Performance of distributed mechanisms for flow admission in wireless adhoc networks

Given a wireless network where some pairs of communication links interfere with each other, we study sufficient conditions for determining whether a given set of minimum bandwidth quality-of-service (QoS) requirements can be satisfied. We are especially interested in algorithms which have low communication overhead and low processing complexity. The interference in the network is modeled using a conflict graph whose vertices correspond to the communication links in the network. Two links are adjacent in this graph if and only if they interfere with each other due to being in the same vicinity and hence cannot be simultaneously active. The problem of scheduling the transmission of the various links is then essentially a fractional, weighted vertex coloring problem, for which upper bounds on the fractional chromatic number are sought using only localized information. We recall some distributed algorithms for this problem, and then assess their worst-case performance. Our results on this fundamental problem imply that for some well known classes of networks and interference models, the performance of these distributed algorithms is within a bounded factor away from that of an optimal, centralized algorithm. The performance bounds are simple expressions in terms of graph invariants. It is seen that the induced star number of a network plays an important role in the design and performance of such networks.Comment: 21 pages, submitted. Journal version of arXiv:0906.378

Multi-Objective Optimization in Friction Welding Process Parameters on EN353 Alloy Steel using Taguchi based GRA

Joining of similar materials by varying the input factors on a continuous drive friction welding process is done in this study. The intention is to find the optimal solution in friction welding input process parameters. Among several types of welding processes, friction welding forms good metal joints. The process factors considered for this material joining practice are Upset Time (UT), Heating Time (HT), Heating Pressure (HP), Upset Pressure (UP), chemical composition and measurements of the materials. Frictional joints provide better mechanical properties, hence it is attracted by researchers. Here, EN353 is used as the specimen, for its extensive usage in the automobile and manufacturing sectors. Axial shortening, hardness testing and the temperature during welding are evaluated, compared and optimized using Taguchi Design of Experiments (DoE) scheme using L27 orthogonal array and Grey Relational Analysis (GRA)

CONSEQUENCES OF WEIGHTED VEST AND WEIGHTED SLED RUNNING ON ELASTIC POWER OF SCHOOL SPRINTERS

The purpose of the study was to cause of weighted vest and weighted sled running on elastic power of school sprinters. To achieve the purpose of this study, forty five male sprinters from the Public school. The age, height and weight of the subjects ranged from 17 to 19 years, 155 to 165 centimetres and 50 to 55 kilograms in that order. They were divided into three groups; each group consisted of fifteen subjects. Group-I underwent weighted vest sprint training, group-II underwent weight sled training and group-III acted as control who does not participate in any training programme. The data collected from the three groups prior to and post experimentation were statistically analyzed by analysis of covariance (ANCOVA). When the obtained ‘F’ ratio value in the analysis of covariance test was significant, the Scheffe’s test was applied as post hoc test to determine the paired mean differences, if any. In all the cases, statistical significance was fixed at .05 levels. Conclusion: The experimental group sprinters had significant improvement on elastic power when comparing to the control group sprinters.  Article visualizations

Multi-Walled Carbon Nanotubes Percolation Network Enhanced the Performance of Negative Electrode for Lead-Acid Battery

The discharge performance of lead-acid battery is improved by adding multi-walled carbon nanotubes (MWCNTs) as an alternate conductive additive in Negative Active Mass (NAM).We report thatMWCNTs added to the negative electrode, exhibits high capacity, excellent cycling performances at 10-h rate, high rate partial state of charge (HRPSoC) cycling and various rates of discharge. It significantly reduces the irreversible lead sulfate on the NAM, increases the active material utilization and improves the electrode performance. The improvement of capacity and cyclic performance of the cell is attributed to the nanoscale dimension of the MWCNTs as additive. Subsequent characterization using high resolution transmission electron microscopy and scanning electron microscopy were carried out to understand the influence of MWCNTs on the negative electrode of lead-acid battery

PHYTOCHEMICALS SCREENING OF PHYSICO-CHEMICAL PARAMETERS AND FLUORESCENCE ANALYSIS OF PLANT ETHANOLIC LEAF EXTRACT Costus pictus

Drugs originating from plant sources are reflection to be a promising alternative for other synthetic anti-diabetics such as sulphonylureas, insulin treatment and biguanides. Plant products are believed to more preferable due to less toxicity, economic and better patient compliance. Hence, medicinal plants and products thereof are used in many countries in the treatment and management of diabetes. Vitamins are organic substances that are essential in minute amounts designed for the growth and activity of the body. They are obtained naturally on or after plant and animal foods. Organic in this definition refers in the direction of the chemistry with molecules. The word organic means that the molecules of substance contain the element carbon. The term also means that vitamins can be destroyed and become unable to perform their functions in our bodies. Every component plays an important role and deficiency of anyone constituent may lead to abnormal developments in the body. Plants are a rich source of all the elements essential for a human being. Qualitative analysis of various inorganic elements revealed the presence of calcium, magnesium, potassium, Iron, sulphates and phosphates. The present study of a good source of pharmacognostical and physicochemical parameters have pivotal roles in identification, authentication and establishment of quality parameters and vitamins of the species. Supplementation of this Costus pictus may be useful for human health associated emerging diseases such as diabetes, hypertension and cancer. &nbsp

Sex- and tissue-specific Bkm(GATA)-binding protein in the germ cells of heterogametic sex

The ZZ male/ZW female system of sex determination (female heterogamety) is found in snakes and birds whereas XY male/XX female system of sex determination (male heterogamety) operates in mammals including humans. The W and Y chromosomes are largely heterochromatic and undergo cycles of condensation and decondensation in the germ cells of ovary and testis, respectively, whereas they remain highly condensed and transcriptionally inactive in all somatic cells. Both chromosomes have enriched stretches of GATA repeats along their entire length (which is identified as banded krait minor satellite DNA and called Bkm) that are highly conserved through widely separated orders of eukaryotes. Here we report the existence of a factor, which specifically binds to Bkm, in the germ cells of the heterogametic sex (ovary in female heterogamety and testis in male heterogamety) where decondensation (activation) of the W and Y chromosomes, respectively, occurs; it has been purified as a polypeptide of 57.5 kDa from the rat snake ovary and designated as Bkm-binding protein (BBP) by virtue of its binding to GATA repeats of Bkm. Such a sex- and tissue-specific BBP is also present in the ovary of other species of snakes and in the testis of mouse and human where the Y chromosome is highly decondensed. We suggest that GATA repeats of Bkm brings about a coordinated decondensation of the W and Y sex chromosomes in the germ cells of the heterogametic sex in response to BBP which may serve as a "switch" for the activation of the genes present on the W and Y chromosomes

Incremental elasticity for array databases

Relational databases benefit significantly from elasticity, whereby they execute on a set of changing hardware resources provisioned to match their storage and processing requirements. Such flexibility is especially attractive for scientific databases because their users often have a no-overwrite storage model, in which they delete data only when their available space is exhausted. This results in a database that is regularly growing and expanding its hardware proportionally. Also, scientific databases frequently store their data as multidimensional arrays optimized for spatial querying. This brings about several novel challenges in clustered, skew-aware data placement on an elastic shared-nothing database. In this work, we design and implement elasticity for an array database. We address this challenge on two fronts: determining when to expand a database cluster and how to partition the data within it. In both steps we propose incremental approaches, affecting a minimum set of data and nodes, while maintaining high performance. We introduce an algorithm for gradually augmenting an array database's hardware using a closed-loop control system. After the cluster adds nodes, we optimize data placement for n-dimensional arrays. Many of our elastic partitioners incrementally reorganize an array, redistributing data only to new nodes. By combining these two tools, the scientific database efficiently and seamlessly manages its monotonically increasing hardware resources.Intel Corporation (Science and Technology Center for Big Data