Computers testing

Ticktin A., Whitaker B. J., McCaffery A. J. Computational test of fitting laws of rotational energy transfer, Chem. Phys. Lett. 139, 571-5 (1987). 

Green S., Monchik L., Goldflam R., Kouri D. J. Computational tests of angular momentum decoupling approximations for pressure broadening cross sections, J. Chem. Phys. 66, 1409-12 (1977). 

A good computational test of the validity of OEMO theory is a high quality ab initio calculation6. However, other computational methods which are popular with chemists and which avoid the expense of ab initio approaches can also be useful, if judiciously applied, in testing the predictions of OEMO theory. These methods fall into two groups ... 

Comment Computational test is needed to determine the sign of sigma nonbonded interaction. 

This sequence of analytical expressions has been computationally tested... 

The modeling system GAMS (Brooke et al., 1996) is used for setting up the optimization models. The computational tests were carried out on a Pentium M... 

The modeling system GAMS (Brooke et al., 1996) is used for setting up the optimization models. The computational tests were carried out on a Pentium M processor 2.13 GHz. The models were solved with DICOPT (Viswanathan and Gross-mann, 1990). The NLP subproblems were solved with CONOPT2 (Drud, 1994), while the MILP master problems were solved with CPLEX (CPLEX Optimization Inc, 1993). 

Questions have been raised about the feasibility of establishing evaluation norms that can be used across different populations and settings, or with similar tests used on different computer test systems. Certainly, situational factors influence performance on computerized performance tests. In addition, epidemiological factors, such as gender and age, have been demonstrated to influence performance on these tests. Due to mechanical and electronic differences across computer systems,... 

The runtime performances of the Optimized Retrieval Model have been tested using different computers. Tests have been performed on simulated observations using two different sets of microwindows, a preliminary standard set and a set which optimizes the trade-off between accuracy and run-time performance. In these tests we used initial guess profiles of the retrieval that are sufficiently close to the reference profiles (the ones used to simulate the observations), so that convergence is reached in only one iteration. 

These questions are essentially standard, multiple-choice questions. Every problem-solving question has one correct answer and four incorrect ones. Although the answer choices in this book are labeled a, b, c, d, and e, keep in mind that on the computer test, they will appear as blank ovals in front of each answer choice. Specific tips and strategies for each question type are given directly before the practice problems later in the book. This will help keep them fresh in your mind during the test. 

To understand the mechanisms of solids slug flows, a two-dimensional coupled DEM/CFD numerical model was built to simulate the motion of a pre-formed slug (ca. 0.3 m long) in a 1 m long horizontal 50 mm bore pipe as shown in Fig. 1. The pipe was initially filled with a layer of particles, approximately 15 mm thick at the bottom. (The thickness of this stationary layer was determined based on experience from previous experiments and computer test runs). 

The long-standing interest of Boyd and his coworkers in radicals and radical ions has led to many papers since 1993 on hyperfine structures. These papers have pushed the conventional multireference configuration interaction methods to the limits of the available computers, tested the predictive ability of various functionals commonly used in DFT calculations, and, among other topics, modeled the effect of a noble gas matrix on the hyperfine structures of radicals. Recent research focused primarily on radicals formed as a consequence of radiation damage to DNA. 

H. Yamataka, S. Nagase, J. Org. Chem. 53, 3232 (1988). Ah Initio Calculations of Hydrogen Transfers. A Computational Test of Variations in the Transition-State Structure and the Coefficient of Rate-Equilibrium Correlation. 

In reviewing the history of VB methods there stand out a few ideas concerning approximations that might be made. The author has chosen four that allow simple computational tests in today s world, and these are discussed in this section. There is little connection between them. 

The computational tests that have been performed in a variety of difficult cases show that the description is consistent and reasonably accurate, in view of... 

In addition to D2S2, this method was computationally tested for the chiral purification of J = 1 1, 3 dimethylallene [104], described in Sec. V.F. As in D2S2 we use three perpendicular laser polarizations so as to be able to work with unpolarized samples. Here, as distinct from Eq. (75), levels 3) and 5) are coupled as well as 4) and 5). In this case there is no population in level 5) during the time evolution so that level 5), a state chosen as one that would undergo internal conversion, does not suffer such losses. 

There exist (4, 5, 8, 9, 27) simple direct relations, between isotope effect, structure, and force field, which do not necessarily require a complete knowledge of all molecular parameters and avoid the solution of the secular equation. These relations are, however, approximations restricted to limited ranges of temperature. [Newer approximation methods, based on expansions in Jacobi polynomials, are applicable over wide ranges of temperatures (6, i6).] In the past, before the ready availability of fast digital computers, tests of the validity of these approximations were usually fairly limited in nature, but recent extensive tests on model calculations of kinetic isotope effects have been carried out 23, 28). In addition, extensive tests of power-series approximations (not considered in the present paper) have now been performed (6,16). 

Apart from purely electronic effects, an asymmetric nuclear relaxation in the electric field can also contribute to the first hyperpolarizability in processes that are partly induced by a static field, such as the Pockels effect [55, 56], and much attention is currently devoted to the study of the vibrational hyperpolarizability, can be deduced from experimental data in two different ways [57, 58], and a review of the theoretical calculations of p, is given in Refs. [59] and [60]. The numerical value of the static P is often similar to that of static electronic hyperpolarizabilities, and this was rationalized with a two-state valence-bond charge transfer model. Recent ab-initio computational tests have shown, however, that this model is not always adequate and that a direct correlation between static electronic and vibrational hyperpolarizabilities does not exist [61]. 

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