On the rupture of DNA molecule

Using Langevin Dynamic simulations, we study effects of the shear force on the rupture of a double stranded DNA molecule. The model studied here contains two single diblock copolymers interacting with each other. The elastic constants of individual segments of the diblock copolymer are considered to be different. We showed that the magnitude of the rupture force depends on whether the force is applied at $3'-3'-$ends or $5'-5'-$ends. Distributions of extension in hydrogen bonds and covalent bonds along the chain show the striking differences. Motivated by recent experiments, we have also calculated the variation of rupture force for different chain lengths. Results obtained from simulations have been validated with the analytical calculation based on the ladder model of DNA.Comment: 7 pages and 4 figure

Operational interpretations of quantum discord

Quantum discord quantifies non-classical correlations going beyond the standard classification of quantum states into entangled and unentangled ones. Although it has received considerable attention, it still lacks any precise interpretation in terms of some protocol in which quantum features are relevant. Here we give quantum discord its first operational meaning in terms of entanglement consumption in an extended quantum state merging protocol. We further relate the asymmetry of quantum discord with the performance imbalance in quantum state merging and dense coding.Comment: v4: 5 pages, 1 fig. Refs added, text improved. Main results unchanged. See arXiv:1008.4135v2 for a related work. v5: close to the published versio

Collaborative IDS Framework for Cloud

Cloud computing is used extensively to deliver utility computing over the Internet. Defending network acces- sible Cloud resources and services from various threats and attacks is of great concern. Intrusion Detection Sys- tem (IDS) has become popular as an important network security technology to detect cyber-attacks. In this paper, we propose a novel Collaborative IDS (CIDS) Framework for cloud. We use Snort to detect the known stealthy attacks using signature matching. To detect unknown at- tacks, anomaly detection system (ADS) is built using De- cision Tree Classi�er and Support Vector Machine (SVM). Alert Correlation and automatic signature generation re- duce the impact of Denial of Service (DoS) /Distributed DoS (DDoS) attacks and increase the performance and accuracy of IDS

Statistical Mechanics of DNA Rupture: Theory and Simulations

We study the effects of the shear force on the rupture mechanism on a double stranded DNA. Motivated by recent experiments, we perform the atomistic simulations with explicit solvent to obtain the distributions of extension in hydrogen and covalent bonds below the rupture force. We obtain a significant difference between the atomistic simulations and the existing results in the iterature based on the coarse-grained models (theory and simulations). We discuss the possible reasons and improve the coarse-grained model by incorporating the consequences of semi-microscopic details of the nucleotides in its description. The distributions obtained by the modified model (simulations and theoretical) are qualitatively similar to the one obtained using atomistic simulations.Comment: 18 pages, 9 figures. Accepted in J. Chem. Phys. (2013). arXiv admin note: text overlap with arXiv:1104.305

A survey on security issues and solutions at different layers of Cloud computing

Cloud computing offers scalable on-demand services to consumers with greater flexibility and lesser infrastructure investment. Since Cloud services are delivered using classical network protocols and formats over the Internet, implicit vulnerabilities existing in these protocols as well as threats introduced by newer architectures raise many security and privacy concerns. In this paper, we survey the factors affecting Cloud computing adoption, vulnerabilities and attacks, and identify relevant solution directives to strengthen security and privacy in the Cloud environment

Demonstration of non-Markovian process characterisation and control on a quantum processor

In the scale-up of quantum computers, the framework underpinning fault-tolerance generally relies on the strong assumption that environmental noise affecting qubit logic is uncorrelated (Markovian). However, as physical devices progress well into the complex multi-qubit regime, attention is turning to understanding the appearance and mitigation of correlated -- or non-Markovian -- noise, which poses a serious challenge to the progression of quantum technology. This error type has previously remained elusive to characterisation techniques. Here, we develop a framework for characterising non-Markovian dynamics in quantum systems and experimentally test it on multi-qubit superconducting quantum devices. Where noisy processes cannot be accounted for using standard Markovian techniques, our reconstruction predicts the behaviour of the devices with an infidelity of $10^{-3}$. Our results show this characterisation technique leads to superior quantum control and extension of coherence time by effective decoupling from the non-Markovian environment. This framework, validated by our results, is applicable to any controlled quantum device and offers a significant step towards optimal device operation and noise reduction

Implementation Performance of Mobile Wimax for Various Propagation Models

Nowadays the Worldwide Interoperability of Microwave Access (WiMAX) technology becomes popular and receives growing acceptance as a Broadband Wireless Access (BWA) system. These networks enable high data transmission rates. WiMAX is the newest wireless broadband Internet technology based on IEEE 802.16 standard. Based on OFDM (Orthogonal Frequency Division Multiplexing), this system uses radio frequency range from 2 to 11 GHz. WiMAX has potential success in its line-of-sight (LOS) and non line-of-sight (NLOS) conditions which operating below 11 GHz frequency. There are going to be a surge all over the world for the deployment of WiMAX networks. Estimation of path loss and signal coverage is very important in initial deployment of wireless network and cell planning. Numerous path loss (PL) models (e.g. Okumura Model, Hata Model) are available to predict the propagation loss, but they are inclined to be limited to the lower frequency bands (up to 2 GHz). In this thesis we compare and analyze different path loss models and signal coverage (i.e. COST 231 Hata model, ECC-33 model, SUI model, Ericsson model and COST 231 Walfish-Ikegami model) in different receiver antenna heights in urban, suburban and rural environments in NLOS condition. Our main concentration in this thesis is to find out a suitable model for different environments to provide guidelines for cell planning of WiMAX at cellular frequency. From calculations, that I made, can be concluded, that FSPL model, gives the lowest path loss, in all type of terrains – rural, suburban and rural areas. Model ECC-33 can predict path loss in urban and suburban areas, but it is unusable in rural areas. Also I can conclude, that model SUI, has approximately the same values of path loss with those, computed with FSPL model. My research shows that all Pathloss will be less in Rural areas compared to urban and suburban, Signal coverage will be more in suburban areas than in urban areas

Energy and Exergy Analysis on Si Engine by Blend of Ethanol with Petrol

Need to use renewable energy in the form of ethanol fuel derived using agriculture waste to reduce load on petrol derived from crude oil, which is available in limited quantity. This is mostly due to stock of petroleum product are depleting day by day, hence more use of renewable fuels gets attraction in developing country like India. In recent years, Considerable efforts made to develop and introduce alternative renewable fuel, to replace conventional petroleum-base fuels.The main objective of the current work id to investigate influences of blends of ethanol-petrol blend used in IC engine performance using energy and exergy analysis. Here, experimental work divided into mainly two parts. In first part, Engine performance carried out using E0, E25, E40 and E100 blends of ethanol-petrol blends. In other part, exergy analysis carried out. Experimental test set-up developed in laboratory. The stationary petrol engine was run in laboratory at a medium speed, variable load condition experienced in most urban driving conditions and various measurements like fuel flow, exhaust temperature, exhaust emission measurement and exhaust smoke test were carried out. The fuel properties of biodiesel such as kinematic viscosity, calorific value, flash point, carbon residue and specific gravity investigated. Heat balance sheet and availability calculated for different condition like E0, E25, E40 and E100 blends of ethanol-petrol blends