•Pseudo-labeling as a strategy to annotate unsupervised samples from only 1% of supervised samples.•A semi-supervised pseudo-labeling approach to reduce human effort in data annotation.•Learning ...features and labels from multiple pseudo-labeling iterations.•Exploiting 2D non-linear projections and connectivity-based information for data annotation.•Clustering-based metric to select the optimal-learned model for generalization.
Display omitted
The absence of large annotated datasets to train deep neural networks (DNNs) is an issue since manual annotation is time-consuming, expensive, and error-prone. Semi-supervised learning techniques can address the problem propagating pseudo labels from supervised to unsupervised samples. However, they still require training and validation sets with many supervised samples. This work proposes a methodology, namely Deep Feature Annotation (DeepFA), that dismisses the validation set and uses very few supervised samples (e.g., 1% of the dataset). DeepFA modifies the feature spaces of a DNN along with meta-pseudo-labeling iterations in a 2D non-linear projection space using the most confidently labeled samples of an optimum-path forest semi-supervised classifier. We present a comprehensive study on DeepFA and a new variant that detects the best DNN model for generalization during the pseudo-labeling iterations. We evaluate components of DeepFA on eight datasets, finding the best DeepFA approach and showing that it outperforms self-pseudo-labeling.
•Feature space projections to increase semi-supervised learning.•Data annotation using feature space projections outperforms automatic methods.•Combining automatic and user-driven labeling methods ...improves annotation and classification results.•Confidence measures reduce human labeling effort as compared to fully-manual labeling.
Display omitted
Data annotation using visual inspection (supervision) of each training sample can be laborious. Interactive solutions alleviate this by helping experts propagate labels from a few supervised samples to unlabeled ones based solely on the visual analysis of their feature space projection (with no further sample supervision). We present a semi-automatic data annotation approach based on suitable feature space projection and semi-supervised label estimation. We validate our method on the popular MNIST dataset and on images of human intestinal parasites with and without fecal impurities, a large and diverse dataset that makes classification very hard. We evaluate two approaches for semi-supervised learning from the latent and projection spaces, to choose the one that best reduces user annotation effort and also increases classification accuracy on unseen data. Our results demonstrate the added-value of visual analytics tools that combine complementary abilities of humans and machines for more effective machine learning.
Background: Dermatological conditions are a very common presentation of pet rabbits to the veterinarian. The aetiology varies; problems such as pododermatitis and parasitic and bacterial infections ...constitute a higher percentage of these cases, while viral infections are considered less common. Stress and pain also play an important role and should be considered during the initial consultation and treatment planning.Aim of the article: This article provides an overview of skin diseases that may be presented to general veterinary practitioners, helping the practitioner to approach these cases with more confidence.
The discovery of neutrinoless ββ decay could soon be within reach. This hypothetical ultrarare nuclear decay offers a privileged portal to physics beyond the standard model of particle physics. Its ...observation would constitute the discovery of a matter-creating process, corroborating leading theories of why the Universe contains more matter than antimatter, and how forces unify at high energy scales. It would also prove that neutrinos and antineutrinos are not two distinct particles but can transform into each other, with their mass described by a unique mechanism conceived by Majorana. The recognition that neutrinos are not massless necessitates an explanation and has boosted interest in neutrinoless ββ decay. The field stands now at a turning point. A new round of experiments is currently being prepared for the next decade to cover an important region of parameter space. In parallel, advances in nuclear theory are laying the groundwork to connect the nuclear decay with the underlying new physics. Meanwhile, the particle theory landscape continues to find new motivations for neutrinos to be their own antiparticle. This review brings together the experimental, nuclear theory, and particle theory aspects connected to neutrinoless ββ decay to explore the path toward, and beyond, its discovery.
The work presents an in-depth analysis of the real performance of an air heat pump unit installed in a single-family building and quantitatively determines the reduction in energy consumption ...achieved by the integration of an air-geothermal heat exchanger. The case study is a single-family building located in northern Italy. It is equipped with a heating, ventilation, and air conditioning (HVAC) system consisting of an air-geothermal heat exchanger coupled with a compact air source heat pump supported by an electric heater installed in a thermal storage and devoted to cover the peak demand. The main objectives of the work are to analyse the HVAC performance under real operating conditions compared to the design values and to highlight the existence of factors that affect this performance. The analysis was carried out by developing an accurate model of the heat pump system based on the real operating data acquired by the on-board monitoring system. The results confirmed the influence of the air-inlet conditions (temperature and humidity) and of the control strategy (more specifically, the ventilation flow rate) on the unit performance in both the heating and cooling modes. In particular, the analysis showed that minimising indoor ventilation in the case of low outdoor temperatures is of paramount relevance not only because it reduces the indoor heat demand, but also because it maintains the unit efficiency close to the design values. Furthermore, the installation of a geothermal heat exchanger guarantees a reduction in electricity consumption of approximately 30%.
•The performance of an air heat pump is analysed in real operating conditions.•The heat pump is installed in a single-family building located in northern Italy.•Real performance is compared to the manufacturer's data.•The control strategy of the ventilation system significantly affects the performance of the system.•Integrating an air-geothermal heat exchanger allows a 30% reduction in electricity consumption.
Despite biogas renewability, it is mandatory to experimentally assess its combustion products in order to measure their pollutants content. To this purpose, the Authors selected six in-operation ...biogas plants fed by different substrates and perform an on-site experimental campaign for measuring both biogas and engines exhausts composition. Firstly, biogas measured compositions are compared among them and with data available in literature. Then, biogas engines’ exhaust compositions are compared among them, with data available in literature and with measurements obtained from an engine characterised by the same design power but fuelled with natural gas. Finally, the Health Impact Assessment analysis is used to estimate the damage on human health caused by both biogas and natural gas engines emissions. Results show that biogas causes a damage on human health three times higher than the natural gas one. But, this approach does not consider biogas renewability. So, to include this important aspect, also an analysis which considers Global Warming categories is carried out. Results highlight that natural gas is twice harmful than biogas.
Resumo: Este artigo nasceu do “desassossego”, como diria Fernando Pessoa. Aqueles que conhecem o trabalho de Ibn ‘Arabī sabem da importância do feminino no seu pensamento e na consolidação das suas ...experiências espirituais. No entanto, ele também afirma que a mulher é segunda ao homem, surge de uma costela deste e lhe é inferior em um grau. Natural o desassossego, uma sensação de pinçamento cirúrgico e dolorido que não apenas inquieta a alma, mas penetra silenciosamente na sua carne mais profunda. Desfazer este nó intangível - mas opressor - é o que vamos tentar aqui, usando as próprias palavras do Šayḫ como fio condutor, a partir de seus vários conceitos associados à “triplicidade” como fundamento da vida.
Abstract: This article springs out of a “disquietness”, as Fernando Pessoa would say. Those who are familiar with Ibn ‘Arabī’s work know how important is the feminine in his thought as well in the consolidation of his spiritual experiences. However, he also states that the woman is second to man, rises from his rib and is one degree inferior to him. The “disquietness” so happen, naturally, as a sensation of a surgical and painful clamping that not only distresses the soul, but silently penetrates into its deepest flesh. To untie this intangible - but oppressive - knot, is what we will try here, by using the Sheikh’s very words as a guiding thread, looking for the various forms where his concept of triplicity shows up as foundation of life.
Renewable energy sources are the most useful way to generate clean energy and guide the transition toward green power generation and a low-carbon economy. Among renewables, the best alternative to ...electricity generation from fossil fuels is solar energy because it is the most abundant and does not release pollutants during conversion processes. Despite the photovoltaic (PV) module ability to produce electricity in an eco-friendly way, PV cells are extremely sensitive to temperature increments. This can result in efficiency drop of 0.25%/ ∘ C to 0.5%/ ∘ C. To overcome this issue, manufacturers and researchers are devoted to the improvement of PV cell efficiency by decreasing operating temperature. For this purpose, the authors have developed a low-cost and high-performance PV cooling system that can drastically reduce module operating temperature. In the present work, the authors present a set of experimental measurements devoted to selecting the PV cooling arrangement that guarantees the best compromise of water-film uniformity, module temperature reduction, water-consumption minimization, and module power production maximization. Results show that a cooling system equipped with 3 nozzles characterized by a spraying angle of 90 ∘ , working with an inlet pressure of 1.5 bar, and which remains active for 30 s and is switched off for 120 s, can reduce module temperature by 28 ∘ C and improve the module efficiency by about 14%. In addition, cost per single module of the cooling system is only 15 €.
In power systems, the steady-state operations following any disturbance can be assessed by means of time-domain simulations, which consider the dynamic of the system without simplifying hypotheses. ...This paper proposes a formulation of the power flow problem with distributed slack bus model able to determine the steady-state impact on frequency and generation set-points of primary and secondary frequency regulation. This is done by deriving the real power balance expressions (including power losses, primary/secondary regulation, and the real frequency deviation) before and after the occurrence of any event or disturbance. This is achieved without resorting to the solution of a time-domain simulation. The performance of the proposed formulation is discussed through the standard WSCC 9-bus system and a 102-bus model of the Sicilian grid. Solutions are compared with those obtained with conventional time-domain simulations.
It is widely ascertained that the multiconductor analysis is a powerful tool which can solve any structurally complex circuit (e.g., high-speed railway supply system, gas insulated lines, etc.). ...Moreover, this method can be also used as an in-depth analysis of the electric networks after the power-flow studies when they introduce simplifying hypotheses especially in the presence of asymmetry. In this paper, the multiconductor cell analysis has been applied to AC underground cable lines (UGC). This multiconductor procedure based on the use of
admittance matrices, which account for the
line cells (with earth return currents), different types of sheath bonding, possible multiple circuits, allows predicting the steady-state (and faulty) regime of any cable system. The method calculates the proportion and behavior of the phase currents carried by each parallel conductor, the circulating current in the sheath of each cable and the stray current in the earth. Moreover, some comparisons have been made with traditional programs showing the great accuracy of multiconductor cell model.
PDF
