This research investigated whether 4D construction model effectively helps project participants on construction sites in detecting time-space conflicts in the schedule. Previous researchers on construction space management typically modeled space requirements for equipment and paths for material and focused primarily on static or dynamic layout planning. Some researchers regarded time-space conflicts as an essential aspect of construction space management. They demonstrated the use of 4D modules in time-space conflict analysis. Although these 4D prototypes have been successful in tackling time-space conflict analysis, they have been validated with only post-hoc analysis of construction projects. Also, various currently commercially available 4D visualization softwares do not take into account the workspace required during the construction of a component unless space is modeled as a separate component into the CAD application. Therefore, without modeling space as a component in the 3D model it is necessary to assess whether 4D visualization can be effectively used on construction sites to detect time-space conflicts in the schedule. In order to fulfill the research goal an experiment was conducted. A 4D construction model of an ongoing project was developed. Project participants were introduced to two different graphic representations of the schedule; namely, an overlay drawing - the conventional method used on site to detect conflicts and the 4D construction model. Analysis of the results compared the performance of the participants in detecting time-space conflicts in the schedule using the two methods. The experiment produced empirical evidence that a 4D construction model may be effective on construction sites in detecting time-space conflicts in the schedule.

Utvecklingen inom byggbranschen går i en riktning mot mer komplicerade konstruktioner och installationer. För att bibehålla en konkurrenskraftig position på marknaden efterfrågas nu bättre planeringsunderlag som kan öka produktiviteten, kvaliteten och säkerheten inom byggprojekt. Utvecklingmöjligheter finns inom planering, där en är att inkludera en fjärde dimension, tiden. 4D-planering är ett arbetssätt som innebär att en 3D-modell kopplas samman med en produktionstidplan. Syftet med examensarbetet är att kartlägga förutsättningar för tillämpning av 4D-planering i produktionsskedet. Syftet är även att undersöka och kunskapsåterföra 4D-planering till ett byggföretag i Sverige. En enkätundersökning har skickats ut till projektverksamma medarbetare aktiva i Stockholmsområdet för att redogöra för i vilken omfattning 4D-planering tidigare har använts. Personliga intervjuer har även genomförts med medarbetare från hela Sverige, som innehar erfarenhet och kunskap inom 4D-planering. Intervjuerna har utgjort underlag för framtagandet av vilka förutsättningar som är nödvändiga för att tillämpa 4D-planering. I enkätundersökningen deltog 112 respondenter, där 59,8 % tidigare hört talas om 4D-planering. Av de 112 respondenter hade tretton personer också deltagit i projekt där 4D-planering tillämpats. 89,3 % av samtliga respondenter uppvisade ett intresse för en ökad användning av 4D-planering inom byggproduktion. Det har framkommit via de personliga intervjuerna att totalentreprenad är den lämpligaste upphandlingsformen för tillämpning av 4D-planering. Utöver det anser respondenterna att storlek, komplexitet och programvara påverkar tillämpningen av 4D-planering. Slutsatsen är att 4D-planering idag används i en liten omfattning. De viktigaste förutsättningarna för att tillämpa 4D-planering är en för ändamålet korrekt utformad 3D-modell, produktionstidplan och ett lämpligt 4D-simuleringsprogram. Dessutom är det nödvändigt att tidigt i projektprocessen ta beslut om att 4D-planeringen ska tillämpas och till vilken utsträckning. Det är även avgörande att ha en väl fungerande kommunikation mellan projektörer och entreprenörer. Rekommendation till företaget är att inleda en tillämpning av 4D-planering med långsiktiga mål. / The development in the construction industry is continuously progressing towards more complex buildings and installations. In order to retain a competitive market position careful planning is required since it can increase productivity, quality and worker safety in construction projects. 4D-planning is a method of planning a construction project which means that a 3D-model and a production schedule are interconnected. The main purpose of this study is to investigate information on 4D-planning and to identify the conditions that need to be fulfilled to effectively use 4D-planning in construction. A second purpose has been to collect information regarding the knowledge and experience in using 4D-planning possessed by employees at a company in Sweden. A survey has been sent out to employees located in Stockholm, Sweden, to investigate the scope in which 4D-planing has previously been used. Personal interviews have also been made with employees whom possess experience and knowledge of 4D-planning, located in different places of Sweden. These persons form the basis for identifying the conditions required to use 4D-planning in construction projects. There were 112 participants in the survey of whom 59,8% had previously heard of 4D-planning. A number of 13 participants had also participated in projects where 4D-planning had been used. A total of 89,3% of the participants in the survey answered that they have an interest in further progress in the area of 4D-planning. Answers have also given some insight into how 4D-planning has been applied and how well it has worked. The personal interviews have demonstrated how factors such as contract form, type of computer planning software, size and complexity of the construction project all affect the execution of 4D-planning. The three main conditions which affect the use of 4D-planning is the shape and design of the 3D-model, the production time schedule and the 4D-simulation program used. Moreover, it is necessary to make an early decision whether to and to what extent 4D-planning is to be used. The communication between consultant and entrepreneur are also of great importance for the implementation of 4D-planning. The survey showed that the employees at the studied company has only used 4D-planning in a small scope. They are however, interested in an increased use of 4D-planning but emphasize the importance of guidelines and clear applications for its usage. Implementation of 4D-planning is deemed viable for the company with the recommendation to start the process immediately by establishing long-term goals.

Cette thèse a pour objectif la mise en place d'une stratégie mathématique pour l'étude du processus physique de l'agrégation des protéines. L'étude de ce processus largement inconnu est particulièrement importante puisqu'il a été identifiée comme un élément clé d'une vaste gamme de maladies incurables, appelées maladies amyloïdes. Les maladies à prions appartiennent à cette classe et sont causées par l'agrégation d'une configuration mal pliée de la protéine prion. Notre travail contribue à la recherche sur les maladies à prions, en se concentrant sur deux types d'agrégats : les oligomères et les fibres.Les oligomères suspectés d'être les agrégats les plus toxiques sont étudiés dans la première partie de cette thèse. Nous fondons notre travail sur l'analyse de deux types de données expérimentales. D'une part, nous considérons les données de dispersion statique de la lumière (SLS), qui peuvent être interprétées biologiquement comme la mesure de la taille moyenne des oligomères et mathématiquement comme le deuxième moment de la concentration des agrégats. D'autre part, nous considérons les données de distribution de taille d'oligomère collectées à plusieurs instants en utilisant la Chromatographie d'Exclusion de Taille (SEC). Notre étude conduit à la conclusion importante selon laquelle au moins deux types différents d'oligomères sont présents. De plus, nous proposons une description de l'interaction entre ces oligomères en proposant pour la première fois un modèle à deux espèces. Notre modèle est composé d'un ensemble d'ODE avec les taux cinétiques comme paramètres. La description qualitative fournie par ce modèle a été couplée à l'information contenue dans les données expérimentales de SLS dans le cadre de l'assimilation de données. Au moyen de la méthode du filtre de Kalman étendue, nous résolvons un problème inverse non linéaire, estimant ainsi les coefficients cinétiques associés aux données expérimentales. Pour valider ce modèle, nous avons comparé notre estimation aux données expérimentales de SEC, en observant un très bon accord entre les deux. Notre caractérisation des espèces d'oligomères peut conduire à de nouvelles stratégies pour concevoir un premier traitement ciblé pour les maladies à prions.La méthodologie appliquée à l'étude des oligomères peut être considérée comme une première étape dans l'analyse des fibres. En raison des propriétés physiques de ces agrégats, des expériences moins nombreuses et moins précises peuvent être effectuées, et une approche mathématique peut donc apporter une contribution précieuse à leur étude. Notre contribution est de proposer une stratégie générale pour estimer l'état initial d'un système de fibres. Inspiré par la théorie de Lifshitz-Slyozov, nous décrivons ce système par une équation de transport couplée à une équation intégrale. L'estimation est faite en utilisant quelques observations empiriques sur le système. Nous considérons le cas général d'observation d'un moment d'ordre $n$. Il est en effet possible de mesurer le moment d'ordre $1$ par fluorescence de thioflavine T ou le moment d'ordre $2$ par SLS. Nous proposons une solution théorique et numérique du problème d'estimation de la condition initiale dans le cas linéaire d'un système de dépolymérisation. En particulier, pour des taux de dépolymérisation constants, nous proposons une stratégie de régularisation par noyau, qui fournit une première caractérisation de l'estimation. Dans le cas de taux de dépolymérisation variables, nous proposons la méthode d'assimilation variationnelle 4d-Var et la méthode d'assimilation de données séquentielle du filtrage de Kalman. Ces deux méthodes sont plus générales et peuvent être facilement adaptée pour traiter différents problèmes. Ce problème inverse est particulièrement intéressant puisqu'il peut également être appliqué dans d'autres domaines tels que le cycle cellulaire ou la formation de poussière. / The aim of this PhD thesis is to set up a mathematical strategy to investigate the physical process of protein aggregation. The study of this largely unknown process is particularly important since it has been identified as a key feature of a wide class of incurable diseases, called amyloid diseases. Prion diseases belong to this class and are caused by the aggregation of a misfolded configuration of the prion protein. Our work contributes to the research on prion diseases, by focusing on two kinds of aggregates: oligomers and fibrils. Oligomers, which are suspected of being the most toxic aggregates, are studied in the first part of this thesis. We base our work on the analysis of two types of experimental data. On the one hand, we consider Static Light Scattering (SLS) data, which can be interpreted biologically as the measurement of the average oligomer size and mathematically as the second moment of aggregate concentration. On the other hand, we consider oligomer size distribution data collected at several instants by using Size Exclusion Chromatography (SEC). Our study leads to the important conclusion that at least two different types of oligomers are present. Moreover, we provide a description of the interaction between these oligomers by proposing, for the first time, a two-species model. Our model is composed of a set of ODEs with the kinetic rates as parameters. The qualitative description provided by this model has been coupled to the information contained in the noisy experimental SLS data in a data assimilation framework. By means of the extended Kalman filter method, we solve a non-linear inverse problem, thereby estimating the kinetic coefficients associated to the experimental data. To validate this model we have compared our estimation to the experimental SEC data, observing a very good agreement between the two. Our oligomer species characterisation may lead to new strategies to design a first targeted treatment for prion diseases. The methodology applied to the study of oligomers can be seen as a first step in the analysis of fibrils. Due to the physical properties of these aggregates, fewer and less precise experiments can be performed and so a mathematical approach can provide a valuable contribution to their study. Our contribution is to propose a general strategy to estimate the initial condition of a fibril system. Inspired by the Lifshitz-Slyozov theory, we describe this system by a transport equation coupled with an integral equation. The estimation is performed making use of some empirical observations on the system. We consider the general case of observing a moment of order $n$. It is indeed possible to measure the first moment by Thioflavine T fluorescence or the second moment by SLS. We provide a theoretical and numerical solution of the initial condition estimation problem in the linear case of a depolymerising system. In particular, for constant depolymerisation rates, we propose a kernel regularisation strategy, that provides a first characterisation of the estimation. In the variable depolymerisation rates, we outline the variational data assimilation method $4$d-Var.This method is more general and can be easily adapted to treat different problems. This inverse problem is particularly interesting since it can also be applied in other fields such as the cell cycle or dust formation.

The majority of studies examining the role of prenatal androgens on abnormal behavior have focused on developmental disorders showing large male to female ratios (i.e., autism and Tourette's Syndrome). There is a scarcity of research examining the role of prenatal sex hormones on female-linked disorders or disorders showing adult onset. This study is the first to evaluate the organizational and activational influences of sex hormones on adult levels of anxiety, while simultaneously examining previously reported hormone-behavior associations. In addition, this study explores the relation between prenatal and postnatal sex hormones and two other female-linked disorders, depression and borderline personality. As part of this study, participants (n = 110) completed a battery of psychopathology questionnaires, gender role measures, and spatial/cognitive tasks. Prenatal androgen levels were indirectly measured by means of the index to ring finger ratio (2D:4D), and testosterone and estrogen levels were obtained from saliva samples. Results replicate previously reported sex differences in anxiety and gendered behavior and confirm various hormone-behavior associations. More importantly, results provide preliminary evidence for the organizational role of prenatal androgens in two female-linked conditions, anxiety and borderline personality. Individuals with a higher (i.e., more feminine) 2D:4D reported greater symptoms of trait anxiety and borderline personality (i.e., affective instability), and this effect appeared to be strongest in males.

The majority of studies examining the role of prenatal androgens on abnormal behavior have focused on developmental disorders showing large male to female ratios (i.e., autism and Tourette's Syndrome). There is a scarcity of research examining the role of prenatal sex hormones on female-linked disorders or disorders showing adult onset. This study is the first to evaluate the organizational and activational influences of sex hormones on adult levels of anxiety, while simultaneously examining previously reported hormone-behavior associations. In addition, this study explores the relation between prenatal and postnatal sex hormones and two other female-linked disorders, depression and borderline personality. As part of this study, participants (n = 110) completed a battery of psychopathology questionnaires, gender role measures, and spatial/cognitive tasks. Prenatal androgen levels were indirectly measured by means of the index to ring finger ratio (2D:4D), and testosterone and estrogen levels were obtained from saliva samples. Results replicate previously reported sex differences in anxiety and gendered behavior and confirm various hormone-behavior associations. More importantly, results provide preliminary evidence for the organizational role of prenatal androgens in two female-linked conditions, anxiety and borderline personality. Individuals with a higher (i.e., more feminine) 2D:4D reported greater symptoms of trait anxiety and borderline personality (i.e., affective instability), and this effect appeared to be strongest in males.

Die Kombination von Positronen-Emissions-Tomographie (PET) und Röntgen-Computertomographie (CT) in Form moderner PET/CT-Geräte ermöglicht die Nutzung der CT-Information zur Korrektur der Photonenschwächung in der PET. Allerdings können Bewegungen, die zum Beispiel durch die Atmung hervorgerufen werden können, zu einer fehlerhaften Schwächungskorrektur führen. Die Einführung von zeitlich aufgelöster Bildgebung für beide Modalitäten (4D-PET/4D-CT) ermöglicht nicht nur die Auflösung von periodischen Bewegungen, sondern auch die Reduktion dieser Fehler in der Schwächungskorrektur. Dazu werden die einzelnen Datensätze des 4D-PET, die jeweils einer bestimmten Bewegungsphase entsprechen, mit dem entsprechenden CT-Datensatz dieser Atemphase schwächungskorrigiert. In der vorliegenden Arbeit wurde diese phasenkorrelierte Schwächungskorrektur des 4D-PET mit dem 4D-CT am Universitästsklinikum Dresden installierten PET/CT ermöglicht und anhand von Phantomexperimenten mit anderen Schwächungskorrekturmethoden für 4D-PET verglichen. Dazu musste zunächst die Aufnahme von 4D-CT an dem verwendeten PET/CT ermöglicht und dessen Synchronität mit dem 4D-PET hergestellt werden. Außerdem wurde ein vorhandenes Atemphantom so modifiziert, dass es typische Bewegungen von Bronchialkarzinomen in zwei Dimensionen und mit zwei möglichen Atemmustern simuliert. Die phasenkorrelierte Schwächungskorrektur führte zu einer quantitativ korrekten Wiederherstellung des Aktivitätsvolumens, der darin enthaltenen Aktivität sowie der Bewegungsamplitude und stellt somit die beste der hier verglichenen 4D-PET-Schwächungskorrekturmethoden dar. Diese Ergebnisse lassen vermuten, dass die phasenkorrelierte Schwächungskorrektur auch bei klinischer Anwendung eine signifikante Verbesserung in oben genannten Punkten darstellt. Dies sollte in Zukunft an Patientendaten überprüft werden. / The combination of Positron Emission Tomography (PET) and Computed Tomography (CT) in one device allows the use of CT-information for attenuation correction in PET. Though motion, for example induced by respiration, can cause inaccurate attenuation correction. The implementation of time-resolved imaging methods for both modalities (4D-PET/4D-CT) enables not only the resolution of motion but also the reduction of artifacts caused by attenuation correction. Therefore, the single datasets of the 4D-PET that are related to a individual respiratory phase, are attenuation corrected with the corresponding dataset of the 4D-CT. This phase correlated attenuation correction of the 4D-PET with the 4D-CT was implemented at the PET/CT installed at the Universitätsklinikum Dresden. For that purpose the acquisition of 4D-CT was implemented at the PET/CT and its synchronisation with the 4D-PET was verified. Furthermore the new attenuation correction method was compared with other attenuation correction methods by performing phantom experiments. Therefore an exisisting respiratory phantom had to be modified to perform typical lung tumor motion in two dimensions with two possible patterns of respiration. The phase correlated attenuation correction leads to a quantitatively correct restauration of the activity volume, its total activity and its motion amplitude. Compared with other correction methods, the phase correlated attenuation correction shows the best results in all examined criteria. This findings suggest that the clinical application of the phase correlated attenuation correction will also lead to a significant improvement in all mentioned points. This has to be verified by analyzing patient data.

Transportation projects often involve communication of project information between diverse parties and have been a challenge with increasing complexity. Communication, review and feedback are very important for planners, builders/developers and traffic engineers for successful project execution. Past research was successful in finding effective ways to communicate to stakeholders and improve project performance. 3D/4D CAD modeling has been one among them which offers potential benefits from planning to construction phase owing to its wide range of capabilities. However, there is no single tool to analyze traffic conditions and changing geometry during construction for reviewing and better decision-making. A methodology to use DTA models as a source for traffic information and development of traffic visualization during construction with microsimulation output is discussed in this thesis. The benefits of adding traffic information to 3D/4D CAD models and some potential areas of application are explored. Two case studies on TxDOT transportation construction projects are considered to explain the modeling and analysis for better understanding of different phases of the projects. Also, a small construction scenario was analyzed to validate the traffic data generated from DTA models for their use as an input to microsimulation models. / text

The Cranfield field, located in southwest Mississippi, is an enhanced oil recovery and carbon sequestration project that has been under a continuous supercritical CO₂ injection by Denbury Onshore LLC since 2008. Two 3D seismic surveys were collected in 2007, pre-CO₂ injection, and in 2010 after > 2 million tons of CO₂ was injected into the subsurface. The goal of this study is to characterize a time-lapse response between two seismic surveys to understand where injected CO₂ is migrating and to map the injected CO₂ plume edge. In order to characterize a time-lapse response, the seismic surveys were cross equalized using a trace-by-trace time shift. A normalized root-mean-square (NRMS) difference value was then calculated to determine the repeatability of the data. The data were considered to have “good repeatability,” so a difference volume was calculated and showed a coherent seismic amplitude anomaly located through the area of interest. A coherent seismic amplitude anomaly was also present below the area of interest, so a time delay analysis was performed and calculated a significant added velocity change. A Gassmann-Wood fluid substitution workflow was then performed at two well locations to predict a saturation profile and observe post-injection expected changes in compressional velocity values at variable CO₂ saturations. Finally, acoustic impedance inversions were performed on the two seismic surveys and an acoustic impedance difference volume was calculated to compare with the fluid substitution results. The Gassmann-Wood fluid substitution results predicted smaller changes in acoustic impedance than those observed from acoustic impedance inversions. At the Cranfield field, time-lapse seismic analysis was successful in mapping and quantifying the acoustic impedance change for some seismic amplitude anomalies associated with injected CO₂. Additional well log data and refinement of the fluid substitution workflow and the model-based inversion performed is necessary to obtain more accurate impedance changes throughout the field instead of at a single well location. / text

Transportation projects are unique projects that have many issues such as ROW acquisition, traffic control, and utilities. To help solve some of these issues projects should utilize constructability. Over the past 25 years research on constructability has consistently shown to have substantial cost and schedule benefits. To fully obtain those benefits, constructability should be utilized from the very beginning of the project at the conceptual planning phase. One of the tools to support implementation is 3D and 4D visualization. The benefits and applications of 3D and 4D for transportation project research is still lagging behind building projects. This thesis aims to provide a frame work for how 3D and 4D visualization could have an impactful role if used in the early planning and design process. Two case studies are used for developing that frame work, the Woodall Rodgers Deck Plaza and the Eastern Extension of President George Bush Turnpike projects in Dallas, Texas. Information taken from interviews of Texas Department of Transportation staff are used to develop a list of issues for each project, as well as the impacts those issues have had on the project. For each of those issues a proposal of how using 3D and 4D visualization could help mitigate those issues when implemented during the early planning phases. / text

Vascular endothelial cells (VECs) maintain vascular integrity by regulating the passage of solutes, macromolecules, and cells between the vascular and perivascular space and are critical in a wide number of physiological processes, such as the delivery of nutrients and oxygen to surrounding tissues, leukocyte trafficking, angiogenesis, and tissue repair. VEC permeability is regulated, at least in part, by VE-cadherin-based adherens junctions that coordinate inter-VEC contacts and communicate the strength of these interactions to the cell via the actin cytoskeleton. Although the ubiquitous second messenger, cyclic adenosine 3'€™, 5'€™-monophosphate (cAMP), has been shown to reduce VEC permeability, the molecular basis of this effect is currently unclear. Herein, we report that cAMP and its two effectors, cAMP-dependent protein kinase A-II (PKA-II) and exchange protein activated by cAMP-1 (EPAC1), improve barrier function and differentially coordinate this effect through both VE-cadherin and actin cytoskeletal structures. We have also identified cyclic nucleotide phosphodiesterase (PDE) 4 as the major PDE regulating VEC barrier function. Through the use of cAMP-elevating agents and RNAi-mediated knockdown of PKA-Cα, EPAC1 and PDE4D, we have identified a dominant role for EPAC1 in VEC permeability as well as recognized PDE4D as a potential adaptor protein VE-cadherin-based complexes. Our results are consistent with previous reports of a role for both PKA and EPAC1 in controlling VE-cadherin mediated barrier function and additionally provide novel insight into the differential roles that PKA, EPAC1 and PDE4D play in stabilizing VEC barrier function. / Thesis (Master, Pathology & Molecular Medicine) -- Queen's University, 2009-09-18 16:09:59.12