1,720,986 research outputs found
Design of a robotic arm for laboratory simulations of spacecraft proximity navigation and docking
Full text linkThe increasing number of human objects in space has laid the foundation of a novel class of orbital missions for servicing and maintenance. The main goal of this thesis is the development, building and testing of a robotic manipulator for the simulation of orbital maneuvers, with particular attention to Active Debris Removal (ADR) and On-Orbit Servicing (OOS).
There are currently very few ways to reproduce microgravity in a non-orbital environment: among the main techniques, it is worth mentioning parabolic flights, pool simulations and robotic facilities. Parabolic flights allow to reproduce orbital conditions quite faithfully, but simulation conditions are very constraining. Pool simulations, on the other hand, have fewer constrictions in terms of cost, but the drag induced by the water negatively affects the simulated microgravity. Robotic facilities, finally, permit to reproduce indirectly (that is, with an appropriate control system) the physics of microgravity. State of the art on 3D robotic simulations is nowadays limited to industrial robots facilities, that bear conspicuous costs, both in terms of hardware and maintenance.
This project proposes a viable alternative to these costly structures. Through dedicated algorithms, the system is able to compute in real time the consequences of these contacts in terms of trajectory modifications, which are then fed to the hardware in the loop (HIL) control system. Moreover, the governing software can be commanded to perform active maneuvers and relocations: as a consequence, the manipulator can be used as the testing bench not only for orbital servicing operations but also for attitude control systems, providing a faithful, real-time simulation of the zero-gravity behavior.
Furthermore, with the aid of dynamic scaling laws, the potentialities of the facility can be exponentially increased: the simulation environment is not longer bounded to be as big as the robot workspace, but could be several orders of magnitude bigger, allowing for the reproduction of otherwise preposterous scenarios.
The thesis describes the detailed mechanical design of the facility, corroborated by structural modeling, static and vibrational finite element verification. A strategy for the simulation of impedance-matched contacts is presented and an analytical control analysis defines the set of allowable inertial properties of the simulated entities. Focusing on the simulation scenarios, an innovative information theoretic approach for simultaneous localization and docking has been designed and applied for the first time to a 3D rendezvous scenario.
Finally, in order to instrument the facility’s end effector with a consistent sensor suite, the design and manufacturing of an innovative Sun sensor is proposed
Adultos mayores polimedicados : estrategias de intervención en una farmacia comunitaria de Alta Gracia (Córdoba)
No full textTrabajo Integrador Final (Especialista en Farmacia Comunitaria) - - Universidad Nacional de Córdoba. Facultad de Ciencias Químicas, 2024Fil. : Antonello, Andrea Alejandra. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina.Un elevado número de adultos mayores consume medicamentos en forma crónica, la pluripatología, características fisiológicas y psicosociales generan procesos farmacoterapéuticos complejos, produciendo variaciones en la efectividad y seguridad de los tratamientos.
El objetivo del estudio fue diseñar estrategias de intervención farmacéutica para AM polimedicados desde la farmacia comunitaria. Se describieron características sociodemográficas y farmacoterapéuticas de los AM. Se analizó adherencia, prevalencia, tipos de medicamentos potencialmente inadecuados (MPI), automedicación, aparición de eventos adversos, duplicidades, prescripción en cascada y factibilidad de deprescripción.
Estudio descriptivo transversal realizado en 30 pacientes mayores de 65 años, utilizándose 2 fuentes de información: -base de datos de la farmacia comunitaria -entrevista semiestructurada con ficha farmacoterapéutica. Para la detección de MPI se utilizaron criterios STOPP-START y Lista IFASPIAM. Se estudió adherencia con 2 métodos indirectos.
Resultados: promedio de edad 74,1 ± 7,5 años, la mayoría estaba casado, tenía hijos, vivía acompañado, nivel educativo alcanzado primario completo, dijeron tener hábitos saludables, aunque el promedio de IMC fue 30 ± 5 y el 66.7 % no realizaba actividad física. La mayoría realizó consultas médicas y análisis bioquímicos en los últimos 6 meses.
El 66.7% se automedicaba, la media de medicamentos consumidos fue 8,5 ± 2,7, el número de recetas y el promedio de médicos prescriptores fue de 4 ± 1,7 y 2,6 ± 1,4 respectivamente.
El 40% manifestó ser no adherente según cuestionario aplicado, aunque retiraron sus medicamentos en tiempo acorde al tratamiento en los últimos 3 meses.
La prevalencia de AM con MPI fue 86,7% y 2,8 ± 1,9 la media de MPI por paciente. La frecuencia de MPI según criterios STOPP fue 31,8% e IFASPIAM 13,3%. El 29,4% de los medicamentos prescriptos fueron identificados como potencialmente inadecuados. Las categorías más frecuentes según STOPP fueron las relacionadas a duración superior a la indicada, fármacos que aumentan el riesgo de producir caídas e Inhibidores de la Bomba de Protones con duración superior a 8 semanas a dosis plenas. Los grupos terapéuticos más frecuentes detectados por IFASPIAM fueron ansiolíticos, AINES y cardiovasculares. Se encontró una prevalencia de AM con eventos adversos del 63,3%, prescripción en cascada del 43,3% y posibilidad de deprescripción del 86,7%.
Conclusiones: la revisión sistemática de la medicación surge como un recurso para mejorar el uso de los medicamentos y la farmacia comunitaria como ámbito propicio para diseñar y aplicar estrategias para AM.2026-07-31Fil. : Antonello, Andrea Alejandra. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dynamic behavior of a semi-androgynous small satellite docking interface
No full textSince the first mating manoeuvre performed in 1966 between the Gemini VIII and the Agena Target Vehicle, many different docking mechanisms were developed, although the few systems dedicated to small satellites have never been verified in space nor scaled to CubeSat size. In the near future, small spacecraft docking procedures could acquire great importance, since the significant cut in the cost of development and access to space due to current advancements on miniature satellites technology, that is creating a new market, dedicated to commercial low risk application, low budget scientific missions and educational purposes. In this context, this paper presents a novel docking system to provide small spacecraft with the ability to join and separate in space, to realize multi-body platforms able to rearrange, be repaired or updated, thus overcoming the actual on board resources limitations of single small-scale satellites. Possible implementations include many different examples, from small and low cost space tugs to segmented mirror telescopes, making nano-satellite market competitive with respect to traditional vehicles. As for now, proposed docking ports present (1) simple probe-drogue interfaces or (2) androgynous geometries, with complex and non-axis-symmetric latches, but with the ability to dock with same-gender ports. The proposed solution overcomes the aforementioned drawbacks, using a semi-androgynous shape-shifting mechanism that actuating one interface changes the port into a “drogue" configuration, letting the other port penetrate it and closing around to create a solid joint. Main advantages of this solution lie in the possibility to conjugate the shape shifting actuation and the solid joint creation, thanks to a cam mechanism able to preload the structure. The mechanism design through the requirement definition and a trade-off between different concepts is presented in this paper, followed by the dynamic behaviour of the selected solution, numerically analysed with particular attention to two aspects, i.e. the loads transmitted between the mating ports and the alignment tolerances requested to perform successful docking manoeuvres. Such analysis led to the definition of instrumented prototypes to verify the solution through simple validation tests
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