Route planning in a four-dimensional environment

Robots must be able to function in the real world. The real world involves processes and agents that move independently of the actions of the robot, sometimes in an unpredictable manner. A real-time integrated route planning and spatial representation system for planning routes through dynamic domains is presented. The system will find the safest most efficient route through space-time as described by a set of user defined evaluation functions. Because the route planning algorthims is highly parallel and can run on an SIMD machine in O(p) time (p is the length of a path), the system will find real-time paths through unpredictable domains when used in an incremental mode. Spatial representation, an SIMD algorithm for route planning in a dynamic domain, and results from an implementation on a traditional computer architecture are discussed

Gilbreth field system

Organization in the contracting field presents two phases which often seem to greatly diverge. One, the possibilities in theory, and the other, the possibilities in practice. It is in the application of theory, in its reduction to an ultimate working basis, that proof lies. The proof of the pudding lies in the eating no less truly than the proof of theory in the result of its application. The factor which varies, and which often brings apparently logical theories to an unfortunate conclusion, is the difference between working conditions which obtain in actuality, and ideal conditions which unfortunately exist only in theory

Assessment of the performance of the Chilbolton 3-GHz Advanced Meteorological radar for cloud-top height retrieval

The Chilbolton 3-GHz Advanced Meteorological Radar (CAMRa), which is mounted on a fully steerable 25 metre dish, can provide three-dimensional information on the presence of hydrometeors. We investigate the potential for this radar to make useful measurements of low-altitude liquid water cloud structure. In order to assess the cloud-height assignment capabilities of the 3-GHz radar, low-level cloud-top heights were retrieved from CAMRa measurements made between May and July 2003 and compared with cloud-top heights retrieved from a vertically pointing 94-GHz radar that operates alongside CAMRa. The average difference between 94-GHz and 3-GHz radar derived cloud-top heights is shown to be -0.1±0.4 km. In order to assess the capability of 3-GHz radar scans to be used for satellite-derived cloud-top height validation, Multi-angle Imaging SpectroRadiometer (MISR) cloud-top heights were compared with both 94-GHz and 3-GHz radar retrievals. The average difference between 94-GHz radar and MISR cloud-top heights is shown to be 0.1±0.3 km while the 3-GHz radar and MISR average cloud-top height difference is shown to be –0.2±0.6 km. In assessing the value of the CAMRa measurements, the problems associated with low reflectivity values from stratiform liquid water clouds, ground clutter, and Bragg scattering resulting from turbulent mixing are all addressed. We show that in spite of the difficulties, the potential exists for CAMRa measurements to contribute significantly to liquid water cloud-top height retrievals leading to the production of twodimensional transects (i.e. maps) of cloud-top height

Design, characterization, and fabrication of solar-retroreflective cool-wall materials

Raising urban albedo increases the fraction of incident sunlight returned to outer space, cooling cities and their buildings. We evaluated the angular distribution of solar radiation incident on exterior walls in 17 U S. climates to develop performance parameters for solar-retroreflective walls, then applied first-principle physics and ray-tracing simulations to explore designs. Our analysis indicates that retroreflective walls must function at large incidence angles to reflect a substantial portion of summer sunlight, and that this will be difficult to attain with materials that rely on total internal reflection. Gonio-spectrophotometer measurements of the solar spectral bi-directional reflectivity of a bicycle reflector showed little to no retroreflection at large incidence angles. Visual comparisons of retroreflection to specular first-surface reflection for four different retroreflective safety films using violet and green lasers suggest their retroreflection to be no greater than 0.09 at incidence angles up to 45°, and no greater than 0.30 at incidence angles of up to 70°. Attempts to produce a two-surface retroreflector with orthogonal mirror grooves by cutting and polishing an aluminum block indicate that residual surface roughness impedes retroreflection. Ongoing efforts focus on forming orthogonal surfaces with aluminized Mylar film, a material with very high specular reflectance across the solar spectrum. We investigated (1) folding or stamping a free film; (2) adhering the film to a pre-shaped substrate; or (3) attaching the film to a flat ductile substrate, then shaping. The latter two methods were more successful but yielded imperfect right angles

Use of computer-aided detection (CAD) tools in screening mammography: a multidisciplinary investigation

We summarise a set of analyses and studies conducted to assess the effects of the use of a computer-aided detection (CAD) tool in breast screening. We have used an interdisciplinary approach that combines: (a) statistical analyses inspired by reliability modelling in engineering; (b) experimental studies of decisions of mammography experts using the tool, interpreted in the light of human factors psychology; and (c) ethnographic observations of the use of the tool both in trial conditions and in everyday screening practice. Our investigations have shown patterns of human behaviour and effects of computer-based advice that would not have been revealed by a standard clinical trial approach. For example, we found that the negligible measured effect of CAD could be explained by a range of effects on experts' decisions, beneficial in some cases and detrimental in others. There is some evidence of the latter effects being due to the experts using the computer tool differently from the intentions of the developers. We integrate insights from the different pieces of evidence and highlight their implications for the design, evaluation and deployment of this sort of computer tool

Path Planning Through Time and Space in Dynamic Domains

Realistic robot problems involve navigating the robot through time as well as space. The obstacles that a robot must avoid and the pathways on which it travels are subject to changes throughout time. These changes can occur in a predictable or unpredictable fashion. This paper presents an integrated route planning and spatial representation system that allows paths to be calculated in dynamic domains. The path planner finds the "best route" through a given n-dimensional space. The "best route" is defined as the path through space-time with the best score as determined by a set of user-defined evaluatio

Collaboration and teamwork: immersion and presence in an online learning environment

In the world of OTIS, an online Internet School for occupational therapists, students from four European countries were encouraged to work collaboratively through problem-based learning by interacting with each other in a virtual semi-immersive environment. This paper describes, often in their own words, the experience of European occupational therapy students working together across national and cultural boundaries. Collaboration and teamwork were facilitated exclusively through an online environment, since the students never met each other physically during the OTIS pilot course. The aim of the paper is to explore the observations that here was little interaction between students from different tutorial groups and virtual teamwork developed in each of the cross-cultural tutorial groups. Synchronous data from the students was captured during tutorial sessions and peer-booked meetings and analysed using the qualitative constructs of ‘immersion’, ‘presence’ and ‘reflection in learning’. The findings indicate that ‘immersion’ was experienced only to a certain extent. However, both ‘presence’ and shared presence were found by the students, within their tutorial groups, to help collaboration and teamwork. Other evidence suggests that communities of interest were established. Further study is proposed to support group work in an online learning environment. It is possible to conclude that collaborative systems can be designed, which encourage students to build trust and teamwork in a cross cultural online learning environment.</p

An evaluation of a mental toughness education and training program for early-career English football league referees

The present study evaluated the effectiveness of a Mental Toughness Education and Training Program (MTETP) in elite football officiating. The MTETP consisted of four individual and two group-based workshops designed to develop Mental Toughness (MT) and enhance performance in three English Football League (EFL) referees. Adopting a single-subject, multiple-baseline-across-participants design, MT and referee-assessor reports were evaluated. Self and coach-ratings of MT highlighted an instant and continued improvement in all three referees during the intervention phases. Performance reports of all referees improved throughout the intervention phases compared to the baseline phase. Social validation data indicated that an array of strategies within the MTETP facilitated MT development. Discussions acknowledge theoretical and practical implications relating to the continued progression of MT interventions in elite sport

Compensation for research-related injury in South Africa: A critique of the good clinical practice (GCP) guidelines

This article examines the current South African Department of Health Good Clinical Practice (2006) guideline recommendations regarding compensation for harm incurred in clinical trials. It applies the case of a phase IIb HIV vaccine trial in South Africa, for which enrolments and vaccinations were suspended early, based on data from an international companion study that indicated no evidence of efficacy and greater susceptibility to HIV infection in a subgroup of vaccinees. The case application indicates certain substantive and procedural limitations within the South African Department of Health Good Clinical Practice (2006) guideline recommendations on compensation for harm, which should be re-considered in order to improve protections for trial participants

Strategy management through quantitative modelling of performance measurement systems

This paper is based on previous works on performance measurement and on quantification of relationships between factors which affect performance. It demonstrates how tools and techniques developed can be used to evaluate the performance of alternative strategic choices through a quantitative approach to modelling of performance measurement systems. The paper provides a brief background to the research problem and preceding works. The tools and techniques used are briefly introduced. Use of these tools and techniques to evaluate the performance of alternative manufacturing strategies is demonstrated. Finally, the capability of the approach to deal with dynamic environments is demonstrated using sensitivity analysis