Measuring cycle riding comfort in Southampton using an instrumented bicycle

The increased environmental awareness and the rising fuel costs make bicycles a more and more attractive mode of travel for short journeys. Considering the future prospect of this mode of transportation and the great advantages that it offers in terms of space consumption, health and environmental sustainability, several city authorities worldwide are presently undertaking schemes aiming at improving cycling infrastructure. The aim of the present study is to monitor the impact of such schemes on the riding comfort of cyclists, as expressed by the, usually lower, quantity and magnitude of vibrations occurring as a result of cycling over pavement defects. Millbrook Road East in the western edge of the city center of Southampton is used as a case study, where vibration measurements are taken by means of an instrumented bicycle during periods before and after a redevelopment scheme involving the resurfacing of the road pavement. The results show a clear overall improvement in cycling comfort post-redevelopment, with statistically significant reductions in both the number of high severity vibrations and of their magnitude in "typical" cycling trips taken on the road. However, instances of finishing "snags" in some parts of the surface appear to introduce new minor defects (e.g. around manholes) that are not visible to the naked eye, and these still have some negative effect on the riding experience. Moreover, the study highlights the detrimental impact that widespread pavement defects can have on riding comfort, which affect cyclists of all ages, abilities and styles

Beam quality improvement of high-power semiconductor lasers using laterally inhomogeneous waveguides

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 113, 221107 (2018) and may be found at https://doi.org/10.1063/1.5054645.High-brightness vertical broad-area edge-emitting (HiBBEE) semiconductor lasers in the 1060 nm wavelength range with excellent beam quality in both lateral and vertical directions are presented. An approach to modify the thresholds of the transverse lateral modes of ridge-waveguide (RW) lasers is investigated. It has been experimentally shown that inhomogeneities in both sides of the ridges increase optical losses of the higher-order lateral modes as compared to the fundamental mode. The resulting enhancement in the contrast of the optical losses favors the emission of the fundamental mode and improves the beam quality. Reference RW HiBBEE lasers with a 15 μm wide conventional ridge and a 2.0 mm long cavity provide laterally multi-lateral mode emission which is typical for RW lasers with such wide and homogeneous ridges. On the other hand, RW HiBBEE lasers with triangular-shaped corrugations in both sides of 15 μm wide ridges provide single-lateral mode emission across a wide current range and improve the lateral M2 factor by more than a factor of 2 in the investigated current range. The corrugated RW HiBBEE lasers provide an almost 2 times higher brightness than the reference RW lasers

Development and testing of a prototype instrumented bicycle model for the prevention of cyclist accidents

Cycling is an increasingly popular mode of travel in cities owing to the great advantages that it offers in terms of space consumption, health and environmental sustainability, and is therefore favoured and promoted by many city authorities worldwide. However, cycling is also perceived as relatively unsafe, and therefore it has yet to be adopted as a viable alternative to the private car. Rising accident numbers, unfortunately, confirm this perception as reality, with a particular source of hazard (and a significant proportion of collisions) appearing to originate from the interaction of cyclists with Heavy Vehicles (HVs). This paper introduces Cyclist 360° Alert, a novel technological solution aimed at tackling this problem and ultimately improving the safety of cyclists and promoting it to non-riders. Following a thorough review of the trends of cyclist collisions, which sets the motivation of the research, the paper goes on to present the Cyclist 360° Alert system architecture design, and examines possible technologies and techniques that can be employed in the accurate positioning of cyclists and vehicles. It then focuses in particular on the aspect of bicycle tracking, and proposes a localisation approach based on micro-electromechanical systems (MEMS) sensor configurations. Initial experimental results from a set of controlled experiments using a purpose-developed prototype bicycle simulator model, are reported, and conclusions on the applicability of specific sensor configurations are drawn, both in terms of sensor accuracy and reliability in taking sample measurements of motion

An Innovative Multi-Sensor Fusion Algorithm to Enhance Positioning Accuracy of an Instrumented Bicycle

Cycling is an increasingly popular mode of travel in cities, but its poor safety record currently acts as a hurdle to its wider adoption as a real alternative to the private car. A particular source of hazard appears to originate from the interaction of cyclists with motorized traffic at low speeds in urban areas. But while technological advances in recent years have resulted in numerous attempts at systems for preventing cyclist-vehicle collisions, these have generally encountered the challenge of accurate cyclist localization. This paper addresses this challenge by introducing an innovative bicycle localization algorithm, which is derived from the geometrical relationships and kinematics of bicycles. The algorithm relies on the measurement of a set of kinematic variables (such as yaw, roll, and steering angles) through low-cost on-board sensors. It then employs a set of Kalman filters to predict-correct the direction and position of the bicycle and fuse the measurements in order to improve positioning accuracy. The capabilities of the algorithm are then demonstrated through a real-world field experiment using an instrumented bicycle, called ``iBike'', in an urban environment. The results show that the proposed fusion achieves considerably lower positioning errors than that would be achieved based on dead-reckoning alone, which makes the algorithm a credible basis for the development of future collision warning and avoidance systems

Investment in fish seed multiplication farms in Bangladesh: Evidences of an attractive business

This study mainly evaluated the profitability of Fish Seed Multiplication Farms (FSMFs) having hatchery, nursery and hatchery-cum-nursery located in the districts of Jessore, Jhenidah and Narail in Bangladesh. The general findings of the study were that the investment in FSMFs with hatchery, nursery and hatchery-cum-nursery was highly profitable business. The results clearly indicated that the investment on hatchery was the most profitable than those of nursery and hatchery-cum-nursery operations from the viewpoints of individual investors. The results of sensitivity analysis suggested that the investment in nursery farm was a risky business with 20 per cent increase in operation and management as well was production costs or 20 per cent reduction in benefits if other things remaining the same. It was also evident from the study that the investors of FSMFs had currently been facing some crucial problems, which among others are: problems of inbreeding, shortage of brood fish, incidence of diseases, unavailability of certain inputs and lack of credit

What factors influence UK medical students' choice of foundation school?

Background: We aimed to identify the factors influencing UK medical student applicants’ choice of foundation school. We also explored the factors that doctors currently approaching the end of their 2-year program believe should be considered. Methods: A cross-sectional study was conducted during the 2013–2014 academic year. An online questionnaire was distributed to 2092 final-year medical students from nine UK medical schools and 84 foundation year-2 (FY2) doctors from eight foundation schools. Participants were asked to rank their top 3 from a list of 12 factors that could potentially influence choice of foundation school on a 5-point Likert scale. Collated categorical data from the two groups were compared using a chi-square test with Yates correction. Results: Geographic location was overwhelmingly the most important factor for medical students and FY2 doctors with 97.2% and 98.8% in agreement, respectively. Social relationships played a pivotal role for medical student applicants. Clinical specialties within the rotations were of less importance to medical students, in comparison to location and social relationships. In contrast, FY2 doctors placed a significantly greater importance on the specialties undertaken in their 2-year training program, when compared to medical students (chi-square; p=0.0001). Conclusion: UK medical schools should make their foundation program applicants aware of the importance of choosing rotations based on specialties that will be undertaken. Individual foundation schools could provide a more favorable linked application system and greater choice and flexibility of specialties within their 2-year program, potentially making their institution more attractive to future applicants

Contact transmission of influenza virus between ferrets imposes a looser bottleneck than respiratory droplet transmission allowing propagation of antiviral resistance

Influenza viruses cause annual seasonal epidemics and occasional pandemics. It is important to elucidate the stringency of bottlenecks during transmission to shed light on mechanisms that underlie the evolution and propagation of antigenic drift, host range switching or drug resistance. The virus spreads between people by different routes, including through the air in droplets and aerosols, and by direct contact. By housing ferrets under different conditions, it is possible to mimic various routes of transmission. Here, we inoculated donor animals with a mixture of two viruses whose genomes differed by one or two reverse engineered synonymous mutations, and measured the transmission of the mixture to exposed sentinel animals. Transmission through the air imposed a tight bottleneck since most recipient animals became infected by only one virus. In contrast, a direct contact transmission chain propagated a mixture of viruses suggesting the dose transferred by this route was higher. From animals with a mixed infection of viruses that were resistant and sensitive to the antiviral drug oseltamivir, resistance was propagated through contact transmission but not by air. These data imply that transmission events with a looser bottleneck can propagate minority variants and may be an important route for influenza evolution