21 research outputs found
Combining a morphological interpolation approach with a surface reconstruction method for the 3-D representation of tomographic data
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Passive seismic tomography and 3‐D velocity structure of the uppermost crust below Lesvos Island, Greece
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Geothermal exploration of kos island, Greece: Magnetotelluric and microseismicity studies
No full textThis paper reports the results of magnetotelluric (MT) and microseismicity studies, conducted as part of a multi-disciplinary project to explore the geothermal potential of the island of Kos, Greece. The MT survey, comprising 18 soundings, was carried out in the bandwidth 128 Hz-40 s, in order to determine the deep conductivity structure in the geothermally prospective western part of the island. Rigorous dimensionality analysis has indicated that the geoelectric structure could adequately be approximated with 1-D interpretation tools. Two significant and seemingly communicating conductive zones of potential geothermal interest were found within the first 2 km. The first is extensive and shallow, detected at depths of 400-600 m; the second is deeper (1000-1300 m), but of considerably smaller lateral dimensions. A very deep relative conductor (<25 Ωm) was also detected at depths of 7-10 km, which is thought to comprise part of an old magma chamber with brine-saturated rocks. The microseismicity studies revealed the partial or total attenuation of shear waves in many microearthquake records. The analysis of these observations determined the vertical and lateral extent of that attenuation zone, the greatest part of which is located underneath the marine area between western Kos and Nissyros island to the south, extending approximately from near the surface to about 1.5 km depth. The nature of this zone is discussed in terms of fluid concentration due to the geothermal system of the area. © 1994
Hermite Kernels for slice interpolation in medical images
No full textUnivariate Hermite interpolation of the total degree (HTD) is an algebraically demanding interpolation method that utilizes information of the values of the signal to be interpolated at distinct support positions, as well as the values of its derivatives up to a maximum available order. In this work the interpolation kernels of the univariate HTD are derived, using several approximations of the 1st and 2nd order of discrete signal derivative. We assess the derived Hermite kernels in the task of medical image slice interpolation, against several other well established interpolation techniques. Results show that specific Hermite kernels can outperform other established interpolation methods with similar computational complexity, in terms of root mean square error (RMSE), in a number of interpolation experiments, resulting in higher accuracy interpolated images. © 2012 IEEE
Microseismic activity and seismotectonics of Heraklion Area (central Crete Island, Greece)
No full textMicroseismic activity and seismotectonics of Heraklion area (central Crete Island, Greece)
No full textA seismological network of 10 portable analogue stations was installed in the area of Heraklion (central Crete) from September to December 1995. During this period, more than 1000 events were recorded by at least 4 stations with magnitudes ranging from 0.5 to 4.6 and depths up to 70 km. Analysis of 336 well located events revealed high seismic activity. In the onshore area seismicity is shallow (<20 km) and concentrated along the eastern margin of the Heraklion Basin and in the Messara graben to the south. Seismicity decreases rapidly from east to west, with practically no events located along the western boundary of Heraklion Basin. Epicenter distribution indicates that microseismicity is closely associated to the tectonics of the region. Significant seismic activity was also observed in the southern offshore area, restricted north of the Hellenic Trench and related to the subduction process. The determination of different types of focal mechanisms in the area indicates that the investigated region is characterized by complex tectonics related to the southward subduction of the African plate and the northward extension of the Aegean lithosphere
MITIS: A WWW-based medical system for managing and processing gynecological-obstetrical-radiological data
No full textMITIS: a WWW-based medical system for managing and processing gynecological-obstetrical-radiological data
No full textIn this paper a World Wide Web (WWW)-based medical system, called MITIS, is designed and developed for the management and processing of obstetrical, gynecological and radiological medical data. The system records all the necessary medical information in terms of patient data, examinations, and operations and provides the user-expert with advanced image processing toots for the manipulation, processing and storage of ultrasound and mammographic images. The system can be installed in a hospital’s Local Area Network (LAN) where it can access picture archival and communication systems (PACS) servers (if available), or any other server within the radiology department, for image archiving and retrieval, based on the digital imaging and communication in medicine (DICOM) 3.0 protocol, over TCP/IP and also it is accessible to external physicians via the hospital’s Internet connection. MITIS is composed as a set of independent WWW modules (ISAPI server extension dlls) and a Win32 application (COM+ server) for mammography image processing and evaluation. (C) 2004 Elsevier Ireland Ltd. All rights reserved
