Abstract. Cd1 − xAgxS nanoparticles were synthesized by a simple cost-effective chemical method in air atmosphere. We have achieved novel hybrid ternary nanoparticles of high quality. The prepared samples were characterized by x-ray diffraction, Fourier transform-Raman, field emission scanning electron microscopy, transmission electron microscopy, and UV–visible absorption spectroscopy. The results

Abstract. In the framework of effective mass envelope function approximation, the impurity states in GaN / AlxGa1 − xN spherical quantum dot (QD) are calculated by plane-wave expansion method. The binding energies of the impurity in 1s and 2p± states and the transition energy between 1s state and 2p± state are calculated and analyzed in detail. Several critical influencing factors of impurity states

Abstract. We propose the two-stage cascaded-tapered silica photonic crystal fiber (PCF) for the supercontinuum (SC) generation. The cascaded-tapered silica PCF is designed to have a spatial periodic structure. The physical scenarios of the spectral broadening due to the interaction between the structure-induced periodic dispersion and Kerr nonlinearity under different pulse widths and peak powers are

Abstract. Light detection and ranging (LiDAR) return signal generation technology applied in the LiDAR indoor test and simulation is significant to design, develop, test, and validate a LiDAR’s capability and performance. To generate a target’s information carried by the return signal, the dimensional decomposition and equivalent generation method of the LiDAR return signal are proposed. The target

By using first-principle calculations, trivalent ytterbium with different ring structures were investigated in Yb-doped silica fiber. The influence of ring structure is considered to study the geometric structures, stability, and valence state of these models. The population analysis, electronic properties, energy level diagram, and optical absorption were performed in the combination of DFT and TDDFT

We theoretically and experimentally examined the assumption that the lifetime excited state of Fe2+ in ZnSe:Fe crystal is quenched by free electrons. The effect of the electron beam current value on the temporal characteristics of the luminescence was studied. Three variants, including a sample in the electronic circuit in the case of Fe2+ ions luminescence excitation in a ZnSe:Fe crystal by a beam

The current study proposed outstanding thin films of NaIO3 doped PVA with higher linear and nonlinear optical parameters using a practical, effective, simple, and low-cost approach. Polymeric thin films based on the combination of the polyvinyl alcohol (PVA), used as a matrix, with sodium iodate (NaIO3) nanoparticles, considered a filler, were synthesized using a solution casting approach. The structural

The linear and non-linear optical absorption coefficients of a D2+ artificial molecule confined in GaAs nano-scaled rings under a threading magnetic field were calculated. The results showed that by varying the position and the angle formed by the double-donor system, the total optical absorption can be enhanced, quenched, or even totally nullified. On the other hand, small changes of the optical response

In this paper, according to the complete discriminant system for polynomial method, a series of analytical solutions of the perturbed nonlinear Schrödinger equation with variable coefficient and Kerr law are obtained. These solutions show the abundant propagation patterns of optical waves with Kerr law.

In this paper, simulation study of electron stochastic heating arising from density fluctuation which in turn appears during laser interaction with Hydrogen atoms is considered by use of a massively parallel particle-in-cell (PIC) code. In order to examine the effect of ionization, different mechanisms of electron stochastic heating have been considered and analyzed. Our results reveal that since the

In Laser self-mixing interferometry (SMI), phase unwrapping methods are widely utilized for high-resolution displacement measurements. In this work, a Time-frequency signal processing (TFSP) method for SMI based displacement retrieval is analyzed. Its limitations are identified, and an improved and more robust version of TFSP is proposed for enhanced resolution and better sensing in a non-ideal situation

A technique to characterize amplitude distortions and optical carrier frequency variations (chirp) using optical heterodyne reception and data post-processing is presented. Predominantly, dynamic performances of electro-optical switching action based on semiconductor optical amplifiers (SOA) are analyzed, through the measuring of the SOA chirp imposed on the switched optical carrier. The employment

As one of the most successful nonvolatile phase change materials (PCMs), Ge2Sb2Te5 (GST) can be reversibly switched between amorphous and crystalline phases by nanosecond laser pulses, which enables its applications in optical disks and various emerging reconfigurable photonic devices. Instead of simply inducing temperature rising of GST thin film via light absorption, high-energy laser irradiation

Invar alloy has an important application in the manufacture of composite forming mould. The laser melting deposition (LMD) technology was utilized to fabricate multi-layer multi-pass deposited samples in this study. The effect of heat accumulation on the microstructure of deposition layer (DL) was investigated through experimental and simulation method. A finite element (FE) model was established to

Graphene plasmons have attracted great interest for constructing high-performance functional metamaterial devices, among which graphene-based narrowband metamaterial absorbers are valuable in numerous applications. In this paper, a graphene-dielectric-metal hybrid structure is proposed to achieve dual-band excellent absorption and high-performance refractive index sensing. Numerical simulations show

In this research, FeCrMoMn coatings with excellent corrosion resistance and metallurgical quality were deposited on the 45# steel substrate by conventional and high-speed laser cladding at the scanning speed of 0.4 m/min, 40 m/min and 70 m/min, respectively. Their microstructure, phase composition, hardness and corrosion resistance were characterized and compared. The results show that compared with

To correct for phase distortions in high-power laser setups a stacked-actuator deformable mirror with water cooling was developed. The main characteristics of the mirror such as the initial surface profile, response functions of the actuators, maximal stroke and amplitude frequency characteristic were shown. The quality of initial surface was equal to 0.14 µm (P-V). The maximal stroke of the mirror

This work reports the effect of deposition time on the properties of indium tin oxide ITO thin film deposited by RF magnetron sputtering on glass and Si substrates. The structural investigation shows that the as-deposited ITO thin films on a glass substrate have a polycrystalline structure, where the crystalline size increase with the deposition time. Moreover, the XRD results reveal that the ITO films

The PtCl4@PVA composites films were prepared by casting an aqueous solutions technique. Based on the effect of PtCl4 concentrations, the PVA structure was modified from semi-crystal to amorphous material. Corresponding to FTIR and XRD, PtCl4 is interlinked with a hydroxyl group in the matrix. Both refractive index and extinction coefficient were calculated in the UV–Vis region. The energy gaps of PtCl4@PVA

A new kind of cationic initiator IRGACURE 784 (TI, BASF) was dispersed into PMMA matrix to fabricate TI/PMMA polymer, which exhibited excellent absorptive and polarization sensitivities under 532 nm wavelength laser beam exposure. Theoretical investigations on the grating formation mechanisms under two different time scales of exposure were performed (short time duration: millisecond level, long time

Incompressible fluids are studied in such disciplines as ocean engineering, astrophysics and aerodynamics. Under investigation in this paper is a (3+1)-dimensional Boiti–Leon–Manna–Pempinelli (BLMP) equation in an incompressible fluid. Based on the known bilinear form, BLMP hybrid solutions comprising a lump wave, a periodic wave and two kink waves, and hybrid solutions comprising a breather wave and

Ultrasonic impact treatment (UIT) is an effective method that has been widely applied in welding structure to improve the fatigue properties of materials. It combines mechanical impact and ultrasonic vibration to produce plastic deformation on the weld joints surface, which introduces beneficial compressive residual stress distribution. To evaluate the effect of UIT technology on alleviating the residual

The main benefits of submerging tiny-solid particles with the host fluid are to enhance the capability of storing heat, heat exchanger and interaction between the nanomaterials. The objective of this paper is to investigate the steady flow of bio-convective couple stress nanofluid across an inclined stretching cylinder with activation energy, motile microorganisms and nonlinear thermal radiation. The

This paper focuses on the issue of fuzzy resilient control for synchronizing chaotic systems with time-variant delay and external disturbance. The goal is to design a fuzzy resilient controller with additive gain perturbations to guarantee that not only the drive and response systems are asymptotically synchronized in the absence of external disturbance, but also the synchronization error system has

This paper aims to study the effects of activation energy and thermal radiation in the bioconvection flow of nanofluid (third-grade nanofluid) containing swimming microorganisms in the presence of a heat source-sink past a stretching sheet. Brownian movement and thermophoresis diffusion are used in mathematical modeling. The given flow phenomenon is modeled in the form of governing partial differential

The study of contagion dynamics in multilayer networks has become a hot topic. Networks have the characteristics of community structure. In this work, we present a comprehensive epidemic spreading model in multilayer networks with community structure. We consider the effects of population mobility, natural mortality and natural birth rate on population dynamics and contagion dynamics. The population

The stability of the existence of the topological properties even in non-equilibrium condition such as irradiation of external time-periodic perturbation paves the way for designing and controlling the properties of materials. We study the change in the structure of the quasi-energy spectrum under the influence of the circularly polarized laser field with various intensities. The system is two-dimensional

The era of SoC design has great dependency on CMOS circuits owing to its low power and high reliability which could contribute in the effective circuit designing. Here, a unique approach for the designing of voltage tunable current differencing transconductance amplifier (CDTA) is reported for the realization of Kerwin–Huelsman–Newcomb (KHN) filter. The proposed design has been simulated by using Cadence

In this paper, the spin wave theory is applied to the one-dimensional Heisenberg antiferromagnet in the coexistence of two different anisotropies D1 and D2, which are separately the easy-axis single-ion anisotropies for sublattice A and sublattice B of the system. Both the ground-state and low-temperature properties of the system are strongly affected by the competition between these two anisotropies

The identification of influential nodes is one of the most significant and challenging research issues in network science. Many centrality indices have been established starting from topological features of networks. In this work, we propose a novel gravity model based on position and neighborhood (GPN), in which the mass of focal and neighbor nodes is redefined by the extended outspreading capability

Detecting human motion and predicting human intentions by analyzing body signals are challenging but fundamental steps for the implementation of applications presenting human–robot interaction in different contexts, such as robotic rehabilitation in clinical environments, or collaborative robots in industrial fields. Machine learning techniques (MLT) can face the limit of small data amounts, typical

This study aimed to investigate the effects of knee flexion during the preparation phase of a serve on the tennis serve performance, using inertial sensors. Thirty-two junior tennis players were divided into two groups based on their maximum knee flexion during the preparation phase of serve: Smaller (SKF) and Greater (GKF) Knee Flexion. Their racket velocity, racket height, and knee extension velocity

Single-pixel noise commonly appearing in a star sensor can cause an unexpected error in centroid extraction. To overcome this problem, this paper proposes a star image denoising algorithm, named Improved Gaussian Side Window Filtering (IGSWF). Firstly, the IGSWF algorithm uses four special triangular Gaussian subtemplates for edge protection. Secondly, it exploits a reconstruction function based on

The functional connectivity (FC) patterns of resting-state functional magnetic resonance imaging (rs-fMRI) play an essential role in the development of autism spectrum disorders (ASD) classification models. There are available methods in literature that have used FC patterns as inputs for binary classification models, but the results barely reach an accuracy of 80%. Additionally, the generalizability

Robust autonomous driving, as long as it relies on satellite-based positioning, requires carrier-phase-based algorithms, among other types of data sources, to obtain precise and true positions, which is also primarily true for the use of GNSS geodetic receivers, but also increasingly true for mass-market devices. The experiment was conducted under line-of-sight conditions on a straight road during

This paper proposes an innovative method for classifying the physical properties of the seasonal snowpack using near-infrared (NIR) hyperspectral imagery to discriminate the optical classes of snow at different degrees of metamorphosis. This imaging system leads to fast and non-invasive assessment of snow properties. Indeed, the spectral similarity of two samples indicates the similarity of their chemical

Nearest neighbor (NN) and range (RN) queries are basic query types in spatial databases. In this study, we refer to collections of NN and RN queries as spatial proximity (SP) queries. At peak times, location-based services (LBS) need to quickly process SP queries that arrive simultaneously. Timely processing can be achieved by increasing the number of LBS servers; however, this also increases service

Edge computing offers a promising paradigm for implementing the industrial Internet of things (IIoT) by offloading intensive computing tasks from resource constrained machine type devices to powerful edge servers. However, efficient spectrum resource management is required to meet the quality of service requirements of various applications, taking into account the limited spectrum resources, batteries

Surface plasmonic sensors have been widely used in biology, chemistry, and environment monitoring. These sensors exhibit extraordinary sensitivity based on surface plasmon resonance (SPR) or localized surface plasmon resonance (LSPR) effects, and they have found commercial applications. In this review, we present recent progress in the field of surface plasmonic sensors, mainly in the configurations

In problems of parameter estimation from sensor data, the Fisher information provides a measure of the performance of the sensor; effectively, in an infinitesimal sense, how much information about the parameters can be obtained from the measurements. From the geometric viewpoint, it is a Riemannian metric on the manifold of parameters of the observed system. In this paper, we consider the case of parameterized

Firefly Algorithm (FA) is a recent swarm intelligence first introduced by X.S. Yang in 2008. It has been widely used to solve several optimization problems. Since then, many research works were elaborated presenting modified versions intending to improve performances of the standard one. Consequently, this article aims to present an accelerated variant compared to the original Algorithm. Through the

Smart cities use the Internet of Things (IoT) devices such as connected sensors, lights, and meters to collect and analyze data to improve infrastructure, public utilities, and services. However, the true potential of smart cities cannot be leveraged without addressing many security concerns. In particular, there is a significant challenge for provisioning a reliable access control solution to share

Due to the fast evolution of Sensor and Internet of Things (IoT) technologies, several large-scale smart city applications have been commercially developed in recent years. In these developments, the contracts are often disputed in the acceptance due to the fact that the contract specification is not clear, resulting in a great deal of discussion of the gray area. Such disputes often occur in the acceptance

In recent years, Artificial Intelligence Technologies (AIT) have been developed to improve the quality of life of the elderly and their safety in the home. This work focuses on developing a system capable of recognising the most usual activities in the daily life of an elderly person in real-time to enable a specialist to monitor the habits of this person, such as taking medication or eating the correct

Signal denoising is one of the most important issues in signal processing, and various techniques have been proposed to address this issue. A combined method involving wavelet decomposition and multiscale principal component analysis (MSPCA) has been proposed and exhibits a strong signal denoising performance. This technique takes advantage of several signals that have similar noises to conduct denoising;

Sequence time-domain reflectometry (STDR) and spread spectrum time-domain reflectometry (SSTDR) detect, locate, and diagnose faults in live (energized) electrical systems. In this paper, we survey the present SSTDR literature for discussions on theory, algorithms used in its analysis, and its more prominent implementations and applications. Our review includes both scientific litera-ture and selected

Diabetes is a chronic disease caused by the inability of the pancreas to produce insulin or problems in the body to use it efficiently. It is one of the fastest growing health challenges affecting more than 400 million people worldwide, according to the World Health Organization. Intensive research is being carried out on artificial intelligence methods to help people with diabetes to optimize the

Action observation (AO)-based brain-computer interface (BCI) is an important technology in stroke rehabilitation training. It has the advantage of simultaneously inducing steady-state motion visual evoked potential (SSMVEP) and activating sensorimotor rhythm. Moreover, SSMVEP could be utilized to perform classification. However, SSMVEP is composed of complex modulation frequencies. Traditional canonical

This paper reports on the progress of a wearable assistive technology (AT) device designed to enhance the independent, safe, and efficient mobility of blind and visually impaired pedestrians in outdoor environments. Such device exploits the smartphone’s positioning and computing capabilities to locate and guide users along urban settings. The necessary navigation instructions to reach a destination

Monitoring the indoor environment of historic buildings helps to identify potential risks, provide guidelines for improving regular maintenance, and preserve cultural artifacts. However, most of the existing monitoring systems proposed for historic buildings are not for general digitization purposes that provide data for smart services employing, e.g., artificial intelligence with machine learning

A recommendation system is often used to recommend items that may be of interest to users. One of the main challenges is that the scarcity of actual interaction data between users and items restricts the performance of recommendation systems. To solve this problem, multi-modal technologies have been used for expanding available information. However, the existing multi-modal recommendation algorithms

Yearly population growth will lead to a significant increase in agricultural production in the coming years. Twenty-first century agricultural producers will be facing the challenge of achieving food security and efficiency. This must be achieved while ensuring sustainable agricultural systems and overcoming the problems posed by climate change, depletion of water resources, and the potential for increased

(2021). Ethics and Fallacies of Human-Centric Lighting and Artificial Light at Night. LEUKOS: Vol. 17, No. 4, pp. 319-320.

In this work, new highly sensitive graphene-based flexible strain sensors are produced. In particular, polyvinylidene fluoride (PVDF) nanocomposite films filled with different amounts of graphene nanoplatelets (GNPs) are produced and their application as wearable sensors for strain and movement detection is assessed. The produced nanocomposite films are morphologically characterized and their waterproofness

Narrow band-gap semiconductors, namely ternary InAsSb alloys, find substantial technological importance for mid-infrared application as photodetectors in medical diagnostics or environmental monitoring. Thus, it is crucial to develop electrical contacts for these materials because they are the fundamental blocks of all semiconductor devices. This study demonstrates that electroplated gold contacts