Storage capacity of a constructive learning algorithm

Upper and lower bounds for the typical storage capacity of a constructive algorithm, the Tilinglike Learning Algorithm for the Parity Machine [M. Biehl and M. Opper, Phys. Rev. A {\bf 44} 6888 (1991)], are determined in the asymptotic limit of large training set sizes. The properties of a perceptron with threshold, learning a training set of patterns having a biased distribution of targets, needed as an intermediate step in the capacity calculation, are determined analytically. The lower bound for the capacity, determined with a cavity method, is proportional to the number of hidden units. The upper bound, obtained with the hypothesis of replica symmetry, is close to the one predicted by Mitchinson and Durbin [Biol. Cyber. {\bf 60} 345 (1989)].Comment: 13 pages, 1 figur

Effects of material nonlinearity on the global analysis and stability of stainless steel frames

© 2017 Elsevier Ltd In structural frames, second order effects refer to the internal forces and moments that arise as a result of deformations under load (i.e. geometrical nonlinearity). EN 1993-1-1 states that global second order effects may be neglected if the critical load factor of the frame αcris greater than or equal to 10 for an elastic analysis, or greater than or equal to 15 when a plastic global analysis is used. No specific guidance is provided in EN 1993-1-4 for the design of stainless steel frames, for which the nonlinear stress-strain behaviour of the material will result in greater deformations as the material loses its stiffness. A study of the effects of material nonlinearity on the stability of stainless steel frames is presented herein. A series of different frame geometries and loading conditions are considered. Based on the findings, proposals for the treatment of the influence of material nonlinearity on the global analysis and design of stainless steel frames are presented

Two 2MASS-Selected Young Stellar Clusters: Photometry, Spectroscopy, and the IMF

We present near-infrared J, H, and K_s images and K-band spectroscopy of two newly discovered stellar clusters at different stages of evolution. Our spectra suggest the presence of massive YSOs in the heavily embedded cluster in the star-forming region near radio source G353.4-0.4 and an O5-O6V star in the cluster near radio source G305+00.2. We determine a K-band luminosity function (KLF) for both clusters and an initial mass function (IMF) for the cluster near G305+00.2. The derived IMF slope is -1.5 if the KLF is used to derive the IMF and is -0.98 if the color-magnitude diagram and spectra are used. The more reliable CMD-based slope is flatter than the Salpeter value usually found for stellar clusters. We find that using the KLF alone to derive an IMF is likely to produce an overly steep slope in stellar clusters subject to variable extinction.Comment: 16 pages, 18 figures, accepted to A

Absence of anomalous negative lattice-expansion for polycrystalline sample of Tb2Ti2O7

High resolution X-ray powder-diffraction experiments on a well-characterized polycrystalline sample of the spin liquid Tb2Ti2O7 reveal that it shows normal positive thermal-expansion above 4 K, which does not agree with the intriguing anomalous negative thermal-expansion due to a magneto-elastic coupling reported for a single crystal sample below 20 K. We also performed a Rietveld profile refinement of a powder-diffraction pattern taken at a room temperature, and confirmed that it is consistent with the fully ordered cubic pyrochlore structure.Comment: 2 pages, 3 figure

Large Deviation Property of Free Energy in p-Body Sherrington-Kirkpatrick Model

Cumulant generating function phi(n) and rate function Sigma(f) of the free energy is evaluated in p-body Sherrington-Kirkpatrick model by using the replica method with the replica number n finite. From a perturbational argument, we show that the cumulant generating function is constant in the vicinity of n = 0. On the other hand, with the help of two analytic properties of phi(n), the behavior of phi(n) is derived again. However this is also shown to be broken at a finite value of n, which gives a characteristic value in the rate function near the thermodynamic value of the free energy. Through the continuation of phi(n) as a function of n, we find out a way to derive the 1RSB solution at least in this model, which is to fix the RS solution to be a monotone increasing function.Comment: 7 pages, 5 figures. accepted for publication in J.Phs.Soc.Jp

Language attitudes and use in a transplanted setting: Greek Cypriots in London

In this paper we explore language attitudes and use in the Greek Cypriot community in London, England. Our study is based on an earlier survey carried out in Nicosia, Cyprus and we compare attitudes to language and reported language use in the two communities. We thereby highlight the significance of sociolinguistic variables on similar groups of speakers. We further extend our investigation to include codeswitching practices in the London community. \ud Analysis of language attitudes and use within the Greek-Cypriot population of London, and comparisons with findings in Nicosia, reflect symbolic forces operating in the two contexts. Despite obvious differences between the two communities, (most obviously the official languages and distinct cultural backgrounds of the two nations), the Greek Cypriot Dialect continues to play an active role in both. English is however the ‘default choice‘ for young Cypriots in the UK and Standard Modern Greek occupies a much more limited role than in Cyprus. It is argued that differences in language attitudes and use can be interpreted in light of different market forces operating in the nation (i.e. Cyprus) and the Diaspora (i.e. UK)

Analysis of three epoetin alpha products by LC and LC-MS indicates differences in glycosylation critical quality attributes, including sialic acid content

Erythropoietin (EPO) is one of the main therapeutics used to treat anaemic patients, greatly improving their quality of life. In this study, biosimilars Binocrit and a development product, called here CIGB-EPO, were compared to the originator product, Eprex. All three are epoetin alpha products, reputed to have similar glycosylation profiles. The quality, safety and efficacy of this biotherapeutic depend on the following glycosylation critical quality attributes (GCQAs): sialylation, N-glycolyl-neuraminic acid (Neu5Gc) content, branching, N-acetyl-lactosamine (LacNAc) extensions and O-acetylation pattern. Reverse-phase ultra high pressure liquid chromatography (RP-UHPLC) analysis of acid-released, 1,2-diamino-4,5-methylenedioxybenzene (DMB) labelled sialic acid derivatives and hydrophilic interaction liquid chromatography (HILIC) in combination with mass spectrometry (HILIC-UHPLC-MS) of procainamide (PROC) labelled N-glycans were the analytical tools used. An automated method for enzymatic release and PROC labelling was applied for the first time to the erythropoiesis stimulating agent (ESA) products, which facilitated novel, in-depth characterisation, and allowed identification of precise structural features including the location of O-acetyl groups on sialic acid (SA) moie-ties. Samples were digested by a sialate-O-acetylesterase (NanS) to confirm the presence of O-acetyl groups. It was found that Eprex contained the greatest relative abundance of O-acetylated derivatives, Binocrit expressed the least Neu5Gc, and CIGB-EPO showed the greatest variety of high-mannose-phosphate structures. The sialylation and LacNAc extension patterns of the three ESAs were similar, with a maximum of four N-acetyl-neuraminic acid (Neu5Ac) moieties detected per glycan. Such differences in SA derivatisation, particularly O-acetylation, could have consequences for the quality and safety of a biotherapeutic, as well as its efficacy

Symmetries of Differential Equations via Cartan's Method of Equivalence

We formulate a method of computing invariant 1-forms and structure equations of symmetry pseudo-groups of differential equations based on Cartan's method of equivalence and the moving coframe method introduced by Fels and Olver. Our apparoach does not require a preliminary computation of infinitesimal defining systems, their analysis and integration, and uses differentiation and linear algebra operations only. Examples of its applications are given.Comment: 15 pages, LaTeX 2.0

Galaxy number counts- IV. surveying the Herschel deep field in the near-infrared

(abridged) We present results from two new near-infrared imaging surveys. One covers 47.2 arcmin^2 to K(3\sigma)<20 whilst a second, deeper survey covers a sub-area of 1.8 arcmin^2 to K(3\sigma)<22.75. Over the entire area we have extremely deep UBRI photometry. Our K- counts are consistent with the predictions of non-evolving models with 0 < q0 <0.5. The K-selected (B-K) galaxy colour distributions move sharply bluewards fainter than K~20 and at at brighter magnitudes (K<20) our observed colour distributions indicate a deficiency of red, early-type galaxies at z~1 in comparison with passively evolving models. This implies either a pure luminosity evolution (PLE) model with a low level of continuing star-formation following an an initial burst, or dynamical merging. At fainter magnitudes, the continuing bluewards trend observed in (B-K) can be explained purely in terms of passively evolving PLE models. Our observed numbers of (I-K)>4 galaxies at K<20 exhibit the same deficiency, suggesting that at least part of the larger deficit observed in (B-K) at K<20 may be due to star-formation rather than dynamical merging. Finally, as we and others have noted, the number-redshift distribution at 18<K<19 of recent, deep K- selected redshift surveys is well fitted by non-evolving models; passively evolving models with a Salpeter or Scalo initial mass functions overpredict the numbers of galaxies with z>1. Dynamical merging is one possible solution to reduce the numbers of these galaxies but a dwarf-dominated IMF for early-type galaxies could offer an alternative explanation; we show that this model reproduces both the optical-infrared colour distributions and the K- band galaxy counts.Comment: 15 pages, 9 figures, revised version, requires astrobib.sty, mn-abs.sty, submitted to MNRA