检索结果-南通市图书馆

Image Processing for Denoising Using Composite Adaptive Filtering Methods Based on RMSE

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Applied Sciences 2024年第3期14卷 660-675页

作者： Yanlu Chen Ruijie Wang Puming Zong Da Chen Control Theory and Control engineering College of Railway Transportation Hunan University of Technology Zhuzhou China Inner Mongolia Power Group Xilingol Extra High Voltage Power Supply Company Xilinhot China Inner Mongolia Power Group Limited Liability Company XilinGol Power Supply Branch Xilinhot China

As one of the carriers for human communication and interaction, images are prone to contamination by noise during transmission and reception, which is often uncontrollable and unknown. Therefore, how to denoise images contaminated by unknown noise has gradually become one of the research focuses. In order to achieve blind denoising and separation to restore images, this paper proposes a method for image processing based on Root Mean Square Error (RMSE) by integrating multiple filtering methods for denoising. This method includes Wavelet Filtering, Gaussian Filtering, Median Filtering, Mean Filtering, Bilateral Filtering, Adaptive Bandpass Filtering, Non-local Means Filtering and Regularization Denoising suitable for different types of noise. We can apply this method to denoise images contaminated by blind noise sources and evaluate the denoising effects using RMSE. The smaller the RMSE, the better the denoising effect. The optimal denoising result is selected through comprehensively comparing the RMSE values of all methods. Experimental results demonstrate that the proposed method effectively denoises and restores images contaminated by blind noise sources.

关键词： Blind Denoising Adaptive RMSE Image Restoratio

Fast nuclide identification based on a sequential Bayesian method

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2021年第12期32卷 116-127页

作者： Xiao-Zhe Li Qing-Xian Zhang He-Yi Tan Zhi-Qiang Cheng Liang-Quan Ge Guo-Qiang Zeng Wan-Chang Lai Chengdu University of technology The College of Nuclear Technology and Automation EngineeringChengdu 610059China

The rapid identification of radioactive substances in public areas is ***,traditional nuclide identification methods only consider information regarding the full energy peaks of the gamma-ray spectrum and require long recording times,which lead to long response *** this paper,a novel identification method using the event mode sequence(EMS)information of target radionuclides is *** EMS of a target radionuclide and natural background radiation were established as two different probabilistic models and a decision function based on Bayesian inference and sequential testing was *** proposed detection scheme individually processes each *** a photon is detected and accepted,the corresponding posterior probability distribution parameters are estimated using Bayesian inference and the decision function is ***,value of the decision function is compared to preset detection thresholds to obtain a detection ***ments on different target radionuclides(137Cs and 60Co)were *** count rates of the regions of interest(ROI)in the backgrounds between[651,671],[1154,1186],and[1310,1350]keV were 2.35,5.14,and 0.57 CPS,*** experimental results demonstrate that the average detection time was 6.0 s for 60Co(with an activity of 80400 Bq)at a distance of 60 cm from the *** average detection time was 7 s for 137Cs(with an activity of 131000 Bq)at a distance of 90 cm from the *** results demonstrate that the proposed method can detect radioactive substances with low activity.

关键词： Natural radiation Nuclide identification Sequential testing Nuclear safety

Noise level estimation method with application to EMD-based signal denoising

在线全文

学校读者我要写书评

暂无评论

Journal of Systems engineering and Electronics 2016年第4期27卷 763-771页

作者： Xiaoyu Li Jing Jin Yi Shen Yipeng Liu School of Astronautics Harbin Institute of Technology college of Information engineering Zhejiang University of Technology

This paper proposes a new signal noise level estimation approach by local regions. The estimated noise variance is applied as the threshold for an improved empirical mode decomposition（EMD） based signal denoising method. The proposed estimation method can effectively extract the candidate regions for the noise level estimation by measuring the correlation coefficient between noisy signal and a Gaussian filtered signal. For the improved EMD based method, the situation of decomposed intrinsic mode function（IMFs） which contains noise and signal simultaneously are taken into account. Experimental results from two simulated signals and an X-ray pulsar signal demonstrate that the proposed method can achieve better performance than the conventional EMD and wavelet transform（WT） based denoising methods.

关键词： signal denoising empirical mode decomposition(EMD) Gaussian filter correlation coefficient noise level estimation

On-line Dynamic Model Correction Based Fault Diagnosis in Chemical Processes

在线全文

学校读者我要写书评

暂无评论

过程工程学报 2007年第5期7卷 952-959页

作者：田文德孙素莉 college of Chemical engineering Qingdao University of Science & Technology School of Polymer Science and engineering Qingdao University of Science & Technology

A novel fault detection and diagnosis method was proposed, using dynamic simulation to monitor chemical process and identify faults when large tracking deviations occur. It aims at parameter failures, and the parameters are updated via on-line correction. As it can predict the trend of process and determine the existence of malfunctions simultaneously, this method does not need to design problem-specific observer to estimate unmeasured state variables. Application of the proposed method is presented on one water tank and one aromatization reactor, and the results are compared with those from the traditional method.

关键词：在线动态模型故障诊断化学过程修正参数估计动态模拟

Design and dynamic characteristic prediction of air-powered twin-rotor piston engine

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2015年第12期22卷 4585-4596页

作者：徐海军张雷潘存云张湘 college of Mechatronic engineering and Automation National University of Defense Technology

A novel air-powered twin-rotor piston engine(ATPE) utilizing a differential velocity driving mechanism to achieve a high output torque was *** ATPE had eight separated rotary cylinders which can dynamically enlarge the engine displacement as a result of the special driving mechanism,which was named dynamic volume *** mathematical model of ATPE comprising a dynamic model and a thermodynamic model was established under the assumption of no mechanical *** model was numerically simulated in *** results show that shortage of low output torque confusing traditional air-powered engines can be *** average output torque sharply increases to 100 N·m,which is about three times that of traditional air-powered engines with equal cylinder displacement under the pressure of 0.6 MPa at 480 r/*** can be used to drive vehicles directly without transmission box,therefore the energy transfer efficiency of ATPE can be ***,benefitting from the novel gas distribution system,the engine shows an ability in self-adjusting under different *** arrangements of air ports automatically adjust the open interval of air ports according to the load,which may simplify the speed control system.

关键词： air-powered engine twin-rotor piston engine numerical simulation dynamic characteristics

Evolutionary Trajectory Planning for an Industrial Robot

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2010年第2期7卷 190-198页

作者： R.Saravanan S.Ramabalan C.Balamurugan A.Subash Department of Mechanical engineering Bannariamman Institute of Technology Department of Mechanical engineering J.J. College of Engineering and Technology Department of Production engineering J.J.College of Engineering and Technology Department of Mechanical engineering J.J.College of Engineering and Technology

This paper presents a novel general method for computing optimal motions of an industrial robot manipulator （AdeptOne XL robot） in the presence of fixed and oscillating obstacles. The optimization model considers the nonlinear manipulator dynamics, actuator constraints, joint limits, and obstacle avoidance. The problem has 6 objective functions, 88 variables, and 21 constraints. Two evolutionary algorithms, namely, elitist non-dominated sorting genetic algorithm （NSGA-II） and multi-objective differential evolution （MODE）, have been used for the optimization. Two methods （normalized weighting objective functions and average fitness factor） are used to select the best solution tradeoffs. Two multi-objective performance measures, namely solution spread measure and ratio of non-dominated individuals, are used to evaluate the Pareto optimal fronts. Two multi-objective performance measures, namely, optimizer overhead and algorithm effort, are used to find the computational effort of the optimization algorithm. The trajectories are defined by B-spline functions. The results obtained from NSGA-II and MODE are compared and analyzed.

关键词： Multi-objective optimal trajectory planning oscillating obstacles elitist non-dominated sorting genetic algorithm (NSGA-II) multi-objective differential evolution (MODE) multi-objective performance metrics.

Algebraic solution of differential geometric guidance command and time delay control

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2015年第3期58卷 565-573页

作者： LI KeBo CHEN Lei TANG GuoJin college of Aerospace Science and engineering National University of Defense Technology

According to the three-dimensional geometry of the engagement,the explicit algebraic expression of differential geometric guidance command(DGGC)is *** with the existing solutions,the algebraic solution is much simpler and better for the further research of the characteristics of *** delay control(TDC)is a useful method to tackle the uncertainty problem of a control *** on TDC,taking the target maneuvering acceleration as a disturbance,the estimation algorithm of the target maneuvering acceleration is presented,which can be introduced in DGGC to improve its ***,the augmented DGGC(ADGGC)is *** numerical simulation of intercepting a high maneuvering target is conducted to demonstrate the effectiveness of ADGGC.

关键词： differential geometric guidance command explicit expression time delay control target acceleration estimation

Effect of specifically-adsorbed polysulfides on the electron transfer kinetics of sodium metal anodes

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2022年第11期31卷 26-33,I0003页

作者： Huazhao Yang Yu Li Xianxian Zhou Xiaotao Ma Donghong Duan Shibin Liu college of Chemical engineering and technology Taiyuan University of TechnologyTaiyuan 030024ShanxiChina

Room-temperature sodium-sulfur(RT Na-S)batteries hold great promise for large-scale energy storage applications owing to the high energy density and earth-abundance of Na and ***,the dissolution and migration of sodium polysulfides,uncontrollable Na dendrite growth,and the lack of studies on Na electrodeposition kinetics have hindered the development of these ***,we reveal the mechanism of sodium polysulfides on the Na plating/stripping kinetics using a three-electrode ***,the kinetic behavior deviates from the commonly supposed Butler-Volmer model,which is well described by the Marcus *** addition,the specific adsorption of polysulfides on the sodium electrode surface is a key factor influencing the ***-order polysulfides(S_(8)^(2-)and S_(6)^(2-))exhibit distinct specific adsorption behaviors because of their high adsorption energies compared to lower-order polysulfides(S_(4)^(2-)and S_(2)^(2-)).The electrostatic effect caused by specific adsorption can accelerate the kinetics,whereas the blocking effect can slow the ***,this competitive relationship enables low concentrations of high-order polysulfides to stimulate *** implies that a weak shuttle effect is beneficial for obtaining a stable Na deposition in RT Na-S *** in-depth understanding of the Na electrodeposition kinetics provides beneficial clues for future metal sodium/electrolyte interface designs.

关键词： Sodium anode kinetics Polysulfides Specific adsorption The electrostatic effect The blocking effect

锆/铪氧簇中硫原子导向的金属-配体协同高效催化胺氧化反应

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2024年第4期69卷 492-501页

作者：孙胜男牛倩林焦敏何莉玲石景文黄青刘江兰亚乾 School of Chemistry South China Normal UniversityGuangzhou 510006China college of Materials Science and engineering Nanjing Forestry UniversityNanjing 210037China School of Chemistry and Materials Science Nanjing Normal UniversityNanjing 210023China

The performance applications(e.g.,photocatalysis)of zirconium(Zr)and hafnium(Hf)based complexes are greatly hindered by the limited development of their structures and the relatively inert metal *** this work,we constructed two ultrastable Zr/Hf-based clusters(Zr_(9)-TC4A and Hf_(9)-TC4A)using hydrophobic 4-tert-butylthiacalix[4]arene(H4TC4A)ligands,in which unsaturated coordinated sulfur(S)atoms on the TC4A^(4-)ligand can generate strong metal–ligand synergy with nearby active metal Zr/Hf *** a result,these two functionalized H4TC4A ligands modified Zr/Hf-oxo clusters,as catalysts for the amine oxidation reaction,exhibited excellent catalytic activity,achieving very high substrate conversion(>99%)and product selectivity(>90%).Combining comparative experiments and theoretical calculations,we found that these Zr/Hf-based cluster catalysts accomplish efficient amine oxidation reactions through synergistic effect between metals and ligands:(i)The photocatalytic benzylamine(BA)oxidation reaction was achieved by the synergistic effect of the dual active sites,in which,the naked S sites on the TC4A^(4-)ligand oxidize the BA by photogenerated hole and oxygen molecules are reduced by photogenerated electrons on the metal active sites;(ii)in the aniline oxidation reaction,aniline was adsorbed by the bare S sites on ligands to be closer to metal active sites and then oxidized by the oxygen-containing radicals activated by the metal sites,thus completing the catalytic reaction under the synergistic catalytic effect of the proximity metal–*** this work,the Zr/Hf-based complexes applied in the oxidation of organic amines have been realized using active S atom-directed metal–ligand synergistic catalysis and have demonstrated very high reactivity.

关键词： Zirconium/hafnium-oxo clusters Amine oxidation reaction Photocatalytic reaction Synergistic catalysis