A Note on “Uniqueness of Limit Cycles in
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Robert E. Kooij; Sun Jianhua
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Article
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1997
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Elsevier Science
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English
⚖ 255 KB
proposed a theorem to guarantee the uniqueness of limit cycles for the generalized Lienard system Ž . Ž . Ž . dxrdt s h y y F x , dyrdt s yg x . We will give a counterexample to their Ž . theorem. It will be shown that their theorem is valid only if F x is monotone on certain intervals. For this ca