Due to the unsustainable space debris environment in Low Earth Orbit, debris objects must be removed to ensure future safe satellite operations. One proposed concept for deorbiting larger space debris objects, such as decommissioned satellites or spent upper rocket stages, is to use a chaser spacecraft connected to the debris object by an elastic tether, but the required technology is immature and there is a lack of flight experience. The inoperable satellite, Envisat, has been chosen as a representative object for controlled re-entry by performing several high thrust burns. The aim of this paper is to develop a control system for the deorbit phase of such a mission. Models of the spacecraft dynamics, the tether, and sensors are developed to create a simulator. Two different tether models are considered: the massless model and the lumped mass model. A switched linear-quadratic-Gaussian (LQG) controller is designed to control the relative position of the debris object, and a switched proportional-integral-derivative (PID) controller is designed for attitude control. Feedforward compensation is used to counteract the couplings between relative position and attitude dynamics. An analysis of the system suggests that the tether should be designed in regard to the control system and it is found that the lumped mass model comes with higher cost than reward compared to the massless tether model in this case. Simulations show that the control system is able to control the system under the influence of modeling errors during a multi-burn deorbit strategy and even though more extensive models are suggested to enable assessment of the feasibility to perform this mission in reality, this study has resulted in extensive knowledge and valuable progress in the technical development. / En ökande mängd rymdskrot har lett till en ohållbar miljö i låga omloppsbanor och föremål måste nu tas bort för att säkerställa framtida satellitverksamhet. En föreslagen metod för att avlägsna större skrotföremål, såsom avvecklade satelliter och använda övre raketsteg, är att koppla en jagande rymdfarkost till föremålet med en elastisk lina. Dock är den teknik som behövs inte mogen och det finns en brist på praktisk erfarenhet. Den obrukbara satelliten Envisat har valts som representativt objekt för kontrollerat återinträde genom flera perigeumsänkande raketmanövrar. Syftet med detta arbete är att utveckla ett system för att kontrollera de två sammankopplade rymdfarkosterna under avlägsningsfasen under ett sådant uppdrag. Modeller för farkosternas dynamik, den sammankopplande linan och sensorer byggs för att utveckla en simulator. Två olika modeller för linan undersöks: den masslösa modellen och den klumpade nodmassmodellen. En omkopplande regulator designas genom minimering av kvadratiska kriterier för att kontrollera skrotföremålets relativa position till den jagande farkosten. Vidare designas en omkopplande proportionerlig-integrerande-deriverande (PID) regulator för att reglera pekningen hos den jagande farkosten. Kompensering genom framkoppling används för att motverka de korskopplingar som förekommer mellan translations- och rotationsdynamiken. En analys av systemet visar att linan bör designas med reglersystemet i åtanke och det framkommer att nackdelarna överväger fördelarna för den klumpade nodmassmodellen jämfört med den masslösa modellen. Simuleringar visar att reglersystemet klarar att kontrollera systemet under ett scenario med flera manövrar och under inverkan av modellfel. Även om mer omfattande modeller föreslås för att möjliggöra en fullständig bedömning av genomförbarheten för detta uppdrag så har denna studie resulterat i en omfattande kunskapsvinst och värdefulla framgångar i det tekniska utvecklingsarbetet.

Improved utilization of scarce resources such as health care personnel is necessary to address well-known problem of long waiting times within the health care. Implementing mathematically modeled scheduling in the operating theatre has the potential to result in more efficient allocation of resources and financial gains. Despite the promising results, the adoption rate of such models is low. This thesis examines the impact of a mixed-integer linear programming model using an overlapping strategy. We perform a computational experiment where both sequential and parallel schedules are produced with real surgery data from an orthopedic department at a Swedish university hospital. The generated schedules are compared against each other in measurements of cost productivity. Statistical analysis shows that there is a statistical significant difference between the two schedules, favoring the optimized schedule. The results further suggest that three operating rooms and four surgery teams is the most optimal combination of the 18 combinations analyzed, where operating rooms and surgery teams varies between 1-4 and 1-6, respectively.

Certainly one of the most powerful and important modeling languages of our time is the Calculus. But research consistently shows that students do not understand how the variables in calculus-based mathematical models relate to aspects of the systems that those models are supposed to represent. Because of this, students never access the true power of calculus: its suitability to model a wide variety of real-world systems across domains. In this paper, we describe the motivation and theoretical foundations for the DeltaTick and HotLink Replay applications, an effort to address these difficulties by a) enabling students to model a wide variety of systems in the world that change over time by defining the behaviors of that system, and b) making explicit how a system\''s behavior relates to the mathematical trends that behavior creates. These applications employ the visualization and codification of behavior rules within the NetLogo agent-based modeling environment (Wilensky, 1999), rather than mathematical symbols, as their primary building blocks. As such, they provide an alternative to traditional mathematical techniques for exploring and solving advanced modeling problems, as well as exploring the major underlying concepts of calculus.

Aujourd’hui, plusieurs niveaux de complexité ont émergé dans l’étude des phénotypes T CD4 auxiliaires. 1) le nombre important de cytokines différentes pouvant être secrétées par les lymphocytes T CD4. 2) la multiplicité de signaux pouvant agir durant la différenciation des T CD4 pour spécifier leur profile de sécrétion cytokinique. 3) l’association de ces différents profils de cytokines à des pathologies complexes. Au cours de mon doctorat je me suis concentré sur ces trois niveaux de complexité en étudiant la génération de la diversité cytokinique T CD4 et ses associations aux différents sous types de cancer du sein en utilisant des analyses multivariées et des modèles statistiques. Tout d’abord, j’ai pu construire le premier modèle multivarié de la différentiation T CD4 reliant 37 signaux venant de cellules dendritiques à 18 cytokines T CD4. Utilisant ce modèle pour dériver des prédictions, j’ai pu trouver un nouveau rôle à l’IL-12p70 en tant qu’inducteur de différenciation Th17, mais également comme inducteur spécifique d’IL-17F mais pas d’IL-17A lorsqu’il est combiné à l’IL-1. Ensuite, j’ai étudié l’association de ces cytokines T CD4 avec les différents sous types de cancer du sein connus. J’ai pu trouver que les cytokines Th17 étaient préférentiellement associées avec les cancers du sein dits triple négatifs (TNBC). J’ai pu mettre en évidence qu’une forte signature Th17 était associée à une meilleure survie. De plus, en combinant cette signature Th17 à des scores utilisés pour définir le pronostic clinique, tel que l’index pronostic de Nottingham, j’ai pu proposer une nouvelle et meilleure stratification de la survie de ces patients. / Today several levels of complexity have emerged in the field of T helper cytokines: 1) the important number of distinct cytokines that Th cell can secrete in various combinations; 2) The multiplicity of signals that can act during Th differentiation to define the Th cytokine secretion profiles 3) The associations of these T helper secretion profiles with complex diseases. During my PhD I focused on these three levels of complexity and study the generation of T helper cytokine diversity and its association to breast cancer subtypes using multivariate analysis and statistical modeling. First, I was able to build the first statistical model linking 37 dendritic cell derived signals to 18 T helper cytokines. Using this model to derive in silico predictions, I was able to found a new role for IL-12p70 as a promoter of Th17 differentiation and as a main differential inducer of IL-17F independently of Il-17A in presence of IL-1. Then, studying the associations of the Th cytokine diversity with the different subtypes of human breast cancers, I found that Th17 cytokines were preferentially associated to Triple Negative Breast Cancer (TNBC). I found that TNBC patients with a high Th17 signature had a better survival. In addition, I showed that Th17 can be combined to clinical prognosis assessment scores, such as the Nottingham Prognosis Index, to better stratify TNBC patients in relevant subgroups for survival prognosis assessment.

No description available.

abstract: Behavior-driven obesity has become one of the most challenging global epidemics since the 1990s, and is presently associated with the leading causes of death in the U.S. and worldwide, including diabetes, cardiovascular disease, strokes, and some forms of cancer. The use of system identification and control engineering principles in the design of novel and perpetually adaptive behavioral health interventions for promoting physical activity and healthy eating has been the central theme in many recent contributions. However, the absence of experimental studies specifically designed with the purpose of developing control-oriented behavioral models has restricted prior efforts in this domain to the use of hypothetical simulations to demonstrate the potential viability of these interventions. In this dissertation, the use of first-of-a-kind, real-life experimental results to develop dynamic, participant-validated behavioral models essential for the design and evaluation of optimized and adaptive behavioral interventions is examined. Following an intergenerational approach, the first part of this work aims to develop a dynamical systems model of intrauterine fetal growth with the prime goal of predicting infant birth weight, which has been associated with subsequent childhood and adult-onset obesity. The use of longitudinal input-output data from the “Healthy Mom Zone” intervention study has enabled the estimation and validation of this fetoplacental model. The second part establishes a set of data-driven behavioral models founded on Social Cognitive Theory (SCT). The “Just Walk” intervention experiment, developed at Arizona State University using system identification principles, has lent a unique opportunity to estimate and validate both black-box and semiphysical SCT models for predicting physical activity behavior. Further, this dissertation addresses some of the model estimation challenges arising from the limitations of “Just Walk”, including the need for developing nontraditional modeling approaches for short datasets, as well as delivers a new theoretical and algorithmic framework for structured state-space model estimation that can be used in a broader set of application domains. Finally, adaptive closed-loop intervention simulations of participant-validated SCT models from “Just Walk” are presented using a Hybrid Model Predictive Control (HMPC) control law. A simple HMPC controller reconfiguration strategy for designing both single- and multi-phase intervention designs is proposed. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2021

Continuous caster moulds are the last and most important stage in the steelmaking process, where inclusions can either be generated or removed. With increasing casting speed using conventional immersion nozzles critical problems, such as unstable bulk mould flow have been noticed. Mould flux entrapment due to vortex and shearing action from the oscillating surface waves have become of particular concern. It is therefore necessary to have a calm inlet flow at the entrance of the mould. Recently, it has been acknowledged that a swirl blade placed at the upstream of the immersion nozzle effectively resolves the problems arising from unstable bulk mould flow. Therefore, to increase the knowledge of effect of swirling flow on the flow pattern in the mould, fundamental mathematical models of a billet mould equipped with a swirl blade in the nozzle have been developed. The model was used to study the effect of divergent angle of the immersion nozzle and mould aspect ratio on the flow field and temperature distribution inside billets moulds. Data from water model experiments were used to verify the mathematical model predictions. A fairly good agreement was found between physical modeling data and predictions, which ensured that the numerical model is reliable. Thereafter, the differences between square and round billet moulds were studied. Next, the effect of changing aspect ratio of the rectangular mould on the fluid flow and heat transfer, while keeping mould surface area constant, was studied. Two types of immersion nozzles, bottomless and conventional, were also analyzed during the research. The model moulds were changed gradually from a square billet with an aspect ratio of 1x1 to a rectangular billet with an aspect ratio of 3x1. First, the temperature and velocity distributions were calculated. Later, unsteady calculations were done to determine velocity fluctuations on the meniscus level for two types of nozzles and several moulds geometries. / <p>QC 20101110</p>

The relevance of the topic is due to the fact that copper is used in all sectors of industry: engineering, electrical industry, household industry, construction, etc. It produces wires and cables, pipes, cooling systems and much more. Thus, the scope of copper is constantly expanding, so the need for it is growing from year to year. Copper mining from natural sources is expensive and not environmentally friendly. Therefore, it is much more efficient to produce copper by secondary processing. In modern conditions, it is important to be able to predict the resource base of the enterprise in the short and long term, because this helps to direct investments in the right direction and to avoid economic losses. The aim of the work is to build a predictive model of the copper scrap market using key parameters. Tasks of work: • to consider the theoretical aspects of the development of the Russian copper scrap market; • to evaluate key indicators of the copper scrap market and adjust the model characterizing the dynamics of the volume of copper scrap; • to develop a forecast model and produce a forecast; • to analyze the enterprises of the metallurgy market; • to identify the behavior strategies of agents in the copper scrap market and build a diagram of competitive behavior strategies; • to evaluate the effectiveness of the competitive behavior strategy chart; • to evaluate the economic efficiency of creating a new information system. / Актуальность темы обусловлена тем, что медь используется во всех секторах промышленности: для машиностроения, электротехнической промышленности, бытовой промышленности, в строительстве и т.д. Из нее изготавливаются провода и кабели, трубы, системы охлаждения и многое другое. Таким образом, сферы применения меди постоянно расширяются, поэтому потребности в ней растут из года в год. Добыча меди из природных источников процесс дорогостоящий и не экологичный. Поэтому гораздо эффективнее получать медь путем вторичной обработки. В современных условиях, важно уметь прогнозировать ресурсную базу предприятия в краткосрочной и долгосрочной перспективе, т.к. это помогает направить инвестиции в нужное русло и избежать экономических потерь. Целью работы является построение прогнозной модели рынка медного лома с использованием ключевых параметров. Задачи работы: • рассмотреть теоретические аспекты развития рынка медного лома РФ; • оценить ключевые показатели рынка медного лома и скорректировать модель, характеризующую динамику объема медного лома; • разработать прогнозную модель и произвести прогноз; • провести анализ предприятий рынка металлургии; • выявить стратегии поведения агентов на рынке медного лома и построить диаграмму конкурентной стратегии поведения; • оценить эффективность диаграммы конкурентной стратегии поведения; • оценить экономическую эффективность создания новой информационной системы.

The thesis is devoted to the development of software for the system of optimal distribution of fuel and energy resources in the group of blast furnaces. In the course of work, the main stages of software development are considered: analysis of the subject area; creation of software architecture, user interface, database structure; development of algorithmic support and reference documentation; preparation of the distribution. The result of the work is a software product intended for the engineering and technological personnel of the blast furnace shop of the metallurgical plant. The results of the work can also be used in the educational process for training bachelors and undergraduates in the areas of "Metallurgy" and "Information Systems and Technologies". / Диссертационная работа посвящена разработке программного обеспечения системы оптимального распределения топливно-энергетических ресурсов в группе доменных печей. В ходе работы рассмотрены основные этапы разработки программного обеспечения: анализ предметной области; создание архитектуры программного обеспечения, пользовательского интерфейса, структуры базы данных; разработка алгоритмического обеспечения и справочной документации; подготовка дистрибутива. Результатом работы является программный продукт, предназначенный для инженерно-технологического персонала доменного цеха металлургического комбината. Результаты работы могут быть использованы также в учебном процессе для обучения бакалавров и магистрантов по направлениям «Металлургия» и «Информационные системы и технологии».

Понимание влияния макроэкономических показателей на экономику государства актуально для институтов власти, таких как центральный банк. Целью данной диссертационной работы является разработка методики динамического моделирования для исследования взаимодействий макроэкономических показателей, а также для создания инструментов для осуществления монетарной политики. Объект данного исследования выступают макроэкономические процессы. Предметом исследования является макроэкономическая модель Российской федерации и ее основные регуляторы. В результате магистерского исследования решены ряд задач: изучена теории мировой экономики, а также проведен анализ макроэкономических показателей, разработанная и произведена программная реализована методики динамических моделей: проведено тестирование программного продукта, и построение сетевых моделей. / Understanding the impact of macroeconomic indicators on the state’s economy is relevant to government institutions, such as the central bank. The purpose of this dissertation is to develop a dynamic modeling methodology for studying the interactions of macroeconomic indicators, as well as for creating tools for implementing monetary policy. The object of this study are macroeconomic processes. The subject of the research is the macroeconomic model of the Russian Federation and its main regulators. As a result of the master's research, a number of problems were solved: the theory of the world economy was studied, and macroeconomic indicators were analyzed, a dynamic model methodology was developed and software implemented: a software product was tested, and network models were built.