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Murshed M.S.,Northern University of Bangladesh | Murshed M.S.,Chonnam National University | Seo Y.A.,Chonnam National University | Park J.-S.,Chonnam National University
Stochastic Environmental Research and Risk Assessment | Year: 2014

The study of distribution tails is a fundamental research in statistical frequency analysis relevant to many research fields, such as insurance, hydrological events, earthquake, etc. Here, we describe and investigate the effect and feasibility of the high-order L-moment (LH-moment) method for estimating heavy-tail conditions by fitting a four parameter kappa distribution. Details of parameter estimation using LH-moments for the four parameter kappa distribution (K4D) are described and formulated. Monte-Carlo simulation is performed to illustrate the performance of the LH-moment method in terms of heavy-tail quantiles over all quantiles using K4D and non K4D samples, respectively. The result suggests that the method is either useful (when the method of L-moment estimation fails to give a feasible solution) or as effective as the L-moment approach in handling data following K4D. Applications to the annual maximum flood and sea level data are presented. © 2013 Springer-Verlag Berlin Heidelberg.

Jeong B.Y.,National Cancer Center Institute | Murshed M.S.,Northern University of Bangladesh | Seo Y.A.,Chonnam National University | Park J.-S.,Chonnam National University
Stochastic Environmental Research and Risk Assessment | Year: 2014

A three-parameter kappa distribution (K3D) as a special case of the four-parameter kappa distribution is studied. This distribution (K3D) is viewed as a generalized Gumbel distribution. A description of the mathematical properties of K3D is provided. We consider the moment generating function, the moments, the L-moments, LH-moments, the asymptotic distribution of the extreme order statistics, and its graphical illustrations. Parameters are estimated by using the method of L-moments and maximum likelihood method. A Monte-Carlo simulation study is given to compare the estimation methods. To illustrate its applicability, heavy rainfall data from Korea is analyzed, and the fitness is compared with Gumbel, generalized extreme value and four-parameter kappa distributions. © 2014, Springer-Verlag Berlin Heidelberg.

Khatun A.,Manarat International University | Rahman M.,Northern University of Bangladesh | Jahan S.,Manarat International University
Oriental Pharmacy and Experimental Medicine | Year: 2014

The methanol extract of leaves of traditionally used medicinal plant Murraya exotica Linn. (Family: Rutaceae) was evaluated for possible cytotoxic, thrombolytic and antioxidant activities in this study. The extract was tested for phytochemical group test by standard method using chromogenic reagents, in vivo brine shrimp lethality assay using Artemia salina, thrombolytic effect by using the standard streptokinase and antioxidant activity by using 2,2-diphenyl-1-picryl-hydrazyl (DPPH). The study revealed the presence of reducing sugars, tannins, saponins and alkaloids. The extract showed statistically significant (p < 0.01) potent cytotoxic effect in brine shrimp lethality bioassay where the value of LC50 and LC90 were 1.27 μg/ml and 5.09 μg/ml respectively compared with the standard vincristine sulphate with the value of LC50 and LC90 0.09 μg/ml and 4.83 μg/ml respectively after 24 h. The study gave a significant indication to the use of the plant extract as a potential source for cytotoxic compounds. The extract showed mild thrombolytic effect of 15.78 % thrombolytic activity whereas the standard streptokinase showed 76.50 ± 0.82 %. In the antioxidant activity study, the extract showed free radical scavenging activity where IC50 = 1.25 μg/ml and IC90 = 4.4 μg/ml, compared with the standard ascorbic acid showing IC50 = 0.01 μg/ml and IC90 = 3.58 μg/ml. Based on the findings of phytochemical, toxicological and anti-oxidative activity, it is evident that the plant may contain some novel compounds that possess potent anti-mutagenic and anti-oxidative activities. The obtained results support the use of this plant in traditional medicine. © 2014 Institute of Korean Medicine, Kyung Hee University.

Sadeque S.,Simon Fraser University | Ahmed I.,Northern University of Bangladesh | Vaughan R.,Simon Fraser University
Canadian Conference on Electrical and Computer Engineering | Year: 2011

This paper deals with the sub-carrier and bit allocations for multi-user orthogonal frequency division multiplexing (OFDM) systems by a modified particle swarm optimization (MPSO) method for a specific bit error rate (BER). The resources (subcarriers and the number of bits per symbol per subcarrier) are allocated according to the instantaneous channel state information (CSI) which is assumed to be perfect and available with no latency and at no cost. To allocate the resources, we optimize total transmit power and throughput simultaneously with MPSO for a multi-user OFDM system. Simulation results show that for a large number of users, the MPSO performs better than existing algorithms, and that joint optimization (margin adaptive and rate adaptive) converges quickly. © 2011 IEEE.

Ul Masood M.R.,Northern University of Bangladesh
16th Int'l Conf. Computer and Information Technology, ICCIT 2013 | Year: 2014

The requirement of Bangla character recognition has become one of the prime attentions among the current researchers due to the increase of automated systems and usage of hand held devices. This paper presents a novel approach to recognize handwritten bangla numerals and addresses a robust feature extraction scheme that spawns 23-dimensional features based on the numeral's structure and topology. The recognition scheme is organized with a proposed decision tree that has been justified using entropy calculation. Considering inconsistency in individuals' writing style and the presence of significant curves and loops, the proposed feature extraction method restricts to less dimensional features of each numeral from 14600 data samples. The recognition time of this scheme is much lower than the existing procedures, since the preprocessing tasks have been performed during down sampling operation. The quick response time 13.04 ms and the higher accuracy (96.82%) explore a new era for the proposed scheme of being implemented in Bangla numeral LeadPad toys. © 2014 IEEE.

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