1,186 research outputs found
An Efficient Implementation of the Finite-volume Method For the Solution of Radiation Transport in Circuit Breakers
In this paper, we propose to revisit the method to solve the radiation transport equation in circuit breakers to reduce the computation time. It is based on an explicit approach using a space marching algorithm. The method can further be accelerated using a Cartesian grid and using the axisymmetric assumption. Comparisons performed in terms of accuracy and efficiency between the P1 model, the implicit finite-volume discrete ordinate method and the space-marching finite-volume discrete ordinate method show that the explicit approach is more that an order of magnitude faster than the implicit approach, for the same accuracy
Обнаружение автомобильных номерных знаков с использованием предварительной обработки кандидатов
Статья посвящена проблеме ускорения процесса поиска объектов на изображениях, основанного на
использовании мультимасштабного сканирования. Для решения этой задачи предлагается использовать\ud
предварительную обработку кандидатов с использованием интегральных характеристик, которая
реализуется как первый этап каскада классификаторов смешанного типа. В качестве тестовой задачи
выбрана задача обнаружения на цифровых изображениях номерных знаков автомобилей. Полученный
каскад классификаторов позволил увеличить быстродействие обработки изображений при обнаружении
номерных знаков в 1.6 раза по сравнению с каскадом линейных классификаторов, полученным с помощью
алгоритма AdaBoost. Результаты проведенных экспериментов могут быть распространены на задачи
поиска других объектов на изображениях.Стаття присвячена проблемі прискорення процесу пошуку об'єктів на зображеннях, заснованого на
використанні мультимасштабного сканування. Для вирішення цього завдання пропонується використати
попередню обробку кандидатів, що реалізується як перший етап каскаду класифікаторів змішаного типу.
Як тестове завдання обрана задача виявлення на цифрових зображеннях номерних знаків автомобілів.
Отриманий каскад класифікаторів дозволив збільшити швидкодію обробки зображень при виявленні
номерних знаків в 1.6 рази в порівнянні з каскадом лінійних класифікаторів, отриманим за допомогою
алгоритму AdaBoost. Результати проведених експериментів можуть бути поширені на завдання пошуку
інших об'єктів на зображеннях.The article is devoted to a problem of acceleration of objects detection process on the images, the multiscale
scanning based on use. For the solution of this task it is offered to use preliminary processing of candidates with
use of integrated characteristics which is realized as the first stage of the classifiers cascade of the mixed type. As a
test task the problem of detection on digital images of cars registration plates is chosen. The received cascade of
classifiers allowed to increase computational performance of images processing at detection of registration plates
by 1.6 times in comparison with the cascade of linear classifiers received by means of AdaBoost algorithm. Results
of the made experiments can be extended to problems of search of other objects on images
Influence of metal exposure on metallothionein synthesis and lipid peroxidation in two bivalve mollusks: the oyster (Crassostrea gigas) and the mussel (Mytilus edulis)
The impact of metals (silver, cadmium, copper, mercury and zinc) on metallothionein (MT) and malondialdehyde (MDA) levels of the oyster (Crassostrea gigas) and the mussel (Mytilus edulis) was studied after 4 or 21 days of metal exposure. Moreover, total protein levels were determined. After 4 days of metal exposure, although C. gigas and M. edulis accumulated cadmium and mercury concentrations in the gills and digestive gland, no significant variation of total protein level was occurred. After 21 days of exposure, metals were bioaccumulated in the gills and the digestive gland of both mollusks. A decrease of total protein concentrations in the gills of oysters and the digestive gland of mussels and an increase on metallothionein concentrations in the gills of both mollusks were observed. An increase of MDA levels was noticed for the gills and the digestive gland of mussels exposed for 21 days to either cadmium, silver or mercury whereas a decrease of MDA levels was observed in the gills of the oysters exposed for the same time to the same metals. The levels of proteins, MDA and MT were metal, species or organ dependent.info:eu-repo/semantics/publishedVersio
Competition between electron pairing and phase coherence in superconducting interfaces
In LaAlO3/SrTiO3 heterostructures, a gate tunable superconducting electron gas is confined in a quantum well at the interface between two insulating oxides. Remarkably, the gas coexists with both magnetism and strong Rashba spin–orbit coupling. However, both the origin of superconductivity and the nature of the transition to the normal state over the whole doping range remain elusive. Here we use resonant microwave transport to extract the superfluid stiffness and the superconducting gap energy of the LaAlO3/SrTiO3 interface as a function of carrier density. We show that the superconducting phase diagram of this system is controlled by the competition between electron pairing and phase coherence. The analysis of the superfluid density reveals that only a very small fraction of the electrons condenses into the superconducting state. We propose that this corresponds to the weak filling of high- energy dxz/dyz bands in the quantum well, more apt to host superconductivity
Analysis of Last Development Results for High Voltage Circuit-breakers Using New G3 Gas
Among many alternative gases proposed to replace SF6 as insulating gas, g3 (green gas for grid), fluoronitril based component officially introduced at CIGRE 2014, can be now used for insulation projects and new environmental friendly circuit breakers. This gas mixture g3, presents a reduction of the global warming potential by 98% compared to SF6 gas and shows quite good dielectric withstand capability. Many new investigations about thermal and chemical behavior have been done and are precised in this paper. Last switching test campaigns will be presented for 145 kV applications. Simulation tools should be updated to be applicable to these projects. Developments and comparisons with last test results will be analyzed
Second gradient models and concrete structures
peer reviewedDamage induces strain localization in quasi-brittle materials such as concrete. In order to correctly simulate this behaviour, it is necessary to introduce a length scale parameter in the continuum model. The second gradient model, a special case of kinematically enriched continua, uses an internal length parameter by taking into account the second order derivatives of the displacements in the virtual power principle. A penalty term is added in the original second gradient finite element formulation in order to improve convergence and to avoid erroneous damage distribution. A three points bending test of a reinforced concrete beam show the performance of the improved second gradient finite element formulation. © Springer International Publishing AG 2017
Comparative genetic analysis of quantitative traits in sunflower (Helianthus annuus L.)
One hundred and fifty F2–F3 families from a cross between two inbred sunflower lines FU and PAZ2 were used to map quantitative trait loci (QTL) for resistance to white rot (Sclerotinia sclerotiorum) attacks of terminal buds and capitula, and black stem (Phoma macdonaldii). A genetic linkage map of 18 linkage groups with 216 molecular markers spanning 1,937 cM was constructed. Disease resistances were measured in field experiments for S. sclerotiorum and under controlled conditions for P. macdonaldii. For resistance to S. sclerotiorum terminal bud attack, seven QTL were identified, each explaining less than 10% of phenotypic variance. For capitulum attack by this parasite, there were four QTL (each explaining up to 20% of variation) and for P. macdonaldii resistance, four QTL were identified, each having effects of up to 16%. The S. sclerotiorum capitulum resistance QTL were compared with those reported previously and it was concluded that resistance to this disease is governed by a considerable number of QTL, located on almost all the sunflower linkage groups
Medium Modifications of Hadron Properties and Partonic Processes
Chiral symmetry is one of the most fundamental symmetries in QCD. It is
closely connected to hadron properties in the nuclear medium via the reduction
of the quark condensate , manifesting the partial restoration of
chiral symmetry. To better understand this important issue, a number of
Jefferson Lab experiments over the past decade have focused on understanding
properties of mesons and nucleons in the nuclear medium, often benefiting from
the high polarization and luminosity of the CEBAF accelerator. In particular, a
novel, accurate, polarization transfer measurement technique revealed for the
first time a strong indication that the bound proton electromagnetic form
factors in 4He may be modified compared to those in the vacuum. Second, the
photoproduction of vector mesons on various nuclei has been measured via their
decay to e+e- to study possible in-medium effects on the properties of the rho
meson. In this experiment, no significant mass shift and some broadening
consistent with expected collisional broadening for the rho meson has been
observed, providing tight constraints on model calculations. Finally, processes
involving in-medium parton propagation have been studied. The medium
modifications of the quark fragmentation functions have been extracted with
much higher statistical accuracy than previously possible.Comment: to appear in J. Phys.: Conf. Proc. "New Insights into the Structure
of Matter: The First Decade of Science at Jefferson Lab", eds. D.
Higinbotham, W. Melnitchouk, A. Thomas; added reference
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