On the base of the 17 GHz radio maps of the Sun taken with the Nobeyama Radio Heliograph we estimate plasma parameters in the specific region of the sunspot atmosphere in the active region AR 11312. This region of the sunspot atmosphere is characterized by the depletion in coronal emission (soft X-ray and EUV lines) and the reduced absorption in the a chromospheric line (He I 1.083 μm). In the ...

This paper presents a feedforward neural network approach to sunspot forecasting. The sunspot series were analyzed with feedforward neural networks, formalized based on statistical models. The statistical models were used as comparison models along with recurrent neural networks. The feedforward networks had 24 inputs (depending on the number of predictor variables), one hidden layer with 20 ...

To continue our study of waves related to sunspots in the photosphere, we analyzed CCD, high resolution sunspot observations obtained in the Fe i 557.6 nm line. We produced " time slice images " which reveal inward slow propagating waves in the photospheric penumbra and outward propagating waves in the area around the sunspot. The phase velocity of the waves is near 0.5 km s −1 in both cases an...

This paper argues that self-fulfilling beliefs in credit conditions can generate endogenously persistent business cycle dynamics. We develop a tractable dynamic general equilibrium model with idiosyncratic firm productivity shocks. Capital from less productive firms is lent to more productive ones in the form of credit secured by collateral and also as unsecured credit based on reputation. A dy...

A property of nonlinear oscillators—mutual dependence between their instantaneous amplitude and frequency—is tested in the yearly and monthly records of the sunspot numbers using the histogramadjusted isospectral surrogate data and the Barnes model as the autoregressive moving average surrogates. The instantaneous amplitudes and frequencies are obtained by means of the analytic signal approach ...

We reappraise the robustness of sunspot effects in overlapping-generations models. Azariadis’s wellknown example economies have stationary, deterministic fundamentals (preferences, technologies, and endowments), yet sunspots affect multiple equilibria. And those equilibria are robust to common perturbations of underlying fundamentals. However, we find that judiciously splitting each of Azariadi...

In this paper, we extend our original work on multiresolution learning, and present a new concept and method of adaptive neural activation functions in multiresolution learning, to maximize the learning efficacy of multiresolution learning paradigm for neural networks. Real-world sunspot series (yearly sunspot data from 1700 to 1999) prediction has been used to evaluate our method. We demonstra...

Facular emission is one of the major contributors to long-term solar irradiance variations. Reconstructions of past facular variations, however, are strongly hampered by the lack of reliable proxies, particularly on time-scales longer than a solar cycle. We consider the five potential facular proxies with records covering more than 40 years. By suitably weighting and combining them we create a ...

This paper compares four equilibrium business cycle models with increasing returns to scale production technologies that allow for aggregate fluctuations due to self-fulfilling expectations. Necessary and sufficient conditions for the existence of stationary sunspot equilibria are derived. Numerical examples demonstrate that the degree of increasing returns necessary for the existence of statio...

There exists a considerable amount of research claiming a puzzling anti-correlation between the neutrino detection rate at the Homestake experiment and indicators of solar activity such as the sunspot number, giving rise to explanations involving the hypothesis of a neutrino magnetic moment. It is argued here that the claimed significant anti-correlation is due to a statistical fallacy. A prope...