Development of High-speed Optical Coherence Tomography for Time-lapse Non-destructive Characterization of Samples

Optical coherence tomography (OCT) is an established optical imaging modality which can obtain label-free, non-destructive 3D images of samples with micron-scale resolution and millimeter penetration. OCT has been widely adopted for biomedical researches

Design of sensory multi-session trials with preparation constraints

Design of sensory multi-session trials with preparation constraints Designs for sensory studies must satisfy several requirements. Usually a given number of products are to be evaluated and there is an upper limit to the number of assessors available. Due to variation in sensory perception, inter-assessor product comparisons are preferred. For large product numbers, trials are split into sessions to avoid sensory fatigue and the sequential presentation of products can cause order and carry-over effects. Thus, resolvable row-column or cross-over designs are required, which ensure that each assessor tastes all products the same number of times. In this thesis a three-step procedure is proposed to generate designs for trials where the number of products prepared for or served in each session is limited. First, an incomplete block design with a special column structure, the preparation design, is created, assigning products to sessions. Secondly, a cross-over design is constructed, assigning the columns of the preparation design to assessors. In the third step the two designs are combined by identifying the column-order of the preparation design that results in the highest average efficiency of the complete cross-over design. Search algorithms for incomplete block and cross-over designs are modified to produce preparation and panel designs with a special structure to guarantee resolvability of the complete sensory design. This procedure has been enhanced to produce designs for trials involving a control and several test products, in which control-test comparisons are estimated with higher precision than test-test comparisons. Two distinct construction methods have been developed for this case. By using factorial preparation designs the three step procedure can also be adapted for creating factorial multi-session designs with or without a control product

Interferometric observations of planetary nebulae

Imperial Users onl

The existence of subspace designs

We prove the existence of subspace designs with any given parameters, provided that the dimension of the underlying space is sufficiently large in terms of the other parameters of the design and satisfies the obvious necessary divisibility conditions. This settles an open problem from the 1970s. Moreover, we also obtain an approximate formula for the number of such designs.Comment: 61 page

Real-time imaging systems for superconducting nanowire single-photon detector arrays

Superconducting nanowire singe-photon detectors (SNSPD) are promising detectors in the field of applications, where single-photon resolution is required like in quantum optics, spectroscopy or astronomy. These cryogenic detectors gain from a broad spectrum in the optical and infrared range and deliver low dark count rates and low jitter times. This thesis improves the understanding of the detection mechanism of SNSPDs and intodruces new and promising multi-pixel readout concepts