Detection of False Data Injection Attacks Using Cross Wavelet Transform and Machine Learning

2021 ◽  
Author(s):  
Mohammad Sadegh Seyyed Hakim ◽  
Hossein Kazemi Karegar
Keyword(s):  
Machine Learning ◽  
Wavelet Transform ◽  
False Data Injection ◽  
Injection Attacks ◽  
Cross Wavelet Transform ◽  
Cross Wavelet

Cross-wavelet transform as a new prototype for classification of EEG signals

2018 ◽  
Vol 7 (3) ◽  
pp. 348-358 ◽  
Author(s):  
Priyadarshiny Dhar ◽  
Saibal Dutta ◽  
V. Mukherjee ◽  
Abhijit Dhar ◽  
Prithwiraj Das
Keyword(s):  
Wavelet Transform ◽  
Eeg Signals ◽  
Cross Wavelet Transform ◽  
Cross Wavelet

scholarly journals A Network Parameter Database False Data Injection Correction Physics-Based Model: A Machine Learning Synthetic Measurement-Based Approach

2021 ◽  
Vol 11 (17) ◽  
pp. 8074
Author(s):  
Tierui Zou ◽  
Nader Aljohani ◽  
Keerthiraj Nagaraj ◽  
Sheng Zou ◽  
Cody Ruben ◽  
...  
Keyword(s):  
Machine Learning ◽  
Power Systems ◽  
State Of The Art ◽  
Real Life ◽  
The State ◽  
Wide Area ◽  
Network Parameter ◽  
False Data Injection ◽  
Network Parameters ◽  
Injection Attacks

Concerning power systems, real-time monitoring of cyber–physical security, false data injection attacks on wide-area measurements are of major concern. However, the database of the network parameters is just as crucial to the state estimation process. Maintaining the accuracy of the system model is the other part of the equation, since almost all applications in power systems heavily depend on the state estimator outputs. While much effort has been given to measurements of false data injection attacks, seldom reported work is found on the broad theme of false data injection on the database of network parameters. State-of-the-art physics-based model solutions correct false data injection on network parameter database considering only available wide-area measurements. In addition, deterministic models are used for correction. In this paper, an overdetermined physics-based parameter false data injection correction model is presented. The overdetermined model uses a parameter database correction Jacobian matrix and a Taylor series expansion approximation. The method further applies the concept of synthetic measurements, which refers to measurements that do not exist in the real-life system. A machine learning linear regression-based model for measurement prediction is integrated in the framework through deriving weights for synthetic measurements creation. Validation of the presented model is performed on the IEEE 118-bus system. Numerical results show that the approximation error is lower than the state-of-the-art, while providing robustness to the correction process. Easy-to-implement model on the classical weighted-least-squares solution, highlights real-life implementation potential aspects.

scholarly journals Multi-scale investigation on streamflow temporal variability and its connection to global climate indices for unregulated rivers in India

2021 ◽  
Author(s):  
Pavan Kumar Yeditha ◽  
Tarun Pant ◽  
Maheswaran Rathinasamy ◽  
Ankit Agarwal
Keyword(s):  
Wavelet Transform ◽  
Temporal Variability ◽  
Global Climate ◽  
Phase Relationship ◽  
Wavelet Coherence ◽  
Climate Indices ◽  
Coherence Analysis ◽  
Cross Wavelet Transform ◽  
Wavelet Coherence Analysis ◽  
Cross Wavelet

Abstract With the increasing stress on water resources for a developing country like India, it is pertinent to understand the dominant streamflow patterns for effective planning and management activities. This study investigates the spatiotemporal characterization of streamflow of six unregulated catchments in India. Firstly, Mann Kendall (MK) and Changepoint analysis were carried out to detect the presence of trends and any abrupt changes in hydroclimatic variables in the chosen streamflows. To unravel the relationships between the temporal variability of streamflow and its association with precipitation and global climate indices, namely, Niño 3.4, IOD, PDO, and NAO, continuous wavelet transform is used. Cross-wavelet transform and wavelet coherence analysis was also used to capture the coherent and phase relationships between streamflow and climate indices. The continuous wavelet transforms of streamflow data revealed that intra-annual (0.5 years), annual (1 year), and inter-annual (2–4 year) oscillations are statistically significant. Furthermore, a better understanding of the in-phase relationship between the streamflow and precipitation at intra-annual and annual time scales were well-captured using wavelet coherence analysis compared to cross wavelet transform. Furthermore, our analysis also revealed that streamflow observed an in-phase relationship with IOD and NAO, whereas a lag correlation with Niño 3.4 and PDO indices at intra-annual, annual and interannual time scales.

scholarly journals Estudos de Variabilidades Interanuais e Interdecenais da Precipitação Pluvial das Regiões Hidrográficas Tocantins-Araguaia e São Francisco no Brasil

2021 ◽  
Vol 14 (2) ◽  
pp. 1116
Author(s):  
José Nildo da Nóbrega ◽  
Carlos Antonio Costa dos Santos ◽  
Francisco de Assis Salviano de Sousa ◽  
Bergson Guedes Bezerra ◽  
Geber Barbosa de Albuquerque Moura ◽  
...  
Keyword(s):  
Wavelet Transform ◽  
Geographical Area ◽  
Monthly Data ◽  
The Pacific ◽  
Cross Wavelet Transform ◽  
Wavelet Transform Analysis ◽  
The Cross ◽  
Hydrographic Regions ◽  
Cross Wavelet ◽  
Phase Differences

O objetivo é investigar as fases temporais das variabilidades de precipitação pluvial das Regiões Hidrográficas do Tocantins-Araguaia e São Francisco, como, também, correlacioná-las com índices de anomalias de Temperatura da Superfície do Mar (TSM) do Pacífico, na região do Niño 3.4, utilizando a análise de transformada ondaleta. A área geográfica está localizada entre os paralelos 0,5º S a 20º S e meridianos 34,8º W a 55,4º W. Foram utilizados dados mensais de precipitação observados e de reanálise (1º x 1º), no período de 1945-2016, e de TSM de 1950-2016 provenientes de órgãos governamentais nacionais e internacionais. As Ondaletas Contínuas mostraram que as variabilidades dominantes, de precipitação total anual, nas Regiões Hidrográficas do Tocantins-Araguaia e do São Francisco são nas escalas de três a cinco anos, de 11 a 12 anos e em torno de 22 anos. Para ambas as Regiões essas frequências estão em fases, pela Transformada Ondaleta Cruzada e confirmada pela Ondaleta Coerente. Nas análises de Ondaletas Cruzada e Coerente das precipitações com os índices oceânicos se verificou que houve avanço (135º) na série do Niño 3.4 em relação as das precipitações das Regiões nas escalas de três a cinco anos, mas foram verificadas diferenças de fase nas escalas decenais da precipitação das Regiões com os índices oceânicos. Concluiu-se que as variabilidades da precipitação de ambas as Regiões estão em fase e que os eventos ENOS influenciam nas precipitações das Regiões Hidrográficas do Tocantins-Araguaia e São Francisco.  Studies of Interannual and Interdecennial Variabiliteis of Rainfall in the Tocantins-Araguaia and São Francisco Hydrographic Regions in Brazil ABSTRACTThe objective is to investigate the temporal phases of the variability of rainfall in the Hydrographic Regions of Tocantins-Araguaia and São Francisco, as well as to correlate them with anomalies indexes of the Sea Surface Temperature (SST) of the Pacific, in the Niño 3.4 region, using wavelet transform analysis. The geographical area is located between the parallels 0.5º S to 20º S and meridians 34.8º W to 55.4º W. We used monthly data of observed and reanalysis precipitation (1º x 1º), in the period from 1945 to 2016, and from 1950 to 2016 for SST. The data are from national and international government agencies. The continuous wavelet showed that the dominant variability of total annual precipitation, in the Hydrographic Regions of Tocantins-Araguaia and São Francisco, are in the frequencies of three to five years, 11 to 12 years and about 22 years. These frequencies are in phases by the cross wavelet transform and confirmed by the coherent wavelet. In the cross and coherent wavelet analysis of the precipitation with the oceanic indices, there was an advance (135º) in the Niño 3.4 series in relation to the precipitation of the Regions in the frequency of three to five years, but phase differences were observed in the decadal frequencies between the precipitation of the Regions and oceanic indices. We concluded that the variability of precipitation in both regions is in phase and that the ENOS events influence the rainfall in the Hydrographic Regions of Tocantins-Araguaia and São Francisco.Keywords: El Niño, hydrographic catchment, wavelet, climate variability.

scholarly journals Cross-Wavelet Bias Corrected by Normalizing Scales

2012 ◽  
Vol 29 (9) ◽  
pp. 1401-1408 ◽  
Author(s):  
Doris Veleda ◽  
Raul Montagne ◽  
Moacyr Araujo
Keyword(s):  
Wavelet Transform ◽  
Harmonic Series ◽  
Skeletal Structure ◽  
Shortwave Radiation ◽  
Brazilian Coast ◽  
Correct Result ◽  
Standard Application ◽  
Cross Wavelet Transform ◽  
Periodic Signals ◽  
Cross Wavelet

Abstract The cross-wavelet transform (XWT) is a powerful tool for testing the proposed connections between two time series. Because of XWT’s skeletal structure, which is based on the wavelet transform, it is suitable for the analysis of nonstationary periodic signals. Recent work has shown that the power spectrum based on the wavelet transform can produce a deviation, which can be corrected by choosing a proper rectification scale. In this study, it is shown that the standard application of the XWT can also lead to a biased result. A corrected version of the standard XWT was constructed using the scale of each series as normalizing factors. This correction was first tested with an artificial example involving two series built from combinations of two harmonic series with different amplitudes and frequencies. The standard XWT applied to this example produces a biased result, whereas the correct result is obtained with the use of the proposed normalization. This analysis was then applied to a real geophysical situation with important implications to climate modulation on the northwestern Brazilian coast. The linkage between the relative humidity and the shortwave radiation measurements, obtained from the 8°S, 30°W Autonomous Temperature Line Acquisition System (ATLAS) buoy of the Southwestern Extension of the Prediction and Research Moored Array in the Tropical Atlantic (PIRATA-SWE), was explored. The analysis revealed the importance of including the correction in order to not overlook any possible connections. The requirements of incorporating this correction in the XWT calculations are emphasized.

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