We explore the photon transfer in nonlinear parity-time-symmetry system of two coupled cavities, which contains gain and loss dependent on intracavity photons. Analytical solution to steady state gives a saturated gain, satisfy parity-time symmetry automatically. The eigen-frequency self-adapts reach maximum efficiency state. find that weak coupling regime does not match state, exhibiting an ap...

The eigenvalues of a symmetric matrix depend on the matrix nons-moothly. This paper describes the nonsmooth analysis of these eigen-values. In particular, I present a simple formula for the approximate (limiting Fr echet) subdiierential of an arbitrary function of the eigen-values, subsuming earlier results on convex and Clarke subgradients. As an example I compute the subdiierential of the k't...

In this paper, by assuming equiprobable centrosymmetric constellation adopted for modulation, the mathematic expectation of the sample auto-correlation matrix obtained through the least-squared channel estimation is derived under a rigorous model of the doubly selective fading channel for orthogonal frequency division multiplexing (OFDM) systems. Based on the derived expectation, the bias-prope...

Many advanced techniques are being developed for Power Systems Stability Assessment. We can use Eigen value techniques for the purpose of increasing the calculation performance of eigen-algorithms for Power System Small Signal Stability Analysis. Firstly, we introduce a bulge chasing algorithm called the BR algorithm which is a novel and efficient method to find all Eigen values of upper Hessen...

In this paper, multi objective design of multi-machine Power System Stabilizers (PSSs) using Particle Swarm Optimization (PSO) is presented. The stabilizers are tuned to simultaneously shift the lightly damped and undammed electro-mechanical modes of all machines to a prescribed zone in the s-plane. A multi objective problem is formulated to optimize a composite set of objective functions compr...

In this paper, a new parallel procedure is proposed to accelerate the solution of linear systems required by iterative Eigen analysis methods. Now days Eigen analysis of power systems is frequently used to study the effect and tune the response of existing controllers, to guide the design of new controllers. Recent developments in the area lead to the necessity of studying larger power system m...

[1] In this study, using the nonlinear principal analysis (NLPCA) technique, we demonstrated that the leading El Nino-Southern Oscillation (ENSO) mode in a physical basis changed since the late 1970s. The ENSO mode during the pre-1980s resembles the destabilized ‘ocean basin mode’, while during the post-1980s does ‘the recharge-mode’. In particular, for the pre-1980s, the surface zonal current ...