While Metaheuristic optimization techniques are known to work well for clustering and large-scale numerical optimization,algorithms in this category suffer from issues like reinforcement stagnation and poor late-stage...While Metaheuristic optimization techniques are known to work well for clustering and large-scale numerical optimization,algorithms in this category suffer from issues like reinforcement stagnation and poor late-stage refinement.In this paper,we propose the Improved Geyser-Inspired Optimization Algorithm(IGIOA),an enhancement of the Geyser-Inspired Optimization Algorithm(GIOA),which integrates two primary components:the Adaptive Turbulence Operator(ATO)and the Dynamic Pressure Equilibrium Operator(DPEO).ATO allows IGIOA to periodically disrupt stagnation and explore different regions by using turbulence,while DPEO ensures refinement in later iterations by adaptively modulating convergence pressure.We implemented IGIOA on 23 benchmark functions with both unimodal and multimodal contours,in addition to eight problems pertaining to cluster analysis at the UCI.IGIOA,out of all the tested methods,was able to converge most accurately while also achieving a stable convergence rate.The mitigation of premature convergence and low-level exploitation was made possible by the turbulence and pressure-based refinements.The findings from the tests confirm that the adaptation of baseline strategies by IGIOA helps deal with complex data distributions more effectively.However,additional hyperparameters which add complexity are introduced,along with increased computational cost.These include automatic tuning of parameters,ensemble or parallel variations,and hybridization with dedicated local search strategies to extend the reach of IGIOA for general optimization while also specializing it for clustering focused tasks and applications.展开更多
Future power system faces several challenges,one of them is the high penetration level of intermittent wind power generation,providing small or even no inertial response and being not contributing to the frequency sta...Future power system faces several challenges,one of them is the high penetration level of intermittent wind power generation,providing small or even no inertial response and being not contributing to the frequency stability.The effect of shaft stiffness on inertial response of fixed speed wind turbines is presented.Four different drive-train models based on the multi-body system are developed.The small-signal analysis demonstrates no significant differences between models in terms of electro-mechanical eigen-values for increasing shaft stiffness.The natural resonance frequency of drive-train torsion modes shows slightly different values between damped and undamped models,but no significant differences are found in the number-mass models.Time-domain simulations show the changes in the active power contribution of a wind farm based on a fixed speed wind turbine during the system frequency disturbance.The changes in the kinetic energy during the dynamic process are calculated and their contribution to the inertia constant is small and effective.The largest contribution of the kinetic energy is provided at the beginning of the system frequency disturbance to reduce the rate of the frequency change,it is positive for the frequency stability.展开更多
Ozone is a green house gas. Ozone absorption cross sections have been reported with discrepancies and inconsistencies. In this paper, simultaneous effects of the optical path length and temperature variations on ozone...Ozone is a green house gas. Ozone absorption cross sections have been reported with discrepancies and inconsistencies. In this paper, simultaneous effects of the optical path length and temperature variations on ozone gas absorption cross sections are investigated at different wavelengths. HITRAN 2012, the latest available line list on spectralcalc.com simulator, is used in this study to simulate ozone gas absorption cross sections in relation to the simultaneous effects of the optical path length and temperature at the wavelengths of 603 nm and 575 nm. Results obtained for gas cells with the optical path length from 10 cm to 120 cm show that the decrease in temperatures from 313 K to 103 K results in the increase in ozone gas absorption cross sections. At wavelengths of 603 nm and 575 nm, the percentage increase of ozone gas absorption cross sections is 1.22% and 0.71%, respectively. Results obtained in this study show that in the visible spectrum, at constant pressure, ozone gas absorption cross sections are dependent on the temperature and wavelength but do not depend on the optical path length. Analysis in this work addresses discrepancies in ozone gas absorption cross sections in relation to the temperature in the visible spectrum; thus, the results can be applied to get optimal configuration of high accuracy ozone gas sensors.展开更多
Background: The universal goniometer is commonly used to measure knee range of movement in clinical practice. However, research has demonstrated that the universal goniometer lacks reliability failing to meet the stan...Background: The universal goniometer is commonly used to measure knee range of movement in clinical practice. However, research has demonstrated that the universal goniometer lacks reliability failing to meet the standard of clinically acceptable error (5°). Objective: This study tested the concurrent validity and intra-rater reliability of a photographic based “app” developed for feedback in sport, the Hudl Ubersense App, as an alternative instrument for measuring knee range of movement. Methods: Measurements of knee range of movement were made concurrently with the electrogoniometer (the gold standard) and the Hudl Ubersense App across a pre-determined randomised set of 20 functional knee angles between 35° and 130°. This was then repeated. The pre-agreed standard of concurrent validity was that 95% of Hudl Ubersense App measurements would be within 5° of the electrogoniometer and differences were displayed in Bland-Altman plots. Results: Thirty nine (97%) of the forty app readings differed from the corresponding electrogoniometer readings by less than 5°. The mean differences between the electrogoniometer and Hudl Ubersense App measurements over each trial were 1.75° and 0.80° respectively, indicating a high level of concurrent validity. There was less than 1.0° mean difference between the first and second set of results indicating a high level of intra-rater reliability. Conclusions: The results suggest that the Hudl Ubersense App has high levels of concurrent validity (using the electrogoniometer as the gold standard) and intra-rater reliability, scoring better than previous research on the current clinical measuring device, the universal goniometer. The Hudl Ubersense App has clinical advantages over the electrogoniometer, so further research is recommended to determine its inter-rater reliability, acceptability, and appropriate clinical practice procedures.展开更多
This study develops a high-order computational scheme for analyzing unsteady tangent hyperbolic fluid flow with variable thermal conductivity,thermal radiation,and coupled heat andmass transfer effects.Amodified twost...This study develops a high-order computational scheme for analyzing unsteady tangent hyperbolic fluid flow with variable thermal conductivity,thermal radiation,and coupled heat andmass transfer effects.Amodified twostage Exponential Time Integrator is introduced for temporal discretization,providing second-order accuracy in time.A compact finite difference method is employed for spatial discretization,yielding sixth-order accuracy at most grid points.The proposed framework ensures numerical stability and convergence when solving stiff,nonlinear parabolic systems arising in fluid flow and heat transfer problems.The novelty of the work lies in combining exponential integrator schemes with compact high-order spatial discretization,enabling accurate and efficient simulations of tangent hyperbolic fluids under complex boundary conditions,such as oscillatory plates and varying thermal conductivity.This approach addresses limitations of classical Euler,Runge–Kutta,and spectral methods by significantly reducing numerical errors(up to 45%)and computational cost.Comprehensive parametric studies demonstrate how viscous dissipation,chemical reactions,the Weissenberg number,and the Hartmann number influence flow behaviour,heat transfer,and mass transfer.Notably,heat transfer rates increase by 18.6%with stronger viscous dissipation,while mass transfer rates rise by 21.3%with more intense chemical reactions.The real-world relevance of the study is underscored by its direct applications in polymer processing,heat exchanger design,radiative thermal management in aerospace,and biofluid transport in biomedical systems.The proposed scheme thus provides a robust numerical framework that not only advances the mathematical modelling of non-Newtonian fluid flows but also offers practical insights for engineering systems involving tangent hyperbolic fluids.展开更多
This study investigates back-reaction effects from matter accretion onto a cylindrically symmetric black hole using a perturbative scheme,focusing on cases where accretion reaches a quasi-steady state.We examine three...This study investigates back-reaction effects from matter accretion onto a cylindrically symmetric black hole using a perturbative scheme,focusing on cases where accretion reaches a quasi-steady state.We examine three distinct models by deriving corrections to the metric coefficients and obtaining expressions for the mass function.We analyze energy conditions and the self-consistency of the corrected solution and present formulas for the corrected apparent horizon and discussed thermodynamic properties.Our results align with the Vaidya form near the apparent horizon,regardless of the energy-momentum tensor form.Furthermore,we show that for a charged cylindrically symmetric black hole,the corrected mass term resembles that of a static case,indicating that charge does not alter the corrected metric form in this perturbative approach.展开更多
基金King Saud University for funding this work through Researchers Supporting Project number(RSPD2024R697),King Saud University,Riyadh,Saudi Arabiafinancial support European Union under the REFRESH-Research Excellence For REgion Sustainability and High-tech Industries project number CZ.10.03.01/00/22_/0000048 via the Operational Programme Just Transition.
文摘While Metaheuristic optimization techniques are known to work well for clustering and large-scale numerical optimization,algorithms in this category suffer from issues like reinforcement stagnation and poor late-stage refinement.In this paper,we propose the Improved Geyser-Inspired Optimization Algorithm(IGIOA),an enhancement of the Geyser-Inspired Optimization Algorithm(GIOA),which integrates two primary components:the Adaptive Turbulence Operator(ATO)and the Dynamic Pressure Equilibrium Operator(DPEO).ATO allows IGIOA to periodically disrupt stagnation and explore different regions by using turbulence,while DPEO ensures refinement in later iterations by adaptively modulating convergence pressure.We implemented IGIOA on 23 benchmark functions with both unimodal and multimodal contours,in addition to eight problems pertaining to cluster analysis at the UCI.IGIOA,out of all the tested methods,was able to converge most accurately while also achieving a stable convergence rate.The mitigation of premature convergence and low-level exploitation was made possible by the turbulence and pressure-based refinements.The findings from the tests confirm that the adaptation of baseline strategies by IGIOA helps deal with complex data distributions more effectively.However,additional hyperparameters which add complexity are introduced,along with increased computational cost.These include automatic tuning of parameters,ensemble or parallel variations,and hybridization with dedicated local search strategies to extend the reach of IGIOA for general optimization while also specializing it for clustering focused tasks and applications.
文摘Future power system faces several challenges,one of them is the high penetration level of intermittent wind power generation,providing small or even no inertial response and being not contributing to the frequency stability.The effect of shaft stiffness on inertial response of fixed speed wind turbines is presented.Four different drive-train models based on the multi-body system are developed.The small-signal analysis demonstrates no significant differences between models in terms of electro-mechanical eigen-values for increasing shaft stiffness.The natural resonance frequency of drive-train torsion modes shows slightly different values between damped and undamped models,but no significant differences are found in the number-mass models.Time-domain simulations show the changes in the active power contribution of a wind farm based on a fixed speed wind turbine during the system frequency disturbance.The changes in the kinetic energy during the dynamic process are calculated and their contribution to the inertia constant is small and effective.The largest contribution of the kinetic energy is provided at the beginning of the system frequency disturbance to reduce the rate of the frequency change,it is positive for the frequency stability.
基金supported by Universiti Teknologi Malaysia under Research University Grant Scheme under Grant No.05J60 and No.04H35Ministry of Higher Education under Fundamental Research Grant Scheme under Grant No.4F317 and No.4F565Nigerian Education Trust Fund under Tertiary Education Trust Fund
文摘Ozone is a green house gas. Ozone absorption cross sections have been reported with discrepancies and inconsistencies. In this paper, simultaneous effects of the optical path length and temperature variations on ozone gas absorption cross sections are investigated at different wavelengths. HITRAN 2012, the latest available line list on spectralcalc.com simulator, is used in this study to simulate ozone gas absorption cross sections in relation to the simultaneous effects of the optical path length and temperature at the wavelengths of 603 nm and 575 nm. Results obtained for gas cells with the optical path length from 10 cm to 120 cm show that the decrease in temperatures from 313 K to 103 K results in the increase in ozone gas absorption cross sections. At wavelengths of 603 nm and 575 nm, the percentage increase of ozone gas absorption cross sections is 1.22% and 0.71%, respectively. Results obtained in this study show that in the visible spectrum, at constant pressure, ozone gas absorption cross sections are dependent on the temperature and wavelength but do not depend on the optical path length. Analysis in this work addresses discrepancies in ozone gas absorption cross sections in relation to the temperature in the visible spectrum; thus, the results can be applied to get optimal configuration of high accuracy ozone gas sensors.
文摘Background: The universal goniometer is commonly used to measure knee range of movement in clinical practice. However, research has demonstrated that the universal goniometer lacks reliability failing to meet the standard of clinically acceptable error (5°). Objective: This study tested the concurrent validity and intra-rater reliability of a photographic based “app” developed for feedback in sport, the Hudl Ubersense App, as an alternative instrument for measuring knee range of movement. Methods: Measurements of knee range of movement were made concurrently with the electrogoniometer (the gold standard) and the Hudl Ubersense App across a pre-determined randomised set of 20 functional knee angles between 35° and 130°. This was then repeated. The pre-agreed standard of concurrent validity was that 95% of Hudl Ubersense App measurements would be within 5° of the electrogoniometer and differences were displayed in Bland-Altman plots. Results: Thirty nine (97%) of the forty app readings differed from the corresponding electrogoniometer readings by less than 5°. The mean differences between the electrogoniometer and Hudl Ubersense App measurements over each trial were 1.75° and 0.80° respectively, indicating a high level of concurrent validity. There was less than 1.0° mean difference between the first and second set of results indicating a high level of intra-rater reliability. Conclusions: The results suggest that the Hudl Ubersense App has high levels of concurrent validity (using the electrogoniometer as the gold standard) and intra-rater reliability, scoring better than previous research on the current clinical measuring device, the universal goniometer. The Hudl Ubersense App has clinical advantages over the electrogoniometer, so further research is recommended to determine its inter-rater reliability, acceptability, and appropriate clinical practice procedures.
基金supported and funded by the Deanship of Scientific Research at Imam Mohammad Ibn Saud Islamic University(IMSIU)(grant number IMSIU-DDRSP2503).
文摘This study develops a high-order computational scheme for analyzing unsteady tangent hyperbolic fluid flow with variable thermal conductivity,thermal radiation,and coupled heat andmass transfer effects.Amodified twostage Exponential Time Integrator is introduced for temporal discretization,providing second-order accuracy in time.A compact finite difference method is employed for spatial discretization,yielding sixth-order accuracy at most grid points.The proposed framework ensures numerical stability and convergence when solving stiff,nonlinear parabolic systems arising in fluid flow and heat transfer problems.The novelty of the work lies in combining exponential integrator schemes with compact high-order spatial discretization,enabling accurate and efficient simulations of tangent hyperbolic fluids under complex boundary conditions,such as oscillatory plates and varying thermal conductivity.This approach addresses limitations of classical Euler,Runge–Kutta,and spectral methods by significantly reducing numerical errors(up to 45%)and computational cost.Comprehensive parametric studies demonstrate how viscous dissipation,chemical reactions,the Weissenberg number,and the Hartmann number influence flow behaviour,heat transfer,and mass transfer.Notably,heat transfer rates increase by 18.6%with stronger viscous dissipation,while mass transfer rates rise by 21.3%with more intense chemical reactions.The real-world relevance of the study is underscored by its direct applications in polymer processing,heat exchanger design,radiative thermal management in aerospace,and biofluid transport in biomedical systems.The proposed scheme thus provides a robust numerical framework that not only advances the mathematical modelling of non-Newtonian fluid flows but also offers practical insights for engineering systems involving tangent hyperbolic fluids.
文摘This study investigates back-reaction effects from matter accretion onto a cylindrically symmetric black hole using a perturbative scheme,focusing on cases where accretion reaches a quasi-steady state.We examine three distinct models by deriving corrections to the metric coefficients and obtaining expressions for the mass function.We analyze energy conditions and the self-consistency of the corrected solution and present formulas for the corrected apparent horizon and discussed thermodynamic properties.Our results align with the Vaidya form near the apparent horizon,regardless of the energy-momentum tensor form.Furthermore,we show that for a charged cylindrically symmetric black hole,the corrected mass term resembles that of a static case,indicating that charge does not alter the corrected metric form in this perturbative approach.
