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Md. Rafiqul Islam

Bio: Md. Rafiqul Islam is an academic researcher from Khulna University of Engineering & Technology. The author has contributed to research in topics: Computer science & Medicine. The author has an hindex of 20, co-authored 334 publications receiving 1915 citations. Previous affiliations of Md. Rafiqul Islam include National University of Singapore & International Islamic University, Islamabad.


Papers
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Journal ArticleDOI
TL;DR: The effect of antenna losses due to rain on a 26 GHz microwave link and the technique of extracting the losses from the measured rain attenuation will provide useful information in the microwave link planning and design in tropical regions.
Abstract: This letter discusses the effect of antenna losses due to rain on a 26 GHz microwave link and the technique of extracting the losses from the measured rain attenuation A 2-feet parabolic dish antenna with horizontal polarization has been used in the study The measurement results have been compared with those obtained from other locations in Malaysia and some other Published Research works The study will provide useful information in the microwave link planning and design in tropical regions; and it can also be adapted to satellite communication operating at ka-band

158 citations

Journal ArticleDOI
TL;DR: In this paper, the authors reviewed and discussed the recent advances in InN-based solar cells and the status and issues for multi-junction tandem solar cells using the conventional III-V materials (InGaP/InGaAs systems).
Abstract: In this paper, we review and discuss the recent advances in InN-based solar cells. Before the discussion on InN-based solar cells, two major losses in a solar cell, transparency loss and excess excitation loss, are explained and the effectiveness of a multi-junction tandem cell in reducing the both losses simultaneously is described. Then, the status and issues for multi-junction tandem solar cells using the conventional III-V materials (InGaP/InGaAs systems) are reviewed briefly in order to understand the advantages of InN-based material as a multi-junction solar cell material. It is shown that main problem in the conventional III-V multi-junction solar cell is the current mismatching between sub-cells, which reduces significantly the conversion efficiency of the tandem cells. The main advantage of InGaN and InAlN as a multi-junction solar cell is that a wanted band-gap between 0.7 and 2.5 eV is realized by changing only their composition. This means that current matching between sub-cells will be easily achieved using InGaN and InAlN systems. After the status of InGaN solar cell research is summarized, the results on the MOVPE growth of InGaN with an In content up to 0.4, Mg doping using Cp2Mg, and the formation of an n+-p homo-junction are described. The insertion of step-graded InxGa1-xN interlayer between the GaN and InGaN epilayer is also shown to be effective to improve the epilayer quality. The study on InAlN solar cell is on the stage of the growth of In-rich InAlN. Single-crystalline InAlN films with an Al content from 0 (Eg = 0.7 eV) to 0.43 (2 eV) have been successfully grown by employing atmospheric-pressure MOVPE. The study on Mg-doping for InAlN will be the next step. Finally, we will summarize and discuss the challenges in InGaN and InAlN solar cells. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

121 citations

Journal ArticleDOI
TL;DR: The statistics for the worst month in Malaysia is lower than what was predicted by the ITU model, and the average percentage of error calculated between the measurements and predicted results for the rain rate and rain attenuation were 143% and 159%, respectively.
Abstract: In this paper, real measurements were conducted to investigate the impact of rain on the propagation of millimeter waves at 26 GHz. The measurements were accomplished using a microwave fifth generation radio link system with 1.3 km path length implemented at Universiti Teknologi Malaysia Johor Bahru, Malaysia. The implemented system consisted of Ericsson CN500 mini E-link, radio unit, rain gauge, and data logger. The measurements were attained and logged daily for a continuous year, with 1-min time intervals. Next, the MATLAB software was used to process and analyze the annual rain rate and rain attenuation, including for the worst month. From the analyzed results, it was found that at 0.01% percentage of time, the rain rate was 120 mm/hr; while the specific rain attenuation was 26.2 dB/km and the total rain attenuation over 1.3 km was 34 dB. In addition, the statistics acquired from the measurements for the worst month were lower than what was predicted by the international telecommunication union (ITU) model; around 51% and 34% for the rain rate and rain attenuation, respectively. The average percentage of error calculated between the measurements and predicted results for the rain rate and rain attenuation were 143% and 159%, respectively. Thus, it can be concluded that the statistics for the worst month in Malaysia is lower than what was predicted by the ITU model.

98 citations

Proceedings ArticleDOI
11 May 2010
TL;DR: The objective of this paper is to produce analysis result of the different weather attenuations that have effect on FSO link and to provide more knowledge on the feasibility of FSO deployment under tropical weather condition especially for a long range link.
Abstract: Free Space Optics communications (FSO) has attracted a lot of attention for a variety of applications in telecommunications field. The unlicensed, higher speed, broader and unlimited bandwidth, low cost solutions, and shortest deployment time frame are some of the drive to deploy FSO. However, weather attenuation has a big impact on the transmission line of FSO. There are a lot of studies and experiments have been done on FSO in the temperate climate region where the attenuation due to snow and fog are the two major problems in the deployment of FSO. However, there are no comprehensive study is done for the deployment of FSO in the tropical climate region where the rain and haze are present throughout the year. The objective of this paper is to produce analysis result of the different weather attenuations that have effect on FSO link. The parameters are attenuation due to geometric, molecular, atmospheric, rain, haze, and scintillation. The parameters are used to evaluate link availability of the FSO link. The result of the evaluation can provide more knowledge on the feasibility of FSO deployment under tropical weather condition especially for a long range link.

45 citations

Journal Article
TL;DR: An approach to license plate localization and recognition is presented and a proposed method to perform recognition of license plates under any environmental conditions, with no assumptions about the orientation of the plate or its distance from the camera is designed.
Abstract: Vehicle license plate recognition is an image-processing technology used to identify vehicles by their license plates. This technology can be used in various security and traffic applications, such as finding stolen cars, controlling access to car parks and gathering traffic flow statistics. In this paper an approach to license plate localization and recognition is presented. A proposed method to perform recognition of license plates under any environmental conditions, with no assumptions about the orientation of the plate or its distance from the camera is designed. To solve the problem of localization of a license plate, a simple texture-based approach based on edge information is used. Segmentation of characters is performed by using connected components analysis on license plate’s image, and a simple multi-layer Perceptron neural network is used to recognize them. Simulation results were shown to be an efficient method for real time plate recognition.

44 citations


Cited by
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[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

01 Jan 2016
TL;DR: The electronic transport in mesoscopic systems is universally compatible with any devices to read, and is available in the book collection an online access to it is set as public so you can get it instantly.
Abstract: Thank you very much for reading electronic transport in mesoscopic systems. Maybe you have knowledge that, people have look numerous times for their favorite readings like this electronic transport in mesoscopic systems, but end up in harmful downloads. Rather than reading a good book with a cup of tea in the afternoon, instead they juggled with some harmful bugs inside their computer. electronic transport in mesoscopic systems is available in our book collection an online access to it is set as public so you can get it instantly. Our book servers spans in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Merely said, the electronic transport in mesoscopic systems is universally compatible with any devices to read.

1,220 citations

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507 citations