1,037 research outputs found
Experimental Tests of Non-Perturbative Pion Wave Functions
We use the transverse-momentum dependence of the cross section for
diffractive dissociation of high energy pions to two jets to study some
non-perturbative Light-Cone wave functions of the pion. We compare the
predictions for this distribution by Gaussian and Coulomb wave functions as
well as the wave function derived from solution of the Light-Cone Hamiltonian
in the Singlet Model. We conclude that this experimentally measured information
provides a powerful tool for these studies.Comment: 5 pages, 4 figure
Measurement of Light-Cone Wave Functions by Diffractive Dissociation
Diffractive dissociation of particles can be used to study their light-cone
wave functions. Results from Fermilab experiment E791 for diffractive
dissociation of 500 GeV/c pi- mesons into di-jets show that the |q qbar>
light-cone asymptotic wave function describes the data well for Q^2 ~ 10
(GeV/c)^2 or more.Comment: Talk given at the Recontres de Moriond, QCD and High Energy Hadronic
Interactions, Les Arcs, March 2002. 5 pages 4 figure
Comparative Energy Dependence of Proton and Pion Degradation in Diamond
A comparative theoretical study of the damages produced by protons and pions,
in the energy range 50 MeV - 50 GeV, in diamond, is presented. The
concentration of primary defects (CPD) induced by hadron irradiation is used to
describe material degradation. The CPD has very different behaviours for
protons and pions: the proton degradation is important at low energies and is
higher than the pion one in the whole energy range investigated, with the
exception of the Delta33 resonance region, where a large maximum of the
degradation exists for pions. In comparison with silicon, the most investigated
and the most studied material for detectors, diamond theoretically proves to be
one order of magnitude more resistant, both to proton and pion irradiation.Comment: 7 pages, 5 figure
Diamond degradation in hadron fields
The energy dependence of the concentration of primary displacements induced
by protons and pions in diamond has been calculated in the energy range 50 MeV
- 50 GeV, in the frame of the Lindhard theory. The concentrations of primary
displacements induced by protons and pions have completely different energy
dependencies: the proton degradation is very important at low energies, and is
higher than the pion one in the whole energy range investigated, with the
exception of the delta33 resonance region. Diamond has been found,
theoretically, to be one order of magnitude more resistant to proton and pion
irradiation in respect to silicon.Comment: 7 pages, 3 figure
Medical image retrieval for augmenting diagnostic radiology
Even though the use of medical imaging to diagnose patients is ubiquitous in clinical settings, their interpretations are still challenging for radiologists. Many factors make this interpretation task difficult, one of which is that medical images sometimes present subtle clues yet are crucial for diagnosis. Even worse, on the other hand, similar clues could indicate multiple diseases, making it challenging to figure out the definitive diagnoses. To help radiologists quickly and accurately interpret medical images, there is a need for a tool that can augment their diagnostic procedures and increase efficiency in their daily workflow. A general-purpose medical image retrieval system can be such a
tool as it allows them to search and retrieve similar cases that are already diagnosed to make comparative analyses that would complement their diagnostic decisions. In this thesis, we contribute to developing such a system by proposing approaches to be integrated as modules of a single system, enabling it to handle various information needs of radiologists and thus augment their diagnostic processes during the interpretation of medical images.
We have mainly studied the following retrieval approaches to handle radiologists’different information needs; i) Retrieval Based on Contents, ii) Retrieval Based on Contents, Patients’ Demographics, and Disease Predictions, and iii) Retrieval Based on Contents and Radiologists’ Text Descriptions. For the first study, we aimed to find an effective feature representation method to distinguish medical images considering their semantics and modalities. To do that, we have experimented different representation techniques based on handcrafted methods (mainly texture features) and deep learning (deep features). Based on the experimental results, we propose an effective feature representation approach and deep learning architectures for learning and extracting medical image contents. For the second study, we present a multi-faceted method that complements image contents with patients’ demographics and deep learning-based disease predictions, making it able to identify similar cases accurately considering the clinical context the radiologists seek.
For the last study, we propose a guided search method that integrates an image with a radiologist’s text description to guide the retrieval process. This method guarantees that the retrieved images are suitable for the comparative analysis to confirm or rule
out initial diagnoses (the differential diagnosis procedure). Furthermore, our method is based on a deep metric learning technique and is better than traditional content-based approaches that rely on only image features and, thus, sometimes retrieve insignificant random images
Mjerenje valnih funkcija na svjetlosnom konusu difraktivnom disocijacijom
Diffractive dissociation of particles can be used to study their light-cone wave functions. Results are presented for the pion from Fermilab experiment E791 and for the photon from HERA/ZEUS experiment at DESY.Valne funkcije čestica na svjetlosnom konusu mogu se proučavati njihovom difraktivnom disocijacijom. Predstavljamo ishode mjerenja E791 u Fermilabu i mjerenja HERA/ZEUS u DESYju
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Digital Death and the Digital Afterlife: Oreet Ashery in Conversation with Korina Giaxoglou
Korina Giaxoglou: Let’s talk about digital death, an area we have both been
interested in for some time now. To start with, what is digital death?
Oreet Ashery: Digital death for me is how death, dying, and mourning are
experienced through digital technologies, such as online social media or digital wills
- …