Feature-based tracking of urethral motion in low-resolution trans-perineal ultrasound

This paper describes a novel algorithm for tracking the motion of the urethra from trans-perineal ultrasound. Our work is based on the structure-from-motion paradigm and therefore handles well structures with ill-defined and partially missing boundaries. The proposed approach is particularly well-suited for video sequences of low resolution and variable levels of blurriness introduced by anatomical motion of variable speed. Our tracking method identifies feature points on a frame by frame basis using the SURF detector/descriptor. Inter-frame correspondence is achieved using nearest-neighbor matching in the feature space. The motion is estimated using a non-linear bi-quadratic model, which adequately describes the deformable motion of the urethra. Experimental results are promising and show that our algorithm performs well when compared to manual tracking.

Feature-based tracking of urethral motion in low-resolution trans-perineal ultrasound

This paper describes a novel algorithm for tracking the motion of the urethra from trans-perineal ultrasound. Our work is based on the structure-from-motion paradigm and therefore handles well structures with ill-defined and partially missing boundaries. The proposed approach is particularly well-suited for video sequences of low resolution and variable levels of blurriness introduced by anatomical motion of variable speed. Our tracking method identifies feature points on a frame by frame basis using the SURF detector/descriptor. Inter-frame correspondence is achieved using nearest-neighbor matching in the feature space. The motion is estimated using a non-linear bi-quadratic model, which adequately describes the deformable motion of the urethra. Experimental results are promising and show that our algorithm performs well when compared to manual tracking.

Numerical modeling and experimental validation of the recrystallization behaviour in the extrusion of 6XXX aluminum alloys

The microstructure of 6XXX aluminum alloys deeply affects mechanical, crash, corrosion and aesthetic properties of extruded profiles. Unfortunately, grain structure evolution during manufacturing processes is a complex phenomenon because several process and material parameters such as alloy chemical composition, temperature, extrusion speed, tools geometries, quenching and thermal treatment parameters affect the grain evolution during the manufacturing process. The aim of the present PhD thesis was the analysis of the recrystallization kinetics during the hot extrusion of 6XXX aluminum alloys and the development of reliable recrystallization models to be used in FEM codes for the microstructure prediction at a die design stage. Experimental activities have been carried out in order to acquire data for the recrystallization models development, validation and also to investigate the effect of process parameters and die design on the microstructure of the final component. The experimental campaign reported in this thesis involved the extrusion of AA6063, AA6060 and AA6082 profiles with different process parameters in order to provide a reliable amount of data for the models validation. A particular focus was made to investigate the PCG defect evolution during the extrusion of medium-strength alloys such as AA6082. Several die designs and process conditions were analysed in order to understand the influence of each of them on the recrystallization behaviour of the investigated alloy. From the numerical point of view, innovative models for the microstructure prediction were developed and validated over the extrusion of industrial-scale profiles with complex geometries, showing a good matching in terms of the grain size and surface recrystallization prediction. The achieved results suggest the reliability of the developed models and their application in the industrial field for process and material properties optimization at a die-design stage.

Finite-Element Analysis of Stress on Dental Implant Prosthesis

Background: Understanding how clinical variables affect stress distribution facilitates optimal prosthesis design and fabrication and may lead to a decrease in mechanical failures as well as improve implant longevity. Purpose: In this study, the many clinical variations present in implant-supported prosthesis were analyzed by 3-D finite element method. Materials and Method: A geometrical model representing the anterior segment of a human mandible treated with 5 implants supporting a framework was created to perform the tests. The variables introduced in the computer model were cantilever length, elastic modulus of cancellous bone, abutment length, implant length, and framework alloy (AgPd or CoCr). The computer was programmed with physical properties of the materials as derived from the literature, and a 100N vertical load was used to simulate the occlusal force. Images with the fringes of stress were obtained and the maximum stress at each site was plotted in graphs for comparison. Results: Stresses clustered at the elements closest to the loading point. Stress increase was found to be proportional to the increase in cantilever length and inversely proportional to the increase in the elastic modulus of cancellous bone. Increasing the abutment length resulted in a decrease of stress on implants and framework. Stress decrease could not be demonstrated with implants longer than 13 mm. A stiffer framework may allow better stress distribution. Conclusion: The relative physical properties of the many materials involved in an implant-supported prosthesis system affect the way stresses are distributed.

Tuning Iris Recognition for Noisy Images

The use of iris recognition for human authentication has been spreading in the past years. Daugman has proposed a method for iris recognition, composed by four stages: segmentation, normalization, feature extraction, and matching. In this paper we propose some modifications and extensions to Daugman's method to cope with noisy images. These modifications are proposed after a study of images of CASIA and UBIRIS databases. The major modification is on the computationally demanding segmentation stage, for which we propose a faster and equally accurate template matching approach. The extensions on the algorithm address the important issue of pre-processing that depends on the image database, being mandatory when we have a non infra-red camera, like a typical WebCam. For this scenario, we propose methods for reflection removal and pupil enhancement and isolation. The tests, carried out by our C# application on grayscale CASIA and UBIRIS images show that the template matching segmentation method is more accurate and faster than the previous one, for noisy images. The proposed algorithms are found to be efficient and necessary when we deal with non infra-red images and non uniform illumination.

Structural Analysis of Networks

Network analysis naturally relies on graph theory and, more particularly, on the use of node and edge metrics to identify the salient properties in graphs. When building visual maps of networks, these metrics are turned into useful visual cues or are used interactively to filter out parts of a graph while querying it, for instance. Over the years, analysts from different application domains have designed metrics to serve specific needs. Network science is an inherently cross-disciplinary field, which leads to the publication of metrics with similar goals; different names and descriptions of their analytics often mask the similarity between two metrics that originated in different fields. Here, we study a set of graph metrics and compare their relative values and behaviors in an effort to survey their potential contributions to the spatial analysis of networks.

Influence of deep sternal wound infection on long-term survival after cardiac surgery.

BACKGROUND: This study aimed to investigate the influence of deep sternal wound infection on long-term survival following cardiac surgery. MATERIAL AND METHODS: In our institutional database we retrospectively evaluated medical records of 4732 adult patients who received open-heart surgery from January 1995 through December 2005. The predictive factors for DSWI were determined using logistic regression analysis. Then, each patient with deep sternal wound infection (DSWI) was matched with 2 controls without DSWI, according to the risk factors identified previously. After checking balance resulting from matching, short-term mortality was compared between groups using a paired test, and long-term survival was compared using Kaplan-Meier analysis and a Cox proportional hazard model. RESULTS: Overall, 4732 records were analyzed. The mean age of the investigated population was 69.3±12.8 years. DSWI occurred in 74 (1.56%) patients. Significant independent predictive factors for deep sternal infections were active smoking (OR 2.19, CI95 1.35-3.53, p=0.001), obesity (OR 1.96, CI95 1.20-3.21, p=0.007), and insulin-dependent diabetes mellitus (OR 2.09, CI95 1.05-10.06, p=0.016). Mean follow-up in the matched set was 125 months, IQR 99-162. After matching, in-hospital mortality was higher in the DSWI group (8.1% vs. 2.7% p=0.03), but DSWI was not an independent predictor of long-term survival (adjusted HR 1.5, CI95 0.7-3.2, p=0.33). CONCLUSIONS: The results presented in this report clearly show that post-sternotomy deep wound infection does not influence long-term survival in an adult general cardio-surgical patient population.

Assimilació, integració laboral, domini de l'idioma i segregació residencial

La literatura econòmica sobre immigració i mercat de treball ha analitzat dos grans temes. Un és l’efecte que genera la immigració sobre les condicions laborals (ocupació i salaris) dels nadius. L’altre és l’assimilació dels immigrants en el país d’acollida. Aquest projecte s'emmarca en aquesta segona línia de recerca. L’assimilació s’entén com un procés complex en el que un immigrant s’integra completament en el seu país d’acollida en diferents aspectes interrelacionats: l’estatus socioeconòmic, el progrés salarial, el domini de l’idioma o la segregació residencial, entre d'altres. El nostre projecte es centra en l’anàlisi de l’assimilació dels immigrants que han arribat recentment al nostre mercat de treball. Des d'aquesta perspectiva, s'ha analitzat si com a conseqüència de la transferibilitat limitada del capital humà entre països, es produeix o no una degradació ocupacional inicial que porti associada una quantiosa diferència salarial amb els nadius de similars característiques. De fet, com menys transferible sigui el capital humà d'origen, major serà la degradació ocupacional i la consegüent bretxa salarial inicial. També s'ha analitzat de manera més directa quin paper juga la portabilitat del capital humà a l'hora d'explicar el progrés econòmic dels immigrants. L’evidència obtinguda permet concloure que, a mesura que s'amplia el temps de residència al país de destinació, el capital humà es va adaptant als requeriments del mercat laboral del país hoste, especialment a través de l'experiència en el lloc de treball, però també per aprenentatge del nou idioma o fins i tot realització d'estudis. El capital humà així acumulat permet millorar posicions en l'escala ocupacional i augmentar en paral•lel els ingressos, assimilant-los amb el temps als dels nadius d'iguals característiques. Per últim, l’anàlisi del paper de les xarxes socials dels immigrants mostra un efecte positiu sobre la probabilitat de trobar feina però un pitjor emparellament en el mercat de treball.

Análisis y diseño de antenas dipolo y parche para aplicaciones implantadas en el cuerpo humano

En els darrers anys, els sistemes de telemetria per a aplicacions mèdiques han crescut significativament en el diagnòstic i en la monitorització de, per exemple, la glucosa, la pressió de la sang, la temperatura, el ritme cardíac... Els dispositius implantats amplien les aplicacions en medicina i incorpora una millora de qualitat de vida per a l’usuari. Per aquest motiu, en aquest projecte s’estudien dues de les antenes més comuns, com son l’antena dipol i el patch, aquesta última és especialment utilitzada en aplicacions implantades. En l’anàlisi d’aquestes antenes s’han parametritzat característiques relacionades amb l’entorn de l’aplicació, així com també de la pròpia antena, explicant el comportament que, a diferencia amb l’espai lliure, les antenes presenten a canvis d’aquests paràmetres. Al mateix temps, s’ha implementat una configuració per a la mesura d’antenes implantades basat en el model del cos humà d’una capa. Comparant amb els resultats de les simulacions realitzades mitjançant el software FEKO, s’ha obtingut gran correspondència en la mesura empírica d’adaptació i de guany de les antenes microstrip. Gràcies a l’anàlisi paramètric, aquest projecte també presenta diversos dissenys de les antenes optimitzant el guany realitzable amb l’objectiu d’aconseguir la millor comunicació possible amb el dispositiu extern o estació base.

Questionnaire d'attitudes et de préférences éducatives des intervenants (QAPÉI) : structure factorielle et relations avec les traits de personnalité

La psychoéducation de même que plusieurs approches théoriques en psychologie clinique suggèrent que l’intervenant constitue un élément actif fondamental des interventions auprès des individus en difficulté. Parmi l’ensemble des caractéristiques des intervenants qui sont utiles de considérer, les attitudes et préférences éducatives des intervenants apparaissent importantes puisqu’elles peuvent être reliées à un bon appariement avec un milieu d’intervention donné, au sentiment d’efficacité professionnelle et, ultimement, à l’efficacité d’une intervention. Or, très peu d’instruments psychométriques d’évaluation validés existent pour évaluer ces construits importants. Cette étude visait principalement à effectuer un examen préliminaire des propriétés psychométriques de la version française du Questionnaire d’attitudes et de préférences des intervenants (QAPÉI; Jesness & Wedge, 1983; Le Blanc, Trudeau-Le Blanc, & Lanctôt, 1999). Le premier objectif de la présente étude était d’évaluer si la structure théorique originale était reproductible empiriquement ou si une structure factorielle alternative était nécessaire. Le deuxième objectif était d’évaluer si les attitudes et préférences éducatives des intervenants étaient reliées à leurs traits de personnalité. L’échantillon utilisé était composé d’intervenants faisant partie de Boscoville2000, un projet d’intervention cognitive-comportementale en milieu résidentiel pour les adolescents en difficulté. Des analyses factorielles exploratoires ont démontré que la structure théorique originale n’était pas reproduite empiriquement. Une structure alternative en cinq facteurs a été recouvrée. Cette structure alternative était plus cohérente sur le plan conceptuel et démontrait une bonne adéquation aux données. Les facteurs identifiés ont été nommés Distance affective, Évitement thérapeutique, Exaspération, Permissivité et Coercition. Des analyses corrélationnelles ont démontré que ces échelles d’attitudes et de préférences éducatives étaient reliées de façon conceptuellement cohérente aux traits de personnalité des intervenants, ce qui appuie la validité de critère de la nouvelle structure de l’instrument.

TU Graz: Course: 707.000 Web Science and Web Technology: Lecture 7: Link Analysis and Search

What are ways of searching in graphs? In this class, we will discuss basics of link analysis, including Google's PageRank algorithm as an example. Readings: The PageRank Citation Ranking: Bringing Order to the Web, L. Page and S. Brin and R. Motwani and T. Winograd (1998) Stanford Tecnical Report

Sostenibilidad del proyecto industrial del plástico .

El reciclaje se ha caracterizado por ser un tema importante en la última década, por el desarrollo económico, social y tecnológico que tiene consigo. Evidentemente, el sector de reciclaje se ha convertido en un sector con visión para poder conseguir un nuevo sector. Por este motivo lo que se ha querido con este trabajo de investigación es buscar nuevas manera de ver los recursos que se encuentran en cualquier lugar de las ciudades. La tesis cuenta con un sin número de argumentos que ayudarán a que las personas que lean el documento se interesen cada vez más en reutilizar los materiales que día a día encuentran. De esta manera, se puede ver una cadena de suministro, que llevará a que la materia prima que se haya mejorado sirva para realizar otro tipo de productos y genere un sostenimiento significativo a miles de personas que pueden sacarle provecho a estos materiales. Nuestros hábitos más cotidianos tienen mucho que ver con la degradación global del planeta. Actos tan rutinarios como tirar la basura sin separarla, comprar utensilios de usar y tirar o adquirir los alimentos envasados en materiales anti ecológicos o no reciclables contribuyen en gran medida a la contaminación medioambiental (Inzillo, 2000).

A violência no âmbito de escolas públicas do ensino fundamental do Município de Aracaju

RESUMO: A violência escolar, entendida como todo ato praticado de maneira isolada ou em grupo nas instituições de ensino ou em suas redondezas, envolvendo o corpo discente e/ou docente desses estabelecimentos, é uma realidade vivenciada pelos mesmos e reconhecida por toda a sociedade. Nessa perspectiva, a presente pesquisa investigou a problemática nas instituições de ensino público da Cidade de Aracaju, capital de Sergipe, Brasil. A pesquisa possibilitou demonstrar algumas das causas e consequências da violência, e entender os motivos que permitem o seu desenvolvimento em escolas públicas, campo da pesquisa, com subsídios não somente na ciência da educação como também na ciência jurídica, visto que fundamenta suas ideias em Leis e Normas que orientam e tipificam o comportamento do indivíduo na sociedade. Nesta pesquisa – de caráter exploratório e descritivo, de cunho analítico, coerente com as questões e objetivos propostos ao objeto de estudo – recorreu-se a uma pesquisa de campo com análise quali-quantitativa com resultados apresentados em gráficos, quadros e registros de ocorrência, utilizando como universo pesquisado escolas públicas municipais de Aracaju, através de questionário aplicado aos diretores e funcionários em visita “in loco”. A pesquisa é baseada em teorias que fundamentam os resultados encontrados de que o “homem é produto do meio”, isto é, a sociedade em que vive e a família têm uma influência e um papel fundamental na formação da personalidade do indivíduo, seja ele bom ou ruim. ABSTRACT: The school violence, understood as any act performed in isolation or in groups in educational institutions or in its surroundings, involving the student body and / or teaching of these establishments, is a reality faced by them and recognized throughout society. From this perspective, this research investigated the issue in public education institutions in the city of Aracaju, capital of Sergipe, Brazil. The research allow us to demonstrate some of the causes and consequences of violence, and understand the reasons that allow its development in public schools, field of research, with subsidies not only in science education as well as in legal science, since it bases its ideas on Laws and Regulations that guide and typify the behavior of the individual in society. In this research, exploratory and descriptive character, of an analytical view, consistent with the proposed objectives and issues to the object of this study - resorted to a field research with quantitative and qualitative analysis with results presented in graphs, charts and records of occurrence, using as group studied public schools in Aracaju, through a questionnaire applied to directors and employees to visit in the place. The research is based on theories that motivate the results found that “the man is the product of the environment”, this means, the society in which they live and the family have an influence and a key role in shaping the character of the individual, be it good or bad. KEYWORDS: school

Wiggle-match dating of tree-ring sequences

Given the non-monotonic form of the radiocarbon calibration curve, the precision of single C-14 dates on the calendar timescale will always be limited. One way around this limitation is through comparison of time-series, which should exhibit the same irregular patterning as the calibration curve. This approach can be employed most directly in the case of wood samples with many years growth present (but not able to be dated by dendrochronology), where the tree-ring series of unknown date can be compared against the similarly constructed C-14 calibration curve built from known-age wood. This process of curve-fitting has come to be called "wiggle-matching." In this paper, we look at the requirements for getting good precision by this method: sequence length, sampling frequency, and measurement precision. We also look at 3 case studies: one a piece of wood which has been independently dendrochronologically dated, and two others of unknown age relating to archaeological activity at Silchester, UK (Roman) and Miletos, Anatolia (relating to the volcanic eruption at Thera).

New algorithms for synthesized design of optical filters

Chebyshev optical-filter algorithms for low-cost microcomputers have been improved. An offset ripple is now used for better transmission/matching in low-pass stacks. A prototype for narrowband filters is now more general and nearer practicability.