Search results for " Opera"
showing 10 items of 3606 documents
Human Factor and LEAN Analysis at Industrial Manufacturing Plants
2018
The aim of the research was to find out effective identification and prevention of ergonomics problems in industrial metal processing manufacturing plant, based on human factor workload analysis and LEAN failure mode and effect analysis. Creation of safe, effective work places, emphasizing human oriented approach and implementing ergonomics in business process management is one of the main conditions for sustainable development of an enterprise. For the research were chosen packaging, assembling and quality control manufacturing plant operations due to main complaints from workers about physical overload, intensive work pace and task complexity. Human factor analysis provides holistic under…
Par svārstīgiem nestriktiem Hamahera agregācijas operatoriem daudzkritēriju lēmumu pieņemšanai
2015
Bakalaura darbs veltīts dažiem svārstīgo nestrikto Hamahera agregācijas operatoru pielietojumiem daudzkritēriju lēmumu pieņemšanas procesa modelēšanā. Darbā aplūkoti tādi nestriktās matemātikas jēdzieni, kā t-norma, t-konorma, involūcija, svārstīga nestrikta kopa, darbības ar svārstīgiem nestriktiem elementiem, kas nepieciešami, lai definētu svārstīgo nestrikto agregācijas operatoru. Izmantojot svārstīgos nestriktos Hamahera agregācijas operatorus, aprakstīts daudzkritēriju lēmumu pieņemšanas modelis, kas pielietots skaitlisku datu apstrādē. Iegūtie rezultāti analizēti.
Electronic structure trends of Möbius graphene nanoribbons from minimal-cell simulations
2014
Investigating topological effects in materials requires often the modeling of material systems as a whole. Such modeling restricts system sizes, and makes it hard to extract systematic trends. Here, we investigate the effect of M\"obius topology in the electronic structures of armchair graphene nanoribbons. Using density-functional tight-binding method and minimum-cell simulations through revised periodic boundary conditions, we extract electronic trends merely by changing cells' symmetry operations and respective quantum number samplings. It turns out that for a minimum cell calculation, once geometric and magnetic contributions are ignored, the effect of the global topology is unexpectedl…
Quantum Simulations of One-Dimensional Nanostructures under Arbitrary Deformations
2016
A powerful technique is introduced for simulating mechanical and electromechanical properties of one-dimensional nanostructures under arbitrary combinations of bending, twisting, and stretching. The technique is based on a novel control of periodic symmetry, which eliminates artifacts due to deformation constraints and quantum finite-size effects, and allows transparent electronic structure analysis. Via density-functional tight-binding implementation, the technique demonstrates its utility by predicting novel electromechanical properties in carbon nanotubes and abrupt behavior in the structural yielding of Au7 and MoS nanowires. The technique drives simulations markedly closer to the reali…
The S-kernel: A measure of symmetry of objects
2007
In this paper we introduce a new symmetry feature named ''symmetry kernel'' (SK) to support a measure of symmetry. Given any symmetry transform S, SK of a pattern P is the maximal included symmetric sub-set of P for all directions and shifts. We provide a first algorithm to exhibit this kernel where the centre of symmetry is assumed to be the centre of mass. Then we prove that, in any direction, the optimal axis corresponds to the maximal correlation of a pattern with its symmetric version. That leads to a second algorithm. The associated symmetry measure is a modified difference between the respective surfaces of a pattern and its kernel. A series of experiments supports the actual algorit…
Visual Discrimination of the 17 Plane Symmetry Groups
2011
Within most of the 17 plane symmetry groups, individual symmetry operations act in multiple, nonequivalent ways. This, and the fact that many groups can be realized on the basis of different unit cells and generating regions, poses difficulties for visual discrimination and identification. Because of inherent confounds, only few of the groups can be studied by traditional experimental methodology. The use of an oddity paradigm and specific tiling patterns that camouflage groups in complex textures are recommended as partial remedy to this impasse. In order to prepare readers for an appreciation of the aforementioned issues and to provide a rationale for their investigation, the reporting of…
Overestimation of the strength of size-assortative pairing in taxa with cryptic diversity: a case of Simpson's paradox.
2015
5 pages; International audience; Size-assortative pairing is one of the most common pairing patterns observed in nature and it probably occurs in many taxa with cryptic diversity. Observed patterns of size-assortative pairing in natural populations may thus be influenced by the co-occurrence of noninterbreeding cryptic groups of individuals living in sympatry. To quantify this potential bias, we sampled amphipods from the Gammarus pulex/Gammarus fossarum crustacean species complex in rivers containing two sympatric and morphologically cryptic groups, i.e. molecular operational taxonomic units (MOTUs). Within each river, MOTUs did not interbreed and differed in mean body size. We measured th…
Editorial: Special issue on Simulation in Transportation
2020
Transportation systems and related policies are complex and cross-sectoral, covering different socio-economic and management aspects, and involving multiple stakeholders (such as users, operators, and public policymakers). Mobility and accessibility are central to economic and societal well-being, yet the process of doing so may have significant impacts on land use, environment, and public health. Furthermore, the many feedbacks involved occur at varying degrees of spatial, temporal, and socio-demographic granularity and levels of uncertainty. Simulation models are well established in transportation-related operational research and management science, and the alternative approaches of Syste…
A best proximity point approach to existence of solutions for a system of ordinary differential equations
2019
We establish the existence of a solution for the following system of differential equations (y x ′′((t t ) ) = = g f ((t t ,y x ((t t )) )) ,y x ((t t 0 0) ) = = x x *** in the space of all bounded and continuous real functions on [0, +∞[. We use best proximity point methods and measure of noncompactness theory under suitable assumptions on f and g. Some new best proximity point theorems play a key role in the above result.
Systems of quasilinear elliptic equations with dependence on the gradient via subsolution-supersolution method
2017
For the homogeneous Dirichlet problem involving a system of equations driven by \begin{document}$(p,q)$\end{document} -Laplacian operators and general gradient dependence we prove the existence of solutions in the ordered rectangle determined by a subsolution-supersolution. This extends the preceding results based on the method of subsolution-supersolution for systems of elliptic equations. Positive and negative solutions are obtained.