Optimising the Analysis Stage in the Internationalisation of Manufacturing Operations

[EN] The internationalisation of the manufacturing operations process includes decision-making about new facility implementation (NFI) and global supplier network development (GSND), whose first step is to analyse the situation of a company and its environment. The purpose of this paper is to investigate the optimal design of a manufacturing production and distribution network for global small-and medium-sized enterprises (SMEs). This research uses a mixed-integer linear programming (MILP) model to support decision-making in the analysis stage of the internationalisation of manufacturing operations for global SMEs. A real-world case study is presented to illustrate the application of the proposed model. Different scenarios were evaluated not only to identify the strengths and limitations of the mathematical programming model, but to also provide support for the next strategic decisions that the examined company has to make in the near future.This work was supported by the Spanish Ministry of Science, Innovation and Universities project entitled `Optimisation of zero-defects production technologies enabling supply chains 4.0 (CADS4.0)' (RTI2018-101344-B-I00).Comer, F.; Mula, J.; Díaz-Madroñero Boluda, FM.; Grillo, H. (2021). Optimising the Analysis Stage in the Internationalisation of Manufacturing Operations. The South African Journal of Industrial Engineering. 32(2):124-132. https://doi.org/10.7166/32-2-2371S12413232

Long-wavelength approximation for string cosmology with barotropic perfect fluid

The field equations derived from the low energy string effective action with a matter tensor describing a perfect fluid with a barotropic equation of state are solved iteratively using the long-wavelength approximation, i.e. the field equations are expanded by the number of spatial gradients. In the zero order, a quasi-isotropic solution is presented and compared with the general solution of the pure dilaton gravity. Possible cosmological models are analyzed from the point of view of the pre-big bang scenario. The second order solutions are found and their growing and decaying parts are studied.Comment: 19 pages, 1 figur

Riquesa d'espècies i interès per a la conservació dels ocells a l'àrea metropolitana de Barcelona : relacions amb la xarxa actual d'espais protegits

En aquest treball s'analitza la distribució espacial de la riquesa d'espècies d'ocells i la seva relació amb diverses variables territorials i amb la distribució dels espais del Pla d'Espais d'Interès Natural de Catalunya (PEIN) en tres conjunts d'espècies amb un interès de conservació contrastat: (1) el total d'espècies; (2) les que tenen un estatus de conservació desfavorable a Europa (categories 2 i 3 de la classificació SPEC [Species of European Conservation Concern; Tucker & Heath, 1994]; és a dir, SPEC 2+3); i (3) les incloses a l'Annex I de la Directiva del Consell 79/409/EEC per a la conservació de les aus silvestres (Directiva Ocells). L'estudi es va dur a terme al Vallès Oriental i àrees limítrofes. La riquesa d'espècies d'ocells es va obtenir d'un mostreig de camp previ, realitzat durant vuit anys separadament per a les espècies nidificants (primavera) i hivernants (hivern), i prenent com a unitat d'estudi les quadrícules UTM d'1 km × 1 km. La relació entre els diversos grups d'ocells i entre aquests i les variables territorials més significatives es va dur a terme mitjançant correlacions de Pearson. També es van comparar els valors de riquesa d'espècies dels grups estudiats i de les variables territorials seleccionades dins i fora dels espais del PEIN sobre una mostra aleatòria de les quadrícules. La riquesa total i el nombre d'espècies SPEC 2+3 són significativament més alts fora dels espais del PEIN, i es concentren en els mosaics agroforestals del Moianès i Osona per a les nidificants, i a la plana del Vallès per a les hivernants. Tots aquests grups d'espècies presenten correlacions positives i significatives amb la proporció de conreus i la diversitat de cobertes del sòl. La riquesa d'SPEC 2+3 mostra, a més, unes correlacions moderadament altes amb la riquesa total d'ocells. Contràriament, la riquesa d'espècies incloses a la Directiva Ocells segueix patrons de distribució diferents, amb alguns hot spots locals dins del Parc Natural del Montseny, i com a conseqüència, les correlacions amb la riquesa total i SPEC 2+3 són discretes. L'estudi posa de manifest un panorama de conservació complex al Vallès Oriental, amb uns espais protegits que afavoreixen la conservació d'algunes espècies de la Directiva Ocells i uns espais agroforestals molt rics en espècies, però no protegits per cap figura especial. També cal destacar la necessitat de potenciar i conservar els hàbitats oberts resultants d'un aprofitament agroramader extensiu,tant dins com fora dels espais protegits

Anisotropic stresses in inhomogeneous universes

Anisotropic stress contributions to the gravitational field can arise from magnetic fields, collisionless relativistic particles, hydrodynamic shear viscosity, gravitational waves, skew axion fields in low-energy string cosmologies, or topological defects. We investigate the effects of such stresses on cosmological evolution, and in particular on the dissipation of shear anisotropy. We generalize some previous results that were given for homogeneous anisotropic universes, by including small inhomogeneity in the universe. This generalization is facilitated by a covariant approach. We find that anisotropic stress dominates the evolution of shear, slowing its decay. The effect is strongest in radiation-dominated universes, where there is slow logarithmic decay of shear.Comment: 7 pages Revte

Spontaneous Scalarization and Boson Stars

We study spontaneous scalarization in Scalar-Tensor boson stars. We find that scalarization does not occur in stars whose bosons have no self-interaction. We introduce a quartic self-interaction term into the boson Lagrangian and show that when this term is large, scalarization does occur. Strong self-interaction leads to a large value of the compactness (or sensitivity) of the boson star, a necessary condition for scalarization to occur, and we derive an analytical expression for computing the sensitivity of a boson star in Brans-Dicke theory from its mass and particle number. Next we comment on how one can use the sensitivity of a star in any Scalar-Tensor theory to determine how its mass changes when it undergoes gravitational evolution. Finally, in the Appendix, we derive the most general form of the boson wavefunction that minimises the energy of the star when the bosons carry a U(1) charge.Comment: 23 pages, 5 postscript figures. Typing errors corrected. Includes some new text that relates the paper to several previous results. Accepted for publication in PR

Using Electronic Health Record Data to Improve Community Health Assessment

Background: Community health assessments assist health departments in identifying health needs as well as disparities, and they enable linking of needs with available interventions. Electronic health record (EHR) systems possess growing volumes of clinical and administrative data, making them a valuable source of data for ongoing community health assessment. Purpose: To produce population health indicators using data from EHR systems that could be combined and visually displayed alongside social determinants data, and to provide data sets at geographic levels smaller than a county. Methods: Data from multiple EHR systems used by major health systems covering \u3e90% of the population in a metropolitan urban area were extracted and linked using a health information exchange (HIE) network for individuals who had at least two clinical encounters within the HIE network over a 3-year period. Population health indicators of highest interest to public health stakeholders were calculated and visualized at varying levels of geographic granularity. Results: Ten population health indicators were calculated, visualized, and shared with public health partners. Indicators ranged from the prevalence of a disease to the proportion of individuals with poor maintenance of their chronic condition. Calculating rates at the census-tract level or larger (e.g., average population size \u3e 4000 people) is preferable to smaller geographic units of analysis. Implications: Extraction and linking of EHR system data are feasible for public health via an HIE network. While indicators can be derived, biases exist in the data that require more study. Further, HIE networks do not yet possess data for all conditions and measures desired by local public health stakeholders. The data that can be extracted, however, can be combined with public datasets on social determinant

Oscillations of General Relativistic Multi-fluid/Multi-layer Compact Stars

We develop the formalism for determining the quasinormal modes of general relativistic multi-fluid compact stars in such a way that the impact of superfluid gap data can be assessed. Our results represent the first attempt to study true multi-layer dynamics, an important step towards considering realistic superfluid/superconducting compact stars. We combine a relativistic model for entrainment with model equations of state that explicity incorporate the symmetry energy. Our analysis emphasises the many different parameters that are required for this kind of modelling, and the fact that standard tabulated equations of state are grossly incomplete in this respect. To make progress, future equations of state need to provide the energy density as a function of the various nucleon number densities, the temperature (i.e. entropy), and the entrainment among the various components

Rotation and twist regular modes for trapped ghosts

A parameter-independent notion of stationary slow motion is formulated then applied to the case of stationary rotation of massless trapped ghosts. The excitations correspond to a rotation mode with angular momentum $J\neq 0$ and twist modes. It is found that the rotation mode, which has no parity, causes excess in the angular velocity of dragged distant coordinate frames in one sheet of the wormhole while in the other sheet the angular velocity of the ghosts is that of rotating stars: $2J/r^3$. As to the twist modes, which all have parity, they cause excess in the angular velocity of one of the throat's poles with respect to the other.Comment: 11 pages, 3 figures; General Relativity and Gravitation - 201