Closed loop models for analyzing the effects of simulator characteristics

The optimal control model of the human operator is used to develop closed loop models for analyzing the effects of (digital) simulator characteristics on predicted performance and/or workload. Two approaches are considered: the first utilizes a continuous approximation to the discrete simulation in conjunction with the standard optimal control model; the second involves a more exact discrete description of the simulator in a closed loop multirate simulation in which the optimal control model simulates the pilot. Both models predict that simulator characteristics can have significant effects on performance and workload

Analyzing power in nucleon-deuteron scattering and three-nucleon forces

Three-nucleon forces have been considered to be one possibility to resolve the well known discrepancy between experimental values and theoretical calculations of the nucleon analyzing power in low energy nucleon-deuteron scattering. In this paper, we investigate possible effects of two-pion exchange three-nucleon forces on the analyzing power and the differential cross section. We found that the reason for different effects on the analyzing power by different three-nucleon forces found in previous calculations is related to the existence of the contact term. Effects of some variations of two-pion exchange three-nucleon forces are investigated. Also, an expression for the measure of the nucleon analyzing power with quartet P-wave phase shifts is presented.Comment: 11 pages including 2 eps figures, use epsfig.sty, to appear in Phys. Rev.

Demographic Transitions: analyzing the effects of mortality on fertility

The effect of mortality reductions on fertility is one of the main mech- anisms stressed by the recent growth literature in order to explain demo- graphic transitions. We analyze the empirical relevance of this mechanism based on the experience of all countries since 1960. We distinguish be- tween the e¤ects on gross and net fertility, take into account the dynamic nature of the relationship and control for alternative explanatory factors and for endogeneity. Our results show that mortality plays a large role in fertility reductions, that the change in fertility behavior comes with a lag of about 10 years and that both net and gross fertility are a¤ected. We find comparatively little support for explanations of the demographic transition based on economic development or technological change.mortality, fertility, demographic transitions, unified growth models.

Irreducible pionic effects in nucleon-deuteron scattering below 20 MeV

The consequences of a recently introduced irreducible pionic effect in low energy nucleon-deuteron scattering are analyzed. Differential cross-sections, nucleon (vector) and deuteron (vector and tensor) analyzing powers, and four different polarization transfer coefficients have been considered. This 3NF-like effect is generated by the pion-exchange diagram in presence of a two-nucleon correlation and is partially cancelled by meson-retardation contributions. Indications are provided that such type of effects are capable to selectively increase the vector (nucleon and deuteron) analyzing powers, while in the considered energy range they are almost negligible on the differential cross sections. These indications, observed with different realistic nucleon-nucleon interactions, provide additional evidences that such 3NF-like effects have indeed the potential to solve the puzzle of the vector analyzing powers. Smaller but non negligible effects are observed for the other spin observables. In some cases, we find that the modifications introduced by such pionic effects on these spin observables (other than the vector analyzing powers) are significant and interesting and could be observed by experiments.Comment: 33 pages, 17 figures, 3 Tables, RevTe

Analyzing the effects of past prices on reference price formation

We propose a new reference price framework for brandchoice. In this framework, we employ a Markov-switching processwith an absorbing state to model unobserved price recall ofhouseholds. Reference prices result from the prices households areable to remember. Our model can be used to learn how many pricesobserved in the past are used for reference price formation.Furthermore, we learn to what extent households have sufficientprice knowledge to form an internal reference price. For A.C.Nielsen scanner panel data on catsup purchases, we find that theprices observed at the previous purchase occasion have an averagerecall probability of about 20%. Furthermore, the averageprobability that a household has sufficient price knowledge toform a reference price is estimated at about 30%. Even thoughprice recall is very limited the impact of reference priceformation on brand choice is substantial, and it is stronger thantwo popular alternative models in the literature suggest.Moreover, contrary to the two alternative models, our model doesnot suggest asymmetry between price gains and losses.brand choice;household scanner panel data;Markov switching process;reference price

On The Teaching Of Analyzing The Effects Of Parameter Changes On The Graph Of Function

The proficiency level of some tenth and eleventh graders on analyzing the effects of parameter changes on the graph of function is observed in this project. The result shows the level is low. It seems that those students did not sufficiently work on math problems involving deep reasoning. The students used to solve math problems by plugging in formulas only. In this project, the causes are found and reported. At the end part, an alternative teaching approach is proposed. Key Words: parameter, graph of function, alternative teaching

A Framework for Analyzing the Effects of Spring Load Restriction

Spring Load Restrictions (SLR) impose load restrictions on heavy trucks during the spring thaw period. Although the policies have been implemented for many years, we are still unsure of their economic effects on truckers. This paper overviews practices around the world and sets up a framework to estimate the Benefit/Cost of the SLR policy. A freight demand model in Minnesota was built to estimate the impacts of SLR on the freight transportation pattern. The model allows various policy scenarios to be tested before being tested in practice. A preliminary result of the freight demand model shows the SLR policy increased truck Vehicle Kilometers of Travel (VKT) in Lyon County, Minnesota by about 13 percent.Spring load restrictions, Benefit/Cost analysis, EMME/2, Freight demand model

A systematic framework for analyzing the dynamic effects of permanent and transitory shocks

This paper proposes a systematic framework for analyzing the dynamic effects of permanent and transitory shocks on a system of n economic variables. We consider a two-step orthogonolization on the residuals of a VECM with r cointegrating vectors. The first step separates the permanent from the transitory shocks, and the second step isolates n?r mutually uncorrelated permanent shocks and r transitory shocks. The decomposition is computationally straightforward and entails only a minor modification to the Choleski decomposition commonly used in the literature. We then show how impulse response functions can be constructed to trace out the propagating mechanism of shocks distinguished by their degree of persistence. In an empirical example, the dynamic responses to the identified permanent shocks have properties similar to shocks to productivity, the real interest rate, and money growth, even though no economic theory was used to achieve the identification. We highlight two numerical issues that could affect any identification of permanent and transitory shocks.Publicad

Analyzing the Effects of Neutron Polarizabilities in Elastic Compton Scattering off 3{}^3He

Motivated by the fact that a polarized ${}^3$He nucleus behaves as an `effective' neutron target, we examine manifestations of neutron electromagnetic polarizabilities in elastic Compton scattering from the Helium-3 nucleus. We calculate both unpolarized and double-polarization observables using chiral perturbation theory to next-to-leading order (${\mathcal O}(e^2 Q)$) at energies, $\omega \leq m_{\pi}$, where $m_{\pi}$ is the pion mass. Our results show that the unpolarized differential cross section can be used to measure neutron electric and magnetic polarizabilities, while two double-polarization observables are sensitive to different linear combinations of the four neutron spin polarizabilities. [Note added in 2018] The qualitative conclusions and analytic formulae presented in this paper are correct, but several of the numerical results are wrong: see the erratum posted as arXiv:1804.01206 for further details. A full suite of corrected numerical results for cross sections and asymmetries can be found in Margaryan et al., arXiv:1804.00956. They can also be obtained as an interactive Mathematica notebook by emailing [email protected]: 40 pages, 16 figure