Decision support systems in crowdfunding: A fuzzy cognitive maps (FCM) approach

Crowdfunding as an alternative source of finance to banking is the subject of numerous research works. This research proposes the guidelines of a Decision Support System (DSS) in the area of crowdfunding based on a Fuzzy Cognitive Maps (FCM) approach. A framework consisting of three phases (ten steps) has been proposed to design the guidelines of a DSS in crowdfunding. The first phase focusses in the construction of the FCM. FCM- based scenarios have been built in the second phase. Finally, in the third phase the guidelines of the DSS in crowdfunding have been defined. Results show that DSS using FCM-based scenarios could be useful tools to promoters, funders and managers of crowdfunding projects.Premio Mensual Publicación Científica Destacada de la US. Facultad de Turismo y Finanza

Dissolution of a CO2 spherical cap bubble adhered to a flat surface in air-saturated water

Bubbles adhered to partially hydrophobic flat surfaces often attain a spherical cap shape with a contact angle much greater than zero. We address the fundamental problem of the diffusion-driven dissolution of a sessile spherical cap bubble (SCB) adhered to a flat smooth surface. In particular, we perform experiments on the dissolution of CO2 bubbles (with initial radii similar to 1 mm) immersed in air-saturated water adhered to two substrates with different levels of hydrophobicity. It is found that the contact angle dynamics plays an important role in the bubble dissolution rate. A dissolution model for a multicomponent SCB in an isothermal and uniform pressure environment is then devised. The model is based on the quasi-stationary approximation. It includes the effect of the contact angle dynamics, whose behaviour is predicted by means of a simplified model based on the results obtained from adhesion hysteresis. The presence of an impermeable substrate hinders the overall rate of mass transfer. Two approaches are considered in its determination: (a) the inclusion of a diffusion boundary layer-plate interaction model and (b) a finite-difference solution. The model solutions are compared with the experimental results, yielding fairly good agreement.The authors gratefully acknowledge the support of Total E&P Recherche et Développement through study agreement FR00006995, and the Spanish Ministry of Economy and Competitiveness through grant DPI2014-59292-C3-1-P

Diffusion of dissolved CO2 in water propagating from a cylindrical bubble in a horizontal Hele-Shaw cell

The dissolution of a gas bubble in a confined geometry is a problem of interest in technological applications such as microfluidics or carbon sequestration, as well as in many natural flows of interest in geophysics. While the dissolution of spherical or sessile bubbles has received considerable attention in the literature, the case of a two-dimensional bubble in a Hele-Shaw cell, which constitutes perhaps the simplest possible confined configuration, has been comparatively less studied. Here, we use planar laser-induced fluorescence to experimentally investigate the diffusion-driven transport of dissolved CO2 that propagates from a cylindrical mm-sized bubble in air-saturated water confined in a horizontal Hele-Shawcell. We observe that the radial trajectory of an isoconcentration front, r(f) (t), evolves in time as approximately r(f) - R-0 alpha root t, where R-0 denotes the initial bubble radius. We then characterize the unsteady CO2 concentration field via two simple analytical models, which are then validated against a numerical simulation. The first model treats the bubble as an instantaneous line source of CO2, whereas the second assumes a constant interfacial concentration. Finally, we provide an analogous Epstein-Plesset equation with the intent of predicting the dissolution rate of a cylindrical bubble.We acknowledge the support of the Spanish Ministry of Economy and Competitiveness through Grants No. DPI2014-59292-C3-1-P and No. DPI2015-71901-REDT, partly funded through European Funds

The history effect in bubble growth and dissolution. Part 1. Theory

The term "history effect" refers to the contribution of any past mass transfer events between a gas bubble and its liquid surroundings towards the current diffusion-driven growth or dissolution dynamics of that same bubble. The history effect arises from the (non-instantaneous) development of the dissolved gas concentration boundary layer in the liquid in response to changes in the concentration at the bubble interface caused, for instance, by variations of the ambient pressure in time. Essentially, the history effect amounts to the acknowledgement that at any given time the mass flux across the bubble is conditioned by the preceding time history of the concentration at the bubble boundary. Considering the canonical problem of an isolated spherical bubble at rest, we show that the contribution of the history effect in the current interfacial concentration gradient is fully contained within a memory integral of the interface concentration. Retaining this integral term, we formulate a governing differential equation for the bubble dynamics, analogous to the well-known Epstein-Plesset solution. Our equation does not make use of the quasi-static radius approximation. An analytical solution is presented for the case of multiple step-like jumps in pressure. The nature and relevance of the history effect is then assessed through illustrative examples. Finally, we investigate the role of the history effect in rectified diffusion for a bubble that pulsates under harmonic pressure forcing in the non-inertial, isothermal regime.The authors acknowledge the support of the Spanish Ministry of Economy and Competitiveness through grant DPI2014-59292-C3-1-P, partly financed by European funds

Economic losses reduction through the implementation of statistical process control: case study in the process of medical accounts in a technology company

Statistical process control (SPC) is one of the most important tools for process continuous improvement. Its usefulness lies on the fact that it helps in the identification of causes of variation in the process. This allows the decision maker to take the corresponding actions in such a way that the improvement of the associated indicators is achieved. In this particular case, the methodology of the SPC was used to intervene a process of verification and collection of medical accounts by a technology company. The errors in these accounts can cause that the health companies do not pay the correct amount to hospitals. This situation may affect the service to users or that the health companies have economic losses. The implementation of the statistical process control (SPC) had a big impact in the identification of problems, stabilization of the process, and improvement of satisfaction and reduction of quality costs

Las sociedades portuarias regionales en el comercio exterior colombiano: una reseña sobre la importancia del Puerto de Buenaventura 1990-2004

Este documento analizó la evolución de la movilización de carga de los principales terminales Marítimos2 del país entre los años 1990-2004, con el objetivo de conocer el puerto que moviliza mayor cantidad de carga en el comercio exterior colombiano. Los resultados revelaron que la mayor parte de la carga exportada e importada en Colombia se realizó por vía marítima (95.9%), demostrando la importancia de este transporte en la movilización de carga. Asimismo, se encontró que el 57% del total de la carga importada en el país se realizó principalmente por las Sociedades Portuarias Regionales (SPR’s), mientras que en la movilización total de exportaciones, las SPR’s poseen una participación relativamente baja (7.8%) al compararse con la carga movilizada por los puertos especializados, mas no baja si se compara con la carga movilizada en los demás medios de transporte de carga existentes. Dada la importancia de las SPR’s en el comercio exterior, se comparó las participaciones de las cuatro principales SPR’s en la carga movilizada en el período considerado, participando el puerto de Buenaventura, con el 51%, seguido de Santa Marta (22%), Cartagena (14%) y Barranquilla (12%). De este modo, para profundizar sobre la importancia del puerto de Buenaventura, se analizó durante los tres últimos años de estudio, la participación que posee cada zona geográfica del país en la movilización de carga por Buenaventura, así como los principales destinos y orígenes de los productos que se importan y exportan por este puerto. Se encontró que la zona con mayor participación es la del Valle del Cauca (41.5%) seguido de Cundinamarca (37.1%) y Antioquia (12.9%), demostrando que no solo por el puerto Buenaventura se transita esencialmente la carga proveniente del Valle del Cauca, sino que también su infraestructura es utilizada para el proceso de importación y exportación de otras regiones. Lo anterior demuestra la importancia que se le debe brindar al puerto, aportando mayores recursos destinados a su adecuación, para que el Terminal que más moviliza carga en el país no quede rezagado frente a las nuevas necesidades que plantea el tráfico marítimo del comercio global.The objective of this document is to analyze the evolution of the mobilization of cargo of the main Maritime terminals of the country between the years 1990-2004, to know the terminal that mobilizes greater amounts of cargo in Colombian foreign trade. The results of this study show that the majority of the cargo exported and imported in the country was done by maritime transportation (95.9%), showing the great importance of maritime transportation in the cargo mobilization. Likewise, it was found that the 57% of total cargo imported was mainly carried out by the SPR’s of the country; while in the total mobilization of exports, the SPR’s have a relatively low participation (7.8%) when compared to the cargo mobilized by specialized ports, however, not low if compared to the cargo mobilized in the rest of the means of transportation of the existing cargo. |Given the importance of the SPR’s in foreign trade, the participation of the four principal SPR’s on the mobilized cargo in the considered period was compared., with the participation of the port of Buenaventura, under the control of the Regional Port Company (Sociedad Portuaria Regional), had an average share of 51% of Colombian maritime trade, followed by Santa Marta (22%), Cartagena (14%) and Barranquilla (12%).This way, to be profound about the importance of the port of Buenaventura, it was analyzed during the last three years of study, the participation that each geographical area of the country has in the cargo mobilization for this Regional Port Society, as well as the main destinations and origins of the products that are imported and exported for this port. It was found that the region with more participation is Valle del Cauca (41.5%) followed by Cundinamarca (37.1%) and Antioquia (12.9%), which demonstrates that not only through the Marine Terminal of Buenaventura is the cargo coming from the Valle de Cauca essentially traveled, but rather its infrastructure is also used for the import and export process of other important regions. The above-mentioned demonstrates the importance that should be given to the port, contributing greater resources dedicated to its adaptation, so that the Terminal that mobilizes more cargo in the country is not straggled before the new needs outlined by the maritime traffic of global trade

Measuring the quality of management in education. Review article

The objective of this study is to perform a review and contextualize the existing definitions of educational quality from the managerial point of view. We will be presenting also the factors that have been considered to support managerial decision making within educational institutions. Relevant research related to the different models for measuring educational quality and the different factors that affect this quality are discussed. The existing methodological gap of the statistical processes, the theoretical evidences and the number of investigations in every level of education are identified. The results provide a framework for future research and can become the basis for the design and construction of multidimensional models for educational management quality measurement needs of educational institutions. The results evidence also the lack of a single criterion to build the indicators, as well as the fact that there is a strong of subjectivity in the measuring processes

¿Se justifica la existencia de las asambleas departamentales?

No obstante que las Asambleas Departamentales gozan de una estabilidad más que centenaria en el ordenamiento jurídico colombiano, tales instituciones han sido objeto de un evidente olvido por parte de la opinión pública, la jurisprudencia y la doctrina especializadas, lo cual no hace más que reflejar la pobre importancia que estas corporaciones revisten en el acontecer jurídico y político. Sin embargo, tan lamentable situación no obedece únicamente a los vicios intrínsecos a las malas costumbres políticas que tan fuertemente han golpeado a las regiones, y que sin duda justifican en gran parte los continuos ataques que se han dirigido de tiempo atrás en contra de las Asambleas. Ellas, a su vez, son víctimas de un sistema de ordenamiento territorial connotado por la indefinición y la falta de desarrollo práctico y legislativo, que al mismo tiempo terminan por deslegitimar la propia figura del departamento. En todo caso, los principios democráticos de la representación popular y la separación de poderes demandan corporaciones de elección popular en las entidades territoriales que permitan canalizar la opinión y modo de pensar de sus habitantes, buscando así una mayor intervención de los ciudadanos en los asuntos locales. Por ello, es necesario fortalecer las Asambleas y darles un lugar preponderante en el escenario de la realidad local. Y si bien en los últimos años se han dado pasos muy acertados en esa dirección, todavía resta mucho por hacer, en especial en lo concerniente a la importante tarea de dotar al departamento de un marco normativo idóneo.Although the Departmental Assemblies have been stable for more than a hundred years in the Colombian legal system, these institutions have undergone an obvious omission on the part of public opinion, the jurisprudence and doctrine specialist, which merely reflects the low importance of these corporations are in the legal and political developments. However, this regrettable situation is not due solely to the errors inherent to the bad political habits that have been beaten so heavily the regions, and certainly have justified in large part the continuing attacks that have been directed for some time against the Assemblies. They, in turn, are victims of a territorial system known by the vagueness and lack of practical and legislative development, which has ended to delegitimize the figure of the department. In any case, the democratic principles of popular representation and the separation of powers (check and balances) demand popular elected corporation in the territorial entities that are able to channel the views and mindset of its inhabitants, looking for greater citizen engagement in local affairs. It is therefore necessary to strengthen the Assembly and give them a place in the arena of local reality. And although in recent years there have been very successful steps in this direction, much remains to be done, particularly with regard to the important task of providing the department an appropriate regulatory framework.Abogado (a)Pregrad

A reconnection driven magnetic flux cancellation and a quiet Sun Ellerman bomb

The focus of this investigation is to quantify the conversion of magnetic to thermal energy initiated by a quiet Sun cancellation event and to explore the resulting dynamics from the interaction of the opposite polarity magnetic features. We used imaging spectroscopy in the H$\alpha$ line, along with spectropolarimetry in the \ion{Fe}{I} 6173~{\AA} and \ion{Ca}{II} 8542~{\AA} lines from the Swedish Solar Telescope (SST) to study a reconnection-related cancellation and the appearance of a quiet Sun Ellerman bomb (QSEB). We observed, for the first time, QSEB signature in both the wings and core of the \ion{Fe}{I} 6173~{\AA} line. We also found that, at times, the \ion{Fe}{I} line-core intensity reaches higher values than the quiet Sun continuum intensity. From FIRTEZ-dz inversions of the Stokes profiles in \ion{Fe}{I} and \ion{Ca}{II} lines, we found enhanced temperature, with respect to the quiet Sun values, at the photospheric ($\log\tau_c$ = -1.5; $\sim$1000 K) and lower chromospheric heights ($\log\tau_c$ = -4.5; $\sim$360 K). From the calculation of total magnetic energy and thermal energy within these two layers it was confirmed that the magnetic energy released during the flux cancellation can support heating in the aforesaid height range. Further, the temperature stratification maps enabled us to identify cumulative effects of successive reconnection on temperature pattern, including recurring temperature enhancements. Similarly, Doppler velocity stratification maps revealed impacts on plasma flow pattern, such as a sudden change in the flow direction.Comment: 16 pages, 12 figures, accepted for publication in MNRA

Lattice three-gluon vertex in extended kinematics: Planar degeneracy

We present novel results for the three-gluon vertex, obtained from an extensive quenched lattice simulation in the Landau gauge. The simulation evaluates the transversely projected vertex, spanned on a special tensorial basis, whose form factors are naturally parametrized in terms of individually Bose-symmetric variables. Quite interestingly, when evaluated in these kinematics, the corresponding form factors depend almost exclusively on a single kinematic variable, formed by the sum of the squares of the three incoming four-momenta, q, r, and p. Thus, all configurations lying on a given plane in the coordinate system (q2,r2,p2) share, to a high degree of accuracy, the same form factors, a property that we denominate planar degeneracy. We have confirmed the validity of this property through an exhaustive study of the set of configurations satisfying the condition q2=r2, within the range [0,5GeV]. This drastic simplification allows for a remarkably compact description of the main bulk of the data, which is particularly suitable for future numerical applications. A semi-perturbative analysis reproduces the lattice findings rather accurately, once the inclusion of a gluon mass has cured all spurious divergences.The authors thank A. C. Aguilar, G. Eichmann and C. D. Roberts for useful discussions. M.N.F. acknowledges financial support from the FAPESP projects 2017/05685-2 and 2020/12795-1, respectively. J.P. is supported by the Spanish MICINN grant PID2020-113334GB-I00 and the regional Prometeo/2019/087 from the Generalitat Va-lenciana; while F.D.S. and J.R.Q. are by the Spanish MICINN grant PID2019-107844GB-C22 and the regional Andalusian P18-FR-5057. All calculations have been performed at the UPO computing center, C3UPO