9,050 research outputs found

    Adaptive BDDC algorithms for the system arising from plane wave discretization of Helmholtz equations

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    Balancing domain decomposition by constraints (BDDC) algorithms with adaptive primal constraints are developed in a concise variational framework for the weighted plane wave least-squares (PWLS) discritization of Helmholtz equations with high and various wave numbers. The unknowns to be solved in this preconditioned system are defined on elements rather than vertices or edges, which are different from the well-known discritizations such as the classical finite element method. Through choosing suitable "interface" and appropriate primal constraints with complex coefficients and introducing some local techniques, we developed a two-level adaptive BDDC algorithm for the PWLS discretization, and the condition number of the preconditioned system is proved to be bounded above by a user-defined tolerance and a constant which is only dependent on the maximum number of interfaces per subdomain. A multilevel algorithm is also attempted to resolve the bottleneck in large scale coarse problem. Numerical results are carried out to confirm the theoretical results and illustrate the efficiency of the proposed algorithms

    Stochastic Linear Quadratic Stackelberg Differential Game with Overlapping Information

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    This paper is concerned with the stochastic linear quadratic Stackelberg differential game with overlapping information, where the diffusion terms contain the control and state variables. Here the term "overlapping" means that there are common part between the follower's and the leader's information, while they have no inclusion relation. Optimal controls of the follower and the leader are obtained by the stochastic maximum principle, the direct calculation of the derivative of the cost functional and stochastic filtering. A new system of Riccati equations is introduced to represent the state estimate feedback of the Stackelberg equilibrium strategy. A special solvable case is then studied and is applied to the continuous-time principal-agent problem.Comment: 43 page

    Leader-Follower Stochastic Differential Game with Asymmetric Information and Applications

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    This paper is concerned with a leader-follower stochastic differential game with asymmetric information, where the information available to the follower is based on some sub-σ\sigma-algebra of that available to the leader. Such kind of game problem has wide applications in finance, economics and management engineering such as newsvendor problems, cooperative advertising and pricing problems. Stochastic maximum principles and verification theorems with partial information are obtained, to represent the Stackelberg equilibrium. As applications, a linear-quadratic leader-follower stochastic differential game with asymmetric information is studied. It is shown that the open-loop Stackelberg equilibrium admits a state feedback representation if some system of Riccati equations is solvable.Comment: 20 pages. The main content of this paper is presented by the first author in IMS-China International Conference on Statistics and Probability, Kunming, P.R. China, June 201

    Anomalous magnetohydrodynamics with longitudinal boost invariance and chiral magnetic effect

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    We study relativistic magnetohydrodynamics with longitudinal boost invariance in the presence of chiral magnetic effects and finite electric conductivity. With initial magnetic fields parallel or anti-parallel to electric fields, we derive the analytic solutions of electromagnetic fields and the chiral number and energy density in an expansion of several parameters determined by initial conditions. The numerical solutions show that such analytic solutions work well in weak fields or large chiral fluctuations. We also discuss the properties of electromagnetic fields in the laboratory frame.Comment: 27 pages, 5 figure

    Randomized Consensus based Distributed Kalman Filtering over Wireless Sensor Networks

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    This paper is concerned with developing a novel distributed Kalman filtering algorithm over wireless sensor networks based on randomized consensus strategy. Compared with the centralized algorithm, distributed filtering techniques require less computation per sensor and lead to more robust estimation since they simply use the information from the neighboring nodes in the network. However, poor local sensor estimation caused by limited observability and network topology changes which interfere the global consensus are challenging issues. Motivated by this observation, we propose a novel randomized gossip-based distributed Kalman filtering algorithm. Information exchange and computation in the proposed algorithm can be carried out in an arbitrarily connected network of nodes. In addition, the computational burden can be distributed for a sensor which communicates with a stochastically selected neighbor at each clock step under schemes of gossip algorithm. In this case, the error covariance matrix changes stochastically at every clock step, thus the convergence is considered in a probabilistic sense. We provide the mean square convergence analysis of the proposed algorithm. Under a sufficient condition, we show that the proposed algorithm is quite appealing as it achieves better mean square error performance theoretically than the noncooperative decentralized Kalman filtering algorithm. Besides, considering the limited computation, communication, and energy resources in the wireless sensor networks, we propose an optimization problem which minimizes the average expected state estimation error based on the proposed algorithm. To solve the proposed problem efficiently, we transform it into a convex optimization problem. And a sub-optimal solution is attained. Examples and simulations are provided to illustrate the theoretical results

    Morita Equivalence and Interpolation of The Dirac-Born-infeld Theory on the Non-Commutative Torus

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    In the noncommutative Dirac-Born-Infeld action with Chern-Simons term, an interpolation field Ί\Phi is used in both DBI action and Chern-Simons term. The Morita equivalence is discussed in both the lagrangian and the Hamiltonian formalisms, which is more transparent in this treatment.Comment: 6 pages, latex, no figure

    Computing optimal interfacial structure of ordered phases

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    We propose a general framework of computing interfacial structure. If an ordered phase is involved, the interfacial structure can be obtained by simply minimizing the free energy with compatible boundary conditions. The framework is applied to Landau- Brazovskii model and works efficiently

    Exact solutions to the three-dimensional Gross-Pitaevskii equation with modulated radial nonlinearity

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    We study the Bose-Einstein condensate trapped in a three-dimensional spherically symmetrical potential. Exact solutions to the stationary Gross-Pitaevskii equation are obtained for properly modulated radial nonlinearity. The solutions contain vortices with different winding numbers and exhibit the shell-soliton feature in the radial distributions.Comment: 5 figure

    Computing optimal interfacial structure of modulated phases

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    We propose a general framework of computing interfacial structures between two modulated phases. Specifically we propose to use a computational box consisting of two half spaces, each occupied by a modulated phase with given position and orientation. The boundary conditions and basis functions are chosen to be commensurate with the bulk structures. It is observed that the ordered nature of modulated structures stabilizes the interface, which enables us to obtain optimal interfacial structures by searching local minima of the free energy landscape. The framework is applied to the Landau-Brazovskii model to investigate interfaces between modulated phases with different relative positions and orientations. Several types of novel complex interfacial structures are obtained from the calculations.Comment: 15 pages, 7 figures. arXiv admin note: substantial text overlap with arXiv:1511.0362

    Inheritance Study on the Culture of Traditional Music in Middle and Primary Education: Taking South Korean Music Curriculum as an Example

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    “Music” and “education” are the organic components of culture. South Korea show great solicitude for the succeeding of traditional culture in middle and primary education. During the instant, pluralistic and open globalization period, it gives consideration to the ultimate value pursuit of both the times and its own laws, forming a distinctive music curriculum. This paper clarifies the feasibility and necessity of the succeeding of such sort of culture. On the basis of actively elaborating the concept and curriculum content, this paper does propose a whole string of inheritance trajectory of this kind of culture, which has important reference significance for further coming true the succeeding of traditional culture in students’ education
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