1,580 research outputs found
Covariance Steering of Discrete-Time Linear Systems with Mixed Multiplicative and Additive Noise
In this paper, we study the covariance steering (CS) problem for
discrete-time linear systems subject to multiplicative and additive noise.
Specifically, we consider two variants of the so-called CS problem. The goal of
the first problem, which is called the exact CS problem, is to steer the mean
and the covariance of the state process to their desired values in finite time.
In the second one, which is called the ``relaxed'' CS problem, the covariance
assignment constraint is relaxed into a positive semi-definite constraint. We
show that the relaxed CS problem can be cast as an equivalent convex
semi-definite program (SDP) after applying suitable variable transformations
and constraint relaxations. Furthermore, we propose a two-step solution
procedure for the exact CS problem based on the relaxed problem formulation
which returns a feasible solution, if there exists one. Finally, results from
numerical experiments are provided to show the efficacy of the proposed
solution methods
Evolution of Superconductivity in Electron-Doped Cuprates: Magneto-Raman Spectroscopy
The electron-doped cuprates Pr_{2-x}Ce_xCuO_4 and Nd_{2-x}Ce_xCuO_4 have been
studied by electronic Raman spectroscopy across the entire region of the
superconducting (SC) phase diagram. The SC pairing strength is found to be
consistent with a weak-coupling regime except in the under-doped region where
we observe an in-gap collective mode at 4.5 k_{B}T_c while the maximum
amplitude of the SC gap is ~8 k_{B}T_{c}. In the normal state, doped carriers
divide into coherent quasi-particles (QPs) and carriers that remain incoherent.
The coherent QPs mainly reside in the vicinity of (\pi/2, \pi/2) regions of the
Brillouin zone (BZ). We find that only coherent QPs contribute to the
superfluid density in the B_{2g} channel. The persistence of SC coherence peaks
in the B_{2g} channel for all dopings implies that superconductivity is mainly
governed by interactions between the hole-like coherent QPs in the vicinity of
(\pi/2, \pi/2) regions of the BZ. We establish that superconductivity in the
electron-doped cuprates occurs primarily due to pairing and condensation of
hole-like carriers. We have also studied the excitations across the SC gap by
Raman spectroscopy as a function of temperature (T) and magnetic field (H) for
several different cerium dopings (x). Effective upper critical field lines
H*_{c2}(T, x) at which the superfluid stiffness vanishes and
H^{2\Delta}_{c2}(T, x) at which the SC gap amplitude is suppressed by field
have been determined; H^{2\Delta}_{c2}(T, x) is larger than H*_{c2}(T, x) for
all doping concentrations. The difference between the two quantities suggests
the presence of phase fluctuations that increase for x< 0.15. It is found that
the magnetic field suppresses the magnitude of the SC gap linearly at
surprisingly small fields.Comment: 13 pages, 8 figures; submitted to Phys. Rev.
Polypyrrole grafts with poly[(methyl methacrylate)-CO-(2-(N-pyrrolyl)ethyl methacrylate)]
Cataloged from PDF version of article.Conducting polymer grafts of pyrrole and poly[(methyl methacrylate)-co-(2-
(N-pyrrolyl) ethyl methacrylate)] containing 0.7% PEMA units were prepared
by potentiostatic anodic polymerization of pyrrole in different electrolytic
media. Grafting between copolymer and pyrrole was achieved in media where
tetrabutylammonium fluoroborate and sodium perchlorate were used as the
supporting electrolytes. Characterizations were made by using IT-IR, DSC,
TGA, SEM, CV, and elemental analysis. The conductivities of the resultant
polymers seemed to be in the order of pure polypyrrole prepared under the
same conditions. Copyright o 1997 Elsevier Scienc
Procjena nekih čimbenika okoliša i genetskih čimbenika (CSN3 i AGPAT6) na prinos i sastav mlijeka u sanske koze
This study was designed to determine the effect of some environmental factors on milk yield and composition in Saanen goats and the effect of CSN3 and AGPAT6 gene polymorphisms on milk production traits. Saanen goats were genotyped for milk traits, and the samples were collected during the lactation, and the milk yield/compositions of each goat were specified. In terms of the CSN3 and AGPAT6 genes, the genotypes were defined by PCR-RFLP. The milk yield (MY), lactation length (LL), protein, fat, total solid (TS), solid not fat (SNF), casein, lactose rates and yields were as follows; 388.9 ± 17.5 kg, 243 ± 5.81 days, 3.29 ± 0.05%, 3.59 ± 0.07%, 11.60 ± 0.13%, 8.43 ± 0.06%, 2.57 ± 0.04%, 4.31 ± 0.03%, 11.21 ± 0.47 kg, 12.79 ± 0.64 kg, 40.95 ± 1.82 kg, 29.53 ± 1.31 kg, 8.82 ± 0.37 kg, 15.40 ± 0.74 kg respectively. The determined genotype and allele frequencies of CSN3 and AGPAT6 gene were as follows; FF (%99.20), MF (%0.80), F (0.996), M (0.004); GG (%12), GC (%43.20), CC (%44.80), G (0.336), C (0.664). The impacts of lactation length on all milk yield parameters (protein, fat, TS, SNF, casein, lactose, MY) (PG), the herd was found to be monomorphic (FF) for the CSN3 gene. The effect of the AGPAT6 gene on milk traits in Saanen goats was determined not to be statistically significant. Environmental factors, such as maternal age and lactation length, were found to significantly affect some milk traits in Saanen goats. So consideration of factors such as maternal age or lactation length could be useful for improving breeding strategies for dairy goats.Istraživanje je provedeno kako bi se odredili učinci čimbenika okoliša te učinci genskih polimorfizama CSN3 i AGPAT6 na prinos i sastav mlijeka u sanske koze. Tijekom laktacije koza provedena je genotipizacija te prikupljani uzorci za utvrđivanje prinosa i sastava mlijeka. Genotipovi gena CSN3 i AGPAT6 određeni su PCR-RFLP-om. Prinos mlijeka (MY), duljina laktacije (LL), udio proteina, udio masnoće, udio suhe tvari (TS), udio nemasne suhe tvari (SNF), udio kazeina, udio laktoze bili su kako slijedi: 388,9 ± 17,5 kg, 243 ± 5,81 dana, 3,29 ± 0,05 %, 3,59 ± 0,07 %, 11,60 ± 0,13 %, 8,43 ± 0,06 %, 2,57 ± 0,04 %, 4,31 ± 0,03 %. Prinos u kg za protein, masnoću, suhu tvar, nemasnu suhu tvar, kazein i laktozu bili su kako slijedi: 11,21 ± 0,47 kg, 12,79 ± 0,64 kg, 40,95 ± 1,82 kg, 29,53 ± 1,31 kg, 8,82 ± 0,37 kg, 15,40 ± 0,74 kg. Utvrđeni genotipovi i učestalost alela gena CSN3 i AGPAT6 bili su: FF (99,20 %), MF (0,80 %), F (0,996), M (0,004), GG (12 %), GC (43,20 %), CC (44,80 %), G (0,336), C (0,664). Statistički znakoviti utjecaji utvrđeni su za: duljinu laktacije na pokazatelje prinosa mlijeka (proteine, masnoću, TS, SNF, kazein, laktozu, MY) (P G), dok je stado za gen CSN3 bilo monomorfno (FF). Učinak gena AGPAT6 na svojstva mlijeka nije bio statistički znakovit. čimbenici kao što su dob majke i duljina laktacije znakovito su utjecali na svojstva mlijeka sanske koze, stoga bi oni mogli biti korisni za unapređenje uzgojnih strategija mliječnih pasmina koza
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