1,287 research outputs found
Towards agent-based crowd simulation in airports using games technology
We adapt popular video games technology for an agent-based crowd simulation in an airport terminal. To achieve this, we investigate the unique traits of airports and implement a virtual crowd by exploiting a scalable layered intelligence technique in combination with physics middleware and a socialforces approach. Our experiments show that the framework runs at interactive frame-rate and evaluate the scalability with increasing number of agents demonstrating
navigation behaviour
Thermochemical recovery technology for improved modern engine fuel economy – part 1: analysis of a prototype exhaust gas fuel reformer
Exhaust gas fuel reforming has the potential to improve the thermal efficiency of internal combustion engines, as well as simultaneously reduce gaseous and particulate emissions.</p
The existence of an inverse limit of inverse system of measure spaces - a purely measurable case
The existence of an inverse limit of an inverse system of (probability) measure spaces has been investigated since the very beginning of the birth of the modern probability theory. Results from Kolmogorov
[10], Bochner [2], Choksi [5], Metivier [14], Bourbaki [3] among others have paved the way of the deep understanding of the problem under consideration. All the above results, however, call for some topological concepts, or at least ones which are closely related topological ones. In this paper we investigate purely measurable inverse systems of (probability) measure spaces, and give a sucient condition for the existence of a unique inverse limit. An example for the considered purely measurable inverse systems of (probability) measure spaces is also given
How primary care can contribute to good mental health in adults.
The need for support for good mental health is enormous. General support for good mental health is needed for 100% of the population, and at all stages of life, from early childhood to end of life. Focused support is needed for the 17.6% of adults who have a mental disorder at any time, including those who also have a mental health problem amongst the 30% who report having a long-term condition of some kind. All sectors of society and all parts of the NHS need to play their part. Primary care cannot do this on its own. This paper describes how primary care practitioners can help stimulate such a grand alliance for health, by operating at four different levels - as individual practitioners, as organisations, as geographic clusters of organisations and as policy-makers
The perception and management of risk in UK office property development
Risk is an ever-present aspect of business, and risk taking is necessary for profit and economic progress. Speculative property development is popularly perceived as a 'risky business' yet, like other entrepreneurs, developers have opportunities to manage the risks they face; techniques include phasing and joint ventures. The associated areas of investment portfolio risk, development risk analysis and construction risk management have all been addressed by research. This article presents new knowledge about how developers perceive risks and the means they subsequently adopt to manage them. The developers of office projects across the UK were sent questionnaires by post. Respondents were asked about their perceptions of risks at the first appraisal stage and currently and about the risk management techniques that they had adopted. In-depth interviews with a selection of respondents were then used to discuss and augment the findings. Developers were most concerned about market-based risks at both stages. Concern about production-orientated risks was lower and fell significantly between the two stages. A fixed price contract was the most common risk management technique. Risk management techniques were used more often outside London and the South East. Developer type affects both the perception and management of risk. While developers do manage risk, decisions are made on the basis of professional and business experience. These findings should help development companies manage risk in a more objective and analytical way
Experimental Evaluation of Dual-Modality Electrical Tomographic Systems on Gas-Oil-Water Flow in Horizontal Pipeline
A variety of dual-modality tomographic systems have been proposed for the characterisation of multiphase flow, but the evaluation of such systems are generally carried out under simplified flow conditions, such as stratified flow and slug flow. This paper reports the evaluation results of a dualmodality electrical tomographic system in an industry-scale gas-oil-water three-phase flow. Experimental conditions include water-to-liquid ratio (WLR) from 0% to 100% in parallel with gas volume fractions from 0% to 100%, which produces a variety of flow patterns, such as stratified-wavy flow, slug flow, plug flow, bubbly flow, and annular flow. Commercialised ITS M3C (ECT) and V5R (ERT) dual-modality systems were applied to perform the measurement. A threshold-based multidimensional data fused approach was implemented for the data fusion process. The results demonstrated that the ERT system is able to measure water continuous flow with WLR higher than 40%, which is in good agreement with previous reports. The ECT system is able to measure from 0% to 100% WLR, far beyond its conventional capabilities. Even though the tomograms are distorted when WLR is higher than 90%, this result is much better than the reported 40% limit. Visualisation and mean concentration derived from the tomograms by advanced data fusion verify the capability of the system in the application of gas-oil-water flow characterisation
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UK landscape ecology: trends and perspectives from the first 25 years of ialeUK
Context
The 25th anniversary of the founding of the UK chapter of the International Association for Landscape Ecology (ialeUK) was marked in 2017.
Objectives
To assess trends in UK landscape ecology research over ialeUK’s first 25 years, to compare these trends to changes elsewhere in the world, and to consider how ialeUK can continue to support landscape ecology research and practice.
Methods
A database of conference abstracts was compiled and examined in combination with a questionnaire that surveyed existing and former active members of ialeUK.
Results
Across 1992–2017 we observe noticeable trends including the declining roles of statutory bodies, the development of the ecosystem services concept, and a decrease in use of empirical methods. Analysis of questionnaire results highlighted four key areas: Developing new researchers; Facilitating conferences for networking, learning and discussion; Linking policy with practice; and Driving the continued growth of landscape ecology as a discipline. Challenges were also noted, especially regarding the adoption of a wider understanding of landscape ecological principles in management.
Conclusions
Increases in qualitative research, decreases in studies explicitly examining connectivity/fragmentation and an absence of landscape genetics studies in the UK are seemingly distinct from US landscape ecology and elsewhere around the world, based on published accounts. ialeUK has had success in increasing the role of landscape ecology in policy and practice, but needs to continue to aim for improved collaboration with other landscape-related professional bodies and contributions to wider sustainability agendas
A 6 year study of mammographic compression force : practitioner variability within and between screening sites
Background
The application of compression force in mammography is more heavily influenced by the practitioner rather than the client. This can affect client experience, radiation
dose and image quality. This research investigates practitioner compression force variation over a 6 year screening cycle in three different screening units.
Methods:
Recorded data included: practitioner code, applied compression force(N), breast thickness(mm), BI-RADS® density category. Exclusion criteria included: previous
breast surgery, previous/ongoing assessment, breast implants. 975 clients (2925) client visits, 11,700 mammogram images) met inclusion criteria across three sites.
Data analysis assessed practitioner variation of compression force and breast thickness.
Results:
Practitioners across three breast screening sites behave differently in the application of compression force. Two of the three sites demonstrate variability within
themselves, though they demonstrated no significant difference in mean, first and third quartile compression force and breast thickness values CC(p>0.5), MLO(p>0.1)
between themselves. However, the third site (where mandate dictates a minimum compression force is applied) greater consistency was demonstrated; a significant
difference in mean, first and third quartile compression force and breast thickness values(p<0.001) was demonstrated between this site and the other two sites.
Conclusion:
Stabilisation of variations in compression force may have a positive impact on image quality, radiation dose reduction, re-attendance levels and potentially cancer detection. The large variation in compression forces could negatively impact on client experience between the units and within a unit.
Further research is required to establish best practice guidelines for compression force within mammography.
Keywords: Compression force, Breast compression, Compression variabilit
Extra patient movement during mammographic imaging : an experimental study
Objectives: To determine if movement external to the patient occurring during mammography may be a source of image blur. Methods: Four mammography machines with seven flexible and nine fixed paddles were evaluated. In the first stage, movement at the paddle was measured mechanically using two calibrated linear potentiometers. A deformable breast phantom was used to mimic a female breast. For each paddle, the movement in millimeters and change in compression force in Newton was recorded at 0.5 and 1 second intervals respectively for 40 seconds with the phantom in an initially compressed state under a load of 80N. In the second stage, clinical audit on 28 females was conducted on one mammography machine with the 18x24cm and 24x29cm flexible paddles. Results: Movement at the paddle followed an exponential decay with a settling period of approximately 40 seconds. The compression force readings for both fixed and flexible paddles decreased exponentially with time while fixed paddles have a larger drop in compression force than flexible paddles. There is a linear relationship between movement at the paddle and change in compression force. Conclusions: Movement measured at the paddle during an exposure can be represented by a second order system. The amount of extra-patient movement during the actual exposure can be estimated using the linear relationship between movement at the paddle and the change in compression force. Advances in knowledge: This research provides a possible explanation to mammography image blurring caused by extra patient movement and proposes a theoretical model to analyze the movement
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