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Dissertations / Theses on the topic 'Calculating time'

Author: Grafiati

Published: 4 June 2021

Last updated: 12 February 2022

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1

Wesslund, Lovisa. "Beräkningsmall för vindlast enligt Eurokoder samt jämförelsestudie av vindlastberäkningsmetoder." Thesis, KTH, Byggteknik och design, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-102022.

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Detta examensarbete har genomförts i samarbete med byggteknikavdelning på Ramböll Sverige AB, i Norrköping/Linköping. På företaget finns ett behov av att förenkla arbetet med vindlastberäkningar för hallbyggnader enligt Eurokoden. Idag använder företaget en förenklad metod som överdimensionerar. För att kunna göra en mer exakt beräkning helt enligt Eurokoden och effektivisera arbetet har det i detta examensarbete skapats en beräkningsmall för detta ändamål. Beräkningsmallen har tagits fram i programmet Microsoft Excel. För att också kunna se konsekvenserna av att jobba med en förenklad metod, har det utförts en jämförelsestudie mellan två befintliga projekt på företaget. Resultatet av jämförelsestudien visar på vad som är anledningen till skillnaden mellan det förenklade sättet, metod 1 och det mer exakta, metod 2. Rapporten innehåller en studie kring de faktorer som används vid beräkning av vindlast. Detta har gjorts för att kunna se vilken av faktorerna som bidrar till störst skillnad i resultat mellan de båda metoderna. Som grund till allt detta, innehåller rapporten också en teoretiskt bakgrund till hur vindlast ska dimensioneras enligt Eurokoden. Detta utgör första delen av rapporten.
This study has been performed in a collaboration with the company Ramböll Sweden AB in Norrköping/Linköping. At the company there is a need to simplify calculations concerning the wind load on industrial buildings according to the Eurocode. Today the company uses a simplify method which result in an over-dimension. To make a more exact method in accordance to the Eurocode and increase the efficiency at the work, it has in this study created a calculation model for this purpose. The calculation model has been created in the program Microsoft Excel. To be able to see the consequences to work with a simplified method, it has been done a comparison study between two current project at the company. The results of the comparison study show the reason to the difference between the simplified method, method 1 and the more exact method, method 2. The report containing a study of the factors that uses in the calculations. This has been done to see which of the factors that contributes to the largest difference in result between the both methods. As the basis for all this, the report also contains a theoretical background about how the wind load should be dimensioned according to the Eurocode. This is the first part of this report.

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Eriksson, Jesper. "Implementing a Level Design Tool for Calculating and Tuning the Travel Time of Paths in a Digital Game." Thesis, Blekinge Tekniska Högskola, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-16838.

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3

Raymundo, Albornoz Ian Paulo. "Disminución y gestión de suspensiones quirúrgicas basada en el apoyo de la toma de decisiones en pabellón quirúrgico del Hospital Exequiel González Cortés." Tesis, Universidad de Chile, 2016. http://repositorio.uchile.cl/handle/2250/140427.

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Magíster en Ingeniería de Negocios con Tecnologías de Información
Un medio de apoyo a la toma de decisiones mejora la programación de pabellón quirúrgico y reduce las suspensiones quirúrgicas, que fueron el 14% de las operaciones en el 2015. El cálculo de la duración de las operaciones y el cálculo de la cantidad de operaciones condicionales (sobreventa), de manera idónea, brinda parte de la solución, sin embargo los principales beneficios son pequeños, debido a la escasa información, complejidad de las decisiones, recolección y procesamiento de datos. Los sistemas de producción con gran demanda para servicios especializados generan retos que el personal del hospital resuelve en parte. Esto motiva a utilizar la Metodología de la Ingeniería de Negocios que planifica, diseña e implementa una solución para superar estas complejidades, acorde con los objetivos de la institución. En específico, se diseñó e implemento un aplicativo el cual fue probado en un piloto durante dos meses. Con los datos generados se utilizaron técnicas de inteligencia de negocio para determinar el método más adecuado para el cálculo de duraciones de los servicios y se generó un modelo para gestionar la sobreventa. Como resultado se brinda tres aportes, primero se distingue los factores que originan disfuncionalidades, las acciones de los gestores para afrontar esas disfuncionalidades y la forma de generar oportunidades de mejorar los resultados de las decisiones de los gestores. Segundo, se demuestra la capacidad de mejorar en la precisión del cálculo de la duración de una operación, de 26% a 52%, utilizando la mediana agrupada por tipo de operación. Tercero, se presenta un modelo de sobreventa que considera la factibilidad operativa y prioridad médica.

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4

Poivey, Christian. "Methodes d'optimisation pour la cao de circuits integres : interface avec le simulateur electrique spice-pac : applications." Clermont-Ferrand 2, 1987. http://www.theses.fr/1987CLF2D203.

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La conception des circuits integres consiste a determiner des valeurs acceptables des parametres afin de satisfaire certains criteres de fonctionnement du circuit donne par sa topologie. Le probleme est reformule en un probleme non lineaire a plusieurs dimensions avec contraisntes. Les fonctions a minimiser et les contraintes dependent implicitement des parametres d'optimisation par les equations du circuit, ce qui exige une simulation complete pour obtenir l'evaluation de la fonction. Les methodes du gradient et hessienne ne conviennent pas. La methode du simplex de nelder et head adjointe a une methode de recherche globale des meilleurs points d'attraction a ete retenue. Toutefois, la dimension n doit rester inferieure a 10. On tente de resoudre le probleme d'un grand nombre de variables en le fractionnant: au lieu d'agir sur la totalite des variables, on effectue des minimisations successives sur des sous-ensembles. Des essais sur des fonctions tests comportant jusqu'a 100 variables sont satisfaisants. On obtient la proportionnalite du temps de calcul et du nombre des variables. Ces methodes ont ete interfacees avec le simulateur electrique spice-pac et appliquees a la caracterisation de modeles de transistors et a l'optimisation de circuits

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5

Alimin, E. K. "Dissipation and discretization in time marching CFD calculation." Thesis, Cranfield University, 1995. http://hdl.handle.net/1826/4021.

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This thesis concentrates on accuracy improvements for an existing software package that solves the three dimensional Reynolds Averaged Navier-Stokes equations in rotating coordinates. It is a cell centred explicit time marching code. Two topics are considered: improvement to the discretization scheme, and reduction of the artificial dissipation. The first topic is the analysis of the straight averaging process which demonstrates that the process can result in inconsistency with a skewed grid. An alternative consistent scheme is proposed which is based upon quadratic interpolation. Improved accuracy can also be obtained by modifying the grid or adopting a cell vertex scheme. The stability of the iterative process is also shown to depend on the time step. The reduction of artificial dissipation (second topic) first considers the role of the so called aspectratio and velocity functions. These are found to be limited in influence and a new function is proposed based upon the local flow gradient. Both two and three dimensional turbomachinery cases are tested and improvements demonstrated. In the second part of the analysis, the eigenvalues of the stability matrix are used to reduce the dissipation in overdamped regions. Again this method is applied to various test cases and improvements demonstrated. The management part of this Total Technology PhD Program discusses topics concerned with collaboration and technology development in the aero engine industry with particular emphasis on the role of an "emerging" partner.

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6

Rubio, Pedro, Francisco Fernandez, and Francisco Jimenez. "REAL TIME C BAND LINK BUDGET MODEL CALCULATION." International Foundation for Telemetering, 2016. http://hdl.handle.net/10150/624184.

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The purpose of this paper is to show the integration of the transmission gain values of a telemetry transmission antenna according to its relative position and integrate them in the C band link budget, in order to obtain an accuracy vision of the link. Once our C band link budget was fully performed to model our link and ready to work in real time with several received values (GPS position, roll, pitch and yaw) from the aircraft and other values from the Ground System (azimuth and elevation of the reception telemetry antenna), it was necessary to avoid a constant value of the transmitter antenna and estimate its values with better accuracy depending of the relative beam angles between the transmitter antenna and receiver antenna. Keeping in mind an aircraft is not a static telecommunication system it was necessary to have a real time value of the transmission gain. In this paper, we will show how to perform a real time link budget (C band).

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7

Cohen, Joseph P. "Digital calculation of real time velocity profiles using ultrasonics." Thesis, Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/17977.

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8

Van, Caillie Carole. "Electronic structure calculations using time-dependent density functional theory." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621205.

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9

Díaz, José Antonio, and Virendra N. Mahajan. "Diffraction and geometrical optical transfer functions: calculation time comparison." SPIE-INT SOC OPTICAL ENGINEERING, 2017. http://hdl.handle.net/10150/626488.

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In a recent paper, we compared the diffraction and geometrical optical transfer functions (OTFs) of an optical imaging system, and showed that the GOTF approximates the DOTF within 10% when a primary aberration is about two waves or larger [Appl. Opt., 55, 3241-3250 (2016)]. In this paper, we determine and compare the times to calculate the DOTF by autocorrelation or digital autocorrelation of the pupil function, and by a Fourier transform (FT) of the point-spread function (PSF); and the GOTF by a FT of the geometrical PSF and its approximation, the spot diagram. Our starting point for calculating the DOTF is the wave aberrations of the system in its pupil plane, and the ray aberrations in the image plane for the GOTF. The numerical results for primary aberrations and a typical imaging system show that the direct integrations are slow, but the calculation of the DOTF by a FT of the PSF is generally faster than the GOTF calculation by a FT of the spot diagram.

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10

Turer, Ibrahim. "Specific Absorption Rate Calculations Using Finite Difference Time Domain Method." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605200/index.pdf.

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This thesis investigates the problem of interaction of electromagnetic radiation with human tissues. A Finite Difference Time Domain (FDTD) code has been developed to model a cellular phone radiating in the presence of a human head. In order to implement the code, FDTD difference equations have been solved in a computational domain truncated by a Perfectly Matched Layer (PML). Specific Absorption Rate (SAR) calculations have been carried out to study safety issues in mobile communication.

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11

Lorenzo, Martín Francisco. "Time-dependent crustal deformation after strong earthquakes rheological model calculations /." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=984503889.

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Pogén, Tobias. "Asynchronous Particle Calculations on Secondary GPU for Real Time Applications." Thesis, Blekinge Tekniska Högskola, Institutionen för datavetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-18239.

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13

Siqueira, Sunni Ann. "Calculation of Time-Dependent Heat Flow in a Thermoelectric Sample." ScholarWorks@UNO, 2012. http://scholarworks.uno.edu/honors_theses/24.

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In this project, the time-dependent one-dimensional heat equation with internal heating is solved using eigenfunction expansion, according to the thermoelectric boundary conditions. This derivation of the equation describing time-dependent heat flow in a thermoelectric sample or device yields a framework that scientists can use (by entering their own parameters into the equations) to predict the behavior of a system or to verify numerical calculations. Allowing scientists to predict the behavior of a system can help in decision making over whether a particular experiment is worthy of the time to construct and execute it. For experimentalists, it is valuable as a tool for comparison to validate the results of an experiment. The calculations done in this derivation can be applied to pulsed cooling systems, the analysis of Z-meter measurements, and other transient techniques that have yet to be invented. The vast majority of the calculations in this derivation were done by hand, but the parts that required numerical solutions, plotting, or powerful computation, were done using Mathematica 8. The process of filling in all the steps needed to arrive at a solution to the time-dependent heat equation for thermoelectrics yields many insights to the behavior of the various components of the system and provides a deeper understanding of such systems in general.

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Castro, Pareja Carlos Raul. "Real-time 3D elastic image registration." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1086185793.

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Thesis (Ph. D.)--Ohio State University, 2004.
Title from first page of PDF file. Document formatted into pages; contains xv, 105 p. : ill. (some col.). Advisor: Jogikal Jagadeesh, Department of Electrical and Computer Engineering. Includes bibliographical references (p. 101-105).

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Akbulut, Derya. "Survival Modelling Approach To Time To First Claim And Actuarial Premium Calculation." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613113/index.pdf.

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Health problems of the human beings in a society are one of the main components of the social security systems due to the dimension of the financial burden it might bring on individuals, employers, insurance companies and governments. Morbidity measures, such as incidence and prevalence of a specific disease in a certain population enable researchers to estimate for individuals the probability of being diagnosed or being prone to the diseases. This information is usually not tractable because of the non-availability of the convenient data or recordings for many countries as well as Turkey. Even if it is available, it is commonly limited with largely varying characteristics about the type and coverage of the diseases. In this regard, the pattern that a population follows for an acute disease may not be the same for chronic diseases. Having those indicators determined for a group of insureds will enable underwriters to have more profitable and economical premium calculation and precision on required reserve estimation. v Based on their characteristics such as acute or chronic behaviour, the gender, and the location of residency of people, the diseases show different behaviour on their occurrences. From the insurer

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Wang, Xuesi. "Calculation of time variations in mineral grades from high resolution geostatistical models." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0010/MQ59897.pdf.

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17

DAHL, JOAO MAGALHAES. "CALCULATION OF SECURITY INDEXES IN POWER SYSTEMS BASED ON TIME DOMAIN SIMULATION." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2006. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=9140@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
Os sistemas de energia elétrica estão operando atualmente próximos dos limites de estabilidade, comprometendo a segurança. Este fato tem sido evidenciado por diversos blackouts no mundo inteiro. A avaliação da segurança dinâmica torna-se, então, fundamental. O objetivo é a busca de um método rápido e, sobretudo, confiável, para analisar o comportamento dinâmico de um sistema de energia elétrica. Esta dissertação trata, portanto, do problema da avaliação da segurança dinâmica de sistemas de energia elétrica. A avaliação é realizada através da determinação das margens de estabilidade, utilizando os resultados de simulações no domínio do tempo, que fornece informações qualitativas a respeito da estabilidade na primeira oscilação. O grupo de geradores severamente perturbados é determinado e a margem de estabilidade de cada um deles é calculada. O gerador que apresentar a menor margem determina a margem de estabilidade do sistema. Quando a margem de estabilidade assume valor nulo, o tempo crítico de eliminação da falta é obtido. Estes resultados são comparados com aqueles determinados pelo método de tentativa e erro, utilizando um programa convencional de estabilidade transitória. Desta forma, as contingências são classificadas em função dos tempos críticos de eliminação de falta, de acordo com o nível de severidade. Essa classificação permite reduzir o conjunto de contingências a ser estudado. A contribuição deste trabalho é mostrar que o critério baseado na aceleração imediatamente após a eliminação da falta é mais eficaz que aquele baseado na aceleração imediatamente após a ocorrência da falta para a indicação do grupo de geradores severamente perturbados.
Power systems have been operating nowadays near to the stability limits putting security under risk. This is one of the reasons why the dynamic security assessment is a fundamental tool to avoid the occurrence of blackouts in the whole world. The goal is a reliable and fast way to evaluate the dynamic behavior of a power system. This dissertation deals with the problem of dynamic security assessment of power systems. The evaluation is performed based on stability margins calculated from time domain simulation results, providing qualitative information about the first swing stability. The group of severely disturbed machines is defined and the stability margins are determined. The machine with the lowest margin determines the stability margin of the system. When the system margin approaches the zero value, the critical clearing time is obtained. These outcomes are compared with that ones determined by trial and error method using a conventional transient stability program. Having done that, a contingency ranking is defined according to the critical clearing time. The ranking minimizes the number of contingencies that have to be studied. This dissertation shows that the criterion to define the group of severely disturbed machines based on the machine accelerations at the instant immediately after the fault clearing time is more efficient than that one based on the machine accelerations at the instant immediately after the fault occurrence.

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18

Duggan, Tim. "Seismic studies and travel time calculations for the Lachlan Fold Belt Seismic Array /." Adelaide, 1999. http://web4.library.adelaide.edu.au/theses/09SB/09sbd866.pdf.

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19

Sutherland, Fritz. "Driver traffic violation detection and driver risk calculation through real-time image processing." Diss., University of Pretoria, 2005. http://hdl.handle.net/2263/66246.

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Road safety is a serious problem in many countries and affects the lives of many people. Improving road safety starts with the drivers, and the best way to make them change their habits is to offer incentives for better, safer driving styles. This project aims to make that possible by offering a means to calculate a quantified indicator of how safe a driver's habits are. This is done by developing an on-board, visual road-sign recognition system that can be coupled with a vehicle tracking system to determine how often a driver violates the rules of the road. The system detects stop signs, red traffic lights and speed limit signs, and outputs this data in a format that can be read by a vehicle tracking system, where it can be combined with speed information and sent to a central database where the driver safety rating can be calculated. Input to the system comes from a simple, standard dashboard mounted camera within the vehicle, which generates a continuous stream of images of the scene directly in front of the vehicle. The images are subjected to a number of cascaded detection sub-systems to determine if any of the target objects (road signs) appear within that video frame. The detection system software had to be optimized for minimum false positive detections, since those will unfairly punish the driver, and it also had to be optimized for speed to run on small hardware that can be installed in the vehicle. The first stage of the cascaded system consists of an image detector that detects circles within the image, since traffic lights and speed signs are circular and a stop sign can be approximated by a circle when the image is blurred or the resolution is lowered. The second stage is a neural network that is trained to recognize the target road sign in order to determine which road sign was found, or to eliminate other circular objects found in the image frame. The output of the neural network is then sent through an iterative filter with a majority voted output to eliminate detection 'jitter' and the occasional incorrect classifier output. Object tracking is applied to the 'good' detection outputs and used as an additional input for the detection phase on the next frame. In this way the continuity and robustness of the image detector are improved, since the object tracker indicates to it where the target object is most likely to appear in the next frame, based on the track it has been following through previous frames. In the final stage the detection system output is written to the chosen pins of the hardware output port, from where the detection output can be indicated to the user and also used as an input to the vehicle tracking system. To find the best detection approach, some methods found in literature were studied and the most likely candidates compared. The scale invariant feature transform (SIFT) and speeded up robust features (SURF) algorithms are too slow compared to the cascaded approach to be used for real-time detection on an in-vehicle hardware platform. In the cascaded approach used, different detection stage algorithms are tested and compared. The Hough circle transform is measured against blob detection on stop signs and speed limit signs. On traffic light state detection two approaches are tested and compared, one based on colour information and the other on direct neural network classification. To run the software in the user's vehicle, an appropriate hardware platform is chosen. A number of promising hardware platforms were studied and their specifications compared before the best candidate was selected and purchased for the project. The developed software was tested on the selected hardware in a vehicle during real public road driving for extended periods and under various conditions.
Dissertation (MEng)--University of Pretoria, 2017.
Electrical, Electronic and Computer Engineering
MEng
Unrestricted

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20

Reddy, Prashanth G. "EFFICIENT TIME OF ARRIVAL CALCULATION FOR ACOUSTIC SOURCE LOCALIZATION USING WIRELESS SENSOR NETWORKS." Cleveland State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=csu1323970390.

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21

Ly, Eddie, and Eddie Ly@rmit edu au. "Numerical schemes for unsteady transonic flow calculation." RMIT University. Mathematics and Geospacial Sciences, 1999. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20081212.163408.

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An obvious reason for studying unsteady flows is the prediction of the effect of unsteady aerodynamic forces on a flight vehicle, since these effects tend to increase the likelihood of aeroelastic instabilities. This is a major concern in aerodynamic design of aircraft that operate in transonic regime, where the flows are characterised by the presence of adjacent regions of subsonic and supersonic flow, usually accompanied by weak shocks. It has been a common expectation that the numerical approach as an alternative to wind tunnel experiments would become more economical as computers became less expensive and more powerful. However even with all the expected future advances in computer technology, the cost of a numerical flutter analysis (computational aeroelasticity) for a transonic flight remains prohibitively high. Hence it is vitally important to develop an efficient, cheaper (in the sense of computational cost) and physically accurate flutter simulation tech nique which is capable of reproducing the data, which would otherwise be obtained from wind tunnel tests, at least to some acceptable engineering accuracy, and that it is essentially appropriate for industrial applications. This need motivated the present research work on exploring and developing efficient and physically accurate computational techniques for steady, unsteady and time-linearised calculations of transonic flows over an aircraft wing with moving shocks. This dissertation is subdivided into eight chapters, seven appendices and a bibliography listing all the reference materials used in the research work. The research work initially starts with a literature survey in unsteady transonic flow theory and calculations, in which emphasis is placed upon the developments in these areas in the last three decades. Chapter 3 presents the small disturbance theory for potential flows in the subsonic, transonic and supersonic regimes, including the required boundary conditions and shock jump conditions. The flow is assumed irrotational and inviscid, so that the equation of state, continuity equation and Bernoulli's equation formulated in Appendices A and B can be employed to formulate the governing fluid equation in terms of total velocity potential. Furthermore for transonic flow with free-stream Mach number close to unity, we show in Appendix C that the shocks that appear are weak enough to allow us to neglect the flow rotationality. The formulations are based on the main assumption that aerofoil slopes are everywhere small, and the flow quantities are small perturbations about their free-stream values. In Chapter 4, we developed an improved approximate factorisation algorithm that solves the two-dimensional steady subsonic small disturbance equation with nonreflecting far-field boundary conditions. The finite difference formulation for the improved algorithm is presented in Appendix D, with the description of the solver used for solving the system of difference equations described in Appendix E. The calculation of steady and unsteady nonlinear transonic flows over a realistic aerofoil are considered in Chapter 5. Numerical solution methods, based on the finite difference approach, for solving the two-dimensional steady and unsteady, general-frequency transonic small disturbance equations are presented, with the corresponding finite difference formulation described in Appendix F. The theories and solution methods for the time-linearised calculations, in the frequency and time domains, for the problem of unsteady transonic flow over a thin planar wing undergoing harmonic oscillation are presented in Chapters 6 and 7, respectively. The time-linearised calculations include the periodic shock motion via the shock jump correction procedure. This procedure corrects the solution values behind the shock, to accommodate the effect of shock motion, and consequently, the solution method will produce a more accurate time-linearised solution for supercritical flow. Appendix G presents the finite difference formulation of these time-linearised solution methods. The aim is to develop an efficient computational method for calculating oscillatory transonic aerodynamic quantities efficiently for use in flutter analyses of both two- and three-dimensional wings with lifting surfaces. Chapter 8 closes the dissertation with concluding remarks and future prospects on the current research work.

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Zhu, Ying. "A Comparison of Calculation by Real-Time and by Linear-Response Time-Dependent Density Functional Theory in the Regime of Linear Optical Response." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1460554444.

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23

Hankel, Marlies. "Time-dependent wavepacket methods for the calculation of state-to-state molecular reactive cross sections." Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391180.

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Bergmark, Fabian. "Online aggregate tables : A method forimplementing big data analysis in PostgreSQLusing real time pre-calculations." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-207808.

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In modern user-centric applications, data gathering and analysis is often of vitalimportance. Current trends in data management software show that traditionalrelational databases fail to keep up with the growing data sets. Outsourcingdata analysis often means data is locked in with a particular service, makingtransitions between analysis systems nearly impossible. This thesis implementsand evaluates a data analysis framework implemented completely within a re-lational database. The framework provides a structure for implementations ofonline algorithms of analytical methods to store precomputed results. The re-sult is an even resource utilization with predictable performance that does notdecrease over time. The system keeps all raw data gathered to allow for futureexportation. A full implementation of the framework is tested based on thecurrent analysis requirements of the company Shortcut Labs, and performancemeasurements show no problem with managing data sets of over a billion datapoints.
I moderna användarcentrerade applikationer är insamling och analys av dataofta av affärskritisk vikt. Traditionalla relationsdatabaser har svårt att hanterade ökande datamängderna. Samtidigt medför användning av externa tjänster fördataanalys ofta inlåsning av data, vilket försvårar byte av analystjänst. Dennarapport presenterar och utvärderar ett ramverk för dataanalys som är imple-menterat i en relationsdatabas. Ramverket tillhandahåller strukturer för attförberäkna resultat för analytiska beräkningar på ett effektivt sätt. Resultatetblir en jämn resursanvändning med förutsägbar prestanda som inte försämrasöver tid. Ramverket sparar även all insamlad data vilket möjliggör exporter-ing. Ramverket utvärderas hos företaget Shortcut Labs och resultatet visar attramverket klarar av datamängder på över en miljard punkter.

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Alexandra, Markovic Markovic, and Edforss Arvid. "An evaluation of current calculations for safety stock levels." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Maskinteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-36505.

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ABDALLAH, HAISCAM. "Construction d'un logiciel de calcul des elements transitoires de chaines de markov a temps continu." Rennes 1, 1989. http://www.theses.fr/1989REN10055.

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Developpement d'une methode et construction d'un logiciel permettant l'evaluation quantitative des mesures de la surete de fonctionnement des systemes informatiques. La methode proposee realise un calcul precis et rapide des elements transitoires. Des bornes relatives aux differentes erreurs sont mises en evidence. Plus precisement, elles concernent le probleme de precision relatif a la troncature et celui des erreurs d'arrondi. Des valeurs critiques, a partir desquelles les resultats avec un chiffre decimal significatif ne sont plus garantis, sont definies. Cette definition a permis le calcul de l'ensemble de la reponse transitoire par une seule execution du logiciel elabore

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Niesert, Manfred [Verfasser]. "Ab initio calculations of spin-wave excitation spectra from time-dependent density-functional theory / Manfred Niesert." Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2012. http://d-nb.info/102156754X/34.

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Hoshmeh, Abdullah, Uwe Schmidt, and Akif Gürlek. "Investigations on the Developed Full Frequency-Dependent Cable Model for Calculations of Fast Transients." MDPI AG, 2018. https://monarch.qucosa.de/id/qucosa%3A31827.

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The knowledge about the behavior of cables is substantial in cases of transients or in cases of faults. However, there are only a few models that are tailored to the current requirements for calculations of transient phenomena in three-phase cable systems. These models are based on complex structures. PI-section cable models with simple structures were previously qualified only for calculations in the frequency domain. A new full frequency-dependent cable model to simulate transient phenomena is introduced and validated. The model is based on lumped parameters with cascaded frequency-dependent PI-sections. For the implementation and the integration in simulation tools, it is important to investigate the impact of the PI-section parameters to the accuracy, the stability and the mathematical robustness. In this work, the impact of the frequency dependence of cable parameters, the length distribution and the number of PI-sections on the results of the developed three-phase cable model have been discussed. For simulations in the time domain, two algorithms have been presented to optimize the number of PI-sections based on a specified accuracy.

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Mahmoud, S. A. "Motion detection and velocity computation of moving objects in time-varying image sequences : Application of the exponential area transform in computation of presence and velocity of objects of different sizes and occurences." Thesis, University of Bradford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379903.

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Ghani, Zadegan Farrokh. "Analysis and Optimization for Testing Using IEEE P1687." Thesis, Linköpings universitet, ESLAB - Laboratoriet för inbyggda system, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-60534.

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The IEEE P1687 (IJTAG) standard proposal aims at providing a standardized interface between on-chip embedded test, debug and monitoring logic (instruments), such as scan-chains and temperature sensors, and the Test Access Port of IEEE Standard 1149.1 mainly used for board test. A key feature in P1687 is to include Segment Insertion Bits (SIBs) in the scan path. SIBs make it possible to construct a multitude of different P1687 networks for the same set of instruments, and provide flexibility in test scheduling. The work presented in this thesis consists of two parts. In the first part, analysis regarding test application time is given for P1687 networks while making use of two test schedule types, namely concurrent and sequential test scheduling. Furthermore, formulas and novel algorithms are presented to compute the test time for a given P1687 network and a given schedule type. The algorithms are implemented and employed in extensive experiments on realistic industrial designs. In the second part, design of IEEE P1687 networks is studied. Designing the P1687 network that results in the least test application time for a given set of instruments, is a time-consuming task in the absence of automatic design tools. In this thesis work, novel algorithms are presented for automated design of P1687 networks which are optimized with respect to test application time and the required number of SIBs. The algorithms are implemented and demonstrated in experiments on industrial SOCs.

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Cardoso, Rui Manuel Rodrigues. "Numerical algorithms for the calculation of finite time ruin probabilities in generalisations of the classical risk model." Thesis, Heriot-Watt University, 2004. http://hdl.handle.net/10399/343.

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Singels, Francois. "Real-time stereo reconstruction using hierarchical dynamic programming and LULU filtering." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4294.

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Thesis (MSc (Mathematics))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: In this thesis we consider the essential topics relating to stereo-vision and the correspondence problem in general. The aim is to reconstruct a dense 3D scene from images captured by two spatially related cameras. Our main focus, however, is on speed and real-time implementation on a standard desktop PC. We wish to use the CPU to solve the correspondence problem and to reserve the GPU for model rendering. We discuss three fundamental types of algorithms and evaluate their suitability to this end. We eventually choose to implement a hierarchical version of the dynamic programming algorithm, because of the good balance between accuracy and speed. As we build our system from the ground up we gradually introduce necessary concepts and established geometric principles, common to most stereovision systems, and discuss them as they become relevant. It becomes clear that the greatest weakness of the hierarchical dynamic programming algorithm is scanline inconsistency. We nd that the one-dimensional LULU- lter is computationally inexpensive and e ective at removing outliers when applied across the scanlines. We take advantage of the hierarchical structure of our algorithm and sub-pixel re nement to produce results at video rates (roughly 20 frames per second). A 3D model is also constructed at video rates in an on-line system with only a small delay between obtaining the input images and rendering the model. Not only is the quality of our results highly competitive with those of other state of the art algorithms, but the achievable speed is also considerably faster.
AFRIKAANSE OPSOMMING: In hierdie tesis beskou ons die noodsaaklike onderwerpe wat in die algemeen verband hou met stereovisie en die ooreenstemmingsprobleem. Die mikpunt is om 'n digte 3D toneel te rekonstrueer vanaf beelde wat deur twee ruimtelik-verwante kameras vasgelê is. Ons hoofdoel is egter spoed, en intydse implementering op 'n standaard rekenaar. Ons wil die SVE (CPU) gebruik om die ooreenstemmingsprobleem op te los, en reserveer die GVE (GPU) vir model-beraping. Ons bespreek drie fundamentele tipes algoritmes en evalueer hul geskiktheid vir hierdie doel. Ons kies uiteindelik om 'n hiërargiese weergawe van die dinamiese programmeringsalgoritme te implementeer, as gevolg van die goeie balans tussen akkuraatheid en spoed. Soos wat ons ons stelsel van die grond af opbou, stel ons geleidelik nodige konsepte voor en vestig meetkundige beginsels, algemeen tot meeste stereovisie stelsels, en bespreek dit soos dit toepaslik word. Dit word duidelik dat skandeerlyn-strydigheid die grootste swakheid van die hiërargiese dinamiese programmeringsalgoritme is. Ons vind dat die een-dimensionele LULU- lter goedkoop is in terme van berekeninge, en e ektief aangewend kan word om uitskieters te verwyder as dit dwarsoor skandeerlyne toegepas word. Ons buit die hiërargiese struktuur van ons algoritme uit en kombineer dit met sub-piksel verfyning om resultate te produseer teen video tempo (ongeveer 20 raampies per sekonde). 'n 3D model word ook gekonstrueer teen video tempo in 'n stelsel wat aanlyn loop, met slegs 'n klein vertraging tussen die verkryging van die intree-beelde en die beraping van die model. Die kwaliteit van ons resultate is nie net hoogs mededingend met dié van die heel beste algoritmes nie, maar die verkrygbare spoed is ook beduidend vinniger.

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Oliveira, Anabela Pacheco de. "Eulerian-Lagrangian analysis of transport and residence times in estuaries and coasts /." Full text open access at:, 1997. http://content.ohsu.edu/u?/etd,209.

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Rahmani, Maryam. "On the calculation of time-domain impulse-response of systems from band-limited scattering-parameters using wavelet transform." Thesis, Mississippi State University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10270053.

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In the aspect of electric-ship grounding, the time-domain behavior of the ship hull is needed. The grounding scheme impacts the nature of voltage transients during switching events and faults, identifiability and locatability of ground faults, fault current levels, and power quality. Due to the large size of ships compared with the wavelengths of the desired signals, time-domain measurement or simulation is a time-consuming process. Therefore, it is preferred that the behavior be studied in the frequency-domain. In the frequency-domain one can break down the whole ship hull into small blocks and find the frequency behavior of each block (scattering parameters) in a short time and then con- nect these blocks and find the whole ship hull scattering parameters. Then these scattering parameters should be transferred to the time-domain. The problem with this process is that the measured frequency-domain data (or the simulated data) is band-limited so, while calculating time-domain solutions, due to missing DC and low frequency content the time-domain response encounters causality, passivity and time-delay problems. Despite availability of several software and simulation packets that convert frequency-domain information to time-domain, all are known to suffer from the above mentioned problems. This dissertation provides a solution for computing the Time-Domain Impulse-Response for a system by using its measured or simulated scattering parameters. In this regard, a novel wavelet computational approach is introduced.

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Ouafi, Rachid. "Analyse et contrôle des réseaux de trafic urbain par la méthode de Frank-Wolfe." Paris 6, 1988. http://www.theses.fr/1988PA066453.

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La méthode de Frank Wolfe offre une approche efficace pour la résolution des programmes convexes avec contraintes linéaires. Dans le contexte des réseaux de transport l'algorithme se réduit à une série de problèmes de plus court chemin et de recherches unidimensionnelles. Nous présentons une approche unifiée de la résolution d'une large variété de problèmes lies au système de planification du trafic urbain par la méthode de Frank Wolfe. Enfin, nous proposons une modification de l'algorithme de Frank Wolfe pour la résolution du problème de l'affectation du trafic urbain.

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Devitt, Andrew Maurice. "Time and angle resolved phonon absorption in the fractional quantum hall regime." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342525.

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Bond, Daniel Alan. "Analysis of Real-Time Monitoring Of Trace Contaminants in a Pilot-Scale Treatment System and Calculation of UV Dose Using Hydrogen Peroxide Actinometry." Thesis, The University of Arizona, 2012. http://hdl.handle.net/10150/268513.

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The use of two online sensors, the S::CAN and the FLD, was used to evaluate the treatment of synthetic wastewater by UV/H₂O₂ advanced oxidation. The UV dose and intensity for the flow through reactor was also determined using H₂O₂ actinometry. The total power of the lamps in the reactor was determined to be 139 W which, with the absorbance of the water, produced a UV dose of 39.4 mJ/cm². It was determined that the S::CAN was unable to differentiate between treatment of a particular water, however it could differentiate between different test waters. The FLD was very sensitive and was able to detect minute variations in treatment of the test water.

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Tellioglu, Zafer Hasim. "Real Time 3d Surface Feature Extraction On Fpga." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612200/index.pdf.

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Three dimensional (3D) surface feature extractions based on mean (H) and Gaussian (K) curvature analysis of range maps, also known as depth maps, is an important tool for machine vision applications such as object detection, registration and recognition. Mean and Gaussian curvature calculation algorithms have already been implemented and examined as software. In this thesis, hardware based digital curvature processors are designed. Two types of real time surface feature extraction and classification hardware are developed which perform mean and Gaussian curvature analysis at different scale levels. The techniques use different gradient approximations. A fast square root algorithm using both LUT (look up table) and linear fitting technique is developed to calculate H and K values of the surface described by the 3D Range Map formed by fixed point numbers. The proposed methods are simulated in MatLab software and implemented on different FPGAs using VHDL hardware language. Calculation times, outputs and power analysis of these techniques are compared to CPU based 64 bit float data type calculations.

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Lau, Wai-ping, and 劉偉平. "Minimising the calculation time of the cluster program by choosing theminimum convergent cluster size and the best relaxation factor." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B29760392.

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40

Rüger, Robert, Lenthe Erik van, Thomas Heine, and Lucas Visscher. "Tight-binding approximations to time-dependent density functional theory: A fast approach for the calculation of electronically excited states." AIP Publishing, 2016. https://ul.qucosa.de/id/qucosa%3A21501.

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We propose a new method of calculating electronically excited states that combines a density functional theory based ground state calculation with a linear response treatment that employs approximations used in the time-dependent density functional based tight binding (TD-DFTB) approach. The new method termed time-dependent density functional theory TD-DFT+TB does not rely on the DFTB parametrization and is therefore applicable to systems involving all combinations of elements. We show that the new method yields UV/Vis absorption spectra that are in excellent agreement with computationally much more expensive TD-DFT calculations. Errors in vertical excitation energies are reduced by a factor of two compared to TD-DFTB.

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Kelley, Daniel. "Derivation of three methods of calculation of heat conduction, applications of these methods, and calculation of time from emplacement to solidification of dikes of varying widths, Egersund dike swarm, SW Norway /." Columbus, Ohio : Ohio State University, 2003. http://hdl.handle.net/1811/6187.

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42

Asani, Golnaz. "Test Scheduling with Power and Resource Constraints for IEEE P1687." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-81472.

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IEEE P1687 (IJTAG) is proposed to add more exibility|compared with IEEE 1149.1 JTAG|for accessing on-chip embedded test features called instruments. This exibility makes it possible to include and exclude instruments from the scan path. To reach a minimal test time, all instruments should be accessed concurrently. However, constraints such as power and resource constraints might limit concurrency. There is a need to consider power and resource constraints while developing the test schedule. This thesis consists of two parts. In the rst part, three test time calculation approaches, namely session-based test schedule with a xed scan path, session-based test schedule with a recongurable scan path, and session-less test schedule with a recongurable scan path are proposed. In the second part, three test scheduling approaches, namely session-based test scheduling, optimized session-based test scheduling, and optimized session-less test scheduling are studied and three algorithms are presented for each of the test scheduling approaches. Experiments are carried out using the test scheduling approaches and the results show that optimized sessionless test scheduling can signicantly reduce the test time compared with session-based test scheduling.

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Fukuda, Masahiro. "Theoretical Studies of Quantum Electrodynamics for Local Picture of Electron Spin and Time-evolution Simulation Method of Operators." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215962.

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Lau, Wai-ping. "Minimising the calculation time of the cluster program by choosing the minimum convergent cluster size and the best relaxation factor /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21415213.

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Hoshmeh, Abdullah, and Uwe Schmidt. "A Full Frequency-Dependent Cable Model for the Calculation of Fast Transients." Universitätsbibliothek Chemnitz, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-228649.

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The calculation of frequency-dependent cable parameters is essential for simulations of transient phenomena in electrical power systems. The simulation of transients is more complicated than the calculation of currents and voltages in the nominal frequency range. The model has to represent the frequency dependency and the wave propagation behavior of cable lines. The introduced model combines an improved subconductor method for the determination of the frequency-dependent parameters and a PI section wave propagation model. The subconductor method considers the skin and proximity effect in all conductors for frequency ranges up to few megahertz. The subconductor method method yields accurate results. The wave propagation part of the cable model is based on a cascaded PI section model. A modal transformation technique has been used for the calculation in the time domain. The frequency-dependent elements of the related modal transformation matrices have been fitted with rational functions. The frequency dependence of cable parameters has been reproduced using a vector fitting algorithm and has been implemented into an resistor-inductor-capacitor network (RLC network) for each PI section. The proposed full model has been validated with measured data.

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Pénet, Pierre. "Calculating and governing risk in times of crisis : the role of credit ratings in regulatory reasoning and legal change (1930s - 2010s)." Thesis, Paris, Institut d'études politiques, 2014. http://www.theses.fr/2014IEPP0053.

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Située à l’articulation de la sociologie de l’économie, de l’histoire de la finance et de la sociologie de la connaissance, cette thèse présente donc une analyse du rôle de la notation du crédit dans la régulation financière, et plus largement, du rôle de l’incertitude et de l’incomplétude juridiques sur les anticipations économiques des acteurs financiers. Le cadre d’analyse de la recherche se résume en quatre points : Premièrement, la thèse rompt avec une lecture strictement intellectualiste de l’action publique et présente une approche de la régulation financière par ses instruments, empruntant ainsi l’approche pragmatiste développée par les social studies of finance et par la nouvelle sociologie économique d’inspiration américaine. Deuxièmement, l’hypothèse centrale de la recherche est que les instruments réglementaires sont à la fois des techniques de connaissance et des outils juridiques. Aussi, ce sont les frictions qu’occasionnent les deux activités parfois contradictoires de calculer et de gouverner qui donnent au changement réglementaire sa dynamique historique. Troisièmement, prenant l’exemple de l’usage de la notation dans la supervision financière comme dispositif de calcul et technique de gouvernement, la thèse propose une histoire de longue durée (1865-2010) de l’activité réglementaire sur les marchés financiers aux Etats-Unis et en Europe au travers de cinq régimes de régulation (régime statutaire, d’appel, disciplinaire, fictionnel et contractuel). Quatrièmement, l’originalité de la recherche est de combiner une approche macroscopique du changement réglementaire avec une approche méticuleuse de plusieurs courtes séquences historiques durant lesquelles d’importantes innovations réglementaires ont vu le jour, notamment le New Deal aux Etats-Unis et la crise de la dette souveraine en Europe. Ainsi, en plus de définir les contours de cinq régimes réglementaires, la thèse analyse la façon dont les régulateurs se sont saisis de la notation financière comme « mécanisme d’embrayage » afin d’opérationnaliser la transition d’un régime à un autre
Located at the intersection of economic sociology, financial history, and the sociology of knowledge, this dissertation examines the role of credit ratings in financial regulation, and more broadly, the role of financial uncertainties and legal incompleteness on financial actors’ anticipatory decisions. The framework set forth in this study can be summarized as follows. First, this study breaks with an intellectualist approach of public action to analyze financial regulation from the perspective of its instruments. As such, this research draws on a pragmatist agenda developed in social studies of finance and recent work in economic sociology. Second, the main hypothesis of this dissertation is to approach regulatory instruments as technologies of knowing and tools of government. From this double viewpoint, I hypothesize that the frictions generated by the two competing activities of calculating and governing impart the regulatory activity with both its structural features and historical dynamics. Third, using the example of regulatory reliance on ratings, I propose a longue durée historical analysis (1865-2010) of the regulatory activity in the U.S. and Europe through the examination of five regulatory regimes (statutory, appeal, disciplinary, fictional, and contractual). Four, one original feature of this dissertation is to combine a macroscopic analysis of regulatory change with a meticulous approach of several short historical sequences during which important regulatory innovations came into being, notably the New Deal in the U.S. and the European sovereign debt crisis. Thus, in addition to setting the contours of five regulatory frameworks, this dissertation analyses the ways in which regulators used ratings as “clutching” devices to operationalize the legal transition from one regime to another

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Löfgren, Kim, and Virving Lisa Hannula. "Avstämningsmetod för installatörer kopplat till slutkostnadsprognos." Thesis, KTH, Byggteknik och design, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-256227.

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This master thesis has mainly been built on interviews with interested parties at Arcona and the installer, Nymans Elektriska, since it was decided to limit the study only to the project Glömstaskolan. The aim of the study is that Arcona should be able to report a more accurate final cost forecast to the client regarding the installer and to simplify the reconciliation for both the construction company and the installer. The background is based on the fact that installers do not calculate components and activities such as other building production, which makes it difficult to reconcile if an activity has been carried out in accordance with budget. Both parties agree that it is working hours that need to be checked, as this is where the difficulty of control lies. To be able to check real hours, knowledge of the planned number of hours is needed. The time schedule is an important tool in the project and should be included in reconciliation. Arcona and Nymans Elektriska are recommended to use existing control documents with certain appendixes for the measuring progress.
Detta examensarbete har mestadels byggts av intervjuer med berörda parter hos Arcona samt installatören Nymans Elektriska då avgränsning gjorts till att endast omfatta projekt Glömstaskolan. Syftet med studien är att Arcona ska kunna redovisa en träffsäkrare slutkostnadsprognos gentemot kunden/beställaren gällande installatören samt att underlätta för både byggföretaget och installatören kring avstämningen. Bakgrunden ligger i att installatörerna ej kalkylerar på byggdelar och aktiviteter som övrig byggproduktion, vilket då gör det svårt att stämma av om en aktivitet har genomförts i enlighet med budget. Båda parter är överens om att det är arbetstimmar som önskas följas upp, då det är där svårigheten till kontroll ligger. För att kunna följa upp verkliga timmar behövs kunskap om planerade antal timmar. Tidplanen är ett viktigt verktyg i projekt och bör involveras i avstämningen. Arcona och Nymans Elektriska rekommenderas att nyttja befintliga styrdokument med visst tillägg för mätning av framdrift.

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Venkatapathi, Sarankumar. "Temperature effects on the electronic properties of lead telluride (PbTe) and the influence of nano-size precipitates on the performance of thermoelectric materials. (SrTe precipitates in PbTe bulk material)." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/51947.

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This study seeks to evaluate the temperature effects on the electronic properties of thermoelectric materials, using first principles Density Functional Theory (DFT) calculations by incorporating the temperature effects on structural properties of the material. Using the electronic properties attained, the charge carrier scattering relaxation times were determined. The effect of interface between PbTe and SrTe on the charge carrier mobility was studied by finding out the relative alignment of energy bands at the semiconductor heterojunction. The crystal shape of the SrTe precipitates in the PbTe host matrix was evaluated from the interface energies using the Wulffman construction. We also attempted to develop a relation between the interface energies and electronic band alignment for different interface orientations. In this research, we incorporated the temperature effects on the structural properties of PbTe to get the temperature dependence of electronic properties like energy bandgap and effective masses of charge carriers. We used the values of bandgap and effective masses to determine the charge carrier scattering relaxation time at different temperatures which is used in evaluating the transport properties of thermoelectric materials like the Seebeck coefficient and electrical conductivity.
Master of Science

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López, Claudio David. "Shortening time-series power flow simulations for cost-benefit analysis of LV network operation with PV feed-in." Thesis, Uppsala universitet, Elektricitetslära, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-242099.

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Time-series power flow simulations are consecutive power flow calculations on each time step of a set of load and generation profiles that represent the time horizon under which a network needs to be analyzed. These simulations are one of the fundamental tools to carry out cost-benefit analyses of grid planing and operation strategies in the presence of distributed energy resources, unfortunately, their execution time is quite substantial. In the specific case of cost-benefit analyses the execution time of time-series power flow simulations can easily become excessive, as typical time horizons are in the order of a year and different scenarios need to be compared, which results in time-series simulations that require a rather large number of individual power flow calculations. It is often the case that only a set of aggregated simulation outputs is required for assessing grid operation costs, examples of which are total network losses, power exchange through MV/LV substation transformers, and total power provision from PV generators. Exploring alternatives to running time-series power flow simulations with complete input data that can produce approximations of the required results with a level of accuracy that is suitable for cost-benefit analyses but that require less time to compute can thus be beneficial. This thesis explores and compares different methods for shortening time-series power flow simulations based on reducing the amount of input data and thus the required number of individual power flow calculations, and focuses its attention on two of them: one consists in reducing the time resolution of the input profiles through downsampling while the other consists in finding similar time steps in the input profiles through vector quantization and simulating them only once. The results show that considerable execution time reductions and sufficiently accurate results can be obtained with both methods, but vector quantization requires much less data to produce the same level of accuracy as downsampling. Vector quantization delivers a far superior trade-off between data reduction, time savings, and accuracy when the simulations consider voltage control or when more than one simulation with the same input data is required, as in such cases the data reduction process can be carried out only once. One disadvantage of this method is that it does not reproduce peak values in the result profiles with accuracy, which is due to the way downsampling disregards certain time steps in the input profiles and to the averaging effect vector quantization has on the them. This disadvantage makes the simulations shortened through these methods less precise, for example, for detecting voltage violations.

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50

Reimfelt, Tobias. "Fönsterutredning för radhusområdet Skeppsvägen." Thesis, KTH, Byggteknik och design, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-49192.

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Mitt examensarbete innefattar en fönsterutredning för radhusområdet Skeppsvägen i Bålsta. Fastighetsägare är Håbohus AB och examensarbetet har skrivits för Skanska Sverige AB. Arbetet har skrivits på plats i Bålsta där Skanska Direkt AB har eget kontor och erhåller idag totalentreprenaden för renovering av Skeppsvägen. Arbetets syfte är att klart och tydligt redovisa eventuell effekt och energibesparing vid byte av befintliga fönster och altandörrar. Undersökning av fönster och altandörrar har gjorts okulärt, med värmekamera och med fuktkvotsmätare. Vid den okulära besiktningen noterades färgsläpp på fönster. Fotografierna med värmekamera visar att fönstren och altandörrarna tätar väldigt dåligt mellan båge och karm och risk för drag finns. Fuktkvotsmätaren gav ett högsta utslag på 14 % i bågen trä vilket är anmärkningsvärt. Effekt och energiberäkningar har gjorts för att jämföra de befintliga värdena med de nya efter ett eventuellt byte. Beräkningarna visar att Håbohus kan minska sin energiförbrukning med 15400- 16707 kWh/år beroende på vilka fönster och altandörrar de vill montera. De skulle även sänka effektbehovet med 16,5- 18,4%.
My graduate work is an evaluation of exchanging the existing windows for terrace houses on Skeppsvägen in Bålsta. Property owner is Håbohus AB and the assigner is written for Skanska Sweden AB. I’ve been working in Bålsta were Skanska Direct AB has their own office, Skanska also have the turnkey contract on the renovation job on Skeppsvägen. The intention of the work is to clearly report any power and energy savings when replacing existing windows and patio doors. Investigation of windows and patio doors has been made visually, with an infrared camera and a moisture meter. When the visual examination was made I recorded color release. The photograph of infrared camera shows that the windows and patio doors seals badly between sash and frame. Moisture content meter gave a maximum response of 14 % which is remarkable. Power and energy calculations have been done to compare the existing values with the new values after a possible replacement. The calculations shows that Håbohus can reduce their energy consumption by 15400-16707 kWh/year depending on which windows and patio doors they want to mount. They would also reduce the power requirement about 16,5 to 18,4 %.

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