We give a general derivation of the gravitational hamiltonian starting from the Einstein-Hilbert action, keeping track of all surface terms. The surface term that arises in the hamiltonian can be taken as the definition of the ‘total energy’, even for spacetimes that are not asymptotically flat. (In the asymptotically flat case, it agrees with the usual ADM energy.) We also discuss the relation...

In 2001, S. Bulman-Fleming et al. initiated the study of three flatness properties (weakly kernel flat, principally weakly kernel flat, translation kernel flat) of right acts $A_{S}$ over a monoid $S$ that can be described by means of when the functor $A_{S} otimes -$ preserves pullbacks. In this paper, we extend these results to $S$-posets and present equivalent descriptions of weakly kernel p...

objectives: the aim of this study was to determine the prevalence of flat foot in a population of 7-12 year old students and to investigate the relationship between flat foot and age and sex. methods: in this cross-sectional study, a total of 945 students (460 girls and 485 boys) were examined. the presence of flatfoot and the degree of its severity according to tachdjian's system of gradi...

We report on a microsimulation model under development whose purpose it is to construct scenarios for the assessment of a novel wastewater management technology: the separate collection, transport, and handling of human urine. Levelling the urine flow to the treatment plant or removing it from conventional treatment altogether has many benefits for wastewater management. For an effective techno...

The broad goals of this project are to develop new techniques of human interaction with stereo displays, particularly autostereoscopic (AS) displays. Autostereoscopic displays produce a 3D visual sensation to one or more observers without the use of glasses, goggles, helmets, or headtracking. We are developing new techniques for interactive input and manipulation of threedimensional data using ...

In this study the acoustic and articulatory variabilities of speakers with different palate shapes were compared. Since the cross-sectional area of the vocal tract changes less for a slight change in tongue position if the palate is domeshaped than if it is flat, the acoustic variability should be greater for flat palates than for domeshaped ones. Consequently, it can be hypothesized that speak...

Permanent monitoring sites in Flat Top Hill Conservation Area in Central Otago were resurveyed in the spring of 1997, following a four-year interval in which rabbit numbers had been very low, and stock absent. All study sites showed considerable vegetation change between 1993 and 1997. The most significant changes in the vegetation were large increases in overall vascular species richness and d...

We present a conjecture, based on computational results, on the area minimizing way to enclose and separate two arbitrary volumes in the flat cubic three-torus T 3. For comparable small volumes, we prove that an area minimizing double bubble in T 3 is the standard double bubble from R 3 .

The classical isoperimetric inequality states that the surface of smallest area enclosing a given volume in R3 is a sphere. We show that the least area surface enclosing two equal volumes is a double bubble, a surface made of two pieces of round spheres separated by a flat disk, meeting along a single circle at an angle of 2π/3.