Simple Implementation Research Articles

Cross-Component Prediction Boosted With Local and Non-Local Information in Video Coding.

In the versatile video coding (VVC) standard, cross-component prediction (CCP) is introduced to utilize the correlation between luma and chroma components. To further exploit the cross-component redundancy, a bundle of novel CCP methods with more sophisticated models are studied in enhanced compression model (ECM), which is a platform targeting at the next generation video coding standard, developed by JVET. This paper presents two methods, known as local-boosting CCP (LB-CCP) and non-local CCP (NL-CCP) to improve CCP with local and non-local information. With LB-CCP, prediction samples of CCP can be filtered with neighbouring samples. Besides, neighbouring template costs are calculated to determine the range of training samples, as well as the cross-component prediction method used in the chroma fusion mode. With NL-CCP, a CCP model can be derived with samples non-adjacent to the current block. As an equivalent but simpler implementation, the CCP model can be inherited from a CCP-coded neighbouring block as a spatial CCP candidate. Moreover, the CCP model of a previous CCP-coded block can be stored in a history-based table, which can be fetched and used by the current block as a history-based CCP candidate. A NL-CCP candidate list is built with the two kinds of candidates. The encoder can select the optimal candidate and send an index to the decoder. Experimental results show that LB-CCP together with NL-CCP can provide an average Bjontegaard delta rate (BD-rate) reduction of 0.27%, 2.31%, 2.44% on Y, Cb, Cr components, respectively, with a negligible change in the running time, compared with ECM-8.0 in all intra configurations. Both LB-CCP and NL-CCP have been adopted into ECM.

ОЦЕНКА ВЛИЯНИЯ КОЭФФИЦИЕНТА МАСШТАБИРОВАНИЯ БАЗОВОЙ ФУНКЦИИ ВЕЙВЛЕТ-ПРЕОБРАЗОВАНИЯ НА СТЕПЕНЬ ПРОЯВЛЕНИЯ ОСНОВНЫХ НЕИСПРАВНОСТЕЙ ЦЕНТРОБЕЖНЫХ НАСОСНЫХ АГРЕГАТОВ В ВЕЙВЛЕТ-КАРТИНАХ

Relevance Rotary-type machines, which include centrifugal pumping units, are widely used in the oil refining and petrochemical industries and represent an integral part of technological processes. Therefore, preventing their emergency failure is the most important task, which is solved using vibroacoustic diagnostics. Vibration diagnostic services of technical supervision departments process signals mainly using the spectral method of vibration signal analysis based on the Fourier transform. Along with the undeniable advantages, which include the simplicity of software implementation and the admissibility of optimization for the analysis of many functions of physical processes, this transformation has certain disadvantages. For example, due to the loss of information about the time factor, the idea of the dynamics of changes in the spectral composition of the signal is distorted, which does not allow for a comprehensive analysis of the vibration signal. In this regard, there is a need for additional methods of digital signal processing. In recent years, in the process of research carried out at the Ufa State Petroleum Technological University, it has been proven that a method based on wavelet transformation of vibration signals can be used to assess the technical condition of pumping and compressor equipment. This type of transformation is capable of recognizing not only periodic components of the signal, but also local ones, determining their time and frequency characteristics, and establishing the relationship between the levels of wavelet decomposition and the frequency ranges of wavelet filters. It has been determined that the level of decomposition during the wavelet transform of the signal can be taken as a criterion for clearing the vibration signal of the digital pump from the noise component in the presence of faults such as «imbalance» and «misalignment». Discrete wavelet transform of vibration signals makes it possible to determine amplitude modulation caused by the manifestation of faults of electromagnetic origin and inhomogeneity of the air flow in the gap between the rotor and stator of an electric motor, as well as to identify slowly developing (trend) signals associated with lubrication defects in the motor bearings of centrifugal pumping units. Wavelet patterns store complex information about the signal, however, when several types of faults or defects are combined, it is very difficult to identify the leading one and the degree of its development, especially in the early stages. In this case, the value of the scaling factor can serve as a characteristic of the degree of development of the fault, since it was found that wavelet patterns begin to differ comprehensively when setting the scaling factor of the wavelet transform of signals, starting from a value of 192, confirming the presence of an anomalous signal. Aim of research Increasing the accuracy of assessing the technical condition of centrifugal pumping units by selecting the scaling factor of the basic function of the wavelet transform of vibration signals. Research methods To practically solve the problems, methods and algorithms for digital processing of vibration signals based on the Fourier transform and wavelet transform were used. Results It has been established that for a more accurate assessment of the stage of development of the main faults of the digital pump using the continuous wavelet transform, it is necessary to use a scaling factor of the basic wavelet function equal to 512.

Approximate Equivalence of Higher-Order Feedback and Its Application in Chaotic Systems

Based on the feature of piecewise linear (PWL) functions, a nonlinear feedback of a higher-order system can be transformed to an approximately equivalent PWL function so as to ease system implementation in engineering. As an example, a cubic feedback term can be approximately equivalently transformed to be a PWL function. Since the PWL function can be expressed by many simple functions such as signum function and absolute-valued function, the cubic term can be approximately equivalently replaced with these functions. Consequently, the method of approximate equivalence is employed in the JCS-08-13-2022 (JCS) chaotic system for simple circuit design and implementation. In this approach, the widely used multipliers are avoided and the circuits become more economical and also more robust. In this paper, the cubic Chua’s resistor is equivalently approximately replaced by a PWL function. To show the effectiveness of the approximate equivalence, numerical simulations are demonstrated and verified by circuit implementation.

Hearing Loss and its Impact in the Community

Hearing is considered an important sense of the human being. Hearing impairment cannot be visible and hence its effects are not seen by others, so the deaf suffer in silence. Hearing impairment is not only a communication problem but also a community problem. Hearing loss, which is gradual and permanent, can be brought on by congenital or acquired damage to the auditory nerve and cochlear hair cells. It reduces the working ability and performance of an individual, thus diminishing one’s participation. Hearing loss is often associated with loneliness and social isolation which has an impact on cognitive and psychosocial health. Early identification of hearing impairment in a child is vital for effective management. Hearing loss has a detrimental impact on family dynamics and, as a result, the child’s development. The widespread prevalence of deafness necessitated a reliable management system and simple clinical implementation. This public health burden can be managed by raising awareness of hearing impairment. There are plenty of clinical assessment and therapy options in hearing impairment research, but lack of knowledge about it implies that public education or awareness should be prioritized more. This review article discusses the epidemiology, etiopathogenesis, clinical features, impact of hearing impairment, and its impact on the community along with current treatment options.

STEM SerialED: achieving high-resolution data for ab initio structure determination of beam-sensitive nanocrystalline materials.

Serial electron diffraction (SerialED), which applies a snapshot data acquisition strategy for each crystal, was introduced to tackle the problem of radiation damage in the structure determination of beam-sensitive materials by three-dimensional electron diffraction (3DED). The snapshot data acquisition in SerialED can be realized using both transmission and scanning transmission electron microscopes (TEM/STEM). However, the current SerialED workflow based on STEM setups requires special external devices and software, which limits broader adoption. Here, we present a simplified experimental implementation of STEM-based SerialED on Thermo Fisher Scientific STEMs using common proprietary software interfaced through Python scripts to automate data collection. Specifically, we utilize TEM Imaging and Analysis (TIA) scripting and TEM scripting to access the STEM functionalities of the microscope, and DigitalMicrograph scripting to control the camera for snapshot data acquisition. Data analysis adapts the existing workflow using the software CrystFEL, which was developed for serial X-ray crystallography. Our workflow for STEM SerialED can be used on any Gatan or Thermo Fisher Scientific camera. We apply this workflow to collect high-resolution STEM SerialED data from two aluminosilicate zeolites, zeolite Y and ZSM-25. We demonstrate, for the first time, ab initio structure determination through direct methods using STEM SerialED data. Zeolite Y is relatively stable under the electron beam, and STEM SerialED data extend to 0.60 Å. We show that the structural model obtained using STEM SerialED data merged from 358 crystals is nearly identical to that using continuous rotation electron diffraction data from one crystal. This demonstrates that accurate structures can be obtained from STEM SerialED. Zeolite ZSM-25 is very beam-sensitive and has a complex structure. We show that STEM SerialED greatly improves the data resolution of ZSM-25, compared with serial rotation electron diffraction (SerialRED), from 1.50 to 0.90 Å. This allows, for the first time, the use of standard phasing methods, such as direct methods, for the ab initio structure determination of ZSM-25.

A Chaotic Oscillator With Three Independent Offset Boosters and Its Simplified Circuit Implementation

A Chaotic Oscillator With Three Independent Offset Boosters and Its Simplified Circuit Implementation

Cell chip device for real-time monitoring of drug release from drug-laden microparticles.

A cell chip is a microfluidic cell culture device fabricated using microchip manufacturing methods for culturing living cells in a micrometer-sized chamber to model the physiological functions of tissues and organs. It has been extensively investigated in the domain of drug transport and toxicity research. Herein, we developed a cell chip for real-time monitoring of drug release from drug carriers. The proposed system integrates three core functions: cell culture, real-time analysis, and drug delivery tests. This device was designed to be loaded with microparticles for drug release and to enable real-time drug measurement. The efficacy of the developed system was evaluated by measuring the concentration of drugs released from the microparticles prepared with poly(lactic-co-glycolic acid) (PLGA). Doxorubicin, an anticancer drug, was used as a model drug and A549 cells, a type of lung cancer cell, were simultaneously cultured to compare the drug release concentrations in the presence of cells. Furthermore, variations in cell viability with respect to the presence of drug-loaded microparticles were observed and analyzed. Notably, as the proposed system requires an extremely small number of microparticles, it affords simple implementation in a single device, thereby eliminating the need for complex accessories and instruments for analysis. Thus, the analysis process becomes more convenient and cost-efficient. Thus, the proposed method offers an easy analysis of the release behavior of various cells and drugs. The simplicity and low cost of this innovative system without sacrificing analytical precision demonstrate its potential for applications across various fields.

Three-Dimension Space Vector Modulation for Three-Phase Series-End Winding Voltage-Source Inverters

Series-end winding voltage-source inverters (SEW-VSIs) can effectively improve the dc-link voltage utilization and provide the capabilities to handle the zero-sequence loop. However, the existing modulation schemes for SEW-VSIs cannot fully utilize the output capability of SEW-VSIs while guaranteeing simple implementation. To this end, a three-dimensional space vector modulation (3D-SVM) scheme is proposed for driving three-phase SEW-VSIs in this paper. The modulation is conducted in the 3D-space made up of the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">α-β</i> plane and the zero-sequence-axis, and the reference voltage vector in the 3D-space is synthesized by three adjacent basic voltage vectors and the null voltage vector, which can fully utilize the output capability of three-phase SEW-VSI. Then, a convenient implementation method based on a look-up table is developed to find three basic voltage vectors adjacent to the reference voltage vector. Moreover, in the 3D-space, the feasible region and the linear modulation region of the proposed 3D-SVM are investigated. Accordingly, intuitive overmodulation between different subspaces and the switching sequence generation are developed. A series of simulation and experimental results are presented to validate the effectiveness of the proposed 3D-SVM for three-phase SEW-VSI drives.

A Proposed Controller for Pitch Angle of Wind Turbine

Wind turbines are complicated non-linear systems with certain random disruptions. The pitch control system is a commonly employed method for regulating the electricity generated by a wind turbine. Many researchers have observed developments in the pitch control field during the last few decades. Traditional PID controllers have the drawback of being slow or imprecise when wind and pitch angles suddenly change. These drawbacks can be solved with artificial intelligent algorithms. However, the algorithms' design and implementation are highly complex. A new pitch-regulated variable-speed control strategy for wind turbines to address their nonlinear properties is presented. To manage the pitch system's control mechanisms with disturbances, this research evolved a mathematical model that illustrates HAWT's pitch angle control system and applied a proposed Simple Optimal Intelligent PID Controller (SOI-PID). Under various operating conditions, the proposed SOI-PID controller was tested with the Traditional PID, Fuzzy Logic Controller (FLC), and Fuzzy-Adaptive-PID controller. For system simulation, the MATLAB/Simulink software was used. According to simulation results, compared to PID, FLC, and Fuzzy-Adaptive-PID controllers, the proposed SOI-PID controller responds faster and has a better rise and settling time. Other benefits of the SOI-PID controller are its simplicity of implementation and design, distinguishing it from other intelligent algorithms.

A development of high sensitivity magnetic sensor based on giant magnetoresistance with simple implementation on smartphone

In this paper, the magnetic field-based sensor that can connect with smartphones through Bluetooth connectivity was developed. The design of this high sensitivity magnetic sensor system used Giant Magnetoresistance (GMR) sensors in the form of SOIC8 with AA002-02 series from NVE Corp. The results obtained from the measurements show that the sensor is able to work well when connected to an Android-based smartphone. Measurements were carried out by placing a magnet with a magnetic field strength of 0.4 T in the direction of the sensitivity plane of the GMR sensor. The result showed that the closer the magnet distance relative to the GMR sensor the more voltage signal output from the sensor. Since this developed method is simple but effective for detecting position of magnetic object, the further development of this method will be benefit for many applications.

Increasing the accuracy of electrostatic fields strength measurement by using an improved differential transimpedance amplifier circuit

An electrostatic field mill (EFM) is widely used to measure the strength of electrostatic fields, the main drawback of which is the occurrence of large measurement errors (up to 15 % in the range from 0 to 1 kV/m). This paper examines the aspects of using transimpedance amplifiers (TIAs) for the tasks of converting the current received from the EFM sensor into voltage, which will make it possible to reduce the instrumental error and ensure the linearity of the atmospheric electrostatic field strength measurement. In the general case, for the functional circuits of the electrostatic field mill, which include a differential transimpedance amplifier, there is the use of two TIA circuits, which are connected in parallel. Despite the simplicity of implementation, such a configuration contains a number of disadvantages and is not optimal. In the paper, a comparative analysis of a typical circuit of a differential TIA and a circuit of an ungrounded differential transimpedance amplifier with zero voltage drop proposed by the authors is carried out. As a result of the analysis, it was established that the designed authentic circuit of the ungrounded differential transimpedance amplifier with zero voltage drop has better parameters of linearity and interference resistance, in contrast to the generally accepted one. The value of the signal-to-noise ratio for the proposed scheme improved by 42 % on average compared to the typical one. The main difference of the proposed scheme is that the stability of the amplification factor is ensured, the influence of the bias parameters of the operational amplifier is leveled, and the overall noise level is reduced. The use of the designed scheme of an ungrounded differential transimpedance amplifier with zero voltage drop could make it possible to increase the accuracy of the measurement of the electrostatic field strength

Biomimetic Materials Based on Poly-3-hydroxybutyrate and Chlorophyll Derivatives.

Electrospinning of biomimetic materials is of particular interest due to the possibility of producing flexible layers with highly developed surfaces from a wide range of polymers. Additionally, electrospinning is characterized by a high simplicity of implementation and the ability to modify the produced fibrous materials, which resemble structures found in living organisms. This study explores new electrospun materials based on polyhydroxyalkanoates, specifically poly-3-hydroxybutyrate, modified with chlorophyll derivatives. The research investigates the impact of chlorophyll derivatives on the morphology, supramolecular structure, and key properties of nonwoven materials. The obtained results are of interest for the development of new flexible materials with low concentrations of chlorophyll derivatives.

A novel global RBF direct collocation method for solving partial differential equations with variable coefficients

Conventional radial basis function (RBF) approximation techniques face two fundamental challenges: determining the optimal shape parameter and solving the ill-conditioned linear system, which result from the use of typical kernel functions such as the Multiquadric (MQ) RBF. The objective of this study is to address these challenges by employing a novel RBF kernel, termed the coupled MQ RBF (CMQ-RBF). The new kernel combines the MQ with an m-order conical spline, where m denotes the optimal value determined by the so-called back check method (BCM) introduced in this study. Leveraging the CMQ-RBF kernel, we present a novel global RBF collocation method that generates a well-conditioned linear system, enabling direct solver utilization and delivering highly accurate numerical results without the need for laborious shape parameter selection. Consequently, the previously challenging issues can be effectively circumvented by switching to the "better kernel" offered by the CMQ-RBF. The proposed methodology is characterized by its mathematical simplicity and ease of numerical implementation. Several benchmark examples are investigated to verify its performance.

Gold-tipped CdSe/CdZnS colloidal quantum wells as non-quenching plasmonic particles for optical applications

Here, a new one-pot and heterogeneous synthesis method for AuNP-tipped CdSe/CdZnS colloidal quantum wells (CQWs) as non-quenching plasmonic particles is reported. We propose and demonstrate the synthesis and characterization of such plasmonic particles that prevent the quenching of photoluminescence of the emitters. A synthesis of the gold-tipped CQWs in a heterogeneous phase was performed without gold organosol preparation. The size of gold nanoparticles attached to the CdSe/CdZnS CQWs was controlled by reaction time and the addition of octanethiol ligand, which has a tendency to bind gold nanoparticles. Absorption and photoluminescence spectra of the CQWs after the addition of progressively higher amounts of AuNP-tipped CdSe/CdZnS CQWs into solutions proved their usability as non-quenching plasmonic particles. These highly photoluminescent CQWs retain their photostability for more than 6 months when they are mixed with AuNP-tipped CQWs in organic solvents. Besides, AuNP-tipped CdSe/CdZnS CQWs dopped polystyrene films were prepared to observe temperature increase under near-infrared (NIR) excitation. The temperature increase from 25.6 °C to 38.0 °C caused by the plasmonic effect of AuNPs in the composite films was measured by exciting the films with an 808 nm laser. These easy-to-produce plasmonic particles offer new opportunities for the simple implementation of high-performance optical resonators for colloidal lasers.

Convex Combination for Wireless Localization Using Biased RSS Measurements

Received signal strength- (RSS-) based localization in wireless sensor networks (WSNs) has attracted significant attention due to its advantages of low cost and simple implementation. In practice, RSS measurements may suffer from sensor biases, which deteriorates the localization accuracy. However, most of the existing localization methods are designed for bias-free measurements. In this paper, we propose a convex combination method for RSS localization in the presence of sensor biases. The parameter vector composed of unknown location and sensor biases is estimated simultaneously by using a convex combination of some virtual points. These virtual points form a convex hull, into which the parameter vector falls with large probability. By this, the original nonconvex estimation problem is converted to be convex. Numerical examples demonstrate the superiority of the proposed method in terms of localization accuracy, compared to the existing semidefinite programming (SDP) methods.

A spatial carrier dynamic quantitative differential phase imaging method

Differential interference contrast (DIC) microscopy is an important method for quantitative phase imaging (QPI) due to its high compatibility regarding to partial coherent light illumination and excellent optical sectioning ability. However, limited by the on-axis interferometric configuration of Nomarski DIC microscopic imaging system, it is difficult to achieve single-shot phase retrieval. Here, we propose a simple and efficient method for dynamic quantitative differential phase imaging (QDPI) by introducing a spatial carrier device into DIC microscope. A Wollaston prism (WP) is placed on the imaging plane of DIC microscope and then projected by a 4f imaging system, so two orthogonally polarized imaging beams with a certain shearing amount will interfere on the conjugate plane of the 4f imaging system and form a spatial carrier DIC image, thus the QDPI can be conveniently realized. Importantly, the system not only possesses high temporal phase stability provided by the common-path geometries and low spatial phase noise due to partially coherent light illumination, but also the advantages of simple optical implementation, no additional phase distortion, high light energy utilization efficiency, and high signal-to-noise ratio. The experimental result demonstrates that using the proposed method, the phase measurement sensitivity reaches 0.003 rad, the corresponding applicability is verified by a polystyrene microsphere crown and biological cells.

Efficient implementation on accuracy improvement of the two-dimensional node-to-segment contact approach for explicit dynamic analysis

AbstractThe penalty-method-based node-to-segment (NTS) approach is widely employed in the explicit dynamic analysis owing to its computational efficiency and implementation simplicity. However, the classical approach does not pass the contact patch test and results in severe inaccuracies. This study attempts the accuracy enhancement of an explicit dynamic contact analysis with minimum efficiency loss using the NTS algorithm with the modified area regularization technique (NTS-mAR). The computational procedure is compared to an allied modified penalty-method-based NTS approach, i.e., the virtual node-to-segment algorithm passing the patch test (VTS-PPT). Then, an extension to an explicit dynamic analysis framework is attempted, wherein the speed of the contact force calculation significantly influences the overall computational efficiency. The cost of the remaining computation was minimized by employing a lumped mass matrix and a one-point integration rule for the internal force. Elastoplasticity was considered to extend its application. The accuracy improvement compared to the classical one-pass NTS approach was similar for the modified approaches. The VTS-PPT approach requires more than twice the cost of contact force estimation compared with the classical one-pass NTS approach. In contrast, NTS-mAR approach induces a cost increase from 6 to 36% that of classical one-pass NTS approaches. For the given examples, the NTS-mAR approach is beneficial when an improvement in accuracy is desired with minimum efficiency loss.

Generalized equilibria for color-gradient lattice Boltzmann model based on higher-order Hermite polynomials: A simplified implementation with central moments.

We propose generalized equilibria of a three-dimensional color-gradient lattice Boltzmann model for two-component two-phase flows using higher-order Hermite polynomials. Although the resulting equilibrium distribution function, which includes a sixth-order term on the velocity, is computationally cumbersome, its equilibrium central moments (CMs) are velocity-independent and have a simplified form. Numerical experiments show that our approach, as in Wen etal. [Phys. Rev. E 100, 023301 (2019)2470-004510.1103/PhysRevE.100.023301] who consider terms up to third order, improves the Galilean invariance compared to that of the conventional approach. Dynamic problems can be solved with high accuracy at a density ratio of 10; however, the accuracy is still limited to a density ratio of 1000. For lower density ratios, the generalized equilibria benefit from the CM-based multiple-relaxation-time model, especially at very high Reynolds numbers, significantly improving the numerical stability.

ALGORITHMS FOR CONVERTING VOXEL 3D MODELS INTO POLYGONAL ONES

This document explores the using of voxels today in such areas as medicine, 3D scanning, game industry and why do we need to convert them to polygonal mesh. It also describes and analyses the currently existing algorithms for converting voxel 3D models into polygonal ones. Aim of converting algorithms is extracting the surface information from the voxel grid and generate a polygonal mesh composed of triangles that approximate the original shape. The research identified about 10 existing algorithms: Marching Cubes, Dual Contouring, Surface Nets, Voxel Carving, Sparse Voxel Octree, Surface Extraction from Volume Data (SEV), Cubical Marching Squares, Adaptive Grid Subdivision, Occupancy Networks, Deep Implicit Fields. Their features, pros and cons were described. It was chosen among the converting algorithms, taking into account the simplicity, efficiency and availability of implementation, one algorithm, which can become the basis of the program for converting voxel 3d models into polygonal mesh. The choice of algorithm depends on various factors, including the desired surface quality, computational efficiency, handling of sharp features, and implementation complexity, but there were several main criteria selected. The chosen algorithm is Marching Cubes, because it is widely used, has available implementations, has good performance. Future research will focus on creating a converter program since there are currently no freely available converters that would produce a high-quality editable polygonal mesh. All existing voxel editors and online converters export the voxel 3d model into polygonal mesh without any approximation, so the export result is a cube set, poorly united into one surface with surface breaks. Export polygonal mesh models also have a problem with a large number of triangles, which makes the model hard to edit. To create a converter that solves those problems, first, we must choose an algorithm that will become the basis of the future converter. Target algorithm will be customized in future to improve the quality of output polygonal mesh comparing to the existing convertors.

Energy optimization for full-duplex wireless-powered IoT networks using rotary-wing UAV with multiple antennas

In this paper, we propose a novel design for the rotary-wing unmanned aerial vehicle (UAV)-enabled full-duplex (FD) wireless-powered Internet of Things (IoT) networks. In this network, the UAV is equipped with an antenna array, and the K IoT sensors, which are distributed randomly, use single-antenna to communicate. By sending the energy, the UAV as a hybrid access point, charges the sensors and collects information from them. Then, to manage the time and optimize the energy, the sensors are divided into N groups, so that the UAV equipped with multi-input multi-output (MIMO) technology can serve the sensors in a group, during the total time T. We provide a simple implementation of the wireless power transfer protocol in the sensors by using the time division multiple access (TDMA) scheme to receive information from the users. In other words, the sensors of each group receive energy from the UAV, when it hovers over the sensors of the previous group, and also when the UAV flies over the previous group to the current group. The sensors of each group send their information to the UAV, when the UAV is hovering over their group. Under these assumptions, we formulate two optimization problems: a sum throughput maximization problem, and a total time minimization problem. Numerical results show that our proposed optimal network provides better performance than the existing networks. In fact, our novel design can serve more sensors at the cost of using more antennas compared to that of the conventional networks.