in many statistical systems, a type of survey called “sampling over time” is common, which repeats continuously over time. one method of sampling over time is panel survey. panel survey is a method in which a “fixed sample” is contacted during different waves. the most important challenge in a panel survey is debility in providing response from some sample units and having non-response that usu...

we propose a scheme for localizing an atom in a four-level configuration inside a classical standing wave field, conditioned upon the measurement of frequency of a weak probe field. in the classical standing wave field, the interaction between the atom and the field is position dependent due to the rabi-frequency of the driving field. hence, as the absorption frequency of the probe field is mea...

BACKGROUND Atom environments and fragments find wide-spread use in chemical information and cheminformatics. They are the basis of prediction models, an integral part in similarity searching, and employed in structure search techniques. Most of these methods were developed and evaluated on the relatively small sets of chemical structures available at the time. An analysis of fragment distributi...

Missing data are often a problem in statistical modeling. The Bayesian paradigm offers a natural modelbased solution for this problem by treating missing values as random variables and estimating their posterior distributions. This paper reviews the Bayesian approach and describes how the MCMC procedure implements it. Beginning with SAS/STAT® 12.1, PROC MCMC automatically samples all missing va...

Implicit solvation is a mean force approach to model solvent forces acting on a solute molecule. It is frequently used in molecular simulations to reduce the computational cost of solvent treatment. In the first instance, the free energy of solvation and the associated solvent-solute forces can be approximated by a function of the solvent-accessible surface area (SASA) of the solute and differe...

Before examining what a molecular orbital is, it is good to refresh our memories with respect to the types of bonding that can occur between atoms when molecules are formed. Basically there are two prevalent types of bonding that occur in organic chemistry. (There are several ways that bonding can occur but most of these ways can be classified into two very broad categories.) The first category...

A study of structural relaxations of Si(n)C(m) clusters corresponding to different compositions, different relative arrangements of Si/C atoms, and different types of initial structure, reveals that the Si(n)C(m) bucky-diamond structure can be obtained for an initial network structure constructed from a truncated bulk 3C-SiC for a magic composition corresponding to n = 68 and m = 79. This stud...

Minyoung Lee and Alan J. H. McGaughey Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA (Received 2 February 2011; published 29 April 2011) The energetics and kinetics of the c(2 × 2) to (2√2 ×√2)R45◦ missing-row reconstruction transition on the Cu(100) surface are investigated using density functional theory calculations. First, oxygen-molecu...

The centrosymmetric tetranuclear title molecule, [Sn4(C3H7O)4Cl4O2], contains two types of Sn atoms, Sn(II) and Sn(IV). The Sn(II) atom has a trigonal-pyramidal coordination environment and is bonded to two O atoms from two iso-propano-late groups and one μ3-oxide atom. The Sn(IV) atom has an octa-hedral coordination environment, formed by two chloride atoms, two μ3-oxide atoms and two O atoms ...