879 resultados para Analytic torsion


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The title compound, C14H18ClNO3, adopts an extended conformation, with all of the main chain torsion angles associated with the ester and amino groups trans. In the crystal, inversion dimers linked by pairs of N-H center dot center dot center dot O hydrogen bonds are observed.

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The topic of this dissertation lies in the intersection of harmonic analysis and fractal geometry. We particulary consider singular integrals in Euclidean spaces with respect to general measures, and we study how the geometric structure of the measures affects certain analytic properties of the operators. The thesis consists of three research articles and an overview. In the first article we construct singular integral operators on lower dimensional Sierpinski gaskets associated with homogeneous Calderón-Zygmund kernels. While these operators are bounded their principal values fail to exist almost everywhere. Conformal iterated function systems generate a broad range of fractal sets. In the second article we prove that many of these limit sets are porous in a very strong sense, by showing that they contain holes spread in every direction. In the following we connect these results with singular integrals. We exploit the fractal structure of these limit sets, in order to establish that singular integrals associated with very general kernels converge weakly. Boundedness questions consist a central topic of investigation in the theory of singular integrals. In the third article we study singular integrals of different measures. We prove a very general boundedness result in the case where the two underlying measures are separated by a Lipshitz graph. As a consequence we show that a certain weak convergence holds for a large class of singular integrals.

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A composition operator is a linear operator between spaces of analytic or harmonic functions on the unit disk, which precomposes a function with a fixed self-map of the disk. A fundamental problem is to relate properties of a composition operator to the function-theoretic properties of the self-map. During the recent decades these operators have been very actively studied in connection with various function spaces. The study of composition operators lies in the intersection of two central fields of mathematical analysis; function theory and operator theory. This thesis consists of four research articles and an overview. In the first three articles the weak compactness of composition operators is studied on certain vector-valued function spaces. A vector-valued function takes its values in some complex Banach space. In the first and third article sufficient conditions are given for a composition operator to be weakly compact on different versions of vector-valued BMOA spaces. In the second article characterizations are given for the weak compactness of a composition operator on harmonic Hardy spaces and spaces of Cauchy transforms, provided the functions take values in a reflexive Banach space. Composition operators are also considered on certain weak versions of the above function spaces. In addition, the relationship of different vector-valued function spaces is analyzed. In the fourth article weighted composition operators are studied on the scalar-valued BMOA space and its subspace VMOA. A weighted composition operator is obtained by first applying a composition operator and then a pointwise multiplier. A complete characterization is given for the boundedness and compactness of a weighted composition operator on BMOA and VMOA. Moreover, the essential norm of a weighted composition operator on VMOA is estimated. These results generalize many previously known results about composition operators and pointwise multipliers on these spaces.

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It is well known that an integrable (in the sense of Arnold-Jost) Hamiltonian system gives rise to quasi-periodic motion with trajectories running on invariant tori. These tori foliate the whole phase space. If we perturb an integrable system, the Kolmogorow-Arnold-Moser (KAM) theorem states that, provided some non-degeneracy condition and that the perturbation is sufficiently small, most of the invariant tori carrying quasi-periodic motion persist, getting only slightly deformed. The measure of the persisting invariant tori is large together with the inverse of the size of the perturbation. In the first part of the thesis we shall use a Renormalization Group (RG) scheme in order to prove the classical KAM result in the case of a non analytic perturbation (the latter will only be assumed to have continuous derivatives up to a sufficiently large order). We shall proceed by solving a sequence of problems in which theperturbations are analytic approximations of the original one. We will finally show that the approximate solutions will converge to a differentiable solution of our original problem. In the second part we will use an RG scheme using continuous scales, so that instead of solving an iterative equation as in the classical RG KAM, we will end up solving a partial differential equation. This will allow us to reduce the complications of treating a sequence of iterative equations to the use of the Banach fixed point theorem in a suitable Banach space.

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The concept of an atomic decomposition was introduced by Coifman and Rochberg (1980) for weighted Bergman spaces on the unit disk. By the Riemann mapping theorem, functions in every simply connected domain in the complex plane have an atomic decomposition. However, a decomposition resulting from a conformal mapping of the unit disk tends to be very implicit and often lacks a clear connection to the geometry of the domain that it has been mapped into. The lattice of points, where the atoms of the decomposition are evaluated, usually follows the geometry of the original domain, but after mapping the domain into another this connection is easily lost and the layout of points becomes seemingly random. In the first article we construct an atomic decomposition directly on a weighted Bergman space on a class of regulated, simply connected domains. The construction uses the geometric properties of the regulated domain, but does not explicitly involve any conformal Riemann map from the unit disk. It is known that the Bergman projection is not bounded on the space L-infinity of bounded measurable functions. Taskinen (2004) introduced the locally convex spaces LV-infinity consisting of measurable and HV-infinity of analytic functions on the unit disk with the latter being a closed subspace of the former. They have the property that the Bergman projection is continuous from LV-infinity onto HV-infinity and, in some sense, the space HV-infinity is the smallest possible substitute to the space H-infinity of analytic functions. In the second article we extend the above result to a smoothly bounded strictly pseudoconvex domain. Here the related reproducing kernels are usually not known explicitly, and thus the proof of continuity of the Bergman projection is based on generalised Forelli-Rudin estimates instead of integral representations. The minimality of the space LV-infinity is shown by using peaking functions first constructed by Bell (1981). Taskinen (2003) showed that on the unit disk the space HV-infinity admits an atomic decomposition. This result is generalised in the third article by constructing an atomic decomposition for the space HV-infinity on a smoothly bounded strictly pseudoconvex domain. In this case every function can be presented as a linear combination of atoms such that the coefficient sequence belongs to a suitable Köthe co-echelon space.

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We study a Hamiltonian describing a pendulum coupled with several anisochronous oscillators, giving a simple construction of unstable KAM tori and their stable and unstable manifolds for analytic perturbations. When the coupling takes place through an even trigonometric polynomial in the angle variables, we extend analytically the solutions of the equations of motion, order by order in the perturbation parameter, to a large neighbourhood of the real line representing time. Subsequently, we devise an asymptotic expansion for the splitting (matrix) associated with a homoclinic point. This expansion consists of contributions that are manifestly exponentially small in the limit of vanishing gravity, by a shift-of-countour argument. Hence, we infer a similar upper bound for the splitting itself. In particular, the derivation of the result does not call for a tree expansion with explicit cancellation mechanisms.

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This paper presents a simple hybrid computer technique to study the transient behaviour of queueing systems. This method is superior to stand-alone analog or digital solution because the hardware requirement is excessive for analog technique whereas computation time is appreciable in the latter case. By using a hybrid computer one can share the analog hardware thus requiring fewer integrators. The digital processor can store the values, play them back at required time instants and change the coefficients of differential equations. By speeding up the integration on the analog computer it is feasible to solve a large number of these equations very fast. Hybrid simulation is even superior to the analytic technique because in the latter case it is difficult to solve time-varying differential equations.

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CDH406P-.Na +.H20 , M r = 208.0, is monoclinic, Cc, a = 11.423 (2), b = 23.253 (5), c - 6.604 (1) A, fl = 123.63 (1) °, U = 1460.6 A 3, D x =. 1.89 Mg m -a, Z = 8, 2(Mo Ka) = 0.7107 A, p(Mo Ka) = 0.44 mm -~, F(000) = 840. Final R = 0.063 for 1697 reflections.The two crystallographically independent molecules of phosphoenolpyruvate (PEP) (A and B) are almost mirror images of each other, the mirror being the planar enolpyruvate group. The torsion angle C(3)-C(2)- O(1)-P(1) is 122.6 in A and -112.0 ° in B, in contrast to -209.1 ° in PEP.K. The enolic C(2)-O(1) has a partial double-bond character [1.401 (A), 1.386A (B)]. The high-energy P~O bond (1.595 and 1.610A) is comparable to that in PEP.K (1.612 A). Na(1) has six nearest neighbours while Na(2) has only five. The Na + ions are involved in binding only the phosphates of different molecules, in contrast to the K ÷ ion in PEP. K, which binds to both the phosphate and carboxyl ends of the same molecule. The planar carboxyl groups stack on each other at an average distance of 3.2 A instead of forming hydrogen-bonded dimers usually found in carboxylate structures.

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CaH406P-.K +, M r = 206.10, is orthorhombic, space group Pbca (from systematic absences), a = 14.538(4), b = 13.364(5), c = 6.880 (6)A, U = 1383.9 A 3, D x = 2.07 Mg m -a, Z = 8, ~.(Mo Ka) = 0.7107/~, p(MO Ka) = 1.015 mm -1. The final R value is 0.042 for a total of 1397 reflections. The high energy P-O(13) and the enolic C(1)-O(13) bonds are 1.612 and 1.374 A respectively. The enolpyruvate moiety is essentially planar. The orientation of the phosphate with respect to the pyruvate group in PEP.K is distinctly different from that in the PEP-cyclohexylammonium salt, the torsion angle C (2)-C (1)-O(13)- P being -209.1 in the former and -90 ° in the latter. The K + ion binds simultaneously to both the phosphate and carboxyl ends of the same PEP molecule. The ester O(13) is also a binding site for the cation. The K + ion is coplanar with the pyruvate moiety and binds to 0(22) and O(13) almost along their lone-pair directions. The carbonyl 0(22) prefers to bind to the K + ion rather than take part in the formation of hydrogen bonds usually observed in carboxylic acid structures.

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Major infrastructure and construction (MIC) projects are those with significant traffic or environmental impact, of strategic and regional significance and high sensitivity. The decision making process of schemes of this type is becoming ever more complicated, especially with the increasing number of stakeholders involved and their growing tendency to defend their own varied interests. Failing to address and meet the concerns and expectations of stakeholders may result in project failures. To avoid this necessitates a systematic participatory approach to facilitate decision-making. Though numerous decision models have been established in previous studies (e.g. ELECTRE methods, the analytic hierarchy process and analytic network process) their applicability in the decision process during stakeholder participation in contemporary MIC projects is still uncertain. To resolve this, the decision rule approach is employed for modeling multi-stakeholder multi-objective project decisions. Through this, the result is obtained naturally according to the “rules” accepted by any stakeholder involved. In this sense, consensus is more likely to be achieved since the process is more convincing and the result is easier to be accepted by all concerned. Appropriate “rules”, comprehensive enough to address multiple objectives while straightforward enough to be understood by multiple stakeholders, are set for resolving conflict and facilitating consensus during the project decision process. The West Kowloon Cultural District (WKCD) project is used as a demonstration case and a focus group meeting is conducted in order to confirm the validity of the model established. The results indicate that the model is objective, reliable and practical enough to cope with real world problems. Finally, a suggested future research agenda is provided.

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TRAUTMAN has postulated1 that the usual space−time singularity occurring in classical cosmological models and in the gravitational collapse of massive objects could be averted if intrinsic spin effects are incorporated into general relativity by adding torsion terms to the usual Einstein field equations, that is through the Einstein−Cartan theory. Invoking a primordial magnetic field for aligning all the individual nuclear spins he shows that his universe consisting of 1080 aligned neutrons collapses to a minimum radius of the order of 1 cm with a corresponding matter density of 1055 g cm-3.

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Public rental housing (PRH) projects are the mainstream of China's new affordable housing policies, and their integrated sustainability has a far-reaching effect on medium-low income families' well-being and social stability. However, there are few quantitative researches on the integrated sustainability of PRH projects. Our study tries to fill this gap through proposing an assessment model of the integrated sustainability for PRH projects. First, this paper defines what the sustainability of a PRH project is. Second, after constructing the sustainable system of a PRH project from the perspective of complex eco-system, the paper explores the internal operation mechanism and the coupling mechanism among the ecological, economic and social subsystems. Third, it identifies fourteen indices to represent the sustainability system of a PRH project, including six indices of ecological subsystem, five of economic subsystem and three of social subsystem. Fourth, it qualifies the weights of three subsystems and their internal representative indices. In addition, an assessment model is established through expert surveys and analytic network process (ANP). Finally, the paper carries out an empirical research on a PRH project in Nanjing city of China, followed by suggestions to enhance the integrated sustainability. The sustainability system and its evaluation model proposed in this paper are concise and easy to understand and can provide a theoretical foundation and a scientific basis for the evaluation and optimization of PRH projects.

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The damping capacity of cast graphitic aluminum alloy composites has been measured using a torsion pendulum at a constant strain amplitude. It was found that flake-graphite particles dispersed in the matrix of aluminum alloys increased the damping capacity; the improvement was greater, the higher the amount of graphite dispersed in the matrix. At sufficiently high graphite contents the damping capacity of graphitic aluminum composites approaches that of cast iron. The ratio between the damping capacity and the density of graphitic aluminum alloys is higher than cast iron, making them very attractive as light-weight, high-damping materials for possible aircraft applications. Machinability tests on graphite particle-aluminum composites, conducted at speeds of 315 sfm and 525 sfm, showed that the chip length decreased with the amount of graphite of a given size. When the size of graphite was decreased, at a given machining speed, the chip length decreased. Metallographic examination shows that graphite particles act as chip breakers, and are frequently sheared parallel to the plane of the

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An analytic treatment of localization in a weakly disordered system is presented for the case where the real lattice is approximated by a Cayley tree. Contrary to a recent assertion we find that the mobility edge moves inwards into the band as disorder increases from zero.

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The Church in one s heart. The formation of religion and individuation in the lives of Ingrian Finns in the 20th century. Sinikka Haapaniemi University of Helsinki, Finland 302 pages The study falls within the sphere of religious views and the problematique of the life trajectory. The target group comprises those Finnish speakers (Ingrian Finns, Ingrians) living in what was historically Ingermanland and who in varying circumstances became scattered. These times were characterized by pressures for change due to societal reasons and reasons of war. In conditions of change external living conditions matters of religious conviction may assume new meaning and form. The examination focuses on sustaining personal faith in difficult life situations and on how crises affected religious views. Another level of scrutiny takes shape through the terminology of the analytic psychology of C.G. Jung. Individuation is deemed to occur as a cumulative process through the stages of life. The basic data for the study comprises interviews with twenty (20) natives of Ingria and their biographical narratives written in standard language. Many biographical accounts and memoirs serve as secondary data. The interviewees, who were largely selected at random, recounted their lives without questions formulated in advance. The study falls within the field of comparative religion and adheres to the principles of qualitative research practice and the case-study method. Effort was made to get to know each interviewee in the situation which his/her narrative presents. The aim is to pay attention to the interpretations given by the narrators of their various experiences and to understand their meanings on a personal level. The years during which the Ingrians were scattered, wandering and returning raise problems of survival. An individual s own initiative assumes individual forms and emphases. Religion was part of the narrators lives as one factor in the quality of life. Their religious thinking was influenced by both their home upbringing and the teaching of the Church. The interviewees took a serious attitude to the informative teaching of confirmation training. When there was no longer a church, it was claimed that the church travelled with them. Changed circumstances tested the validity of the teachings. The message of the Church institution persisted and helped them to preserve their traditions. A striving for unity and for the presence of a community emerged both in the form of ritual behaviour and in a predilection to sociability. Gradually, as they returned, the activity of the Church of Ingria began to revive. At the turn of the millennium the network of parishes was extensive and cultural activity flourished wherever the Ingrians settled in the postwar decades. Religion is part of the process of individuation. Examination of religion and individuation shows that religion remained an individual view, whose factual base was formed by Christianity and the tradition of the Church. Home upbringing served to orientate, but not to bind. With ageing the importance of independent thought is emphasized, for example in relation to confession, it did not pose a threat to individuality. Keywords: Life story, Religiosity, individuation, Ingrian, the Church of Ingria