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4722 Uppsatser om Transport model - Sida 1 av 315
Numerisk modell för global transport av spårämnen i atmosfären
The aim of this project was to develop a numerical model simulating the global transport of air pollution. The model currently used by SMHI, the Swedish Meteorological and Hydrological Institute, was intended to perform such simulations at regional scales. However, the usage of a grid based on longitudes and latitudes makes this model work poorly in global simulations. The problem with this grid is that the nodes are concentrated near the North and South Poles. Due to this characteristic, the Courant, Friedrich and Lewy-condition for numerical stability puts a sharp bound on the timestep length.
Transferfunktionsmodeller modellering och prognoser av Sjötransportindex
We have by Statistics Sweden (SCB) been given the task of using different dynamic regression models in order to forecast service price index for sea transport. The aim is to see whether these models provide better forecasts than those previously used. This essay aim to identify, estimate and evaluate the selected prediction models. Through our data material we were given access to 28 sightings of sea transport index during the period of 2004 q1 to 2010 q4. We have chosen to evaluate three different transfer function models, one ARIMA model and one naive forecasting model. The input variables we decided to test in our transfer function models were the price of petroleum products, the port activity in Swedish ports and the lending rate of Swedish Central bank. The results of our study suggest that transfer function models generally provide better models than the ARIMA model and the naive forecast model.
Spridning av bekämpningsmedel i banvall : Modellutveckling och känslighetsanalys
The stability of railway embankment is essential for safe transport. In order to ensure safe transport, water should be allowed to freely drain. Furthermore, as the engine driver has to be able to see signs, and people working on the embankment are supposed to easily see flaws on the rails to ensure safety for the passing trains, plants should not be allowed to grow on the embankment. In Sweden there are 12 000 kilometers of railway tracks and 25?30 % of them are treated for weed control every year.
Förslag till modell av kemikaliespridning i mark anpassad för användning vid räddningsinsats - Kemspill Mark 4.0
After emergencies involving chemical spills it is of great importance that correct measures are taken with short notice, both for the security of people and in order to minimize future environmental consequences. The RIB-unit at the Swedish Rescue Services Agency initiated this study, the aim of which is to propose changes to the existing chemical transport calculation tool: Chemical Spill 3.4, included in RIB - Integrated Decision Support for Civil Protection, so that it can be used for decision support as well as in preventive work. A rough estimation of chemical transport in the subsurface is considered being of great importance when making decisions during emergency response operations.The proposition presented in this report is a non site specific chemical Transport model which is designed to give a rough estimation of NAPL flow in homogenous isotropic soil shortly after an instantaneous release. The model can be used at two levels; both in situations without access to information on subsurface properties, and with more accuracy in situations with knowledge of the included parameters. For that reason the user can choose among predefined alternatives or assign the parameters a numeric value to increase the quality of the model output.
BIM på Trafikverket : Förslag till en utvidgad investeringsprocess
2013 a decision was made that all projects at the Swedish Transport Administration shoulduse BIM (Building Information Modeling) to some extent from 2015. BIM is an approachthat allows for streamlining of projects by the use of a 3D-model created in an early stage ofthe project. The 3D-model can carry information about the facility throughout its life cyclefrom planning to management. The use of a 3D-model can help the project to detect errors inearly stages of the project when it is easy and cheap to fix the error instead of finding theerror in the construction phase when it is costly and time consuming to fix it. 3D-models alsolead to improved communication both within the project groups and with the public.
Adaptiv katalysatormodell för reglering
This master?s thesis describes the development of a model of the catalystsystem aiming at control by an MPC. A well functioning model, which is suitable in control purpose, is important while emission legislation become more and more hard to fulfill for the car manufacturers. Much research has been done in the field of physical modeling of the system, but in this work a linear adaptive time discrete ARX-model is developed and validated.The systems tendency to change its dynamic during usage implies that the model must be adaptive. The developed model proved to be well functioning and shows promising conditions for the MPC design.
Energieffektivisering av linjesjöfarten till och från Tasmanien
Tasmania is a state in Australia, and is also the country?s largest island. It is separated from the main land by a 429 kilometer wide strait. Every year, a large amount of people, cars and goods are transported to the island using a government owned ferry line, which generates approximately 300 million Australian dollars to the state?s economy ,every year. This bachelor thesis investigates the possibility of reducing the fuel consumption for the ferry traffic to and from Tasmania, which would also reduce the overall cost.
Uppdatering av båtnadskalkyl med hänsyn till nya faktorer :
Sweden have 419 000 km road in the country and about half of these roads is forestroads. The forest road net most important mission is to make it possible to deliver wood from the forest to the industries. With a raw material that is spread over a large area the road network is important. Each year has the forest road network been extended with about 1 700 km new roads. To decide if a new road is to be built different forest road cost estimation models has been used.
Busshållplatsers kapacitet : Utvärdering av tillämpbarhet av modell från Highway Capacity Manual 2000 med uinderlag från busstrafik i Stockholms innerstad
Stockholm is growing with almost two fully loaded SL-buses a day. One of the consequences that derive from this is the increase of public transport travelers who put the regionally governed public transport up to the test in terms of its capacity. The Transport administration in Stockholm County initiated 2015 a project with the purpose of simplifying the calculation of bus stop capacities. A hypothesis (set up by the Transport administration) based on that a model for calculation of bus stop capacities could be calibrated for Stockholm conditions is being researched in this bachelor?s essay.The study is implemented by self-collected traffic data from bus stops located in the Stockholm city center.
Modell för dimensionering av AGV-system inom tung industri
Interest in the implementation of AGV-systems (Automated Guided Vehicle) has in recent decades increased. The reason is that it allows companies to perform reliably and secure internal transport while reducing the need of personnel. It is one of todays most advanced and complex material handling system that can independently make their own decisions regarding flow paths and traffic control. An AGV-system consists of transport units carrying cargo from point A to point B, and communicates using a computer.The purpose of this study is to develop a model on how to proceed in order to design an AGV system in heavy industry. The model is tested by a case study of a company in the metal industry to determine if the model works and gives the correct result.
Grundvattenmodellering i Badelundaåsen
Over an extended period of time there have been plans to establish a shared facility in Lennheden to extract groundwater from the Badelunda esker to provide drinking water for the cities of Borlänge and Falun. The city of Falun is dissatisfied with the quality of its drinking water and the city of Borlänge is concerned about the risk of contamination of its existing groundwater supply at its current location. To provide a basis for a decision on this issue, the company Midvatten AB has been commissioned to perform hydrogeological investigations in the area of Lennheden.The purpose of this thesis is to design a functional groundwater model of the area between Lennheden, place of planned extraction, and Övre Tjärna, place of existing extraction, to get a better understanding of the groundwater situation in the area. A groundwater model enables simulations of different scenarios in risk assessment and contaminant transport. The aim of the thesis is that the model can be used as an aid in Midvatten?s investigations in Lennheden and that it also can be used in future projects in the area.The model has been made in Processing Modflow 5.3 and encompasses an area of 19,5 × 11 km along the Badelunda esker and the river Dalälven between Djurmo and Frostbrunnsdalen.
Kartläggning av ruttplaneringsprocesser för rundvirkestransportörer
Transportation represents 10-15 % of wood supply costs. It is therefore important to improve efficiency in the transport system to decrease these costs. The aim of this study is to map the timber vehicle routing processes used by a sample of timber hauling contractors and to identify possible links between the vehicle routing process and service and economic variables. The study was carried out at Södra Skog in autumn 2008. 15 timber hauling contractors were sampled and interviewed about their work with timber transports.
Jämförelse mellan MultiScat och konventionell beräkning av intensiteter till koncentrationer vid analys med röntgenflourescensspektrometri
In this master thesis work, a new method called MultiScat, is compared with the conventional method with alfa-correction, for computing concentrations from intensities in X-ray spectrometric analysis. The conventional model is a linear model, which only takes the photoelectric effect into consideration. It doesn't consider Rayleigh and Compton scattering even though it has a great impact on the measured intensities. Here MultiScat differs a lot. MultiScat is based on a solution of the Boltzmann transport equation.
Identifiering och reducering av köer i samband med återbesök
Purpose ? The purpose of this thesis is to develop a total cost model for container transports and create a tool that calculates a suitable transport quantity from an economic view, which fulfills the demands on delivery service. To achieve this purpose the following questions will be answered:Which costs are affected by the decision between the two transport alternatives LCL and FCL? How does the decision of sending product LCL or FCL influence the delivery service? How can a tool be constructed to simplify the decision-making process regarding the choice of sending products LCL or FCL? Method ? A total cost model was developed. This model is supported from existing literature.
Utvärdering av Transportstyrelsens flygtrafiksmodeller
The Swedish Transport Agency has for a long time collected data on a monthly basis for different variables that are used to make predictions, short projections as well as longer projections. They have used SAS for producing statistical models in air transport. The model with the largest value of coefficient of determination is the method that has been used for a long time. The Swedish Transport Agency felt it was time for an evaluation of their models and methods of how projections is estimated, they would also explore the possibilities to use different, completely new models for forecasting air travel. This Bachelor thesis examines how the Holt-Winters method does compare with SARIMA, error terms such as RMSE, MAPE, R2, AIC and BIC will be compared between the methods. The results which have been produced showing that there may be a risk that the Holt-Winters models adepts a bit too well in a few variables in which Holt-Winters method has been adapted.