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SOME INVERSE OPTIMIZATION PROBLEMS ON NETWORK

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Journal of Systems Science & Complexity 2013年第3期26卷 350-364页

作者： xu Cheng xu Xiaoming School of Management University of Shanghai for Science and Technology College of Mathematics Qingdao University

In this paper,the authors consider some inverse problems on network,such as the inverse transport problems with gains(IGTP) and the inverse linear fractional minimum cost flow problem(IFFP).Firstly,the authors give the mathematics model of(IGTP) and an efficient method of solving it under l_1 norm;Secondly,taking advantage of the optimality conditions,the authors consider the(IFFP) and give a simple method of solving ***,an numerical example test is also developed.

关键词： Dual problem fractional minimum cost flow problem gain network inverse problem.

Riverine sulfate sources and behaviors in arid environment,Northwest China:Constraints from sulfur and oxygen isotopes

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Journal of Environmental Sciences 2024年第3期137卷 716-731页

作者： Yifu xu Wenjing Liu Bing xu Zhifang xu Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

The fate of riverine sulfate ion (SO_(4)^(2-)) and its environmental effects in arid environment are difficult to evaluate due to its complicated sources and strongly coupled behaviors with water cycle which is significantly modified by *** understand the sulfur cycle in aquatic systems in arid environment,the chemical and sulfur and oxygen isotopic compositions (δ^(34)S_(SO4)and δ^(18)O_(SO4)) of major rivers around the Badain Jaran Desert,northwestern China,were *** rivers had averaged SO_(4)^(2-)content at 1336μmol/L,over 10times higher than the global *** δ^(34)S_(SO4)and δ^(18)O_(SO4)values ranged from-5.3‰to+11.8‰and+1.6‰to+12.8‰,*** end-member analysis and the inverse model showed that riverine sulfate was mainly derived from evaporites dissolution (0-87%),sulfide oxidation (13%-100%) and precipitation (0-33%),indicating heterogeneity in sulfur sources and behaviors along the river drainage with the lithology variations and climate *** isotopic tools combining with hydro-chemistry compositions could be applied to reveal sulfur cycle in arid *** on the calculation,sulfide oxidation plays the primary role in the headwater and upstream in the Qilian-Mountains area,where sulfide is widely *** the proportion of evaporites dissolution contributing to riverine sulfate is much higher in downstream in a drier ***,less precipitation and higher temperature can lead to more intensive evaporation,affecting the process of sulfide oxidation and enhancing the rates of evaporites dissolution and sulfate precipitation in the basin.

关键词： Sulfur and oxygen isotopes Source apportionment Inverse model Arid environment Inland rivers Northwestern China

Health management based on fusion prognostics for avionics systems

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Journal of Systems Engineering and Electronics 2011年第3期22卷 428-436页

作者： Jiuping xu Lei xu Uncertain Decision-making Laboratory Sichuan UniversityChengdu 610064China

Health management permits the reliability of a system and plays a increasingly important role for achieving efficient system-level *** has been used for remaining useful life（RUL） prognostics of electronics-rich system including *** and health management（PHM） have become highly desirable to provide avionics with system level health *** paper presents a health management and fusion prognostic model for avionics system,combining three baseline prognostic approaches that are model-based,data-driven and knowledge-based approaches,and integrates merits as well as eliminates some limitations of each single approach to achieve fusion prognostics and improved prognostic performance of RUL estimation.A fusion model built upon an optimal linear combination forecast model is then utilized to fuse single prognostic algorithm representing the three baseline approaches correspondingly,and the presented case study shows that the fusion prognostics can provide RUL estimation more accurate and more robust than either algorithm alone.

关键词： prognostics and health management(PHM) avionics system fusion model prognostic approach remaining useful life(RUL).

Effect of Free-Stream Mach Number on the Base Thermal Environment of LaunchVehicle

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Journal of Thermal Science 2024年第6期33卷 2426-2436页

作者： WANG xu xu xu YU Jiaqi YANG Qingchun School of Astronautics Beihang UniversityBeijing 100191China Shenyuan Honors College Beihang UniversityBeijing 100191China

Convective heating of the rocket base caused by high-temperature reverse flow has long been a focus of thermal protection *** distinctive structural characteristics,the base thermal environment of a twin-nozzle engine proves more susceptible to the recirculation region than its multi-nozzle *** the transonic stage,significant alterations in the flow field structure at the rocket base strongly influence the recirculation *** study investigated the thermal environment of the rocket base with a twin-nozzle configuration in freestream at Mach numbers of 0.6 to *** indicate that the freestream Mach number significantly affects the thermal environment at the rocket base during the transonic *** increase of Mach number from 0.6 to 1.0 causes the convective heating of the rocket base to increase by 7.7 *** phenomenon arises due to the plume-induced shock wave caused by the impact of the supersonic free shear layer and plume shear layer while the flight speed exceeds the sound *** interaction between the shock wave and the shear layer amplifies turbulence in the recirculation region and at the inflection point,resulting in a stronger high-temperature reverse *** addition,the cause of low-altitude base heating was analyzed,and it was found that the mechanism is different from the high-temperature countercurrent effect caused by plume interaction.

关键词： rocket base heating free stream Mach number shock-turbulence interaction twin-nozzle

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基于非线性分析的无线通信识别系统优化研究

农机化研究 2025年第1期47卷 125-129页

作者：王永虎乔旭安重庆交通大学重庆402265 重庆城市职业学院重庆402160

为了进一步提升插秧机的通信效率及整机作业效率,以无线通信识别模块为研究对象,基于非线性分析控制理论展开优化研究。结合插秧机的作业环境特征和各组件协调作业特点,从通信信号的非线性处理和保证抗干扰能力角度入手,建立通信识别系... 详细信息

为了进一步提升插秧机的通信效率及整机作业效率,以无线通信识别模块为研究对象,基于非线性分析控制理论展开优化研究。结合插秧机的作业环境特征和各组件协调作业特点,从通信信号的非线性处理和保证抗干扰能力角度入手,建立通信识别系统的非线性控制器模型,并针对系统的输入输出和接口模块完成电路控制与程序优化布局。同时,进行插秧作业通信监测验证试验,结果表明:此非线性分析应用机理下,插秧机作业的智能性与精准性得到显著提高,通过非线性控制实现了细致有效的数据计算分析,通信传输效率相对提升了5.69%,插秧深度合格率可达96.78%,满足智能插秧设计要求。

关键词：智能插秧无线通信识别非线性分析电路控制通信传输效率

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基于粒子群优化算法的农业机器人控制策略研究

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农机化研究 2025年第1期47卷 205-209页

作者：王娜吴延凯许娜河南工业职业技术学院河南南阳473000

介绍了粒子群优化算法的概念,并由数学模型、边界约束和环境约束对农业机器人优化约束模型进行了分析,实现了对农业机器人的动态避障和路径规划。仿真实验表明:针对复杂的作业环境,农业机器人可以进行最优避障路径规划,且算法收敛速度较... 详细信息

介绍了粒子群优化算法的概念,并由数学模型、边界约束和环境约束对农业机器人优化约束模型进行了分析,实现了对农业机器人的动态避障和路径规划。仿真实验表明:针对复杂的作业环境,农业机器人可以进行最优避障路径规划,且算法收敛速度较快,能够满足设计要求,证明系统具有一定的可行性。

关键词：农业机器人粒子群优化约束模型避障路径规划

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Initial Development of a Novel Amphibious Robot with Transformable Fin-Leg Composite Propulsion Mechanisms

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Journal of Bionic Engineering 2013年第4期10卷 434-445页

作者： Shiwu Zhang xu Liang Lichao xu Min xu Department of Precision Machinery and Precision Instrumentation University of Science and Technology of China Hefei 230026 P. R. China

Amphibious robots are very attractive for their broad applications in resource exploration, disaster rescue, and recon- naissance. However, it is very challenging to develop the robots for their complex, amphibious working environments. In the complex amphibious environment, amphibious robots should possess multi-capabilities to walk on rough ground, maneuver underwater, and pass through transitional zones such as sandy and muddy terrain. These capabilities require a high-performance propulsion mechanism for the robots. To tackle a complex task, a novel amphibious robot （AmphiHex-I） with,transformable fin-leg composite propulsion mechanisms is developed. With the fin-leg composite propulsions, AmphiHex-I can walk on rough and soft substrates and swim in water with many maneuvers. This paper presents the structural design of the transformable fin-leg propulsion mechanism and its driving module. A hybrid model is used to explore the dynamics between the trans- formable legs and transitional environment such as granular medium. The locomotion performances of legs with various ellip- tical shapes are analyzed, which is verified by the coincidence between the model predictions and the simulation results. Further, an orthogonal experiment is conducted to study the locomotion performance of a two-legged platform walking with an asyn- chronous gait in the sandy and muddy terrain. Finally, initial experiments of AmphiHex-I walking on various lands and swimming in water are implemented. These results verify that the transformable fin-leg mechanisms enable the amphibious robot to pass through a complex, amphibious working environment.

关键词： amphibious robot transformable fin-leg composite propulsion mechanism amphibious environment

C^0-Sufficiency,Kuiper-Kuo and Thorn Conditions for Non-isolated Singularity

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Acta Mathematica Sinica,English Series 2007年第7期23卷 1251-1256页

作者： xu xu School of Mathematics and Statistics Wuhan University

In this paper, a criterion on the C^0-sufficiency for a function germ with non-isolated singularity is obtained analogously to that of Kuiper-Kuo for the case of isolated singularities. Moreover, the Kuiper Kuo condit... 详细信息

关键词： non-isolated singularity C^0-sufficiency Kuiper-Kuo condition Thom condition

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预切缝辅助TBM滚刀破岩贯入荷载演化规律

土木与环境工程学报（中英文） 2025年第1期47卷 63-70页

作者：蒋亚龙徐彭楚璇曾建军徐长节熊扶阳华东交通大学土木建筑学院南昌330013 江西省交通科学研究院有限公司南昌330200

基于全断面隧道掘进机(Tunnel Boring Machine,TBM)滚刀贯入室内模型试验,研究了3种不同破岩模式(完整岩样破岩、同轨迹破岩和异轨迹破岩)在不同围压条件下高强度花岗岩样贯入荷载演化特征,重点揭示贯入荷载-贯入度特征曲线、峰值荷载... 详细信息

基于全断面隧道掘进机(Tunnel Boring Machine,TBM)滚刀贯入室内模型试验,研究了3种不同破岩模式(完整岩样破岩、同轨迹破岩和异轨迹破岩)在不同围压条件下高强度花岗岩样贯入荷载演化特征,重点揭示贯入荷载-贯入度特征曲线、峰值荷载、最大跌落幅值变化规律,获取不同破岩模式在不同围压条件下TBM滚刀受力特性。结果表明:1)高围压组贯入荷载-贯入度特征曲线较低围压组先跌落,跌落幅度较小,但其对应的贯入荷载并非峰值荷载,而低围压组初次跌落荷载为峰值荷载,且跌落幅值较大;2)在中高围压10~15 MPa时,峰值荷载及贯入荷载最大跌落幅值均最小,表明此围压范围较利于TBM的掘进;3)低围压条件下选用异轨迹破岩模式较同轨迹破岩模式能更有效地降低TBM滚刀贯入荷载,但同轨迹破岩模式的岩样发生楔裂破坏,其最大跌落幅值最小,更能减少刀具所受冲击荷载,减少刀具磨损。

关键词：高强度超硬岩全断面隧道掘进机预切缝破岩模式贯入荷载

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