Kazi Khairul Islam

Cooperative communication in wireless sensor network using low density parity check codes

Energy efficient data transmission is one of the key factors for energy constraint wireless sensor network (WSN). Cooperative communication explores the energy efficient wireless communication schemes between multiple sensors and data gathering node (DGN). In this paper, an energy efficient cooperative technique is proposed considering low density parity check (LDPC) codes. The result shows that the proposed cooperative communication outperforms SISO transmission when the error correction code is considered. Bit error rate (BER) analysis is also performed. In this work, it shows that the lower encoding rate offers better error characteristics for same signal to noise ratio (SNR)

Nominal and Detailed LTE Radio Network Planning considering Future Deployment in Dhaka City

Long Term Evolution (LTE) is the next major step in mobile radio communications and is introduced in 3rd Generation Partnership Project (3GPP) Release 8. It is the last step toward the 4th generation (4G) of radio technologies designed to increase the capacity and speed of mobile telephone networks. With industrial attachment very few radio planning works of LTE are going on. But because of certain commercial issues those works aren‟t widely available. Radio network planning is a very vital step for wireless communication technology. As standardization work of LTE is approaching the end line, it is high time to go for efficient radio network planning guideline for LTE. In LTE just like other cellular technologies, initial planning is normally guided by various industries and vendors at their own discretion. They aren‟t likely to disclose their advancements and findings. That makes the job even more challenging. As a result, going on with LTE radio network planning perspective is a well-chosen challenge and a certain hot topic in the current research arena. In this work, a detailed LTE radio network planning procedure has been elaborated which concentrates on nominal and detailed planning considering possible network implementation in the densely populated South-Asian city-Dhaka.

Control of autonomous nanorobots in neural network

This paper describes an innovative approach for the development of nanorobots that use neural network for medical target identification. The nanorobots operate in a virtual environment with nerve signals carrying nerve impulses. Our work addresses the possible applications of such nanorobots and presenting a control system for their autonomous movement.

Differential evolution algorithm based load frequency control in a two-area conventional and renewable energy based nonlinear power system

Load Frequency Control (LFC) for any power generating station is a subject of great concern for power system researchers. With the changes of load demand, frequency starts fluctuating which results in deviation in tie line power flow and frequency deviation at consumer end. To overcome this problem, many control techniques have been adopted. In early days fixed value integral/proportional-integral control, Optimal Control, Quantitative feedback theory, pole placement etc. methods were applied. In recent times, neural network, fuzzy logic, genetic algorithm controllers are replacing the conventional techniques. All the control techniques are used to find the optimal values of the PID/PI controller gain parameters (Kp, Ki, Kd) for which system stability is confirmed with minimum of Area Control Error (ACE). Differential Evolution (DE) which is a newer branch of genetic algorithms has been successfully applied in this problem. In this paper DE based PI controller has been implemented for Hydro-Thermal power plants to find out the optimal value of gain parameters for system stability. Nonlinearity has been considered in governor part of the thermal area for practical scenario. 1% step load changes have been applied to both areas simultaneously and individually to confirm its performance. Desired set of controller gain parameters (Kp, Ki) are selected based on eigenvalue and minimum value of Objective Function. All simulations are done in the MATLAB/SIMULINK environment.

A comparative analysis of processing periods for strain images generated using 1D spline based approach and 2D thin plate smoothing spline method

In the recent years strain imaging technique which is Elastography incepted a promising horizon of potentiality for detecting deep lying abnormal stiff nodules such as tumor, one of the primary symptoms of vulnerability towards cancer. Generating strain images applying two dimensional thin plate smoothing (TPS) spline based approach is definitely a superior method with its 1D counterpart considering several elastographic performance parameters (e.g., SNRe,CNRe). But 1D smooth spline based technique still comes into consideration for its capability to generate elastograms with acceptable resolution and more faster processing period which is a pre-requisite parameter for Real-time clinical applications. This paper presents a structured comparative analysis of the processing periods between both the methods and quantitative measurement of spatial resolution of strain images with the change of smoothing parameter.

Automatic generation control in a multi-area conventional and renewable energy based power system using differential evolution algorithm

The function of Automatic Generation Control (AGC) is to regulate the output power of the corresponding generator in response to changes in system frequency or tie line loading or in both cases within a prescribed limit. In this paper Differential Evolution (DE) based Proportional-Integral (PI) controller is designed and simulated to observe its performance for a two area Hydro-Thermal power system. The purpose of the DE is to find out the optimal parameter values of the PI controller (Kp and Ki). The Optimal set of values is chosen based on eigenvalue of system matrix and objective function. The performance was evaluated based on the transient response (Settling time and peak overshoot) of the system while different step load changes were applied on both or either of the areas. The proposed controller has been found functioning properly for not only smaller (1%) but also larger (5%) load disturbances. All the simulations are done using MATLAB/SIMULINK software.

Non-isolated single stage PFC based LED driver with THD minimization using Cúk converter

This paper proposes a utility supply driven single stage PFC based LED driver using Cúk converter. For low DC voltage output requirement of LED driver, Cúk converter is a convenient choice due to its topological suitability for PFC application and stepping the voltage down at a desired level unlike the Boost Converter. A hysteresis current control scheme is adopted to operate the converter in Continuous Conduction Mode (CCM) and fast enough to follow the current reference causing power factor to approach near unity. Although the converter operates at variable switching frequency, the response is very fast and independent of the converter dynamics. At the same time the converter ensures a constant current drive at the output side to operate the LED. Theoretical analysis, design calculation and simulation results confirm that the proposed single stage control scheme operates with an improved THD and performs better compared to the commercially available controller because the same converter is used for both PFC and LED Driver. As it diminishes one stage of power conversion, the efficiency of the driver is increased whereas the complexity in controller design and implementation is decreased.

Improved strain estimation using a novel 1.5D approach: Preliminary results

Changes in biological tissues change their elasticity. Elasticity imaging enjoys an ever increasing role in disease diagnosis. In elastography, tissue strain is estimated using signal processing. Strain is conventionally calculated from estimated displacements between the pre- and post-compression ultrasonic echo signals. In this paper, we introduce a novel 1.5D strain estimator. The proposed algorithm uses 1D windows for fast computation, but searches in the lateral direction to account for non-axial motion. The performance of our method outperforms traditional methods, especially in the presence of higher applied strain. The image quality also improves significantly.

A novel and robust automatic seed point selection method for breast ultrasound images

Accurate segmentation of breast lesions is among the several challenges in the development of a fully automatic Computer-Aided Diagnosis system for solid breast mass classification. Many high level segmentation methods rely heavily on proper initialization and the seed point selection is usually the necessary first step. In this paper, a fully automatic and robust seed point selection method is proposed. The method involves a number of processing steps in both space and frequency domain and endeavors to incorporate the breast anatomical knowledge. Using a database of 498 images, we compared the proposed method with two other state-of-the-art methods; the proposed method outperforms both methods significantly with a success rate of 62.85% vs. 44.97% and 13.05% on seed point select.

Experimental verification of regenerative braking characteristics by applying different motor armature voltage

Simpler design of control system is the key advantage of DC motor. In recent decade, however use of dc motor in battery-operated electric vehicles (BEV) are declined spectacularly. Without significant improvement of efficiency of such system the use of dc motor in BEV will be objectionable. Regenerative braking is the possible way to improve the efficiency. In this paper a novel regenerative braking mechanism for electric vehicles based on DC motor is proposed. The performance of the proposed braking system has been evaluated experimentally for different motor armature voltage. For this a prototype model of BEV has been used. Simulation results show that the proposed regenerative braking technique is feasible and effective. Also this research provides a new possibility of cost effective equipments and simplest system for regenerative braking to improve the drive distance of electric vehicles.