Experience

Publications

• Modeling of Hysteresis Effect of SMA using Neuro Fuzzy Inference System

  54th AIAA/ASME/ASCE/AHS/ASC structures, Structural Dynamics, and Materials Conference and Co-located Events

• Modeling of Hysteresis Effect of SMA using Neuro Fuzzy Inference System

  54th AIAA/ASME/ASCE/AHS/ASC structures, Structural Dynamics, and Materials Conference and Co-located Events

• The quadratic compression method for model updating and its noise filtering properties

  Mechanical Systems and Signal Processing

• Modeling of Hysteresis Effect of SMA using Neuro Fuzzy Inference System

  54th AIAA/ASME/ASCE/AHS/ASC structures, Structural Dynamics, and Materials Conference and Co-located Events

• The quadratic compression method for model updating and its noise filtering properties

  Mechanical Systems and Signal Processing

• vibro-acoustics of a pressurized optical membrane

  Mechanical Systems and Signal Processing

  ► The work presented herein studies the coupling effects of a circular membrane to an air cavity. ► The effects of air loading and radiation are considered and compared to that of a membrane in vacuum. ► Coupling is carried using an impedance based modeling approach. ► A novel acoustic actuation method is used for vibration suppression. ► The novel approach proves to be feasible as a way of vibration suppression.

• Modeling of Hysteresis Effect of SMA using Neuro Fuzzy Inference System

  54th AIAA/ASME/ASCE/AHS/ASC structures, Structural Dynamics, and Materials Conference and Co-located Events

• The quadratic compression method for model updating and its noise filtering properties

  Mechanical Systems and Signal Processing

• vibro-acoustics of a pressurized optical membrane

  Mechanical Systems and Signal Processing

  ► The work presented herein studies the coupling effects of a circular membrane to an air cavity. ► The effects of air loading and radiation are considered and compared to that of a membrane in vacuum. ► Coupling is carried using an impedance based modeling approach. ► A novel acoustic actuation method is used for vibration suppression. ► The novel approach proves to be feasible as a way of vibration suppression.

• Mimicking the cochlear amplifier in a cantilever beam using nonlinear velocity feedback control

  Smart Materials and Structures

  he mammalian cochlea exhibits a nonlinear amplification which allows mammals to detect a large range of sound pressure levels while maintaining high frequency sensitivity. This work seeks to mimic the cochlea's nonlinear amplification in a mechanical system. A nonlinear, velocity-based feedback control law is applied to a cantilever beam with piezoelectric actuators. The control law reduces the linear viscous damping of the system while introducing a cubic damping term. The result is a system which is positioned close to a Hopf bifurcation. Modelling and experimental results show that the beam with this control law undergoes a one-third amplitude scaling near the resonance frequency and an amplitude-dependent bandwidth. Both behaviors are characteristic of data obtained from the mammalian cochlea. This work could provide insight on the biological cochlea while producing bio-inspired sensors with a large dynamic range and sharp frequency sensitivity.

• Modeling of Hysteresis Effect of SMA using Neuro Fuzzy Inference System

  54th AIAA/ASME/ASCE/AHS/ASC structures, Structural Dynamics, and Materials Conference and Co-located Events

• The quadratic compression method for model updating and its noise filtering properties

  Mechanical Systems and Signal Processing

• vibro-acoustics of a pressurized optical membrane

  Mechanical Systems and Signal Processing

  ► The work presented herein studies the coupling effects of a circular membrane to an air cavity. ► The effects of air loading and radiation are considered and compared to that of a membrane in vacuum. ► Coupling is carried using an impedance based modeling approach. ► A novel acoustic actuation method is used for vibration suppression. ► The novel approach proves to be feasible as a way of vibration suppression.

• Mimicking the cochlear amplifier in a cantilever beam using nonlinear velocity feedback control

  Smart Materials and Structures

  he mammalian cochlea exhibits a nonlinear amplification which allows mammals to detect a large range of sound pressure levels while maintaining high frequency sensitivity. This work seeks to mimic the cochlea's nonlinear amplification in a mechanical system. A nonlinear, velocity-based feedback control law is applied to a cantilever beam with piezoelectric actuators. The control law reduces the linear viscous damping of the system while introducing a cubic damping term. The result is a system which is positioned close to a Hopf bifurcation. Modelling and experimental results show that the beam with this control law undergoes a one-third amplitude scaling near the resonance frequency and an amplitude-dependent bandwidth. Both behaviors are characteristic of data obtained from the mammalian cochlea. This work could provide insight on the biological cochlea while producing bio-inspired sensors with a large dynamic range and sharp frequency sensitivity.

• Effect of Strain Nodes and Electrode Configuration on Piezoeletric Energy Harvesting from Cantilever Beams

  ASME Journal of Vibration and Acoustics

• Modeling of Hysteresis Effect of SMA using Neuro Fuzzy Inference System

  54th AIAA/ASME/ASCE/AHS/ASC structures, Structural Dynamics, and Materials Conference and Co-located Events

• The quadratic compression method for model updating and its noise filtering properties

  Mechanical Systems and Signal Processing

• vibro-acoustics of a pressurized optical membrane

  Mechanical Systems and Signal Processing

  ► The work presented herein studies the coupling effects of a circular membrane to an air cavity. ► The effects of air loading and radiation are considered and compared to that of a membrane in vacuum. ► Coupling is carried using an impedance based modeling approach. ► A novel acoustic actuation method is used for vibration suppression. ► The novel approach proves to be feasible as a way of vibration suppression.

• Mimicking the cochlear amplifier in a cantilever beam using nonlinear velocity feedback control

  Smart Materials and Structures

  he mammalian cochlea exhibits a nonlinear amplification which allows mammals to detect a large range of sound pressure levels while maintaining high frequency sensitivity. This work seeks to mimic the cochlea's nonlinear amplification in a mechanical system. A nonlinear, velocity-based feedback control law is applied to a cantilever beam with piezoelectric actuators. The control law reduces the linear viscous damping of the system while introducing a cubic damping term. The result is a system which is positioned close to a Hopf bifurcation. Modelling and experimental results show that the beam with this control law undergoes a one-third amplitude scaling near the resonance frequency and an amplitude-dependent bandwidth. Both behaviors are characteristic of data obtained from the mammalian cochlea. This work could provide insight on the biological cochlea while producing bio-inspired sensors with a large dynamic range and sharp frequency sensitivity.

• Effect of Strain Nodes and Electrode Configuration on Piezoeletric Energy Harvesting from Cantilever Beams

  ASME Journal of Vibration and Acoustics

• Gender Classification of Walkers Via Underfloor Accelerometer Measurements

  IEEE Internet of Things Journal

  The ability to classify the gender of occupants in a building has far-reaching applications including security and retail sales. The authors demonstrate the success of machine learning techniques for gender classification. High-sensitivity accelerometers mounted non-invasively beneath an actual building floor provide the input for these machine learning methods. While other approaches using gait measurements, such as vision systems and wearable sensors, provide the potential for gender classification, they each face limitations. These limitations include an invasion of privacy, occupant compliance, required line of sight, and/or high sensor density. Underfloor mounted accelerometers overcome these limitations. The authors utilize the highly-instrumented Goodwin Hall smart building on the Virginia Tech campus to measure vibrations of the walking surface caused by walkers. In this study, the gait of fifteen individual walkers was recorded as they, alone, walked down the instrumented hallway. Fourteen accelerometers, mounted underneath the walking surface, recorded walking trials with the placement of the sensors unknown to the walker. This work studies Bagged Decision Trees, Boosted Decision Trees, Support Vector Machines (SVMs), and Neural Networks as the machine learning techniques for their ability to classify gender. A ten-fold-cross-validation method is used to comment on the validity of the algorithm’s ability to generalize to new walkers. This work demonstrates that a gender classification accuracy of 88% is achievable using the underfloor vibration data from the Virginia Tech Goodwin Hall by using Decision Tree approaches.

• Modeling of Hysteresis Effect of SMA using Neuro Fuzzy Inference System

  54th AIAA/ASME/ASCE/AHS/ASC structures, Structural Dynamics, and Materials Conference and Co-located Events

• The quadratic compression method for model updating and its noise filtering properties

  Mechanical Systems and Signal Processing

• vibro-acoustics of a pressurized optical membrane

  Mechanical Systems and Signal Processing

  ► The work presented herein studies the coupling effects of a circular membrane to an air cavity. ► The effects of air loading and radiation are considered and compared to that of a membrane in vacuum. ► Coupling is carried using an impedance based modeling approach. ► A novel acoustic actuation method is used for vibration suppression. ► The novel approach proves to be feasible as a way of vibration suppression.

• Mimicking the cochlear amplifier in a cantilever beam using nonlinear velocity feedback control

  Smart Materials and Structures

  he mammalian cochlea exhibits a nonlinear amplification which allows mammals to detect a large range of sound pressure levels while maintaining high frequency sensitivity. This work seeks to mimic the cochlea's nonlinear amplification in a mechanical system. A nonlinear, velocity-based feedback control law is applied to a cantilever beam with piezoelectric actuators. The control law reduces the linear viscous damping of the system while introducing a cubic damping term. The result is a system which is positioned close to a Hopf bifurcation. Modelling and experimental results show that the beam with this control law undergoes a one-third amplitude scaling near the resonance frequency and an amplitude-dependent bandwidth. Both behaviors are characteristic of data obtained from the mammalian cochlea. This work could provide insight on the biological cochlea while producing bio-inspired sensors with a large dynamic range and sharp frequency sensitivity.

• Effect of Strain Nodes and Electrode Configuration on Piezoeletric Energy Harvesting from Cantilever Beams

  ASME Journal of Vibration and Acoustics

• Gender Classification of Walkers Via Underfloor Accelerometer Measurements

  IEEE Internet of Things Journal

  The ability to classify the gender of occupants in a building has far-reaching applications including security and retail sales. The authors demonstrate the success of machine learning techniques for gender classification. High-sensitivity accelerometers mounted non-invasively beneath an actual building floor provide the input for these machine learning methods. While other approaches using gait measurements, such as vision systems and wearable sensors, provide the potential for gender classification, they each face limitations. These limitations include an invasion of privacy, occupant compliance, required line of sight, and/or high sensor density. Underfloor mounted accelerometers overcome these limitations. The authors utilize the highly-instrumented Goodwin Hall smart building on the Virginia Tech campus to measure vibrations of the walking surface caused by walkers. In this study, the gait of fifteen individual walkers was recorded as they, alone, walked down the instrumented hallway. Fourteen accelerometers, mounted underneath the walking surface, recorded walking trials with the placement of the sensors unknown to the walker. This work studies Bagged Decision Trees, Boosted Decision Trees, Support Vector Machines (SVMs), and Neural Networks as the machine learning techniques for their ability to classify gender. A ten-fold-cross-validation method is used to comment on the validity of the algorithm’s ability to generalize to new walkers. This work demonstrates that a gender classification accuracy of 88% is achievable using the underfloor vibration data from the Virginia Tech Goodwin Hall by using Decision Tree approaches.

• Experimental validation of the vibro-acoustic model of a pressurized membrane

  Mechanical Systems and Signal Processing

  The work presented here focuses on the validation of an impedance-based model of a membrane in air and of a coupled membrane–cavity system using experimental results. The impedance based model takes into account sound radiation and energy loss to the far field. This is crucial in earth-based telescopes and also very important when testing and validating these systems on earth before being launched into space.

• Modeling of Hysteresis Effect of SMA using Neuro Fuzzy Inference System

  54th AIAA/ASME/ASCE/AHS/ASC structures, Structural Dynamics, and Materials Conference and Co-located Events

• The quadratic compression method for model updating and its noise filtering properties

  Mechanical Systems and Signal Processing

• vibro-acoustics of a pressurized optical membrane

  Mechanical Systems and Signal Processing

  ► The work presented herein studies the coupling effects of a circular membrane to an air cavity. ► The effects of air loading and radiation are considered and compared to that of a membrane in vacuum. ► Coupling is carried using an impedance based modeling approach. ► A novel acoustic actuation method is used for vibration suppression. ► The novel approach proves to be feasible as a way of vibration suppression.

• Mimicking the cochlear amplifier in a cantilever beam using nonlinear velocity feedback control

  Smart Materials and Structures

  he mammalian cochlea exhibits a nonlinear amplification which allows mammals to detect a large range of sound pressure levels while maintaining high frequency sensitivity. This work seeks to mimic the cochlea's nonlinear amplification in a mechanical system. A nonlinear, velocity-based feedback control law is applied to a cantilever beam with piezoelectric actuators. The control law reduces the linear viscous damping of the system while introducing a cubic damping term. The result is a system which is positioned close to a Hopf bifurcation. Modelling and experimental results show that the beam with this control law undergoes a one-third amplitude scaling near the resonance frequency and an amplitude-dependent bandwidth. Both behaviors are characteristic of data obtained from the mammalian cochlea. This work could provide insight on the biological cochlea while producing bio-inspired sensors with a large dynamic range and sharp frequency sensitivity.

• Effect of Strain Nodes and Electrode Configuration on Piezoeletric Energy Harvesting from Cantilever Beams

  ASME Journal of Vibration and Acoustics

• Gender Classification of Walkers Via Underfloor Accelerometer Measurements

  IEEE Internet of Things Journal

  The ability to classify the gender of occupants in a building has far-reaching applications including security and retail sales. The authors demonstrate the success of machine learning techniques for gender classification. High-sensitivity accelerometers mounted non-invasively beneath an actual building floor provide the input for these machine learning methods. While other approaches using gait measurements, such as vision systems and wearable sensors, provide the potential for gender classification, they each face limitations. These limitations include an invasion of privacy, occupant compliance, required line of sight, and/or high sensor density. Underfloor mounted accelerometers overcome these limitations. The authors utilize the highly-instrumented Goodwin Hall smart building on the Virginia Tech campus to measure vibrations of the walking surface caused by walkers. In this study, the gait of fifteen individual walkers was recorded as they, alone, walked down the instrumented hallway. Fourteen accelerometers, mounted underneath the walking surface, recorded walking trials with the placement of the sensors unknown to the walker. This work studies Bagged Decision Trees, Boosted Decision Trees, Support Vector Machines (SVMs), and Neural Networks as the machine learning techniques for their ability to classify gender. A ten-fold-cross-validation method is used to comment on the validity of the algorithm’s ability to generalize to new walkers. This work demonstrates that a gender classification accuracy of 88% is achievable using the underfloor vibration data from the Virginia Tech Goodwin Hall by using Decision Tree approaches.

• Experimental validation of the vibro-acoustic model of a pressurized membrane

  Mechanical Systems and Signal Processing

  The work presented here focuses on the validation of an impedance-based model of a membrane in air and of a coupled membrane–cavity system using experimental results. The impedance based model takes into account sound radiation and energy loss to the far field. This is crucial in earth-based telescopes and also very important when testing and validating these systems on earth before being launched into space.

• Continuous Scanning for Acoustics Field Characterization

  International Modal Analysis Conference (IMAC) XXXI

• Modeling of Hysteresis Effect of SMA using Neuro Fuzzy Inference System

  54th AIAA/ASME/ASCE/AHS/ASC structures, Structural Dynamics, and Materials Conference and Co-located Events

• The quadratic compression method for model updating and its noise filtering properties

  Mechanical Systems and Signal Processing

• vibro-acoustics of a pressurized optical membrane

  Mechanical Systems and Signal Processing

  ► The work presented herein studies the coupling effects of a circular membrane to an air cavity. ► The effects of air loading and radiation are considered and compared to that of a membrane in vacuum. ► Coupling is carried using an impedance based modeling approach. ► A novel acoustic actuation method is used for vibration suppression. ► The novel approach proves to be feasible as a way of vibration suppression.

• Mimicking the cochlear amplifier in a cantilever beam using nonlinear velocity feedback control

  Smart Materials and Structures

  he mammalian cochlea exhibits a nonlinear amplification which allows mammals to detect a large range of sound pressure levels while maintaining high frequency sensitivity. This work seeks to mimic the cochlea's nonlinear amplification in a mechanical system. A nonlinear, velocity-based feedback control law is applied to a cantilever beam with piezoelectric actuators. The control law reduces the linear viscous damping of the system while introducing a cubic damping term. The result is a system which is positioned close to a Hopf bifurcation. Modelling and experimental results show that the beam with this control law undergoes a one-third amplitude scaling near the resonance frequency and an amplitude-dependent bandwidth. Both behaviors are characteristic of data obtained from the mammalian cochlea. This work could provide insight on the biological cochlea while producing bio-inspired sensors with a large dynamic range and sharp frequency sensitivity.

• Effect of Strain Nodes and Electrode Configuration on Piezoeletric Energy Harvesting from Cantilever Beams

  ASME Journal of Vibration and Acoustics

• Gender Classification of Walkers Via Underfloor Accelerometer Measurements

  IEEE Internet of Things Journal

  The ability to classify the gender of occupants in a building has far-reaching applications including security and retail sales. The authors demonstrate the success of machine learning techniques for gender classification. High-sensitivity accelerometers mounted non-invasively beneath an actual building floor provide the input for these machine learning methods. While other approaches using gait measurements, such as vision systems and wearable sensors, provide the potential for gender classification, they each face limitations. These limitations include an invasion of privacy, occupant compliance, required line of sight, and/or high sensor density. Underfloor mounted accelerometers overcome these limitations. The authors utilize the highly-instrumented Goodwin Hall smart building on the Virginia Tech campus to measure vibrations of the walking surface caused by walkers. In this study, the gait of fifteen individual walkers was recorded as they, alone, walked down the instrumented hallway. Fourteen accelerometers, mounted underneath the walking surface, recorded walking trials with the placement of the sensors unknown to the walker. This work studies Bagged Decision Trees, Boosted Decision Trees, Support Vector Machines (SVMs), and Neural Networks as the machine learning techniques for their ability to classify gender. A ten-fold-cross-validation method is used to comment on the validity of the algorithm’s ability to generalize to new walkers. This work demonstrates that a gender classification accuracy of 88% is achievable using the underfloor vibration data from the Virginia Tech Goodwin Hall by using Decision Tree approaches.

• Experimental validation of the vibro-acoustic model of a pressurized membrane

  Mechanical Systems and Signal Processing

  The work presented here focuses on the validation of an impedance-based model of a membrane in air and of a coupled membrane–cavity system using experimental results. The impedance based model takes into account sound radiation and energy loss to the far field. This is crucial in earth-based telescopes and also very important when testing and validating these systems on earth before being launched into space.

• Continuous Scanning for Acoustics Field Characterization

  International Modal Analysis Conference (IMAC) XXXI

• Parametric study of Continuous scanning methods characterizing acoustic field

  International Modal Analysis Conference (IMAC) XXXII

• Modeling of Hysteresis Effect of SMA using Neuro Fuzzy Inference System

  54th AIAA/ASME/ASCE/AHS/ASC structures, Structural Dynamics, and Materials Conference and Co-located Events

• The quadratic compression method for model updating and its noise filtering properties

  Mechanical Systems and Signal Processing

• vibro-acoustics of a pressurized optical membrane

  Mechanical Systems and Signal Processing

  ► The work presented herein studies the coupling effects of a circular membrane to an air cavity. ► The effects of air loading and radiation are considered and compared to that of a membrane in vacuum. ► Coupling is carried using an impedance based modeling approach. ► A novel acoustic actuation method is used for vibration suppression. ► The novel approach proves to be feasible as a way of vibration suppression.

• Mimicking the cochlear amplifier in a cantilever beam using nonlinear velocity feedback control

  Smart Materials and Structures

  he mammalian cochlea exhibits a nonlinear amplification which allows mammals to detect a large range of sound pressure levels while maintaining high frequency sensitivity. This work seeks to mimic the cochlea's nonlinear amplification in a mechanical system. A nonlinear, velocity-based feedback control law is applied to a cantilever beam with piezoelectric actuators. The control law reduces the linear viscous damping of the system while introducing a cubic damping term. The result is a system which is positioned close to a Hopf bifurcation. Modelling and experimental results show that the beam with this control law undergoes a one-third amplitude scaling near the resonance frequency and an amplitude-dependent bandwidth. Both behaviors are characteristic of data obtained from the mammalian cochlea. This work could provide insight on the biological cochlea while producing bio-inspired sensors with a large dynamic range and sharp frequency sensitivity.

• Effect of Strain Nodes and Electrode Configuration on Piezoeletric Energy Harvesting from Cantilever Beams

  ASME Journal of Vibration and Acoustics

• Gender Classification of Walkers Via Underfloor Accelerometer Measurements

  IEEE Internet of Things Journal

  The ability to classify the gender of occupants in a building has far-reaching applications including security and retail sales. The authors demonstrate the success of machine learning techniques for gender classification. High-sensitivity accelerometers mounted non-invasively beneath an actual building floor provide the input for these machine learning methods. While other approaches using gait measurements, such as vision systems and wearable sensors, provide the potential for gender classification, they each face limitations. These limitations include an invasion of privacy, occupant compliance, required line of sight, and/or high sensor density. Underfloor mounted accelerometers overcome these limitations. The authors utilize the highly-instrumented Goodwin Hall smart building on the Virginia Tech campus to measure vibrations of the walking surface caused by walkers. In this study, the gait of fifteen individual walkers was recorded as they, alone, walked down the instrumented hallway. Fourteen accelerometers, mounted underneath the walking surface, recorded walking trials with the placement of the sensors unknown to the walker. This work studies Bagged Decision Trees, Boosted Decision Trees, Support Vector Machines (SVMs), and Neural Networks as the machine learning techniques for their ability to classify gender. A ten-fold-cross-validation method is used to comment on the validity of the algorithm’s ability to generalize to new walkers. This work demonstrates that a gender classification accuracy of 88% is achievable using the underfloor vibration data from the Virginia Tech Goodwin Hall by using Decision Tree approaches.

• Experimental validation of the vibro-acoustic model of a pressurized membrane

  Mechanical Systems and Signal Processing

  The work presented here focuses on the validation of an impedance-based model of a membrane in air and of a coupled membrane–cavity system using experimental results. The impedance based model takes into account sound radiation and energy loss to the far field. This is crucial in earth-based telescopes and also very important when testing and validating these systems on earth before being launched into space.

• Continuous Scanning for Acoustics Field Characterization

  International Modal Analysis Conference (IMAC) XXXI

• Parametric study of Continuous scanning methods characterizing acoustic field

  International Modal Analysis Conference (IMAC) XXXII

• Modified Quadratic Compression Method for mass and stiffness updating

  Mechanical Systems and Signal Processing

• Modeling of Hysteresis Effect of SMA using Neuro Fuzzy Inference System

  54th AIAA/ASME/ASCE/AHS/ASC structures, Structural Dynamics, and Materials Conference and Co-located Events

• The quadratic compression method for model updating and its noise filtering properties

  Mechanical Systems and Signal Processing

• vibro-acoustics of a pressurized optical membrane

  Mechanical Systems and Signal Processing

  ► The work presented herein studies the coupling effects of a circular membrane to an air cavity. ► The effects of air loading and radiation are considered and compared to that of a membrane in vacuum. ► Coupling is carried using an impedance based modeling approach. ► A novel acoustic actuation method is used for vibration suppression. ► The novel approach proves to be feasible as a way of vibration suppression.

• Mimicking the cochlear amplifier in a cantilever beam using nonlinear velocity feedback control

  Smart Materials and Structures

  he mammalian cochlea exhibits a nonlinear amplification which allows mammals to detect a large range of sound pressure levels while maintaining high frequency sensitivity. This work seeks to mimic the cochlea's nonlinear amplification in a mechanical system. A nonlinear, velocity-based feedback control law is applied to a cantilever beam with piezoelectric actuators. The control law reduces the linear viscous damping of the system while introducing a cubic damping term. The result is a system which is positioned close to a Hopf bifurcation. Modelling and experimental results show that the beam with this control law undergoes a one-third amplitude scaling near the resonance frequency and an amplitude-dependent bandwidth. Both behaviors are characteristic of data obtained from the mammalian cochlea. This work could provide insight on the biological cochlea while producing bio-inspired sensors with a large dynamic range and sharp frequency sensitivity.

• Effect of Strain Nodes and Electrode Configuration on Piezoeletric Energy Harvesting from Cantilever Beams

  ASME Journal of Vibration and Acoustics

• Gender Classification of Walkers Via Underfloor Accelerometer Measurements

  IEEE Internet of Things Journal

  The ability to classify the gender of occupants in a building has far-reaching applications including security and retail sales. The authors demonstrate the success of machine learning techniques for gender classification. High-sensitivity accelerometers mounted non-invasively beneath an actual building floor provide the input for these machine learning methods. While other approaches using gait measurements, such as vision systems and wearable sensors, provide the potential for gender classification, they each face limitations. These limitations include an invasion of privacy, occupant compliance, required line of sight, and/or high sensor density. Underfloor mounted accelerometers overcome these limitations. The authors utilize the highly-instrumented Goodwin Hall smart building on the Virginia Tech campus to measure vibrations of the walking surface caused by walkers. In this study, the gait of fifteen individual walkers was recorded as they, alone, walked down the instrumented hallway. Fourteen accelerometers, mounted underneath the walking surface, recorded walking trials with the placement of the sensors unknown to the walker. This work studies Bagged Decision Trees, Boosted Decision Trees, Support Vector Machines (SVMs), and Neural Networks as the machine learning techniques for their ability to classify gender. A ten-fold-cross-validation method is used to comment on the validity of the algorithm’s ability to generalize to new walkers. This work demonstrates that a gender classification accuracy of 88% is achievable using the underfloor vibration data from the Virginia Tech Goodwin Hall by using Decision Tree approaches.

• Experimental validation of the vibro-acoustic model of a pressurized membrane

  Mechanical Systems and Signal Processing

  The work presented here focuses on the validation of an impedance-based model of a membrane in air and of a coupled membrane–cavity system using experimental results. The impedance based model takes into account sound radiation and energy loss to the far field. This is crucial in earth-based telescopes and also very important when testing and validating these systems on earth before being launched into space.

• Continuous Scanning for Acoustics Field Characterization

  International Modal Analysis Conference (IMAC) XXXI

• Parametric study of Continuous scanning methods characterizing acoustic field

  International Modal Analysis Conference (IMAC) XXXII

• Modified Quadratic Compression Method for mass and stiffness updating

  Mechanical Systems and Signal Processing

• Gender Classification using Vibration Measurements

  Society of Experimental Mechanics - IMAC Conference

• Modeling of Hysteresis Effect of SMA using Neuro Fuzzy Inference System

  54th AIAA/ASME/ASCE/AHS/ASC structures, Structural Dynamics, and Materials Conference and Co-located Events

• The quadratic compression method for model updating and its noise filtering properties

  Mechanical Systems and Signal Processing

• vibro-acoustics of a pressurized optical membrane

  Mechanical Systems and Signal Processing

  ► The work presented herein studies the coupling effects of a circular membrane to an air cavity. ► The effects of air loading and radiation are considered and compared to that of a membrane in vacuum. ► Coupling is carried using an impedance based modeling approach. ► A novel acoustic actuation method is used for vibration suppression. ► The novel approach proves to be feasible as a way of vibration suppression.

• Mimicking the cochlear amplifier in a cantilever beam using nonlinear velocity feedback control

  Smart Materials and Structures

  he mammalian cochlea exhibits a nonlinear amplification which allows mammals to detect a large range of sound pressure levels while maintaining high frequency sensitivity. This work seeks to mimic the cochlea's nonlinear amplification in a mechanical system. A nonlinear, velocity-based feedback control law is applied to a cantilever beam with piezoelectric actuators. The control law reduces the linear viscous damping of the system while introducing a cubic damping term. The result is a system which is positioned close to a Hopf bifurcation. Modelling and experimental results show that the beam with this control law undergoes a one-third amplitude scaling near the resonance frequency and an amplitude-dependent bandwidth. Both behaviors are characteristic of data obtained from the mammalian cochlea. This work could provide insight on the biological cochlea while producing bio-inspired sensors with a large dynamic range and sharp frequency sensitivity.

• Effect of Strain Nodes and Electrode Configuration on Piezoeletric Energy Harvesting from Cantilever Beams

  ASME Journal of Vibration and Acoustics

• Gender Classification of Walkers Via Underfloor Accelerometer Measurements

  IEEE Internet of Things Journal

  The ability to classify the gender of occupants in a building has far-reaching applications including security and retail sales. The authors demonstrate the success of machine learning techniques for gender classification. High-sensitivity accelerometers mounted non-invasively beneath an actual building floor provide the input for these machine learning methods. While other approaches using gait measurements, such as vision systems and wearable sensors, provide the potential for gender classification, they each face limitations. These limitations include an invasion of privacy, occupant compliance, required line of sight, and/or high sensor density. Underfloor mounted accelerometers overcome these limitations. The authors utilize the highly-instrumented Goodwin Hall smart building on the Virginia Tech campus to measure vibrations of the walking surface caused by walkers. In this study, the gait of fifteen individual walkers was recorded as they, alone, walked down the instrumented hallway. Fourteen accelerometers, mounted underneath the walking surface, recorded walking trials with the placement of the sensors unknown to the walker. This work studies Bagged Decision Trees, Boosted Decision Trees, Support Vector Machines (SVMs), and Neural Networks as the machine learning techniques for their ability to classify gender. A ten-fold-cross-validation method is used to comment on the validity of the algorithm’s ability to generalize to new walkers. This work demonstrates that a gender classification accuracy of 88% is achievable using the underfloor vibration data from the Virginia Tech Goodwin Hall by using Decision Tree approaches.

• Experimental validation of the vibro-acoustic model of a pressurized membrane

  Mechanical Systems and Signal Processing

  The work presented here focuses on the validation of an impedance-based model of a membrane in air and of a coupled membrane–cavity system using experimental results. The impedance based model takes into account sound radiation and energy loss to the far field. This is crucial in earth-based telescopes and also very important when testing and validating these systems on earth before being launched into space.

• Continuous Scanning for Acoustics Field Characterization

  International Modal Analysis Conference (IMAC) XXXI

• Parametric study of Continuous scanning methods characterizing acoustic field

  International Modal Analysis Conference (IMAC) XXXII

• Modified Quadratic Compression Method for mass and stiffness updating

  Mechanical Systems and Signal Processing

• Gender Classification using Vibration Measurements

  Society of Experimental Mechanics - IMAC Conference

• Frequency Range Selection for Impedance-Based Structural Health Monitoring

  Journal of Vibration and Acoustics

• Modeling of Hysteresis Effect of SMA using Neuro Fuzzy Inference System

  54th AIAA/ASME/ASCE/AHS/ASC structures, Structural Dynamics, and Materials Conference and Co-located Events

• The quadratic compression method for model updating and its noise filtering properties

  Mechanical Systems and Signal Processing

• vibro-acoustics of a pressurized optical membrane

  Mechanical Systems and Signal Processing

  ► The work presented herein studies the coupling effects of a circular membrane to an air cavity. ► The effects of air loading and radiation are considered and compared to that of a membrane in vacuum. ► Coupling is carried using an impedance based modeling approach. ► A novel acoustic actuation method is used for vibration suppression. ► The novel approach proves to be feasible as a way of vibration suppression.

• Mimicking the cochlear amplifier in a cantilever beam using nonlinear velocity feedback control

  Smart Materials and Structures

  he mammalian cochlea exhibits a nonlinear amplification which allows mammals to detect a large range of sound pressure levels while maintaining high frequency sensitivity. This work seeks to mimic the cochlea's nonlinear amplification in a mechanical system. A nonlinear, velocity-based feedback control law is applied to a cantilever beam with piezoelectric actuators. The control law reduces the linear viscous damping of the system while introducing a cubic damping term. The result is a system which is positioned close to a Hopf bifurcation. Modelling and experimental results show that the beam with this control law undergoes a one-third amplitude scaling near the resonance frequency and an amplitude-dependent bandwidth. Both behaviors are characteristic of data obtained from the mammalian cochlea. This work could provide insight on the biological cochlea while producing bio-inspired sensors with a large dynamic range and sharp frequency sensitivity.

• Effect of Strain Nodes and Electrode Configuration on Piezoeletric Energy Harvesting from Cantilever Beams

  ASME Journal of Vibration and Acoustics

• Gender Classification of Walkers Via Underfloor Accelerometer Measurements

  IEEE Internet of Things Journal

  The ability to classify the gender of occupants in a building has far-reaching applications including security and retail sales. The authors demonstrate the success of machine learning techniques for gender classification. High-sensitivity accelerometers mounted non-invasively beneath an actual building floor provide the input for these machine learning methods. While other approaches using gait measurements, such as vision systems and wearable sensors, provide the potential for gender classification, they each face limitations. These limitations include an invasion of privacy, occupant compliance, required line of sight, and/or high sensor density. Underfloor mounted accelerometers overcome these limitations. The authors utilize the highly-instrumented Goodwin Hall smart building on the Virginia Tech campus to measure vibrations of the walking surface caused by walkers. In this study, the gait of fifteen individual walkers was recorded as they, alone, walked down the instrumented hallway. Fourteen accelerometers, mounted underneath the walking surface, recorded walking trials with the placement of the sensors unknown to the walker. This work studies Bagged Decision Trees, Boosted Decision Trees, Support Vector Machines (SVMs), and Neural Networks as the machine learning techniques for their ability to classify gender. A ten-fold-cross-validation method is used to comment on the validity of the algorithm’s ability to generalize to new walkers. This work demonstrates that a gender classification accuracy of 88% is achievable using the underfloor vibration data from the Virginia Tech Goodwin Hall by using Decision Tree approaches.

• Experimental validation of the vibro-acoustic model of a pressurized membrane

  Mechanical Systems and Signal Processing

  The work presented here focuses on the validation of an impedance-based model of a membrane in air and of a coupled membrane–cavity system using experimental results. The impedance based model takes into account sound radiation and energy loss to the far field. This is crucial in earth-based telescopes and also very important when testing and validating these systems on earth before being launched into space.

• Continuous Scanning for Acoustics Field Characterization

  International Modal Analysis Conference (IMAC) XXXI

• Parametric study of Continuous scanning methods characterizing acoustic field

  International Modal Analysis Conference (IMAC) XXXII

• Modified Quadratic Compression Method for mass and stiffness updating

  Mechanical Systems and Signal Processing

• Gender Classification using Vibration Measurements

  Society of Experimental Mechanics - IMAC Conference

• Frequency Range Selection for Impedance-Based Structural Health Monitoring

  Journal of Vibration and Acoustics

• Control of Space Rigidizable-Inflatable Boom Using Macro-Fiber Composite

  Journal of Vibration and Control

• Modeling of Hysteresis Effect of SMA using Neuro Fuzzy Inference System

  54th AIAA/ASME/ASCE/AHS/ASC structures, Structural Dynamics, and Materials Conference and Co-located Events

• The quadratic compression method for model updating and its noise filtering properties

  Mechanical Systems and Signal Processing

• vibro-acoustics of a pressurized optical membrane

  Mechanical Systems and Signal Processing

  ► The work presented herein studies the coupling effects of a circular membrane to an air cavity. ► The effects of air loading and radiation are considered and compared to that of a membrane in vacuum. ► Coupling is carried using an impedance based modeling approach. ► A novel acoustic actuation method is used for vibration suppression. ► The novel approach proves to be feasible as a way of vibration suppression.

• Mimicking the cochlear amplifier in a cantilever beam using nonlinear velocity feedback control

  Smart Materials and Structures

  he mammalian cochlea exhibits a nonlinear amplification which allows mammals to detect a large range of sound pressure levels while maintaining high frequency sensitivity. This work seeks to mimic the cochlea's nonlinear amplification in a mechanical system. A nonlinear, velocity-based feedback control law is applied to a cantilever beam with piezoelectric actuators. The control law reduces the linear viscous damping of the system while introducing a cubic damping term. The result is a system which is positioned close to a Hopf bifurcation. Modelling and experimental results show that the beam with this control law undergoes a one-third amplitude scaling near the resonance frequency and an amplitude-dependent bandwidth. Both behaviors are characteristic of data obtained from the mammalian cochlea. This work could provide insight on the biological cochlea while producing bio-inspired sensors with a large dynamic range and sharp frequency sensitivity.

• Effect of Strain Nodes and Electrode Configuration on Piezoeletric Energy Harvesting from Cantilever Beams

  ASME Journal of Vibration and Acoustics

• Gender Classification of Walkers Via Underfloor Accelerometer Measurements

  IEEE Internet of Things Journal

  The ability to classify the gender of occupants in a building has far-reaching applications including security and retail sales. The authors demonstrate the success of machine learning techniques for gender classification. High-sensitivity accelerometers mounted non-invasively beneath an actual building floor provide the input for these machine learning methods. While other approaches using gait measurements, such as vision systems and wearable sensors, provide the potential for gender classification, they each face limitations. These limitations include an invasion of privacy, occupant compliance, required line of sight, and/or high sensor density. Underfloor mounted accelerometers overcome these limitations. The authors utilize the highly-instrumented Goodwin Hall smart building on the Virginia Tech campus to measure vibrations of the walking surface caused by walkers. In this study, the gait of fifteen individual walkers was recorded as they, alone, walked down the instrumented hallway. Fourteen accelerometers, mounted underneath the walking surface, recorded walking trials with the placement of the sensors unknown to the walker. This work studies Bagged Decision Trees, Boosted Decision Trees, Support Vector Machines (SVMs), and Neural Networks as the machine learning techniques for their ability to classify gender. A ten-fold-cross-validation method is used to comment on the validity of the algorithm’s ability to generalize to new walkers. This work demonstrates that a gender classification accuracy of 88% is achievable using the underfloor vibration data from the Virginia Tech Goodwin Hall by using Decision Tree approaches.

• Experimental validation of the vibro-acoustic model of a pressurized membrane

  Mechanical Systems and Signal Processing

  The work presented here focuses on the validation of an impedance-based model of a membrane in air and of a coupled membrane–cavity system using experimental results. The impedance based model takes into account sound radiation and energy loss to the far field. This is crucial in earth-based telescopes and also very important when testing and validating these systems on earth before being launched into space.

• Continuous Scanning for Acoustics Field Characterization

  International Modal Analysis Conference (IMAC) XXXI

• Parametric study of Continuous scanning methods characterizing acoustic field

  International Modal Analysis Conference (IMAC) XXXII

• Modified Quadratic Compression Method for mass and stiffness updating

  Mechanical Systems and Signal Processing

• Gender Classification using Vibration Measurements

  Society of Experimental Mechanics - IMAC Conference

• Frequency Range Selection for Impedance-Based Structural Health Monitoring

  Journal of Vibration and Acoustics

• Control of Space Rigidizable-Inflatable Boom Using Macro-Fiber Composite

  Journal of Vibration and Control

• A study of active artificial hair cell models inspired by outer hair cell somatic motility​

  Journal Intelligent Material Systems and Structures

  The cochlea displays an important, nonlinear amplification of sound-induced oscillations. In mammals, this amplification is largely powered by the somatic motility of the outer hair cells. The resulting cochlear amplifier has three important characteristics useful for hearing: an amplification of responses from low sound pressures, an improvement in frequency selectivity, and an ability to transduce a broad range of sound pressure levels. These useful features can be incorporated into designs for active artificial hair cells, bio-inspired sensors for use as microphones, accelerometers, or other dynamic sensors. The sensor consists of a cantilever beam with piezoelectric actuators. A feedback controller applies a voltage to the actuators to mimic the outer hair cells’ somatic motility. This article describes three control laws for an active artificial hair cell inspired by models of the outer hair cells’ somatic motility. The first control law is based on a phenomenological model of the cochlea while the second and third models incorporate physiological aspects of the biological cochlea to further improve sensor performance. Simulations show that these models qualitatively reproduce the key aspects of the mammalian cochlea, namely, amplification of oscillations from weak stimuli, higher quality factors, and a wider input dynamic range.