388 research outputs found
GPCALMA: a Grid Approach to Mammographic Screening
The next generation of High Energy Physics experiments requires a GRID
approach to a distributed computing system and the associated data management:
the key concept is the "Virtual Organisation" (VO), a group of geographycally
distributed users with a common goal and the will to share their resources. A
similar approach is being applied to a group of Hospitals which joined the
GPCALMA project (Grid Platform for Computer Assisted Library for MAmmography),
which will allow common screening programs for early diagnosis of breast and,
in the future, lung cancer. HEP techniques come into play in writing the
application code, which makes use of neural networks for the image analysis and
shows performances similar to radiologists in the diagnosis. GRID technologies
will allow remote image analysis and interactive online diagnosis, with a
relevant reduction of the delays presently associated to screening programs.Comment: 4 pages, 3 figures; to appear in the Proceedings of Frontier
Detectors For Frontier Physics, 9th Pisa Meeting on Advanced Detectors, 25-31
May 2003, La Biodola, Isola d'Elba, Ital
A Computer Aided Detection system for mammographic images implemented on a GRID infrastructure
The use of an automatic system for the analysis of mammographic images has
proven to be very useful to radiologists in the investigation of breast cancer,
especially in the framework of mammographic-screening programs. A breast
neoplasia is often marked by the presence of microcalcification clusters and
massive lesions in the mammogram: hence the need for tools able to recognize
such lesions at an early stage. In the framework of the GPCALMA (GRID Platform
for Computer Assisted Library for MAmmography) project, the co-working of
italian physicists and radiologists built a large distributed database of
digitized mammographic images (about 5500 images corresponding to 1650
patients) and developed a CAD (Computer Aided Detection) system, able to make
an automatic search of massive lesions and microcalcification clusters. The CAD
is implemented in the GPCALMA integrated station, which can be used also for
digitization, as archive and to perform statistical analyses. Some GPCALMA
integrated stations have already been implemented and are currently on clinical
trial in some italian hospitals. The emerging GRID technology can been used to
connect the GPCALMA integrated stations operating in different medical centers.
The GRID approach will support an effective tele- and co-working between
radiologists, cancer specialists and epidemiology experts by allowing remote
image analysis and interactive online diagnosis.Comment: 5 pages, 5 figures, to appear in the Proceedings of the 13th
IEEE-NPSS Real Time Conference 2003, Montreal, Canada, May 18-23 200
Automated detection of lung nodules in low-dose computed tomography
A computer-aided detection (CAD) system for the identification of pulmonary
nodules in low-dose multi-detector computed-tomography (CT) images has been
developed in the framework of the MAGIC-5 Italian project. One of the main
goals of this project is to build a distributed database of lung CT scans in
order to enable automated image analysis through a data and cpu GRID
infrastructure. The basic modules of our lung-CAD system, consisting in a 3D
dot-enhancement filter for nodule detection and a neural classifier for
false-positive finding reduction, are described. The system was designed and
tested for both internal and sub-pleural nodules. The database used in this
study consists of 17 low-dose CT scans reconstructed with thin slice thickness
(~300 slices/scan). The preliminary results are shown in terms of the FROC
analysis reporting a good sensitivity (85% range) for both internal and
sub-pleural nodules at an acceptable level of false positive findings (1-9
FP/scan); the sensitivity value remains very high (75% range) even at 1-6
FP/scanComment: 4 pages, 2 figures: Proceedings of the Computer Assisted Radiology
and Surgery, 21th International Congress and Exhibition, Berlin, Volume 2,
Supplement 1, June 2007, pp 357-35
S.T.R.E.S.S. : Stress Testing and Reverse Engineering for System Security
In modern wireless networks the functions included into layer
II have to deal with complex problems, such as security and
access control, that were previously demanded to upper layers.
This growing complexity led some vendors to implement layer
II primitives directly in software, e.g. IEEE 802.11i has been
largely distributed as a software patch to be used with legacy
802.11b/g hardware. In any extremely complex software the
likelihood of committing errors during the implementation raises,
and it is well known that software bugs can lead to instability
of the system and possibly to security vulnerability. Software
bugs are the most common cause of successful attacks against
any kind of network and represent a real plague for system
administrators. Stress test is a widely used methodology to
find and eliminate software bugs. In this paper we present a
platform to perform a stress test of generic network protocols
implementations but especially optimized for Layer II stress tests,
that present specific problems. With our approach a generic
network protocol described with ABNF language can be tested
transmitting arbitrary frame sequences and interpreting the
responses to verify consistence with the communication standard
used. Our platform can interact dynamically with the tested
machine (an access point, a router etc.) to verify its robustness
and its compliance with the standard. Experiments confirmed the
validity of our approach both as a stress test technique for system
under development and as a reverse engineering technique for
interaction with closed source system
Article going forward from b to a? Proposals for the eurozone crisis
After reviewing the main determinants of the current Eurozone crisis, this paper discusses the feasibility of introducing fiscal currencies as a way to restore fiscal space in peripheral countries, such as Greece, which have so far adopted austerity measures in order to abide by their commitments with Eurozone institutions and the IMF. We show that the introduction of fiscal currencies would speed up the recovery, without violating the rules of Eurozone Treaties. At the same time, these processes could help the transition of the euro from its current status of single currency to a status of “common clearing currency” along the lines proposed by Keynes at Bretton Woods as a system of international settlements. Eurozone countries could therefore move from “Plan B” aimed at addressing member state domestic problems, to a “Plan A” of a better European monetary system
Spectral splitting photovoltaics using perovskite and wideband dye-sensitized solar cells
The extension of the light absorption of photovoltaics into the near-infrared region is important to increase the energy conversion efficiency. Although the progress of the lead halide perovskite solar cells is remarkable, and high conversion efficiency of >20% has been reached, their absorption limit on the long-wavelength side is similar to 800 nm. To further enhance the conversion efficiency of perovskite-based photovoltaics, a hybridized system with near-infrared photovoltaics is a useful approach. Here we report a panchromatic sensitizer, coded DX3, that exhibits a broad response into the near-infrared, up to similar to 1100 nm, and a photocurrent density exceeding 30 mA cm(-2) in simulated air mass 1.5 standard solar radiation. Using the DX3-based dye-sensitized solar cell in conjunction with a perovskite cell that harvests visible light, the hybridized mesoscopic photovoltaics achieved a conversion efficiency of 21.5% using a system of spectral splitting.open0
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