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RS码的Step-by-step译码及软件实现
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作者 孙军英 张淑娥 冯冀宁 《电力系统通信》 2005年第9期57-59,共3页
RS码以其强大的纠正随机错误和突发错误的能力,被广泛地应用于各种数字通信系统中。其译码算法是实现RS码的核心,Step-by-step算法与传统的译码算法相比,不用计算错误位置多项式,可以大大地节省译码时间。文章在分析RS码的基本原理及Ste... RS码以其强大的纠正随机错误和突发错误的能力,被广泛地应用于各种数字通信系统中。其译码算法是实现RS码的核心,Step-by-step算法与传统的译码算法相比,不用计算错误位置多项式,可以大大地节省译码时间。文章在分析RS码的基本原理及Step-by-step译码算法的基础上,介绍了一种用软件来实现Step-by-step译码算法的方案,并且给出了流程图。 展开更多
关键词 RS码 MDS码 step-by-step译码算法 错误位置多项式
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Effects of curing under step-by-step load on mechanical and deformation properties of cemented gangue backfill column 被引量:9
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作者 GUO Yu-xia RAN Hong-yu +3 位作者 FENG Guo-rui DU Xian-jie QI Ting-ye WANG Ze-hua 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第11期3417-3435,共19页
A step-by-step load was utilized to mimic the load history of the backfill column in the in-situ curing process.The inner damage of the specimen during curing and uniaxial compressive testing was monitored by electric... A step-by-step load was utilized to mimic the load history of the backfill column in the in-situ curing process.The inner damage of the specimen during curing and uniaxial compressive testing was monitored by electrical resistivity and ultrasonic equipment.Results show that:1)Uniaxial compressive strength(UCS)and elastic modulus(EM)of the samples curing under pressure are higher than those of the control samples without pressure,ranging in ratio from 0.5%to 20.2%and 7.1%to 52.3%,respectively,and are influenced by the initial loading age(ILA)and stress strength ratio(SSR).The SSR during curing should not exceed 80%.2)The earlier the ILA is,the higher the total strain becomes.The higher the SSR applies,the larger the total strain gets.The creep strain increases with the increase of SSR and can be described by Burger’s viscoelastic creep model.When SSR is less than 80%,the earlier the ILA is,the smaller the creep strain becomes after the last step-loading.3)The stability of the early age backfill column under pressure can be monitored based on the change of ultrasonic pulse velocity(UPV)and electrical resistivity. 展开更多
关键词 cemented gangue backfill column curing under step-by-step load compressive strength elastic modulus deformation electrical resistivity
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Application of a Step-by-Step Fingerprinting Identification Method on a Spilled Oil Accident in the Bohai Sea Area 被引量:4
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作者 SUN Peiyan GAO Zhenhui +4 位作者 CAO Lixin WANG Xinping ZHOU Qing ZHAO Yuhui LI Guangmei 《Journal of Ocean University of China》 SCIE CAS 2011年第1期35-41,共7页
In recent years,oil spill accidents occur frequently in the marine area of China.Finding out the spilled oil source is a key step in the relevant investigation.In this paper,a step-by-step fingerprinting identificatio... In recent years,oil spill accidents occur frequently in the marine area of China.Finding out the spilled oil source is a key step in the relevant investigation.In this paper,a step-by-step fingerprinting identification method was used in a spilled oil accident in the Bohai Sea in 2002.Advanced chemical fingerprinting and data interpretation techniques were used to characterize the chemical composition and determine the possible sources of two spilled oil samples.The original gas chromatography -flame ionization detec-tion (GC-FID) chromatogram of saturated hydrocarbons was compared.The gas chromatography-mass spectrometry (GC/MS) chromatograms of aromatic hydrocarbons terpane and sterane,n-alkane and poly-aromatic hydrocarbons (PAHs) were analyzed.The correlation analysis on diagnostic ratios was performed with Student’s t-test.It is found that the oil fingerprinting of the spilled oil (designated as sz1) from the polluted sand beach was identical with the suspected oil (designated as ky1) from a nearby crude oil refinery factory.They both showed the fingerprinting character of mixed oil.The oil fingerprinting of the spilled oil (designated as ms1) collected from the port was significantly different from oil ky1 and oil sz1 and was with a lubricating oil fingerprint character.The identification result not only gave support for the spilled oil investigation,but also served as an example for studying spilled oil accidents. 展开更多
关键词 step-by-step fingerprinting identification saturated hydrocarbons poly-aromatic hydrocarbons biomarkers Student'st-test
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3D Step-by-step inversion strategy for audio magnetotellurics data based on unstructured mesh 被引量:3
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作者 Cheng San Zhang Zhi-Yong +5 位作者 Zhou Feng Li Man Chen Hui Shi Fu-Sheng Huang Lin-Pin Li Yong 《Applied Geophysics》 SCIE CSCD 2021年第3期375-385,433,共12页
A three-dimensional(3D)step-by-step inversion strategy for audio magnetotellurics(AMT)is investigated in this study.The objective function is minimized by iteratively solving the Gauss-Newton normal equation,and the i... A three-dimensional(3D)step-by-step inversion strategy for audio magnetotellurics(AMT)is investigated in this study.The objective function is minimized by iteratively solving the Gauss-Newton normal equation,and the inversion region is discretized with unstructured tetrahedral elements.The inversion proceeds step-by-step from a coarse mesh to a fine mesh.In the inversion iteration process,a mesh is adaptively optimized according to the spatial gradient information about the model resistivity to fine delineate the boundaries of abnormal bodies.In the early stage of inversion execution,a coarse mesh is used for inversion,and the inversion stability is improved by reducing the number of inversion elements.In addition,mesh refinement is performed in the iterative inversion process.The inversion results obtained from the previous mesh are used as the reference and initial models for the next mesh iterative inversion.The step-by-step inversion strategy can ensure that the inversion is performed in the correct direction,improving the inversion stability and results gradually.Synthetic results show that the step-by-step inversion strategy with a Gauss-Newton method for 3D AMT inversion is stable and reliable,which lays a foundation for further practical 3D AMT data inversion. 展开更多
关键词 Audio magnetotellurics 3D inversion step-by-step inversion Gauss-Newton unstructured gird
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Step-by-step external fixation of unstable pelvis with separate anterior and posterior modules
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作者 Ivan Viktorovich Borozda Nikolay Alexandrovich Ganzhurov +2 位作者 Alexander Alexandrovich Kapustyansky Roman Valerievich Nikolaev Kirill Sergeevich Golokhvast 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2016年第2期164-172,共9页
Objective: To evaluate the treatment outcomes of patients with pelvic ring injury by applying step-by-step external pelvic fixation and circular external fixation device.Methods: A total of 28 patients suffering from ... Objective: To evaluate the treatment outcomes of patients with pelvic ring injury by applying step-by-step external pelvic fixation and circular external fixation device.Methods: A total of 28 patients suffering from disintegrated pelvic ring injury are involved in the study. Fourteen patients(the treatment group) underwent step-by-step external pelvic fixation by applying anterior(anti-shock) and posterior modules. For the rest 14 patients(the experimental group), the osteosynthesis were conducted by means of a circular external fixation device. The long-term outcomes were evaluated in a year after the injury.Results: The residual deformity of 5(4–7) mm was observed in 10 patients(71.4%) from the experimental group. In the treatment group, the residual deformity was evident only in 4(28.6%) cases being 2.5(2–3) mm(P = 0.000 319) on the average. The functional result(according to the Majeed scale) was statistically better in the treatment group(P = 0.000 319). Nine(64.3%) and five(35.7%) patients in treatment group showed excellent and positive results, respectively. The excellent result was demonstrated by 3patients(21.4%) of the experimental group, the positive outcomes were observed in 6 cases(42.9%) and the unsatisfactory one was displayed by 1 patient(7.1%) of the same group.Conclusions: The modular approach applied is the advantage of the transosseous osteosynthesis allowing for a separate anterior(anti-shock) fixation and final posterior reposition of the pelvic ring preceded by the stabilization of vital functions. The above mentioned method gives an opportunity to increase the amount of techniques applied for the pelvic external fixation in polytrauma cases. 展开更多
关键词 UNSTABLE PELVIC injuries External fixation Separate step-by-step REPOSITION TRAUMATOLOGY
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A STEP-BY-STEP INTEGRAL METHOD FOR ACTIVELY CONTROLLED STRUCTURES
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作者 CAI Guo-ping(蔡国平) +1 位作者 HUANG Jin-zhi(黄金枝) 《Journal of Shanghai Jiaotong university(Science)》 EI 2002年第2期144-146,共3页
A new active control method was proposed, in which the analytical control law was deduced by using a step by step integral method to differential equation of motion under the condition of static error being zero. This... A new active control method was proposed, in which the analytical control law was deduced by using a step by step integral method to differential equation of motion under the condition of static error being zero. This control law is terse in mathematical expression and convenient for practical use. The simulation results demonstrate that the proposed method can provide much more remarkable peak response reduction of seismically excited structures than the classical LQR method. 展开更多
关键词 step-by-step INTEGRAL static error control LAW linear QUADRATIC regular(LQR)
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COORDINATION OF THE MOTION PARAMETERS WITHIN STEP-BY-STEP INTEGRATION FOR DYNAMIC EQUATION
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作者 HuangQingfeng WangQuanfeng HuYunchang 《Acta Mechanica Solida Sinica》 SCIE EI 2004年第1期27-31,共5页
A method is presented that coordinates the calculation of the displacement, velocity and acceleration of structures within the time-steps of different types of step-by-step integration. The dynamic equation is solved ... A method is presented that coordinates the calculation of the displacement, velocity and acceleration of structures within the time-steps of different types of step-by-step integration. The dynamic equation is solved using an energy equation and the calculating data of the original method. The method presented is better than the original method in terms of calculating postulations and is in better conformity with the system's movement. Take the Wilson-θ method as an example. By using the coordination process, the calculation precision has been greatly im proved (reducing the errors by approximately 90% ), and the greater part of overshooting of the calculation result has been eliminated. The study suggests that the mal-coordination of the motion parameters within the time-step is the major factor that contributes to the result errors of step-by-step integration for the dynamic equation. 展开更多
关键词 step-by-step integration motion parameters COORDINATION dynamic equation en- ergy equation
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Simple Program for Step-by-Step Time Integration in Chemical Kinetics, Applied to Simple Model for Hydrogen Combustion
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作者 Panagis G. Papadopoulos Christopher G. Koutitas +2 位作者 Panos D. Kiousis Christos G. Karayannis Yannis N. Dimitropoulos 《Open Journal of Physical Chemistry》 2020年第2期99-116,共18页
A simple algorithm is proposed for step-by-step time integration of stiff ODEs in Chemical Kinetics. No predictor-corrector technique is used within each step of the algorithm. It is assumed that species concentration... A simple algorithm is proposed for step-by-step time integration of stiff ODEs in Chemical Kinetics. No predictor-corrector technique is used within each step of the algorithm. It is assumed that species concentrations less than 10-6 mol·L-1 do not activate any chemical reaction. So, within each step, the time steplength Δt of the algorithm is determined from the fastest reaction rate maxR by the formula Δt = 10-6mol·L-1/max R. All the reversible elementary reactions occur simultaneously;however, by a simple book-keeping technique, the updating of species concentrations, within each step of the algorithm, is performed within each elementary reaction separately. The above proposed simple algorithm for Chemical Kinetics is applied to a simple model for hydrogen combustion with only five reversible elementary reactions (Initiation, Propagation, First and Second Branching, Termination by wall destruction) with six species (H2, O2, H, O, HO, H2O). These five reversible reactions are recommended in the literature as the most significant elementary reactions of hydrogen combustion [1] [2]. Based on the proposed here simple algorithm for Chemical Kinetics, applied to the global mechanism of proposed five reversible elementary reactions for hydrogen combustion, a simple and short computer program has been developed with only about 120 Fortran instructions. By this proposed program, the following are obtained: 1) The total species concentration of hydrogen combustion, starting from the sum of initial reactants concentrations [H2] + [O2], gradually diminishes, due to termination reaction by wall destruction, and tends to the final concentration of the product [H2O], that is to the 2/3 of its initial value, in accordance to the established overall stoichiometric reaction of hydrogen combustion 2H2 + O2 → 2H2O. 2) Time-histories for concentrations of main species H2, O2, H, H2O of hydrogen combustion, in explosion and equilibrium regions, obtained by the proposed program, are compared to corresponding ones obtained by accurate computational studies of [3]. 3) In the first step of the algorithm, the only nonzero species concentrations are those of reactants [H2], [O2]. So, the maximum reaction rate is that of the forward initiation reaction max R = Rif = kif[H2] [O2], where the rate constant kif is very slow. Thus, the first time steplength Δt1 = 10-6mol·L-1/max R results long in sec. After the first step, the sequences of all the following Δt’s are very short, in μsec. So, the first time steplength Δt1 can be considered as ignition delay time. 4) It is assumed that explosion corresponds to ignition delay time Δt1 t1 = 10 sec., can be considered as explosion limit curve. This curve is compared to the corresponding one obtained by the accurate computational studies of [2]. 展开更多
关键词 Chemical KINETICS step-by-step Time Integration ELEMENTARY REACTIONS Hydrogen Combustion IGNITION DELAY Explosion
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The step-by-step CFD design method of pressure-compensating emitter
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作者 Wei Zhengying 《Engineering Sciences》 EI 2013年第1期62-67,77,共7页
In order to improve the design and research and development (R & D) efficiency of the pressure- compensating drip irrigation emitter,a step-by-step computational fluid dynamics (CFD) design method was proposed bas... In order to improve the design and research and development (R & D) efficiency of the pressure- compensating drip irrigation emitter,a step-by-step computational fluid dynamics (CFD) design method was proposed based on CFD theory combined with the finite element method. By analyzing its hydraulic performance through the step-by-step CFD method,the prediction pressure-flow curve(p-Q curve) of the pressure-compensating emitter was obtained. Then the test samples were fabricated using rapid prototype and manufacturing(RP & M) technology. The emitters' hydraulic performance experiment was carried out and the experimental p-Q curve was obtained. The step-by-step CFD design method was verified by comparing the experimental p-Q curve with the prediction values,which showed that the prediction values met the experimental results well within the normal range of the emitter's working pressure. On this basis,the effect of the emitter structure on its pressure-compensating performance was studied,which showed that the height of the pressure-compensating region had significant effects on the emitter's pressure-compensating performance. Series products of the pressure-compensating emitter could be designed by changing the region's height. 展开更多
关键词 pressure-compensating drip irrigation emitter step-by-step CFD hydraulic performance experiment
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Distributed Step-by-step Finite-time Consensus Design for Battery Energy Storage Devices with Droop Control 被引量:2
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作者 Yalin Zhang Yunzhong Song Shumin Fei 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2023年第5期1893-1904,共12页
As all generators are distributed in different areas among large scale power systems,the cooperative manipulation of the multi-generator system cannot operate well without consideration of the distance information of ... As all generators are distributed in different areas among large scale power systems,the cooperative manipulation of the multi-generator system cannot operate well without consideration of the distance information of the generators.A distributed step-by-step finite-time consensus scheme for the heterogeneous battery energy storage system(BESS)is proposed in this paper,where the coordinated consensus can come into reality within a limited time,which is appealing for the electrical engineering community.To be concrete,at first,all BESSs are classified into several clusters according to their locations,and in each cluster,there is an active leader in charge of information receiving from outside.Then,in order to coordinate the multi BESSs,five inputs,which are function oriented,were used to achieve energy level balancing,active/reactive power sharing,and the consensus of voltage and frequency of the multi BESSs.Furthermore,the frequency and voltage restoration to the nominal values of the main grid were made possible by the introduction of a virtual leader,which is actually an external leader.Compared with the centralized methods,this control scheme is entirely distributed,and each BESS only utilizes the information of its own and its neighbors.In addition,this control is robust to the load perturbation and the plug-and-play of the communication topology.Finally,some simulation experiments are executed on the modified IEEE 57-bus system to verify the suggested scheme. 展开更多
关键词 Battery energy storage system distributed cooperative control finite-time consensus multi-agent system step-by-step consensus
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A step-by-step multiple stimuli-responsive metal-phenolic network prodrug nanoparticles for chemotherapy 被引量:2
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作者 Xiaoqing Yi Weijia Zeng +7 位作者 Cui Wang Ying Chen Liangyuan Zheng Xinlin Zhu Yuqiu Ke Xiaoyan He Ying Kuang Qitong Huang 《Nano Research》 SCIE EI CSCD 2022年第2期1205-1212,共8页
Currently,chemotherapy is the main clinical therapy of tumors.Depressingly,most chemotherapeutic drugs such as doxorubicin and paclitaxel(PTX)have poor water solubility,leading to low bioavailability and serious side ... Currently,chemotherapy is the main clinical therapy of tumors.Depressingly,most chemotherapeutic drugs such as doxorubicin and paclitaxel(PTX)have poor water solubility,leading to low bioavailability and serious side effects.Till now,although a variety of nanoparticulate drug delivery systems have been designed to ameliorate the above disadvantage of chemotherapy drugs,their application is still severely limited due to the complex preparation,poor stability,low drug loading,and premature drug release.Herein,a metal phenolic network-based drug delivery system with superior stability,satisfactory drug loading capacity,good biocompatibility,reduced undesired premature release,and excellent anti-tumor ability has been established for achieving step-by-step multiple stimuli-responsive drug delivery.Firstly,the redox-responsive dimeric paclitaxel(diPTX)prodrug was synthesized.Then diPTX@Fe&tannic acid(diPTX@Fe&TA)complex nanoparticles with satisfactory PTX loading capacity were obtained by deposition of Fe&TA network complex on the nanocore of diPTX rapidly with a simple method.The diPTX@Fe&TA nanoparticles have a hydrodynamic diameter of 152.6±1.2 nm,long-term colloidal stability,and high PTX loading content of 24.7%.Besides,diPTX@Fe&TA could expose to the acidic lysosomal environment and the reduction cytoplasmic environment continuously,resulting in the sequential release of diPTX and PTX when it was phagocytosed by tumor cells.Meanwhile,PTX showed almost no release under physiological condition(pH 7.4),which effectively inhibited the undesirable premature release of PTX.More importantly,diPTX@Fe&TA could suppress the growth of tumor effectively in vivo,along with negligible toxicity for organs.This work developed a simple and novel approach for the construction of a stepwise multiple stimuli-responsive drug delivery system with superior stability and satisfactory drug loading capacity to inhibit tumor growth effectively. 展开更多
关键词 drug delivery step-by-step multiple stimuli-responsive metal-phenolic network superior stability
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A pipelined Reed-Solomon decoder based on a modified step-by-step algorithm 被引量:1
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作者 Xing-ru PENG Wei ZHANG Yan-yan LIU 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2016年第9期954-961,共8页
We propose a pipelined Reed-Solomon(RS) decoder for an ultra-wideband system using a modified stepby-step algorithm. To reduce the complexity, the modified step-by-step algorithm merges two cases of the original algor... We propose a pipelined Reed-Solomon(RS) decoder for an ultra-wideband system using a modified stepby-step algorithm. To reduce the complexity, the modified step-by-step algorithm merges two cases of the original algorithm. The pipelined structure allows the decoder to work at high rates with minimum delay. Consequently, for RS(23,17) codes, the proposed architecture requires 42.5% and 24.4% less area compared with a modified Euclidean architecture and a pipelined degree-computationless modified Euclidean architecture, respectively. The area of the proposed decoder is 11.3% less than that of the previous step-by-step decoder with a lower critical path delay. 展开更多
关键词 Reed-Solomon codes step-by-step algorithm ULTRA-WIDEBAND Pipelined structure
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纠两个错的二进制BCH码新译码算法 被引量:2
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作者 孟凡刚 李万顺 刘玉君 《信息工程大学学报》 2002年第4期10-12,共3页
对码长n=2m-1纠两个错误的二进制BCH码,本文介绍了一种新的step by step译码算法。译码算法能直接确定接收的比特是否正确而不需要知道接收矢量的错误数目,也不需要知道相应的错误位置多项式。基于这种译码算法的译码器的优点在于占用... 对码长n=2m-1纠两个错误的二进制BCH码,本文介绍了一种新的step by step译码算法。译码算法能直接确定接收的比特是否正确而不需要知道接收矢量的错误数目,也不需要知道相应的错误位置多项式。基于这种译码算法的译码器的优点在于占用硬件资源最少,实现简单快速。此外,这种译码方法特别适合于长码。 展开更多
关键词 二进制BCH码 循环码 step-by-step译码算法 纠错码 译码原理 纠错能力
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An Improved Adaptive Multi-way Principal Component Analysis for Monitoring Streptomycin Fermentation Process 被引量:8
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作者 何宁 王树青 谢磊 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2004年第1期96-101,共6页
Multi-way principal component analysis (MPCA) had been successfully applied to monitoring the batch and semi-batch process in most chemical industry. An improved MPCA approach, step-by-step adaptive MPCA (SAMPCA), usi... Multi-way principal component analysis (MPCA) had been successfully applied to monitoring the batch and semi-batch process in most chemical industry. An improved MPCA approach, step-by-step adaptive MPCA (SAMPCA), using the process variable trajectories to monitoring the batch process is presented in this paper. It does not need to estimate or fill in the unknown part of the process variable trajectory deviation from the current time until the end. The approach is based on a MPCA method that processes the data in a sequential and adaptive manner. The adaptive rate is easily controlled through a forgetting factor that controls the weight of past data in a summation. This algorithm is used to evaluate the industrial streptomycin fermentation process data and is compared with the traditional MPCA. The results show that the method is more advantageous than MPCA, especially when monitoring multi-stage batch process where the latent vector structure can change at several points during the batch. 展开更多
关键词 step-by-step adaptive multi-way principal component analysis batch monitoring streptomycin fermentation static process monitoring
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An Overview and Experimental Study of Learning-Based Optimization Algorithms for the Vehicle Routing Problem 被引量:5
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作者 Bingjie Li Guohua Wu +2 位作者 Yongming He Mingfeng Fan Witold Pedrycz 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2022年第7期1115-1138,共24页
The vehicle routing problem(VRP)is a typical discrete combinatorial optimization problem,and many models and algorithms have been proposed to solve the VRP and its variants.Although existing approaches have contribute... The vehicle routing problem(VRP)is a typical discrete combinatorial optimization problem,and many models and algorithms have been proposed to solve the VRP and its variants.Although existing approaches have contributed significantly to the development of this field,these approaches either are limited in problem size or need manual intervention in choosing parameters.To solve these difficulties,many studies have considered learning-based optimization(LBO)algorithms to solve the VRP.This paper reviews recent advances in this field and divides relevant approaches into end-to-end approaches and step-by-step approaches.We performed a statistical analysis of the reviewed articles from various aspects and designed three experiments to evaluate the performance of four representative LBO algorithms.Finally,we conclude the applicable types of problems for different LBO algorithms and suggest directions in which researchers can improve LBO algorithms. 展开更多
关键词 End-to-end approaches learning-based optimization(LBO)algorithms reinforcement learning step-by-step approaches vehicle routing problem(VRP)
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Is There Any Correlation Between Landscape Characteristics and Total Nitrogen in Wetlands Receiving Agricultural Drainages?
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作者 YU Han WANG Xiaodong +5 位作者 CHU Lijuan WANG Guodong SUN Guangzhi SUN Mingyang WANG Jingyu JIANG Ming 《Chinese Geographical Science》 SCIE CSCD 2019年第4期712-724,共13页
In the case of increasing fragmentation of wetlands, the study of the relationship between wetland landscape characteristics and total nitrogen(TN) in water is of great significance to reveal the mechanism of wetland ... In the case of increasing fragmentation of wetlands, the study of the relationship between wetland landscape characteristics and total nitrogen(TN) in water is of great significance to reveal the mechanism of wetland water purification. Taking the Naoli River(NR) wetlands in Northeast China as the research object, 10 uniformly distributed sampling sites in the study area were sampled in August 2015 to test the TN concentration and interpret the images of NR wetlands in the same period. Taking the sampling site as the control point, the whole wetlands were divided into 10 regions, and the landscape index of each region was extracted. In order to reveal whether the landscape characteristics are related to the TN concentration in the wetlands water body, the landscape index and the TN concentration in the control point water body were analyzed by correlation analysis, step-by-step elimination analysis and path analysis to reveal whether the landscape characteristics are related to the TN concentration under wetlands receiving agricultural drainages. The results showed that the correlation coefficients between four area indexes or eight shape indexes and TN concentration did not reach a significant correlation level(P > 0.05), indicating that TN removal was not only determined by a single landscape index. The path coefficient of edge density(ED) index is –0.41, indicating that wetland patch connectivity is the primary factor of TN removal, and there is no relationship between the larger patch area and the higher TN removal. The removal of TN in wetlands is restricted by the synergistic effect of landscape area and shape characteristics. 展开更多
关键词 Naoli River WETLANDS TOTAL nitrogen removal spatial pattern step-by-step ELIMINATION analysis AGRICULTURAL drainages
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EFFECTIVE SOLUTION METHOD OF CHEMICAL REACTION KINETICS WITH DIFFUSE
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作者 吕和祥 邱崑玉 陈建峰 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第4期435-442,共8页
The time integration method with four-order accuracy, self-starting and implicit for the diffuse chemical reaction kinetics equation or the transient instantaneous temperature filed equation was presented. The example... The time integration method with four-order accuracy, self-starting and implicit for the diffuse chemical reaction kinetics equation or the transient instantaneous temperature filed equation was presented. The examples show that both accuracy and stability are better than Runge-Kutta method with four-order. The coefficients of the equation are stored with sparse matrix pattern, so an algorithm is presented which combines a compact storage scheme with reduced computation cost. The computation of the competitive and consecutive reaction in the rotating packed bed, taken as examples, shows that the method is effective. 展开更多
关键词 step-by-step integration DIFFUSE chemical reaction kinetics rotating packedbed MICRO-MIXING
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DIRECT INTEGRATION METHODS WITH INTEGRAL MODEL FOR DYNAMIC SYSTEMS
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作者 吕和祥 于洪洁 裘春航 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2001年第2期173-179,共7页
A new approach which is a direct integration method with integral model (DIM-IM) to solve dynamic governing equations is presented. The governing equations ore integrated into the integral equations. An algorithm with... A new approach which is a direct integration method with integral model (DIM-IM) to solve dynamic governing equations is presented. The governing equations ore integrated into the integral equations. An algorithm with explicit and predict-correct and self-starting and fourth-order accuracy to integrate the integral equations is given. Theoretical analysis and numerical examples shaw that DIM-IM described in this paper suitable for strong nonlinear and non-conservative system have higher accuracy than central difference, Houbolt, Newmark and Wilson-Theta methods. 展开更多
关键词 numerical integration step-by-step integration NONLINEAR integral equation
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Extensions of nonlinear error propagation analysis for explicit pseudodynamic testing
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作者 Shuenn-Yih Chang 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2009年第1期77-86,共10页
Two important extensions of a technique to perform a nonlinear error propagation analysis for an explicit pseudodynamic algorithm (Chang, 2003) are presented. One extends the stability study from a given time step t... Two important extensions of a technique to perform a nonlinear error propagation analysis for an explicit pseudodynamic algorithm (Chang, 2003) are presented. One extends the stability study from a given time step to a complete step-by-step integration procedure. It is analytically proven that ensuring stability conditions in each time step leads to a stable computation of the entire step-by-step integration procedure. The other extension shows that the nonlinear error propagation results, which are derived for a nonlinear single degree of freedom (SDOF) system, can be applied to a nonlinear multiple degree of freedom (MDOF) system. This application is dependent upon the determination of the natural frequencies of the system in each time step, since all the numerical properties and error propagation properties in the time step are closely related to these frequencies. The results are derived from the step degree of nonlinearity. An instantaneous degree of nonlinearity is introduced to replace the step degree of nonlinearity and is shown to be easier to use in practice. The extensions can be also applied to the results derived from a SDOF system based on the instantaneous degree of nonlinearity, and hence a time step might be appropriately chosen to perform a pseudodynamic test prior to testing. 展开更多
关键词 nonlinear error propagation explicit pseudodynamic algorithm stability condition step-by-step integration procedure step degree of nonlinearity
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