36 research outputs found
The multi-layer network nature of systemic risk and its implications for the costs of financial crises
The inability to see and quantify systemic financial risk comes at an immense
social cost. Systemic risk in the financial system arises to a large extent as
a consequence of the interconnectedness of its institutions, which are linked
through networks of different types of financial contracts, such as credit,
derivatives, foreign exchange and securities. The interplay of the various
exposure networks can be represented as layers in a financial multi-layer
network. In this work we quantify the daily contributions to systemic risk from
four layers of the Mexican banking system from 2007-2013. We show that focusing
on a single layer underestimates the total systemic risk by up to 90%. By
assigning systemic risk levels to individual banks we study the systemic risk
profile of the Mexican banking system on all market layers. This profile can be
used to quantify systemic risk on a national level in terms of nation-wide
expected systemic losses. We show that market-based systemic risk indicators
systematically underestimate expected systemic losses. We find that expected
systemic losses are up to a factor four higher now than before the financial
crisis of 2007-2008. We find that systemic risk contributions of individual
transactions can be up to a factor of thousand higher than the corresponding
credit risk, which creates huge risks for the public. We find an intriguing
non-linear effect whereby the sum of systemic risk of all layers underestimates
the total risk. The method presented here is the first objective data driven
quantification of systemic risk on national scales that reveal its true levels.Comment: 15 pages, 6 figure
Ultra-High-Resolution Time-of-Flight MR-Angiography for the Noninvasive Assessment of Intracranial Aneurysms, Alternative to Preinterventional DSA?
Purpose
The 3DÂ time-of-flight (TOF) magnetic resonance angiography (MRA) at 3TÂ shows high sensitivity for intracranial aneurysms but is inferior to three-dimensional digital subtraction angiography (3D-DSA) regarding aneurysm characteristics. We applied an ultra-high-resolution (UHR) TOF-MRA using compressed sensing reconstruction to investigate the diagnostic performance in preinterventional evaluation of intracranial aneurysms compared to conventional TOF-MRA and 3D-DSA.
Methods
In this study 17Â patients with unruptured intracranial aneurysms were included. Aneurysm dimensions, configuration, image quality and sizing of endovascular devices were compared between conventional TOF-MRA at 3TÂ and UHR-TOF with 3D-DSA as gold standard. Quantitatively, contrast-to-noise ratios (CNR) were compared between TOF-MRAs.
Results
On 3D-DSA, 25 aneurysms in 17 patients were detected. On conventional TOF, 23 aneurysms were detected (sensitivity: 92.6%). On UHR-TOF, 25 aneurysms were detected (sensitivity: 100%). Image quality was not significantly different between TOF and UHR-TOF (pâŻ=â0.17). Aneurysm dimension measurements were significantly different between conventional TOF (3.89âŻmm) and 3D-DSA (4.2âŻmm, pâŻ=â0.08) but not between UHR-TOF (4.12âŻmm) and 3D-DSA (pâŻ=â0.19). Irregularities and small vessels at the aneurysm neck were more frequently correctly depicted on UHR-TOF compared to conventional TOF. Comparison of the planned framing coil diameter and flow-diverter (FD) diameter revealed neither a statistically significant difference between TOF and 3D-DSA (coil pâŻ=â0.19, FD pâŻ=â0.45) nor between UHR-TOF and 3D-DSA (coil: pâŻ=â0.53, FD 0.33). The CNR was significantly higher in conventional TOF (pâŻ=â0.009).
Conclusion
In this pilot study, ultra-high-resolution TOF-MRA visualized all aneurysms and accurately depicted aneurysm irregularities and vessels at the base of the aneurysm comparably to DSA, outperforming conventional TOF. UHR-TOF with compressed sensing reconstruction seems to represent a non-invasive alternative to pre-interventional DSA for intracranial aneurysms
Mapping and assessment of forest ecosystems and their services - Applications and guidance for decision making in the framework of MAES
The aim of this report is to illustrate by means of a series of case studies the implementation of mapping and assessment of forest ecosystem services in different contexts and geographical levels. Methodological aspects, data issues, approaches, limitations, gaps and further steps for improvement are analysed for providing good practices and decision making guidance. The EU initiative on Mapping and Assessment of the state of Ecosystems and their Services (MAES), with the support of all Member States, contributes to improve the knowledge on ecosystem services. MAES is one of the building-block initiatives supporting the EU Biodiversity Strategy to 2020.JRC.H.3-Forest Resources and Climat
MMB & DFT 2014 : Proceedings of the International Workshops ; Modeling, Analysis and Management of Social Networks and their Applications (SOCNET 2014) & Demand Modeling and Quantitative Analysis of Future Generation Energy Networks and Energy-Efficient Systems (FGENET 2014)
At present, a comprehensive set of measurement, modeling, analysis, simulation, and performance evaluation techniques are employed to investigate complex networks. A direct transfer of the developed engineering methodologies to related analysis and design tasks in next-generation energy networks, energy-efficient systems and social networks is enabled by a common mathematical foundation.
The International Workshop on "Demand Modeling and Quantitative Analysis of Future Generation Energy Networks and Energy-Efficient Systems" (FGENET 2014) and the International Workshop on "Modeling, Analysis and Management of Social Networks and their Applications" (SOCNET 2014) were held on March 19, 2014, at University of Bamberg in Germany as satellite symposia of the 17th International GI/ITG Conference on "Measurement, Modelling and Evaluation of Computing Systems" and "Dependability and Fault-Tolerance" (MMB & DFT 2014). They dealt with current research issues in next-generation energy networks, smart grid communication architectures, energy-efficient systems, social networks and social media. The Proceedings of MMB & DFT 2014 International Workshops summarizes the contributions of 3 invited talks and 13 reviewed papers and intends to stimulate the readersâ future research in these vital areas of modern information societies.GegenwĂ€rtig wird eine reichhaltige Klasse von Verfahren zur Messung, Modellierung, Analyse, Simulation und Leistungsbewertung komplexer Netze eingesetzt. Die unmittelbare Ăbertragung entwickelter Ingenieurmethoden auf verwandte Analyse- und Entwurfsaufgaben in Energienetzen der nĂ€chsten Generation, energieeffizienten Systemen und sozialen Netzwerken wird durch eine gemeinsame mathematische Basis ermöglicht. Die Internationalen Workshops "Demand Modeling and Quantitative Analysis of Future Generation Energy Net-works and Energy-Efficient Systems" (FGENET 2014) und "Modeling, Analysis and Management of Social Networks and their Applications" (SOCNET 2014) wurden am 19. MĂ€rz 2014 als angegliederte Symposien der 17. Internationalen GI/ITG Konferenz "Measurement, Modelling and Evaluation of Computing Systems" und "Dependability and Fault-Tolerance" (MMB & DFT 2014) an der Otto-Friedrich-UniversitĂ€t Bamberg in Deutschland veranstaltet. Es wurden aktuelle Forschungsfragen in Energienetzen der nĂ€chsten Generation, Smart Grid Kommunikationsarchitekturen, energieeffizienten Systemen, sozialen Netzwerken und sozialen Medien diskutiert. Der Tagungsband der Internationalen Workshops MMB & DFT 2014 fasst die Inhalte von 3 eingeladenen VortrĂ€gen und 13 begutachteten BeitrĂ€gen zusammen und beabsichtigt, den Lesern Anregungen fĂŒr ihre eigenen Forschungen auf diesen lebenswichtigen Gebieten moderner
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Raw data from Figure 2<div><br></div><div>doi:10.1371/journal.pone.0194561<br></div
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Raw data from Figure 4 of Publication:<div><br></div><div>doi:10.1371/journal.pone.0194561<br></div
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<div>Raw data from Figure 5 of publication:</div><div><br></div>doi:10.1371/journal.pone.019456
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Raw data from Figure 3 of publication:<div><br></div><div>doi:10.1371/journal.pone.0194561<br></div
Sample handler for x-ray tomographic microscopy and image-guided failure assessment
X-ray tomographic microscopy (XTM) yields a three-dimensional data model of an investigated specimen. XTM providing micrometer resolution requires synchrotron light, high resolution area detectors, and a precise sample handler. The sample handler has a height of 270 mm only, is usable for 1 ”m resolution, and is able to carry loading machines with a weight of up to 20 kg. This allows exposing samples to load between scans for image-guided failure assessment. This system has been used in the XTM end station of the materials science beamline of the Swiss Light Source at the Paul Scherrer Institut