«frequency analysis»
۱۳۸٬۰۶۹ نتیجهComparative Study Of Time-Frequency Analysis Approaches With Application To Economic Indicators
Presented paper deals with comparison of various methods for time-frequency representation of a signal with time-varying behavior. We choose methods such as wavelet analysis, multiple window method using Slepian sequences, time-frequency varying autoregressive process estimation
Decrypting English Text Using Enhanced Frequency Analysis
Frequency analysis is the fundamental cryptanalytic technique besides brutal force, threat, blackmail, torture, bribery, etc. [1]. Conventionally, it is applied on monogram, bigram and trigram together with anagramming technique [2]. The efficiency of anagramming depends on the c
Significance of Cohen's Class for Time Frequency Analysis of Signals
In this paper, a study of quadratic transformations under Cohen‟s class is presented, to see the variations in resolution for performing time-frequency analysis of signals. The study concentrated on the analysis of linear chirp signals and nonstationary signals in presence of noi
Comprehensive Joint Time-Frequency Analysis toward Condition Based Maintenance Regimes for Electrical and Mechanical Components
Based upon a framework of time-frequency analysis, a path towards systematic and comprehensive implementation of condition based maintenance (CBM), or maintenance only upon evidence of need, is outlined for both electrical and mechanical systems. Specifically, metrics are propose
Theory of Modulation Frequency Analysis and Modulation Filtering, with Applications to Hearing Devices
Theory of Modulation Frequency Analysis and Modulation Filtering, with Applications to Hearing Devices Steven Marco Schimmel Chair of the Supervisory Committee: Professor Les E. Atlas Electrical Engineering Natural signals such as speech and music can be faithfully represented by
Identification of time-varying cable tension forces based on adaptive sparse time-frequency analysis of cable vibrations
For cable bridges, the cable tension force plays a crucial role in their construction, assessment and long-term structural health monitoring. Cable tension forces vary in real time with the change of the moving vehicle loads and environmental effects, and this continual variation
Time-Frequency Analysis Using Short Time Fourier Transform
A time-frequency analysis, which represents the time change of a signal, is significant in all fields. Wigner distribution, a short time Fourier transform (STFT), a kernel method, and a characteristic function method etc. are known as a time-frequency analyzing method, and those
Comparison of Methods for Different Time-frequency Analysis of Vibration Signal
Vibration problems in rotors can be extremely frustrating and may lead to greatly reduced reliability. By utilizing the proper data collection and analysis techniques, the faults because of vibration can be discovered and predicted. The signal analysis is important in extracting
A High Precision Time-frequency Analysis Method
To analysis the signal whose frequency changes as time, this article presents a new time-frequency analysis method based on short-time fractional Fourier transform (FRFT) and integration of midpoints. This method uses window functions to divide the signal to many pieces, then the
A note on the optimality of frequency analysis vs. lp-optimization
Naveed, Kamara, and Wright’s recent paper “Inference Attacks on Property-Preserving Encrypted Databases” (ACM-CCS 2015) evaluated four attacks on encrypted databases, such as those based on the design of CryptDB (Popa et al., SOSP 2011). Two of these attacks—frequency analysis an