189 research outputs found
Generation of rule-adhering robot programs for aluminium welding automatically from CAD
This paper presents a method to automatically generate robot welding programs from CAD to address the ever-constant demand for product customisation. Furthermore, to ensure that proper welding operations and structural integrity are met, the generated programs also consider the welding conditions and requirements. These welding conditions and requirements are defined by the weld direction and face relative to gravity and surrounding geometry, which has not been observed in the present research sphere. To achieve this, the approach leverages information that can be extracted from a topological analysis of tessellated geometry local to the weld joint in conjunction with available CAD API functions. Finally, an implementation of the method using Siemens NX and the Robotics Toolbox for Python is presented and tested on three geometrically different node configurations and a stiffener piece provided by industrial collaborators. In all, the proposed system was able to correctly generate programs adhering to allowed welding operations as long as a solution existed. For the more complex node configurations (which require reorientation when welded by humans), 32 weld path programs out of 42 were generated based on the given criteria. For the least complex node, a total of 20 out of 24 were generated with the same criteria. All 14 weld programs were generated for the stiffener representation.publishedVersio
The Higgs Sector of the Minimal 3 3 1 Model Revisited
The mass spectrum and the eigenstates of the Higgs sector of the minimal 3 3
1 model are revisited in detail. There are discrepancies between our results
and previous results by another author.Comment: 20 pages, latex, two figures. One note and one reference are adde
Pulsed Electric Discharge in Active Metallic Grains for Water Purification Processes
Chemical reactions in electric metal pulse dispersion in the aqueous solutions of inorganic substance (НSiO[3]{–}, Ni{2+}, Н[2]AsO[4]{–}, Mn{2+}, Cr[2]O[7]{2–}) were determined through IR spectroscopy, X-ray phase, chemical, kinetic, and thermodynamic analyses. Under such conditions, both reduction and oxidation reactions occur, as well as, locally initiated by heating, hydrolysis and exchange reactions without changing the oxidation rate of the dissolved substance itself. Reduction and oxidation of dissolved substances is determined by the generation and activation of high dispersed Fe in an electric discharge. Physical and chemical processes which take place under the action of pulse electric discharges upon the layer of metallic grains in salt solution, containing НSiO[3]{–}, Ni{2+}, Н[2]AsO[4]{–}, Mn{2+}, Cr[2]O[7]{2–} ions were determined on the basis of product composition, obtained experimentally and the thermodynamic data. It was shown, that PED discharge in heterogeneous mediums can be used for waste and natural water purification
Neural Amortized Inference for Nested Multi-agent Reasoning
Multi-agent interactions, such as communication, teaching, and bluffing,
often rely on higher-order social inference, i.e., understanding how others
infer oneself. Such intricate reasoning can be effectively modeled through
nested multi-agent reasoning. Nonetheless, the computational complexity
escalates exponentially with each level of reasoning, posing a significant
challenge. However, humans effortlessly perform complex social inferences as
part of their daily lives. To bridge the gap between human-like inference
capabilities and computational limitations, we propose a novel approach:
leveraging neural networks to amortize high-order social inference, thereby
expediting nested multi-agent reasoning. We evaluate our method in two
challenging multi-agent interaction domains. The experimental results
demonstrate that our method is computationally efficient while exhibiting
minimal degradation in accuracy.Comment: 8 pages, 10 figure
Contributions of rotation, expansion and line broadening to the morpho-kinematics of the inner CSE of oxygen-rich AGB star R Hya
We use archival ALMA observations of the CO(2-1) and SiO(5-4) molecular line
emissions of AGB star R Hya to illustrate the relative contributions of
rotation, expansion and line broadening to the morpho-kinematics of the
circumstellar envelope (CSE) within some ~0.5 arcsec from the centre of the
star. We give evidence for rotation and important line broadening to dominate
the inner region, within ~100 mas from the centre of the star. The former is
about an axis that projects a few degrees west of north and has a projected
rotation velocity of a few km/s. The latter occurs within some 50-100 mas from
the centre of the star, the line width reaching two to three times its value
outside this region. We suggest that it is caused by shocks induced by stellar
pulsations and convective cell ejections. We show the importance of properly
accounting for the observed line broadening when discussing rotation and
evaluating the radial dependence of the rotation velocity.Comment: 8 pages, 8 figure
On Metal-Insulator Transitions due to Self-Doping
We investigate the influence of an unoccupied band on the transport
properties of a strongly correlated electron system. For that purpose,
additional orbitals are coupled to a Hubbard model via hybridization. The
filling is one electron per site. Depending on the position of the additional
band, both, a metal--to--insulator and an insulator--to--metal transition occur
with increasing hybridization. The latter transition from a Mott insulator into
a metal via ``self--doping'' was recently proposed to explain the low carrier
concentration in . We suggest a restrictive parameter regime for
this transition making use of exact results in various limits. The predicted
absence of the self--doping transition for nested Fermi surfaces is confirmed
by means of an unrestricted Hartree--Fock approximation and an exact
diagonalization study in one dimension. In the general case metal--insulator
phase diagrams are obtained within the slave--boson mean--field and the
alloy--analog approximation.Comment: 9 pages, Revtex, 6 postscript figure
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