2,765 research outputs found
A class of abstract quasi-linear evolution equations of second order
In this paper we study the abstract quasi-linear evolution equation of second order
formula here
in a general banach space z. it is well-known that the abstract quasi-linear theory due to kato [10, 11] is widely applicable to quasi-linear partial differential equations of second order and that his theory is based on the theory of semigroups of class (C0). (for example, see the work of hughes et al. [9] and heard [8].) however, even in the special case where a (t,w, v) = a is independent of (t, w, v), it is found in [2] and [14] that there exist linear partial differential equations of second order for which cauchy problems are not solvable by the theory of semigroups of class (C0) but fit into the mould of well-posed problems where the solution and its derivative depend continuously on the initial data if the initial condition is measured in the graph norm of a suitable power of a. (see also work by krein and khazan [13] and fattorini [6, chapter 8].) this kind of cauchy problem has recently been studied extensively, using the theory of integrated semigroups or regularized semigroups. the theory of integrated semigroups was studied intensively by arendt [1] and that of regularized semigroups was initiated by da prato [3] and renewed by davies and pang [4]. for the theory of regularized semigroups we refer the reader to [5] and [16].
(u(t),v(t))' = Ãu(t)(u(t),v(t)) for t∈[0,T] and (u(0),v(0)) = (φ,ψ)
in a suitable Banach space X, where for each solution w of equation (1.1) the matrix operator Aw(t) in X is defined by Aw(t)(u,v)=(v,A(t,w(t),w'(t)) u). We are here interested in studying the case where each matrix operator Aw(t) is the (complete infinitesimal) generator of a regularized semigroup on X. In Section 3 we set up basic hypotheses on the operators appearing in equation (1.1), and prove a fundamental existence and uniqueness theorem (Theorem 3.6) for the Cauchy problem (1.1). The proof is based on the theory of regularized evolution operators developed by the
author [15], and a method of successive approximations proposed by Kobayasi and Sanekata [12] is applied to construct a unique twice continuously differentiable function u satisfying equation (1.1).
Our formulation includes the abstract quasi-linear wave equation of Kirchhoff
type
u"(t)+m(|A1/2u(t)|2)Au(t)=0 (1.2)
in a real Hilbert space H, where A is a nonnegative selfadjoint operator in H. Section 4 presents a regularized semigroup theoretical approach to the local solvability of equation (1.2) in the `degenerate case' where the function m(r) has zeros (Theorems 4.1 and 4.2), by using the result obtained in Section 3. In Section 2 we summarize some results on the generation of a regularized evolution operator associated with the linearized equation of (1.1), under the `regularized stability ' condition, and show that the family of matrix operators used to solve the linearized equation (1.2) satisfies the regularized stability condition. This fact will be useful for our arguments in Section 4.</p
Phase Transition in Potts Model with Invisible States
We study phase transition in the ferromagnetic Potts model with invisible
states that are added as redundant states by mean-field calculation and Monte
Carlo simulation. Invisible states affect the entropy and the free energy,
although they do not contribute to the internal energy. The internal energy and
the number of degenerated ground states do not change, if invisible states are
introduced into the standard Potts model. A second-order phase transition takes
place at finite temperature in the standard -state ferromagnetic Potts model
on two-dimensional lattice for , and 4. However, our present model on
two-dimensional lattice undergoes a first-order phase transition with
spontaneous -fold symmetry breaking (, and 4) due to entropy effect
of invisible states. We believe that our present model is a fundamental model
for analysis of a first-order phase transition with spontaneous discrete
symmetry breaking.Comment: 8 pages, 4 figure
Single-epoch supernova classification with deep convolutional neural networks
Supernovae Type-Ia (SNeIa) play a significant role in exploring the history
of the expansion of the Universe, since they are the best-known standard
candles with which we can accurately measure the distance to the objects.
Finding large samples of SNeIa and investigating their detailed characteristics
have become an important issue in cosmology and astronomy. Existing methods
relied on a photometric approach that first measures the luminance of supernova
candidates precisely and then fits the results to a parametric function of
temporal changes in luminance. However, it inevitably requires multi-epoch
observations and complex luminance measurements. In this work, we present a
novel method for classifying SNeIa simply from single-epoch observation images
without any complex measurements, by effectively integrating the
state-of-the-art computer vision methodology into the standard photometric
approach. Our method first builds a convolutional neural network for estimating
the luminance of supernovae from telescope images, and then constructs another
neural network for the classification, where the estimated luminance and
observation dates are used as features for classification. Both of the neural
networks are integrated into a single deep neural network to classify SNeIa
directly from observation images. Experimental results show the effectiveness
of the proposed method and reveal classification performance comparable to
existing photometric methods with multi-epoch observations.Comment: 7 pages, published as a workshop paper in ICDCS2017, in June 201
PART 7 Policy Coordination of Trade Issues : 19. Policy Coordination in the Asian-Pacific Region
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