145 research outputs found
Vegetarian architecture. Case studies on building and nature
What is “good” architecture? This seemingly simple question is connected to a wide range of criteria—just like the radical quest for “good” food, which has produced a wealth of insights over the past few decades.
Vegetarian Architecture showcases buildings based on simple technology, good craftsmanship, and careful choice of local and natural materials, as well as local development initiatives which demonstrate excellence in building quality, landscape restoration, and community revitalisation. The selection of case studies is broad and definitely unconventional: it encompasses Europe and Japan, and privileges lesser-known authors, unobtrusive works, and marginal localities where radically fresh attitudes have been able to develop
Simplified Quantum Process Characterization by Specialised Neural Networks
Characterization of quantum objects based on previous knowledge is a valuable
approach, especially as it leads to routine procedures for real-life
components. To this end, Machine Learning algorithms have demonstrated to
successfully operate in presence of noise. However, there might be instances in
which unknown parasitic effects occur in tandem with the sought one we aim at
characterizing. Here we show that the accurate design of a two-stage neural
network can account for these class of disturbances as well, applying our
technique to the characterization of several quantum channels. We demonstrate
that a stable and reliable characterization is achievable by training the
network only with simulated data. The obtained results show the viability of
this approach as an effective tool based on a completely new paradigm for the
employment of NNs in the quantum domain
The Probabilistic Random Forest applied to the selection of quasar candidates in the QUBRICS Survey
The number of known, bright () QSOs in the
Southern Hemisphere is considerably lower than the corresponding number in the
Northern Hemisphere due to the lack of multi-wavelength surveys at .
Recent works, such as the QUBRICS survey, successfully identified new,
high-redshift QSOs in the South by means of a machine learning approach applied
on a large photometric dataset. Building on the success of QUBRICS, we present
a new QSO selection method based on the Probabilistic Random Forest (PRF), an
improvement of the classic Random Forest algorithm. The PRF takes into account
measurement errors, treating input data as probability distribution functions:
this allows us to obtain better accuracy and a robust predictive model. We
applied the PRF to the same photometric dataset used in QUBRICS, based on the
SkyMapper DR1, Gaia DR2, 2MASS, WISE and GALEX databases. The resulting
candidate list includes sources with . We estimate for our proposed
algorithm a completeness of and a purity of on the test
datasets. Preliminary spectroscopic campaigns allowed us to observe 41
candidates, of which 29 turned out to be QSOs. The performances of the
PRF, currently comparable to those of the CCA, are expected to improve as the
number of high-z QSOs available for the training sample grows: results are
however already promising, despite this being one of the first applications of
this method to an astrophysical context.Comment: Accepted for publication in MNRAS, 12 pages, 11 figures, 4 table
Characterizing multisegment foot kinematics during gait in diabetic foot patients
<p>Abstract</p> <p>Background</p> <p>The prevalence of diabetes mellitus has reached epidemic proportions, this condition may result in multiple and chronic invalidating long term complications. Among these, the diabetic foot, is determined by the simultaneous presence of both peripheral neuropathy and vasculopathy that alter the biomechanics of the foot with the formation of callosity and ulcerations. To diagnose and treat the diabetic foot is crucial to understand the foot complex kinematics. Most of gait analysis protocols represent the entire foot as a rigid body connected to the shank. Nevertheless the existing multisegment models cannot completely decipher the impairments associated with the diabetic foot.</p> <p>Methods</p> <p>A four segment foot and ankle model for assessing the kinematics of the diabetic foot was developed. Ten normal subjects and 10 diabetics gait patterns were collected and major sources of variability were tested. Repeatability analysis was performed both on a normal and on a diabetic subject. Direct skin marker placement was chosen in correspondence of 13 anatomical landmarks and an optoelectronic system was used to collect the data.</p> <p>Results</p> <p>Joint rotation normative bands (mean plus/minus one standard deviation) were generated using the data of the control group. Three representative strides per subject were selected. The repeatability analysis on normal and pathological subjects results have been compared with literature and found comparable. Normal and pathological gait have been compared and showed major statistically significant differences in the forefoot and midfoot dorsi-plantarflexion.</p> <p>Conclusion</p> <p>Even though various biomechanical models have been developed so far to study the properties and behaviour of the foot, the present study focuses on developing a methodology for the functional assessment of the foot-ankle complex and for the definition of a functional model of the diabetic neuropathic foot. It is, of course, important to evaluate the major sources of variation (true variation in the subject's gait and artefacts from the measurement procedure). The repeatability of the protocol was therefore examined, and results showed the suitability of this method both on normal and pathological subjects. Comparison between normal and pathological kinematics analysis confirmed the validity of a similar approach in order to assess neuropathics biomechanics impairment.</p
Multifractal fluctuations in the survival probability of an open quantum system
We predict a multifractal behaviour of transport in the deep quantum regime
for the opened kicked rotor model. Our analysis focuses on
intermediate and large scale correlations in the transport signal and
generalizes previously found parametric {\em mono}-fractal fluctuations in the
quantum survival probability on small scales.Comment: 8 pages, 3 figures, 2 tables. Physica A, accepted 200
Can quantum fractal fluctuations be observed in an atom-optics kicked rotor experiment?
We investigate the parametric fluctuations in the quantum survival
probability of an open version of the delta-kicked rotor model in the deep
quantum regime. Spectral arguments [Guarneri I and Terraneo M 2001 Phys. Rev. E
vol. 65 015203(R)] predict the existence of parametric fractal fluctuations
owing to the strong dynamical localisation of the eigenstates of the kicked
rotor. We discuss the possibility of observing such dynamically-induced
fractality in the quantum survival probability as a function of the kicking
period for the atom-optics realisation of the kicked rotor. The influence of
the atoms' initial momentum distribution is studied as well as the dependence
of the expected fractal dimension on finite-size effects of the experiment,
such as finite detection windows and short measurement times. Our results show
that clear signatures of fractality could be observed in experiments with cold
atoms subjected to periodically flashed optical lattices, which offer an
excellent control on interaction times and the initial atomic ensemble.Comment: 18 pp, 7 figs., 1 tabl
Spectroscopy of QUBRICS quasar candidates: 1672 new redshifts and a Golden Sample for the Sandage Test of the Redshift Drift
The QUBRICS (QUasars as BRIght beacons for Cosmology in the Southern
hemisphere) survey aims at constructing a sample of the brightest quasars with
z>~2.5, observable with facilities in the Southern Hemisphere. QUBRICS makes
use of the available optical and IR wide-field surveys in the South and of
Machine Learning techniques to produce thousands of bright quasar candidates of
which only a few hundred have been confirmed with follow-up spectroscopy.
Taking advantage of the recent Gaia Data Release 3, which contains 220 million
low-resolution spectra, and of a newly developed spectral energy distribution
fitting technique, designed to combine the photometric information with the
Gaia spectroscopy, it has been possible to measure 1672 new secure redshifts of
QUBRICS candidates, with a typical uncertainty . This
significant progress of QUBRICS brings it closer to (one of) its primary goals:
providing a sample of bright quasars at redshift 2.5 < z < 5 to perform the
Sandage test of the cosmological redshift drift. A Golden Sample of seven
quasars is presented that makes it possible to carry out this experiment in
about 1500 hours of observation in 25 years, using the ANDES spectrograph at
the 39m ELT, a significant improvement with respect to previous estimates.Comment: 11 pages, 10 figures, accepted for publication in MNRA
Simplified electrophysiological evaluation of peripheral nerves in critically ill patients: the Italian multi-centre CRIMYNE study
Stereotactic Ablative Radiotherapy for stage I histologically proven non-small cell lung cancer: An Italian multicenter observational study.
Utility of neutrophil-to-lymphocyte ratio to identify long-term survivors among HCC patients treated with sorafenib
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