699 research outputs found

    New Finite Rogers-Ramanujan Identities

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    We present two general finite extensions for each of the two Rogers-Ramanujan identities. Of these one can be derived directly from Watson's transformation formula by specialization or through Bailey's method, the second similar formula can be proved either by using the first formula and the q-Gosper algorithm, or through the so-called Bailey lattice.Comment: 19 pages. to appear in Ramanujan

    Towards intelligent CFRP composite machining: surface analysis methods and statistical data analysis of machined fibre laminate surfaces

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    Many carbon fibre reinforced polymer composite parts need to be edged trimmed before use to ensure both geometry and mechanical performance of the part edge matches the design intent. Measurement and control of machining induced surface damage of composite material is key to ensuring the part retains its strength and fatigue properties. Typically, the overall surface roughness of the machined face is taken to be an indicator of the amount of damage to the surface, and it is important that the measurement and prediction of surface roughness is completed reliably. It is known that the surface damage is heavily dependent on the fibre orientation of the composite and cutting tool edge condition. This research has developed a new ply-by-ply surface roughness measurement methods using optical focus variation surface analysis and image segmentation for calculating areal surface roughness parameters of a machined carbon fibre composite laminate. Machining experiments have been completed using a polycrystalline diamond edge trimming tool at increasing levels of cutting edge radius. Optical surface measurement and µ-CT scanning have been used to assess machining induced surface and sub-surface defects on individual fibre orientations. Statistical analysis has been used to assess the significance of machining parameters on Sa (arithmetic mean height of area) and Sv (areal magnitude of maximum valley depth) areal roughness parameters, on both overall roughness and ply-by-ply fibre orientations. Empirical models have been developed to predict surface roughness parameters using statistical methods. It has been shown that cutting edge degradation, fibre orientation and feed rate will significantly affect the cutting mechanism, machining induced surface defects and surface roughness parameters

    Riemannian submersions from almost contact metric manifolds

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    In this paper we obtain the structure equation of a contact-complex Riemannian submersion and give some applications of this equation in the study of almost cosymplectic manifolds with Kaehler fibres.Comment: Abh. Math. Semin. Univ. Hamb., to appea

    Genetic Assimilation and Canalisation in the Baldwin Effect

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    The Baldwin Effect indicates that individually learned behaviours acquired during an organism’s lifetime can influence the evolutionary path taken by a population, without any direct Lamarckian transfer of traits from phenotype to genotype. Several computational studies modelling this effect have included complications that restrict its applicability. Here we present a simplified model that is used to reveal the essential mechanisms and highlight several conceptual issues that have not been clearly defined in prior literature. In particular, we suggest that canalisation and genetic assimilation, often conflated in previous studies, are separate concepts and the former is actually not required for non-heritable phenotypic variation to guide genetic variation. Additionally, learning, often considered to be essential for the Baldwin Effect, can be replaced with a more general phenotypic plasticity model. These simplifications potentially permit the Baldwin Effect to operate in much more general circumstances

    Special functions associated to a certain fourth order differential equation

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    We develop a theory of "special functions" associated to a certain fourth order differential operator Dμ,ν\mathcal{D}_{\mu,\nu} on R\mathbb{R} depending on two parameters μ,ν\mu,\nu. For integers μ,ν1\mu,\nu\geq-1 with μ+ν2N0\mu+\nu\in2\mathbb{N}_0 this operator extends to a self-adjoint operator on L2(R+,xμ+ν+1dx)L^2(\mathbb{R}_+,x^{\mu+\nu+1}dx) with discrete spectrum. We find a closed formula for the generating functions of the eigenfunctions, from which we derive basic properties of the eigenfunctions such as orthogonality, completeness, L2L^2-norms, integral representations and various recurrence relations. This fourth order differential operator Dμ,ν\mathcal{D}_{\mu,\nu} arises as the radial part of the Casimir action in the Schr\"odinger model of the minimal representation of the group O(p,q)O(p,q), and our "special functions" give KK-finite vectors

    Methylmercury exposure and developmental neurotoxicity.

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    Comment on: Global methylmercury exposure from seafood consumption and risk of developmental neurotoxicity: a systematic review. [Bull World Health Organ. 2014]]]> Humans; Methylmercury Compounds; Neurotoxicity Syndromes eng https://serval.unil.ch/resource/serval:BIB_B254C52AD78C.P001/REF.pdf http://nbn-resolving.org/urn/resolver.pl?urn=urn:nbn:ch:serval-BIB_B254C52AD78C2 info:eu-repo/semantics/altIdentifier/urn/urn:nbn:ch:serval-BIB_B254C52AD78C2 info:eu-repo/semantics/publishedVersion info:eu-repo/semantics/openAccess Copying allowed only for non-profit organizations https://serval.unil.ch/disclaimer application/pdf oai:serval.unil.ch:BIB_B254CA78ED67 2022-05-07T01:25:17Z openaire documents urnserval <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_B254CA78ED67 Application of a computationally efficient method to approximate gap model results with a probabilistic approach info:doi:10.5194/gmd-7-1543-2014 info:eu-repo/semantics/altIdentifier/doi/10.5194/gmd-7-1543-2014 Scherstjanoi, M. Kaplan, J. O. Lischke, H. info:eu-repo/semantics/article article 2014 Geoscientific Model Development, vol. 7, no. 4, pp. 1543-1571 urn:issn:1991-959x eng https://serval.unil.ch/resource/serval:BIB_B254CA78ED67.P001/REF.pdf http://nbn-resolving.org/urn/resolver.pl?urn=urn:nbn:ch:serval-BIB_B254CA78ED677 info:eu-repo/semantics/altIdentifier/urn/urn:nbn:ch:serval-BIB_B254CA78ED677 info:eu-repo/semantics/publishedVersion info:eu-repo/semantics/openAccess Copying allowed only for non-profit organizations https://serval.unil.ch/disclaimer application/pdf oai:serval.unil.ch:BIB_B254D0E85D5E 2022-05-07T01:25:17Z <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_B254D0E85D5E Meningite purulente aigue a Listeria seeligeri chez un adulte immunocompetent. [Acute purulent Listeria seelingeri meningitis in an immunocompetent adult] info:eu-repo/semantics/altIdentifier/pmid/3082004 Rocourt, J. Hof, H. Schrettenbrunner, A. Malinverni, R. Bille, J. info:eu-repo/semantics/article article 1986-02 Schweizerische Medizinische Wochenschrift, vol. 116, no. 8, pp. 248-51 info:eu-repo/semantics/altIdentifier/pissn/0036-7672 <![CDATA[Within the genus Listeria, the species L. monocytogenes most frequently causes disease in animals and humans. L. Seeligeri, a species recently described, has been considered experimentally nonpathogenic so far. The authors report the first case of human infection in a previously healthy adult presenting with acute purulent meningitis due to L. seeligeri. The patient recovered promptly after a course of ampicillin and gentamicin, but developed severe neurological sequelae (epilepsy, hydrocephalus) one year after the acute episode. The pathogenic properties of this isolate were investigated in two experimental animal models and the results were as follows. The clinical isolate of L. seeligeri was able to colonize the spleens of adult mice without bacterial multiplication, in contrast to the type strain of L. seeligeri (no colonization) and to a L. monocytogenes strain (colonization and multiplication). Previous infection of adult mice with the clinical L. seeligeri isolate protected moderately against spleen colonization and bacterial multiplication after challenge with L. monocytogenes. No lethal effect was observed after inoculation of suckling mice with the clinical L. seeligeri isolate, in contrast to L. monocytogenes strains. Thus, L. seeligeri, previously described as experimentally nonpathogenic for mice, may in fact be a heterogeneous species regarding its pathogenicity, and include strains that may cause life-threatening diseases in humans

    Adaptation of Robot Behaviour through Online Evolution and Neuromodulated Learning

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    Abstract. We propose and evaluate a novel approach to the online syn-thesis of neural controllers for autonomous robots. We combine online evolution of weights and network topology with neuromodulated learn-ing. We demonstrate our method through a series of simulation-based ex-periments in which an e-puck-like robot must perform a dynamic concur-rent foraging task. In this task, scattered food items periodically change their nutritive value or become poisonous. Our results show that when neuromodulated learning is employed, neural controllers are synthesised faster than by evolution alone. We demonstrate that the online evolu-tionary process is capable of generating controllers well adapted to the periodic task changes. An analysis of the evolved networks shows that they are characterised by specialised modulatory neurons that exclusively regulate the output neurons

    Noncolliding Squared Bessel Processes

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    We consider a particle system of the squared Bessel processes with index ν>1\nu > -1 conditioned never to collide with each other, in which if 1<ν<0-1 < \nu < 0 the origin is assumed to be reflecting. When the number of particles is finite, we prove for any fixed initial configuration that this noncolliding diffusion process is determinantal in the sense that any multitime correlation function is given by a determinant with a continuous kernel called the correlation kernel. When the number of particles is infinite, we give sufficient conditions for initial configurations so that the system is well defined. There the process with an infinite number of particles is determinantal and the correlation kernel is expressed using an entire function represented by the Weierstrass canonical product, whose zeros on the positive part of the real axis are given by the particle-positions in the initial configuration. From the class of infinite-particle initial configurations satisfying our conditions, we report one example in detail, which is a fixed configuration such that every point of the square of positive zero of the Bessel function JνJ_{\nu} is occupied by one particle. The process starting from this initial configuration shows a relaxation phenomenon converging to the stationary process, which is determinantal with the extended Bessel kernel, in the long-term limit.Comment: v3: LaTeX2e, 26 pages, no figure, corrections made for publication in J. Stat. Phy

    Propagator of a Charged Particle with a Spin in Uniform Magnetic and Perpendicular Electric Fields

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    We construct an explicit solution of the Cauchy initial value problem for the time-dependent Schroedinger equation for a charged particle with a spin moving in a uniform magnetic field and a perpendicular electric field varying with time. The corresponding Green function (propagator) is given in terms of elementary functions and certain integrals of the fields with a characteristic function, which should be found as an analytic or numerical solution of the equation of motion for the classical oscillator with a time-dependent frequency. We discuss a particular solution of a related nonlinear Schroedinger equation and some special and limiting cases are outlined.Comment: 17 pages, no figure
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