Polynomial Nonlinear Regression Research Articles

Process Parameters Optimization and Numerical Simulation of AlCoCrFeNi High-Entropy Alloy Coating via Laser Cladding.

The use of laser cladding technology to prepare coatings of AlCoCrFeNi high-entropy alloy holds enormous potential for application. However, the cladding quality will have a considerable effect on the properties of the coatings. In this study, considering the complex coupling relationship between cladding quality and the process parameters, an orthogonal experimental design was employed, with laser power, scanning speed, and powder feed rate as correlation factor variables, and microhardness, dilution rate, and aspect ratio as characteristic variables. The experimental data underwent gray correlation analysis to determine the effect of various process parameters on the quality of cladding. Then, the NSGA-II algorithm was used to establish a multi-objective optimization model of process parameters. Finally, the ANSYS Workbench simulation model was employed to conduct numerical simulations on a group of optimized process parameters and analyze the change rule of the temperature field. The results demonstrate that the laser cladding coating of AlCoCrFeNi high-entropy alloy with the single pass is of high quality within the determined orthogonal experimental parameters. The powder feed rate exerts the most significant influence on microhardness, while laser power has the greatest impact on dilution rate, and scanning speed predominantly affects aspect ratio. The designed third-order polynomial nonlinear regression model exhibits a high fitting accuracy, and the NSGA-II algorithm can be used for multi-objective optimization to obtain the Pareto front solution set. The numerical simulation results demonstrate that the temperature field of AlCoCrFeNi high-entropy alloy laser cladding exhibits a "comet tail" phenomenon, where the highest temperature of the molten pool is close to 3000 °C. The temperature variations in the molten pool align with the features of laser cladding technology. This study lays the groundwork for the widespread application of laser cladding AlCoCrFeNi high-entropy alloy in surface engineering, additive manufacturing, and remanufacturing. Researchers and engineering practitioners can utilize the findings from this research to judiciously manage processing parameters based on the results of gray correlation analysis. Furthermore, the outcomes of multi-objective optimization can assist in the selection of appropriate process parameters aligned with specific application requirements. Additionally, the methodological approach adopted in this study offers valuable insights applicable to the exploration of various materials and diverse additive manufacturing techniques.

Optimization of a novel vacuum sublimation-rehydration thawing process.

To better guarantee the quality of the thawed meat, maximize the thawing rate, and minimize the system energy consumption, the multiparameter and multi-objective coupling optimizations for the newly proposed vacuum sublimation-rehydration thawing (VSRT) process was conducted. The polynomial nonlinear regression equations of single and comprehensive objectives were established by the central composite rotatable design, and the corresponding test of fitting degree and the analysis of influencing factors order were carried out. Furthermore, the interaction effects of influencing factors were investigated through the response surface methodology and were experimentally validated to obtain the optimal process parameters. The results showed that the established regression equations were in good agreement with the experimental values. For the different objectives, there were great differences in the influence order and interaction of factors. In the sublimation and rehydration stages, there existed an optimal region in the response surface to achieve a better value for the single and comprehensive objectives. When the sublimation time was 19min, the heating plate temperature was 26°C, the rehydration water volume was 1634ml, the rehydration water temperature was 29°C, the thawing time was relatively short (1.00h), and the thawing loss (1.19%), the total color difference (1.02), and the system-specific energy consumption (0.026kWh/kg) were relatively low. The comprehensive performance of the VSRT system reached the best state. PRACTICAL APPLICATION: The purpose of this work is to make the novel vacuum sublimation-rehydration thawing method not only better guarantee the quality of thawed meat but also maximize the thawing rate and minimize the energy consumption of the system, which can provide a new idea and reference for the development of new high-efficiency thawing equipment.

Restoration of High Frequency Auditory Perception After Robot-Assisted or Manual Cochlear Implantation in Profoundly Deaf Adults Improves Speech Recognition.

Background and Purpose: Robot-assisted cochlear implantation has recently been implemented in clinical practice; however, its effect on hearing outcomes is unknown. The aim of this preliminary study was to evaluate hearing performance 1 year post-implantation whether the electrode array was inserted manually or assisted by a robot.Methods: Forty-two profoundly deaf adults were implanted either manually (n = 21) or assisted by a robot (RobOtol®, Collin, Bagneux, France) with three different electrode array types. Participants were paired by age, and electrode array type. The scalar position of the electrode array in the cochlea was assessed by 3D reconstruction from the pre- and post-implantation computed tomography. Pure-tone audiometry and speech perception in silence (percentage of disyllabic words at 60 dB) were tested on the implanted ear 1 year post-implantation in free-field conditions. The pure-tone average was calculated at 250–500–750 Hz, 500–1,000–2,000–3,000 Hz, and 3,000–4,000–8,000 Hz for low, mid, and high frequencies, respectively.Results: One year after cochlear implantation, restoration of the high-frequency thresholds was associated with better speech perception in silence, but not with low or mid frequencies (p < 0.0001; Adjusted R2 = 0.64, polynomial non-linear regression). Although array translocation was similar using either technique, the number of translocated electrodes was lower when the electrode arrays had been inserted with the assistance of the robot compared with manual insertion (p = 0.018; Fisher's exact test).Conclusion: The restoration of high-frequency thresholds (3,000–4,000–8,000 Hz) by cochlear implantation was associated with good speech perception in silence. The numbers of translocated electrodes were reduced after a robot-assisted insertion.

The Application of Non-linear Cubic Regression in Rice Yield Predictions

The rice yields have fluctuated in Wonogiri Regency. This occasion happened in 2016-2018. Therefore, a prediction is needed to know whether rice yields will increase or decrease in the following year. The purpose of this study was to apply the polynomial non-linear regression method of third-degree in predicting rice yields. This study utilized the Unified Modeling Language (UML) as the system design, black-box testing as the functional testing, and MSE testing as the validity testing. The computed data was data of 2016-2018. The results showed that the prediction of 2017-2019 using the harvested area model produced more accurate calculations. The harvested area model produced the same MSE value in manual and application calculations, which were 405433,1349 in 2017, 312677,7798 in 2018, and 171183.6347 in 2019. The polynomial non-linear cubic regression is a solution to predict rice yields. The output of the application is the prediction information for rice yields

Modeling and Forecasting Car Ownership Based on Socio-Economic and Demographic Indicators in Turkey

Since car ownership is an important determinant to analyze car travel behavior especially in developing countries, this paper deals with modeling and forecasting car ownership in Turkey based on socio-economic and demographic indicators such as Gross Domestic Product (GDP) per capita, Gasoline Price (GP), car price and number of employees by using multiple nonlinear regression analysis. Although most of the studies on this subject prefer using annual data, we use monthly data for the analysis of car ownership since all explanatory variables and exchange rates used for the modeling are unstable and vary even in a short period in developing countries such as Turkey. Thus, it may be possible to reflect the effects of socio-economic and demographic indicators on car ownership more properly. During the modeling process, exponential and polynomial nonlinear regression models are set up and then tested to investigate their applicability for car ownership forecasting. Based on results of the Kolmogorov-Smirnov test, the polynomial models has been selected to forecast car ownership for the year 2035. In order to reveal the possible different trends of the independent variables in future, car ownership is forecasted along the scenarios which are related to the GDP per capita and GP. Results show that Turkey’s car ownership may vary between 230 and 325 per thousand capita in 2035 depending on economic achievements, global oil prices and national taxation policies. The lowest and the highest values of the car ownership may provide insight to car producers and transport planners in Turkey. Another significant result presented in this study is that car ownership rate will be substantially lower in Turkey than that in the European Union countries despite it has an increasing trend in the past two decades.

Characterization of vegetative and grain filling periods of winter wheat by stepwise regression procedure: I. Vegetative period

Modeling plant growth by mathematical functions is important for understanding plant development and growth. Most of the models of dry matter accumulation in small cereals simulated the period of grain filling while small attention has been devoted to mathematical simulation of vegetative period till anthesis. The aim of this research was to determine the most appropriate polynomial non-linear regression for dry matter accumulation till anthesis in winter wheat. Pobeda, a medium early variety, was used as model genotype for this research. A 5-year field data were analyzed by the forward procedure of stepwise regression. Although the procedure requires the maximum power of the polynomial regression to be used, we suggest using a lower power since it is easier for understanding and explanation and it is taking into account literature sources and biological laws. It can be accepted that quadratic regression model appropriately fits the process of dry matter accumulation till anthesis in winter wheat.

Does lead interfere with hemoglobin-based oxygen carrier (HBOC) function? A pilot study of lead concentrations in three approved or tested HBOCs and oxyhemoglobin dissociation with HBOCs and/or bovine blood with varying lead concentrations.

We measured lead concentrations in three hemoglobin-based oxygen carriers (HBOCs; Oxyglobin, Hemopure, and Hemolink) and compared them with lead concentrations from blood-bank blood. Oxyhemoglobin dissociation was measured with large concentrations of lead in bovine HBOC, with or without bovine blood, and in bovine blood. Samples of each were prepared by combining one with normal saline (control), the second with small lead concentrations (22 micro g/dL), and the third with toxic lead concentrations (70 micro g/dL). They were blended in 2 tonometers at oxygen concentrations (2.5%, 5%, 8%, 10%, 21%, and 95%) with 5% CO(2) and the remainder nitrogen for 5 min per sample after a 15-min wash-in with each level of oxygen and were measured with co-oximetry. Oxygen saturation was plotted against PO(2), fitting fourth-order polynomial nonlinear regression to the data. The lead concentrations of the three HBOCs were 0.51, 0.22, 0.40 micro g/dL. There were no clinically important differences of the oxyhemoglobin dissociation curves as a function of lead concentration. The lead concentrations of the three tested HBOCs were small and no larger than the average for blood-bank blood. The presence of increasing concentrations of lead in either concentrated solution of bovine HBOC or a 1:1 mixture of bovine HBOC and native bovine blood does not appear to affect hemoglobin oxygenation in an acute in vitro model of increased lead concentrations. Gunshot wounds rapidly increase circulating lead concentrations. Lead concentrations are small in three hemoglobin-based oxygen carriers (HBOCs), and HBOCs and/or bovine blood do not appear to be affected by lead concentrations in terms of immediate oxygen on-loading and off-loading. HBOCs may be useful in patients with gunshot wounds.

Neonatal serum bilirubin from skin reflectance.

Summary: To provide a noninvasive method for serum bilirubin determination in newborn infants, a reflectometer system was developed using a novel fiber optic arrangement permitting measurement of the light reflected from a small area (3 cm2) of the infant's skin. The reflectometer was operated over the spectral region 400–750 nm with a 30-sec scan time. The reflectometer consisted of a monochomatic light source, fiber optic probe, detector, and data acquisition system Spectral reflectance measurements were performed on the blanched and unblanched skin on the backs of 56 Caucasian newborn infants. Examples of the spectra and corresponding serum bilirubin values of 30 of the infants are presented, illustrating that near 460 nm, the spectral reflectance of the skin decreases with increasing serum bilirubin concentrations. It was also observed that the individualities in epidermal hemoglobin concentration affected the skin reflectance spectra. For this reason the statistical analysis was limited to inclusion of only reflectance spectra of blanched skin. The multispectral analysis of the data was based upon statistical regression analysis investigating the predictability of serum bilirubin level from reflectance spectra. The spectrum between 400 and 740 nm was divided into 5-nm intervals (71 discrete bands). First order linear, multiple linear, and polynomial nonlinear regressions were performed on the spectral reflectance values at each of the intervals with respect to serum bilirubin level. The coefficients of determination (R2 values) are summarized. Because an R2 of only 0.783 was observed at 450 nm, scatter diagrams of serum bilirubin concentration versus spectral skin reflectance at a given wavelength were studied. These indicated that a logarithmic transformation of the data might yield improved results. The double natural logarithm was taken of the 71 discrete spectral reflectance values and a polynomial nonlinear regression was performed with respect to serum bilirubin concentration. The best results of this regression analysis were obtained for a combination of five wavelengths yielding an R2 value of 0.931. The ability to predict serum bilirubin concentration from skin reflectance using this relationship was tested using the original observations. The 95% prediction limit for this empirical relationship was shown to be ± 2 mg/100 ml. Speculation: Spectral reflectance measurements on the newborn skin provide a noninvasive screening method for neonatal jaundice and may also be useful in assessing the efficacy of phototherapy and the potential for kernicterus.