595 research outputs found
Regular phantom black hole gravitational lensing
We study regular and asymptotically flat phantom black holes as gravitational
lenses. We obtain the deflection angle in both the weak and the strong
deflection limits, from which we calculate the positions, magnifications, and
time delays of the images. We compare our results with those corresponding to
the Schwarzschild solution and to the vacuum Brans-Dicke black hole.Comment: 14 pages, 4 figures; v2: improved and extended version, new
references added. Accepted for publication in Phys. Rev.
Strong deflection lensing by charged black holes in scalar-tensor gravity
We examine a class of charged black holes in scalar-tensor gravity as
gravitational lenses. We find the deflection angle in the strong deflection
limit, from which we obtain the positions and the magnifications of the
relativistic images. We compare our results with those corresponding to the
Reissner-Norstrom spacetime and we analyze the observational aspects in the
case of the Galactic supermassive black hole.Comment: 12 pages, 3 figures; v2: improved version, new references adde
Rational conchoid and offset constructions: algorithms and implementation
This paper is framed within the problem of analyzing the rationality of the components of two classical geometric constructions, namely the offset and the conchoid to an algebraic plane curve and, in the affirmative case, the actual computation of parametrizations. We recall some of the basic definitions and main properties on offsets (see [13]), and conchoids (see [15]) as well as the algorithms for parametrizing their rational components (see [1] and [16], respectively). Moreover, we implement the basic ideas creating two packages in the computer algebra system Maple to analyze the rationality of conchoids and offset curves, as well as the corresponding help pages. In addition, we present a brief atlas where the offset and conchoids of several algebraic plane curves are obtained, their rationality analyzed, and parametrizations are provided using the created packages
Metabolic functions and inheritance of the microsporidian mitosome
Phd ThesisMicrosporidia are a group of obligate intracellular parasites of economic and
medical importance. Many aspects of microsporidian genomes and cell biology are a
result of an extensive reductive evolution during adaptation to their intracellular
parasitic lifestyle. Microsporidian mitochondrial homologues called mitosomes have
only a single known conserved metabolic function in biosynthesis of the essential
iron-sulfur clusters. Based on genomic data an additional function of the mitosome in
the alternative respiratory pathway (ARP) was proposed for some microsporidians
including human pathogenic Trachipleistophora hominis. This thesis provides the first
direct experimental evidence for a mitosomal localization of the two components of
the ARP in T. hominis. Quantitative analyses of the immunofluorescence data
together with western blotting experiments provided results consistent with the life
cycle-stage specific function of the organelle. In the proliferative stages of the T.
hominis life cycle, capable of stealing ATP from the host, mitosomes seem to
function mostly in the biosynthesis of the essential iron sulfur clusters. The ARP
proteins are enriched in the T. hominis spores, which is consistent with the
hypothetical functions of the mitosome in energy metabolism of the spore that is
unable to rely on its host for ATP production. This thesis also provides the first
bioinformatics characterization of the molecular machineries involved in the
processes required for inheritance of the microsporidian mitosomes: organelle fission
and segregation during the cell division. Specific antibodies were generated and
used to detect the microsporidian spindle pole body (SPB), an organelle
hypothesized to play a role in inheritance of the microsporidian mitosomes. Double
labelling experiments using the specific antibodies against the SPB and mitosomal
markers provide evidence for a stable connection between the two organelles
throughout the life cycle of the parasite.European Union as a part of a
Marie Curie Initial Training Network Symbiomics
Router Power Consumption Analysis: Towards Green Communications
2nd International Conference on Green Communications and Networking, GreeNets 2012; Gandia; Spain; 25 October 2012 through 26 October 2012In recent years, the number of network devices which are being used in new network infrastructure and intelligent buildings, are growing more and more. Because these devices can often have high processing activity, we must consider their power consumption. Their energy requirements may vary depending on their operation mode, their processing capacity and even the type of devices to which are connected. The ability to determine exact consumption of network can provide an optimal network design and the other auxiliary systems, such as cool system, which may be necessary for the proper operation of the network. In this paper we determine the power consumption generated by network devices of different manufacturers and models. These tests allow us to see the energy consumed when they are in await mode and when they are working, running a routing protocol in order to interconnect different networks, promoting the development of the sustainable Green Networks.Andrade Morelli, S.; Ruiz Sanchez, E.; Sendra, S.; Lloret, J. (2013). Router Power Consumption Analysis: Towards Green Communications. Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering. 113:28-37. doi:10.1007/978-3-642-37977-2_3S2837113Balasubramanian, N., Balasubramanian, A., Venkataraman, A.: Energy Consumption in Mobile Phones: A Measurement Study and Implications for Network Applications. In: Proceedings of the 9th ACM SIGCOMM Conference on Internet Measurement Conference, IMC 2009, Chicago, IL, USA, November 4-6 (2009)Bianco, C., Cucchietti, F., Griffa, G.: Energy consumption trends in the next generation access network - a telco perspective. In: 29th International Telecommunications Energy Conference, INTELEC 2007, Rome, Italy, September 30-October 4 (2007)Datasheet of Router Cisco184, Available at Cisco web site: http://www.cisco.com/en/US/prod/collateral/routers/ps5853/ps5875/product_data_sheet0900aecd806c4e2a.pdfDatasheet of Router Allied AR410, Available at Alied telesync web site: http://www.alliedtelesis.com/media/fount/datasheet/AR410Series_Datasheet_RevQ.pdfFisher, W., Suchara, M., Rexford, J.: Greening Backbone Networks: Reducing Energy Consumption by Shutting Off Cables in Bundled Links. In: Proceedings of the First ACM SIGCOMM Workshop on Green Networking, New Delhi, India, August 30 (2010)González, N., Moran, L., Angioleti, J.M., Varela, J.A.: Green IT, ch. 4. Green Telecom Networks. eKISS nº82. Internal publication of Telefónica (2009)Mohsin, A.H., Bakar, K.A., Adekiigbe, A., Ghafoor, K.Z.: A Survey of Energy-aware Routing protocols in Mobile Ad-hoc Networks: Trends and Challenges. Network Protocols and Algorithms 4(2), 82–107 (2012)Duan, Q.: Performance Evaluation on Traffic Control in Combined Input and Cross-point Queuing Switches. Network Protocols and Algorithms 3(4), 18–31 (2011)Sendra, S., Fernández, P.A., Quilez, M.A., Lloret, J.: Study and Performance of Interior Gateway IP routing Protocols. Network Protocols and Algorithms 2(4), 88–117 (2010)Sendra, S., Lloret, J., Garcia, M., Toledo, J.F.: Power saving and energy optimization techniques for Wireless Sensor Networks. J. Commun. Acad. Publ. 6, 439–459 (2011)Cisco Report. Server power calculator analysis: Cisco UCS power calculator and HP power advisor (2011)Kakemizu, M., Chugo, A.: Approaches to Green Networks. Fujitsu Scientific and Technical Journal 45(4), 398–403 (2009)Bianzino, A.P., Chaudet, C., Rossi, D., Rougier, J.-L.: A Survey of Green Networking Research. IEEE Communications Surveys & Tutorials 14(1), 3–20 (2012)Stevens, W.R.: TCP/IP Illustrated. The Protocols (Addison-Wesley Professional Computing Series), vol. 1 (1994
Moore-Penrose approach in the Hough transform framework
Maria-Laura Torrente is a member of GNAMPA - Gruppo Nazionale per l’Analisi Matematica, la Probabilità e le loro Applicazioni of INDAM. J.R. Sendra is member of the Research Group ASYNACS (Ref.CT-CE2019/683).Let F(x, a) be a real polynomial in two sets of variables, x and a, that is linear with respect to one of the variable sets, say a. In this paper, we deal with two of the main steps of the Hough transform framework for the pattern recognition technique to detect loci in images. More precisely, we present an algorithmic process, based on the Moore–Penrose pseudo-inverse, to provide a region of analysis in the parameter space. In addition, we state an upper bound for the sampling distance of the discretization of the parameter space region.Agencia Estatal de Investigació
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