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		| Paper: | 
		Changes of the Physical State in Semiregular Variables | 
	 
	
		| Volume: | 
		203, The Impact of Large-Scale Surveys on Pulsating Star Research, IAU Colloquium 176 | 
	 
	
		| Page: | 
		117 | 
	 
	
		| Authors: | 
		Kiss, L. L.; Szabó, Gy.; Szatmáry, K.; Mattei, J. A. | 
	 
	
	
		| Abstract: | 
		We present a progress report on a detailed analysis of long-term (70-90 years) visual observations for seven semiregular variables. Fundamental changes of the physical state (amplitude and/or frequency modulations, mode change and switching) are studied with conventional Fourier- and wavelet analyses. Besides two examples of repetitive mode changes we report a simple geometric model of a rotationally induced amplitude modulation in RY Ursae Majoris. | 
	 
	
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