We investigate charmonium production in the hot medium created by heavy-ion collisions by setting up a framework in which in-medium charmonium properties are constrained by thermal lattice QCD (lQCD) and subsequently implemented into kinetic approaches. A Boltzmann transport equation is employed to describe the time evolution of the charmonium phase space distribution with the loss and gain term accounting for charmonium dissociation and regeneration (from charm quarks), respectively. The momentum dependence of the charmonium dissociation rate is worked out. The dominant process for in-medium charmonium regeneration is found to be a 3-to-2 process. Its corresponding regeneration rates from different input charmquark momentum spectra are evaluated. Experimental data on J/[psi] production at CERN-SPS and BNL-RHIC are compared with our numerical results in terms of both rapidity-dependent inclusive yields and transverse momentum (pt) spectra. Within current uncertainties from (interpreting) lQCD data and from input charm-quark spectra the centrality dependence of J/[psi] production at SPS and RHIC (for both mid-and forward rapidity) is reasonably well reproduced. The J/[psi] pt data are shown to have a discriminating power for in-medium charmonium properties as inferred from different interpretations of lQCD results.

Kinodynamic motion planning is an important problem in robotics. It consists of planning the dynamic motion of a robotic system taking into account its kinematic and dynamic constraints. For this class of problems, high dimensionality is a major difficulty and finding an exact time optimal robot motion trajectory is proven to be NP-hard. Probabilistic approximate techniques have therefore been proposed in the literature to solve particular problem instances. These methods include Randomized Potential Field Planners (RPP), Probabilistic Roadmaps (PRM) and Rapidly Exploring Random Trees (RRT). When physical obstacles and differential constraints are added to the problem, applying RPPs or PRMs encounter difficulties. In order to handle these difficulties, RRTs have been proposed. In this study, we consider a multiple camera industrial inspection problem where the concurrent motion of these cameras needs to be planned. The cameras are required to capture maximum number of defect locations while globally avoiding collisions with each other and with obstacles. Our approach is to consider a solution to the kinodynamic planning problem of multiple camera inspection by making use of the RRT algorithm. We explore and resolve issues arising when RRTs are applied to this specific problem class. Along these lines, we consider the cases of a single camera without obstacles and then with obstacles. Then, we attempt to extend the study to the case of multiple camera where we also need to avoid collisions between cameras. We present simulation results to show the performance of our RRT based approach to different instrument configurations and compare with existing deterministic approaches.

This thesis focuses on the development of guidance algorithms in order to avoid a prescribed obstacle primarily using the Collision Cone Method (CCM). The Collision Cone Method is a geometric approach to obstacle avoidance, which forms an avoidance zone around the obstacles for the vehicle to pass the obstacle around this zone. The method is reactive as it helps to avoid the pop-up obstacles as well as the known obstacles and local as it passes the obstacles and continue to the prescribed trajectory. The algorithm is first developed for a 2D (planar) avoidance in 3D environment and then extended for 3D scenarios. The algorithm is formed for the optimized CCM as well. The avoidance zone radius and velocity are optimized using constraint optimization, Lagrange multipliers with Karush-Kuhn-Tucker conditions and direct experimentation.

<p>The purpose of the present study was to examine effects of driver, vehicle, and environment characteristics on Collision Warning System (CWS) design. One hypothesis was made that the capability of collision avoidance would not be same among a driver, vehicle, and environment group with different characteristics. Accident analysis and quantitative analysis was used to examine this hypothesis in terms of ‘risk’ and ‘safety margin’ respectively. Rear-end collision had a stronger focus in the present study. </p><p>As a result of accident analysis, heavy truck showed a higher susceptibility of the fatal rear-end accidents than car and light truck. Also, dry road surface compared to wet or snow, dark condition compared to daylight condition, straight road compared to curved road, level road compared to grade, crest or sag, roadway having more than 5 travel lanes compared to roadway having 2, 3 or 4 travel lanes showed a higher susceptibility of the fatal rear-end accidents. Relative rear-end accidents involvement proportion compared to the other types of collision was used as a measure of susceptibility. </p><p>As a result of quantitative analysis, a significant difference in terms of Required Minimum Warning Distance (RMWD) was made among a different vehicle type and braking system group. However, relatively small difference was made among a different age, gender group in terms of RMWD. Based on the result, breaking performance of vehicle should be regarded as an input variable in the design of CWS, specifically warning timing criteria, was concluded.</p>

<p>This Master’s thesis is a pilot study that investigates different systems to drive autonomous and non-autonomous vehicles simultaneously on test tracks. The thesis includes studies of communication, positioning, collision avoidance, and techniques for surveillance of vehicles which are suitable for implementation. The investigation results in a suggested system outline.</p><p>Differential GPS combined with laser scanner vision is used for vehicle state estimation (position, heading, velocity, etc.). The state information is transmitted with IEEE 802.11 to all surrounding vehicles and surveillance center. With this information a Kalman prediction of the future position for all vehicles can be estimated and used for collision avoidance.</p>

<p>Today many car manufactures are developing systems that help the driver to avoid collisions. Examples of this kind of systems are: adaptive cruise control, collision warning and collision mitigation / avoidance. </p><p>All these systems need to track and predict future positions of surrounding objects (vehicles ahead of the system host vehicle), to calculate the risk of a future collision. To validate that a prediction is correct the predictions must be correlated to observations. This is called the data association problem. If a prediction can be correlated to an observation, this observation is used for updating the tracking filter. This process maintains the low uncertainty level for the track. </p><p>From the work behind this thesis, it has been found that a sequential nearest- neighbour approach for the solution of the problem to correlate an observation to a prediction can be used to find the solution to the data association problem. </p><p>Since the computational power for the collision mitigation system is limited, only the most dangerous surrounding objects can be tracked and predicted. Therefore, an algorithm that classifies and selects the most critical measurements is developed. The classification into order of potential risk can be done using the measurements that come from an observed object.</p>

Mon travail de thèse, concernant les collisions centrales Au+Au entre 40 et 100 MeV/A, se place dans le cadre d'une analyse comprenant le dépouillement et l'interprétation des résultats de la 4ème campagne de mesure du multidétecteur INDRA. La première phase de cette étude, dite de "dépouillement", a permis de reconstruire, à partir des données brutes des deux premiers étages de détection d'INDRA (chambre d'ionisation, Silicium), les énergies cinétiques et la charge des fragments détectés. Pour la première fois, il a été possible de mettre en évidence et de corriger les effets de non-linéarité dans la chaîne d'acquisition <br />d'INDRA. A l'issue de ce travail, je me suis attaché à selectionner les collisions centrales. <br />Pour ce faire, et dans le souci de ne pas biaiser les interprétations physiques résultantes, j'ai mis en oeuvre deux méthodes distinctes: sélection en paramètre d'impact ainsi qu'une analyse en composante principale. Une étude comparative de ces deux outils mathématiques a été entreprise donnant lieu à des résultats très instructifs.<br /><br /><br />L'interprétation des résultats a fait appel à plusieurs types de modèles lesquels impliquant la validité de certaines hypothèses (équilibre thermodynamique, existence d'un volume de "freeze-out"). L'emploi de modèles statistiques (SMM, MMMC) a permis <br />d'extraire la taille du système émetteur, dit "source unique", ainsi que son énergie d'excitation. L'anisotropie des distributions en énergie cinétiques des fragments, a permis de <br />mettre en évidence, en fonction de l'énergie incidente de la collision, une déformation de la source, mais également de reconstruire les énergies thermique et collective entrant en jeu. Une nouvelle comparaison des données à l'aide de modèles dits "dynamique" (QMD,CMD) a été également entreprise. A l'issu de cette étude, des critiques portant sur la validité d'une approche telles SMM ou MMMC ont pu être émises remettant en jeu le fondement de l'interprétation physique du flot collectif couramment employé.

Σκοπός αυτής της διπλωματικής εργασίας είναι να αναπτυχθεί ένα μοντέλο αποφυγής συγκρόυσεων μεταξύ των οχημάτων μέσω της επικοινωνίας αυτών. Το σύστημα αυτό θα πρέπει να αναγνωρίζει τις περιπτώσεις που εγκυμονούν κίνδυνο μέσω της ανταλλαγής μηνυμάτων από τα οχήματα κάθε χρονική στιγμή και μέσα από διάφορους μηχανισμούς που επιτελούνται από αυτό, τελικά, να επεμβαίνει και να αποτρέπει τη σύγκρουση ή να ειδοποιεί τον οδηγό ώστε αυτός να αντιδράσει εγκαίρως. Για να το πετύχουμε αυτό ακολουθήσαμε τα εξής βήματα: 1. Προσομοιώσαμε τη λειτουργία μίας συσκευής GPS. 2. Σχεδιάσαμε λεκτικά και γραφικά τα μοντέλα κίνησης στα οποία θα τρέχει το σύστημά μας. 3. Ορίσαμε ένα πρωτόκολλο ανταλλαγής μηνυμάτων και προειδοποίησης σε περίπτωση συγκρουσης για αυτά τα μοντέλα κίνησης. 4. Αναπτύξαμε το σύστημα μέσω της matlab, λαμβάνοντας υπόψιν το πρωτόκολλο και τα σενάρια κίνησης των προηγούμενων βημάτων. 5. Κατασκευάσαμε μία διεπαφή εποπτίας και ελέγχου όλου του συστήματος. 6. Τέλος, κατασκευάσαμε ένα GUI ειδοποίησης του οδηγού σε περιπτώσεις κινδύνου. / Distributed traffic Control for Optimisation of the Safety Conditions.

Low energy (tens of eV) polyatomic cations were used as probes for characterization of monolayers of spontaneously chemisorbed thiols on gold. Characteristics including chemical composition, surface order and orientation of the self-assembled monolayers (SAMs) can be derived by monitoring the products of projectile ion neutralization, surface-induced dissociation (SID), and ion-surface reactions.To study the influence of the terminal group chemical structures and orientations of the SAMs on ion-surface interactions, a series of semi-fluorinated alkane thiols with difluoromethylenes buried underneath hydrocarbon terminal groups were examined (CH3CF2CH2− and CH3CH2CF2−). Compared to terminally fluorinated SAMs, they showed more projectile ion neutralization and less internal to vibrational energy deposition into precursor ions. Projectile ion-hydrocarbon reactions decreased significantly when difluoromethylenes are one or two bonds away from the terminal group. Furthermore, ion-surface reaction results on surfaces with odd and even chain lengths suggested that they have similar terminal methyl orientations to their hydrocarbon counterparts.Mixed monolayers of CF3CF2(CH2)14SH (F-SAMs) and CH3(CH2)15SH (H-SAMs) with systematically changing electron transfer, energy deposition and ion-surface reaction were prepared using mixed thiols solution and micro-contact printing (μ-CP). The solution mixture system showed linear variations in electron transfer and energy deposition with different F-SAM surface concentrations, while non-linear changes occur for ion-surface reaction suggesting strong lateral interactions between the two components. These interactions are minimized in the μ-CP system containing domains of each thiol. Energy deposition on the patterned surfaces varies non-linearly with changing F-SAM concentration which differs from the homogenously mixed system.To explore SID with a 90 collision angle, eV SID of a series of protonated peptide ions were performed in an in-line sector Time-Of-Flight (TOF) mass spectrometer. The results were compared to keV collision-induced dissociation (CID) data collected with the same instrument. Fragmentation efficiency for SID was higher than CID for those peptides. In addition to the excellent control over laboratory collision energies with SID, different amount of energy deposition can be achieved when varying surface composition, e.g. using mixed F-SAM/H-SAM.Reactive ion scattering spectrometry (RISS) results provided more in-depth knowledge of low energy ion-surface interactions that will promote usage of RISS as a novel surface characterization technique.

This Master’s thesis is a pilot study that investigates different systems to drive autonomous and non-autonomous vehicles simultaneously on test tracks. The thesis includes studies of communication, positioning, collision avoidance, and techniques for surveillance of vehicles which are suitable for implementation. The investigation results in a suggested system outline. Differential GPS combined with laser scanner vision is used for vehicle state estimation (position, heading, velocity, etc.). The state information is transmitted with IEEE 802.11 to all surrounding vehicles and surveillance center. With this information a Kalman prediction of the future position for all vehicles can be estimated and used for collision avoidance.