Hot-mix asphalt concrete (HMAC) mixture fatigue characterization constitutes a fundamental component of HMAC pavement structural design and analysis to ensure adequate field fatigue performance. HMAC is a heterogeneous complex composite material of air, binder, and aggregate that behaves in a non-linear elasto-viscoplastic manner, exhibits anisotropic behavior, ages with time, and heals during traffic loading rest periods and changing environmental conditions. Comprehensive HMAC mixture fatigue analysis approaches that take into account this complex nature of HMAC are thus needed to ensure adequate field fatigue performance. In this study, four fatigue analysis approaches; the mechanistic empirical (ME), the calibrated mechanistic with (CMSE) and without (CM) surface energy measurements, and the proposed NCHRP 1-37A 2002 Pavement Design Guide (MEPDG) were comparatively evaluated and utilized to characterize the fatigue resistance of two Texas HMAC mixtures in the laboratory, including investigating the effects of binder oxidative aging. Although the results were comparable, the CMSE/CM approaches exhibited greater flexibility and potential to discretely account for most of the fundamental material properties (including fracture, aging, healing, visco-elasticity, and anisotropy) that affect HMAC pavement fatigue performance. Compared to the other approaches, which are mechanistic-empirically based, the CMSE/CM approaches are based on the fundamental concepts of continuum micromechanics and energy theory.

Hot-mix asphalt concrete (HMAC) mixture fatigue characterization constitutes a fundamental component of HMAC pavement structural design and analysis to ensure adequate field fatigue performance. HMAC is a heterogeneous complex composite material of air, binder, and aggregate that behaves in a non-linear elasto-viscoplastic manner, exhibits anisotropic behavior, ages with time, and heals during traffic loading rest periods and changing environmental conditions. Comprehensive HMAC mixture fatigue analysis approaches that take into account this complex nature of HMAC are thus needed to ensure adequate field fatigue performance. In this study, four fatigue analysis approaches; the mechanistic empirical (ME), the calibrated mechanistic with (CMSE) and without (CM) surface energy measurements, and the proposed NCHRP 1-37A 2002 Pavement Design Guide (MEPDG) were comparatively evaluated and utilized to characterize the fatigue resistance of two Texas HMAC mixtures in the laboratory, including investigating the effects of binder oxidative aging. Although the results were comparable, the CMSE/CM approaches exhibited greater flexibility and potential to discretely account for most of the fundamental material properties (including fracture, aging, healing, visco-elasticity, and anisotropy) that affect HMAC pavement fatigue performance. Compared to the other approaches, which are mechanistic-empirically based, the CMSE/CM approaches are based on the fundamental concepts of continuum micromechanics and energy theory.

Disertacijoje nagrinėjamos papildomos informacijos panaudojimo galimybės konstruojant baigtinės populiacijos sumos, dispersijos ir kovariacijos įvertinius, bei sluoksniuojant baigtines populiacijas. Pirmiausia darbe sprendžiamas populiacijų sluoksniavimo uždavinys, kai tyrimo kintamojo skirstinys yra asimetrinis. Pasiūlomas naujas - pataisytasis geometrinis - sluoksniavimo metodas. Šis metodas modeliuojant lyginamas su trimis kitais žinomais metodais: kvadratinės šaknies iš skirstinio dažnio, geometriniu ir laipsninio sluoksniavimo metodu. Modeliavimo rezultatai rodo, kad vidutiniškai asimetrinėms populiacijoms geriausiai tinka laipsninio sluoksniavimo metodas, o ypač asimetrinėms populiacijoms geriausias yra pataisytasis geometrinis sluoksniavimas. Toliau nagrinėjami baigtinės populiacijos sumos kalibruotieji įvertiniai, sukonstruoti taikant skirtingas atstumo funkcijas. Modeliuojant tiriama šių įvertinių kokybė. Sukonstruoti nauji populiacijos kovariacijos kalibruotieji įvertiniai, naudojantys vieną, dvi ir tris svorių sistemas. Šie įvertiniai konstruojami pasirenkant skirtingas kalibravimo lygtis. Remiantis modeliais pagrįstų įvertinių teorija, čia taip pat sukonstruojamas pataisytasis tiesiniu regresiniu modeliu pagrįstas kalibruotasis populiacijos kovariacijos įvertinys. Modeliuojant įvertiniai lyginami tarpusavyje ir su standartiniais atitinkamų parametrų įvertiniais. Kalibruotieji įvertiniai yra kur kas tikslesni, jei tyrimo ir papildomų kintamųjų koreliacija yra... [toliau žr. visą tekstą] / The dissertation analyzes how to incorporate auxiliary information into the estimation of the finite population total, variance, covariance, and how to use it for the stratification of finite populations. First of all, the problem of efficient stratification in the case of skewed population is considered. A new adjusted geometric stratification method is introduced. This method is compared by simulation with the cumulative root frequency method, the geometric method, and the power method. The simulation results show that in most cases considered the power method is the most efficient one, but the adjusted geometric stratification method outperforms all the methods in the case of highly skewed populations. The calibrated estimators of finite population total, constructed using different distance functions, are considered. The quality of such estimators is analyzed by simulation. The new calibrated estimators of the finite population covariance (variance) are derived, using one or more weighting systems. Applying the model calibration theory, we construct here an adjusted linear regression model-assisted and calibrated estimator of the population covariance. The estimators derived are compared by simulation with the standard estimators of the respective parameters. The calibrated estimators of the population covariance are more efficient compared to the straight estimators provided the auxiliary variables are well correlated with the study variables. The problem of estimation... [to full text]

The dissertation analyzes how to incorporate auxiliary information into the estimation of the finite population total, variance, covariance, and how to use it for the stratification of finite populations. First of all, the problem of efficient stratification in the case of skewed population is considered. A new adjusted geometric stratification method is introduced. This method is compared by simulation with the cumulative root frequency method, the geometric method, and the power method. The simulation results show that in most cases considered the power method is the most efficient one, but the adjusted geometric stratification method outperforms all the methods in the case of highly skewed populations. The calibrated estimators of finite population total, constructed using different distance functions, are considered. The quality of such estimators is analyzed by simulation. The new calibrated estimators of the finite population covariance (variance) are derived, using one or more weighting systems. Applying the model calibration theory, we construct here an adjusted linear regression model-assisted and calibrated estimator of the population covariance. The estimators derived are compared by simulation with the standard estimators of the respective parameters. The calibrated estimators of the population covariance are more efficient compared to the straight estimators provided the auxiliary variables are well correlated with the study variables. The problem of estimation... [to full text] / Disertacijoje nagrinėjamos papildomos informacijos panaudojimo galimybės konstruojant baigtinės populiacijos sumos, dispersijos ir kovariacijos įvertinius, bei sluoksniuojant baigtines populiacijas. Pirmiausia darbe sprendžiamas populiacijų sluoksniavimo uždavinys, kai tyrimo kintamojo skirstinys yra asimetrinis. Pasiūlomas naujas - pataisytasis geometrinis - sluoksniavimo metodas. Šis metodas modeliuojant lyginamas su trimis kitais žinomais metodais: kvadratinės šaknies iš skirstinio dažnio, geometriniu ir laipsninio sluoksniavimo metodu. Modeliavimo rezultatai rodo, kad vidutiniškai asimetrinėms populiacijoms geriausiai tinka laipsninio sluoksniavimo metodas, o ypač asimetrinėms populiacijoms geriausias yra pataisytasis geometrinis sluoksniavimas. Toliau nagrinėjami baigtinės populiacijos sumos kalibruotieji įvertiniai, sukonstruoti taikant skirtingas atstumo funkcijas. Modeliuojant tiriama šių įvertinių kokybė. Sukonstruoti nauji populiacijos kovariacijos kalibruotieji įvertiniai, naudojantys vieną, dvi ir tris svorių sistemas. Šie įvertiniai konstruojami pasirenkant skirtingas kalibravimo lygtis. Remiantis modeliais pagrįstų įvertinių teorija, čia taip pat sukonstruojamas pataisytasis tiesiniu regresiniu modeliu pagrįstas kalibruotasis populiacijos kovariacijos įvertinys. Modeliuojant įvertiniai lyginami tarpusavyje ir su standartiniais atitinkamų parametrų įvertiniais. Kalibruotieji įvertiniai yra kur kas tikslesni, jei tyrimo ir papildomų kintamųjų koreliacija yra... [toliau žr. visą tekstą]

Les études d’imagerie par résonance magnétique fonctionnelle (IRMf) ont pour prémisse générale l’idée que le signal BOLD peut être utilisé comme un succédané direct de l’activation neurale. Les études portant sur le vieillissement cognitif souvent comparent directement l’amplitude et l’étendue du signal BOLD entre des groupes de personnes jeunes et âgés. Ces études comportent donc un a priori additionnel selon lequel la relation entre l’activité neurale et la réponse hémodynamique à laquelle cette activité donne lieu restent inchangée par le vieillissement. Cependant, le signal BOLD provient d’une combinaison ambiguë de changements de métabolisme oxydatif, de flux et de volume sanguin. De plus, certaines études ont démontré que plusieurs des facteurs influençant les propriétés du signal BOLD subissent des changements lors du vieillissement. L’acquisition d’information physiologiquement spécifique comme le flux sanguin cérébral et le métabolisme oxydatif permettrait de mieux comprendre les changements qui sous-tendent le contraste BOLD, ainsi que les altérations physiologiques et cognitives propres au vieillissement. Le travail présenté ici démontre l’application de nouvelles techniques permettant de mesurer le métabolisme oxydatif au repos, ainsi que pendant l’exécution d’une tâche. Ces techniques représentent des extensions de méthodes d’IRMf calibrée existantes. La première méthode présentée est une généralisation des modèles existants pour l’estimation du métabolisme oxydatif évoqué par une tâche, permettant de prendre en compte tant des changements arbitraires en flux sanguin que des changements en concentrations sanguine d’O2. Des améliorations en terme de robustesse et de précisions sont démontrées dans la matière grise et le cortex visuel lorsque cette méthode est combinée à une manipulation respiratoire incluant une composante d’hypercapnie et d’hyperoxie. Le seconde technique présentée ici est une extension de la première et utilise une combinaison de manipulations respiratoires incluant l’hypercapnie, l’hyperoxie et l’administration simultanée des deux afin d’obtenir des valeurs expérimentales de la fraction d’extraction d’oxygène et du métabolisme oxydatif au repos. Dans la deuxième partie de cette thèse, les changements vasculaires et métaboliques liés à l’âge sont explorés dans un groupe de jeunes et aînés, grâce au cadre conceptuel de l’IRMf calibrée, combiné à une manipulation respiratoire d’hypercapnie et une tâche modifiée de Stroop. Des changements de flux sanguin au repos, de réactivité vasculaire au CO2 et de paramètre de calibration M ont été identifiés chez les aînés. Les biais affectant les mesures de signal BOLD obtenues chez les participants âgés découlant de ces changements physiologiques sont de plus discutés. Finalement, la relation entre ces changements cérébraux et la performance dans la tâche de Stroop, la santé vasculaire centrale et la condition cardiovasculaire est explorée. Les résultats présentés ici sont en accord avec l’hypothèse selon laquelle une meilleure condition cardiovasculaire est associée à une meilleure fonction vasculaire centrale, contribuant ainsi à l’amélioration de la santé vasculaire cérébrale et cognitive. / Functional MRI (fMRI) studies using the BOLD signal are done under the general assumption that the BOLD signal can be used as a direct index of neuronal activation. Studies of cognitive aging often compare BOLD signal amplitude and extent directly between younger and older groups, with the additional assumption that the relationship between neuronal activity and the hemodynamic response is unchanged across the lifespan. However, BOLD signal arises from an ambiguous mixture of changes in oxidative metabolism, blood flow and blood volume. Furthermore, previous studies have shown that several BOLD signal components may be changed during aging. More physiologically-specific information on blood flow and oxidative metabolism would allow a better understanding of these signal changes and of the physiological and cognitive changes seen with aging. The work presented here demonstrates techniques to estimate oxidative metabolism at rest and during performance of a task. These techniques are extensions of previous calibrated fMRI methods and the first method presented is based on a generalization of previous models to take into account both arbitrary changes in blood flow and blood O2 content. The improved robustness and accuracy of this method, when used with a combined hypercapnia and hyperoxia breathing manipulation, is demonstrated in visual cortex and grey matter. The second technique presented builds on the generalization of the model and uses a combination of breathing manipulations including hypercapnia, hyperoxia and both simultaneously, to obtain experimentally-determined values of resting oxygen extraction fraction and oxidative metabolism. In the second part of this thesis, age-related vascular and metabolic changes are explored in a group of younger and older adults using a calibrated fMRI framework with a hypercapnia breathing manipulation and a modified Stroop task. Changes in baseline blood flow, vascular reactivity to the CO2 challenge and calibration parameter M were identified in the older participants. Potential biases in BOLD signal measurements in older adults arising from these physiological changes are discussed. Finally, the relationship between these cerebral changes and performance on the modified Stroop task, central vascular health and cardiovascular fitness are explored. The results of this thesis support the hypothesis that greater cardiovascular fitness is associated with improvements in central vascular function, contributing in turn to improved brain vascular health and cognition.

The present investigation is focused on the thermal performance of building materials, specifically their thermal transmittance, and consequent impact on building envelope and building thermal performance. Thermal performance of building materials plays a crucial role in regulating indoor thermal comfort when suitably integrated as part of the building envelope. Studies into thermal performance of building materials are few, particularly in the context of designing building blocks to achieve a particular thermal transmittance in buildings. Such studies require both theoretical (numerical) investigations augmented with experimental investigation into material thermal performance. A unique contribution of this study has been assessing the temperature-dependent performance of building material and their influence on thermal conductivity. The thermal performance of conventional and alternative (low energy) building materials have also been investigated to assess their suitability for naturally ventilated building in salient climatic zones in India. The study has also investigated the impact of varying mix proportions in Cement Stabilized Soil Block on thermal performance. There is little evidence of such studies, involving both experimental and theoretical studies, tracing the thermal performance of building materials to building performance. The current study involves three parts: studying thermo-physical properties of building materials, building-envelope performance evaluation and case-study investigation on buildings in various climatic zones. The thermo-physical study involves understanding the role of materials mix-proportion, composition, and microstructure for its influence on building-envelope thermal performance. Studies into building envelope performance for conventional and alternative building materials, includes, steady and dynamic thermal performance parameters. As part of the study, a calibrated hot-box thermal testing facility has been tested to experimentally determine the thermal performance of building envelopes. Case-study investigation involves real-time monitoring and simulation based assessment of naturally ventilated buildings in three climatic zones of India. The study finds noticeable temperature-dependent performance for various building materials tested. However, their impact on overall thermal performance of buildings is limited for the climatic zones tested. Further, the study validates the hitherto unexplored possibility of customizing building materials for specific thermal performances.

In this thesis will the question of how to construct implied volatility surfaces in a robust and arbitrage free way be investigated. To be able to know if the solutions are arbitrage free was an initial investigation about arbitrage in volatility surfaces made. From this investigation where two comprehensive theorems found. These theorems came from Roper in \cite{Roper2010}. Based on these where then two applicable arbitrage tests created. These tests came to be very important tools in the remaining thesis.The most reasonable classes of models for modeling the implied volatility surface where then investigated. It was concluded that the classes that seemed to have the best potential where the stochastic volatility models and the parametric representation models. The choice between these two classes where concluded to be based on a trade-off between simplicity and quality of the result. If it where possible to make the parametric representation models improve its result the best applicable choice would be that class. For the remaining thesis was it therefore decided to investigate this class. The parametric representation model that was chosen to be investigated where the SVI parametrization family since it seemed to have the most potential outside of its already strong foundation.The SVI parametrization family is diveded into 3 parametrizations, the raw SVI parametrization, the SSVI parametrization and the eSSVI parametrization. It was concluded that the raw SVI parametrization even though it gives very good market fits, was not robust enough to be chosen. This ment that the raw SVI parametrization would in most cases generate arbitrage in its surfaces. The SSVI model was concluded to be a very strong model compared to the raw SVI, since it was able to generate completely arbitrage free solutions with good enough results. The eSSVI is an extended parametrization of the SSVI with purpose to improve its short maturity results. It was concluded to give small improvements but with the trade of making the optimization procedure harder. It was therefore concluded that the SSVI parametrization might be the better application.To try to improve the results of the SSVI parametrization was a complementary procedure developed which got named the calibrated SSVI method. This method compared to the eSSVI parametrization would not change the parametrization but instead focusing on calibrating the initial fit that the SSVI generated. This method would heavily improve the initial fit of the SSVI surface but was less robust since it generated harder cases for the interpolation and extrapolation. / I det här examensarbetet undersöks frågan om hur man bör modellera implied volatilitetsytor på ett robust och arbitragefritt sätt. För att kunna veta om lösningarna är arbigtragefria börjades arbetet med en undersökning inom arbitrageområdet. De mest heltäckande resultatet som hittades var två theorem av Roper i \cite{Roper2010}. Baserat på dessa theorem kunde två applicerbara arbitragetester skapas som sedan kom att bli en av hörnstenarna i detta arbete. Genom att undersöka de modellklasser som verkade vara de bästa inom området valdes den parametriseringsbeskrivande modellklassen.  I denna klass valdes sedan SVI parametriseringsfamiljen för vidare undersökning eftersom det verkade vara den familj av modeller som hade störst potential att uppnå jämnvikt mellan enkel applikation samt bra resultat.  För den klassiska SVI modellen i SVI familjen drogs slutsatsen att modellen inte var tillräcklig för att kunna rekommenderas. Detta berodde på att SVI modellen i princip alltid genererade lösningar med arbitrage i. SVI modellen genererar dock väldigt bra lösningar mot marknadsdatan enskilt och kan därför vara ett bra alternativ om man bara ska modellera ett implied volatilitetssmil. SSVI modellen ansågs däremot vara ett väldigt bra alternativ. SSVI modellen genererar komplett aribragefria lösningar men har samtidigt rimligt bra marknadspassning.  För att försöka förbättra resultaten från SSVI modellen, var en kompleterande metod kallad den kalibrerade SSVI metoden skapad. Denna metod kom att förbättra marknadspassningen som SSVI modellen genererade men som resultat kom robustheten att sjunka, då interpoleringen och extrapoleringen blev svårare att genomföra arbitragefritt.

The goal of this work is to expand the knowledge on the field of Venn Prediction employed with Survival Data. Standard Venn Predictors have been used with Random Forests and binary classification tasks. However, they have not been utilised to predict events with Survival Data nor in combination with Random Survival Forests. With the help of a Data Transformation, the survival task is transformed into several binary classification tasks. One key aspect of Venn Prediction are the categories. The standard number of categories is two, one for each class to predict. In this work, the usage of ten categories is explored and the performance differences between two and ten categories are investigated. Seven data sets are evaluated, and their results presented with two and ten categories. For the Brier Score and Reliability Score metrics, two categories offered the best results, while Quality performed better employing ten categories. Occasionally, the models are too optimistic. Venn Predictors rectify this performance and produce well-calibrated probabilities. / Målet med detta arbete är att utöka kunskapen om området för Venn Prediction som används med överlevnadsdata. Standard Venn Predictors har använts med slumpmässiga skogar och binära klassificeringsuppgifter. De har emellertid inte använts för att förutsäga händelser med överlevnadsdata eller i kombination med Random Survival Forests. Med hjälp av en datatransformation omvandlas överlevnadsprediktion till flera binära klassificeringsproblem. En viktig aspekt av Venn Prediction är kategorierna. Standardantalet kategorier är två, en för varje klass. I detta arbete undersöks användningen av tio kategorier och resultatskillnaderna mellan två och tio kategorier undersöks. Sju datamängder används i en utvärdering där resultaten presenteras för två och tio kategorier. För prestandamåtten Brier Score och Reliability Score gav två kategorier de bästa resultaten, medan för Quality presterade tio kategorier bättre. Ibland är modellerna för optimistiska. Venn Predictors korrigerar denna prestanda och producerar välkalibrerade sannolikheter.

High-efficiency point cloud 3D object detection is important for autonomous driving. 3D object detection based on point cloud data is naturally more complex and difficult than the 2D task based on images. Researchers keep working on improving 3D object detection performance in autonomous driving scenarios recently. In this report, we present our optimized point cloud 3D object detection model based on CenterPoint method. CenterPoint detects centers of objects using a keypoint detector on top of a voxel-based backbone, then regresses to other attributes. On the basis of this, our modified model is featured with an improved Region Proposal Network (RPN) with extended receptive field, an added sub-head that produces an IoU-aware confidence score, as well as box ensemble inference strategies with more accurate predictions. These model enhancements, together with class-balanced data pre-processing, lead to a competitive accuracy of 72.02 mAP on ONCE Validation Split, and 79.09 mAP on ONCE Test Split. Our model gains the fifth place of ICCV 2021 Workshop SSLAD Track 3D Object Detection Challenge. / Högeffektiv punktmoln 3D-objektdetektering är viktig för autonom körning. 3D-objektdetektering baserad på punktmolnsdata är naturligtvis mer komplex och svårare än 2D-uppgiften baserad på bilder. Forskare fortsätter att arbeta med att förbättra 3D-objektdetekteringsprestandan i scenarier för autonom körning nyligen. I den här rapporten presenterar vi vår optimerade 3D-objektdetekteringsmodell baserad på CenterPoint. CenterPoint upptäcker objektcentrum med hjälp av en nyckelpunktsdetektor ovanpå en voxelbaserad ryggrad och går sedan tillbaka till andra attribut. På grundval av detta presenteras vår modifierade modell med ett förbättrat regionförslagsnätverk med utökat receptivt fält, en extra underrubrik som producerar en IoU-medveten konfidenspoäng och ensemblestrategier med mer exakta förutsägelser. Dessa modellförbättringar, tillsammans med klassbalanserad dataförbehandling, leder till en konkurrenskraftig noggrannhet på 72,02 mAP på ONCE Validation Split och 79,09 mAP på ONCE Test Split. Vår modell vinner femteplatsen i ICCV 2021 Workshop SSLAD Track 3D Object Detection Challenge.

V této diplomové práci bylo zkoumáno téma kalibrace zařízení a sekcí ve vztahu k aerodynamickému tunelu na brněnském institutu leteckého inženýrství. Přístroje používané v aerodynamickém tunelu jsou kalibrovány a jsou popsány a provedeny kalibrace sekcí na testovací sekci. Kalibrační listy a šablony sestav jsou vytvořeny za účelem zjednodušení budoucích procesů. Nově kalibrovaná sestava se používá k provádění měření síly a probuzení na modelovém voze, která jsou porovnána s předkalibrací měření, aby dále ilustrovala užitečnost kalibrací.