Mathematical Model Validation of Search Protocols in MP2P Networks

Broadcasting is a basic technique in Mobile ad-hoc network (MANET), and it refers to sending a packet from one node to every other node within the transmission range. Flooding is a type of broadcast where the received packet is retransmitted once by every node. The naive flooding technique, floods the network with query messages, while the random walk technique operates by contacting the subsets of every node’s neighbors at each step, thereby restricting the search space. One of the key challenges in an ad-hoc network is the resource or content discovery problem which is about locating the queried resource. Many earlier works have mainly focused on the simulation-based analysis of flooding, and its variants under a wired network. Although, there have been some empirical studies in peer-to-peer (P2P) networks, the analytical results are still lacking, especially in the context of P2P systems running over MANET. In this paper, we describe how P2P resource discovery protocols perform badly over MANETs. To address the limitations, we propose a new protocol named ABRW (Address Broadcast Random Walk), which is a lightweight search approach, designed considering the underlay topology aimed to better suit the unstructured architecture. We provide the mathematical model, measuring the performance of our proposed search scheme with different widely popular benchmarked search techniques. Further, we also derive three relevant search performance metrics, i.e., mean no. of steps needed to find a resource, the probability of finding a resource, and the mean no. of message overhead. We validated the analytical expressions through simulations. The simulation results closely matched with our analytical model, justifying our findings. Our proposed search algorithm under such highly dynamic self-evolving networks performed better, as it reduced the search latency, decreased the overall message overhead, and still equally had a good success rate.     

Multilevel spatial modulation

In this paper, a new Multilevel Spatial Modulation technique is proposed. It combines computationally efficient multilevel oding and spatial modulation based on trellis codes to increase coding gain, diversity gain, and bandwidth efficiency. The trellis complexity of the single-stage system increases exponentially, whereas in the proposed multilevel system the complexity increases linearly. The proposed system is analyzed with optimal Viterbi and suboptimal sequential decoding algorithms. The results show that sequential decoding saves 75% of the computational power with a loss of 2 dB SNR approximately, when compared with optimal Viterbi decoding, over both fast- and slow-fading channel conditions. Since the antenna index is used as a source of information in spatial modulation, the number of antennae required increases with the throughput and packing a large number of antennas make cross-correlation unavoidable. In this paper, a low complexity modified decoding technique is also proposed for the multilevel spatial modulation system, in which the correlated received signals are equally combined and decoded by the multistage decoder using the Viterbi algorithm. This technique exploits the receiver antenna correlation and makes the decoding complexity independent of number of antennas. The simulation results indicate that the proposed low complexity algorithm gives approximately 8–10 dB gain when compared with optimal Viterbi decoder with equivalent computational complexity when the eight highly correlated signals are equally combined. This may be a suitable solution for mobile handsets where size and computational complexity are the major issues.     

Evaluation of hydroxyapatite coatings on borate passivated 316L SS in Ringer's solution

Surgical grade stainless steel (316L SS) is one of the widely used implant material in orthopedic surgeries. But often the release of metal ions is evidenced from the implants and subsequently a second surgery is required to remove the implant material. One way to control this release of metal ions is to coat the implant material with a biocompatible material like hydroxyapatite. In this paper we have reported a successful coating of hydroxyapatite over borate passivated 316L SS by a dip coating method. The coatings were characterized by electrochemical techniques such as potentiodynamic polarization, electrochemical impedance and cyclic voltammetry (CV). Also X-ray diffraction (XRD) and scanning electron microscopic (SEM) studies were performed to confirm the quality of the coatings. Results of accelerated leach out characteristics by inductively coupled plasma–atomic emission spectroscopy (ICP–AES) and the evaluation of shear strength are also presented to support the corrosion resistant nature of the coatings. The enhanced bio-resistivity of the as-formed HAP coatings on passivated 316L SS is attributed to the protective passive layer formed by borate buffer solution at selected potentials.     

Analysing the process behaviour of abrasive reaming using an experimental approach

Abrasive reaming is an innovative technique for bore finishing. Despite its widespread use, its process behaviour is still under-explored. Accurate control of bore precision in abrasive reaming is affected by many parameters such as feed rate, stock removal and abrasive grit size. Previous research work in this area concentrated only on key parameters and hence failed to deliver reliable information to improve the process. This paper analyses the process behaviour of abrasive reaming using the data obtained from detailed experiments. The effect and significance of individual factors on the bore geometry were assessed using a statistical approach. Process characteristics such as material removal, sidewall stripping and stick–slip behaviour have been analysed and it is shown that inputs such as grit size, amount of stock removal and dressing type are to be controlled.     

Plasma treated fabrics coated with naturally derived Ag‐NPs for biomedical application

Ethnic value of many known plants are underexploited for medicinal application besides their proven traditional qualities. One such plant known for wound healing is Tridax procumbens. This plant has wound healing property and is commercially unexploited. Silver nanoparticle (Ag‐NP) were synthesized using this plant extracts using different solvents (methanol, ethyl acetate and aqueous), which exhibit resonance at 426, 424 and 418 nm, respectively. This plant‐mediated Ag‐NPs have strong anti‐bactericidal activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Streptococcus pyogenes, Klebsiella pneumonia, Serratia marcescens and Bacillus subtilis with methanol extract. Further instance, elemental composition was confirmed by energy dispersive X‐ray analysis and particle size ranges were observed at 80–200 nm with spherical shape nanoparticles by scanning electron microscopy and transmission electron microscopy analysis. The biocompatibility of Ag‐NPs was assessed using fibroblast cell line (L929) by MTT assay with 109.35 µg IC₅₀ value. The oxygen plasma treated and non‐treated bamboo spunlaced nonwoven fabrics were coated with the Ag‐NPs by exhaust method. Contact angle and water retention revealed significant difference in absorption ability of plasma treated fabric. Field emission scanning electron microscopy revealed the presence of Ag‐NPs in plasma coated fabrics. The fabricated cloth was studied for anti‐microbial and microbial penetration ability.Inspec keywords: solvents (industrial), organic compounds, woven composites, field emission scanning electron microscopy, plasma materials processing, contact angle, transmission electron microscopy, X‐ray diffraction, fabrics, biomedical materials, wounds, silver, nanoparticles, particle size, nanofabrication, thermal analysis, antibacterial activity, microorganisms, X‐ray chemical analysisOther keywords: biomedical application, ethnic value, medicinal application, wound healing property, silver nanoparticle synthesis, methanol, ethyl acetate, Escherichia coli, Pseudomonas aeruginosa, Streptococcus pyogenes, Klebsiella pneumonia, nonwoven fabrics, field emission scanning electron microscopy, plasma coated fabrics, fabricated cloth, solvents, antibactericidal activity, Staphylococcus aureus, particle size, transmission electron microscopy, oxygen plasma treatment, bamboo material, Tridax procumbens extracts, Serratia marcescens, Bacillus subtilis, elemental composition, energy dispersive X‐ray analysis, scanning electron microscopy, material biocompatibility, fibroblast cell line, exhaust method, contact angle, water retention, absorption ability, antimicrobial property, microbial penetration ability, size 424.0 nm, size 418.0 nm, size 80.0 nm to 200.0 nm, size 426.0 nm, Ag     

Task unit bid- spatial coverage and post input density (TUBSC_PID) based crowd sourcing network

Multimedia Tools and Applications - A huge number of items are associated with the Internet of Things (IoT) which is fixed with software, electronics and sensors. It has a wide variety of...     

Combustion synthesis and characterization of Ba<Subscript>2</Subscript>NdSbO<Subscript>6</Subscript> nanocrystals

Nanocrystalline Ba₂NdSbO₆, a complex cubic perovskite metal oxide, powders were synthesized by a self-sustained combustion method employing citric acid. The product was characterized by X-ray diffraction, differential thermal analysis, thermogravimetric analysis, Fourier transform infrared spectroscopy, transmission electron microscopy and scanning electron microscopy. The as-prepared powders were single phase Ba₂NdSbO₆ and a mixture of polycrystalline spheroidal particles and single crystalline nanorods. The Ba₂NdSbO₆ sample sintered at 1500°C for 4 h has high density (∼ 95% of theoretical density). Sintered nanocrystalline Ba₂NdSbO₆ had a dielectric constant of ∼ 21; and dielectric loss = 8 × 10⁻³ at 5 MHz.     

Mathematics Research in India Today: What Does the Literature Reveal?

Mathematics research in India, as reflected by papers indexed inMathsci 1988–1998, is quantified and mapped. Statistics, quantum theory and general topology are the three subfields contributing the most to India's output in mathematics research, followed by special functions, economics and operations research, and relativity and gravitational theory. Indian Statistical Institute and Tata Institute of Fundamental Research are the two leading publishers of research papers. Unlike in many other fields, Calcutta publishes the largest number of papers in mathematics, followed by Mumbai, New Delhi, Chennai and Bangalore. West Bengal, Uttar Pradesh, Maharashtra, Tamil Nadu and Delhi are the leading states. Researchers from 257 institutions spread over 134 cities/towns have published 17,308 papers in the 11 years. About 92% of these papers have appeared in 877 journals published from 62 countries. Journals published in the USA, UK and the Netherlands are popular with Indian mathematicians. Of the 36 journals that have published at least a hundred papers, 20 are Indian journals of which only two are indexed in Journal Citation Reports. In all, about 38.5% of papers have been published in Indian journals, as against about 70% in agriculture, 55% in life sciences, 33.5% in medicine and 20% in physics. In the later years, there has been a moderate shift to non-Indian journals. Close to 78% of papers have come from universities and colleges and 13% from the institutions under science related departments. Almost all papers in high impact journals are physics related and most of them have come from institutions under the Department of Atomic Energy. Over 15% of the 9760 papers published during 1993–1998 are internationally coauthored. In all of science, as seen from Science Citation Index, 14% of Indian papers were internationally coauthored in 1991 and 17.6% in 1998. The USA, Canada, and Germany are the important collaborating nations, followed by France, Italy, Japan and the UK. This revised version was published online in June 2006 with corrections to the Cover Date. This revised version was published online in June 2006 with corrections to the Cover Date. This revised version was published online in June 2006 with corrections to the Cover Date.