• Title/Summary/Keyword: Luis

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MEDIUM RESOLUTION SPECTRAL LIBRARY OF LATE-TYPE STELLAR TEMPLATES IN NEAR-INFRARED BAND

  • Le, Huynh Anh Nguyena;Kang, Won-Seok;Pak, Soo-Jong;Im, Myung-Shin;Lee, Jeong-Eun;Ho, Luis C.;Pyo, Tae-Soo;Jaffe, Daniel T.
    • Journal of The Korean Astronomical Society
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    • v.44 no.4
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    • pp.125-134
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    • 2011
  • We present medium resolution (R = 5000 - 6000) spectra in the near-infrared band, 1.4 - 1.8 ${\mu}m$, for template stars in G, K, and M types observed by the echelle spectrometer, IRCS, at the SUBARU 8.2 m telescope. The identification of lines is based on the spectra of Arcturus (K2 III) in the literature. We measured the equivalent of widths and compared our results to those of Meyer et al. (1998). We conclude that our spectral resolution (R = 6000) data can investigate more accurately the properties of lines in stellar spectra. The library of the template stellar spectra in ASCII format are available for download on the World Wide Web.

Generalized Quadrature Spatial Modulation Scheme Using Antenna Grouping

  • Castillo-Soria, Francisco Ruben;Cortez-Gonzalez, Joaquin;Ramirez-Gutierrez, Raymundo;Maciel-Barboza, Fermin Marcelo;Soriano-Equigua, Leonel
    • ETRI Journal
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    • v.39 no.5
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    • pp.707-717
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    • 2017
  • This paper presents a novel generalized quadrature spatial modulation (GQSM) transmission scheme using antenna grouping. The proposed GQSM scheme combines QSM and conventional spatial multiplexing (SMux) techniques in order to improve the spectral efficiency (SE) of the system. Analytical and simulation results show that the proposed transmission scheme has minimal losses in terms of the average bit error probability along with the advantage of an increased SE compared with previous SM and QSM schemes. For the case studies, this advantage represents a reduction of up to 81% in terms of the number of required transmit antennas compared with QSM. In addition, a detection architecture based on the ordered successive interference cancellation scheme and the QR decomposition is presented. The proposed QRD-M adaptive algorithm showed a near-maximum-likelihood performance with a complexity reduction of approximately 90%.

Experimental characterization of timber framed masonry walls cyclic behaviour

  • Goncalves, Ana Maria;Ferreira, Joao Gomes;Guerreiro, Luis;Branco, Fernando
    • Structural Engineering and Mechanics
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    • v.53 no.2
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    • pp.189-204
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    • 2015
  • After the large destruction of Lisbon due to the 1755 earthquake, the city had to be almost completely rebuilt. In this context, an innovative structural solution was implemented in new buildings, comprising internal timber framed walls which, together with the floors timber elements, constituted a 3-D framing system, known as "cage", providing resistance and deformation capacity for seismic loading. The internal timber framed masonry walls, in elevated floors, are constituted by a timber frame with vertical and horizontal elements, braced with diagonal elements, known as Saint Andrew's crosses, with masonry infill. This paper describes an experimental campaign to assess the in-plane cyclic behaviour of those so called "frontal" walls. A total series of 4 tests were conducted in 4 real size walls. Two models consist of the simple timber frames without masonry infill, and the other two specimens have identical timber frames but present masonry infill. Experimental characterization of the in-plane behaviour was carried out by static cyclic shear testing with controlled displacements. The loading protocol used was the CUREE for ordinary ground motions. The hysteretic behaviour main parameters of such walls subjected to cyclic loading were computed namely the initial stiffness, ductility and energy dissipation capacity.

HIGH-RESOLUTION NEAR-INFRARED SPECTRA OF NEARBY QUASARS

  • Le, Huynh Anh Nguyen;Pak, Soojong;Im, Myungshin;Ho, LuisC.
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.91-91
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    • 2012
  • We present high-resolution near-infrared host galaxy spectra of low-z quasars, PG0844+349 (z=0.064), PG1226+023 (z=0.158), and PG1426+015 (z=0.086). The observation was done by using the near-IR high resolution echelle spectrometer, IRCS, at the SUBARU 8.2 m telescope. The full width at half maximum of the point spread function was about 0.3 arcsec by using an Adaptive Optics system, which can effectively resolve the quasar spectra from the host galaxy spectra. The signal-to-noise ratios are increased by the total exposure time up to several hours per targets and the development of data reduction method. We compare our results to the stellar spectra library and sample spectra from Dasyra et al. (2007) and Watson et al. (2008). The identified spectral lines will be used to study the physical mechanism of quasars, and the velocity dispersions of the stars in the bulge of the host galaxy.

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Optimal cross-section and configuration design of cyclic loaded elastic-plastic structures

  • Valido, Anibal J.;Sousa, Luis G.;Cardoso, J. Barradas
    • Structural Engineering and Mechanics
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    • v.4 no.1
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    • pp.25-35
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    • 1996
  • This paper describes a continuum variational formulation for design optimization of nonlinear structures in the elastic-plastic domain, where unloading and reloading of the structures are allowed to occur. The Total Lagrangian procedure is used for the description of the structural deformation. The direct differentiation approach is used to derive the sensitivities of the various structural response measures with respect to the design parameters. Since the material goes into the inelastic range and unloading and reloading of the structure are allowed to occur, the structural response is path dependent and an additional step is needed to integrate the constitutive equations. It can be shown, consequently, that design sensitivity analysis is also path-dependent. The theory has been discretized by the finite element technique and implemented in a structural analysis code. Mathematical programming approach is used for the optimization process. Numerical applications on trusses are performed, where cross-sectional areas and nodal point coordinates are treated as design variables. Optimal designs have been obtained and compared by using two different strategies: a two level strategy where the levels are defined accordingly the type of design variables, cross sectional areas or node coordinates, and optimizing simultaneously with respect to both types of design variables.

Hysteretic behavior of dissipative welded fuses for earthquake resistant composite steel and concrete frames

  • Calado, Luis;Proenca, Jorge M.;Espinha, Miguel;Castiglioni, Carlo A.
    • Steel and Composite Structures
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    • v.14 no.6
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    • pp.547-569
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    • 2013
  • In recent years there has been increasing international interest about designing structures that cost less to repair after they have been subjected to strong earthquakes. Considering this interest, an innovative repairable fuse device has been developed for dissipative beam-to-column connections in moment-resisting composite steel and concrete frames. The seismic performance of the device was assessed through an extensive experimental program comprising ten cyclic and two monotonic tests. These tests were conducted on a single beam-to-column specimen with different fuse devices for each test. The devices varied in terms of the chosen geometric and mechanical parameters. The tests showed that the devices were able to concentrate plasticity and to dissipate large amounts of energy through non-linear behavior. Numerical models were developed with Abaqus and simplified design models are also proposed.

Comparative Study of the Behavior of a Wind Farm Integrating Three Different FACTS Devices

  • Sarrias, Raul;Gonzalez, Carlos;Fernandez, Luis M.;Garcia, Carlos Andres;Jurado, Francisco
    • Journal of Electrical Engineering and Technology
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    • v.9 no.4
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    • pp.1258-1268
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    • 2014
  • Improving grid connection of wind farms is a relevant issue to be addressed, especially for fixed-speed wind turbines. Certain elements, such as FACTS (Flexible AC Transmission Systems), are able to perform voltage and reactive power regulation in order to support voltage stability of wind farms, and compensate reactive power consumption from the grid. Several devices are grouped under the name of FACTS, which embrace different technologies and operating principles. Here, three of them are evaluated and compared, namely STATCOM (Static Synchronous Compensator), SVC (Static Var Compensator) and SSSC (Static Synchronous Series Compensator). They have been modeled in MATLAB/Simulink, and simulated under various scenarios, regarding both normal operation and grid fault conditions. Their response is studied together with the case when no FACTS are implemented. Results show that SSSC improves the voltage stability of the wind farm, whereas STATCOM and SVC provide additional reactive power.

Chair-side CAD/CAM fabrication of a single-retainer resin bonded fixed dental prosthesis: a case report

  • Jurado, Carlos Alberto;Tsujimoto, Akimasa;Watanabe, Hidehiko;Villalobos-Tinoco, Jose;Garaicoa, Jorge Luis;Markham, Mark David;Barkmeier, Wayne Walter;Latta, Mark Andrew
    • Restorative Dentistry and Endodontics
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    • v.45 no.2
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    • pp.15.1-15.7
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    • 2020
  • This clinical report describes designing and fabricating a single-retainer resin-bonded fixed dental prosthesis with a chair-side computer-aided design/computer-aided manufacturing system. The whole procedure, from tooth extraction to final placement of the prosthesis, was completed in one day, and a single clinic visit. No clinical complications were found at the 2-year follow-up after placement of the restoration, and satisfactory functional and esthetic results were achieved.

Identification of the σ70-Dependent Promoter Controlling Expression of the ansPAB Operon of the Nitrogen-Fixing Bacterium Rhizobium etli

  • Angelica, Moreno-Enriquez;Zahaed, Evangelista-Martinez;Luis, Servin-Gonzalez;Maria Elena, Flores-Carrasco
    • Journal of Microbiology and Biotechnology
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    • v.25 no.8
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    • pp.1241-1245
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    • 2015
  • The aim of the present work was to examine the putative promoter region of the operon ansPAB and to determine the general elements required for the regulation of transcriptional activity. The transcriptional start site of the ansPAB promoter was determined by using highresolution S1-nuclease mapping. Sequence analysis of this region showed -10 and -35 elements, which were consistent with consensus sequences for R. etli promoters that are recognized by the major form of RNA polymerase containing the σ70 transcription factor. Mutation studies affecting several regions located upstream of the transcriptional start site confirmed the importance of these elements on transcriptional expression.

Loss of infectivity of Neospora caninum oocysts maintained for a prolonged time

  • Uzeda, Rosangela Soares;Costa, Kattyanne De Souza;Santos, Sara Lima;Pinheiro, Alexandre Moraes;Almeida, Maria Angela Ornelas De;McAllister, Milton M.;Gondim, Luis Fernando Pita
    • Parasites, Hosts and Diseases
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    • v.45 no.4
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    • pp.295-299
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    • 2007
  • The purpose of this study was to investigate whether sporulated Neospora caninum oocysts, which had been stored for 46 mo in a 2% sulfuric acid solution at $4^{\circ}C$, remain morphologically viable and infective to gerbils (Meriones unguiculatus). Six gerbils were orally inoculated with doses of 400 or 1,200 oocysts. Two mo after inoculation, the animals did not show any clinical signs, had no histological lesions, and were seronegative for N. caninum at 1:50 in an immunofluorescent antibody test. PCR using the brain from each gerbil did not reveal N. caninum specific DNA. We conclude that oocysts preserved for 46 mo are not infective, despite being morphologically intact.