Kazi Tanvir Ahmmed

Distance controlled rescue and security mobile robot

The intention of designing a robot is to facilitate the human beings through giving security and working as a helping hand through reprieving. The technology used in this rescue and security robot has a number of important features such as robotic car control by cell phone, automatically avoiding obstacles in its way. It can sense gas, smoke and provide an alert through text messaging. The robot can detect bombs, pick and place objects and also do distance measurements. A high quality wireless video camera equipped with a stepper motor for the omni-directional view is used for the spying purpose which is mounted on the robo car to send real video images and audio signals. These audio and video stream received by the receiver unit can be used to take proper steps according to the received signals. This robot can also be used to reach places where humans cannot reach like hidden places, small tunnels. The ultimate focus of this system is to offer far possible security for the human being. In this paper, we have illustrated our work by using the entire sub modules.

Multi-junction solar cells and microwave power transmission technologies for solar power satellite

Solar power satellite (SPS) is a renewable and infinite energy system in the Geostationary Earth Orbit, which works as an electric power plant in space. Main theme of our research work is that SPS will collect solar energy, converts sunlight to electricity and beam the power to ground-based receiving stations. The attenuation that results from passing through the atmosphere, sunlight in Earth orbit is about 25% more intense than on the ground. Four main parts of microwave power transmission (MPT) for Solar power satellite system are- highly efficient solar cell for space solar panel, a microwave generator (for high power application magnetron can be used and for low power application we can use solid state amplifier), an antenna to transmit microwave power, and a rectenna to receive and convert the microwave energy into usable DC power. With the increases in energy cost and recent interest in finding ways to produce energy with reduced emission of greenhouse gasses, SPS can play a vital role. The ultimate concentration of this research work is to introduce Solar Power Satellite system with multi-junction solar cell which enhances overall efficiency of space solar panel and modern technologies associated with MPT for proposed SPS system.

An expression for average Bit Error Rate of Free Space Optical links over Exponentiated Weibull atmospheric turbulence channel

In this paper, assuming Intensity-Modulation/Direct Detection (IM/DD) with On-Off Keying (OOK), a novel expression for average BER of FSO over Exponentiated Weibull (EW) atmospheric turbulence channel is derived. In the free space optical (FSO) channel the optical signal suffers from irradiance and phase fluctuations caused by the atmospheric turbulence, which results in Bit Error Rate (BER) performance degradation. We investigate the aperture-averaging effect on BER performance under weak and moderate turbulence regime. In our work we consider EW distribution which is more accurate in the presence of finite-size receiving apertures under weak and moderate turbulence regime.

Performance analysis and redistribution among RIPv2, EIGRP & OSPF Routing Protocol

In a network topology, it is very usual to use various kinds of routing protocol for forwarding packets. A routing table is used in the memory of a router that keeps the track of routes to particular network destination and the most popular routing algorithms used to forward packets are Routing Information Protocol (RIPv2), Enhanced Interior Gateway Routing Protocol (EIGRP) and Open Shortest Path First (OSPF). The ultimate concentration of this research work is to depict the performance analysis comparison of these three dynamic routing protocols and redistribution among the protocols. Eight Cisco routers and a switch are used in our simulated network topology where four routers with different protocols directly connected with the switch take the responsibility for the redistribution algorithm.

Optimal design and performance study of a low-index-contrast MMI optical coupler

The multimode interference (MMI) coupler is a versatile component for photonic signal processing applications. In present day, research scenarios based on low-index-contrast MMI couplers give more scope of study as it has certain advantages over high-index-contrast MMI couplers. In this work we presented an optimal design for the low-index-contrast MMI coupler. From various possible structures, we considered Silica-on-Silicon based 4×4 MMI coupler. Various techniques such as conventional self imaging, improved self-imaging and Genetic algorithm are used here, with numerical analysis such as mode propagation analysis, beam propagation method for evaluating optimal performance by adjusting the parameters of the structure. The optimum structure is finally selected one from them by comparing the results of these different techniques.

Broadband high-order mode pass filter based on mode conversion

We propose a unique concept to implement a higher-order mode pass filter using mode-converters. The proposed filter has a simulated extinction ratio greater than 20 dB with an excess loss less than 0.6 dB in the C-Band.

3rd Hand: A device to support elderly and disabled person

This paper represents a system “3rd HAND”, that can serve a disable person or elder person to perform some of their regular tasks without any helping hand. This system helps a person to switch the regular home loads (light, fan etc.) using his voice commands and his location can be tracked when he travels outside alone with the system. In self-regulated system we used an EASY_VR voice recognition module. The recognized control commands are sent to an ARDUINO for proper program controlling and then to a Bluetooth module. After that, the commands are routed to the target device over Bluetooth network and finally carried out by the control circuit. In GPS tracking system, we used the GPS and SMS services of an android mobile phone. When a client sends a request SMS to the system to get its location, the GPS receiver of the phone calculates the location coordinates and converts it to location name using GEOCODING API. Finally the location name is sent to the client automatically. Generally it is not comfortable and secured for a disabled or elder person to switch their home loads and to travel alone. So the system “3rd hand” provides them a safety switching system and supports them to travel independently in safe.

Implementation of a 1×16 router using 2×2 Mach-Zehnder interferometer electro-optic Switch

In optical communication signal router is a novel photonic component used to ensure communication between optical networks. Signal routing has a significant commercial demand in dense wavelength division multiplexing. This paper presents the description of designing a 1 × 16 signal router using Mach-Zehnder electro-optic Switch operating at 1.55 μm. To design the router we used 2×2 Mach-Zehnder electro-optic switch made by titanium diffused lithium niobate (Ti:LiNbO3) which is used as waveguide medium in designing the desired signal router. Enhanced performance of the switch with reduced insertion loss, excess loss and high extinction ratio was evaluated first and then the router was implemented using that optimized switch. 16 switches were required to implement the router. Optical power can be switched to each of the 16 output ports with the application of applied voltage at each central electrode of the 16 MZI switches. The results are observed using finite difference beam propagation method of OptiBPM12.2 simulation software.

Design and performance analysis of a low-index-contrast cascaded multimode interference switch

The multimode interference (MMI) switch is a versatile component for photonic signal processing applications. A 4×4 silica-on-silicon (SOS) all-optical MMI switch design is presented in this paper. This structure is based on two cascaded 4×4 MMI couplers and phase compensation arms. First a 4×4 MMI coupler is designed using self-imaging principle and then it is optimized for minimum loss and uniformity using improved self-imaging principle, as weakly guiding features of SOS waveguides are different from the strongly guiding features considered in the self-imaging principle. BPM simulation is used to analyze the coupler structure. This optimized MMI couplers are then cascaded using phase compensation arms; from the calculation of relative phases of MMI sections the phase compensations are obtained. Numerical simulation results of the designed structure consequences a better device performance with a loss of 1.12dB and crosstalk level of less than -22dB.

Automated energy saving and safety system

This paper reports on a system that can save electricity. Many times we leave the room and hall without switching off lights and fans, thus electricity is wasted. In this work we have presented a system in which energy will be saved based on number of people entering in or leaving out of the room. If there is no person in the room, then light and fan will be switched OFF. On the other hand as soon as any person enters the room, light and fan will be switched ON. On the basis of the intensity of sunlight we can increase or decrease the intensity of light. Simultaneously we can vary the speed of the fan sensing the room temperature. The more temperature the more speed of the fan. A smoke sensor module is used for detecting any smoke within the room and provides safety by alarming the audio device.