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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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

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

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

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.

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.

[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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