Application Of Regression Equations Research Articles

Analysis of Pathogen Characteristics and Nursing Factors of Tonsil Infection Based on Regression Equation.

In order to meet the needs of the analysis and application of regression equation in clinical medicine of tonsil infection, this paper focuses on the semiparametric regression model method, cross-validation method, empirical method, and multiple regression equation analysis of atypical data using regression equation. The general method of analyzing this kind of data is given, and the parameter estimation and hypothesis testing of the model are systematically studied. The experimental results showed that among the 90 paraffin-embedded tissue specimens of chronic tonsillitis and adenoid hypertrophy in this study, 26 out of 49 male children were EBERs positive, accounting for 53.06% of male children (26/49 cases). 28 of the 41 female children were positive, accounting for 68.29 of the female children (28/41 cases). There were 14 cases in infant group, 20 cases in preschool age group, 25 cases in school-age group, and 31 cases in adolescence group; the EBERs-positive rate was 42.86% (6/14 cases) in early childhood and 55.00% in early school-age (11/20 cases), and the EBERs-positive rate was 60.00% in school-age group (15/20 cases) and 70.97% in adolescent group. The results showed that the latent infection rate of adenoid hypertrophy EBV in children with chronic tonsillitis showed no significant difference between genders. It is proved that the regression equation method can meet the needs of clinical analysis and application of tonsil infection.

Correlation of Body Length and Certain Linear Parameters of the Tubular Bones of the Hand in Tajik Children and Adolescents

The intensifying integration processes between the Russian Federation and the Republic of Tajikistan update creation of databases and development of regression models that allow determining the body length by individual bones in representatives of both genders of this ethnic group.The aim of the study was to verify application of regression equations to determine the body length in Tajik children and adolescents, aged 6–17, according to the linear parameters of the short tubular bones of the hand.Material and methods. There were performed osteometric studies of 251 X-ray images of the right hand to determine the body length of the examined individuals. Linear regression analysis was carried out to identify dependence of the body length on linear parameters of the short tubular bones of the hand. The quality of the regression was assessed through the coefficient of determination R2 and significance by the F-criterion. There were considered coefficients of determination higher than 0.8.Results. It was found that for boys the linear parameter of the length of the tubular bones of the hand was the best to predict the body length. When applying regression equations to determine the body length according to the length of the hand rays in boys, it was determined that the best results were obtained when applying a model developed for the bones of the 2nd and 4th hand rays. For Tajik girls, regression models that included parameters of the length and width of the tubular bones of the hand were more reliable. More reliable results for identifying the body length of Tajik children were obtained when regression models were developed separately for individuals of different genders.Conclusion. The results obtained demonstrated that osteometric parameters of the short tubular bones of the hand can be used to assess the body length of Tajik children and adolescents of both genders.

Mathematical Simulation of Microstructural Phase Transformations in the Course of Welding Heating for the Case of Cladding of Protective Layer in the WWER-1000 Reactor Vessel

By using the developed finite-element models, we perform the numerical investigation of nonstationary temperature fields and the kinetics of microstructural phase transformations in the base material of the WWER -1000 reactor vessel (15Kh2NMFА steel) under the conditions of submerged-arc cladding of protective anticorrosion layers of austenitic materials. We perform the comparative analysis of the results of simulation of microstructural phase transformations obtained by using two methods of prediction of the decomposition of austenite in the process of cooling. The first method is based on the application of regression equations and the characteristic cooling time Δ t8/5. The second method is based on the diagrams of isothermal decomposition of austenite, the Avrami equation, and the Koistinen–Marburger equation. As a result of simulation of microstructural transformations under cladding, we obtain the bainite-martensite composition in the heat-affected zone of the base material of reactor vessel, which is confirmed by results of the dilatometric analysis and metallography.

Prediction of the length of the femur from its fragments in a Sri Lankan population

ABSTRACTIn many forensic circumstances, the femur is fragmented due to decomposition and mutilation, thus necessitating development and application of regression equations to estimate the length of the femur from its fragments. In this study, regression equations were derived for the prediction of the femoral length, utilizing 11 standard femoral measurements (maximum length of femur, epicondylar breadth, vertical head diameter, transverse head diameter, vertical neck diameter, transverse neck diameter, neck length, subtrochanteric anterior–posterior diameter, subtrochanteric transverse diameter, mid-shaft anterior–posterior diameter and mid-shaft transverse diameter) obtained from 86 femora belonging to a contemporary Sri Lankan population. Univariate regression equations with moderate to high correlations (0.226 to 0.714) were formulated for the estimation of the maximum femoral length from the measurements of fragments of the femur. Of the single variables, the transverse neck diameter emerged as the best predictor (r = 0.714, SEE = 18.6596) of the maximum length of the femur. The multiple regression equations using a combination of variables yielded higher correlations (0.774–0.857) with lower error estimates (14.18–16.96). The regression equations presented in this study can be used to estimate the length of the femur of unknown, mutilated and dismembered human skeletal remains with considerable accuracy.

Application of intermediate temperature semi-circular bending test results to design mixtures with improved load-associated cracking resistance

This paper describes the development and practical application of regression equations to estimate the relative load-associated cracking resistance of asphalt mixtures from properties that are included in specifications and controlled through current quality control and acceptance procedures. This work was part of a research study performed through the Wisconsin Highway Research Program to evaluate changes to the composition of asphalt concrete mixtures that should be considered to improve the durability of flexible pavements. Based on the findings of a synthesis of current research, a laboratory experiment was conducted to quantify the effect of (1) effective binder volume, (2) virgin binder low temperature performance grade, (3) recycled binder content, and (4) polymer modification on the resistance of typical Wisconsin mixtures to ageing and load-associated cracking. For the types of mixtures normally used in Wisconsin, the laboratory experiment found mixture composition had little effect on ageing; however, load-associated cracking resistance was significantly affected. The laboratory experiment produced a regression equation that was used to recommend revised volumetric criteria that provide equivalent load-associated cracking resistance and allow producers the flexibility to design mixtures using a range of effective binder contents, recycled binder contents, and virgin binders.

Area under the curve predictions of dalbavancin, a new lipoglycopeptide agent, using the end of intravenous infusion concentration data point by regression analyses such as linear, log-linear and power models

1. Dalbavancin, a lipoglycopeptide, is approved for treating gram-positive bacterial infections. Area under plasma concentration versus time curve (AUCinf) of dalbavancin is a key parameter and AUCinf/MIC ratio is a critical pharmacodynamic marker.2. Using end of intravenous infusion concentration (i.e. Cmax) Cmax versus AUCinf relationship for dalbavancin was established by regression analyses (i.e. linear, log–log, log–linear and power models) using 21 pairs of subject data.3. The predictions of the AUCinf were performed using published Cmax data by application of regression equations. The quotient of observed/predicted values rendered fold difference. The mean absolute error (MAE)/root mean square error (RMSE) and correlation coefficient (r) were used in the assessment.4. MAE and RMSE values for the various models were comparable. The Cmax versus AUCinf exhibited excellent correlation (r > 0.9488). The internal data evaluation showed narrow confinement (0.84–1.14-fold difference) with a RMSE < 10.3%. The external data evaluation showed that the models predicted AUCinf with a RMSE of 3.02–27.46% with fold difference largely contained within 0.64–1.48.5. Regardless of the regression models, a single time point strategy of using Cmax (i.e. end of 30-min infusion) is amenable as a prospective tool for predicting AUCinf of dalbavancin in patients.

On the Dynamic Characteristics and the Soil Compaction under the Influence of the Mole Plow

The development of many processes associated with changes in soil properties in the construction of irrigation and civil engineering requires justification of the geometric parameters and modes of operation of the tools, which are used to implement these processes. One of the tools for the implementation of such processes is mole plough. To conduct the research the authors have chosen a model in which the soil is considered as a viscoelastic medium, and can be formalized by Kelvin-Voigt model in solving the task of interaction of mole plough with soil. In the course of research we have built the physical equations that relate the stress components with strain rate taking into consideration modules of elasticity, viscosity and time of loading by using the method of analytical transformations the generalized Hooke's law and the equations for linear connection components of stress with strain rate. The authors obtained the stress components of the soil at the contact surface, depending on its mechanical properties, geometric parameters of the mole plough and its speed of movement. The time of deformation was determined from the equation of speed of passage of the wave stresses in a continuous medium. Application of regression equations that relate the changes in soil density with hydrostatic and maximum tangent stress allowed predicting changes in soil density depending on the geometrical parameters of the mole plough, the speed of its movement and mechanical properties of the soil. Finally, we obtained the components of resistance forces to the movement of mole plough in the soil depending on the mechanical properties of the soil, as well as geometrical parameters and speed of tool movement. To sum up, on the basis of the analysis of the dynamics of contact interaction of mole plough with soil the components of normal and shear stresses of the soil at the contact surface are installed. We have determined the direction and value of soil compaction and components of the resistance forces of the soil the movement of mole plough depending on its geometric parameters, the speed of the translational movement and the mechanical properties of the soil. The change functions of the density of the soil under the influence of the mole plough were obtained.

Calculation methods of develpment of welding technology of low-carbon low-alloy steels

The application of calculation methods under the development of welding technology of low-carbon low-alloy steels is considered. The aim of paper is to develop the engineering methodology and design program of welding technology of low-carbon low-alloy steels, including the increased and high strength on the basis of presented regression equations. The estimation results of the HAZ expected structural composition for the 09Г2 steel have been analyzed according to the thermokinetic transformation diagram and calculation with the usage of regression equation for different variants of chemical composition provided by the standard. In this case, the task of determination of parameters of mode and technological methods which provide the obtaining of appropriate structure and mechanical properties of the HAZ metal. The calculation procedure of welding mode which provides the optimal structure of the welded joint has been considered using data analysis and on the example of automatic submerged-arc welding of the butt joint of 30 mm thick from the 14ХМНФДР high-strength steel. One of the most important advantages of the considered calculation method is the simplicity of its operation on the computer which simplifies and speeds the work of an engineer and increases the results accuracy. After the analysis of these results the engineer can introduce another value of the preheat temperature and therefore to choose the appropriate structure and mechanical properties of the welded joint. The application of regression equations allows taking into account the specific steel chemical composition and obtaining more trustworthy calculation result comparing to the result of thermokinetic transformation diagram. Moreover, these equations give more full information both on metal structural composition of heat-affected zone and on its mechanical properties. The calculation is easily performed on the computer which allows simplifying and speeding the work of engineer, increasing the results accuracy.

Calibration and use of plate meter regressions for pasture mass estimation in an Appalachian silvopasture

A plate meter for measuring pasture mass was calibrated at Agroforestry Research Site in Blacksburg, Virginia, USA, using six ungrazed plots of established tall fescue overseeded with orchardgrass. Each plot was interplanted with bare root honey locust and black walnut seedlings spaced along a gradient ranging from 1.8 to 11.0 m. Plate height (PH) of forage between trees was measured by placing a 46 mm × 46 mm × 5.6-mm-thick acrylic plastic plate meter on pasture canopy at six locations four times a season. PH was measured between ground and plate as it rested on pasture canopy. To calibrate the plate meter against a known dry matter yield, 50 × 50-cm clip plots followed each PH measurement. The resulting regression slope was 421 kg ha−1 cm−1, with an r 2 value of 0.86. Unique research investigating the response of forage mass to site elevation is presented using the developed equation. The field-calibrated regression slope of ruler height (RH) to PH was 1.71 cm cm−1, with an r 2 value of 0.87, showing good correlation between RH and PH. A comparable regional regression equation was found to adequately predict independent calibration clip plot data reported at this site. The results support the application of regression equations for estimating pasture mass in areas having similar climates and pasture composition.

Cephalopod diet of the Australian fur seal: Variation due to location, season and sample type

In Tasmanian waters, Arctocephalus pusillus doriferus preyed on 11 species of cephalopods, predominantly Nototodarus gouldi followed by Sepioteuthis australis and Sepia apama. Cephalopods were more important in the diet of the seals in Bass Strait than in southern Tasmanian waters. The species composition in the diet of the seals in these two areas also differed, with the seals in Bass Strait eating mainly N. gouldi, whereas the seals in southern waters fed on benthic octopods. The seals preyed on mainly adult cephalopods over the continental shelf. The size range and species composition of the diet varied according to the sample types, with faeces containing only small beaks relative to regurgitates and stomachs. Errors associated with sample types and application of regression equations are discussed.

BIRTH WEIGHT VARIABLE IN REGRESSION ANALYSIS TO PREDICT INTERNAL LENGTH OF UMBILICAL CATHETERS IN SICK NEWBORNS

Shoulder umbilical length (SUL) &/or total body length (TBL) have been been traditional parameters used to estimate internal umbilical catheter (cath) length. To improve these estimates & to act quickly in emergencies when traditional measurements may be difficult to measure or calculate from nomograms, the reliable weight variable in predicting internal length was used. 35 Sick NB with inserted UA lines (using Dunn's Graph of SUL) & cath tips between T6 & T10 vertebra, by (x-rays) were studied. Independent variables measured on each patient included SUL, TBC, birth weight, distance between suprasternal notch & symphisis pubis, total cath length before insertion & external length of cath after insertion. Dependent variable was calculated portion of cath within the patient.Results: (1) All r* values between point of reference & internal length were excellent (p**<.001);(2) No significant diff. between pairs of r values;(3) Application of regression equation (Y=2.5 X+10) prospectively on 8 patients showed inserted cath tip between T6 & T10; (4) Similar regression analysis for 10 umbilical venous cath insertion with tips above diaphragm showed r value of 0.98, equation Y = 1.5 BW + 5.5.