96 research outputs found
Deep attention recognition for attack identification in 5G UAV scenarios: Novel architecture and end-to-end evaluation
Despite the robust security features inherent in the 5G framework, attackers will still discover ways to disrupt 5G unmanned aerial vehicle (UAV) operations and decrease UAV control communication performance in Air-to-Ground (A2G) links. Operating under the assumption that the 5G UAV communications infrastructure will never be entirely secure, we propose Deep Attention Recognition (DAtR) as a solution to identify attacks based on a small deep network embedded in authenticated UAVs. Our proposed solution uses two observable parameters: the Signal to Interference plus Noise Ratio (SINR) and the Received Signal Strength Indicator (RSSI) to recognize attacks under Line-of-Sight (LoS), Non-Line-of-Sight (NLoS), and a probabilistic combination of the two conditions.
Several attackers are located in random positions in the tested scenarios, while their power varies between simulations. Moreover, terrestrial users are included in the network to impose additional complexity on attack detection. Additionally to the application and deep network architecture, our work innovates by mixing both observable parameters inside DAtR and adding two new pre-processing and post-processing techniques embedded in the deep network results to improve accuracy. We compare several performance parameters in our proposed Deep Network. For example, the impact of Long Short-Term-Memory (LSTM) and Attention layers in terms of their overall accuracy, the window size effect, and test the accuracy when only partial data is available in the training process. Finally, we benchmark our deep network with six widely used classifiers regarding classification accuracy. The eXtreme Gradient Boosting (XGB) outperforms all other algorithms in the deep network, for instance, the three top scoring algorithms: Random Forest (RF), CatBoost (CAT), and XGB obtain mean accuracy of 83.24 \%, 85.60 \%, and 86.33\% in LoS conditions, respectively. When compared to XGB, our algorithm improves accuracy by more than 4\% in the LoS condition (90.80\% with Method 2) and by around 3\% in the short-distance NLoS condition (83.07\% with Method 1).info:eu-repo/semantics/acceptedVersio
Preprint arXiv: 2203.10027 Submitted on 18 Mar 2022
Pairing of mobile charge carriers in doped antiferromagnets plays a key role
in the emergence of unconventional superconductivity. In these strongly
correlated materials, the pairing mechanism is often assumed to be mediated by
magnetic correlations, in contrast to phonon-mediated interactions in
conventional superconductors. A precise understanding of the underlying
mechanism in real materials is, however, still lacking, and has been driving
experimental and theoretical research for the past 40 years. Early theoretical
studies established the emergence of binding among dopants in ladder systems,
where idealised theoretical toy models played an instrumental role in the
elucidation of pairing, despite repulsive interactions. Here, we realise this
long-standing theoretical prediction and report on the observation of hole
pairing due to magnetic correlations in a quantum gas microscope setting. By
engineering doped antiferromagnetic ladders with mixed-dimensional couplings we
suppress Pauli blocking of holes at short length scales. This results in a
drastic increase in binding energy and decrease in pair size, enabling us to
observe pairs of holes predominantly occupying the same rung of the ladder. We
find a hole-hole binding energy on the order of the superexchange energy, and,
upon increased doping, we observe spatial structures in the pair distribution,
indicating repulsion between bound hole pairs. By engineering a configuration
in which binding is strongly enhanced, we delineate a novel strategy to
increase the critical temperature for superconductivity
Gamma Radiation Absorption Characteristics of Concrete with Components of Different Type Materials
Nuclear facilities as nuclear power stations, nuclear research reactors, particle accelerators and linear accelerator in medical institution using concrete in building construction. The different type materials of the aggregate as component of concrete were analyzed to provide radiation protection. The energy deposited the transmission factor and the mass attenuation coefficients in ordinary and barite concretes have been calculated with the photon transport Monte Carlo software. The numerical simulations results show that using barite as an aggregate in the concrete is one of the solutions for gamma ray shielding. Thereat, it is shown non-destructive method for determining the gamma radiation absorption characteristics of concrete.11th Annual Conference of the Materials-Research-Society-of-Serbia (YUCOMAT 2009), Aug 31-Sep 04, 2009, Herceg Novi, Montenegr
Seasonal forecasts of the rainy season onset over Africa: Preliminary results from the FOCUS-Africa project
Precipitation seasonality is the main factor controlling vegetation phenology in many tropical and subtropical regions. Anticipating the rain onset is of paramount importance for field preparation and seeding. This is of particular importance in various African countries that rely on agriculture as a main source of food, subsistence and income. In such countries, skilful and accurate onset forecasts could also inform early warning and early actions, such as aids logistics planning, for food security. Here, we assess the skill of the seasonal forecast data provided by the Copernicus Climate Change Service in predicting the rain onset over Africa. The skill, i.e. the accuracy of the seasonal forecasts simulation ensemble compared to the climatology, is computed in a probabilistic fashion by accounting for the frequencies of normal, early and late onsets predicted by the forecast system. We compute the skill using the hindcasts (forecast simulations conducted for the past) starting at the beginning of each month in the period 1993–2016. We detect the onset timing of the rainy season using a non-parametric method that accounts for double seasonality and is suitable for the specific time-window of the seasonal forecast simulations. We find positive skills in some key African agricultural regions some months in advance. Overall, the multi-model ensemble outperforms any individual model ensemble. We provide targeted recommendations to develop a useful climate service for the agricultural sector in Africa
Routes to sustainability in public food procurement: An investigation of different models in primary school catering
Increasingly, policymakers are setting ambitious goals for sustainability in public procurement, integrated across different pillars. Such ambitions are apparent in public catering services, where procurement models have been shifting towards greater localisation of supply chains and purchasing of more organically grown food. To date however, few studies have examined empirically what the impacts of different procurement models are across these multiple pillars of sustainability. This research aimed to fill the gap, by measuring and comparing the environmental, economic and nutritional outcomes of different models of school meals procurement. Case studies were undertaken of ten primary school meals services in five European countries, capturing different procurement model types. Results showed carbon emissions ranged from 0.95 kgs CO2e per meal in the lowest case to 2.41 kgs CO2e in the highest case, with adoption of low carbon food waste disposal methods and reduction of the amount of ruminant meat in the menus being the most important actions for lowering emissions. In terms of economic impact, local economic multiplier ratios ranged from 1.59 to 2.46, and although the level of local food sourcing contributed to these ratios, the effect was eclipsed, in some cases, by investment in local catering staff. Meanwhile, implementation of a robust standards regime and improving canteen environment and supervision were the most important actions for nutritional quality and intake. The paper discusses the implications of the findings for integrated, sustainable models of food procurement
Structural Modeling and DNA Binding Autoinhibition Analysis of Ergp55, a Critical Transcription Factor in Prostate Cancer
BACKGROUND: The Ergp55 protein belongs to Ets family of transcription factor. The Ets proteins are highly conserved in their DNA binding domain and involved in various development processes and regulation of cancer metabolism. To study the structure and DNA binding autoinhibition mechanism of Ergp55 protein, we have produced full length and smaller polypeptides of Ergp55 protein in E. coli and characterized using various biophysical techniques. RESULTS: The Ergp55 polypeptides contain large amount of α-helix and random coil structures as measured by circular dichorism spectroscopy. The full length Ergp55 forms a flexible and elongated molecule as revealed by molecular modeling, dynamics simulation and structural prediction algorithms. The binding analyses of Ergp55 polypeptides with target DNA sequences of E74 and cfos promoters indicate that longer fragments of Ergp55 (beyond the Ets domain) showed the evidence of auto-inhibition. This study also revealed the parts of Ergp55 protein that mediate auto-inhibition. SIGNIFICANCE: The current study will aid in designing the compounds that stabilize the inhibited form of Ergp55 and inhibit its binding to promoter DNA. It will contribute in the development of drugs targeting Ergp55 for the prostate cancer treatment
In Pursuit of Impact: How Psychological Contract Research Can Make the Work-World a Better Place
This paper is the result of the collective work undertaken by a group of Psychological Contract (PC) and Sustainability scholars from around the world, following the 2023 Bi-Annual PC Small Group Conference (Kedge Business School, Bordeaux, France). As part of the conference, scholars engaged in a workshop designed to generate expert guidance on how to aid the PC field to be better aligned with the needs of practice, and thus, impact the creation and maintenance of high-quality and sustainable exchange processes at work. In accordance with accreditation bodies for higher education, research impact is not limited to academic papers alone but also includes practitioners, policymakers, and students in its scope. This paper therefore incorporates elements from an impact measurement tool for higher education in management so as to explore how PC scholars can bolster the beneficial influence of PC knowledge on employment relationships through different stakeholders and means. Accordingly, our proposals for the pursuit of PC impact are organized in three parts: (1) research, (2) practice and society, and (3) students. Further, this paper contributes to the emerging debate on sustainable PCs by developing a construct definition and integrating PCs with an ‘ethics of care’ perspective
Application of a precise fiber-optical dee position measurement system in the cyclotron RF system design
A new fiber-optical dee position measurement system is developed for the VINCY cyclotron. The system includes a sensor head, a coherent optical fiber bundle and a light detector with control electronics. The sensor head is placed in the dee, all the electronic components are placed out of the vacuum chamber of the machine, while the position information is carried by the optical fiber bundle. Two sensor heads on the dee enable the measurement of the position of the dee tip in all three dimensions, as well as the twist of the dee, with a resolution better than 50 mu m. The precise dee position measurement can be useful for beam optimization, study of sparking phenomena, and study of phenomena causing errors in RF cavity geometry (vacuum, heating, etc.) These points tend to be even more important in future high current machines. (C) 1999 Elsevier Science B.V. All rights reserved
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