Chittagong University of Engineering & Technology

About: Chittagong University of Engineering & Technology is a education organization based out in Chittagong, Bangladesh. It is known for research contribution in the topics: Computer science & Renewable energy. The organization has 1200 authors who have published 1444 publications receiving 10418 citations. The organization is also known as: Engineering College, Chittagong & Bangladesh Institute of Technology, Chittagong.

An FPGA-Based Neuron Activity Extraction Unit for a Wireless Neural Interface

Abstract: As computational and functional brain model development are solely dependent upon the data acquired from the neural interface, this device plays a vital role in both prosthetic developments and neurological experiments. A wireless neural interface is preferred over a traditional wired one because it can maximize the comfort of the subject and ensure the freedom of movement while implemented. This paper describes the field programmable gate array (FPGA) prototype design of a low-power multichannel neuron activity extraction unit suitable for a wireless neural interface. To achieve the low-power requirement, we proposed a novel neural signal extraction algorithm which can provide an up to 6000X transmission rate reduction considering the input signal. Consequently, this technique offers at least 2X power reduction compared to the state-of-the-art systems. We implemented this scheme in Xilinx Zynq-7000 FPGA, which can be used as an intermediate transition towards the application specific integrated circuit (ASIC) design for on-chip neural signal processing. The proposed FPGA prototype offers reconfigurable computability, which means the model can be modified and verified according to prerequisites before the final ASIC design. This prototype consists of a signal filtering unit and a signal extraction unit which can be used either as stand-alone units or combined as a complete system. Our proposed scheme also provides a provision to work as a single-channel or a scalable multichannel interface based on user’s demands. We collected practical neural signals from rat brains and validated the efficacy of the implemented system using in-silico signal processing.

Tropical cyclone risk mapping for a coastal city using geospatial techniques

Abstract: Tropical cyclone associated storm surges and their disastrous influences are becoming a major concern amongst the worldwide coastal community. The detailed risk modelling study seems an urgent need to support the storm surge mitigation actions. Using a Geographic Information System (GIS) based risk model, this study attempted to obtain both present and future storm surge wave heights in the Cox’s Bazar Sadar Upazilla in Bangladesh. Linear storm surge model setup was done for the different return periods includes 5, 10, 20, 50, and 100 years. Also, to assess climate change effects, a 0.34 m sea-level rise in 2050 was tested using the regional scale surge models. The simulated storm surge model provided a time series dataset for the risk model and obtained risk maps comprised of the relationship among risk zone and the return periods. With the present inundation depth trend, the acquired risk maps of 50 and 100 year return period showed that 10.13% and 36.4% of the study area belongs to very high-risk zone respectively. Conversely, for future inundation depth conditions 30.83% and 49.9% of the study area would be within a very high-risk zone in 50 and 100 year return period respectively. This is envisaged that a detailed historical inundation dataset could enrich the adopted approach considering both present and future storm surge risk modelling for the Decision Support System (DSS). Also, this approach might be adopted for other identical coastal environments to aid mitigation programs and strategies.

A Brief Review of Snubber Circuits for Flyback Converter

Abstract: This paper reviews the different snubber circuit topologies for flyback converters. At low power levels, flyback converters are required to operate at fast switching frequencies to achieve higher power densities, low flux linkage and reduced converter size. However, at high frequencies, switching losses in flyback converters increase along with voltage and current stresses on the main electronic switches. Moreover, additional stored energy in the transformer's leakage inductance can give rise to high EMI losses and reduce the overall efficiency of the converter. Different proposed snubber circuit schemes to mitigate these problems in a flyback converter are reviewed and discussed. Finally, the features of these snubber circuits are analyzed and compared based on their advantages, possible improvements and number of components used.

An Approach for Recognizing Vehicle Based on Appearance

Abstract: In Intelligent Transportation System (ITS) vehicle detection from the road image is very important for drivers and pedestrians awareness. Detection of vehicles from the road area is important to prevent the accident or collisions. This paper proposes a method for improving traffic control and management system for different condition of roads. Four basic steps based on appearance are presented in our proposed method. Initially, to segment the object, we use pitch color from the road image. In the next step, labeling and filtering is applied on foreground objects for getting the region of interest (ROI). Then, for extracting features we use Haar-like feature on ROI. Finally, test images are classified by support vector machine (SVM) classifier for recognizing the vehicle, which provides high accuracy with a very fast and reliable detection rate. Various road images were used with a variety of conditions to test proposed method and results are presented to prove it effectiveness. Moreover, it will satisfy the needs of ITS.

Electrical Properties of CSS Deposited CdTe Thin Films for Solar Cell Applications

Abstract: CdTe is a very potential absorber material for thin film solar cell application. In this work CdTe thin films (TF) were deposited on CdS thin films by close-spaced sublimation (CSS) technique at different source and substrate temperature in inert gas condition. To bring out the optimum temperature set for CSS deposited CdTe films, several experiments were done. The process pressure of the chamber during deposition was maintained at 1.5 Torr in a dynamic condition. The effects of deposition temperature on the electrical properties of the as-deposited CdTe films were investigated by Hall Effect measurement. The films were deposited at 610 °C, 630 °C, 650 °C and 670 °C source temperatures. The first three films showed p-type conductivity while n-type conductivity appeared in the film deposited at 670 °C. The hole concentration of the as-grown p-type CdTe films followed an upward trend with the increase of source temperature and it reached a peak value at 650 °C. The highest hole mobility was observed for the lowest source temperature. However, the resistivity of the CdTe films was found increasing with the increase of source temperature. Thus, the CdTe thin film deposited at 650 °C showed better electrical properties for solar cell applications.