Comilla, Bangladesh

Comilla University

www.cou.ac.bd/
Comilla, Bangladesh

The Comilla University is a public university located at Kotbari, Comilla, Bangladesh. The university was constructed on 50 acres of land at Lalmai Bihar, Moynamoti. Comilla University is affiliated by University Grants Commission, Bangladesh.Golam Mowlah is the founder vice-chancellor of Comilla University who served until he was removed on July 30, 2008. Zulfikar Ali, a professor of mathematics, was given the charge as acting Vice Chancellor. The next vice-chancellor of Comilla University, A.K.M. Zehadul Karim declared his resignation on 7 October 2009 after a major violence in campus. Amir Hossen Khan, a professor of Physics department of Jahangirnagar University, was appointed as Vice Chancellor on 22 November 2009. After expiration of the duration of Professor Dr. Amir Hossen khan then Professor Dr. Ali Ashraf, a professor of Economics department and Ex-President of Chittagong University Teachers Association has been appointed as the 5th Vice Chancellor of Comilla University. He joined the university in 3rd December,2013. The chancellor of the university is Honorable President of Bangladesh Abdul Hamid.It started with 7 functional departments. Now there are a total of 17 departments Under 5 faculties including Information & Communication Technology ,Computer Science & Engineering , Pharmacy, Physics, Chemistry, Statistics, Mathematics, Finance and Banking, Accounting & Information Systems , Marketing, Management Studies, Economics, Public Administration, Archeology, Anthropology, Bengali, and English. Wikipedia.

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Raza S.,Hamdard University | Hasan M.,Comilla University | Islam O.,Hamdard University | Ali S.,Islamic University
2016 International Conference on Innovations in Science, Engineering and Technology, ICISET 2016 | Year: 2016

Orthogonal frequency-division multiplexing (OFDM) is the most effective technique for high speed wireless communication systems. The key challenge of OFDM based transceiver is its large peak to average power ratio (PAPR) due to non-linearity effects of power amplifier at final stage of OFDM transmitter. In this work performance of OFDM system using logical clipper and de-clipper in the OFDM transmitter and receiver respectively has been studied. In the proposed method the clipped portion of the signal is transmitted as side information which is subsequently used by the receiver to reproduce the original signal. The whole system was simulated in MATLAB environment considering AWGN channel. It is observed that the proposed system can significantly reduce PAPR of OFDM signal. © 2016 IEEE.


Hossen S.,Comilla University | Ahmed T.,Comilla University | Rahim M.S.,University of Rajshahi
2016 International Conference on Innovations in Science, Engineering and Technology, ICISET 2016 | Year: 2016

In Delay-Tolerant Network (DTN), there exists a lack of direct path from source to destination, and it is also featured by extremely high bit error rate, unwanted delay, limited resource, etc. For such network, we have investigated the effects of buffer size and mobility models on the optimization of the number of message copies for multi-copy routing protocols such as Spray-And-Focus (SNF) and Spray-And-Wait (SNW). This investigation is essential for providing us with the insight on the number of message copies that would provide better delivery, lower latency and lower overhead considering the effects of buffer size and mobility models in scalable delay-Tolerant networks. In this investigation, we have considered three performance metrics, namely delivery probability, average latency, and overhead ratio. Simulation is done using Opportunistic Network Environment (ONE) simulator, which is designed basically for evaluating the performance of DTN routing strategies. Here we have considered three mobility models, namely Shortest Path Map Based (SPMB) movement, Random Walk, and Random Direction. Simulation results show that for increasing buffer size and number of nodes on these considered mobility models for a particular value of number of message copies, indicated by L, SNF routing exhibits satisfactory performance, especially in the case of SPMB movement using only L = 2 copies. Since our purpose is to provide a satisfactory performance, i.e., higher delivery, lower latency and lower overhead, SNW routing shows overall good performance using L = 10 copies. Therefore, it would be a good optimization using Shortest Path Map Based movement model using L = 2 copies for SNF routing, and L = 10 copies for SNW in scalable DTN scenario, where there may be a high possibility of varying buffer size with number of mobile nodes. © 2016 IEEE.


Pramanik M.I.,City University of Hong Kong | Lau R.Y.K.,City University of Hong Kong | Chowdhury M.K.H.,Comilla University
Pacific Asia Conference on Information Systems, PACIS 2016 - Proceedings | Year: 2016

In the era of "big data", a huge number of people, devices, and sensors are connected via digital networks, and there is tremendous amount of data generated from their interactions every day. Effective processing and analysis of big data could reveal valuable knowledge that enable us to deal with emerging problems in a timely manner. However, rarely we can find big data analytics models and methods for crime forensics discussed in existing literature. In this paper, we illustrate a novel big data analytics framework that leverages heterogeneous big data resources for criminal pattern detection. The proposed framework can uncover the inherent structural properties of criminal networks which are essential for both crime investigation and the development of operational strategies to disrupt criminal networks. The structural analysis functionality generated by our proposed system could significantly improve the efficiency and accuracy of network analysis tasks. The proposed framework consists of two important analytical approaches, namely structure analysis, and network mapping. Based on the proposed framework, we have developed a prototype system called Automatic Crime Detector (ACD) that incorporates several big data analytic methods. Our empirical evaluation shows that the proposed framework is effective for criminal network discovery.


Sarkar R.,University of Dhaka | Haque A.,Comilla University | Ranjan S.,Southeast University of Bangladesh | Sarker M.,University of Dhaka
Pharmacologyonline | Year: 2015

Abutilon indicum is an important shrub which is traditionally used as folk medicine on various diseases. The aim of our study was to investigate phytochemicals, antioxidant and anti-microbial potential of the shrub that will potentiate its significance in traditional medicine. Ethanol (EAI), chloroform (CAI) and aqueous (AAI) extracts of A. indicum leaves were taken to perform these experiments. Phytochemical screening was done qualitatively; total phenolic (TPC) and total flavonoid content (TFC) of the extracts were evaluated quantitatively by Folin-Ciocalteau regent and aluminium trichloride methods, respectively. Antioxidant effect of the extracts was evaluated by 1, 1 Diphenyl −2- picrylhydrazyl (DPPH) radical scavenging and ferric reducing power (FRP) assay methods. Anti-microbial potential was determined by Agar diffusion method. Phytochemical screening revealed the presence of major phytoconstituents. TPC and TFC were expressed as gallic acid and quercenin equivalents. Among the three extracts, EAI showed the highest TPC and TFC. The order of TPC and TFC among the extracts is EAI>CAI>AAI. In DPPH test, IC 50 value of EAI, CAI and AAI were 25.11±2.57, 35.48±3.29 and 50.11±3.40 µg/ml, respectively. In case of FRP, EAI showed lowest EC 50 value (28.18±2.53) followed by CAI (39.81±3.47) and AAI (70.79±4.56 µg/ml). In anti- microbial assay, both the EAI and CAI showed zone of bacterial growth inhibition of the tested organisms as concentration dependent manner whereas AAI did not show any inhibition up to 500 µg/ml concentration © 2015, SILAE (Italo-Latin American Society of Ethnomedicine). All Rights Reserved.


Dendrophthoe falcata (Linn.) was a parasitic plant widely used to treat various ailments as traditional medicine. The objective of the present study was to investigate analgesic, anti-inflammatory and central nervous system (CNS) depressant effects of aqueous, ethanol, chloroform and petroleum ether extracts of D. falcata stem (ADFS, EDFS, CDFS and PDFS) on experimental mice. The analgesic activity of the extracts was determined by tail immersion and acetic acid induced writhing methods. Carrageenan-induced paw edema model was applied to find out anti-inflammatory potential. The CNS-depressant effect of the extracts were evaluated by using open field and hole cross tests. All the extracts had exhibited significant (Pb<0.01, Pa<0.001) analgesic, anti-inflammatory and CNS-depressant effects at dose dependent manner. Chloroform fraction showed maximum analgesic effect (77.58% inhibition of abdominal writhing and 82.12% elongation of tail withdrawal time) at 200mg/kg dose. Moreover, the highest anti-inflammatory potential (90.24% inhibition of paw edema volume) had shown by the chloroform fraction at 200mg/kg dose. On the other hand, ethanol extract had proved to have significant (97.33% and 85.91% inhibition of locomotion in open field and in hole cross test respectively) CNS-depressant activities after 120min of oral administration of the extract at 200mg/kg dose. © 2016, SILAE (Italo-Latin American Society of Ethnomedicine). All rights reserved.


Miah M.J.,Bangladesh University of Engineering and Technology | Miah M.J.,Comilla University | Khan M.N.I.,Atomic Energy Center | Hossain A.K.M.A.,Bangladesh University of Engineering and Technology
AIP Conference Proceedings | Year: 2016

Multiferroic xBa0.95Sr0.05TiO3-(1-x)BiFe0.90Gd0.10O3 [xBST-(1-x)BFGO] (x = 0.00, 0.10 and 0.20) ceramics were prepared by the standard solid-state reaction technique. Crystal structure of the ceramics was determined by X-ray diffraction pattern. All the compositions exhibited rhombohedral crystal structure. The tolerance factor 't' varied from 0.847 to 0.864. The AC conductivity spectrum followed the Jonscher's power law. The Nyquist plots indicated that only grains have the contribution to the resistance in this material and the values of grain resistance (Rg) increased with BST content. The real part of complex initial permeability decreased with the increase in frequency and increased with increasing BST content. Magnetoelectric coefficient was determined for all compositions. The maximum value of magnetoelectric coefficient was found to be 1.467 mV.cm-1.Oe-1 for x = 0.20. © 2016 Author(s).


Mazumdar S.C.,Bangladesh University of Engineering and Technology | Mazumdar S.C.,Comilla University | Khan M.N.I.,Atomic Energy Center | Islam M.F.,Bangladesh University of Engineering and Technology | Hossain A.K.M.A.,Bangladesh University of Engineering and Technology
Journal of Magnetism and Magnetic Materials | Year: 2015

Multiferroic composites (1-y)BiFeO3-yNi0.50Cu0.05Zn0.45Fe2O4 (y=0.0, 0.1, 0.2, 0.3 and 0.4) are synthesized by the standard solid state reaction method. The X-ray diffraction analysis affirms the formation of both the component phases and also reveals that there is no chemical reaction between them. From the energy-dispersive X-ray spectroscopy study it is observed that the percentage of the elements in the component phases is well consistent with the nominal composition of the composites. Field Emission Scanning Electron Microscopy analysis shows almost homogeneous mixture of the two phases. The real part of the initial permeability increases (up to 67%) and the loss decreases with the ferrite content in the composites which is important in application point of view. Dielectric constant (ε′), loss tangent and AC conductivity are measured as a function of frequency at room temperature. The highest ε′ is obtained for 0.6BiFeO3-0.4Ni0.50Cu0.05Zn0.45Fe2O4 composite. The dielectric dispersion at lower frequency (<105 Hz) is due to the interfacial polarization. The complex impedance spectroscopy is used to correlate between the electrical properties of the studied samples with their microstructures. Two semicircular arcs corresponding to both grain and grain boundary contribution to electrical properties have been observed in all the studied samples. The maximum magnetoelectric voltage coefficient is found to be ∼38 mV cm-1 Oe-1 for the composite with 80% ferroelectric+20% ferrite phases. The present composite might be a promising candidate as multiferroic materials showing effective electric and magnetic properties. © 2015 Elsevier B.V. All rights reserved.


Mahmud A.,Comilla University | Sattar A.,Comilla University
Proceedings - 2013 International Conference on Advanced Computer Science Applications and Technologies, ACSAT 2013 | Year: 2014

A novel 'ICTization framework' has been proposed to establish a standard interface between assigned and received services and advances the administrative and technical infrastructure to share information resources among local, regional, national, and international platforms. This framework is based on capability, connectivity and context provided in three separate layers namely core, management and distribution that support centralization, decentralization and parallelization features. In this paper the Information and communication technology (ICT) impacting factors have been analyzed and prioritized through a survey. Due to lack of a combined work plan, Bangladesh is still staying behind in comparison to other ICT developed countries whereas the suggested framework is capable to manage and maintain the ICT impacting factors and also can get quickly adapted with the ICT infrastructure. The framework will lessen the misconception about infrastructure, development and communication and capable to improve the synchronization between managements and services. © 2013 IEEE.


Miah M.J.,Bangladesh University of Engineering and Technology | Miah M.J.,Comilla University | Akther Hossain A.K.M.,Bangladesh University of Engineering and Technology
Acta Metallurgica Sinica (English Letters) | Year: 2016

xBa0.95Sr0.05TiO3-(1 - x)BiFe0.9Gd0.1O3 [xBST-(1 - x)BFGO] (x = 0.00, 0.10, 0.20 and 0.25) multiferroic ceramics were prepared by the standard solid-state reaction technique. Structural characterization was performed by X-ray diffraction. All the samples showed rhombohedral distorted perovskite structure. Surface morphology of the ceramics was studied by the field emission scanning electron microscope (FESEM). From the FESEM observation, the grain size was observed to be decreased with increasing BST content. Enhanced magnetic properties were observed in BFGO with the increase in BST content because of large lattice distortion. The complex initial permeability increased with the increasing of BST content. The study of dielectric properties showed that the dielectric constant increased, whereas dielectric loss decreased with increasing of BST content due to the reduction of oxygen vacancies. An analysis of the electric impedance and modulus with frequency was performed at different temperatures. Non-Debye-type relaxation processes occur in the compound which was confirmed from the nature of the Cole-Cole plot. The DC conductivity was found to increase with the rise in temperature which indicates the semiconducting behavior of the compound with characteristics of the negative temperature coefficient of resistance. The activation energy, responsible for the relaxation determined from the modulus spectra (0.246 eV), was found to be almost same as the value obtained from the impedance study (0.240 eV), indicating that charge carriers overcome the same energy barrier during relaxation. The frequency response of imaginary parts of electric impedance and modulus suggested that the relaxation in xBST-(1 - x)BFGO ceramics follows the same mechanism at various temperatures. © The Chinese Society for Metals and Springer-Verlag 2016.


Rashid A.N.M.B.,Comilla University | Islam M.S.,Bangladesh University of Engineering and Technology | Hoque A.S.M.L.,Bangladesh University of Engineering and Technology
Communications in Computer and Information Science | Year: 2011

Because of the query intensive nature of data warehousing or online analytical processing applications, materialized view is quite promising in efficiently processing the queries and for improving the query performance. It is costly to rematerialize the view each time a change is made to the base tables that might affect it. So, it is desirable to propagate the changes incrementally. Hence, all of the views cannot be materialized due to the view maintenance cost. In this paper, we have developed a dynamic cost model based on threshold level incorporating the factors like view complexity, query access frequency, execution time and update frequency of the base table to select a subset of views from a large set of views to be materialized. A number of algorithms and mathematical equations have been designed and developed to define the dynamic threshold level. © 2011 Springer-Verlag Berlin Heidelberg.

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