2,417 research outputs found
Secure Leader Election for Intrusion Detection in MANET
This paper shows the leader election in presence of selfish nodes. To balance the resource consumption among the nodes and prolong the life time of manet. Nodes with highest resource should be elected as a leaders. But there is obstacles in doing so. First, node may lie about its available resources. Second, electing multiple leaders may leads to additional overhead. Considering first, solution is based on Mechanism design. It provides incentives to the nodes to honestly participate in the election process. The amount of incentives provide to the nodes is based on Vickrey, Clarke, and Groves (VCG) model. Considering second, series of algorithms are there to address optimal leader election
Formation and evolution of clumpy tidal tails around globular clusters
We present some results of numerical simulations of a globular cluster
orbiting in the central region of a triaxial galaxy on a set of 'loop' orbits.
Tails start forming after about a quarter of the globular cluster orbital
period and develop, in most cases, along the cluster orbit, showing clumpy
substructures as observed, for example, in Palomar 5. If completely detectable,
clumps can contain about 7,000 solar masses each, i.e. about 10% of the cluster
mass at that epoch. The morphology of tails and clumps and the kinematical
properties of stars in the tails are studied and compared with available
observational data. Our finding is that the stellar velocity dispersion tends
to level off at large radii, in agreement to that found for M15 and Omega
Centauri.Comment: LaTeX 2e, uses AASTeX v5.x, 40 pages with 18 figures. Submitted to
The Astronomical Journa
On fuzzy subbundles of vector bundles
This paper considers fuzzy subbundles of a vector bundle. We define the operations sum, product, tensor product, Hom, and intersection of fuzzy subbundles and in each case, we characterize the corresponding flag of vector subbundles. We then propose two alternative definitions of integrability on fuzzy subbundles of a given type and discuss their naturality, merits, and shortcomings. We do these here with a view to introduce and study integrable fuzzy subbundles of tangent bundles on manifolds and foliations in further papers
Noise-assisted Multibit Storage Device
In this paper we extend our investigations on noise-assisted storage devices
through the experimental study of a loop composed of a single Schmitt trigger
and an element that introduces a finite delay. We show that such a system
allows the storage of several bits and does so more efficiently for an
intermediate range of noise intensities. Finally, we study the probability of
erroneous information retrieval as a function of elapsed time and show a way
for predicting device performance independently of the number of stored bits.Comment: 5 figure
Chimeric Yellow Fever/Dengue Virus as a Candidate Dengue Vaccine: Quantitation of the Dengue Virus-Specific CD8 T-Cell Response
We have constructed a chimeric yellow fever/dengue (YF/DEN) virus, which expresses the premembrane (prM) and envelope (E) genes from DEN type 2 (DEN-2) virus in a YF virus (YFV-17D) genetic background. Immunization of BALB/c mice with this chimeric virus induced a CD8 T-cell response specific for the DEN-2 virus prM and E proteins. This response protected YF/DEN virus-immunized mice against lethal dengue encephalitis. Control mice immunized with the parental YFV-17D were not protected against DEN-2 virus challenge, indicating that protection was mediated by the DEN-2 virus prM- and E-specific immune responses. YF/DEN vaccine-primed CD8 T cells expanded and were efficiently recruited into the central nervous systems of DEN-2 virus challenged mice. At 5 days after challenge, 3 to 4% of CD8 T cells in the spleen were specific for the prM and E proteins, and 34% of CD8 T cells in the central nervous system recognized these proteins. Depletion of either CD4 or CD8 T cells, or both, strongly reduced the protective efficacy of the YF/DEN virus, stressing the key role of the antiviral T-cell response
Effects of fentanyl on isobaric ropivacaine in subarachnoid anaesthesia for lower abdominal and lower extremity surgeries
Background:The addition of fentanyl to ropivacaine has shown to improve the quality of analgesia without compromising its benefits such as early mobilization and early voiding. This study evaluated the effects of adding fentanyl 25 mcg to isobaric ropivacaine 0.75% for spinal anaesthesia with regards to the onset of sensory block, maximum sensory level reached and the time to achieve it, time to two dermatome segment regression, onset of motor block, time for maximum motor blockade, duration of motor block, hemodynamic parameters and incidence of side effects.Methods: Hundred patients, male and female, ASA I or ASA II, aged 18 to 65 years scheduled for elective lower abdominal and lower extremity surgeries were randomized into two groups. Group R (control group) received 0.75% isobaric ropivacaine 22.5 mg (3 ml) and Group RF (study group) received 0.75% isobaric ropivacaine 22.5 mg (3 ml) and 25 mcg of fentanyl (0.5 ml). Intra operatively, sensory blockade was assessed by pin-prick method and motor parameters were assessed by modified Bromage scale at different time intervals. Haemodynamic parameters were monitored and side effects were also recordedResults: Both groups were comparable with respect to age, height, weight and duration of surgery. There was no significant difference in hemodynamics, onset of sensory and motor block, peak level of block, recovery from motor block, return of micturition and incidence of side effects with the addition of fentanyl to ropivacaine. There was a significant prolongation of the duration of sensory block (250.8±20.7 VS 362.1±15.1* min) and postoperative analgesia (320.56+15.32 VS462.41±38.42 *min) in Group RF (P < 0.001).Conclusions: It was concluded that the addition of 25 mcg fentanyl to 22.5mg of 0.75% isobaric ropivacaine for spinal anaesthesia significantly increases the duration of sensory block and decreases the rescue of analgesia with better hemodynamic stability, early recovery and mobilization.
Proposed Energy Aware Scheduling Algorithm in Data Center by using Map Reduce
The majority of large-scale data intensive applications executed by data centers are based on MapReduce or its open-source implementation, Hadoop. Such applications are executed on large clusters requiring large amounts of energy, making the energy costs a considerable fraction of the data center's overall costs. Therefore minimizing the energy consumption when executing each MapReduce job is a critical concern for data centers. We propose a framework for improving the energy efficiency of MapReduce applications, while satisfying the service level agreement (SLA). We first model the problem of energy-aware scheduling of a single MapReduce job as an Integer Program. We then propose two heuristic algorithms, called Energy-aware MapReduce Scheduling Algorithms (EMRSA-I and EMRSA-II), that find the assignments of map and reduce tasks to the machine slots in order to minimize the energy consumed when executing the application. We perform extensive experiments on a Hadoop cluster to determine the energy consumption and execution time for several workloads from the HiBench benchmark suite including TeraSort, PageRank, and K-means Clustering, and then use this data in an extensive simulation study to analyze the performance of the proposed algorithms. The results show that EMRSA-I and EMRSA-II are able to find near optimal job schedules consuming approximately 40% less energy on average than the schedules obtained by a common practice scheduler that minimizes the makespan
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Soil strength from geophysical measurements for soft clays
Knowledge of seabed soils is essential if offshore and nearshore structures are to be safely designed and properly built. A large part of the commercial and operational risk involved relates to uncertainties about the soil properties at the site. It is therefore important to perform sufficient investigation to evaluate these risks thoroughly. Geophysical surveys are required to understand the nature and characteristics of the seabed. Site specific correlations between soil strength and various geophysical measurements can be developed, but a controlled laboratory study is required to highlight variability in these correlations for a range of geotechnical material.
This work presents the development of a framework for correlating sediment strength, undrained shear strength, for soft clays to geophysical measurements, primarily shear wave and body wave velocities. Small strain measurements using elastic waves provide valuable soil information without altering the soil fabric. The small strain shear modulus (Gmax) is an indicator of many soil properties such as density, soil stiffness, sample disturbance, and can be calculated using the shear wave velocity (Vs) values measured by bender elements. Influence of variables such as soil density, confining stress, and stress history on shear modulus are also examined.The authors would like to acknowledge the Naval Facilities Engineering Service Center (NAVFAC ESC) and the project Material Uncertainties in Assessing Soil Strength from Geophysical Surveys, BAA number: N6258312R0708.This is the accepted manuscript. The final version is available at http://www.isope.org/publications/proceedings/ISOPE/ISOPE%202015/index.htm
Bacteriostatic effect of Coumarin 2-(3,4- Dihydroxyphenyl)-3,5,7-Trihydroxy-4H-Chromen-4-One Isolated from the root extract of Strychnos nux vomica.
Introduction and Aim: Strychnos nux-vomica (S. nux-vomica) being Loganiaceae is a well-known herb in India as well in Srilanka, Northern and Southeast Asia America. The present investigation has been carried out to evaluate the bacteriostatic effects of 2-(3,4- dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one isolated from root ethyl acetate extract of S. nux-vomica.
Materials and Methods: Structure elucidation was carried out using 1HNMR.The bacteriostatic effect of isolated compound at 75 and 100 µg/ml was evaluated using agar well diffusion method against MRSA (Methicillin Resistant Staphylococcus aureus, B. subtilis, B. cereus, P.aeruginosa, E.coli, S. typhi.
Result: Based on the result, we noted that, MRSA was most susceptible bacterial strain with 5.4mm and 11.3mm zone of inhibitions recorded at 75 and 100µg/ml respectively. Result is compared with known standard gentamycin sulphate.
Conclusion: In accordance to the result of the investigation, here we conclude that, the isolated compound is coumarin derivative compound and it exhibit significant activity against MRSA
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