Monte Carlo Localization in Hand-Drawn Maps

Robot localization is a one of the most important problems in robotics. Most of the existing approaches assume that the map of the environment is available beforehand and focus on accurate metrical localization. In this paper, we address the localization problem when the map of the environment is not present beforehand, and the robot relies on a hand-drawn map from a non-expert user. We addressed this problem by expressing the robot pose in the pixel coordinate and simultaneously estimate a local deformation of the hand-drawn map. Experiments show that we are able to localize the robot in the correct room with a robustness up to 80

Energy Aware Multipath Routing in Wireless Sensor Networks

Wireless Sensor Networks(WSNs) are made of sensor nodes with restricted battery life and transmission capability. In this work we propose an energy efficient multipath routing algorithm in WSN. This protocol is designed to improve the latency, resiliency and efficiency through discovering multiple paths from the source to the destination. It has a sink initiated Route Discovery process with the location information of the source known to the sink. There are two types of nodes which are used here one is primary and the other is alternate. At the end of the route formation one primary path and multiple number of alternate paths are built,and, all nodes except the primary are put to sleep mode which helps us to save energy and generate a collision free path, the primary path is used to transmit the data from source to the sink and if the route disrupts, the next best alternate route is used for the purpose and if no path exists between the source and destination then process starts from the beginning. Our simulation finds the latency, packet delivery ratio, average control packet overhead and total energy consumed. The proposed protocol has 12% (approx.) less control packet overhead in comparison to MR2 and LIEMRO,5% less average energy consumption in comparison to MR2 and 28% less average energy consumption in comparison to LIEMRO. Regarding latency the proposed protocol has similar result to MR2 but in comparison to LIEMRO the algorithm is 24% faster. Lastly in case of Packet Delivery Ratio the proposed protocol gives 5% better result in comparison to MR2 and, 12% better result in comparison to LIEMRO on an average

Microstructure and Properties Of Az91 Magnesium Alloy

Magnesium is the lightest structural metal present on Earths surface. With a density of 1.74g/cc, it gives a high strength to weight ratio. This has made it very useful for many applications like automobile, aeronautical etc. Magnesium has many limitations and because of which it cannot be used directly as a replacement of steel and aluminium. Many alloys of magnesium have been developed to partially or completely overcome the limitations of magnesium without sacrificing other properties. One of the most commonly used commercial alloys is magnesium alloy AZ91, which gives better properties than magnesium. In this project, microstructure and properties of AZ91 in two different casting conditions is compared. The microstructure is observed under the optical microscope. The hardness is measured by Vickers hardness tester. The wear resistance of the sample is compared. The SEM analysis of the wear tested sample is observed. The approximate corrosion rate is also calculated and compared

Multi-wavelength study of TeV blazar 1ES 1218+304 using gamma-ray, X-ray and optical observations

We report the multi-wavelength study for a high-synchrotron-peaked BL Lac 1ES 1218+304 using near-simultaneous data obtained during the period from January 1, 2018, to May 31, 2021 (MJD 58119-59365) from various instruments including Fermi-LAT, Swift-XRT, AstroSat, and optical from Swift-UVOT $\&$ TUBITAK observatory in Turkey. The source was reported to be flaring in TeV $\gamma$-ray band during 2019, but no significant variation is observed with Fermi-LAT. A sub-hour variability is seen in the SXT light curve, suggesting a compact emission region for their variability. However, hour scale variability is observed in the $\gamma$-ray light curve. A "softer-when-brighter" trend is observed in $\gamma$-rays, and an opposite trend is seen in X-rays suggesting both emissions are produced via two different processes as expected from an HBL source. We have chosen the two epochs in January 2019 to study and compare their physical parameters. A joint fit of SXT and LAXPC provides a constraint on the synchrotron peak, roughly estimated to be $\sim$1.6 keV. A clear shift in the synchrotron peak is observed from $\sim$1 keV to above 10 keV revealing its extreme nature or behaving like an EHBL-type source. The optical observation provides color-index variation as "blue-when-brighter". The broadband SED is fitted with a single-zone SSC model, and their parameters are discussed in the context of a TeV blazar and the possible mechanism behind the broadband emission.Comment: 13 pages, 10 figures, 5 tables, Accepted for publication in MNRA