Sök:

Sökresultat:

4722 Uppsatser om Transport model - Sida 20 av 315

Termomekanisk utmattning av Sanicro 25 : Materialmodellering med finita elementmetoden

The report aims to describe the austenitic stainless steel Sanicro 25 from a thermomechanical point of view. The thermal and mechanical properties of the material make it suitable for use in coal ? and thermal power plants. By the use of Sanicro 25 it would be possible to bring the efficiency of these plants up while bringing the carbon emissions down.A material model is created from material testing and validated through simulation in the finite element software Abaqus. The model that has been derived describes the material behavior during loading and stress relaxation for the first cycle in a thermomechanical fatigue test well.

Utveckling av lastmodell för Uppsala fjärrvärmenät

The aim of this study was to develop a load prognosis model for Uppsala district heating system to be used as a tool for heat production optimization. The methodwas to build three models for the different customer types; housing, industry andoffices and then scale them for the total system using data from Uppsala districtheating system. The heat load consists of two parts, one that is temperaturedependent and one that is dependent of the social behavior of the customers. Thetemperature part was modelled with an ARX model using an outdoor temperatureprognosis as input signal. The social behavior part was modelled using the mean ofthe social behavior from some days before and additionally by distinguishing betweenweekdays and weekends.

Kunskapsteori och kunskapsorganisation: En diskursanalys

This Masters thesis concerns epistemology in Knowledge Organization KO, as a field of study in Library and Information Science LIS. Using a theoretical model by Birger Hjørland and foucauldian discourse analysis as springboards, this study analyses three epistemological discourses in the practice of KO. The aim of the study is to show how these discourses are constituted and demarcated in relation to KO, as well as to examine how they fit into Hjørlands model. A brief historical outline of some epistemological trends in LIS is sketched, as well as examples of how different epistemological schools influence different parts of KO, e.g. information retrieval, indexing- and classification theory.

Modellering av reserv- och nödkraftsystem i JAS 39 Gripen

Simulation is a vital tool during development of JAS 39 Gripen, since money and time can be saved.The Auxiliary and Emergency Power System, AEPS, is a subsystem of the secondary power system in Gripen. It has the function of providing the aircraft with electrical and hydraulical power before activation and after deactivation of the main engine. The system also functions as backup in case of a safety critical problem in the main power supply system. The system basically consists of a control unit and an auxiliary gearbox. The gearbox is driven by an air turbine.

Metoder för prediktion av kardiovaskulär sjukdom med njurfunktionen

This study examines if the prediction of cardiovascular disease in hypertensive patients can be improved upon when renal function and microalbuminuria are added to the classical risk factors The predictive capability of a model is measured by discrimination, calibration, reclassification and Harrell's C.The results are ambigious. In most cases, microalbuminuria should be included in the model, but the results regarding the other measures of renal function are varied. Therefore, the selection of risk factors to include in the model depends on which measure of prediction one prioritizes..

En analys av kostnadseffektiva metoder för inköp och logistik

This thesis aims to find a more cost effective model for purchasing and logistics at asmall company. The studied company is a BMX (bicycle motocross) and MTB(mountain bike) retailer. The questions to be answered are: How large parties shouldbe ordered and what mode of transportation is to be used? A literature orientation ofthe field was followed by visits to the company, obtaining information from twodifferent logistics companies and interviews of four other companies in the sameindustry. The study shows that it´s difficult to develop an optimum order quantity fora small company since there often are other factors affecting how large amountshould be ordered.

Modellbaserad systemutveckling i komplexa verksamheter. En fallstudie av Coremetoden

In system development it is today increasingly common to use a model-based system development method. These methods that are suited for Agile work with simple and quick updates and implementations of new applications in systems conform to the requirements that are becoming more important today, namely more flexible and less expensive system that still maintain high quality and safety.A company that has been working with this type of system development method for a long time is Genicore AB, which also has developed their own tools and model language in order to better model the information management systems in complex and abstract operations. Genicore AB is trying to spread their method other developers and have therefore taken the initiative to start this study. The method is evaluated and tested by two students with relatively little experience in model-based systems engineering in order to gain a new perspective on how the method functions. The method has been applied to an educational activity in order to test it in a new domain, and this led us to our research question;?What criteria are of particular relevance in the implementation of a MBSD method on on complex businesses??Through literature reviews and interviews, we formed an idea of how model-based system development works from a theoretical perspective, and then continued to the case study conducted on the educational activities at the faculty of IT at University of Gothenburg.

Livscykelanalys: Pelletspanna från kvänum energi

This study will identify the environmental impact in terms of carbon dioxide for a boiler house on behalf of Kvänum energi. The boiler central consists of a main building, which in turn contains multiple components such as boilers, pipes, etc, the boiler central uses pellets fuel. It also includes a silo and an ash container. The total weight of the boiler is about 63 tons. Each boiler has an output of 600 kW; the central includes three boilers with room for a fourth if necessary.

Ett företags internationaliseringsprocess : - i ett land kulturellt skilt från dess hemmamarknad

AbstractPurpose:The purpose of the study is to describe the internationalization process of one firm when in a country culturally diverse from the firm?s original market.Methodology/approach:The study is a single case study which examines one firm?s internationalization process when entering the Chinese market. The approach has been an empiric interaction between empirical and theoretical data.Findings:The theory of the Uppsala model was applied to the case-company to test the model?s completeness. The authors found weaknesses and added three more aspects to the model.

Transport av häst på land :

The aim of this review is to evaluate the best way to transport the horse. When it comes to transporting horses there are a number of different types of trailers and trucks that you can choose from today. The most common type of trailer is designed for two horses and the horses are transported facing the direction of travel. Studies has been performed to determine if that is the most advantageous direction for the horse to travel in, in terms of balance and levels of stress. Stress is a widely discussed subject and the definition is not fully developed.

Gestaltningsförslag till ny förskola på Zakrisdal

Due to increasing regulations regarding new diesel vehicles particulate matteremissions the new Scania truck, Scania Euro 6, has been equipped with a particulatefilter. This component effectively stores the particles in the exhaust gas but must becleaned in order to prevent itself from clogging. The filter is cleaned through aprocess named regeneration which is a thermodynamic process in which thetemperature of the filter is raised through fuel supplied to the exhaust gas.The purpose of this thesis is to contribute to the development of improved controlstrategies of the temperature during the regeneration process through thedevelopment of model-based controllers. These controllers are designed in order tohave good performance in stationary as well as automatic regeneration.In order to develop these model-based controllers a model of the system isconstructed. The model is described as a linear thermodynamic grey-box model withflow varying parameters, showing good results in validation.The model provides a simulation environment during the controller design, which isfocused around the development of linear regulators with the exhaust gas mass flowas a scheduling variable whose size determines controllers? mode of operation.

Postoperativa transporter: Patientsäkerhet under intrahospitala transporter

Få studier är gjorda om intrahospitala transporter och i synnerhet postoperativa transporter. De studier som finns behandlar framförallt intensivvårdspatienter som transporteras till behandlingar och undersökningar. Tidigare forskning visar att den intrahospitala transporten av intensivvårdskrävande patienter är en patientsäkerhetsrisk då patienten kan få fysiska komplikationer och en förlängd vårdtid. Den postoperativa transporten av den nyopererade patienten sker dagligen inom sjukvården. För att erhålla grundläggande kunskap om denna transport genomfördes en ostrukturerad observationsstudie med fokus på patientsäkerhet.

Ledtidsreducering vid Saab Training Systems Ab : Lead time reduction at Saab Training Systems AB

Detta examensarbete är utfört på Saab Training Systems AB i Huskvarna. Saab Training Systems utvecklar, tillverkar och säljer kompletta militära träningssystem.Syftet med arbetet var att minska ledtiderna, då korta leveranstider blir ett allt viktigare konkurrensmedel. Arbetet innebar en kartläggning av nuvarande reserv- och reparationsflöde samt att identifiera problem och komma fram till förbättringsförslag.Vidare har vi studerat reservdelslagrets lagernivå och dess kapitalbindning.Arbetet genomfördes med hjälp av intervjuer med berörd personal, observationer, enkätundersökning samt statistiska studier. Vi har även arbetat med Supply Chain Operations Reference Model som är en öppen referensmodell med vars hjälp man kan kartlägga, förändra och optimera sin verksamhet.Saab Training Systems har som mål att ledtiderna för reservdelsflödet och reparationsflödet skall vara 14 dagar, men i själva verket är det inte så. Dessa ledtider är idag längre, hur långa är dock oklart.De långa ledtiderna beror främst på att i flödena förekommer det mycket passiv tid.

Klimatsimulering av ett kontorsrum : Hur de termiska stigkrafterna påverkar ventilationseffektiviteten

AbstractIn urban societies people spend more and more time indoors, which put great demands on the indoor environment. If the ventilation is to manage the removal of unwanted substances in the indoor air, a good mixing of the air is required. The question arises that, whether the buoyancy forces will counteract a good mixing of the indoor air or not?This report aims to clear up the difficulties whether you need to consider the buoyancy forces or not, when adjusting a ventilation unit. For studying the indoor mixing of the air a two dimensional model is constructed in COMSOL Multiphysics.

Modell och analysverktyg för beräkningav frekvensförlopp

The power system modelled in this thesis work has been developed for simulationwhen e.g. the production in some part of the power system is changed. The powersystem has been modelled according to the swing mass of the system, the frequencydependency of the load and the turbine governor. The model determines the systemfrequency, the period of regulation and the power exchange between the differentsubsystems in the Nordic synchronized system.In this model the system frequency is assumed to be the same in all different parts ofthe power system and the voltage conditions in the power system are neglected. Forthat reason power swings does not occur between different subsystems in the powersystem, which usually occur as a result of the swinging connection between thetransmissions line.

<- Föregående sida 20 Nästa sida ->