Numeric Approach Research Articles

Comparative study of Eyring–Powell fluid flow with temperature-dependent viscosity in roll-rotating systems: An analytic, numeric, and machine learning approach

Comparative study of Eyring–Powell fluid flow with temperature-dependent viscosity in roll-rotating systems: An analytic, numeric, and machine learning approach

THE EFFECT OF DISCOUNT AND SHOPPING LIFE STYLE ON IMPULSE BUYING WITH POSITIVE EMOTION AS AN INTERVENING VARIABLE ON THE SHOPEE SHOPPING PLATFORM

Business that employs an online store using Shopee platform is Ghealsy.id. The aim of this study is to ascertain: (1) whether Discounts have an influence on Impulse buying, (2) whether Shopping lifestyle has an influence on Impulse buying, (3) whether Positive emotions have an influence on Impulse buying, (4) whether Discounts have an influence on Positive emotions, (5) whether Shopping lifestyle has a positive influence on Positive emotions, (6) whether Discounts have an influence on Impulse buying through Positive emotions as an Intervening Variable, and (7) whether Shopping lifestyle has an influence on Impulse buying through Positive emotions as an Intervening Variable. This study employs a quantitative (numeric) approach with 100 respondents as its sample. The results of this research demonstrate that: (1) Discounts have an effect on Impulse buying, (2) Shopping lifestyle does not have an effect on Impulse buying, (3) Positive emotions have an effect on Impulse buying, (4) Discounts have an effect on Positive emotions, (5) Shopping lifestyle has a positive effect on Positive emotions, (6) Through Positive emotions as an Intervening Variable, Discounts have an effect on Impulse buying, and (7) Through Positive emotions as an Intervening Variable, Shopping lifestyle has an effect on Impulse buying

A finite element method study to compare enmasse retraction of maxillary anteriors using mini implant and conventional anchorage method

Increased upper lip procumbency is associated with protrusive maxillary dentition in Angle’s class I malocclusion, creating unaesthetic facial profile, leading to the need of orthodontic treatment where Enmasse retraction will require maximum anchorage.The present study was conducted to compare Enmasse retraction of maxillary anteriors using mini implant and conventional anchorage in Angle’s Class I malocclusion with bimaxillary protrusion. A numeric approach was adopted. Finite element method was used to determine the stress and displacement of various components at a given time by dividing it into two groups namely, Implant arrangement and T- loop arrangement for enmasse retraction. Significant differences were observed when the stress values were compared between Implant arrangement and T-loop arrangement. In Implant arrangement highest stress values were seen around the lateral incisors and in T loop arrangement stresses were found around canine and premolar. Comparison of displacement in both arrangements gave results of greater displacement in anterior and posterior segments in T-loop arrangement. Mini implants were considered more effective for enmasse retraction but in this study, it was found that although the rate of retraction/ displacement was more in T-loop arrangement but Mini implants in implant arrangement served as an absolute anchorage.

Exploring Regular Exercisers' Experiences with Readiness/Recovery Scores Produced by Wearable Devices: A Descriptive Qualitative Study.

Meta-session autoregulation, a person-adaptive exercise programming approach, is characterized by individuals' matching exercise demands specifically to their current readiness states. Some consumer wearables provide 'recovery' or 'readiness' scores, computed primarily based on heart rate variability. Despite the growing popularity of consumer wearables and interest in person-adaptive programming, limited research exists on how exercisers interact, interpret and use these scores. This study explores individuals' experiences with wearable devices and their associated readiness or recovery scores. Seventeen regular exercisers who owned and used a Whoop™ band or Oura™ ring for at least 3 months participated in a one-on-one virtual semi-structured interview. Interviews were analyzed using reflexive thematic analysis, with themes supported by 'in-vivo' quotes. This paper focuses on three key themes for a comprehensive demonstration. Theme 1, 'It's more about how I can make adjustments to optimize my programming,' (MPR) highlights users' intended use of wearables for guiding training decisions. Theme 2, 'So many things outside of training modifications have changed,' (Misty) reveals that users also modify non-exercise behaviors to manage and optimize their scores. Theme 3, 'You can't really capture the complexities of a human on a device' (Letty) underscores users' recognition of the limitations and errors associated with these devices emphasizing self-reliance to further direct behavioral adjustments. While wearable devices provide a numeric approach to measuring readiness and recovery, users prioritize self-awareness, flexibility, and personal judgment for exercise decisions. Understanding these experiences, in addition to exploring the psycho-behavioral aspects of user interactions, can contribute to refining meta-session autoregulation.

N-BIR: A NUMERIC OPTIMIZATION APPROACH FOR POWER ELECTRONIC CONVERTER BURN-IN TESTING TIME REDUCTION

Burn-in testing is an effective method for detecting early faults in electronic products before they reach the market. This test has a high cost due to lengthy test time on a test bench. In this paper, we propose N-BIR (Numeric optimization approach for power electronic Burn-In testing time Reduction), an algorithm capable of predicting the burn-in (BI) test temperature of power electronic converters, intending to shorten the duration of such tests. This algorithm optimizes by least squares a theoretical model of the system, using as data a fraction of the total burn-in test. Moreover, not only is it capable of making accurate predictions, but it also accompanies them with a prediction interval (PI), so that the algorithm itself can quantify how confident it is of its predictions. We show that using 40% of a conventional rolling test total, our algorithm outperforms several of today's most common Machine Learning (ML) algorithms. Furthermore, we show that it can reduce burning time by 50% to 60% by making accurate predictions, which makes it possible to identify a significant portion of converters that don't require full testing, ultimately lowering costs and boosting productivity. Keywords: Burn-in temperature prediction, Burn-in time reduction, Levelized Cost of Energy, Machine Learning, Electronic Power Converter, Reliability.

Gabor-type holography solved analytically for complex-valued phase disks

Solving the holography equation has long been a numerical task. While effective, the numeric approach has its own set of limitations. Relying solely on numerical approaches often obscures the intricate interplay and influence of the individual terms within the equation. This not only hampers a deeper understanding of the underlying physics but also makes it challenging to predict or control specific outcomes. In this study, we address these challenges by leveraging our recently published updated Fraunhofer diffraction expression. This approach allows us to derive an analytic solution for complex-valued phase disks in in-line holography. This solution facilitates the direct computation of each term’s influence within the holographic equation, paving the way for a more profound comprehension and application of the holographic process. When compared to experimental results and the numeric Fresnel diffraction solution, our analytic approach shows impressive accuracy, considering the inherent approximations. Notably, it remains precise for Fresnel numbers that extend well beyond the traditionally accepted boundaries of the Fraunhofer regime.

The quantum exchange effects on the electromagnetic solitonic excitations in warm plasma

The phenomena related to the high energy regime in a plasma medium are studied in the framework of relativistic quantum hydrodynamics at the classical level. This theory leads to nonlinear equations even at the weak relativistic regime. These nonlinearities give rise to interesting and novel phenomena in the dynamics of the medium. Here, we consider these effects on the dynamics of a warm plasma environment. In addition, we study the effects of the exchange interaction between electrons on the dynamic of such a plasma. This interaction is a quantum mechanical effect and its strength is influenced by the spin polarization ratio of the electrons. Both the analytical and the numerical solutions are presented which are stable and bounded soliton waves. For the analytical solutions, an extended tanh approach, and for the numeric approach, the techniques of solving eigenvalue problems are applied. The behavior of the vector potential and the density under the spin polarization effects and thermal effects in terms of the speed of the wave are discussed.

Analyzing the effect of radiation on the unsteady 2D MHD Al2O3-water flow through parallel squeezing sheets by AGM and HPM

In this essay, the impact of magnetism amplitude on two-dimensional squeezing nanoparticle stream betwixt two equidistant sheets is inspected. The novelty of this research the dimensionless values of various fluids, such as Prandtel number and friction coefficient, influence the investigation of the velocity and heat transfer parameters of aluminum oxide nanofluid. Three mathematical techniques—AGM, HPM, and NUM—have been used in these experiments, and the outcomes and graphs have been computed and compared using these techniques. The non-dimensioned differential equations have been solved using three methods: Akbari-Ganji Method, Homotopy Perturbation Method, and Numeric technique. A comparison is then made between the resolutions of the presented strategies with the numeric approach in a separate chart. We arrived at the generalization that as the Prandtl number increases, the temperature and thermal of the nanofluid flow increase and its concentration drops, and as the Nusselt number declines. This was done by examining the results of the numerical model that was used to solve the equations. As S is increased, it is seen that the temperature drops while the concentration rises. The Nusselt number has increased in value following the growth in permeability value. Displacement increases along with the heat transfer coefficient.

Increasing Structural Performance of Space Telescope Mirrors through Simultaneous Shape and Size Optimization

In this paper, a numeric optimization approach for designing space telescope mirrors will be presented. It is fundamental to space telescopes that each element—including their mirrors—are as lightweight as possible. Moreover, the performance of space telescopes is driven by how strongly these mirrors are distorted upon removal of gravitational load. These distortions result in a deterioration in the optical performance, which is also known as the wavefront error. This error can best be described via Zernike polynomials. To increase the optical performance, along with making the mirror lightweight, the overall root mean square (RMS) of the deformation is used as the optimization objective. An approach utilizing size and shape variables is used to define the feasible design space for the optimization. Lastly, general findings will be discussed, as well as numerical advantages of deploying structural optimization (e.g., robustness evaluation).

Statistically Optimized Repaglinide-loaded Floating Microspheres for the Gastric Sustained Delivery via Central Composite Design

Repaglinide (RPD) is a short-acting insulin secretagogue widely prescribed for the treatment of type 2 diabetes. In this study, RPD loaded ethyl cellulose/hydroxypropylmethylcellulose (EC/HPMC) floating microspheres (FM) have been formulated for gastric sustained release and improved bioavailability of RPD. Floating microspheres were prepared by oil in water emulsion solvent evaporation technique. A three levels Central-composite design (CCD) was applied to investigate the influence of different formulation components and process variables on the formulation responses and indicate the optimum using the numeric approach through the Minitab® software.

The Smooth Transition From Many-Legged to Bipedal Locomotion-Gradual Leg Force Reduction and its Impact on Total Ground Reaction Forces, Body Dynamics and Gait Transitions.

Most terrestrial animals move with a specific number of propulsive legs, which differs between clades. The reasons for these differences are often unknown and rarely queried, despite the underlying mechanisms being indispensable for understanding the evolution of multilegged locomotor systems in the animal kingdom and the development of swiftly moving robots. Moreover, when speeding up, a range of species change their number of propulsive legs. The reasons for this behaviour have proven equally elusive. In animals and robots, the number of propulsive legs also has a decisive impact on the movement dynamics of the centre of mass. Here, I use the leg force interference model to elucidate these issues by introducing gradually declining ground reaction forces in locomotor apparatuses with varying numbers of leg pairs in a first numeric approach dealing with these measures’ impact on locomotion dynamics. The effects caused by the examined changes in ground reaction forces and timing thereof follow a continuum. However, the transition from quadrupedal to a bipedal locomotor system deviates from those between multilegged systems with different numbers of leg pairs. Only in quadrupeds do reduced ground reaction forces beneath one leg pair result in increased reliability of vertical body oscillations and therefore increased energy efficiency and dynamic stability of locomotion.

Influence of Moisture Content and Wet Environment on the Fatigue Behaviour of High-Strength Concrete.

The influence of a wet environment on the fatigue behaviour of high-strength concrete has become more important in recent years with the expansion of offshore wind energy systems. According to the few investigations documented in the literature, the fatigue resistance of specimens submerged in water is significantly lower compared to that of specimens in dry conditions. However, it is still not clear how the wet environment and the moisture content in concrete influence its fatigue behaviour and which damage mechanisms are involved in the deterioration process. Here the results of a joint project are reported, in which the impact of moisture content in concrete on fatigue deterioration are investigated experimentally and numerically. Aside from the number of cycles to failure, the development of stiffness and acoustic emission (AE) hits are analysed as damage inductors and discussed along with results of microstructural investigations to provide insights into the degradation mechanisms. Subsequently, an efficient numeric modelling approach to water-induced fatigue damage is presented. The results of the fatigue tests show an accelerated degradation behaviour with increasing moisture content of the concrete. Further, it was found that the AE hits of specimens submerged in water occur exclusively close to the minimum stress level in contrast to specimens subjected to dry conditions, which means that additional damage mechanisms are acting with increasing moisture content in the concrete.

Validation of a numeric approach for modelling delamination damage caused by low energy impact

A numerical approach has been developed for modelling the behaviour of a carbon fibre woven laminate under low-level energy impact. The model results have been compared with dart drop tests under sub and supercritical impact energies in fibre carbon textile laminates of different thickness.The models were developed using Ls-Dyna explicit finite element code. The validation approach was based in increasingly complexity approach. First models were developed and compared with subcritical impact energy test. Afterwards, supercritical impact energy has been applied in the laminates and delamination failure has been considered. In order to model delamination damage, cohesive law has been applied using Ls-Dyna cohesive and contact elements. The validation of the model has been carried out by comparing force and displacements.

Secure and High-Quality Watermarking Algorithms for Relational Database Based on Semantic

Relational databases are widely applied in various industries, such as government departments, medical institutions and enterprises, for data storage and relationship management. It is convenience to data maintenance, however, the data in it maybe vulnerable to be forged or tampered with. Therefore, protecting the copyright of relational databases is a critical issue. Fortunately, watermarking technology can be used to prove copyright ownership. Since the digital watermarking technology can solve this problem effectively, based on semantic, we propose two watermarking approaches with high security and strong robustness for numeric and non-numeric data of relational databases in this paper. On the one hand, we propose a reversible numeric watermarking approach. It performs the replacement operation at the semantic level and retain the statistical characteristics of the data. On the other hand, based on word segmentation and word embedding, the non-numerical attributes of the relational database with natural language are chosen to embed watermark. It is noteworthy that the proposed mechanism can be applied to both Chinese and English with minimum distortion. Additionally, we also propose the virtual splitting of attribute column and the principle of modification minimum to guarantee the capacity of watermark and reduce the data modification rate. Additionally, the BCH (31,16,7) error control code is added to the binary watermark string to improve the detection rate of watermark. Based on the above innovations, the security of watermarking algorithm is improved successfully by double encryption (chaos encryption and hash encryption) with two keys (the user's private key and the attribute column key). The simulation results demonstrate that the proposed two algorithms in this paper have stronger robustness on defensing malicious attacks than previous works.

A practical strategy to improve performance of Newton's method in solving nonlinear equations

Newton's method is a popular numeric approach due to its simplicity and quadratic convergence to solve nonlinear equations that cannot be solved with exact solutions. However, the initial point chosen to activate the iteration of Newton's method may cause difficulties in slower convergence, stagnation, and divergence of the iterative process. The common advice to deal with these special cases was to choose another inner point to repeat the process again or use a graph of the nonlinear equation (function) to choose a new initial point. Based on the recent experiences in teaching preservice secondary-school mathematics teachers, this classroom note presents a simple and practical strategy to avoid many of the difficulties encountered in using Newton's method during solving nonlinear equations. Instead of plotting the graph of an equation to help choose the initial point, the practical strategy is to use the middle point of the range as the initial point to start the iterative process of Newton's method. By solving ten different nonlinear equations using Newton's method initiated from the endpoints and the middle point respectively, the results show that choosing the middle point of a defined range to initiate the iterative process for Newton's method seems a general and practical strategy to avoid the difficulties encountered in using the method to solve nonlinear equations with faster convergence in most cases.

Visco-elastic-plastic model to represent the compression behaviour of sugarcane agricultural residue

The objective was to develop a visco-elastic-plastic model for the prediction and characterisation of the compaction behaviour of sugarcane agricultural residues during the production of bales under different moisture contents (27%, 37% and 48%) and different particle sizes (∼300 mm, 150 mm and 80 mm). Data of confined-compaction and stress relaxation experiments were used to calibrate the model parameters. The proposed constitutive equation was composed of a generalised Maxwell model with three branches in series with a plastic component. The procedure was developed to characterise model parameters and used a numeric approach to calculate the hereditary integral when fitting the experimental curves, whilst the stress due to the plastic strains was fitted with a polynomial. The model provided good accuracy ( R 2 > 0.92) to fit the compaction and relaxation stages with the same set of parameters. Thus, it predicted the energy required to produce bales as well as the final relaxed density of this sustainable material that may become an important source of energy. • Biomass was characterised using a new visco-elasto-plastic model. • Fit of compaction and relaxation stages with unique set of parameters achieved. • Model could be applied to study the compaction of any type of biomass.

Genotype-Phenotype Correlation Study in a Large Series of Patients Carrying the p.Pro51Ser (p.P51S) Variant in COCH (DFNA9) Part II: A Prospective Cross-Sectional Study of the Vestibular Phenotype in 111 Carriers.

DFNA9 is characterized by adult-onset hearing loss and evolution toward bilateral vestibulopathy (BVP). The genotype-phenotype correlation studies were conducted 15 years ago. However, their conclusions were mainly based on symptomatic carriers and the vestibular data exclusively derived from the horizontal (lateral) semicircular canal (SCC). The last decade was marked by the emergence of new clinical diagnostic tools, such as the video head impulse test (vHIT) and vestibular-evoked myogenic evoked potentials (VEMPs), expanding our evaluation to all six SCCs and the otolith organs (saccule and utricule). The aim of this study was to comprehensively evaluate vestibular function in the largest series presymptomatic as well as symptomatic p.P51S variant carriers, to determine which labyrinthine part shows the first signs of deterioration and which SCC function declines at first and to determine the age at which p.P51S variant carriers develop caloric areflexia on VNG and vHIT vestibulo-ocular reflex (VOR)-gain dysfunction as defined by the Barany Society criteria for BVP. One hundred eleven p.P51S variant carriers were included. The following vestibular function tests were applied in two different centers: ENG/VNG, vHIT, and VEMPs. The following parameters were analyzed: age (years), hearing loss (pure-tone average of 0.5-4 kHz [PTA0.5-4, dB HL]), sum of maximal peak slow-phase eye velocity obtained with bi-thermal (30°C and 44°C, water irrigation; 25°C and 44°C, air irrigation) caloric test (°/s), vHIT VOR-gain on LSCC, superior SCC and posterior SCC, C-VEMP both numerical (threshold, dB nHL) and categorical (present or absent), and O-VEMP as categorical (present or absent). The age of onset of vestibular dysfunction was determined both with categorical (onset in decades using Box & Whisker plots) and numeric approach (onset in years using regression analysis). The same method was applied for determining the age at which vestibular function declined beyond the limits of BVP, as defined by the Barany Society. With the categorical approach, otolith function was declining first (3rd decade), followed by caloric response (5th decade) and vHIT VOR-gains (5th-6th decade). Estimated age of onset showed that the deterioration began with C-VEMP activity (31 years), followed by caloric responses (water irrigation) (35 years) and ended with vHIT VOR-gains (48-57 years). Hearing deterioration started earlier than vestibular deterioration in female carriers, which is different from earlier reports. BVP was predicted at about 53 years of age on average with VNG caloric gain (water irrigation) and between 47 and 57 years of age for the three SCCs. Loss of C-VEMP response was estimated at about 46 years of age. Former hypothesis of vestibular decline preceding hearing deterioration by 9 years was confirmed by the numeric approach, but this was less obvious with the categorical approach. Wide confidence intervals of the regression models may explain deviation of the fits from true relationship. There is a typical vestibular deterioration hierarchy in p.P51S variant carriers. To further refine the present findings, a prospective longitudinal study of the auditory and vestibular phenotype may help to get even better insights in this matter.

Is we they? A cross-cultural study of responses to COVID-19 updates in Uganda, Kenya and Rwanda

This article delineates the material relations, routines and sensorial responses inhabited by people in Uganda, Kenya and Rwanda during the first wave of the coronavirus pandemic. It grounds views on a discourse of behavioural change while exploring how Ugandans, Kenyans and Rwandans responded to COVID-19 messages populated on selected official government Twitter accounts. The article is a mixed methods study that employs a numeric and discursive analytic approach, with the nudge theory proving particularly congenial. Findings show that a civic nationalism was enunciated in the hinterland. The nomenclature evoked in the wake of enforcing pandemic restrictive measures is both politically and socially repressive. Far from presuming fixed identities, the conceptual thread that is knit together during the pandemic oscillates from broad support to a problem of behavioural fatigue.

Initial study of an alternative technology aimed at measuring and controlling the flow rate in air conditioning ducts

This paper states that there might have around 1000 small size business jets (until nine occupants) flying across the world equipped with flow control and regulating shut-off valves that uses hot wire anemometer devices to regulate massflow rate from the bleed airflow to supply the air-conditioning and pressurization systems. However, these valves present low reliability in the field. The purpose of this paper is to evaluate the implications of a flow control and regulating shut-off valve with a non-intrusive airflow measurer device under the perspective of fluid mechanics. The Venturi technology that is commonly used technology, given its construction simplicity, precision, and broad use in the industry, is selected to substitute the flow control and regulating shut-off valves with hot wire anemometer of the mentioned small size business jets applications. This paper has adopted a numeric simulation approach utilizing the ANSYS-CFX computational fluid dynamics software to verify both the differential pressure at the Venturi device and its correspondent mass flow rate to supply the air conditioning systems of some small size business jets, considering the mass-flow rate as requested by the FAA certification requirement (0.55 lb/min per occupant). This paper shows that a mass-flow rate control and regulating shut-off valve with a Venturi device, of 1 inch and β of 0.67, is compliant with the minimum fresh air flow requested by the FAA certification requirement to operate in some small size business jets. Besides that, the software ANSYS-CFX is also effective to support the engineering analysis of flow field characteristics inherent to the applications of internal compressible flow. The numeric simulation utilizing the ANSYS-CFX computational fluid dynamics software outlined herein can lay the basis for further research related to the design of a flow control and regulating shut-off valves with a Venturi device.

Exploration of Maximum-to-Minimum Shifts in Generic Methods for Departure Time Choice Models

Vickrey’s seminal departure time choice model is based on a penalty function which is a linear combination of travel time, earliness, and lateness. The original model depicts a single link from a single origin to a single destination, serving homogeneous travelers by a deterministic point-queue regime. Numerous variants of the basic model, relaxing one or more of these assumptions, have been used in a wide range of contexts. The equilibrium solution of the basic model can be computed directly by exact formula. Specific convergent methods have been proposed for certain variants. One of the troubling challenges in this model is the need for a generic iterative numeric approach, that may address complex models in which departure time choice is embedded. Natural candidates were shown to fail even on the basic model. In this paper we explore a fairly naive approach, where, in each iteration, demand is shifted from the maximum cost time interval to the minimum cost time interval. Results for the basic model are promising, demonstrating that, with a fixed shift, solutions converge to a deviation which is proportional to the shift size and that semi-adaptive or adaptive shift size may offer convergence to any desirable level of approximation of the exact equilibrium.