Faculty Publications, Department of Electrical and Electronic Engineering (EEE)

Permanent URI for this collectionhttps://hdl.handle.net/10361/7555

Browse

Now showing 1 - 16 of 16

Electrically facilitated solar cargo hauler - a key to easy and safe transportation of goods without dependency on the national grid
(© 2016 IEEE, 2016-10) Purbasha, A. E.; Khan, F. R.; Sanjib, M.; Azad, Akm M.M.Abdul Malek; Department of Electrical and Electronic Engineering
Cargo is a vital mode of transporting goods. In Bangladesh, most of the cargo haulers are manually driven in rural areas. If motorized, the cargos are likely to draw a huge amount of power from the national grid which in turn increases load shedding. Considering the necessity to technologically improve the manually driven cargo hauler and for the development of rural areas, Control & Applications Research Centre (CARC), BRAC University, has projected an easy, eco-friendly and safe way of transporting large amount of goods without being dependent on the national grid. After CARC has provided solution to power dependency for electrically assisted torque sensor based rickshaw-van (human hauler) with PV panel, the cargo hauler has been improved with extra features added to enhance the performance and comfort of the cargo puller. The final designed cargo hauler consists of three 500W hub motors, shock absorber, high performance heavy duty drum brakes and pedicab wheels. An additional carrier attached at the rear further maximizes the load carrying capacity of the vehicle. The paper depicts field test data and qualitative analysis of the cargo hauler and it has been found that cargo hauler gives almost twice maximum and average speed than the human hauler in half of the run time than that of human hauler.
Solar electric ambulance van unfolding medical emergencies of rural Bangladesh
(© 2016 IEEE, 2016-10) Tarek, R.; Anjum, Adiba; Hoque, Md Ashiqul; Azad, Akm M.M.Abdul Malek; Department of Electrical and Electronic Engineering
Rickshaws are a key mode of transportation in Bangladesh. When it was changed to electrically-assisted ones, it achieved prevalence but was soon banned because of overconsumption of power from the national grid. In determination, Control and Applications Research Centre (CARC), BRAC University has proposed the idea to give a complete off grid course of action by using the PV array, torque sensor pedal and solar battery charging station. Since a significant number of people live in the rural areas, the probability of reaching the hospitals in the towns is low because of absence of proper mode of transportation. The torque sensor pedal decreases the over-usage of battery-bank. The control structure lessens the human effort and curtails over-usage of motor. 400W PV panel share power with the battery bank and the solar battery charging station completely detaches itself from the national grid. Previous model called 'The Human Hauler' implemented these techniques but our modifications made the entire system more efficient. We have achieved up to 25% increase in total distance travelled and 37% increase in speed. Further modifications to chassis with five wheels made the vehicle stable. This paper comprises of the configuration and usage of the thought proposed via CARC.
Transient anode voltage modeling of IGBT and its carrier lifetime dependence
(© 2015 IEEE, 2015-11) Das, Avijit; Islam, Nazmul; Haq, Masud Ul; Khan, Ziaurrahman; Department of Electrical and Electronic Engineering
This work presents a minority carrier lifetime estimation technique through investigation into transient anode voltage modeling of Non-punch Through (NPT) Insulated Gate Bipolar Transistor (IGBT). Parabolic approximation has been used for derivation of minority carrier concentration within the base. With the help of derived expression, an analytical model has been developed for turn-off voltage of IGBT in all minority carrier lifetime conditions. Better agreements with experimental data have been found compared to the linear model generally used. Finally, the implications of carrier lifetime dependence on the anode voltage are discussed, including implementation of such a carrier lifetime measurement technique.
Learning algorithms for anomaly detection from images
(© 2017 IGI Global, 8/30/2016) Ahmed, Tarem; Pathan, Al Sakib Khan; Ahmed, Supriyo Shafkat; Department of Electrical and Electronic Engineering
Visual surveillance networks are installed in many sensitive places in the present world. Human security officers are required to continuously stare at large numbers of monitors simultaneously, and for lengths of time at a stretch. Constant alert vigilance for hours on end is difficult to maintain for human beings. It is thus important to remove the onus of detecting unwanted activity from the human security officer to an automated system. While many researchers have proposed solutions to this problem in the recent past, significant gaps remain in existing knowledge. Most existing algorithms involve high complexities. No quantitative performance analysis is provided by most researchers. Most commercial systems require expensive equipment. This work proposes algorithms where the complexities are independent of time, making the algorithms naturally suited to online use. In addition, the proposed methods have been shown to work with the simplest surveillance systems that may already be publicly deployed. Furthermore, direct quantitative performance comparisons are provided.
Real-time monitoring of Solar Battery Charging Station
(© 2016 IEEE, 8/31/2016) Priyanka, Mirza Karishma; Chowdhury, Abrar Alvi; Mahmud, Bushra; Chowdhury, Sheri Jahan; Azad, Akm M.M.Abdul Malek; Department of Electrical and Electronic Engineering
This paper represents a real-time monitoring technique of all the components of a Solar Battery Charging Station (SBCS). Its ability to generate clean energy at free of cost, along with availability almost all year round makes SBCS very popular in tropical countries like Bangladesh. Successful implementation of this technique in any existing SBCS can increase its efficiency and distribute more power to rural areas where National Grid is unavailable. The purpose of our project is to monitor every available aspect in any existing SBCS so that manual labor of any kind would not be required. In order to do so, we have created a new software for Windows operating system to monitor the battery voltages, SOC, approximate time remaining to become fully charged as well as each individual panel status and overall solar voltage and solar current, along with a manual backup system in case of low solar radiation. To take readings, we used a Data Acquisition (DAQ) Card and interfaced it with our software in a computer, so that we can take the most out of our available resources and give reliable readings in real time.
Two switch three phase ĆUK regulated rectifier
(© 2016 IEEE, 11/22/2016) Abedin, Amina Hasan; Choudhury, Mohammad Ali A.Shoukat; Department of Electrical and Electronic Engineering
A three phase Vienna/Modular-Boost rectifier provides only boost voltage gain regulation using three single phase PFC controller to achieve power factor correction and input current waveform improvement. A Buck-Boost voltage gain regulated two switch three phase ĆUK AC-DC converter is considered in this paper with only output voltage feedback control. The proposed circuit has fewer active and passive components. Reduction is done on controlled switches and diodes of the power circuit and also on sensors, isolation and base drive supply circuits. The proposed three phase boost-buck PFC rectifier can easily be explained and analyzed on per phase basis. The concept of ĆUK DC-DC conversion can be applied on AC-DC converter operation to describe the circuit operation.
Luminous measurement of LED lights in cost effective way using cylindrical method
(© 2016 Elsevier Ltd, 2/1/2017) Haque, Fahimul; Azad, Akm M.M.Abdul Malek; Department of Electrical and Electronic Engineering
Because of several Solar Home System (SHS) components’ manufacturers in the market, overall quality of LED lamps fluctuates from organization to organization. There is an increment in unsteady quality with the number of SHS installation, which eventually causes system ineffectiveness. As a result, testing of LED lamps used in SHS plays significant role in maintaining the quality. However, existing procedures i.e. integrated sphere, goniophotometer method for lumen testing are quite costly in Bangladesh's perspective; so we have used our handmade cylindrical black box of different dimensions and sizes in CARC (previously known as CARG) lab, BRAC University. In this research we have included the testing results collected from our measurement process and also have established some relevant equations from what we have measured the total lumen of the light sources. Moreover, we used graphical analysis to find out the characteristics of different cylinders under different conditions.
Mathematical modeling and DLQR based controller design for a non-minimum phase Electro Hydraulic Servo system (EHS)
(© 2016 IEEE, 2/8/2017) Ahmed, Mazid Ishtique; Azad, Akm M.M.Abdul Malek; Department of Electrical and Electronic Engineering
In this paper, an Electro-Hydraulic Servo system is presented which bears the characteristics of basic Non-minimum phase (NMP) systems. Controlling problems encountered in NMP systems and optimizing the system response with optimal control strategy is the prime objective of this study. The described EHS system is mathematically modeled to obtain the discrete-time transfer function for analyzing its characteristics of Non-minimum phase system and illustrated by computer simulation using MATLAB ©. Discrete Linear Quadratic Regulator (DLQR) is presented as the controller for optimal controlling of the NMP behavior of EHS system. Response of the system is studied with and without the application of the DLQR. The comparative study illustrates an improvement in system behavior which can be used for obtaining perfect tracking and position tracking control of such systems.
A comprehensive study and performance based evaluation on routing protocols of WiMAX
(© 2016 IEEE, 2/14/2017) Shabnam, Farzana; Saha, Aparna; Sobhan, Rifat Binte; Debnath, Tanmoy; Department of Electrical and Electronic Engineering
Worldwide Interoperability for Microwave Access (WiMAX) technology is a subdivision of the vast field of wireless communications, which breaks the restrictions of DSL, cablemodem or T1 infrastructure based wire line of our broadband Internet connections [1]. Wireless networking has become an important area of research in academic and industry. The four high-speed intensive applications such as high-speed data, video, voice and streaming media are being served properly by the WiMAX network, which overcomes the term digital divide. It has a number of spearhead applications with at-home and dynamic internet accessibility along with large geographical coverage and relatively low expense to pursuit. Routing overhead, unidirectional link support, delay, throughput, QoS support and multicast are the analysable terms by whom we can define the WiMAX protocols. To attain best use of this technology selection of suitable protocol is very important. In our paper, most imperative protocols of 802.16 WiMAX network called AODV, DSDV and OLSR is ventilated as well as further criticized in accordance with their performance on WiMAX where AODV is a reactive (on demand) protocol and both DSDV and OLSR are proactive.
Improvisation of Magnetic Resonance Imaging (MRI) with development and feasible evaluation of fiber optic sensors: a survey
(© 2016 IEEE, 3/27/2017) Shabnam, Farzana; Karim, Kazi Lamiyah Daraksha; Shahrear, S. M.Fardin; Department of Electrical and Electronic Engineering
Since the dawn of 21st century, the advent of fiber optic in the field of medical science has been elevated significantly. It is needless to mention that the feature of fiber optic towards MRI has been ever growing with the emergence of fiber optic sensors. Among specific criterion in this promising field of MRI technology, temperature and noise cancellation are two of the major factors that lacks partially. The nature of optic overhauls the drawback and submerges it into a merely advanced route in medical science operation. An overview on catheterization into the specialized field of fiber optic is being detailed in this paper. Additionally, the latest cynosure into the field of MRI gambles toward the smooth operation in consequent to the arena under the factor of temperature and noise. To sum up, this paper proposes an overview in the specialized sensor of fiber optic in MRI, mainly targeting on the recent development employed for advancing the temperature sensing system and noise cancellation procedure.
Three phase one switch modular-boost/vienna power factor corrected (PFC) rectifier
(© 2017 IEEE, 4/26/2017) Uddin, Mohammad Nasir; Abedin, Amina Hasan; Bashar, Khandaker Lubaba; Islam, Samia M.Naeemul; Choudhury, Mohammad Ali A.Shoukat; Department of Electrical and Electronic Engineering
The power conversion circuit of a three phase Vienna or Modular-Boost switching power factor corrected (PFC) rectifier uses three controlled switches, eighteen diodes and two output split capacitors. Three PFC controller circuits are necessary for conversion circuit's voltage regulation, power factor control and input current waveform improvement. The circuit has been modified to have fewer active and passive components in the power circuit. The input voltages and currents are sensed and conditioned to one voltage and one current signal for the feedback controller circuit. Reduction of controlled switches, diodes of the power circuit, sensors, isolation, base drive supply circuits makes overall operation of the circuit reliable. The proposed three phase boost PFC rectifier circuit is easy to design, fabricate, operate and maintain. It occupies less space and is lighter in weight. Disadvantages of unidirectional power flow and only step-up voltage gain characteristics of conventional three phase Vienna/Modular-Boost rectifiers remain in the proposed modified circuits.
A modular one-switch three-phase Single Ended Primary Inductor (SEPIC) rectifier
(© 2017 IEEE, 4/26/2017) Bashar, Khandaker Lubaba; Islam, Samia M.Naeemul; Choudhury, Mohammad Ali A.Shoukat; Abedin, Amina Hasan; Uddin, Mohammad Nasir; Department of Electrical and Electronic Engineering
An input switch based modular Single Ended Primary Inductor (SEPIC) three phase AC-DC converter is proposed in this paper. The proposed rectifier has the advantage of step-up/down voltage gain with boost input stage. Input boost stage allows input current shaping accompanied by power factor correction. The topology will also provide possible capacitive isolation of input/output sides of the converter. The rectifier has minimum number of controlled switch, less number of diodes, fewer controller components and driver, isolators, sensors and heat sinks than other input switched three phase rectifiers. As a result, the proposed rectifier will be easy to operate, maintain, reliable in operation, light weight, compact and cost effective. The proposed three phase SEPIC rectifier is presented in this paper with its typical simulation and prototype's experimental results.
The interference management and cost analysis perspective of femtocell in 4G network
(© 2016 IEEE., 12/19/2016) Shabnam, Farzana; Shemonti, Nazifa M.; Ibnat, Aniqa A.; Chakraborty, Arnoba; Department of Electrical and Electronic Engineering
Telecommunication has seen distinct upgrade since the innovation of wireless communication. The latest addition is LTE-Advanced. LTE-Advanced requires implementation of femtocell. Spontaneous femtocell deployment introduces cross-tier and co-tier interference as well as further cost for uniform installation. In this paper, we describe outlines to solve the encountered problems and discuss the feasibility of the proposed outlines. The outlines contain efficient reuse of macrocell RF channels to indoor femtocells by dynamic spectrum allocation. The autonomous, Cognitive Radio-enabled technology is the premise of femtocells driven by LTE-Advanced. Cognitive Radio ensures offloading from macrocells by craftily imparting over accessible range. Application of on Access Control List concept further enhances femtocell capability. Additionally, hardware and software deployment costs are matched with macrocell. The reservations aim to satisfy the criterion identified as Quality of Service. The choice of femtocell over WLAN is favored by considering authorization and co-existential constraints.
Performing sentiment analysis in Bangla microblog posts
(© 2014 IEEE Computer Society, 2014) Chowdhury, Shaika; Chowdhury, Wasifa; Department of Computer Science and Engineering
Much of the research work on sentiment analysis has been carried out in the English language, but work in Bangla is limited to only news corpus and blogs. Microblogging sites are becoming a valuable source for publishing huge volumes of user-generated information, as users express their views, opinions, and sentiments over various topics. In this paper, we aim to automatically extract the sentiments or opinions conveyed by users from Bangla microblog posts and then identify the overall polarity of texts as either negative or positive. We use a semi-supervised bootstrapping approach for the development of the training corpus which avoids the need for labor intensive manual annotation. For classification, we use Support Vector Machine (SVM) and Maximum Entropy (MaxEnt) and do a comparative analysis on the performance of these two machine learning algorithms by experimenting with a combination of various sets of features.
Automated intruder detection from image sequences using minimum volume sets
(© 2012 International Journal of Communication Networks and Information Security, 2012) Ahmed, Tarem; Wei, Xianglin; Ahmed, Supriyo Sabbir; Pathan, Al-Sakib Khan; Department of Electrical and Electronic Engineering
We propose a new algorithm based on machine learning techniques for automatic intruder detection in visual surveillance networks. The proposed algorithm is theoretically founded on the concept of Minimum Volume Sets. Through application to image sequences from two different scenarios and comparison with existing algorithms, we show that it is possible for our proposed algorithm to easily obtain high detection accuracy with low false alarm rates.
Transient anode voltage modeling of IGBT and its base doping profile investigation
(© 2015 Institute of Electrical and Electronics Engineers Inc., 2015-12) Das, Avijit; Md Ziaur Rahman, Khan; Department of Electrical and Electronic Engineering
In many power converter applications, study of doping concentration in the carrier storage region of IGBT is considered desirable. This paper introduces an estimation technique for base doping concentration through investigation into transient anode voltage modeling of Non-punch through (NPT) Insulated Gate Bipolar Transistor (IGBT). Parabolic profile has been used for derivation of minority carrier concentration within the base. With the derived expression, an analytical model has been developed for turn-off anode voltage of IGBT in all doping profile conditions. Better agreements with the experimental results have been found compared to the previously used linear model. Finally, the implications of base doping dependence on the anode voltage are discussed, including implementation of such a doping concentration estimation technique

Browse

Recent Submissions