A better way for finding the optimal number of nodes in a distributed database management system

Distributed Database Management System (DDBMS) is one of the prime concerns in distributed computing. The driving force of development of DDBMS is the demand of the applications that need to query very large databases (order of terabytes). Traditional Client- Server database systems are too slower to handle such applications. This paper presents a better way to find the optimal number of nodes in a distributed database management systems. Keywords: DDBMS, Data Fragmentation, Linear Search, RMI. DOI: 10.3329/diujst.v4i2.4362 Daffodil International University Journal of Science and Technology Vol.4(2) 2009 pp.19-22

Performance Analysis Of Cooperative Relaying In Nakagami-M Fading Channels

This paper is concerned with the analysis of exact symbol error probability (SEP) for cooperative diversity using amplify-and-forward (AF) relaying over independent and non-identical Nakagami-m fading channels. The mathematical formulations for Probability Density Function (pdf) and Moment Generating Function (MGF) of a cooperative link have been derived for calculating symbol error probability with well-known MGF based approach taking M-ary Phase Shift Keying (MPSK) signals as input. The numerical results obtained from this research have been compared with different fading conditions. It is observed that the existence of the diversity link in a relay network plays a dominating role in error performance. Keywords: Symbol Error Probability; Probability Density Function; Moment Generating Function; Nakagami-m fading. DOI: http://dx.doi.org/10.3329/diujst.v6i2.9338 DIUJST 2011; 6(2): 1-5

Estimation of Optimal Time Step and Compare with of ODE Solver of MATLAB Package of RLC Circuit using Numerical Methods

In this paper analysis of a RLC circuit model that has been described optimal time step and minimize of error using numerical method. The goal is to reach the optimal time response due to the input for which optimal output response reaches a minimum error and also compared with ODE solver of MATLAB packages for the different cell (mesh) size of the RLC model. Table is constructed of the model to evaluate optimal time step and also CPU time into the simulation using MATLAB 7.6.0(R2008a).The values of register, capacitor and inductor as well as electromagnetic force are obtained through the mathematical relations of the model. The general analysis of the RLC circuit due to the optimal time step and minimum error is developed after several analysis and operations. The theoretical results show effectiveness of optimized of the model. Keywords: Optimal time step; MATLAB; Trapezoidal; Implicit Euler; Runge-Kutta method; RLC circuit. DOI: http://dx.doi.org/10.3329/diujst.v7i1.9650 Daffodil International University Journal of Science and Technology Vol.7(1) 2012 67-73

Dissipation Effect On A Free Convection Flow Past A Porous Vertical Plate

A Numerical study on the effect of dissipation on a steady free convection flow through a porous vertical plate is made. The relevant non-leaner boundary equations are made dimensionless using specific non-dimensional variables. The corresponding non-similar partial differential equations are solved using implicit finite difference method with Keller-Box scheme. The results are then presented graphically and discussed thereafter. Keywords: porous plate; viscous dissipation; natural convection. DOI: http://dx.doi.org/10.3329/diujst.v6i1.9334 DIUJST 2011; 6(1): 52-59

An Application Of Pde To Predict Brain Tumor Growth Using High Performance Computing System

This study is to predict two-dimensional brain tumors growth through parallel algorithm using the High Performance Computing System. The numerical finite-difference method is highlighted as a platform for discretization of twodimensional parabolic equations. The consequence of a type of finite difference approximation namely explicit method will be presented in this paper. The numerical solution is applied in the medical field by solving a mathematical model for the diffusion of brain tumors which is a new technique to predict brain tumor growth. A parabolic mathematical model used to describe and predict the evolution of tumor from the avascular stage to the vascular, through the angiogenic process. The parallel algorithm based on High Performance Computing (HPC) System is used to capture the growth of brain tumors cells in two-dimensional visualization. PVM (Parallel Virtual Machine) software is used as communication platform in the HPC System. The performance of the algorithm evaluated in terms of speedup, efficiency, effectiveness and temporal performance. Keywords: Partial Differential Equation (PDE); parabolic equation; explicit method; Red Black Gauss-Seidel; Parallel Virtual Machine (PVM); High Performance Computing (HPC); Brain Tumor. DOI: http://dx.doi.org/10.3329/diujst.v6i1.9335 DIUJST 2011; 6(1): 60-68

Machine and web translator for English to Bangla using natural language processes

The modern web contents are mostly written in English and developing a system with the facility of translating web pages from English to Bangla that can aid the massive number of people of Bangladesh. It is very important to introduce Natural Language Processing (NLP) and is required to developing a solution of web translator. It is a technique that deals with understanding natural languages and natural language generation. It is really a challenging job to building a Web Translator with 100% efficiency and our proposed Web Translator basically uses Machine Translator as its mother concern. This paper represents an optimal way for English to Bangla machine and the Web translation & translation methods are used by translator. Naturally there are three stages for MT but here we propose a translation system which includes 4 stages, such as, POS tagging, Generating parse tree, Transfer English parse tree to Bengali parse tree and Translate English to Bangla and apply AI. An innovation initiative has scope of being upgraded in future and hopefully this work will assist to develop more improved English to Bangla Web Translator. Keywords: Machine Translator, Web Translator, POS Tagging, Parsing, HTML Parsing, Verb Mapping DOI: 10.3329/diujst.v5i1.4382 Daffodil International University Journal of Science and Technology Vol.5(1) 2010 pp.53-61

Linear differential algebraic equations with constant coefficients

Differential-algebraic equations (DAEs) arise in a variety of applications. Their analysis and numerical treatment, therefore, plays an important role in modern mathematics. The paper gives an introduction to the topics of DAEs. Examples of DAEs are considered showing their importance for practical problems. Some essential concepts that are really essential for understanding the DAE systems are introduced. The canonical forms of DAEs are discussed widely to make them more efficient and easy for practical use. Also some numerical examples are discussed to clarify the existence and uniqueness of the system's solutions. Keywords: differential-algebraic equations, index concept, canonical forms. DOI: 10.3329/diujst.v4i2.4365 Daffodil International University Journal of Science and Technology Vol.4(2) 2009 pp.28-35

The Effects Of Radiation And Heat Generation On Magnetohydrodynamic(MHD) Natural Convection Flow Along A Vertical Flat Plate In Presence Of Viscous Dissipation

This article investigates the effects of radiation and heat generation on magnetohydrodynamic( MHD) natural convection flow of an incompressible viscous electrically conducting fluid along a vertically placed flat plate in presence of viscous dissipation and heat conduction. Appropriate transformations were employed to transform governing equations of this flow into dimensionless form and then solved using the implicit finite difference method with Keller box scheme. The resulting numerical solutions of transformed governing equations are presented graphically in terms of velocity profile, temperature distribution, skin friction coefficient and surface temperature and the effects of magnetic parameter (M), radiation parameter (R), Prandtl number (Pr) and heat generation parameter (Q) and viscous dissipation parameter (N) on the flow have been studied with the help of graphs. Keywords: Radiation; Heat Generation Parameter; Viscous Dissipation Parameter; MHD; Finite Difference Method; Vertical Flat Plate. DOI: http://dx.doi.org/10.3329/diujst.v6i1.9330 DIUJST 2011; 6(1): 20-29

Identification and impact analysis of invasive species: A case study in the Mongla Sea Port Area of Bagerhat District of Bangladesh

Manipulation through invasion is a major problem in most of the port areas in recent world. Mongla is an important sea port that has accomplished the activities like import and export of various goods inside and outside Bangladesh. The process not only involves the moving of goods, it also carries the invasive species purposely or accidentally which invading to the new location of the Mongla port area through exploration and colonization with varieties diversity and scale. The paper identifies the invasive species and analyses the causes and ways of invasion in the coastal waters with possible impacts of invasion in the Mongla Port area. To achieve the objectives of the research, different aquatic species were collected by random sampling from the confluence of the River Passur Mongla port and the adjacent area around the Sundarbans from September 2006 to April 2007. The fishermen and local communities including indigenous people were interviewed to explore the invasion situation. The research reveals that ballast water of cargo ships is one of the means of invasion of the coastal waters of Mongla Port. Aquaculture is another reason of invasion due to introduction of many exotic fishes and shrimp species such as Pangus (Pangasius sutchi), African Magur (Clarias gariepinus), Tilapia (Tilapia mossambica) and Nilotica (Oreochromis niloticus) etc. that have the active roles for altering the aquatic ecosystem of Mongla Port. Finally, the research also finds out some possible environmental impacts caused by those invasive species. Key words: Invasive species, Aquaculture, Indigenous species, Aquatic ecosystem, Ballast water DOI: 10.3329/diujst.v4i1.4353 Daffodil International University Journal of Science and Technology Vol.4(1) 2009 pp.35-41

Power System Stabilization By Fuzzy Set Theory Based Control Of SMES

At present fuzzy logic control is receiving increasing emphasis in process control applications. The paper describes the application of fuzzy logic control in a power system that uses a 12- pulse bridge converter associated with Superconductive Magnetic Energy Storage (SMES) unit. The fuzzy control is used in both the frequency and voltage control loops, replacing the conventional control method. The control algorithms have been developed in detail and simulation results are presented. These results clearly indicate the superior performance of fuzzy control during the dynamic period of energy transfer between the power system and SMES unit. Keywords: Fuzzy logic controller; power system dynamic performance; SMES unit. DOI: http://dx.doi.org/10.3329/diujst.v6i2.9343 DIUJST 2011; 6(2): 33-41