A Discrete Event Simulation Based Approach for Digital Twin Implementation

Nowadays, manufacturing companies need to improve their production monitoring and prediction to be more flexible and re-configurable. To do so, the digitization of the manufacturing environment is a very critical issue. This paper proposes an approach to develop digital twins in this environment. Digital twins are virtual systems, real time connected with their physical counterpart, which replicate exactly their behaviour. Discrete event simulation models, connected in real-time with their real system counterparts, are developed in this work. Two industrial use cases are analysed, to show the benefits that this promising technology can bring to the manufacturing industry

Fine-tuning or top-tuning? Transfer learning with pretrained features and fast kernel methods

The impressive performances of deep learning architectures is associated to massive increase of models complexity. Millions of parameters need be tuned, with training and inference time scaling accordingly. But is massive fine-tuning necessary? In this paper, focusing on image classification, we consider a simple transfer learning approach exploiting pretrained convolutional features as input for a fast kernel method. We refer to this approach as top-tuning, since only the kernel classifier is trained. By performing more than 2500 training processes we show that this top-tuning approach provides comparable accuracy w.r.t. fine-tuning, with a training time that is between one and two orders of magnitude smaller. These results suggest that top-tuning provides a useful alternative to fine-tuning in small/medium datasets, especially when training efficiency is crucial

Effect of high level of bladder filling on spinal nociception and motoneuronal excitability

To verify whether high level of bladder distension may counteract the inhibitory effect of descending pathways on sacral spinal cord neurons and to investigate which spinal circuitries are possibly involved in such a viscero-somatic interaction. Nociceptive withdrawal reflex (NWR), cutaneous silent period (CSP), and H-reflex were recorded in both lower and upper limbs of twenty-eight healthy subjects. Subjects were examined during baseline (empty bladder, no voiding desire), high level of bladder filling (urgency desire), and control (empty bladder, no voiding desire) sessions. Results showed that the NWR and its related pain perception were reduced in the upper limbs, while only a pain perception reduction in males was observed in the lower limbs. The H-reflex was inhibited in both limbs. No effects were found on the CSP duration. The decrease in both the NWR and its related pain perception in the upper limbs confirms the presence of a bladder distension-induced descending inhibitory modulation on nociception at spinal level. The lack of a similar inhibitory effect in the lower limbs suggests that excitatory nociceptive inputs from bladder afferents counterbalance the inhibitory effect on sacral spinal cord. The lack of the descending inhibitory effect may be a mechanism aimed at forcing the micturition phase to avoid bladder damage caused by bladder sovradistension

Egas Moniz: 90 years (1927-2017) from cerebral angiography

In June 2017 we celebrate the 90th anniversary of the pioneer discovery of cerebral angiography, the seminal imaging technique used for visualizing cerebral blood vessels and vascular alterations as well as other intracranial disorders. Egas Moniz (1874-1955) was the first to describe the use of this revolutionary technique which, until 1975 (when computed tomography, CT, scan was introduced in the clinical practice), was the sole diagnostic tool to provide an imaging of cerebral vessels and therefore alterations due to intracranial pathology. Moniz introduced in the clinical practice this fundamental and important diagnostic tool. The present contribution wishes to pay a tribute to the Portuguese neurosurgeon, who was also a distinguished neurologist and statesman. Despite his tremendous contribution in modern brain imaging, Egas Moniz was awarded the Nobel Prize in Physiology or Medicine in 1949 for prefrontal leucotomy, the neurosurgical intervention nowadays unacceptable, but should rather be remembered for his key contribution to modern brain imaging. KEYWORDS

Efficient Unsupervised Learning for Plankton Images

Monitoring plankton populations in situ is fundamental to preserve the aquatic ecosystem. Plankton microorganisms are in fact susceptible of minor environmental perturbations, that can reflect into consequent morphological and dynamical modifications. Nowadays, the availability of advanced automatic or semi-automatic acquisition systems has been allowing the production of an increasingly large amount of plankton image data. The adoption of machine learning algorithms to classify such data may be affected by the significant cost of manual annotation, due to both the huge quantity of acquired data and the numerosity of plankton species. To address these challenges, we propose an efficient unsupervised learning pipeline to provide accurate classification of plankton microorganisms. We build a set of image descriptors exploiting a two-step procedure. First, a Variational Autoencoder (VAE) is trained on features extracted by a pre-trained neural network. We then use the learnt latent space as image descriptor for clustering. We compare our method with state-of-the-art unsupervised approaches, where a set of pre-defined hand-crafted features is used for clustering of plankton images. The proposed pipeline outperforms the benchmark algorithms for all the plankton datasets included in our analysis, providing better image embedding properties

Late aortic lymphocele and residual ovary syndrome after gynecological surgery

<p>Abstract</p> <p>Background</p> <p>Gynecological surgery, as radical hysterectomy or pelvic and aortic lymphadenectomy, accounts for more than 50% of iatrogenic injuries. In premenopausal women, an hysterectomy with ovarian sparing and concomitant lateral ovarian transposition is frequently performed. However, the fate of the retained ovary is complicated by the residual ovarian syndrome (ROS) and one of the most common postoperative complications of the lymphadenectomy procedure is the lymphocele, with an average incidence of 22–48.5%. The differential diagnosis of a postoperative fluid collection includes, in addition to a lymphocele, urinoma, hematoma, seroma or abscess and the computed tomography (CT) findings alone is not enough.</p> <p>Case presentation</p> <p>We describe a patient, affected by ROS concomitant with a asymptomatic lymphocele, initially confused with an aortic lymph nodes relapse, after abdominal radical hysterectomy. The patient was subjected to a surgical approach, included a diagnostic open laparoscopy and laparotomy with sovraombelico-pubic incision, wide opening of the pelvic peritoneum and retroperitoneum. Examination of the mass revealed, macroscopically, a ovary with multiloculated cystic masses filled with clear or yellow serous fluid and the layers were composed by flat or cuboidal mesothelial cells.</p> <p>Conclusion</p> <p>The tribute of this case illustrates the atypical appearance with uncertain aetiology after complex imaging. Gynecologist and radiologist should acquaint with the appearance of fluid collection (urinoma, lymphocele, seroma, hematoma, abscess) in gynecologic oncology follow-up to properly differentiated from tumor recurrence.</p

Non-phenomenological description of the time-resolved emission in solution with quantum-classical vibronic approaches-application to coumarin C153 in methanol

We report a joint experimental and theoretical work on the steady-state spectroscopy and time-resolved emission of the coumarin C153 dye in methanol. The lowest energy excited state of this molecule is characterized by an intramolecular charge transfer thus leading to remarkable shifts of the time-resolved emission spectra, dictated by the methanol reorganization dynamics. We selected this system as a prototypical test case for the first application of a novel computational protocol aimed at the prediction of transient emission spectral shapes, including both vibronic and solvent effects, without applying any phenomenological broadening. It combines a recently developed quantum–classical approach, the adiabatic molecular dynamics generalized vertical Hessian method (Ad-MD (Formula presented.) VH), with nonequilibrium molecular dynamics simulations. For the steady-state spectra we show that the Ad-MD|gVH approach is able to reproduce quite accurately the spectral shapes and the Stokes shift, while a ∼0.15 eV error is found on the prediction of the solvent shift going from gas phase to methanol. The spectral shape of the time-resolved emission signals is, overall, well reproduced, although the simulated spectra are slightly too broad and asymmetric at low energies with respect to experiments. As far as the spectral shift is concerned, the calculated spectra from 4 ps to 100 ps are in excellent agreement with experiments, correctly predicting the end of the solvent reorganization after about 20 ps. On the other hand, before 4 ps solvent dynamics is predicted to be too fast in the simulations and, in the sub-ps timescale, the uncertainty due to the experimental time resolution (300 fs) makes the comparison less straightforward. Finally, analysis of the reorganization of the first solvation shell surrounding the excited solute, based on atomic radial distribution functions and orientational correlations, indicates a fast solvent response (≈100 fs) characterized by the strengthening of the carbonyl–methanol hydrogen bond interactions, followed by the solvent reorientation, occurring on the ps timescale, to maximize local dipolar interactionsThis research was funded by ICSC—Centro Nazionale di Ricerca in High Performance Computing, Big Data and Quantum Computing, funded by European Union—NextGenerationEU— PNRR, Missione 4 Componente 2 Investimento 1.4 (F.S and G.P); MICINN Project PID2019-110091GBI00 (JC); H2020-LC-SC3-2020-RES-RIA-101006839 project “CONDOR” and MUR-PNRR (NEST— Network 4 Energy Sustainable Transition, Estended Partnership—PE000002 (SG, BV and NA