In this paper, we introduce a novel amplitude shift keying modulation technique, suitable for biomedical implants, which works by switching a class-E amplifier between two tuned modes of operation ...selected by the input data level. Using this technique, transmission of power and data could be accomplished with higher power transfer efficiency compared with the commonly used drain/collector amplitude modulation topology. We also present a practical design methodology covering details of the class-E power amplifier together with its inductive link and the proposed modulator circuit. This methodology can be further utilized in other applications like cochlear implants for which we will compare the performance of both topologies at the same operating conditions. Moreover, we implemented both topologies, and we made various physical measurements at the same inductive link and set-up conditions. Both theoretical and measurement results will justify the advantage of our proposed topology and its overall energy efficiency over a typical one (42% to 30%). Utilizing a carrier frequency of 10 MHz and a modulation index of 10%, our system is able to transmit data at a bit rate of 1 Mbps, while delivering 24-mW power at the nominal coil separation of 6 mm.
•An application of i-Tree Eco model in Strasbourg city to assess air pollution removal by trees in public green spaces across Strasbourg city was conducted.•The contribution of urban trees in air ...pollution removal is small in comparison with local emission rates in Strasbourg city.•Public trees of Strasbourg remove about 7% of the emitted PM10coarse in the city’s atmosphere.
This study integrates i-Tree Eco model in order to estimate air pollution removal by urban trees in Strasbourg city, France. Applied for the first time in a French city, the model shows that public trees, i.e., trees managed by the city, removed about 88t of pollutants during one year period (from July 2012 to June 2013): about 1 ton for CO; 14 tons for NO2; 56 tons for O3; 12 tons for PM10coarse (particles with diameter ranging from 2.5 to 10μm); 5 tons for PM2.5 and 1 ton for SO2. Air pollution removal varied mainly with the tree cover and the level of air pollutants concentrations. Comparison between simulated pollution removal rates and local emissions shows that public trees of Strasbourg reduce about 7% of the emitted PM10coarse in the city’s atmosphere; however, effect on other air pollutants is small. Thus, our study reveals that urban trees are a significant element to reduce air pollution but are not the only solution to this problem. It’s then recommended to associate planting and managing urban forest resources to other strategies that take into account the urban environment characteristics: built structures, street design, location of local sources; etc.
This brief presents a new amplitude shift-keying (ASK) demodulator for biomedical implants based on waveform shaping on detected envelope signals. The proposed demodulator incorporates a novel ...switching-mode signal shaper, which can operate with much lower power consumption. The design does not require any comparator or Schmitt trigger and operates with a very low number of elements; thus, the silicon area is highly saved. With a carrier frequency of 5 MHz and a data rate of 500 kb/s, the proposed ASK demodulator can extract data with modulation indexes down to 5%, whereas the bit-error rate can be as low as 10-5 depending on the input signal-to-noise ratio. Using a 0.18-μm CMOS process, the demodulator occupies a die size of 920 μm 2 . The average power consumption of the proposed demodulator is only 17 μW by physical measurement on silicon.
Shock waves have undesirable effects, such as excessive dynamic pressure on spillway walls and the extension of flow beyond spillway conduits. To eliminate these detrimental impacts, designers have ...attempted to detect the characteristics of these waves. Flow interaction with chute piers generates triple waves in the middle walls and sidewalls of spillway conduits. The present study quantitatively investigated the characteristics of these waves with respect to variations in the bottom inclination angle (θ), wall contraction (φ), and Fr numbers (). The results indicated that with the increment of θ, , (φ, ), and (θ, ), the height () and distance () of the first wave increased, which can be helpful for flow aeration. Furthermore, owing to a boost in θ, , (φ, ), and (θ, ), the height of the second wave was decreased. Therefore, the amount of dynamic pressure on the spillway walls was reduced. Moreover, the distance of decreased with a rise in θ, φ and increased with the increment of and (φ, ). As for , raising φ and (φ, ) elevated the height of this wave and declined its distance. An increase in the height of boosted the flow turbulence and aeration. HIGHLIGHTS The characteristics of shock waves under the influence of Bottom inclination.; The impacts of Fr number on shockwaves characteristics.; The effects of wall contraction on shockwaves characteristics.; The characteristics of shock waves under the influence of Fr number and wall contraction.;
Sperm motility is known as an effective parameter in male fertility, and it depends on energy consumption. Low-level laser irradiation could increase energy supply to the cell by producing adenosine ...triphosphate. The purpose of this study is to evaluate how the low-level laser irradiation affects the human sperm motility. Fresh human semen specimens of asthenospermic patients were divided into four equal portions and irradiated by 830-nm GaAlAs laser irradiation with varying doses as: 0 (control), 4, 6 and 10 J/cm
2
. At the times of 0, 30, 45 and 60 min following irradiation, sperm motilities are assessed by means of computer-aided sperm analysis in all samples. Two additional tests HOS and sperm chromatin dispersion (SCD) tests were also performed on the control and high irradiated groups as well. Sperm motility of the control groups significantly decreased after 30, 45 and 60 min of irradiation, while those of irradiated groups remained constant or slightly increased by passing of time. Significant increases have been observed in doses of 4 and 6 J/cm
2
at the times of 60 and 45 min, respectively. SCD test also revealed a non-significant difference. Our results showed that irradiating human sperms with low-level 830-nm diode laser can improve their progressive motility depending on both laser density and post-exposure time.
Using the recent weighted generalized fractional order operators of Hattaf, a general fractional optimal control problem without constraints on the values of the control functions is formulated and a ...corresponding (weak) version of Pontryagin’s maximum principle is proved. As corollaries, necessary optimality conditions for Caputo–Fabrizio, Atangana–Baleanu and weighted Atangana–Baleanu fractional dynamic optimization problems are trivially obtained. As an application, the weighted generalized fractional problem of the calculus of variations is investigated and a new more general fractional Euler–Lagrange equation is given.
The novel coronavirus disease (COVID-19) pneumonia has posed a great threat to the world recent months by causing many deaths and enormous economic damage worldwide. The first case of COVID-19 in ...Morocco was reported on 2 March 2020, and the number of reported cases has increased day by day. In this work, we extend the well-known SIR compartmental model to deterministic and stochastic time-delayed models in order to predict the epidemiological trend of COVID-19 in Morocco and to assess the potential role of multiple preventive measures and strategies imposed by Moroccan authorities. The main features of the work include the well-posedness of the models and conditions under which the COVID-19 may become extinct or persist in the population. Parameter values have been estimated from real data and numerical simulations are presented for forecasting the COVID-19 spreading as well as verification of theoretical results.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Introduction: In this paper, an encryption algorithm for the security of medical images is presented, which has extraordinary security. Given that the confidentiality of patient data is one of the ...priorities of medical informatics, the algorithm can be used to store and send medical image.Material and Methods: In this paper, the solutions of chaotic differential equations are used to generate encryption keys. This method is more than other methods used in encoding medical images, resistant to statistics attacks, low encryption and decryption time and very high key space. In the proposed algorithm, unlike other methods that use random key generation, this method uses the production of solutions of the chaotic differential equations in a given time period for generating a key. All simulations and coding are done in MATLAB software.Results: Chaotic Differential Equations have two very important features that make it possible to encode medical images. One is the unpredictability of the system's behavior and the other is a severe sensitivity to the initial condition.Conclusion: These two features make the method resistant to possible attacks to decode the concept of synchronization chaotic systems. Using the results of the method, medical information can be made safer than existing ones.
The health insurance system can play an effective role to control health expenditures. The purpose of this study is to provide a model for estimating the physician visit tariffs. To achieve this ...goal, a hybrid model was used. fuzzy logic is the most appropriate tool for controlling systems and deriving rules for the relationship between inputs and outputs. So, the output of the data mining techniques enter the fuzzy logic as an input variable. The data were collected from the Health Insurance Organization of Iran in two sections including the physicians' costs and physicians' deductions. Owing to the techniques used in this model, NN had the least error, as compared to other data mining techniques (0.0034 and 0.0013, respectively). After defining the variables, membership functions and fuzzy logic rules, the accuracy of the whole control model was confirmed by random data. This research has dealt with the domains of health insurance , their connections and defining effective variables better and more extensively than the other studies in the field.
Using the Laplace transform method and the convolution theorem, we introduce new and more general definitions for fractional operators with non-singular kernels, extending well-known concepts ...existing in the literature. The new operators are based on a generalization of the Mittag–Leffler function, characterized by the presence of a key parameter p. This power parameter p is important to enable researchers to choose an adequate notion of the derivative that properly represents the reality under study, to provide good mathematical models, and to predict future dynamic behaviors. The fundamental properties of the new operators are investigated and rigorously proved. As an application, we solve a Caputo and a Riemann–Liouville fractional differential equation.
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