MATLAB Research Articles

Effect of cannabis on brain activity in males: Quantitative electroencephalography and its relationship with duration, dosage, and age of onset.

Brain function changes as a result of cannabis use. This study examined the brain activity of cannabis users compared to a healthy group and nicotine smokers, focusing on the age of onset, duration of use, and dosage. Demographic and quantitative electroencephalography (QEEG) data of 15 healthy individuals, 20 patients with chronic cannabis use, and 15 nicotine smokers were collected and recorded during the eyes-closed and eyes-open conditions in the resting state. The data were analyzed using MATLAB software and the EEGLAB toolbox. In the eyes-closed condition, cannabis users exhibited significantly elevated relative theta band power in widespread brain regions compared to both the healthy group and nicotine smokers. They showed decreased relative power in the beta and gamma bands in the parietal and occipital regions when compared to nicotine smokers. In the eyes-open condition, cannabis users displayed increased relative theta band power in widespread brain regions relative to both groups. Additionally, lower relative power in the beta and gamma bands was observed in cannabis users compared to the healthy group in the frontal region, as well as in various brain regions compared to nicotine smokers. A significant relationship was identified between gamma-band power, age of onset, and dosage of cannabis use. These findings suggest that cannabis use leads to changes in brain wave patterns during the resting state, which may be linked to cognitive impairments affecting functions. Understanding these associations is essential for developing effective intervention programs aimed at mitigating cognitive deficits related to cannabis use.

Predicting terrain deformation patterns in off-road vehicle-soil interactions using TRR algorithm

Soil deformation is one of the parameters affecting the performance of off-road vehicles, including traction, mobility, and steering. This study offers an examination of soil deformation resulting from interactions with pneumatic and track wheels. Experiments were conducted using a soil bin with a single-wheel test rig, equipped with both a standard agricultural tire and a customized track wheel. Three distinct levels of vertical loads (2, 3, and 4kN) and forward velocities (1, 2, and 3 km/h) were applied using the wheel tester. The displacement and deformation of the soil layers, visualized as a vertical cross-section along the motion path, were consistently prepared and photographed for all experiments. Image analysis was undertaken with MATLAB software to scale images and extract graphical data. The highest deformation, with a value of 60.86 mm, is associated with the interaction of a pneumatic wheel with a force of 4 kN, while the lowest deformation occurs when the soil interacts with a track wheel with a force of 2 kN, with a value of 25.05 mm. Furthermore, the fitted surfaces obtained using the optimization algorithm showed good convergence with the experimental data, with R2 values of 0.9783 and 0.9516 for the pneumatic tire and tracked tire, respectively. The results demonstrated that the TRR model performs well in accurately predicting soil deformation induced by various types of wheels. A comparison between soil deformations caused by track wheels and pneumatic wheels revealed that track wheels result in less deformation and disturbance, particularly in the upper soil layers. These findings underscore the importance of considering the type of traction device and loading conditions when assessing soil deformation in agricultural environments.

Audio File Cryptography using Variable Number of Rounds for Blocks Substitution

An efficient method of audio file cryptography will be introduced, the method will decrease both the encryption and decryption times comparing with other existing methods, the method will speed up the process of audio file cryptography. The introduced method will use a variable number of rounds for audio file cryptography, each round will use a block size, number of blocks and generated indices keys, these parameters will be variable and change from round to another. The private key will have a variable length, and it will depend on the selected number of rounds (192 bits for each round), this length will be good enough to produce a huge key space capable to resist hacking attacks, the produced decrypted file will be very sensitive to the selected values of the private key. The introduced method will be simple and easy to implement, it will use a simple chaotic logistic map model to generate the required for each round indices key. The introduced method will use a simple substitution operation to apply audio file samples substitution without altering the samples values and without using any extra logical and arithmetic operations (required for other existing methods). The introduced method will be tested and implemented using mat lab; the obtained results will be used to show that the method will satisfy the requirements of good crypto method.

Towards contention resolution model to enhance rate of interference during dynamic spectrum utilization in cognitive radio network environment

In cognitive radio networks (CRNs), contention resolution is a fundamental challenge for optimizing dynamic spectrum access among secondary users (SUs) without causing interference to primary users (PUs). This study introduces a contention resolution model within cognitive radio networks. The queuing theory model of M/G/1/K with a First Come First Serve (FCFS) algorithm was employed. This paper proposes a novel contention resolution model using the First-Come-First-Served (FCFS) strategy, framed within a Markov Decision Process (MDP). The model dynamically allocates spectrum to SUs based on their arrival time. It leverages on M/G/1/K queuing model, providing a theoretical foundation for optimizing contention resolution. Through the FCFS algorithm, the model ensures equitable access to the spectrum, prioritizing the first arriving users. As a proof of concept and in order to validate the effectiveness of the model, simulations were performed using MATLAB and Minitab software. MATLAB was employed to simulate the dynamic behavior of the network under varying conditions, providing insights into throughput, delay, and collision metrics while Minitab was used for statistical analysis and validation of the simulation data, ensuring accuracy and reliability of the results. The results obtained from the simulations indicates that the MDP-based FCFS model significantly improves spectrum efficiency, reduces access delays, and minimizes collision rates compared to traditional contention resolution techniques. Another main contribution of this model formulation and evaluation is to help Nigerian Communication Commission (NCC) and other Dynamic Spectrum Usage functionaries in analyzing and optimizing the contention resolution predominant challenge, for the effective utilization of available spectrum resources in dynamic cognitive radio environment.

Radiation impact on heat and mass transfer of an unsteady MHD nanofluid flow past an exponentially accelerating vertical plate with heat generation

This paper comprehensively analyzes the consequences of thermal radiation on natural convection, electrical and thermally conducted water-based flowing nanofluid past an exponentially accelerating surface. The paper investigates the thermal and momentum boundary layers with the effects of radiation and heat generation on the nanofluid flow. The magnetic field acts perpendicular to the flow direction. The non-dimensional governing equations were numerically solved using the Finite Difference Method (FDM) and illustrated through the use of MATLAB software. Thermal radiation enhances the nanofluid temperature and velocity, an essential phenomenon for designing solar collectors. The heat generation factor reduces the skin friction of the flow. It improves heat transfer by convection rather than conduction mode, enhancing the velocity and dropping the temperature of the nanofluid. The influence of some dimensionless parameters on the nanofluid velocity and temperature led to this paper's conclusion. Mass and heat transmission are fundamental due to their daily applications, including human body temperature regulations, electronic devices, and heating/cooling systems.

Application of fractional shifted vieta-fibonacci polynomials in nonlinear reaction diffusion equation with variable order time-space fractional derivative

Abstract In this article, an accurate optimization algorithm based on new polynomials namely generalized shifted Vieta-Fibonacci polynomials (GSVFPs) is employed to solve the nonlinear variable order time-space fractional reaction diffusion equation (NVOTSFRDE). The algorithm combines GSVFPs, new variable order fractional operational matrices in the Caputo sense, and the Lagrange multipliers to achieve the optimal solution. First, the solution of the NVOTSFRDE is approximated as a series of GSVFPs with unknown coefficients and parameters. Then, the Lagrange multipliers method is adopted so that the NVOTSFRDE can be transformed into a class of nonlinear algebraic system of equations and we solve these equations using MATLAB and MAPLE software. Solving this system and substituting the coefficients and parameters into the approximation of the guessed functions, the solution of the NVOTSFRDE is obtained. The convergence analysis of the approach are discussed. The accuracy of the algorithm is verified through error analysis and mathematical examples. The accuracy of the new method is higher than that of the exciting method. The reconstruction results demonstrate that the proposed optimization algorithm is efficient for the NVOTSFRDE, and the algorithm is also convergent.

Thermal inspection on MHD Prandtl fluid flow past a stretching sheet in the presence of heat generation/absorption and suction/injection

Abstract For the past several years, researchers have been investigating the thermal boundary layer behavior under various assumptions due to contemporary requirements. From the existing literature, it has been noticed that no investigation has been conducted to examine the thermal and mass transport of a magnetohydrodynamic (MHD) flow of a Prandtl fluid past a stretching sheet with heat generation/absorption and suction/injection. To address this gap, this study looks at how the changed thermal flux, heat generation/absorption, and suction/injection affect the convective flow of MHD Prandtl fluid over a stretching surface. The governing system of nonlinear partial differential equations (PDEs) has been reduced to a system of ordinary differential equations (ODEs) through appropriate transformations. The desired numerical solutions of the resulting ODEs have been obtained using the bvp5c MATLAB package. We have analyzed and presented the effects of the physical parameters on the velocity, temperature, and concentration fields using graphs and tables. Also, the drag coefficient, heat, and mass transport rates were examined. Additionally, an entropy analysis has been conducted to explore the reusability of heat production. It has been observed that intensifying the magnetic and porosity parameters reduces the flow velocity while increasing the Eckert number, heat generation parameter, and the Biot number significantly increases the temperature. The concentration drops with an increase in the Schmidt number and the chemical reaction parameter. This study holds significant implications for industries that rely on drug delivery, heat exchanger technology, polymerization, and refining processes.

Implementation of Fuzzy Logic in Temperature and Fermentation Time Control Systemon Alcohol Content of Cassava Tape Product

The fermentation process of cassava tape involves complex biochemical reactions and requires careful attention to various factors. Temperature and fermentation time are crucial parameters that significantly affect the final quality of cassava tape. Along with the development of artificial intelligence (AI), the fermentation process can be controlled and monitored more precisely, thereby increasing the efficiency and consistency of the final product. This study aims to determine the Mamdani fuzzy logic approach in the temperature control system and fermentation duration in the cassava tape production process to optimally regulate the alcohol content of cassava tape. The research method is a literature study, testing Mamdani fuzzy logic using Matlab software, and analyzing input variables manually. The results of the study showed that the optimal temperature for cassava tape fermentation was between 25°C - 30°C and the optimal time for cassava tape fermentation was with a "long" duration. From the defuzzification results, the final results showed an alcohol content of 15.9% at a temperature of 29°C and a fermentation time of 80 hours so that the alcohol content of cassava tape was in accordance with the specifications.

Computational analysis of linear chain of holey nanographene and their molecular characterizations.

Holey nanographene, an allotrope of carbon arranged in two dimensions, has gained remarkable attention as a nanomaterial with several potential uses in numerous industries, such as electronics, energy storage, healthcare, and environmental cleanup, because of its high carrier mobility, flexibility, transparency, high surface area, conductivity, and chemical stability. The fundamental holey nanographene is assembled in a linear form to create the holey nanographene chain (HNC) that is being discussed. To fully utilize it in various applications, it is essential to comprehend the basic ideas guiding its behavior at the nanoscale; for that, we find various topological indices for this holey nanographene chain using the cut method. Because topological indices are a robust mathematical tool that links molecular structure with chemical, physical, and biological properties, they are essential in diverse areas, namely chemistry, pharmaceutical research, environmental science, and materials science METHODS: The cut method is essential for calculating topological indices in large structures as standard definitions become increasingly complex for such computations. In this study, we apply the cut method to compute each topological index for holey nanographene structures, which involves extensive summations. MATLAB software is employed to simplify these calculations. To generate the DDSV (Distance Degree Sequence Vector) for each vertex within any dimension of holey nanographene, we utilize the NEWGRAPH interface. Python code is then used to analyze the DDSVs assigned to each vertex. Additionally, MATLAB code is applied to validate the numerical results derived from analytical formulae for the topological indices of the HNCs under consideration.

Application of Fuzzy Logic to Motorcycle Oil Change Cycle with 10W 30 Oil Viscosity

Oil is a fluid that serves to lubricate the engine, so that friction between engine components is relatively small. Oil changes are based on mileage, oil volume, and oil viscosity levels which usually vary depending on the needs of the vehicle's engine. Most riders are often late and do not even know the routine time of oil changes so that the user's motorcycle engine feels damaged. The application of fuzzy logic has become an important approach in modeling the complex and ambiguous system of motorcycle oil change periods with 10W 30 oil viscosity. The purpose of this study is to determine the application of fuzzy logic in determining the optimal oil. exchange interval. Oil is based on factors such as mileage, oil volume, and oil viscosity when viewed from motorcycle use. To represent these variables using fuzzy sets, a fuzzy logic control system was developed that takes into account oil wear and motorcycle operating conditions which was implemented using the mamdani method and calculated using matlab software. The results showed that oil change intervals tailored to operating conditions and the environment can improve engine performance, reduce maintenance costs and extend component life.

ADAPTIVE HYBRID DIFFERENTIAL EVOLUTION PARTICLE SWARM OPTIMIZATION ALGORITHM FOR OPTIMIZATION DISTRIBUTED GENERATION IN DISTRIBUTION NETWORKS

The incorporation of Distributed Generation (DG) into the Radial Distribution System (RDS) aids in resolving power system issues such as power loss. However, finding the ideal location and size for DG is challenging yet crucial for maximizing these advantages. Inappropriate location and sizing of DG can negatively impact its benefits, highlighting the need for effective optimization methods. To address these challenges, metaheuristic methods like Particle Swarm Optimization (PSO), Differential Evolution (DE), and Firefly algorithms are particularly useful. This research aims to determine the best location and size of DG to minimize active power losses in the RDS. Despite the success of DE and PSO in previous works, a gap remains in achieving optimal convergence performance and computational efficiency. Building on the success of DE and PSO, this study presents a hybrid optimization approach, Adaptive Hybrid Differential Evolution and Particle Swarm Optimization (AHDEPSO), to reduce power loss in RDS. This approach combines the strengths of DE and PSO, enhancing exploration and exploitation capabilities while improving convergence performance. The effectiveness of this approach is demonstrated through testing on the IEEE 33 and IEEE 69 bus systems using MATLAB software, showing that AHDEPSO can achieve optimal computational time and best fitness function, being 38.3% faster than other algorithms. This hybrid approach offers a significant improvement over traditional methods, filling the research gap and providing a more efficient solution.

Determination of Equilibrium Loading by Empirical Models for the Modeling of Breakthrough Curves in a Fixed-Bed Column: From Experience to Practice

Empirical models have been found to be inadequate in both accounting for breakthrough behaviors and reflecting the performance of fixed-bed systems, primarily due to their lack of a robust theoretical foundation. This limitation severely restricts their practical application. To address this difficulty, the adjustable parameters of six empirical models were first determined using the Levenberg–Marquardt iteration algorithm. The fitting quality of these models was subsequently evaluated by several error statistics, including the reduced chi-square (χ2), adjusted coefficient of determination (Adj. R2), residual sum of squares (RSS) and root of mean squared error (RMSE). In addition, the Akaike information criterion (AIC) and Bayesian information criterion (BIC) were employed to further compare these empirical models with the different parameters. The equilibrium loading, breakthrough capacity and saturation capacity were then solved by the int command of MATLAB 2023b software. Meanwhile, the breakthrough time and saturation time were determined by its fzero command. Regardless of whether empirical or mechanistic models were used, the model with the asymmetric S-shaped curve could well describe the measured breakthrough curves. Based on the parallel sigmoidal model, the predicted equilibrium loadings were 101.11, 116.69 and 129.50 mg g−1, respectively, at adsorbent masses of 0.1, 0.3 and 0.5 g. This study aimed to conveniently obtain the critical process parameters through MATLAB software using empirical breakthrough models, thereby providing reliable information for the design and optimization of fixed-bed adsorbers.

First principle design load assessment of LH2 fuel gas supply systems for ships by means of 0D approach

ABSTRACT Within the framework of the Sustainable Development Goals, the United Nations (UN) General Assembly has declared its firm intention to combat climate change and the associated changes in the environment. Shipping is an important factor since its exhaust gases account for just over two per cent of global greenhouse gas (GHG) emissions. Liquid hydrogen is a promising candidate to enable this transition. In this work, a simulation-based approach for the estimation of design loads with respect to liquid hydrogen fuel tanks is presented. The MATLAB software was employed to implement a 0-dimensional approach for the calculation of the bulk thermodynamic behavior. There is good correlation between validation data and simulation. An exemplary cruise ship and corresponding power-demand profiles were utilized to simulate different fuel gas supply systems. The results were then analyzed with regard to occurring loads and operational efficiency.

Modeling creep for a closed cylindrical shell under hydrostatic pressure

Objective. The paper presents general equations of the moment theory of a shell of zero Gaussian curvature taking into account creep deformation. The problem of the stress-strain state of a shell is considered, with the boundary conditions: rigidly fixed at the base and free edge at the top. The cylinder is subject to internal hydrostatic pressure. Method. A linear non-homogeneous differential equation of the fourth order with respect to deflection is obtained. The solution is given in the MATLAB software package. The non-linear MaxwellGurevich equation is used as the equation of state between creep deformations and stresses. To determine creep deformations, a linear approximation of the first derivative with respect to time (Euler's method) was used. Result. The calculation of the shell made of secondary PVC was performed using the grid method. The method was tested. A program for calculation in the MATLAB package was developed with the possibility of varying the initial data and outputting a graph of the dependence of stress displacements on time. During creep in the shell, circumferential stresses increase by 14.7%. Conclusion. The proposed approach can be applied to the analysis of the stress-strain state and bearing capacity of a reinforced concrete shell as well. There are no restrictions on boundary conditions and the type of loading, and the beam material can be not only polymers and composites for construction purposes, but also concrete.

Velocity Analysis of a Slider Crank Mechanism for Delta Robot Arm Manipulation: A Computational Approach

In this research, a velocity analysis of the slider crank mechanism's (SCM) for the delta robot arm manipulation was carried out. For the slider crank mechanism, new velocity response models were created. Trigonometric and inverse trigonometric functions are used in the novel Akozietic mathematical method, which is appropriate for kinematic analysis of intricate mechanisms like the four-bar mechanism (slider crank). The equilibrium conditions of the forces in a four-bar mechanism are used in the Akozietic mathematical technique to create simple mathematical models that enable user-written computer programs in Matlab and other programming languages. According to the velocity profile, the mechanism is under the most stress when the crank angle exceeds 300°, and the velocity is lowest at 180° and 0°.The crank angles where the slider shifts direction are the locations where the velocity passes zero. The novel mathematical procedure created in this study outperformed the other two kinematic analysis methods that were currently in use, according to a comparison of spreadsheets and this new mathematical method for mechanism analysis (Akozietic) with standard numerical solutions completed in Mathematica.

Research on adaptive robust sliding mode control of Horizontal vibration of high-speed elevator car system considering time delay

In this paper, a new adaptive robust sliding mode control (ASMC) strategy is proposed for high-speed elevator car systems with input delay and unknown nonlinear dynamic characteristics. Firstly, considering the inherent time delay of the system, the active control model of the four-degree-of-freedom time-delay car system with the symmetrical distribution of the actuator is established. Then, for the car system with unknown disturbance, a robust integral sliding mode control strategy is designed, and an adaptive law is designed to ensure the reachability of sliding mode motion. Then, considering the time delay of vibration signal transmission and actuator actuation, a time-delay optimal adaptive robust sliding mode control strategy (TDASMC) based on the state transformation method is designed, and the stability of the system is proved by constructing the Lyapunov function. Finally, Matlab software is used for simulation analysis, and the results show that the proposed control strategy can attenuate more than 45% of the peak and RMS of the horizontal vibration acceleration, and the large vibration suppression degree is not more than 14% under different working conditions, which has good vibration suppression performance and robustness.

MEPFeatX-automated feature extraction of motor-evoked potentials in transcranial magnetic stimulation.

Motor evoked potentials (MEPs) are an important measure in transcranial magnetic stimulation (TMS) when assessing neuronal excitability in clinical diagnostics related to motor function, as well as in neuroscience research. However, manual feature extraction from large datasets can be time-consuming and prone to human error, and valuable features, such as MEP polyphasia and duration, are often neglected. Several packages have been developed to simplify the process; however, they are often tailored to specific studies or are not accessible. Here, we introduce MEPFeatX, a verified MATLAB package designed for automated and comprehensive MEP feature extraction across a wide range of stimulation paradigms. MEPFeatX is designed and documented for easy integration into any MEP analysis pipeline. Primed templates for specific paradigms, as well as additional analysis coded in R language, are also provided. Thus, MEPFeatX provides its users with a comprehensive and accurate set of MEP features, along with their visuals, facilitating quick and reliable MEP analysis in TMS studies.

Enhanced speed sensorless control of IPMSM using integral synergetic observer

Owing to the benefits of uncomplicated design, compact dimensions, and superior power density, interior permanent magnet synchronous motors (IPMSMs) have garnered the attention of numerous researchers, both nationally and internationally. Nevertheless, conventional IPMSM models incorporating sensors, encoders, and additional apparatus often incur substantial equipment expenses and heavily depend on sensor accuracy for effective control. Consequently, the pursuit of sensorless control has emerged as a prominent trend in the domain of IPMSM control. In this work, a new sensorless control based on an integral synergetic observer (ISO) for an IPMSM is presented. The suggested observer has been developed to overcome the challenges posed by conventional observers, such as fragility against various disturbances, and establishing a sensorless control scheme capable of easily integrating into a modern application like electric vehicles. A comparison through numerical simulation tests using MATLAB software, between the proposed observer and the classic Luenberger observer (LO) clearly showed its qualities and its great importance. Notably, the ISO achieves improved performance metrics, such as the integral absolute error (IAE), integral square error (ISE), and integral time absolute error (ITAE). In low-speed control tests, the proposed ISO reduced the IAE by 56.90%, the ITAE by 55.83%, and the ISE by 75.82% compared to the LO.

Digitizing Low-Frequency Analog Control Circuit Using Bilinear Function Algorithm

In the past, low-frequency analog control circuits were largely used in analog control systems. With the rapid development of modern digital electronic technology, the digitization of traditional low-frequency analog control circuits while retaining the same functions as the original analog control systems has become an important trend in the field of electronic design. For this reason, this study aimed to develop an analog signal digitization model for control signals at a low frequency below 10 Hz. In terms of signal receiving and transmission requirements, the proposed model is configured with analog-to-digital converter (ADC), digital-to-analog converter (DAC), and pulse width modulation (PWM) functions. In the development environment, the input and output signals are first normalized and processed with PWM, enabling the digital signal processor to deal with analog signal receiving, processing, and external transmission. To replace the existing compensator in analog circuits, a digital compensator is used in the digital signal processor. Based on the bilinear function in MATLAB software, the parameter values demanded for the digital compensator can thus be obtained, achieving the automatic calculation of bilinear transformation in the system. Multisim simulation is then used to simulate analog circuit systems for comparison with the digitized outcomes. The experimental results reveal that the performance of the designed digital control circuit matches the simulation outcomes in both Bode gain (dB) and phase responses when the signal frequency is below 10 Hz. The effectiveness of the digitized analog control circuit for low-frequency control signals is therefore confirmed.

ВИКОРИСТАННЯ ФІЛЬТРУ КАЛМАНА У ВЕКТОРНІЙ СИСТЕМІ ЕКСТРЕМАЛЬНОГО КЕРУВАННЯ АСИНХРОННОЮ МАШИНОЮ

In the article the reactive power of an asynchronous machine (AM) in a stable mode is obtained as a function of three vari-ables: the angular speed of rotation of the AM shaft, the module of the rotor flux coupling and the moment of static load on the shaft. The AM power factor decreases in electric drives (ED) of industrial mechanisms in which the load moment while maintaining its direction of action can take a static value less than the nominal value. Therefore, in order to ensure a high power factor of an asynchronous ED in long-term operating modes with a variable load, a vector AM control system was created, in which the magnitude of the rotor flux coupling is regulated by the reactive power channel as a function of the mo-ment of static load on the shaft. To identify the moment of loading, as well as the angular speed of the rotor and its flux cou-pling, a Kalman observer is synthesized, which allows creating a vector control system with simultaneous regulation of the speed and power factor of the AM without physical sensors of the reference vector of the rotor flux coupling and its angular speed of rotation. The significant dependence of the extreme values of the rotor flux coupling for reactive power on the torque on the AM shaft and insignificant dependence on the speed has been proved. Stability and high control quality are achieved by simultaneous use of relay control laws, invariant to coordinate and parametric perturbations, and the effectiveness of the Kalman filter algorithm for identifying variable states in the feedback loop. Thus, the article theoretically substantiates the idea of creating a sensorless relay-vector control system for an asynchronous ED with simultaneous speed regulation and optimization of AM energy indicators. The mathematical model is created as a program written in the Matlab programming language. The operability of the proposed asynchronous ED control system was confirmed by the method of mathematical modeling. References 12, figures 6.