Since its invention in the early seventies, the Shack-Hartmann wavefront sensor has seen a wide variety of applications and has had great success in the fields of Adaptive Optics and Ophthalmology, where interferometry is usually impractical. Its application to optical shop testing has been less visible perhaps because shop environments can be manipulated to sufficiently remove vibration and turbulence to a degree that can support interferometry. However, with the growing need to accurately test aspheric optics, the Shack-Hartmann has an advantage; its dynamic range can be manipulated through the design of the lenslet array, rather than being directly tied to the wavelength of light and therefore lessen the need for expensive null optics.When the Shack-Hartmann is pushed to the limits of dynamic range, several issues must be dealt with. First, to reach the limits of dynamic range, those limits must be well understood. This dissertation presents a graphical approach to designing the Shack-Hartmann sensor that makes the trade-off between sensitivity and dynamic range, and accuracy and resolution intuitively clear. Next, the spots that once landed neatly in the region behind each lenslet, may now wander several lenslets away and the data reduction must be able handle this. This dissertation presents a novel and robust method for sorting these widely wondering spots and is shown to work in measurements of highly aspheric elements. Finally, in the high dynamic range regime, induced aberrations can severely limit the accuracy of the instrument. In this dissertation, these non-linear and measurement-dependent errors are studied in detail and a method of compensation is presented along with experimental results that illustrate the efficacy of the approach.

The primary purpose of this thesis was to understand the relationship between the variation in athlete segment lengths (trunk, thigh, shank) and front squat depth as represented by maximum thigh segment rotation angle within the recommended guidelines. A validated segmental anthropometric model was used to simulate the effects of progressively altering thigh and trunk lengths on front squat depth. Both the thigh and trunk lengths were independently progressed through +/- 3 standard deviations, using the anthropometry collected from 41 athletes. This was done for simulated subjects of short (1.65 m for male and 1.55 m for females), average (1.82 m for male and 1.70 m for female), and tall (2.01 m for male and 1.87 m for females) statures. As thigh length increased, the ability to perform a full front squat (to a thigh depth of 180 degrees relative to the right horizontal) decreased. Conversely, as trunk length decreased, the ability to perform a full front squat decreased. The model was modified to progressively alter the thigh-to-trunk ratio from 0.8 to 1.2 for individuals of short, average and tall statures. Effects were similar for all heights for both males and females. Individuals with a thigh-to-trunk ratio above 1 were simulated to not be able to achieve a full front squat. This effect was greater in tall individuals, followed by average and then short. The ankle flexibility measured from the 41 athletes was run in simulations to determine its effects on front squat depth. For 25 of the athletes, the ankle flexibility did not allow their knees to pass the vertical plane of the toes. Flexibility constraints were removed from the model and the knees were moved to the vertical plane of the toes, 5 cm past, and 10 cm past. When the knees were allowed to move to the vertical projection of the toes, 8 athletes could not achieve a full front squat. When the knees were allowed to move 5 cm past the vertical projection of the toes, all athletes were predicted to be able to achieve a full front squat. When ankle flexibility was factored into the model, the results predicted that 16 athletes could not achieve a full front squat. The effects of ankle flexibility on front squat depth appeared to be influenced by the thigh-to-trunk ratio. Of the eight participants predicted not to be able to achieve a full front squat when the knees were allowed to reach the vertical projection of the toes, five had the largest thigh-to-trunk ratios. Athletes with a thigh-to-trunk ratio of 1 or greater may physically not be able to complete a full front squat according to the NSCA guidelines. It is however, more likely that the thigh-to-trunk ratio, which may limit the ability to achieve a full front squat, is significantly less than 1 when a trunk angle greater than 60 degrees is used. Furthermore, anterior knee translation initiated through rotation of the shank appears to be a strategy to maintain equilibrium at the end ranges of the front squat movement. It appears plausible that horizontal knee motion up to 5 cm past the vertical projection of the toes may allow athletes with large thigh-to-trunk ratios to reach full front squat depth and perhaps reduce loading on the low back. Additionally, ankle inflexibility may limit front squat depth.

Currently, nutritional labelling is difficult to interpret and time-consuming to read. This is a major problem as many consumers are overweight and resort to eating readymade meals and snacks. These are likely to be energy-dense food and beverages that are high in fat, sugar and artificial preservatives. Simplifying nutritional labels could help stem rising obesity rates. Front-of-pack labels are a tool to help overcome this problem by providing consumers with understandable, visible information to aid them into making healthier food choices. This study expands on past research by evaluating 7 separate pre-existing, proposed and fictitious front-of-pack nutritional labels. It includes Information, Image or a combination of both Information and Image based labels. Plus No label, which is a control variable to determine the effectiveness of each label. The nutritional labels were placed on a chicken salad sandwich which was kept consistent for all 14 manipulations. The nutritional components were altered to reflect either an Unhealthy or Healthy sandwich. The design of this experiment is a 2 (nutritional level: Healthy, Unhealthy) X7 (labelling system: Traffic Light, Star, Running, Walking, Third Party, Daily Intake, Caloric, None) between subjects design. The results provide evidence of the urgent need to communicate nutritional information more effectively. Images, simplicity, colour and reliability, are determining label elements that influence consumption behaviour. The results from this study help to understand behaviours associated to labels. This study draws differences between those who partake in health behaviours and those who do not. This information could help to trigger support for a new, more effective front-of-pack labelling system to be put in place globally to guide consumers in making healthier food choices.

No description available.

Neural recording systems have attracted an increasing amount of attention in recent years, and researchers have put major efforts into designing and developing devices that can record and monitor neural activity. Understanding the functionality of neurons can be used to develop neuroprosthetics for restoring damages in the nervous system. An analog front-end block is one of the main components in such systems, by which the neuron signals are amplified and processed for further analysis. In this work, our goal is to design and implement a field-programmable 16-channel analog front-end block, where its programmability is used to deal with process variation in the chip. Each channel consists of a two-stage amplifier as well as a band-pass filter with digitally tunable low corner frequency. The 16 recording channels are designed using four different architectures. The first group of recording channels employs one low-noise amplifier (LNA) as the first-stage amplifier and a fully differential amplifier for the second stage along with an NMOS transistor in the feedback loop. In the second group of architectures, we use an LNA as the first stage and a single-ended amplifier for implementing the second stage. Groups three and four have the same design as groups one and two; however the NMOS transistor in the feedback loop is replaced by two PMOS transistors. In our design, the circuits are optimized for low noise and low power consumption. Simulations result in input-referred noise of 6.9 ??Vrms over 0.1 Hz to 1 GHz. Our experiments show the recording channel has a gain of 77.5 dB. The chip is fabricated in AMS 0.35 ??m CMOS technology for a total die area of 3 mm??3 mm and consumes 2.7 mW power from a 3.3 V supply. Moreover, the chip is tested on a PCB board that can be employed for in-vivo recording.

No description available.

No description available.

Thesis (M.S.)--Rochester Institute of Technology, 1991. / Typescript. Includes bibliographical references (leaves 86-93).

Thesis (Ph.D.)--York University, 2006. Graduate Programme in Sociology. / Typescript. Includes bibliographical references (leaves 541-554). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NR19795

Th.--Hist. militaire et études de défense nationale--Montpellier 3, 1990.