24,214 research outputs found
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Hybrid system of expert system and artificial neural networks for objective evaluation of product sensuous quality
Basic problems and the bottleneck of current approaches for objective assessment of product sensuous quality (PSQ) are discussed. As a solution, a new approach, an expert system (ES) based on artificial neural networks (ANNs) is proposed, in which the ES and ANNs co-operate in a superiority compensation way. T he knowledge base of the system can be effectively built and the evaluation of PSQ can be conducted on-line. As a case study, the new approach has been applied in leather handle test and it proves that the approach is capable of handling non-linear relationships among multiple measured PSQ parameters
Non-damping oscillations at flaring loops
Context. QPPs are usually detected as spatial displacements of coronal loops
in imaging observations or as periodic shifts of line properties in
spectroscopic observations. They are often applied for remote diagnostics of
magnetic fields and plasma properties on the Sun. Aims. We combine imaging and
spectroscopic measurements of available space missions, and investigate the
properties of non-damping oscillations at flaring loops. Methods. We used the
IRIS to measure the spectrum over a narrow slit. The double-component Gaussian
fitting method was used to extract the line profile of Fe XXI 1354.08 A at "O
I" window. The quasi-periodicity of loop oscillations were identified in the
Fourier and wavelet spectra. Results. A periodicity at about 40 s is detected
in the line properties of Fe XXI, HXR emissions in GOES 1-8 A derivative, and
Fermi 26-50 keV. The Doppler velocity and line width oscillate in phase, while
a phase shift of about Pi/2 is detected between the Doppler velocity and peak
intensity. The amplitudes of Doppler velocity and line width oscillation are
about 2.2 km/s and 1.9 km/s, respectively, while peak intensity oscillate with
amplitude at about 3.6% of the background emission. Meanwhile, a quasi-period
of about 155 s is identified in the Doppler velocity and peak intensity of Fe
XXI, and AIA 131 A intensity. Conclusions. The oscillations at about 40 s are
not damped significantly during the observation, it might be linked to the
global kink modes of flaring loops. The periodicity at about 155 s is most
likely a signature of recurring downflows after chromospheric evaporation along
flaring loops. The magnetic field strengths of the flaring loops are estimated
to be about 120-170 G using the MHD seismology diagnostics, which are
consistent with the magnetic field modeling results using the flux rope
insertion method.Comment: 9 pages, 9 figures, 1 table, accepted by A&
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Gearbox life cycle assessment
Sustainable production has been attracting more and more attention nowadays. Gearbox is a widely applied mechanical engineering product. However, little work of life cycle assessment (LCA) aimed at the gearbox could be found in the literature. This paper presents a LCA of gearbox to fill in the gap. The life cycle of the gearbox is modelled parametrically with a three-tier approach. Eco-impact caused by human labour is considered in the LCA. The LCA is conducted using a popular LCA software, SimaPro, and a widely accepted LCIA method, ReCiPe. Based on analysis of the results, optimisation plans are proposed at the end
Simple algebras of Weyl type
Over a field of any characteristic, for a commutative associative algebra
with an identity element and for the polynomial algebra of a
commutative derivation subalgebra of , the associative and the Lie
algebras of Weyl type on the same vector space are
defined. It is proved that , as a Lie algebra (modular its center) or as
an associative algebra, is simple if and only if is -simple and
acts faithfully on . Thus a lot of simple algebras are obtained.Comment: 9 pages, Late
Model anisotropic quantum Hall states
Model quantum Hall states including Laughlin, Moore-Read and Read-Rezayi
states are generalized into appropriate anisotropic form. The generalized
states are exact zero-energy eigenstates of corresponding anisotropic two- or
multi-body Hamiltonians, and explicitly illustrate the existence of geometric
degrees of in the fractional quantum Hall effect. These generalized model
quantum Hall states can provide a good description of the quantum Hall system
with anisotropic interactions. Some numeric results of these anisotropic
quantum Hall states are also presented.Comment: 10 pages, 5 figure
Motion state recognition of debris ejected in vehicular collision after contact with the ground
The motion state of debris ejected from the vehicle involved in vehicular collision is important for finding out the vehicle collision speed. This research developed an analytical model to recognise the debris motion state. With the model, analyses were conducted, which reveal that if α, which is the contact angle between the debris and the ground at the moment when the debris collides the ground, is within the range from 0° to its boundary value, then the debris slides; if α is within the range from its boundary value to 90°, then the debris bounces. With debris' initial angular velocity ω = 0, the boundary value is 11.8° for sphere debris and 7.8° for rectangular debris; with ω ≠0, the boundary value for rectangular debris is arcsin(g/Rω2) where g represents the acceleration due to gravity and R is the distance from the debris centre to the point of its contact with the ground. Experiment tests were conducted for debris motion states with ω = 0, which confirmed the analytical results
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Advanced integrated manufacture by application of sustainable technology through product lifecycle: a circular economy approach
An approach has been developed for sustainable integrated manufacture, covering the whole product development process from material acquisition till the product end of life treatment, which is part of the CIRC4Life project supported by the European Commission's Horizon 2020 programme. The approach consists of three new circular economy business models (CEBMs) including Co-creation of products/services, Sustainable consumption and Collaborative recycling/reuse. The CEBMs are supported by an eco-point approach, information and communication technologies, traceability techniques, online data mining, and other enable techniques/methods. In this paper, the overview and three new CEBMs are presented, followed by a case study of domestic lighting products, illustrating how the approach is implemented in an industrial application
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