A detailed examination of low visibility (LV) occurrences and the weather types that cause low visibility, with a focus on fog, was performed for five weather stations in the western Canadian Arctic, in the vicinity of the Amundsen Gulf area of the eastern Beaufort Sea. A series of climatologies were developed that established patterns of LV occurrence as a proportion of all observations and as a function of LV events caused by fog. Frequency climatologies for other weather types were also performed; in particular, for snow, blowing snow, rain, and drizzle. Annual climatologies were used to identify trends in several weather parameters over the 1980-2015 period of study. Monthlies were used to identify typical patterns of occurrence over the course of a year, and hourlies over the course of a day. A dataset of multi-hour fog events was also created; some of these were related to synoptic patterns. Analysis was also broken down by season. Results indicate several things. Monthly climatologies showed considerable diversity across the study area. Three distinct groupings were noted: Tuktoyaktuk and Ulukhaktok with a maximum frequency of LV conditions in February, Aklavik and Inuvik with a maxiumum frequency in October, and Sachs Harbour in August. The February maximum in Tuktoyaktuk and Ulukhaktok was related to cold air temperatures combined with small amounts of moisture from sea ice leads. The Alkavik and Inuvik October maximum was related to moisture advected over land from remaining open water, as well as diurnal snow melt adding moisture to the boundary layer that condenses as the evening cools off. The August maximum in Sachs Harbour is a reflection of proximity to open water and cold air temperatures. Hourly climatologies in the spring/fall season showed most stations have maximum occurrence of LV events caused by fog in the early morning. This is a radiative effect; cooling overnight causes radiation fog that peaks in occurrence just as morning begins. This peak is pushed into the midday in the winter, and is much weaker in the summer, both reflections of the changing pattern of daylight hours. / Graduate

Thesis advisor: Kenji Hayao / This paper discusses the forces driving variation in the success of state pension system retrenchment. Two case studies are presented: the United Kingdom’s largely successful effort in 1986, and Germany’s less than stellar effort in 2001. After examining the general impact of institutional effects, ideology, path dependency, and demographic pressures on retrenchment, the importance of these factors in each country is discussed. These two countries are particularly enlightening due to their prototypical natures and opposing democratic traditions. One objective of this paper is to explain an unexpected outcome: the successful retrenchment produced in a low-pressure environment in the U.K., and ineffective reform in Germany in a high-pressure environment. This discussion frames the factors that determine successful retrenchment as such: whether a government has the ‘will,’ or motive, to retrench, whether it has the capability to do so, and whether it has the awareness and acumen to implement low-visibility strategies. I find that low-visibilities are extremely important to success in this area, and due to the nature of pension policy, the implications of this conclusion may be applicable to other policy-making challenges. / Thesis (BA) — Boston College, 2009. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: College Honors Program. / Discipline: Political Science Honors Program. / Discipline: Political Science.

This thesis presents the design and development of a hand-held electronic reader, designed to decode conductive patterns printed on a paper substrate. Data read from the patterns, by the reader, is used to trigger events in the digital domain. The reader and associated conductive patterns are devices for linking paper documents with the digital world. The patterns are formed by masking conductive-coated paper with a non-conductive, printed lacquer. The reader is a low cost and ergonomic device, capable of transmitting the embedded data from the conductive paper to the computer. The first reader designed and developed was tethered to a computer by data cable, using the USB communication protocol. The second design was developed further, with transmission of data achieved by replacing the cable with short-range Bluetooth wireless technology. Both devices were designed and developed using embedded systems and low cost electronic components. Additional work was undertaken to optimise the device's mechanical structure, ergonomics and integration of hardware. Alongside the development of the reader, test and development work was carried out to optimise the printed media, in materials and design. User trials demonstrated that the complete printed and reading system was functional, with varied rates of success among participants. Further work is required to improve the conductivity of the coated paper, and the accuracy of the decoding algorithm.

This thesis focuses on the development of a distributed mobile robot localization and communication system for special interventions like those carried out by fire-fighters in fire ground search and rescue. The use case scenario is related to the one described for the GUARDIANS EU project, where a swarm formation of mobile robots accompany a fire fighter during a rescue intervention in a warehouse. In this line, localizing the robots and the fire fighter during an indoor intervention with the presence of smoke is one of the more interesting challenges in this scenario. Several localization techniques have been developed using ultrasonic sensors, radio frequency signals and visual information. It has also been studied several communication protocols that can help to improve the efficiency of the system in such scenario and a proposal for designing a cross-layer communication platform that improves the connectivity of the mobile nodes during an intervention and reduces the number of lost data packets.