Vol. 08, Issue 1, January 2013
Browse
11 results
Search Results
Item XML BASE SECURED DATA ENCRYPTION AND TRANSMISSION TECHNOLOGY(Daffodil International University, 2013-01) Sobuz, Md. ShamsuzzamanWith the development of data transmission and Web Service technology, XML is widely used in all kinds of information transformation. So, Security in XML data transmission is very important, nowadays, in most of the sensitive issue like Bank transaction, online transaction, e-commerce, Diplomatic data etc. For secure XML Transaction, several methods are proposed. We will study the technologies of secure XML transmission which propose the XML's security encryption based on the importance and sensitivity of data.Item THERMOPHORESIS EFFECT ON THE MHD FLOW OVER AN INCLINED STRETCHING SHEET WITH HEAT GENERATION AND MAGNETIC FIELD(Daffodil International University, 2013-01) Karim, M Enamul; Kabir, Md. AlamgirThe thermophoretic effect of particle deposition on an electrically conducting, viscous, incompressible fluid past an inclined stretching porous plate in the presence of a uniform magnetic field with heat generation was studied experimentally and numerically. The equations governing the flow, temperature and concentration fields are reduced to a system of joined non-linear ordinary differential equations by similarity transformation. Non-linear differential equations are integrated numerically by using Nachtsheim-Swigert shooting iteration technique along with sixth order Runge-Kutta integration scheme. Finally the significance of physical parameters which are of engineering interest are examined both in graphical and tabular form.Item PERFORMANCE ANALYSIS OF LS ESTIMATED OFDM SYSTEM OVER RAYLEIGH FADING CHANNEL(Daffodil International University, 2013-01) Rahim, Md. Noor -A; Islam, Sheikh Md. Rabiul; Anjum, Md. NashidThis paper investigates the bit error rate analysis of orthogonal frequency division multiplexing (OFDM) system over Rayleigh fading channel. We have compared the performances of the system by measuring the bit error rate with varying system parameters (No. of subcarriers, Doppler shift, and modulation scheme) where the channel estimation is done with block type pilot based Least square (LS) algorithm.Item PAPR REDUCTION TECHNIQUE FOR 3GPP LTE OFDM SYSTEM BY J ROTATION(Daffodil International University, 2013-01) Rahaman, D.M. MotiurLTE (long term evolution) is the last step toward the 4th generation (4G) of radio technologies designed to increase the capacity and speed of mobile telephone networks. Where the current generation of mobile telecommunication networks are collectively known as 3G (for "third generation"), LTE is marketed as 4G. LTE uses Orthogonal Frequency Division Multiplexing (OFDM) for the downlink – that is, from the base station to the terminal. OFDM meets the LTE requirement for spectrum flexibility and enables cost-efficient solutions for very wide carriers with high peak rates. However, one of the main drawbacks of the OFDM modulation technique is the large peak-to-average power ratio (PAPR) of the transmitting signals. This high PAPR causes interference when the OFDM signals are passed through an amplifier which does not have enough linear range. Several PAPR reduction techniques such as magnitude clipping, block coding, and partial transmit sequence (PTS) and pulse shaping have been proposed to reduce the PAPR. In this paper, we evaluate PAPR reduction technique by changing the phase of some subcarriers. The cumulative distribution function (CDF) of the PAPR, which can be used to evaluate the PAPR reduction performance, is derived for OFDM signals.Item NEWTON’S NUMERICAL METHOD FOR OPTIMIZATION: A SIMPLER APPROACH(Daffodil International University, 2013-01) Bhuyan, Muhibul HaqueIn this paper, a simpler approach of Newton's numerical method for optimization has been proposed. The first and second derivatives of the original function in the Newton's method have been replaced by the first and second order finite-divided difference formulas. A problem has been chosen and MATLAB program has been developed for finding the optimum value using both Newton's method and the proposed modified Newton's method. It has been observed that the proposed method produces the same result produced by the Newton's method and takes same number of iterations and same amount of execution time. The proposed method eliminates the need for finding the first and second derivatives of the original function and hence this approach is simplerItem MOLECULAR SCREENING OF TRICHODERMA ISOLATES(Daffodil International University, 2013-01) Bajwa, Amna Ali, RukhsanaThe molecular study is based on genomic DNA therefore DNA must be extracted in a pure and uncontaminated form. In this study, genomic DNA of twenty four isolates of Trichoderma species (T. harzianum, T. hamatum, T. koningii and T. pseudokoningii) indicated band of ~15Kb on 0.8% agarose gel and quality was determined by obtaining absorbance ratio (260/280) in the range of 1.7-1.9. Restriction fragment length polymorphism (RFLP) analyses were performed by using two restriction endonulease enzymes i.e., BamHI and HindIII. The BamHI represented results in the range of 500bp-750bp. 18S rRNA gene targeting was further carried out through optimization in ribotyping analysis.Item ESTIMATION OF OPTIMAL TIME STEP AND COMPARE WITH THE ODE SOLVER OF MATLAB PACKAGE OF RLC CIRCUIT USING NUMERICAL METHODS(Daffodil International University, 2013-01) Islam, Sheikh Md. RabiulIn 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.Item EFFECT OF PULVERIZED SILICA AND RADIATION DOSE ON THE MECHANICAL PROPERTIES OF RADIATION (GAMMA-RADIATION) VULCANIZED NATURAL RUBBER LATEX FILM(Daffodil International University, 2013-01) Roy, Juganta K.; Hossain, K. M. Zakir; Rahman, A.; Chowdhury, A. M. Sarwaruddin; Dafader, N. C.A study of the effect of pulverized silica on the properties of radiation vulcanized natural rubber latex (RVNRL) film has been done. Radiation vulcanization of natural rubber latex was done by using Co-60 gamma radiator at room temperature using n-butyl acrylate (n-BA) as sensitizer. The additives (pulverized silica and n-BA) were blended with NR latex just before irradiation. It was found that both silica concentrations and radiation doses were important for the improvement of the tensile and swelling properties of natural rubber latex film. The tensile strength, tear strength and gel content were found increasing and the elongation at break, permanent set and swelling ratio of rubber film were found decreasing with increasing concentration of silica and also increase in absorbed doses. The optimum radiation dose and silica concentration were found at 12 kGy and 1.0 phr respectively which showed the tensile strength 12.77 MPa and tear strength 52.97 N/mm.Item BANGLA TO ENGLISH TEXT CONVERSION USING OPENNLP TOOLS(Daffodil International University, 2013-01) Uddin, Sk. Borhan; Hossain, Dr. Md. Fokhray; Biswas, KamanashisNatural Language Processing is one of the most difficult areas in artificial intelligence. Because, completely different grammatical rules (on which the languages are based on) make the task more complicated. The same problems are found in conversion of Bangla text to English text. Bangla grammar maintains so many rules which make the task harder. Although, a number of researches are done in different area such as Bangla keyboard layout design, English to Bangla translator etc., very few researches are done to translate Bangla text to English. In this paper, we developed a system to do the conversion using OpenNLP tool that performs both statistical and rule based conversion. We have found that using this conversion method it is possible to translate about 40% of text from Bangla to English correctly.Item ACTIVITY LEVEL OF 214BI AND 228AC IN LOCALLY AVAILABLE FERTILIZER USING HPGE DETECTING SYSTEM(Daffodil International University, 2013) Bhuiyan, Md. Mahbubur Rahman; Arefin, Sk. Abdul Kader; Islam, S. M Azharul; Hossain, Sayed MohammadFertilizers are mainly derived from phosphate rock, natural gas as raw material and others chemicals. These materials contain few amounts of radionuclides. The aim of this study is to investigate the activity concentration of 214Bi & 228Ac in fertilizer. High purity Germanium detecting system was employed to determine the activity level of 214Bi & 228Ac in the fertilizer sample. The mean activity concentration of 214Bi is found to be 142.4±6.3 Bq.kg-1 ranges from 11.2±3.8 Bq.kg-1 to 921.4±34.3 Bq.kg-1 and that of 228Ac is found to be 61.3±7.7 Bq.kg-1 ranges from 31.3±10.1Bq.kg-1 to 397.7±17.5 Bq.kg-1. This result indicates that the activity concentrations of the radionuclides in the fertilizers of Gazipur in Bangladesh are within the range of values reported in other countries.