25,570 research outputs found
Soil penetrometer
An auger-type soil penetrometer for burrowing into soil formations is described. The auger, while initially moving along a predetermined path, may deviate from the path when encountering an obstruction in the soil. Alterations and modifications may be made in the structure so that it may be used for other purposes
Burrowing apparatus
A soil burrowing mole is described in which a housing has an auger blade wound around a front portion. This portion is rotatable about a housing longitudinal axis relative to an externally finned housing rear portion upon operation of driving means to cause an advance through soil and the like. The housing carries a sensor sensitive to deviation from a predetermined path and to which is coupled means for steering the housing to maintain the path
Spaceborne VHSIC multiprocessor system for AI applications
A multiprocessor system, under design for space-station applications, makes use of the latest generation symbolic processor and packaging technology. The result will be a compact, space-qualified system two to three orders of magnitude more powerful than present-day symbolic processing systems
Fluctuations and correlations in population models with age structure
We study the population profile in a simple discrete time model of population
dynamics. Our model, which is closely related to certain ``bit-string'' models
of evolution, incorporates competition for resources via a population dependent
death probability, as well as a variable reproduction probability for each
individual as a function of age. We first solve for the steady-state of the
model in mean field theory, before developing analytic techniques to compute
Gaussian fluctuation corrections around the mean field fixed point. Our
computations are found to be in good agreement with Monte-Carlo simulations.
Finally we discuss how similar methods may be applied to fluctuations in
continuous time population models.Comment: 4 page
Separatrix Reconnections in Chaotic Regimes
In this paper we extend the concept of separatrix reconnection into chaotic
regimes. We show that even under chaotic conditions one can still understand
abrupt jumps of diffusive-like processes in the relevant phase-space in terms
of relatively smooth realignments of stable and unstable manifolds of unstable
fixed points.Comment: 4 pages, 5 figures, submitted do Phys. Rev. E (1998
A study of preferences from nineteen selections in current children's literature.
Thesis (Ed.M.)--Boston Universit
The Place of History in Modern Education
The following is• an abstract of an address delivered by. Prof. Howard at the opening of the winter term of the Nebraska University, at the time the Nebraska State Historical Society was in session, and by agreement before a joint session of the two organizations, to serve also as the annual address of the Historical Society
The Place of History in Modern Education
The following is• an abstract of an address delivered by. Prof. Howard at the opening of the winter term of the Nebraska University, at the time the Nebraska State Historical Society was in session, and by agreement before a joint session of the two organizations, to serve also as the annual address of the Historical Society
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