Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
Articles 1 - 2 of 2
Full-Text Articles in Engineering
Non‐Rayleigh Statistics Of Ultrasonic Backscattered Echo From Tissues, V. Manjo Narayanan, Robert C. Molthen, P. M. Shankar, J. M. Reid
Non‐Rayleigh Statistics Of Ultrasonic Backscattered Echo From Tissues, V. Manjo Narayanan, Robert C. Molthen, P. M. Shankar, J. M. Reid
Biomedical Engineering Faculty Research and Publications
The envelope of the backscattered signal from tissues can exhibit non‐Rayleigh statistics if the number density of scatterers is small or if the variations in the scattering cross sections are random. The K distribution which has been used extensively in radar, is introduced to model this non‐Rayleigh behavior. The generalized K distribution is extremely useful since it encompasses a wide range of distributions such as Rayleigh, Lognormal, and Rician. Computer simulations were conducted using a simple one‐dimensional discrete scatteringmodel to investigate the properties of the echo envelope. In addition to cases of low number densities, significant departures from Rayleigh statistics …
Immittance Spectroscopy Of Smart Components And Novel Devices, Mohammad Anwarul Alim, Sanjida Khanam, Martin A. Seitz
Immittance Spectroscopy Of Smart Components And Novel Devices, Mohammad Anwarul Alim, Sanjida Khanam, Martin A. Seitz
Electrical and Computer Engineering Faculty Research and Publications
AC small-signal immittance spectroscopy is employed as a viable tool to demonstrate electrical characterization, performance improvement, and quality assurance issues of smart materials-based components and novel devices. The variation in the ac response, complemented via dc measurements within a range of tolerating temperature, delineates competing phenomena occurring in the microstructures of these engineering material systems. The results are presented in a generic manner with possible explanations on the mechanisms for two selected Debye-like (nearly ideal) and non-Debye (non-ideal) low-capacitance resistors. This spectroscopic approach allows systematic development of a representative equivalent circuit, considered to be the characteristic of the devices and …