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      • An Augmented SLAM Method with a Visual-Lidar-Equipped Unmanned Vehicle for Detecting Control Measures against COVID-19

        Liang Siyuan,Xie Mengna,Garg Sahil,Kaddoum Georges,Hassan Mohammad Mehedi,AlQahtani Salman A. 한국컴퓨터산업협회 2023 Human-centric Computing and Information Sciences Vol.13 No.-

        In epidemic prevention and control measures, unmanned devices based on autonomous driving technology have stepped into the front lines of epidemic prevention, playing a vital role in epidemic prevention measures such as protective measures detection. Autonomous positioning technology is one of the key technologies of autonomous driving. The realization of high-precision positioning can provide accurate location epidemic prevention services and a refined intelligent management system for the government and citizens. In this paper, we propose an unmanned vehicle (UV) positioning system REW_SLAM based on lidar and stereo camera, which realize real-time online pose estimation of UV by using high-precision lidar pose correction visual positioning data. A six-element extended Kalman filter (6-element EKF) is proposed to fusion lidar and stereo camera sensors information, which retains the second-order Taylor series of observation and state equation, and effectively improves the accuracy of data fusion. Meanwhile, considering improving lidar outputs quality, a modified wavelet denoising method is introduced to preprocess the original data of lidar. Our approach was tested on KITTI datasets and real UV platform, respectively. By comparing with the other two algorithms, the relative pose error and absolute trajectory error of this algorithm are increased by 0.26 m and 2.36 m on average, respectively, while the CPU occupancy rate is increased by 6.685% on average, thereby proving the robustness and effectiveness of the algorithm.

      • The Performance Analysis of Cognitive-based Overlay D2D Communication in 5G Networks

        Abdullilah Alotaibi,Salman A. AlQahtani International Journal of Computer ScienceNetwork S 2024 International journal of computer science and netw Vol.24 No.2

        In the near future, it is expected that there will be billions of connected devices using fifth generation (5G) network services. The recently available base stations (BSs) need to mitigate their loads without changing and at the least monetary cost. The available spectrum resources are limited and need to be exploited in an efficient way to meet the ever-increasing demand for services. Device to Device communication (D2D) technology will likely help satisfy the rapidly increasing capacity and also effectively offload traffic from the BS by distributing the transmission between D2D users from one side and the cellular users and the BS from the other side. In this paper, we propose to apply D2D overlay communication with cognitive radio capability in 5G networks to exploit unused spectrum resources taking into account the dynamic spectrum access. The performance metrics; throughput and delay are formulated and analyzed for CSMA-based medium access control (MAC) protocol that utilizes a common control channel for device users to negotiate the data channel and address the contention between those users. Device users can exploit the cognitive radio to access the data channels concurrently in the common interference area. Estimating the achievable throughput and delay in D2D communication in 5G networks is not exploited in previous studies using cognitive radio with CSMA-based MAC protocol to address the contention. From performance analysis, applying cognitive radio capability in D2D communication and allocating a common control channel for device users effectively improve the total aggregated network throughput by more than 60% compared to the individual D2D throughput without adding harmful interference to cellular network users. This approach can also reduce the delay.

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        Electro-magnetic Visco-plastic Nanofluid Flow Considering Buongiorno Two-component Model in Frames of Darcy-Forchheimer Porosity, Transpiration and Joule Heating

        Shuguang Li,M. Waqas,Salman A. AlQahtani,M. Ijaz Khan 한국자기학회 2023 Journal of Magnetics Vol.28 No.2

        Enhancing heat transfer is of utmost importance in modern industrial applications. Pure liquids for illustration ethylene glycol, propylene glycol and water having lower conductivity are commonly used as cooling liquids in distinct applications. This approach helps conserve and optimize the enhancement of heat transportation. However, in order to achieve enhanced thermal efficiency, state-of-the-art liquids known as nanoliquids have been recommended. Thus the Buongiorno two-component nanoliquid model, which exhibits superior thermal efficiency compared to the aforementioned standard cooling liquids is being considered for formulating and analyzing the behavior of Casson nanoliquid configured by cylindrical convected surface. The problem formulation incorporates various factors such as Darcy-Forchheimer porosity, thermophoresis, magnetohydrodynamics, Brownian diffusion, suction/injection and Joule heating. Boundary-layer stretching flow is formulated. Dimensionless differential form from governing nonlinear problems is achieved by employing relevant variables. The application of the homotopy procedure results in convergent solutions for strongly nonlinear systems. The graphs are used to reveal the plots of significant factors in the analysis.

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