ORCID Profile
0000-0002-9543-7496
Current Organisation
Noakhali Science and Technology University
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Publisher: Springer Berlin Heidelberg
Date: 2011
Publisher: Kaunas University of Technology (KTU)
Date: 18-10-2012
Publisher: IEEE
Date: 09-2011
Publisher: Walter de Gruyter GmbH
Date: 06-2011
DOI: 10.1515/JOC.2011.024
Abstract: The transmission of a spectrum-sliced WDM channel at 2.5 Gbit/s for 50 km of single mode fiber using an system channel spacing only 0.4 nm is reported. We have investigated the system performance using NRZ modulation format. The proposed system is compared with conventional system. The system performance is characterized as the bit-error-rate (BER) received against the system bit rates. Simulation results show that the NRZ modulation format performs well for 2.5 Gbit/s system bit rates. Using this narrow channel spectrum-sliced technique, the total number of multiplexed channels can be increased greatly in WDM system. Therefore, 0.4 nm channel spacing spectrum-sliced WDM system is highly recommended for the long distance optical access networks, like the Metro Area Network (MAN), Fiber-to-the-Building (FTTB) and Fiber-to-the-Home (FTTH).
Publisher: Science Publications
Date: 10-2013
Publisher: Trans Tech Publications, Ltd.
Date: 2012
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.433-440.3878
Abstract: In this paper a hybrid optical code ision multiple access (OCDMA) over wavelength ision multiplexing (WDM) network is proposed to support large number of subscribers. The system combines two different techniques, namely OCDMA and WDM for supporting many subscribers simultaneously. We used modified double weight (MDW) codes as a signature address in designing the system because this code can accommodate more number of simultaneous active users under considerable standard bit error rate (e.g. ≤ 10-9). The induced MDW code for hybrid system can eliminate multiuser interference fully and increase the bit-error-rate performance compared to other codes at the same time. We ascertained by simulation results that the proposed scheme provides very good performance and enhance the network capability. Therefore, this system can be considered as a promising solution for the next generation optical access network.
Publisher: MDPI AG
Date: 26-02-2021
DOI: 10.3390/S21051638
Abstract: The electrocardiogram (ECG) has significant clinical importance for analyzing most cardiovascular diseases. ECGs beat morphologies, beat durations, and litudes vary from subject to subject and diseases to diseases. Therefore, ECG morphology-based modeling has long-standing research interests. This work aims to develop a simplified ECG model based on a minimum number of parameters that could correctly represent ECG morphology in different cardiac dysrhythmias. A simple mathematical model based on the sum of two Gaussian functions is proposed. However, fitting more than one Gaussian function in a deterministic way has accuracy and localization problems. To solve these fitting problems, two hybrid optimization methods have been developed to select the optimal ECG model parameters. The first method is the combination of an approximation and global search technique (ApproxiGlo), and the second method is the combination of an approximation and multi-start search technique (ApproxiMul). The proposed model and optimization methods have been applied to real ECGs in different cardiac dysrhythmias, and the effectiveness of the model performance was measured in time, frequency, and the time-frequency domain. The model fit different types of ECG beats representing different cardiac dysrhythmias with high correlation coefficients ( .98). Compared to the nonlinear fitting method, ApproxiGlo and ApproxiMul are 3.32 and 7.88 times better in terms of root mean square error (RMSE), respectively. Regarding optimization, the ApproxiMul performs better than the ApproxiGlo method in many metrics. Different uses of this model are possible, such as a syntactic ECG generator using a graphical user interface has been developed and tested. In addition, the model can be used as a lossy compression with a variable compression rate. A compression ratio of 20:1 can be achieved with 1 kHz s ling frequency and 75 beats per minute. These optimization methods can be used in different engineering fields where the sum of Gaussians is used.
Publisher: Elsevier BV
Date: 07-2013
Publisher: Springer Science and Business Media LLC
Date: 2012
No related grants have been discovered for Mohd Abdur Rashid.