Maximum-likelihood estimation prevents unphysical Mueller matrices

We show that the method of maximum-likelihood estimation, recently introduced in the context of quantum process tomography, can be applied to the determination of Mueller matrices characterizing the polarization properties of classical optical systems. Contrary to linear reconstruction algorithms, the proposed method yields physically acceptable Mueller matrices even in presence of uncontrolled experimental errors. We illustrate the method on the case of an unphysical measured Mueller matrix taken from the literature.Comment: 3 pages, 1 figur

Performance Analysis of 3-Level 5-Phase Multilevel Inverter Topologies

Now a day’s many industrial applications requires high power. Some other appliances may require intermediate power either more or less depending upon their operation. With these consequences, MULTI LEVEL INVERTERS are introduced in 1975.for above intermediate voltage applications. The name MULTI LEVEL began with the three-level converter.By enormous advancement in power semiconductor switches, in electric drives increasing the phase number greater than the conventional three phase especially in locomotives, naval, aerospace, and electrical vehicles industry has many advantages than three phase. In this view, here five phase VSI has developed. This paper aims at comparing the performance of conventional two level inverter Diode clamped and Capacitor clamped topologies of 5-phase multilevel inverter (3-level) using sinusoidal pulse width modulation. SPWM is highly economical, has more efficiency, controllability. These circuits are analyzed by using simulation software package such as MATLAB

Control of Indirect Matrix Converter by Using Improved SVM Method

A novel space vector modulation (SVM) method for an indirect matrix converter (IMC) is used to reduce the common -mode voltage (CMV) in the output. The process of selecting required active vectors and to describe the switching sequence in the inverter stage of the IMC is explained in this paper. This novel SVM method used to decrease the peak -to-peak amplitude voltage of CMV without using any external hardware. The other advantage of this SVM method is to reduce the total harmonic distortion of line-to-line output voltage. This new modulation technique is easily implemented through simulation and its results are used to demonstrate the improved performance of the input/output waveforms

Magnetic rock properties of the gabbros from the ODP Drill Hole 1105 A of the Atlantis Bank, Southwest Indian Ridge

Laboratory studies of 30 samples from 158 m long drill core of the Hole 1105 A (ODP Leg 179) of the Atlantis Bank, Southwest Indian Ridge have revealed magnetic properties of the gabbros, olivine gabbros, oxide gabbros and olivine oxide gabbros down the core. Comparison of modal proportions of the oxides, grain sizes and magnetization parameters of the rocks has confirmed that most coarse-grained oxide mineral bearing rocks record low Koenigsberger ratio (2 to 5) and median destructive fields (5 to 7 mT). Average natural remanent magnetization (Jnrm) and stable remanent magnetization (Jst) of the core samples are 5.8 A/m and 1.9 A/m, respectively. Their mean stable magnetic inclination is 66° ± 4°, about 14° steeper than the expected dipole inclination of the area similar to the one reported at Hole 735 B. The excess inclination perhaps marks a tectonic block rotation of the reversely magnetized rocks of the bank. We interpret that gabbros and serpentinites devoid of basaltic carapace significantly contribute to seafloor spreading anomalies of the bank