Md. Shafayat Hossain

Design and Development of an Y4 Copter Control System

The y4 copter is intended to be a UAV (Unmanned Aerial Vehicle) with autonomous subsystems. Automation is implemented in case of maintaining the desired roll, pitch and yaw. An improved algorithm that uses Quaternion is implemented to determine Euler angles avoiding Gimbal lock. It has a self-stabilization system achieved using Proportional Integral Derivative (PID) control system. A custom remote is built to communicate with the y4 copter using XBee modules which offer long range and security. Secured data transmission between the controller and the copter makes it suitable for military applications. Perhaps the most significant purpose of this y4 copter is to exercise a low cost and efficient engineering design with total automation considering all possible aerodynamics which is intended to be the first y4 copter built in the Indian subcontinent.

Prospect of decentralized hybrid power generation in Bangladesh using biomass, solar PV & wind

Limited fossil fuels will soon not be enough to meet up the energy-shortage in Bangladesh and therefore enhanced attention must be given to utilize renewable energy sources. Solar and wind are two prominent renewable energy sources in Bangladesh. We propose an optimum decentralized solar PV-wind-biomass-fossil fuel based hybrid power system to meet up the energy-demand of a typical community in an environment-friendly way. The potential of the decentralized hybrid system in Bangladesh is estimated utilizing Geospatial toolkit, NASA SSE solar radiation data and HOMER optimization software. Financial viability of the system for Bangladesh is also assessed utilizing a proposed decentralized hybrid system using HOMER for Rangpur which has unique high solar (4.75 kWh/m2/day) and high wind (over 2m/s wind-speed throughout the year with 250W/m2 power density) supply in Bangladesh. The annual electricity generation of the proposed system is almost 21.55 MWh and its cost of energy is less in Rangpur (minimum 0.246

Inherent Inter-vehicle Signaling Using Radio Frequency and Infra-red Communication

/kWh) relative to other areas due to its rich green energy resources. The proposed system, simulated for four different fuel-combinations, is most cost-effective but most detrimental to environment if the generator is run with natural gas. On the other hand, Co-firing with biomass results in doubling the cost but reduces pollutant-generation to almost 50%.

Long distance appliance control using mobile Short Messaging Service and internet in parallel

This paper suggests two alternative schemes to avoid the use of hydraulic and pneumatic horns responsible for severe sound pollution. Cost effective signaling systems using radio frequency (RF) and infra-red (IR) have been developed and working circuitry has been implemented to replace the conventional horns. The greater impact of these signaling schemes on the environment has been discussed-especially in case of reducing sound pollution. Use of global positioning system (GPS) and cellular data network has been avoided intentionally to ensure simplicity, cost-effectiveness and independent operation. Special emphasis has been put to ensure compatibility with any types of vehicles and thereby avoid factory level modification. These systems are successfully tested by establishing communication between two cars. IR communication has been found faster and more reliable at smaller distance than the RF communication. Both of these communication systems can be means of cost-effective reduction of sound pollution.

Self-consistent determination of threshold voltage of In-rich Gate-All-Around In x Ga 1−x As nanowire transistor incorporating quantum mechanical effect

This paper illustrates a secure and reliable system for remotely controlling electrical appliances by Short Messaging Service (SMS) and/or internet. The system requires serial interfacing of two micro-controllers with SIEMENS AX75 cell phone and a personal computer respectively. A microcontroller unit was used to merge the independent subsystems for SMS and internet based control. The micro-controllers were programmed in C and a webpage was created using PHP for internet based controlling. The proposed parallel controlling system incorporates user verification and registration, password protection and RF communication between central controller and the remote receiver segments. The overall scheme offers advantages over so far reported rigid control systems, which involve high cost GSM or GPRS modems. Also the proposed scheme can serve the purpose of appliance controlling in a large scale.

Analytical modeling of gate capacitance and drain current of gate-all-around In x Ga 1−x As nanowire MOSFET

This paper presents quantum definition based threshold voltage calculation of Gate-All-Around InGaAs nanowire transistor. Though similar determination was previously established for TG FinFETs in recent literature, application of this method on Gate-All-Around Nanowire Transistor is yet to be done. A self-consistent solver, which takes wave function penetration and other quantum mechanical effects into account, has been used here to establish the capacitance-voltage characteristics that have been used for threshold voltage calculation. Using the extracted threshold voltages, effect of channel width and channel material composition variation on threshold has been studied and a modification of classical analytical formula is proposed based on a fitting parameter.

Uncoupled mode space approach towards transport modeling of Gate-All-Around In x Ga 1−x As nanowire MOSFET

Gate-all-around structure with III-V channel material shows improved channel performance with high carrier mobility and less short channel effect and therefore is being studied rigorously for next generation transistors. We propose an analytical model to calculate gate capacitance and drain current of gate-all-around (GAA) nanowire MOSFET, a prospective device to replace the state-of-art FinFET in near future as per ITRS roadmap. The gate capacitance in strong inversion region is modeled incorporating quantum mechanical effects which are verified against the results obtained from self-consistent simulation of Schrödinger-Poisson equation appeared in recent literature. This model can also be extended for calculating gate capacitance in strong inversion region of different Multi-gate MOSFETs. A Spice compatible analytic model for drain current is also proposed which shows excellent agreement with the reported results of experimentally demonstrated In0.53Ga0.47As (2×1016/cm3) GAA MOSFET. Using the proposed formula for gate capacitance in strong inversion region and drain current together with semi-numerical ballistic MOSFET model, the performance of In0.53Ga0.47As (2×1016/cm3) GAA MOSFET is examined. This device is found suitable for ultra-high performance application with very high intrinsic cut-off frequency resulting from very low gate delay and very high on current and gate capacitance. The proposed analytical model of gate capacitance utilizes a modified form of co-axial cable capacitance along with the quantum capacitance limit to form a computationally efficient formula that is in well agreement with the results appeared in recent literature. On the other hand, Landauer-Buttiker formula and compact model for drain current of planar bulk-MOSFET are utilized to form the model for analytic drain current that shows excellent agreement with the experimental results appeared in the literature in recent past. The proposed model can be used for Spice modeling and circuit simulation of In0.53Ga0.47As GAA MOSFET. Moreover, this model is flexible and can be modified for other high performance multi-gate nano-devices.

Prospect of biogas & biomass as potential sources of renewable energy in Bangladesh

Since the fabrication of first III-V Gate-All-Around (GAA) MOSFET it is under extensive research, as it is one of the potential candidates to replace the state of art tri-gate FinFETs, to continue progressive scaling. In this work, transport characterization of experimentally demonstrated gate-all-around (GAA) InxGa1-xAs nanowire MOSFET in near-ballistic regime is performed using 3D self-consistent Schrödinger-Poisson solver based on Uncoupled Mode Space approach, taking wave function penetration and other quantum mechanical effects into account. The effects of channel length variation on transport characteristics are also examined.

Ballistic performance limit and gate leakage modeling of Rectangular Gate-all-around InGaAs Nanowire Transistors with ALD Al 2 O 3 as Gate Dielectric

Bangladesh, not being bestowed with fossil fuels is compelled to rely on renewable energy sources. Despite having potentiality as sustainable energy sources, due to the lack of proper planning, biogas and biomass contribution to master plan by Bangladesh government of having 5% of total generation from renewable energy sources will be insufficient. Even IDCOL, the leading contributor in this field is struggling to keep up with their envisioned target of 37,269 Biogas plants within Dec. 2012 as their trend of installment estimate only 29,320 plants at end of year 2012. By 2015, if their current scheme sustains, only 3268 cubic meter per year for biogas will be produced and 14.5 million tons of coal equivalent for biomass generation will be insufficient comparing to demand of 66.46 million tons of coal equivalent. Trend analysis by means of least mean square algorithm is presented to show the demand-supply discrepancy up to 2015.

Analytical modeling of potential profile and threshold voltage for rectangular gate-all-around III–V nanowire MOSFETs with ATLAS verification

This paper presents the ballisitic current limit and gate leakage due to direct tunneling of a Rectangular Gate-all-around InGaAs Nanowire Transistor and their variation with fin width, oxide thickness and In compostion in InGaAs. Ballistic current is found to be higher (1.5×1011 Am-2) for about 20nm fin width, sub-5nm oxide thickness and In-rich InGaAs channel. On the other hand, gate leakage is prominent for sub-4nm oxide thickness, larger fin width and In-rich InGaAs.