bluuebunny/crossref_metadata_2025_split huggingface dataset:
RETRACTED: Channel Estimation of MIMO-OFDM through Wavelet Transform to Improve the Spectral Efficiency and Data Transmission Rate
Authors: Yogeeswaran S , Parasuraman S , Manimaran A 
Published: October 2020

Abstract
We define a new wavelet transform that is based on a recently defined family of scaling functions: the fractional B-splines. The interest of this family is that they interpolate between the integer degrees of polynomial B- splines and that they allow a fractional order of approximation. The approximation can determine noise in communication signals and help in signal reconstruction and channel estimation in MIMO receiver system. In free space optical communication links, the turbulent atmospheric channel causes fluctuations in both intensity and phase of the transmitted optical signal which degrades their performance. In order to make free space optical communications commercially viable, there is a need for characterizing the atmospheric effects on the received signal statistics, and possibly correcting for the signal degradation using physical optics principles and advanced real-time signal processing techniques. As part of this work, we have constructed an experimental free space optical link over 100 meters so as to characterize the effects of inner-scale and outer-scale turbulence effects, and used it as the platform for carrying out the above objectives. Through these techniques, we have demonstrated bit error rate (BER) reduction and propose to estimate channel accurately.
Twitter Spammer Identification using URL based Detection
Authors: Hasan Fayez Jbara Yosef , Ali Segu Mohamed Hyder 
Published: October 2020

Abstract
Millions of users worldwide participate in social networking sites. The interactions between users and those social sites, as Facebook and Twitter, have an enormous effect as well as sometimes unwanted impact on daily life. Spammers have become a target platform on the prominent social networking sites to scatter huge amounts of damaging and irrelevant information. Twitter has become one of the best-used platforms of all times also thus permits unreasoning spamming. Fake users send unwanted tweets to users to encourage services or sites that affect not just genuine users, but also disrupt the consumption of resources. The main aim of this study is to identify forged users who harm real users, threaten users’ identity and therefore their safety and privacy. In this paper, suggest to URL based detection plus machine learning techniques has been developed for the detection of malicious users, celebrities as well as malicious users, based on user characteristics. A crawler is developed for Twitter for the purpose of detecting malicious users, celebrities and non-malicious users and celebrities, and data from around 22 K users were collected from public information. For training and testing purposes, data from around 7,500 users were used in machine learning classifications to classify users. On basis of performance metrics like accuracy, recall, F-measurement also accuracy 5 classifiers were used and compared. With a precision of 99.8 percent, Random Forest is above all classifiers.
Analysis and Design of Modular Multilevel Converter (MMC) Based on Full Bridge Switching Modules (FBSM) for Harmonic Elimination using POD PWM Control Method
Authors: Hari Babu Varaparla , Balaji K 
Published: October 2020

Abstract
Modular Multilevel Converter (MMC) in HVDC for transmitting the power in longer distance because of high in transmission efficiency rate and cost-effective compared to AC system in many industries. The control of voltage and power is earlier and superior method is modular multilevel converter for HVDC transmission. The use of MMC has reduced the filter size and low frequency. Staircase, carrier-based PWM, space vector and selective harmonic elimination are the method using in MMC system control. Unbalanced networks are studied, and strategies are introduced such that in these circumstances MMC contributes to improving the grid efficiency. It involves the key applications in the transmission of high voltage direct current (HVDC) along with other applications of Medium Voltage (MV) and Low Voltage (LV). The MMC with POD-PWM is built using the MATLAB / Simulink method and concludes the advantages and improvements of converter modulation to reduce the voltage ripple and increase the voltage levels.
Computational Fracture Mechanics: Evaluation of The Structural Integrity in a Penstock Applying the BS7910 Standard and Finite Element Analysis
Authors: Barrionuevo G O , Guerrero B A , Walczak M 
Published: October 2020

Abstract
The present work aims to determine the structural integrity of penstocks, applying the BS7910 standard and finite element analysis (FEA). For the study of fracture mechanics in thin-walled cylinders that have defects inside, the structural integrity of the element is determined through a failure assessment diagram (FAD) where the fracture failure index (Kr) is graphed versus plastic collapse index (Lr). Based on the locus of the initial point of failure, the safety factor is calculated, and it is defined if the element is fit for service or if corrective action must be taken to continue operating; later, crack growth is analyzed, where the critical point of rupture of the penstock and therefore its useful life is determined. To contrast results, a simulation of fracture mechanics is performed in ANSYS, where the stress intensity factor (KI) is determined using the fracture tool, and the useful life of the element is also calculated through a fatigue analysis. The use of tetrahedral elements is recommended for the overall meshing and a cobweb configuration for meshing at crack-tip. Finally, the results obtained are compared, where the mean average percentage error of 3.24% was obtained, denoting the usefulness of the two methods as well as the simplicity of the Paris’ law.
Free vibration studies on skew sandwich plates by FEM
Authors: Pavan Kumar Dhotre , Srinivasa C V 
Published: October 2020

Abstract
Present study mainly deals with the extraction of fundamental frequencies using simply supported and clamped isotropic and laminated faced skew sandwich plates with the orthotropic core. Available literature values were referred to validate the fundamental frequencies obtained using the finite element method. The effects of aspect ratio, skew angle, a ratio of the length-to total thickness of the sandwich plate, and the ratio of a thickness of the core to a thickness of face sheet on the free vibration of skew sandwich plates were examined. The present method is also used to study the effect of fiber orientation angle and laminate stacking sequence on free vibration of antisymmetric cross-ply laminated skew sandwich plates are also extracted. CQUAD8 type of element gives converged, accurate results than the CQUAD4 element in the present study. The variation of frequencies is directly proportional with the skew angle.
Multiple Object detection using Autonomous UAVs based on YOLOv3 algorithm
Authors: Murugendrappa N , Gayathri KE , Harshitha GM , Gupta Sony 
Published: October 2020

Abstract
Currently, there has been an enormous increase in interest towards autonomous UAVs and applications with respect to autonomous UAVs such as scientific data collection and security monitoring, infrastructure inspection, search and rescue and much more. Recognizing objects visually is a key step in such applications and is very pivotal to build a complete autonomous system. Nevertheless, the chore of detecting an object is very much challenging and is even more difficult when we have low quality images aboard low cost consumer UAVs. More frequently due to the motion of UAVs, images get blurred, noisy and even onboard cameras have low resolution hence object detection becomes more challenging since identifying objects are quite small and these tasks get even more difficult as there is a necessity of real time detection of objects. This paper focuses on all these aspects and brings an outcome for the object detection and identification.
Portable Intensive Care Unit Equipment Using IoT
Authors: Rakesh Kumar S M , Srikanth K V , Kumar Shubham , Vaibhav Kumar , Madan H T 
Published: October 2020

Abstract
Many lives have been affected every day in remote areas mainly because the patients are not timely and properly treated by the healthcare centers, that unfortunately resulting in loss of human lives. In most of the rural hospitals, patients are unable to get the timely response because of lack of human resources and facilities. In some cases, it becomes even difficult for hospitals to frequently check patients’ conditions and update their record on a regular basis. To deal with these sort of real time problems, we have designed a portable healthcare system, which can be easily adopted in the health care centers. The proposed health care system can be used to measure and monitor various health indicators like temperature, ECG, Blood Pressure, heartbeat etc. The measured parameters of the patient will be recorded using ESP32 module and stored in the cloud server. The Doctors can login to the website, view the parameters and can take the necessary action.
Smart Monitor for Enhancing Security in Smart Home Systems
Authors: Janita Bhuvana , Kannan Jagadeesh 
Published: October 2020

Abstract
This Smart Home device like smart TV, Refrigerator, Smart Thermostat, Smart bulbs, Smart garage doors are preferred for hassle free life, better ambience and to automate mundane tasks. Smart Home helps in Mindful resource utilization and also in Wellness assisted living. Though there are many advantages, Smart Home devices are basically embedded devices that comes with firmware and limited memory capacity. These devices cannot have an Antivirus installed for preventing Virus, Malware, Worms and other security hazards. The Internet of Things has no standard protocol for communication. This is a serious security threat for Home Automation systems. Proposed Idea is to introduce an edge device that will monitor and manage all the home devices and alert user in the event of their abnormal activity. The proposed idea would mitigate Man-in the –Middle (MITM) attacks and Denial of service (DOS) attacks.
Inelastic Behavior of En 31 Steel Metallic Surface Subjected to Hard Body
Authors: Darshan C J , Mahendra H S , Hemaraju  , Rashmi S N 
Published: October 2020

Abstract
In machineries of thermal power plants elements such as coal conveying systems, grinding balls, slurry carrying systems involves transfer of load and displacements. In all these machineries every element is subjected to the hard body such as particles from coal and slurry cause continuous wear results with abrasive wear. Due to this abrasive wear there is inelastic and damage of both the objects was takes place. Since many elements of all these machineries were made from En category steels this study was focused on En 31 steel. In the present study rubber wheel abrader was used to conduct the experiments. 106 microns, 212 microns and 425 microns graded abrader was used for conducting the test. En category steel i.e. En 31 was used as target material for the studies. The sand flow rate of 95 grams/minute was maintained. The weight loss was calculated and found that 0.004, 0.012 and 0.021, for an abrader size of 106 microns following with 0.005, 0.012 and 0.020 & 0.007, 0.022 and 0.023 for an abrader size 425 microns. For all these three tests a normal load of 11.37 N, 35.31 N, and 58.85 N was applied. Scanning electron microscope (SEM) was used to study the morphological analysis. There is light influence on volume loss due to the influence of abrader. Weight loss of the material does not solely depend on increasing in abrader size. Inelastic deformation and wear modes are seen as subject to mechanical properties of the target material. Disfigurement highlights describe the volume loss of the wear.
Protective Coatings for Bio-Composites – A Review
Authors: Srinivasa C V , Ani Allamaprabhu S , Jyothi Prasad B M 
Published: October 2020

Abstract
Even though Bio-based composites are eco-friendly, they are susceptible to degradation owing to both mechanical as well as biological factors. While it is evident that moisture affects the composites considerably, there are other factors such as heat and abrasion that could further accelerate the degradation. This article aims to encapsulate a few techniques for protection of the natural fibre-based composites. The reasons of thermal degradation and efforts to minimize the combustibility of substrates by application of aqueous, organic as well as intumescent coatings along with chemical treatments is discussed in brief. An account on the methods of applying a barrier coat and its subsequent curing is given. The need of gel coats, their advantages and several treatments to enhance the fibres to combat against degradation are outlined.
CFD Simulation of Producer Gas Fuelled SI Engine
Authors: Kumar Amit , Rajakumar D G , Mownesh G K , Basavarajappa  
Published: October 2020

Abstract
Syngas generated from the thermochemical conversion of biomass in a gasifier is increasingly being used for fuelling internal combustion engines, especially for distributed power generation. Producer gas as a fuel has thermo physical properties significantly different from those of conventional fuels. As of date, there are no dedicated engines for alternative fuels in general and producer gas in particular. A review of the available literature indicates experimental experience with producer gas but very little information on modelling and simulation studies are available. While experimental investigations provide actual performance parameters, the information is essentially spatial or temporal average only. Apart from that, fluid dynamic and combustion progress parameters cannot be acquired inexpensively. The current work primarily addresses the combustion progression parameters in a typical spark ignited engine under naturally aspirated and turbocharged after cooled configuration at varying mixture quality using the ANSYS FLUENT computational fluid dynamics software. The CHEMKIN software is used for determining the laminar flame speed for producer gas as a function of the mixture quality. Spatially averaged pressure traces from the simulation are compared with literature pressure traces at the desired condition and various simulation parameters are tuned till a match between the literature and simulation pressure is obtained. Once the simulation is validated, the progress of combustion parameters is derived from the simulation in post processing.
Adaptive Noise Cancellation Using Kalman Filter for Non-Stationary Signals
Authors: Murugendrappa N , Ananth A G , Mohanesh K M 
Published: October 2020

Abstract
The present paper states with the Adaptive Noise Cancellation (ANC) of speech signal corrupted with additive Gaussian white noise. A new method is proposed based on adaptive Kalman filtering. The probabilistic approach of kalman filters over a packet-delaying network given the postpone distribution and decide the minimum required buffer length and algorithm has been used for estimation of unknown state variables within the system. Any work has been achieved for structures with fractional-order dynamics. The new techniques based totally at the kalman filter proposed within the beyond, function in steps: first the noise variance and the parameters of the signal version is estimated and secondly the speech signal expected. The strategies provided inside the paper gives an exclusive method consequently it does not require estimation of the noise variance. The noise variance estimation is always will become part of the kalman advantage calculation. The results of the application of Kalman filter on a non-stationary acoustic signal indicated that SNR of the ∼ 1.17 dB and MSE`0.032 can be achievable using Kalman filters and Kalman filter can be efficiently used for noise cancellation in place of other adoptive filters.
Exploring the role of surface modifications of TiNi-based alloys in evaluating in vitro cytocompatibility: a comparative study
Authors: Kokorev Oleg , Chekalkin Timofey , Marchenko Ekaterina , Yasenchuk Yuri , Gunther Sergey , Serebrov Vladimir , Chernyshova Alena , Obrosov Aleksei , Uludintceva Elena , Kang Ji-Hoon 
Published: October 2020

Abstract
The aim of this study was the comparative analysis of in vitro bio-testing of solid and porous TiNi samples with modified surfaces (intact, oxidated, and etched). Tests for cytocompatibility, hemolysis, and cytotoxicity (MTT) as well as visualization by confocal and scanning electron microscopy have shown that the chemically modified samples are the most cytocompatible. The intact and etched samples did not induce hemolysis greater than 2%, and thus they comply with the ISO 10993-4:2018 standard for hemolysis by blood-contacting biomaterials. Direct culture of etched samples with MCF-7 cells and human leukocytes showed low cytotoxicity. At the same time, the cytotoxicity of samples oxidated at 500 °C was significantly greater than that of the etched samples. Confocal and electron microscopy also confirmed the abovementioned quantitative data. The cells attached to the etched surface in numbers sufficient for them to be able to grow and proliferate on this substrate in vitro. These findings indicate that solid and porous TiNi alloy with surface modifications achieved by a cost-effective method is biotolerable and promising for clinical use and for tissue engineering.
Effect of laser remelting on microstructure and properties of two Ni-base coatings by supersonic particles deposition
Authors: Bingyuan Han , Shaoyi Bei , Kebing Zhou , Yuxiang Liu , Yan Zhang , Xue Yan , Weixing Hang , Fangfang Cui , Wenwen Xu , Wei Du , Sheng Zhu 
Published: October 2020

Abstract
Remelting treatment of In718 and In625 coatings deposited by supersonic particles were conducted by using laser technology. The microstructure, phase composition, microhardness, wear resistance and corrosion of the coating before and after remelting were studied. The results showed that defects such as voids and cracks of the deposited coating were eliminated by laser remelting treatment, the microstructure of the coating became compact and uniform and the bonding mode changed from mechanical bonding to metallurgical bonding. The deposited coating consisted of γ-Ni solid solution and Fe3Ni2 intermetallic compound phase, remelting to form a new phase Ni3(Al,Ti) and high hard phase carbide (Nb,Mo) C. The average microhardness of the remelted coating was 6.96 GPa, which was 1.72 times than that of the deposited coating. The wear resistance of remelting coating was significantly better than that of deposited coating and substrate, and its wear form was mainly abrasive wear. The corrosion resistance of the coating was significantly improved after remelting treatment.
Ellipsometric and ultrasonic studies of nano titanium dioxide specimens doped with Erbium
Authors: Al-Shomar S M , Barakat Mirham A Y , Abdallah A W 
Published: October 2020

Abstract
Nano Er-doped TiO2 thin films prepared by sol-gel technique at different doping concentrations (5%, 7%, 9%, and 11%). The prepared thin films were studied through ultrasonic and ellipsometric measurements. Mechanical properties are known from the ultrasonic method that investigated the effect of the Er-doped amount on the cross-link density, bond strength, elastic properties, and stress-strain relation between atoms of TiO2 thin films. Ellipsometric measurements studied the variation of optical transmittance, energy band gap, refractive index, Urbach energy roughness, and porosity with changing Er-doped amount. Finally, contact angle measurements are done to ensure the self-cleaning property of the prepared thin films. Results deduced that Er-doped enhanced greatly TiO2 thin films, to be used in many industrial applications as self-cleaning glass fabrication.
A new modifier for microstructure and mechanical properties of 6063 aluminum alloy
Authors: Ding Wanwu , Liu Xiaoxiong , Zhao Xiaoyan , Chen Taili , Zhang Haixia , Zhao Wenjun , Li Changfeng 
Published: October 2020

Abstract
In this paper, 6063 aluminum alloy for common building profiles is used as the research object. The effect of 6063 aluminum alloy on the microstructure and properties of 6063 aluminum alloy is studied by adding a new type of Al-Ti-C-La master alloy. The results show that Al-Ti-C-La master alloy has an obvious influence on grain refinement of 6063 aluminum alloy. With the addition of Al-Ti-C-La master alloy, the grain size decreased significantly. When the additional amount of Al-Ti-C-La master alloy is 1%, the grain size is reduced from 482 μm to 121 μm. Rare earth La is mainly distributed near the Mg2Si phase and β-AlFeSi, and complex compounds such as AlFeSiMgLa are formed. After aging for 270 days based on T6 heat treatment, the tensile strength, and elongation of 6063 aluminum alloy increase with the addition of Al-Ti-C-La master alloy, while Vickers hardness decreases gradually. When the content of Al-Ti-C-La master alloy is 1%, the tensile strength, elongation, and Vickers hardness of 6063 aluminum alloy reach 177.2 MPa, 17.8% and 60.9 HV respectively, and the tensile strength is increases by 16.3%. The elongation rate increased by 50.8%, the Vickers hardness decreased by 15.4%, and the ductile fracture was the main fracture of the alloy.
Effect of the matrix material and electroplating process on the microstructure and properties of isolation switch contacts
Authors: Qianqian Yang , Zhang Changle , Yuan Liu , Molin Zhao , Yao Wang , Xinghai Shao , Shouhong Xue , Biao Wang , Yu Xu , Yutong Lv 
Published: October 2020

Abstract
In the KI system, Ag plating, hard-Ag plating and graphene-Ag plating were prepared on the surface of the copper and Cu–Cr alloy matrix materials by the electrodeposition method. The purpose of this paper is to define the copper-based material and related plating process suitable for the contacts of the isolating switch, obtaining excellent comprehensive properties and revealing the strengthening mechanism and wear mechanism of contact materials. Copper alloy was obtained by smelting in a high-frequency vacuum induction furnace, and then cold rolled. Effects of different plating processes and matrix materials on the microstructure, bonding degree between the plating and matrix, microhardness, contact resistance and wear resistance of copper-based contact materials were studied. The results showed that the matrix and the plating are well bonded. Both the Cu–Cr alloy matrix and the hard-Ag plating were rich in a large number of nano twins, dislocations and precipitates, which can strengthen the matrix and the plating. Moreover, they are beneficial to obtaining contact materials with high strength, high toughness and high conductivity. The contact resistance of the 3 kinds of plating changed little. The contact resistance of the Ag plating was the smallest, which was the largest of the hard-Ag plating, increased by 19.5%. The hard-Ag plating has the highest hardness and best wear resistance. Under the same test conditions, the combination of the hard-Ag plating and the Cu–Cr alloy matrix enables the copper-based contact material to obtain good cooperation of hardness, wear resistance and conductivity, and the comprehensive performance is the best.