Wave field continuation transforms seismic record section data directly into velocity-depth space, simultaneously providing an estimate of model nonuniqueness. This inversion, previously used for reflection and refraction data, converts readily to spherical earth problems through simple adjustments in each of the two linear transformations: the slant stack and downward continuation. Because the...

various sources of geodetic, geological and geophysical information can improve our understanding about the crustal density. in this paper we propose a methodology for determination of crustal density based on terrestrial gravity observations, geopotential models, digital terrain models (dtm), geological maps and cross-sections, deep geophysical profiles, and geoid models. the method can be alg...

noise is one of the major hazardous occupational exposures and one of the occupations at risk is the transportation industry. however, few studies have measured and reported the amount of noise exposure in drivers. in this study, we evaluated noise exposure among the public transportation bus drivers of one major iranian city, kerman, southeast iran. eighty public transportation buses in the st...

The process of wave equation continuation (migration) is adapted for refraction data in order to produce velocity-depth models directly from the recorded data. The procedure consists of two linear transformations: a slant stack of the data produces a wave field in the p T plane which is then downward continued using T = 0 as the imaging condition. The result is that the data wave field is linea...

This paper describes the three Fast Downward Aidos portfolios we submitted to the Unsolvability International Planning Competition 2016. All three Aidos variants are implemented in the Fast Downward planning system (Helmert 2006). We use a pool of techniques as a basis for our portfolios, including various techniques already implemented Fast Downward, as well as three newly developed techniques...

A 900-MHz phase-locked loop frequency synthesizer implemented in a 0.6m CMOS technology is developed for the Wireless Integrated Network Sensors applications. It incorporates an automatic switched-capacitor (SC) discrete-tuning loop to extend the overall frequency tuning range to 20%, while the VCO gain ( VCO) resulting from the CMOS varactor continuous-tuning is kept low at only 20 MHz/V in or...

I propose a finite-difference offset continuation filter for interpolating seismic reflection data. The filter is constructed from the offset continuation differential equation and is applied on frequency slices in the log-stretch frequency domain. Synthetic and real data tests demonstrate that the proposed method succeeds in structurally complex situations where more simplistic approaches fail.

I propose a finite-difference offset continuation filter for interpolating seismic reflection data. The filter is constructed from the offset continuation differential equation and is applied on frequency slices in the log-stretch frequency domain. Synthetic data tests produce encouraging results: nearly perfect interpolation of a constant-velocity dataset with a complex reflector model and rea...

We describe an approach for finding the eigenfrequencies of solar acoustic modes (p modes) in a convective envelope in the WKB limit. This approximation restricts us to examining the effects of fluid motions which are large compared to the mode wavelength, but allows us to treat the three-dimensional mode as a localized ray. The method of adiabatic switching is then used to investigate the freq...