In the present work, a reliable and low cost system has been designed and implemented to measure greenhouse gases (GHG) in United Arab Emirates (UAE) by using unmanned aerial vehicle (UAV). A set of accurate gas, temperature, pressure, humidity sensors are integrated together with a wireless communication system on a microcontroller based platform to continuously measure the required data. The system instantaneously sends the measured data to a center monitoring unit via the wireless communication system. In addition, the proposed system has the features that all measurements are recorded directly in a storage device to allow effective monitoring in regions with weak or no wireless coverage. The obtained data will be used in all further sophisticated calculations for environmental research and monitoring purposes.
In the present work, wireless sensor network and real-time controlling and monitoring system are integrated for efficient
water quality monitoring for environmental and domestic applications. The proposed system has three main components
(i) the sensor circuits, (ii) the wireless communication system, and (iii) the monitoring and controlling unit. LabView
software has been used in the implementation of the monitoring and controlling system. On the other hand, ZigBee and
myRIO wireless modules have been used to implement the wireless system. The water quality parameters are accurately
measured by the present computer based monitoring system and the measurement results are instantaneously transmitted
and published with minimum infrastructure costs and maximum flexibility in term of distance or location. The mobility
and durability of the proposed system are further enhanced by fully powering via a photovoltaic system. The reliability
and effectiveness of the system are evaluated under realistic operating conditions.
In the present work, a wireless two dimensional microcontroller based sun tracker is designed and implemented. The proposed system has three main components namely the controlling unit, the wireless communication system, and the monitoring and recording unit. Controlling features are fully obtained in the present system using an efficient microcontroller based programming environment. Design equations, which are implemented, allow the usage of the system anywhere anytime without extra hardware tracking circuits. The sun tracker continuously calculates the photovoltaic module’s tilt and azimuth angles by using accurate sun movement equations. The system generates the motors controlling signals to allocate the photovoltaic module to receive the maximize amount of solar energy on its surface from sunrise to sunset. For monitoring purpose the output of the movable photovoltaic module and from a south faced fixed module are wirelessly transmitted to the local monitoring system where the data are recorded, analyzed, and published. The proposed system is successfully implemented and tested for long periods under realistic operating conditions and the obtained positioning results are in excellent agreement with the theoretical ones.
KEYWORDS: Geographic information systems, Roads, Analytical research, Decision support systems, Remote sensing, Ecosystems, Visualization, Data modeling, Satellites, Global system for mobile communications
In the present work, the potential ecotourism sites in Wadi Wurayha, Fujairah, United Arab Emirates (UAE), are identified and prioritized using Geographic Information System (GIS). The identification criteria are based on landscape or naturalness characteristics; visibility and land use or land cover, the topography characteristics; elevation and slope, the accessibility characteristics; distance from roads, and community characteristics; settlement size. After developing the list of ecotourism criteria, GIS techniques were used to measure the ranking of different sites according to the set criteria and thus identify those with the best potential. Subsequently, the land suitability map for ecotourism was created. The degree of suitability of each factor was classified as highly suitable, moderately suitable, marginally suitable, and not suitable for ecotourism. Based on the suitability map, the areas of high ecotourism potential are located in protected areas. The methodology proposed was useful in identifying ecotourism sites by linking the criteria deemed important with the actual resources of the area. This study results helped to identify optimal use of the land for tourism facilities development and ecotourism resource utilization within Wadi Wurayha area in the near future. Additionally, the results from the present work can also serve as a starting point for more detailed studies in the future.
In the present work, wireless sensor network and smart real-time controlling and monitoring system are integrated for
efficient energy management of standalone photovoltaic system. The proposed system has two main components namely
the monitoring and controlling system and the wireless communication system. LabView software has been used in the
implementation of the monitoring and controlling system. On the other hand, ZigBee wireless modules have been used to
implement the wireless system. The main functions of monitoring and controlling unit is to efficiently control the energy
consumption form the photovoltaic system based on accurate determination of the periods of times at which the loads are
required to be operated. The wireless communication system send the data from the monitoring and controlling unit to
the loads at which desired switching operations are performed. The wireless communication system also continuously
feeds the monitoring and controlling unit with updated input data from the sensors and from the photovoltaic module
send to calculate and record the generated, the consumed, and the stored energy to apply load switching saving schemes
if necessary. It has to be mentioned that our proposed system is a low cost and low power system because and it is
flexible to be upgraded to fulfill additional users’ requirements.
KEYWORDS: Solar energy, Sensors, Computer programming, Solar cells, Photovoltaics, Control systems, Transceivers, Computing systems, Environmental monitoring, Data acquisition
In the present work, a computer based smart integrated energy monitoring and management system for standalone photovoltaic systems is designed and implemented. Monitoring, controlling, and recording features are fully obtained in the present system using an efficient programming environment. All required data are monitored as real-time data therefore the system status is continuously evaluated and decisions are made to take immediate actions. The energy consumption of different appliances are automatically controlled and optimized using a hierarchical self adaptive algorithm based on input data and real-time information provided by the system sensors. The proposed system is successfully implemented for photovoltaic modules under realistic operating conditions.
In the present work, a computer based photovoltaic sun tracker module is designed and implemented. Monitoring,
controlling, and recording features are fully obtained in the present system using an efficient programming environment
Design equations which are implemented allow the usage of the system anywhere anytime without extra hardware
tracking circuits. A carefully design hardware motor deriving circuit is designed and implemented to simplify the
controlling program without scarifying the required accuracy. The system generates the motors' controlling signals to
allocate the photovoltaic module to receive the maximize amount of the solar energy on its surface from sunrise to
sunset. The proposed system is successfully implemented for photovoltaic modules under realistic operating conditions.
In the present work, a reliable wireless healthcare monitoring network which is compatible with common platforms and
operating systems is designed and implemented. The main advantages of our suggested wireless monitoring network are
the ability to monitor any required quantity, the usage of an efficient programming environment to allow all features of
monitoring, controlling, and data processing to be implemented, the ability to extend the number of monitored patients,
and the ability to transfer measurement data over wired or wireless channels. In addition to all of the above mentioned
features, the system is implemented with components which achieve the minimum costs without scarifying accuracy.
The use of low cost wireless communication and internet network facilities makes our suggested monitoring system
reliable for all capital projects with minimum costs and ensures upgradability to adapt additional wide user requirements.
KEYWORDS: Magnetic sensors, Field effect transistors, Magnetism, Sensors, Magnetic semiconductors, Semiconductors, Solid modeling, Systems modeling, Electrons, Instrument modeling
Characteristics of Metal Oxide Semiconductor Field Effect Transistor (MOSFET) magnetic sensors have been
investigated using a three-dimensional physical simulator which accurately couples the magnetic field equation and the
carrier transport equations. The effects of the device geometric parameters, the bias conditions, and the magnetic field on
the relative sensitivity of a split drain magnetic sensors are accurately determined. The MOSFET magnetic sensor
capability is further enhanced by suggesting an integrated smart structure which is able to fully detect the magnetic field
variations in two-directions. The current deflection and relative sensitivity for the suggested magnetic sensor under
different operating conditions are finally investigated with the present efficient physical simulator.
A precise two-dimensional MOS magnetic sensor is suggested and its performance is investigated. The dependence of
sensor sensitivity on the device geometric parameters and on the biasing conditions is accurately determined by a twodimensional
physical simulator which self-consistently solves the magnetic field equations and the carrier transport
equations. From the simulation results, a modified equivalent circuit model for MOS magnetic sensor is proposed and
included in SPICE model to fully analyze the operation of suggested magnetic field sensor.
KEYWORDS: Instrument modeling, Monte Carlo methods, Electrons, Semiconductors, Performance modeling, Scattering, Field effect transistors, Solid modeling, Systems modeling, Device simulation
Based on Boltzmann transport equation, the drift-diffusion, hydrodynamic, and Monte-Carlo physical models are
accurately developed. The model equations are self-consistently solved with Poisson equation, and with Schrödinger
equation when quantization effects take place, in one and two-dimensions to characterize the operation and optimize the
structure of mm-wave devices. The effects of the devices dimensions, biasing conditions and operating frequencies on
the accuracy of the obtained model (simulator) results are thoroughly investigated. Based on physical understanding of
the models, the simulation results are analyzed and conclusions are drawn to fully determine the limits at which a certain
device simulator can be accurately and efficiently used to characterize the noise behaviour of mm-wave devices.
Analytical expressions for the PM noise in FET oscillators are derived in terms of the FET equivalent circuit elements
and the passive circuitry. Efficient methods to reduce the PM noise in fundamental and in harmonic mode are suggested
and implements. The effects of the different FET equivalent circuit parameters on large-signal, small-signal, and noise
behaviour of FET oscillators are thoroughly investigated. Finally, the effects of harmonic signal on both fundamental
and harmonic output noise are determined.
In the present work, a rigorous two-dimensional physical simulator is developed to characterize the operation and to
optimize the structure of a highly sensitive linear 2D MOSFET magnetic sensor. The magnetic field equation and the
carrier transport equations are efficiently coupled and accurately solved to determine the effects of external applied
magnetic field on the electrical characteristics of the MOSFET based sensor. The accuracy of the present simulator is
tested for different device and circuit parameters to allow the use of it as an efficient CAD tool to fully characterize smart
two-directions MOSFET magnetic sensor.
KEYWORDS: Magnetism, Field effect transistors, Magnetic sensors, Sensors, Solid modeling, Magnetic semiconductors, Semiconductors, Instrument modeling, Systems modeling, Electrons
D.C. and A. C. characteristics of a magnetic sensor, based on Metal Oxide Semiconductor Field Effect Transistor
(MOSFET) structure, have been investigated using an efficient two-dimensional physical simulator. With the coupling
scheme between the magnetic field equation and the carrier transport equations in the present simulator, the effects of the
device geometric parameters, the bias conditions, and the magnetic field on the current deflection due to magnetic field
and on the magnetic sensor relative sensitivity are accurately determined. The MOSFET magnetic sensor capability is
further enhanced by using an integrated smart structure which is able to fully detect the magnetic field variations in two directions.
The current deflection and relative sensitivity for the smart two-directions magnetic sensor under different
operating conditions are finally investigated with the present efficient physical simulator.
A novel graded band gap channel Si-SiGe MOSFET structure has been suggested and its characteristics has been
investigated. The investigations indicated that the suggested structure reduces the short-channel effects, increases the cutoff
frequency, and hence makes it usage at high frequency and Low noise applications prefeable. To show the superior
performance of the suggested structure at GHz frequencies, and as an example, the noise behavior of the structure is
thoroughly investigated. First the device noise model parameters are calculated from D.C. and A.C. characteristics. The
extracted noise model parameters are then used to determine the minimum noise figure and minimum noise temperature
at GHz frequencies. The effects of the different device parameters on the noise performance are determined. Finally, the
results are compared with those of conventional MOSFET structure to show the superior performance of graded band
gap Si-SiGe MOSFETs at these frequency ranges.
KEYWORDS: Field effect transistors, Monte Carlo methods, Instrument modeling, Electrodes, Performance modeling, Particles, Data modeling, Capacitance, Quantization, Computer simulations
Linear, noise-generating systems in electronics are usually described by mathematical techniques which were originally designed for linear, time-invariant systems, e.g. output noise spectra are computed by application of the Fourier-transform to the autocorrelation function of the output signal. Recently, it was pointed out that this description might be incomplete, since the parameters of noise-generating systems fluctuate, i.e. they vary with time. Therefore, rather than using the theory of time-invariant systems, the theory of linear time-variant systems should be applied. This theory will be adapted to electronic circuits which are fed by noise, and which have inner niose soruces. It will be applied to simple electronic circuits like a simple equivalent circuit of an integrate ohmic resistor, in order to show the effect of the time-variance of parameters to the noise spectrum.
The noise performance of sub-quarter micrometer gate length FETs is determined by using physical simulators. The hydrodynamic transport model equations are linearized and efficiently solved in two dimensions to determine the small-signal parameters and the minimum noise figure up to frequencies near the device cut-off frequency. For higher frequencies, the noise performance is obtained by using a 2D Monte Carlo code which fully takes into account the non-stationary transport properties and quantization effects. The relation between the terminal noise currents and the internally generated noise at the different device regions are determined. Different device stuctures are simulated and the obtained results are compared with experimental data.
A rigorous two-dimensional physical device simulator is developed to characterize the operation of ultra-small and highly doped semiconductor devices. To allow a better understanding of the device behavior, the physical phenomena which are taking place inside these devices are accurately modeled and included in the simulator. Implicit and explicit numerical schemes are applied to self-consistently solve the model equations and the effects of both schemes on the computational efficiency of the simulator are discussed. Finally, the obtained results from the simulator are compared with experimental characteristics of a device with similar structure.
The influence of alloy composition on the noise behavior of heterostructure semiconductor devices is investigated by using a rigorous two-dimensional physical simulator. The model takes into account non-stationary transport properties and quantization effects to allow a better understanding of the carrier transport properties inside the heterostructure devices and consequently to explain the noise performance of these devices by making use of the microscopic nature of the model. As an example, the model is applied to study the effects of alloy composition and the resulting band discontinuity on the 2DEG properties and on the noise performance of Hetero-FETs at millimeter-wave frequencies, and to extract the optimum alloy composition which leads to the minimum noise figure in different frequency ranges.
A new graded band gap channel MOSFET is suggested to make use of the improved electrical properties of SiGe over Si at high frequencies of operation. The device performance is analyze by using an analytical model and the obtained results are compared with those of conventional Si and non- uniform doped channel MOSFETs. Finally, the noise behavior of the new MOSFET is investigated to show its superior performance over conventional Si MOSFETs at GHZ frequencies of operation.
A rigorous 2D physical simulator is developed to determine the noise behavior of subhalf-micrometer gate-length FETs taking into account the non-stationary transport properties and the quantization effects. The microscopic nature of the simulator allows better understanding of the physical operation of these devices. As an example, the model is applied to compare and to accurately interpret the noise behavior of similar MESFET and Hetero-FET structures, to determine the physical phenomena which dominate their behavior, and to suggest different possibilities to improve the noise performance in a wide frequency range of operation.
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