检索结果-南通市图书馆

Frontiers of Information Technology & Electronic Engineering 2016年第3期17卷 250-257页

作者： Jing li Xiao-run li li-jiao WANG liao-ying ZHAO College of Electrical Engineering Zhejiang University Institute of Computer Application Technology Hangzhou Dianzi University

Endmember extraction is a key step in the hyperspectral image analysis process. The kernel new simplex growing algorithm （KNSGA）, recently developed as a nonlinear alternative to the simplex growing algorithm （SGA）, has proven a promising endmember extraction technique. However, KNSGA still suffers from two issues limiting its application. First, its random initialization leads to inconsistency in final results; second, excessive computation is caused by the iterations of a simplex volume calculation. To solve the first issue, the spatial pixel purity index （SPPI） method is used in this study to extract the first endrnember, eliminating the initialization dependence. A novel approach tackles the second issue by initially using a modified Cholesky fac- torization to decompose the volume matrix into triangular matrices, in order to avoid directly computing the determinant tauto- logically in the simplex volume formula. Theoretical analysis and experiments on both simulated and real spectral data demonstrate that the proposed algorithm significantly reduces computational complexity, and runs faster than the original algorithm.

关键词： Endmember extraction Modified Cholesky factorization Spatial pixel purity index (SPPI) New simplex growingalgorithm (NSGA) Kernel new simplex growing algorithm (KNSGA)

On the dynamics of the gravitational lifting system in the deep sea mining industry

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean Engineering and Science 2021年第4期6卷 400-404页

作者： Jing li Shijun liao State Key Laboratory of Ocean Engineering Shanghai 200240China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

The dynamics of the gravitational lifting system of the deep sea mining industry is demonstrated in this article.A simplified dynamic model is obtained when gravity,buoyancy and drag force are the major *** quantitative analysis,different variables like bucket size,distribution distance,and filling rate are considered to measure their influence on lifting speed and production rate,which ends up with that the most influential factor is the bucket size,and it has a positive correlation with both the two targets:lifting speed and production *** to the breaking strength of the cable wire rope,a feasible design of such a lifting system should take the tension force into ***,the feasibility is also examined and a conclusion is summarized that a combination of the bucket size and the distribution distance should be optimized according to the concrete working conditions.

关键词： Deep sea mining lifting system Dynamics lifting speed Production rate Cable tension

Solving Nonlinear Equations Systems with an Enhanced Reinforcement Learning Based Differential Evolution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Complex System Modeling and Simulation 2022年第1期2卷 78-95页

作者： Zuowen liao Shuijia li Beibu Gulf Ocean Development Research Center Beibu Gulf UniversityQinzhou 535000China School of Computer Science China University of GeosciencesWuhan 430074China

Nonlinear equations systems(NESs)arise in a wide range of *** NESs requires the algorithm to locate multiple roots *** deal with NESs efficiently,this study presents an enhanced reinforcement learning based differential evolution with the following major characteristics:(1)the design of state function uses the information on the fitness alternation action;(2)different neighborhood sizes and mutation strategies are combined as optional actions;and(3)the unbalanced assignment method is adopted to change the reward value to select the optimal *** evaluate the performance of our approach,30 NESs test problems and 18 test instances with different features are selected as the test *** experimental results indicate that the proposed approach can improve the performance in solving NESs,and outperform several state-of-the-art methods.

关键词： nonlinear equations systems reinforcement learning differential evolution multiple roots location

Water’s motions in x–y and z directions of 2D nanochannels:Entirely different but tightly coupled

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2023年第5期16卷 6298-6307页

作者： Shouwei liao Qia Ke Yanying Wei libo li Guangdong Provincial Key Lab of Green Chemical Product Technology School of Chemistry&Chemical EngineeringSouth China University of TechnologyGuangzhou 510640China State Key Laboratory of Pulp and Paper Engineering South China University of TechnologyGuangzhou 510640China

Two-dimensional(2D)material-based membrane separation has attracted increasing attention due to its promising performance compared with traditional ***,in-depth understanding of water transportation behavior in such confined nanochannels is still lacking,which hinders the development of 2D nanosheets ***,we investigated water confined in graphene or MoS_(2)nanochannels by molecular dynamics(MD)simulations and found water’s diffusivity always varied linearly with their mean square displacement along z direction(Δz^(2))when system variables(e.g.,water molecules’number,channel height,nonbonded interaction parameter,harmonic potential constraining water’s z-coordinate)*** linear correlation applies to different water models and different force fields(FFs)of channel walls(e.g.,different Lennard–Jones parameters or even flexible FF),no matter whether water molecules form 3-,2-,or quasi-2-layer structure in the *** indicates,though water molecules’motion along z direction(z-fluctuation,confined within 1 nm)and that in xy plane(xydiffusion)are entirely different,they are tightly coupled:Violent z-fluctuation would produce more transient void to facilitate xydiffusion,which is to the sharp contrary of bulk water,where motions in x,y,z directions are symmetric,but *** work could help design high performance 2D nanochannels and discover more novel principles in nano-fluidics and membrane separation fields.

关键词： graphene membranes nanochannel nanofluidics water diffusion

An Optimal Control Strategy for Multi-UAVs Target Tracking and Cooperative Competition

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2021年第12期8卷 1931-1947页

作者： Yiguo Yang liefa liao Hong Yang Shuai li Jiangxi University of Science and Technology Ganzhou 341000China College of Engineering Swansea UniversitySwansea SA18ENUK

An optimal control strategy of winner-take-all(WTA)model is proposed for target tracking and cooperative competition of multi-UAVs(unmanned aerial vehicles).In this model,firstly,based on the artificial potential field method,the artificial potential field function is improved and the fuzzy control decision is designed to realize the trajectory tracking of dynamic ***,according to the finite-time convergence high-order differentiator,a double closed-loop UAV speed tracking the controller is designed to realize the speed control and tracking of the target tracking *** simulation results show that the designed speed tracking controller has the advantages of fast tracking,high precision,strong stability and avoiding ***,a cooperative competition scheme of multiple UAVs based on WTA is designed to find the minimum control energy from multiple UAVs and realize the optimal control *** analysis and numerical simulation results show that the model has the fast convergence,high control accuracy,strong stability and good robustness.

关键词： Artificial potential field(APF) fuzzy control higher-order differentiator optimal control strategy winner-take-all(WTA)

Pythagorean probabilistic hesitant triangular fuzzy aggregation operators with applications in multiple attribute decision making

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2023年第2期34卷 422-438页

作者： liao Fuping li Wu liU Gang ZHOU Xiaoqiang School of Information Science and Engineering Hunan Institute of Science and TechnologyYueyang 414006China

As a generalization of fuzzy set,hesitant probabilistic fuzzy set and pythagorean triangular fuzzy set have their own unique advantages in describing decision *** modern socioeconomic decision-making problems are becoming more and more complex,it also becomes more and more difficult to appropriately depict decision makers’cognitive information in decision-making *** order to describe the decision information more comprehensively,we define a pythagorean probabilistic hesitant triangular fuzzy set(PPHTFS)by combining the pythagorean triangular fuzzy set and the probabilistic hesitant fuzzy ***,the basic operation and scoring function of the pythagorean probabilistic hesitant triangular fuzzy element(PPHTFE)are proposed,and the comparison rule of two PPHTFEs is ***,some pythagorean probabilistic hesitant triangular fuzzy aggregation operators are developed,and their properties are also ***,a multi-attribute decision-making(MADM)model is constructed based on the proposed operators under the pythagorean probabilistic hesitant triangular fuzzy information,and an illustration example is given to demonstrate the practicability and validity of the proposed decision-making method.

关键词： pythagorean probabilistic hesitant triangular fuzzy set(PPHTFS) aggregation operator multi-attribute decisionmaking(MADM)

Cooperative fault detection and recovery in the GNSS positioning of mobile agent swarms based on relative distance measurements

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2022年第5期35卷 129-144页

作者： Qifeng CHEN Yunhe MENG Song li Yuxin liao School of Aeronautics and Astronautics Central South UniversityChangsha 410083China School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519082China

Relative measurements are exploited to cooperatively detect and recover faults in the positioning of Mobile Agent(MA)Swarms(MASs).First,a network vertex fault detection method based on edge testing is *** each edge,a property that has a functional relationship with the properties of its two vertices is measured and *** on the edge testing results of the network,the maximum likelihood principle is used to identify the vertex fault ***,an edge distance testing method based on the noncentral chi-square distribution is developed for detecting faults in the Global Navigation Satellite System(GNSS)positioning of ***,a recovery strategy for faults in the positioning of MASs based on distance measurement is *** effectiveness of the proposed methods is validated by a simulation case in which an MAS passes through a GNSS spoofing *** proposed methods are conducive to increasing the robustness of the positioning of MASs in complex *** main novelties include the following:(A)network vertex fault detection is based on concrete probability analysis rather than simple majority voting,and(B)the relation of detectability and recoverability of MAS positioning faults with the structure of the relative measurement network is first disclosed.

关键词： Fault detection and recovery Global Navigation Satellite System Mobile agents Network topology Positioning

Extraction and separation of yttrium from other rare earths in chloride medium by phosphorylcarboxylic acids

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2022年第6期40卷 958-964,I0004页

作者： Guolong Wu Zhifeng Zhang Yanling li Wuping liao State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China University of Science and Technology of China Hefei 230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341000China

Two phosphorylcarboxylic acids,3-((bis(2-ethylhexyloxy))phosphoryl)propanoic acid(PPA) and 3-((bis(2-ethylhexyloxy))phosphoryl)-3-phenylpropanoic acid(PPPA),were synthesized for separating yttrium from other rare earths in the chloride feed of ion-adsorption type rare earth *** effect of the factors such as pH_(1/2),temperature,saponification degree and phase modifiers was *** separation efficiencies of PPA and PPPA are obviously better than the typical extractants such as sec-octylphenoxy acetic acid(CA-12) and naphthenic acid(NA).The extraction process of rare earths by PPA and PPPA is a cation exchanging reaction,which is similar to those of CA-12 and *** loaded rare earths in both PPA and PPPA systems can be effectively back-extracted by 0.5 mol/L HCl or higher concentration.A cascade extraction process for separating yttrium from other rare earths was developed using PPPA as the *** yttrium product with the purity of 97.20 wt% was obtained by 35 stages of extraction and 12 stages of scrubbing.

关键词： Phosphorylcarboxylic acids Extraction Separation Yttrium Chloride Ion-adsorption type rare earth concentrate

Pre-operative enhanced magnetic resonance imaging combined with clinical features predict early recurrence of hepatocellular carcinoma after radical resection

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第4期16卷 1192-1203页

作者： Jian-Ping Chen Ri-Hui Yang Tian-Hui Zhang li-An liao Yu-Ting Guan hai-Yang Dai Department of Intervention Meizhou People’s HospitalMeizhou 514031Guangdong ProvinceChina Department of Medical Imaging Meizhou People’s HospitalMeizhou 514031Guangdong ProvinceChina Department of Medical Imaging Huizhou Municipal Central HospitalHuizhou 516001Guangdong ProvinceChina

BACKGROUND Indentifying predictive factors for postoperative recurrence of hepatocellular carcinoma(HCC)has great significance for patient *** To explore the value of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid(Gd-EOB-DTPA)enhanced magnetic resonance imaging(MRI)combined with clinical features in predicting early recurrence of HCC after *** A total of 161 patients with pathologically confirmed HCC were *** patients were divided into early recurrence and non-early recurrence group based on the follow-up *** clinical,laboratory,pathological results and Gd-EOB-DTPA enhanced MRI imaging features were *** Of 161 patients,73 had early recurrence and 88 were had non-early *** analysis showed that patient age,gender,serum alpha-fetoprotein level,the Barcelona Clinic liver Cancer stage,China liver cancer(CNLC)stage,microvascular invasion(MVI),pathological satellite focus,tumor size,tumor number,tumor boundary,tumor capsule,intratumoral necrosis,portal vein tumor thrombus,large vessel invasion,nonperipheral washout,peritumoral enhancement,hepatobiliary phase(HBP)/tumor signal intensity(SI)/peritumoral SI,HBP peritumoral low signal and peritumoral delay enhancement were significantly associated with early recurrence of HCC after *** logistic regression analysis showed that patient age,MVI,CNLC stage,tumor boundary and large vessel invasion were independent predictive *** data validation indicated that the area under the curve of the combined predictors was 0.861,suggesting that multivariate logistic regression was a reasonable predictive model for early recurrence of *** Gd-EOB-DTPA enhanced MRI combined with clinical features would help predicting the early recurrence of HCC after operation.

关键词： Hepatocellular carcinoma Enhanced magnetic resonance imaging Microvascular invasion Hepatobiliary phase Recurrence

A lithosphere-atmosphere-ionosphere coupling model for ELF electromagnetic waves radiated from seismic sources and its possibility observed by the CSES

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2021年第11期64卷 2551-2559页

作者： ZHAO ShuFan SHEN XuHui liao li ZEREN ZhiMa National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Institute of Geophysics China Earthquake AdministrationBeijing 100081China

Over the last century, abnormal electromagnetic(EM) emissions associated with earthquake(EQ) activities have been widely reported and recorded by ground-based and satellite observations. The mechanism of extremely low-frequency(ELF) EM waves radiated from earthquakes has been gradually established. However, whether EM waves radiated from earthquakes can be detected by low Earth orbit(LEO) satellites remains controversial. In this paper, to address these concerns, a lithosphereatmosphere-ionosphere model of ELF wave propagation is constructed. The features of the simulated EM field at LEO satellite altitudes radiated from earthquakes have been studied. The simulated EM field at the altitude of the China Seismo-Electromagnetic Satellite(CSES) is compared with the sensitivity of electromagnetic(EM) sensors onboard the CSES. The results illustrate that an earthquake with a magnitude over 6.0 can be detected by the EM sensors of the CSES. However, this depends on the focal depth, seismogenic environment and ionospheric parameters.

关键词： earthquakes CSES satellite sensitivity trans-lithosphere-atmosphere-ionosphere ELF wave propagation model