Using a task-based approach in evaluating the usability of BoBIs in an e-book environment

This paper reports on a usability evaluation of BoBIs (Back-of-the-book Indexes) as searching and browsing tools in an e-book environment. This study employed a task-based approach and within-subject design. The retrieval performance of a BoBI was compared with a ToC and Full-Text Search tool in terms of their respective effectiveness and efficiency for finding information in e-books. The results demonstrated that a BoBI was significantly more efficient (faster) and useful compared to a ToC or Full-Text Search tool for finding information in an e-book environment

Kinematic characteristics of elite men's 50 km race walking.

Race walking is an endurance event which also requires great technical ability, particularly with respect to its two distinguishing rules. The 50 km race walk is the longest event in the athletics programme at the Olympic Games. The aims of this observational study were to identify the important kinematic variables in elite men's 50 km race walking, and to measure variation in those variables at different distances. Thirty men were analysed from video data recorded during a World Race Walking Cup competition. Video data were also recorded at four distances during the European Cup Race Walking and 12 men analysed from these data. Two camcorders (50 Hz) recorded at each race for 3D analysis. The results of this study showed that walking speed was associated with both step length (r=0.54,P=0.002) and cadence (r=0.58,P=0.001). While placing the foot further ahead of the body at heel strike was associated with greater step lengths (r=0.45,P=0.013), it was also negatively associated with cadence (r= -0.62,P<0.001). In the World Cup, knee angles ranged between 175 and 186° at initial contact and between 180 and 195° at midstance. During the European Cup, walking speed decreased significantly (F=9.35,P=0.002), mostly due to a decrease in step length between 38.5 and 48.5 km (t=8.59,P=0.014). From this study, it would appear that the key areas a 50 km race walker must develop and coordinate are step length and cadence, although it is also important to ensure legal walking technique is maintained with the onset of fatigue

Towards Resilient Roads to Storm-Surge Flooding:Case Study of Bangladesh

Operating roads are critical during emergency operations at a disaster area. Prolonged inundation of pavements accelerates rapid deterioration of pavements and increases maintenance cost. The upgrade of vulnerable pavements with a raised subgrade and gabion walls is proposed as the means to increase the resiliency of strategic roads vital during the emergency attention in the aftermath of a cyclone. Hence, optimal pavement management can be used to allocate upgrade and maintenance and rehabilitation (M&amp;R) operations to reduce the damage and mitigate the geo-physical risk and community vulnerability before the disaster even occurs. A case study is presented for regional highways, arterial and collector roads of Barguna district in Bangladesh that is frequently affected by cyclones and storm surges. The geo-physical risk and vulnerability (GEOPHRIV) index of each road segments is estimated by integrating the geo-physical risk; community, structure and infrastructure vulnerabilities; and damage indices. Dynamic linear programming is applied to optimise M&amp;R strategies and the conversion of strategic roads into resilient perpetual pavements. The same budget required to optimise roads condition is also used to guide the conversion of roads into perpetual pavements, therefore increasing the overall network resiliency. As expected, the results show that most of the annual budget is equally expended into the conversion or the resurfacing of pavements. The decision-making approach herein proposed is very useful to roads agencies around the world, because it provides them with the ability to increase the resiliency of their strategic network ex-ante any flooding disaster.</p

Surface condition and safety at signalised intersections

The study reported herein focuses on assessing the effects and contributions of pavement surface condition parameters including roughness, rut depth and skid resistance on crash frequencies and rates at signalised intersections. The assessment has been performed using graphical trend analysis and negative binomial regression. For each signalised intersection in the sample, condition data are collected for the year before and after the year of surface treatment. Crash data, however, are collected for a minimum of 3 and maximum of 5 years before and after treatment years. Analyses results show that before treatment, light condition (day/night), road surface moisture condition (wet/dry) and skid resistance are the significant contributors to crash occurrence. For after-treatment; light condition, road surface moisture condition and the interaction between roughness and traffic volume are the significant contributors. The study aim and approach are presented herein together with a discussion of the main findings