Estimating total ultrasound attenuation from backscatter data is essential in the field of quantitative ultrasound (QUS) because of the need to compensate for attenuation when estimating the backscatter coefficient and QUS parameters. This work uses a reference phantom method of attenuation estimation to create a spatial map of attenuation slope (AS) from backscatter radio-frequency (RF) data o...

Background: In this study, a method for linear attenuation coefficient calculation was introduced.Methods: Linear attenuation coefficient was calculated with a new method that base on the physics of interaction of photon with matter, mathematical calculation and x-ray spectrum consideration. The calculation was done for Cerrobend as a common radiotherapy modifier and Mercury.Results: The values...

local site conditions have a strong effect on ground response during earthquakes. two important soil parameters that control the amplification effects of seismic motions by a soil column are the soil hysteretic damping ratio and shear wave velocity. this paper presents the results of in situ damping ratio measurements performed using continuous surface wave attenuation data at a site in semnan ...

In order to solve the amplitude attenuation of electric fast transient (EFT) generator operating in high frequency, the charging and discharging process of energy storage capacitor in EFT generator are analyzed, the main circuit voltage variation mathematical model is established, the parameters of main loop circuit and the parameters of switch driving waveform which affect burst amplitude are ...

Experiments show that waves propagating through the earth’s crust experience frequency-dependent attenuation. Three regimes have been identified with specific attenuation properties: the low-, mid-, and high-frequency regimes with attenuation in general increasing with frequency. This paper shows how the observed behavior can be explained via theory for waves in random media. It considers multi...

Load flow is a very significant and essential tool for the analysis of any power system and is used in the operational as well as development stages. In this work, a modified load flow method is formulated for radial distribution systems. The topological characteristics of distribution systems are employed to make proposed load flow solution possible. The proposed method makes use of two matric...

For airand spaceborne weather radars, which typically operate at frequencies of 10 GHz and above, attenuation correction is usually an essential part of any rain estimation procedure. For ground-based radars, where the maximum range within the precipitation is usually much greater than that from airor spaceborne radars, attenuation correction becomes increasingly important at frequencies above ...

introduction superficial x-ray therapy is one of the most important treatment methods in radiotherapy especially in the treatment of superficial skin lesions (up to 300 kvp). quality of the x-ray beam that can be expressed by half-value layer (hvl), are important indices for this type of treatment effective energy of photon and homogeneity coefficient (hc). materials and methods the hc of the s...

This paper presents multi-font/multi-size Kannada numerals and vowels recognition based on spatial features. Directional spatial features viz stroke density, stroke length and the number of stokes in an image are employed as potential features to characterize the printed Kannada numerals and vowels. Based on these features 1100 numerals and 1400 vowels are classified with Multi-class Support Ve...