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1.
Sensors (Basel) ; 23(6)2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36991830

RESUMO

This paper presents a comprehensive investigation of machine learning-based intrusion detection methods to reveal cyber attacks in railway axle counting networks. In contrast to the state-of-the-art works, our experimental results are validated with testbed-based real-world axle counting components. Furthermore, we aimed to detect targeted attacks on axle counting systems, which have higher impacts than conventional network attacks. We present a comprehensive investigation of machine learning-based intrusion detection methods to reveal cyber attacks in railway axle counting networks. According to our findings, the proposed machine learning-based models were able to categorize six different network states (normal and under attack). The overall accuracy of the initial models was ca. 70-100% for the test data set in laboratory conditions. In operational conditions, the accuracy decreased to under 50%. To increase the accuracy, we introduce a novel input data-preprocessing method with the denoted gamma parameter. This increased the accuracy of the deep neural network model to 69.52% for six labels, 85.11% for five labels, and 92.02% for two labels. The gamma parameter also removed the dependence on the time series, enabled relevant classification of data in the real network, and increased the accuracy of the model in real operations. This parameter is influenced by simulated attacks and, thus, allows the classification of traffic into specified classes.

2.
J Environ Manage ; 264: 110461, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32250894

RESUMO

The projected increase of the world's population and the sustainability challenges the agricultural sector is facing, call for the enhancement of multi-functionality in agriculture in order to simultaneously provide food while meeting environmental targets. Here, we use the Functional Land Management (FLM) framework to assess the supply of and the demand for soil functions to inform agri-environmental policy for Udalo, a mountainous site in the Philippines. As many emerging communities in developing nations, Udalo is on the cusp of rapid development due to the construction of a major road increasing its accessibility and attractiveness for land investment. We assessed the supply of four soil functions in relation to six land-use types and four slope categories. The function "productivity" was assessed by interviews with 128 farmers, "habitat for biodiversity" by a vegetation survey, and "soil conservation" and "water conservation" via a literature review. The demand for functions was first assessed from the "top-down" policy perspective via interviews and reviews of policy targets, then complemented by integrating the local "bottom-up" demands for functions. These were assessed by applying a Q methodology, providing insights in the prioritisation of functions from the perspective of 22 local actors. Maps of supply and demands were generated for each function: supply maps by overlaying land use and slope category, top-down demand maps from administrative zoning/land-use plans, and bottom-up demand maps from local actors designation of geomorphological areas. Our results revealed contrasting demands for functions, as well as a heterogeneous spatial distribution of supply and demands. Discrepancies emerged (i) between supply and demand, (ii) between bottom-up (local) demands and the top-down (policy driven) demand, and (iii) among local actors perspectives. Our study indicates that discrepancies are not necessarily conflicting, but can uncover pathways for defining compromises, representing attainable policy entry points. Not one single development model can meet the needs of every stakeholder; however, a combination of land uses and management strategies can meet divergent interests and allow for optimisation of functions. This integrative approach of FLM provides a socially embedded biophysical analysis and is a valuable tool for the design of customized land-use and agri-environmental policies.


Assuntos
Conservação dos Recursos Naturais , Solo , Agricultura , Biodiversidade , Filipinas
3.
MethodsX ; 6: 1252-1260, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31194036

RESUMO

Uranium silicide, U3Si2, is an accident tolerant fuel type which is gaining momentum as a replacement fuel for uranium dioxide (UO2). Idaho National Laboratories has been fabricating phase pure U3Si2 fuel pellets for use in various irradiation and material characterization experiments. Stoichiometric U3Si2 fuel pellets were fabricated using a powder metallurgy and arc melting technique. The use of the stoichiometric ratio to alloy uranium and silicon, and sintering in a vacuum environment allowed for the fabrication of high density (>94% theoretical density), phase pure pellets, greater than 94% U3Si2. Silicon volatilization was not observed in the as-sintered microstructure, which has been verified through XRD and SEM, thus eliminating the need to alloy a substoichiometric U/Si ratio. •Stoichiometric ratio of U to Si used to form U3Si2 phase.•Decrease in secondary phases present confirm absence of silicon volatilization.•Analysis via XRD and SEM confirm the phase purity of the U3Si2 fuel pellets.

4.
Rev Sci Instrum ; 87(5): 053112, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27250397

RESUMO

We report on the development of a highly miniaturized vacuum package for use in an atomic clock utilizing trapped ytterbium-171 ions. The vacuum package is approximately 1 cm(3) in size and contains a linear quadrupole RF Paul ion trap, miniature neutral Yb sources, and a non-evaporable getter pump. We describe the fabrication process for making the Yb sources and assembling the vacuum package. To prepare the vacuum package for ion trapping, it was evacuated, baked at a high temperature, and then back filled with a helium buffer gas. Once appropriate vacuum conditions were achieved in the package, it was sealed with a copper pinch-off and was subsequently pumped only by the non-evaporable getter. We demonstrated ion trapping in this vacuum package and the operation of an atomic clock, stabilizing a local oscillator to the 12.6 GHz hyperfine transition of (171)Y b(+). The fractional frequency stability of the clock was measured to be 2 × 10(-11)/τ(1/2).

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