It is well known that the ratio of the number of clauses to the number of variables in a random k-SAT instance is highly correlated with the instance’s empirical hardness. We consider the problem of identifying such features of random SAT instances automatically using machine learning. We describe and analyze models for three SAT solvers—kcnfs, oksolver and satz—and for two different distributi...

abstract one of the major risks in the agricultural sector is the price fluctuations risk of agricultural products. futures markets for agricultural products as one of the policies and executive approach have a significant impact on reducing price fluctuations of agricultural products. so in this study, in this study the factors affecting farmers likely to participate in the future market for p...

We derive the probability density of the ratio of components of the bivariate normal distribution with arbitrary parameters. The density is a product of two factors, the first is a Cauchy density, the second a very complicated function. We show that the distribution under study does not possess an expected value or other moments of higher order. Our particular interest is focused on the shape o...

The purposes of this study were to investigate the validity of the simple ratio and three alternative deflation models and examine how the variation of the numerator and denominator variables affects the reliability of a ratio variable. A simple ratio and three alternative deflation models were fitted to four empirical data sets, and common criteria were applied to determine the best model for ...

Various characterizations of the distribution of the ratio of two independent Rayleigh random variables are presented. These characterizations are based, on a truncated moment; on hazard function; and on certain functions of order statistics.

We propose an estimation method for an errors-in-variables model with unknown input and output noise variances. The main assumption that allows identifiability of the model is clustering of the data into two clusters that are distinct in a certain specified sense. We show an application of the proposed method for system identification.

Many estimators of the population parameters are constructed using known auxiliary variables. The classical well known ratio estimator is one of them. Ratio estimators are frequently employed in sample surveys when estimating the population mean Y of a variate Y with the help of the known population means of a correlated auxiliary variables. Various improvements of this ratio estimator have bee...

BACKGROUND The treatment of chronic kidney disease through dialysis is a considerable expense in most health systems. The two chief methods of providing dialysis, haemodialysis (HD) and peritoneal dialysis (PD) have significant differences in cost composition and factors of production. The aim of this article is to identify and quantify the macroeconomic variables that influence the relative co...

During the last decade, the computational paradigms known as inflzcence diagrams and belief networks have become to dominate the diagnostic expert systems field. Using elaborate collections of nodes and arcs, these representations describe how propositions of interest interact with each other through a variety of causal and predictive links. The links are parameterized with inexact degrees of s...

OBJECTIVE To develop a clinical prediction rule to identify patients with patellofemoral pain (PFP) who are more likely to benefit from foot orthoses. DESIGN Posthoc analysis of one treatment arm of a randomised clinical trial. SETTING Single-centre trial in a community setting in Brisbane, Australia. PARTICIPANTS 42 participants (mean age 27.9 years) with a clinical diagnosis of PFP (med...