shear-wave velocity ( ) is an important parameter used for site characterization in geotechnical engineering. however, dispersion curve inversion is challenging for most inversion methods due to its high non-linearity and mix-determined trait. in order to overcome these problems, in this study, a joint inversion strategy is proposed based on the particle swarm optimization (pso) algorithm. the ...

The inversion of electron density from total electron content (TEC) measurements of GPS radio occultation is investigated by means of simulated data from the International Reference Ionosphere IRI-2001 and observations by the GPS/MET satellite experiment. In both cases a meridional slice of electron density is derived for northern summer solstice June/July 1995 from the midnight to the noon sec...

S U M M A R Y A new technique for multimode dispersion measurement has been developed by employing fully non-linear waveform inversion for a path-specific 1-D profile using a neighbourhood algorithm (NA). One-dimensional models derived from waveform inversion are quite sensitive to the model parametrization and the reference model used to start the inversion. With different approaches to the pa...

One of the most challenging problems of electromagnetic (EM) geophysical methods is developing three-dimensional (3-D) EM inversion techniques. This problem is of utmost importance in practical applications because of the 3-D nature of the geological structures. The main difficulties in 3-D inversion are related to (1) limitations of 3-D forward modeling codes available and (2) ill-posedness of...

helicopter-borne electromagnetic (hem) is a fast and high resolution airborne electromagnetic (aem) method that is frequently used for imaging of the subsurface resistivity structures. this is a versatile and cost effective method, frequently has used in mineral and groundwater exploration and various environmental problems. modern frequency-domain hem systems utilize small electromagnetic, mag...

a rare case of non-puerperal uterine inversion caused by a large fundal leiomyoma in a 39-year nulliparous, infertile woman resulting in intractable hemorrhage was reported after a myomectomy. attempts to reduce the inversion vaginally by transecting the anterior and posterior cervix were unsuccessful and a laparotomy was performed. the inversion was not successfully corrected and hysterectomy ...

The ability of a block inversion scheme, in which polygons are employed to define layers andror bodies of equal resistivity, in determining the geometry and true resistivity of subsurface structures has been investigated and a simple strategy for deriving the starting model is proposed. A comparison has also been made between block inversion and smooth inversion, the latter being a cell-based s...

oculo-auriculovertebral dysplasia (goldenhar) is a congenital syndrome. its phenotype differs from craniofacial anomalies to cardiac, vertebral or central nervous system defects. this syndrome is rare and its etiology is not apparent yet. pericentric inversion of chromosome 9 is one of the most common structural balanced chromosomal aberrations with its incidences 15% to 25%. herein we present ...