18,050 research outputs found
Applications of degree estimate for subalgebras
Let be a field of positive characteristic and be the free
algebra of rank two over . Based on the degree estimate done by Y.-C. Li and
J.-T. Yu, we extend the results of S.J. Gong and J.T. Yu's results: (1) An
element is a test element if and only if does not
belong to any proper retract of ; (2) Every endomorphism preserving the
automorphic orbit of a nonconstant element of is an automorphism; (3)
If there exists some injective endomorphism of such that
where , then is a coordinate. And
we reprove that all the automorphisms of are tame. Moreover, we also
give counterexamples for two conjectures established by Leonid Makar-Limanov,
V. Drensky and J.-T. Yu in the positive characteristic case.Comment: 12 page
Multimedia Chinese Web Search Engines: A Survey
The objective of this paper is to explore the state of multimedia search functionality on major general and dedicated Web search engines in Chinese language. The authors studied: a) how many Chinese Web search engines presently make use of multimedia searching, and b) the type of multimedia search functionality available. Specifically, the following were examined: a) multimedia features - features allowing multimedia search; and b) extent of personalization - the extent to which a search engine Web site allows users to control multimedia search. Overall, Chinese Web search engines offer limited multimedia searching functionality. The significance of the study is based on two factors: a) little research has been conducted on Chinese Web search engines, and b) the instrument used in the study and the results obtained by this research could help users, Web designers, and Web search engine developers. By large, general Web search engines support more multimedia features than specialized one
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