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Yayın A precision estimation method for volumetric changes(IEEE, 2019-06) Akça, Mehmet Devrim; Stylianidis, Efstratios; Gruen, Armin W.; Altan, Mehmet Orhan; Hofer, Martin; Smagas, Konstantinos; Sanchez Martin, Victor; Walli, Andreas; Jimeno, Elisa; Garcia, AlejandroEarth surface changes are often computed by comparing the sequences of digital elevation models (DEMs) so called the DEM of difference (DoD) method. We present an operational DEM generation, co-registration and DoD comparison software in which the surface changes are quantified in metric units of volume. A practical method, which is based on the law of error propagation, is developed to estimate the theoretical precisions of volumetric changes. The proposed pipeline can estimate the change of object volumes (in terms of loss and gain) together with their precision numbers. Change of the forest volume in a fire effected region in a test site is analyzed for the validation. The method can be used for various change detection applications related to forestry as well as other topics such as earthworks, geomorphology, mining, and urbanization.Yayın Beamforming and hardware design for a multichannel front-end integrated circuit for real-time 3D catheter-based ultrasonic imaging(SPIE-Int Soc Optical Engineering, 2006) Wygant, Ira O.; Karaman, Mustafa; Oralkan, Ömer; Khuri-Yakub, Butrus ThomasWe are working on integrating front-end electronics with the ultrasound transducer array for real-time 3D ultrasound imaging systems. We achieve this integration by flip-chip bonding a two-dimensional transducer array to an integrated circuit (IC) that comprises the front-end electronics. The front-end IC includes preamplifiers, multiplexers, and pulsers. We recently demonstrated a catheter-based real-time ultrasound imaging system based on a 16 x 16-element capacitive micromachined ultrasonic transducer (CMUT) array. The CMUT array is flip-chip bonded to a front-end IC that includes a pulser and preamplifier for each element of the array. To simplify the back-end processing and signal routing on the IC for this initial implementation, only a single array element is active at a time (classic synthetic aperture (CSA) imaging). Compared with classic phased array imaging (CPA), where multiple elements are used on transmit and receive, CSA imaging has reduced signal-to-noise ratio and prominent grating lobes. In this work, we evaluate three array designs for the next generation front-end IC. The designs assume there are 16 receive channels and that numerous transmit pulsers are provided by the IC. The designs presented are: plus-transmit x-receive, boundary-transmit x-receive with no common elements, and full-transmit x-receive with no common elements. Each design is compared with CSA and CPA imaging. We choose to implement an IC for the full-transmit x-receive with no common elements (FT-XR-NC) design for our next-generation catheter-based imaging system.
