نتایج جستجو برای: approximate inversion

تعداد نتایج: 118525  

This paper describes the application of approximate methods to invert airborne magnetic data as well as helicopter-borne frequency domain electromagnetic data in order to retrieve a joint model of magnetic susceptibility and electrical resistivity. The study area located in Semnan province of Iran consists of an arc-shaped porphyry andesite covered by sedimentary units which may have potential ...

Journal: :Journal of Marine Science and Engineering 2023

Geoacoustic inversion is a challenging task in marine research due to the complex environment and acoustic propagation mechanisms. With rapid development of deep learning, various designs neural networks have been proposed solve this issue with satisfactory results. As data-driven method, learning aim approximate inverse function by extracting knowledge from multiple replicas, outperforming con...

Journal: :فیزیک زمین و فضا 0
اکو علیپور دانشجوی کارشناسی ارشد ژئومغناطیس-دانشگاه شاهرود علی نجاتی کلاته هیت علمی دانشگاه شاهرود، دانشکده معدن، نفت و ژئوفیزیک علیرضا عرب امیری هیت علمی دانشگاه شاهرود، دانشکده معدن، نفت و ژئوفیزیک

generally, the measured secondary field data is inverted into resistivity using two principal models; the homogeneous half-space model and the layered half-space model. while the homogeneous half-space inversion uses single frequency data, the inversion is done individually for each of the frequencies used, the multi-layer 1d inversion is able to take the data of all frequencies available into ...

Journal: :Journal of Computational Physics 2022

We introduce two data completion algorithms for the limited-aperture problems in inverse acoustic scattering. Both are independent of topological and physical properties unknown scatterers. The main idea is to relate full-aperture via prolate matrix. simple fast since only approximate inversion matrix involved. then combine with imaging methods such as factorization method direct sampling objec...

Inversion of magnetic data is an important step towards interpretation of the practical data. Smooth inversion is a common technique for the inversion of data. Physical bound constraint can improve the solution to the magnetic inverse problem. However, how to introduce the bound constraint into the inversion procedure is important. Imposing bound constraint makes the magnetic data inversion a n...

Amir Khacpai Hosein Abolghasemi, Hozhabr Sohbat zadeh Mohammad Ghannadi maragheh

In this paper, we studied effect of different parameters including density, viscosity, interfacial tension and solute transfer concentration on phase inversion hold-up. The results showed that change in phase density ratio had no effect on phase inversion hold-up. It also disclosed that the phase viscosity ratio was the most effective parameter affecting phase inversion hold-up and each phase h...

ژورنال: ژئوفیزیک ایران 2020
Mahjoobeh Meskaranian Peyman Pour Moghaddam

This study derives the discretized adjoint states full waveform inversion (FWI) in both time and frequency domains based on the Lagrange multiplier method. To achieve this, we applied adjoint state inversion on the discretized wave equation in both time domain and frequency domain. Besides, in this article, we introduce reliability tests to show that the inversion is performing as it should be ...

Journal: :Magnetic resonance in medicine 2010
Ke Li Zhongliang Zu Junzhong Xu Vaibhav A Janve John C Gore Mark D Does Daniel F Gochberg

Inversion recovery sequences that vary the inversion time (t(i)) have been employed to determine T(1) and, more recently, quantitative magnetization transfer parameters. Specifically, in previous work, the inversion recovery pulse sequences varied t(i) only while maintaining a constant delay (t(d)) between repetitions. T(1) values were determined by fitting to a single exponential function, and...

2017
Kai Fan Qi Wei Lawrence Carin Katherine A. Heller

We propose a new method that uses deep learning techniques to accelerate the popular alternating direction method of multipliers (ADMM) solution for inverse problems. The ADMM updates consist of a proximity operator, a least squares regression that includes a big matrix inversion, and an explicit solution for updating the dual variables. Typically, inner loops are required to solve the first tw...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید