National Centre of Scientific Research "Demokritos"

About: National Centre of Scientific Research "Demokritos" is a facility organization based out in Athens, Greece. It is known for research contribution in the topics: Computer science & Aerosol. The organization has 471 authors who have published 640 publications receiving 14478 citations. The organization is also known as: Demokritos.

Drug-Drug Interaction Prediction on a Biomedical Literature Knowledge Graph

Abstract: Knowledge Graphs provide insights from data extracted in various domains. In this paper, we present an approach discovering probable drug-to-drug interactions, through the generation of a Knowledge Graph from disease-specific literature. The Graph is generated using natural language processing and semantic indexing of biomedical publications and open resources. The semantic paths connecting different drugs in the Graph are extracted and aggregated into feature vectors representing drug pairs. A classifier is trained on known interactions, extracted from a manually curated drug database used as a golden standard, and discovers new possible interacting pairs. We evaluate this approach on two use cases, Alzheimer’s Disease and Lung Cancer. Our system is shown to outperform competing graph embedding approaches, while also identifying new drug-drug interactions that are validated retrospectively.

Differentiation of coarse-mode anthropogenic, marine and dust particles in the High Arctic islands of Svalbard

Abstract: . Understanding aerosol–cloud–climate interactions in the Arctic is key to predicting the climate in this rapidly changing region. Whilst many studies have focused on submicrometer aerosol (diameter less than 1 µ m), relatively little is known about the supermicrometer aerosol (diameter above 1 µ m). Here, we present a cluster analysis of multiyear (2015–2019) aerodynamic volume size distributions, with diameter ranging from 0.5 to 20 µ m, measured continuously at the Gruvebadet Observatory in the Svalbard archipelago. Together with aerosol chemical composition data from several online and offline measurements, we apportioned the occurrence of the coarse-mode aerosols during the study period (mainly from March to October) to anthropogenic (two sources, 27 %) and natural (three sources, 73 %) origins. Specifically, two clusters are related to Arctic haze with high levels of black carbon, sulfate and accumulation mode (0.1–1 µ m) aerosol. The first cluster (9 %) is attributed to ammonium sulfate-rich Arctic haze particles, whereas the second one (18 %) is attributed to larger-mode aerosol mixed with sea salt. The three natural aerosol clusters were open-ocean sea spray aerosol (34 %), mineral dust (7 %) and an unidentified source of sea spray-related aerosol (32 %). The results suggest that sea-spray-related aerosol in polar regions may be more complex than previously thought due to short- and long-distance origins and mixtures with Arctic haze, biogenic and likely blowing snow aerosols. Studying supermicrometer natural aerosol in the Arctic is imperative for understanding the impacts of changing natural processes on Arctic aerosol.

Reconfigurable proximity coupled patch antenna using magnetic bias

Abstract: In this paper, we present the design, fabrication and characterization measurements of a proximity-coupled fed patch antenna that uses a ferrimagnetic compound, Yttrium Iron Garnet (YIG), as part of its substrate. External magnetic field is applied in order to achieve reconfigurability. Specifically, by applying a suitable external magnetic field, the linearly polarized single-band antenna exhibits dual-band behavior. Furthermore, it is proved via simulation and experimental measurements that we can achieve antenna polarization reconfigurability.

An SINR balancing based multiuser relaying scheme

Abstract: We consider a relay network with multiple users and propose a signal-to-interference and noise-ratio (SINR) balancing based relay signal forwarding scheme. Each relay receives a combined signal from multiple sources and processes it using a complex valued scalar and transmits towards the destinations so that the SINR at the receiver of each user is maximised. We solve this problem using semidefinite and geometric programming along with bisection search methods. The performance of the proposed scheme has been studied in terms of worst case SINR for various numbers of users and relays.

An ODL system and Virtual Class for the electrical engineering sector

Abstract: The rapid development of information and communication technologies (ICTs) and the move towards more knowledge-intensive, interdependent and internationalized societies created new challenges and opportunities for the design and delivery of education. This evolution also influenced the educational branches of life long training, continuing vocational training and distance training. This paper presents an e-training system which gives information about contemporary electrical installations simulating them as a virtual class. The presented material is organized into four separate courses because each one describes different features of electrical installations and has its own importance. The type of information provided, is both theoretical and practical. Moreover, this paper projects a market research on training needs of the electrical engineering sector across four EU countries. All the above, are implemented with new digital technology methods, using multimedia content management techniques and Open and Distance Learning (ODL) principles. Its main goal is to transfer knowledge to the electricians' workforce in order to achieve their adaptation to the transition from conventional installation technology to an intelligent one.