Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

This article presents a theoretical discussion of the most accepted forms of social capital in the literature: bonding, bridging, and linking. It studies the relationship between the forms of social capital and Granovetter's strength of weak ties thesis, the principle of homo-heterophilia and Lin's status attainment theory. In addition, an extension of the theoretical model of the forms of social capital is proposed. Considering the relationship between the strength of the tie and the position that the individual occupies in the social structure results in considering not only the hierarchical weak ties (linking), but also the hierarchical strong ties (or hierarchical bonding).

This article presents a theoretical review of the perspectives of social capital. First, the concept of social capital is defined, taking into consideration the different interpretations that social capital has been the object of. Then, the two fundamental perspectives of social capital recognized in the literature are identified: the individual perspective, also called the network approach, which considers social capital an individual resource; and the community perspective, which made the theory of social capital famous and considers it a characteristic of a group. Finally, the bridges that unite them and the abysses that separate them are analyzed.

In classical sociological texts, history has a strong presence, and the theoretical defence of an historical aware sociology has been common, in particular in Latin America. However, those arguments had been unsuccessful. In this paper we will present some hypothesis around this fact, and we will conclude defending the need of a sociology that is based on an historical knowledge in depth. Without that knowledge, we obtain bad empirical sociology and insufficient theorical approaches.

La economía colaborativa relacionada con el transporte de personas, el alojamiento, la comida y la vivencia de experiencias muestra gran relevancia en el sector del turismo. El objetivo de esta investigación es valorar cuatro plataformas de economía colaborativa (Airbnb, Blablacar, Eatwith y Trip4Real) en base a la valor de uso, la confianza, la utilidad de leer y hacer comentarios, e intención de uso y de recomendar. En la valoración de las plataformas se analiza la influencia del sexo, la edad y la forma en que los participantes del estudio acceden a las plataformas. Metodológicamente, se aplica un modelo de análisis de variancia multivariado, manova, en un diseño factorial 2x2x2x4 (Generación x Grupo x Sexo x Plataforma) para analizar los efectos principales y las interacciones entre factores. El tipo de muestreo es no probabilístico, intencional, basado en cuotas de edad y sexo. La muestra final fue de 222 participantes (n = 222). La plataforma Trip4Real, relacionada con el turismo experiencial, es la que despierta el mayor grado de interés en los participantes del estudio. El factor con más influencia sobre las distintas valoraciones ha sido el Grupo, corroborando la importancia de acercarse a los distintos servicios analizados de la economía colaborativa desde una perspectiva real o necesidad creada. Por otra parte, los jóvenes o millennials son más receptivos, muestran más confianza ante las plataformas presentadas y perciben más útiles los comentarios online emitidos.

The main objective of this article is to provide an updated portrait of the Social Economy sector in Portugal. For this purpose, we first analyse how in Portugal the concept of Social Economy has been defined and delimited, particularly by legal means. The difficulties in establishing clear and unquestionable boundaries are highlighted, as well as the observation of the concept from the diversity that composes it, both in terms of guiding principles and of groups of entities that integrate this sector. Subsequently, a quantitative portrait of the Portuguese Social Economy is drawn, with the most recent data, made public in 2019 and for 2016, as a source. These data result from work done by the National Statistics Institute (INE - Statistics Portugal) through the Social Economy Satellite Account. In addition to the main general indicators of the sector (number of units, gross value added, main activities, groups of entities, total and paid employment), a specific analysis by groups of entities is also carried out. By making use of Satellite Account to draw this picture, we aim to provide conceptually structured statistical information with a form and content that may facilitate its subsequent use in the context of broader studies, both diachronic analysis as well as international comparisons.

In nonprofit organisations, a mix of financial and nonfinancial information is necessary to discharge accountability, and with this aim, social accounting emerged some years ago. Integrated reporting has been more recently developed with the aim of reporting the connections and relationships between all the factors that affect an organisation’s ability to create value over time. This paper analyses what integrated reporting can add to accountability and management in nonprofit organisations, considering that it includes performance as well as social and environmental aspects. The paper uses a case study to analyse how integrated social reporting has been implemented in some organisations and what are the particularities that must be considered to develop a model for these organisations. Semi-structured interviews with the responsible of three social organisations have been carried out to find out what improvements integrated reporting can make and what is necessary for their implementation.

Realistic real-time water-solid interaction has been an open problem in Computer Graphics since its beginnings, mainly due to the complex interactions that happen at the interface between solid objects and liquids, both when objects are completely or partially wet, or when they are fully submerged.In this paper we present a method that tackles the two main aspects of this problem, namely the buoyancy of objects submerged into fluids, and the superficial liquid propagation and appearance changes that arises at the interface between the surface of solid objects in contact with a liquids.For the first problem (buoyancy) a method is proposed to realistically compute the fluid-to-solid coupling problem. Our proposal is suitable for a wide spectrum of cases, such as rigid or deformable objects, hollow or filled, permeable or impermeable, and with variable mass distribution. In the case of permeable materials, which allow liquid to pass through the object, the presented method incorporates the dynamics of the fluid in which the object is submerged, and decouples the computation of the physical quantities involved in the buoyancy force of the empty object with respect to to the liquid contained within it. On the other hand, the visual appearance of certain materials depends on their intrinsic light transfer properties, the lighting present and other environmental contributions. Thus, complementing the first approach in this paper, a new technique is introduced to model and render the appearance changes of absorbent materials when there is liquid on their surface. Also, a new method was developed to solve the problem of the interaction between the object surface and liquids, taking advantage of texture coordinates. An algorithm was proposed to model the main physical processes that occur on the surface of a wet or wet solid object. Finally, we model the change in appearance that typically arise in most materials in contact with fluids, and an algorithm is implemented achieving real-time performance. The complete solution is designed taking advantage of superscalar architectures and GPU acceleration, allowing a flexible integration with the pipelines of current graphic engines.

Electronic commerce, as a new way of commercialization, is not only a business decision, since not all companies, nor all consumers in a region, are technologically prepared to adopt electronic commerce. To implement this type of trade, companies should carry out a diagnostic study, both to know if the technological resources are available internally, and to determine if the potential clients are also ready and willing to use the channel. From this perspective, this work seeks to design an instrument that allows diagnosing the e-Commerce readiness of micro and small businesses, and their potential consumers in rural areas. An iterative process to create the diagnosis instruments was used.  It involved iterations of design and evaluation stages. Academic experts with extensive experience in instrument design carried out the first evaluation; the second iteration was evaluated in a pilot field study where 6 companies and 10 consumers from similar regions participated. Finally, in a case study in the canton of Río Cuarto de Alajuela, 29 companies and 261 consumers from the region participated in this study. The diagnosis highlights that most of these companies express that they are not technologically prepared to implement e-commerce, while most of the participating consumers indicated that they do feel technologically prepared to use these platforms.

Quality indicators (QIs) are functions that assign a real value to a set that represents the Pareto front approximation of a multi-objective optimization problem. In the evolutionary multi-objective optimization community, QIs have been mainly employed in two ways: (1) for the performance assessment of multi-objective evolutionary algorithms (MOEAs), which produce Pareto front approximations, and (2) to be adopted as the backbone of selection mechanisms of MOEAs. Regardless of the continuing advances on QIs and their utilization in MOEAs, there are currently a vast number of open questions in this researcharea. In this doctoral thesis, we have focused on two main research directions: the design of new selection mechanisms based on the competition and cooperation of multiple QIs, aiming to compensate for the weaknesses (in terms of convergence and diversity properties) of individual QIs with the strengths of the others. The second research axis is the generation of new QIs that are compliant with the Pareto dominance relation extended to sets. Such QIs have a direct impact on the type of conclusions that can be drawn about the performance of MOEAs. Our experimental results have shown that the use of multiple QIs either to design new selection mechanisms or to construct new Pareto-compliant QIs is a promising research direction that can improve the capabilities of MOEAs and that allows for a performance assessment of MOEAs with a higher degree of confidence.

Automatic recognition using ear images is an active area of interest within the biometrics community. Human ears are a stable and reliable source of information since they are not affected by facial expressions, do not suffer extreme change over time, are less prone to injuries, and are fully visible in mask-wearing scenarios. In addition, ear images can be passively captured from a distance, making it convenient when implementing surveillance and security applications. At the same time, deep learning-based methods have proven to be powerful techniques for unconstrained recognition. However, to truly benefit from deep learning techniques, it is necessary to count on a large-size variable set of samples to train and test networks. In this work, we built a new dataset using the VGGFace dataset, fine-tuned pre-train deep models, analyzed their sensitivity to different covariates in data, and explored the score-level fusion technique to improve overall recognition performance. Open-set and close-set experiments were performed using the proposed dataset and the challenging UERC dataset. Results show a significant improvement of around 9% when using a pre-trained face model over a general image recognition model; in addition, we achieve 4% better performance when fusing scores from both models.