In this paper, the security enhanced OCDMA system based on spectral encoding using code-switching scheme is analyzed. The security issues are investigated by measuring eye diagrams and received signals for various cases. It has been observed; an eavesdropper based on a simple energy detector can easily read the information being transmitted by a single user using on-off keying. In order to increase the security a code-switching scheme is implemented on OCDMA. It is shown that the eye diagram ...

Sintering of nanocrystalline WC-Co, retaining the nanoscaled grain sizes is a matter of great interest. Many non traditional methods have been used to achieve this goal as the required result has not been achieved using the traditional method of liquid phase sintering. The present study is an attempt to find out the limitations of traditional sintering method and optimize it to get nanocrystalline WC-Co composites. The effect of temperature, time and composition variation has been studied to ...

In this paper, we have proposed an efficient wavelength assignment algorithm for dynamic provisioning of lightpath. This proposed algorithm is based on most-used wavelength assignment algorithm. We have also suggested a mathematical model for WDM optical networks for minimization of blocking probability. The results of proposed algorithm and suggested model are then compared with the conventional wavelength assignment algorithms such as first-fit, best-fit, random and most-used wavelength ass...

In this paper, two-dimensional (2D) wavelength/time codes are designed and implemented. The 2D codes are constructed by a technique based on folding of Golomb rulers. The performance evaluation of OCDMA system based on wavelength/time code has been analyzed by measuring the values of bit error rates and eye diagrams for different number of active users. It is shown that eye opening decreases and BER increases with increase in number of active users. It is also shown that BER further increases...

Sintering of nanocrystalline WC-Co, retaining the nanoscaled grain sizes is a matter of great interest. Many non traditional methods have been used to achieve this goal as the required result has not been achieved using the traditional method of liquid phase sintering. The present study is an attempt to find out the limitations of traditional sintering method and optimize it to get nanocrystalline WC-Co composites. The effect of temperature, time and composition variation has been studied to ...

We report the structural and magnetic properties of the Eu doped Cd <inf>1-x</inf> Zn <inf>x</inf> S nanoparticles synthesized by wet chemical method. The idea is to exploit the room temperature magnetic behavior of nanoparticles. The particles size as observed by Transmission electron microscopy (TEM) and X-ray diffraction (XRD) is about 5 nm. The magnetic loop observed at room temperature using SQUID indicates the ferromagnetic behaviour of doped particles. © 2010 Springer Science+Business ...

The dynamical cluster-decay model (DCM) of Gupta and Collaborators has been used to study the decay of various Pt-isotopes 176, 182, 188, 196Pt* formed in 64Ni+ 112, 118, 124Sn and 132Sn+64Ni reactions. The evaporation residue (ER) and fission cross-sections (σ<inf>ER</inf> and σ<inf>fiss</inf>) are calculated in reference to available experimental data at near- and sub-barrier energies. The calculated σ<inf>ER</inf> show excellent agreement with experimental data at all incident center-of-ma...

Solar power is gaining importance in the light of discussion about climate change and renewable energy sources. In most parts of India, clear sunny weather is experienced 250-300 days in a year. The annual global radiation varies from 1600 to 2200 kWh/m2, which is comparable with radiation received in the tropical and subtropical regions. This paper runs simulation scenarios for various sites in India for technical and financial viability of solar power generation with photo voltaic (PV) tech...

Emeraldine base (EB) polymer-ZnO nanoparticles composite films has been synthesized by solution casting technique on ITO-coated glass substrate and characterized by XRD, FTIR and TEM for their structure and morphology. Dielectric behaviour of these composite films has been investigated in the very low frequency region to medium frequency region (1 kHz-1 MHz). The dielectric constant of the composite with 30% nanoparticles is almost onetenth of the pure EB. The dielectric value becomes constan...