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In this paper, a class of BAMtype Cohen-Grossberg neural networks with delays are studied. Some sufficient conditions ensuring global exponential stability of the system are obtained on time scales. The results extend and improve some recent works for neural networks.

In this paper, with assuming global Lipschitz conditions on the activation functions, applying idea of vector Lyapunov function, Young inequality and Halanay differential inequality with delay, the global exponential stability of the equilibrium point for a class of cellular neural networks with distributed delays and large impulses is investigated, the sufficient conditions for globally exponential stability of neural networks are obtained.

The main purpose of this paper is to study the globally exponential stability of the equilibrium point for a class of cellular neural networks with distributed delays and large impulses. With assuming global Lipschitz conditions on the activation functions, applying idea of vector Lyapunov function, combining Halanay differential inequality with delay, the sufficient conditions for globally exponential stability of neural networks are obtained.

The main purpose of this paper is to study the globally exponential stability of the equilibrium point for a class of impulsive neural networks with time-varying delays. Without assuming global Lipschitz conditions on the activation functions, applying idea of vector Lyapunov function, combining Halanay differential inequality with delay, the sufficient conditions for globally exponential stability of neural networks are obtained.

This paper is concerned with the stability and periodicity for a class of impulsive neural networks with delays. By means of the Fixed point theory, Lyapunov functional and analysis technique, some sufficient conditions of exponential stability and periodicity are obtained. We can see that impulses do contribution to the stability and periodicity. An example is given to demonstrate the effectiveness of the obtained results.

Restoring contour is a prominent problem of embroidery information recognizing. This paper discusses several relative algorithms and presents their applicability and limitation. Combined the characteristics of stitch with existing relative algorithms, a new contour restoring algorithm is provided. Furthermore, it discusses time complexity of algorithm. A test is given in the end. The algorithm has been applied to an embroidery CAD system which has gotten reputation among end users.

The main purpose of this paper is to study the globally exponential stability of the equilibrium point for a class of impulsive neural networks with time-varying delays. Without assuming global Lipschitz conditions on the activation functions, applying idea of vector Lyapunov function, combining Young inequality and Halanay differential inequality with delay, the sufficient conditions for globally exponential stability of neural networks are obtained.

In this paper, an elliptic system with sign-changing weights is considered. By variational methods, we show that the problem has at least three nontrivial solutions.

This paper is concerned with a class of neural networks with delays and impulses. Some sufficient conditions are obtained for the existence and globally exponential stability of a unique equilibrium solution without assuming the activation function to be bounded, monotonic or differentiable. An example is given to demonstrate the effectiveness of the obtained results.

In this paper, a class of impulsive neural networks with time-varying delays is studied. Without assumption of global Lipschitz conditions on the activation functions, applying idea of vector Lyapunov function, combining Halanay differential inequality with delay, a sufficient condition for globally exponential stability of the equilibrium is obtained

In this paper , With assumption of global Lipschitz conditions on the activation functions, by Lyapunov function and Halanay differential inequality with delay, we study a class of cellular neural networks with distributed delays and large impulses. It obtained a sufficient condition for globally exponential stability of the equilibrium point.

Stitch partition is a prominent problem of embroidery information restoring. This paper concerns several relative algorithms and presents their applicability and limitation. Combined the characteristics of stitch with BP neural network, a stitch partition algorithm is provided. An experiment is given in the end. The algorithm has been applied to an embroidery CAD system which has gotten reputation among end users.

In this paper we study the globally exponential stability of a class of neural networks with time-varying delays. Applying idea of vector Lyapunov function, Young inequality and Halanay differential inequality with delay, the sufficient conditions for the existence and globally exponential stability of the equilibrium point are obtained

The existence and the asymptotic behavior of solutions of a class of free boundary problems arising in planar vortex theory are discussed.

By Lyapunov function and Halanay inequality, a class of the BAM type Cohen-Grossberg neural network with delays and impulsive is considered. It obtained some sufficient conditions about the existence of equilibrium point, globally exponential stability and globally exponentially robust stability. We can see the impulses do contribution to the exponential stability and robust stability.At last, an example can be demonstrate the results.

Employing general Halanay inequalities, Dinipsilas derivative and functional analysis techniques, several global exponential stability criteria of the equilibrium point are established for a class of delayed reaction-diffusion recurrent neural networks. These criteria are only dependent on the parameters of the system. The results correct some errors of the earlier publication.

Some sufficient conditions are obtained for the global exponential stability of a solution and existence of the periodic solution to the general bidirectional associative memory (BAM) neural networks with distributed delay and impulsive by using the Lyapunov functional and some inequality technique. These results are helpful for designing a globally exponential stable and periodic oscillatory BAM neural network, and the conditions can be easily applied in practice. An example is also given to illustrate our results.

By using the method of Lyapunov function and analysis technique, a model for bidirectional associative memory with impulsive is studied. Sufficient conditions are obtained for the existence and uniformly stability of a unique equilibrium solution . We can see that impulses do contribute to systempsilas uniformly stability. This stability property is independent of the stability of continuous-time BAM model.

This paper is concerned with the stability of the impulsive Cohen-Grossberg neural networks with variable delays. By means of matrices theory, Lyapunov function and analysis technique, sufficient conditions are obtained for the uniform stability of a unique equilibrium solution of this system. We can see that impulses do contribution to system's uniform stability, so the impulsive system is stable whether the corresponding continuous-time system is stable or not. As the applications of the main theorems, some uniform stability criteria are established for several well known impulsive ecological models with variable delays.

In this paper, a model of impulsive general BAMs neural networks is first formulated.We investigate impulsive effects on the stability of BAMs neural networks with variable delays and obtain some sufficient conditions ensuring exponential stability of the impulsive variable delays system.The results extend and improve some recent works for impulsive neural networks as well as non-impulsive neural networks.

We proved a multiplicity result for a nonlinear elliptic system in R-N. The functional related to the system is strongly indefinite. We investigated the relation between the number of solutions and the topology of the set of the global maxima of the coefficients.

We consider the solvability of the Neumann problem for the equation $$ -\Delta u+\lambda u =0, \quad \frac {\partial u}{\partial \nu}=Q(x)|u|^{q-2}u $$ on $\partial \Omega$, where $Q$ is a positive and continuous coefficient on $\partial \Omega$, $\lambda$ is a parameter and $q= {2(N-1)}/{(N-2)}$ is a critical Sobolev exponent for the trace embedding of $H^1(\Omega)$ into $L^q(\partial \Omega)$. We investigate the joint effect of the mean curvature of $\partial \Omega$ and the shape of the graph of $Q$ on the existence of solutions. As a by product we establish a sharp Sobolev inequality for the trace embedding. In Section 6 we establish the existence of solutions when a parameter $\lambda$ interferes with the spectrum of $-\Delta$ with the Neumann boundary conditions. We apply a min-max principle based on the topological linking.

In this paper we are concerned with the existence of solutions for the Hamiltonian system where N ≥ 3, Q, K : ℝN → ℝ are bounded positive continuous functions and the numbers p, q > 1 satisfy Using dual variational methods we show that under certain conditions on Q and K the system (S∊) has a positive solution which concentrates as ∊ → 0 in a point xo ∈ ℝN where related functionals realize its minimum energy.

We establish in this paper existence results for critical strongly indefinite semilinear elliptic systems defined on both bounded domains and $\mathbb R^N$.

A proof is given of an a priori bound for positive solutions of semilinear elliptic systems with nonlinearities depending on the gradients.

Derating of the working current level does not work for improving GaN-based light-emitting diode (LED) devices' reliability. The present work demonstrates that it is not the levels but the specific components of the applied electrical currents weighing more on LEDs' degradation. Existing defects are sources for tunneling currents and Shockley-Read-Hall (SRH) non-radiative recombination current, and the component of tunneling currents and SRH non-radiative recombination current in the applied electrical current will in turn induce fast increase of defect density. The current component from electron tunneling to deep levels in the vicinity of mixed/screw dislocations will affect more on LEDs' degradation than other components, such as heavy-hole tunneling via intermediate state. In a whole, the overflow leakage current from the active region and Auger recombination currents in the applied electrical current will generate positive effects to alleviate LEDs' degradation.

The present work demonstrates that aging at higher temperatures significantly aggravates “efficiency droop” in the n-side-up vertical-structured GaN-based light-emitting diodes (LEDs). The observed luminous efficiency droop is over 40% at the measuring current of 350 mA. This phenomenon closely relates with creeping of Au80Sn20 eutectic bonds. On one hand, the plastic deformation accumulated during creeping at higher aging temperatures will make the LED epilayers tensile strained at room temperature. The tensile strain induces a change of the internal quantum efficiency (IQE). The maximum variation of IQE related with strain states was around 20%. On the other hand, creeping under the thermal-mismatching induced tensile stress activates voids' nucleation and growth in the solder bonds. The distribution profile of voids in solder bonds will be mapped on the multiple quantum-well structure in vertical-structured LED chips. Local current densities can be much higher than the average current density used in t...

With this work, we demonstrate a three-stage degradation behavior of GaN based LED chips under current/thermal co-stressing. The three stages in sequence are the initial improvement stage, the platform stage, and the rapid degradation stage, indicating that current/thermal co-stressing activates positive effects and negative ones simultaneously, and the dominant degradation mechanisms evolve with aging time. Degradation mechanisms are discussed. Electric current stress has dual characters: damaging the active layers by generating defects and at the same time improving the p-type conductivity by activating the Mg-dopant. High temperature stresses will promote the effects from electric current stresses. The activation of the Mg-dopant will saturate, whereas the generation of defects is carried on in a progressive way. Other mechanisms, such as deterioration of ohmic contacts, also operate. These mechanisms compete/cooperate with each other and evolve with aging time, resulting in the observed three-stage degradation behavior. There exist risks to predict the lifetime of LEDs by a model with a constant accelerated factor.

The main purpose of this paper is to establish the existence of a solution of the semilinear Schr¨odinger equation (1) −u + V (x)u = K(x)|u|2−2u + f(x, u) in RN, involving a critical Sobolev exponent 2 = 2N/(N − 2) with N 4 and a subcritical nonlinearity f : RN × R ! R. Throughout this paper it is assumed that (A) The coefficients V and K are continuous and 1-periodic functions in each variable xi, i = 1, . . . ,N. Moreover, we assume that K 0 on RN. In this case it is known that the operator − + V on L2(RN) has a purely continuous spectrum consisting of closed disjoint intervals. In this paper we consider the case: (B) 0 is in the spectral gap of the operator − + V . There are many existence results in the case K 0 on RN and we refer to the papers [4], [5], [9], [10], [13]. 1991 Mathematics Subject Classification. 35J65.