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81.
Region representation as a quadtree data structure is a rich field in computer science with many different approaches. Forests of quadtrees offer space savings over regular quadtrees by concentrating the vital information [4, 5, 6]. They scavenge unused and unneeded space (i.e., node containing no information). This paper investigates several properties of forests of quadtrees which can be used to design manipulation algorithms for forest-quadtree data structure. In addition, the paper discusses the space saving and shows how the basic operations that can be performed on a quadtree can also be done on the more space efficient representation (a forest of quadtrees). 相似文献
82.
Discovery of the neutron in 1932 by Chadwick ushered in a new era of scientific research and technology. The neutron is endowed
with unique properties in its mass, life time, spin and magnetic moment etc and every important property has been used in
the study of condensed matter, biological molecules, nuclear forces, stellar objects and other fields. Neutron has a wide
range of applications in power production, breeding of fissile fuel, radiography, medicine and others. 相似文献
83.
The motion of a rigid plastic cantilever beam which is surrounded by a damping medium and struck transversely at the tip by a moving mass is studied. The elementary theory, which disregards effects due to rate of straining and geometry changes is used. The governing equations of motion are integrated numerically. For comparison the case of discrete damping provided at the tip only is also solved. Results are presented for a wide range of parameters. 相似文献
84.
Reduction of dehydronerolidol with lithium aluminum hydride in the presence of sodium methoxide gave, in addition to the expected nerolidol, geranyl acetone. Labeling experiments established that the C-1 methyl of geranyl acetone is derived from one of the carbons of the acetylene. 相似文献
85.
P. G. Oza H. S. Mazumdar A. K. Choudhary K. Gopalan 《Journal of Chemical Sciences》1984,93(2):189-193
A microcomputer system has been designed for semi-automatic operation of a solid source mass spectrometer used for geochronological
studies. It sequentially steps the magnetic field through pre-selected values, reads the digitized ion currents for a given
time and temporarily stores the data which can be transferred to a paper tape or directly to a desk top calculator for further
analysis. The unit is relatively inexpensive, made of readily available components and can be adapted to many laboratory automation
tasks 相似文献
86.
Monte Carlo calculations on a stochastic Ising model of a concentrated binary magnetic system with very strong, quenched bond disorder were done on square lattices. The specific heat and static susceptibility show rounded peaks at a temperature below which field-cooling effects and long time relaxation, typical of spin-glasses, start appearing. 相似文献
87.
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89.
The analysis of the free and forced vibration of a randomly time-varying system is the subject matter of this paper. This is a complicated problem which has received relatively little discussion in the literature. Herein two methods are presented, apart from the digital simulation technique, of finding the response moments. The first one is a series technique which can be considered as a generalization of the well known Galerkin method. The second method belongs to the class of closure techniques. Upon presuming some of the joint distributions to be Gaussian, equations are derived for the first two response moments. It is shown further that the non-Gaussian output density can be approximately predicted by a simple transformation. Detailed numerical results are obtained and compared with computer simulated response statistics. It is demonstrated that the methods developed here are highly efficient. In particular it is found that the Gaussian closure approximation has a wide range of application. 相似文献
90.