Jedol Dayou | Universiti Malaysia Sabah (original) (raw)

Jedol Dayou

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Papers by Jedol Dayou

Research paper thumbnail of GLOBAL CONTROL OF STRUCTURAL VIBRATION USING MULTIPLE-TUNED TUNABLE VIBRATION NEUTRALIZERS

Journal of Sound and Vibration, 2002

Research paper thumbnail of A comparison between active and semi-active global vibration control of structures

Journal of The Acoustical Society of America, 1999

Research paper thumbnail of GLOBAL CONTROL OF VIBRATION USING A TUNABLE VIBRATION NEUTRALIZER

Journal of Sound and Vibration, 2000

Research paper thumbnail of Global control of vibration using a tunable vibration neutraliser

Noise & Vibration Worldwide, 2001

Research paper thumbnail of Experimental verification of the optimal tuning of a tunable vibration neutralizer for global vibration control

Research paper thumbnail of Optimum tuning of a vibration neutralizer for global vibration control

Proceedings of The Institution of Mechanical Engineers Part C-journal of Mechanical Engineering Science, 2001

Research paper thumbnail of Fixed-points theory for global vibration control using vibration neutralizer

Journal of Sound and Vibration, 2006

Research paper thumbnail of Mode shape reconstruction of an impulse excited structure using continuous scanning laser Doppler vibrometer and empirical mode decomposition

Review of Scientific Instruments, 2008

For vibration testing, discrete types of scanning laser Doppler vibrometer (SLDV) have been devel... more For vibration testing, discrete types of scanning laser Doppler vibrometer (SLDV) have been developed and have proven to be very useful. For complex structures, however, SLDV takes considerable time to scan the surface of structures and require large amounts of data storage. To overcome these problems, a continuous scan was introduced as an alternative. In this continuous method, the Chebyshev demodulation (or polynomial) technique and the Hilbert transform approach have been used for mode shape reconstruction with harmonic excitation. As an alternative, in this paper, the Hilbert-Huang transform approach is applied to impact excitation cases in terms of a numerical approach, where the vibration of the tested structure is modeled using impulse response functions. In order to verify this technique, a clamped-clamped beam was chosen as the test rig in the numerical simulation and real experiment. This paper shows that with additional innovative steps of using ideal bandpass filters and nodal point determination in the postprocessing, the Hilbert-Huang transformation can be used to create a better mode shape reconstruction even in the impact excitation case.

Research paper thumbnail of Scaling the Operating Deflection Shapes Obtained from Scanning Laser Doppler Vibrometer

Journal of Nondestructive Evaluation, 2011

Operating Deflection Shapes (ODS) has emerged as one of the powerful techniques in vibration anal... more Operating Deflection Shapes (ODS) has emerged as one of the powerful techniques in vibration analysis to understand and to evaluate the absolute dynamic behaviour of a machine, component or an entire structure. Traditionally, accelerometers have been used to get the ODS of a structure. However, recent development shows that certain situation may not allow direct contact with the structure under investigation. Therefore, Scanning Laser Doppler Vibrometer (SLDV) has become popular in the investigation. In this paper, a new ODS Frequency Response Function (ODS FRF) for investigations using SLDV is formulated. The ODS FRF is used to construct the ODS of the structure. A new form of scale factor for the ODS FRF is also introduced to normalize the effects from variable excitation force. The importance of this scale factor is demonstrated on a beam and plate under the excitation of varying forces. It is found that the suggested ODS FRF and the scale factor give the desired result in comparison with theory.

Research paper thumbnail of Derivation of the Fixed-Points Theory with Some Numerical Simulations for Global Vibration Control of Structure with Closely Spaced Natural Frequencies

Mechanics Based Design of Structures and Machines, 2006

Research paper thumbnail of Information Theoretic Approach Based on Entropy for Classification of Bioacoustics Signals

A new hybrid method for automated frog sound identification by incorporating entropy and spectral... more A new hybrid method for automated frog sound identification by incorporating entropy and spectral centroid concept is proposed. Entropy has important physical implications as the amount of "disorder" of a system. This study explores the use of various definitions of entropies such as the Shannon entropy, Kolmogorov-Rényi entropy and Tsallis entropy as measure of information contents or complexity for the purpose of the pattern recognition of bioacoustics signal. Each of these definitions of entropies characterizes different aspects of the signal. The entropies are combined with other standard pattern recognition tools such as the Fourier spectral analysis to form a hybrid spectral-entropic classification scheme. The efficiency of the system is tested using a database of sound syllables are obtained from a number of species of Microhylidae frogs. Nonparametric k-NN classifier is used to recognize the frog species based on the spectral-entropic features. The result showed that the k-NN classifier based on the selected features is able to identify the species of the frogs with relativity good accuracy compared to features relying on spectral contents alone. The robustness of the developed system is also tested for different noise levels.

Research paper thumbnail of Acoustic classification of Australian anurans based on hybrid spectral-entropy approach

Research paper thumbnail of Information Theoretic Approach Based on Entropy for Classification of Bioacoustics Signals

Research paper thumbnail of GLOBAL CONTROL OF STRUCTURAL VIBRATION USING MULTIPLE-TUNED TUNABLE VIBRATION NEUTRALIZERS

Journal of Sound and Vibration, 2002

Research paper thumbnail of A comparison between active and semi-active global vibration control of structures

Journal of The Acoustical Society of America, 1999

Research paper thumbnail of GLOBAL CONTROL OF VIBRATION USING A TUNABLE VIBRATION NEUTRALIZER

Journal of Sound and Vibration, 2000

Research paper thumbnail of Global control of vibration using a tunable vibration neutraliser

Noise & Vibration Worldwide, 2001

Research paper thumbnail of Experimental verification of the optimal tuning of a tunable vibration neutralizer for global vibration control

Research paper thumbnail of Optimum tuning of a vibration neutralizer for global vibration control

Proceedings of The Institution of Mechanical Engineers Part C-journal of Mechanical Engineering Science, 2001

Research paper thumbnail of Fixed-points theory for global vibration control using vibration neutralizer

Journal of Sound and Vibration, 2006

Research paper thumbnail of Mode shape reconstruction of an impulse excited structure using continuous scanning laser Doppler vibrometer and empirical mode decomposition

Review of Scientific Instruments, 2008

For vibration testing, discrete types of scanning laser Doppler vibrometer (SLDV) have been devel... more For vibration testing, discrete types of scanning laser Doppler vibrometer (SLDV) have been developed and have proven to be very useful. For complex structures, however, SLDV takes considerable time to scan the surface of structures and require large amounts of data storage. To overcome these problems, a continuous scan was introduced as an alternative. In this continuous method, the Chebyshev demodulation (or polynomial) technique and the Hilbert transform approach have been used for mode shape reconstruction with harmonic excitation. As an alternative, in this paper, the Hilbert-Huang transform approach is applied to impact excitation cases in terms of a numerical approach, where the vibration of the tested structure is modeled using impulse response functions. In order to verify this technique, a clamped-clamped beam was chosen as the test rig in the numerical simulation and real experiment. This paper shows that with additional innovative steps of using ideal bandpass filters and nodal point determination in the postprocessing, the Hilbert-Huang transformation can be used to create a better mode shape reconstruction even in the impact excitation case.

Research paper thumbnail of Scaling the Operating Deflection Shapes Obtained from Scanning Laser Doppler Vibrometer

Journal of Nondestructive Evaluation, 2011

Operating Deflection Shapes (ODS) has emerged as one of the powerful techniques in vibration anal... more Operating Deflection Shapes (ODS) has emerged as one of the powerful techniques in vibration analysis to understand and to evaluate the absolute dynamic behaviour of a machine, component or an entire structure. Traditionally, accelerometers have been used to get the ODS of a structure. However, recent development shows that certain situation may not allow direct contact with the structure under investigation. Therefore, Scanning Laser Doppler Vibrometer (SLDV) has become popular in the investigation. In this paper, a new ODS Frequency Response Function (ODS FRF) for investigations using SLDV is formulated. The ODS FRF is used to construct the ODS of the structure. A new form of scale factor for the ODS FRF is also introduced to normalize the effects from variable excitation force. The importance of this scale factor is demonstrated on a beam and plate under the excitation of varying forces. It is found that the suggested ODS FRF and the scale factor give the desired result in comparison with theory.

Research paper thumbnail of Derivation of the Fixed-Points Theory with Some Numerical Simulations for Global Vibration Control of Structure with Closely Spaced Natural Frequencies

Mechanics Based Design of Structures and Machines, 2006

Research paper thumbnail of Information Theoretic Approach Based on Entropy for Classification of Bioacoustics Signals

A new hybrid method for automated frog sound identification by incorporating entropy and spectral... more A new hybrid method for automated frog sound identification by incorporating entropy and spectral centroid concept is proposed. Entropy has important physical implications as the amount of "disorder" of a system. This study explores the use of various definitions of entropies such as the Shannon entropy, Kolmogorov-Rényi entropy and Tsallis entropy as measure of information contents or complexity for the purpose of the pattern recognition of bioacoustics signal. Each of these definitions of entropies characterizes different aspects of the signal. The entropies are combined with other standard pattern recognition tools such as the Fourier spectral analysis to form a hybrid spectral-entropic classification scheme. The efficiency of the system is tested using a database of sound syllables are obtained from a number of species of Microhylidae frogs. Nonparametric k-NN classifier is used to recognize the frog species based on the spectral-entropic features. The result showed that the k-NN classifier based on the selected features is able to identify the species of the frogs with relativity good accuracy compared to features relying on spectral contents alone. The robustness of the developed system is also tested for different noise levels.

Research paper thumbnail of Acoustic classification of Australian anurans based on hybrid spectral-entropy approach

Research paper thumbnail of Information Theoretic Approach Based on Entropy for Classification of Bioacoustics Signals

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