Collective behavior of stock price movements in an emerging market

To investigate the universality of the structure of interactions in different markets, we analyze the cross-correlation matrix C of stock price fluctuations in the National Stock Exchange (NSE) of India. We find that this emerging market exhibits strong correlations in the movement of stock prices compared to developed markets, such as the New York Stock Exchange (NYSE). This is shown to be due to the dominant influence of a common market mode on the stock prices. By comparison, interactions between related stocks, e.g., those belonging to the same business sector, are much weaker. This lack of distinct sector identity in emerging markets is explicitly shown by reconstructing the network of mutually interacting stocks. Spectral analysis of C for NSE reveals that, the few largest eigenvalues deviate from the bulk of the spectrum predicted by random matrix theory, but they are far fewer in number compared to, e.g., NYSE. We show this to be due to the relative weakness of intra-sector interactions between stocks, compared to the market mode, by modeling stock price dynamics with a two-factor model. Our results suggest that the emergence of an internal structure comprising multiple groups of strongly coupled components is a signature of market development.Comment: 10 pages, 10 figure

Digital Watermarking using Multiscale Ridgelet Transform

The multi-resolution watermarking method for digital images proposed in this work. The multiscale ridgelet coefficients of low and high frequency bands of the watermark is embedded to the most significant coefficients at low and high frequency bands of the multiscale ridgelet of an host image, respectively. A multi-resolution nature of multiscale ridgelet transform is exploiting in the process of edge detection. Experimental results of the proposed watermarking method are compared with the previously available watermarking algorithm wavelet transform. Moreover, the proposed watermarking method also tested on images attached by Discrete Cosine Transform (DCT) and wavelet based lossy image compression techniques

Study on abnormal uterine bleeding among adult women in a tertiary care hospital in Bihar, India

Background: Abnormal uterine bleeding (AUB) is the most common problem among patients coming to gynaecology outpatient department. There are various pathologies which can lead to AUB. History, blood investigations, ultrasonography, hysteroscopy and endometrial aspiration are the methods to rule out different causes. Later on, they are classified as per PALM-COEIN classification. It helps in better and successful management of AUB patients.Methods: It was a retrospective study done in Obstetrics and Gynaecology Department of AIIMS Patna from March 2014 to March 2016. A total of 272 cases were selected and data were collected in structured proforma on excel sheet.Results: The most common age-group presenting with AUB was 40 to 49 years of age (58%) and the most common histological pattern was secretory (47.7%).  Menorrhagia was found to be the most common problem in AUB patients (58.45%). As per PALM- COEIN classification, the most common type in our study was found to be AUB-E (26.8%). In a sub-set of patients, who underwent hysterectomy, histopathological samples were compared to endometrial samples which were similar in 81.6% cases.Conclusions: Incidence and pattern of AUB varies according to the age of the patient. It is more common in perimenopausal age-group. Classification of AUB as per PALM-COEIN helps in better understanding of disease and successful management of patients.

Ultrasound Image Denoising using Multiscale Ridgelet Transform with Hard and NeighCoeff Thresholding

Ultrasound imaging utilizes sound waves reflected from different organs of the body to give local details and important diagnostic information on the human body. However, using ultrasound images for diagnosis is difficult because of the existence of speckle noise in the image. The speckle noise is due to interference between coherent waves which are backscattered by targeted surfaces and arrive out of phase at the sensor. This hampers the perception and the extraction of fine details from the image. Speckle reduction/filtering i.e. visual enhancement techniques are used for enhancing the visual quality of the images. The multscale ridgelet transform based denoising algorithm for Ultrasound images is proposed for effective edge preservation in comparison to filtering techniques using the Adaptive Filters

Structural plasticity and associative memory in balanced neural networks with spike-time dependent inhibitory plasticity

Peer reviewe

Elasticity of Stiff Biopolymers

We present a statistical mechanical study of stiff polymers, motivated by experiments on actin filaments and the considerable current interest in polymer networks. We obtain simple, approximate analytical forms for the force-extension relations and compare these with numerical treatments. We note the important role of boundary conditions in determining force-extension relations. The theoretical predictions presented here can be tested against single molecule experiments on neurofilaments and cytoskeletal filaments like actin and microtubules. Our work is motivated by the buckling of the cytoskeleton of a cell under compression, a phenomenon of interest to biology.Comment: Submitted for publication, five pages, three figure