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Perimetria flicker em individuos normais : influencia da idade e sexo, efeito aprendizado e flutuação a curto prazo / Flicker perimetry in healthy subjects : influence of age and gender, learning effect and short term fluctuationBernardi, Luciana 02 June 2006 (has links)
Orientador: Vital Paulino Costa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-06T07:32:57Z (GMT). No. of bitstreams: 1
Bernardi_Luciana_M.pdf: 10999549 bytes, checksum: d383c5723aeda31781676f1567189a65 (MD5)
Previous issue date: 2006 / Resumo: O objetivo deste estudo foi determinar os valores médios da freqüência crítica de fusão (FCF), a flutuação a curto prazo e a variabilidade inter e intra-individual, analisar a influência da idade e sexo e investigar a ocorrência de efeito aprendizado em indivíduos normais submetidos à perimetria ¿flicker¿. A investigação foi dividida em dois estudos. No estudo 1, 95 indivíduos normais foram submetidos à perimetria ¿flicker¿ com o perímetro Octopus 301 (programa G1, estratégia dinâmica) em um olho. Determinaram-se os seguintes valores da FCF: média global, média dos pontos centrais, média dos pontos periféricos, média foveal e média dos quadrantes. Os valores médios foram comparados entre ambos os sexos e a influência da idade foi avaliada utilizando análise de regressão linear. No estudo 2, 20 indivíduos normais foram submetidos à perimetria ¿flicker¿ cinco vezes. Os três primeiros exames foram realizados em dias diferentes, separados por intervalos que variaram de um a 30 dias, enquanto os três últimos exames foram realizados no mesmo dia com intervalos de pelo menos 15 minutos. Os valores obtidos nos três primeiros exames foram utilizados para investigar o efeito aprendizado. A flutuação a curto prazo foi definida como a média das diferenças obtidas entre o valor da FCF mais alto e o mais baixo para cada ponto testado considerando-se os três últimos exames. Também determinou-se a variabilidade média dos valores de FCF inter e intra-individual. No estudo 1, os valores médios de FCF global, foveal, central e periférica foram, respectivamente, 38,2±4,3Hz, 36,4±3,5Hz, 38,7±3,7Hz e 37,9±5,0Hz. O valor médio de FCF periférica foi significativamente menor do que o valor médio de FCF central (p=0,007). A análise de regressão linear demonstrou que os valores médios FCF global, foveal, central, periférico e por quadrante diminuíram significativamente com a idade, porém com baixo coeficiente de determinação (R2 variando entre 0,074 e 0,163). Não houve diferença estatisticamente significante nos valores médios de FCF entre os indivíduos do sexo masculino e feminino (p>0,05) com exceção da área central e do quadrante nasal inferior, onde os valores foram significativamente menores no sexo feminino (p=0,029 e p=0,008 respectivamente). No estudo 2, a comparação entre os três primeiros exames não mostrou diferença estatisticamente significante em relação à duração do teste, porcentagem de respostas falso-positivas e falso-negativas (p>0,05). Os valores médios de FCF global (p=0,010), central (p=0,13) e periférico (p=0,033) foram significativamente menores no 1º exame em relação ao 2º exame . A média global da flutuação a curto prazo foi 5,06±1,13Hz, a li
variabilidade média inter-individual foi 11,2±2,3% e a variabilidade média intra-individual foi 6,4±1,5%. Este estudo sugere que os valores da FCF diminuem com a idade e não são influenciados significativamente pelo sexo. Também sugere que a perimetria ¿flicker¿ está associada a efeito aprendizado e que flutuação a curto prazo e variabilidade inter e intra-individual moderadas são esperadas em indivíduos normais submetidos a este teste / Abstract: The aim of this study was to determine the mean critical fusion frequency (CFF), the short term fluctuation and inter and intraindividual variability, to analyze the influence of age and gender, and to investigate the occurrence of a learning effect in healthy subjects undergoing flicker perimetry. The investigation was divided in two study. In study 1, 95 normal subjects underwent flicker perimetry (Octopus 301, G1 program, dynamic strategy) in one eye. Mean global, central, peripheral, and foveal CFF values were determined, as well as mean CFFs per quadrant. Mean CFF values were compared between the two genders, and the influence of age was evaluated using linear regression analysis. In study 2, 20 normal subjects underwent flicker perimetry 5 times. The first 3 sessions were separated by an interval of 1 to 30 days, whereas the last 3 sessions were performed within the same day, with 15-minute intervals. The analysis of the first 3 sessions was used to investigate the presence of a learning effect. The mean of the differences between the highest and the lowest CFF value for each tested point during the last 3 tests were used to calculate the short term fluctuation (SF). Mean interindividual and intraindividual variabilities were determined. In study 1, mean global, foveal, central, and peripheral CFFs were 38.2±4.3Hz, 36.4±3.5Hz, 38.7±3.7Hz, and 37.9±5.0Hz, respectively. The mean peripheral CFF was significantly lower than the mean central CFF (p=0.007). Linear regression analysis demonstrated that mean global, foveal, central, and CFF per quadrant significantly decreased with age, however with a low correlation coefficient (R2 ranging between 0.074 and 0.163). There were no statistically significant differences in mean CFF values between males and females (p> 0.05), with the exception of the central area and the inferonasal quadrant, where the values were significantly lower in females (p=0.029 and p=0.008, respectively). In study 2, there were no statistically significant differences among the first three sessions regarding test duration, rates of false positive and false negative responses (p>0.05). The mean global (p=0.010), central (p=0.013), and peripheral (p=0.033) CFFs were significantly lower in first session compared to the second session. The mean global SF was 5.06+1.13Hz, the mean interindividual variability was 11.2±2.8%, and the mean intraindividual variability was 6.4+1.5%. This study suggests that CFFs decrease with age, and that CFFs are not significantly influenced by gender. It also suggests that flicker perimetry is associated with a learning effect, and that moderately high short term fluctuation and inter and intraindividual variability were expected in normal subjects undergoing such test / Mestrado / Oftalmologia / Mestre em Ciências Médicas
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Flimmerverschmelzungsfrequenz bei Normalpersonen, AMD und Optikopathien / Critical Flicker-fusion Frequency in healthy probands, patients with AMD and optic neuropathyMeyer-Rüsenberg, Hans Helge 25 September 2017 (has links)
No description available.
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Quaternion distinguished representations and unstable base change for unitary groups / 四元数群に関する格別表現とユニタリ群の表現の非安定係数拡大Suzuki, Miyu 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22230号 / 理博第4544号 / 新制||理||1653(附属図書館) / 京都大学大学院理学研究科数学・数理解析専攻 / (主査)教授 池田 保, 教授 雪江 明彦, 教授 並河 良典 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
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The Effect of Bilingualism on Perceptual Processing in AdultsJanuary 2019 (has links)
abstract: The experience of language can, as any other experience, change the way that the human brain is organized and connected. Fluency in more than one language should, in turn, change the brain in the same way. Recent research has focused on the differences in processing between bilinguals and monolinguals, and has even ventured into using different neuroimaging techniques to study why these differences exist. What previous research has failed to identify is the mechanism that is responsible for the difference in processing. In an attempt to gather information about these effects, this study explores the possibility that bilingual individuals utilize lower signal strength (and by comparison less biological energy) to complete the same tasks that monolingual individuals do. Using an electroencephalograph (EEG), signal strength is retrieved during two perceptual tasks, the Landolt C and the critical flicker fusion threshold, as well as one executive task (the Stroop task). Most likely due to small sample size, bilingual participants did not perform better than monolingual participants on any of the tasks they were given, but they did show a lower EEG signal strength during the Landolt C task than monolingual participants. Monolingual participants showed a lower EEG signal strength during the Stroop task, which stands to support the idea that a linguistic processing task adds complexity to the bilingual brain. Likewise, analysis revealed a significantly lower signal strength during the critical flicker fusion task for monolingual participants than for bilingual participants. Monolingual participants also had a significantly different variability during the critical flicker fusion threshold task, suggesting that becoming bilingual creates an entirely separate population of individuals. Future research should perform analysis with the addition of a prefrontal cortex electrode to determine if less collaboration during processing is present for bilinguals, and if signal complexity in the prefrontal cortex is lower than other electrodes. / Dissertation/Thesis / Masters Thesis Psychology 2019
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Studies on dynamics of functionalized lipid bilayers / 機能化された脂質二重膜小胞の動力学に関する研究Shimobayashi, Shunsuke 23 March 2016 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19478号 / 理博第4138号 / 新制||理||1595(附属図書館) / 32514 / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)講師 市川 正敏, 教授 佐々 真一, 教授 山本 潤 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
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Die dunkle Seite des Lichts: Diskomfort durch Flicker bei (LED-)Lichtern im Straßenverkehr in Bezug zu peripheren FlimmerverschmelzungsfrequenzenMühlstedt, Jens, Roßner, Patrick, Bullinger, Angelika C. January 2013 (has links)
Leuchtdioden (light-emitting diode, LED) werden seit einigen Jahren mit hohen Wachstumsraten in allen Bereichen moderner Lichttechnik eingesetzt. Auch im Straßenverkehr, insbesondere bei Lichtzeichenanlagen wie z. B. Ampeln und in Scheinwerfern, kommen LEDs zum Einsatz. Dies hat verschiedene Vorteile, wie hoher Wirkungsgrad, längere Lebensdauer, kurze Ansprechzeiten und günstiges Defektverhalten. Speziell im Straßenverkehr steht diesen jedoch ein wesentlicher Nachteil entgegen: durch eine gepulste Ansteuerung der LEDs entsteht ein optischer Flicker: ein hochfrequentes Pulsieren der Lichter, das Diskomfort auslösen kann.
Der Beitrag steht unter der Forschungsfrage des Diskomforts durch Flicker. Analysiert wird der subjektive Diskomfort im Bezug zu objektiven Flimmerverschmelzungsfrequenzen sowie Unterschiede von zentralen und peripheren Flimmerverschmelzungsfrequenzen. Die erste von zwei durchgeführten Studien hat zum Ergebnis, dass etwa ein Drittel der Probanden den Flicker wahrgenommen haben und davon etwa die Hälfte diesen als (sehr) unangenehm empfinden. Die periphere Flimmerverschmelzungsfrequenz differiert nach der zweiten Studie von der zentralen Flimmerverschmelzungsfrequenz und hat im Bereich zwischen 20° und 30° um den zentralen Sehpunkt um ca. 10 Hz höhere Frequenzen. Die zentrale Flim-merverschmelzungsfrequenz beträgt 47 Hz ± 5 Hz, die peripheren betragen um 25° etwa 54-56 Hz.
Die Ergebnisse zeigen sehr deutlich, dass der Flicker seit der Nutzung von LEDs in Verbindung mit gepulster Ansteuerung ein relevantes Phänomen im Straßenverkehr ist. Technische sowie ergonomische Fragestellungen sind offen und bedürfen dringend einer Untersuchung. Insbesondere die Frage, wie es zu dem Diskomfort bei Frequenzen von 100-200 Hz verursacht durch Ampeln und Fahrzeugleuchten kommt, sollte beantwortet und in Vorgaben für die Leuchtenhersteller überführt werden.
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Does Justin Capes successfully show that Eleonore Stump’s rejection of the flicker of freedom defense fails?Josephsson, Elias January 2023 (has links)
Firstly, I will introduce the thought experiments known as the Frankfurt-style cases. Secondly,I will present the flicker of freedom defense. Thirdly, I will clarify why Stump rejects the flicker of freedom defense. Then I will present Capes’s response to Stump’s assessment of the 2flicker of freedom defense. Next, I will analyze Capes’s and Stump’s positions and argue that Capes successfully shows that Stump’s rejection fails. Lastly, I will discuss an implication the flicker of freedom defense has for the Frankfurt-style cases, which has not been addressed to my knowledge.
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[pt] OTIMIZAÇÃO DO RUÍDO DE FASE DE OSCILADORES NA FAIXA DE MICROONDAS / [en] PHASE NOISE OPTIMIZATION OF MICROWAVE OSCILLATORSBRUNO PALHARES DOS SANTOS 19 December 2005 (has links)
[pt] Nesta dissertação foram projetados e desenvolvidos
osciladores
apresentando ruído de fase otimizado. Em virtude das
limitações dos
equipamentos analisadores de espectro na precisa medição
do ruído de fase dos
osciladores desenvolvidos nos laboratórios do CETUC, foi
implementada a
técnica de medição Método do Detector de Fase. Esta
técnica consiste no
desenvolvimento de um segundo oscilador com as mesmas
características do
existente, e com auxílio de misturadores, realizar o
batimento dos mesmos para
freqüências próximas a DC, onde nesta região a medição do
ruído de fase torna-se
viável. Entretanto, em aplicações dedicadas, verificou-se
que o batimento entre
dois osciladores operando em torno de 10 GHz produz uma
freqüência
intermediária instável, variando de 10 kHz à 50 kHz. Para
evitar a realização de
uma medição extremamente instável, utilizou-se o método de
sincronização de
freqüências (Injection Locking) entre os osciladores. Foi
também destacada a
influência do ruído de cintilação (Flicker Noise) na
medida final do ruído de fase.
A melhor medida aferida foi em torno de -100 dBc/Hz @ 3,25
kHz. Foi
verificado através de diversas simulações que a freqüência
de cintilação int c f ,
situada em 10 MHz, apresenta grande influência sobre as
medições do ruído de
fase realizadas à 3,25 kHz da portadora, degradando-o em
cerca de 30dB. / [en] In this dissertation, oscillators presenting optimized
phase noise had been
projected and develloped. Because of the limitation of the
specter analyzer
devices in the accurate measurements of the oscillators
phase noise developed in
the CETUC laboratories, it was implemented the measurement
technique called
Phase Detector Method. This technique consists on the
development of a second
oscillator with the same characteristics of the already
existent one and, with aid of
mixers, multiplies these signals together and provides the
difference of the two
signals next to DC, where, in this region, the measurement
of the phase noise
becomes viable. However, in dedicated applications, it was
verified that the
beating between two oscillators operating around 10GHz
produces instable
intermediate frequency, varying between 10kHz to 50kHz. To
prevent the
accomplishment of an extremely unstable measurement, the
method of
synchronization of frequency (Injection Locking) between
the oscillators was
used. Also the influence of the Flicker Noise in the final
measure of the phase
noise was detached. The best measure was around -100dBc/Hz@3,25kHz. It was
verified through lots of simulations that the flicker
corner frequency int c f , situated
in 10MHz, presents great influence on the measures of the
phase noise carried
through to the 3,25kHz of the carrier, degrading it in
about 30dB.
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General non linear perturbation model of phase noise in LC oscillatorsMukherjee, Jayanta 08 August 2006 (has links)
No description available.
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Still Wet: On Painting, Presence, Pleasure, and YouShabtay, Talia Bess 29 September 2009 (has links)
No description available.
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