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The record of the sunspot number visible on the sun is regularly collected over the centuries by various observatories for studying the different factors influencing the sunspot cycle and solar activity. Sunspots appear in cycles, and last several years. These cycles follow a certain pattern which is well known. We analyzed monthly and yearly averages of sunspot data observed from year 1818 to 2002 using rescaled range analysis. The Hurst exponent calculated for monthly data sets are 0.8899, 0.8800 and 0.8597 and for yearly data set is 0.7187. Fractal dimensions1 calculated are 1.1100, 1.1200, 1.1403 and 1.2813. From the study of Hurst exponent and fractal dimension, we conclude that time series of sunspots show persistent behavior. The fundamental tool of signal processing is the fast Fourier transform technique (FFT). The sunspot data is also analyzed using FFT. The power spectrum of monthly and yearly averages of sunspot shows distinct peaks at 11 years confirming the well known 11-year cycle. The monthly sunspot data is also analyzed using FFT to filter the noise in the data.

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In this paper, the study of traffic noise is presented from the point of view of 1/f noise. Samples of Traffic Noise are collected from selected locations from busy roads of Aurangabad city in Maharashtra state (India) and data is analyzed. It is observed that in many cases the traffic noise possesses pink noise (1/f noise) prevailing over appreciable range of frequency. The log log plot of noise power versus frequency results in a straight line with a slope approximately equal to unity confirming the presence of pink noise. After certain frequency, the noise power no longer behaves like pink noise (1/f noise) and becomes more or less constant with random fluctuations. Plots of noise power versus frequency on log log basis for different locations studied are presented and the inferences are discussed.

In this paper, the study of traffic noise is presented from the point of view of 1/f noise. Samples of Traffic Noise are collected from selected locations from busy roads of Aurangabad city in Maharashtra state (India) and data is analyzed. It is observed that in many cases the traffic noise possesses pink noise (1/f noise) prevailing over appreciable range of frequency. The log log plot of noise power versus frequency results in a straight line with a slope approximately equal to unity confirming the presence of pink noise. After certain frequency, the noise power no longer behaves like pink noise (1/f noise) and becomes more or less constant with random fluctuations. Plots of noise power versus frequency on log log basis for different locations studied are presented and the inferences are discussed.