Position of the vehicle is essential to navigate the vehicle along a desired path without any human interference. Global Positioning System (GPS) loses significant power due to signal attenuation caused by construction buildings. A good positioning system should have both good positioning accuracy and reliability. The purpose of this thesis is to implement a new positioning system using camera and examine the accuracy of the estimated vehicle position on a real-time scenario. The major focus of the thesis is to develop two algorithms for estimation of the position of the vehicle using a static camera and to evaluate the performance of the proposed algorithms. The proposed positioning system is based on two different processes. First process uses center of mass to estimate the position, while the second one utilizes gradient information to estimate the position of the vehicle. Two versions of the positioning systems are implemented. One version uses center of mass concept and background subtraction to estimate the position of the vehicle and the other version calculates gradients to estimate the position of the vehicle. Both algorithms are sensitive to point of view of the image i.e height of the camera. On comparing both algorithms, gradient based algorithm is less sensitive to the camera view. Finally, the performance is greater dependent on the height of the camera position for center of mass positioning system, as compared to the gradient positioning system but the accuracy of the systems can be improved by increasing the height of the camera. In terms of the speed of processing, the gradient positioning system is faster than the center of mass positioning system. The first algorithm, based on center of mass has 89.75\% accuracy with a standard deviation of 3 pixels and the second algorithm has an accuracy of 92.26\%. Accuracy of the system is estimated from the number of false detected positions.

Doctor of Philosophy / Department of Mechanical and Nuclear Engineering / Prakash Krishnaswami / Xiao J. Xin / Over the past two decades meshless methods have attracted much attention owing to their advantages in adaptivity, higher degree of solution field continuity, and capability to handle moving boundary and changing geometry. In this work, a meshless integral method based on the regularized boundary integral equation has been developed and applied to two-dimensional linear elasticity and elastoplasticity with small or large deformation. The development of the meshless integral method and its application to two-dimensional linear elasticity is described first. The governing integral equation is obtained from the weak form of elasticity over a local sub-domain, and the moving least-squares approximation is employed for meshless function approximation. This formulation incorporates: a subtraction method for singularity removal in the boundary integral equation, a special numerical integration for the calculation of integrals with weak singularity which further improves accuracy, a collocation method for the imposition of essential boundary conditions, and a method for incorporation of natural boundary conditions in the system governing equation. Next, elastoplastic material behavior with small deformation is introduced into the meshless integral method. The constitutive law is rate-independent flow theory based on von Mises yielding criterion with isotropic hardening. The method is then extended to large deformation plasticity based on Green-Naghdi’s theory using updated Lagrangian description. The Green-Lagrange strain is decomposed into the elastic and plastic part, and the elastoplastic constitutive law is employed that relates the Green-Lagrange strain to the second Piola-Kirchhoff stress. Finally, a pre- and post-processor for the meshless method using node- and pixel-based approach is presented. Numerical results from the meshless integral method agree well with available analytical solutions or finite element results, and the comparisons demonstrate that the meshless integral method is accurate and robust. This research lays the foundation for modeling and simulation of metal cutting processes.

Depuis que leur particularité a été mise en évidence, lesmatériaux non-linéaires mésoscopiques tels que le béton,les roches, les composites, les tissus biologiques, etc.suscitent un intérêt de plus en plus croissant. L’étude ducomportement dynamique de ces matériaux à l’aide de lathéorie classique de Landau s’est révélée incapabled’expliquer les différentes observations expérimentaleseffectuées sur cette “nouvelle classe“ de matériaux. Eneffet, ces derniers présentent des singularités(microfissures, contacts, joins de grains, dislocations, etc.)distribuées de manière hétérogène à l’échellemésoscopique. Par conséquent, différents mécanismesphysiques associés au comportement desdites singularitéspeuvent être à l’origine des non-linéarités observées.Ce travail de thèse s’intéresse à la réponse macroscopiquede différents matériaux mésoscopiques et ce dans le butd’extraire des indicateurs non-linéaires y dont ladépendance en fonction de l’amplitude d’excitation x estune loi de puissance y = axb indépendamment de laméthode expérimentale adoptée. En général, l’exposant bconnu pour être lié au mécanisme physique responsablede la non-linéarité varie de 1 à 3. Dans un premier temps,le lien existant entre les propriétés de la microstructure dechacun des matériaux étudiés et la valeur de l’exposant bnous a permis de définir différentes classes de matériaux.Par ailleurs, ce travail de thèse est également destiné àétudier la relation entre la valeur mesurée de l’exposent bet les mécanismes physiques microscopiques générés parla perturbation acoustique. A cet effet, le formalisme dePreisach-Mayergoyz a été généralisé pour définir desmodèles multi-états. Cela s’est effectué en discrétisant lesdifférentes équations continues qui décrivent différentsmécanismes physiques microscopiques tels que l’adhésionou le clapping entre les deux surfaces d’une microfissure,les forces capillaires dues à la présence de fluides ou lemouvement des dislocations au sein d’un polycristal. Danschaque modèle, on définit un ensemble statistiqued’éléments microscopiques où chaque élément estcaractérisé par ses constantes élastiques décrivant sonétat mécanique et ses paramètres de transition inter-états.La prise en compte de tous les éléments microscopiquespermet de décrire le comportement global mésoscopique.Moyennant cette démarche, il nous a ainsi été possible deremonter aux résultats expérimentaux par simplerésolution de l’équation de propagation dans un milieucomposé de plusieurs éléments mésoscopiques.L’un des résultats importants de cette thèse est que lavaleur de l’exposant b peut être théoriquement préditeconnaissant le nombre de paramètres de transition dans lemodèle, les contraintes géométriques ainsi que leurdistribution statistique. De plus, l’application de cetteétude dans le cas du béton de génie civil graduellementmicrofissuré a permis de montrer que la prise en compted’un seul mécanisme de non-linéarité n’était passuffisante pour expliquer les observations expérimentales.En effet, l’étude théorique a montré que l’évolution de lamicrofissuration entraine celle des mécanismesnon-linéaires mis en jeu où la combinaison“hystérésis-clapping“, par exemple, a permis d’expliquerl’évolution du comportement non-linéaire du béton degénie civil à l’échelle microscopique. / Nonlinear mesoscopic elastic (NME) materials present ananomalous nonlinear elastic behavior, which could not beexplained by classical theories. New physical mechanismsshould be individuated to explain NMEs response.Dislocations in damaged metals, fluids in rocks andadhesion (in composites) could be plausible. In this thesisI have searched for differences in the macroscopic elasticresponse of materials which could be ascribed to differentphysical processes. I have found that the nonlinearindicators follow a power law behavior as a function of theexcitation energy, with exponent ranging from 1 to 3 (thisis not completely new). This allowed to classify materialsinto well-defined classes, each characterized by a value ofthe exponent and specific microstructural properties. Tolink the measured power law exponent to plausiblephysical mechanisms, I have extended thePreisach-Mayergoyz formalism for hysteresis to multi-statemodels. Specific multi-state discrete models have beenderived from continuous microscopic physical processes,such as adhesion-clapping, adhesion-capillary forces,dislocations motion and hysteresis. In each model, themicroscopic behavior is described by a multistate equationof state, with parameters which are statisticallydistributed. Averaging over many microscopic elements theso-called mesoscopic equation of state is derived and, fromwave propagation simulations in a sample composed bymany mesoscopic elements, the experimental results couldbe reproduced. In the work of the thesis, I have shownthat model predictions of the exponent b ( the exponent bhas not been introduced before) are linked in a ‘a priori’predictable way to the number of states and the propertiesof the statistical distribution adopted. We have classifiedmodels into classes defined by a different exponent b andcomparing with experimental results we have suggestedplausible mechanisms for the nonlinearity generation.

Teaching mathematics towards mathematical proficiency cannot easily be described since mathematical proficiency is complex and no term alone capture all aspects. The purpose of the study was to examine how mathematical proficiency in conceptual understanding can be discriminated through the concept of subtraction in grade 1 and 3 primary school. Question raised by the study was 1. What different levels in quality can be discriminated in the ways students subtracts?   2. Can progression be discriminated within subtraction operations between grade 1 and 3? Concepts like mathematical artefacts, capability and ability have been useful tools when analyzing the material. Developing mathematical thinking in students is about developing conceptual understanding anchored in the process rather than focus on procedures and outcome. When subtracting with comprehension one knows that subtraction undoes addition since subtraction is the inverse operation of addition.      The methods used are qualitative studies using observations and interviews. The material consists of notes from observations, recordings of interviews and written solutions. The study developed an analysis tool in order to compare the different ways of thinking when doing subtraction activities. Developing the tool was critical in order to compare and discriminate different levels of mathematical thinking. The results indicate that the Swedish curricula in mathematics do not support mathematical teaching towards mathematical proficiencies because it’s lack of concrete measurable goals.

La presente tesis está enmarcada en el área de visión por computador y en ella se realizan aportaciones encaminados a resolver el problema de segmentar automáticamente objetos en imágenes de escenas adquiridas en entornos donde se está realizando actividad, es decir, aparece movimiento de los elementos que la componen, y con iluminación variable o no controlada. Para llevar a cabo los desarrollos y poder evaluar prestaciones se ha abordado la resolución de dos problemas distintos desde el punto de vista de requerimientos y condiciones de entorno. En primer lugar se aborda el problema de segmentar e identificar, los códigos de los contenedores de camiones con imágenes tomadas en la entrada de un puerto comercial que se encuentra ubicada a la intemperie. En este caso se trata de proponer técnicas de segmentación que permitan extraer objetos concretos, en nuestro caso caracteres en contenedores, procesando imágenes individuales. No sólo supone un reto el trabajar con iluminación natural, sino además el trabajar con elementos deteriorados, con contrastes muy diferentes, etc. Dentro de este contexto, en la tesis se evalúan técnicas presentes en la literatura como LAT, Watershed, algoritmo de Otsu, variación local o umbralizado para segmentar imágenes en niveles de gris. A partir de este estudio, se propone una solución que combina varias de las técnicas anteriores, en un intento de abordar con éxito la extracción de caracteres de contenedores en todas las situaciones ambientales de movimiento e iluminación. El conocimiento a priori del tipo de objetos a segmentar nos permitió diseñar filtros con capacidad discriminante entre el ruido y los caracteres. El sistema propuesto tiene el valor añadido de que no necesita el ajuste de parámetros, por parte del usuario, para adaptarse a las variaciones de iluminación ambientales y consigue un nivel alto en la segmentación e identificación de caracteres. / Rosell Ortega, JA. (2011). Study of segmentation and identification techniques applied to environments with natural illumination and moving objects [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/10863 / Palancia

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18460号 / 医博第3915号 / 新制||医||1005(附属図書館) / 31338 / 京都大学大学院医学研究科医学専攻 / (主査)教授 伊達 洋至, 教授 平岡 眞寛, 教授 福山 秀直 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

In this paper, a computer vision system for counting people standing in line is presented. In this application, common techniques such as Adaptive Background Subtraction (ABS), blob tracking with Kalman filter, and occlusion resistive techniques are used to detect and track people. Additionally, a novel method using Dual Adaptive Background Subtractors (DABS) is implemented for dynamically determining the line region in a real-world crowded scene, and also as an alternative target acquisition to regular ABS. The DABS technique acts as a temporal bandpass filter for motion, helping identify people standing in line while in the presence of other moving people. This is achieved by using two ABS with different temporal adaptiveness. Unlike other computer vision papers which perform tests in highly controlled environments, the DABS technique is tested in a crowded Starbucks© at the Cal Poly student union. For any length of people standing in line, result shows that DABS has a lower mean error by one or more people when compared to ABS. Even in challenging crowded scenes where the line can reach 19 people in length, DABS achieves a Normalized RMS Error of 43%.

This diploma thesis deals with posibilities of tracking object movement using computer vision algorithms. First chapters contain review of methods used for background subtraction, there are also listed basic detection approaches and thesis also mentions algorithms which allows tracking and movement prediction. Next part of this work informs about algoritms implemented in resulting software and its graphical user interface. Evaluation and comparison of original and modified algorithms is stationed at the end of this text.

This work proposes a system that utilizes both infrared and visual imagery to create a more robust object detection and classification system. The system consists of two main parts: a moving object detector and a target classifier. The first stage detects moving objects in visible and infrared spectrum using background subtraction based on Gaussian Mixture Models. Low-level fusion is performed to combine the foreground regions in the respective domain. For the second stage, a Convolutional Neural Network (CNN), pre-trained on the ImageNet dataset is used to classify the detected targets into one of the pre-defined classes; human and vehicle. The performance of the proposed object detector is evaluated using multiple video streams recorded in different areas and under various weather conditions, which form a broad basis for testing the suggested method. The accuracy of the classifier is evaluated from experimentally generated images from the moving object detection stage supplemented with publicly available CIFAR-10 and CIFAR-100 datasets. The low-level fusion method shows to be more effective than using either domain separately in terms of detection results. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

Experimental grade III furcation defects were developed bilaterally at the second and fourth premolars in 18 conditioned, laboratory-source, adult Beagles and maintained for 12 weeks. All defects were treated with debridement and mucoperiosteal flap repositioning alone, or with the addition of autologous fibrinogen, Resolut® barrier membrane, or autologous fibrinogen and Resolut® barrier membrane. The defects were analyzed by digital subtraction radiography, histopathologic, and histomorphometric analysis of healing at 1, 3, and 6 months post-treatment to determine: percent increase in defect bone volume, height and area, and length of periodontal regeneration along the perimeter of the defect. Comparisons at post-treatment intervals indicated significantly (P < 0.05) greater healing of debridement and autologous fibrinogen treated defects at 3 months, however by 6 months there were no significant differences in defect healing for all histomorphometric parameters. Defects receiving Resolut® were associated with significantly less root ankylosis. Defects receiving debridement alone had significantly greater increases in bone volume, as calculated with digital subtraction radiography, at 6 months post-treatment compared with groups receiving Resolut®. There was a significant correlation between regenerated bone area, bone volume, and periodontal regeneration for all treatments at 3 and 6 months post-treatment. In this study autologous fibrinogen and Resolut® barrier membrane did not enhance the amount of periodontal healing compared with debridement only. However, Resolut® treated defects were essentially absent of root ankylosis. Therefore, canine periodontitis causing grade III furcation involvement may respond equally well to conservative periodontal surgery compared with guided tissue regenerative techniques. However, the prevention of root ankylosis may provide a substantial benefit favoring this latter methodology. / Master of Science