stability, this research study provides a method for predicting beam behavior during lifting, with application in the construction of bridges. A beam lifting cracking limit state is developed based on analytical equations for calculating the roll angle of the beam, the internal forces and moments, the weak-axis and strong-axis deflections, and the cross-sectional angle of twist. Finite element simulations are performed to investigate the behavior of concrete beams during lifting and to validate the proposed method. Additionally, a statistical characterization of beam imperfections is presented, based on recently conducted field measurements of beam lateral sweep and eccentricity of lift supports. Finally, numerical examples for two typical precast prestressed concrete beam cross-sections are included to demonstrate the proposed method. / Master of Science

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