Mixed Logical Dynamical Nonlinear Model Predictive Controller for Large‐Scale Solar Fields

This paper presents a control algorithm for reducing heat losses caused by clouds in large solar fields. The formulation is based on a Mixed Logical Dynamical (MLD) representation of the solar field plus the application of a Practical Nonlinear Model Predictive Controller (PNMPC) for calculating the optimal control action. The main purpose of the controller is to deactivate fields with inlet temperature greater than outlet temperature and to manipulate the oil flow rate of the activated fields for tracking the reference of the outlet temperature. A simplified lumped parameters model is used for prediction and simulation of the solar fields.     

A multi-objective approach for multi-material topology and shape optimization

An automated multi-material approach that integrates multi-objective Topology Optimization (TO) and multi-objective shape optimization is presented. A new ant colony optimization algorithm is presented and applied to solving the TO problem, estimating a trade-off set of initial topologies or distributions of material. The solutions found usually present irregular boundaries, which are not desirable in applications. Thus, shape parameterization of the internal boundaries of the design region, and subsequent shape optimization, is performed to improve the quality of the estimated Pareto-optimal solutions. The selection of solutions for shape optimization is done by using the PROMETHEE II decision-making method. The parameterization process involves identifying the boundaries of different materials and describing these boundaries by non-uniform rational B-spline curves. The proposed approach is applied to the optimization of a C-core magnetic actuator, with two objectives: the maximization of the attractive force on the armature and the minimization of the volume of permanent magnet material.     

Personalizing self-organizing music spaces with anchors: design and evaluation

We propose and evaluate a system for content-based visualization and exploration of music collections. The system is based on a modification of Kohonen’s Self-Organizing Map algorithm and allows users to choose the locations of clusters containing acoustically similar tracks on the music space. A user study conducted to evaluate the system shows that the possibility of personalizing the music space was perceived as difficult. Conversely, the user study and objective metrics derived from users’ interactions with the interface demonstrate that the proposed system helped individuals create playlists faster and, under some circumstances, more effectively. We believe that personalized browsing interfaces are an important area of research in Multimedia Information Retrieval, and both the system and user study contribute to the growing work in this field.     

Automated conceptual model clustering: a relator-centric approach

Software and Systems Modeling - In recent years, there has been a growing interest in the use of reference conceptual models to capture information about complex and sensitive business domains...     

Poly(lactic acid)/poly(vinyl pyrrolidone) membranes produced by solution blow spinning: Structure,thermal, spectroscopic,and microbial barrier properties

Submicrometric and nanometric poly(lactic acid)/poly(vinyl pyrrolidone) (PLA/PVP) fibrous membranes containing 0, 5, 10, 15, and 20 wt % PVP, with or without 20 wt % Copaiba oil (Copaifera sp.), were produced by solution blow spinning (SBS), using polymer injection rate of 120 μL min^?1, gas pressure of 2.4 kPa, working distance of 20 cm, and collector rotation of 200 rpm. The morphological, thermal, and spectroscopic properties of these membranes were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetry (TG), and Fourier transform infrared spectroscopy (FTIR). A method for the evaluation of membrane microbial barrier properties based on resazurin colorimetric method was proposed. Results showed that the addition of both PVP and Copaiba oil produced thicker fibers; otherwise, there was no effect on morphology. Thermal analyses (TG and DSC) indicated the immiscible nature of polymer blends produced, also confirmed by the spectroscopic studies. Antimicrobial barrier properties were related to the antimicrobial effect of Copaiba oil, combined with it hydrophobic nature. The hydrophilic nature of PVP favored degradation of fiber mats, impairing barrier property when higher concentrations of PVP were added. Results indicate that produced spun mats can potentially be used in applications such as wound dressing. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44802.     

Development of Brazilian steel construction

This article presents a concise short overview of the development of the steel industry in Brazil, with the emphasis on civil construction. The relatively rapid increase in the application of steel structures for both low and tall buildings and the modern bridges in Brazil are the results of an extensive effort of the steel producers and the improvement of steel courses and research programmes in several universities and institutions during the last two decades. The steel industry in collaboration with the universities, which have provided the results of their recent studies, contributed to the improved steel technologies and composite construction. Data, supplied by the Brazilian Institute of Metallurgy, IBS, is presented on the actual steel production and fabrication with regard to application in civil engineering. Case studies of steel structures, such as multi-storey buildings, space structures, light gauge steel construction and bridges, are presented and commented on. Further, steel structures subjected to corrosion or to fire, as well as steel and composite semi-rigid joints, are mentioned and finally the Brazilian experience with steel architecture is introduced.     

Developing Smart Grids Based on GPRS and ZigBee Technologies Using Queueing Modeling–Based Optimization Algorithm

Smart metering systems have become widespread around the world. RF mesh communication systems have contributed to the creation of smarter and more reliable power systems. This paper presents an algorithm for positioning GPRS concentrators to attain delay constraints for a ZigBee‐based mesh network. The proposed algorithm determines the number and placement of concentrators using integer linear programming and a queueing model for the given mesh network. The solutions given by the proposed algorithm are validated by verifying the communication network performance through simulations.     

Exploring Social Networks and Improving Hypertext Results for Cloud Solutions

Internet technologies are constantly evolving as well as the way people use them. Search engines help users to find higher and better relevant results to their searches. Cloud Computing is an evolution of the Internet services and provides a step further ecosystem that can be used to improve the search of more relevant results. Each search engine is based on different modules in order to retrieve the results expected by users using specific keywords. Social networks appear as a reliable Web technology that can directly support a content search. Several studies have been performed showing the growth of social networks in people lives. Using the cloud computing paradigm it is possible to propose a more scalable and efficient way to explore public information available on online social networks. This paper includes the analyses of several social networks services, available contents, cloud-crawlers, and information extraction. In order to collect relevant data from social networks, a social crawler on cloud is proposed. The new approach provides a cloud-based crawler for low-cost, effective, and personalized search models. Moreover, a new algorithm to rank Web documents is proposed and demonstrated. The proposed system is evaluated in comparison with the top Internet search engine, Google, its behavior is very promising, and it is ready for use.