Prolific Compositions

Under what circumstances might every extension of a combinatorial structure contain more copies of another one than the original did? This property, which we call prolificity, holds universally in some cases (e.g., finite linear orders) and only trivially in others (e.g., permutations). Integer compositions, or equivalently layered permutations, provide a middle ground. In that setting, there are prolific compositions for a given pattern if and only if that pattern begins and ends with 1. For each pattern, there is an easily constructed automaton that recognises prolific compositions for that pattern. Some instances where there is a unique minimal prolific composition for a pattern are classified

Glorified Fantasies and Masterpieces of Deception on Importing L as V egas into the ‘New S outh A frica’

With the end of apartheid, J ohannesburg and other S outh A frican cities are now part of a new global race to become ‘world‐class’ tourist and business centers. At the center of this development is the importation of V egas‐style spectacle by local entrepreneurs, firms and other city boosters who create fantasyscapes such as the E mperor's P alace and G rand W est. Financed and run by S outh A frican impresarios — whose luxurious empires transcend the continent — these resorts represent not only the globalization of gaming but the way in which S outh A frican cities see themselves within the worldwide urban hierarchy. As such, this article seeks to untangle the global and local aspects of importing fantasy into the ‘new S outh A frica’.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106859/1/ijur12006.pd

Water content of the Martian soil: Laboratory simulations of reflectance spectra

Reflectance spectra from the surface of Mars collected by instruments such as the imaging spectrometer (ISM) onboard the 1988 Soviet Phobos 2 spacecraft exhibit strong 3 μm absorption features that have long been attributed to hydrated materials on the Martian surface. This interpretation is consistent with a series of chemical weathering models suggesting an abundance of palagonites, clays, and other hydrated mineral phases in the Martian fines. Little work, however, has been done to constrain the actual water content of the Martian surface materials. New laboratory data presented here show that the ISM spectra are consistent with up to 4% water by weight and that the deep hydration features observed in the spacecraft data could be due to less than 0.5% water if the hydrated phases are present in the form of grain coatings. These results are consistent with the somewhat uncertain in situ measurements obtained by the Viking landers which yielded approximately 2 wt % water from samples heated to 500°C. On the basis of this work, we expect the TEGA instrument on the Mars '98 lander to find less than 4% adsorbed or bound water in the upper few centimeters of the Martian soil

Immunization Dynamics on a 2-layer Network Model

We introduce a 2-layer network model for the study of the immunization dynamics in epidemics. Spreading of an epidemic is modeled as an excitatory process in a small-world network (body layer) while immunization by prevention for the disease as a dynamic process in a scale-free network (head layer). It is shown that prevention indeed turns periodic rages of an epidemic into small fluctuation. The study also reveals that, in a certain situation, prevention actually plays an adverse role and helps the disease survive. We argue that the presence of two different characteristic time scales contributes to the immunization dynamics observed.Comment: 5 pages, 7 figure

A Short Description of the JNS Control Program

Control Systems Laboratory changed its name to Coordinated Science LaboratoryContract DA-36-039-SC-5669

Evaluation of the Icon I (JNS) Control Program

Control Systems Laboratory changed its name to Coordinated Science LaboratoryContract DA-36-039-SC-5669