20,476 research outputs found
On the Numerical Solution of the Time-Dependent Schroedinger Equation
An algorithm for the numerical solution of the Schr\"odinger equation in the
case of a time dependent potential is proposed. Our simple modification
upgrades the well known method of Koonin while negligibly increasing the
computing time. In the presented test the accuracy is enhanced by up to an
order of magnitude.Comment: 4 pages, Revtex, Published in J. Comp. Physics 119, (1995) p. 206-20
Selfishness Level of Strategic Games
We introduce a new measure of the discrepancy in strategic games between the
social welfare in a Nash equilibrium and in a social optimum, that we call
selfishness level. It is the smallest fraction of the social welfare that needs
to be offered to each player to achieve that a social optimum is realized in a
pure Nash equilibrium. The selfishness level is unrelated to the price of
stability and the price of anarchy and is invariant under positive linear
transformations of the payoff functions. Also, it naturally applies to other
solution concepts and other forms of games.
We study the selfishness level of several well-known strategic games. This
allows us to quantify the implicit tension within a game between players'
individual interests and the impact of their decisions on the society as a
whole. Our analyses reveal that the selfishness level often provides a deeper
understanding of the characteristics of the underlying game that influence the
players' willingness to cooperate.
In particular, the selfishness level of finite ordinal potential games is
finite, while that of weakly acyclic games can be infinite. We derive explicit
bounds on the selfishness level of fair cost sharing games and linear
congestion games, which depend on specific parameters of the underlying game
but are independent of the number of players. Further, we show that the
selfishness level of the -players Prisoner's Dilemma is ,
where and are the benefit and cost for cooperation, respectively, that
of the -players public goods game is , where is
the public good multiplier, and that of the Traveler's Dilemma game is
, where is the bonus. Finally, the selfishness level of
Cournot competition (an example of an infinite ordinal potential game, Tragedy
of the Commons, and Bertrand competition is infinite.Comment: 34 page
The Skyrme Model piNN Form Factor and the Sea Quark Distribution of the Nucleon
We calculate the sea quark distribution of the nucleon in a meson cloud
model. The novel feature of our calculation is the implementation of a special
piNN form factor recently obtained by Holzwarth and Machleidt. This form factor
is hard for small and soft for large momentum transfers. We show that this
feature leads to a substantial improvement.Comment: 9 pages, 5 figures; v2: some typos corrected, including eq. (9
A new Australian species of Luffa (Cucurbitaceae) and typification of two Australian Cucumis names, all based on specimens collected by Ferdinand Mueller in 1856
As a result of his botanical explorations in northern Australia, Ferdinand von Mueller named several Cucurbitaceae that molecular data now show to be distinct, requiring their resurrection from unjustified synonymy. We here describe and illustrate Luffa saccata F. Muell. ex I.Telford, validating a manuscript name listed under L. graveolens Roxb. since 1859, and we lectotypify Cucumis picrocarpus F. Muell. and C. jucundus F. Muell. The lectotype of the name C. jucundus, a synonym of C. melo, is mounted on the same sheet as the lectotype of C. picrocarpus, which is the sister species of the cultivated C. melo as shown in a recent publication
Simple circuit performs binary addition and subtraction
Ripple adder reduces the number of logic circuits required to preform binary addition and subtraction. The adder uses dual input and delayed output flip-flops in one register. The contents of this register are summed with those of a standard register through conventional AND/gates
Ripple add and ripple subtract binary counters Patent
Logic circuit to ripple add and subtract binary counters for spaceborne computer
Application of PN and avalanche silicon photodiodes to low-level optical
New approaches to the discovery of other planetary systems require very sensitive and stable detection techniques in order to succeed. Two methods in particular, the astrometric and the photometric methods, require this. To begin understanding the problems and limitations of solid state detectors regarding this application, preliminary experiments were performed at the National Bureau of Standards and a low light level detector characterization facility was built. This facility is briefly described, and the results of tests conducted in it are outlined. A breadboard photometer that was used to obtain stellar brightness ratio precision data is described. The design principles of PN and avalanche silicon photodiodes based on low light level measuring circuits are discussed
- …