منابع مشابه
Penetration Experiments under Reduced Gravity
Penetration experiments will find several applications in exploration missions in the near future. Penetrators are common tools for the investigation of physical surface properties. The techniques and theories are widely applied under 1g condition on Earth and the results are used by engineers and scientists. The main contribution to the bearing resistance of a soil is combined of shaft and bas...
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We have experimented with different SOM-based architectures for bio-inspired self-organizing texture and hardness perception systems. To this end we have developed a microphone based texture sensor and a hardness sensor that measures the compression of the material at a constant pressure. We have implemented and successfully tested both monomodal systems for texture and hardness perception, bim...
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Nix and Gao established an important relation between microindentation hardness and indentation depth. Such a relation has been verified by many microindentation experiments (indentation depths in the micrometer range), but it does not always hold in nanoindentation experiments (indentation depths approaching the nanometer range). We have developed a unified computational model for both microan...
متن کاملon semihypergroups and hypergroups
in this thesis, first the notion of weak mutual associativity (w.m.a.) and the necessary and sufficient condition for a $(l,gamma)$-associated hypersemigroup $(h, ast)$ derived from some family of $lesssim$-preordered semigroups to be a hypergroup, are given. second, by proving the fact that the concrete categories, semihypergroups and hypergroups have not free objects we will introduce t...
15 صفحه اولThe effect of prices on fixed and mobile telephone penetration: Using price subsidies as natural experiments
A natural experiment, unintentionally conducted by the price subsidy program Lifeline Assistance, underpins our innovative strategy to estimate consumer demand for communications services. Using a national household panel containing demographic and billing information, we estimate own and cross elasticities of demand for fixed and mobile services and find moderate substitution between the two. ...
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ژورنال
عنوان ژورنال: Nature
سال: 1923
ISSN: 0028-0836,1476-4687
DOI: 10.1038/111116b0