Extracting mobility pattern from target trajectory in wireless sensor networks

Target tracking in wireless sensor networks is a well‐known application. In real life scenario, target mobility can be predicted using well‐known filters. In this paper, we explain an approach to model the pattern of movement of a target on the basis of target data available. This method utilizes filter techniques to predict the target and a curve‐fitting algorithm to model the mobility of a target in both linear and non‐linear motion patterns. Two alternate strategies to achieve mobility approximation have been proposed and compared. The efficacy of the algorithm is, further, adjudged by comparing its mobility prediction vis‐a‐vis the Kalman filter. Simulation results show that with sufficient data, the mobility pattern of the target can be fairly calculated even if the target moves unpredictably. Copyright © 2013 John Wiley & Sons, Ltd.     

Microstructural Evolution and the Precipitation Behavior in X90 Linepipe Steel During Isothermal Processing

Thermomechanical controlled processing of 560-MPa (X90) linepipe steel was simulated in the laboratory using a thermomechanical simulator to study the microstructural evolution and precipitation behavior during isothermal holding. The results indicated that martensite was obtained when the steels were isothermally held for 5 s at 700 °C. Subsequently, granular bainite and acicular ferrite transformation occurred with increased holding time. Different amount of polygonal ferrite formed after isothermally holding for 600-3600 s. Pearlite nucleated after isothermally holding for 3600 s. Precipitation occurred after isothermal holding for 5 s and continuous precipitation occurred at grain boundaries after isothermally holding for 600 s. After isothermally holding for 3600 s, large Nb/Ti carbide precipitated. The presence of MX-type precipitates was confirmed by diffraction pattern. The interphase precipitation (IP) occurred between 5 and 30 s. Maximum hardness was obtained after isothermally holding for 600 s when IP occurred and rapidly decreased to a low value, mainly because polygonal ferrite dominated the microstructure after isothermally holding for 3600 s.     

Crystallography of Interfaces and Grain Size Distributions in Sr‐Doped LaMnO3

Grain‐boundary plane distributions (GBPDs), grain size distribution (GSDs), and upper tail departure from log‐normal GSDs were quantified in dense and porous La_0.8Sr_0.2MnO₃ samples to understand expected microstructures in solid oxide fuel cells. Samples were sintered at 1450°C for 4 h and then annealed between 800°C and 1450°C. The GBPDs and normalized GSDs reached steady state during sintering and little variation occurred during annealing. The GBPDs were nearly isotropic, with the relative areas of {001} planes being slightly higher than random (and the relative areas of {111} planes being less than random). The porous sample had an almost identical GBPD, whereas the almost isotropic pore boundary plane distribution was essentially opposite to the GBPD. The upper tails of the experimental GSDs, and several theoretical distributions, were characterized using peaks‐over‐threshold analysis. Dense samples, and all normal grain growth models, exhibit lower frequencies of large grains in the upper tail than would a log‐normal distribution, and the experimental distributions are similar to the Mullins distribution. Porous samples, however, have an anomalous increased frequency of large grains in the upper tail, as compared to all the model distributions, even though other metrics of the microstructure indicate the dense and porous systems are similar.     

Mechanical characteristics of glass fibre reinforced polymer made of furfuryl alcohol bio-resin

Conventional fiber reinforced polymers (FRPs) require polymers such as epoxies that are not biodegradable, which have a significant impact on the environment. This study aims at replacing conventional polymers with bio-polymers which are more sustainable. The study investigates the tensile mechanical properties of glass-FRP (GFRP) laminates fabricated by wet layup using two types of organic furfuryl alcohol bio-resins extracted renewable resources, such as corncobs. Results are compared to control specimens fabricated using conventional epoxy resin. The study investigates the effects of catalyst type and dosage as well as the curing time on the tensile strength and modulus of the GFRP. The study also investigates the optimal overlap splice of the laminates. It was shown that by careful selection of viscosity of bio-resin, and type and dosage of catalyst similar mechanical properties to epoxy-GFRP can be achieved. The optimal catalyst proportion was 3 % by weight. Full strength occurred after 13 days curing but 84 % occurred in 2 days. The optimal lap splice length was 200 mm, however, the maximum strength was only 68 % of the full ultimate tensile strength as bond failure always governs at the splice.     

Ant Colony Optimization Based Sub-channel Allocation Algorithm for Small Cell HetNets

Two-tier heterogeneous networks (HetNets) composed of a conventional macrocellular network and small cell networks (SCNs) have been proposed in the literature with the aim to extend indoor coverage and realize efficient radio resource usage. As SCN shares the same frequency band with the underlying macrocell, the cross tier interference needs to be mitigated since the inter-SCN and cross tier interference at the SCN boundary may result in undesirable network performance degradation. In this paper, we propose an intelligent physical resource block (PRB) allocation as a solution to mitigate the downlink intra-SCN interference as well as the inter-tier interference in OFDM-based systems. The allocation of the PRBs to the network users is formulated as a graph coloring problem, and solved using an ant colony optimization (ACO)-based approach. Simulation results are provided, showing that our ACO-based algorithm outperforms the Received Power-based Allocation (RPA) and Received SINR-based Allocation (RSA) algorithms in terms of average SINR experienced by network users, outage probability, and number of required PRBs.     

Compression modeling of plain weave textile fabric using finite elements

Textile composite are used extensively in aerospace as they offer a 3D reinforcement in a single layer providing better mechanical properties in both in‐plane and transverse directions. This paper reports on the mechanical behavior of a plain weave textile fabric under the compressive loading. Unit cell geometry of the plain weave fabric structure is identified and its model is created using TexGen geometric modeling scheme developed by the University of Nottingham (U.K.). Later on its mechanical behavior is predicted using finite element modeling (FEM) based simulation software ABAQUS^® incorporating a transversely isotropic material law. Strain energy of the developed model has been compared with that of the published results and shows very good agreement. The analysis indicated that transverse‐longitudinal shear (TLS) modulus plays an important role in characterizing the behavior of the woven fabric under compression, while the friction between the yarns and longitudinal stiffness has less significant influence on compaction behavior. In order to ascertain the effectiveness of the developed model, exhaustive parametric studies have also been conducted to investigate the effect of transverse‐longitudinal shear modulus on some of the important parameters such as artificial strain energy, external work, frictional dissipation, internal energy, kinetic energy, strain energy and total energy of the model. The developed model has the capacity to predict and simulate the behavior of variety of fabric architectures based on their constituent yarn properties under various regimes of service loads.     

Lightweight Localization Using Trilateration for Sensor Networks

Localization is an unavoidable procedure in location aware sensor networks. In such networks, management of a large amount of location information along with its processing and updating is highly desirable at a central station of the network. In this paper, we have discussed the implementation of software layer to be run on various types of sensor nodes in the localization network, which has been dealt with extensively along with some of the addressed problems and their respective solutions. In addition, the article discusses implementation of an already mathematical formulation of least squares trilateration, which has not yet been attempted in the space of wireless sensor networks. To support our clam we performed experimental analysis on \(telosb\) motes. Experimental results of proposed framework shows that average error with respect to the physical location estimation can be reduced upto 46.66 % using 4 anchor node as compare to three anchor nodes at outdoor scenario and upto 40 % in indoor scenario.     

Optimized Zn-doped hydroxyapatite/doxorubicin bioceramics system for efficient drug delivery and tissue engineering application

The synthesis and fabrication of multifunctional nanostructures with enhanced biocompatibility are the most important characteristics for biomedical research. The goal of our present research is to study the optimum zinc (Zn)-loading on pure hydroxyapatite (HAp) bioceramics and its potential advantages in biomedical application. In this study, different mole concentrations (1, 2, 5 mol%) of Zn doped HAp (Zn-HAp) nanoparticles were synthesized through a facile co-precipitation technique using zinc nitrate as a source for Zn metal. The synthesized Zn-HAp nanoparticles were critically characterized for their structural and morphological changes by different spectroscopy and electron microscopy analysis. The potential advances of Zn-HAp nanoparticles in biological application was studied by using MG-63 cell line, drug model experiment and scaffold cell attachment, proliferation study. The cell cytotoxicity test (MTT assay and trypan blue) was first conducted to confirm the nontoxic characteristics of Zn-HAp with enhanced MG-63 cell proliferation activity. The drug loading experiment of Zn-HAp nanoparticles was then confirmed with 1 mol% Zn-HAp (which had the maximum drug loading efficiency with pH responsive drug interaction). Furthermore, the optimized 1 mol% Zn-HAp constructed biomimetic scaffold shows excellent cell attachment and proliferation behavior with MG-63 cells. The result suggests that the biomimetic 1 mol% Zn-HAp scaffolds may be of enormous potential in bone repair and regeneration. This research distinguishes from other research by showing an advanced analysis of the Zn-HAp and its enhanced physicochemical properties for tissue engineering and pH responsive drug delivery application.