Using Metaheuristic OFA Algorithm for Service Placement in Fog Computing

The use of fog computing in the Internet of Things(IoT)has emerged as a crucial solution,bringing cloud services closer to end users to process large amounts of data generated within the system.Despite its advantages,the increasing task demands from IoT objects often overload fog devices with limited resources,resulting in system delays,high network usage,and increased energy consumption.One of the major challenges in fog computing for IoT applications is the efficient deployment of services between fog clouds.To address this challenge,we propose a novel Optimal Foraging Algorithm(OFA)for task placement on appropriate fog devices,taking into account the limited resources of each fog node.The OFA algorithm optimizes task sharing between fog devices by evaluating incoming task requests based on their types and allocating the services to the most suitable fog nodes.In our study,we compare the performance of the OFA algorithm with two other popular algorithms:Genetic Algorithm(GA)and Randomized Search Algorithm(RA).Through extensive simulation experiments,our findings demonstrate significant improvements achieved by the OFA algorithm.Specifically,it leads to up to 39.06%reduction in energy consumption for the Elektroensefalografi(EEG)application,up to 25.86%decrease in CPU utilization for the Intelligent surveillance through distributed camera networks(DCNS)application,up to 57.94%reduction in network utilization,and up to 23.83%improvement in runtime,outperforming other algorithms.As a result,the proposed OFA algorithm enhances the system’s efficiency by effectively allocating incoming task requests to the appropriate fog devices,mitigating the challenges posed by resource limitations and contributing to a more optimized IoT ecosystem.

Voltage-Dependent Electronic Transport Properties of Reduced Graphene Oxide with Various Coverage Ratios

Graphene is mainly implemented by these methods: exfoliating, unzipping of carbon nanotubes, chemical vapour deposition, epitaxial growth and the reduction of graphene oxide. The latter option has the advantage of low cost and precision. However, reduced graphene oxide(rGO) contains hydrogen and/or oxygen atoms hence the structure and properties of the rGO and intrinsic graphene are different. Considering the advantages of the implementation and utilization of rGO, voltage-dependent electronic transport properties of several rGO samples with various coverage ratios are investigated in this work. Ab initio simulations based on density functional theory combined with non-equilibrium Green's function formalism are used to obtain the current–voltage characteristics and the voltage-dependent transmission spectra of rGO samples. It is shown that the transport properties of rGO are strongly dependent on the coverage ratio. Obtained results indicate that some of the rGO samples have negative differential resistance characteristics while normally insulating rGO can behave as conducting beyond a certain threshold voltage. The reasons of the peculiar electronic transport behaviour of rGO samples are further investigated, taking the transmission eigenstates and their localization degree into consideration.The findings of this study are expected to be helpful for engineering the characteristics of rGO structures.

Algebraic Current-voltage and Voltage Dependent Resistance Expressions for Ballistic Nano Conductors and Their Low Voltage Nonlinearity

In this study, an algebraic current-voltage(I-V) equation suitable for the hand-calculation of ballistic nano conductors is derived from Landauer's formulation. A voltage and temperature dependent resistance expression is also obtained. It is shown that the presented algebraic I-V expression and the original Landauer's formula give the same characteristics as expected. Moreover, the I-V characteristics of ballistic nano conductors are investigated and it is concluded that there is an inescapable nonlinearity originating from the curvature of Fermi-Dirac distribution function in low voltage range. Finally, the total harmonic distortion(THD) of a sample ballistic nano conductor caused from its low voltage nonlinearity is computed via HSPICE simulations.

Power Domain Multiplexing Waveform for 5G Wireless Networks

Power domain non-orthogonal multiple access combined with a universal filtered multi-carrier(NOMA-UFMC)has the potential to cope with fifth generation(5G)unprecedented challenges.NOMA employs powerdomainmultiplexing to support several users,whereasUFMC is robust to timing and frequency misalignments.Unfortunately,NOMA-UFMC waveform has a high peak-to-average power(PAPR)issue that creates a negative affect due to multicarrier modulations,rendering it is inefficient for the impending 5G mobile and wireless networks.Therefore,this article seeks to presents a discrete Hartley transform(DHT)pre-coding-based NOMA enabled universal filter multicarrier(UFMC)(DHT-NOMA-UFMC)waveform design for lowering the high PAPR.Additionally,DHT precoding also takes frequency advantage variations in the multipath wireless channel to get significant bit error rate(BER)gain.In the recommended arrangement,the throughput of the systemis improved by multiplexing the users in the power domain and permitting the users with good and bad channel conditions to concurrently access the apportioned resources.The simulation outcomes divulge that the projected algorithm accomplished a gain of 5.8 dB as related to the conventional framework.Hence,it is established that the proposed DHT-NOMA-UFMC outperforms the existing NOMA-UFMC waveform.The key benefit of the proposed method over the other waveforms proposed for 5G is content gain due to the power domain multiplexing at the transmitting side.Thus,a huge count of mobile devices could be supported under specific restrictions.DHTNOMA-UFMC can be regarded as the most effective applications for 5G Mobile andWireless Networks.However,the main drawback of the proposed method is that the Fourier peak and phase signal is not easily estimated.

An Assessment of Renewable Energy Options for Somalia Turkey Hospital

Somalia Mogadishu-Turkey Training and Research Hospital is only powered by diesel generator currently.In this paper,the energy demand of this hospital is supplied by determining the optimum hybrid power renewable generating system.Therefore,numerous hybrid renewable power generating systems including the components like diesel generator,wind turbine,photovoltaic(PV)and battery are considered in different configurations.Eventually,they are technically,environmentally and economically analyzed by using the well-known HOMER software.Furthermore,a sensitivity analysis is also performed considering variations in three important parameters,namely average wind speed,current diesel price and also solar radiation.According to the results,the optimal system is the standalone Wind/Diesel/Battery hybrid renewable energy system(HRES)with the configuration of 1,000 kW wind turbine,350 kW diesel generator,250 kW power converters and 750 batteries.Additionally,this system has the net present cost of$5,056,700 as well as the cost of energy as$0.191/kWh.Lastly,it is clearly occurred that the Wind/Diesel/Battery HRES is eco-friendlier than other HRESs.

Performance Analysis of Techniques Used for Determining Land Mines

Today, remote sensing is used for different methods and different purposes. In all of the detection methods, some considerations such as low energy consumption, low cost, insensitivity to environmental changes, high accuracy, high reliability and robustness become important. Taking into account these facts, remote sensing methods are used in applications such as geological and archeological research, engineering areas, health services, preserving and controlling natural life, determination of underground sources, controlling air, sea and road traffic, military applications, etc. The method to be used is based on the object type to be detected, material to be made, and location to be found. The remote sensing methods from the past up to today can be listed as acoustic and seismic, ground penetration radar (GPR) detection, electromagnetic induction, infrared (IR) imaging, neutron quadrupole resonance (NQR), thermal neutron activation (TNA), neutron back scattering, X-ray back scattering, and magnetic anomaly detection. In these methods, detected raw images have to be processed, filtered and enhanced. In order to achieve these operations, some algorithms are needed to be developed. In this study, the methods used in detecting land mines remotely and their performance analysis have been given. In this way, the last situation on the advantages and disadvantages of methods used, application areas and detection accuracies are determined. Furthermore, the algorithms such as transmission line matrix (TLM), finite difference time-domain (FDTD), the method of moment (MoM), split step parabolic equation (SSPE) and image processing and intelligent algorithms are presented in detail.

Magnetic filtration with magnetized granular beds:Basic principles and filter performance

This study is devoted to the explanation of different characteristics of magnetic filtration and the way these characteristics affect the important filtration parameters. Magnetic fields in pores and the force effect of these fields on magnetic particles and the magnetization properties of packed beds composed of ferromagnetic spheres and metal chips are evaluated. The profile of accumulation and capture regions of the particles, the variation of the fluid velocity in these regions and analytic expressions of particle capture radius are presented. The effects of filtration regime parameters on magnetic filter performance were investigated. An analytical expression has been obtained for the dependence of the logarithmic efficiency coefficient on filtration velocity, the geometry of filter elements, the particle size and other parameters of filtration. The stationary and non-stationary equations of the magnetic filtration processes are given. An expression of magnetic filter performance is shown with dimensionless parameters obtained from the filtration system. These relations are useful for calculations in engineering practice, including the design of magnetic filters, provision of suggestions on construction, and optimization and control of filter operation.

Deep learning model for estimating the mechanical properties of concrete containing silica fume exposed to high temperatures

In this study,the deep learning models for estimating the mechanical properties of concrete containing silica fume subjected to high temperatures were devised.Silica fume was used at concentrations of 0%,5%,10%,and 20%.Cube specimens(100 mm×100 mm×100 mm)were prepared for testing the compressive strength and ultrasonic pulse velocity.They were cured at 20℃zb2℃ in a standard cure for 7,28,and 90 d.After curing,they were subjected to temperatures of 20℃,200℃,400℃,600℃,and 800℃.Two well-known deep learning approaches,i.e.,stacked autoencoders and long short-term memory(LSTM)networks,were used for forecasting the compressive strength and ultrasonic pulse velocity of concrete containing silica fume subjected to high temperatures.The forecasting experiments were carried out using MATLAB deep learning and neural network tools,respectively.Various statistical measures were used to validate the prediction performances of both the approaches.This study found that the LSTM network achieved better results than the stacked autoencoders.In addition,this study found that deep learning,which has a very good prediction ability with little experimental data,was a convenient method for civil engineering.

A novel PV sub-module-level power-balancing topology for maximum power point tracking under partial shading and mismatch conditions

Partial shading and mismatch conditions among the series-connected modules/sub-modules suffer from a nonconvex power curve with multiple local maxima and decreased peak power for the whole string. Energy transfer between the sub-modules brings them to the same operating voltage, and this collective operation produces a convex power curve, which results in increased peak power for the string. The proposed topology benefits from the switched-capacitor （SC） converter concept and is an application for sub-module-level power balancing with some novelties, including stopping the switching in absence of shading, string-level extension, and a reduced number of power electronics components as compared to those in the literature. Reduction in the number of power electronics components is realized by the fact that two sub-modules share one SC converter. This leads to reduced power electronics losses as well as less cost and volume of the converter circuit. Insertion loss analysis of the topology is presented. The proposed topology is simulated in the PSpice environment, and a prototype is built for experimental verification. Both simulation and experimental results confirm the loss analysis. This proves that with the proposed topology it is possible to extract almost all the power available on the partially shaded string and transfer it to the load side.

Nonlinear and saturable absorption properties of PbS nanocrystalline thin films

The structural,morphological,optical,and nonlinear optical properties of a lead sulfde(PbS) thin film grown by chemical bath deposition(CBD) are investigated by X-ray difraction(XRD),scanning electron microscope(SEM),ultraviolet-visible(UV-Vis),and open aperture Z-scan experiments.The band gap energy of the PbS nanocrystalline film is 1.82 eV,higher than that of bulk PbS at 300 K.The nonlinear absorption properties of the film are investigated using the open aperture Z-scan technique at 1064 nm and pulse durations of 4 ns and 65 ps.Intensity-dependent switching of the film from nonlinear absorption to saturable absorption is observed.The nonlinear absorption coefficient increases monotonically with increasing pulse duration from 65 ps to 4 ns.

On Weakly 1-Absorbing Primary Ideals of Commutative Rings

Let R be a commutative ring with 1≠0.We introduce the concept of weakly 1-absorbing primary ideal,which is a generalization of 1-absorbing primary ideal.Aproperideal I of R is said tobeweakly1-absorbing primary if whenevernonunit elements a,b,c∈R and O≠abc∈I,we have ab∈I or c∈√I.A number of results concerning weakly 1-absorbing primary ideals are given,as well as examples of weakly 1-absorbing primary ideals.Furthermore,we give a corrected version of a result on 1-absorbing primary ideals of commutative rings.

QSPCA: A two-stage efficient power control approach in D2D communication for 5G networks

The existing literature on device-to-device(D2D)architecture suffers from a dearth of analysis under imperfect channel conditions.There is a need for rigorous analyses on the policy improvement and evaluation of network performance.Accordingly,a two-stage transmit power control approach(named QSPCA)is proposed:First,a reinforcement Q-learning based power control technique and;second,a supervised learning based support vector machine(SVM)model.This model replaces the unified communication model of the conventional D2D setup with a distributed one,thereby requiring lower resources,such as D2D throughput,transmit power,and signal-to-interference-plus-noise ratio as compared to existing algorithms.Results confirm that the QSPCA technique is better than existing models by at least 15.31%and 19.5%in terms of throughput as compared to SVM and Q-learning techniques,respectively.The customizability of the QSPCA technique opens up multiple avenues and industrial communication technologies in 5G networks,such as factory automation.

Nonlinear and saturable absorption properties of PbS nanocrystalline thin films

The structural, morphological, optical, and nonlinear optical properties of a lead sulfide （PbS） thin film grown by chemical bath deposition （CBD） are investigated by X-ray diffraction （XRD）, scanning electron microscope （SEM）, ultraviolet-visible （UV-Vis）, and open aperture Z-scan experiments. The band gap energy of the PbS nanocrystalline film is 1.82 eV~ higher than that of bulk PbS at 300 K. The nonlinear absorption properties of the film are investigated using the open aperture Z-scan technique at 1064 nm and pulse durations of 4 ns and 65 ps. Intensity-dependent switching of the film from nonlinear absorption to saturable absorption is observed. The nonlinear absorption coefficient increases monotonically with increasing pulse duration from 65 ps to 4 ns.

Anisotropy effect on multi-Gaussian beam propagation in turbulent ocean

Average transmittance of multi-Gaussian （flat-topped and annular） optical beams in an anisotropic turbulent ocean is examined analytically based on the extended Huygens-Fresnel principle. Transmittance variations depending on the link length, anisotropy factor, salinity and temperature contribution factor, source size, beam flatness order of fiat-topped beam, Kolmogorov microscale length, rate of dissipation of turbulent kinetic energy, rate of dissipation of the mean squared temperature, and thickness of annular beam are examined. Results show that all these parameters have effects in various tbrms on the average transmittance in an anisotropic turbulent ocean. Hence, the performance of optical wireless communication systems can be improved by taking into ac- count the variation of average transmittance versus the above parameters.