Abstract: Remote Sensing in agriculture makes possible the acquisition of large amount of data without physical contact, providing diagnostic tools with important impacts on costs and quality of production. Hyperspectral imaging sensors attached to airplanes or unmanned aerial vehicles (UAVs) can obtain spectral signatures, that makes viable assessing vegetation indices and other charac-teristics of crops and soils. However, some of these imaging technologies are expensive and therefore less attractive to familiar and/or small producers. In this work a method for estimating Near Infrared (NIR) bands from a low-cost and well-known RGB camera is presented. The method is based on a weighted sum of NIR previously acquired from pre-classified uniform areas, using hyperspectral images. Weights (belonging degrees) for NIR spectra were obtained from outputs of K-nearest neighbor classification algorithm. The results showed that presented method has potential to estimate near in-frared band for agricultural areas by using only RGB images with error less than 9%.

Abstract: With increasing interest in unconventional resources, understanding the flow in fractures, the gathering system for fluid production in these reservoirs, becomes an essential building block for developing effective stimulation treatment designs. Accurate determination of stress-dependent permeability of fractures requires time-intensive physical experiments on fractured core samples. Unlike previous attempts to estimate permeability through experiments, we utilize 3D Lattice Boltzmann Method simulations for increased understanding of how rock proper-ties and generated fracture geometries influence the flow. Here, both real induced shale rock fractures and synthetic fractures are studied. Digital representations are characterized for descriptive topological parameters, then duplicated, with the upper plane translated to yield an aperture and variable degree of throw. We pre-sent several results for steady LBM flow in characterized, unpropped fractures, demonstrating our methodology. Results with aperture variation in these com-plex, rough-walled geometries are described with a modification to the theoretical cubic law relation for flow in a smooth slit. Moreover, a series of simulations mimicking simple variation in proppant concentration, both in full and partial monolayers, are run to better understand their effects on the permeability of propped fractured systems.

Abstract: The plastics industry is continuously demanding for plastic parts with higher surface quality and improved mechanical properties. The injection molding process is the most widely used, and allows producing a huge variety of parts. Computer simulation can be a valuable tool when needing to optimize manufacturing processes, and along the last couple of decades, software was developed specifically to predict the outcome and optimize parameters in injection molding. However, several non-conventional injection molding processes still lack proper computational techniques/approaches. Such is the case of RHCM (Rapid Heating Cycle Molding), involving both heating and cooling cycles, with the injection of the material into the mold being made with a hot mold surface (against the conventional approach where the mold surface is cold). In this work, we explored the limits of state-of-the-art models for simulating this process, given the necessity to use it in a practical industrial application, and we propose a way to use homogenization theory to solve the heat transfer problem. It provides an assessment that in a periodic medium, the solution of the convection-conduction energy equation is approximated by the solution of a heat equation. In this equation, a new term appears: a homogenized conductivity tensor that includes terms that account for convection. This equation can be used for the first time to: (i) study in great detail one single periodic cell of the microstructure and use its results to characterize the performance of the macroscale domain (ii) serve as a model for material engineering in heat transfer applications (iii) model problems in other fields that possess the same physical and geometric nature. Our results are illustrated with analytical analyses and numerical simulations, proving this model can accurately reconstruct the physics behind the heat transfer process. With this novel approach, we can better understand the process, and improve industrial practice for RHCM in injection molding.

Abstract: Multi-hop D2D (Device-to-Device) communication may be exposed to many intrusions for its inherent properties, such as openness and weak security protection. To mitigate the intrusions in time, one of significant approaches is to establish a Cooperative Intrusion Response System (CIRS) to detect and respond to the intrusion activities, i.e., during data transmission, User Equipments that act as relays (RUEs) cooperatively help destination nodes to detect and respond intrusion events. However, the CIRS cannot efficiently work in multi-hop D2D communication because the RUEs are selfish and unwilling to spend extra resources on undertaking the intrusion detection and response tasks. To address this problem, an incentive mechanism is required. In this paper, we formulate an incentive mechanism for CIRS in multi-hop D2D communication as a dynamic game and achieve an optimal solution to help RUEs decide whether to participate in detection or not. Theoretical analysis shows that only Nash equilibrium exists for the proposed game. Simulations demonstrate that our mechanism can efficiently motivate potential RUEs to participate in intrusion detection and response, and can also block intrusion propagation in time.

Abstract: The main characteristics of Software-Defined Networks are the separation of the control and data planes, as well as a logically centralized control plane. This emerging network architecture simplifies the data forwarding and allows managing the network in a exible way. Controllers play a key role in SDNs since they manage the whole network. It is crucial to determine the minimum number of controllers and where they should be placed to provide low latencies between switches and their assigned controller. It is worth to underline that, if there are long propagation delays between controllers and switches, their ability of reacting to network events quickly is affected, degrading reliability. Thus, the Reliability-Aware Controller Placement (RCP) problem in Software-Defined Networks (SDNs) is a critical issue. In this work we propose a k-cover based model for the RCP problem in SDNs. It simultaneously optimizes the number and placement of controllers, as well as latencies of primary and backup paths between switches and controllers, providing reliable networks against link, switch and controller failures. Although RCP problem is NP-hard, the simulation results show that reliabilities greater than 97%, satisfying low latencies, were obtained and the model can be used to find the optimum solution for different network topologies, in negligible time.