one of the common problems in reflection seismic records in the land is the existence of surface waves with high amplitude and low frequency which cause the most important parts of reflective signals to be masked. therefore, it is necessary to attenuate them by processing and acquisition methods. as it is impossible to attenuate the surface waves completely, and sometimes it is likely to damage...

Cognitive rehabilitation treatment (CRT) has been described in patients with brain injury, but it has not been attempted in cases of cognitive dysfunction without organic cause. This case report describes CRT of neurocognitive impairment in a 54-year-old female patient with conversion disorder (CD). She experienced difficulties with regard to speaking, motor function, and pain symptoms, which d...

The seismic phase PKJKP, which traverses the inner core as a shear wave and would provide direct evidence for its solidity, has been difficult to detect. Using stacked broadband records from the Grafenberg array in Germany, we documented a high signal-to-noise phase, the arrival time and slowness of which agree with theoretical predictions for PKJKP. The back azimuth of this arrival is also con...

One of the most critical decisions in the design of a localslant-stack transform (LSST) is the selection of its aperture, or more precisely, the selection of the appropriate number of traces and their weighting coefficients for each slant stack. The challenge is to achieve a good compromise between the slowness and the spatial resolution. Conventionally, the window size is chosen in a more intu...

[1] We introduce a coherence measure for seismic signal enhancement through incoherent noise attenuation. Our processing tool is designed for densely spaced arrays and identifies signals by their coherent appearance. The approach is based on the determination of the lateral phase coherence as function of distance, time, frequency, and slowness. The coherence is derived from the local phases of ...

In this thesis, we investigate slowness as an unsupervised learning principle of sensory processing. Two aspects are given particular emphasis: (a) the mathematical analysis of Slow Feature Analysis (SFA) as one particular implementation of slowness learning and (b) the question, how slowness learning can be implemented in a biologically plausible fashion. In the first part of the thesis, we de...

Several recent studies have used the coherence of seismic noise between stations to retrieve the phase slowness and attenuation. However, there is considerable debate on the feasibility of attenuation retrieval, its interpretation, and its dependence on the noise directionality and has been the subject of several analytical and numerical studies. In this article, we perform a detailed analysis ...

Acoustic wave propagation in elastic media is characterized by the slowness surface. The slowness surface consists of three sheets associated with three modes of wave propagation and the two outer sheets can have zero-curvature locally. It is shown that the outmost sheet can admit extraordinary zero-curvature and the slowness curve can appear as a straight line locally. Using the perturbation m...

Obsessional slowness is regarded as an uncommon but severely disabling variant of obsessive-compulsive disorder. This paper examines the psychopathology, classification, pathophysiology and treatment of obsessional slowness. It argues that primary obsessional slowness does not require classification as a separate syndrome because it can be found to be secondary to recognised phenomena of obsess...