Simulation of wave propagation in plate structures by using new spectral element with piezoelectric coupling

This paper presents an efficient approach to simulate Lamb wave propagations in thin plate structures by using new time domain spectral plate elements. A novel approach is proposed to incorporate the coupling of piezoelectric transducers within the two-dimensional plate element. The diagonal mass matrix is obtained by using a simple method with less computational effort. Detailed formulations are given. The benchmark problem of a thin aluminum plate with two surface-mounted piezoelectric transducers was investigated in detail. Comparisons are made with results obtained by using ABAQUS to verify the developed spectral plate element. It is shown that the proposed element can efficiently simulate the propagation of Lamb wave generated by a piezoelectric actuator and picked up by a piezoelectric sensor

High Quality Image Interpolation via Local Autoregressive and Nonlocal 3-D Sparse Regularization

In this paper, we propose a novel image interpolation algorithm, which is formulated via combining both the local autoregressive (AR) model and the nonlocal adaptive 3-D sparse model as regularized constraints under the regularization framework. Estimating the high-resolution image by the local AR regularization is different from these conventional AR models, which weighted calculates the interpolation coefficients without considering the rough structural similarity between the low-resolution (LR) and high-resolution (HR) images. Then the nonlocal adaptive 3-D sparse model is formulated to regularize the interpolated HR image, which provides a way to modify these pixels with the problem of numerical stability caused by AR model. In addition, a new Split-Bregman based iterative algorithm is developed to solve the above optimization problem iteratively. Experiment results demonstrate that the proposed algorithm achieves significant performance improvements over the traditional algorithms in terms of both objective quality and visual perceptionComment: 4 pages, 5 figures, 2 tables, to be published at IEEE Visual Communications and Image Processing (VCIP) 201

Continuity of the Value Function for Deterministic Optimal Impulse Control with Terminal State Constraint

Deterministic optimal impulse control problem with terminal state constraint is considered. Due to the appearance of the terminal state constraint, the value function might be discontinuous in general. The main contribution of this paper is the introduction of an intrinsic condition under which the value function is continuous. Then by a Bellman dynamic programming method, the corresponding Hamilton-Jacobi-Bellman type quasi-variational inequality (QVI, for short) is derived for which the value function is a viscosity solution. The issue of whether the value function is characterized as the unique viscosity solution to this QVI is carefully addressed and the answer is left open challengingly.Comment: 29 page

Backward Stackelberg Differential Game with Constraints: a Mixed Terminal-Perturbation and Linear-Quadratic Approach

We discuss an open-loop backward Stackelberg differential game involving single leader and single follower. Unlike most Stackelberg game literature, the state to be controlled is characterized by a backward stochastic differential equation (BSDE) for which the terminal- instead initial-condition is specified as a priori; the decisions of leader consist of a static terminal-perturbation and a dynamic linear-quadratic control. In addition, the terminal control is subject to (convex-closed) pointwise and (affine) expectation constraints. Both constraints are arising from real applications such as mathematical finance. For information pattern: the leader announces both terminal and open-loop dynamic decisions at the initial time while takes account the best response of follower. Then, two interrelated optimization problems are sequentially solved by the follower (a backward linear-quadratic (BLQ) problem) and the leader (a mixed terminal-perturbation and backward-forward LQ (BFLQ) problem). Our open-loop Stackelberg equilibrium is represented by some coupled backward-forward stochastic differential equations (BFSDEs) with mixed initial-terminal conditions. Our BFSDEs also involve nonlinear projection operator (due to pointwise constraint) combining with a Karush-Kuhn-Tucker (KKT) system (due to expectation constraint) via Lagrange multiplier. The global solvability of such BFSDEs is also discussed in some nontrivial cases. Our results are applied to one financial example.Comment: 38 page

Impact of technology habitual domain on ambidextrous innovation:Case study of a Chinese high-tech enterprise

To obtain a sustainable competitive advantage in the dynamic environment, it is necessary for Chinese high-tech enterprises to focus on their technology habitual domains in formulating ambidextrous innovation strategy. This study integrates technology habitual domain, exploratory innovation and exploitative innovation within a framework and explores the influence mechanism among them. Based on an in-depth case study on KTE, representing a high-tech enterprise in China, we have several findings. Firstly, we depict the evolution mechanism of technology habitual domain; secondly, we find that the high-tech enterprise’s technology habitual domain will cultivate and develop the firms’ dynamic capabilities; and thirdly, the expansion of technology habitual domain will promote exploitative innovation, while the transformation of technology habitual domain will promote exploratory innovation. These findings can be useful guidance for high-tech enterprises in China who are aiming to achieve ambidextrous innovation to better adapt to the turbulent environment, and thus achieving sustainability