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Full-Text Articles in Mechanical Engineering
Frequency Division Multiplexing Of A Multi-Channel Resistive Pulse Sensor, Ashish Jagtiani, Jiang Zhe, Joan Carletta
Frequency Division Multiplexing Of A Multi-Channel Resistive Pulse Sensor, Ashish Jagtiani, Jiang Zhe, Joan Carletta
Joan Carletta
We present the design, fabrication and testing of a microfluidic multichannel resistive pulse sensor for high throughput counting of microparticles. The high throughput counting results from using multiple parallel microfluidic channels to analyze the sample. Detection is achieved by using frequency division multiplexing where a known and unique frequency is applied to modulate each microchannel and a combined measurement is made across a single pair of electrodes. Testing results using 30μm polystyrene particles demonstrate that the throughput of the multiplexed device is improved 300% over a single channel device. In addition, the AC modulation method reduces the polarization effect on …
Frequency Division Multiplexing Of A Multi-Channel Resistive Pulse Sensor, Ashish Jagtiani, Jiang Zhe, Joan Carletta
Frequency Division Multiplexing Of A Multi-Channel Resistive Pulse Sensor, Ashish Jagtiani, Jiang Zhe, Joan Carletta
Dr. Jiang Zhe
We present the design, fabrication and testing of a microfluidic multichannel resistive pulse sensor for high throughput counting of microparticles. The high throughput counting results from using multiple parallel microfluidic channels to analyze the sample. Detection is achieved by using frequency division multiplexing where a known and unique frequency is applied to modulate each microchannel and a combined measurement is made across a single pair of electrodes. Testing results using 30μm polystyrene particles demonstrate that the throughput of the multiplexed device is improved 300% over a single channel device. In addition, the AC modulation method reduces the polarization effect on …
Optimization Of Threshold Values For Estimators Based On Single-Bit Quantized Sensors Using Genetic Algorithms, Nishant Unnikrishnan, Ajay Mahajan, Antonios Mengoulis, R. Viswanathan
Optimization Of Threshold Values For Estimators Based On Single-Bit Quantized Sensors Using Genetic Algorithms, Nishant Unnikrishnan, Ajay Mahajan, Antonios Mengoulis, R. Viswanathan
Dr. Ajay Mahajan
The paper considers the problem of signal parameter estimation using a collection of distributed sensors called a sensor pack. Each sensor quantizes its data to one-bit information and sends it to a fusion processor for the estimation of the parameter. Estimation of a constant signal in additive noise is considered. Estimators are formulated based on one-bit sensor data and their mean squared error (MSE) performances are evaluated through simulation studies. It is shown that selecting certain threshold values for quantizing the sensor outputs can lower the MSE. Genetic algorithms are used to find the optimal threshold values for the sensors. …
Intelligent Sensors For Integrated Health Management Systems, Christopher Oesch, Ajay Mahajan, Lucas Utterback, Haricharan Padmanaban, Sanjeevi Chitikeshi, Fernando Figueroa
Intelligent Sensors For Integrated Health Management Systems, Christopher Oesch, Ajay Mahajan, Lucas Utterback, Haricharan Padmanaban, Sanjeevi Chitikeshi, Fernando Figueroa
Dr. Ajay Mahajan
This paper describes work being conducted on the development of intelligent sensors with learning capabilities as part of an integrated systems approach. The integrated systems approach treats the sensor as a complete system with its own sensing hardware (the traditional sensor), A/D converter, processing and storage capabilities, software drivers, self-assessment algorithms, communication protocols and evolutionary methodologies that allow the system to learn its own behavior. The immediate application is the monitoring of rocket test stands, but the technology should be generally applicable to the Integrated Systems Health Monitoring (ISHM) vision. This paper outlines progress made in the development of intelligent …
Application Of Intelligent Sensors In The Integrated Systems Health Monitoring Of A Rocket Test Stand, Ajay Mahajan, Sanjeevi Chitikeshi, Lucas Utterback, Pavan Bandhil, Fernando Figueroa
Application Of Intelligent Sensors In The Integrated Systems Health Monitoring Of A Rocket Test Stand, Ajay Mahajan, Sanjeevi Chitikeshi, Lucas Utterback, Pavan Bandhil, Fernando Figueroa
Dr. Ajay Mahajan
This paper describes the application of intelligent sensors in the Integrated Systems Health Monitoring (ISHM) as applied to a rocket test stand. The development of intelligent sensors is attempted as an integrated system approach, i.e. one treats the sensors as a complete system with its own physical transducer, A/D converters, processing and storage capabilities, software drivers, self-assessment algorithms, communication protocols and evolutionary methodologies that allow them to get better with time. Under a project being undertaken at the NASA Stennis Space Center, an integrated framework is being developed for the intelligent monitoring of smart elements associated with the rocket tests …