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基于DRL的主动RIS安全无线通信优化方法

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计算机应用研究 2023年第9期40卷 2808-2814页

作者：刘文涛 manzoor ahmed 林青青岛大学计算机科学技术学院山东青岛266071

针对可重构智能表面(reconfigurable intelligent surface,RIS)辅助的安全无线通信系统在保密率优化问题中存在的信道空间连续变化、传统数学优化方法难以逼近最优解等问题,提出一种基于深度强化学习的SEC-DDPG(security deep determini... 详细信息

针对可重构智能表面(reconfigurable intelligent surface,RIS)辅助的安全无线通信系统在保密率优化问题中存在的信道空间连续变化、传统数学优化方法难以逼近最优解等问题,提出一种基于深度强化学习的SEC-DDPG(security deep deterministic policy gradient)算法。通过将RIS通信系统建模为连续变化空间中的马尔可夫决策过程,联合优化传输波束赋形和反射波束赋形达到最大化用户保密率的目的。仿真实验结果显示,在不同的传输功率及反射单元数量下,SEC-DDPG算法在主动和被动RIS系统中得到的最优保密率均比传统的交替优化算法有15%~20%的提升。研究结果表明,主动RIS场景下的安全性要优于被动RIS,与交替优化算法相比,SEC-DDPG算法能显著提高安全无线通信系统的用户保密率且具有鲁棒性,接近系统的最佳保密性能。

关键词：主动可重构智能表面深度强化学习深度确定性策略梯度波束赋形乘法衰落多输入单输出物理层安全

晚期视网膜母细胞瘤53例的临床挑战(英文)

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国际眼科杂志 2009年第2期9卷 227-230页

作者： Partab Rai Imtiaz Ali Shah Ashok kumar Narsani Mahesh Kumar Lohana Muhammad Khan Memon manzoor ahmed Memon Chandka医学院附属医院眼科巴基斯坦Larkana Liaquat大学眼科医院眼科巴基斯坦海德拉巴 Liaquat大学眼科医院诊断研究实验室巴基斯坦海德拉巴 Kalsoom Bai Valieka医院眼科巴基斯坦卡拉奇 Liaquat大学医学及健康科学院病理科巴基斯坦Jamshoro

目的:评价肿瘤的位置、大小、组织学以及复发率。方法:前瞻性研究Larkana的Chandka医学院附属医院眼科的53例组织学诊断为视网膜母细胞瘤患者,肿瘤侵及眼球、眼眶、颅内以及其他组织。为研究肿瘤广泛性,检查包括:眼眶X线片,眼球B超,眼... 详细信息

目的:评价肿瘤的位置、大小、组织学以及复发率。方法:前瞻性研究Larkana的Chandka医学院附属医院眼科的53例组织学诊断为视网膜母细胞瘤患者,肿瘤侵及眼球、眼眶、颅内以及其他组织。为研究肿瘤广泛性,检查包括:眼眶X线片,眼球B超,眼眶及头颅CT扫描/MRI,全骨扫描,胸部前后位X线片,腹部B超,腰椎穿刺,全血细胞计数,包括肝肾功能检查的血生化,根据肿瘤的位置、大小、复发及转移选择包括手术、局部放疗、系统化疗的治疗方案。有局部和系统转移的患者,由Larkana的核医学和放疗机构的肿瘤专家进行局部放疗和系统化疗。术后1,3,6,12mo复查随访,随后5a及5a以上,1a复查一次。评估肿瘤的位置、大小、组织类型和复发率。结果:患者53例,年龄8mo^8岁。男25例(47%),女28例(53%)。肿瘤的眼别,左眼25例(47%),右眼19例(36%),双眼9例(17%)。患者的首发症状,斜视3例(6%),假性眼内炎4例(8%),眼眶炎性假瘤6例(11%),转移性包块7例(13%),蕈样生长的包块8例(15%),白瞳征12例(23%),眼眶浸润13例(25%)。行单纯眼球摘除术19例(36%),行眼球摘除及改良型眶内容物剜除术并局部放疗和系统化疗19例(36%),行眼球摘除及完全型眶内容物剜除术并局部放疗和系统化疗15例(28%)。肿瘤的组织类型,含大量染色质的高分化视网膜母细胞瘤25例(47%),高度未分化视网膜母细胞瘤28例(53%)。首次手术后,由于手术切除点以上视神经受累,眼眶浸润和系统转移,发生复发和转移37例(70%)。结论:儿童红眼或白瞳征在确诊之前应怀疑视网膜母细胞瘤,应该及时经眼科专家检查,因为患者在肿瘤初期的早期表现提示会降低肿瘤的扩散、复发和死亡率。

关键词：晚期症状视网膜母细胞瘤挑战

Total Fragmentation Cross Section of 158A GeV Lead Projectiles in Cu Target

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Chinese Physics Letters 2008年第9期25卷 3208-3211页

作者： Mukhtar ahmed Rana Shahid manzoor Physics Division Directorate of Science PINSTECH PO Nilore Islamabad Pakistan

Total fragmentation cross section for the reaction 158A Pb ions ＋ Cu target is measured using the most sensitive track detector CR-39. Measured values are compared with calculations. Exposures of target-detector stack with 158A P5 projectiles are made at CERN-SPS beam facility. Results of calibration of CR-39 detector in a charge region （63 ≤ Z ≤ 83） are also reported, which can be used for high energy particle identification using CR-39 and in determination of partial charge changing cross sections. The charge resolution δz achieved by this technique is about 0.2e. A systematic dependence of total fragmentation cross section on target properties is revealed and the corresponding results are presented.

关键词： the power-law exponents precipitation durative abrupt precipitation change

Fission of Weakly Prolate 119Sn and Weakly Oblate ^(209)Bi Nuclei Induced by 500 and 672 MeV Negative Pions

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Chinese Physics Letters 2011年第9期28卷 88-91页

作者： Mukhtar ahmed Rana Gul Sher Shahid manzoor M.I.Shahzad Physics Division Pakistan Institute of Nuclear Science and Technology(PINSTECH)P.O.NiloreIslamabadPakistan

Fission cross-sections of ^(119)Sn and ^(209)Bi induced by negative pions of two energies 500 and 672 MeV were measured using a CR−39 nuclear track ***-detector stacks were exposed to pion beams at the Brookhaven National Laboratory(USA).Measurement results are compared with the corresponding calculations using the computer code *** between measurements and calculations is fairly good for the ^(209)Bi target nuclei whereas it is poor for 119Sn at both investigated energies of 500 and 672 *** cross−section results of^( 119)Sn and ^(209)Bi are explained using the equilibrium properties of these nuclides including nuclear electric quadrupole moments which determine the shapes of nuclei.A logarithmic dependence of fission cross−section on Z^(2)/A is observed for the above−mentioned reactions and a critical limit of Z^(2)/A is identified with the value of 30 which divides the curve ofσf versus Z2/A into two regimes,one with weak dependence and the other with strong dependence.

关键词： Weakly mentioned limit

A journey towards shared governance: status and prospects for collaborative management in the protected areas of Bangladesh

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Journal of Forestry Research 2013年第3期24卷 599-605,602-605页

作者： A. Z. M. manzoor Rashid Donna Craig Sharif ahmed Mukul Niaz ahmed Khan Environmental Law School of Law University of Western SydneyAustralia Department of Forestry and Environmental Science Shahjalal University of Science and TechnologySylhet Bangladesh School of Agriculture and Food Sciences The University of QueenslandAustralia Department of Development Studies University of DhakaBangladesh

Establishment of Protected Areas （PAs）, in the face of rapid deforestation, forest degradation and climate change has been one of the key efforts in conservation of biodiversity worldwide in recent times. While Bangladesh has gained a degree of prominence in the world for its successful social forestry programs, the concept of collaborative pro- tected area management is rather new in the country, initiated in 2004 by the Bangladesh Forest Department in five PAs with financial assistance from USAID. Based on empirical evidence from three of the pilot PAs, we examined the achievements and associated challenges and prospects for co-management. Our fieldwork revealed a number of challenges faced by co-management institutions：（1） institutions were dominated by the elite group, overshadowing the voice of the community people; （2） mutual trust and collective performance are key to good governance but had not taken root in the PAs; （3） encroachment onto forest land and subsequent conversion to agriculture remained a serious problem that discouraged forest-dependent people from participating actively in co-management initiatives; （4） legal provisions （including acts, rules and policies） were not clearly and adequately disseminated and understood at the community level; （5） there remained a degree of ambiguity regarding the roles and responsibilities of forest department （FD） and co-management committees （CMC） in field operations, and this was not enhancing transparency and accountability of the overall initiative; （6） the long-term sustainability of co-management institutions was another major concern, as the local intuitional structure was still in a nascent stage, and provisioning of resources （either internally or externally） remained somewhat uncertain. We offer recommendations for improve- ment.

关键词： protected area co-management Nishorgo IPAC govern-ance

Numerical Study of Hydrogen Peroxide Thermal Decomposition in a Shock Tube

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Journal of Thermal Science 2017年第3期26卷 235-244页

作者： Muhammad Rizwan Bhatti Nadeem ahmed Sheikh Shehryar manzoor Muhammad Mahabat Khan Muzaffar Ali Department of Mechanical Engineering Capital University of Science and Technology Islamabad Pakistan Mechanical Engineering Department University of Engineering and Technology Taxila Pakistan

Hydrogen peroxide(H_2O_2) has its significance during the combustion of heavy hydrocarbons in the internal combustion(IC) engines. Owing to its importance the measurements of H_2O_2 dissociation rate have been reported mostly using the shock tube apparatus. These types of experimental measurements are although quite reliable but require high cost. On the other hand, numerical simulations provide low cost and reliable solutions especially using computation fluid dynamics(CFD) software. In the current study an experimental shock tube flow is modeled using open access platform OpenFOAM to investigate the thermal decomposition of H_2O_2. Using two different convective schemes, limited Linear and upwind, the propagation of shock wave and resultant dissociation reaction are simulated. The results of the simulations are compared with the experimental data. It is observed that the rate constant measured using the simulation data deviates from the experimental results in the low temperature range and approaches the experimental values as the temperature is raised.

关键词： Reaction kinetics Rate constant Numerical simulation Shock wave Reflected shock wave Contact discontinuity Expansion fan Internal flow Compressible flow Gas dynamics

Bioinspired Multi-material Polyjet-printed Frog Robot for Synchronous and Asynchronous Swimming

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Journal of Bionic Engineering 2023年第3期20卷 923-933页

作者： Afaque manzoor Soomro Jae-Wook Lee Fida Hussain Memon Faheem ahmed Kashif Hussain Kyung Hyun Choi Department of Mechatronics Engineering Jeju National UniversityJeju63243South Korea Department of Electrical Engineering Sukkur IBA UniversitySukkur65200Pakistan

This paper proposes the bioinspired soft frog robot. All printing technology was used for the fabrication of the robot. Polyjet printing was used to print the front and back limbs, while ultrathin filament was used to print the body of the robot, which makes it a complete soft swimming robot. Dual thrust generation approach has been proposed by embedding the main muscle and antagonistic muscle in all the limbs, which enables it to attain high speed (18 mm/s), significant control to swim in dual mode (synchronous and asynchronous modes). To achieve the swimming motion of frog, four SMA (BMF 300) muscle wires were used. The frog robot is named as (FROBOT). The hind limbs are 60 mm long and 10 mm thick on average, while the front limbs are 35 mm long and 7 mm thick. Model-based design and rigorous analysis of the dynamics of real frogs have allowed FROBOT to be developed to swim at a level that is remarkably consistent with real frogs. Electrical and mechanical characteristics have been performed. In addition, the test data were further processed using TRACKER to analyze angle, displacement and velocity. FROBOT (weighs 65 g) can swim at different controllable frequencies (0.5–2 Hz), can rotate in any direction on command from custom built LabVIEW software allowing it to swim with speed up to 18 mm/s on deep water surface (100 cm) with excellent weight balance.

关键词： Bioinspired Soft robotics Frog FROBOT Asynchronous swimming

Multi-material Bio-inspired Soft Octopus Robot for Underwater Synchronous Swimming

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Journal of Bionic Engineering 2022年第5期19卷 1229-1241页

作者： Faheem ahmed Muhammad Waqas Bushra Shaikh Umair Khan Afaque manzoor Soomro Suresh Kumar Hina Ashraf Fida Hussain Memon Kyung Hyun Choi Department of Mechatronics Engineering Jeju National UniversityJeju 63243South Korea Department of Electrical Engineering Sukkur IBA UniversityAirport RoadSukkur 65200SindhPakistan Advanced Micro Mechatronics and Energy Lab Sukkur IBA UniversitySukkur 65200Pakistan Department of Ocean Sciences Jeju National UniversityJeju 63243South Korea

Inspired by the simple yet amazing morphology of the Octopus, we propose the design, fabrication, and characterization of multi-material bio-inspired soft Octopus robot (Octobot). 3D printed molds for tentacles and head were used. The tentacles of the Octobot were casted using Ecoflex-0030 while head was fabricated using relatively flexible material, i.e., OOMOO-25. The head is attached to the functionally responsive tentacles (each tentacle is of 79.12 mm length and 7 void space diameter), whereas Shape Memory Alloy (SMA) muscle wires of 0.5 mm thickness are used in Octobot tentacles for dual thrust generation and actuation of Octobot. The tentacles were separated in two groups and were synchronously actuated. Each tentacle of the developed Octobot contains a pair of SMA muscles (SMA-α and SMA-β). SMA-α muscles being the main actuator, was powered by 9 V, 350 mA power supply, whereas SMA-β was used to provide back thrust and thus helps to increase the actuation frequency. Simulation work of the proposed model was performed in the SolidWorks environment to verify the vertical velocity using the octopus tentacle actuation. The design morphology of Octobot was optimized using simulation and TRACKER software by analyzing the experimental data of angle, displacement, and velocity of real octopus. The as-developed Octobot can swim at variable frequencies (0.5–2 Hz) with the average speed of 25 mm/s (0.5 BLS). Therefore, the proposed soft Octopus robot showed an excellent capability of mimicking the gait pattern of its natural counterpart.

关键词： Bio-inspired Octopus Octobot Sub-surface Soft robotics Swimming

Synthesis of yttrium and cerium doped ZnO nanoparticles as highly inexpensive and stable photocatalysts for hydrogen evolution

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Journal of Rare Earths 2021年第4期39卷 440-445页

作者： Irshad Ahmad Muhammad Shoaib Akhtar Mian Faisal manzoor Muhammad Wajid Muhammad Noman Ejaz ahmed Mukhtar Ahmad Waheed Qamar Khan Anwar M.Rana Department of Physics.Bahauddin Zakariya University Multan60800Pakistan School of Computer and Communication Lanzhou University of Technology.Lanzhou730050China Department of Physics University of Agriculture Faisalabad38040Pakistan Institute of Advanced Materials Bahauddin Zakariya UniversityMultan6800Pakistan

Yttrium and cerium co-doped ZnO nanoparticles were synthesized by combustion route and characterized using X-ray diffraction(XRD),scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET),energy dispersive spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS),UV-visible diffuse reflectance spectroscopy(UV-vis DRS),photoluminescence(PL)and electrochemical impedance spectroscopy(EIS)*** introduction of yttrium ions has efficiently increased the relative percentage of Ce^(3+)ions in *** and cerium co-doped ZnO shows efficient photo activity for hydrogen evolution(10.61 mmol/((g·h))higher than previously reported optimal value for rare earth codoped ZnO *** remarkably increased hydrogen evolution can be ascribed to the synergy between electronic anchoring effect of Y^(3+)/Y^(2+)and Ce^(4+)/Ce^(3+)redox *** report presents new idea for the synthesis of efficient photocatalyst using economical route and ion anchoring *** hydrogen evolution was also tested using Na_(2)S and Na_(2)SO_(3)as electron donors under visible light *** synthesized photocatalysts also exhibit high stability.

关键词： ZnO H_(2)evolution Na_(2)SO_(3) PL Stability Rare earths