Regression Formula Research Articles

Analysis and Research Based on the Crowdsourcing Corpus System in Guangdong-Hong Kong-Macao Greater Bay Area (GBA)

Objective. To sort out the application and status quo of some domestic crowdsourcing models, explore the factors affecting multilingual manual annotation through experiments and offer suggestions. Methodology. Crawling the government news texts in Mandarin, Cantonese, English, and Portuguese in Guangdong, Hong Kong, and Macao, and enter them into the database. Combine it with corpus tagging uses the established web platform to practice crowdsourcing and collect a large number of annotation results and behavior data. Results. Made assumptions about factors that may affect the quality of manual annotation, used SPSS and other data analysis software to evaluate the degree of interpretation of the assumptions, provided a regression formula for calculating the accuracy, and provided constructive suggestions for the corpus annotation quality assurance projects. Limitations. More corpus information in more languages and more professional annotators are needed. Conclusions. The study found that the accuracy of annotation is strongly related to the attributes of the corpus itself, such as the total number of vocabularies, the number of rare words, the complexity of parts of speech, etc., and the condition of languages are different from each other.

Taguchi Approach and Multiple Regression Analysis for IDI Engine with RBME Optimization

Diesel engines are suited to human usage. With the trend of Petro diesel running out, experts have been concentrating more on alternative fuels. One such alternative fuel whose fuel characteristics are more similar to diesel is bio-diesel. The majority of researchers came to the conclusion that by using 100% bio-diesel, emissions might be lowered while still retaining efficiency, with a minor increase in NOX emissions relative to diesel fuel. In this study, we looked at adding isopropanol to reduce these NOX emissions. An IDI (Indirect Diesel Injection) single-cylinder, four-stroke diesel engine is selected for testing. It is feasible to ascertain the engine characteristics and emissions of fuels like diesel and rice bran methyl ester (RBME) mixed with iso-propanol additive by conducting tests on IDI engines. The goal of the task is to determine the best settings for each answer, analyse the impact of each input component on the response, compare projected values using Taguchi's Additive Law and multiple regression techniques, and determine Confidence Intervals (CI). The regression formulas are derived from multiple regression analysis with a coefficient of regression up to 83% for the responses Exhaust Gas Temperature (EGT), Brake Thermal Efficiency (BThe), Brake Specific Fuel Consumption (BSFC), Hydrocarbons (HC), Carbon Monoxide (CO), Carbon Dioxide (CO2), Oxygen (O2), Nitrogen Oxides (NOX), and Smoke. RBME+2% Isopropanol is shown to be the optimum fuel overall based on engine performance and emission characteristics, particularly for EGT, BThe, BSFC, O2, NOX, and Smoke.

Accuracy of the Cameriere's method and its variant the European Formula for age estimation in subadult peruvian population

To determine the accuracy of the Cameriere method and its variant, the European Formula, in a sub-adult Peruvian population; and determine a chronological age predictor equation. Descriptive, observational, cross-sectional and retrospective study. It was used 257 digital panoramic radiographs of patients in mixed dentition from 5 to 12 years of age belonging to the "Dental Cientifica" Dental Center of the Universidad Cientifica del Sur in the city of Lima, Peru. All morphological variables and gender of the subjects were used as predictor variables for age estimation. To evaluate the accuracy of each estimation method, the age of each individual was compared with the estimated age using the mean prediction error. Multiple linear regression was used to generate the predictive equation for chronological age. It was found that the mean prediction error between the chronological age with respect to the age estimated by the Cameriere method Formula and the European Formula was 0.73±0.55 years and 0.77±0.57 years, respectively. A model was generated whose predictor variables for age were s and N0, both variables were statistically significant and the Adjusted R2 for the number of variables was 75.96%. It was determined that Cameriere's Formula was more accurate than the European Formula; however, there was no statistically significant difference between the two. Additionally, it was possible to establish a specific linear regression formula for a Peruvian population aged 5 to 12 years with an adequate predictive capacity.

The Precise Location of the Stylomastoid Foramen and Clinical Implication for Facial Nerve Block

Aim: We aimed to develop linear regression formulas for determining the precise localization of the stylomastoid foramen on the base of the morphometric features of the person’s own skull. 
 Material and Method: The study was conducted on 22 stylomastoid foramina (11 skulls). The 10 parameters determined for the stylomastoid foramen were measured on the photographs taken from the skull base and the 17 parameters determined for the morphometric features of the skull were measured on the photographs taken from the anterior plane, lateral plane, and posterior plan using Image J measurement software. The data obtained were evaluated with SPSS 20.0 statistical software. 
 Results: To determine the morphometric and topographic features of the stylomastoid foramen the equations have been developed such as; P1 (The distance between stylomastoid foramen and root of the zygomatic arch)=18.758+(0.472xP12)-(2.092x P16)+(0.831xP17)–(0.390xP18)–(0.101x P20); Adjusted R2=0.865, Standard Error of the Estimation=1.389. 
 Conclusion: Mean values can give misleading information in determining the topographical relationship between the stylomastoid foramen and the surrounding anatomical structures. We have developed regression formulas that will estimate the accurate location of the stylomastoid foramen and the accurate distances between other surrounding anatomical structures, taking into account the morphometric characteristics of the person’s own skull.

Quantitative and Qualitative Approaches for Dental Age Assessment in Sub Adult Portuguese Population: European Regression Formula and Demirjian Stages.

Over the last decade, the criminal justice system among the European countries deals with a new group of people, the undocumented people. In the criminal field, most of the suspected claimed to be under the minor legal age according to the type of crime. The government of each European country is committed to protecting the children and vulnerable people. There are serious safety concerns since adults falsely claim to be minors and legal systems oppose to such claims. In this study, we have used different age assessment methods and some of them without accuracy. To meet the general considerations we developed a study using the current dental age assessment methods. Hence, for the Portuguese population, this study aims to validate the European regression formula between the ages of 6 and 15 years of age; to estimate the cut-off point for the age of 12 years, and to compare the quantitative approach of European regression formula with Demirjian's qualitative approach for age estimation. 483 orthopantomograms were analysed using the European formula and Demirjian scoring stages. A new method, Model 2, was designed to better suit the Portuguese population. The European formula: average age underestimation of 4.88 for the third quadrant and 4.04 months for the fourth quadrant; and a mean absolute error (MAE) of 10.93 and 10.68 months respectively. Demirjian method: average overestimation of 8.70 months, MAE of 12.85 months. In Model 2: MAE of 9.37 months for the third quadrant, and 9.28 months for the fourth quadrant. Both European formula and Demirjian method had an area under ROC curves results above 0.93. Discrepancy of sensitivity between methods for the specific cut-off point: 11.48. The results obtained in this study can be extrapolated to 87.33% of the Portuguese population. The European regression formula can be applied for the Portuguese population, and seems to be more accurate than Demirjian's methodology in this population. Nevertheless, both European regression formula and Demirjian method present similarly suitable results in the classification of 12 years of age, although there is a noticeable discrepancy favouring the European regression formula. The European Formula when applied for criminal age assessment, independently of population, is mandatory to indicate to the judicial institutions, the sensitivity of the results.

Use of potassium ion channel and spliceosome proteins as diagnostic biomarkers for sudden unexplained death in schizophrenia

Sudden unexplained death in schizophrenia (SUD-SCZ) is not uncommon and its incidence is approximately three times higher than that in the general population. However, diagnosis of SUD-SCZ remains a great challenge in forensic pathology. This study designed a two-phase study to investigate whether three proteins, namely two potassium ion channel proteins (KCNJ3 and KCNAB1) and one spliceosome protein (SF3B3) that were identified in our previous work, could be applied in the postmortem diagnosis of SUD-SCZ. Immunohistochemical staining of the three biomarkers, followed by a rigorous quantitative analysis, was performed on heart specimens from both SUD-SCZ and control groups. A diagnostic software based on the logistic regression formula derived from the test phase data was then constructed. In the test phase, we found that the staining intensities of KCNJ3, KCNAB1, and SF3B3 were all significantly lower in the SUD-SCZ group (n = 20) as compared with the control group that died from non-natural causes (n = 25), with fold-changes being 14.85 (p < 0.001), 4.13 (p = 0.028) and 2.12 (p = 0.048), respectively. Receiver operating characteristic analysis further illustrated that combination of the three biomarkers achieved the optimal diagnostic specificity (92%) and area under the curve (0.886). In the validation phase, the diagnostic software was confirmed to be a promising tool for predicting the risk of SUD-SCZ in authentic cases. Our study provided a valid strategy towards the practical diagnosis of SUD-SCZ by using KCNJ3, KCNAB1, and SF3B3 proteins as diagnostic biomarkers.

Temperature Effects on Two-Cell Field Impedance Testing of Epoxy and Polysulfide-Modified Epoxy Coatings

Two-cell field impedance spectroscopy provides coating condition assessment in situ, i.e., on coated structures. This study evaluated the dependence of impedance data on environmental conditions encountered during testing, especially temperature. Field impedance spectroscopy measurements were applied to two coated steel substrates over the course of a diurnal heating-cooling cycle. One coated substrate provided a high-barrier epoxy and the second a low-barrier polysulfide-modified epoxy (polysulfide). The temperature range examined was approximately 80 degrees Fahrenheit (ºF) to 110ºF for air, surface, and solution temperature, with baseline measurements made at 70ºF. The results showed coating impedance decreases as the coating surface temperature increases. The coatings showed time-dependent recovery of their initial properties during the cooling cycle, with the greater hysteresis observed by the high-barrier epoxy. Linear regression of temperature and impedance provided a strong correlation, with R2 exceeding 0.80. Therefore, field impedance data with varied temperatures can be corrected via a linear regression formula derived by measuring one sample at two or more temperatures within the encountered range. Coating surface temperature is preferred based on a stronger correlation with impedance than atmospheric or test cell solution temperatures. An Arrhenius relationship is also acceptable for temperature correction and may be preferred where the highest accuracy is needed. This correlation had an R2 of 0.96 or higher, demonstrating a logarithmic dependence of impedance on the inverse of the absolute temperature, i.e., the temperature in Kelvin. The effect of humidity on the impedance was low and could not be resolved from the strongly correlated effect of temperature. The repeated impedance testing, about 40 repetitions at a single location, applied in this experiment showed no discernable effect on the coating impedance, suggesting the voltage amplitudes utilized of 100 mV for low-barrier polysulfide and 500 mV for high-barrier epoxy were nondestructive.

Anthropometric study using three-dimensional pelvic CT scan in sex determination among adult Indonesian population

This study aims to determine pelvic anthropometry characteristics and logistic regression formula for adult sex identification obtained from adult three-dimensional pelvic computed tomography images. This study was an observational analytical study with retrospective regression and cross-sectional approach. The population was all patients at Radiology Installation of Dr. Soetomo General Academic Hospital as referral hospital in East Indonesian region, from September to December 2019 who underwent 3D pelvic CT examination. Then, age distribution and pelvic measurements data were obtained. In this case, statistical analysis was conducted for all the data obtained. A number of 204 samples were included in this study. All radiologic components were also significantly different between sexes (p < 0.05) except for transverse diameter of sacral segment (p = 0.180). Moreover, the conjugate pelvic inlet diameter (CPID), the left innominate height (LIH), and sub pubic angle (SPA) showed significant values for regression formula to determine an adult’s sex using 3D pelvic CT. The calculation result > 0 is a prediction for female while < 0 is a prediction for male. From logistic regression model calculation, a high validity value (91.05%) was found with 100% sensitivity to identify male sex and 81.1% specificity to identify female sex. There were differences on radiometric variable characteristics in pelvic anthropometric study among adult Indonesians at Dr. Soetomo General Academic Hospital, Surabaya. The estimated values of pelvic measurements using 3D CT images could develop a pelvic model with a regression formula with high accuracy value using CPID, LIH, and SPA values.

A machine-learning approach using pubic CT based on radiomics to estimate adult ages

PurposeAdult skeletal age estimation is an active research field. To evaluate the performance of a pubic CT radiomics-based machine learning model for estimating age, we established a multiple linear regression model based on radiomics and machine learning methods. MethodsA total of 355 subjects were enrolled in this retrospective study from August 2016 to August 2021, and divided into a training cohort (N = 325) and a testing cohort (N = 30). Computerized texture analysis of the semi-automatically segmentation was performed and 107 texture features were extracted from the regions. Then we used univariate linear regression and multivariate stepwise regression to assess correlations of texture parameters with age. The most vital features were used to make the best predictive model. Eventually, the established radiomics model was tested with an additional 30 patients. ResultsClinical characteristics include age, sex, height, weight and BMI were not statistically significant different between training and testing cohort (p = 0.098–0.888). Through a multivariate regression analysis using stepwise regression, six texture parameters were found to have significant correlations with age. The regression formula estimating the age was constructed. ConclusionsThe radiomics model using machine learning is considered as a new approach forage estimation frompubic symphysis CT features.Digital osteology is obtained in a non-invasive way so that it can be an ideal collection for anthropological studies.

Development and validation of a risk prediction model for lost to follow-up among adults on active antiretroviral therapy in Ethiopia: a retrospective follow-up study

BackgroundOver 420,000 people have initiated life-saving antiretroviral therapy (ART) in Ethiopia; however, lost-to-follow-up (LTFU) rates continues to be high. A clinical decision tool is needed to identify patients at higher risk for LTFU to provide individualized risk prediction to intervention. Therefore, this study aimed to develop and validate a statistical risk prediction tool that predicts the probability of LTFU among adult clients on ART.MethodsA retrospective follow-up study was conducted among 432 clients on ART in Gondar Town, northwest, Ethiopia. Prognostic determinates included in the analysis were determined by multivariable logistic regression. The area under the receiver operating characteristic (AUROC) and calibration plot were used to assess the model discriminative ability and predictive accuracy, respectively. Individual risk prediction for LTFU was determined using both regression formula and score chart rule. Youden index value was used to determine the cut-point for risk classification. The clinical utility of the model was evaluated using decision curve analysis (DCA).ResultsThe incidence of LTFU was 11.19 (95% CI 8.95–13.99) per 100-persons years of observation. Potential prognostic determinants for LTFU were rural residence, not using prophylaxis (either cotrimoxazole or Isoniazid or both), patient on appointment spacing model (ASM), poor drug adherence level, normal Body mass index (BMI), and high viral load (viral copies > 1000 copies/ml). The AUROC was 85.9% (95% CI 82.0–89.6) for the prediction model and the risk score was 81.0% (95% CI 76.7–85.3) which was a good discrimination probability. The maximum sensitivity and specificity of the probability of LTFU using the prediction model were 72.07% and 83.49%, respectively. The calibration plot of the model was good (p-value = 0.350). The DCA indicated that the model provides a higher net benefit following patients based on the risk prediction tool.ConclusionThe incidence of LTFU among clients on ART in Gondar town was high (> 3%). The risk prediction model presents an accurate and easily applicable prognostic prediction tool for clients on ART. A prospective follow-up study and external validation of the model is warranted before using the model.

Refining the Eikonal Model to Reproduce the Influence of Atrial Tissue Geometry on Conduction Velocity

Abstract Atrial fibrillation is responsible for a significant and steadily rising burden. Simultaneously, the treatment options for atrial fibrillation are far from optimal. Personalized simulations of cardiac electrophysiology could assist clinicians in the risk stratification and therapy planning for atrial fibrillation. However, the use of personalized simulations in clinics is currently not possible due to either too high computational costs or non-sufficient accuracy. Eikonal simulations come with low computational costs but cannot replicate the influence of cardiac tissue geometry on the conduction velocity of the wave propagation. Consequently, they currently lack the required accuracy to be applied in clinics. Biophysically detailed simulations on the other hand are accurate but associated with too high computational costs. To tackle this issue, a regression model is created based on biophysically detailed bidomain simulation data. This regression formula calculates the conduction velocity dependent on the thickness and curvature of the heart wall. Afterwards the formula was implemented into the eikonal model with the goal to increase the accuracy of the eikonal model without losing its advantage of computational efficiency. The results of the modified eikonal simulations demonstrate that (i) the local activation times become significantly closer to those of the biophysically detailed bidomain simulations, (ii) the advantage of the eikonal model of a low sensitivity to the resolution of the mesh was reduced further, and (iii) the unrealistic occurrence of endo-epicardial dissociation in simulations was remedied. The results suggest that the accuracy of the eikonal model was significantly increased. At the same time, the additional computational costs caused by the implementation of the regression formula are neglectable. In conclusion, a successful step towards a more accurate and fast computational model of cardiac electrophysiology was achieved.

PENGARUH KOMPETENSI GURU TERHADAP KEDISIPLINAN SISWA MADRASAH IBTIDAIYAH AL-BASYARIYAH BALONG

This study aims to determine whether there is an influence of teacher competence either individually or simultaneously on students' discipline attitudes. This research method is quantitative and descriptive. In measuring the research variables, the researcher tested the instrument first, namely the validity and reliability tests, while measuring the two variables' influence using a simple linear correlation and regression formula. To prove these problems, the authors conducted research at MI Al-Basyariyah Balong with the object of study being teachers and students in grades IV, V and VI, taking samples of 63 students and 25 educators. Based on the results of the analysis of research data from the two variables, it can be concluded that there is a significant influence between teacher competence on student discipline at MI Al-Basyariyah Balong. This is evidenced by statistical calculation data with a correlation test that rcount is greater than rtable with a respondent's confidence level of 25 teachers and 63 students. The story of the influence of teacher competence on student discipline is 73.2%, and the rest is influenced by other factors not examined in this study.

Improvement of empirical formulas to estimate the reduction effects by berms on irregular wave runup over a dune-berm coast

This study formulates the reduction effects of a sandy berm on irregular wave runup over a dune-berm coast. The numerical experiments by Park and Cox (2016) are closely re-examined to develop an empirical formula describing the variability of reduction effects of a sandy berm over a broad range of conditions. Based on a sequence of regression analyses, the reduction effects are expressed as a reduction factor in terms of normalized berm width, normalized surge level, and wave steepness in deep water. The comparison with the numerical experiments demonstrates that the regression formula can satisfactorily reproduce the variability of the reduction effects over the range of numerical experiments. The analysis of prediction uncertainty demonstrated that the derived formula reproduced the reduction effects observed in the numerical experiments with negligible bias and a 90% confidence interval of approximately ±20% relative error. In addition, conversion formulas between representative runup values based on different statistical definitions are derived to enable consistent comparisons between them. The proposed reduction formula is implemented into three empirical runup models that are applicable to the quick estimations of irregular wave runup on a dune-berm coast: the models by Park and Cox (2016), Stockdon et al. (2006), and Mase et al. (2013). Consistent comparisons were conducted among the empirical predictions and numerical experiments based on the statistical conversion formulas. Combined with the proposed reduction formula, all three models well reproduced the normalized 2% runup in the numerical experiments over a wide range of conditions. On the other hand, the uncertainty in the runup prediction appeared in different forms depending on the selected model. When the proposed reduction formula was implemented in the modified Park and Cox (2016) and modified Stockdon et al. (2006) models, the uncertainty was described by a log-normal distribution of the error ratio between the empirical predictions and numerical experiments. Quantitatively, these two models predicted 90% of the normalized runup on a dune within a range of relative error of less than approximately 20–30%. When the proposed reduction formula was combined with the model by Mase et al. (2013), the uncertainty followed a normal distribution of the residual error between the empirical predictions and numerical experiments. On the normalized runup, the model prediction indicated a small conservative bias (+0.05) and a root-mean-square error of 0.13.

Obesity As A Cause of Restrictive Ventilatory Defect

Abstract There is an association between obesity and restriction on pulmonary function testing when relying on the forced vital capacity (FVC) as the defining parameter for restriction. Body mass index (BMI) may not be the best measure of obesity, but it is the most commonly used. Multiple examples of regression formulae have been developed to explain the relationship between obesity and restriction, but these may be too complicated for general use. This article reviews the medical literature concerning this association.

Study of the relationship between flatwise and edgewise modulus of elasticity of plantation fibre-managed E. nitens sawn boards

• Testing 331 fibre-managed E.nitens sawn boards to verify the normal distribution of static edgewise MoE values. • Testing 147 boards in flatwise to explore the relationship between flatwise and edgewise MoE values. • Visual grading 147 boards to obtain the correlation between visual features and static flatwise MoE values. This study investigated the relationship between flatwise and edgewise modulus of elasticity (MoE) of plantation fibre-managed E. nitens sawn boards. 331 boards were used to build a complete picture of this resource by measuring the density, moisture content, and static edgewise MoE. Then, 147 boards were tested for static flatwise MoE. Results showed that average static flatwise MoE is highly linearly related to static edgewise MoE. The average flatwise MoE could be predicted through the linear relationship considering the contribution of the width of the boards. The R 2 value of this linear regression formula is 0.9.

Cloud Droplet Nucleation Simulation and Parameterization

Abstract Cloud droplet nucleation is classically defined as a droplet growing to a size such that its ambient supersaturation exceeds its surface equilibrium water vapor pressure. Unactivated particles are always in equilibrium with the ambient vapor pressure. Further studies showed that such an equilibrium assumption leads to many more cloud droplets being nucleated due to neglecting kinetic growth limitations, including the inertial mechanism, evaporation mechanism, and deactivation mechanism. Moreover, the inertial mechanism results in great discrepancy between the actual size and the critical size of nucleation for large aerosol particles. These issues complicate cloud droplet nucleation parameterization for applications in cloud modeling. To establish a physically based nucleation scheme, we established a highly size-resolved Lagrangian parcel model. Vapor diffusion and heat conduction were calculated according to Maxwell theory, and the surface vapor density and temperature were explicitly simulated. The surface temperature variation of a droplet with its size was considered. The surface supersaturation of a droplet, taking into account the surface temperature variation, is different from its equilibrium supersaturation at its large sizes. The nucleation simulation showed that the inertial and deactivation mechanisms can impact droplet nucleation. Moreover, very large nuclei can trigger rain embryo formation in a short time period. Even though there are kinetic limitations, the classical equilibrium assumption can be applied to determine the primary nucleation number of cloud droplets. Meanwhile, a regression formula for the size of a nucleated droplet and its dry aerosol size was established.

The Impact of Academic Information System to Students’ Satisfaction in Higher Education

Academic information systems reflect the quality of management of a college and are one of the efforts of educational institutions to provide quality services to provide convenience and comfort to students. There are obstacles such as the difficulty of controlling the scheduling of courses and information that is less updated on academic information systems. This study aims to determine how much influence the academic information system has on student satisfaction. This study uses a type of research based on a quantitative approach. The research subjects were bachelor and graduate school students from Universitas Negeri Yogyakarta. The data collection method used a questionnaire. Data processing techniques and data analysis using simple linear regression formulas. The results showed that (i) there was a significant influence between the implementation of academic information systems on the level of satisfaction of Universitas Negeri Yogyakarta bachelor and graduate school students amount 41% (ii) supporting and inhibiting factors perceived by students in the implementation of academic information systems found in speed, timeliness, and ease of access. This article has empirical contributions related to academic information systems in higher education and can be used as insights for policy holders in universities in making policies.

Obtaining Linear Regression Formulas Depending on Upper Arm Lenght for Estimating Stature

Objective: In our study, it was aimed to obtain linear regression formulas for estimating stature from upper arm length values of young adult female and male individuals and to examine the effect of right-left side asymmetry on regression formulas. Materials &amp;amp; Methods: The study was carried out on 70 healthy young adult volunteers (35 males, 35 females) aged 18-36 years. Upper arm length was obtained by measuring the distance from the acromion to the olecranon. Asymmetry and gender differences analyzed. For the estimation of stature, regression formulas were created by simple linear regression analysis separately according to the genders.Results: The linear regression formulas required for the stature calculation were obtained. Among the linear regression formulas based on upper arm length, the Standard Error of the Estimate (SEE) value was the lowest in the female upper right arm. SEE values for women were 5.22882 for the right upper arm and 5.4979 for the left upper arm; in men it was 6.62943 for the right upper arm and 6.60019 for the left upper arm. A moderately positive correlation was found between arm length and stature in both genders.Conclusion: In the formulas obtained for the estimation of arm length in men, the SEE value was found to be higher than in women. According to the regression analysis, arm length values in women give a better estimation of stature compared to men. In women, asymmetry was detected between the right and left upper arm lengths. The regression equation of the right side was found to be more reliable.

Evaluating The Morphometric-Topographic Features of the Occipital Condyle and the Clinical Significance

Aim: To reduce morbidity and mortality in surgical operations to be applied to the craniovertebral junction,&#x0D; it is important to know the anatomical structures in the skull base and the topographical relationship&#x0D; between these structures. Lateral suboccipital craniotomy and occipital condyle resection are among&#x0D; the preferred methods. Surrounding neurovascular structures may be damaged during occipital condyle&#x0D; resection. The aim of study was to develop regression formulas that will determine the precise location&#x0D; of the occipital condyle and estimate the distances to the surrounding anatomical structures, based on&#x0D; the skull morphometry of the person.&#x0D; Material and Methods: The study was carried out on 22 condylus occipitalis (11 skulls) at Harran&#x0D; University, Medical Faculty Anatomy Laboratory. The determined 27 parameters were measured via the&#x0D; Image J program on the skulls’ inferior, anterior, lateral and posterior aspect photographs. Multiple linear&#x0D; regression analysis was performed.&#x0D; Results: To determine the morphometric and topographic features of the occipital condyle, the&#x0D; equations have been developed such as; The occipital condyle length= -2.142 + (0.330 x P15) – (0.468&#x0D; x P19) – (0.748 x P20) + (0.807 x P21); Adjusted R2= 0.911, Standard Error of the Estimation= 0.938.&#x0D; Conclusion: Considering the difference between the minimum and the maximum values observed in&#x0D; descriptive statistics, the distribution between these values, the different findings in the studies in the&#x0D; literature, there may be erroneous applications in the attempts to be made over the mean values. We&#x0D; believe that the formulas we have developed will be beneficial in personal-specific approaches.

Fatigue strength of partial penetration butt welds of mild steel

This paper presents the influences of the irregularity “insufficient penetration welding” on the fatigue strength based on experimental and numerical investigations. For this purpose, the fatigue strength of partial penetration butt welds of mild steel (S355) with different non-welded gaps were subjected to fatigue loading. Three different planned gap dimensions (h = 4, 6, 8 mm) at one-sided (Y-seam) and two-sided (DY-seam) partial penetration butt welds were analysed. The results were obtained on a small-scale test specimen with a steel plate thickness of t = 20 mm, without axial and angular misalignment. For the numerical effective notch stress approach, regression formula for efficient analysis of stress concentration factors was determined. The results show that butt joints which are not fully penetrated on one or both sides, and which were previously not permissible for welded joints subject to fatigue loading, can be evaluated in the future on the basis of these investigations.