907 resultados para forced mobility


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The electron and hole mobility of nickel-bis(dithiolene) (NiDT) are determined in a metal– insulator–semiconductor (MIS)structure using admittance spectroscopy. The relaxation times found in the admittance spectra are attributed to the diffusion time of carriers to reach the insulator interface and via Einstein’s relation this yields the mobility values. In this way, an electron mobility of 1:9 104 cm2=Vs and a hole mobility of 3:9 106 cm2=Vs were found. It is argued that the low mobility is caused by an amphoteric mid-gap trap level. The activation energy for electrons and holes from these traps is found to be 0.46 eV and 0.40 eV, respectively.

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Tese de doutoramento, Antropologia (Antropologia da Religião e do Simbólico), Universidade de Lisboa, Instituto de Ciências Sociais, 2014

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This paper employs a ‘regional approach’ in the study of Hong Kong population that goes beyond the taken-for-granted analytical framework defined by fixed geographical and social boundaries. It identifies the pattern and tend of population movement between Hong Kong and mainland China, with emphasis on trans-border marriage and child-bearing, trans-border housing and retirement and trans-border employment. The author argues that a 'regional approach' will shed new light on existing trans-migration studies, and bring in a new way of thinking for the making of population policies.

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Reforms which increase the stock of education in a society have long been held by policy-makers as key to improving rates of intergenerational social mobility. Yet, despite the intuitive plausibility of this idea, the empirical evidence in support of an effect of educational expansion on social fluidity is both indirect and weak. In this paper we use the raising of the minimum school leaving age from 15 to 16 years in England and Wales in 1972 to estimate the effect of educational participation and qualification attainment on rates of intergenerational social class mobility. Because, in expectation, children born immediately before and after the policy was implemented are statistically exchangeable, the difference in the amount of education they received may be treated as exogenously determined. The exogenous nature of the additional education gain means that differences in rates of social mobility between cohorts affected by the reform can be treated as having been caused by the additional education. The data for the analysis come from the ONS Longitudinal Study, which links individual records from successive decennial censuses between 1971 and 2001. Our findings show that, although the reform resulted in an increase in educational attainment in the population as a whole and a weakening of the association between attainment and class origin, there was no reliably discernible increase in the rate of intergenerational social mobility.

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The article presents the “LungoSolofrana” project, carried out during the course “Urban and Mobility” in the academic year 2009/2010, held during the bachelor in Environmental Engineering at the University of Naples “Federico II”. The work has also been chosen as a finalist at the “UrbanPromo 2010” contest, the urban and territorial marketing event sponsored by the National Institute of Urban Planning and Urbit which was held in Venice in 2010. The project consists in a green mobility proposal, developed with an approach based on the integration of the environmental redevelopment of a portion of river Solofrana, located in the Salerno Province, and of the renewal of seven local stations of the railway line Mercato San Severino – Nocera Inferiore, including the realization of a cycle-path network for the natural environment fruition. Furthermore the work drew attention to the local and regional administration. The main intent of the project is to integrate sustainable mobility themes with the environment recovery in a territory affected by high environmental troubles. The area includes the municipalities of Nocera Inferiore, Nocera Superiore, Mercato San Severino, Castel San Giorgio and Roccapiemonte, situated in Salerno’s province, with a total population about 114.000 (font Demo ISTAT 2010). The area extension is about 84,30 sqkm and it is crossed by river Solofrana that is the central point of the project idea. The intervention strategy is defined in two kinds of actions: internal and external rail station interventions. The external rail station interventions regard the construction of pedestrian-cycle paths with the scope of increasing the spaces dedicated to cyclists and to pedestrians along the river Solofrana sides and to connect the urban areas with the railway station. In this way, it’s also possible to achieve an urban requalification of the interested area. On the other side, the interventions inside the station , according to Transit Oriented Development principles, aim at redeveloping common spaces with the insertion of new activities and at realizing new automatic cycle parks covered by photovoltaic panels. The project proposal consists of the urban regeneration of small railway stations along the route-Nocera-Codola Mercato San Severino in the province of Salerno, through interventions aimed at improving pedestrian accessibility. The project involves in particular the construction of pedestrian paths protected access to the station and connecting with neighboring towns and installation of innovative bike parking stations in elevation, covering surfaces coated with solar panels and spaces information. The project is aimed to propose a new model of sustainable transport for small and medium shifts as an alternative to private transportation

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In recent years, airlines have been servicing a greater variety, and increasing numbers, of disabled persons and persons with reduced mobility (PRMs), particularly associated with ageing, obesity and medical needs. With the quantity of PRMs likely to increase in the future, there will be a growing impact on the airlines' associated actual and opportunity costs, about which there is minimal literature and data. Therefore the aim of this paper is to identify standard functional key factors (FKFs) with which airlines could audit their PRMs costs, and which could be used by other interested bodies, such as governments, when considering relevant aviation policy. These FKFs are related to nine areas, namely PRMs’ transfers; mobility aids; aircraft delays/diversions costs; staff training costs; staff health, safety and welfare; aircraft fixtures and equipment costs; airport costs; transaction costs; and opportunity costs. Further research is needed to obtain the data for these FKFs.

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Mobile applications are becoming increasingly more complex and making heavier demands on local system resources. Moreover, mobile systems are nowadays more open, allowing users to add more and more applications, including third-party developed ones. In this perspective, it is increasingly expected that users will want to execute in their devices applications which supersede currently available resources. It is therefore important to provide frameworks which allow applications to benefit from resources available on other nodes, capable of migrating some or all of its services to other nodes, depending on the user needs. These requirements are even more stringent when users want to execute Quality of Service (QoS) aware applications, such as voice or video. The required resources to guarantee the QoS levels demanded by an application can vary with time, and consequently, applications should be able to reconfigure themselves. This paper proposes a QoS-aware service-based framework able to support distributed, migration-capable, QoS-enabled applications on top of the Android Operating system.

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PROFIBUS is an international standard (IEC 61158, EN 50170) for factory-floor communications, with several thousands of installations worldwide. Taking into account the increasing need for mobile devices in industrial environments, one obvious solution is to extend traditional wired PROFIBUS networks with wireless capabilities. In this paper, we outline the major aspects of a hybrid wired/wireless PROFIBUS-based architecture, where most of the design options were made in order to guarantee the real-time behaviour of the overall network. We also introduce the timing unpredictability problems resulting from the co-existence of heterogeneous physical media in the same network. However, the major focus of this paper is on how to guarantee real-time communications in such a hybrid network, where nodes (and whole segments) can move between different radio cells (inter-cell mobility). Assuming a simple mobility management mechanism based on mobile nodes performing periodic radio channel assessment and switching, we propose a methodology to compute values for specific parameters that enable an optimal (minimum) and bounded duration of the handoff procedure.

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In this paper we consider a complex-order forced van der Pol oscillator. The complex derivative Dα1jβ, with α, β ∈ ℝ+, is a generalization of the concept of an integer derivative, where α = 1, β = 0. The Fourier transforms of the periodic solutions of the complex-order forced van der Pol oscillator are computed for various values of parameters such as frequency ω and amplitude b of the external forcing, the damping μ, and parameters α and β. Moreover, we consider two cases: (i) b = 1, μ = {1.0, 5.0, 10.0}, and ω = {0.5, 2.46, 5.0, 20.0}; (ii) ω = 20.0, μ = {1.0, 5.0, 10.0}, and b = {1.0, 5.0, 10.0}. We verified that most of the signal energy is concentrated in the fundamental harmonic ω0. We also observed that the fundamental frequency of the oscillations ω0 varies with α and μ. For the range of tested values, the numerical fitting led to logarithmic approximations for system (7) in the two cases (i) and (ii). In conclusion, we verify that by varying the parameter values α and β of the complex-order derivative in expression (7), we accomplished a very effective way of perturbing the dynamical behavior of the forced van der Pol oscillator, which is no longer limited to parameters b and ω.

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This study was developed with the purpose to investigate the effect of polysaccharide/plasticiser concentration on the microstructure and molecular dynamics of polymeric film systems, using transmission electron microscope imaging (TEM) and nuclear magnetic resonance (NMR) techniques. Experiments were carried out in chitosan/glycerol films prepared with solutions of different composition. The films obtained after drying and equilibration were characterised in terms of composition, thickness and water activity. Results show that glycerol quantities used in film forming solutions were responsible for films composition; while polymer/total plasticiser ratio in the solution determined the thickness (and thus structure) of the films. These results were confirmed by TEM. NMR allowed understanding the films molecular rearrangement. Two different behaviours for the two components analysed, water and glycerol were observed: the first is predominantly moving free in the matrix, while glycerol is mainly bounded to the chitosan chain. (C) 2013 Elsevier Ltd. All rights reserved.

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Transport is an essential sector in modern societies. It connects economic sectors and industries. Next to its contribution to economic development and social interconnection, it also causes adverse impacts on the environment and results in health hazards. Transport is a major source of ground air pollution, especially in urban areas, and therefore contributing to the health problems, such as cardiovascular and respiratory diseases, cancer, and physical injuries. This thesis presents the results of a health risk assessment that quantifies the mortality and the diseases associated with particulate matter pollution resulting from urban road transport in Hai Phong City, Vietnam. The focus is on the integration of modelling and GIS approaches in the exposure analysis to increase the accuracy of the assessment and to produce timely and consistent assessment results. The modelling was done to estimate traffic conditions and concentrations of particulate matters based on geo-references data. A simplified health risk assessment was also done for Ha Noi based on monitoring data that allows a comparison of the results between the two cases. The results of the case studies show that health risk assessment based on modelling data can provide a much more detail results and allows assessing health impacts of different mobility development options at micro level. The use of modeling and GIS as a common platform for the integration of different assessments (environmental, health, socio-economic, etc.) provides various strengths, especially in capitalising on the available data stored in different units and forms and allows handling large amount of data. The use of models and GIS in a health risk assessment, from a decision making point of view, can reduce the processing/waiting time while providing a view at different scales: from micro scale (sections of a city) to a macro scale. It also helps visualising the links between air quality and health outcomes which is useful discussing different development options. However, a number of improvements can be made to further advance the integration. An improved integration programme of the data will facilitate the application of integrated models in policy-making. Data on mobility survey, environmental monitoring and measuring must be standardised and legalised. Various traffic models, together with emission and dispersion models, should be tested and more attention should be given to their uncertainty and sensitivity

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The second half of the XX century was marked by a great increase in the number of people living in cities. Urban agglomerations became poles of attraction for migration flows and these phenomena, coupled with growing car-ownership rates, resulted in the fact that modern transport systems are characterized by large number of users and traffic modes. The necessity to organize these complex systems and to provide space for different traffic modes changed the way cities look. Urban areas had to cope with traffic flows, and as a result nowadays typical street pattern consists of a road for motorized vehicles, a cycle lane (in some cases), pavement for pedestrians, parking and a range of crucial signage to facilitate navigation and make mobility more secure. However, this type of street organization may not be desirable in certain areas, more specifically, in the city centers. Downtown areas have always been places where economic, leisure, social and other types of facilities are concentrated, not surprisingly, they often attract large number of people and this frequently results in traffic jams, air and noise pollution, thus creating unpleasant environment. Besides, excessive traffic signage in central locations can harm the image and perception of a place, this relates in particular to historical centers with architectural heritage.