velocity analysis is one of the most important step in seismic data processing. it affects not only many processing steps directly and indirectly, but also is known as a primary interpretation of the data. however, it can also be assumed as one of the most time consuming processing step. the conventional velocity analysis method measures the energy amplitude along hyperbolic trajectories within...

introduction: for a velocity profile in turbulent flows, the flow conditions in the vicinity of the wall are described by logarithmic law of the wall. however, it has been extensively verified that the log-law does not apply in the outer region of the boundary layer. for example, in free surface flows, the law of the wall holds only for 20 percent of the flow depth from the wall. coles (1956) c...

In cruise control systems, the performance of the controller is important. Hence, in order to have accurate results, the nonlinear behavior of a vehicle model should also be considered. In this article, a vehicle with a nonlinear model is controlled by using a nonlinear method. The nonlinear term of the model is the generated torque of engine, which is a polynomial equation. In addition, feedba...

In areas of complex geology, migration-velocity estimation should use methods that describe the complexity of wavefield propagation, such as focusing and defocusing, multipathing, and frequency-dependent velocity sensitivity. Migration-velocity analysis by wavefield extrapolation has the ability to address these issues because, in contrast to ray-based methods, it uses wavefields as carriers of...

medical information plays a pivotal role in collecting health information which can be used to determine the main health problems at national and international levels and to change main health policies. patient management is impossible without having accurate information regarding prevention, treatment and recovery of diseases. thus, in this issue of international electronic journal of medicine...

most organizations need to information systems to survive and thrive. therefore, they should seriously protect their information assets. creating structured and justifiable exchanges between cost, security and mission control systems security risks is essential. this is important in the planning and development of such systems. initial appropriate decisions can reduce costs and increase ease of...

Acoustic waveform tomography is applied to a 2D synthetic dataset from Saudi Aramco to test if we will be able to obtain an accurate and highly resolved velocity tomogram. Source and receiver locations are not located along a flat surface so we assume a surface topography from the source and receiver locations. The initial velocity model was obtained using traveltime tomography and the source w...