The first static spherically symmetric perfect fluid solution with constant density was found by Schwarzschild in 1918. Generically, perfect fluid spheres are interesting because they are first approximations to any attempt at building a realistic model for a general relativistic star. Over the past 90 years a confusing tangle of specific perfect fluid spheres has been discovered, with most of ...

Ever since Karl Schwarzschild’s 1916 discovery of the spacetime geometry describing the interior of a particular idealized general relativistic star — a static spherically symmetric blob of fluid with position-independent density — the general relativity community has continued to devote considerable time and energy to understanding the general-relativistic static perfect fluid sphere. Over the...

An (s; n; q; t)-perfect hash family is a set of functions 1 ; 2 ; : : :; s from a set V of cardinality n to a set F of cardinality q with the property that every t-subset of V is injectively mapped into F by at least one of the functions i. The paper shows that the maximum value n s;t (q) that n can take for xed s and t has a leading term that is linear in q if and only if t > s. Moreover, for ...

In the summer of 1965, my paleontological colleague, Bryan Patterson, was in charge of a Harvard expedition working near the shore of Lake Turkana in northern Kenya. At a locality called Kanapoi, while he was searching in deposits believed to be of the early Pleistocene the last geological epoch before the present, he picked up an important fossil. The broken lower end of a left humerus the upp...

The article deals with several issues related to the concept of happiness that emerge from Plato’s triptych: Gorgias, Republic and Laws. focus is on (1) question alleged overcoming eudaimonistic imperative, i.e., natural human pursuit happiness, in didactic message Republic; (2) what extent path cognition ending contemplation perfect being at same time a strive for supreme happiness; (3) dilemm...

in his 1853 chapter " The nature of Gothic, " John ruskin famously aligns different visual styles with different ethical connotations. The crude, unpolished style of Gothic ornament symbolizes a free and autonomous art production, while the perfect symmetry of modern english ornaments signifies the arduous, mechanical labor typical of the victorian factory. While ruskin's essay has stood as the...

To date, automatic handwriting text recognition systems are far from being perfect and heavy human intervention is often required to check and correct the results of such systems. As an alternative, an interactive framework that integrates the human knowledge into the transcription process has been presented in previous works. In this work, multimodal interaction at character-level is studied. ...