Measurement Science

This paper describes the development of a low cost coaxial moisture sensor for the determination of moisture content (30% to 80% wet-weight basis) of the oil palm fruits of various degree of fruit ripeness. The sensor operating between 1 GHz and 5 GHz was ...

Simulation and measurements of muzzle blast overpressure and its physical manifestations are studied in this paper. The use of a silencer can have a great influence on the overpressure intensity. A silencer is regarded as an acoustic transducer and a waveguide. Wave equations for an acoustic dotted source of directed effect are used for physical interpretation of overpressure as an acoustic phenomenon. Decomposition approach has proven to be suitable to describe the formation of the output wave of the wave transducer. Electroacoustic analogies are used for simulations. A measurement chain was used to compare the simulation results with the experimental ones.

The last two decades have shown an increasing trend in the use of navigation technologies in several applications including land vehicles and automated car navigation. Navigation systems incorporate the global positioning system (GPS) and the inertial navigation system (INS). While GPS provides position information when there is direct line of sight to four or more satellites, INS utilizes the local measurements of angular velocity and linear acceleration to determine both the vehicle's position and attitude. Both systems are integrated together to provide reliable navigation solutions by overcoming each of their respective shortcomings. The present integration schemes, which are predominantly based on Kalman filtering, have several inadequacies related to sensor error models, immunity to noise and observability. This paper aims at introducing a multi-sensor system integration approach for fusing data from an INS and GPS hardware utilizing wavelet multi-resolution analysis (WMRA) and artificial neural networks (ANN). The WMRA is used to compare the INS and GPS position outputs at different resolution levels. The ANN module is then trained to predict the INS position errors in real time and provide accurate positioning of the moving vehicle. The field-test results have demonstrated that substantial improvements in INS/GPS positioning accuracy could be obtained by applying the proposed neuro-wavelet technique.

This paper describes instrumental measurement uncertainties and their influence on the result obtained from determination of rock sample uniaxial compressive strength and deformability. The interdependence of uncertainty contribution is analyzed and guides for improving measurement uncertainty are given. The achieved uncertainties are compared to typical uncertainties in the determination of concrete and metallic material compressive strength and deformability.

https://www.ijert.org/monitoring-temperature-and-humidity-using-arduino-nano-and-module-dht11-sensor-with-real-time-ds3231-data-logger-and-lcd-display

https://www.ijert.org/research/monitoring-temperature-and-humidity-using-arduino-nano-and-module-dht11-sensor-with-real-time-ds3231-data-logger-and-lcd-display-IJERTV9IS120214.pdf

Humidity and Temperature are crucial parameters for the optimal response of biological systems e.g. each has its own impact on growth and production of quality crops. There are several techniques of measuring humidity and temperature. However, there is still a need for continuous technological innovation to enable fast, real time and remote monitoring of these parameters. The aim of this study research was to fabricate a functional hardware and software system to measure temperature and humidity. The system was designed to allow multiple communication with user by recording of the data in Real time, storing the acquired data in an SD card, incorporate an alarming system (piezo buzzer) together with an LED indication mechanism. The study utilized an Arduino Nano board interfaced with a Temperature and Humidity sensor, Real Time Clock (RTC), LCD, and Micro SD card Module, piezo buzzer and LED, and had the ability to store the data as text file. A code was generated using the computer with the appropriate Arduino program and sent to the Arduino microcontroller for running the circuit. To study the performance characteristics of the Arduino-based humidity and temperature sensor, two independent running test were done, one outside the Physics laboratories and the second inside a Green House, both at Chuka University, Kenya.

This paper presents a device that uses three cardiography signals to characterize several important parameters of a subject's circulatory system. Using electrocardiogram, finger photoplethysmogram, and ballistocardiogram, three heart rate estimates are acquired from beat-to-beat time interval extraction. Furthermore, pre-ejection period, pulse transit time (PTT), and pulse arrival time (PAT) are computed, and their long-term evolution is analyzed. The system estimates

This review presents possible strategies to increase the operational frequency range of vibration-based micro-generators. Most vibration-based micro-generators are spring-mass-damper systems which generate maximum power when the resonant frequency of the generator matches the frequency of the ambient vibration. Any difference between these two frequencies can result in a significant decrease in generated power. This is a fundamental limitation of resonant vibration generators which restricts their capability in real applications. Possible solutions include the periodic tuning of the resonant frequency of the generator so that it matches the frequency of the ambient vibration at all times or widening the bandwidth of the generator. Periodic tuning can be achieved using mechanical or electrical methods. Bandwidth widening can be achieved using a generator array, a mechanical stopper, nonlinear (e.g. magnetic) springs or bi-stable structures. Tuning methods can be classified into intermittent tuning (power is consumed periodically to tune the device) and continuous tuning (the tuning mechanism is continuously powered). This review presents a comprehensive review of the principles and operating strategies for increasing the operating frequency range of vibration-based micro-generators presented in the literature to date. The advantages and disadvantages of each strategy are evaluated and conclusions are drawn regarding the relevant merits of each approach.

Epileptic seizure attack is caused by abnormal brain activity of human subjects. Certain cases will lead to death. The detection and diagnosis is therefore an important task. It can be performed either by direct patient activity during seizure or by electroencephalogram (EEG) signal analysis by neurologists. EEG signal processing and detection of seizures using machine learning techniques make this task easier than manual detection. To overcome this problem related to a neurological disorder, we have proposed the ensemble learning technique for improved detection of epilepsy seizures from EEG signals. In the first stage, EEG signal decomposition is done by utilizing empirical wavelet transform (EWT) for smooth analysis in terms of sub-bands. Further, features are extracted from each sub. Time and frequency domain features are the two categories used to extract the statistical features. These features are used in a stacked ensemble of deep neural network (DNN) model along with multil...

This paper presents an approach to estimate the orientation of the rectangular defect in the ferromagnetic specimen using the magnetic flux leakage technique. Three components of the magnetic flux leakage profile, such as radial, axial, and tangential component are considered to estimate the orientation of the rectangular defect. The orientation of the rectangular defect is estimated by the proposed analytical model using MATLAB software. The results calculated by the analytical model are validated by the three-dimensional finite element analysis using COMSOL Multiphysics software. Tangential component provides better performance to estimate the orientation of the rectangular defect compared with radial and axial component of the magnetic flux leakage profile.