4,674 research outputs found
Computational Economics: Help for the Underestimated Undergraduate
Our concern in this paper is that the capability of economics undergraduates is substantially underestimated in the design of the present college curriculum and that our students are insufficiently challenged and motivated. Students enter our classrooms with substantial previous knowledge about computers and computation and we are not taking full advantage of this opportunity. We suggest a set of examples from computational economics which are challenging enough to motivate students and simple enough that they can master them within a few hours. By encouraging the students to modify the models in directions of their own interest avenues for creative endeavor are opened which deeply involve the students in their own education.teaching computational economics
New polyimide polymer has excellent processing characterisitcs with improved thermo-oxidative and hydrolytic stabilities
Polyimide P10P and its processing technique apply to most high temperature plastic products, devices and castings. Prepolymer, when used as varnish, impregnates fibers directly and is able to be processed into advanced composities. Material may also be used as molding powder and adhesive
The Feasibility of a Zone of Peace
Starting in 1964 there has been a movement to declare the Indian Ocean a Zone of Peace. In an age when many in the world feel threatened by the potential of nuclear holocaust this is not striking in and of itself. What the Zone of Peace proposal provides is more valuable than the actual resolution. Empirically, it is obvious that nuclear free zones and peace zones have little validity. Historically, the weak have been vanquished by the powerful; their proclaimed neutrality notwithstanding. Consequently, a study of the peace movement in the Indian ocean may be utilized to investigate why proclamations which attempt to restrict military involvement in a given region are unworkable. A study of the peace movement in the region rapidly moves toward discussion of the military posture of the United States and the Soviet Union. Many littoral states argue that a removal of superpower forces would inevitably result in regional concord. This, as we shall see, is unlikely. this remote ocean is actually an area of high intrigue and endemic political maneuver. This paper will focus on the presence of the superpowers in the region, as well as that of China. Other western states with an interest will also be considered. The prospects for peace amongst the littoral states (should the superpowers abandon the Indian ocean), will also be examined. lastly, some analysis will be provided which will identify major problems with attempts to proclaim any area of the world as a zone of peace
Expected optimal feedback with Time-Varying Parameters
In this paper we derive, by using dynamic programming, the closed loop form of the Expected Optimal Feedback rule with time varying parameter. As such this paper extends the work of Kendrick (1981, 2002, Chapter 6) for the time varying parameter case. Furthermore, we show that the Beck and Wieland (2002) model can be cast into this framework and can be treated as a special case of this solution.
Expected optimal feedback with Time-Varying Parameters
In this paper we derive the closed loop form of the Expected Optimal Feedback rule, sometimes called passive learning stochastic control, with time varying parameters. As such this paper extends the work of Kendrick (1981,2002, Chapter 6) where parameters are assumed to vary randomly around a known constant mean. Furthermore, we show that the cautionary myopic rule in Beck and Wieland (2002) model, a test bed for comparing various stochastic optimizations approaches, can be cast into this framework and can be treated as a special case of this solution.Optimal experimentation, stochastic optimization, time-varying parameters, expected optimal feedback
Formation of molecular oxygen in ultracold O + OH reaction
We discuss the formation of molecular oxygen in ultracold collisions between
hydroxyl radicals and atomic oxygen. A time-independent quantum formalism based
on hyperspherical coordinates is employed for the calculations. Elastic,
inelastic and reactive cross sections as well as the vibrational and rotational
populations of the product O2 molecules are reported. A J-shifting
approximation is used to compute the rate coefficients. At temperatures T = 10
- 100 mK for which the OH molecules have been cooled and trapped
experimentally, the elastic and reactive rate coefficients are of comparable
magnitude, while at colder temperatures, T < 1 mK, the formation of molecular
oxygen becomes the dominant pathway. The validity of a classical capture model
to describe cold collisions of OH and O is also discussed. While very good
agreement is found between classical and quantum results at T=0.3 K, at higher
temperatures, the quantum calculations predict a larger rate coefficient than
the classical model, in agreement with experimental data for the O + OH
reaction. The zero-temperature limiting value of the rate coefficient is
predicted to be about 6.10^{-12} cm^3 molecule^{-1} s^{-1}, a value comparable
to that of barrierless alkali-metal atom - dimer systems and about a factor of
five larger than that of the tunneling dominated F + H2 reaction.Comment: 9 pages, 8 figure
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