102 research outputs found
Deep crustal electromagnetic structure of Bhuj earthquake region (India) and its implications
The existence of fluids and partial melt in the lower crust of the seismically active Kutch rift basin (on the western continental margin of India) owing to underplating has been proposed in previous geological and geophysical studies. This hypothesis is examined using magnetotelluric (MT) data acquired at 23 stations along two profiles across Kutch Mainland Uplift and Wagad Uplift. A detailed upper crustal structure is also presented using twodimensional inversion of MT data in the Bhuj earthquake (2001) area. The prominent boundaries of reflection in the upper crust at 5, 10 and 20 km obtained in previous seismic reflection profiles correlate with conductive structures in our models. The MT study reveals 1-2 km thick Mesozoic sediments under the Deccan trap cover. The Deccan trap thickness in this region varies from a few meters to 1.5 km. The basement is shallow on the northern side compared to the south and is in good agreement with geological models as well as drilling information. The models for these profiles indicate that the thickness of sediments would further increase southwards into the Gula of Kutch. Significant findings of the present study indicate 1) the hypocentre region of the earthquake is devoid of fluids, 2) absence of melt (that is emplaced during rifting as suggested from the passive seismological studies) in the lower crust and 3) a low resistive zone in the depth range of 5-20 km. The present MT study rules out fluids and melt (magma) as the causative factors that triggered the Bhuj earthquake. The estimated porosity value of 0.02% Hill explain 100-500 ohm•m resistivity values observed in the lower crust. Based on the seismic velocities and geochemical studies, presence of garnet is inferred. The lower crust consists of basalts - probably generated by partial melting of metasomatised garnet peridotite at beeper depths in the lithosphere - and their composition might be modified by reaction with the spinel peridotites
Multi Modal Medical Image Registration: A New Data Driven Approach
Image registration is a challenging task in building computer-based diagnostic systems. One type of image modality will not be able to provide all information needed for better diagnostic. Hence data from multiple sources/image modalities should be combined. In this work canonical correlation analysis (CCA) based image registration approach has been proposed. CCA provides the framework to integrate information from multiple sources. In this work, the information contained in both images is used for image registration task. T1-weighted, T2- weighted and FLAIR MRI images has Multimodal registration done on it. The algorithm provided better results when compared with mutual information based image registration approach. The work has been carried out using the 3D rigid registration of CT and MRI images. The work is carried out using the public datasets, and later performance is evaluated with the work carried out by Research scholars previously. Our algorithm performs better with mutual information based image registration. Medical image registration of multimodality images like MRI, MRI-CT, and MRI-CT-PET. In this paper for MRI-CT Medical Image Registration CT image is used as a fixed image and MRI image as moving image and later compared results with some benchmark algorithm presented in literature such as correlation coefficient, correlation ratio, and mutual information and normalized mutual information methods
Multi Indicator based Hierarchical Strategies for Technical Analysis of Crypto market Paradigm
The usage of technical analysis in the crypto market is very popular among algorithmic traders. This involves the application of strategies based on technical indicators, which shoot BUY and SELL signals to help the investors to take trading decisions. However, instead of depending on the popular myths of the market, a proper empirical analysis can be helpful in lucrative endeavors in trading cryptocurrencies. In this work, four technical indicators namely Exponential Moving Averages (EMA), Bollinger Bands (BB), Relative Strength Index (RSI), and Parabolic Stop And Reverse (PSAR) are used individually to devise strategies that are implemented, and their performance is validated using the price data of Bitcoin from yahoo finance for 2018-22, individually for each year and all the five years consolidated to compute the performance metrics including Profit percentage, Net profitability percentage, and Number of total transactions. The results show that the performance of strategies based on trend indicators is better than that of momentum indicators where the EMA strategy provided the best result with a profit percentage of 394.13%. Further, the performance of these strategies is analyzed in three different market scenarios namely Uptrend/Bullish trend, Downtrend/Bearish trend, and Fluctuating/oscillating markets to analyze the applicability of each of these smart strategies in the three scenarios. Based on the insights obtained from the analysis, Hybrid strategies using multiple indicators with a hierarchical approach are developed whose performance is further improved by imposing constraints in a Downtrend market scenario. The novelty of these algorithms is that they identify the scenario in the market using multiple indicators in a hierarchal approach, and utilize appropriate indicators as per the market scenario. Four strategies namely, Multi indicator based Hierarchical Strategy (MIHS) with EMA9, Multi indicator based Hierarchical Strategy (MIHS) with EMA7, Multi-Indicator based Hierarchical Constrained Strategy (MIHCS) with EMA9, and Multi-Indicator based Hierarchical Constrained Strategy (MIHCS) with EMA7 are developed which give profit percentage of 154.45%, 437.48%, 256.31%, and 701.77% respectively when applied on the Bitcoin price data during 2018-22
Geophysical signatures of fluids in a reactivated Precambrian collisional suture in central India
The Central India Tectonic Zone (CITZ) marks the trace of a major suture zone along which the south Indian and the north Indian continental blocks were assembled through subduction-accretion-collision tectonics in the Mesoproterozoic. The CITZ also witnessed the major, plume-related, late Cretaceous Deccan volcanic activity, covering substantial parts of the region with continental flood basalts and associated magmatic provinces. A number of major fault zones dissect the region, some of which are seismically active. Here we present results from gravity modeling along five regional profiles in the CITZ, and combine these results with magnetotelluric (MT) modeling results to explain the crustal architecture. The models show a resistive (more than 2000 Ω·m) and a normal density (2.70 g/cm3) upper crust suggesting dominant tonalite–trondhjemite–granodiorite (TTG) composition. There is a marked correlation between both high-density (2.95 g/cm3) and low-density (2.65 g/cm3) regions with high conductive zones (<80 Ω·m) in the deep crust. We infer the presence of an interconnected grain boundary network of fluids or fluid-hosted structures, where the conductors are associated with gravity lows. Based on the conductive nature, we propose that the lower crustal rocks are fluid reservoirs, where the fluids occur as trapped phase within minerals, fluid-filled porosity, or as fluid-rich structural conduits. We envisage that substantial volume of fluids were transferred from mantle into the lower crust through the younger plume-related Deccan volcanism, as well as the reactivation, fracturing and expulsion of fluids transported to depth during the Mesoproterozoic subduction tectonics. Migration of the fluids into brittle fault zones such as the Narmada North Fault and the Narmada South Fault resulted in generating high pore pressures and weakening of the faults, as reflected in the seismicity. This inference is also supported by the presence of broad gravity lows near these faults, as well as the low velocity in the lower crust beneath regions of recent major earthquakes within the CITZ
Filtered OFDM PAPR performance for 5G communications is improved utilizing PTS
A waveform candidate for fifth-generation (5G) communications has been recommended: the filtered orthogonal frequency division multiplexing (F-OFDM) system. Filtering-based waveform frameworks are distinguished by the suppression of out-of-band emission (OOBE) and asynchronous transmission. As a result, the new waveform candidates are still struggling with the PAPR issue. In multicarrier systems, partial transmit sequence (PTS) is an efficient way to combat the rising tendency of PAPR. The high PAPR value of an F-OFDM system is reduced using the PTS technique in this study. The OFDM system is then put up against this one. Other relevant metrics, such as frequency localization, bit error rate (BER), and computational complexity, are evaluated and analysed in both systems with and without PTS. According to simulation studies, F-OFDM based on PTS provides better PAPR, BER, and OOBE than OFDM. F-BER OFDM's is unaffected by the PTS technique's implementation
Analysis of Different Colour Image Enhancement Techniques Using Interpolation and Super Resolution Methods
Abstract- The objective of image processing is to get better resolution for further processing. Several enhancement techniques are proposed for colour image enhancement among these interpolation methods and wavelets are most popularly used. In this paper different colour images are enhanced by using different methods. The Proposed method is compared with existing methods like Bicubic interpolation method, Wavelet zero padding method with respect to PSNR and it has shown that the proposed technique method gives better performance than the existing methods. Index Terms- Bicubic interpolation method, Wavelet zero padding method and Super Resolution method. I
Study Of Acoustic Source Localization Algorithm For Planar Arrays
The source localization algorithms in the earlier works, mostly used non-planar arrays. If we consider scenarios like human-computer communication, or human-television communication where the microphones need to be placed on the computer monitor or television front panel, i.e we need to use the planar arrays. The algorithm proposed in 1], is a Linear Closed Form source localization algorithm (LCF algorithm) which is based on Time Difference of Arrivals (TDOAs) that are obtained from the data collected using the microphones. It assumes non-planar arrays. The LCF algorithm is applied to planar arrays in the current work. The relationship between the error in the source location estimate and the perturbation in the TDOAs is derived using first order perturbation analysis and validated using simulations. If the TDOAs are erroneous, both the coefficient matrix and the data matrix used for obtaining source location will be perturbed. So, the Total least squares solution for source localization is proposed in the current work. The sensitivity analysis of the source localization algorithm for planar arrays and non-planar arrays is done by introducing perturbation in the TDOAs and the microphone locations. It is shown that the error in the source location estimate is less when we use planar array instead of the particular non-planar array considered for same perturbation in the TDOAs or microphone location. The location of the reference microphone is proved to be important for getting an accurate source location estimate if we are using the LCF algorithm
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