Dissertations / Theses: 'Modelli statistici'

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Mugianesi, Francesca. "Modelli statistici per l'organizzazione della struttura tridimensionale del DNA umano." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/12342/.

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Il grande sviluppo della tecnica di genome-wide conformation capture (Hi-C) permette di indagare la complessa ed interessante relazione che intercorre tra la struttura 3D dinamica organizzata gerarchicamente della cromatina e la funzionalità del genoma. In altre parole, questa tecnica consente di avere informazioni tridimensionali sulla struttura dei nuclei delle cellule. Il lavoro di tesi si è incentrato sullo studio multirisoluzione dei domini topologici (TAD) della cromatina di sette tipi cellulari umani. L'algoritmo impiegato è basato sulla segmentazione spettrale iterativa del laplaciano normalizzato associato alla mappa intra-cromosomiale Hi-C. L'analisi dei dati ha rivelato che i TAD boundary tendono ad una distribuzione spaziale regolare, conservata tra tipi cellulari. É possibile che il maggior grado di similarità riscontrato tra alcune linee cellulari abbia basi biologicamente rilevanti. Le dimensioni dei TAD individuati vanno da ∼ 450 kb, con i dati alla risoluzione di 50 kb, fino a ∼ 4.7 Mb, alla risoluzione di 1 Mb, e risultano indipendenti dalla lunghezza specifica del cromosoma.

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Faedi, Roberto. "Studio di modelli statistici di scattering da pareti di edifici." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/4689/.

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Disegna, Marta <1979&gt. "Dal Macro al Micro Marketing: modelli statistici per valutare l'efficacia pubblicitaria sul punto vendita." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/211/.

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Cicero, Simone. "Modelli statistici per il calcolo dello stock di carbonio nei suoli: applicazione al database della Regione Emilia Romagna." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.

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Lo scopo principale della tesi è stato quello di verificare se l’Agricoltura Conservativa è in grado di aumentare nel tempo le quantità di Carbonio Organico del Suolo (SOC) in modo più efficiente rispetto alle comuni pratiche di Agricoltura Convenzionale. Utilizzando i dati del progetto Europeo LifeHelpSoil, sono state effettuate delle simulazioni predittive delle dinamiche del carbonio in diversi tipi di suoli presenti nelle 4 aziende di progetto tramite RothC un modello molto utilizzato in ambito scientifico a livello internazionale. La prima parte del lavoro ha riguardato il reperimento di tutti i dati di input per il modello ovvero: A) dati climatici storici e proiezioni future di valori medi mensili relativi ai siti aziendali provenienti da ARPAE e JRC; B) dati relativi al tipo di suolo (% Argilla e Stock di Carbonio Organico); C) dati riguardanti gli ordinamenti colturali e le pratiche agricole nelle tre annualità del progetto Life (2014-2016): tipo di coltura; irrigazione; lavorazioni del terreno; cover-crops; concimazioni; inoltre a partire dai quantitativi in peso del prodotto raccolto sono stati calcolati prima i diversi residui colturali e poi i relativi apporti in termini di carbonio organico al suolo. La seconda parte si è sviluppata con le simulazioni utilizzando diversi archi temporali. Il modello richiede una prima fase di parametrizzazione utilizzando dati climatici del passato e dati di input di materiale organico tali da portare la simulazione all’equilibrio ossia ottenere valori di SOC simulati pari al valore di carbonio misurato in campo; segue poi la fase di simulazione futura utilizzando gli schemi di gestione agronomica del suolo adottati nel progetto Life e i dati climatici di climate change. I risultati ottenuti hanno confermato l’ipotesi che l’Agricoltura Conservativa aumenti il contenuto di Carbonio organico nel terreno (quindi di Sostanza Organica) il quale è un parametro importante in quanto principale indicatore di qualità del suolo.

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Mariotti, Gianluca. "Valutazione delle caratteristiche dei modelli di previsione degli impatti odorigeni di tipo gaussiano e lagrangiano." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16995/.

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Le emissioni in atmosfera di inquinanti, come le polveri o gli odori, rappresentano una pressione antropica diffusa e la loro gestione implica la conoscenza del fenomeno e della dispersione all’interno del Planetary Boundary Layer. Questa tesi è incentrata sull’uso di due modelli previsionali: il Dimula, modello gaussiano a plume, e il Lapmod, modello lagrangiano a particelle. Sono state valutate le singole funzionalità, che consentono di stimare la dispersione, e si è analizzata l’affidabilità e la comparabilità dei risultati, in termini di concentrazione, in un reticolo di lati 10.000 m (asse X) ∙ 10.000 m (asse Y). Le simulazioni, relative a sorgenti puntiformi ed areali, a polveri ed odori, sono state condotte a livello orario (short term), usando come input un unico set di dati meteorologici (vento da Ovest e con velocità 1,5 m⁄s, T=293 K), per condizioni atmosferiche instabili, neutre e stabili, e a livello annuale (long term), impiegando come set di dati meteorologici 8760 record relativi al 2016 per la provincia di Ravenna. Nel post-processamento dei risultati, per singole sorgenti e sorgenti totali, sono stati prodotti quattro tipi di grafici: mappe con le curve di iso-concentrazione (per modello), istogrammi con il confronto delle concentrazioni calcolate nei nodi comuni lungo l’asse Y centrale, grafici normalizzati, per una percezione punto per punto dell’andamento dei modelli, e la validazione dei risultati stessi. A livello orario si è apprezzato il comportamento, nella restituzione delle concentrazioni, sopra e sottovento dei due modelli, per classe di stabilità, valutando come l’ubicazione di un recettore sensibile possa guidare la scelta dello strumento previsionale. A livello annuale, invece, si è valutato il diverso grado di modellizzazione del PBL ed in particolare del plume rise, dovuto all’utilizzo di due differenti algoritmi, nonché il diverso approccio nel calcolo dei percentili per le medie di un’ora.

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Mingolini, Riccardo. "Investimenti in lobby: Un modello per stimare il loro impatto sull'azienda." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/13291/.

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In questo elaborato di tesi verrà analizzata l’attitudine di una azienda ad investire in lobbying, misurato attraverso varie variabili importanti per la stessa quali ad esempio il capitale, il reddito netto dell’impresa, il numero degli impiegati (et simila) e il loro impatto scoraggiante o incentivante rispetto alla nostra variabile dipendente. Cercheremo infine di trovare un modello che approssima in modo sostanziale suddette dipendenze e variabili, in modo da tracciare un filo logico e matematico fra la nostra variabile dipendente Y ( investimento in lobbying) e le nostre variabili indipendenti X cioè gli indici e le variabili in valore monetario importanti per definire una azienda e il suo settore di appartenenza (SIC CODE).

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Gustavsson, André. "Prognossäkerhet : Tillför en heteroskedastisk modell någon säkerhet hos Box och Jenkins prognosmodeller?" Thesis, Umeå University, Department of Statistics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-34825.

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Follestad, Turid. "Stochastic Modelling and Simulation Based Inference of Fish Population Dynamics and Spatial Variation in Disease Risk." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Information Technology, Mathematics and Electrical Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-41.

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We present a non-Gaussian and non-linear state-space model for the population dynamics of cod along the Norwegian Skagerak coast, embedded in the framework of a Bayesian hierarchical model. The model takes into account both process error, representing natural variability in the dynamics of a population, and observational error, reflecting the sampling process relating the observed data to true abundances. The data set on which our study is based, consists of samples of two juvenile age-groups of cod taken by beach seine hauls at a set of sample stations within several fjords along the coast. The age-structure population dynamics model, constituting the prior of the Bayesian model, is specified in terms of the recruitment process and the processes of survival for these two juvenile age-groups and the mature population, for which we have no data. The population dynamics is specified on abundances at the fjord level, and an explicit down-scaling from the fjord level to the level of the monitored stations is included in the likelihood, modelling the sampling process relating the observed counts to the underlying fjord abundances.

We take a sampling based approach to parameter estimation using Markov chain Monte Carlo methods. The properties of the model in terms of mixing and convergence of the MCMC algorithm and explored empirically on the basis of a simulated data set, and we show how the mixing properties can be improved by re-parameterisation. Estimation of the model parameters, and not the abundances, is the primary aim of the study, and we also propose an alternative approach to the estimation of the model parameters based on the marginal posterior distribution integrating over the abundances.

Based on the estimated model we illustrate how we can simulate the release of juvenile cod, imitating an experiment conducted in the early 20th century to resolve a controversy between a fisherman and a scientist who could not agree on the effect of releasing cod larvae on the mature abundance of cod. This controversy initiated the monitoring programme generating the data used in our study.

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Gustavsson, André. "Elpriserna på den nordiska elbörsen : Prognosmodellering med hjälp av ARIMA-modeller." Thesis, Umeå University, Department of Statistics, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-34820.

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Hägg, David, and Henrik Olsson. "Komorbida sjukdomar hos individer med svår psoriasis : En analys med logistiska och loglinjära modeller." Thesis, Umeå University, Department of Statistics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-34829.

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Motzi, Edward. "En enkel modell i utslagningsturneringar." Thesis, Uppsala universitet, Analys och sannolikhetsteori, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-388122.

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Månsson, Vogel Andreas, and Armin Spreco. "En modell för väderjustering av cykelflöden." Thesis, Linköping University, Statistics, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-19034.

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Vectura är ett företag vars verksamhet är koncentrerad till transportinfrastruktur och deras mål är att hitta bättre lösningar för infrastrukturen. En stor del av trafikanterna i Sverige använder cykeln som transportmedel men cyklingen är i hög grad beroende av vädret som varierar hela tiden. Det varierande vädret gör det svårt att se hur cyklingen förändras över tiden och för att kunna se denna förändring behövs en modell som rensar cykelflödet från vädrets påverkan.

Syftet med denna rapport är just att utveckla en sådan modell. Denna modell ska tas fram med hjälp av dels cykelflödesdata och dels väderdata från ett antal gator i städer runt om i Sverige och ska vara tillämpbar överallt i landet.

Metoden som används för att ta fram modellen är multiplikativ tidsserieregression. Då syftet är att ta fram en rikstäckande modell måste en gemensam variabeluppsättning väljas som vi ska använda oss av när vi anpassar regressionskoefficienterna för varje gata. Detta variabelval gör vi med hjälp av

P-värden från individuella t-test och Akaikes informationskriterium. När lämpliga variabler har valts ut anpassas en separat regressionsmodell med dessa variabler för varje gata och därefter vägs betaskattningarna samman så att vi får en allmän modell. För att validera modellen utför vi en korsvalidering som går ut på att utelämna en av städerna när vi väger samman betaskattningarna och sedan testa den nya modellen på någon gata i den utelämnade staden.

Resultaten visar att modellen som vi utvecklat kan användas som en allmän modell för Sverige. Dels reducerar modellen standardavvikelsen för cykelflödet tillfredsställande och dels fungerar korsvalideringen bra. Modellen är utvecklad så att man ska kunna justera bort antingen endast vädereffekter från cykelflödet eller, utöver vädereffekter, justera bort även kalendereffekter och periodiska effekter från cykelflödet.

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Bengtsson, Pernilla. "Framtagande av modell för skattning av antalet vakanser med poissonregression i konjunkturstatistiken över vakanser." Thesis, Örebro universitet, Institutionen för ekonomi, statistik och informatik, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-1331.

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SCB gör en vakansundersökning varje månad, granskningssystemet för undersökningen ska eventuellt ändras till en metod som kallas för significance editing. Med den granskningsmetoden behövs ett jämförelsevärde för att kunna avgöra om enkäten är korrekt besvarad eller om ett värde är misstänkt och behöver granskas ytterligare. Uppsatsens syfte är att genom poissonregression ta fram en bra modell som kan generera detta jämförelsevärde. Ett antal hjälpvariabler togs fram och testades för att se om de passade i poissonregressionen och om de kunde förklara antalet vakanser. De hjälpvariabler som har använts är antal vakanser föregående månad, antal anställda på arbetsstället, dummyvariabel för Sveriges län och månaderna. Metoden testades på två olika branscher, pappersmassaindustrin och metallindustrin. I de resultat som togs fram kan man se att variablerna antal anställda på arbetsstället och antalet vakanser föregående månad alltid blir signifikanta och tillför till att skatta antalet vakanser. Därför kan dessa användas för att skatta ett jämförelsevärde. Län och månader behövs i modellen men det är olika län och månader som blir signifikanta för de två olika branscherna. Generellt kan man dra slutsatsen att antalet vakanser ökar på våren och sommaren. Huruvida metoden går att tillämpa på det ogranskade datamaterialet får vidare undersökningar visa.

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Ferm, Martin. "Prediktering av skogliga variabler med data från flygburen laser : En jämförelse mellan multipla regressionsmodeller och k nearest neighbour-modeller." Thesis, Umeå University, Department of Statistics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-34833.

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Massip, Florian. "The Statistical Fate of Genomic DNA : Modelling Match Statistics in Different Evolutionary Scenarios." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS008/document.

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Le but de cette thèse est d'étudier la distribution des tailles des répétitions au sein d'un même génome, ainsi que la distribution des tailles des appariements obtenus en comparant différents génomes. Ces distributions présentent d'importantes déviations par rapport aux prédictions des modèles probabilistes existants. Étonnamment, les déviations observées sont distribuées selon une loi de puissance. Afin d'étudier ce phénomène, nous avons développé des modèles mathématiques prenant en compte des mécanismes évolutifs plus complexes, et qui expliquent les distributions observées. Nous avons aussi implémenté des modèles d'évolution de séquences in silico générant des séquences ayant les mêmes propriétés que les génomes étudiés. Enfin, nous avons montré que nos modèles permettent de tester la qualité des génomes récemment séquencés, et de mettre en évidence la prévalence de certains mécanismes évolutifs dans les génomes eucaryotes
In this thesis, we study the length distribution of maximal exact matches within and between eukaryotic genomes. These distributions strongly deviate from what one could expect from simple probabilistic models and, surprisingly, present a power-law behavior. To analyze these deviations, we develop mathematical frameworks taking into account complex mechanisms and that reproduce the observed deviations. We also implemented in silico sequence evolution models that reproduce these behaviors. Finally, we show that we can use our framework to assess the quality of sequences of recently sequenced genomes and to highlight the importance of unexpected biological mechanisms in eukaryotic genomes

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Arvidsson, Dan. "Cross-Platform Modelling for Human Activity Recognition System." Thesis, Umeå universitet, Statistik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-149731.

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Human activity recognition (HAR) systems have a large set of potential applications in healthcare, e.g. fall detection and tracking physical activities. HAR systems based on wearable sensors have gained the most attraction, due to smartphones having these sensors embedded in them. This makes them a great candidate for collecting human activity sensor data. By utilizing the smartphone sensors, no other sensors need to be supplied and instead only a mobile application needs to be supplied. However, this comes with a trade-off, sensors embedded in smartphones display specific heterogeneity and biases, depending on platform and price range. Normally in such a scenario, multiple HAR systems have to be built and trained for each device. This is both a time consuming effort and gives no guarantees that the different systems will have similar activity recognition accuracy. Therefore, in this thesis, a HAR system is constructed, where classification methods and filtering techniques are explored and evaluated, in an effort to give some guidelines for how to construct a HAR system, that can be embedded in multiple platforms. This study shows that when considering a few common activities, this HAR system performs well even when sensor data is collected from multiple sources. Ensemble method AdaBoost, in combination with decision trees, gives the overall best performance. Filtering techniques, such as Butterworth and Chebyshev performs better than constant- and linear detrending. This is primarily due to their ability to distinguish between low frequency activities, such as standing and sitting. The best result in this study was given when combining Chebyshev filtering and AdaBoosted decision trees, with a F-score of 0.9877.

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Falk, Soylu Denniz. "Recovery Rate Modelling of Non-performing Consumer Loans." Thesis, Uppsala universitet, Tillämpad matematik och statistik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-322495.

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Mhitarean, Ecaterina. "Marketing Mix Modelling from the multiple regression perspective." Thesis, KTH, Matematisk statistik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-208474.

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The optimal allocation of the marketing budget has become a difficult issue that each company is facing. With the appearance of new marketing techniques, such as online advertising and social media advertising, the complexity of data has increased, making this problem even more challenging. Statistical tools for explanatory and predictive modelling have commonly been used to tackle the problem of budget allocation. Marketing Mix Modelling involves the use of a range of statistical methods which are suitable for modelling the variable of interest (in this thesis it is sales) in terms of advertising strategies and external variables, with the aim to construct an optimal combination of marketing strategies that would maximize the profit. The purpose of this thesis is to investigate a number of regression-based model building strategies, with the focus on advanced regularization methods of linear regression, with the analysis of advantages and disadvantages of each method. Several crucial problems that modern marketing mix modelling is facing are discussed in the thesis. These include the choice of the most appropriate functional form that describes the relationship between the set of explanatory variables and the response, modelling the dynamical structure of marketing environment by choosing the optimal decays for each marketing advertising strategy, evaluating the seasonality effects and collinearity of marketing instruments. To efficiently tackle two common challenges when dealing with marketing data, which are multicollinearity and selection of informative variables, regularization methods are exploited. In particular, the performance accuracy of ridge regression, the lasso, the naive elastic net and elastic net is compared using cross-validation approach for the selection of tuning parameters. Specific practical recommendations for modelling and analyzing Nepa marketing data are provided.
Att fördela marknadsföringsbudgeten optimalt är en svår uppgift som alla företag ställs inför. Med uppkomsten av nya marknadsföringstekniker, som reklam på nätet och sociala media, har komplexiteten av data ökat, vilket gör detta problem ännu mer utmanande. Statistiska verktyg för förklarande och prediktiv modellering har vanligtvis använts för att hantera problemet med budgetallokering. Marknadsföringsmix Modellering är en term som omfattar klassen av statistiska metoder som är lämpliga för modellering av den intressanta variabeln (i denna uppsats är det försäljning) när det gäller reklamstrategier och externa variaber, med målet att maximera vinsten genom att konstruera en optimal kombination av marknadsstrategier. Syftet med denna uppsats är att konstruera ett antal modellbyggnadsstrategier, som även inkluderar avancerade regulariseringsmetoder för linjär regression, med en analys av fördelar och nackdelar för varje metod. Flera stora problem som den moderna marknadsföringsmix modellering står inför har beaktats, som till exempel: att välja en passande funktionsformel som bäst beskriver relationen mellan den oberoende variabeln och de beroende variablerna, att hantera marknadsföringens dynamiska omgivningar genom att välja det optimala förfallet hos varje marknadsföringsstrategi, utvärdera säsongsmässiga effekten och marknadsföringsverktygens kollinjäritet. För att överkomma de två vanligaste problemen inom marknadsföringsekonometri, som är multikollinearitet och val av variabler, har regulariseringsmetoder använts. I synnerhet har prestationsnoggrannheten av ridge regression, lasso, naive elastic net och elastic net jämförts- för att ge specifika rekommendationer för Nepa data. Parametrarna för de regulariserade regressionsmetoderna har valts genom korsvalidering. Modellens resultat visar en hög nivå av förutsägelse noggrannhet. Skillnaden mellan nämnda metoder är inte signifikanta för det givna datasetet.

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Kinene, Alan. "Modelling the Passenger Demand for Buses in Örebro City." Thesis, Örebro universitet, Handelshögskolan vid Örebro Universitet, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-51426.

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Bojarova, Jelena. "Toward Sequential Data Assimilation for NWP Models Using Kalman Filter Tools /." Stockholm : Department of Mathematics, Stockholm University, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-38820.

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Diss. (sammanfattning) Stockholm : Stockholms universitet, 2010.
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 2: Manuscript. Paper 3: Accepted. Paper 4: Manuscript. Härtill 4 uppsatser.

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Beneš, Martin. "HMM modelling for the spread of the SARS–CoV–2." Thesis, Linköpings universitet, Statistik och maskininlärning, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-176735.

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The aim of the project is to develop an HMM for the current spread of the SARS–CoV–2 virus. The HMM could be coupled with a SIR+ based compartmental model for the different types of statistics — confirmed cases, hospitalizations, deaths. The confirmed cases should be treated as a random sample from the whole population of infected and the probability of sampling should try to take into account the different testing strategies. The aim of the project would be to compare the spread of the virus in different countries (e.g. Czech Republic, Poland, Sweden, Italy, but other depending on the availability of data are possible) through regional (whenever possible) dynamics. For the thesis publicly available COVID–19 connected data will be used.

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Mattsson, Johan. "Constructing Residential Price Property Indices Using Robust and Shrinkage Regression Modelling." Thesis, KTH, Matematisk statistik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-252555.

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This thesis intends to construct and compare multiple Residential Price Property Indices (RPPI) with the aim to express the price development of houses in Stockholm county from January 2013 to September 2018. The index method used is the hedonic time dummy variable method. Different methods of imputation of missing data will be applied and new variables will be derived from the available data in order to develop various regression models. Observations judged as not part of the index's target population will be excluded to improve the quality of the training data. The indices will be computed by fitting the final model with OLS regression (as a benchmark), Huber regression, Tukey regression, Ridge regression as well as least-angle regression. Lastly, the obtained indices will be assessed by analyzing different measures of performance when included in \textit{Booli}'s valuation engine. The main result of this thesis is that a specific regression model is produced and that it is concluded that Huber regression slightly outperforms the other methods.
Denna uppsats ämnar att konstruera och jämföra flera prisindex för hus med syftet att beskriva prisutvecklingen i Stockholms län från januari 2013 till september 2018. Indexmetoden som tillämpas är den hedoniska time dummy variabel metoden. Olika tillvägagångssätt för imputering av saknade värden används och nya variabler härleds för att skapa diverse regressionsmodeller. Observationer som ej anses representera indexets målgrupp utesluts för att således förbättra kvalitén på träningsdatan. Indexen beräknas genom att passa den slutgiltiga modellen med OLS regression (som ett riktmärke), Huber regression, Tukey regression, Ridge regression samt least-angle regression. Avslutningsvis utvärderas de erhållna prisindexen genom att analysera dess prestanda när de implementeras i \textit{Boolis} värderingsmotor. Huvudresultatet av denna uppsats är att en specifik regressionsmodell tas fram och att det fastslås att Huber regression aningen överträffar de

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Hammi, Malik, and Ahmet Hakan Akdeve. "Poweranalys : bestämmelse av urvalsstorlek genom linjära mixade modeller och ANOVA." Thesis, Linköpings universitet, Statistik och maskininlärning, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-149026.

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In research where experiments on humans and animals is performed, it is in advance important to determine how many observations that is needed in a study to detect any effects in groups and to save time and costs. This could be examined by power analysis, in order to determine a sample size which is enough to detect any effects in a study, a so called “power”. Power is the probability to reject the null hypothesis when the null hypothesis is false. Mälardalen University and the Caroline Institute have in cooperation, formed a study (The Climate Friendly and Ecological Food on Microbiota) based on individual’s dietary intake. Every single individual have been assigned to a specific diet during 8 weeks, with the purpose to examine whether emissions of carbon dioxide, CO2, differs reliant to the specific diet each individuals follows. There are two groups, one treatment and one control group. Individuals assigned to the treatment group are supposed to follow a climatarian diet while the individuals in the control group follows a conventional diet. Each individual have been followed up during 8 weeks in total, with three different measurements occasions, 4 weeks apart. The different measurements are Baseline assessment, Midline assessment and End assessment. In the CLEAR-study there are a total of 18 individuals, with 9 individuals in each group. The amount of individuals are not enough to reach any statistical significance in a test and therefore the sample size shall be examined through power analysis. In terms of, data, every individual have three different measurements occasions that needs to be modeled through mixed-design ANOVA and linear mixed models. These two methods takes into account, each individual’s different measurements. The models which describes data are applied in the computations of sample sizes and power. All the analysis are done in the programming language R with means and standard deviations from the study and the models as a base. Sample sizes and power have been computed for two different linear mixed models and one ANOVA model. The linear mixed models required less individuals than ANOVA in terms of a desired power of 80 percent. 24 individuals in total were required by the linear mixed model that had the factors group, time, id and the covariate sex. 42 individuals were required by ANOVA that includes the variables id, group and time.
Inom forskning där försök, dels utförs på människor och djur, vill man försäkra sig om en lämplig urvalsstorlek för att spara tid och kostnad samtidigt som en önskad statistisk styrka uppnås. Mälardalens högskola och Karolinska institutet har gjort en pilotstudie (CLEAR) som undersöker människors koldioxidutsläpp i förhållande till kosthållning. Varje individ i studien har fått riktlinjer om att antingen följa en klimatvänlig- eller en konventionell kosthållning i totalt 8 veckor. Individerna följs upp med 4 veckors mellanrum, vilket har resulterat i tre mättillfällen, inklusive en baslinjemätning. I CLEAR-studien finns variabler om individernas kön, ålder, kosthållning samt intag av makro- och mikronäringsämnen. Nio individer i respektive grupp finns, där grupperna är klimat- och kontrollgruppen. Totala antalet individer i pilotstudien är för få för att erhålla statistisk signifikans vid statistiska tester och därför bör urvalsstorleken undersökas genom att göra styrkeberäkningar. Styrkan som beräknas är sannolikheten att förkasta nollhypotesen när den är falsk. För att kunna beräkna urvalsstorlekar måste modeller skapas utifrån strukturen på data, vilket kommer att göras med metoderna mixed-design ANOVA och linjära mixade modeller. Metoderna tar hänsyn till att varje individ har fler än en mätning. Modellerna som beskriver data tillämpas i beräkningarna av styrka. Urvalsstorlekarna och styrkan som beräknats är simuleringsbaserad och har analyserats i programspråket R med modellerna och värden från pilotstudien som grund. Styrka och urvalsstorlekar har beräknats för två linjära mixade modeller och en ANOVA. De linjära mixade modellerna kräver färre individer än ANOVA för en önskad styrka på 80 procent. Av de linjära mixade modellerna som krävde minst individer behövdes totalt 24 individer medan mixed design-ANOVA krävde 42 individer totalt.

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Malina, Karel. "Zpracování statistik generátoru síťového provozu IxChariot v prostředí simulátoru OPNET Modeler." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-219909.

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This thesis "Processing statistics generator IxChariot network traffic in an environmentsimulator OPNET Modeler" is focused on collaboration solution simulation tool OPNET Modeler with IxChariot traffic generator and the principle of their connection. The goal is to display the statistics generated in IxChariot software by OPNET Modeler. In this thesis is described procedure of settings inside simulation environment OPNET modeler which are necessary for correct functionality of simulation.

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Russo, Riccardo. "Modelli di arbitraggio statistico: teoria ed evidenza empirica." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/6697/.

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Maupin, Thomas. "Can Bitcoin, and other cryptocurrencies, be modeled effectively with a Markov-Switching approach?" Thesis, KTH, Matematisk statistik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-252569.

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This research is an attempt at deepening the understanding of hyped cryptocurrencies. A deductive nature is used where we attempt to estimate the linear dependencies of cryptocurrencies with four different time series models. Investigating linear dependencies of univariate time series offers the reader an understanding on how previous prices of cryptocurrencies affect future prices. The linear interdepencies for a multivariate scenario will provide an apprehension on how, and if, the cryptocurrency market is correlated. The dataset used consists of the prices between January 1, 2016 to March 31, 2019 of the four cryptocurrency rivals: Bitcoin, Ethereum, Ripple and Litecoin. The modeling is performed by using autoregression and fitting on 80% of the data. Thereafter, the models are forecasted on the last 20% of the data in order to test the accuracy of the model. The four types of model are used in this thesis and are named by the abbreviations AR(p), MSAR(p), VAR(p) and MSVAR(p) where AR(p) represents an autoregressive model of order p; MSAR(p) represents a Markov-Switching autoregressive model of order p; VAR(p) represents a multivariate model for of the AR(p) also known as the vector autoregressive model of order p; finally MSVAR(p) stands for a Markov-Switching vector autoregressive model of order p. As cryptocurrencies are said to be very volatile, we hope that the Markov-Switching approach would help to classify the level of volatility into different regimes. Further, we anticipate that the fitted time series for each regime will offer a greater accuracy than the regular AR(p) and VAR(p) models. By using scale-dependent error estimators, the thesis concludes that the Markov-Switching approach does in fact improve the efficiency of chosen time series models for our cryptocurrencies.
Denna forskning är ett försök att fördjupa förståelsen för välkända kryptovalutor. En deduktiv forskningsmetodik används där vi försöker att uppskatta de linjära beroendena av kryptovalutor med fyra olika tidsseriemodeller. En undersökning på linjära beroenden av univariata tidsserier ger läsaren en förståelse för hur tidigare priser på kryptovalutor påverkar framtida priser. För det multivariata fallet kommer vi försöka att uppskatta korrelationen inom kryptomarknaden. Den datan som används består av priserna mellan 1 januari 2016 och 31 mars 2019 av de följande kryptovalutor: Bitcoin, Ethereum, Ripple och Litecoin. Modelleringen utförs genom att använda autoregression på 80% av datan. Därefter prognostiseras modellerna för de sista 20% av datan för att testa modellens noggrannhet. De fyra typer av modeller som används är: AR(p) som representerar en autoregressiv modell av ordning p; MSAR(p) som representerar en Markov-Switching autoregressiv modell av ordning p; VAR(p) som representerar en AR(p) modell i ett multivariat fall, som kallas för en vektor autoregressiv modell av ordning p; MSVAR(p) som representerar en Markov-Switching vektor autoregressiv modell av ordning p. Eftersom kryptovalutor sägs vara väldigt volatila hoppas vi på att Markov-Switching metoden skulle bidra till att klassificera volatiliteten i olika regimer. Genom klassificeringen hoppas vi på att de anpassade tidsserierna kommer att ge större noggrannhet för varje regim än de vanliga AR(p) och VAR(p) modellerna. Med två skalaberoende feltyper drar vi slutsatsen att Markov-Switching metoden faktiskt förbättrar effektiviteten hos de valda tidsseriemodellerna för våra kryptovalutor.

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27

Mundt, Henrik. "Oddssättning : - utvärdering av modeller för skattning av matchodds i Svenska Superligan i innebandy." Thesis, Örebro universitet, Handelshögskolan vid Örebro Universitet, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-48002.

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Ericsson, Tomas. "Tennismodellen II : En undersökning om fördelaktiga odds och spelstrategi för spel på tennismatcher med hjälp av en statistisk modell." Thesis, Örebro universitet, Handelshögskolan vid Örebro Universitet, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-46855.

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Gašić, Milica. "Statistical dialogue modelling." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609496.

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Lind, Joar. "Discrete choice modelling – Estimering och utvärdering av multinomial logitmodell i R för tillämpning i godstransportmodellering." Thesis, Uppsala universitet, Tillämpad matematik och statistik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-388629.

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Westerberg, Marcus. "Modelling short and long term consequences of changes in diagnostic activity and treatment." Licentiate thesis, Uppsala universitet, Tillämpad matematik och statistik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-417822.

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Since the late 90’s the diagnostic activity for prostate cancer has increased in Sweden, primarily due to increased use of PSA testing, and this has led to a large increase in diagnoses. Simultaneously, there have been changes in treatment strategies, and more effective treatments have been introduced. This thesis aims to increase the understanding of short and long term consequences of these changes by use of high quality data on virtually all men diagnosed with prostate cancer in Sweden. In paper I, the survival of men with metastatic prostate cancer at diagnosis was investigatedby use of survival models, including Kaplan-Meier analyses and Cox proportional hazards regression.The median survival from diagnosis increased with 6 months when comparing mendiagnosed 1998-2001 with men diagnosed 2010-2015, and the risk of death decreased with 13%, while median levels of prostate specific antigen at diagnosis dropped with up to 50%. In paper II, the interplay between diagnostic activity, incidence and risk of death by prostate cancer was modelled using a discrete time model. Data on diagnostic activity, e.g. in termsof testing frequencies, was not available and therefore a proxy for the diagnostic activity wasused. The hazards were estimated within the framework of generalized additive models. Two simulations were performed, assuming low and high diagnostic activity respectively, to compare incidence and mortality from 2017-2060. Higher diagnostic activity, compared to lower, led to more men being diagnosed, primarily with lower risk prostate cancer, but in the long run it led to fewer men diagnosed with metastatic disease and fewer prostate cancer deaths.

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Nilsson, Mattias. "Förändringar i Ålands omsättningsindex : Val av ledande förklarande variabler och undersökning av de branschindex som ingår." Thesis, Linköping University, Statistics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-56851.

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Denna uppsats har gjorts på uppdrag av Ålands statistik- och utredningsbyrå (ÅSUB) i syfte att förklara och prognostisera de åländska företagens omsättningsutveckling över tiden.

I uppsatsen har jag undersökt om en tidigare framtagen modell för att förklara Ålands omsättningsindex kan användas för att förklara olika branschindex på Åland.

Jag har även tagit fram två olika modeller på ledande indikatorer från Sverige och Finland med ARIMA-feltermer. De ledande indikatorerna är svenska och finska konsumenters förtroendeindex samt industrins förtroendeindex och svenska OMX 30 börsindex. Modellerna använder olika fördröjningar på dessa fem indikatorer som förklaringsvariabler. Modell 1 använder utvalda fördröjningar och Modell 2 använder glidande medelvärden på fördröjningsintervall.

Jag har testat hur bra de två modellerna kan förklara och prognostisera Ålands omsättningsindex och de olika branschindexen. Båda modellerna förklarar Ålands omsättningsindex bra. Modell 2 är klart bättre än Modell 1 på att förklara de olika branschindexen. Prognosförmågan för båda modellerna är diskutabel. Modell 2 är bättre än Modell 1 på att prognostisera både Ålands omsättningsindex och dess branschindex.

Jag har visat att det går att ta fram en bra modell för att förklara Ålands omsättningsindex och dess branschindex med hjälp av ledande indikatorer från Sverige och Finland.

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Abey, Rebecca. "The statistics of topic modelling." Thesis, University of Canterbury. Mathematics and Statistics, 2015. http://hdl.handle.net/10092/11264.

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This research project aims to provide a clear and concise guide to latent dirichlet allocation which is a form of topic modelling. The aim is to help researchers who do not have a strong background in mathematics or statistics to feel comfortable with using topic modelling in their work. In order to achieve this, the thesis provides a step-by-step explanation of how topic modelling works. A range of tools that can be used to perform a topic model analysis are also described. The first chapter gives an explanation of how topic modelling, and (more specifically), latent dirichlet allocation works; it offers a very basic explanation and then provides an easy to follow mathematical explanation. The second chapter explains how to perform a topic model analysis; this is done through an explanation of each step used to run a topic model analysis, starting from the type of dataset through to the software packages available to use. The third section provides an example topic model analysis, based on the Philpapers dataset. The final section provides a discussion on the highlights of each chapter and areas for further research.

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Southey, Richard. "Bayesian hierarchical modelling with application in spatial epidemiology." Thesis, Rhodes University, 2018. http://hdl.handle.net/10962/59489.

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Disease mapping and spatial statistics have become an important part of modern day statistics and have increased in popularity as the methods and techniques have evolved. The application of disease mapping is not only confined to the analysis of diseases as other applications of disease mapping can be found in Econometric and financial disciplines. This thesis will consider two data sets. These are the Georgia oral cancer 2004 data set and the South African acute pericarditis 2014 data set. The Georgia data set will be used to assess the hyperprior sensitivity of the precision for the uncorrelated heterogeneity and correlated heterogeneity components in a convolution model. The correlated heterogeneity will be modelled by a conditional autoregressive prior distribution and the uncorrelated heterogeneity will be modelled with a zero mean Gaussian prior distribution. The sensitivity analysis will be performed using three models with conjugate, Jeffreys' and a fixed parameter prior for the hyperprior distribution of the precision for the uncorrelated heterogeneity component. A simulation study will be done to compare four prior distributions which will be the conjugate, Jeffreys', probability matching and divergence priors. The three models will be fitted in WinBUGS® using a Bayesian approach. The results of the three models will be in the form of disease maps, figures and tables. The results show that the hyperprior of the precision for the uncorrelated heterogeneity and correlated heterogeneity components are sensitive to changes and will result in different results depending on the specification of the hyperprior distribution of the precision for the two components in the model. The South African data set will be used to examine whether there is a difference between the proper conditional autoregressive prior and intrinsic conditional autoregressive prior for the correlated heterogeneity component in a convolution model. Two models will be fitted in WinBUGS® for this comparison. Both the hyperpriors of the precision for the uncorrelated heterogeneity and correlated heterogeneity components will be modelled using a Jeffreys' prior distribution. The results show that there is no significant difference between the results of the model with a proper conditional autoregressive prior and intrinsic conditional autoregressive prior for the South African data, although there are a few disadvantages of using a proper conditional autoregressive prior for the correlated heterogeneity which will be stated in the conclusion.

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D'Ignazi, Jacopo. "Dal microscopico al macroscopico: concetti e formalismo della termodinamica statistica." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18376/.

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I fenomeni macroscopici possono sempre essere considerati come "il comportamento emergente" da sottostanti fenomeni microscopici. Riuscire a formalizzare questa "emergenza" è un problema che richiede non solo una buona conoscenza delle interazioni coinvolte, ma anche una strategia modellistica piuttosto sofisticata: l'obbiettivo delle teorie che si occupano di questi modelli è quello di descrivere contemporaneamente un sistema nella sua "globalità" macroscopica, e nel suo "dettaglio" microscopico. Questa strategia richiede approssimazioni ponderate e strumenti matematici idonei: la Teoria degli Insiemi Statistici, nel contesto della termodinamica dell'equilibrio, è un ottimo esempio di questa strategia matematica. In questa tesi si percorre quindi il procedimento che porta dalla descrizione meccanica delle particelle, alla descrizione termodinamica di un numeroso insieme di queste; nel primo e secondo capitolo si cercherà di estrapolare da questo procedimento le idee fondamentali che lo rendono possibile, mentre nel terzo si vedrà come queste idee operino nell'applicazione ad un Gas ideale: la prospettiva è quella di comprendere quali siano i passaggi chiave con cui si legano il mondo microscopico e macroscopico, nell'ottica di riconoscere elementi validi in generale per tutti i sistemi complessi. Si cercherà quindi di ricavare da questa teoria quale sia l'impalcatura, formale e concettuale, grazie alla quale l'emergenza di comportamenti macroscopici è calcolabile a partire dal sottostante comportamento microscopico: si vedrà che l'uso della statistica, unito ad un'adeguata rappresentazione del sistema, permette di ricavare gli osservabili macroscopici come proprietà probabili di certe "classi" di microstati.

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Del, Giovane Cinzia <1979&gt. "Modello multilevel a classi latenti: estensione al modello multidimensionale." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/718/.

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Breznik, Alexander, and Truls Malmberg. "Volatilitetsprognoser för OMXS30 : Utvärdering av ARCH/GARCH-modeller till prognostisering av volatilitet för OMXS30 med realiserad volatilitet som referenspunkt." Thesis, Örebro universitet, Handelshögskolan vid Örebro Universitet, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-67985.

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38

Kazakevičiūtė, Jolita. "Europos valstybių švietimo duomenų statistinės analizės modeliai ir programinė įranga." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110902_093229-84256.

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Darbe pateikti švietimo duomenų statistinės analizės modeliai ir programinė įranga, kurie palengvina sprendimų priėmimą bei jų pagrindimą sprendžiant švietimo valdymo organizavimo uždavinius. Modeliai ir programinė įranga realizuoti naudojant taikomosios statistikos metodus, objektinio programavimo technologiją ir SAS sistemą.
The statistical analysis models and software of education data for support the decisionmaking is presented in this paper. The models and software were developed using applied statistics methods, object programming technology and software SAS.

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Llewelyn, Stephanie Jane. "Statistical modelling of fingerprints." Thesis, University of Sheffield, 2014. http://etheses.whiterose.ac.uk/7722/.

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It is believed that fingerprints are determined in embryonic development. Unlike other personal characteristics the fingerprint appears to be a result of a random process. For example fingerprints of identical twins (whose DNA is identical) are distinct, and extensive studies have found little evidence of a genetic relationship in terms of types of fingerprint, certainly at the small scale. At a larger scale the pattern of ridges on fingerprints can be categorised as belonging to one of five basic forms: loops (left and right), whorls, arches and tented arches. The population frequencies of these types show little variation with ethnicity and a list of the types occurring on the ten digits can be used as an initial basis for identification of individuals. However, such a system would not uniquely identify an individual although the frequency of certain combinations could be extremely small. At a smaller scale various minutiae or singularities can be observed in a fingerprint. These include ridge endings and bifurcations, amongst others. Typical fingerprints have several hundred of these as well as two key points (with the exception of a simple arch) referred to as the core and delta, which are focal points of the overall pattern of ridges. Modern identification systems are based upon ridge endings and bifurcations, not least because they are the easiest to determine automatically from image analysis. The configuration of these minutiae is unique to the individual. This research explores the relationship between the locations of minutiae to determine if they can be modelled using a statistical process. In addition, since the approach is based on how fingerprints can be examined in a forensic situation an algorithm is created and tested which allows the strength of a match between a fingermark left at a crime and a fingerprint from a known suspect to be calculated. Currently the result of matching a fingermark and fingerprint is expressed as a categorical value of; match, no match or inconclusive. The method in this research allows this to be expressed as a numerical value allowing for a wider and more flexible use of fingerprint evidence.

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Gao, Yu. "Statistical modelling of games." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/33298/.

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This thesis mainly focuses on the statistical modelling of a selection of games, namely, the minority game, the urn model and the Hawk-Dove game. Chapters 1 and 2 give a brief introduction and survey of the field. In Chapter 3, the key characteristics of the minority game are reproduced. In addition, the minority game is extended to include wealth distribution and leverage effect. By assuming that each player has initial wealth which rises and falls according to profit and loss, with the potential of borrowing and bankruptcy, we find that modelled wealth distribution may be power law distributed and leverage increases the instability of the system. In Chapter 4, to explore the effects of memory, we construct a model where agents with memories of different lengths compete for finite resources. Using analytical and numerical approaches, our research demonstrates that an instability exists at a critical memory length; and players with different memory lengths are able to compete with each other and achieve a state of co-existence. The analytical solution is found to be connected to the well-known urn model. Additionally, our findings reveal that the temperature is related to the agent's memory. Due to its general nature, this memory model could potentially be relevant for a variety of other game models. In Chapter 5, our main finding is extended to the Hawk-Dove game, by introducing the memory parameter to each agent playing the game. An assumption is made that agents try to maximise their profits by learning from past experiences, stored in their finite memories. We show that the analytical results obtained from these two games are in agreement with the results from our simulations. It is concluded that the instability occurs when agents' memory lengths reach the critical value. Finally, Chapter 6 provides some concluding remarks and outlines some potential future work.

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Du, Toit Carl. "Modelling market risk with SAS Risk Dimensions : a step by step implementation." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1015.

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42

Metulini, Rodolfo <1983&gt. "Modelli Gravitazionali per l'analisi del Commercio Internazionale." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5166/.

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Il modello gravitazionale e' ormai diventato un "cavallo da battaglia" in economia internazionle ed e' comunemente utilizzato nella determinazione dei flussi commerciali. Recentemente, molti studi hanno mostrato l'importanza della dipendenza spaziale, che va' a considerare quegli effetti dovuti al cosiddetto "third country". Intervengono a questo scopo la modellistica e le tecniche di stima di Econometria Spaziale. Verra' fatto uso di tali tecniche allo scopo di stimare con un modello gravitazionale spaziale il commercio internazionale tra paesi dell'OCSE per un panel di 22 anni. L'obiettivo e' quindi duplice: da un lato, si andra' ad applicare le piu' moderne tecniche di Econometria Spaziale, in un campo in cui tali contributi scarseggiano. Dall'altro lato,verra' fornita una interpretazione del comportamento del commercio internazionale tra paesi dell'OCSE, approfondendo gli aspetti relativi all'effetto del"third country" e del fenomeno migratorio. Inoltre , viene proposta un'analisi che ha lo scopo di validare l'ipotesi di omissione della distanza dal modello gravitazione strutturale.
The Gravity Model is the "workhorse for empirical studies" in International Economies and it is commonly used in explaining the trade flow between countries. Recently, several studies have showed the importance of taking into account the spatial effect. Spatial Econometric techniques meet this matter, proposing the specification of a set of models and estimators. We will make use of these Spatial Econometric techniques in order to estimate a Spatial Gravity of Trade for a 22-year-long panel of the OECD countries. The aim, therefore, is twofold: on one hand, we are going to use the newest Spatial Econometric techniques in a field where they aren't widely applicated. On the other hand, we provide an updated interpretation of the behaviour of the International Trade in an OECD context, going deeply on the explanation of the spatial spillover effect due to the third country dependence, and of the migratory phenomenon. Moreover, we propose an economically-based analysis whose aim is to avoid the use of the "distance" variable in the Gravity Model. The empirical results confirm the importance of taking into account the spatial dependence and they allow us to estimate the model wirhout the "distance", if properly replaced by a set of fixed effects.

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Saleem, Aban, and Jacob Blomgren. "Modelling Pupils’ Grades with Multiple Linear Regression Model." Thesis, KTH, Matematisk statistik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-275672.

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This thesis was based on the subjects of mathematical statistics and industrial economics and management in order to analyze the grades of pupils in the final year of elementary school. The purpose was to find out what variables had a statistically significant impact on pupils’ final grades so that municipalities and schools could better understand what variables are important when trying to improve the average school results. A multiple regression model was used on data, obtained from the database of Skolverket, in order to examine what variables were statistically important. The final regression model acquired through a model reduction procedure showed that mostly structural covariates such as the academic background of pupils, percentage of female pupils and the percentage with Swedish background had a statistically significant impact on the academic performances of the students. R2 adjusted of the final model was 0.5289. The multiple regression model was discussed by referencing to previous research. In addition, the strategic management performance framework known as Balanced Scorecard which was introduced by Robert S. Kaplan and David P. Norton was used to discuss relevant key performance indicators to achieve the strategic objectives of schools.
Detta examensarbete, inom ämnet för matematisk statistik och industriell ekonomi, genomfördes med syftet att analysera avgångsbetygen för år 9 i den svenska skolan. Syftet var att förstå vilka variabler som hade en statistisk signifikant påverkan på elevers avgångsbetyg, så kommuner kan förstå vilka variabler som är viktiga för att förbättra de genomsnittliga skolresultaten. En regressionsanalys utfördes, på data från Skolverket, för att se vilka variabler som var statistiskt signifikanta. Den slutgiltiga regressionsmodellen, erhållen genom iterativ reducering av variabler, visade att främst strukturella kovariat, som akademisk bakgrund hos elever, andel kvinnliga studenter och andel studenter med svensk bakgrund hade en signifikant betydelse på studenters akademiska resultat. Justerad R2 var 0.5289 för den slutgiltiga modellen. I diskussionen utvärderades modellen utifrån tidigare forskning. Vidare användes teorin om balanserat styrkort, utvecklat av Robert S. Kaplan och David P. Norton, för att diskutera relevanta nyckeltal för att uppnå strategiska mål för skolan.

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Aas, Kjersti. "Statistical Modelling of Financial Risk." Doctoral thesis, Norwegian University of Science and Technology, Department of Mathematical Sciences, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1780.

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老瑞欣 and Sui-yan Victor Lo. "Statistical modelling of gambling probabilities." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1992. http://hub.hku.hk/bib/B3123270X.

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Preece, T. D. "Statistical modelling of population evolution." Thesis, University of Nottingham, 2009. http://eprints.nottingham.ac.uk/10730/.

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In this thesis analytical and simulation techniques are applied to problems in biological evolution. The thesis is divided into four parts. Firstly, chapter two investigates anomalies that occur in the Penna bit-string model of ageing, an influential model of mutation accumulation and selection. These anomalies result in unusual demographic distributions and can lead to the so-called Eve effect. The anomalies are characterised along with their associated demographic distributions. It is argued that the anomalies are similar in nature to the well known first-passage problem. Secondly, chapter three uses evolutionary game theory to investigate the evolution of harmful mating tactics in hermaphrodites. These tactics benefit the function of the sperm donor at the expense of sperm recipient. The model predicts evolutionary stable values of resource allocation between sexual functions, and the level of harm. The analysis provides support for empirical observations and makes predictions about the effects of harmful mating tactics on population evolution. Thirdly, chapter four considers the sustainability of the two main types of sexual reproduction; hermaphroditism and dioecy (male and female individuals). By use of stochastic spatial simulations it is demonstrated that hermaphroditism can have an even greater advantage over dioecy than predicted by mean-field analysis. This result provides support for the observation that hermaphroditism is associated with sedentary species. Finally, chapter five considers the evolution of gynodioecy, a breeding system of plants in which populations consist of hermaphrodite and female individuals. It is both a common and widespread polymorphism, and has been identified in many species of ecological and economic interest. Mean-field calculations and stochastic spatial simulations are used to identify the conditions necessary for gynodioecy to evolve.

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Polson, Nicholas G. "Bayesian perspectives on statistical modelling." Thesis, University of Nottingham, 1988. http://eprints.nottingham.ac.uk/11292/.

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This thesis explores the representation of probability measures in a coherent Bayesian modelling framework, together with the ensuing characterisation properties of posterior functionals. First, a decision theoretic approach is adopted to provide a unified modelling criterion applicable to assessing prior-likelihood combinations, design matrices, model dimensionality and choice of sample size. The utility structure and associated Bayes risk induces a distance measure, introducing concepts from differential geometry to aid in the interpretation of modelling characteristics. Secondly, analytical and approximate computations for the implementation of the Bayesian paradigm, based on the properties of the class of transformation models, are discussed. Finally, relationships between distance measures (in the form of either a derivative of a Bayes mapping or an induced distance) are explored, with particular reference to the construction of sensitivity measures.

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Burt, Mary Louise. "Statistical modelling of volcanic hazards." Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282730.

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Neil, Martin David. "Statistical modelling of software metrics." Thesis, London South Bank University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332031.

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Lo, Sui-yan Victor. "Statistical modelling of gambling probabilities /." [Hong Kong] : University of Hong Kong, 1992. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13205389.

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Dissertations / Theses on the topic 'Modelli statistici'

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