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Chinese Journal of Chemical Engineering 2021年第12期34卷 197-217页

作者： Abd El-Aziz S.Fouda Mohamed A.Ismail abdulraqeb a.al-khamri Ashraf S.Abousalem Department of Chemistry Faculty of ScienceEl-Mansoura UniversityEl-Mansoura 35516Egypt Department of Chemistry Faculty of EducationArts and SciencesUniversity of Saba RegionMaribYemen Quality Control Laboratory Operations DepartmentJotunEgypt

This study describes the adsorption behavior of three arylthiophene derivatives namely:2-(4-amidino-3-fluorophenyl)-5-[4-methoxy phenyl] thiophene dihydrochloride salt(MA-1217),2-(4-amidinophenyl)-5-[4-chlorophenyll thiophene dihydrochloride salt(MA-1316) and 2-(4-amidino-3-fluorophenyl)-5-[4-ch lorophenyllthiophene dihydrochloride salt(MA-1312) at C-steel in 1.0 mol·L^(-1) HCl interface using experimental and theoretical *** and mass loss measurements showed that the inhibition efficiency(IE) of the arylthiophene derivatives increases with increasing concentrations and exhibited maximum efficiency 89% at 21×10^(-6) mol·L^(-1)(MA-1217) by mass loss *** investigated arylthiophene derivatives obey the Langmuir adsorption *** polarization studies the arylthiophene derivatives act as mixed-type *** a.alysis were carried out and *** mode of orientation and adsorption of inhibitor molecules on C-steel surface was studied using molecular dynamics(MD) *** chemical parameters as well as the radial distribution function indices and binding energies confirm the experimental results.

关键词： Carbon steel Corrosion inhibition Adsorption Arylthiophene derivatives Polarization Electrochemical frequency modulation

Enhancing Indoor User Localization:An Adaptive Bayesian Approach for Multi-Floor Environments

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Computers, Materials & Continua 2024年第8期80卷 1889-1905页

作者： abdulraqeb alhammadi Zaid Ahmed Shamsan Arijit De Center for Artificial Intelligence and Robotics(CAIRO) Malaysia-Japan International Institute of TechnologyUniversiti Teknologi MalaysiaKuala Lumpur54100Malaysia Department of Electrical Engineering College of EngineeringImam Mohammad Ibn Saud Islamic University(IMSIU)Riyadh11432Saudi Arabia Department of Information Engineering Electronics and TelecommunicationsSapienza UniversityRome00185Italy

Indoor localization systems are crucial in addressing the limitations of traditional global positioning system(GPS)in indoor environments due to signal attenuation *** complex indoor spaces become more sophisticated,indoor localization systems become essential for improving user experience,safety,and operational *** localization methods based on Wi-Fi fingerprints require a high-density location fingerprint database,but this can increase the computational burden in the online *** networks,which integrate prior knowledge or domain expertise,are an effective solution for accurately determining indoor user *** networks use probabilistic reasoning to model relationships among various localization parameters for indoor environments that are challenging to *** article proposes an adaptive Bayesian model for multi-floor environments based on fingerprinting techniques to minimize errors in estimating user *** proposed system is an off-the-shelf solution that uses existing Wi-Fi infrastructures to estimate user’s *** operates in both online and offline *** the offline phase,a mobile device with Wi-Fi capability collects radio signals,while in the online phase,generating samples using Gibbs sampling based on the proposed Bayesian model and radio map to predict user’s *** results unequivocally showcase the superior performance of the proposed model when compared to other existing models and *** proposed model achieved an impressive lower average localization error,surpassing the accuracy of competing ***,this noteworthy achievement was attained with minimal reliance on reference points,underscoring the efficiency and efficacy of the proposed model in accurately estimating user locations in indoor environments.

关键词： Localization positioning Bayesian fingerprinting received signal strength(RSS)

Mean Opinion Score Estimation for Mobile Broadband Networks Using Bayesian Networks

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Computers, Materials & Continua 2022年第9期72卷 4571-4587页

作者： Ayman A.El-Saleh abdulraqeb alhammadi Ibraheem Shayea Azizul Azizan Wan Haslina Hassan College of Engineering A’Sharqiyah University(ASU)Ibra400Oman Communication Systems and Networks Research Lab Malaysia-Japan International Institute of TechnologyUniversiti Teknologi MalaysiaKuala Lumpur54100Malaysia Department of Electronics and Communication Engineering Faculty of Electrical and Electronics EngineeringIstanbul Technical University(ITU)Istanbul34467Turkey Advanced Informatics Department Razak Faculty of Technology and InformaticsUniversiti Teknologi MalaysiaKuala Lumpur54100Malaysia

Mobile broadband(MBB)networks are expanding rapidly to deliver higher data *** fifth-generation cellular network promises enhanced-MBB with high-speed data rates,low power connectivity,and ultralow latency video ***,existing cellular networks are unable to perform well due to high latency and low bandwidth,which degrades the performance of various *** a result,monitoring and evaluation of the performance of these network-supported services is *** network providers optimize and monitor their network performance to ensure the highest quality of service to their *** paper proposes a Bayesian model to estimate the minimum opinion score(MOS)of video streaming services for any particular cellular *** MOS is the most commonly used metric to assess the quality of *** proposed Bayesian model consists of several input data,namely,round-trip time,stalling load,and bite *** was examined and evaluated using several test data sizes with various performance *** results show the proposed Bayesian network achieved higher accuracy overall test data sizes than a neural *** proposed Bayesian network obtained a remarkable overall accuracy of 90.36%and outperformed the neural network.

关键词： Quality of experience quality of service bayesian networks minimum opinion score artificial intelligence prediction mobile broadband

Conflict Resolution Strategy in Handover Management for 4G and 5G Networks

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Computers, Materials & Continua 2022年第9期72卷 5215-5232页

作者： abdulraqeb alhammadi Wan Haslina Hassan Ayman A.El-Saleh Ibraheem Shayea Hafizal Mohamad Yousef Ibrahim Daradkeh Communication Systems and Networks Research Lab Malaysia-Japan International Institute of TechnologyUniversiti Teknologi Malaysia54100Kuala LumpurMalaysia College of Engineering A’sharqiyah University(ASU)Ibra400Oman Department of Electronics and Communication Engineering Faculty of Electrical and Electronics EngineeringIstanbul Technical University(ITU)Istanbul34467Turke Faculty of Engineering and Built Environment Universiti Sains Islam MalaysiaBandar Baru Nilai71800Malaysia Department of Computer Engineering and Networks College of Engineering at Wadi AddawasirPrince Sattam Bin Abdulaziz UniversityAl Kharj11991KSA

Fifth-generation(5G)cellular networks offer high transmission rates in dense urban ***,a massive deployment of small cells will be required to provide wide-area coverage,which leads to an increase in the number of handovers(HOs).Mobility management is an important issue that requires considerable attention in heterogeneous networks,where 5G ultra-dense small cells coexist with current fourth-generation(4G)*** mobility robustness optimization(MRO)and load balancing optimization(LBO)functions have been introduced in the 3GPP standard to address HO problems,non-robust and nonoptimal algorithms for selecting appropriate HO control parameters(HCPs)still exist,and an optimal solution is subjected to compromise between LBO and MRO ***,HO decision algorithms become *** paper proposes a conflict resolution technique to address the contradiction between MRO and LBO *** proposed technique exploits received signal reference power(RSRP),cell load and user speed to adapt HO margin(HM)and time to trigger(TTT).Estimated HM and TTT depend on a weighting function and HO type which is represented by user status during *** proposed technique is validated with other existing algorithms from the *** results demonstrate that the proposed technique outperforms existing algorithms overall performance *** proposed technique reduces the overall average HO ping-pong probability,HO failure rate and interruption time by more than 90%,46%and 58%,respectively,compared with the other schemes overall speed scenarios and simulation time.

关键词： Mobility management handover 5G heterogeneous networks

Survey of Indoor Localization Based on Deep Learning

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Computers, Materials & Continua 2024年第5期79卷 3261-3298页

作者： Khaldon Azzam Kordi Mardeni Roslee Mohamad Yusoff alias abdulraqeb alhammadi Athar Waseem Anwar Faizd Osman Centre for Wireless Technology Faculty of EngineeringMultimedia UniversityCyberjaya63100Malaysia Communication Systems&Networks Research Lab Malaysia-Japan International Institute of TechnologyUniversiti Teknologi MalaysiaKuala Lumpur54100Malaysia Department of Electrical Engineering(DEE) International Islamic UniversityIslamabad44000Pakistan Rohde&Schwarz(M)Sdn Bhd Shah Alam40150Malaysia

This study comprehensively examines the current state of deep learning (DL) usage in indoor *** emphasizes the significance and efficiency of convolutional neural networks (CNNs) and recurrent neuralnetworks (RNNs). Unlike prior studies focused on single sensor modalities like Wi-Fi or Bluetooth, this researchexplores the integration of multiple sensor modalities (e.g.,Wi-Fi, Bluetooth, Ultra-Wideband, ZigBee) to expandindoor localization methods, particularly in obstructed environments. It addresses the challenge of precise objectlocalization, introducing a novel hybrid DL approach using received signal information (RSI), Received SignalStrength (RSS), and Channel State Information (CSI) data to enhance accuracy and stability. Moreover, thestudy introduces a device-free indoor localization algorithm, offering a significant advancement with potentialobject or individual tracking applications. It recognizes the increasing importance of indoor positioning forlocation-based services. It anticipates future developments while acknowledging challenges such as multipathinterference, noise, data standardization, and scarcity of labeled data. This research contributes significantly toindoor localization technology, offering adaptability, device independence, and multifaceted DL-based solutionsfor real-world challenges and future advancements. Thus, the proposed work addresses challenges in objectlocalization precision and introduces a novel hybrid deep learning approach, contributing to advancing *** deep learning-based indoor localization techniques have improved accuracy, challenges likedata noise, standardization, and availability of training data persist. However, ongoing developments are expectedto enhance indoor positioning systems to meet real-world demands.

关键词： Deep learning indoor localization wireless-based localization

干砂地层基坑开挖对旁侧隧道影响离心模型试验研究

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干砂地层基坑开挖对旁侧隧道影响离心模型试验研究

作者： al-MADHAGI ASHRAF abdulraqeb ABDO QASEM 浙江大学

学位级别：硕士

经过近几十年的快速发展,中国许多城市已建成多条地铁线路,有的已经形成密集的交通网络。与此同时,已建成甚至运营的地铁隧道频繁面临着邻近基坑开挖的不利影响,有的造成了既有隧道的裂缝甚至渗漏水。基坑开挖卸荷会导致旁侧地铁隧道产... 详细信息

经过近几十年的快速发展,中国许多城市已建成多条地铁线路,有的已经形成密集的交通网络。与此同时,已建成甚至运营的地铁隧道频繁面临着邻近基坑开挖的不利影响,有的造成了既有隧道的裂缝甚至渗漏水。基坑开挖卸荷会导致旁侧地铁隧道产生附加内力和变形,引起周围土体不同程度的应力释放,使基坑周围地层产生位移,从而引起隧道变形,严重时甚至影响地铁隧道的安全运行。因此,研究基坑开挖对既有隧道的影响机理具有重要意义。目前对基坑开挖对旁侧地铁隧道影响表现出浓厚兴趣的学者不在少数,但仍缺乏针对性的研究。因此,为系统研究基坑开挖对旁侧地铁隧道影响机理,本文采用三维离心模型试验和数值分析开展了干砂地层中基坑开挖对旁侧地铁隧道影响研究。主要工作和成果如下:(1)开展离心模型试验,采用转机过程中排放重液的方法模拟基坑开挖的卸载作用,获得隧道上浮、隧道内力、隧道周围土压力、地表沉降等变化规律。试验结果表明,基坑开挖引起的隧道最大上浮量接近0.024%倍开挖深度,而距离隧道中心0.625B(B为基坑长度)的隧道上浮仅约0.012%开挖深度,约为最大上浮量的一半;基坑底回弹量与采用Boussinesq解计算的回弹量比较接近;地表沉降量与相关文献给出的试验结果相近;靠近基坑一侧的隧道周围土压力有所减小,而远离基坑一侧的隧道周围土压力则有所增加。(2)通过离心模型试验,研究隔断墙对基坑旁侧隧道的影响,同时与无隔断墙工况的试验结果进行了对比。分析了隔断墙对控制基坑开挖对邻近隧道影响机理。研究发现,设置隔断墙可明显降低地表最大沉降,这与隔断墙阻隔基坑开挖引起的土体位移有关。比较而言,隔断墙对基坑底回弹基本无影响,这主要是因为隔断墙设置在基坑外,对基坑内土体开挖卸载引起的坑底回弹影响可忽略不计。围护墙外设置隔断墙可明显减小围护墙水平位移,并一定程度减轻了邻近基坑一侧的土压力减小程度和远离基坑一侧的土压力增加程度,这与隔断墙对隧道与基坑中间土体卸载作用以及位移场的阻隔作用有关。隔断墙可一定程度上减小隧道上浮量和弯矩,但作用有限。(3)采用PLAXIS3D中的小应变硬化土模型(HS-small模型)研究了不同隧道埋深、隧道与基坑距离、基坑开挖深度等因素对旁侧地铁隧道影响,模拟了七个基坑开挖工况。数值计算结果表明,隧道上浮量和水平位移随着隧道埋深及其与围护墙距离增大而减小,而随着基坑开挖深度的增大而增大。基坑开挖过程中,隧道水平位移量随着隧道埋深、围护墙与隧道距离、开挖深度的增大而减小,且受隧道埋深、隧道与围护墙距离影响明显。基坑底回弹随着基坑开挖深度增加、隧道埋深增加、隧道与围护墙距离增加均有减少趋势。在隧道埋深12m处,围护墙最大水平位移为0.193%倍开挖深度。隧道竖向平面内的纵向弯矩明显大于水平面内,隧道承受的竖直向及水平向土压力随着隧道埋深增加均逐渐降低,而且竖直向土压力要明显大于水平向土压力。基坑开挖对旁侧隧道上浮值的数值模拟规律与离心模型试验基本一致,得出的最大隧道上浮值比较相近。本文研究结果对类似工程具有指导意义。

关键词：离心模型试验数值分析基坑开挖隧道隔断墙

双馈风力发电机组在电网干扰和故障状态下的性能分析与控制方法研究

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双馈风力发电机组在电网干扰和故障状态下的性能分析与控制方法研...

作者：陆艾（al-MADHEHAGI LUAI abdulraqeb ABDO）兰州理工大学

学位级别：硕士

世界能源结构正在从以化石能源为基础的系统转变为以新能源为基础的系统。作为可再生能源,风电产业发展迅速,但也伴随着许多问题。由于风电厂所处环境偏远恶劣,风速等因素的骤变就会使电能质量受到波及,使得机组的运行状态监测和故障诊... 详细信息

世界能源结构正在从以化石能源为基础的系统转变为以新能源为基础的系统。作为可再生能源,风电产业发展迅速,但也伴随着许多问题。由于风电厂所处环境偏远恶劣,风速等因素的骤变就会使电能质量受到波及,使得机组的运行状态监测和故障诊断难度大大增加。因此,研究并网运行条件下的风机状态监测和故障诊断技术具有十分重要的意义,也是亟待解决的关键问题。本文主要研究内容如下:(1)首先介绍了风力发电机的类型以及结构类型,继而介绍了风力发电机基本工作原理以及双馈风力发电机(Doubly-fed Induction Generator DFIG)的系统模型,并且基于三相静止坐标下建立了双馈风力发电机的数学模型,也介绍额双馈电机的电压方程、磁链方程等,为后续的研究奠了定基础。(2)针对电网电压不平衡的情况下,对网侧变流器的运行特性进行了分析;同时,本章提出了分别抑制直流侧电压二次谐波正、负序电流的双闭环控制策略,还针对电网不平衡情况下存在的振荡锁相环进行了改善,通过PSCAD/EMTDC的仿真验证,证明提出的新型软锁相环技术符合快速、准确的要求。(3)在PSCAD/EMTDC仿真环境下建立了双馈风力发电系统、风电场扰动发生装置主电路及其控制系统的模型,在不同工况下仿真验证了所设计的双馈风力发电系统、风电场扰动发生装置的各功能均满足技术条件中的要求,并说明双馈风力发电系统、风电场扰动发生装置结构、参数及控制策略均设计合理。最后叙述了PSCAD仿真软件下电网电压不平衡情况下网侧变流器的响应及相应的控制策略,仿真验证了网侧电压不平衡时抑制直流电压二倍频脉动的参考电流算法及正、负序分别控制的闭环控制策略的有效性。

关键词：双馈风力发电机电压不平衡变流器正负序分离