Experience is the best teacher. Yet, in the context of repeated decisions, experience was found to trigger deviations from maximization in the direction of underweighting of rare events. Evaluations of alternative explanations for this bias led to contradicting conclusions. Studies that focused on the aggregate choice rates, including a series of choice prediction competitions, favored the assumption that this bias reflects reliance on small samples. In contrast, studies that focused on individual decisions suggest that the bias reflects a strong myopic tendency by a significant minority of participants. The current analysis clarifies the apparent inconsistency by reanalyzing a data set that previously led to contradicting conclusions. Our analysis suggests that the apparent inconsistency reflects the differing focus of the cognitive models. Specifically, sequential adjustment models (that assume sensitivity to the payoffs’ weighted averages) tend to find support for the hypothesis that the deviations from maximization are a product of strong positive recency (a form of myopia). Conversely, models assuming random sampling of past experiences tend to find support to the hypothesis that the deviations reflect reliance on small samples. We propose that the debate should be resolved by using the assumptions that provide better predictions. Applying this solution to the data set we analyzed shows that the random sampling assumption outperforms the weighted average assumption both when predicting the aggregate choice rates and when predicting the individual decisions.

The principle of loss aversion is thought to explain a wide range of anomalousphenomena involving tradeoffs between losses and gains. In this article, I showthat the anomalies loss aversion was introduced to explain - the risky betpremium, the endowment effect, and the status-quo bias - are characterized notonly by a loss/gain tradeoff, but by a tradeoff between the status-quo andchange; and, that a propensity towards the status-quo in the latter tradeoff issufficient to explain these phenomena. Moreover, I show that two basicpsychological principles - (1) that motives drive behavior; and (2) thatpreferences tend to be fuzzy and ill-defined - imply the existence of a robustand fundamental propensity of this sort. Thus, a loss aversion principle isrendered superfluous to an account of the phenomena it was introduced toexplain.

This paper presents a numerical study about lubricant inertia effect onthermohydrodynamic (THD) characteristics of Rayleigh step bearings running under steady,incompressible and laminar condition. To reach this goal, the set of governing equationsis solved numerically with and without considering the inertia terms. The discretizedforms of the momentum and energy equations are obtained by the finite volume method andsolved using the Computational Fluid Dynamic (CFD) technique. These equations are solvedsimultaneously because the dependency of lubricant viscosity with temperature. Thehydrodynamic and thermal behaviors of the slider step bearings are demonstrated bypresenting several figures including the lubricant pressure and temperature distributionswith and without considering the fluid inertia effect. Numerical results show that inertiaterm has considerable effect on THD characteristics of step bearings, especially when theyrun with high velocity of runner surface.

A simple model for a randomly oscillating variable is suggested, which is a variant of the two-state random velocity model. As in the latter model, the variable keeps rising or falling with constant velocity for some time before randomly reversing its direction. In contrast however, its propensity to reverse depends on its current value and it is for this desirable feature that the model is proposed here. This feature has two implications: (a) neither the changing variable nor its velocity is Markovian, although the joint process is, and (b) the linear differential equations arising in the case of our model do not have constant coefficients. The results given in this paper are meant to illustrate the straightforward nature of some of the calculations involved and to highlight the relationship with one-dimensional diffusions.

Let $A$ and $B$ be $n\,\times \,n$ complex Hermitian (or real symmetric) matrices with eigenvalues ${{a}_{1}}\,\ge \,\cdots \,\ge \,{{a}_{n}}$ and ${{b}_{1}}\,\ge \,\cdots \,\ge \,{{b}_{n}}$. All possible inertia values, ranks, and multiple eigenvalues of $A\,+\,B$ are determined. Extension of the results to the sum of $k$ matrices with $k\,>\,2$ and connections of the results to other subjects such as algebraic combinatorics are also discussed.

We suggest a diversity-dependent strategy, based on Principle Component Analysis, for selecting distinct accessions/parents for breeding from a soybean germplasm collection comprising of 463 lines, characterized and evaluated for 10 qualitative and eight quantitative traits. A sample size of six accessions included all the three states, namely low, medium and high of the individual quantitative traits, while a sample of 16–19 accessions included all the 60–64 distinct states of qualitative as well as quantitative traits. Under certain assumptions, the paper also develops an expression for estimating the size of a target population for capturing maximum variability in a sample three accessions.

Dans le cadre d'une expérience sur la migration de bulles dans un écoulement de Couette cylindrique, un bilan dynamique sur ces bulles a été formulé. Deux cas ont été traités. Le premier pour des écoulements en condition de gravité terrestre, à nombre de Reynolds de bulle important. Le second dans des conditions de microgravité avec des nombres de Reynolds de bulle inférieurs à l'unité. Le premier régime est fortement inertiel et permet la détermination des coefficients de portance et de traînée s'appliquant dans le bilan dynamique. Le second régime est essentiellement visqueux. Utilisant les développements récents établis dans ce domaine, le bilan de forces prend en compte les effets de paroi et de courbure qui peuvent intervenir. En effet, outre la correction de Fàxen, les effets inertiels et de déformation, de même ordre, sont conjointement pris en compte dans la migration des inclusions. Les particules se trouvant dans ce cas dans une zone intermédiaire entre la très proche paroi et l'écoulement sans frontière, les coefficients des forces inertielles de migration ont été approchés à partir des résultats existants pour des sphères solides.