Searched for: department:"Imaging%5C+Science%5C+and%5C+Technology"
(1 - 20 of 232)

Pages

document
Soni, A.K. (author), Verschuur, D.J. (author)
For vertical-seismic-profiling (VSP) measurements, the use of blended acquisition, with time-overlapping shot records, can greatly reduce the downtime and, thereby, provide large cost savings. For directly imaging blended VSP measurements, we have used full-wavefield migration (FWM). FWM is an inversion-based imaging scheme that enables us to...
journal article 2015
document
Van Ravesteijn, V.F. (author)
CT colonography (CTC) is a minimally invasive method for detection of colorectal polyps and colon cancer. Limitations of CTC related to the efficiency as well as the sensitivity of radiologists. Additionally, the patient's preparation was considered burdensome and the X-ray radiation that is inherent to the technique increases the risk of cancer...
doctoral thesis 2013
document
Weiss, N. (author), Van Leeuwen, T.G. (author), Kalkman, J. (author)
We report on localized measurement of the longitudinal and transverse flow velocities in a colloidal suspension using optical coherence tomography. We present a model for the path-length resolved autocorrelation function including diffusion and flow, which we experimentally verify. For flow that is not perpendicular to the incident beam, the...
journal article 2013
document
De Luca, G.M.R. (author), Breedijk, R.M.P. (author), Brandt, R.A.J. (author), Zeelenberg, C.H.C. (author), De Jong, B.E. (author), Timmermans, W. (author), Nahidi Azar, L. (author), Hoebe, R.A. (author), Stallinga, S. (author), Manders, E.M.M. (author)
We present a new super-resolution technique, Re-scan Confocal Microscopy (RCM), based on standard confocal microscopy extended with an optical (re-scanning) unit that projects the image directly on a CCD-camera. This new microscope has improved lateral resolution and strongly improved sensitivity while maintaining the sectioning capability of a...
journal article 2013
document
Raghunathan, S.B. (author), Schouten, H.F. (author), Ubachs, W. (author), Ea Kim, B. (author), Gan, C.H. (author), Visser, T.D. (author)
Dynamic control of the direction of radiation of the light emanating from a subwavelength slit carved out of a thin metal film is experimentally demonstrated. This is achieved by selective excitation of the individual guided modes in the slit by setting the phase of three coherent laser beams. By changing the voltage across a piezoelement, we...
journal article 2013
document
Bol, K. (author), Haeck, J.C. (author), Groen, H.C. (author), Niessen, W.J. (author), Bernsen, M.R. (author), De Jong, M. (author), Veenland, J.F. (author)
Although efficient delivery and distribution of treatment agents over the whole tumor is essential for successful tumor treatment, the distribution of most of these agents cannot be visualized. However, with single-photon emission computed tomography (SPECT), both delivery and uptake of radiolabeled peptides can be visualized in a neuroendocrine...
journal article 2013
document
Righolt, C.H. (author), Slotman, J.A. (author), Young, I.T. (author), Mai, S. (author), Van Vliet, L.J. (author), Stallinga, S. (author)
Various aspects of image filtering affect the final image quality in Structured Illumination Microscopy, in particular the regularization parameter and type of regularization function, the relative height of the side bands, and the shape of the apodization function. We propose an apodization filter without adjustable parameters based on the...
journal article 2013
document
Soni, A.K. (author), Verschuur, D.J. (author)
Blended source and/or simultaneous source acquisition for multi-offset and multi-azimuth VSP measurements can prove significantly beneficial in saving expensive borehole down-time. In the last few years, for the case of surface seismic data, it was proposed to redefine imaging and inversion of the blended data to handle the data directly without...
journal article 2013
document
Li, M. (author), Liang, L. (author), Abubakar, A. (author), Van den Berg, P.M. (author)
We introduce a new regularization scheme for multiparameter seismic full-waveform inversion (FWI). Using this scheme, we can constrain spatial variations of parameters which are having a weak sensitivity with the one that having a good sensitivity to the measurement, assuming that these parameters have similarities in their structures. In...
journal article 2013
document
Verschuur, D.J. (author)
Today, the problem of surface-related multiples, especially in shallow water, is not fully solved. Although surface-related multiple elimination (SRME) method has proved to be successful on a large number of data cases, the involved adaptive subtraction acts as a weak link in this methodology, where primaries can be distorted due to their...
journal article 2013
document
Righolt, C.H. (author), Zatreanu, D.A. (author), Raz, V. (author)
The nuclear lamina is the structural scaffold of the nuclear envelope that plays multiple regulatory roles in chromatin organization and gene expression as well as a structural role in nuclear stability. The lamina proteins, also referred to as lamins, determine nuclear lamina organization and define the nuclear shape and the structural...
journal article 2013
document
Lopez, G.A. (author), Verschuur, D.J. (author)
Recently, a new approach to multiple removal has been intro- duced: estimation of primaries by sparse inversion (EPSI). Al- though based on the same relationship between primaries and multiples as surface-related multiple elimination (SRME), it involves quite a different process: instead of prediction and subtraction of multiples, in EPSI the...
journal article 2013
document
Davydenko, M. (author), Verschuur, D.J. (author)
Full wavefield migration (FWM) is an inversion-based imaging algorithm that utilizes the complete reflection measurements: primaries as well as all multiples, both surface and internal. Using multiples in the imaging can extend the illumination of the subsurface. In this paper we concentrate the study on the internal scattering that can be...
journal article 2013
document
Verweij, M.D. (author), Demi, L. (author), Van Dongen, K.W.A. (author)
Nonlinear ultrasound is important in medical diagnostics because imaging of the higher harmonics improves resolution and reduces scattering artifacts. Second harmonic imaging is currently standard, and higher harmonic imaging is under investigation. The efficient development of novel imaging modalities and equipment requires accurate simulations...
journal article 2013
document
Pereira, S.P. (author), Vuik, K. (author), Pinho, F.T. (author), Nobrega, J.M. (author)
The present work explores the massively parallel capabilities of the most advanced architecture of graphics processing units (GPUs) code named “Fermi”, on a two-dimensional unstructured cell-centred finite volume code. We use the SIMPLE algorithm to solve the continuity and momentum equations that was fully ported to the GPU. The benefits of...
conference paper 2013
document
Ramakrishnan, G. (author), Ramanandan, G.K.P. (author), Adam, A.J.L. (author), Xu, M. (author), Kumar, N. (author), Hendrikx, R.W.A. (author), Planken, P.C.M. (author)
We report on the surprisingly strong, broadband emission of coherent terahertz pulses from ultrathin layers of semiconductors such as amorphous silicon, germanium and polycrystalline cuprous oxide deposited on gold, upon illumination with femtosecond laser pulses. The strength of the emission is surprising because the materials are considered to...
journal article 2013
document
Polo, A. (author), Pereira, S.F. (author), Urbach, H.P. (author)
We analytically demonstrate that Phase Retrieval (PR) from defocused intensity measurements is achievable using a single measurement plane. Following this approach, the predicted plane is found at a defocus distance of 4? optical unit. Experimental results confirm the theoretical predictions
conference paper 2013
document
Ozmen-Eryilmaz, N. (author), Van Dongen, K.W.A. (author)
Tomogrophic ultrasound imaging is gaining popularity in breast cancer detection. Reconstructing the acoustic properties of a breast from the ultrasound measurements is stated as a nonlinear inverse problem, which is usually solved by linearized methods because of computational efficiency. However, linearization of the problem reduces the quality...
conference paper 2013
document
Van Dongen, K.W.A. (author), Ozmen-Eryilmaz, N. (author)
Tomogrophic ultrasound imaging is gaining popularity in breast cancer detection. Reconstructing the acoustic properties of a breast from the ultrasound measurements is stated as a nonlinear inverse problem, which is usually solved by linearized methods because of computational efficiency. However, linearization of the problem reduces the quality...
conference paper 2013
document
Braat, J.J.M. (author), Janssen, A.J.E.M. (author)
Various authors have presented the aberration function of an optical system as a power series expansion with respect to the ray coordinates in the exit pupil and the coordinates of the intersection point with the image field of the optical system. In practical applications, for reasons of efficiency and accuracy, an expansion with the aid of...
journal article 2013
Searched for: department:"Imaging%5C+Science%5C+and%5C+Technology"
(1 - 20 of 232)

Pages