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1 – 10 of 29L. Santen, J. Esser, L. Neubert, J. Wahle, A. Schadschneider and M. Schreckenberg
The modelling and prediction of traffic flow is one of the future challenges for science. We present a simulation tool for an urban road network based on real-time traffic data…
Abstract
The modelling and prediction of traffic flow is one of the future challenges for science. We present a simulation tool for an urban road network based on real-time traffic data and a cellular automaton model for traffic flow. This tool has been applied to the inner city of Duisburg. The quality of the reproduced traffic states is investigated with regard to vehicle densities and typical features of urban traffic.
In 1988 over half of the deaths in the world were due to heartdisease. The recognised risk factors for coronary heart disease aresmoking, plasma cholesterol levels and…
Abstract
In 1988 over half of the deaths in the world were due to heart disease. The recognised risk factors for coronary heart disease are smoking, plasma cholesterol levels and hypertension. These factors, however, account only for some 50‐60 per cent of the variance in incidence of the disease between countries; so other factors must contribute. Recent biochemical evidence suggests that in conditions of oxidant stress a relative deficiency in antioxidants, in conjunction with a relatively high concentration of oxidisable substrates such as cholesterol, may play an important role in the development of atheroma. The efficiency of the human antioxidant defence system depends in part on an adequate intake of foods containing antioxidants such as vitamins C and E. Until intervention trials with these antioxidants show positive effects in reducing coronary heart disease, advising the general population to increase intake of Vitamin C and E is contentious. On the other hand increasing consumption of fruit and vegetables is unlikely to do any harm, and may do us some good.
In this second part of the review the roles that copper and dietarycarbohydrate play in the cardiovascular system, pregnancy and lactation,haemopoiesis, and in male and female…
Abstract
In this second part of the review the roles that copper and dietary carbohydrate play in the cardiovascular system, pregnancy and lactation, haemopoiesis, and in male and female animals, are summarised. The mechanisms that may contribute to the exacerbation of copper deficiency when simple sugars are consumed are discussed.
R Lohner, Muhammad Baqui, Eberhard Haug and Britto Muhamad
The purpose of this paper is to develop a first-principles model for the simulation of pedestrian flows and crowd dynamics capable of computing the movement of a million…
Abstract
Purpose
The purpose of this paper is to develop a first-principles model for the simulation of pedestrian flows and crowd dynamics capable of computing the movement of a million pedestrians in real-time in order to assess the potential safety hazards and operational performance at events where many individuals are gathered. Examples of such situations are sport and music events, cinemas and theatres, museums, conference centres, places of pilgrimage and worship, street demonstrations, emergency evacuation during natural disasters.
Design/methodology/approach
The model is based on a series of forces, such as: will forces (the desire to reach a place at a certain time), pedestrian collision avoidance forces, obstacle/wall avoidance forces; pedestrian contact forces, and obstacle/wall contact forces. In order to allow for general geometries a so-called background triangulation is used to carry all geographic information. At any given time the location of any given pedestrian is updated on this mesh. The model has been validated qualitatively and quantitavely on repeated occasions. The code has been ported to shared and distributed memory parallel machines.
Findings
The results obtained show that the stated aim of computing the movement of a million pedestrians in real-time has been achieved. This is an important milestone, as it enables faster-than-real-time simulations of large crowds (stadiums, airports, train and bus stations, concerts) as well as evacuation simulations for whole cities.
Research limitations/implications
All models are wrong, but some are useful. The same applies to any modelling of pedestrians. Pedestrians are not machines, so stochastic runs will be required in the future in order to obtain statistically relevant ensembles.
Practical implications
This opens the way to link real-time data gathering of crowds (i.e. via cameras) with predictive calculations done faster than real-time, so that security personnel can be alerted to potential future problems during large-scale events.
Social implications
This will allow much better predictions for large-scale events, improving security and comfort.
Originality/value
This is the first time such speeds have been achieved for a micro-modelling code for pedestrians.
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Keywords
This chapter focuses on the differences that younger, middle-aged, and older women with breast cancer experience, particularly in health knowledge and treatment. These…
Abstract
This chapter focuses on the differences that younger, middle-aged, and older women with breast cancer experience, particularly in health knowledge and treatment. These differential experiences, in part, stem from our youth oriented culture. This ideology extends into medicine and can affect day-to-day medical practice. Differential experiences are, therefore, likely to result in inequality and disparity in health and in healthcare. It is argued that older women are less empowered than their younger counterparts to display the same degree of agency. This analysis has important implications for health care professionals in the treatment of older women with breast cancer.
D. Balzani, D. Böse, D. Brands, R. Erbel, A. Klawonn, O. Rheinbach and J. Schröder
The purpose of this paper is to present a computational framework for the simulation of patient‐specific atherosclerotic arterial walls. Such simulations provide information…
Abstract
Purpose
The purpose of this paper is to present a computational framework for the simulation of patient‐specific atherosclerotic arterial walls. Such simulations provide information regarding the mechanical stress distribution inside the arterial wall and may therefore enable improved medical indications for or against medical treatment. In detail, the paper aims to provide a framework which takes into account patient‐specific geometric models obtained by in vivo measurements, as well as a fast solution strategy, giving realistic numerical results obtained in reasonable time.
Design/methodology/approach
A method is proposed for the construction of three‐dimensional geometrical models of atherosclerotic arteries based on intravascular ultrasound virtual histology data combined with angiographic X‐ray images, which are obtained on a routine basis in the diagnostics and medical treatment of cardiovascular diseases. These models serve as a basis for finite element simulations where a large number of unknowns need to be calculated in reasonable time. Therefore, the finite element tearing and interconnecting‐dual primal (FETI‐DP) domain decomposition method is applied, to achieve an efficient parallel solution strategy.
Findings
It is shown that three‐dimensional models of patient‐specific atherosclerotic arteries can be constructed from intravascular ultrasound virtual histology data. Furthermore, the application of the FETI‐DP domain decomposition method leads to a fast numerical framework. In a numerical example, the importance of three‐dimensional models and thereby fast solution algorithms is illustrated by showing that two‐dimensional approximations differ significantly from the 3D solution.
Originality/value
The decision for or against intravascular medical treatment of atherosclerotic arteries strongly depends on the mechanical situation of the arterial wall. The framework presented in this paper provides computer simulations of stress distributions, which therefore enable improved indications for medical methods of treatment.
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Mazeyar Parvinzadeh Gashti, Mohammad Yousefpour Navid and Mohammad Hossein Rahimi
Silicone softeners are widely used in the textile industry to improve the performance of textile products. The thermal characteristics and flammability of polyester fabrics can be…
Abstract
Purpose
Silicone softeners are widely used in the textile industry to improve the performance of textile products. The thermal characteristics and flammability of polyester fabrics can be influenced by these compounds, which need to be considered, as important issues of human safety. The purpose of this paper is to investigate the changes induced on the polyester fibre by silicone softener treatment using a pad/dry/cure method.
Design/methodology/approach
The fibres were first treated with nano‐ and microemulsion silicone softeners. The influence of the silicone emulsion type on thermal properties and flammability of the resultant samples were investigated by various analytical techniques, namely, the differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), dynamical mechanical thermal analysis (DMTA) and horizontal flammability test (HFT).
Findings
Results showed that the silicone softeners increase the thermal degradation and flammability of the polyethylene terephthalate (PET) substrate.
Originality/value
The paper's study of thermal and flammability of the silicone‐treated sample is novel and can be used to optimize the properties of silicone polymers during production and consumption.
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Marsha C. Cale, Candace Delpino and Steve Myran
Instructional leadership has taken center stage in recent years as the emphasis on school leaders’ role in improving instructional programs and impacting student learning has…
Abstract
Instructional leadership has taken center stage in recent years as the emphasis on school leaders’ role in improving instructional programs and impacting student learning has increased under the pressures of the accountability movement. While there is a growing literature that has highlighted the indirect impacts of effective instructional leadership on student learning, little is known about these effects in the area of special education. Because this direct involvement in instructional and curricular matters has typically fallen outside the traditional roles of principals and other school leaders, the need for purposeful focus on developing these skills is paramount in a climate that is calling for leaders who can facilitate growth and improvement in student learning, particularly in the area of special education. This chapter explores instructional leadership in the context of special education with a focus on small to mid-sized schools. We identify a set of factors that are critical to the effective implementation of instructional leadership in the area of special education which include, communication, teacher evaluation and supervision, staff development, instructional programing, and instructional design. The chapter goes on to discuss how school leaders can cultivate growth and improvement in special education programming through the use of coaching models and distributed leadership. Lastly we explore the implications for practice including discussions of reforming principal preparation programs and shared leadership.