995 resultados para data transportation


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Field Lab of Entrepreneurial Innovative Ventures

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The purposes of this report (Phase II of the project) are to specify in mathematical form the individual modules of the conceptual model developed in Phase I, to identify and evaluate sources of data for the model set, and to develop the transport networks necessary to support the models.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Leachate from an untreated landfill or landfill with damaged liners will cause the pollution of soil and ground water. Here an attempt was made to generate knowledge on concentrations of all relevant pollutants in soil due to municipal solid waste landfill leachate and its migration through soil and also to study the effect of leachate on the engineering properties of soil. To identify the pollutants in soil due to the leachate generated from municipal solid waste landfill site, a case study on an unlined municipal solid waste landfill at Kalamassery has been done. Soil samples as well as water samples were collected from the site and analysed to identify the pollutants and its effect on soil characteristics. The major chemicals in the soil were identified as Ammonia, Chloride, Nitrate, Iron, Nickel, Chromium, Cadmium etc.. Engineering properties of field soil samples show that the chemicals from the leachate of landfill may have effect on the engineering properties of soil. Laboratory experiments were formulated to model the field around an unlined MSW landfill using two different soils subjected to a synthetic leachate. The Maximum change in chemical concentration and engineering property was observed on soil samples at a radial distance of 0.2 m and at a depth of 0.3 m. The pollutant (chemicals) transport pattern through the soil was also studied using synthetic leachate. To establish the effect of pollutants (chemicals) on engineering properties of soil, experiments were conducted on two types soils treated with the synthetic chemicals at four different concentrations. Analyses were conducted after maturing periods of 7, 50, 100 and 150 days. Test soils treated with maximum chemical concentration and matured for 150 days were showing major change in the properties. To visualize the flow of pollutants through soil in a broader sense, the transportation of pollutants through soil was modeled using software ‘Visual MODFLOW’. The actual field data collected for the case study was used to calibrate the modelling and thus simulated the flow pattern of the pollutants through soil around Kalamassery municipal solid waste landfill for an extent of 4 km2. Flow was analysed for a time span of 30 years in which the landfill was closed after 20 years. The concentration of leachate beneath the landfill was observed to be reduced considerably within one year after closure of landfill and within 8 years, it gets lowered to a negligible level. As an environmensstal management measure to control the pollution through leachate, permeable reactive barriers are used as an emerging technology. Here the suitability of locally available materials like coir pith, rice husk and sugar cane bagasse were investigated as reactive media in permeable reactive barrier. The test results illustrates that, among these, coir pith was showing better performance with maximum percentage reduction in concentration of the filtrate. All these three agricultural wastes can be effectively utilized as a reactive material. This research establishes the influence of leachate of municipal solid waste landfill on the engineering properties of soil. The factors such as type of the soil, composition of leachate, infiltration rate, aquifers, ground water table etc., will have a major role on the area of influence zone of the pollutants in a landfill. Software models of the landfill area can be used to predict the extent and the time span of pollution of a landfill, by inputting the accurate field parameters and leachate characteristics. The present study throws light on the role of agro waste materials on the reduction of the pollution in leachate and thus prevents the groundwater and soil from contamination

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Food farming in Oyo North, Nigeria is characterised by an increasing use of Intermediary Mode of Transportation (IMT) to ease inputs and outputs mobility and farm access. To assess the influence on food farmer’s productivity, a random sample of 230 respondents was selected and data collected on their socio-economic and farm specific characteristics. Descriptive statistics, Herfindhal Index and Technical Efficiency Approach were used to analyse the data. The results indicate that majority of food farmers were in their middle age with mean age of 50 years and most of them used one plot at a location between 5 and 10km to their village of residence. They acquired land by inheritance and practiced intensive crop diversification as risk management strategy. The transportation modes used in addition to walking include bicycle, motorcycle, and car with increasing trend in the use of motorcycle. The mean Technical Efficiency (TE) of food farmers was 0.82 with significant inefficiency effects. The inefficiency analysis indicates positive effect of distance, crop diversification and un-tarred type of road on farmer’s productivity, while poor level of education among farmers, use of bicycle; trekking and weekly working time negatively affect farmer’s efficiency. The negative effect of trekking and use of bicycle and the excess working time suggest the adoption of more IMT of motorized type to optimize farming time and increase farmer’s productivity.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Embora o objectivo de redução de acidentes laborais seja frequentemente invocado para justificar uma aplicação preventiva de testes de álcool e drogas no trabalho, há poucas evidências estatisticamente relevantes das pressupostas causalidade e correlação negativa entre a sujeição aos testes e os posteriores acidentes. Os dados de testes e dos acidentes ocorridos com os colaboradores de uma transportadora ferroviária portuguesa de âmbito nacional, durante anos recentes, começam agora a ser explorados, em busca de relações entre estas e outras variáveis biográficas. - Although the aim of reducing occupational accidents is frequently cited to justify preventive drug and alcohol testing at work, there is little statistically significant evidence of the assumed causality and negative correlation between exposure to testing and subsequent accidents. Data mining of tests and accidents involving employees of a Portuguese national wide railway transportation company, during recent years, is now beginning in search of relations between these and other biographical variables.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

We consider the problem of discrete time filtering (intermittent data assimilation) for differential equation models and discuss methods for its numerical approximation. The focus is on methods based on ensemble/particle techniques and on the ensemble Kalman filter technique in particular. We summarize as well as extend recent work on continuous ensemble Kalman filter formulations, which provide a concise dynamical systems formulation of the combined dynamics-assimilation problem. Possible extensions to fully nonlinear ensemble/particle based filters are also outlined using the framework of optimal transportation theory.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

GPS technology has been embedded into portable, low-cost electronic devices nowadays to track the movements of mobile objects. This implication has greatly impacted the transportation field by creating a novel and rich source of traffic data on the road network. Although the promise offered by GPS devices to overcome problems like underreporting, respondent fatigue, inaccuracies and other human errors in data collection is significant; the technology is still relatively new that it raises many issues for potential users. These issues tend to revolve around the following areas: reliability, data processing and the related application. This thesis aims to study the GPS tracking form the methodological, technical and practical aspects. It first evaluates the reliability of GPS based traffic data based on data from an experiment containing three different traffic modes (car, bike and bus) traveling along the road network. It then outline the general procedure for processing GPS tracking data and discuss related issues that are uncovered by using real-world GPS tracking data of 316 cars. Thirdly, it investigates the influence of road network density in finding optimal location for enhancing travel efficiency and decreasing travel cost. The results show that the geographical positioning is reliable. Velocity is slightly underestimated, whereas altitude measurements are unreliable.Post processing techniques with auxiliary information is found necessary and important when solving the inaccuracy of GPS data. The densities of the road network influence the finding of optimal locations. The influence will stabilize at a certain level and do not deteriorate when the node density is higher.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The advancement of GPS technology enables GPS devices not only to be used as orientation and navigation tools, but also to track travelled routes. GPS tracking data provides essential information for a broad range of urban planning applications such as transportation routing and planning, traffic management and environmental control. This paper describes on processing the data that was collected by tracking the cars of 316 volunteers over a seven-week period. The detailed information is extracted. The processed data is further connected to the underlying road network by means of maps. Geographical maps are applied to check how the car-movements match the road network. The maps capture the complexity of the car-movements in the urban area. The results show that 90% of the trips on the plane match the road network within a tolerance.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

GPS tracking of mobile objects provides spatial and temporal data for a broad range of applications including traffic management and control, transportation routing and planning. Previous transport research has focused on GPS tracking data as an appealing alternative to travel diaries. Moreover, the GPS based data are gradually becoming a cornerstone for real-time traffic management. Tracking data of vehicles from GPS devices are however susceptible to measurement errors – a neglected issue in transport research. By conducting a randomized experiment, we assess the reliability of GPS based traffic data on geographical position, velocity, and altitude for three types of vehicles; bike, car, and bus. We find the geographical positioning reliable, but with an error greater than postulated by the manufacturer and a non-negligible risk for aberrant positioning. Velocity is slightly underestimated, whereas altitude measurements are unreliable.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

It has been widely recognised that infrastructure systems highly affect the economic development of a country or region. In particular, the quality and quantity of transportation infrastructure have a direct bearing on economic growth in developing countries. Therefore, it is challenging to allocate the infrastructure construction budget across a country so that economic growth as a whole will not be hampered by the lack of infrastructure construction in any local area. In this research, the authors focus on simulating the correlations between economic growth, capital investment and transportation infrastructure construction in China historically and comparing the production and investment indicators at the cross-region based on the statistical data reported from government agencies in China. These computed correlations and indicators are crucial for making financial decisions and investment policies on transportation infrastructure construction at a national level.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Researchers are working to identify and promote environment and policy initiatives to encourage more active and healthy communities. Measuring environmental attributes through objective means can verify which physical environment factors are most important. We describe how Geographic Information Systems (GIS) may be used to measure objectively, the features of the built environment that may influence walking. We show how four key attributes currently believed to be of most relevance to walking for transport may be used to create a ‘walkability’ index. These are dwelling density (higher-density neighbourhoods support greater retail and service variety, resulting in shorter, walkable distances between facilities; driving and parking are more difficult); street connectivity (higher intersection density provides people with a greater choice of potential routes, easier access to major roads where public transport is available and shorter times to get to destinations); land use mix (the more varied the land use mix and built form, the more conducive it is to walk to various destinations); and net retail area (people who live near multiple and diverse retail opportunities are able to make more frequent and shorter shopping trips by walking and can walk to more local employment opportunities). The potential relationships between each of the objective environmental-attribute measures and walking behaviours is discussed, together with suggestions as to how such measures might be used to guide community infrastructure planning. GIS mapping can assist decision makers in where to focus transportation investments and where to guide future growth. Readily accessible GIS data can be used to guide and support urban planning and infrastructure investment decisions in both the private and public sectors, to increase walking in communities.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Currently, there is a public bus transportation route in Waterville, Maine. However, this system could be improved. Our goal was to use GIS to find optimal public transportation routes throughout the city based on given points of interest and high population density areas. Three different groups of points of interest were created in the North, West, and South sections of Waterville. Using the Network Analyst tool, which calculates optimal routes, using existing street data, based on the input of stops, barriers, and impedance, we ran an analysis of what we thought would be the routes that best served the greatest number of people. Two different sets of routes were found: one with length as the impedance (the shortest length between the selected stops was favored), and one with population density as the impedance (the roads with the highest population density were favored). Finally, the times of the resulting routes (given a constant speed limit of 25 mph) were calculated and evaluated.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Introduction: The aim of this study was to assess the occurrence of apical root transportation after the use of Pro Taper Universal rotary files sizes 3 (F3) and 4 (F4). Methods: Instruments were worked to the apex of the original canal, always by the same operator. Digital subtraction radiography images were produced in buccolingual and mesiodistal projections. A total of 25 radiographs were taken from root canals of human maxillary first molars with curvatures varying from 23-31 degrees. Quantitative data were analyzed by intraclass correlation coefficient and Wilcoxon nonparametric test (P = .05). Results: Buccolingual images revealed a significantly higher degree of apical transportation associated with F4 instruments when compared with F3 instruments in relation to the original canal (Wilcoxon test, P = .007). No significant difference was observed in mesiodistal images (P = .492). Conclusions: F3 instruments should be used with care in curved canals, and F4 instruments should be avoided in apical third preparation of curved canals. (J Endod 2010;36:1052-1055)

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A study of the relationships between the amount of energy consumed for transportation purposes and a few selected variables related to urban form and socioeconomic characteristics of some of the largest Brazilian cities is conducted in this work. The studied cities include all 27 state capitals regardless of their size and population and 184 urban areas each with more than 20,000 inhabitants located in the state of São Paulo. Two different techniques were applied for data analyses: a more traditional regression analysis approach and artificial neural networks. In general, the results found in the analyses conducted here support the assumption that urban sprawl increases the energy use for transportation. In the case of the 27 state capitals, the analysis indicated that two spatial variables have a strong impact on the energy consumed for urban transportation: urban density and the ratio between the longest distances in the east-west and north-south directions. In the case of the 184 urbanized areas we also reached a similar conclusion. In that case, however, income and employment level apparently have a stronger influence on the amount of energy consumed. The results of the present study stress the importance of physical planning in developing country cities in order to reduce energy use for transportation. © 2007 International Energy Initiative, Inc.