Chandigarh University

About: Chandigarh University is a education organization based out in Mohali, India. It is known for research contribution in the topics: Materials science & Computer science. The organization has 1358 authors who have published 2104 publications receiving 10050 citations.

Adaptive Flower Pollination Algorithm-Based Energy Efficient Routing Protocol for Multi-Robot Systems

Abstract: The exploration and mapping of unknown environments, where the reliable exchange of data between the robots and the base station (BS) also plays a pivotal role, are some of the fundamental problems of mobile robotics. The maximum energy of a robot is utilized for navigation and communication. The communication between the robots and the BS is limited by the transmission range and the battery capacity. This situation inflicts constraints while designing an effective communication strategy for a multi-robot system (MRS). The biggest challenge lies in designing a unified framework for navigation and communication of the robots. The underlying notion is to utilize the minimum energy for communication (without limiting the range/efficiency of communication) to ensure that the maximum energy can be used for navigation (for larger area coverage). In this work, we present a communication strategy by using adaptive flower pollination optimization algorithm for MRS in conjunction with simultaneous localization and mapping (SLAM) technique for navigation and map making. The proposed strategy has been compared with multiple routing algorithms in terms of network life time and energy efficiency. The proposed strategy performs 4% better compared with harmony search algorithm (HSA) and approximately 10% better compared with distance aware residual energy-efficient stable election protocol (DARE-SEP) in terms of the total network lifetime when 50% of robots are alive. The performance drastically improves by 20% till the last robot is alive compared with HSA and approximately 26% compared with DARE-SEP. Hence, the energy saved during communication with the utilization of proposed strategy helps the robots explore more areas, which ultimately elevates the efficacy of the whole system.

Oxidation Behaviour of HVOF Sprayed NiCrAlY and NiCrAlY-20SiC Coatings on T-91 Boiler Tube Steel

Abstract: In present study, the high temperature oxidation behavior of HVOF sprayed NiCrAlY alloy coating and NiCrAlY–20SiC composite coating on T-91 boiler tube steel has been investigated at elevated temperature of 900°C for 50 cycles. The kinetics of oxidation has been established with weight change measurements. Both coatings and uncoated material obeyed the parabolic law during oxidation studies. XRD, FE-SEM along with EDS, X-ray Mapping characterization tools were utilized to check phase formation, elemental distribution and microstructure. The study resulted that both coatings performed better in oxidizing environment due to the formation of protective oxides in coated surface, however in case of uncoated steel unprotective Fe2O3 oxide was formed which led to extensive spallation. Moreover the composite NiCrAlY–20SiC coating provided more resistance to high temperature oxidation than NiCrAlY alloy coating.

Overview of extremophiles

Abstract: Extremophiles refer to the organisms which adapt their cellular machinery to perform under extreme stress conditions. Both prokaryotic and eukaryotic organisms like microalgae, fungi, lichens, protists, animals and plants can survive in extreme environmental conditions. Microbial extremophiles are categorized into psychrophiles, psychrotrophs and thermophiles based on temperature, alkaliphiles and acidophiles based on alkaline or acidic pH, peizophiles based on pressure, metal and radiation tolerant. All these extremophiles produce enzymes, exopolysaccharides, primary and secondary metabolites which find applications in food, detergent, pharmaceutical, leather, textile, paper and pulp, bioremediation and agricultural sectors. The metabolic products of extremophilic microbes offers properties such as high catalytic efficiency and stability, high salinity and alkalinity, low water activity, oxidant and bleach stability and more shelf life. The advancements of molecular tools including comparative genomics, proteomics, metagenomics and transcriptomics have provided a better way for exploring full metabolic potential of extremophiles. This chapter will provide a broad outline of extremophilic diversity and their habitats and attributes which could be used as suitable bioadditives in different industrial processes.

Metal spray layered hybrid additive manufacturing of PLA composite structures: Mechanical, thermal and morphological properties:

Abstract: The fusion of additive layers is the primary concern, which affects the mechanical properties of the three-dimensional printed structures prepared by material extrusion-based additive manufacturing

An efficient post-processing adaptive filtering technique to rectifying the flickering effects

Abstract: Compression at a very low bit rate(≤0.5bpp) causes degradation in video frames with standard decoding algorithms like H.261, H.262, H.264, and MPEG-1 and MPEG-4, which itself produces lots of artifacts. This paper focuses on an efficient pre-and post-processing technique (PP-AFT) to address and rectify the problems of quantization error, ringing, blocking artifact, and flickering effect, which significantly degrade the visual quality of video frames. The PP-AFT method differentiates the blocked images or frames using activity function into different regions and developed adaptive filters as per the classified region. The designed process also introduces an adaptive flicker extraction and removal method and a 2-D filter to remove ringing effects in edge regions. The PP-AFT technique is implemented on various videos, and results are compared with different existing techniques using performance metrics like PSNR-B, MSSIM, and GBIM. Simulation results show significant improvement in the subjective quality of different video frames. The proposed method outperforms state-of-the-art de-blocking methods in terms of PSNR-B with average value lying between (0.7-1.9db) while (35.83-47.7%) reduced average GBIM keeping MSSIM values very close to the original sequence statistically 0.978.