Underwater Channel Characterization to Design Wireless Sensor Network by Bellhop

Acoustic underwater link due to low attenuation is employed for underwater sensor network (UWSN). Due to water changing physical properties and different environmental conditions, the sound propagation for every underwater channel are different. So, the most important parameters to design reliable UWSN are: the shadow zone determination, optimum nodes placement, high signal to noise ratio and more power efficiency of nodes. This paper simulates underwater channel for 7 KHz carrier frequency, with measured physical water properties and remote sensing data. Based on defined scenario, the research determines optimum nodes placement and link budget analysis based on bottom to surface acoustic link. The paper utilizes Bellhop acoustic toolbox as a simulator, GeoMapApp program to collects bathymetry data and Aviso+ database to determine wind speed on sea surface. As a result the paper based on simulation of sound propagation in channel and transmission loss determination in depth and range, finds the optimum nodes positions and link budget calculation to prove the results

Erosion rate model comparison of electrical discharge machining process

This paper reports a comparison studies between two erosion rate model and experimental results of an Electrical Discharge Machining (EDM) process for high gap current. Two erosion rate models are Dimensional Analysis (DA) model and Artificial Neural Network (ANN) model that have been summarized from the previous author's publication. The data analysis is based on a copper electrode and steel workpiece materials. The result indicated that the ANN model provides better accuracy than the DA model when compared to the experimental results

Month-to-month variability of the melting layer boundaries

The Bright-band is the typical enhancement in radar reflectivity during the melting process, which is still not completely determined. The seasonal variation over the year can give the characteristics that are valuable for designing and planning of a satellite link. The Malaysian Meteorological radar data, from Kluang Radar Station (Johor), is used to trace the signature of the melting layer during stratiform precipitations events. The trends of the boundaries of the melting layer were studied by considering data extended to cover a six-month period (January -June 1998). It was observed that the boundaries and the thickness of the melting layer are found to be seasonally dependent

Evaluation of underwater acoustical intermittent ambient noise

This paper focused on the analysis of underwater intermittent biological noises produced by dolphin, shrimp, seahorse, bubble samples. We analyzed the noise frequency spectrum and calculate sound level pressure for every sample in its frequency distribution. Using stationary test, signal changes in the interval of 0.1 second is observed. Assuming Gaussian distribution, normality trial is investigated. Simulations and examinations are done using MATLAB programs in order to illustrate signal noise behavior to optimize filtering and detection purpose. From this study, all samples exhibit stationary and normality distribution properties, in addition the bubble and shrimp have a higher sound pressure level compare to other samples

PID controller tuning by particle swarm optimization on electrical discharge machining servo control system

Electrical Discharge Machining (EDM) is included in a stochastic process. So maintaining gap between electrode and workpiece is not easy. In order to control the gap, a proportional integral derivative (PID) controller is designed for EDM servo actuator system. The main goal of this work is to get PID parameters through Particle Swarm Optimization (PSO) algorithm to ensure a stable, robust and controlled system. The controller and the model for EDM die sinking are verified by simulation of the control system using MATLAB and simulink program. Simulation results verify the effectiveness of the PID controller in which its parameter determined by PSO to control the electrode position towards workpiece

Analysis of the melting layer from metrological radar data in Malaysia

A developed algorithm based on the vertical profile of radar reflectivity, has been applied to determine the boundaries of "the melting layer and its thickness. The average values of the melting layer heights are compared with ITU-R recommendations and other obtained results in tropical regions at 500 m resolution range. The results obtained showed lower values for heights of the melting layer

Intercarrier interference (ICI) analysis using correlative coding OFDM system

The orthogonal frequency division multiplexing (OFDM) technique is an attractive wireless communication system. In many applications, however, OFDM is very sensitive to frequency errors caused by two destructive effects. One effect is a reduction of signal amplitude; the other is the introduction of intercarrier interference (ICI) from other carriers caused by the loss of orthogonality between subchannels. In order to minimize ICI in OFDM systems, the correlative coding method was proposed. A normalized frequency offset was introduced in order to analyze the performance of the system where subcarrier frequency offset (SCFO) was used to measure the ICI in the system using Matlab software. The result shows that correlative coding OFDM (CCOFDM) can improve the level of the ICI signal compared to OFDM without correlative coding (OFDMWOCC) by about 6.9 dB

PID controller tuning by differential evolution algorithm on EDM servo control system

Maintaining gap between Electrode and workpiece in Electrical Discharge Machining (EDM) is very important since the capability of control system to keep the gap will improve the performance of this machine. Therefore to maintain the gap, a Proportional Integral Derivative (PID) controller is designed and applied to EDM servo actuator system. The objective of this work is to obtain a stable, robust and controlled system by tuning the PID controller using Differential Evolution (DE) algorithm. The controller for EDM die sinking is verified by simulation of the control system using MATLAB/Simulink program. Simulation results verify the capabilities and effectiveness of the DE algorithm to search the best configuration of PID parameters controller to control the electrode position

Development of gel electrophoresis unit to reduce DNA separation process time – a proof of concept

This paper reports the development and experimentation of a Gel Electrophoresis Unit that reduce the DNA separation process time. The power supply unit has been redesigned by employing a flyback converter of Switch Mode Power Supply which offers a compact solution of Gel Electrophoresis power pack. The novel Gel Electrophoresis container has been developed by incorporating four fans to regulate the heat while DNA separation process took place. The fans are controlled by the microcontroller through the heat sensor immersed in the gel. The result shows that the new gel electrophoresis unit is capable of shortening the DNA separation process time by sustaining the working temperature where the temperature proportionally controls the fan speed to regulate the thermal distribution within the DNA separation process

Development of gel electrophoresis unit to reduce DNA separation process time—a proof of concept

This paper reports the development and experimentation of a Gel Electrophoresis Unit that reduce the DNA separation process time. The power supply unit has been redesigned by employing a fly-back converter of Switch Mode Power Supply which offers a compact solution of Gel Electrophoresis power pack. The novel Gel Electrophoresis container has been developed by incorporating four fans to regulate the heat while DNA separation process took place. The fans are controlled by the microcontroller through the heat sensor immersed in the gel. The result shows that the new gel electrophoresis unit is capable of shortening the DNA separation process time by sustaining the working temperature where the temperature proportionally controls the fan speed to regulate the thermal distribution within the DNA separation process