Extreme events and event size fluctuations in biased random walks on networks

Random walk on discrete lattice models is important to understand various types of transport processes. The extreme events, defined as exceedences of the flux of walkers above a prescribed threshold, have been studied recently in the context of complex networks. This was motivated by the occurrence of rare events such as traffic jams, floods, and power black-outs which take place on networks. In this work, we study extreme events in a generalized random walk model in which the walk is preferentially biased by the network topology. The walkers preferentially choose to hop toward the hubs or small degree nodes. In this setting, we show that extremely large fluctuations in event-sizes are possible on small degree nodes when the walkers are biased toward the hubs. In particular, we obtain the distribution of event-sizes on the network. Further, the probability for the occurrence of extreme events on any node in the network depends on its 'generalized strength', a measure of the ability of a node to attract walkers. The 'generalized strength' is a function of the degree of the node and that of its nearest neighbors. We obtain analytical and simulation results for the probability of occurrence of extreme events on the nodes of a network using a generalized random walk model. The result reveals that the nodes with a larger value of 'generalized strength', on average, display lower probability for the occurrence of extreme events compared to the nodes with lower values of 'generalized strength'

A Reliable Peer-to-Peer Platform for Adding New Node Using Trust Based Model

In order to evaluate the trustworthiness of participating peers in unstructured peer-to-peer networks, Reputation aggregation methods are used in this method. Each and every peer of the network will collect the local scores of each transaction and will compute global scores by aggregating all the local scores with the help of global scores, each individual peer can interact with its suitable peers. But the existing method will not consider the score of the new peer. In this condition, requests are handled by existing peers who leads to failure in downloading process. To rectify this, NP-TRUST model is used to distribute the request to all peers including the newly joined peers. The proposed method is compared with gossip and DFR-TRUST model in Transaction Success rate and variation in file request

Technical note: Measuring tropospheric OH and HO₂ by laser-induced fluorescence at low pressure. A comparison of calibration techniques

International audienceThe hydroxyl radical (OH) is one of the most important oxidants in the atmosphere, as it is involved in many reactions that affect regional air quality and global climate change. Because of its high reactivity, measurements of OH radical concentrations in the atmosphere are difficult, and often require careful calibrations that rely on the production of a known concentration of OH at atmospheric pressure. The Indiana University OH instrument, based on the Fluorescence Assay by Gas Expansion technique (FAGE), has been calibrated in the laboratory using two different approaches: the production of OH from the UV-photolysis of water-vapor, and the steady-state production of OH from the reaction of ozone with alkenes. The former technique relies on two different actinometric methods to measure the product of the lamp flux at 184.9 nm and the photolysis time. This quantity derived from N2O actinometry was found to be 1.5 times higher than that derived from O2 actinometry. The water photolysis and ozone-alkene techniques are shown to agree within their experimental uncertainties (respectively 17% and 44%), although the sensitivities derived from the ozone-alkene technique were systematically lower by 40% than those derived from the water-vapor UV- photolysis technique using O2 actinometry. The agreement between the two different methods improves the confidence of the water-vapor photolysis method as an accurate calibration technique for HOx instruments. Because several aspects of the mechanism of the gas phase ozonolysis of alkenes are still uncertain, this technique should be used with caution to calibrate OH instruments

Emergence of multi-drug resistant strains among bacterial isolates in burn wound swabs in a tertiary care centre, Nanded, Maharashtra, India

Background: Infection is a major cause of morbidity and mortality among burn patients. The worldwide emergence of antimicrobial resistance among a wide variety of burn wound pathogens, particularly nosocomial isolates, limits the available therapeutic options for effective treatment of burn wound infections. The study was conducted in the department of Microbiology, Dr. S.C.G.M.C, Nanded, Maharashtra, India to determine aerobic bacterial isolates from burn wound swabs and describe their antibiogram.Methods: Two wound swabs were taken from 570 patients, cultured aerobically. The isolates were identified by standard microbiological methods and antibiotic sensitivity pattern was determined.Results: Among 570 patients, 434 (76.14%) were female and 136 (23.85%) were male. Out of the total swabs collected, 548 (96.14%) were culture positive and 36 (6.56%) were having 2 isolates. Pseudomonas aeruginosa (34.93%) was the commonest isolate followed by Staphylococcus aureus (22.77%), Klebsiella pneumoniae (13.87%), Escherichia coli (13.01%) and Coagulase negative staphylococcus (11.31%). Incidence of MRSA was 59.39% and ESBL producers were 61.46 %. Gram positive isolates were 100% sensitive to Vancomycin, Linezolid and Gram negative organisms to Imipenem.Conclusions: Routine periodic sampling of burn wounds would facilitate the selection of appropriate empirical therapy and reduce the incidence of multidrug resistant infections among burn patients

On a Class of Generalized Elliptic-type Integrals

The aim of this paper is to study a generalized form of elliptic-type integrals which unify and extend various families of elliptic-type integrals studied recently by several authors. In a recent communication [1] we have obtained recurrence relations and asymptotic formula for this generalized elliptic-type integral. Here we shall obtain some more results which are single and multiple integral formulae, differentiation formula, fractional integral and approximations for this class of generalized elliptic-type integrals

Open Source Software Use in Indian Libraries: A Survey.

The term “Open Source” is a trending topic at present among LIS professionals in India. Open Source applications in libraries progressed as a matter of serious discussion among the library professionals. Stakeholders of Indian Library sector now a day’s realize the advantages of embracing Open Source softwares. This Paper attempts to find out the usage of Open Source software in Indian Libraries. It is found that there is a positive attitude from the part of library professionals towards the acceptance of Open Source softwares.The study also underscores the necessity of orientation Programmes for making Professionals more familiar for adoption of Open Source software in libraries

Open Source Software Use in Indian Libraries: A Survey.

The term “Open Source” is a trending topic at present among LIS professionals in India. Open Source applications in libraries progressed as a matter of serious discussion among the library professionals. Stakeholders of Indian Library sector now a day’s realize the advantages of embracing Open Source softwares. This Paper attempts to find out the usage of Open Source software in Indian Libraries. It is found that there is a positive attitude from the part of library professionals towards the acceptance of Open Source softwares.The study also underscores the necessity of orientation Programmes for making Professionals more familiar for adoption of Open Source software in libraries

An energy efficient intrusion detection system in MANET for secure routing and clustering

Security is a primary concerns when protected communication between mobile nodes in a averse environment is the requirement. MANETs are more susceptible to be attacked as compared to the wired networks. These vulnerabilities are due to the operating principles of the MANET which can not be changed. Securing MANET is equally important as securing fixed wired networks. Certain level of security can be obtained form the existing solutions. However, these solutions are not always necessarily suitable for wireless networks. Several intrusion detection techniques that have been developed for fixed wired network cannot be applied in this new environment. Further, energy is also one of the major issues in MANET as the battery life of the network nodes is limited and once discharged these nodes can not be charged again. Energy plays a vital role in determining the reliability of the network as the lifetime of the network highly depends on the energy status of the nodes in the network. Here we have designed a method to incorporate both these factors i.e., security and energy in order to make the network more reliable and secure. We have merged the IDS with the AODV routing protocol such that there is not need to deploy a separate IDS part on each node. Using a separate IDS take considerable amount of processing power of the nodes as well as consumes energy. Thus, by merging the IDS with the routing algorithm itself we are able to decrease the energy consumption at each node which enhances the lifetime of the entire network. Finally we have applied clustering in order to provide stability to out ad hoc network so that the path determination can be made faster and effectiv