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Research on Congestion Free Routing Algorithm for Hybrid SDN Network

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Research on Congestion Free Routing Algorithm for Hybrid SDN...

作者： zakir ULLAH khan 中国科学技术大学

学位级别：硕士

软件定义网络(SDN)是当下的新兴研究领域。传统的TCP/IP网络过去促进了互联网的快速进步,但随着网络服务的变化和高带宽需求应用的快速增长,TCP/IP网络面临着越来越多的问题。SDN拥有掌控全局网络信息的能力,同时,它的可编程属性使它能... 详细信息

软件定义网络(SDN)是当下的新兴研究领域。传统的TCP/IP网络过去促进了互联网的快速进步,但随着网络服务的变化和高带宽需求应用的快速增长,TCP/IP网络面临着越来越多的问题。SDN拥有掌控全局网络信息的能力,同时,它的可编程属性使它能在不改变网络核心架构的情况下提供更加灵活与高效的网络服务。TCP/IP网络不能满足服务质量的多种需求,并且基于最短路的路由策略会使得在仍有其他链路可选的情况下导致局部链路的拥塞。采用SDN技术可以在提供QoS保证的同时有效解决网络拥塞控制问题。在本文采用的SDN技术中,协议无感知转发(POF)扮演着重要的角色。POF是OpenFlow协议的扩展,支持任意用户自定义协议,因此可以充分提高网络的灵活性。然而,现有的POF控制器仅仅是一个缺乏支持基本网络服务功能的原型系统。本文提出一种混合SDN网络架构,旨在提高网络性能的同时兼容传统网络基础设施。在混合SDN网络中,网络被切分成许多孤岛(islands),一些是SDN孤岛,一些是传统网络遗留岛屿(legacy islands),通过SDN交换机连接这些孤岛。为提高系统性能,在如今的网络研究中,路径计算是一个重要研究领域。路径计算旨在为网络流提供合理的路径。随着SDN的发展,路径计算从分布式节点转移到集中式控制器上。本文提出了一种基于混合SDN网络架构面向数据中心网络的路径计算算法,该算法通过数据中心网络的特性和拥塞状态计算来选择合适的路径。此外,本文还给出了混合SDN网络中的拥塞控制实施方案。实验结果显示,该算法的性能优于经典的最短路径算法。同时本文也验证了提出的混合SDN网络的方案能够在复杂的网络环境中提供合适的功能与较好的性能。

关键词：混合网络 SDN POF 路由算法拥塞控制传统网络

Intelligent wireless walls for contactless in-home monitoring

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Light(Science & Applications) 2022年第10期11卷 2308-2320页

作者： Muhammad Usman James Rains Tie Jun Cui Muhammad zakir khan Jalil Ur Rehman Kazim Muhammad Ali Imran Qammer H.Abbasi University of Glasgow James Watt School of EngineeringGlasgow G128QQUK State Key Laboratory of Millimetre Waves Southeast UniversityNanjingChina

Human activity monitoring is an exciting research area to assist independent living among disabled and elderly *** techniques have been proposed to recognise human activities,such as exploiting sensors,cameras,wearables,and contactless microwave *** these,the microwave sensing has recently gained significant attention due to its merit to solve the privacy concerns of cameras and discomfort caused by ***,the existing microwave sensing techniques have a basic disadvantage of requiring controlled and ideal settings for high-accuracy activity detections,which restricts its wide adoptions in non-line-of-sight(Non-LOS)***,we propose a concept of intelligent wireless walls(IWW)to ensure high-precision activity monitoring in complex environments wherein the conventional microwave sensing is *** IWW is composed of a reconfigurable intelligent surface(RIS)that can perform beam steering and beamforming,and machine learning algorithms that can automatically detect the human activities with high *** complex environments are considered:one is a corridor junction scenario with transmitter and receiver in separate corridor sections and the other is a multi-floor scenario wherein the transmitter and receiver are placed on two different floors of a *** each of the aforementioned environments,three distinct body movements are considered namely,sitting,standing,and *** subjects,one male and one female perform these activities in both *** is demonstrated that IWW provide a maximum detection gain of 28%in multi-floor scenario and 25%in corridor junction scenario as compared to traditional microwave sensing without RIS.

关键词： microwave environments floor

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障碍物几何参数对离心泵汽蚀特性的影响

障碍物几何参数对离心泵汽蚀特性的影响

作者：王泽瑞（zakir khan）兰州理工大学

学位级别：硕士

Hydraulic machinery inevitably encounters cavitation problems during *** hazards of the cavitation process are mainly reflected in three aspects: First,cavitation will lead to serious deterioration of hydraulic performance of hydraulic machinery;second,bubbles can cause damage to the surface of the material known as *** the same time,accompanied by cavitation damage,there are also problems such as vibration and noise;third,cavitation will affect the flow’s unsteady characteristics or dynamic response *** to the dynamic response characteristics can make the flow unstable,and the instability caused by cavitation includes rotational cavitation and cavitation *** instabilities can lead to large oscillations in global flow and pressure,resulting in unsteady rotor dynamics and consequently,structural failure of the hydraulic *** present,the research on unsteady flow instability in hydraulic machinery is in its *** research on flow instability caused by cavitation is a hot and difficult issue in the field of hydraulic *** is almost impossible to completely eliminate the harm caused by cavitation flow instability in the engineering ***,the research direction of cavitation hazards has been adjusted to reduce and suppress the negative effects of cavitation instability,that is,the control of ***,there are measures such as adjusting the pipeline layout,installing asymmetric interference plates,installing circumferential grooves,and air supply for hydro-mechanical cavitation *** methods have a certain inhibitory effect on specific cavitation instability,but the cavitation instability is not completely inhibited,and the mechanism of inhibition is not fully ***,exploring and discovering cavitation instability control theory and technology with practical engineering value is significant for improving the anti-cavitation characteristics,and hydro machi

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障碍物对轴流泵空化内部流场的影响

兰州理工大学学报 2024年第3期50卷 33-41页

作者：赵伟国张翠莲 zakir khan 寇相儒周忠亮罗云霞兰州理工大学能源与动力工程学院甘肃兰州730050 兰州理工大学甘肃省流体机械及系统重点实验室甘肃兰州730050

空化会影响泵的正常工作和稳定运行,为了探索能够有效抑制轴流泵内发生空化的策略,提出了将矩形流向障碍物布置在轴流泵叶片背面的方法.以比转数700的轴流泵作为研究对象,采用全流道非定常数值模拟,分析障碍物对轴流泵外特性空化性能的... 详细信息

空化会影响泵的正常工作和稳定运行,为了探索能够有效抑制轴流泵内发生空化的策略,提出了将矩形流向障碍物布置在轴流泵叶片背面的方法.以比转数700的轴流泵作为研究对象,采用全流道非定常数值模拟,分析障碍物对轴流泵外特性空化性能的影响.结果表明:在设计工况下布置障碍物的改进模型在空化各阶段均能有效减少空泡体积,尤其当空泡发展至障碍物位置时效果最好,空泡体积减少了72.5%;布置障碍物能够提高叶片背面出口压力,限制低压区向出口方向扩张,减小逆压梯度,阻挡轮毂侧发生偏流,梳理空化发展的流线,优化流场结构,抑制空化的发展,并将断裂扬程提升了10.19%.

关键词：轴流泵流向障碍物空化抑制非定常

Review of Techniques for Integrating Security in Software Development Lifecycle

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Computers, Materials & Continua 2025年第1期82卷 139-172页

作者： Hassan Saeed Imran Shafi Jamil Ahmad Adnan Ahmed khan Tahir Khurshaid Imran Ashraf College of Electrical and Mechanical Engineering National University of Sciences and Technology(NUST)Rawalpindi46604Pakistan Department of Computer Science Abasyn University Islamabad CampusIslamabad45510Pakistan Military College of Signals National University of Sciences and Technology(NUST)Rawalpindi46600Pakistan Department of Electrical Engineering Yeungnam UniversityGyeongsan38541Republic of Korea Department of Information and Communication Engineering Yeungnam UniversityGyeongsan38541Republic of Korea

Software-related security aspects are a growing and legitimate concern,especially with 5G data available just at our *** conduct research in this field,periodic comparative analysis is needed with the new techniques coming up *** purpose of this study is to review the recent developments in the field of security integration in the software development lifecycle(SDLC)by analyzing the articles published in the last two decades and to propose a way *** review follows Kitchenham’s review *** review has been divided into three main stages including planning,execution,and *** the selected 100 articles,it becomes evident that need of a collaborative approach is necessary for addressing critical software security risks(CSSRs)through effective risk management/estimation *** risks using a numeric scale enables a comprehensive understanding of their severity,facilitating focused resource allocation and mitigation *** a comprehensive understanding of potential vulnerabilities and proactive mitigation efforts facilitated by protection poker,organizations can prioritize resources effectively to ensure the successful outcome of projects and initiatives in today’s dynamic threat *** review reveals that threat analysis and security testing are needed to develop automated tools for the *** estimation of effort required to prioritize potential security risks is a big challenge in software *** accuracy of effort estimation can be further improved by exploring new techniques,particularly those involving deep *** is also imperative to validate these effort estimation methods to ensure all potential security threats are *** challenge is selecting the right model for each specific security *** achieve a comprehensive evaluation,researchers should use well-known benchmark checklists.

关键词： Software development lifecycle systematic literature review critical software security risks national institute of standards and technology DevSecOps open web application security project McGraw’s touch points

Exploring Nanoscale Perovskite Materials for Next‑Generation Photodetectors:A Comprehensive Review and Future Directions

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Nano-Micro Letters 2025年第2期17卷 46-108页

作者： Xin Li Sikandar Aftab Maria Mukhtar Fahmid Kabir Muhammad Farooq khan Hosameldin Helmy Hegazy Erdi Akman State Key Laboratory of Pulsed Power Laser Technology National University of Defense TechnologyHefei 230037AnhuiPeople’s Republic of China Anhui Laboratory of Advanced Laser Technology Hefei 230037AnhuiPeople’s Republic of China Nanhu Laser Laboratory Changsha 410015HunanPeople’s Republic of China Department of Semiconductor Systems Engineering and Clean Energy Sejong UniversitySeoul 05006Republic of Korea Department of Artificial Intelligence and Robotics Sejong UniversitySeoul 05006Republic of Korea School of Engineering Science Simon Fraser UniversityBurnabyBC V5A 1S6Canada Department of Electrical Engineering Sejong UniversitySeoul 05006South Korea Department of Physics Faculty of ScienceKing Khalid UniversityP.O.Box 9004AbhaSaudi Arabia Central Labs King Khalid UniversityAlQura’aP.O.Box 96061413 AbhaSaudi Arabia Scientific and Technological Research and Application Center Karamanoglu Mehmetbey University70100 KaramanTurkey

The rapid advancement of nanotechnology has sparked much interest in applying nanoscale perovskite materials for photodetection *** materials are promising candidates for next-generation photodetectors(PDs)due to their unique optoelectronic properties and flexible synthesis *** review explores the approaches used in the development and use of optoelectronic devices made of different nanoscale perovskite architectures,including quantum dots,nanosheets,nanorods,nanowires,and *** a thorough analysis of recent literature,the review also addresses common issues like the mechanisms underlying the degradation of perovskite PDs and offers perspectives on potential solutions to improve stability and scalability that impede widespread *** addition,it highlights that photodetection encompasses the detection of light fields in dimensions other than light intensity and suggests potential avenues for future research to overcome these obstacles and fully realize the potential of nanoscale perovskite materials in state-of-the-art photodetection *** review provides a comprehensive overview of nanoscale perovskite PDs and guides future research efforts towards improved performance and wider applicability,making it a valuable resource for researchers.

关键词： Nanoscale perovskites Photodetectors Nanosheets Nanorods Nanowires Quantum dots Nanocrystals

A Synergistic Multi-Attribute Decision-Making Method for Educational Institutions Evaluation Using Similarity Measures of Possibility Pythagorean Fuzzy Hypersoft Sets

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 501-530页

作者： Khuram Ali khan Saba Mubeen Ishfaq Atiqe Ur Rahman Salwa El-Morsy Department of Mathematics University of SargodhaSargodha40100Pakistan Department of Mathematics University of Management and TechnologyLahore54000Pakistan Department of Mathematics College of ScienceQassim UniversityBuraydah51452Saudi Arabia

Due to the numerous variables to take into account as well as the inherent ambiguity and uncertainty,evaluating educational institutions can be *** concept of a possibility Pythagorean fuzzy hypersoft set(pPyFHSS)is more flexible in this regard than other theoretical fuzzy set-like models,even though some attempts have been made in the literature to address such *** study investigates the elementary notions of pPyFHSS including its set-theoretic operations union,intersection,complement,OR-and *** results related to these operations are also modified for ***,the similarity measures between pPyFHSSs are formulated with the assistance of numerical examples and ***,an intelligent decision-assisted mechanism is developed with the proposal of a robust algorithm based on similarity measures for solving multi-attribute decision-making(MADM)problems.A case study that helps the decision-makers assess the best educational institution is discussed to validate the suggested *** algorithmic results are compared with the most pertinent model to evaluate the adaptability of pPyFHSS,as it generalizes the classical possibility fuzzy set-like theoretical ***,while considering significant evaluating factors,the flexibility of pPyFHSS is observed through structural comparison.

关键词： Hypersoft set Pythagorean fuzzy hypersoft set computational complexity multi-attribute decision-making optimization similarity measures uncertainty

Secure Channel Estimation Using Norm Estimation Model for 5G Next Generation Wireless Networks

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Computers, Materials & Continua 2025年第1期82卷 1151-1169页

作者： Khalil Ullah Song Jian Muhammad Naeem Ul Hassan Suliman khan Mohammad Babar Arshad Ahmad Shafiq Ahmad Faculty of Information Engineering and Automation Kunming University of Science and TechnologyKunming650500China Department of Computer Science Abbottabad University of Science and TechnologyHavelianAbbottabad22500Pakistan Department of Computing and Electronics Engineering Middle East CollegeMuscat124Oman Department of CS&IT Pak-Austria Fachhochschule Institute of Applied Sciences and Technology MangHaripur22621Pakistan Industrial Engineering Department College of EngineeringKing Saud UniversityRiyadh11421Saudi Arabia

The emergence of next generation networks(NextG),including 5G and beyond,is reshaping the technological landscape of cellular and mobile *** networks are sufficiently scaled to interconnect billions of users and *** in academia and industry are focusing on technological advancements to achieve highspeed transmission,cell planning,and latency reduction to facilitate emerging applications such as virtual reality,the metaverse,smart cities,smart health,and autonomous *** continuously improves its network functionality to support these *** input multiple output(MIMO)technology offers spectral efficiency,dependability,and overall performance in *** article proposes a secure channel estimation technique in MIMO topology using a norm-estimation model to provide comprehensive insights into protecting NextG network components against adversarial *** technique aims to create long-lasting and secure NextG networks using this extended *** viability of MIMO applications and modern AI-driven methodologies to combat cybersecurity threats are explored in this ***,the proposed model demonstrates high performance in terms of reliability and accuracy,with a 20%reduction in the MalOut-RealOut-Diff metric compared to existing state-of-the-art techniques.

关键词： Next generation networks massive mimo communication network artificial intelligence 5G adversarial attacks channel estimation information security

Health risks associated with heavy metals in the drinking water of Swat,northern Pakistan

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Journal of Environmental Sciences 2013年第10期25卷 2003-2013页

作者： Kifayatullah khan Yonglong Lu Hizbullah khan Shahida zakir Ihsanullah Sardar khan Akbar Ali khan Luo Wei Tieyu Wang Department of Environmental Sciences University of Peshawar State Key Laboratory of Urban and Regional Ecology Research Centre for Eco-environmental Sciences Chinese Academy of Sciences Nuclear Institute for Food and Agriculture

The concentrations of heavy metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn were investigated in drinking water sources （surface and groundwater） collected from Swat valley, Khyber Pakhtunkhwa, Pakistan. The potential health risks of heavy metals to the local population and their possible source apportionment were also studied. Heavy metal concentrations were analysed using atomic absorption spectrometer and compared with permissible limits set by Pakistan Environmental Protection Agency and World Health Organization. The concentrations of Cd, Cr, Ni and Pb were higher than their respective permissible limits, while Cu, Mn and Zn concentrations were observed within their respective limits. Health risk indicators such as chronic daily intake （CDI） and health risk index （HRI） were calculated for adults and children separately. CDIs and HRIs of heavy metals were found in the order of Cr 〉 Mn 〉 Ni 〉 Zn 〉 Cd 〉 Cu 〉 Pb and Cd 〉 Ni 〉 Mn 〉 Cr 〉 Cu 〉 Pb 〉 Zn, respectively. HRIs of selected heavy metals in the drinking water were less than 1, indicating no health risk to the local people. Multivariate and univariate statistical analyses showed that geologic and anthropogenic activities were the possible sources of water contamination with heavy metals in the study area.

关键词： daily intake drinking water health risk heavy metals multivariate analysis