Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: Cam; Tension-Member; Cam Follower; Metal Tape; Metal Belt. Includes bibliographical references (leaves 79-80).

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 118-123). Also available via the Internet.

Thesis (Ph. D.)--Lehigh University, 2002. / Includes vita. Includes bibliographical references (leaves 203-206).

Thesis (M.S.)--Brigham Young University. Dept. of Mechanical Engineering, 2008. / Includes bibliographical references (p. 57-59).

Em um sistema came-seguidor a dinâmica do sistema seguidor faz com que o movimento final se desvie daquele especificado. Este efeito pode ser compensado considerando-se o modelo dinâmico inverso do sistema seguidor no projeto da lei de movimento do came. Considerando-se constante a velocidade do came, o sistema seguidor tem dinâmica linear. Entretanto, devido à razão de transmissão variável, e devido a outros efeitos não lineares, o sistema de acionamento como um todo é não linear, e procedimentos não lineares devem ser utilizados para se ajustar a lei de movimento do came. Uma análise teórica, suportada por simulações, mostra o potencial deste procedimento, ao menos no caso de uma dinâmica simples do sistema seguidor: uma considerável redução do erro de movimento, e uma boa robustez relativa a erros na freqüência de ressonância e razão de amortecimento estimadas. Experimentos com o acionamento por um servomotor sub-dimensionado, como é de se esperar, mostram resultados diferentes, devido à velocidade angular não constante. A flutuação observada na velocidade angular em torno do valor constante é então levada em consideração para o projeto da lei de movimento com nonlinear feedforward. / In a cam-follower system the dynamics of the follower-train mechanism cause an actual motion which deviates from the desired one. This effect can be compensated by taking into account the inverse dynamic model of the follower-train in the design of the cam motion law. By considering a constant cam velocity, the follower-train has linear dynamics. However, due to the varying transmission ratio, and due to other nonlinear effects, the whole drive train is a nonlinear system, and nonlinear procedures should be used to fit a motion law. A theoretical analysis with only the linear feed-forward compensation, supported by simulation results, has shown the potential of this approach, at least in the case of simple follower-train dynamics: a considerable reduction of the motion error, and a good robustness with respect to errors in the estimated resonance frequency and damping ratio of the follower-train. Experiments with a small driving servomotor, as expected, show differerit results, due to the non-constant angular velocity. The observed cam angular velocity ripple is then taken into account to design a complete nonlinear feedforward motion law.

"The goal of this project was to investigate the dynamic effects of incipient separation of industrial cam-follower systems. Typical industrial cam-follower systems include a force closed cam joint and a follower train containing both substantial mass and stiffness. Providing the cam and follower remain in contact, this is a one degree-of-freedom (DOF) system. It becomes a two-DOF system once the cam and follower separate or jump, creating two new natural frequencies, which bracket the original. The dynamic performance of the system as it passed through the lower of the two post-separation modes while on the verge of jump was investigated. A study was conducted to determine whether imperfections in the cam surface, while the contact force is on the brink of incipient separation, may cause a spontaneous switch to the two-DOF mode and begin vibration at resonance. A force-closed translating cam-follower train was designed for the investigation. The fixture is a physical realization of the two-mass mathematical model. Pro/Engineer was used to design the follower train, Mathcad and TK Solver were used to analyze the linkage and DYNACAM & Mathcad were used to dynamically model the system. The system is designed to be on the cusp of incipient separation when run. Experiments were carried out by bringing the system up to jump speed and then backing off the preload to get the system on the cusp of separation. Data were collected at the prejump, slight jump, and violently jumping stages. The time traces show the acceleration amplitudes grow to large peaks when the system is jumping. The frequency spectrum shows the two new natural frequencies growing in amplitude from non-existant in the prejump stage, to higher values in the violently jumping stage. The peak amplitudes of the phenomenon are small in magnitude compared to the harmonic content of the cam. It is concluded that the contribution of the two-DOF system natural frequencies is not a significant factor from a practical aspect. Although the actual jump phenomenon is of concern in high-speed applications, calculations show that if the follower system is designed sufficiently stiff then the two-DOF situation will not occur."

Tumor angiogenesis, the ability of tumor cells to stimulate blood vessel growth, is one the most critical steps of tumor progression. To support the growth of the expanding tumor, the “angiogenic switch” is turned on, which is often triggered by hypoxia (i.e., low oxygen)-mediated events such as expression of vascular endothelial growth factor (VEGF), causing normally quiescent endothelial cells to proliferate and sprout. An emerging picture of angiogenesis suggests that while governed by complex mechanisms, cell adhesion molecules (CAMs) plays a pivotal role in the regulation of angiogenesis. Our laboratory recently identified multiple previously unknown proteins including, transmembrane and immunoglobulin domain containing 1 (TMIGD1) and immunoglobulin-containing and proline-rich receptor 1 (IGPR1). Immunoglobulin-containing and cysteine-rich receptor 1 (IGCR1) represents the third remember of IGPR-1 family proteins. To investigate the expression and function of IGCR1, we have developed a rabbit polyclonal anti-IGCR1 antibody and demonstrated that IGCR1 is expressed in the endothelial cells of human blood vessels. To examine possible function of IGCR1, we have generated porcine aortic endothelial (PAE) cells over-expressing IGCR1. We demonstrate that IGCR1 expression in PAE cells inhibited cell proliferation and capillary tube formation as measured by colorimetric MTT and matrigel tube formation assays, respectively. In contrast, over-expression of IGCR1 in PAE cells inhibited cell migration as measured by wounding assay. Taken together, this study identifies IGCR1 as a novel regulator of angiogenesis. Given, angiogenesis is a highly coordinated cellular processes controlled spatially and temporally by a myriad of cell surface receptors and ligands, IGCR1 by modulating the rate of endothelial cell proliferation and migration, plays a significant role in the formation of blood vessels. / 2018-07-11T00:00:00Z

Reducers are commonly used in many types of machines to reduce the speed and increase the torque of motors. For general industrial applications, the reduction ratio of a reducer is usually limited in consideration to its size. To provide high reduction ratios, harmonic drives (speed reducers) can be made very compact and lightweight and thus have been popular with robot manufactures and in other applications where weight is critical. In this study, an innovative design for reducers composed of planar cams and roller followers with high reduction ratios is proposed. It uses the relative motion between rollers and their cams to generate a high reduction ratio. In this thesis, the synthesis procedure of the reducer and the analysis results of the kinematic and dynamic characteristics based on the design parameters are also described. Furthermore, the experiments for testing and verifying the characteristics of the reducer are presented. Finally, a set of design parameters which meets the demand of an application is found by optimization methods.

Ο σκοπός της διπλωματικής εργασίας ήταν η βελτιστοποίηση ενός αλγορίθμου αναγνώρισης ανθρώπινων προσώπων και η εφαρμογή του σε μια έξυπνη κάμερα. Για την αναγνώριση των προσώπων χρησιμοποιήσαμε τον αλγόριθμο PCA ( Αλγόριθμος ανάλυσης κύριων συνιστωσών ). Η εφαρμογή του αλγορίθμου έγινε σε μια εργαστηριακή έξυπνη κάμερα εξοπλισμένη με τον επεξεργαστή LEON 2 όπως επίσης και με ενσωματωμένη μνήμη Sdram μεγέθους 16Mbytes. Η βελτιστοποίηση του αλγορίθμου έγινε με γνώμονα την δυνατότητα εφαρμογής του στην έξυπνη κάμερα. Έτσι η υλοποίηση έγινε αρχικά στο περιβάλλον Matlab στην συνέχεια υλοποιήθηκε σε C γλώσσα προγραμματισμού ενώ τέλος εφαρμόστηκε, μετά από κατάλληλες παραμετροποιήσεις, στην έξυπνη κάμερα. Η έξυπνη κάμερα είναι δυνατόν να καταγράφει και να αναγνωρίζει πρόσωπα με ικανοποιητική ακρίβεια, σε χρόνο μικρότερο του ενός δευτερολέπτου. Τα αποτελέσματα ήταν αρκετά ικανοποιητικά καθώς η κάμερα μπορεί και αναγνωρίζει συγκεκριμένα πρόσωπα, μέσα από ένα σύνολο ανθρώπων που παρακολουθεί. Κύριο πλεονέκτημα της υλοποίησης είναι η μεταφερσιμότητά της που την καθιστά εύχρηστη σε πολλές εφαρμογές που απαιτούν αναγνώριση προσώπων, καθώς επίσης θα μπορούσε να αποτελέσει την βάση για επιπλέον εφαρμογές που θα αποσκοπούσαν στην αναγνώριση διαφορετικών ειδώλων. / The propose of this thesis was the optimizing of an algorithm for Face Recognition, and the implementation of this algorithm to a smart camera. In order to identify the Faces we use the PCA algorithm (Principal Component Analysis) . The implementation of the algorithm was done in a laboratory smart camera, equipped with a LEON2 processor as well as embedded 16Mbytes Sdram memory. The optimization of the algorithm was based on the applicability in the smart camera. This implementation was done originally in Matlab environment, then implemented in C programming code and after the appropriate configurations applied to the smart camera. The smart camera can record and recognize faceswith sufficient accuracy, in less than one second. The results were quite good as the camera can also recognize individual Faces within a group of observed people. Main advantage of the implementation is the portability, which makes it useful in many applications that require identification of persons. Also could be the basis for further applications aimed at identifying different kind of images.

Populations of birds of prey, henceforth raptors, have declined worldwide, mostly from anthropogenic causes. Because their role as apex predators in ecosystems is considered vital for ecosystem health, conservation efforts have been implemented throughout their distribution. In many cases, we do not know enough about their basic food and habitat requirements, which is requisite if we are going to be able to protect them. The purpose of this study was to describe the habits and biology of nesting martial eagles by looking at the chick’s diets and the roles of male and female eagles in provision and presentation (dismemberment) of prey to the chicks. Data were collected non-obtrusively by fitting five nests in the Maasai Mara and one in the Rift Valley region of Kenya with cameras that were both motion-triggered and programmed to take images every five minutes. Based on analysis of 214,000 image frames, the diet of nesting martial eagles and their chicks was found to be comprised of 23 different species within four broad prey categories (gamebirds, domestic poultry, large ungulates and small ungulates), of which gamebirds were the most important. There were sex-based differences in parental feeding, with females selecting for larger and heavier prey items than males. Males were the primary foragers for the chicks up until the eighth to eleventh week of chick development, after which the females became more involved. In addition, before delivery to the nest, large prey were more often dismembered than small and medium-sized prey. This study is the first in Africa to use nest-cams to study martial eagles over the breeding season, corroborating previous studies that have shown sex-dependent differences in chick nurturing. My results contribute to establishing a fuller picture that can be used in future conservation actions and management decisions that can be used to protect this species and their prey base. / Beståndet på rovfåglar (hädanefter raptor) har minskat över hela världen, mestadels på grund av all antropomorfisk verksamhet. Eftersom deras roll som topprovdjur i ekosystem anses vara oerhört viktig för ekosystemens hälsa har bevarandeinsatser genomförts i alla deras habitat. I många fall vet vi inte tillräckligt om deras grundläggande mat- och livsmiljökrav, vilket är nödvändigt om vi skall kunna skydda dem. Syftet med denna studie var att beskriva habitat och biologi hos häckande stridsörnar genom att titta på ungarnas dieter och rollen som hanor och honor i tillhandahållande och presentation (rivning) av byte till ungarna. Data samlades in genom att använda en icke-störande teknik. Kameror som var både rörelsestyrda och programmerade att ta bilder var femte minut monterades vid fem bon i Maasai Mara och en i Rift Valley-regionen i Kenya. Baserat på analys av 214 000 bildramar konstaterades att dieten för häckande stridsörnar och deras ungar bestod av 23 olika arter inom fyra breda byteskategorier (viltfåglar, tamfåglar, stora hovdjur och små hovdjur), varav viltfåglar var de viktigaste. Det fanns könsbaserade skillnader i kost som ungarna fick, med honor som valde större och tyngre byte än hanar valde. Hanar var de främsta furagerare fram till den åttonde veckan av ungarnas utveckling, då blir honor mer involverade. Dessutom blev stort byte ofta delade ned innan leverans till boet än små och medelstora byten. Denna studie är den första i Afrika som använde kamror för stridsörnar under Häckningssäsong och den bekräftar tidigare studier som har visat könsberoende skillnader i skötsel av ungar. Mina resultat bidrar till att skapa en mer fullständig bild som kan användas i framtida bevarandeåtgärder och förvaltningsbeslut som kan användas för att skydda denna art. / <p>Due to Covid-19 all presentations and defences were held online</p>