Pulse time modulation (PTM) techniques have drawn considerable attention over the years as suitable schemes for transmission of information over optical fibres. PTM schemes are known to utilise the vast optical bandwidth to provide efficient transmission characteristics. Pulse code modulation is one such modulation scheme that has been used widely in various communication systems. In this thesis digital pulse interval modulation (DPIM), a form of PTM, is proposed as a suitable modulation scheme for optical communication systems. In this scheme the information is represented by means of varying the anisochronous frame interval between two successive pulses. Each pulse fulfils the dual role of representing the frame boundaries and initiation of the next sampling event within the modulator or sample reconstruction in the demodulator. In this study DPIM frame structure is proposed and sampling criteria, information capacity, bandwidth requirements are discussed in depth. The spectral behaviour of the scheme is investigated and a mathematical model is developed to represent the spectra. The model was numerically evaluated and verified with the practical measurements to prove its validity. Spectral predictions were made for random as well as periodic information signals showing the existence of the distinct slot frequency component, which is used for slot synchronisation. Frame synchronisation is not required as DPIM has self synchronised frame structure. For random signals, slot component is found to be about 15 dB and for periodic single tone sinusoidal signal this was at about 5 dB. Dependency of this component on the various system parameters such as bit resolution, pulse width, pulse shape are discussed. A detailed account of the receiver performance is given. Receiver analysis was carried out for narrow band as well as for wide band channels. Possible error sources are presented and the system performance degradation with these error sources is discussed and a comparison is made with isochronous DPPM and PCM. For performance evaluation of analogue systems, signal-to-noise ratio was mathematically modelled and compared with PCM. This analysis showed that DPIM SNRs shows three important regions as compared to PCM. That is when the SNR is inferior, superior and identical to PCM performance. Threshold levels corresponding to the above regions vary depending on the system bit resolution. A prototype DPIM system was designed and implemented to transmit low speed analogue signal (≈15 kHz) at bit resolutions of 4, 5 and 6 where the slot frequencies are at 510, 990 and 1950 kHz, respectively. Measurements were carried out in order to verify the predicted performance. This results showed close agreement with the predicted. Receiver sensitivity of the prototype at bit error rate of 10^-9 was found to be about -45.5 dBm at all three cases with transmitted average power of -28.8 dBm allowing high optical power budget. The signal-to-noise ratio threshold level of the system was at -47 dBm. Finally, linearity measurements of the overall system were made at the above bit resolutions and the quantitative and qualitative results are presented.

This thesis is concerned with the construction of a transistorized pulse code modulation decoder, the purpose of which is to decode the digital signal into the continuous analog form. The earlier part of this thesis describes the design and construction of a transistorized decoder using the circulated pulse principle. This turned out to be not too practical. The latter part concerns the design and construction of a PCM decoder using a ferrite-core shift register. This design was successful. The decoder has been tested in conjunction with the coder built by R.A. Hafer. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

Submitted by Fabricia Fialho Reginato (fabriciar) on 2015-07-06T23:21:44Z No. of bitstreams: 1 CarlosFranco.pdf: 2349826 bytes, checksum: 04c86e29097d13a9ffab0780b0f37a32 (MD5) / Made available in DSpace on 2015-07-06T23:21:44Z (GMT). No. of bitstreams: 1 CarlosFranco.pdf: 2349826 bytes, checksum: 04c86e29097d13a9ffab0780b0f37a32 (MD5) Previous issue date: 2010-06-16 / UFT - Universidade Federal do Tocantins / A presente tese buscou entender a tensão perceptória no audiovisual quando num plano não há cortes, cortes esses através dos quais tradicionalmente se confere ritmo a um fluxo. Partiuse de Bergson em Matéria e memória e Deleuze em Diferença e repetição, que versam sobre o tempo e o espaço, bem como de pensadores do audiovisual como Eisenstein, Martin e Aumont. A desconstrução das três dimensões do tempo (diegético, enunciatório e perceptório), clássicas no cinema, se deu em paralelo à análise de planos-sequência de materiais expressivos diversos. Utilizou-se o método intuitivo de Bergson, que permitiu cogitar a existência de uma quarta dimensão, a do tempo dos objetos no quadro, que comporta seu dinamismo bem como sua duração. Chegou-se assim a definir, como alternativa ao conceito de ritmo, a modulação do tempo como uma articulação entre o tempo perceptual e o tempo dos objetos, que abarca tanto o intervalo (enquanto espaços ou instantes perceptíveis no quadro) quanto a duração (e outras virtualidades, no fluxo). / This research tried to understand framed temporality phenomena inside audiovisual expression. This has begun from Bergson and Deleuze, with these theories that studies time and space, as well as motion pictured expressions authors as Eisenstein, Martin and Aumont. The unconstructing the three classical time dimensions (story time, opera time and perceptual time) has happened simultaneously with the non-cut scene analyses of several expressive materials. This has used the intuitive method by Bergson, which permitted speculate the existence of the forth time dimension beyond the three classical, the object time on a frame, composed by its spiritual time and dynamic time. This has defined, as alternative from rithm concept, the time modulation as an articulation between perceptual and object time, that contains the dynamic interval and spiritual time (durée).

Orientador: Evandro Conforti / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-08T01:55:52Z (GMT). No. of bitstreams: 1 Castelli_ClaudioSelmi_M.pdf: 2856453 bytes, checksum: 1efb001a79f5f2d885e231abadd78d1f (MD5) Previous issue date: 2007 / Resumo: Uma nova técnica de geração de sinais pulsados de microondas é desenvolvida. Baseia-se na composição de dois sinais arbitrários, um trem de pulsos ultra-rápidos e uma portadora de microondas, originados a partir de diferentes fontes e combinados no domínio óptico de forma a preservar ao máximo as características espectrais e temporais dos sinais. São apresentados os conceitos utilizados na técnica e toda a configuração empregada na sua validação experimental. Os resultados obtidos são discutidos e comparados com os sinais pulsados de microondas gerados a partir de um moderno gerador comercial. Os principais componentes utilizados são também caracterizados e propostas de melhorias são apresentadas. A forma de onda obtida a partir da técnica desenvolvida atingiu os resultados esperados / Abstract: A novel technique of pulsed microwave waveform generation has been developed. It is based on the mixture of two arbitrary signals, an ultra-fast pulse train and a microwave carrier, all generated from different sources and combined in the optical domain in order to preserve the spectral and temporal features as much as possible. The technique's concepts and the setup used for the experimental validation have been presented. The obtained results are discussed and compared to the pulsed microwave signals generated by a modern commercial microwave generator. The main components are also characterized and proposals of improvements have been presented. The waveform resulted from this developed technique reached the expected results / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

Le jugement d’annulation d’une décision administrative a, au Liban comme en France, une autorité de la chose jugée. Cette autorité est relative, face à l’administration, au requérant et au juge qui a rendu le jugement d’annulation et absolue face au tiers et aux autres juges.Cet effet absolu peut mettre en question les intérêts et les droits des tiers qu’ils croyaient acquis. Pour des raisons liées à la stabilité des situations juridiques, le juge administratif, en France plus qu’au Liban, fait prévaloir les droits des tiers sur le principe de légalité. Les tiers peuvent intervenir en cours d’instance ou recourir à la tierce opposition.Le juge administratif et le législateur ont mis des procédures d’incitation pour aider l’administration à respecter l’autorité de la chose jugée, ils ont même posé des procédures de contrainte.Autre cette particularité d’effet dans l’espace, le jugement d’annulation a une caractéristique d’effet dans le temps. L’annulation d’un acte administratif a pour conséquence la suppression rétroactive de cet acte. Cette disparition est parfois difficile voire impossible et provoque des dommages importants sur la sécurité des situations juridiques.Le juge administratif, français autant que libanais, a été persuadé à trouver des solutions de nature de limiter les inconvénients de cette rétroactivité, telles la théorie du service fait et la théorie du fonctionnaire de fait, et la modulation de l’effet rétroactif de jugement d’annulation. / Annulment’s judgment of an administrative decision, in Lebanon and France, has the authority of res judicata. This authority is relative facing the administration, the applicant and the judge who delivered the judgment of annulment and it’s absolute face the third parties and other judges.This absolute effect may question the interests and rights of third parties that they believed acquired. For reasons related to the stability of legal situations, the administrative court in France more than in Lebanon, upholding rights of third parties on the principle of legality. Third parties may intervene in the proceedings or resort to third opposition.The administrative judge and the legislature have incentive procedures to help the administration to respect the authority of res judicata, they even asked constraint procedures.Another special feature of this effect in space, the annulment judgment has effect characteristic in time. The annulment of an administrative act results in the retroactive elimination of the act. This disappearance is difficult sometimes even impossible and causes significant damage to the security of legal situations.The administrative judge, especially French, was persuaded to find solutions to limit the inconvenience of retroactivity, as the done service theory, the fact employee theory, and modulation of the retroactive effect of the judgment annulment.