Two classes of quantile regression estimation methods for the recursive structural equation models of Chesher (2003) are investigated. A class of weighted average derivative estimators based directly on the identification strategy of Chesher is contrasted with a new control variate estimation method. The latter imposes stronger restrictions achieving an asymptotic efficiency bound with respect ...

Researchers are often interested in analyzing data that arise from a longitudinal or clustered design. Although there are a variety of standard likelihood-based approaches to analysis when the outcome variables are approximately multivariate normal, models for discrete-type outcomes generally require a different approach. Liang and Zeger formalized an approach to this problem using generalized ...

Regression models are proposed for predicting conception rate in a dairy herd under South African and especially Natal conditions. Conception rate (CR%) was related to mean monthly temperature-humidity index (THI) by curvilinear regression equation model; CR% = 812.7 +/- 28.61 THI - 0.2322THI2 (P = 0.061), and by linear regression equation model; CR% = 188.0 - 1.906THI (P = 0.023). Conception r...

This study analysed the influence of clinical factors on early postoperative seizures in patients with meningiomas and constructed a logistic regression equation for assessing risk factors. Clinical data from 222 patients with meningiomas were collected. The odds ratios (ORs) for independent variables were determined: the ORs for preoperative seizure history and movement disorder were > 1, whe...

Likelihood ratio criteria are developed for hypotheses concerning multivariate regression matrices when reduced rank is assumed or equivalently hypotheses concerning linear restrictions on regression matrices. In an econometric simultaneous equation model a single restriction may be called a ”structural equation.” A model of reduced rank in statistics is often termed a ”linear functional relati...

OBJECTIVE The purpose of this study is to propose an objective and simple method for assessing surgical outcomes of cleft nasal deformity using two-dimensional digital images. DESIGN Five plastic surgeons evaluated slides of 20 normal and 65 repaired cleft nasal deformities using the full range of values from 0 to 100 with 10-point intervals. Five laypersons rated 12 parameters per image from...

the purpose of this study was to identify daily changes in body weight of broiler chickens using image processing and multi-regression analysis. therefore, thirty 1-day-old broiler chickens were reared under standard rearing condition and after acquiring images they were weighted, individually. from 2490 digital images, six features (perimeter, area convex, major axis, minor axis, eccentricity)...