559 research outputs found
Gauged vortices in a background
We discuss the statistical mechanics of a gas of gauged vortices in the
canonical formalism. At critical self-coupling, and for low temperatures, it
has been argued that the configuration space for vortex dynamics in each
topological class of the abelian Higgs model approximately truncates to a
finite-dimensional moduli space with a Kaehler structure. For the case where
the vortices live on a 2-sphere, we explain how localisation formulas on the
moduli spaces can be used to compute explicitly the partition function of the
vortex gas interacting with a background potential. The coefficients of this
analytic function provide geometrical data about the Kaehler structures, the
simplest of which being their symplectic volume (computed previously by Manton
using an alternative argument). We use the partition function to deduce simple
results on the thermodynamics of the vortex system; in particular, the average
height on the sphere is computed and provides an interesting effective picture
of the ground state.Comment: Final version: 22 pages, LaTeX, 1 eps figur
Quantum Chern-Simons Vortices on a Sphere
The quantisation of the reduced first-order dynamics of the nonrelativistic model for Chern-Simons vortices introduced by Manton is studied on a sphere of given radius. We perform geometric quantisation on the moduli space of static solutions, using a Kaehler polarisation, to construct the quantum Hilbert space. Its dimension is related to the volume of the moduli space in the usual classical limit. The angular momenta associated with the rotational SO(3) symmetry of the model are determined for both the classical and the quantum systems. The results obtained are consistent with the interpretation of the solitons in the model as interacting bosonic particles
HIGH-ORDER FINITE DIFFERENCE METHOD APPLIED TO THE SOLUTION OF THE THREE-DIMENSIONAL HEAT TRANSFER EQUATION AND TO THE STUDY OF HEAT EXCHANGERS
Numerical experiments for four test problems are carried out to demonstrate the performance of the present method and to compare it with the others classical methods. The numerical solutions obtained are compared with the analytical solution as well as the results by other numerical schemes with emphasis on the application involving heat exchange in a rectangular channel. It can be easily seen that the proposed method is simple to implement and very efficient
Development and implementation of the profitability risk module process
Project Work presented as the partial requirement for obtaining a Master's degree in Data Science and Advanced Analytics, specialization in Data ScienceThe main objective of this report is to outline the project carried out at Neyond, where the
main goal was developing an automated E.T.L. reporting process for an international bank,
one of the clients.
This project played a crucial role in solidifying the knowledge gained and implementing the
diverse techniques learned throughout the initial academic year. It also provided an
opportunity to merge academic training with practical professional experience. This report
provides an overview of the project’s goals, methodologies, tools, technologies used, and
the challenges encountered during its execution.
To accomplish this objective, this report describes the project and the main goals to achieve
the desired result, the tools and technologies used, as well as some of the challenges and
how they were surpassed
Myths and legends of the fountains of Trás-os-Montes
O distrito de Bragança para lá de diversas qualidades tanto a nível gastronómico, paisagístico e cultural
possui também um grande caráter histórico, nomeadamente recheado de lendas e mitos relacionadas
com as fontes. Estas histórias mostram, igualmente, que no passado a crença em presságios era algo
permanente, principalmente quando havia algo de mau a acontecer a sociedade tentava encontrar a
sua salvação com algo visível, como a água.The district of Bragança beyond various qualities, landscaping, gastronomic and cultural ones, also
has a great historic nature, namely full of legends and myths related to fountains. These stories also
show that in the past the belief in omens was something permanent, especially when there was something
bad happening, society tried to find their salvation with something visible, like water
Protecting police officers against burnout: Overcoming a fragmented research field
This study aims to identify the determinants of burnout in police officers. We considered a wide range of psychosocial risk factors, individual variables that have been previously found to be associated with burnout in police officers (affective and cognitive empathy, self-care), and variables whose unique impact on burnout of police officers needs further clarification (organizational justice and organizational identification). The study was conducted in Portugal, and the sample was constituted by 573 members of the National Republican Guard (GNR—Guarda Nacional Republicana). The participants were invited to answer an online anonymous survey, which included previously validated measures of the following variables: burnout (exhaustion and disengagement), psychosocial risk factors, self-care, empathy (cognitive and affective), organizational justice, and organizational identification. Furthermore, we controlled for the potential impact of demographic variables (age, gender, years of professional experience, religiosity, political orientation, and income). Multiple regression analysis showed that when taken together, only a few of the variables associated with burnout had a unique impact on both exhaustion and disengagement: quantitative demands and affective empathy were burnout risk factors; meaningful work, organizational justice (distributive justice, procedural justice, and interactional justice), and organizational identification were burnout protective factors. Our results highlight the importance of developing theoretical models and planning interventions to prevent
burnout in police officers, focusing mainly on the above-mentioned variables.info:eu-repo/semantics/publishedVersio
Crosswell seismic tomographic inversion using NSGA II
In the present paper, the solution of the seismic data inversion problem
through multi-objective optimization with NSGA II is addressed. The seismic
inversion consists of estimating the slowness of rocks in the subsurface from
the travel times of the waves through the transmitters and receivers of the
seismic waves. The inversion process uses the multi-objective optimization
technique, in which it is necessary to estimate the trade-off between the
misfit functional and the stabilizing constraint. The constraint used was the
classic first-order Tikhonov. A synthetic model of inclined layers was chosen.
The results obtained were acceptable. Based on the graph of the cumulative
errors related to the solution, it was estimated correctly, that is, the
optimization method used was effective to obtain acceptable results, in
addition to the constraint solving the instability problem of the inverse
problem treated. Another important result was the achievement of a convergence
curve on the Pareto frontier, an important result for future research.Comment: 14 pages, 12 figure
AN ALTERNATIVE AND SIMPLE MANNER TO CALCULATE THE THERMAL EFFICIENCY OF COMBUSTION ENGINES
This papers aims to present techniques and methods to develop an alternative equation to determine the thermal efficiency of internal combustion engines. Towards interpolation of data, obtained from thermodynamic tables, it presents a function that allows a faster calculation of efficiency for combustion engines
Transmontanas medicinal plants: main species, their uses and reliability in combating health problems
Atualmente, grande parte da população recorre às terapias alternativas, verificando-se uma multiplicidade
de motivos para a sua escolha. Estas são, muitas vezes, o único tratamento disponível face aos
recursos médicos existentes e ao nível económico da sociedade. As plantas medicinais são tradicionalmente
recolhidas pelos habitantes ou curandeiros de uma região. Em Trás-os-Montes, a propriedade
vegetativa é variada e abundante em doações e pode acarretar malefícios – aspetos abordados no
presente artigo.Nowadays, many people turn to alternative therapies and there is a multiplicity of reasons for their
choice. These are often the only available treatment as far as medical resources are concerned and
according to the economic level of society. Medicinal plants are traditionally collected by the inhabitants
or healers of the country. In Trás-os-Montes, the vegetative property is varied and abundant in
donations and can cause harm – aspects discussed in this article
Least squares finite element method for 3D unsteady diffusion and reaction-diffusion problems
In this paper a study to application of Least Squares Finite Element Method (LSFEM) is made and with auxiliary equations (temperature derivatives) in the solution of Transient Three-dimensional Diffusion-Reaction. In order to do so, two applications are presented and discussed, one of them Pure Diffusion and another DiffusionReaction, both solved towards the constructive meshes with hexahedron of 8 and 27 nodes. This analysis uses the standard L∞ (maximum error in all meshes) and L2 (average error in all the meshes) to verify the numerical error committed in the solution9196209CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP500382/2011-52014/06679-
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