Islands contribute disproportionately high amounts of evolutionary diversity in passerine birds

Island systems generally have fewer species than continental areas due to their small size and geographical isolation. Low island diversity reduces the possibility of exportation of island lineages and island systems are not thought to have a major influence on the build-up of continental diversity. However, the view that islands represent the end of the colonization road has recently been challenged and islands do represent the origin of some specific continental lineages. Here we assess the net contribution of island systems to global diversity patterns of passerine birds, using a complete phylogeny (5,949 species), biogeographical regionalization and null-model comparisons. We show that, in contrast to major continental regions, island regions export relatively more evolutionary lineages than would be expected based on current distributional patterns. This result challenges a central paradigm in island biogeography and changes our perception of the relative importance of islands for the build-up of global diversity

Modelling and simulation on the tool wear in nanometric cutting

Tool wear is a significant factor affecting the machined surface quality. In this paper, a Molecular Dynamics (MD) simulation approach is proposed to model the wear of the diamond tool in nanometric cutting. It includes the effects of the cutting heat on the workpiece property. MD simulation is carried out to simulate the nanometric cutting of a single crystal silicon plate with the diamond tip of an Atomic Force Microscope (AFM). The wear mechanism is investigated by the calculation of the temperature, the stress in the diamond tip, and the analysis of the relationship between the temperature and sublimation energy of the diamond atoms and silicon atoms. Microstrength is used to characterize the wear resistance of the diamond tool. The machining trials on an AFM are performed to validate the results of the MD simulation. The results of MD simulation and AFM experiments all show that the thermo-chemical wear is the basic wear mechanism of the diamond cutting tool

Risk Aversion and Incentive Effects

A menu of paired lottery choices is structured so that the crossover point to the high-risk lottery can be used to infer the degree of risk aversion. With "normal" laboratory payoffs of several dollars, most subjects are risk averse and few are risk loving. Scaling up all payoffs by factors of twenty, fifty, and ninety makes little difference when the high payoffs are hypothetical. In contrast, subjects become sharply more risk averse when the high payoffs are actually paid in cash. A hybrid "power/expo" utility function with increasing relative and decreasing absolute risk aversion nicely replicates the data patterns over this range of payoffs from several dollars to several hundred dollars

An experimental study of costly coordination

This paper reports data for coordination game experiments with random matching. The experimental design is based on changes in an effort-cost parameter, which do not alter the set of Nash equilibria nor do they alter the predictions of adjustment theories based on imitation or best response dynamics. As expected, however, increasing the effort cost lowers effort levels. Maximization of a stochastic potential function, a concept that generalizes risk dominance to continuous games, predicts this reduction in efforts. An error parameter estimated from initial two-person, minimum-effort games is used to predict behavior in other three-person coordination games

An explanation of anomalous behavior in models of political participation

This paper characterizes behavior with “noisy” decision making for models of political interaction characterized by simultaneous binary decisions. Applications include: voting participation games, candidate entry, the volunteer's dilemma, and collective action problems with a contribution threshold. A simple graphical device is used to derive comparative statics and other theoretical properties of a “quantal response” equilibrium, and the resulting predictions are compared with Nash equilibria that arise in the limiting case of no noise. Many anomalous data patterns in laboratory experiments based on these games can be explained in this manner

An Explanation of Anomalous Behavior in Binary-Choice Games: Entry, Voting, Public Goods, and the Volunteers' Dilemma

This paper characterizes behavior with "noisy" decision making for a general class of N-person, binary-choice games. Applications include: participation games, voting, market entry, binary step-level public goods games, the volunteer's dilemma, the El Farol problem, etc. A simple graphical device is used to derive comparative statics and other theoretical properties of a "quantal response" equilibrium, and the resulting predictions are compared with Nash equilibria that arise in the limiting case of no noise. Many anomalous data patterns in laboratory experiments based on these games can be explained in this manner.participation games, entry, voting, step-level public goods games, volunteers' dilemma, quantal response equilibrium, El Farol problem, bounded rationality.

An investigation on the mechanics of nanometric cutting and the development of its test-bed

The mechanics of machining at a very small depth of cut (100 nm or less) is not well understood. The chip formation physics, cutting forces generation, resulting temperatures and the size effects significantly affect the efficiency of the process and the surface quality of the workpiece. In this paper, the cutting mechanics at nanometric scale are investigated in comparison with conventional cutting principles. Molecular Dynamics (MD) is used to model and simulate the nanometric cutting processes. The models and simulated results are evaluated and validated by the cutting trials on an atomic force microscope (AFM). Furthermore, the conceptual design of a bench-type ultraprecision machine tool is presented and the machine aims to be a facility for nanometric cutting of threedimensional MEMS devices. The paper concludes with a discussion on the potential and applications of nanometric cutting techniques/equipment for the predictabilty, producibility and productivity of manufacturing at the nanoscale

Ten Little Treasures of Game Theory and Ten Intuitive Contradictions

This paper reports laboratory data for a series of two-person games that are played only once. These games span the standard categories: static and dynamic games with complete and incomplete information. For each game, the treasure is a treatment for which behavior conforms quite nicely to the predictions of the Nash equilibrium or relevant refinement. In each case we change a key payoff parameter in a manner that does not alter the equilibrium predictions, but this theoretically neutral payoff change has a major (often dramatic) effect on observed behavior. These contradictions are generally consistent with simple economic intuition and with a model of iterated noisy introspection for one-shot games.Nash equilibrium, noncooperative games, experiments, bounded rationality, introspection

Asymmetric Inequality Aversion and Noisy Behavior in Alternating-Offer Bargaining Games

In two-stage bargaining games with alternating offers, the amount of the pie that remains after a rejection is what the first player should offer to the second player, since the second player can capture this remainder in the final (ultimatum) stage. Fairness considerations will reduce the correlation between first-stage offers and the size of the remaining pie, but randomness in behavior will have the same "flattening" effect. This paper reports an experiment designed to separate these considerations, by introducing asymmetric fixed money payments to each player. These endowments do not affect the perfect positive correlation between initial Nash offers and the remaining pie, but are selected to induce a perfectly negative relationship between the remaining pie size and the first-stage offer that would equalize final earnings of the two players. This negative relationship is apparent in the data, which suggests the importance of fairness considerations. A theoretical model of asymmetric inequality aversion and stochastic choice is used to provide maximum likelihood estimates of utility and logit error parameters. The parameters representing "envy," "guilt," and logit errors are all significant, and the resulting model produces the observed negative relationship between initial offers and residual pie size.bargaining, ultimatum game, bounded rationality, logit equilibrium, fairness, equity aversion, endowment effects, envy, guilt

The Almost Ideal and Translog Demand Systems

This chapter reviews the specification and application of the Deaton and Muellbauer (1980) Almost Ideal Demand System (AIDS) and the Christensen, Jorgensen, and Lau (1975) tranlog (TL) demand system. In so doing we examine various refinements to these models, including ways of incorporating demographic effects, methods by which curvature conditions can be imposed, and issues associated with incorporating structural change and seasonal effects. We also review methods for adjusting for autocorrelation in the model's residuals. A set of empirical examples for the AIDS and a the log TL version of the translog based on historical meat price and consumption data for the United States are also presented.Almost ideal demand system, Autocorrelation, Curvature, Meat Demand, Translog