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In this thesis, we demonstrate an array of photodetection theory and techniques bridging the traditional discrete and continuous variable experimental domains. In quantum optics, the creation and measurement of states of light are intertwined and we present experimental architectures considering both aspects. We describe the measurement of mean photon numbers at optical sideband frequencies using homodyne detection. We use our technique to provide a direct comparison to photon-counting measurements and observe that our technique exhibits superior speed, dynamic range and mode selectivity compared to photon counters. Our analysis also rejects a semiclassical description of the vacuum state, with our observations supporting the quantum mechanical model. We create a new means of describing the detection ???signatures??? of multi-port networks of non-photon-number discriminating detectors. Our model includes the practical effects of loss and dark counts. We use this model to analyse the performance of the loopand balanced- time-division-multiplexed detector architectures in a projective measurement role. Our analysis leads us to describe a prescriptive recipe for the optimisation of each architecture. In light of contemporary technology, we conclude the balanced TDM detector is the better architecture. Our analysis is then extended to the tomographic reconstruction of an unknown optical state using multi-port photon-counting networks. Our new approach is successfully applied to the reconstruction of the photon statistics of weak coherent states and demonstrates reduced error and sensitivity to experimental parameter variations than established techniques. We report the development of a source of quadrature squeezed vacuum at 1550 nm, and characterise the squeezing observed at the first 3 free spectral ranges of the downconversion cavity. This is then used as a source of frequency-entangled photons for a projective photon subtraction operation described by our earlier theory. We propose a new hybrid time/frequency domain approach to homodyne detection and illustrate its application in characterising the prepared state. Our output state has a statistically significant single photon contribution and permits future experimentation in frequency basis quantum information.

No description available.

The efficacy of a Marine Protected Area (MPA) is contingent on it having a design appropriate for the species it is intended to protect. Hector�s dolphin (Cephalorhynchus hectori), a coastal delphinid endemic to New Zealand, is endangered due to bycatch in gillnets. Analyses of survival rate and population viability suggest that the Banks Peninsula population is most likely still declining despite the presence of the Banks Peninsula Marine Mammal Sanctuary (BPMMS), where gillnetting is regulated. More data on distribution and movements of dolphins are therefore required to improve the design of the BPMMS. On aerial surveys of Hector�s dolphin distribution at Banks Peninsula over three years, sightings were made up to 19 n.mi. offshore. On average, 19% of dolphins were sighted outside the BPMMS�s 4 n.mi. offshore boundary in summer, compared to 56% in winter. On similar surveys of the South Island�s west coast, all dolphins were sighted within 6 n.mi. of the coast and there was no seasonal change in distribution. At each location, Mantel tests indicated that distance offshore had the strongest and most consistent effect on distribution. However, a logistic regression model using the combined datasets suggested that distribution was most strongly defined by water depth, with all sightings made inside the 90 m isobath. Boat surveys were carried out at Banks Peninsula (2002 to 2006) to continue the long-term photo-ID project. Using the 22 year dataset, alongshore home-range of the 20 most frequently sighted dolphins was estimated by univariate kernel methods. Mean alongshore range was 49.69 km (SE = 5.29), 60% larger than the previous estimate. Fifteen percent of these individuals had ranges extending beyond the northern boundary of the BPMMS. An acoustic data logger, the T-POD, was trialled for passive acoustic monitoring of Hector�s dolphins. Simultaneous T-POD/theodolite surveys revealed that T-PODs reliably detected dolphins within 200m. No detections were made beyond 500m. To monitor inshore habitat use, T-PODs were deployed in three locations at Banks Peninsula (n = 431 days). A GLM analysis of Detection Positive Minutes (DPM) per day indicated that season had the largest effect on detection rate, with over twice as many DPMs per day in summer (x̄ = 99.8) as winter (x̄ = 47.6). The new findings on Hector�s dolphin distribution and ranging can be used to improve the design of the BPMMS. It is recommended that the offshore boundary of the BPMMS is extended to 20 n.mi. (37 km), the northern boundary is moved 12 km north and recreational gillnetting is prohibited year round. In areas where distribution of Hector�s dolphin has not been studied, the offshore boundary of MPAs should enclose the 100 m isobath.

Lic.-avh. Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 2 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2008. / Härtill 5 uppsatser.

No description available.

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A presente pesquisa foi desenvolvida para entender como ocorre o processo de ensino e aprendizagem da Combinatória, no caso particular dos problemas de contagem de agrupamentos de objetos, considerado difícil por professores e alunos; e para elaborar e experimentar uma proposta didática, com potencial para trazer algo novo ao processo. Com base na Teoria dos Campos Conceituais de Vergnaud, delineou-se os esquemas de um grupo de alunos do ensino médio: resolvem problemas de contagem direta, mas não resolvem os que exigem multiplicação e divisão. Com a análise de outros trabalhos correlatos, pode-se concluir que o ensino tem melhores chances de iniciar com a resolução de problemas, e não a partir de formulários e definições. Consequência deste estudo, foi organizada e posta em prática uma sequência didática que parte da vivência do “jogo de pôquer”. Entende-se o baralho (sem coringas) como um conjunto de 52 objetos, a partir do qual devemos formar agrupamentos de 5 objetos (“mãos”). Os problemas propostos gerados pelo jogo podem ser resolvidos com as quatro operações aritméticas. Ao final, constatou-se evolução nos esquemas dos alunos, que passaram a utilizar a multiplicação com significado e a utilizar uma organização gráfica adequada para as soluções. Mas ainda apareceram erros no uso da divisão, que foram analisados para poder-se oferecer ao professor/leitor, compreensão das dificuldades. / This research was conducted to understand how the teaching and learning of Combinatorics is, in the particular case of counting issues and groupings of objects, which is considered difficult by teachers and students. Also aims to develop and experience a didactic proposal, with the potential to bring something new to the process. Based on Vergnaud's theory of Conceptual Fields, it was outlined schemes of a group of high school students: they solve problems of direct counting, but do not solve problems that require multiplication and division. With the analysis of other related work, we can conclude that a better way of teaching would be starting with problem solving, and not from formulas and definitions. As a result of this study a teaching sequence that takes advantage of the experience of the poker game, was organized and implemented. It is understood the deck (without wildcards) of 52 cards, from which we form groups of 5 objects ("hands"). The proposed problems generated by the game can be solved with the four arithmetic operations. At the end of our experience, we discover changes in the schemes of the students, who start using multiplication meaning and an organization suitable for finding solutions. We notice that still errors appeared in the use of division, which were analyzed in order to offer the teacher / reader the understanding of the difficulties of the students.

No description available.