Στόχος της παρούσας διατριβής είναι η παρουσίαση ενός νέου μαθηματικού πλαισίου, βασιζόμενου στις γνωστές από τη Διαφορική Γεωμετρία κανονικές εξισώσεις (συντετμημένα ΚΕ) της καμπύλης. Όντας πολυωνυμικές εκφράσεις του μήκους τόξου s, οι ΚΕ παρέχουν ακριβέστερο έλεγχο της ταχύτητας πρόωσης σε σύγκριση με τους υπάρχοντες παραμετρικούς αλγορίθμους της ίδιας τάξης. Το ανωτέρω γεγονός, σε συνδυασμό με την εφαρμοσιμότητά τους σε όλες τις συνεχείς καμπύλες με συνεχείς παραγώγους, ανεξάρτητα από τον τρόπο αναπαράστασής τους, καθιστά τις ΚΕ ένα ιδανικό εργαλείο για την ανάπτυξη γενικών αλγορίθμων παρεμβολής, ικανών να εργάζονται επί οποιασδήποτε επίπεδης ή χωρικής καμπύλης σε πραγματικό χρόνο. Δοθέντος ότι οι συντελεστές των ΚΕ συναρτώνται με τις διαφορικές ιδιότητες της καμπύλης (δηλαδή την καμπυλότητα, τη στρέψη και τις παραγώγους τους ως προς το s), αναπτύσσονται αναλυτικές εκφράσεις για τον υπολογισμό των εν λόγω ιδιοτήτων, ανάλογα με τον εκάστοτε τρόπο αναπαράστασης της καμπύλης. Στα αντικείμενα της διατριβής συμπεριλαμβάνεται και ο υπολογισμός των διαφορικών ιδιοτήτων των επιφανειακών τομών, ενός δημοφιλούς τρόπου αναπαράστασης πολύπλοκων χωρικών καμπυλών στα συστήματα CAD. Επιπλέον, εξετάζεται η εισαγωγή διορθωτικών όρων στις ΚΕ, μέσω της οποίας επιτυγχάνεται η βελτίωση της ακρίβειας στον έλεγχο της ταχύτητας πρόωσης, χωρίς το επιπρόσθετο υπολογιστικό κόστος που επιφέρει η χρήση υψηλότερης τάξης όρων της σειράς Taylor. Σημαντικό πλεονέκτημα των προτεινόμενων αλγορίθμων είναι, επίσης, το γεγονός ότι για την εφαρμογή τους δεν απαιτείται η γνώση της αναλυτικής έκφρασης της παρεμβαλλόμενης καμπύλης. Κατά συνέπεια, επιτρέπουν την παρεμβολή πολύπλοκων γεωμετρικών τόπων, οι αναλυτικές εκφράσεις των οποίων είτε είναι δύσκολο να προσδιοριστούν με τις τρέχουσες μεθόδους απαλοιφής αγνώστων από μη γραμμικά συστήματα εξισώσεων, είτε είναι δύσχρηστες, εξ αιτίας της πολυπλοκότητάς τους. Στα πλαίσια της παρούσας διατριβής, μελετάται το πρόβλημα της παρεμβολής δύο γεωμετρικών τόπων με σημαντικές εφαρμογές στον τομέα του αριθμητικού ελέγχου των εργαλειομηχανών, καθώς χρησιμοποιούνται, μεταξύ άλλων, για την αντιστάθμιση της ακτίνας του κοπτικού εργαλείου και τον προγραμματισμό των διαδοχικών διαδρομών του κατά την κατεργασία θυλάκων: των καμπυλών offset και των ισαπεχουσών δύο επίπεδων καμπυλών. Πραγματοποιείται μία εκτενής εξέταση των διαφορικών ιδιοτήτων των προαναφερθέντων γεωμετρικών τόπων και παρουσιάζονται εκφράσεις για τον υπολογισμό τους, βασιζόμενες αποκλειστικά στις αντίστοιχες ιδιότητες των γενετειρών καμπυλών. Γίνεται, επίσης, μία ανασκόπηση των μεθόδων που έχουν προταθεί στη βιβλιογραφία για την αντιμετώπιση των τοπολογικών ιδιομορφιών τους (αυτοτομών και εσωτερικών βρόγχων), ώστε να εξασφαλιστεί η παραμονή των παραγόμενων σημείων επί του πραγματικού γεωμετρικού τόπου. Παράλληλα, συζητείται η επέκταση των προτεινόμενων μεθόδων παρεμβολής των καμπυλών offset για τον έλεγχο της διαδρομής του κέντρου ενός σφαιρικού εργαλείου, ώστε αυτό να διατηρείται σε μόνιμη επαφή με δύο προκαθορισμένες επιφάνειες – μία τεχνική που χρησιμοποιείται συχνά από τα συστήματα CAD/CAM για την επιφανειακή κατεργασία πολύπλοκων εξαρτημάτων. Το εργαλείο μπορεί να εφάπτεται οποιασδήποτε εκ των δύο επιφανειών είτε μέσω του ημισφαιρικού του άκρου, ή μέσω του κυλινδρικού του στελέχους. / The present dissertation aims at introducing a new mathematical framework, based on a curve’s canonical equations (abbreviated as CE), which are known from Differential Geometry. Being polynomial expressions of the curve’s arc length s, the CE provide greater feedrate accuracy, compared to the existing parametric algorithms of the same order. The above fact, combined with the canonical equations’ applicability on any continuous curve with continuous derivatives, regardless of its representation, renders them an ideal tool for the development of general-purpose real-time interpolation algorithms. Given that the CE coefficients consist of the curve’s differential properties (namely, the curvature, torsion and their arc length derivatives), the present dissertation deals with the expression of the aforementioned properties in closed form, depending on the chosen curve representation. This includes the study of surface intersections, which are frequently used by CAD systems in order to represent complex space curves. Moreover, it is proven that the proposed algorithms admit to corrections, supplying a means of improving feedrate accuracy, without the additional cost of employing higher order Taylor series terms. An additional, important advantage of the proposed algorithms, lies in the fact that they do not require knowledge of the curve’s analytic expression. Hence, they allow the interpolation of complex geometrical loci, whose analytic expressions are either difficult to deduce, using current elimination methods for non-linear equation systems, or are extremely impractical, due to their complexity. This dissertation addresses the problem of interpolating two such loci: offset curves and plane bisectors. Both of these entities play an important role in CNC machining, with applications that include the tool’s radius compensation and path planning during pocket clearing. It is shown that the differential properties of the above loci can be linked to the respective properties of their generators and may, hence, be easily computed through successive derivations of the generator curve’s position vector. In addition, previously suggested methods for the handling of possible topological irregularities (self-intersections and internal loops) are reviewed, so as to ensure that the generated points remain on the true locus. Furthermore, the presented offset interpolation methods are extended, in order to accommodate the path planning of a ball-end cutter, moving in constant contact with two given surfaces – a technique which is widely adopted by CAD/CAM systems to guide the tool through the surface machining of complex parts. The tool may contact any of the two surfaces through either its tip, or its cylindrical periphery.

La réalisation de formes complexes comme les moules ou les prothèses médicales nécessite l’utilisation d’opérations de super finition pour obtenir de faibles défauts géométriques, pouvant aller jusqu’au poli-miroir. Ces opérations de pré-polissage et de polissage sont encore régulièrement réalisées manuellement. En effet, malgré des avantages en termes de répétabilité, de productivité et de qualité géométrique, les méthodes de polissage automatique sont peu utilisées car elles nécessitent une mise au point importante. Les travaux de recherche présentés participent à la maîtrise du procédé de polissage automatique tout en contrôlant la qualité géométrique des pièces. Pour parvenir à cette maîtrise, un outil de simulation de l’enlèvement de matière est mis en place. Cet outil permet de simuler l’enlèvement de matière au cours d’une opération de prépolissage réalisée sur centre d’usinage 5 axes. Il se base sur un modèle du contact obtenu entre l’outil de pré-polissage et la pièce, ainsi que sur un modèle du pouvoir abrasif intégrant l’usure et l’encrassement du disque. Cette simulation permet de vérifier la régularité de l’abrasion sur une surface et d’identifier les zones pouvant faire apparaitre des défauts macro-géométriques importants. Une méthode est également proposée pour compenser les variations du pouvoir abrasif au cours du temps. La compensation s’effectue en optimisant les consignes de vitesse d’avance et/ou de fréquence de broche le long de la trajectoire. Cette méthode de pilotage permet d’obtenir un taux d’enlèvement de matière plus constant et ainsi de réduire les défauts géométriques générés pendant une opération de prépolissage. / Complex shapes such as medical implants or injection molds require the use of super-finishing operations to minimize geometrical defects, down to mirror effect finish. These pre-polishing and polishing operations are still regularly performed manually by skilled workers. In spite of advantages in terms of repeatability, productivity and geometrical quality, automatic polishing methods are not widely used because they require systematic and significant developments. The present work contributes to enhance the automatic polishing process compared to the geometric quality of the parts. To achieve this control, a numerical simulation of material removal is implemented. This software simulates the material removal during a pre-polishing operation performed on 5-axis machining center. It is based on a contact model obtained between the pre-polishing tool and the part, as well as an abrasive model including wear of the disc. This simulation allows to check the uniformity of the material removal on the surface and to identify potential areas where macro-geometric defects appear. A method is also proposed to balance variations of the abrasive efficiency. The correction is performed by optimizing the federate and/or the spindle speed along the tool path. This method provides a constant material removal and reduces the geometrical deviations generated during pre-polishing operations.

Approved for public release; distribution in unlimited. / MEMS technology is rapidly taking an important role in today's and future military systems. MEMS are able to lower the device size from millimeter to micrometer and maintain and sometimes surpass the performance of conventional devices. This thesis encompasses the knowledge acquired throughout the MEMS courses to design a two-axis capacitive accelerometer. The required acceleration and operating temperature range were Š50g in each axis and -40ʻC to +80 ʻC, respectively. The accelerometer was also needed to survive within a dynamic shocking environment with accelerations of up to 225g. The parameters of the accelerometer to achieve above specifications were calculated using lumped element approximation and the results were used for initial layout of it. A finite element analysis code (ANSYS) was used to perform simulations of the accelerometer under various operating conditions and to determine the optimum configuration. The simulated results were found to be within about 5% of the calculations indicating the validity of lumped element approach. The response of the designed accelerometer was 7 mV/g and with sensitivity of 1.3g at 3dB. It was also found that the accelerometer was stable in the desired range of operation including under the shock. Two axes sensing can be achieved using two identical accelerometers having their sensing axes perpendicular to each other. / Major, Taiwan Army

Com base nas teorias apresentadas por Howard Gardner e Daniel Goleman relacionadas à inteligência humana, este estudo busca oferecer um subsídio prático, objetivo e operacional aos profissionais que têm contato com alunos do ensino médio, a fim de que possam, através da percepção que os alunos têm de si mesmos em atividades cotidianas, selecionar e conduzir os temas em suas aulas e atividades. Este subsídio é mais um agente facilitador de conhecimento das características individuais e de grupos, visando ao sucesso na aplicação dos temas e atividades propostas. Fundamentado nas teorias da Psicologia da Educação, este trabalho apresenta uma pesquisa realizada junto a um grupo de alunos do ensino médio de uma escola pública de São Paulo, no ano de 2000. O objetivo consistia em investigar as principais afinidades, tendências, competências e talentos mais desenvolvidos, relacionando esses resultados com as habilidades que porventura estivessem menos desenvolvidas e correlacionando-os com as características específicas que a escola em questão apresenta. Nessas relações, pôde-se constatar que determinados talentos deixam de ser priorizados pela escola e pelo próprio aluno devido à necessidade de direcionar seus estudos para os concursos vestibulares. Tais concursos, na maioria das vezes, exigem do aluno determinados conhecimentos para os quais nem sempre tem maior afinidade e satisfação em estar desenvolvendo. Os resultados apontam para um fortalecimento, aproveitamento e respeito às tendências e características individuais mais desenvolvidas em cada aluno, a fim de que este sinta prazer e motivação em estar atuando dentro dos vários campos de conhecimentos oferecidos pela escola. Com isso, o ensino se torna mais proveitoso e significativo para o aluno e para o professor. / Based on the theories presented by Howard Gardner and related to human intelligence Daniel Goleman , this study seeks to provide a practical , objective and operational allowance to professionals who have contact with high school students in order that they may , through the perception that students have of themselves in everyday activities , select and conduct issues in their classes and activities . This grant is another agent facilitator of knowledge of individual and group characteristics , aimed at successful implementation of the proposed activities and themes . Based on theories of Psychology of Education , this paper presents a survey of a group of high school students of a public school in São Paulo , in 2000 . The objective was to investigate the main affinities , trends , skills and talents more developed , relating these results with the skills that were perhaps less developed and correlating them with the specific features that the school in question presents . In these relationships , it could be seen that certain talents are no longer prioritized by the school and by the student due to the need to direct their studies to the vestibular contests . Such procedures, in most cases, require the student to certain knowledge which has not always higher affinity and satisfaction in being developed . The results point to a strengthening recovery and respect for individual characteristics and trends in more developed each student in order to feel this pleasure and motivation to be acting within the various fields of knowledge offered by the school . Thus , education becomes more useful and meaningful to the student and the teacher .

O objetivo do presente trabalho é, através do estudo do material lítico polido do interior de Minas Gerais e São Paulo, compreender melhor os artefatos, identificá-los e, assim, contribuir para o conhecimento do modo de vida das populações que deles fizeram uso. Tratamos inicialmente dos cronistas, primeiras fontes sobre os artefatos, cuja riqueza das descrições nos permite preencher várias lacunas que de outra forma (apenas com os dados arqueológicos) permaneceriam. Em seguida definimos estes artefatos, descrevemos suas características essenciais. Com o auxílio da bibliografia discutimos as classificações elaboradas no passado para algumas destas peças e apontamos possíveis novas abordagens. Através da análise do material, identificamos tipos, apresentamos as peculiaridades e similitudes relativas às diferentes regiões e, quando possível, as respectivas associações a grupos culturais ou afiliações a Tradições Arqueológicas. Trazemos ainda informações obtidas através de trabalho de arqueologia experimental que julgamos essencial para uma compreensão mais ampla dos artefatos, os custos envolvidos em sua produção e manutenção. Finalmente apresentamos uma síntese do conhecimento obtido com toda a análise, buscando explicitar como o material lítico polido, freqüentemente preterido nos estudos, pode trazer contribuições importantes para a reconstrução dos passado dos habitantes desta parte das Américas. / The objective of the present work is, through the study of the polished lithic material from inland Minas Gerais and São Paulo, to have a better understanding of these artifacts, identify them, and to contribute for the knowledge in the way of life of the populations that made use of them. At first we write about the first sources on these artifacts, whose rich descriptions allows us to fill in several gaps that otherwise (trough the archeological data only) would stay. Then we defined these artifacts, describe their essential characteristics. With the aid of the bibliography we discus the classifications elaborated in the past for some of these and point new possible approaches. Through the analysis of these stone artifacts, we create types, present their peculiarities and similarities related with the different areas they were found and, when possible, the respective associations to cultural groups or affiliations to Archeological Traditions. We also bring information obtained through work of experimental archeology that we judged essential for a wider understanding of the artifacts, the costs involved in their production and maintenance. Finally we presented a synthesis of the knowledge obtained with the whole analysis, looking for stress how the polished lithic material, frequently ignored in the studies, can bring important contributions for the reconstruction of the inhabitants of this part of America\'s past.

Com base nas teorias apresentadas por Howard Gardner e Daniel Goleman relacionadas à inteligência humana, este estudo busca oferecer um subsídio prático, objetivo e operacional aos profissionais que têm contato com alunos do ensino médio, a fim de que possam, através da percepção que os alunos têm de si mesmos em atividades cotidianas, selecionar e conduzir os temas em suas aulas e atividades. Este subsídio é mais um agente facilitador de conhecimento das características individuais e de grupos, visando ao sucesso na aplicação dos temas e atividades propostas. Fundamentado nas teorias da Psicologia da Educação, este trabalho apresenta uma pesquisa realizada junto a um grupo de alunos do ensino médio de uma escola pública de São Paulo, no ano de 2000. O objetivo consistia em investigar as principais afinidades, tendências, competências e talentos mais desenvolvidos, relacionando esses resultados com as habilidades que porventura estivessem menos desenvolvidas e correlacionando-os com as características específicas que a escola em questão apresenta. Nessas relações, pôde-se constatar que determinados talentos deixam de ser priorizados pela escola e pelo próprio aluno devido à necessidade de direcionar seus estudos para os concursos vestibulares. Tais concursos, na maioria das vezes, exigem do aluno determinados conhecimentos para os quais nem sempre tem maior afinidade e satisfação em estar desenvolvendo. Os resultados apontam para um fortalecimento, aproveitamento e respeito às tendências e características individuais mais desenvolvidas em cada aluno, a fim de que este sinta prazer e motivação em estar atuando dentro dos vários campos de conhecimentos oferecidos pela escola. Com isso, o ensino se torna mais proveitoso e significativo para o aluno e para o professor. / Based on the theories presented by Howard Gardner and related to human intelligence Daniel Goleman , this study seeks to provide a practical , objective and operational allowance to professionals who have contact with high school students in order that they may , through the perception that students have of themselves in everyday activities , select and conduct issues in their classes and activities . This grant is another agent facilitator of knowledge of individual and group characteristics , aimed at successful implementation of the proposed activities and themes . Based on theories of Psychology of Education , this paper presents a survey of a group of high school students of a public school in São Paulo , in 2000 . The objective was to investigate the main affinities , trends , skills and talents more developed , relating these results with the skills that were perhaps less developed and correlating them with the specific features that the school in question presents . In these relationships , it could be seen that certain talents are no longer prioritized by the school and by the student due to the need to direct their studies to the vestibular contests . Such procedures, in most cases, require the student to certain knowledge which has not always higher affinity and satisfaction in being developed . The results point to a strengthening recovery and respect for individual characteristics and trends in more developed each student in order to feel this pleasure and motivation to be acting within the various fields of knowledge offered by the school . Thus , education becomes more useful and meaningful to the student and the teacher .

URhGe is the first ferromagnet discovered that shows superconductivity at ambient pressure. It shows a rich temperature-magnetic field phase diagram with a re-emergence of superconductivity at high magnetic field where the moments rotate. This suggests that the quantum fluctuations associated with the moment rotation may provide the pairing interaction for superconductivity. The objective of this thesis was to study these critical fluctuations with inelastic neutron scattering and heat capacity measurements, using the latter to test the bulk nature of the superconductivity and determine the types of gap nodes to help test this hypothesis. To perform the heat capacity measurements, it was necessary to develop an apparatus that measures milligram samples in the temperature range 50-1000 mK, and magnetic field range 0-12 T. The field exerts a mechanical force upon the sample, which causes it to rotate, perturbing the system destructively. The apparatus developed in this thesis overcomes this diffculty by holding the sample with tensioned kevlar wires. Testing was done by making measurements on UPt3, a well characterised superconductor. It was then used to measure URhGe in zero magnetic field. The extension to measurements in high magnetic field were not performed however, due to the structural integrity of the apparatus being weak - this was in an attempt to reduce the thermodynamic signature of the background. After many iterations of apparatus design and build, the device was proved not appropriate for high fields. A discussion of the zero-field data, as well as the design and build process, is given. The Curie temperature of URhGe is suppressed with magnetic field (applied along the b-axis), reaching zero temperature at the moment rotation transition referred to above. Small angle neutron scattering (SANS) was measured at both zero and finite fields to detect the evolution and relaxation of the critical fluctuations. The scattering is inelastic and the SANS measurement integrates over energy. Nevertheless it was possible to compare models with different dynamical dependences for the magnetic relaxation. In field, however, the magnitude of the fluctuations was strongly reduced, falling below the detection limit at half the critical field. Comparing Landau damping to various forms of non-Landau damping, a result was found that agrees with that for the ferromagnetic superconductors UGe2 and UCoGe, but the lack of critical scattering at field is found to be in contradiction with NMR measurements, which is discussed. UAu2 is a new material on the heavy fermion landscape. The crystal structure found suggests some frustrated magnetism, culminating in a Neél temperature of 43 K and a further transition at 400 mK; this suggests some new quantum criticality not seen before, and so heat capacity measurements were performed with the already-tested apparatus to see if, as the resistivity measurements suggest, a Fermi-liquid state is found. Results revealed differences between annealed and non-annealed samples in their thermodynamic signature, and the behaviour expected for antiferromagnetic spin-fluctuations is found to continue to temperatures below 150 mK, suggesting the existence of a quantum critical point. The validity of these results along with implications are discussed.

En el presente estudio se propone la Construcción de un Colegio de Alto Rendimiento (COAR) en la Ciudad de San Vicente de Cañete, Provincia de Cañete, Departamento de Lima, en el cual estudiarán los alumnos de los últimos tres grados de secundaria que tengan las mejores calificaciones para que puedan recibir una educación de alta calidad y exigencia, potenciando al máximo sus capacidades para beneficio de los estudiantes, sus familias y de la región donde habitan. La infraestructura propuesta está a nivel de escuelas similares de clase Mundial, con aulas implementadas con las últimas tecnologías, habitaciones y servicios para todos los alumnos, losas deportivas, cafeterías, comedor, biblioteca y áreas de recreación para crear un ambiente ideal para los estudiantes. El proyecto ha sido desarrollado respetando las Normas Arquitectónicas vigentes y requeridas para Colegios e Internados, buscando una integración con el ambiente natural que es una zona eminentemente agrícola y con mucha vegetación. Consta de seis volúmenes totalmente integrados. La infraestructura propuesta, además de ser usada por los alumnos, ha sido diseñada para que pueda ser utilizada por la población durante la temporada de vacaciones, dando así este importante aporte a la comunidad. / The present study proposes the Construction of a High Performance College (COAR) in the City of San Vicente de Cañete, Province of Cañete, Department of Lima, in which the students of the last three grades of high school who have the best grades will study so that they can receive high quality education, maximizing their capacities for the benefit of the students, their families and the region where they live. The proposed infrastructure is at the level of similar World Class schools, with classrooms implemented with the latest technologies, rooms and services for all students, sports facilities, cafeterias, dining room, library and recreation areas to create an ideal environment for students. The project has been developed respecting the current and mandatory Architectural Standards for schools and boarding schools, looking for an integration with the natural environment that is an eminently agricultural area with lots of vegetation. It consists of dix fully integrated volumes. The infrastructure implemented, besides being used by the students, has been designed so that it can be used by the population during the holiday season, thus giving this important contribution to the community. / Tesis

本文證明對∂－方程式在橢圓域中的解皆可用積分形式表現出來而且滿足均勻估計。在此估計中的常數可用橢圓的長短軸表達之。而且，我們也證明了此常數具有穩定性。 / In this thesis, we prove that, given any smooth closed (0,1)-form f near an ellipsoid Ω in Cⁿ, the Henkin's solution H_Ωf of the ∂-equation on Ω satisfies the uniform estimate 　　　　║H_Ωf║_∞≦C_Ω║f║_∞　　， 　　where is the Henkin's constant of Ω which can be explicitly estimated in terms of the maximum and minimum axes of the ellipsoid Ω. Also, a special version of the stability result of the Henkin's constant C_Ω is obtained.

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