Astigmatism in Infants: Study of Changing Visual Axis in Infants and Children

Background: Astigmatism is an abnormality within the curvature of the attention. It occurs when light rays strike a spherical lens obliquely, or the line of vision to its principal axis is not parallel. Refraction away from the axis occurs when light strikes a lens obliquely and distorts the image formed. Aim: This study aimed to look at the prevalence of against-the-rule, with the-rule, and oblique-axis astigmatism in children. The change in cylinder index of refraction power and alignment of astigmatism in babies and young children is studied. Methodology: To conduct the study and thoroughly search the literature separately, references and abstracts were reviewed. Books like Parson’s diseases of the Eye by Dr. Radhika Tandon and several articles, WHO website, etc., were referred. Results: The study relied upon many studies on refractions procured by the near-retinoscopy methodology that knowledgeable Refractionist accomplished. Conclusion: It can be concluded that young children have a high incidence of against (???) type of astigmatism and that after this age (which age?), most children are with the rule.

PERBANDINGAN PRINCIPAL AXIS FACTORING DAN MAXIMUM LIKELIHOOD DALAM MENENTUKAN FAKTOR DOMINAN YANG MEMPENGARUHI PEMBELAJARAN NAHWU SHOROF (STUDI KASUS PONDOK PESANTREN ROUDLOTUL MUTA’ALLIMIN PUTRI)

This study discusses the dominant factors that influence the success of learning nahwu shorof at the Roudlotul Mutaalimin Islamic Boarding School for the daughter of Minggirsari Village. Determining the dominant factor is done to maximize the quality of education in the boarding school, so that the interest of prospective students is increasing. In this study, two extraction methods were compared, namely the Principal Axis Factoring and Maximum Likelihood methods. There are 13 variables that affect the success of nahwu shorof learning, namely the natural environment (P1), social environment (P23), curriculum (P49), madrasa program (P1012), facilities and facilities (P1315), teaching staff (P1619), condition of physiological (P2021), condition of the five senses (P22), interest in learning (P2325), intelligence of students (P26), student talent (P27), motivation of students (P28), cognitive ability (P2930). The purpose of this study, namely to determine the most appropriate extraction method used in the analysis. The result of this study is the Maximum Likelihood method which is more appropriate than the Principal Axis Factoring method, because it has a smaller RMSE (Root Mean Squared Error) value.

Effects of Structural Dimension Variation on the Vibration of MEMS Ring-Based Gyroscopes

This study investigated the effects of structural dimension variation arising from fabrication imperfections or active structural design on the vibration characteristics of a (100) single crystal silicon (SCS) ring-based Coriolis vibratory gyroscope. A mathematical model considering the geometrical irregularities and the anisotropy of Young’s modulus was developed via Lagrange’s equations for simulating the dynamical behavior of an imperfect ring-based gyroscope. The dynamical analyses are focused on the effects on the frequency split between two vibration modes of interest as well as the rotation of the principal axis of the 2θ mode pair, leading to modal coupling and the degradation of gyroscopic sensitivity. While both anisotropic Young’s modulus and nonideal deep trench verticality affect the frequency difference between two vibration modes, they have little contribution to deflecting the principal axis of the 2θ mode pair. However, the 4θ variations in the width of both the ring and the supporting beams cause modal coupling to occur and the degenerate 2θ mode pair to split in frequency. To aid the optimal design of MEMS ring-based gyroscopic sensors that has relatively high robustness to fabrication tolerance, a geometrical compensation based on the developed model is demonstrated to identify the geometries of the ring and the suspension.

A shear center demonstration model using 3D-printing

Locating the shear, or flexural, center of non-symmetric cross-sectional beams is a key element in the teaching of structural mechanics. That is, establishing the point on the plane of the cross-section where an applied load, generating a bending moment about a principal axis, results in uni-directional deflection, and no twisting. For example, in aerospace structures it is particularly important to assess the propensity of an airfoil section profile to resist bending and torsion under the action of aerodynamic forces. Cross-sections made of thin-walls, whether of open or closed form are of special practical importance and form the basis of the material in this paper. The advent of 3D-printing allows the development of tactile demonstration models based on non-trivial geometry and direct observation.

Automated Solving Algorithm and Application for Oriented Bounding Box Based on Principal Axis of Inertia

In mechanical design and manufacture, the minimum size of raw material of each part should be measured before processing. Generally, this size could be equal to the size of minimum bounding box. When the assembled parts of a product reach an enormous quantity, the measurement would be a rough work. This paper introduced an automated solving algorithm for the oriented bounding box based on principal axis of inertia, combined with CATIA structural tree recursive traversal algorithm according to CAA V5 Automation API, to implement an automated solution of the engineering acceptable minimum oriented bounding box of CATIA model.

The LIVES Daily Hassles Scale and Its Relation to Life Satisfaction

Although daily hassles have been of interest since the 1980s, only a few tools have been developed to assess them. Most of them are checklists or open-ended questions that are demanding for participants in panel surveys. Therefore, to facilitate daily hassles integration into large surveys, the aim of this study was to present a new tool assessing daily hassles, the LIVES–Daily Hassles Scale (LIVES-DHS), and to examine its relation to life satisfaction, in a sample of 1,170 French- and German-speaking adults living in Switzerland. In a first random subsample, we conducted a principal axis factor analysis, and the results suggested a five-factor solution. Furthermore, we conducted a confirmatory factor analysis on a second random subsample, and it supported the hierarchical factor structure of the scale. The LIVES-DHS consists of 18 items represented by five factors that describe five sources of daily hassles: financial, physical, relational, environmental, and professional. The bivariate correlations showed that the LIVES-DHS could differentiate the concept of daily hassles from associated concepts. Finally, the hierarchical regression showed that daily hassles negatively predicted life satisfaction and added a significant incremental variance beyond that accounted for by age, gender, household income, education level, and personality traits.

Comparison of stress orientation indicators in Chicxulub’s peak ring: Kinked biotites, basal PDFs, and feather features

ABSTRACT During hypervelocity impacts, target rocks are subjected to shock wave compression with high pressures and differential stresses. These differential stresses cause microscopic shear-induced deformation, which can be observed in the form of kinking, twinning, fracturing, and shear faulting in a range of minerals. The orientation of these shear-induced deformation features can be used to constrain the maximum shortening axis. Under the assumption of pure shear deformation, the maximum shortening axis is parallel to the maximum principal axis of stress, σ1, which gives the propagation direction of the shock wave that passed through a rock sample. In this study, shocked granitoids cored from the uppermost peak ring of the Chicxulub crater (International Ocean Discovery Program [IODP]/International Continental Drilling Project [ICDP] Expedition 364) were examined for structures formed by shearing. Orientations of kink planes in biotite and basal planar deformation features (PDFs) in quartz were measured with a U-stage and compared to a previous study of feather feature orientations in quartz from the same samples. In all three cases, the orientations of the shortening axis derived from these measurements were in good agreement with each other, indicating that the shear deformation features all formed in an environment with similar orientations of the maximum principal axis of stress. These structures formed by shearing are useful tools that can aid in understanding the deformational effects of the shock wave, as well as constraining shock wave propagation and postshock deformation during the cratering process.

Algorithmic jingle jungle: A comparison of implementations of principal axis factoring and promax rotation in R and SPSS

A statistical procedure is assumed to produce comparable results across programs. Using the case of an exploratory factor analysis procedure—principal axis factoring (PAF) and promax rotation—we show that this assumption is not always justified. Procedures with equal names are sometimes implemented differently across programs: a jingle fallacy. Focusing on two popular statistical analysis programs, we indeed discovered a jingle jungle for the above procedure: Both PAF and promax rotation are implemented differently in the psych R package and in SPSS. Based on analyses with 247 real and 216,000 simulated data sets implementing 108 different data structures, we show that these differences in implementations can result in fairly different factor solutions for a variety of different data structures. Differences in the solutions for real data sets ranged from negligible to very large, with 42% displaying at least one different indicator-to-factor correspondence. A simulation study revealed systematic differences in accuracies between different implementations, and large variation between data structures, with small numbers of indicators per factor, high factor intercorrelations, and weak factors resulting in the lowest accuracies. Moreover, although there was no single combination of settings that was superior for all data structures, we identified implementations of PAF and promax that maximize performance on average. We recommend researchers to use these implementations as best way through the jungle, discuss model averaging as a potential alternative, and highlight the importance of adhering to best practices of scale construction.

Exploratory Factor Analysis for Identifying Comorbidities as Risk Factors Among Patients with Cied

The emergence of SARS-CoV-2 affected care both for acute and chronic health conditions. Majority of the patients with cardiac implantable electronic devices (CIEDs) have multiple comorbidities, which can influence their response to COVID-19. An online survey consisting of 45 multiple-choice question was designed for CIED patients assessing comorbidities and overall health condition during September -December 2020. A multivariate analysis based on principal axis factoring (PAF) was performed on the eligible 184 survey response. Three factors were identified. Ten-year survival rates were calculated with Charlson Comorbidity Index. The extracted factors explained 66.1% of the cumulative variance and were consistent with medical literature data.