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3955 Uppsatser om Error correction model - Sida 4 av 264

Flödesmätning i vattenkraftverk : Studie av alternativa mätmetoder

Flow measurement is one of the greatest challenges in order to calculate efficiency in hydropower. Most hydropower plants in Sweden use differential pressure methods for flow measurement. These methods are dependent on constant conditions in the waterways. A change in these conditions, like turbine improvements, prevents differential pressure methods to verify efficiency improvements. Since efficiency improvements can?t be verified by one measurement system, another method, which isn?t affected by changing conditions, can be used.

Fastighetsaktier och inflation : Kortsiktiga och långsiktiga samband

The purpose of this paper was to examine the inflation hedging capabilities of property shares. A common notion is that property is a good hedge against inflation. Indeed, positive correlations have been found for direct investments and inflation. However, property shares are generally perceived as a perverse inflation hedge. This discrepancy has often been quoted as evidence of property shares divergence from the development of the underlying property market.

Utveckling och tillämpning av en GIS-baserad hydrologisk modell

A distributed hydrological rainfall-runoff model has been developed using a GIS integrated with a dynamic programming module (PCRaster). The model has been developed within the framework of the EU-project TWINBAS at IVL Swedish Environmental Research Institute, and is intended for use in WATSHMAN ? a tool for watershed management developed at IVL. The model simulates runoff from a catchment based on daily mean values of temperature and precipitation. The GIS input data consist of maps with soil type, land-use, lakes, rivers and a digital elevation model.

Enhetstestning: Kostnad mot kvalitet

Unit testing is a type of testing technique which is becoming quite fashionable to the developers and companies that are in the business of creating and managing software. Alas there are seldom any concrete data to support the positive claims of the authors in unit testing methodology books. These claims are instead based on empirical studies and the experience of the authors. The problem that arises from this situation is that it becomes problematic for managers and also the developers themselves to convince both customers and their own management to use this type of testing as there is no exact return of investment model. This essay examines this problem from two points, the first point is from the literature itself and interviews conducted with a number of developers at a software company located in Umea, Sweden.

Modellering, identifiering och reglering av skannern i ett laserbatymetrisystem

The purpose with this masters thesis was to model the scanner in a system for laser bathymetry. The model was then used to develop a controller for the scanner so a good search pattern was achieved. Two different types of models have been tested, a physical model and a Black Box model of Box Jenkins type. The physical model has been derived from Lagranges equations. Identification experiments have been used to compute the Black Box model and to find the unknown parameters in the physical model.

Optimering av fackverksmodellering : Ett makro för Tekla Structures

This project is the result of a cooperation between HalmstadUniversity and EABAB. The aim of the project was to create a macro that would help EABAB automate the process of designing steel trusses. When run in Microsoft Excel, the macro imports and processes coordinates from a calculator program. The data is then imported into the Building Information Modelling software Tekla Structures, which creates a 3D structural model of the steel truss.The macro saves much time in the project planning process and also helps minimize the risk of design flaws caused by human error. .

Strömningen i och över en skog : utvärdering av en 'mixing-layer' hypotes

A new theory for predicting the windprofile over a canopy has been evaluated. The theory was first presented by Harman and Finnigan (2007). The theory relies on the forming of a mixing-layer above the canopy, due to different mean wind in and above the canopy. Characteristics from both mixing-layer and Monin Obukhov similarity theory have been used to develop the governingequations that give the wind profile. The theory has been used to calculate wind profiles for sixdifferent atmospheric stabilities.

Evaluation and Comparison of Ecological Models Simulating Nitrogen Processes in Treatment Wetlands,Implemented in Modelica

Two ecological models of nitrogen processes in treatment wetlands have been evaluated and compared. These models have been implemented, simulated, and visualized in the Modelica language. The differences and similarities between the Modelica modeling environment used in this thesis and other environments or tools for ecological modeling have been evaluated. The modeling tools evaluated are PowerSim, Simile, Stella, the MathModelica Model Editor, and WEST. The evaluation and the analysis have been performed using McCall?s factors for software quality (McCall et al, 1977), a correlation analysis and the Constant Comparative Method (Glaser&Strauss, 1999).

Utveckling av en diameterklassmodell för grandominerade bestånd i Sverige :

Growth models are very useful tools for forestry to predict growth and yield. With growth models and optimising tools you can manage forest stands in a way that maximize benefit and income. There are three major types of growth models. Stand models; stage structured models and single-tree models. The most advanced models give the most accurate forecasts.

Metod för användning av Geografiska Informations System vid långsiktig vägplanering : en studie genomförd på Sveaskogs marker i Norrbotten

The forest industry is one of the most important industry branches in Sweden. Since the demand of high precision wood deliveries has increased, the demand on a well constructed forest road net also has increased. A good road net gives the wood-supplier competition advantages and also increases its service level towards its customers, lumber-mills and pulp-mills. In some parts of Norrbotten, the road net is still insufficient and not yet built out enough, and that is why it is important to know how to act and where to improve the road net in these areas. The purpose of this thesis was to create a work-model for long term road planning in areas with no road net or a not yet complete road net. The model has been created in an ArcGis environment, where a long chain of tools has been tied together with the program ?Model builder?.

Modellering av indunstning på Södra Cell Mönsterås

Evaporation is a part of the chemical recovery department at wood pulping mills. The purpose of evaporation is to remove water from the black liquor, which makes the liquor combustible. The process is very energy demanding, and having a well-functioning model of the system is of greatest interest. The model can then be used to study energy consumption and to test different control strategies. Two models have been developed during the master thesis.

Växelkursprognoser för 2000-talet

Titel: Växelkursprognoser för 2000-talet Ämne/kurs: NEKK01, Examensarbete C, 15 högskolepoäng Författare: Kenth Hedberg Handledare: Thomas Elger och Fredrik NG Andersson Nyckelord: Sverige, nominella växelkurser, prognoser, UIP Syfte: Syftet med uppsatsen är att fylla tomrummet av att det bara finns ettfåtal svenska studier för 2000-talet. Uppsatsen kommer att belysa hurden nominella växelkursen ska prognostiseras för att matcha defaktiska värdena på bästa sätt. Metod: Tillvägagångssättet för denna uppsats är att skapa prognoser utifråntre olika prognosmetoder som sedan jämförs med de faktiska värdenaav den nominella växelkursen. Det bestäms sedan utifrån treutvärderingskriterierna vilken metod som därefter ger det bästautfallet. Slutsats: Visar att AR(1) och AR(1) med ränta prognostiserar bättre än randomwalk med en kortsiktig prognoshorisont.

Kommunikationseffektivitet och kommunikationsstrategier för L1- och L2-talare i referentiella problemlösningsuppgifter

This thesis examines and measures differences in effciency between L1- and L2 language use for solving referential problems. Quantitative measures used in the study were time and error frequency. Qualitative measures, such as how the tasks and the participants own performance were experienced, were measured by an post interview and two questionaires. Two different tasks, a sorting task and a construction task, in which each informant was given the role as a constructor or instructor, were used for data gathering. A total of 20 dyads, divided in two language groups (English and Swedish) participated in the study.

Undersökning av modulationsscheman för existerande bredbandsteknologier

In this thesis some different modulation schemes for xDSL-techniques are compared. The investigated techniques are ADSL, G.lite, ADSL2, HDSL, SHDSL and VDSL. The modulation methods used are DMT, CAP and different versions of PAM. Several broadband techniques also use Trellis Coded Modulation (TCM) to increase the coding gain of the transmission. For each one of the different modulation methods the signal-to-noise ratio is calculated for generating a bit error rate probability of 10-7.

Demonstrationsprojektets roll i framväxten av ny teknik: Fallstudier av två vindkraftprojekt

This report describes a synchronous machine model with magnetic saturation in d-axis, neutralconnection and electrical exciter interface for the transient simulator PSCAD/EMTDC. It hasbeen designed and verified in comparison to the regular machine model in EMTDC.The performance of the model is very good when incorporating a linear as well as a saturatedmagnetising inductance. The dynamic deviation is only thousandths to ten thousandths perunit. By using a cubic interpolation of the saturation curve, the model gives a good representationof the saturation effect. The open source code implementation of the synchronousmachine model gives the possibility to easily adapt the model to specific requirements.The derived model makes it possible to simulate a synchronous machine with its excitationsystems, e.g.

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