An intelligent alternative approach to the efficient network management

Due to the increasing complexity and heterogeneity of networks and services, many efforts have been made to develop intelligent techniques for management. Network intelligent management is a key technology for operating large heterogeneous data transmission networks. This paper presents a proposal for an architecture that integrates management object specifications and the knowledge of expert systems. We present a new approach named Integrated Expert Management, for learning objects based on expert management rules and describe the design and implementation of an integrated intelligent management platform based on OSI and Internet management models. The main contributions of our approach is the integration of both expert system and managed models, so we can make use of them to construct more flexible intelligent management network. The prototype SONAP (Software for Network Assistant and Performance) is accuracy-aware since it can control and manage a network. We have tested our system on real data to the fault diagnostic in a telecommunication system of a power utility. The results validate the model and show a significant improvement with respect to the number of rules and the error rate in others systems

Integración de inteligencia en la MIB del Modelo OSI para la gestión de redes de telecomunicaciones

La Gestión de red se define como el conjunto de actividades dedicadas al control y vigilancia de los recursos existentes en las redes de telecomunicaciones. En los complejos sistemas actuales, es necesario realizar una gestión de la red asistida por un software avanzado. La Inteligencia Artificial se incorpora a la gestión de las redes, con el fin de facilitar labores de administración y control de toda la información que proviene de los recursos gestionados, dando origen a la Gestión Inteligente de las Redes. Este nuevo paradigma, proporciona a los sistemas de gestión de un mayor grado de cohesión con las tecnologías de comunicaciones actuales, a la vez de disponer de todas las posibilidades y ventajas aportadas por la Inteligencia Artificial. Nuestro estudio tiene como objetivo perfeccionar las técnicas actuales de gestión. Para ello se establecen mecanismos que permiten una mayor correlación entre las especificaciones de la red y las aplicaciones que efectúan el tratamiento de la información de gestión. Presentamos una nueva concepción denominada “Gestión Inteligente Integrada” y una extensión del modelo de gestión OSI, que contempla la inclusión del conocimiento de gestión, en las propias especificaciones de los objetos gestionados. Este modelo consigue reunir conceptos que actualmente pertenecen a distintos ámbitos de estudio, la Inteligencia Artificial y la Información de Gestión del sistema. De esta forma se obtiene una solución global, que permite a los administradores de redes utilizar la potencia aportada por la Inteligencia Artificial, en particular de los Sistemas Expertos, de una forma sencilla y transparente

Mechanical characterization and elastic stiffness degradation of unstabilized rammed earth

Rammed earth is attracting renewed interest due to its sustainability. In this work, a mechanical characterization of unstabilized rammed earth is presented. Compressive strength, Young’s modulus, and Poisson’s ratio were determined, with the first of these being the most representative mechanical property of rammed earth. Stress – strain curves were obtained from uniaxial compression tests. Creep is of great importance in the long-term assessment of historical buildings and in the design of new ones. Samples of rammed earth were subjected to a constant load for 15 days to study their creep behavior. In order to simulate the long-term behavior of the material, different rheological models were fitted to the experimental results. The instantaneous deformation of rammed earth samples caused by a sudden additional load (maintaining a previous service load level) was also studied. This is the first time that this phenomenon, called elastic stiffness degradation, has been studied for rammed earth material

Mechanical Characterization and Creep Behavior of a Stone Heritage Material Used in Granada (Spain): Santa Pudia Calcarenite

Santa Pudia calcarenite was one of the most commonly used building materials in the construction of historical buildings in the city of Granada (Spain). As a result, Santa Pudia calcarenite has been mainly studied from a petrographical point of view in previous works. In this work, the mechanical properties of Santa Pudia calcarenite are studied. The main mechanical properties (compressive strength, elastic modulus and Poisson’s ratio) were determined using the corresponding tests. Samples of Santa Pudia calcarenite were heated at 550 °C to study the effect of high temperatures on its compressive strength. Two different cooling methods were considered: air-cooling and water-cooling. Stress–strain curves of heated and non-heated samples were obtained from uniaxial compression tests. Creep is of great importance in the long-term structural assessment of historical buildings. To study the creep behaviour of Santa Pudia calcarenite, samples were subjected to uniaxial compressive tests at constant stress until the stabilization of the recorded strains was reached. Different rheological models were adjusted to the experimental results to simulate the long-term behaviour of the material studied. The instantaneous response to additional loadings on the samples (maintaining the long-term loading and deformation) were also studied. Results show that a Santa Pudia calcarenite specimen subjected to dead loads will suffer a higher instantaneous deformation against a sudden load than a non-preloaded specimen. This degradation effect can be particularly important in the case of a seismic evaluation of historical buildings

The octahedron family: a source of tensegrity structures

A tensegrity family is a group of tensegrity structures that share a common connectivity pattern. In the case that just two values of the force density or force:length ratio are adopted (one for cables and another for struts), the members of the octahedron family are: the octahedron, the expanded octahedron and the double-expanded octahedron. In this work a higher number of possible force:length ratio values have been considered in order to find new members of the family. The values of the force:length ratios which satisfy the super-stability conditions have been computed analytically. New super-stable tensegrity forms of the octahedron family have been obtained. Results show that all of them are members of the octahedron family having as folded forms all the lower members of the family. Finally, based on topological rules, it has been proved that the double-expanded octahedron can be defined from a truncated cube

Topological design of the octahedron tensegrity family

Tensegrity structures have developed greatly in recent years due to their unique mechanical and mathematical properties. In this work, the topology of the Octahedron family is presented. New tensegrity structures that belong to this family are defined based on their topology. As an example, the eleven-time-expanded octahedron is shown, a super-stable tensegrity formed by 12,288 nodes, 6,144 struts, and 24,576 cables (the largest superstable tensegrity reported in the literature in terms of number of nodes, cables, and struts so far). The values of the force:length ratios which satisfy the super-stability conditions have also been determined based on the topology of the Octahedron family. Consequently, the computational cost of the process of determining a suitable prestress state and its corresponding equilibrium shape (a process called form-finding) is significantly reduced. The members of the Octahedron family could have promising engineering and bioengineering applications

The Z-octahedron family: a new tensegrity family

The present paper work was sent to Engineering Structures on 23 April 2020 (it is currently under review).A new family of tensegrity structures is presented: the Z-octahedron family. A tensegrity family is a group of tensegrity structures that share a common connectivity pattern. The members of the Z-octahedron family have been obtained replacing the elementary rhombic cells of the members of the octahedron family with elementary Z-shaped cells. In addition, a higher number of possible force density or force:length ratio values have been considered. The values of the force:length ratio of the members of the family that lead to super-stable tensegrity forms have been computed analytically. Two members of the family have been obtained: the Z-expanded octahedron and the Z-double-expanded octahedron. Finally it has been proved that the Z-double-expanded octahedron obtained here from topological rules can also be defined from a truncated cube based on purely geometrical intuition

Topological design of compression structures with prestressing tendons

Compression structures with prestressing tendons are a new type of structures which combines a compression structure with a discrete number of tension members treated as ties. They are an intermediate case between tension-only structures and compression-only structures. As tension and compression members exist, the force density matrix can be singular or ill-conditioned. Consequently, the solution of the equilibrium equation is not as simple as in the case of tension-only and compression-only structures. In this catalogue, nine compression structures with prestressing tendons are presented to show the potential of this new type of structure

Residual capacity assessment of reinforced concrete D-Regions affected by corrosion

Important note: The present paper work was sent to Construction and Building Materials on 15 April 2020 (it is currently under review).The repair and rehabilitation of Reinforced Concrete (RC) structures affected by the corrosion of their reinforcement is a complex task. The estimation of the residual structural capacity of corroded RC structures is becoming a crucial factor in the decision-making process of repair or demolition. Many researchers have studied the effects of reinforcement corrosion on the load capacity of RC beams (Bernoulli or B-Regions) but little attention has been paid to disturbed or D-Regions. This piece of work presents a procedure for the assessment of the residual structural capacity of D-Regions in RC members. The bond deterioration between steel and concrete, the reduction of the cross-sectional area of reinforcement, the deterioration of the concrete area of the cross-section and the softening of concrete has been taken into consideration. The accuracy of the method has been tested with experimental results which exist in relevant literature

Octahedron family: the double-expanded octahedron tensegrity

Es un preprintThe octahedron family of tensegrity structures is presented in this research. The octahedron and the expanded octahedron (well-known tensegrities in the literature) are the first and second components of the family. A new tensegrity is presented: the double-expanded octahedron. This new tensegrity form was obtained following the connectivity pattern of the octahedron family presented in this work. The values of the force densities or force:length ratios that satisfy the minimum required rank deficiency of the force density matrix were computed analytically. Two types of solutions are obtained: full and folded forms. Results show that each lower member of the octahedron family is a folded form of a superior member of this family. Several examples are shown.Grupo de Investigación TEP-19