The Attack-and-Defense Group Contests: Best-shot versus Weakest-link

This study analyzes a group contest in which one group (defenders) follows a weakest-link whereas the other group (attackers) follows a best-shot impact function. We fully characterize the Nash and coalition-proof equilibria and show that with symmetric valuation the coalition-proof equilibrium is unique up to the permutation of the identity of the active player in the attacker group. With asymmetric valuation it is always an equilibrium for one of the highest valuation players to be active; it may also be the case that the highest valuation players in the attacker group free-ride completely on a group-member with a lower valuation. However, in any equilibrium, only one player in the attacker group is active, whereas all the players in the defender group are active and exert the same effort. We also characterize the Nash and coalition-proof equilibria for the case in which one group follows either a best-shot or a weakest-link but the other group follows an additive impact function

Troposphere-stratosphere (surface-55 km) monthly general circulation statistics for the Northern Hemisphere-four year averages

This report presents four year averages of monthly mean Northern Hemisphere general circulation statistics for the period from 1 December 1978 through 30 November 1982. Computations start with daily maps of temperature for 18 pressure levels between 1000 and 0.4 mb that were supplied by NOAA/NMC. Geopotential height and geostrophic wind are constructed using the hydrostatic and geostrophic formulae. Fields presented in this report are zonally averaged temperature, mean zonal wind, and amplitude and phase of the planetary waves in geopotential height with zonal wavenumbers 1-3. The northward fluxes of heat and eastward momentum by the standing and transient eddies along with their wavenumber decomposition and Eliassen-Palm flux propagation vectors and divergences by the standing and transient eddies along with their wavenumber decomposition are also given. Large annual and interannual variations are found in each quantity especially in the stratosphere in accordance with the changes in the planetary wave activity. The results are shown both in graphic and tabular form

Devil's Staircase and Disordering Transitions in Sliding Vortices and Wigner Crystals on Random Substrates with Transverse Driving

Using numerical simulations we show that, in the presence of random quenched disorder, sliding superconducting vortices and Wigner crystals pass through a variety of dynamical phases when an additional transverse driving force is applied. If the disorder is weak, the driven particles form a moving lattice and the transverse response shows a devil's staircase structure as the net driving force vector locks with the symmetry directions of the moving lattice, in agreement with the predictions of Le Doussal and Giamarchi. For strong disorder, and particularly for smoothly varying potential landscapes, the transverse response consists of a sequence of disordering transitions with an intervening formation of stable channel structures.Comment: 7 pages, 6 postscript figures. Version to appear in Phys. Rev.

Remote sensing of changes in morphology and physiology of trees under stress

Measurements on foliage samples collected from several drought and salt treated plants revealed that leaf thickness decreased with increasing severity of the drought treatment and increased with increasing severity of treatment with NaCl, but remained essentially unaffected by treatment with CaCl2. Airborne data collected by multispectral scanner indicated that false color images provide selective enhancement of a diseased area. Comparison of simulated and actual aerial color and color IR photography revealed that the color renditions of the MSS simulations agreed closely with those of the actual photography

Remote sensing applications in forestry - Remote sensing of changes in morphology and physiology of trees under stress Annual progress report

Remote sensing of changes in morphology and physiology of trees under stres

Temperature dependence of the superconducting gap anisotropy in Bi2_{2}Sr2_{2}Ca1_{1}Cu2_{2}O8+x_{8+x}

We present the first detailed data of the momentum-resolved, temperature dependence of the superconducting gap of $Bi_{2}Sr_{2}Ca_{1}Cu_{2}O_{8+x}$, complemented by similar data on the intensity of the photoemission superconducting condensate spectral area. The gap anisotropy between the $\Gamma-\bar{M}$ and $\Gamma-X$ directions increases markedly with increasing temperature, contrary to what happens for conventional anisotropic-gap superconductors such as lead. Specifically, the size of the superconducting gap along the $\Gamma-X$ direction decreases to values indistinguishable from zero at temperatures for which the gap retains virtually full value along the $\Gamma-\bar{M}$ direction.Comment: APS_REVTEX. 19 pages, including 8 figures, available upon request. UW-Madison preprin

How Fine should Grain be Ground for Milk Cows?

IntroductionThe ground beef bin on the Jones farm was empty. Mr. Jones pulled the switch and soon the little mill was humming a song that scarcely changed a note as the first few shovels of grain disappeared down its mouth. Mr. Jones noted that the grain was scarcely more than cracked. He readjusted the mill to grind it finer, and soon it was spewing out an entirely different product. Did Mr. Jones make a mistake when he readjusted his mill to grind the feed finer for his dairy cows?Results of an experiment conducted at the South Dakota Agricultural Experiment Station would indicate that Jones did make a mistake by grinding the grain fine – one that is common in the dairy industry. These are a few results of the experiment:1. It made little difference in the case of milk cows whether grain was ground coarse or fine in relation to the food value obtained by the cow from the entire ration. Feeds need only to be cracked sufficiently to expose the kernel interiors to digestive juices.2. More benefit was derived from grinding corn than from grinding oats. A total of 110 pounds of alfalfa hay and whole corn ration was required to equal 100 pounds of an alfalfa hay and medium-ground corn ration in food value. For whole oats the comparison was 102 pounds to 100 pounds.3. After subtracting the food value of the alfalfa hay, it was found 119 pounds of whole corn were required to equal 100 pounds of medium ground corn in food value, and 105 pounds of whole oats were required to equal 100 pounds of medium ground oats. These figures may be used when combining these grains with o�her roughages in a ration. Little difference was noted in the food value of either grain when ground medium or fine.4. Greater benefits were derived from grinding corn largely because greater amounts pass through the animal undigested when whole corn is fed. Nearly one-fifth (19.9 percent) of the whole corn fed was recovered from the feces (solid manure). For whole oats, recoveries in the feces ranged from 10.8 to 14.8 percent.5. Ground grain rations were much more palatable than whole grain, and were more convenient for mixing with other ingredients in the ration.Futhermore, it is generally understood that it costs more in time and money for fine grinding than for medium coarse grinding. The power cost is greater chiefly because of the greater length of time that the power must be used in grinding fine as compared with coarse. Calculations made from figures obtained from the South Dakota, Indiana and Ohio Stations indicate that it would take about 2 or 2Yz times as much power to grind the finely ground grain as for the medium coarse as used in this experiment. For instance, Indiana reported that it took 0.21 kilowatt hours (K.W.H. electrical power) for coarse grinding of 100 pounds of corn and oats and 0.57 kilowatt hours for fine grinding. If one were paying for electrical power from a highline the cost would be directly proportional to the kilowatt hours used. Essentially the same relationships would exist if tractors or gas engines were used as a source of power

Coherent and Incoherent Vortex Flow States in Crossed Channels

We examine vortex flow states in periodic square pinning arrays with one row and one column of pinning sites removed to create an easy flow crossed channel geometry. When a drive is simultaneously applied along both major symmetry axes of the pinning array such that vortices move in both channels, a series of coherent flow states develop in the channel intersection at rational ratios of the drive components in each symmetry direction when the vortices can cross the intersection without local collisions. The coherent flow states are correlated with a series of anomalies in the velocity force curves, and in some cases can produce negative differential conductivity. The same general behavior could also be realized in other systems including colloids, particle traffic in microfluidic devices, or Wigner crystals in crossed one-dimensional channels.Comment: 5 pages, 4 postscript figure

Localized electronic states and photoemission superconducting condensate in Bi2_{2}Sr2_{2}Ca1_{1}Cu2_{2}O8+x_{8+x}

We present the first detailed angle-resolved photoemission evidence that there are two types of carriers that contribute to the photoemission superconducting condensate in $Bi_{2}Sr_{2}Ca_{1}Cu_{2}O_{8+x}$. Our data indicate that both itinerant and somewhat localized normal state carriers can contribute to the formation of Cooper pairs.Comment: APS_Revtex, 11 pages, including 3 figures, available upon request. UW-Madison preprint#