Optical sectioning in induced coherence tomography with frequency-entangled photons

We demonstrate a different scheme to perform optical sectioning of a sample based on the concept of induced coherence [Zou et al., Phys. Rev. Lett. 67, 318 (1991)]. This can be viewed as a different type of optical coherence tomography scheme where the varying reflectivity of the sample along the direction of propagation of an optical beam translates into changes of the degree of first-order coherence between two beams. As a practical advantage the scheme allows probing the sample with one wavelength and measuring photons with another wavelength. In a bio-imaging scenario, this would result in a deeper penetration into the sample because of probing with longer wavelengths, while still using the optimum wavelength for detection. The scheme proposed here could achieve submicron axial resolution by making use of nonlinear parametric sources with broad spectral bandwidth emission.Comment: Published version. 11 pages, 9 figure

Earthquake Disaster Simulation of Civil Infrastructures. From Tall Buildings to Urban Areas

Adam Martínez, JM. (2017). Earthquake Disaster Simulation of Civil Infrastructures. From Tall Buildings to Urban Areas. Engineering Structures. 148:1-1. doi:10.1016/j.engstruct.2017.07.006S1114

La internacionalización de empresas: relación entre el capital social, las tecnologías de la información relacional y la innovación

Este trabajo tiene como objetivo revisar el proceso de internacionalización de las empresas, estudiando su desempeño exportador y la influencia que ejercen variables como el capital social, las tecnologías de la información relacional (Web 2.0) y la innovación. Para cumplir este propósito se realiza una revisión sobre los fundamentos teóricos y conceptuales sobre la relación entre la internacionalización empresarial, las tecnologías de la información relacional, la innovación y el capital social. Lo que permite formular una hipótesis sobre las relaciones que existen entre estas variables. Hipótesis que se espera validar en un conjunto de empresas del sector del plástico de la Comunidad Valenciana, España, y algunas empresas del Área Metropolitana de la ciudad de Medellín, Colombia

Dynamic self-organization in holonic multi-agent manufacturing systems: The ADACOR evolution

Nowadays, systems are becoming increasingly complex, mainly due to an exponential increase in the number of entities and their interconnections. Examples of these complex systems can be found in manufacturing, smart-grids, traffic control, logistics, economics and biology, among others. Due to this complexity, particularly in manufacturing, a lack of responsiveness in coping with demand for higher quality products, the drastic reduction in product lifecycles and the increasing need for product customization are being observed. Traditional solutions, based on central monolithic control structures, are becoming obsolete as they are not suitable for reacting and adapting to these perturbations. The decentralization of the complexity problem through simple, intelligent and autonomous entities, such as those found in multi-agent systems, is seen as a suitable methodology for tackling this challenge in industrial scenarios. Additionally, the use of biologically inspired self-organization concepts has proved to be suitable for being embedded in these approaches enabling better performances to be achieved. According to these principals, several approaches have been proposed but none can be truly embedded and extract all the potential of self-organization mechanisms. This paper proposes an evolution to the ADACOR holonic control architecture inspired by biological and evolutionary theories. In particular, a two-dimension al self-organization mechanism was designed taking the behavioural and structural vectors into consideration, thus allowing truly evolutionary and reconfigurable systems to be achieved that can cope with emergent requirements. The approach proposed is validated with two simulation use cases.info:eu-repo/semantics/publishedVersio

Hypoxic pre-conditioning increases the infiltration of endothelial cells into scaffolds for dermal regeneration pre-seeded with mesenchymal stem cells.

Many therapies using mesenchymal stem cells (MSC) rely on their ability to produce and release paracrine signals with chemotactic and pro-angiogenic activity. These characteristics, however, are mostly studied under standard in vitro culture conditions. In contrast, various novel cell-based therapies imply pre-seeding MSC into bio-artificial scaffolds. Here we describe human bone marrow-derived MSC seeded in Integra matrices, a common type of scaffold for dermal regeneration (SDR). We show and measured the distribution of MSC within the SDR, where cells clearly establish physical interactions with the scaffold, exhibiting constant metabolic activity for at least 15 days. In the SDR, MSC secrete VEGF and SDF-1α and induce transwell migration of CD34(+) hematopoietic/endothelial progenitor cells, which is inhibited in the presence of a CXCR4/SDF-1α antagonist. MSC in SDR respond to hypoxia by altering levels of angiogenic signals such as Angiogenin, Serpin-1, uPA, and IL-8. Finally, we show that MSC-containing SDR that have been pre-incubated in hypoxia show higher infiltration of endothelial cells after implantation into immune deficient mice. Our data show that MSC are fully functional ex vivo when implanted into SDR. In addition, our results strongly support the notion of hypoxic pre-conditioning MSC-containing SDR, in order to promote angiogenesis in the wounds

Improving the ADACOR2 supervisor holon scheduling mechanism with genetic algorithms

Manufacturing companies are being pushed to their limits due to an increase of production complexity guided by a growing standards demand by the costumers. To respond properly to this, manufacturing companies must adopt innovative control architectures that are able to handle better the occurrence of disturbances at shop-floor level (e.g. workstation breakdown, orders cancellation or modification). Additionally, the selection of a proper scheduling algorithms assumes a crucial point, in the sense that the increase of optimization levels depend on this. This paper presents a Genetic Algorithm (GA) based technique to be embedded into the supervisor entity present at the ADACOR2 aiming to improve the existing fast and non-optimal scheduling technique, improving the overall system processing execution. The main requirements of the GA is to be fast enough to be usable in demanding environments improving the optimization output. The proposed algorithm is tested using a Flexible Manufacturing System using different configurations of transportation and batch sizes. Results show that despite the presented GA technique increased the optimization calculation time it performs better considering the sum of this time with the gain in the optimization output.info:eu-repo/semantics/publishedVersio

Muonic-hydrogen Lamb shift: dispersing the nucleon-excitation uncertainty with a finite-energy sum rule

We assess the two-photon exchange contribution to the Lamb shift in muonic hydrogen with forward dispersion relations. The subtraction constant (T) over bar (0, Q(2)) that is necessary for a dispersive evaluation of the forward doubly virtual Compton amplitude, through a finite energy sum rule, is related to the fixed J = 0 pole generalized to the case of virtual photons. We evaluated this sum rule using excellent virtual photoabsorption data that are available. We find that the "proton polarizability correction" to the Lamb shift in muonic hydrogen is -(40 +/- 5) mu eV. We conclude that nucleon structure-dependent uncertainty by itself is unlikely to resolve the large (300 mu eV) discrepancy between direct measurement of the Lamb shift in mu H and expectations based on conventional hydrogen measurements

La internacionalización de empresas: relación entre el capital social, las tecnologías de la información relacional y la innovación

Este trabajo tiene como objetivo revisar el proceso de internacionalización de las empresas,estudiando su desempeño exportador y la influencia que ejercen variables comoel capital social, las tecnologías de la información relacional (Web 2.0) y la innovación.Para cumplir este propósito se realiza una revisión sobre los fundamentos teóricos y conceptualessobre la relación entre la internacionalización empresarial, las tecnologías dela información relacional, la innovación y el capital social. Lo que permite formular unahipótesis sobre las relaciones que existen entre estas variables. Hipótesis que se esperavalidar en un conjunto de empresas del sector del plástico de la Comunidad Valenciana,España, y algunas empresas del Área Metropolitana de la ciudad de Medellín, Colombia.Tecnologías de la Información (TIC), Web 2.0, Capital Social, Internacionalización de empresas,Cultura, Innovación