565 research outputs found
Morphological classification of radio galaxies: Capsule Networks versus Convolutional Neural Networks
Next-generation radio surveys will yield an unprecedented amount of data, warranting analysis by use of machine learning techniques. Convolutional neural networks are the deep learning technique that has proven to be the most successful in classifying image data. Capsule networks are a more recently developed technique that use capsules comprised of groups of neurons, that describe properties of an image including the relative spatial locations of features. The current work explores the performance of different capsule network architectures against simpler convolutional neural network architectures, in reproducing the classifications into the classes of unresolved, FRI and FRII morphologies. We utilise images from a LOFAR survey which is the deepest, wide-area radio survey to date, revealing more complex radio-source structures compared to previous surveys, presenting further challenges for machine learning algorithms. The 4- and 8-layer convolutional networks attain an average precision of 93.3% and 94.3% respectively, compared to 89.7% obtained with the capsule network, when training on original and augmented images. Implementing transfer learning achieves a precision of 94.4%, that is within the confidence interval of the 8-layer convolutional network. The convolutional networks always outperform any variation of the capsule network, as they prove to be more robust to the presence of noise in images. The use of pooling appears to allow more freedom for the intra-class variability of radio galaxy morphologies, as well as reducing the impact of noise
Bućan v.s. brend - strategije preispitivanja vizualnoga koda
Boris Bućan, prvenstveno slikar, a potom i grafički dizajner koji istovremeno nije dizajner, jer se njegove hvaljene plakate
ne može svrstati u strogu kategoriju plakata pa ih stoga poneki teoretičari i kritičari, ovisno o fazi nastanka, nazivaju antiplakatima ili negacijama plakata te čak i anti-dizajnom, a za slikarske plakate nastale 80-ih, skovan je jedinstven termin
ulična slika.
Riječ je o umjetniku koji se tijekom umjetničke karijere okušava u različitim medijima i umjetničkim izričajima –
urbane intervencije, grafički dizajn, slikarstvo, crtež, fotografija, ready made objekti, instalacije, i tako dalje. Održao
je preko 80 samostalnih i sudjelovao na više od 170 skupnih izložbi u Hrvatskoj i svijetu
Temperature Chaos in Two-Dimensional Ising Spin Glasses with Binary Couplings: a Further Case for Universality
We study temperature chaos in a two-dimensional Ising spin glass with random
quenched bimodal couplings, by an exact computation of the partition functions
on large systems. We study two temperature correlators from the total free
energy and from the domain wall free energy: in the second case we detect a
chaotic behavior. We determine and discuss the chaos exponent and the fractal
dimension of the domain walls.Comment: 5 pages, 6 postscript figures; added reference
THE PROBLEM OF DELIMITATION IN MOUNTAIN REGIONS,
It has been proved for countless number of times, including the case of Goč Mountain, that consulting geographers for various questions is obligatory. The topic of this work is the necessity of establishing borders in mountain regions and ways in which it could be performed. It also points to the fact that toponyms could create confusion. The results of the paper have led to paradox situation. By establishing borders of the Goč Mountain, it has been proved that certain, terrains close to it, which were considered to belong to Goč, are in fact on the slopes of the other mountain, and in addition to it, between them there is one more lower mountain. Namely, it is interesting that conducting an interview among local population in southeast part of the mountain contributed to the process of confirmation of the border established by applying geographic knowledge, while on the southwest part of the Goč Mountain it was not the case. Additional analysis gave the explanation for the diversity. There is no local population in southwest part of the Goč Mountain. Interview was conducting between employees in tourist facilities, forestry workers and weekenders
Large random correlations in individual mean field spin glass samples
We argue that complex systems must possess long range correlations and
illustrate this idea on the example of the mean field spin glass model. Defined
on the complete graph, this model has no genuine concept of distance, but the
long range character of correlations is translated into a broad distribution of
the spin-spin correlation coefficients for almost all realizations of the
random couplings. When we sample the whole phase space we find that this
distribution is so broad indeed that at low temperatures it essentially becomes
uniform, with all possible correlation values appearing with the same
probability. The distribution of correlations inside a single phase space
valley is also studied and found to be much narrower.Comment: Added a few references and a comment phras
Numerical solution to the hermitian Yang-Mills equation on the Fermat quintic
We develop an iterative method for finding solutions to the hermitian
Yang-Mills equation on stable holomorphic vector bundles, following ideas
recently developed by Donaldson. As illustrations, we construct numerically the
hermitian Einstein metrics on the tangent bundle and a rank three vector bundle
on P^2. In addition, we find a hermitian Yang-Mills connection on a stable rank
three vector bundle on the Fermat quintic.Comment: 25 pages, 2 figure
The nature of the different zero-temperature phases in discrete two-dimensional spin glasses: Entropy, universality, chaos and cascades in the renormalization group flow
The properties of discrete two-dimensional spin glasses depend strongly on
the way the zero-temperature limit is taken. We discuss this phenomenon in the
context of the Migdal-Kadanoff renormalization group. We see, in particular,
how these properties are connected with the presence of a cascade of fixed
points in the renormalization group flow. Of particular interest are two
unstable fixed points that correspond to two different spin-glass phases at
zero temperature. We discuss how these phenomena are related with the presence
of entropy fluctuations and temperature chaos, and universality in this model.Comment: 14 pages, 5 figures, 2 table
Assessment of Existing Steel Structures - Recommendations for Estimation of the Remaining Fatigue Life
Due to the demand for freight volume on rail and road, traffic has increased significantly in the past years leading to an increasing number of heavy vehicles in the traffic flows and greater exploitation of their loading capacities. Because of environmental considerations there is also a tendency to further enhance the admissible loads in the design of new heavy vehicles (e.g. by increasing axle loads or using road trains). This all may affect the safety, serviceability and durability of existing bridges. Bridge authorities are therefore interested in agreed methods to assess the safety and durability of existing bridges and to make appropriate provisions for more refined maintenance methods, possible restriction of traffic, bridge-rehabilitation or substitution of old bridges by new ones where necessary.
For steel bridges including the old riveted ones there are numerous approaches to such assessments, partly standardized by national codes or recommendations. In the light of the development of the European single market for construction works and engineering services there is thus a need to harmonize them and to develop agreed European technical recommendations for the safety and durability assessment of existing structures. These recommendations should follow the principles and application rules in the Eurocodes and provide a scheme with different levels of analysis: a basic level with general methods and further levels with higher sophistication that call for specific expertise.
This technical report on ¿Recommendations for the estimation of remaining fatigue life¿ supported by the ECCS could be used as a basis for harmonizing National procedures and for the further evolution of the Eurocodes.JRC.G.5-European laboratory for structural assessmen
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