• Communications of the Korean Mathematical Society
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• v.35 no.2
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• pp.481-486
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• 2020

Let K be a number field. Here we give an explicit description of the group (O_K/I)* for most ideals I. In particular, we give a complete characterization of such group for those ideals I that are coprime to the different ideal 𝒟_K.

• Bulletin of the Korean Mathematical Society
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• v.53 no.4
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• pp.1005-1015
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• 2016

It is a surprising but now well-known fact that there exist algebraic power series of degree higher than two with partial quotients of bounded degrees in their continued fraction expansions, while there is no single algebraic real number known with bounded partial quotients. However, it seems that these special algebraic power series are quite rare and it is hard to determine their continued fraction expansions explicitly. To the short list of known examples, we add a new family of cubic power series with bounded partial quotients.