491 research outputs found
Integration of differential equations by -structures
Several integrability problems of differential equations are addressed by
using the concept of -structure, a recent generalization
of the notion of solvable structure. Specifically, the integration procedure
associated with -structures is used to integrate to a
Lotka-Volterra model and several differential equations that lack sufficient
Lie point symmetries and cannot be solved using conventional methods
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Thematic Report Three - Asylum, Security and Extremism
This is the final of three Thematic Reports published as part of a CREST-funded project carried out by a team of researchers at City, University of London, and Cranfield University at the Defence Academy of the United Kingdom. With the objective of better understanding Tamil diaspora communities’ attitudes and engagement in the Sri Lankan civil conflict (1983-2009) and its aftermath, the project explores diaspora and refugee communities’ relationship with the changing socio-political environment in the homeland, exploring what shapes and influences processes of radicalisation or moderation among these communities. It recognises that the socio-political circumstances in which these processes develop are often crucial to understanding why a community or individuals within that community abroad act in a certain way; this includes analysis of different scales and levels of engagement, both in home and host countries, as well as different ‘areas’ of engagement, which can include social, economic and political interactions. The three thematic reports produced as part of this project cumulatively build a comprehensive picture of the state of knowledge on political action among diaspora, refugee and asylum populations. The theoretically-informed, literature- and evidence-grounded conclusions arising from these three thematic reports are therefore of relevance beyond the case of Sri Lanka. Thematic Report One discussed how four analytical concepts, diaspora, transnationalism, cosmopolitanism, and translocalism, have come to frame the academic discussion of overseas politics and the potential of these concepts to shed light on the relationship between mobility and political action. Thematic Report Two complements the previous report’s broad conceptual discussion by specifically focusing on an analysis of the context and drivers of political action among diaspora and refugee populations, and engaging with the term ‘refugee politics’. The current paper – the final Thematic Report – analyses the growing ‘securitisation’ of refugees and other forcibly displaced populations and calls for greater consideration of structural vulnerabilities in the forced migration and displacement cycle that increase the risk of radicalisation, extremism and related political behaviours
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City of Vancouver EV Infrastructure Strategy Report
The role of the local government in supporting the growth and maintenance of a strong plug‐in electric vehicle market in Vancouver is evaluated in this report. This report identifies areas of action in which a local government, such as Vancouver, can impact their region based on a thorough understanding of the current plug‐in vehicle market, international demonstration projects, and research efforts. Specifically, workplace and public charging is needed to reinforce and fulfill the gaps from home‐based charging in dense urban regions. Local government can encourage investments in workplace and public charging by providing clear regional guidelines for installers and customers, providing appropriate incentives to businesses, allowing for an innovative marketplace in the vehicle charging industry, and collaborating with the regional utility to identify specific opportunities for optimization and encouragement of utility rates and vehicle‐grid interactions
Boussinesq Solitons as Propagators of Neural Signals
We consider certain approximation for determining the equation of motion for nerve signals by using the model of the lipid melting of membranes. The nerve pulses are found to display nonlinearity and dispersion during the melting transition. In this simplified model the nonlinear equation early proposed by Heimburg and coworkers transformed to the well known integrable Boussinesq non linear equation. Under specific values of the parametric space this system shows the existence of singular and regular soliton like structures. After their collisions the mutual creation and annihilation (each other) of nerve signals along the nerve, during their propagation, has been observed.Keywords: Boussinesq equation, singular solitons, single neurons, neural code
-structures in the integration of involutive distributions
For a system of ordinary differential equations (ODEs) or, more generally, an
involutive distribution of vector fields, the problem of its integration is
considered. Among the many approaches to this problem, solvable structures
provide a systematic procedure of integration via Pfaffian equations that are
integrable by quadratures. In this paper structures more general than solvable
structures (named cinf-structures) are considered. The symmetry condition in
the concept of solvable structure is weakened for cinf-structures by requiring
their vector fields be just cinf-symmetries. For cinf-structures there is also
an integration procedure, but the corresponding Pfaffian equations, although
completely integrable, are not necessarily integrable by quadratures. The
well-known result on the relationship between integrating factors and Lie point
symmetries for first-order ODEs is generalized for cinf-structures and
involutive distributions of arbitrary corank by introducing symmetrizing
factors. The role of these symmetrizing factors on the integrability by
quadratures of the Pfaffian equations associated with the \cinf-structure is
also established. Some examples that show how these objects and results can be
applied in practice are also presented
-symmetries of distributions and integrability
An extension of the notion of solvable structure for involutive distributions
of vector fields is introduced. The new structures are based on a
generalization of the concept of symmetry of a distribution of vector fields,
inspired in the extension of Lie point symmetries to
-symmetries for ODEs developed in the recent years.
These new objects, named -structures, play a
fundamental role in the integrability of the distribution: the knowledge of a
-structure for a corank involutive distribution
permits to find its integral manifolds by solving successive completely
integrable Pfaffian equations. These results have important consequences for
the integrability of differential equations. In particular, we derive a new
procedure to integrate an th-order ordinary differential equation by
splitting the problem into completely integrable Pfaffian equations. This
step-by-step integration procedure is applied to integrate completely several
equations that cannot be solved by standard procedures
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Thematic Report Two - The Engagement of Refugees in Transnational Politics: Lessons from the Migration, Diaspora and Refugee Studies Literature
This is the second of three CREST-funded Thematic Reports published by a team of researchers at City, University of London, and Cranfield University at the Defence Academy of the United Kingdom, that cumulatively build a comprehensive picture of the state of knowledge on political action among diaspora and refugee populations. The research team is specifically interested in applying the theoretically-informed, literature and evidence grounded conclusions arising from these reports to understand the attitudes towards and involvement in the Sri Lankan civil conflict (1983-2009) and its aftermath by Tamil diaspora communities, but with a broader application. The CREST project is exploring diaspora and refugee communities’ relationship with the changing socio-political environment in the homeland and how this influences processes of radicalisation or moderation. It recognises that the socio-political circumstances in which these processes develop are often crucial to understanding why a community or individuals within that community abroad act in a certain way; this includes analysis of different scales and levels of engagement, both in home countries and in host countries, as well as different ‘areas’ of engagement, which can include social, economic and political interactions. Thematic Report One discussed how four analytical concepts, diaspora, transnationalism, cosmopolitanism, and translocalism, have come to frame the academic discussion of overseas politics and the potential of the concepts to shed light on the relationship between mobility and political action. The current paper – Thematic Report Two – complements the previous report’s broad conceptual discussion by specifically focusing on an analysis of the context and drivers of political action among diaspora and refugee populations, and engaging with the term ‘refugee politics’. It considers if the available diaspora and migration literature sheds light on whether the processes and dynamics of forced migration are likely to generate identifiable forms of political engagement
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Thematic Report One - Understanding Transnational Diaspora Politics: A Conceptual Discussion
This is the first of three CREST-funded Thematic Reports published by a team of researchers at City, University of London, and Cranfield University at the Defence Academy of the United Kingdom examining political action among diaspora populations. The purpose of the report is to explore the theoretical and conceptual basis underpinning academic debates on engagement in the politics of conflict and post-conflict by communities living overseas. The research team is interested specifically in the Sri Lankan civil conflict between 1983 and 2009 and its aftermath, and understanding the attitudes towards and involvement in that conflict on the part of Tamil diaspora communities. The CREST project is exploring diaspora communities’ relationship with the changing socio-political environment in the homeland and how this influences processes of radicalisation or moderation. It recognises that the socio-political circumstances in which these processes develop are often crucial towards understanding why a community or individuals within that community abroad act in a certain way; this includes analysis of different scales and levels of engagement, both in home countries and in host countries, as well as different ‘areas’ of engagement, which can range from social to economic to political interactions. The following review is not specific to the Sri Lankan situation; it is rather concerned with how four concepts, diaspora, transnationalism, cosmopolitanism, and translocalism, have come to frame the academic discussion of diaspora or more broadly overseas politics and the potential of the concepts to shed light on the relationship between mobility and political action. It considers the extent to which these concepts are helpful in identifying the rationale behind specific methods of political participation offering critical reflections on the analytical and normative usefulness of these terms
Programas y recursos disponibles para una visita guiada: El Canal de Castilla
Este trabajo Fin de Grado se centra en la búsqueda de programas y recursos que existen en la actualidad para realizar una visita escolar guiada al Canal de Castilla, con el fin de concretar las posibilidades que se ofrecen a escolares de diferentes edades para que puedan conocer y disfrutar de este gran patrimonio histórico y ambiental de una forma guiada a lo largo de su recorrido.El Canal de Castilla es un gran recurso para la educación, dado que permite aprender aspectos relativos de nuestra historia y del entorno que rodea al Canal (elementos de ingeniería, flora y fauna).Una salida resulta altamente beneficioso y gratificante para el alumno, porque a través de un contacto directo va a conocer y entender mejor los contenidos que se le están mostrando en el aula, le permite descubrir otros nuevos, desarrollar sus habilidades sociales y mejorar relaciones existentes con sus compañerosGrado en Educación Primari
Acacia Horrida (L.) Willd.: refugio de artrópodos benéficos en la costa peruana
El huarango (Acacia horrida (L.) Willd., 1806) es una leguminosa arbustiva utilizada como cerco vivo en áreas agrícolas para prevenir la erosión, mejorar la nutrición del suelo y servir, además, como refugio para artrópodos benéficos, contribuyendo así a la sostenibilidad de los agroecosistemas productivos. Por ello, se quiso conocer las especies de artrópodos benéficos asociados a A. horrida en agroecosistemas de la costa centro y sur del Perú. Para ello, se colectó especímenes en cercos vivos de A. horrida cercanos a cultivos de hortalizas de La Molina (Lima), campos de mandarina y palto en Cañete (Lima) y huertos caseros con camote y frutales en Los Aquijes (Ica). Los resultados obtenidos permitieron encontrar en La Molina arañas Salticidae y Argiope sp., insectos depredadores como Harmonia axyridis Pallas, 1773, Cycloneda sanguinea Linnaeus, 1743, Scymnus rubicundus Erichson, 1847 y parasitoides del género Bracon. En Cañete se encontró la araña Gasteracantha cancriformis Linnaeus, 1758, insectos depredadores como C. sanguinea, S. rubicundus, Ceraeochrysa cincta (Schneider, 1851), Allograpta sp., Tachycompilus sp., y parasitoides como Venturia sp., Campoletis sp. Anomalon sinuatum Morley, 1912, subfamilias Cryptinae, Campopleginae (Ichneumonidae), Braconinae, Microgastrinae, Opiinae (Braconidae) y la familia Eulophidae. En Los Aquijes se encontró C. sanguinea, Hippodamia convergens Guérin-Méneville, 1842, Polistes sp. y parasitodes del género Bracon, siendo estos últimos depredados por arañas de la familia Thomisidae. Se concluye que al menos 22 taxa de artrópodos benéficos están asociados a A. horrida como refugio
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