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A Fast Vision-inertial Odometer Based on line Midpoint Descriptor

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International Journal of Automation and computing 2021年第4期18卷 667-679页

作者： Wen-Kuan Li Hao-Yuan Cai sheng-lin Zhao Ya-Qian Liu Chun-Xiu Liu State Key Laboratory of Transducer Technology Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China

Visual simultaneous localization and mapping(VSLAM) are essential technologies to realize the autonomous movement of vehicles. Visual-inertial odometry(VIO) is often used as the front-end of VSLAM because of its rich information, lightweight, and robustness. This article proposes the FPL-VIO, an optimization-based fast vision-inertial odometer with points and lines. Traditional VIO mostly uses points as landmarks;meanwhile, most of the geometrical structure information is ignored. Therefore, the accuracy will be jeopardized under motion blur and texture-less area. Some researchers improve accuracy by adding lines as landmarks in the ***, almost all of them use line segment detector(LSD) and line band descriptor(LBD) in line processing, which is very time-consuming. This article first proposes a fast line feature description and matching method based on the midpoint and compares the three line detection algorithms of LSD, fast line detector(FLD), and edge drawing lines(EDlines). Then, the measurement model of the line is introduced in detail. Finally, FPL-VIO is proposed by adding the above method to monocular visual-inertial state estimator(VINSMono), an optimization-based fast vision-inertial odometer with lines described by midpoint and points. Compared with VIO using points and lines(PL-VIO), the line processing efficiency of FPL-VIO is increased by 3-4 times while ensuring the same accuracy.

关键词： High efficiency visual-inertial odometry(VIO) non-linear optimization points and lines sliding window

LB-AGR: level-based adaptive geo-routing for underwater sensor network

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The Journal of China Universities of Posts and Telecommunications 2014年第1期21卷 54-59页

作者： DU Xiu-juan HUANG Ke-jun LAN sheng-lin FENG Zhen-xing LIU Fan School of Computer Science Qinghai Normal University Network Information Center Qinghai Normal University

Underwater sensor network（UWSN） adopts acoustic communication with more energy-consumption and longer propagation-delay, which bring great challenges to protocol design. In this paper, we proposed level-based adaptive geo-routing（LB-AGR） protocol. LB-AGR divides traffics into four categories, and routes different types of traffic in accordance with different decisions. Packets upstream to the sink are forwarded unicast to the best next-hop instead of broadcasting to all neighbor nodes as in present UWSN routing protocols. LB-AGR defines an integrated forwarding factor for each candidate node based on available energy, density, location, and level-difference between neighbor nodes, which is used to determine the best next-hop among multiple qualified candidates. Through simulation experiments, we show the promising performance of LB-AGR.

关键词： UWSN LB-AGR node level neighbor table

Nonlinear dynamics in Internet congestion control model with TCP Westwood under RED

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The Journal of China Universities of Posts and Telecommunications 2009年第4期16卷 53-58页

作者： DING Da-wei ZHU Jie LUO Xiao-shu HUANG lin-sheng HU Yan-jun Key Laboratory of Intelligent Computing and Signal Processing Ministry of Education Anhui University Hefei 230039 China Department of Electronic Engineering Shanghai Jiaotong University Shanghai 200240 China School of Electronic Engineering Guangxi Normal University Guilin 541004 China

This article develops a discrete time dynamic feedback model of a congestion control system for a simple network with TCP Westwood （TCPW） connections and a single bottleneck link with random early detection （RED） gateway. By using this model, the nonlinear dynamics of the TCPW/RED network are analyzed and its parameter sensitivities are studied. It is shown that periodic doubling bifurcation occurs when the RED control parameters or other parameters are varied. By theoretical analysis, the fixed point, the critical value of parameters and the nature of the bifurcation are determined. Moreover, by using bifurcation diagrams and Lyapunov exponent, the result of theoretical analysis is validated and the bifurcation and chaotic phenomena are numerically studied of the congestion control system with TCPW connections and RED gateway.

关键词： nonlinear system bifurcation chaos congestion control TCP Westwood RED

Estimates of Soil Organic Carbon Stocks in Zhejiang Province of China Based on 1:50000 Soil Database Using the PKB Method

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Pedosphere 2015年第1期25卷 12-24页

作者： ZHI Jun-Jun JING Chang-Wei lin sheng-Pan ZHANG Cao WU Jia-Ping College of Environmental and Resource Sciences Zhejiang University Institute of Islands and Coastal Research Zhejiang University Department of Zoology Michigan State University

Soil organic carbon(SOC) is an important component of farming systems and global carbon cycle. Accurately estimating SOC stock is of great importance for assessing soil productivity and modeling global climate change. A newly built 1:50 000 soil database of Zhejiang Province containing 2 154 geo-referenced soil profiles and a pedological professional knowledge-based(PKB) method were used to estimate SOC stock up to a depth of 100 cm for the Province. The spatial patterns of SOC stocks stratified by soil types,watershed(buffer analysis), topographical factors, and land use types were identified. Results showed that the soils in Zhejiang covered an area of 100 740 km2 with a total SOC stock of 831.49 × 106 t and a mean SOC density of 8.25 kg m-2, excluding water and urban areas. In terms of soil types, red soils had the highest SOC stock(259.10 × 106t), whereas mountain meadow soils contained the lowest(0.15 × 106t). In terms of SOC densities, the lowest value(5.11 kg m-2) was found in skel soils, whereas the highest value(45.30 kg m-2) was observed in mountain meadow soils. Yellow soils, as a dominant soil group, determined the SOC densities of different buffer zones in Qiantang River watershed because of their large area percentage and wide variation of SOC density *** area percentages of various soil groups significantly varied with increasing elevation or slope when overlaid with digital elevation model data, thus influencing the SOC densities. The highest SOC density was observed under grassland, whereas the lowest SOC density was identified under unutilized land. The map of SOC density(0–100 cm depth) and the spatial patterns of SOC stocks in the Province would be helpful for relevant agencies and communities in Zhejiang Province, China.

关键词： elevation pedological professional knowledge-based method sampling depth slope SOC density soil groups

Inflammatory myofibroblastic tumor of the pancreatic neck:A case report and review of literature

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World Journal of Clinical Cases 2021年第22期9卷 6418-6427页

作者： Zhi-Tao Chen Yao-Xiang lin Meng-Xia Li Ting Zhang Da-Long Wan sheng-Zhang lin Department of Hepatobiliary and Pancreatic Surgery Shulan(Hangzhou)Hospital Affiliated to Zhejiang Shuren University Shulan International Medical CollegeHangzhou 310000Zhejiang ProvinceChina School of Medicine Zhejiang UniversityHangzhou 310000Zhejiang ProvinceChina School of Medicine Hangzhou Normal UniversityHangzhou 310003Zhejiang ProvinceChina Department of Hepatobiliary and Pancreatic Surgery First Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhou 310003Zhejiang ProvinceChina Department of Pathology Shulan(Hangzhou)Hospital Affiliated to Zhejiang Shuren University Shulan International Medical CollegeHangzhou 310000Zhejiang ProvinceChina Department of Hepatobiliary and Pancreatic Surgery The First Affiliated HospitalCollege of MedicineZhejiang UniversityHangzhou 310003Zhejiang ProvinceChina Department of Hepatobiliary Surgery Shulan(Hangzhou)Hospital Affiliated to Zhejiang Shuren University Shulan International Medical CollegeHangzhou 310000Zhejiang ProvinceChina

BACKGROUND Pancreatic inflammatory myofibroblastic tumor(IMT)is a relatively rare disease that is often confused with pancreatic cancer or pancreatic neuroendocrine *** histological features of IMTs show that tissue from this type of tumor contains an intermingling of fibroblast and myofibroblast proliferation,accompanied by a varying degree of inflammatory cell *** SUMMARY The management of an IMT occurring at the neck of the pancreas is presented in this paper.A 66-year-old female patient was diagnosed with a pancreatic neck mass after a series of *** patient underwent enucleation of the pancreatic neck tumor after a pathological diagnosis of *** research on the clinical features,pathological diagnosis and treatment of pancreatic IMTs was *** with previous reports,this is a unique case of enucleation of a pancreatic *** The enucleation of pancreatic IMTs may be a safe and efficient surgical method for managing such tumors with a better *** cases are required to explore surgical measures for pancreatic IMTs.

关键词： Inflammatory myofibroblastic tumor Pancreatic neck Enucleation Case report

Single-incision vs three-incision laparoscopic cholecystectomy for complicated and uncomplicated acute cholecystitis

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World Journal of Gastroenterology 2013年第43期19卷 7743-7750页

作者： Shu-Hung Chuang Pai-Hsi Chen Chih-Ming Chang Chih-sheng lin Department of Biological Science and Technology National Chiao Tung University Department of Surgery Mackay Memorial HospitalHsin-Chu Branch College of Management Fu Jen Catholic University Department of Nursing Mackay Memorial HospitalHsin-Chu Branch

AIM:To compare the clinical outcome of single-incision laparoscopic cholecystectomy(SILC)and three-incision laparoscopic cholecystectomy(3ILC)for acute ***:From July 2009 to September 2012,136patients underwent SILC or 3ILC for acute cholecystitis at a tertiary referral *** experienced surgeon performed every procedure using 5 or 10 mm 30-degree laparoscopes,straight instruments,and conventional *** patients with perforated gallbladder and diffuse peritonitis and 23 patients with mild acute cholecystitis were *** remaining 108 patients were divided into complicated and uncomplicated groups according to pathologic *** demography,clinical data,operative results and complications were recorded and ***:Fifty patients with gangrenous cholecystitis,gallbladder empyema,or hydrops were classified as the complicated group,and 58 patients with acute cholecystitis were classified as the uncomplicated ***-three(46.0%)of the patients in the complicated group(n=50)and 39(67.2%)of the patients in the uncomplicated group(n=58)underwent SILC;all others underwent *** postoperative length of hospital stay(PLOS)was significantly shorter in the SILC subgroups than the 3ILC subgroups(3.5±1.1 d vs 4.6±1.3 d,P<0.01 in the complicated group;2.9±1.1 d vs 3.7±1.4 d,P<0.05 in the uncomplicated group).The maximum body temperature recorded at day 1 and at day 2 following the procedure was lower in the SILC subgroups,but the difference reached statistical significance only in the uncomplicated group(37.41±0.56℃vs 37.80±0.72℃,P<0.05 on postoperative day 1;37.10±0.43℃vs 37.57±0.54℃,P<0.01 on postoperative day 2).The operative time,estimated blood loss,postoperative narcotic use,total length of hospital stay,conversion rates,and complication rates were similar in both SILC and 3ILC *** complicated group had longer operative time(122.2±35.0 min vs 106.6±43.6 min,P<0.05),longer PLOS(4.1±1.3 d vs 3.2±1.2 d,P<0.

关键词： Single-incision laparoscopic cholecystectomy Single-incision laparoscopic surgery Laparoen doscopic single site surgery Cholecystectomy Acute cholecystitis Complicated cholecystitis Gangrenous cholecystitis

An Efficient Neural-Network and Finite-Difference Hybrid Method for Elliptic Interface Problems with Applications

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Communications in Computational Physics 2023年第4期33卷 1090-1105页

作者： Wei-Fan Hu Te-sheng lin Yu-Hau Tseng Ming-Chih Lai Department of Mathematics National Central UniversityTaoyuan 32001Taiwan Department of Applied Mathematics National Yang Ming Chiao Tung UniversityHsinchu 30010Taiwan Department of Applied Mathematics National University of KaohsiungKaohsiung 81148Taiwan National Center for Theoretical Sciences National Taiwan UniversityTaipei 10617Taiwan

A new and efficient neural-network and finite-difference hybrid method is developed for solving Poisson equation in a regular domain with jump discontinuities on embedded irregular *** the solution has low regularity across the interface,when applying finite difference discretization to this problem,an additional treatment accounting for the jump discontinuities must be ***,we aim to elevate such an extra effort to ease our implementation by machine learning *** key idea is to decompose the solution into singular and regular *** neural network learning machinery incorporating the given jump conditions finds the singular solution,while the standard five-point Laplacian discretization is used to obtain the regular solution with associated boundary *** of the interface geometry,these two tasks only require supervised learning for function approximation and a fast direct solver for Poisson equation,making the hybrid method easy to implement and *** two-and three-dimensional numerical results show that the present hybrid method preserves second-order accuracy for the solution and its derivatives,and it is comparable with the traditional immersed interface method in the *** an application,we solve the Stokes equations with singular forces to demonstrate the robustness of the present method.

关键词： Neural networks sharp interface method fast direct solver elliptic interface problem Stokes equations

Structural diversity and reactivity of d^(10) metal-(4-pyridylthio)acetate system

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Chinese Science Bulletin 2009年第23期54卷 4277-4284页

作者： ZHANG YueHua WANG Jing ZHENG lingling HU sheng lin ZhuoJia TONG MingLiang Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education State Key Laboratory of Optoelectronic Materialsand Technologies School of Chemistry and Chemical Engineering Sun Yat-Sen University Guangzhou 510275 China

The hydrothermal synthesis and crystal structures of four coordination polymers, namely, 2D [Zn(μ3-ta)(pytaH)]n (1), 2D [Zn(μ3-pyta)Cl]n (2), 1D [Cd(μ-pyta)2(H2O)]n (3), and 3D [Cd(μ3-pyta)(μ-Cl)]n (4) (pyta = (4-pyridylthio)acetate, ta = thioglycolate), are reported. They are based on (4-pyridylthio)acetate and its derived ligand. The ta2ligand present in 1 was generated from an in situ C(sp2)-S bond cleavage of the pyta ligand. In these compounds, versatile intermolecular interactions, such as close S…S interactions and strong (O―H…O/N/S) or weak (C―H…O/S, C―H…Cl) hydrogen bonding interactions, play an important role in the formation of three-dimensional supramolecular networks in the solid state.

关键词：晶体结构醋酸多样性氢键相互作用反应金属系统水热合成

Microstructure and Mechanical Behavior of Mg-Based Bimetal Plates with High Formability Sleeve by Co-extrusion

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 499-512页

作者： Yue-Hui Dang sheng-lin Liu Xiao-Lei Ai Xiao-Wei Feng Bo Feng Zhuo Tian Ying-Fei lin Huan-Tao Chen Kai-Hong Zheng School of Materials Science and Engineering Chang’an UniversityShaanxi 710064China Guangdong Key Laboratory of Metal Toughening Technology and Application Institute of New MaterialsGuangdong Academy of SciencesGuangzhou 510650China

In this study,microstructure and mechanical behavior of two types of Mg-based bimetal plates with a high formability sleeve were systematically studied,with a great emphasis on the effect of the interface characteristic and the sleeve fraction on the plasticity of composite *** rule of mixtures(ROM)for elongation was also *** results show that when there is no or thin diffusion layer with thickness of about 3μm,Mg-based bimetal plates have a good plasticity with elongation of about 19-24%,and the ROM predicted elongations are very close to the experimental *** contrast,with a diffusion layer about 95-155μm thick,Mg-based bimetal plates exhibit a poor plasticity with elongation of about 11-17%,and the experimental elongations largely deviate from the ROM *** plasticity of Mg-based bimetal plates increases with increasing sleeve *** study provides new insights on the plastic deformation of Mg-based bimetal composites with a high formability sleeve.

关键词： Mg-based composites Co-extrusion Microstructure Mechanical behavior Plastic deformation