Analysis of neighbour and isolated node of intersection area based geocasting protocol (IBGP) in VANET

Geocasting is a special variant of multicasting, where data packet or message is transmitted to a predefined geographical location i.e., known as geocast region. The applications of geocasting in VANET are to disseminate information like, collision warning, advertising, alerts message, etc. In this paper, we have proposed a model for highway scenario where the highway is divided into number of cells. The intersection area between two successive cells is computed to find the number of common nodes. Therefore, probabilistic analysis of the nodes present and void occurrence in the intersection area is carried out. Further, we have defined different forwarding zones to restrict the number of participated nodes for data delivery. Number of nodes present and void occurrence in the different forwarding zones have also been analysed based on various node density in the network to determine the successful delivery of data. Our analytical results show that in a densely populated network, data can be transmitted with low radio transmission range. In a densely populated network smaller forwarding zones will be selected for data delivery

A Performance Analysis of LAR Protocol for Vehicular Ad Hoc Networks in City Scenarios

In this paper, performance analysis of Location Aided Routing (LAR) protocol in different city scenarios has been done. The mobility model considered is Manhattan model. This mobility model used to emulate the movement pattern of nodes i.e., vehicles on streets defined by maps. Our objective is to provide a qualitative analysis of the LAR protocol in different city scenarios in Vehicular Ad hoc Networks. We have considered three different city scenarios for the analysis of the protocol. The simulation work has been conducted using the Glomosim 2.03 simulator. The results show that LAR1 protocol achieves maximum packet delivery ratio is 99.68 % and maximum average end-to-end delay is 7.319969 ms when the network is sparsely populated. Further, for densely populated network maximum achieved packet delivery ratio is 87.58% and average end-to-end delay is 0.017684 ms

RMS and charge radii in a potential model

The Dalgarno's method of perturbation is used to solve the Schrodinger's equation with the Cornell potential $V(r)=-\frac{4\alpha_s}{3r}+br+c$. The short range and long range effect of the potential is incorporated in the same wave function by using two scales $r^S$ and $r^L$ as an integration limit. The results for bounds on r.m.s. radii of various heavy flavored mesons are reported. We have also showed the relation between r.m.s. and charge radius of mesons.Comment: 10 pages, 3 tables in Indian Journal of Physics (2016

Isgur-Wise function and a new approach to Potential Model

Considering the Cornell potential $V(r)=-\frac{4\alpha_s}{3r}+br+c$, we have revisited the Dalgarno's method of perturbation by incorporating two scales $r^{short}$ and $r^{long}$ as integration limit so that the perturbative procedure can be improved in a potential model. With the improved version of the wave function the ground state masses of the heavy-light mesons $D, D_s, B, B_s$ and $B_c$ are computed. The slopes and curvatures of the form factors of semi-leptonic decays of heavy-light mesons in both HQET limit and finite mass limit are calculated and compared with the available data.Comment: 18 pages, 2 figures, To appear in International Journal of Modern Physics

Study of resonance states of 11^{11}Be with isospectral bound state microscopic potential

The theoretical procedure of supersymmetric quantum mechanics (SQM) is adopted for the first time to study quasi-bound states of a weakly bound nuclear system using microscopic potential. The density dependent M3Y (DDM3Y) effective interaction was found earlier to give a satisfactory description of radioactivity, nuclear matter and scattering. In the present work, we have generated a two-body potential microscopically in a single folding model using the DDM3Y effective interaction. From this potential, SQM generated a family of isospectral potentials for $^{11}$Be ($^{10}$Be + n). We investigated the 5/2$^+$, 3/2$^-$ and 3/2$^+$ resonance states of $^{11}$Be. The experimental data and the present calculations of excitation energies of the above resonance states are found to be in good agreement.Comment: 7 pages, 6 figure

A Kondo route to spin inhomogeneities in the honeycomb Kitaev model

Paramagnetic impurities in a quantum spin-liquid can result in Kondo effects with highly unusual properties. We have studied the effect of locally exchange-coupling a paramagnetic impurity with the spin-1/2 honeycomb Kitaev model in its gapless spin-liquid phase. The (impurity) scaling equations are found to be insensitive to the sign of the coupling. The weak and strong coupling fixed points are stable, with the latter corresponding to a noninteracting vacancy and an interacting, spin-1 defect for the antiferromagnetic and ferromagnetic cases respectively. The ground state in the strong coupling limit in both cases has a nontrivial topology associated with a finite Z2 flux at the impurity site. For the antiferromagnetic case, this result can be obtained straightforwardly owing to the integrability of the Kitaev model with a vacancy. The strong-coupling limit of the ferromagnetic case is however nonintegrable, and we address this problem through exact-diagonalization calculations with finite Kitaev fragments. Our exact diagonalization calculations indicate that that the weak to strong coupling transition and the topological phase transition occur rather close to each other and are possibly coincident. We also find an intriguing similarity between the magnetic response of the defect and the impurity susceptibility in the two-channel Kondo problem.Comment: 9 pages, 4 figures, revtex4-

Magnetoresistive property study of direct and indirect band gap thermoelectric Bi-Sb alloys

We report magnetoresistive properties of direct and indirect band gap Bismuth-Antimony (Bi-Sb) alloys. Band gap increases with magnetic field. Large positive magnetoresistance (MR) approaching to 400 % is observed. Low field MR experiences quadratic growth and at high field it follows a nearly linear behavior without sign of saturation. Carrier mobility extracted from low field MR data, depicts remarkable high value. Correlation between MR and mobility is revealed. We demonstrate that the strong nearly linear MR at high field can be well understood by classical method, co-build by Parish and Littlewood.Comment: To be published in Applied Physics Letter

Effect of node mobility on AOMDV protocol in MANET

In this paper, we have analyzed the effect of node mobility on the performance of AOMDV multipath routing protocol. This routing protocol in ad hoc network has been analyzed with random way point mobility model only. This is not sufficient to evaluate the behavior of a routing protocol. Therefore, in this paper, we have considered Random waypoint, Random Direction and Probabilistic Random Walk mobility Model for performance analysis of AOMDV protocol. The result reveals that packet delivery ratio decreases with the increasing node mobility for all mobility models. Also, average end-to-end delay is also vary with varying node speed, initially upto 20 nodes in all mobility models delay is minimum.Comment: 9 pages, 6 figures, International Journal of Wireless & Mobile Networks (IJWMN) Vol. 6, No. 3, June 201

Imaging polarimetry of the Bok globule CB56

The measurement of polarization of the background stars in the region of Bok globules is important to study the magnetic field geometry and dust grain characteristics in the globule. These parameters are important for the formation and evolution of dark clouds. We made polarimetric observations of Bok globule CB56 in the R-filter from the 2-metre telescope at IUCAA Girawali Observatory (IGO). The observations were carried out on 2011 March 4th and 5th. The CCD images obtained from the instrument (IFOSC) were analyzed, to produce the polarization map of the Bok globule CB56.Comment: 7 pages, 1 figure, 4 tables; To appear in the Bulletin of the Astronomical Society of India (BASI) in the June 2012 issu

Correlation Trends in the Hyperfine Structures of 210,212^{210,212}Fr

We demonstrate the importance of electron correlation effects in the hyperfine structure constants of many low-lying states in $^{210}$Fr and $^{212}$Fr. This is achieved by calculating the magnetic dipole and electric quadrupole hyperfine structure constants using the Dirac-Fock approximation, second order many-body perturbation theory and the coupled-cluster method in the singles and doubles approximation in the relativistic framework. By combining our recommended theoretical results with the corresponding experimental values, improved nuclear magnetic dipole and electric quadrupole moments of the above isotopes are determined. In the present work, it is observed that there are large discrepancies between the hyperfine structure constants of the $7D_{5/2}$ state obtained from the experimental and theoretical studies whereas good agreements are found for the other $D_{5/2}$ states. Our estimated hyperfine constants for the $8P$, $6D$, $10S$ and $11S$ states could be very useful as benchmarks for the measurement of these quantities.Comment: 10 pages, 8 table