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Exponential-Poisson Parameters Estimation in Moving Extremes Ranked Set Sampling Design

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Acta Mathematicae Applicatae Sinica 2024年

作者： Meng CHEN wang-xue CHEN Rui YANG Ya-wen ZHOU Department of Mathematics and Statistics Jishou University

In this article, the maximum likelihood estimators (MLEs) of the scale and shape parameters βandλfrom the Exponential-Poisson distribution will be considered in moving extremes ranked set sampling(MERSS). These MLEs will be compared in terms of asymptotic efficiencies. The numerical results show that these MLEs in MERSS can be real competitors against those in simple random sampling.

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卡尔曼滤波在机器人足球比赛系统中的应用

机器人 2006年第4期28卷 410-414页

作者：王文学王强孙萍东北大学信息科学与工程学院辽宁沈阳110004

在机器人足球比赛系统中使用了卡尔曼滤波.它可以克服视觉传感器采集回来的数据含有的大量噪声,从而准确预报后几个周期小球的速度、加速度和位置.卡尔曼滤波用于线性离散随机系统具有非常好的收敛性和滤除高频噪声的能力.实践证明,此... 详细信息

在机器人足球比赛系统中使用了卡尔曼滤波.它可以克服视觉传感器采集回来的数据含有的大量噪声,从而准确预报后几个周期小球的速度、加速度和位置.卡尔曼滤波用于线性离散随机系统具有非常好的收敛性和滤除高频噪声的能力.实践证明,此方法对小球的预测比较准确,证明了卡尔曼滤波的可行性和优越性.

关键词：足球机器人卡尔曼滤波线性离散随机系统状态方程

An approach for formation design and flight performance prediction based on aerodynamic formation unit:Energy-saving considerations

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Chinese Journal of Aeronautics 2024年第3期37卷 77-91页

作者： Nanxuan QIAO Tielin MA Xiangsheng wang Jie wang Jingcheng FU Pu xue School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Institute of Unmanned System Beihang UniversityBeijing 100191China Key Laboratory of Advanced Technology of Intelligent Unmanned Flight System Ministry of Industry and Information TechnologyBeijing 100191China School of Transportation Science and Engineering Beihang UniversityBeijing 102206China Beijing Institute of Space Long March Vehicle Beijing 100076China

The performance improvement of swarm drones through aerodynamic shape optimization may be challenging due to folded size constraints imposed by the specific launch ***,fixed-wing aircraft swarms can benefit from formation flight in terms of energy *** study introduces the concept of the"aerodynamic formation unit",which consists of two or three aircraft that form an inseparable unit of the *** the Unmanned Aerial Vehicle(UAV)distribution and wingtip vortex interference in the formation,two typical aerodynamic formation units are optimized by the variable-fidelity aerodynamic optimization method based on space *** aerodynamic characteristics of the formation UAVs that affect flight performance,such as lift-to-drag ratio(L/D ratio)and static stability are analyzed by Computational Fluid Dynamics(CFD)*** L/D ratio(cruising condition)of the following aircraft can be increased by 22.8%and 57.5%in the optimal units that involve two and three aircraft ***,this study conducts several CFD simulations for multi-aircraft formations formed by the units,which show that the average L/D ratio of the formation can be improved by more than 19%.These results verify the feasibility and effectiveness of the"aerodynamic formation unit"concept and the optimization framework for formation parameters.

关键词： Formation flight CFD Aerodynamic formation unit Wingtip vortices Foldable tandem-wing aircraft

Galerkin-based quasi-smooth manifold element(QSME)method for anisotropic heat conduction problems in composites with complex geometry

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 137-154页

作者： Pan wang Xiangcheng HAN Weibin wen Baolin wang Jun LIANG School of Civil Engineering Central South UniversityChangsha 410083China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China School of Science Harbin Institute of TechnologyShenzhen 518055Guangdong ProvinceChina

The accurate and efficient analysis of anisotropic heat conduction problems in complex composites is crucial for structural design and performance evaluation. Traditional numerical methods, such as the finite element method(FEM), often face a trade-off between calculation accuracy and efficiency. In this paper, we propose a quasi-smooth manifold element(QSME) method to address this challenge, and provide the accurate and efficient analysis of two-dimensional(2D) anisotropic heat conduction problems in composites with complex geometry. The QSME approach achieves high calculation precision by a high-order local approximation that ensures the first-order derivative *** results demonstrate that the QSME method is robust and stable, offering both high accuracy and efficiency in the heat conduction analysis. With the same degrees of freedom(DOFs), the QSME method can achieve at least an order of magnitude higher calculation accuracy than the traditional FEM. Additionally, under the same level of calculation error, the QSME method requires 10 times fewer DOFs than the traditional FEM. The versatility of the proposed QSME method extends beyond anisotropic heat conduction problems in complex composites. The proposed QSME method can also be applied to other problems, including fluid flows, mechanical analyses, and other multi-field coupled problems, providing accurate and efficient numerical simulations.

关键词： anisotropic heat conduction quasi-smooth manifold element(QSME) composite with complex geometry numerical simulation finite element method(FEM)

Design and validation of a variable camber wing structure

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Chinese Journal of Aeronautics 2024年第2期37卷 1-11页

作者： Xiasheng SUN Jingfeng xue Jin ZHOU Zhigang wang wenjuan wang Mengjie ZHANG Chinese Aeronautical Establishment Beijing 100012China School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Aircraft Strength Research Institute of China Xi’an 710065China Graduate School of Chinese Aeronautical Establishment Yangzhou 225002China

Variable camber wing technology is one of the important development trends of green aviation at *** smooth,seamless,continuous and adaptive change of wing camber,the aerodynamic performance is improved in achieving increase in lift and reduction in resistance and *** on the aerodynamic validation model CAE-AVM,Chinese Aeronautical Establishment(CAE)has carried out the design and validation of a variable camber wing,proposed an aerodynamic deformation matrix for the leading and trailing edges of aircraft wings in takeoff,landing and cruise *** structures and driving schemes are compared,and several key technology problems of leading and trailing edge deformation are solved.A full-size leading edge wind tunnel test piece with a span of 2.7 m and a trailing edge ground function test piece are *** deformation and shape maintenance capabilities of the leading edge is verified under real wind load conditions,and the load bearing and deformation capabilities of the trailing edge is verified under simulated follow-on *** results indicate that the leading and trailing edges of the variable camber wing can achieve the required deformation angle and have a certain load-bearing *** study can provide some insights into the application of variable camber wing technology for civil aircraft.

关键词： Variable camber wing Leading edge Trailing edge Structure Measurement and control Test

Comparing short-term outcomes of robot-assisted and conventional laparoscopic total mesorectal excision surgery for rectal cancer in elderly patients

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World Journal of Gastrointestinal Surgery 2024年第5期16卷 1271-1279页

作者： Hao Yang Gang Yang wen-Ya Wu Fang wang xue-Quan Yao Xiao-Yu Wu The Affiliated Hospital of Nanjing University of Chinese Medicine Nanjing University of Chinese MedicineNanjing 210029Jiangsu ProvinceChina Department of Surgical Oncology The Affiliated Hospital of Nanjing University of Chinese MedicineNanjing 210029Jiangsu ProvinceChina

BACKGROUND Da Vinci Robotics-assisted total mesorectal excision(TME)surgery for rectal cancer is becoming more widely *** is no strong evidence that roboticassisted surgery and laparoscopic surgery have similar outcomes in elderly patients with TME for rectal *** To determine the improved oncological outcomes and short-term efficacy of robot-assisted surgery in elderly patients undergoing TME *** A retrospective study of the clinical pathology and follow-up of elderly patients who underwent TME surgery at the Department of Gastrointestinal Oncology at the Affiliated Hospital of Nanjing University of Chinese Medicine was conducted from March 2020 through September *** patients were divided into a robotassisted group(the R-TME group)and a laparoscopic group(the L-TME group),and the short-term efficacy of the two groups was *** There were 45 elderly patients(≥60 years)in the R-TME group and 50 elderly patients(≥60 years)in the L-TME *** were no differences in demographics,conversion rates,or postoperative complication *** L-TME group had a longer surgical time than the R-TME group[145(125,187.5)vs 180(148.75,206.25)min,P=0.005),and the first postoperative meal time in the L-TME group was longer than that in the R-TME(4 vs 3 d,P=0.048).Among the sex and body mass index(BMI)subgroups,the R-TME group had better out-comes than did the L-TME group in terms of operation time(P=0.042)and intraoperative assessment of bleeding(P=0.042).In the high BMI group,catheter removal occurred earlier in the R-TME group than in the L-TME group(3 vs 4 d,P=0.001),and autonomous voiding function was *** The curative effect and short-term efficacy of robot-assisted TME surgery for elderly patients with rectal cancer are similar to those of laparoscopic TME surgery;however,robotic-assisted surgery has better short-term outcomes for individuals with risk factors such as obesity and pelvic *** the learning

关键词： Robotic surgery Laparoscopy Rectal cancer Total mesorectal excision Elderly

Clinical effect of laparoscopic radical resection of colorectal cancer based on propensity score matching

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World Journal of Gastrointestinal Surgery 2024年第1期16卷 124-133页

作者： Yang Liu Xian-xue wang Yu-Lin Li wen-Tao He Hong Li Hua Chen Department of General Surgery Changde HospitalXiangya School of MedicineCentral South University(The First People’s Hospital of Changde City)Changde 415000Hunan ProvinceChina Department of Anesthesiology Changde HospitalXiangya School of MedicineCentral South University(The First People’s Hospital of Changde City)Changde 415000Hunan ProvinceChina

BACKGROUND The incidence of colorectal cancer(CRC)is increasing *** radical resection of CRC is a minimally invasive procedure preferred in clinical *** To investigate the clinical effect of laparoscopic radical resection of CRC on the basis of propensity score matching(PSM).METHODS The clinical data of 100 patients who received inpatient treatment for CRC at Changde Hospital,Xiangya School of Medicine,Central South University(The First People’s Hospital of Changde City)were analyzed *** control group included patients who underwent open surgery(n=43),and those who underwent laparoscopic surgery formed the observation group(n=57).The baseline information of both groups was equipoised using 1×1 *** in the perioperative parameters,inflammatory response,immune function,degree of pain,and physical status between the groups were *** Thirty patients from both groups were successfully *** PSM,baseline data showed no statistically significant differences between the groups:(1)Periop-erative parameters:The observation group had a longer surgery time,less intra-operative blood loss,earlier first ambulation and first anal exhaust times,and shorter gastric tube indwelling time than the control group;(2)Inflammatory response:24 h after surgery,the levels of interleukin-6(IL-6),C-reactive protein(CRP),and tumor necrosis factor-α(TNF-α)between groups were higher than ***-6,CRP,and TNF-αlevels in the observation group were lower than in the control group;(3)Immune function:At 24 h after surgery,counts of CD4-positive T-lymphocytes(CD4+)and CD4+/CD8-positive T-lymphocytes(CD8+)in both groups were lower than those before surgery,whereas CD8+was higher than that before *** 24 h after surgery,both CD4+counts and CD4+/CD8+in the observation group were higher than those in the control group,whereas CD8+counts were lower;(4)Degree of pain:The visual analog scale scores in the observation gro

关键词： Colorectal cancer Laparoscopic Open surgery Inflammatory reaction Immune function Propensity score

Modified multiple-component scattering power decomposition for PolSAR data based on eigenspace of coherency matrix

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JOURNAL OF INFRARED AND MILLIMETER WAVES 2024年第4期43卷 572-581页

作者： Zhang, Shuang wang, Lu wang, wen-Qing Xian Univ Technol Sch Automat & Informat Engn Xian 710048 Peoples R China Guilin Univ Elect Technol Minist Educ Key Lab Cognit Radio & Informat Proc Guilin 541004 Peoples R China

A modified multiple-component scattering power decomposition for analyzing polarimetric synthetic aperture radar (PolSAR) data is proposed. The modified decomposition involves two distinct steps. Firstly, eigenvectors of the coherency matrix are used to modify the scattering models. Secondly, the entropy and anisotropy of targets are used to improve the volume scattering power. With the guarantee of high double-bounce scattering power in the urban areas, the proposed algorithm effectively improves the volume scattering power of vegetation areas. The efficacy of the modified multiple-component scattering power decomposition is validated using actual AIRSAR PolSAR data. The scattering power obtained through decomposing the original coherency matrix and the coherency matrix after orientation angle compensation is compared with three algorithms. Results from the experiment demonstrate that the proposed decomposition yields more effective scattering power for different PolSAR data sets.

关键词： PolSAR data model-based decomposition eigenvalue decomposition scattering power MODEL-BASED DECOMPOSITION

Enrichment of anammox biomass during mainstream wastewater treatment driven by achievement of partial denitrification through the addition of bio-carriers

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Journal of Environmental Sciences 2024年第3期137卷 181-194页

作者： Yuqing Ma Bo wang Xiaodi Li Shuo wang wen wang Yongzhen Peng National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology Engineering Research Center of BeijingBeijing University of TechnologyBeijing 100124China

Anammox is widely considered as the most cost-effective and sustainable process for nitrogen ***,how to achieve the enrichment of anammox biomass remains a challenge for its large-scale application,especially in mainstream wastewater *** this study,the feasibility of enrichment of anammox biomass was explored through the realization of partial denitrification and the addition of *** using ordinary activated sludge,a sequencing batch reactor(SBR)followed by an up-fow anaerobic sludge bed(UASB)was operated at 25±2℃ for 214 *** long-term operation was divided into five phases,in which SBR and UASB were started-up in Phases I and II,*** eliminating oxygen and adjusting the infow ratios in Phases III-V,advanced nitrogen removal was achieved with the effuent total nitrogen being 4.7 mg/L and the nitrogen removal efficiency being 90.5%in Phase *** in-situ and ex-situ activity tests demonstrated the occurrence of partial denitrification and ***,16S rRNA high-throughput sequencing analysis revealed that Candidatus Brocadia was enriched from below the detection limit to in biofilms(0.4%in SBR,2.2%in UASB)and the foc sludge(0.2%in SBR,1.3%in UASB),while Thauera was mainly detected in the foc sludge(8.1%in SBR,8.8%in UASB),which might play a key role in partial ***,this study provides a novel strategy to enrich anammox biomass driven by rapid achievement of partial denitrification through the addition of bio-carriers,which will improve large-scale application of anammox processes in mainstream wastewater treatment.

关键词： Enrichment Anammox biomass Bio-carriers Partial denitrification Mainstream wastewater