摘要
The （Noerlund） logarithmic means of the Fourier series is：tnf=1/ln ^n-1∑k=1 Skf/n-k, where ln=^n-1∑k=1 1/k In general, the Fej6r （C, 1） means have better properties than the logarithmic ones. We compare them and show that in the case of some unbounded Vilenkin systems the situation changes.
The （Noerlund） logarithmic means of the Fourier series is：tnf=1/ln ^n-1∑k=1 Skf/n-k, where ln=^n-1∑k=1 1/k In general, the Fej6r （C, 1） means have better properties than the logarithmic ones. We compare them and show that in the case of some unbounded Vilenkin systems the situation changes.
基金
The first author is supported by the Békésy Postdoctoral fellowship of the Hungarian Ministry of Education B91/2003
the second author is supported by the Hungarian National Foundation for Scientific Research (OTKA),grant no. M 36511/2001, T 048780
the Széchenyi fellowship of the Hungarian Ministry of Education Sz184/2003.
