1,318 research outputs found
Pointwise Sum of two Maximal Monotone Operators
â Cette recherche a Ă©tĂ© partiellement subventionnĂ©e, en ce qui concerne le premier et le dernier
auteur, par la bourse OTAN CRG 960360 et pour le second auteur par lâAction IntĂ©grĂ©e 95/0849 entre
les universités de Marrakech, Rabat et Montpellier.The primary goal of this paper is to shed some light on the maximality
of the pointwise sum of two maximal monotone operators. The interesting purpose
is to extend some recent results of Attouch, Moudafi and Riahi on the graph-convergence
of maximal monotone operators to the more general setting of reflexive
Banach spaces. In addition, we present some conditions which imply the uniform
Brézis-Crandall-Pazy condition. Afterwards, we present, as a consequence, some
recent conditions which ensure the Mosco-epiconvergence of the sum of convex
proper lower semicontinuous functions
Study on survival and growth rate of three Artemia species fed with Dunaliella tertiolecta, Tetraselmis suecica and Nannochloropsis oculata
In recent years, Artemia has proven to be one of the easiest to prepare and the most nutritious food available to aquaculture. In this research, the process of hatching of Artemia cyst into larval stage using algae as a diet was investigated. The cysts used for this experiment belonged to three species Artemia urmiana, Artemia parthenogenetica and Artemia franciscana. The algae species used for the feeding of the Artemia included Dunaliella tertiolecta, Tetraselmis suecica and Nannochloropsis oculata. The effect of algae feeding on growth rate and survival of the Artemia species from hatching to maturation during 15 days was investigated. The results showed that A. franciscana had better growth rate and survival compared to the other two species
Chiral nature of magnetic monopoles in artificial spin ice
Micromagnetic properties of monopoles in artificial kagome spin ice systems
are investigated using numerical simulations. We show that micromagnetics
brings additional complexity into the physics of these monopoles that is, by
essence, absent in spin models: besides a fractionalized classical magnetic
charge, monopoles in the artificial kagome ice are chiral at remanence. Our
simulations predict that the chirality of these monopoles can be controlled
without altering their charge state. This chirality breaks the vertex symmetry
and triggers a directional motion of the monopole under an applied magnetic
field. Our results also show that the choice of the geometrical features of the
lattice can be used to turn on and off this chirality, thus allowing the
investigation of chiral and achiral monopoles.Comment: 10 pages, 4 figure
Reliability assessment using combination of polynomial chaos and simulations: application to nonlinear fracture mechanics
This paper presents a probabilistic approach based on polynomial chaos expansion, in order to provide accurate explicit approximation of the structural response to be considered in the limit state function. The main difficulties in this approach are related to the calculation of the expansion coefficients which are defined by multi-dimensional integrals. As an alternative to the quadrature methods, Monte-Carlo simulations based on low discrepancy Halton sequence have been used for this issue. The accuracy and the efficiency of the proposed approach have been approved through analytical models. It is shown that the use of low discrepancy sequence provides more rapidly converging estimates. The proposed approach has been applied to assess the integrity of a cracked pipe
Combining Strong Convergence, Values Fast Convergence and Vanishing of Gradients for a Proximal Point Algorithm Using Tikhonov Regularization in a Hilbert Space
In a real Hilbert space . Given any function convex
differentiable whose solution set is nonempty, by
considering the Proximal Algorithm x_{k+1}=\text{prox}_{\b_k f}(d x_k), where
and (\b_k) is nondecreasing function, and by assuming some
assumptions on (\b_k), we will show that the value of the objective function
in the sequence generated by our algorithm converges in order to the global minimum of the objective
function, and that the generated sequence converges strongly to the minimum
norm element of , we also obtain a convergence rate
of gradient toward zero. Afterward, we extend these results to non-smooth
convex functions with extended real values
Three-component ambient noise beamforming in the Parkfield area
ACKNOWLEDGEMENTS Many thanks to Andrew Curtis and Ian Main for their critical and perceptive comments and to Sjoerd de Ridder for fruitful discussions. We are particularly grateful to Elmer Ruigrok for his detailed and constructive review, which has substantially improved our manuscript. We acknowledge the facilities of the IRIS Data Management System for providing access to the seismic data. This work is funded within the DFG project âSynPaThâ and the EU project âGEMexâ.Peer reviewedPublisher PD
Numerical analysis of timber fracture due to mechanical and thermal loads: an approach based on invariant integral
International audienc
Phytoplankton of Aras dam reservoir (Iran): an attempt to assess water quality
The Aras reservoir, located in the north-west of Iran, plays an important role in fisheries, drinking and agricultural water supplies and recreational activities in the region. This study was performed to characterize the seasonal fluctuations of phytoplankton communities and their relationship with environmental factors in the Aras reservoir from August 2013 to May 2014. Sampling was carried out seasonally from 5 sampling locations. In each location three samples were taken for phytoplankton identification and enumeration, chemical analysis and chlorophyll a determination. In total, 72 species belonging to 5 divisions were determined. Cyanobacteria contained the highest density (74%) during the study period with Pseudanabaena limnetica as the most abundant species. This group retained its dominance the whole year round which indicated the poor quality and high nutrient load of the Aras reservoir, mainly due to human activities. On average, Trophic State Index (TSI) showed that water in the reservoir was eu-hypereutrophic. The results indicated that phytoplankton density negatively correlated with Secchi disc depth (R^2 = -0.479), total alkalinity (R^2 = -0.564), total hardness (R^2 = -0.727) and HCO_3 concentration (R^2 = -0.589). On the other hand, there was a positive correlation between the phytoplankton density and TP (R^2 = 0.734). A comparison between the present and a previous study indicated that the cyanobacterial bloom pattern in the Aras reservoir has shifted from warm season toward an all year round cycle which in addition to basin pollution due to anthropogenic activities, can be related to global warming and climate change
Study of mycoflora in cultured Indian white shrimp (Penaeus indicus) in Abadan, Iran
The development of the commercial culture of penaeid shrimps has been accompanied by the occurrence of infectious and noninfectious diseases. The most important penaeid diseases are caused by organisms that are part of the normal microflora of penaeids. In 1998, the samples were collected from five farms in Ghofase area (Ahadan) 2-5 ponds in each farm. The shrimps of these ponds were preserved in full hygienic conditions, from each pond, at least 5 samples were collected and then transferred to the Aquatic Diseases Laboratory of Khouzestan Fisheries Research Center. The main tissues of Gill, Hemolymph, Hepatopancreas and cuticle of live-shrimps were studied in the laboratory. In this research, a total of 40 fungal species were isolated from different tissues with high abundance in Hepatopancrease (19 species) and Hemolymph (12 species). Aspergillus niger was identified as the most abundant species
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