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11 – 20 of over 1000
Article
Publication date: 9 February 2021

Ngo Thai Hung

This study aims to analyze the dynamic relationship between the Bitcoin market and the conventional asset classes in India

Abstract

Purpose

This study aims to analyze the dynamic relationship between the Bitcoin market and the conventional asset classes in India

Design/methodology/approach

This paper aims to cast light on the dynamic linkages between Bitcoin prices and other conventional asset classes in India by using the wavelet transform frameworks, which can allow us to analyze components of time series without losing the information. To do that, the techniques used with the data set include wavelet-based covariance, correlation, coherence spectrum, continuous power spectrum and Granger causality test.

Findings

The findings of the study suggest that interrelationships between Bitcoin and the key financial asset returns are statistically significant at low, medium and high frequencies. This study also finds the existence of the unidirectional connectedness between Bitcoin the other assets in India.

Practical implications

The outcome of the analysis calls for substantial policy implications for investors, portfolio management in India. This research on the existence of the interconnectedness between Bitcoin and other conventional asset classes in a specific country context, India can, therefore, make a significant contribution to the contemporary debate about the speculative nature of the cryptocurrencies. It casts light on whether Bitcoin provides any diversification and risk management benefits for Indian, as well as global investors.

Originality/value

To the best of the author’s knowledge, this is the first paper investigating the interrelatedness between Bitcoin and key conventional asset classes in India. This research makes methodological advancements by using the wavelet coherence transform. The findings provide empirical bases from which to deal with issues regarding hedging purposes and optimal portfolio allocation for an increasing number of investors in the Indian context. Therefore, the main contribution of this study to related literature in this field is significant.

Details

Journal of Indian Business Research, vol. 13 no. 2
Type: Research Article
ISSN: 1755-4195

Keywords

Article
Publication date: 29 March 2013

Mikko Ranta

The purpose of this paper is to examine contagion among the major world markets during the last 25 years and propose a new way to analyze contagion with wavelet methods.

Abstract

Purpose

The purpose of this paper is to examine contagion among the major world markets during the last 25 years and propose a new way to analyze contagion with wavelet methods.

Design/methodology/approach

The analysis uses a novel way to study contagion using wavelet methods. The comparison is made between co‐movements at different time scales. Co‐movement methods of the discrete wavelet transform and the continuous wavelet transform are applied.

Findings

Clear signs of contagion among the major markets are found. Short time scale co‐movements increase during the major crisis while long time scale co‐movements remain approximately at the same level. In addition, gradually increasing interdependence between markets is found.

Research limitations/implications

Because of the chosen method, the approach is limited to large data sets.

Practical implications

The research has practical implications to portfolio managers etc. who wish to have better view of the dynamics of the international equity markets.

Originality/value

The research uses novel wavelet methods to analyze world equity markets. These methods allow the markets to be analyzed in the whole state space.

Details

International Journal of Managerial Finance, vol. 9 no. 2
Type: Research Article
ISSN: 1743-9132

Keywords

Article
Publication date: 12 September 2008

Saeed Reza Allahkaram and Mehdi Khodayari

The aim of this paper is to show that the use of energy distribution plot (EDP), usually employed by researchers to characterize the behavior of electrochemical signals in the…

Abstract

Purpose

The aim of this paper is to show that the use of energy distribution plot (EDP), usually employed by researchers to characterize the behavior of electrochemical signals in the framework of wavelet transform, could provide better understanding of the electrochemical behavior of a corroding surface if used along with the plot that is obtained from the standard deviation (SD) of partial signals (SDPS). A partial signal (PS) is obtained by limiting the inverse discrete wavelet transform to one crystal, and hence an SDPS is obtained by computing the SD of the corresponding PS.

Design/methodology/approach

The electrochemical current signals, obtained from two identical working electrodes (carbon steel electrodes) exposed to simulated concrete pore solution, sparged simultaneously with SO2 and CO2 were studied using wavelet transforms.

Findings

The results show two steps of passive oxide layer formation: formation of defective passive oxide layer, and strengthening of the passive oxide layer. The passive oxide layer breakdown where CO2 as well as SO2 are involved occurred at a pH of approximately 11. Both the EDP and SDPS plots should be used, simultaneously, to characterize the processes occurring on the surfaces of the exposed electrodes.

Practical implications

The results that were obtained can be regarded as the basis for better understanding and improvement of the noise analysis method.

Originality/value

This paper studies the corrosion behavior of carbon steel rebar before and after the simultaneous introduction of CO2 and SO2 gases in simulated pore solution, using EDP and SDPS plots obtained from the electrochemical current signals at different pH values.

Details

Anti-Corrosion Methods and Materials, vol. 55 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Open Access
Article
Publication date: 14 June 2021

Shekhar Mishra and Sathya Swaroop Debasish

This study aims to explore the linkage between fluctuations in the global crude oil price and equity market in fast emerging economies of India and China.

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Abstract

Purpose

This study aims to explore the linkage between fluctuations in the global crude oil price and equity market in fast emerging economies of India and China.

Design/methodology/approach

The present research uses wavelet decomposition and maximal overlap discrete wavelet transform (MODWT), which decompose the time series into various frequencies of short, medium and long-term nature. The paper further uses continuous and cross wavelet transform to analyze the variance among the variables and wavelet coherence analysis and wavelet-based Granger causality analysis to examine the direction of causality between the variables.

Findings

The continuous wavelet transform indicates strong variance in WTIR (return series of West Texas Instrument crude oil price) in short, medium and long run at various time periods. The variance in CNX Nifty is observed in the short and medium run at various time periods. The Chinese stock index, i.e. SCIR, experiences very little variance in short run and significant variance in the long and medium run. The causality between the changes in crude oil price and CNX Nifty is insignificant and there exists a bi-directional causality between global crude oil price fluctuations and the Chinese equity market.

Originality/value

To the best of the authors’ knowledge, very limited work has been done where the researchers have analyzed the linkage between the equity market and crude oil price fluctuations under the framework of discrete wavelet transform, which overlooks the bottleneck of non-stationarity nature of the time series. To bridge this gap, the present research uses wavelet decomposition and MODWT, which decompose the time series into various frequencies of short, medium and long-term nature.

Details

Vilakshan - XIMB Journal of Management, vol. 19 no. 1
Type: Research Article
ISSN: 0973-1954

Keywords

Article
Publication date: 1 April 1998

D.A. Karras, S.A. Karkanis and B.G. Mertzios

This paper suggests a novel methodology for building robust information processing systems based on wavelets and artificial neural networks (ANN) to be applied either in…

Abstract

This paper suggests a novel methodology for building robust information processing systems based on wavelets and artificial neural networks (ANN) to be applied either in decision‐making tasks based on image information or in signal prediction and modeling tasks. The efficiency of such systems is increased when they simultaneously use input information in its original and wavelet transformed form, invoking ANN technology to fuse the two different types of input. A quality control decision‐making system as well as a signal prediction system have been developed to illustrate the validity of our approach. The first one offers a solution to the problem of defect recognition for quality control systems. The second application improves the quality of time series prediction and signal modeling in the domain of NMR. The accuracy obtained shows that the proposed methodology deserves the attention of designers of effective information processing systems.

Details

Kybernetes, vol. 27 no. 3
Type: Research Article
ISSN: 0368-492X

Keywords

Book part
Publication date: 14 December 2018

Ramazan Yildirim and Mansur Masih

The purpose of this chapter is to analyze the possible portfolio diversification opportunities between Asian Islamic market and other regions’ Islamic markets; namely USA, Europe…

Abstract

The purpose of this chapter is to analyze the possible portfolio diversification opportunities between Asian Islamic market and other regions’ Islamic markets; namely USA, Europe, and BRIC. This study makes the initial attempt to fill in the gaps of previous studies by focusing on the proxies of global Islamic markets to identify the correlations among those selected markets by employing the recent econometric methodologies such as multivariate generalized autoregressive conditional heteroscedastic–dynamic conditional correlations (MGARCH–DCC), maximum overlap discrete wavelet transform (MODWT), and the continuous wavelet transform (CWT). By utilizing the MGARCH-DCC, this chapter tries to identify the strength of the time-varying correlation among the markets. However, to see the time-scale-dependent nature of these mentioned correlations, the authors utilized CWT. For robustness, the authors have applied MODWT methodology as well. The findings tend to indicate that the Asian investors have better portfolio diversification opportunities with the US markets, followed by the European markets. BRIC markets do not offer any portfolio diversification benefits, which may be explained partly by the fact that the Asian markets cover partially the same countries of BRIC markets, namely India and China. Considering the time horizon dimension, the results narrow down the portfolio diversification opportunities only to the short-term investment horizons. The very short-run investors (up to eight days only) can benefit through portfolio diversification, especially in the US and European markets. The above-mentioned results have policy implications for the Asian Islamic investors (e.g., Portfolio Management and Strategic Investment Management).

Article
Publication date: 13 August 2018

Parth Sarathi Panigrahy and Paramita Chattopadhyay

The purpose of this paper is to inspect strategic placing of different signal processing techniques like wavelet transform (WT), discrete Hilbert transform (DHT) and fast Fourier…

Abstract

Purpose

The purpose of this paper is to inspect strategic placing of different signal processing techniques like wavelet transform (WT), discrete Hilbert transform (DHT) and fast Fourier transform (FFT) to acquire the qualitative detection of rotor fault in a variable frequency drive-fed induction motor under challenging low slip conditions.

Design/methodology/approach

The algorithm is developed using Q2.14 bit format of Xilinx System Generator (XSG)-DSP design tool in MATLAB. The developed algorithm in XSG-MATLAB can be implemented easily in field programmable gate array, as a provision to generate the necessary VHDL code is available by its graphical user interface.

Findings

The applicability of WT is ensured by the effective procedure of base wavelet selection, which is the novelty of the work. It is found that low-order Daubechies (db) wavelets show decent shape matching with current envelope rather than raw current signal. This fact allows to use db1-based discrete wavelet transform-inverse discrete wavelet transform, where economic and multiplier-less design is possible. Prominent identity of 2sfs component is found even at low FFT points due to the application of suitable base wavelet.

Originality/value

The proposed method is found to be effective and hardware-friendly, which can be used to design a low-cost diagnostic instrument for industrial applications.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Open Access
Article
Publication date: 3 August 2020

Jihad Maulana Akbar and De Rosal Ignatius Moses Setiadi

Current technology makes it easy for humans to take an image and convert it to digital content, but sometimes there is additional noise in the image so it looks damaged. The…

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Abstract

Current technology makes it easy for humans to take an image and convert it to digital content, but sometimes there is additional noise in the image so it looks damaged. The damage that often occurs, like blurring and excessive noise in digital images, can certainly affect the meaning and quality of the image. Image restoration is a process used to restore the image to its original state before the image damage occurs. In this research, we proposed an image restoration method by combining Wavelet transformation and Akamatsu transformation. Based on previous research Akamatsu's transformation only works well on blurred images. In order not to focus solely on blurry images, Akamatsu's transformation will be applied based on Wavelet transformations on high-low (HL), low-high (LH), and high-high (HH) subunits. The result of the proposed method will be comparable with the previous methods. PSNR is used as a measure of image quality restoration. Based on the results the proposed method can improve the quality of the restoration on image noise, such as Gaussian, salt and pepper, and also works well on blurred images. The average increase is around 2 dB based on the PSNR calculation.

Details

Applied Computing and Informatics, vol. 19 no. 3/4
Type: Research Article
ISSN: 2634-1964

Keywords

Article
Publication date: 1 August 2004

C.Y. Xiong, J. Zhang, M. Li, J. Fang and S. Yi

In this paper, two transform methods, the Fourier transform (FT) and the wavelet transform (WT) methods, are utilized to process moiré fringes for the strain analysis of…

Abstract

In this paper, two transform methods, the Fourier transform (FT) and the wavelet transform (WT) methods, are utilized to process moiré fringes for the strain analysis of electronic packaging. With the introduction of fringe carriers, those transform techniques need only one fringe pattern for each deformation state. The strain modulation to the carrier frequency can be subtracted by filtering as the pattern is transformed into spectrum domain by the fast‐FT processing, and the deformation field can thus be restored by the inverse FT transform after spectral shifting. The WT method expands the pattern information involved in the fringe carrier in both spatial domain and spectral domain to analyze the deformation distribution in this combined space. By changing the transform scales in the processing, the wavelet transform offers multi‐resolution analysis for the deformation field with high gradients.

Details

Microelectronics International, vol. 21 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 17 July 2009

Latif Ebrahimnejad and Reza Attarnejad

The purpose of this paper is to introduce a novel approach to solving linear systems arising from applying a Boundary Element Method (BEM) to elasticity problems.

Abstract

Purpose

The purpose of this paper is to introduce a novel approach to solving linear systems arising from applying a Boundary Element Method (BEM) to elasticity problems.

Design/methodology/approach

The key idea is based on using wavelet transforms as a tool to change dense and fully populated matrices of BEM systems into sparse matrices. Wavelets are then used again to produce an algorithm to solve the resultant sparse linear systems. The wavelet transformation part of the method can be added as a black box to existing BEM codes.

Findings

Numerical results focusing on the sensitivity of the solution for various physical variables to the thresholding parameters, and savings in computer time and memory are presented. The results show that the proposed method is efficient for large problems.

Research limitations/implications

Application of the proposed method is restricted to problems with number of DOF equal to an integer power of 2.

Originality/value

The novel algorithm to solve transformed algebraic linear equations uses NS‐form of the modified matrix, taking the advantage of the hierarchical nature of Multi‐Resolution Analysis (MRA) to decompose a parent system into descendant systems with reduced size. These smaller systems are then solved iteratively using generalized minimal residual method.

Details

Engineering Computations, vol. 26 no. 5
Type: Research Article
ISSN: 0264-4401

Keywords

11 – 20 of over 1000