The paper deals with analysis of loading conditions on damping torque coefficient and synchronizing coefficient in SMIB system and design of Delta-Omega type of damping controller for damping of power oscillations in the system. Effect of variation of loading on synchronizing torque and damping torque coefficients has been investigated in detail. A new design approach for optimizing the paramet...

A new compact model of squeeze-film damping is developed based on the numerical solution of the Boltzmann kinetic equation. It provides a simple expression for the damping coefficient and the quality factor valid through the slip, transitional and free-molecular regimes. In this work, we have applied statistical analysis to the current model using the chi-squared test. The damping predictions a...

We determine the class of damped modes ỹ which are related to the common free damping modes y by supersymmetry. They are obtained by employing the factorization of Newton’s differential equation of motion for the free damped oscillator by means of the general solution of the corresponding Riccati equation together with Witten’s method of constructing the supersymmetric partner operator. This pr...

in order to study effect of seed weight on germination and growth of wheat seedling, an experiment in seed technology laboratory of aboureihan paradise university of tehran in 2005 has been done. in this experiment, at first stage, the seeds separated by longitude step, latitude step and set frequency parameters of gravity separator set. in second stage, 10 treatments of 1000 seed weight entere...

This paper investigates damping ratio in micro-beam resonators based on magneto-thermo-elasticity. A unique aspect of the present study is the effect of permanent magnetic field on the stiffness and thermo-elastic damping of the micro resonators. In our modeling the theory of thermo-elasticity with interacting of an externally applied permanent magnetic field is taken into account. Combined the...

In this paper, the Unified Power Flow Controller (UPFC) is enhanced with a Chaotic Particle Swarm Optimization (CPSO) Damping Controller in order to mitigate the Low Frequency Oscillations (LFO) in a Single Machine Infinite Bus (SMIB) power system. The designed damping controller is an optimized lead-lag controller, which extracts the speed deviation of the generator rotor and generates the out...

A discrete-time internal model principle based adaptive algorithm for identifying signals composed of a sum of exponentially damped sinusoids is presented. The time varying state variables of an internal model principle controller in a feedback loop can provide estimates of the exponentially damped sinusoidal signal parameters, the damping factor and the frequency. By using additional integral ...

The seasonal cycle of mid to high latitude surface air temperature is prime example of a climate response to external forcing. Here we examine what controls the amplitude and phase of this cycle. By comparing the seasonal cycle in an numerical model of the atmosphere and ocean mixed layer where the large seasonal variation in humidity is allowed to affect longwave radiation to one where it is n...

A quantum kinetic equation is derived for the description of pair production in a timedependent homogeneous electric field E(t). As a source term, the Schwinger mechanism for particle creation is incorporated. Possible particle production due to collisions and collisional damping are neglected. The main result is a kinetic equation of non-Markovian character. In the low density approximation, t...

Rice (Oryza sativa L.) is often exposed to cool temperatures during spring planting in temperate climates. A better understanding of genetic pathways regulating chilling tolerance will enable breeders to develop varieties with improved tolerance during germination and young seedling stages. To dissect chilling tolerance, five assays were developed; one assay for the germination stage, one assay...