Accurate radial velocity and metallicity of the Large Magellanic Cloud old globular clusters NGC1928 and NGC1939

We present results obtained from spectroscopic observations of red giants located in the fields of the Large Magellanic Cloud (LMC) globular clusters (GCs) NGC1928 and NGC1939. We used the GMOS and AAOmega+2dF spectrographs to obtain spectra centred on the Ca II triplet, from which we derived individual radial velocities (RVs) and metallicities. From cluster members we derived mean RVs of RVNGC1928 = 249.58±4.65 km s-1 and RVNGC1939 = 258.85±2.08 km s-1, and mean metallicities of [Fe/H]NGC1928 = -1.30±0.15 dex and [Fe/H]NGC1939 = -2.00±0.15 dex. We found that both GCs have RVs and positions consistent with being part of the LMC disc, so that we rule out any possible origin, but in the same galaxy. By computing the best solution of a disc that fully contains each GC, we obtained circular velocities for the 15 known LMC GCs. We found that 11/15 of the GCs share the LMC rotation derived from HST and Gaia DR2 proper motions. This outcome reveals that the LMC disc existed since the very early epoch of the galaxy formation and experienced the steep relatively fast chemical enrichment shown by its GC metallicities. The four remaining GCs turned out to have circular velocities not compatible with an in situ cluster formation, but rather with being stripped from the SMC.Fil: Piatti, Andres Eduardo. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Hwang, N.. Korea Astronomy And Space Science Institute; Corea del SurFil: Cole, A. A.. University of Tasmania; AustraliaFil: Angelo, M. S.. Laboratorio Nacional de Astrofisica; BrasilFil: Emptage, B.. University of Tasmania; Australi

A Proposal of Standardised Data Model for Cloud Manufacturing Collaborative Networks

[EN] The growing amount of data to be handled by collaborative networks raises the need of introducing innovative solutions to fulfil the lack of affordable tools, especially for Small and Medium-Sized Enterprises, to manage and exchange data. The European H2020 Project Cloud Collaborative Manufacturing Networks develops and offers a structured data model, called Standardised Tables, as an organised framework to jointly work with existing databases to manage big data collected from different industries belonging to the CNs. The information of the Standardised Tables will be mainly used with optimisation and collaboration purposes. The paper describes an application of the Standardised Tables in one of the pilots of the aforementioned project, the automotive industry pilot, for solving the collaborative problem of a Materials Requirement Plan.The research leading to these results is in the frame of the “Cloud Collaborative Manufacturing Networks” (C2NET) project, which has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 636909.Andres, B.; Sanchis, R.; Poler, R.; Saari, L. (2017). A Proposal of Standardised Data Model for Cloud Manufacturing Collaborative Networks. IFIP Advances in Information and Communication Technology. 560:77-85. https://doi.org/10.1007/978-3-319-65151-4_7S7785560Andres, B., Poler, R.: Models, guidelines and tools for the integration of collaborative processes in non-hierarchical manufacturing networks: a review. Int. J. Comput. Integr. Manuf. 2(29), 166–201 (2016)Zikopoulos, P., Eaton, C.: Understanding Big Data: Analytics for Enterprise Class Hadoop and Streaming Data. McGraw-Hill Osborne Media, New York (2011)Zhou, B., Wang, S., Xi, L.: Data model design for manufacturing execution system. J. Manuf. Technol. Manag. 16(8), 909–935 (2005)Steven, W.: Getting the MES model – methods for system analysis. ISA Trans. 35(2), 95–103 (1996)Reda, A.: Extracting the extended entity-relationship model from a legacy relational database. Inf. Syst. 28(6), 597–618 (2003)Teorey, T.J., Yang, D., Fry, J.P.: A logical design methodology for relational database using the extended entity-relationship model. ACM Comput. Surv. 18(2), 197–222 (1986)Victor, M., Arie, S.: Representing extended entity-relationship structures in relational databases: a modular approach. ACM Trans. Database Syst. 17(3), 423–464 (1992)CORDIS Europa, Factories of the Future, H2020-EU.2.1.5.1. - Technologies for Factories of the Future (2014)H2020 Project C2NET (2015). http://cordis.europa.eu/project/rcn/193440_en.htmlAndres, B., Sanchis, R., Poler, R.: A cloud platform to support collaboration in supply networks. Int. J. Prod. Manag. Eng. 4(1), 5–13 (2016)APICS, “SCOR Framework,” Supply Chain Operations Reference model (SCOR) (2017)Orbegozo, A., Andres, B., Mula, J., Lauras, M., Monteiro, C., Malheiro, M.: An overview of optimization models for integrated replenishment and producction planning decisions. In: Building Bridges Between Researchers and Practitioners. Book of Abstracts of the International Joint Conference CIO-ICIEOM-IISE-AIM (IJC2016), p. 68 (2016)Andres, B., Poler, R., Saari, L., Arana, J., Benaches, J.V., Salazar, J.: Optimization models to support decision-making in collaborative networks: a review. In: Building Bridges Between Researchers and Practitioners. Book of Abstracts of the International Joint Conference CIO-ICIEOM-IISE-AIM (IJC2016), p. 70 (2016)Andres, B., Sanchis, R., Lamothe, J., Saari, L., Hauser, F.: Combined models for production and distribution planning in a supply chain. In: Building Bridges Between Researchers and Practitioners. Book of Abstracts of the International Joint Conference CIO-ICIEOM-IISE-AIM (IJC2016), p. 71 (2016

Impurity scattering in unconventional density waves: non-crossing approximation for arbitrary scattering rate

We present a detailed theoretical study on the thermodynamic properties of impure quasi-one dimensional unconventional charge-, and spin-density waves in the framework of mean-field theory. The impurities are of the ordinary non-magnetic type. Making use of the full self-energy that takes into account all ladder-, and rainbow-type diagrams, we are able to calculate the relevant low temperature quantities for arbitrary impurity concentration and scattering rates. These are the density of states, specific heat and the shift in the chemical potential. Our results therefore cover the whole parameter space: they include both the self-consistent Born and the resonant unitary limits, and most importantly give exact results in between.Comment: 11 pages, 8 figure

Higher-Order Multicuts for Geometric Model Fitting and Motion Segmentation

Minimum cost lifted multicut problem is a generalization of the multicut problem and is a means to optimizing a decomposition of a graph w.r.t. both positive and negative edge costs. Its main advantage is that multicut-based formulations do not require the number of components given a priori; instead, it is deduced from the solution. However, the standard multicut cost function is limited to pairwise relationships between nodes, while several important applications either require or can benefit from a higher-order cost function, i.e. hyper-edges. In this paper, we propose a pseudo-boolean formulation for a multiple model fitting problem. It is based on a formulation of any-order minimum cost lifted multicuts, which allows to partition an undirected graph with pairwise connectivity such as to minimize costs defined over any set of hyper-edges. As the proposed formulation is NP-hard and the branch-and-bound algorithm is too slow in practice, we propose an efficient local search algorithm for inference into resulting problems. We demonstrate versatility and effectiveness of our approach in several applications: geometric multiple model fitting, homography and motion estimation, motion segmentation

Strong covalent bonding between two graphene layers

We show that two graphene layers stacked directly on top of each other (AA stacking) form strong chemical bonds when the distance between planes is 0.156 nm. Simultaneously, C-C in-plane bonds are considerably weakened from partial double-bond (0.141 nm) to single bond (0.154 nm). This polymorphic form of graphene bilayer is meta-stable w.r.t. the one bound by van der Waals forces at a larger separation (0.335 nm) with an activation energy of 0.16 eV/cell. Similarly to the structure found in hexaprismane, C forms four single bonds in a geometry mixing 90^{0} and 120^{0} angles. Intermediate separations between layers can be stabilized under external anisotropic stresses showing a rich electronic structure changing from semimetal at van der Waals distance, to metal when compressed, to wide gap semiconductor at the meta-stable minimum.Comment: tar gzip latex 4 pages 4 figure

Exchange Interactions and High-Energy Spin States in Mn_12-acetate

We perform inelastic neutron scattering measurements on the molecular nanomagnet Mn_12-acetate to measure the excitation spectrum up to 45meV (500K). We isolate magnetic excitations in two groups at 5-6.5meV (60-75K) and 8-10.5meV (95-120K), with higher levels appearing only at 27meV (310K) and 31meV (360K). From a detailed characterization of the transition peaks we show that all of the low-energy modes appear to be separate S = 9 excitations above the S = 10 ground state, with the peak at 27meV (310K) corresponding to the first S = 11 excitation. We consider a general model for the four exchange interaction parameters of the molecule. The static susceptibility is computed by high-temperature series expansion and the energy spectrum, matrix elements and ground-state spin configuration by exact diagonalization. The theoretical results are matched with experimental observation by inclusion of cluster anisotropy parameters, revealing strong constraints on possible parameter sets. We conclude that only a model with dominant exchange couplings J_1 ~ J_2 ~ 5.5meV (65K) and small couplings J_3 ~ J_4 ~ 0.6meV (7K) is consistent with the experimental data.Comment: 17 pages, 12 figure