1,721,345 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Additive Manufacturing & Topology Optimisation of electrical machines.
No full textIn recent years, additive manufacturing has been gaining ground among traditional
manufacturing methods in many different applications. This is mainly due to its ease of
prototyping, material savings and above all the highly complex geometries that can be
achieved. Despite its many advantages, the use of additive manufacturing in electrical
machines has been limited. The lack of maturity of the manufacturing processes and the
increase in losses when applying additive approaches to some parts, mainly stators, have led
little implementation in the field of electrical machines.
The geometric freedom offered by additive manufacturing paves the way for the use of novel
optimisation techniques, such as topology optimisation. Traditionally, topology optimisation
has not been widely used because the complex geometries obtained by these algorithms are
not easily produced by traditional manufacturing methods. However, thanks to additive
manufacturing, topology optimisation has started to be used, mainly for mechanical
applications and it has demonstrated its ability to reduce weight without compromising
mechanical stability in several cases. Nevertheless, topology optimisation for physics other
than mechanical has not been thoroughly studied, let alone for the simultaneous optimisation
of different physics.
In view of the scenario described, this thesis investigates the benefits that additive
manufacturing and topology optimisation can bring to the design of electrical machines.
For the additive manufacturing of electrical machines, a thorough literature review is carried
out on the application of this manufacturing approach to different parts of electrical machines,
active and non-active. Two main case studies are presented: in the first, the rotor, the shaft,
the stator and the housing of an aerospace actuator are manufactured by L-PBF in FeCoV and
the assembled actuator is tested. In the second case, a rotor is manufactured in FeSi by LP-
DED. Finally, not considered an additive manufacturing case study itself in this thesis, but two
electrical conductor prototypes are manufactured in CuCr1Zr and an additional geometry is
manufactured in AlSi10Mg by L-PBF.
With regard to topology optimisation of electrical machines, a description of the main
topology optimisation methods used is given and their application to electrical machine
components is presented. In a similar way to additive manufacturing, two case studies are
analysed. First, a novel multiphysics - mechanical and electromagnetic - topology optimisation
method is presented, in which the rotor and the stator of a permanent magnet motor are
optimised simultaneously. This method is compared with two methods found in the literature,
SIMP and on-off. Secondly, another topology optimisation method is described and applied to
an electrical conductor model. The proposed algorithm involves a multiphysics - thermal and
electromagnetic - hybrid parametric topology optimisation approach. Two reduced length
geometries and one full length prototype are built via additive manufacturing.
Finally, conclusions regarding additive manufacturing and topology optimisation of electrical
machines are drawn from the work presented in this thesis. Future lines of work for additive
manufacturing and topology optimisation of electrical machines are also presented.En los últimos años, la fabricación aditiva ha ido ganando terreno a los métodos de fabricación
tradicionales en muchas aplicaciones diferentes. Esto se debe principalmente a su facilidad
para crear prototipos, al ahorro de material y, sobre todo, a las geometrías altamente
complejas que se pueden conseguir. A pesar de sus muchas ventajas, el uso de la fabricación
aditiva en máquinas eléctricas ha sido limitado. La falta de madurez de los procesos de
fabricación y el aumento de las pérdidas al aplicar enfoques aditivos a algunas piezas,
principalmente estatores, han provocado una escasa implantación en el campo de las
máquinas eléctricas.
La libertad geométrica que ofrece la fabricación aditiva allana el camino para el uso de técnicas
de optimización novedosas, como la optimización topológica. Tradicionalmente, la
optimización de la topología no se ha utilizado mucho porque las geometrías complejas que
obtienen estos algoritmos no son fáciles de producir con los métodos de fabricación
tradicionales. Sin embargo, gracias a la fabricación aditiva, la optimización topológica ha
empezado a utilizarse, principalmente para aplicaciones mecánicas, y ha demostrado su
capacidad para reducir el peso sin comprometer la estabilidad mecánica en varios casos. Sin
embargo, la optimización topológica para físicas distintas de la mecánica no se ha estudiado en
profundidad, y mucho menos para la optimización simultánea de distintas físicas.
Ante el escenario descrito, esta tesis investiga los beneficios que la fabricación aditiva y la
optimización topológica pueden aportar al diseño de máquinas eléctricas.
Para la fabricación aditiva de máquinas eléctricas, se realiza una revisión bibliográfica
exhaustiva sobre la aplicación de este enfoque de fabricación a diferentes partes de máquinas
eléctricas, activas y no activas. Se presentan dos casos prácticos principales: en el primero, el
rotor, el eje, el estator y la carcasa de un actuador aeroespacial se fabrican mediante L-PBF en
FeCoV y se prueba el actuador ensamblado. En el segundo caso, se fabrica un rotor en FeSi
mediante LP-DED. Por último, no se considera un caso de estudio de fabricación aditiva
propiamente dicho en esta tesis, pero se fabrican dos prototipos de conductores eléctricos en
CuCr1Zr y una geometría adicional en AlSi10Mg mediante L-PBF.
En cuanto a la optimización topológica de máquinas eléctricas, se describen los principales
métodos de optimización topológica utilizados y se presenta su aplicación a componentes de
máquinas eléctricas. De forma similar a la fabricación aditiva, se analizan dos casos prácticos.
En primer lugar, se presenta un novedoso método de optimización topológica multifísica -
mecánica y electromagnética- en el que se optimizan simultáneamente el rotor y el estator de
un motor de imanes permanentes. Este método se compara con dos métodos encontrados en
la literatura, SIMP y on-off. En segundo lugar, se describe otro método de optimización
topológica y se aplica a un modelo de conductor eléctrico. El algoritmo propuesto implica un
enfoque de optimización de topología paramétrica híbrida multifísica -térmica y
electromagnética-. Se construyen dos geometrías de longitud reducida y un prototipo de
longitud completa mediante fabricación aditiva.
Finalmente, del trabajo presentado en esta tesis se extraen conclusiones sobre la fabricación
aditiva y la optimización topológica de máquinas eléctricas. También se presentan futuras
líneas de trabajo para la fabricación aditiva y la optimización topológica de máquinas
eléctricas
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Additive Manufacturing & Topology Optimisation of electrical machines.
No full textIn recent years, additive manufacturing has been gaining ground among traditional
manufacturing methods in many different applications. This is mainly due to its ease of
prototyping, material savings and above all the highly complex geometries that can be
achieved. Despite its many advantages, the use of additive manufacturing in electrical
machines has been limited. The lack of maturity of the manufacturing processes and the
increase in losses when applying additive approaches to some parts, mainly stators, have led
little implementation in the field of electrical machines.
The geometric freedom offered by additive manufacturing paves the way for the use of novel
optimisation techniques, such as topology optimisation. Traditionally, topology optimisation
has not been widely used because the complex geometries obtained by these algorithms are
not easily produced by traditional manufacturing methods. However, thanks to additive
manufacturing, topology optimisation has started to be used, mainly for mechanical
applications and it has demonstrated its ability to reduce weight without compromising
mechanical stability in several cases. Nevertheless, topology optimisation for physics other
than mechanical has not been thoroughly studied, let alone for the simultaneous optimisation
of different physics.
In view of the scenario described, this thesis investigates the benefits that additive
manufacturing and topology optimisation can bring to the design of electrical machines.
For the additive manufacturing of electrical machines, a thorough literature review is carried
out on the application of this manufacturing approach to different parts of electrical machines,
active and non-active. Two main case studies are presented: in the first, the rotor, the shaft,
the stator and the housing of an aerospace actuator are manufactured by L-PBF in FeCoV and
the assembled actuator is tested. In the second case, a rotor is manufactured in FeSi by LP-
DED. Finally, not considered an additive manufacturing case study itself in this thesis, but two
electrical conductor prototypes are manufactured in CuCr1Zr and an additional geometry is
manufactured in AlSi10Mg by L-PBF.
With regard to topology optimisation of electrical machines, a description of the main
topology optimisation methods used is given and their application to electrical machine
components is presented. In a similar way to additive manufacturing, two case studies are
analysed. First, a novel multiphysics - mechanical and electromagnetic - topology optimisation
method is presented, in which the rotor and the stator of a permanent magnet motor are
optimised simultaneously. This method is compared with two methods found in the literature,
SIMP and on-off. Secondly, another topology optimisation method is described and applied to
an electrical conductor model. The proposed algorithm involves a multiphysics - thermal and
electromagnetic - hybrid parametric topology optimisation approach. Two reduced length
geometries and one full length prototype are built via additive manufacturing.
Finally, conclusions regarding additive manufacturing and topology optimisation of electrical
machines are drawn from the work presented in this thesis. Future lines of work for additive
manufacturing and topology optimisation of electrical machines are also presented.En los últimos años, la fabricación aditiva ha ido ganando terreno a los métodos de fabricación
tradicionales en muchas aplicaciones diferentes. Esto se debe principalmente a su facilidad
para crear prototipos, al ahorro de material y, sobre todo, a las geometrías altamente
complejas que se pueden conseguir. A pesar de sus muchas ventajas, el uso de la fabricación
aditiva en máquinas eléctricas ha sido limitado. La falta de madurez de los procesos de
fabricación y el aumento de las pérdidas al aplicar enfoques aditivos a algunas piezas,
principalmente estatores, han provocado una escasa implantación en el campo de las
máquinas eléctricas.
La libertad geométrica que ofrece la fabricación aditiva allana el camino para el uso de técnicas
de optimización novedosas, como la optimización topológica. Tradicionalmente, la
optimización de la topología no se ha utilizado mucho porque las geometrías complejas que
obtienen estos algoritmos no son fáciles de producir con los métodos de fabricación
tradicionales. Sin embargo, gracias a la fabricación aditiva, la optimización topológica ha
empezado a utilizarse, principalmente para aplicaciones mecánicas, y ha demostrado su
capacidad para reducir el peso sin comprometer la estabilidad mecánica en varios casos. Sin
embargo, la optimización topológica para físicas distintas de la mecánica no se ha estudiado en
profundidad, y mucho menos para la optimización simultánea de distintas físicas.
Ante el escenario descrito, esta tesis investiga los beneficios que la fabricación aditiva y la
optimización topológica pueden aportar al diseño de máquinas eléctricas.
Para la fabricación aditiva de máquinas eléctricas, se realiza una revisión bibliográfica
exhaustiva sobre la aplicación de este enfoque de fabricación a diferentes partes de máquinas
eléctricas, activas y no activas. Se presentan dos casos prácticos principales: en el primero, el
rotor, el eje, el estator y la carcasa de un actuador aeroespacial se fabrican mediante L-PBF en
FeCoV y se prueba el actuador ensamblado. En el segundo caso, se fabrica un rotor en FeSi
mediante LP-DED. Por último, no se considera un caso de estudio de fabricación aditiva
propiamente dicho en esta tesis, pero se fabrican dos prototipos de conductores eléctricos en
CuCr1Zr y una geometría adicional en AlSi10Mg mediante L-PBF.
En cuanto a la optimización topológica de máquinas eléctricas, se describen los principales
métodos de optimización topológica utilizados y se presenta su aplicación a componentes de
máquinas eléctricas. De forma similar a la fabricación aditiva, se analizan dos casos prácticos.
En primer lugar, se presenta un novedoso método de optimización topológica multifísica -
mecánica y electromagnética- en el que se optimizan simultáneamente el rotor y el estator de
un motor de imanes permanentes. Este método se compara con dos métodos encontrados en
la literatura, SIMP y on-off. En segundo lugar, se describe otro método de optimización
topológica y se aplica a un modelo de conductor eléctrico. El algoritmo propuesto implica un
enfoque de optimización de topología paramétrica híbrida multifísica -térmica y
electromagnética-. Se construyen dos geometrías de longitud reducida y un prototipo de
longitud completa mediante fabricación aditiva.
Finalmente, del trabajo presentado en esta tesis se extraen conclusiones sobre la fabricación
aditiva y la optimización topológica de máquinas eléctricas. También se presentan futuras
líneas de trabajo para la fabricación aditiva y la optimización topológica de máquinas
eléctricas
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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