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The existence of harmonic maps from Finsler manifolds of Riemannian manifolds

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Science China Mathematics 2005年第1期48卷 115-130页

作者： mo Xiaohuan yang Yunyan LMAM School of Mathematical SciencesPeking UniversityBeijing 100871China Department of MathematicsRenmin University of ChinaBeijing 100872China

In this paper,we consider the existence of harmonic maps from a Finsler man-ifold and study the characterisation of harmonic maps,in the spirit of *** heatequation method we show that any map from a compact Finsler manifold M to a com-pact Riemannian manifold with non-positive sectional curvature can be deformed into aharmonic map which has minimum energy in its homotopy class.

关键词： harmonic map,Finsler manifold,existence.

Comparison between chikungunya and dengue viruses transmission based on a mathematical model

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International Journal of Biomathematics 2017年第6期10卷 255-276页

作者： Hyun mo yang Departamento de Matematica Aplicada Universidade Estadual de Campinas Praca Sergio Buarque de Holanda 651 CEP 13083-859 Campinas Sao Paulo Brazil

Chikungunya and dengue viruses are transmitted by mosquitoes of genus Aedes. Based on a mathematical model dealing with arboviruses transmission that encompasses human and mosquito populations, the risks of dengue and chikungunya infections are compared. By the fact that chikungunya virus attains high viral load earlier than dengue virus in both humans and mosquitoes, the potential risk of chikungunya could be higher than the dengue infection. The risk of arboviruses infections is assessed by the reproduction number R, which is obtained by the next generation matrix method and Routh-Hurwitz criteria.

关键词： Reproduction number partial reproduction numbers stability of equilibriumpoints next generation matrix Routh-Hurwitz criteria.

A kind of biomimetic control method to anthropomorphize a redundant manipulator for complex tasks

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Science China(Technological Sciences) 2020年第1期63卷 14-24页

作者： mo yang JIANG ZhiHong LI Hui yang Hong HUANG Qiang School of Mechatronic Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Advanced Innovation Center for Intelligent Robots and Systems Beijing 100081China Key Laboratory of Biomimetic Robots and Systems Ministry of EducationBeijing 100081China Institute of Manned Spacecraft System Engineering China Academy of Space TechnologyBeijing 100080China

It is an urgent problem for robots to operate complex tasks with some unknown motion mechanisms caused by the strong coupling of force and motion. However, humans can perform complex tasks well due to their natural evolution and postnatal training. A novel biomimetic control method based on a human motion mechanism with high movement adaptability is proposed in this paper. The core is to present a novel variable-parameter compliance controller based on human operation mechanisms with an action-planning method derived from optimization by human motion, and the main contribution is to change the parameters of compliance controller according to human operating intention synchronized with humanoid motion;this change could establish a humanoid map between the force and motion for a seven degree-of-freedom redundant manipulator to deal with the unknown motion mechanism in complex tasks, so the redundant manipulator can operate complex tasks with high performance. Sufficient experiments were performed, and the results validated the effectiveness of the proposed algorithm.

关键词： redundant manipulator biomimetic control humanoid mapping complex task

A novel space target-tracking method based on generalized Gaussian distribution for on-orbit maintenance robot in Tiangong-2 space laboratory

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Science China(Technological Sciences) 2019年第6期62卷 1045-1054页

作者： mo yang JIANG ZhiHong LI Hui yang Hong HUANG Qiang School of Mechatronic Engineering Beijing Institute of Technology Beijing 100081 China Beijing Advanced Innovation Center for Intelligent Robots and Systems Beijing 100081 China Key Laboratory of Biomimetic Robots and Systems Ministry of Education Beijing 100081 China Institute of Manned Spacecraft System Engineering China Academy of Space Technology Beijing 100080 China

Accurate target tracking based on visual images is the key for intelligent robots to assist or replace astronauts to work in space station. However, the special space environment such as non-uniform illumination and high-energy particle radiation is a huge challenge, which may lead to complex noise coupling in vision image. This paper proposes a novel method for accurate target tracking, the essence of which is the Retinex image enhancement algorithm in CIELAB color space(LAB-GRetinex) and the generalized maximum correntropy Kalman filter(GMCKF) which are all based on generalized Gaussian distribution. The LABGRetinex algorithm chooses the CIELAB color space, which is closer to the human vision, as the processing color space, and the generalized Gaussian distribution can estimate the light image accurately, so the influence of non-uniform illumination can be reduced effectively. Meanwhile, the GMCKF algorithm adopts the generalized correntropy criterion based on the generalized Gaussian distribution to replace the minimum mean square error(MMSE) criterion to realize the optimal filtering effect under the complex non-Gaussian noise, which can improve the target tracking accuracy. Sufficient ground simulation experiments and application experiments in the Tiangong-2 space laboratory verify the effectiveness of the proposed algorithm which can track the target accurately in the special space environment and provide the precise pose information for on-orbit robot maintenance verification. This research lays a technical foundation for the application of intelligent robot in the construction and operation on space station in the future.

关键词： space robot LAB-GRetinex GMCKF target tracking

Effect of Superplasticizers on the Early Age Hydration of Sulfoaluminate Cement

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Journal of Wuhan University of Technology(Materials Science) 2014年第4期29卷 757-762页

作者：袁晓辉陈伟 yang mo School of Civil Engineering and Architecture Wuhan University of Technology School of Materials Science and Engineering Wuhan University of Technology

The effects of two types of superplasticizers on the properties of CSA cement pastes during early hydration were studied. The influences of two types of superplasticizers on the properties of cement pastes, including the normal consistency, setting time, fl uidity, and compressive strength, were investigated by using various methods. The hydration products of the cement pastes cured for 1 day and 3 days were studied by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. The results show that the PCE type superplasticizer retards the early age hydration while the FDN type superplasticizer accelerates the early age hydration of the CSA cement. Both types of superplasticizers have no infl uence on the further hydration of CSA cement, confi rmed by the calorimeter tests as well. The ultrasonic pulse velocity measurements were used to probe the influence of two types of superplasticizers on the hydration of CSA cement pastes at a high water-cement ratio（0.45）. The results show that the PCE type superplasticizer retards the early age hydration of the CSA cement while the FDN type superplasticizer has little infl uence on the early age hydration of the CSA cement.

关键词： calcium sulfoaluminate cement superplasticizer early age hydration

Semidefinite programming detection for OvHDM signal

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The Journal of China Universities of Posts and Telecommunications 2008年第3期15卷 8-12,18页

作者： mo Yong yang Xing LI Dao-ben School of Information Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

Non-orthogonal time-frequency division multiplexing （NTFDM） transmission scheme has been proposed to further improve the bandwidth efficiency and overcome the drawbacks of the conventional orthogonal frequency division multiplexing （OFDM） method. Based on such approach, the fast signal detection algorithm, semidefinite programming （SDP） detection, has been studied. As the coefficient matrix tends to be ill conditioned, the modified SDP algorithm combined with successive interference cancellation （SIC） has been developed. The improved algorithm is a good tradeoff between performance and detection complexity. Simulation results show that the proposed algorithm can achieve better performance than cutting plane aided SDP method.

关键词： overlapped TDM (OvTDM) overlapped frequency division multiplexing (OvFDM) overlapped hybrid division multiplexing (OvHDM) semidefinite programming successive interference cancellation

Impact of oxaliplatin and trastuzumab combination therapy on tumor markers and T lymphocyte subsets for advanced gastric cancer

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World Journal of Gastrointestinal Oncology 2024年第9期16卷 3905-3912页

作者： Cheng-Wan Zheng Yun-mo yang Hui yang Department of Thyroid Surgery The Affiliated Hospital of Southwest Medical UniversityLuzhou 646000Sichuan ProvinceChina

BACKGROUND Advanced gastric cancer(AGC)remains a challenging malignancy with poor *** combination of oxaliplatin and trastuzumab has shown promising results in AGC *** study aimed to investigate the effects of oxaliplatin and trastuzumab combination therapy on serum tumor markers and T lymphocyte subsets in patients with AGC and to explore their potential as predictive biomarkers for treatment *** To investigate the impact of oxaliplatin and trastuzumab combination therapy on serum markers and T cell subsets in patients with *** This prospective study enrolled 60 patients with *** patients received oxaliplatin(130 mg/m^(2),every 3 weeks)and trastuzumab(8 mg/kg loading dose,followed by 6 mg/kg every 3 weeks)for six *** carcinoembryonic antigen(CEA),cancer antigen 19-9(CA19-9),and cancer antigen 72-4(CA72-4)were measured before and after treatment.T-lymphocyte subsets,including CD3+,CD4+,CD8+,and CD4+/CD8+ratios,were also *** clinical response was assessed using the Response Evaluation Criteria in Solid Tumors version *** After six cycles of treatment,the CEA,CA19-9,and CA72-4 serum levels significantly decreased compared to baseline levels(Pmor markers(≥50%reduction)and a higher increase in CD4+/CD8+ratio(≥1.5-fold)showed better clinical response rates(Pmor marker levels and modulated T lymphocyte subsets in patients with *** therapy not only has a direct antitumor effect,but also enhances the immune response in patients with *** tumor markers and T lymphocyte subsets may serve as potential predictive biomarkers for treatment respon

关键词： Advanced gastric cancer Oxaliplatin Trastuzumab Serum tumor markers T lymphocyte subsets Predictive biomarkers

A new nomogram for predicting lymph node positivity in pancreatic cancer

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Hepatobiliary & Pancreatic Diseases International 2021年第2期20卷 103-104页

作者： Xiao-Dong Tian Yin-mo yang Department of General Surgery Peking University First HospitalBeijing 100034China

Pancreatic cancer(PC)is one of the most dismal malignancies,and radical resection in combination with perioperative systemic chemotherapy provides the only chance of long-term survival[1].However,surgeons have been increasingly aware that some anatomically resectable PC patients cannot benefit from upfront *** majority of PC patients with radical resection will suffer from local recurrence or systematic metastasis in 1-2 years after surgery,especially for those with pathological positive lymph nodes(LNs)[2].

关键词： lymph cancer surgery

Experimental research on nonlinear characteristics of natural convection in a 3-D shallow cavity

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Science China(Technological Sciences) 2011年第12期54卷 3304-3310页

作者： ZHAN NaiYan GAO Qing BAI Li yang mo College of Automotive Engineering Jilin University Changchun 130022 China Scool of Municipal and Environmental Engineering Jilin Institute of Architectural and Civil Engineering Changchun 130021 China College of Power Engineering University of Shanghai for Science and Technology Shanghai 200093 China

Experiments were conducted to study the temperature field,flow field,3-D characteristics and self-sustained oscillation of the natural air convection in a 3-D shallow cavity which was heated from underneath. The experiments were conducted by the methods of laser holographic interferometry photography and smoke visualization. To ensure the temperature of both plates to be constant and the accuracy of laser interferometer,the instrument was calibrated and error has was analyzed. The results showed that the flow field was stable at lower Rayleigh numbers. When the Rayleigh number increased,the flow field became instable and the isotherms distorted. The rolls merged at Ra=12500 and formed along both axes when Ra was over 18500. The air rose from the middle and descended in the circumference while the flow field and heat transfer converted to 3-D characteristic from 2-D characteristic. When the Rayleigh number increased,the flow field became more instable. The rolls became irregular and time dependent when Ra≥Rac(=30500) ,which is nonlinear. When lateral walls were heated or cooled,the rolls merged along the long axis and two rolls formed along the short axis. Three rolls formed occasionally in the process.

关键词： interferometric tomography smoke visualization critical Rayleigh number 3-D characteristic oscillation and chaos