International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / This paper gives an overview on Telemetry, Tracking and Command (TTC) sub-system that are used onboard some telecommunication satellites. Then, a description of the equipments of such a sub-system is given, together with the main performances.

After the deregulation of the power systems, the large-scale power systems may contain several areas. Each area has its own control center and each control center may have its own state estimator which processes the measurements received from its local substations. When scheduling power transactions, which involve several control areas a system-wide state estimation solution is needed. In this dissertation, an estimation approach which coordinates locally obtained decentralized estimates while improving bad data processing capability at the area boundaries is presented. It is assumed that synchronized phasor measurements from different area buses are available in addition to the conventional measurements provided by the substation remote terminal units. The estimator with hierarchical structure is implemented and tested using different measurement configurations for two systems having 118 and 4520 buses. Furthermore, we apply this multi-area solution scheme to the problem of Total Transfer Capability (TTC) calculation. In a restructured power system, the sellers and buyers of power transactions may be located in different areas. Computation of TTC will then require system-wide studies. We investigate a multi-area solution scheme, which takes advantage of the system-wide calculated Power Transfer Distribution Factors (PTDF) in order for each area to calculate its own TTC while a central entity coordinates these results to determine the final value. The proposed problem formulation and its solution algorithm are presented. 30 and 4520 bus test systems are used to demonstrate the approach and numerically verify the proposed TTC calculation method.

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Ciências da Saúde, 2015. / Submitted by Cristiane Mendes (mcristianem@gmail.com) on 2015-07-07T19:15:02Z No. of bitstreams: 1 2015_TiagoNobregaMorato.pdf: 275774 bytes, checksum: 53d29410be3596461f972180faf17305 (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2015-07-08T19:08:55Z (GMT) No. of bitstreams: 1 2015_TiagoNobregaMorato.pdf: 275774 bytes, checksum: 53d29410be3596461f972180faf17305 (MD5) / Made available in DSpace on 2015-07-08T19:08:55Z (GMT). No. of bitstreams: 1 2015_TiagoNobregaMorato.pdf: 275774 bytes, checksum: 53d29410be3596461f972180faf17305 (MD5) / Introdução: O uso de agentes de contraste intravenoso é corriqueiro em pacientes submetidos à tomografia computadorizada (TC) de tórax. Sabe-se que o tempo de trânsito de contraste (TTC) do sítio de injeção até a circulação sistêmica tem relação com o débito cardíaco e pode trazer importantes informações funcionais, pouco estudadas até o momento. Objetivos: Medir o TTC entre o tronco pulmonar e aorta ascendente em exames de TC de artérias coronárias de pacientes saudáveis, definindo padrões de normalidade para estes tempos de circulação. Métodos: Pacientes ambulatoriais sadios encaminhados para realização de TC de artérias coronárias arrolados de forma consecutiva. Os TTC entre o sítio de injeção e a veia cava superior, tronco pulmonar e aorta ascendente foram medidos com base nas imagens de monitorização (bolus tracking). O débito cardíaco foi calculado a partir das imagens da TC pelo método geométrico e correlacionado com os TTC. Resultados: Foram analisados 18 pacientes. O TTC médio entre a artéria pulmonar e a aorta ascendente foi de 6,8 ± 1,6s. Não houve correlação significativa entre o TTC na circulação pulmonar e o débito cardíaco medido pelo método geométrico. Conclusão: O valor de normalidade do TTC entre a artéria pulmonar e aorta ascendente foi estabelecido, servindo de base para avaliação clínica. / Introduction: The use of contrast agents is a common radiological practice in chest tomography (CT) examinations. It’s known that the transit time of the contrast agent (TTC) between the injection site and the systemic circulation is related to the cardiac output and can add important functional information. Nevertheless, there is little information regarding the normal transit times. Objectives: Measure the TTC between main pulmonary artery and ascending aorta in coronary artery CT’s of healthy patients, defining the normality values for such circulatory times. Methods: Healthy ambulatorial patients who underwent coronary artery CT were included. The TTC’s between the injection site and inferior vena cava, main pulmonary artery and ascending aorta were measured using the bolus tracking images. The cardiac output was measured from the CT images using the geometric method. Results: 18 patients were included in the analysis. The mean TTC between the mean pulmonary artery and aorta was 6,8 ± 1,6s. There was no significant correlation between the TTC and cardiac output measured by the geometric method. Conclusion: The normal value for the TTC between main pulmonary artery and ascending aorta was determined, and can be used as a reference for future publications.

No description available.

Yes / An ability to predict the time-to-contact (TTC) of moving objects that become momentarily hidden is advantageous in everyday life and could be particularly so in fast-ball sports. Prediction motion (PM) experiments have sought to test this ability using tasks where a disappearing target moves towards a stationary destination. Here, we developed two novel versions of the PM task in which the destination either moved away from (Chase) or towards (Attract) the moving target. The target and destination moved with different speeds such that collision occurred 750, 1000 or 1250ms after target occlusion. To determine if domain-specific experience conveys an advantage in PM tasks, we compared the performance of different sporting groups ranging from internationally competing athletes to non-sporting controls. There was no difference in performance between sporting groups and non-sporting controls but there were significant and independent effects on response error by target speed, destination speed and occlusion period. We simulated these findings using a revised version of the linear TTC model of response timing for PM tasks (Yakimoff et al. 1987, 1993) in which retinal input from the moving destination biases the internal representation of the occluded target. This revision closely reproduced the observed patterns of response error and thus describes a means by which the brain might estimate TTC when the target and destination are in motion.

Le mouvement d’humidité dans le réseau poreux de certains matériaux est très souvent à l’origine de phénomènes préjudiciables pour la durabilité des constructions du génie civil. C’est en particulier le cas pour le séchage du bois, générateur de fissures et de délaminations aux interfaces de collage, et pour le béton en situation d’incendie où le mouvement d’humidité peut induire des désordres irréversibles (écaillage). Le recours à des modèles prédictifs de ruine des structures nécessite donc la simulation du mouvement d’humidité au sein des matériaux. Ces modèles de transfert de masse et de chaleur sont sophistiqués et nécessitent d’être confrontés à des mesures afin d’être validés. Peu de techniques expérimentales existent pour mesurer les mouvements ou gradients d’humidité dans les réseaux poreux, en particulier en régime transitoire (séchage, incendie). Les techniques existantes sont de plus généralement coûteuses et imposent des conditions sévères de sécurité pour les chercheurs. L’objectif de la thèse est donc de mettre au point un dispositif de mesure de gradients d’humidité basé sur l’imagerie Térahertz. Il s’agit d’une technique de mesure relativement peu onéreuse et permettant de réaliser des mesures en régime transitoire. Un banc expérimental existant sera donc adapté à la mesure du champ d’humidité sur éprouvettes de bois en conditions thermo-hydriques variables, et sur éprouvettes de béton en situation de chauffage. Les résultats constitueront une base de données utile à la compréhension des phénomènes de dégradation des matériaux et seront directement utilisables comme outil de validation de modèles de calcul. / The movement of moisture in the porous network of certain materials is very often at the origin of phenomena prejudicial to the durability of the constructions of the civil engineering. This is particularly the case for the drying of wood, which creates cracks and delaminations at bonding interfaces, and for concrete in situations of fire where the movement of moisture can induce irreversible disorders (chipping). The use of predictive models of structural ruin therefore requires the simulation of the moisture movement within the materials. These mass and heat transfer models are sophisticated and need to be confronted with measurements in order to be validated. Few experimental techniques exist to measure moisture movements or gradients in porous networks, especially in transient conditions (drying, fire). Existing techniques are often expensive and impose severe conditions of safety for the researchers. The objective of the thesis is therefore to develop a device for measuring gradients of moisture based on Terahertz imagery. This is a comparatively inexpensive measuring technique and makes it possible to carry out transient measurements. An existing experimental bench will therefore be adapted to the measurement of the moisture field on wood specimens under variable water-moisture conditions and on concrete specimens in a heating situation. The results will constitute a database useful for understanding the phenomena of degradation of materials and will be directly usable as a validation tool for calculation models.

Increased mutagenesis is a hallmark of cancers. On the other hand, this can trigger the generation of polymorphisms and lead to evolution. Lately, it has become clear that one of the major sources of increased mutation rates in the genome is chromosomal break formation and repair. A variety of factors can contribute to the generation of breaks in the genome. A paradoxical source of breaks is the sequence composition of the genomic DNA itself. Eukaryotic and prokaryotic genomes contain sequence motifs capable of adopting secondary structures often found to be potent inducers of double strand breaks culminating into rearrangements. These regions are therefore termed fragile sequence motifs. Here, we demonstrate that in addition to being responsible for triggering chromosomal rearrangements, inverted repeats and GAA/TTC repeats are also potent sources of mutagenesis. Repeat-induced mutagenesis extends up to 8 kb on either side of the break point. Remarkably, error-prone repair of the break by Polζ reconstitutes the repeats making them a long term source of mutagenesis. Despite its negative connotations for genome stability, the mechanisms underlying the unstable nature of double strand break repair pathways are not known. Previous studies have demonstrated that break induced replication (BIR), a mechanism employed to repair broken chromosomes with only one repairable end, is highly mutagenic, undergoes frequent template switching and often yields half-crossovers. In the work presented here, we show that the instabilities inherent to BIR can be attributed to its unusual mode of synthesis. We determined that BIR proceeds via a migrating bubble with long stretches of single-stranded DNA and culminates with conservative inheritance of the newly synthesized DNA. We propose that the mechanisms described here might be important for generation of repair-associated mutagenesis in higher organisms. Secondary structure forming repeats like inverted repeats have been found to be enriched in cancer cells. These motifs often constitute chromosomal rearrangement hot-spots and demonstrate the phenomenon of kataegis. This study provides a mechanistic insight into how such breakage-prone motifs contribute to hypermutability of cancer genomes.

This thesis is concerned with the accuracy of our estimation of time to make contact with an approaching object as measured by the “Prediction Motion” (PM) technique. The PM task has commonly been used to measure the ability to judge time to contact (TTC). In a PM task, the observer's view of the target is occluded for some period leading up to the moment of impact. The length of the occlusion period is varied and the observer signals the moment of impact by pressing a response key. The interval separating the moment of occlusion and the response is interpreted as the observer's estimate of TTC made at the moment of occlusion. This technique commonly produces large variability and systematic underestimation. The possibility that this reflects genuine perceptual errors has been discounted by most writers, since this seems inconsistent with the accuracy of interceptive actions in real life. Instead, the poor performance in the PM task has been attributed to problems with the PM technique. Several hypotheses have been proposed to explain the poor PM performance. The motion extrapolation hypothesis asserts that some form of mental representation of the occluded part of the trajectory is used to time the PM response; the errors in PM performance are attributed to errors in reconstructing the target motion. The clocking hypothesis assumes that the TTC is accurately perceived at the moment of occlusion and that errors arise in delaying the response for the required period. The fear-of-collision hypothesis proposes that the underestimation seen in the PM tasks reflects a precautionary tendency to anticipate the estimated moment of contact. This thesis explores the causes of the errors in PM measurements. Experiments 1 and 2 assessed the PM performance using a range of motion scenarios involving various patterns of movement of the target, the observer, or both. The possible contribution of clocking errors to the PM performance was assessed by a novel procedure designed to measure errors in the wait-and-respond component of the PM procedure. In both experiments, this procedure yielded a pattern of systematic underestimation and high variability similar to that in the TTC estimation task. Experiment 1 found a small effect of motion scenario on TTC estimation. However, this was not evident in Experiment 2. The collision event simulated in Experiment 2 did not involve a solid collision. The target was simply a rectangular frame marked on a tunnel wall. At the moment of “contact”, the observers passed “through” the target without collision. However, there was still systematic underestimation of TTC and there was little difference between the estimates obtained in Experiments 1 and 2. Overall, the results of Experiments 1 and 2 were seen as inconsistent with either the motion extrapolation hypothesis or the fear-of-collision hypothesis. It was concluded that observers extracted an estimate of the TTC based on optic TTC information at a point prior to the moment of collision, and used a timing process to count down to the moment of response. The PM errors were attributed to failure in this timing process. The results of these experiments were seen as implying an accurate perception of TTC. It was considered possible that in Experiments 1 and 2 observers based their TTC judgements on either the retinal size or the expansion rate of the target rather than TTC. Experiments 3 and 4 therefore investigated estimation of TTC using a range of simulated target velocities and sizes. TTC estimates were unaffected by the resulting variation in expansion rate and size, indicating that TTC, rather than retinal size or image expansion rate per se, was used to time the observers' response. The accurate TTC estimation found in Experiments 1-4 indicates that the TTC processing is very robust across a range of stimulus conditions. Experiment 5 further explored this robustness by requiring estimation of TTC with an approaching target which rotated in the frontoparallel plane. It was shown that moderate but not fast rates of target rotation induced an overestimation of TTC. However, observers were able to discriminate between TTCs for all rates of rotation. This shows that the extraction of TTC information is sensitive to perturbation of the local motion of the target border, but it implies that, in spite of these perturbations, the mechanism is flexible enough to pick up the optic TTC information provided by the looming of the retinal motion envelop of the rotating stimulus.

This thesis proposes turning a Toronto subway station into a gallery that will display temporary exhibitions of contemporary art. Islington subway station, on the corner of Bloor Street West and Islington Avenue, will anchor a future civic and cultural centre and will become the social and public focal point of Etobicoke Centre. The building will turn this neighbourhood into a vibrant community, creating a self-sustaining node around which people will live, work, and play. This proposal has been inspired by urban sociologist Ray Oldenburg’s concept of the ‘third place’. In contrast to the first and second places of home and work, the third place encompasses the social realm, being a neutral space where people can gather and interact. The proposal for the Islington Gallery of Art also adapts new urbanist Peter Calthorpe’s theory of the ‘Transit Oriented Development’ where the subway station is the central node in the neighbourhood. Both of these concepts will be discussed further in the thesis. The Islington Gallery of Art will bring commuters a direct connection with culture. This gallery will transform the public space of infrastructure into a setting for informal public life. A third place will be created where one currently does not exist. The thesis combines the three narratives of public space, public transportation, and civic culture in the design of a mixed-use building. It explores how transportation infrastructure and architecture can combine with contemporary art to instigate the development for a new kind of place, one that isn’t a traditional street or square, near the periphery of the City of Toronto.

This thesis proposes turning a Toronto subway station into a gallery that will display temporary exhibitions of contemporary art. Islington subway station, on the corner of Bloor Street West and Islington Avenue, will anchor a future civic and cultural centre and will become the social and public focal point of Etobicoke Centre. The building will turn this neighbourhood into a vibrant community, creating a self-sustaining node around which people will live, work, and play. This proposal has been inspired by urban sociologist Ray Oldenburg’s concept of the ‘third place’. In contrast to the first and second places of home and work, the third place encompasses the social realm, being a neutral space where people can gather and interact. The proposal for the Islington Gallery of Art also adapts new urbanist Peter Calthorpe’s theory of the ‘Transit Oriented Development’ where the subway station is the central node in the neighbourhood. Both of these concepts will be discussed further in the thesis. The Islington Gallery of Art will bring commuters a direct connection with culture. This gallery will transform the public space of infrastructure into a setting for informal public life. A third place will be created where one currently does not exist. The thesis combines the three narratives of public space, public transportation, and civic culture in the design of a mixed-use building. It explores how transportation infrastructure and architecture can combine with contemporary art to instigate the development for a new kind of place, one that isn’t a traditional street or square, near the periphery of the City of Toronto.