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: Renewable energy & Dielectric. 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.

A Design Consideration for Planar Inverted Fractal Antenna to Minimize Length-Dependent Specific Absorption Rate

Abstract: This paper presents a numerical solution to minimize electromagnetic radiation from a Planar Inverted Fractal Antenna (PIFA) used in cellular phone. The PIFA is simulated using a semiconductor substrate having a dielectric constant of 3.38. The height of the dielectric substrate is 0.813 mm. The designed antenna is simulated at a broad range of microwave frequency spectrum used in cellular communication. A 50-ohm probe of 0.5 mm radius perpendicular to the ground substrate plate is used as a feeding medium. The antenna performance is evaluated for three different lengths keeping all other parameters constant. Simulation results show that the intended PIFA having a length of 20 mm can be used effectively to reduce the Specific Absorption Rate (SAR) of radiation. Moreover, the reflection coefficient was found to be minimal 0.1569 at 20 mm antenna length which is determined by characteristic impedance relation. Therefore, this investigation of minimizing the radiation absorption can be considered during the implementation phase of various cellular antennas to avoid radiation-related health hazards.

Urban Renewal Strategy for a Commercial Area: Case Study-Agrabad Commercial Area, Chittagong

Abstract: Rapid urbanization is a currently a challenging problem for any developing country. To keep pace with the current population growth and ongoing economic development the cities are need to be expanded. But for a developing country, the territorial expansion of any city would be difficult for reducing the load, because of its economic and structural limitations. So for utilizing its limited resources fully, urban renewable strategy is preferable for every developing country. Renewable strategies increase the efficiency of the whole area & bolster economic force. Agrabad Commercial Area, CBD is the main business area in CHITTAGONG. In this study Commercial Business District (CBD) of Chittagong is taken as a case study and paper focuses on finding some suitable strategic proposals for it.

Determination of Active Personal Space Based on Emotion when Interacting with a Service Robot

Abstract: This paper focuses on the determination of active personal space (APS) for a service robot based on emotional status. This is required for human-robot interaction at ease. Here, APS means the active distance (relative distance during interaction and action) between the robot and the human. APS is a function of emotion both in the human and in the robot. The other factors which are considered here are age, height, familiarity with robot, and relative motion between robot and human. According to these factors, the changes in APS are shown with graphs. During the experiments two robot emotions are considered: normal and angry. The causes of variation of APS based on the two modes are also explained.

An empirical approach to autonomous GSM BTS based on OSS and OSH

Abstract: In this era of wireless engineering, Open source application has turned out to be an evolving concept in the development of GSM technology. Nowadays, GSM (Global System for Mobile Communications) networks are receiving increasing attention in the open-source community. Hence, aim of this paper is to illustrate the process of implementation of autonomous GSM BTS (Base Transceiver Station) by using OSH (Open Source Hardware) such as BladeRF device, a multipurpose signal processing board used for Software Defined Radio (SDR) and YateBTS, an OSS (Open Source Software) acts as a GSM access point which is software based. Generally, YateBTS permits available standard GSM phone to be employed as SIP (Session Initiation Protocol) endpoints in VoIP (voice over IP) network system. An experimental study has been conducted to test the feasibility and effectiveness of the implemented system. The outcome of experimental result is thoroughly examined in this paper.

Split inductor based neutral point clamped inverter using improved modulation technique to reduce common mode voltage

Abstract: Due to high switching frequency and modulation strategy, neutral point clamped (NPC) inverter generates varying common mode voltage as well as leakage current in PV and wind turbine system. This leakage current causes electrical hazard, THD at the output voltage, EMI and ultimate pollution at the output power. To reduce this varying common mode voltage and leakage current, this paper proposes a Split Inductor based Neutral Point Clamped (SINPC) inverter with improved modulation technique. The proposed inverter can reduce common mode voltage and suppress leakage current comprehensively. In order to verify the effectiveness of the SINPC inverter with improved modulation, simulation has been carried out in PSIM software. Finally, the output wave shape of reduced common mode voltage and leakage current ensures the effectivity of the proposed circuit.