http://dspace.daffodilvarsity.edu.bd:8080/handle/123456789/1616 2026-04-05T17:28:31Z http://dspace.daffodilvarsity.edu.bd:8080/handle/20.500.11948/876 XML BASE SECURED DATA ENCRYPTION AND TRANSMISSION TECHNOLOGY Sobuz, Md. Shamsuzzaman With 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. 2013-01-01T00:00:00Z http://dspace.daffodilvarsity.edu.bd:8080/handle/20.500.11948/875 THERMOPHORESIS EFFECT ON THE MHD FLOW OVER AN INCLINED STRETCHING SHEET WITH HEAT GENERATION AND MAGNETIC FIELD Karim, M Enamul; Kabir, Md. Alamgir The 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. 2013-01-01T00:00:00Z http://dspace.daffodilvarsity.edu.bd:8080/handle/20.500.11948/874 PERFORMANCE ANALYSIS OF LS ESTIMATED OFDM SYSTEM OVER RAYLEIGH FADING CHANNEL Rahim, Md. Noor -A; Islam, Sheikh Md. Rabiul; Anjum, Md. Nashid This 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. 2013-01-01T00:00:00Z http://dspace.daffodilvarsity.edu.bd:8080/handle/20.500.11948/873 PAPR REDUCTION TECHNIQUE FOR 3GPP LTE OFDM SYSTEM BY J ROTATION Rahaman, D.M. Motiur LTE (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. 2013-01-01T00:00:00Z