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In this paper, a portable wireless biometric attendance system for academic purpose has been designed and developed using fingerprint sensor and NodeMCU microcontroller. One of the cardinal features of this system is the portability of this system and also the reduction of time consumption compared to the conventional stationary wired/wireless systems where students have to stand in serials and wait for his/her turn which costs good amount of time during a class period. The smaller size of our system has enabled the students to pass the device from one to another without interrupting the class lecture and saves valuable time of the class lecturer which is generally a fixed period of time. All the data of a particular student are stored in a database when a student's finger is registered for a particular institute and after that whenever the student enrolls, his/her attendance is counted automatically and stored in the destined database wirelessly. The attendance marks based on attendance percentages of the students are automatically calculated and uploaded on the webpage. So whenever a semester finishes the course teacher can get percentage information as well as the corresponding attendance marks of all the students without having a headache of it in the entire semester. Our system also notifies the user if any student is absent for 10 successive classes (as per Govt. rule in Bangladesh, course teacher has to inform authority if any student is absent for 10 days successively).

Implementation of a real-time bus tracking system in Chittagong University (CU) is proposed and developed to keep monitoring the teachers' buses and to provide the information of buses to the teachers via android application (app) in a more efficient manner. The idea behind is, there is no such tracking system in CU. Moreover, some limitations arise with the present existing tracking systems in the universe-need hardware maintenance in the GSM/GPRS module that is expensive also, use conventional MySQL database that updates data within few seconds etc. Concerning these limitations, the developed system uses two smartphone applications for transmitting and receiving information using Firebase, an online server with real-time database updating data within few milliseconds that makes the system faster than others. The In-vehicle app receives latitude and longitude values from the satellite and transmits them to the firebase. Firebase updates the data continuously and transmits to the user app. A user can get the information of current location address, distance from any bus stop and time to reach a specific destination of the bus through the User app. Hence, the developed tracking system provides more economical, velocious and user-friendly environment to the users.

This research aims at the designing and implementation of an Automatic Voltage Regulator (AVR) with higher precision and hysteresis. AC power supplied by PDB (Power development board) in Bangladesh is subjected to variation from time to time. Moreover in rural areas supplied voltage remains lower than specified. This causes a considerable threat to the sophisticated electronic devices like computer, refrigerator, television etc. So ensuring the input voltage to remain in a tolerable pre-specified limit has become a necessity in rural as well as some urban areas. Current systems available locally lacks precision and suffers the problem of oscillating between two output voltage and hence creating surge at the output which can damage valuable electronics. This research handled both shortcomings and introduced in the tolerable range of 215-237 volt using several taps. Hysteresis has been introduced while changing from one level to other and thus preventing oscillation.

The main objective of this work is to design and construct a PoE switch based system: to control electric appliances such as light, fan, heater, washing machine, motor, TV, etc. and simultaneously data communication facility. Especially PoE switch can manage power and data separately by a splitter which motivated the need to research into it not only for industrial application but also for domestic use or home use. Power is use for controlling devices and data is for communication purpose. This system will play an important role for the elderly and physically disabled people to control their home appliances in intuitive and flexible way through Wi-Fi and internet. This system is password protected so only authorized person can control any sensitive electrical appliances. Most commercially available home automation systems are used only for control purpose. But by our proposed PoE based system we can control electrical appliances as well as data communication by the same switch port.

A pot experiment was conducted to study the growth response of Indian spinach (Basella alba L) to biogas plant residues. There were seven treatments comprising of control, recommended NPK fertilizer and biogas plant residues (BPR) @ 10, 20, 30, 40 and 50 ton ha -1 . The treatments were arranged in a randomized complete block design with three replications. Results indicated that number of leaves; plant height and root length and dry weight of shoot and root obtained with recommended NPK fertilizer were statistically similar to those with control treatment except for number of leaves at 60 DAS. Application of biogas plant residues up to 30 ton ha -1 produced similar number of leaves and plant height compared to control and recommended NPK fertilizer at 30 DAS. At 60 DAS, a significantly higher number of leaves and root length was found with above 20 ton ha -1 biogas plant residues and plant height with above 10 ton ha -1 biogas plant residues than control and recommended NPK fertilizer. Fresh weight of shoot and root found with recommended fertilizer dose were significantly higher than that with the control but lower than that with biogas plant residues above 30 ton ha -1 and 10 ton ha -1 , respectively. Biogas plant residues at 30 ton ha -1 and above gave higher shoot and root dry weight than control and recommended NPK fertilizer. However, there were no significant differences between BPR40 and BPR50 for growth parameters of Indian spinach. The study recommends 40 ton ha -1 of biogas plant

A field experiment was conducted in the crop field of the Department of Soil Science, University of Chittagong, Bangladesh to study the effects of biogas plant residues, poultry manure and NPK fertilizer on growth and yield of ladies finger (Abelmoschus esculentus L Moench). There were six treatments - control (no fertilizer/poultry manure/compost), full NPK @ 120 kg N ha -1 , 60 kg P ha -1 and 80 kg K ha -1 , full biogas plant residues(BPR) @ 30 ton ha -1 , 50% NPK+ 50% BPR, full poultry manure (PM) @ 30 ton ha -1 , 50% NPK+ 50% PM. The treatments were arranged in randomized block design with three replications. The data collected were number of leaves, plant height, fruit length, fruit circumference, number of fruits and fruit yield. The results showed that full NPK fertilizer did not significantly increase the growth and yield of ladies finger over control. Compared to control addition of full poultry manure and its combination with NPK fertilizer resulted in 6.28 to 7.29 fold increases in yield. Relatively lower yields (0.34-0.17 fold) were obtained in treatments with biogas plant residues compared to treatments with poultry manure. Our result indicate that poultry manure can be used in combination with the application of inorganic fertilizers for better growth and yield of ladies finger in the valley soils of Chittagong.

There are Forty ISPs (Internet Service Provider) operate in Bangladesh which provide services like Basic Internet Connection, IP-VPN Services, MPLS, Mail Server, Intranet etc., to both Corporate & SOHO (Small Office/Home Office) users, along with individual users by various delivery method like ADSL, DSL, FTTH, Wi-Fi, WiMAX, Radio or simple Ethernet connection. To cover, vast geographic area & to provide last mile connectivity to their users, ISPs setup numerous PoPs or Point of Presence in strategic locations, equipped with required hardware and connected by backhauling of telecommunication lines or FTTH connections or Radio. Usually the strength of an ISP is measured by its number of PoPs and the number of subscribers these PoPs can handle. Nowadays PoPs are usually resided inside the rented space of telecommunication switching room or BTS (Base Transceiver Station). These PoPs are usually equipped with network equipment like Network Switch, Gateway, Router, E1 Converters, and Media Converters etc. Most of the time, these PoPs are not manned. And because these are rented, the original owners (Telecom Operators) keep those locked in. Problem arises when the mentioned equipment (E1 converter, Media Converter) becomes unresponsive, or in tech slang, gets hanged. To resolve the issue, one has to go to the remote site just to flip the power switch to perform a simple reboot of the unresponsive device. A common phenomenon in this situation is, often there aren't any technically trained personnel at the site who can perform maintenance and resets on equipment. Even if it is a manned station, the risk of wrong equipment getting rebooted is high. To encounter such problems, lower the travel time expense-time, eliminate the man-hour misused and specially minimize downtime, we developed a PoE (Power over Ethernet) switch based remote power control system by which a network administrator can control power of network equipments from anywhere and anytime. Power over Ethernet switch offers advance switching controls and provides power to network devices using Ethernet cables. These are the sole reasons which propelled the motivation to research in this particular issue. We believe this would help this competitive industry (ISP) to minimize cost and maximize service efficiency.

Digital clock is a very common device to show the time. 7-segment, Alphanumeric, Liquid Crystal and Graphic displays are commonly used in digital clock. They show time in English character. But, we were motivated to design this useful device showing time in Bengali to respect our national heroes who sacrificed their lives for our language in 21th February, 1952. In this paper, a digital clock is designed which shows time in Bangla character in 8×8 dot matrix display. Here, a real time clock (DS1307) is used to generate precise timing pulse, a microcontroller (PIC 16F877A) is used to adjust the time and to interface the 8×8 dot-matrix displays. The time of the clock can be adjusted by pressing simple push switches. The design is simple, cost effective and user friendly.