Approved for public release; distribution is unlimited / This thesis attempts to lay a foundation for producing a real-time rope model suitable for game engine usage. The model presented here is only one of the many possible approaches in modeling a rope. The basic premise used was derived from Erkin Tunca's source code. The concept is then attempted on the Open Dynamics Engine (ODE) built by Russell Smith. This work shows promise but much still needs to be done. This thesis only scratches the surface on the subject. In addition, ODE is primarily designed for (articulated) rigid bodies. Therefore, the next step is to create a deformable body (the rope) in ODE. / Major, United States Army

A new method for dynamic chirality control of a magnetic vortex is demonstrated with micromagnetic simulations. Spin transfer torque and giant magnetoresistance in an asymmetric spin valve nanopillar provide fast, reliable, and compact single-bit manipulation and readout. Magnetization relaxation following chirality switching proceeds via formation and dissipation of spin wave eigenmodes. Combined time- and frequency-domain analysis reveals a novel radial eigenmode spectrum with large edge amplitudes and nonuniform phase in the fundamental mode, in contrast with existing analytical models and experimental precedents. With the aim to determine the sources of this departure, we implement signal processing methods to identify and characterize the effects of interlayer coupling and nanoscale spatial confinement on the magnetization dynamics. Variation of the interlayer coupling and relative chirality is found to modify the eigenfrequencies but not the eigenfunctions. Examination of the interlayer phase and dynamic stray field provides quantitative and qualitative explanation of frequency splitting with relative chirality. / Graduate / 0611, 0607

The report describes the project carried out for EasyServ, whose business is based on the monitoring and diagnosis of heat pumps. Their desire for the project was to develop a more efficient test system that makes it possible to easily simulate a heat pump behavior. The purpose of this was to enable more efficient tests with better accuracy for EasyServs product. This simplifies the quality assurance of the software for their product. The main problems the project were facing was how the test system should be designed and how the simulation of the heat pump's temperature sensors would be to mimic a heat pump. Another question mark was which communication interface was best suited for the test system. The method for constructing the test system was based on the use of the simulation technology Hardware-in-the-loop (HIL). The project was thus divided into subsystems Electronics Design and Programming. In Electronic design the decisions regarding the design were taken and the construction of the test system was made. The Programming subsystem deals with the development of the simulation program. The result was a test system consisting of a Raspberry Pi and a manufactured I/O board, where communication takes place through I²C. The I/O board has eight digital potentiometers which are used to simulate the heat pump’s temperature sensors. The simulation program developed in Raspberry Pi uses Python as programming language. The conclusion is that the project's test system provides a good basis for EasyServ to test their diagnostic tool in a simple way. A potential and desirable development that makes the test system even more useful for EasyServ would be to feedback the compressor signal.

Parallel simulation is a well developed technique for executing large and complex simulation models in order to obtain simulation output for analysis within an acceptable time frame. The main contribution of this thesis is the development of different adaptive techniques to improve the consistency, performance and resilience of the BSP Time Warp as a general purpose parallel simulation protocol. We first study the problem of risk hazards in the BSP Time Warp optimistic simulation protocols. Successive refinements to the BSP Time Warp protocol are carried out to eliminate errors in simulation execution due to different risk hazards. We show that these refinements can be incorporated into the BSP Time Warp protocol with minimal performance degradation. We next propose an adaptive scheme for the BSP Time Warp algorithm that automatically throttles the number of events to be executed per superstep. We show that the scheme, operating in a shared memory environment, can minimize computation load-imbalance and rollback overhead at the expense of incurring higher synchronization cost. The next contribution of this thesis is the study of different techniques for dynamic load-balancing and process migration for Time Warp on a cluster of workstations. We propose different dynamic load-balancing algorithms for BSP Time Warp that seek to balance both computation workload and communication workload, optimizing lookaheads between processors, as well as manage interruption from external workload. Finally, we propose an adaptive technique for BSP Time Warp that automatically varies the number of processors used for parallel computation based on the characteristics of the underlying parallel computing platform and the simulation workload.

In this paper we analyze the evolution of output decisions of adaptive firms in an environment of oligopolistic competition. The firm might either choose to produce one of several existing product variants or try to establish a new product variant on the market. The demand for each individual product variant is subject to a life-cycle, but aggregate demand for product variants is constant over time. Every period each firm has to decide whether to produce the product again, to introduce a new product variant itself (which generates an initial advantage on that market), or to follow another firm and change to the production of an already established product. Different firms have heterogeneous abilities to develop products respectively imitate existing designs, and therefore the effects of the decision whether to imitate existing designs or to innovate differ between firms. We examine the evolution of behavior in this market using an agent based simulation model. The firms are endowed with simple rules to estimate market potentials and market founding potentials of all firms including themselves, and make their decisions using a stochastic learning rule. Furthermore, the characteristics of the firms change dynamically due to 'learning by doing' effects. The main questions discussed are how the success and the optimal strategy of a firm depend on the interplay between characteristics of the industry and properties of the firm. / Series: Working Papers SFB "Adaptive Information Systems and Modelling in Economics and Management Science"

Healthcare systems are traditionally characterised by complexity and heterogeneity. With the continuous increase in size and shrinkage of available resources, the healthcare sector faces the challenge of delivering high quality services with fewer resources. Healthcare organisations cannot be seen in isolation since the services of one such affects the performance of other healthcare organisations. Efficient management and forward planning, not only locally but rather across the whole system, could support healthcare sector to overcome the challenges. An example of closely interwoven organisations within the healthcare sector is the emergency medical services (EMS). EMS operate in a region and usually consist of one ambulance service and the available accident and emergency (A&E) departments within the coverage area. EMS provide, mainly, pre-hospital treatment and transport to the appropriate A&E units. The life-critical nature of EMS demands continuous systems improvement practices. Modelling and Simulation (M&S) has been used to analyse either the ambulance services or the A&E departments. However, the size and complexity of EMS systems constitute the conventional M&S techniques inadequate to model the system as a whole. This research adopts the approach of distributed simulation to model all the EMS components as individual and composable simulations that are able to run as standalone simulation, as well as federates in a distributed simulation (DS) model. Moreover, the hybrid approach connects agent-based simulation (ABS) and discrete event simulation (DES) models in order to accommodate the heterogeneity of the EMS components. The proposed FIELDS Framework for Integrated EMS Large-scale Distributed Simulation supports the re-use of existing, heterogeneous models that can be linked with the High Level Architecture (HLA) protocol for distributed simulation in order to compose large-scale simulation models. Based on FIELDS, a prototype ABS-DES distributed simulation EMS model was developed based on the London EMS. Experiments were conducted with the model and the system was tested in terms of performance and scalability measures to assess the feasibility of the proposed approach. The yielded results indicate that it is feasible to develop hybrid DS models of EMS that enables holistic analysis of the system and support model re-use. The main contributions of this thesis is a distributed simulation methodology that derived along the process of conducting this project, the FIELDS framework for hybrid EMS distributed simulation studies that support re-use of existing simulation models, and a prototype distributed simulation model that can be potentially used as a tool for EMS analysis and improvement.

Les composés organiques volatils oxygénés (COVOs) sont des espèces chimiques importantes de l’atmosphère. Ils incluent, par exemple, les alcools aliphatiques, les aldéhydes, les cétones et les acides organiques. Dans la troposphère libre, l’abondance des COVOs est plus importante que celle des hydrocarbures non méthaniques et leur réactivité globale avec OH est comparable avec celle du méthane. En revanche le méthane est présent à une concentration plus élevée. La dégradation des COVOs dans l’atmosphère s’effectue soit par la réaction avec le radical OH, soit par photolyse. La dégradation des COVOs produit des radicaux libres qui vont influencer la capacité oxydante de l’atmosphère, les concentrations en oxydes d’azotes, en radical OH et en ozone troposphérique. L’ozone est le troisième plus important gaz à effet de serre dans l’atmosphère et est l’un des composants toxiques principaux des pollutions urbaines et intervient donc dans des problèmes environnementaux graves comme le réchauffement climatique et la dégradation de la qualité de l’air. L’objectif de ce travail est de contribuer à la compréhension du comportement atmosphérique de quelques COVOs en mesurant leurs paramètres cinétiques et photochimiques apportant des donnés afin de permettre la réalisation de modélisations informatiques et l’amélioration de la connaissance des mécanismes chimiques ayant lieu dans l’atmosphère. / Oxygenated volatile organic compounds (OVOCs) are important constituents of the atmosphere. They include, e.g., aliphatic alcohols, aldehydes, ketones, and organic acids. In the free troposphere, the abundance of OVOCs is higher than that of the non-methane hydrocarbons and their overall reactivity with OH is comparable with that of methane, in contrast that methane is present in much higher concentration. Degradation of OVOCs in the atmosphere takes place via the reaction with OH radicals and, in the case of photochemically active molecules, via photolysis. Free radicals are formed in the photooxidative degradations of the oxygen containing organics which basically determine the oxidative capacity of the atmosphere, the transformation of nitrogen oxides and the concentration of OH radicals and tropospheric ozone. Ozone is the third most important greenhouse gas in the atmosphere, it is one of the toxic components of urban smog and so it is related to such grave environmental problems as global warming and the quality of air. The aim of this work is to contribute to the understanding of the atmospheric behaviour of a few OVOCs by measuring their kinetic and photochemical parameters. One of the major goals of a laboratory basic research in atmospheric chemistry is to provide kinetic and photochemical data for computer modelling and to deduce atmospheric transformation mechanisms in the case of some important chemicals.

Un automate cellulaire est un système dynamique discret qui modélise des objets ayant une évolution parallèle synchrone: l'espace est divisé en cellules ayant chacune un état et qui évoluent toutes selon une même règle locale, qui ne dépend que d'un nombre fini de cellules voisines. Malgré la simplicité de la formalisation de ce système, des comportements très complexes peuvent apparaître, qui en font notamment un modèle de calcul. Cette complexité a été rattachée à diverses théories: topologie, mesure, décidabilité, information...Nous adoptons ici une approche basée sur la dynamique symbolique, c'est à dire l'étude des mots infinis sur un alphabet donné auxquels on applique un décalage, suppression de la première lettre. À chaque automate cellulaire peut en effet être associé son tracé, l'ensemble des mots infinis représentant la séquence des états successifs pris par la cellule centrale de l'espace - ou un groupe de cellules centrales. On a alors une factorisation topologique: la lecture d'une lettre dans un de ces mots correspond exactement à une étape de l'évolution de l'automate. De nombreuses propriétés topologiques sont alors transmises par cette factorisation. Inversement, le fait que les cellules évoluent toutes de la même manière permet de déduire certaines propriétés de l'automate à partir de celles de son tracé. La première partie de la thèse est consacrée à ces nombreux liens. Une deuxième partie présente des conditions suffisantes pour qu'un ensemble de mots infinis soit le tracé d'un automate cellulaire. Enfin, une troisième partie donne un point de vue plus informatique, en récapitulant les principaux résultats d'indécidabilité sur le sujet et en prouvant que toutes les propriétés du tracé qui peuvent se voir infiniment tard sont indécidables / A cellular automaton is a discrete dynamical system which can model objects that evolve parallelly and asynchronously : the space is divided into cells, each of which has a state evolving according to some single local rule and a finite number of neighboring cells. Though this system can easily be formalized, very complex behaviors can appear ; it turns out to be a powerful computational model. That complexity can be studied with respect to various theories : topology, measure, decidability, information...We adopt here an approach bases on symbolic dynamics, linked to the topology and to the study of shifts of infinite words (suppression of their first letter). To each cellular automaton can be associated its trace subshift, the set of infinite words that represent the sequence of successive states taken by the central cell or some group of central cells. We then have a topological factorisation : reading a letter in one of these words correspond to applying a step of evolution of the automaton

Lorsque les joueurs de football réalisent plus d’un match par semaine, la durée de récupération entre deux rencontres successives pourrait être insuffisante, ce qui entraînerait une augmentation du nombre de blessures et/ou une diminution de la performance en match. L’objectif principal de cette thèse était d’identifier les facteurs (environnementaux, intrinsèques, position sur le terrain) susceptibles d’influencer la fatigue et les cinétiques de récupération de joueurs de football professionnels après un match. La présente thèse comprenait quatre études ayant pour objectifs d’analyser l’influence des courses et actions de jeu réalisées au cours d’un match (duel, saut, frappe/centre, tacle, changement de direction) ainsi que la surface de jeu (herbe naturelle contre surface synthétique) sur les cinétiques de récupération de marqueurs de performance physique, cognitive, subjectifs et biochimiques. Nos résultats ont montré que les courses réalisées au cours d’un match de football ne sont pas la cause principale de la fatigue générée par le match. Cette fatigue est également fonction des actions de jeu (duel, saut, frappe et changement de direction) réalisées au cours du match. La fatigue générée par le match est fonction de la position occupée sur le terrain (gardiens de but contre joueurs de champ). La surface de jeu n’influence pas les cinétiques de récupération de joueurs habitués à la surface synthétique. Ces résultats devraient permettre d’optimiser dans le futur les stratégies de récupération réalisées après le match. / During periods when the schedule is particularly congested (i.e. two matches per week over several weeks), the recovery time allowed between two successive matches may be insufficient. As a result, players may experience underperformance and/or injury. The overall aim of the present thesis was to identify underlying factors (environmental and intrinsic factors, playing position) that contribute to fatigue and recovery time of professional soccer players after a match. Four experimental studies were conducted to investigate the influence of soccer running activity profile, playing actions performed during a match (i.e. contact, jump, shot/long pass, tackle, change of direction) and playing surface (natural grass versus artificial turf) on the recovery kinetics of physical performance, cognitive performance, subjective ratings and biochemical parameters. Results showed that soccer running performance does not appear to be the main cause for post soccer match-induced fatigue. Post-match fatigue and recovery time depend on playing actions performed during the match (contact, jump, shot/long pass and change of direction). Post-match fatigue depends on playing position (goalkeepers versus outfield players). Playing surface does not impact recovery kinetics among regular artificial turf players. Present results may promote the prescription of more efficient and individualized recovery practices after soccer match.

Approved for public release; distribution is unlimited / A goal and behavior agent layer Java Model was developed to simulate cruise, correct and avoid Control Modules in an autonomous agent (robot). The model was tested against a deterministic Figure of Merit (FOM) to predict a "best mix" of agents for the simplistic agent economy parameters given. Future works suggests validation of the model with real agents in a real economy. / Lieutenant, United States Navy