189,314 research outputs found
On Equilibrium Prices in Continuous Time
We combine general equilibrium theory and theorie generale of stochastic
processes to derive structural results about equilibrium state prices
Product and country substitution in imports : an empirical comparison of theoretical concepts.
Importsubstitution; Theorie; Frankreich;
The ROSAT North Ecliptic Pole Survey: The Optical Identifications
The X-ray data around the North Ecliptic Pole (NEP) of the ROSAT All Sky
Survey have been used to construct a contiguous area survey consisting of a
sample of 445 individual X-ray sources above a flux of ~2x10^-14 erg cm^-2 s^-1
in the 0.5-2.0 keV energy band. The NEP survey is centered at RA (2000) = 18h
00m, DEC(2000) = +66deg 33arcmin and covers a region of 80.7 sq. deg at a
moderate Galactic latitude of b = 29.8deg. Hence, the NEP survey is as deep and
covers a comparable solid angle to the ROSAT serendipitous surveys, but is also
contiguous. We have identified 99.6% of the sources and determined redshifts
for the extragalactic objects. In this paper we present the optical
identifications of the NEP catalog of X-ray sources including basic X-ray data
and properties of the sources. We also describe with some detail the optical
identification procedure. The classification of the optical counterparts to the
NEP sources is very similar to that of previous surveys, in particular the
Einstein Extended Medium Sensitivity Survey (EMSS). The main constituents of
the catalog are active galactic nuclei (~49%), either type 1 or type 2
according to the broadness of their permitted emission lines. Stellar
counterparts are the second most common identification class (~34%). Clusters
and groups of galaxies comprise 14%, and BL Lacertae objects 2%. One non-AGN
galaxy, and one planetary nebula have also been found. The NEP catalog of X-ray
sources is a homogeneous sample of astronomical objects featuring complete
optical identification.Comment: Accepted for publication in the ApJS; 33 pages including 12
postscript figures and 3 tables; uses emulateapj.sty. On-line source catalog
at http://www.eso.org/~cmullis/research/nep-catalog.htm
Multinational companies and wage inequality in the host country: the case of Ireland.
Multinationales Unternehmen; Technologietransfer; Lohntheorie; Neue Wachstumstheorie; Theorie; SchÀtzung;
Size and Impact of Privatisation â A Survey of Empirical Studies
Privatisierung, Theorie, Empirische Methode, Privatization, Theory, Empirical method
Rigorous Error Bounds on Position and Velocity in Satellite Orbit Theories
Error bounds on position and velocity in satellite orbit theorie
Linear and nonlinear response of a rectangular plate subjected to lateral and inplane sonic boom disturbances
Transient response of rectangular window pane exposed to sonic boom disturbance using linear and nonlinear theorie
Hyperbolic geometry in the work of Johann Heinrich Lambert
The memoir Theorie der Parallellinien (1766) by Johann Heinrich Lambert is
one of the founding texts of hyperbolic geometry, even though its author's aim
was, like many of his pre-decessors', to prove that such a geometry does not
exist. In fact, Lambert developed his theory with the hope of finding a
contradiction in a geometry where all the Euclidean axioms are kept except the
parallel axiom and that the latter is replaced by its negation. In doing so, he
obtained several fundamental results of hyperbolic geometry. This was sixty
years before the first writings of Lobachevsky and Bolyai appeared in print. In
the present paper, we present Lambert's main results and we comment on them. A
French translation of the Theorie der Parallellinien, together with an
extensive commentary, has just appeared in print (A. Papadopoulos and G.
Th{\'e}ret, La th{\'e}orie des lignes parall{\`e}les de Johann Heinrich
Lambert. Collection Sciences dans l'Histoire, Librairie Scientifique et
Technique Albert Blanchard, Paris, 2014)
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