The additive noise response of a charge pump phase-locked loop in the synchronous mode of operation has been studied. In order to determine the tracking and noise performances of the loop, mean square values of tracking error and local oscillator phase jitter have been analytically obtained. Analytical results agree well with the simulation results obtained here and elsewhere [3]. The analysis ...

Based on the high frequency of three-phase voltage source PWM rectifier, this paper established a mathematical model of three phase current inner ring and outer ring voltage, and put forward the setting method of three phase double closed loop control. Finally, it was verified through simulation. The experimental results show that Three-phase output of DC voltage is stable with the operation of...

active filters have proven to be more effective than passive techniques to improve power quality and to solve harmonic and power factor problems due to nonlinear loads. this paper proposes a control scheme based on the instantaneous active and reactive power. the inverter of this active filter is a three-phase, two-level converter. space vector technique is used as modulators and pattern genera...

in this paper we focus on a continuously deteriorating two units series equipment which its failure can not be measured by cost criterion. for these types of systems avoiding failure during the actual operation of the system is extremely important. in this paper we determine inspection periods and maintenance policy in such a way that failure probability is limited to a pre-specified value and ...

a discrete mibi avid lung lesion was found in cinematic views of myocardial perfusion imaging (mpi) of a 59 year-old woman. interestingly, the abnormal uptake in the lung was detectable only in the rest phase images and not in the images acquired in the stress phase. mpi was performed for pre-operation cardiac risk assessment before correction surgery for spinal canal stenosis.  she had no past...

Abstruct-In the present state of the art, coherent optical receivers most often operate in the heterodyne mode. Here a photodiode-,amplifier combination having bandwidth greater than twice the bit rate ( B ) is needed: indeed bandwidths considerably greater than 2B are preferably employed to ease design of the bandpass filter needed for noise limitation, and to avoid demodulator penalties in so...

this paper proposes a flexible power electronic transformer (fpet) for the application in the micro-grids. the low frequency transformer is usually used at the point of common coupling (pcc) to connect the low voltage grid and utility network to each other. the conventional 50hz transformer results in enhanced low voltage-grid power management system during grid-connected operation. in this pap...

Nowadays, UnderBalanced Drilling (UBD) technology is widely applicable in the petroleum industry due to its advantages to an overbalanced drilling operation. UBD success depends on maintaining the drilling fluid circulating pressure below the reservoir pore pressure during operations. One of the main prerequisites of a successful UBD operation is the correct estimation of the pressure profi...

background: the objectives of an educational system in a society are based on society's requirements. since personnel knowledge and skill are not qualified with the advantages of science and invention of new tools, new needs are arisen. comparing the curriculum of undergraduate course of operating room of our country with international societies, it seems that this curriculum is not a good one ...