Iterative Method for Blind Evaluation of Mixed Noise Characteristics on Images

A new method for blind estimation of mixed noise parameters is proposed. The method is based on line fitting into a set of cluster centers obtained from scatter-plot of local variance and mean estimates. Improved estimation of cluster centers is performed on basis of fourth-order statistical moment analysis. The estimation results for the proposed method are compared to the results for other known methods using images from TID2008 database. It is shown that the proposed method provides estimation accuracy comparable to the estimation accuracy of the method based on maximum likelihood estimation of image and noise characteristics (which is considered the best among the existing methods). An advantage of our method is that it is considerably faster

Multilevel Analysis of Oscillation Motions in Active Regions of the Sun

We present a new method that combines the results of an oscillation study made in optical and radio observations. The optical spectral measurements in photospheric and chromospheric lines of the line-of-sight velocity were carried out at the Sayan Solar Observatory. The radio maps of the Sun were obtained with the Nobeyama Radioheliograph at 1.76 cm. Radio sources associated with the sunspots were analyzed to study the oscillation processes in the chromosphere-corona transition region in the layer with magnetic field B=2000 G. A high level of instability of the oscillations in the optical and radio data was found. We used a wavelet analysis for the spectra. The best similarities of the spectra of oscillations obtained by the two methods were detected in the three-minute oscillations inside the sunspot umbra for the dates when the active regions were situated near the center of the solar disk. A comparison of the wavelet spectra for optical and radio observations showed a time delay of about 50 seconds of the radio results with respect to optical ones. This implies a MHD wave traveling upward inside the umbral magnetic tube of the sunspot. Besides three-minute and five-minute ones, oscillations with longer periods (8 and 15 minutes) were detected in optical and radio records.Comment: 17 pages, 9 figures, accepted to Solar Physics (18 Jan 2011). The final publication is available at http://www.springerlink.co

A Probabilistic Analysis of The Trading The Line Strategy

We provide analytic models for which the appropriate statistics of the trading the line strategy, N h , can be derived in closed form. In particular, we provide closed-form expressions concerning the average duration of the open position, E(N h ), the variance of the open duration, Var(N h ), the average of the stopped log price, E(S N h ), the variance of the stopped log price, Var(S N h ), the correlation, Corr(N h , S N h ), and the Laplace transform, E(e−s N h ). These results are obtained, in discrete time settings, for binomial and other price scenarios. Furthermore, when analytic results are not possible, such as the case of a normal distribution for log returns, we show by simulation that our general conclusions still hold. Using these statistics we point out some of the subtle features of the trailing stops strategy

A Probabilistic Analysis of The Trading The Line Strategy

We provide analytic models for which the appropriate statistics of the trading the line strategy, N h , can be derived in closed form. In particular, we provide closed-form expressions concerning the average duration of the open position, E(N h ), the variance of the open duration, Var(N h ), the average of the stopped log price, E(S N h ), the variance of the stopped log price, Var(S N h ), the correlation, Corr(N h , S N h ), and the Laplace transform, E(e−s N h ). These results are obtained, in discrete time settings, for binomial and other price scenarios. Furthermore, when analytic results are not possible, such as the case of a normal distribution for log returns, we show by simulation that our general conclusions still hold. Using these statistics we point out some of the subtle features of the trailing stops strategy

Disturbance of nitric oxide synthase constitutive isoforms expression as a pathogenetic factor of complications development after tooth extraction in experimental diabetes mellitus

The role of constitutive NOS isoforms (endothelial and neuronal) in pathogenesis of complications development and repair processes disturbances in periodontium after tooth extraction in experimental diabetes mellitus is not studied completely. The aim of work – to find out the features of constitutive NOS isoforms (endothelial and neuronal) indices alterations in periodontal tissue of rats with experimental streptozotocin-induced diabetes mellitus on different terms (1st , 7th and 14th day) after mandibular 1st molar extraction. Materials and methods. Immunohistochemical study of endothelial and neuronal NOS isoforms expression indices (content, concentration, area of immunoreactive material distribution) in periodontium tissue was conducted on 120 male rats 8–10 months-old (8 experimental groups). Results. In rats with experimental diabetes mellitus (EDM) without tooth extraction content and concentration of both constitutive NOS isoforms in periodontium were lower than in control group of animals. The extraction of tooth in rats with EDM resulted in significant increase of all indices of both isoforms expression in comparison with EDM rats without tooth extraction. On the 7th day after tooth extraction nNOS content and area of distribution was also increased by 24.3 % and 14.2 % respectively, and concentration decreased by 58.3 %. Indices of eNOS were not reliably changed in comparison with the 1st day after tooth extraction. On the 14th day after tooth extraction in rats with EDM, a significant decrease in all the indices of expression of constitutive NOS was observed, moreover, the concentration and area of nNOS distribution and the content, concentration and area of eNOS become significantly lower than in the corresponding control group. Conclusions. In rats with EDM in periodontal tissues the content and concentration of NOS constitutive isoforms are reduced. Extraction of the tooth in the animal with EDM leads to a moderate increase in the content and concentration of nNOS and eNOS from the 1st to the 7th day. On the 14th day after the extraction, the expression indices of both isoforms decrease lower than in the corresponding control groups, that indicates a low content of endothelial and neuronal isoforms in the periodontium of rats with EDM and probably plays an important role in the pathogenesis of long-term complications development after surgery along with violation of repair processes