Browsing by Title

Now showing items 3897-3916 of 24236

    • Constant Modulus Shaped Beam Synthesis via Convex Relaxation 

      Cao, Pan; Thompson, John; Haas, Harald (2017-07-27)
      Constant modulus shaped beam synthesis is widely employed in multiple-input-multiple-output (MIMO) radar systems and MIMO wireless communication systems to improve the effective power gain by using only phase adjustment. ...

    • A constant molecular gas depletion time in nearby disk galaxies 

      Bigiel, F.; Leroy, A.; Walter, F.; Brinks, E.; de Blok, W.J.G.; Kramer, C.; Rix, H-W.; Schruba, A.; Schuster, K-F.; Usero, A.; Wiesemeyer, H.W. (2011)
      We combine new sensitive, wide-field CO data from the HERACLES survey with ultraviolet and infrared data from GALEX and Spitzer to compare the surface densities of H2, ΣH2, and the recent star formation rate, ΣSFR, over ...

    • Constrained Clustering with Minkowski Weighted K-Means 

      Cordeiro De Amorim, Renato (Institute of Electrical and Electronics Engineers (IEEE), 2012)
      In this paper we introduce the Constrained Minkowski Weighted K-Means. This algorithm calculates cluster specific feature weights that can be interpreted as feature rescaling factors thanks to the use of the Minkowski ...

    • Constrained Intelligent K-Means : Improving Results with Limited Previous Knowledge 

      de Amorim, Renato Cordeiro (Institute of Electrical and Electronics Engineers (IEEE), 2008)
      It is here presented a new method for clustering that uses very limited amount of labeled data, employees two pairwise rules, namely must link and cannot link and a single wise one, cannot cluster. It is demonstrated that ...

    • Constraining AGN duty cycle in the cool-core cluster MS 0735.6+7421 with LOFAR data 

      Biava, Nadia; Brienza, Marisa; Bonafede, Annalisa; Gitti, Myriam; Bonnassieux, Etienne; Harwood, Jeremy; Edge, Alastair C.; Riseley, Christopher J.; Vantyghem, Adrian (2021-06-25)
      MS 0735.6+7421 is a galaxy cluster which hosts a central radio galaxy with a very steep spectrum, produced by one of the most powerful known jetted active galactic nuclei (AGN). The radio plasma, ejected at nearly light ...

    • Constraining cosmic scatter in the Galactic halo through a differential analysis of metal-poor stars 

      Reggiani, Henrique; Meléndez, Jorge; Kobayashi, Chiaki; Karakas, Amanda; Placco, Vinicius (2017-12)
      Context. The chemical abundances of metal-poor halo stars are important to understanding key aspects of Galactic formation and evolution. Aims. We aim to constrain Galactic chemical evolution with precise chemical abundances ...

    • Constraining cosmic scatter in the Galactic halo through a differential analysis of metal-poor stars 

      Reggiani, Henrique; Meléndez, Jorge; Kobayashi, Chiaki; Karakas, Amanda; Placco, Vinicius (2017-12)
      Context. The chemical abundances of metal-poor halo stars are important to understanding key aspects of Galactic formation and evolution. Aims. We aim to constrain Galactic chemical evolution with precise chemical abundances ...

    • Constraining Nucleosynthesis in Two CEMP Progenitors Using Fluorine 

      Mura-Guzmán, A.; Yong, D.; Abate, C.; Karakas, A.; Kobayashi, C.; Oh, H.; Chun, S.; Mace, G.; . (2020-11-01)
      We present new fluorine abundance estimations in two carbon enhanced metal-poor (CEMP) stars, HE 1429-0551 and HE 1305+0007. HE 1429-0551 is also enriched in slow neutron-capture process (s-process) elements, a CEMP-s, and ...

    • Constraining stellar assembly and active galactic nucleus feedback at the peak epoch of star formation 

      Kimm, T.; Kaviraj, S.; Devriendt, J.E.G.; Dubois, Y.; Slyz, A.; Cohen, S.H.; Windhorst, R.A.; Silk, J.; Hathi, N.P.; Ryan, R.E.; O'Connell, R.W.; Dopita, M.A. (2012-09-01)
      We study stellar assembly and feedback from active galactic nuclei (AGN) around the epoch of peak star formation (1 ≲ z ≲ 2), by comparing hydrodynamic simulations to rest-frame UV-optical galaxy colours from the Wide Field ...

    • Constraining the astrophysical origin of the p-nuclei through nuclear physics and meteoritic data 

      Rauscher, T.; Dauphas, N.; Dillmann, I.; Fröhlich, C.; Fülöp, Z.; Gyürky, G. (2013-06-01)
      A small number of naturally occurring, proton-rich nuclides (the p-nuclei) cannot be made in the s- and r-processes. Their origin is not well understood. Massive stars can produce p-nuclei through photodisintegration of ...

    • Constraining the difference in convective blueshift between the components of alpha Centauri with precise radial velocities 

      Pourbaix, D.; Nidever, D.; Butler, R.P.; Tinney, C.G.; Marcy, G.W.; Jones, H.R.A.; Penny, A.J.; Carter, B.D.; Bouchy, F.; Pepe, F.; Hearnshaw, J.B.; Skulijan, J.; Ramm, D.; Kent, D. (2002-04)
      New radial velocities of Cen A & B obtained in the framework the Anglo-Australian Planet Search programme as well as in the CORALIE programme are added to those by Endl et al. (2001) to improve the precision of the orbital ...

    • A Constraint Satisfaction Method for Configuring Non-Local Service Interfaces 

      Zaichenkov, Pavel; Tveretina, Olga; Shafarenko, Alex (Springer Nature, 2016-05-24)
      Modularity and decontextualization are core principles of a service-oriented architecture. However, the principles are often lost when it comes to an implementation of services due to rigid service interfaces. This paper ...

    • Constraints on an optical afterglow and on supernova light following the short burst GRB 050813 

      Ferrero, P.; Sanchez, S.F.; Kann, D.A.; Klose, S.; Greiner, J.; Gorosabel, J.; Hartmann, D.H.; Henden, A.A.; Moller, P.; Palazzi, E.; Rau, A.; Stecklum, B.; Castro-Tirado, C.; Fynbo, J.; Hjorth, J.; Jakobsson, P.; Kouveliotou, C.; Masetti, N.; Pian, E.; Tanvir, N.; Wijers, R.A.M.J. (2007)

    • Constraints on Jupiters from Observations of Galactic bulge microlensing events during 2000 

      Tsapras, Y.; Horne, K.; Carson, R.; Alvarez, J.M.; Batcheldor, D.; Graham, A.W.; James, P.A.; Knapen, J.; Quaintell, H.; Serrano, I.G.; Sorensen, P.; Wooder, N. (2002-11)

    • Constraints on massive star formation : Cygnus OB2 was always an association 

      Wright, Nicholas J.; Parker, Richard J.; Goodwin, Simon P.; Drake, Jeremy J. (2014-02-01)
      We examine substructure and mass segregation in the massive OB association Cygnus OB2 to better understand its initial conditions. Using a well-understood Chandra X-ray selected sample of young stars, we find that Cyg OB2 ...

    • Constraints on photoevaporation models from (lack of) radio emission in the Corona Australis protoplanetary disks 

      Galván-Madrid, Roberto; Liu, Hauyu Baobab; Manara, Carlo Felice; Forbrich, Jan; Pascucci, Ilaria; Carrasco-González, Carlos; Goddi, Ciriaco; Hasegawa, Yasuhiro; Takami, Michihiro; Testi, Leonardo (2014-10-21)
      Photoevaporation due to high-energy stellar photons is thought to be one of the main drivers of protoplanetary disk dispersal. The fully or partially ionized disk surface is expected to produce free-free continuum emission ...

    • Constraints on positron annihilation kinematics in the inner Galaxy 

      Siegert, Thomas; Crocker, Roland M.; Diehl, Roland; Krause, Martin G. H.; Panther, Fiona H.; Pleintinger, Moritz M. M.; Weinberger, Christoph (2019-07-01)
      Context. The annihilation of cosmic positrons with electrons in the interstellar medium results in the strongest persistent γ-ray line signal in the sky. For the past 50 yr, this 511 keV emission - predominantly from the ...

    • Constraints on rotational mixing from surface evolution of light elements in massive stars 

      Frischknecht, U.; Hirschi, R.; Meynet, G.; Ekstroem, S.; Georgy, C.; Rauscher, T.; Winteler, C.; Thielemann, Friedrich-Karl (2010-11)
      Context. Light elements and nitrogen surface abundances together can constrain the mixing efficiencies in massive stars on the main sequence, because moderate mixing in the surface layers leads to depletion of light elements ...

    • Constraints on star-forming galaxies at z≥ 6.5 from HAWK-I Y-band imaging of GOODS-South 

      Hickey, S.; Bunker, A.; Jarvis, M.J.; Chiu, K.; Bonfield, D. (2010)
      We present the results of our search for high-redshift Lyman-break galaxies over the GOODS-South field. We use Hubble Space Telescope (HST)-ACS data in B, V, i' & z', Very Large Telescope (VLT)-ISAAC J and Ks, Spitzer–Infrared ...

    • Constraints on the circumstellar dust around KIC 8462852 

      Thompson, M.A.; Scicluna, Peter; Kemper, F.; Geach, James; Dunham, M. M.; Morata, Oscar; Ertel, S.; Ho, Paul T. P.; Dempsey, J. T.; Coulson, I.M.; Petitpas, G.; Kristensen, L. (2016-05-01)
      We present millimetre (SMA) and sub-millimetre (SCUBA-2) continuum observations of the peculiar star KIC 8462852 which displayed several deep and aperiodic dips in brightness during the Kepler mission. Our observations are ...