Capture of UAVs Through GPS Spoofing Using Low-Cost SDR Platforms

Wireless Personal Communications - The increased use of unmanned aerial vehicles (UAVs), better known as drones, by civilians has grown exponentially and their autonomous flight control systems...     

Image dehazing using morphological opening,dilation and Gaussian filtering

Image pre-processing is a critical stage in computer vision systems, with greater relevance when the input images are captured in outdoor environments because the pictures could contain low contrast and modified colors. A common condition present in outdoor images is haze. In this work, a new dehazing algorithm based on dark channel prior mathematical morphology operations (opening and dilation), and a Gaussian filter, is proposed. Moreover, the proposed algorithm performance is compared qualitatively and quantitatively against previously reported algorithms. Obtained results show that the proposed algorithm requires less processing time providing higher quality dehazing results than other state-of-the-art approaches.     

Data envelopment analysis with multiple modes of functioning. Application to reconfigurable manufacturing systems

In principle, data envelopment analysis (DEA) does not consider the possibility, which can occur in practice, of a production system being able to operate in different modes of functioning. In this paper, a new DEA modelling approach is proposed in which the different modes of functioning are taken into account and included in the analysis. The observed input consumption and output production in each mode of functioning is used to derive a mode-specific technology. The overall DEA technology aggregates these mode-specific technologies according to their respective time allocations. The proposed model computes a target operating point for each mode of functioning so that the operation of the overall system is efficient. The proposed approach is applied to assess the technical, cost and allocative efficiency of a reconfigurable manufacturing system. The inputs considered are modules/tools usage, labour and energy consumption. The outputs are the number of units produced of each part type. The production possibility set is determined by previous observations of the system functioning, from which the best practices can be identified. Technical, cost and allocative efficiency scores can be computed. The proposed approach not only generates input cost savings but also lead time reductions.     

An iron-based T 1 contrast agent made of iron-phosphate complexes: In vitro and in vivo studies

A new iron-based T ₁ contrast agent consisting of a complex of iron ions coordinated to phosphate and amine ligands (Fe_(phos) in short) has been characterized by spectroscopic and magnetic measurements. NMR relaxation studies showed r ₁ values to be dependent on the phosphate salt concentration, K₂HPO₄, present in the medium. r ₁ reaches a maximum value of 2.5 mM^?1 s^?1 for measurements carried out at 7 T and 298 K. ³¹P MRS, Mössbauer spectroscopy and magnetic measurements of Fe_(phos) solutions suggest paramagnetic Fe³⁺ ions present in the studied iron–phosphate complex. In vitro and in vivo toxicity experiments with C6 cells and CD1 mice, respectively, demonstrated lack of toxicity for Fe_(phos) at the highest dose tested in the MRI experiments (12 mM iron for C6 cells and 0.32 mmol iron/kg for mice). Finally, T ₁ weighted images of brain tumours in mice have shown positive contrast enhancement of Fe_(phos) for tumour afflicted regions in the brain.     

Determination of the complex permittivity of cherry,pulped, green,and roasted coffee using a planar dielectric platform and a coaxial probe between 0.3 and 6 GHz

The complex permittivity for four processing stages of coffee: coffee cherries, pulped coffee, green coffee, and roasted coffee was obtained and divided into two groups. The wet group is constituted by cherry and pulped coffee, and the dry group by green and roasted coffee. The wet group presented a dielectric constant between 64 and 43, and a loss factor between 34 and 12. The dry group has values oscillating between 1.55 and 1.1 for the dielectric constant, and 0.037 and 0.005 for the loss factor. The permittivity difference between the wet and dry groups suggests the dependence of the coffee permittivity on the water content, along with the presence of other polar compounds. A decaying response for the dielectric constant was seen, with a proportion of 30:1 from the wet to the dry group. The loss factor presents a convex response for the wet group and a constant response for the dry group with a factor of 500 to a 100:1 from the wet to the dry group. A set of 18 samples at every stage was used to estimate the moisture content by partial least squares. The Meyer and Schilz coefficient was used for these models, that resulted in prediction errors of 2.8% and 3.8% when compared to the stage mean moisture content for the wet group. The dry group resulted in errors of 21% and 89.7%. These results indicate that the complex permittivity of coffee is capable of estimating physicochemical variables as the moisture content of the beans at distinct processing stages.     

Flywheel energy storage systems: Review and simulation for an isolated wind power system

In flywheel based energy storage systems (FESSs), a flywheel stores mechanical energy that interchanges in form of electrical energy by means of an electrical machine with a bidirectional power converter. FESSs are suitable whenever numerous charge and discharge cycles (hundred of thousands) are needed with medium to high power (kW to MW) during short-time periods (seconds–minutes). Monitoring of the FESS state of charge is simple and reliable as only the spinning speed is needed. The materials for the flywheel, the type of electrical machine, the type of bearings and the confinement atmosphere which all together determine the FESSs energy efficiency (>85%) are reviewed. Main FESS applications: power quality, traction and aerospace are presented. Additionally in this paper it is presented the simulation of an isolated wind power system (IWPS) consisting of a wind turbine generator (WTG), a consumer load, a synchronous machine (SM) and a FESS. A low-speed iron flywheel driven by an asynchronous machine (ASM) is sized for the presented IWPS. The simulation results with graphs for system frequency, system voltage, active powers of the different elements, and FESS-ASM speed, direct and quadrature currents are presented showing that the FESS effectively smoothes the wind power and consumer load variations.     

Bifidobacterium Bb-12 microencapsulated by spray drying with whey: Survival under simulated gastrointestinal conditions,tolerance to NaCl,and viability during storage

Bifidobacterium Bb-12 was microencapsulated by spray drying with whey. This present work investigated the survival of these microcapsules under simulated gastrointestinal conditions, as well as their tolerance to NaCl and their viability during storage. The results showed a small decrease in the viability of microencapsulated Bifidobacterium at low pH. In relation to the exposure of Bifidobacterium to bile, microencapsulation with whey did not protect the probiotic cells; however, the viability of the microcapsules remained >6 log cfu/g, even after 24 h of incubation at the highest bile concentration analyzed. No growth was noted with either the free cells or the microencapsulated cells on MRS-LP with NaCl. The viability of the microcapsules stored at 4 °C remained high and constant for 12 weeks. When the microcapsules were added to a dairy dessert, the probiotic count remained above 7 log cfu/g for 6 weeks. Therefore, whey is a promising encapsulating agent for Bifidobacterium Bb-12.