Effect of Leading Edge Protuberance on Thrust Production of a Dynamically Pitching Aerofoil

The paper presents a computational analysis of the characteristics of a NACA 634-021 aerofoil modified by incorporating sinusoidal leading-edge protuberances at Re = 14,000. The protuberances are from the tubercles of the humpback whale flipper with leading edge acting as passive-flow control devices that improve performance and manoeuvrability of the flipper. They are characterized by an amplitude and wavelength of 12% and 50% of the aerofoil chord length respectively. Three-dimensional CFD on the modified aerofoil oscillating about a point located on the centreline at quarter-chord has been performed with the frequency and amplitude of oscillation being 4Hz and 10 deg respectively. In addition to the lift and thrust coefficients, near wall flow visualisations and the shedding of vortices during oscillations are presented to illustrate the unsteady flow features on the performance of the oscillating flipper. The results show an improvement in the thrust production when compared to previous studies on similar symmetric aerofoil without the leading edge modifications

A holistic approach examining RFID design for security and privacy

This paper adopts a holistic approach to Radio Frequency Identification (RFID) security that considers security and privacy under resource constraints concurrently. In this context, a practical realisation of a secure passive (battery-less) RFID tag is presented. The tag consists of an off the shelf front end combined with a bespoke 0.18 μm Application Specific Integrated Circuit (ASIC) assembled as a -sized prototype. The ASIC integrates the authors’ ultra low power novel Advanced Encryption Standard (AES) design together with a novel random number generator and a novel protocol, which provides both security and privacy. The analysis presented shows a security of 64-bits against many attack methods. Both modelled and measured power results are presented. The measured average core power consumed during continuous normal operation is 1.36 μW

Throughput/Area-efficient ECC Processor Using Montgomery Point Multiplication on FPGA

High throughput while maintaining low resource is a key issue for elliptic curve cryptography (ECC) hardware implementations in many applications. In this brief, an ECC processor architecture over Galois fields is presented, which achieves the best reported throughput/area performance on field-programmable gate array (FPGA) to date. A novel segmented pipelining digit serial multiplier is developed to speed up ECC point multiplication. To achieve low latency, a new combined algorithm is developed for point addition and point doubling with careful scheduling. A compact and flexible distributed-RAM-based memory unit design is developed to increase speed while keeping area low. Further optimizations were made via timing constraints and logic level modifications at the implementation level. The proposed architecture is implemented on Virtex4 (V4), Virtex5 (V5), and Virtex7 (V7) FPGA technologies and, respectively, achieved throughout/slice figures of 19.65, 65.30, and 64.48 (106/(Seconds × Slices))

High Speed and Low Latency ECC Implementation over GF(2m) on FPGA

In this paper, a novel high-speed elliptic curve cryptography (ECC) processor implementation for point multiplication (PM) on field-programmable gate array (FPGA) is proposed. A new segmented pipelined full-precision multiplier is used to reduce the latency, and the Lopez-Dahab Montgomery PM algorithm is modified for careful scheduling to avoid data dependency resulting in a drastic reduction in the number of clock cycles (CCs) required. The proposed ECC architecture has been implemented on Xilinx FPGAs' Virtex4, Virtex5, and Virtex7 families. To the best of our knowledge, our single- and three-multiplier-based designs show the fastest performance to date when compared with reported works individually. Our one-multiplier-based ECC processor also achieves the highest reported speed together with the best reported area-time performance on Virtex4 (5.32 μs at 210 MHz), on Virtex5 (4.91 μs at 228 MHz), and on the more advanced Virtex7 (3.18 μs at 352 MHz). Finally, the proposed three-multiplier-based ECC implementation is the first work reporting the lowest number of CCs and the fastest ECC processor design on FPGA (450 CCs to get 2.83 μs on Virtex7)

TEM study of GaN/AlN quantum dots deposited on vicinal silicon

Transmission electron microscopy was performed to investigate the use of AlN epitaxial films deposited on vicinal Si(111) as templates for the growth of GaN quantum dots. It is found that the substrate vicinality induces both a slight tilt of the AlN (0001) direction with respect to the (111) direction and a step bunching mechanism. As a consequence, a dislocation dragging behavior is observed giving rise to dislocation-free areas well suited for the nucleation of GaN quantum dots. The microstructure of different QD encountered in the GaN/AlN system is also described.Transmission electron microscopy was performed to investigate the use of AlN epitaxial films deposited on vicinal Si(111) as templates for the growth of GaN quantum dots. It is found that the substrate vicinality induces both a slight tilt of the AlN (0001) direction with respect to the (111) direction and a step bunching mechanism. As a consequence, a dislocation dragging behavior is observed giving rise to dislocation-free areas well suited for the nucleation of GaN quantum dots. The microstructure of different QD encountered in the GaN/AlN system is also described

Simultaneous wireless information and power transfer based on generalized triangular decomposition

In this paper, a new approach, based on the generalized triangular decomposition (GTD), is proposed for simultaneous wireless information and power transfer (SWIPT) in the spatial domain for a point-to-point multiple-input multiple-output (MIMO) system. The proposed approach takes advantage of the GTD structure to allow the transmitter to use the strongest eigenchannel jointly for energy harvesting and information exchange while these transmissions can be separated at the receiver. The optimal structure of the GTD that maximizes the total information rate constrained by a given power allocation and a required amount of energy harvesting is derived. An algorithm is developed that minimizes the total transmitted power for given information rate and energy harvesting constraints with a limited total power at the transmitter. Both theoretical and simulation results show that our proposed GTD based SWIPT outperforms singular value decomposition (SVD) based SWIPT. This is due to the flexibility introduced by the GTD to increase the energy harvested via interstream interference

Contribution à l’étude de l’huile essentielle de Dipcadi serotinum (l.) Medik du Maroc

Dipcadi serotinum (L.) Medik, est une plante de la famille des Hyacinthaceae, elle est largement utilisée comme réchauffant et aussi pour combattre la jaunisse. Cette plante trouve une large utilisation par la population de la région côtière du Maroc. À notre connaissance l’huile essentielle de cette espèce n’a jamais été étudiée ni chimiquement ni biologiquement. Dans ce contexte, nous avons mené une étude comparative de l’huile essentielle extraite de la partie aérienne et la partie souterraine. Les résultats obtenus pour les rendements et la composition chimique de l’huile essentielle des deux parties étudiés montrent des différences considérables.Mots-clés : Dipcadi serotinum (L.) Medik, huile essentielle, composition chimique, médecine traditionnelle, Maroc.Contribution to the study of the essential oil of Dipcadi serotinum (l.) Medik of MoroccoDipcadi serotinum (L.) Medik, is a plant of the Hyacinthaceae’s family, it is widely used as warming and also to combat the jaundice. This plant is widespread use by the population of the coastal region of Morocco. To our knowledge the essential oil of this species has never been studied or chemically or biologically. In this context, we conducted a comparative study of the essential oil extracted from the aerial part and underground part. The results for yield and chemical composition of essential oil from both sides studied showed significant differences.Keywords : Dipcadi serotinum (L.) Medik, essential oil, chemical composition, traditional medicine, Morocco

Data fusion of activity and CGM for predicting blood glucose levels

This work suggests two methods—both relying on stacked regression and data fusion of CGM and activity—to predict the blood glucose level of patients with type 1 diabetes. Method 1 uses histories of CGM data appended with the average of activity data in the same histories to train three base regressions: a multilayer perceptron, a long short- term memory, and a partial least squares regression. In Method 2, histories of CGM and activity data are used separately to train the same base regressions. In both methods, the predictions from the base regressions are used as features to create a combined model. This model is then used to make the final predictions. The results obtained show the effectiveness of both methods. Method 1 provides slightly better results

Multi-lag stacking for blood glucose level prediction

This work investigates blood glucose level prediction for type 1 diabetes in two horizons of 30 and 60 minutes. Initially, three conventional regression tools—partial least square regression (PLSR), multilayer perceptron, and long short-term memory—are deployed to create predictive models. They are trained once on 30 minutes and once on 60 minutes of historical data resulting in six basic models for each prediction horizon. A collection of these models are then set as base-learners to develop three stacking systems; two uni-lag and one multi-lag. One of the uni-lag systems uses the three basic models trained on 30 minutes of lag data; the other uses those trained on 60 minutes. The multi-lag system, on the other hand, leverages the basic models trained on both lags. All three stacking systems deploy a PLSR as meta-learner. The results obtained show: i) the stacking systems outperform the basic models, ii) among the stacking systems, the multi-lag shows the best predictive performance with a root mean square error of 19.01 mg/dl and 33.37 mg/dl for the prediction horizon of 30 and 60 minutes, respectively