期刊文献+
共找到3,490篇文章
< 1 2 175 >
每页显示 20 50 100
A real-time intelligent lithology identification method based on a dynamic felling strategy weighted random forest algorithm
1
作者 Tie Yan Rui Xu +2 位作者 Shi-Hui Sun Zhao-Kai Hou Jin-Yu Feng 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1135-1148,共14页
Real-time intelligent lithology identification while drilling is vital to realizing downhole closed-loop drilling. The complex and changeable geological environment in the drilling makes lithology identification face ... Real-time intelligent lithology identification while drilling is vital to realizing downhole closed-loop drilling. The complex and changeable geological environment in the drilling makes lithology identification face many challenges. This paper studies the problems of difficult feature information extraction,low precision of thin-layer identification and limited applicability of the model in intelligent lithologic identification. The author tries to improve the comprehensive performance of the lithology identification model from three aspects: data feature extraction, class balance, and model design. A new real-time intelligent lithology identification model of dynamic felling strategy weighted random forest algorithm(DFW-RF) is proposed. According to the feature selection results, gamma ray and 2 MHz phase resistivity are the logging while drilling(LWD) parameters that significantly influence lithology identification. The comprehensive performance of the DFW-RF lithology identification model has been verified in the application of 3 wells in different areas. By comparing the prediction results of five typical lithology identification algorithms, the DFW-RF model has a higher lithology identification accuracy rate and F1 score. This model improves the identification accuracy of thin-layer lithology and is effective and feasible in different geological environments. The DFW-RF model plays a truly efficient role in the realtime intelligent identification of lithologic information in closed-loop drilling and has greater applicability, which is worthy of being widely used in logging interpretation. 展开更多
关键词 Intelligent drilling Closed-loop drilling Lithology identification random forest algorithm Feature extraction
下载PDF
Winter Wheat Yield Estimation Based on Sparrow Search Algorithm Combined with Random Forest:A Case Study in Henan Province,China
2
作者 SHI Xiaoliang CHEN Jiajun +2 位作者 DING Hao YANG Yuanqi ZHANG Yan 《Chinese Geographical Science》 SCIE CSCD 2024年第2期342-356,共15页
Precise and timely prediction of crop yields is crucial for food security and the development of agricultural policies.However,crop yield is influenced by multiple factors within complex growth environments.Previous r... Precise and timely prediction of crop yields is crucial for food security and the development of agricultural policies.However,crop yield is influenced by multiple factors within complex growth environments.Previous research has paid relatively little attention to the interference of environmental factors and drought on the growth of winter wheat.Therefore,there is an urgent need for more effective methods to explore the inherent relationship between these factors and crop yield,making precise yield prediction increasingly important.This study was based on four type of indicators including meteorological,crop growth status,environmental,and drought index,from October 2003 to June 2019 in Henan Province as the basic data for predicting winter wheat yield.Using the sparrow search al-gorithm combined with random forest(SSA-RF)under different input indicators,accuracy of winter wheat yield estimation was calcu-lated.The estimation accuracy of SSA-RF was compared with partial least squares regression(PLSR),extreme gradient boosting(XG-Boost),and random forest(RF)models.Finally,the determined optimal yield estimation method was used to predict winter wheat yield in three typical years.Following are the findings:1)the SSA-RF demonstrates superior performance in estimating winter wheat yield compared to other algorithms.The best yield estimation method is achieved by four types indicators’composition with SSA-RF)(R^(2)=0.805,RRMSE=9.9%.2)Crops growth status and environmental indicators play significant roles in wheat yield estimation,accounting for 46%and 22%of the yield importance among all indicators,respectively.3)Selecting indicators from October to April of the follow-ing year yielded the highest accuracy in winter wheat yield estimation,with an R^(2)of 0.826 and an RMSE of 9.0%.Yield estimates can be completed two months before the winter wheat harvest in June.4)The predicted performance will be slightly affected by severe drought.Compared with severe drought year(2011)(R^(2)=0.680)and normal year(2017)(R^(2)=0.790),the SSA-RF model has higher prediction accuracy for wet year(2018)(R^(2)=0.820).This study could provide an innovative approach for remote sensing estimation of winter wheat yield.yield. 展开更多
关键词 winter wheat yield estimation sparrow search algorithm combined with random forest(SSA-RF) machine learning multi-source indicator optimal lead time Henan Province China
下载PDF
Investigation of Nuclear Binding Energy and Charge Radius Based on Random Forest Algorithm
3
作者 CAI Boshuai YU Tianjun +3 位作者 LIN Xuan ZHANG Jilong WANG Zhixuan YUAN Cenxi 《原子能科学技术》 EI CAS CSCD 北大核心 2023年第4期704-712,共9页
The random forest algorithm was applied to study the nuclear binding energy and charge radius.The regularized root-mean-square of error(RMSE)was proposed to avoid overfitting during the training of random forest.RMSE ... The random forest algorithm was applied to study the nuclear binding energy and charge radius.The regularized root-mean-square of error(RMSE)was proposed to avoid overfitting during the training of random forest.RMSE for nuclides with Z,N>7 is reduced to 0.816 MeV and 0.0200 fm compared with the six-term liquid drop model and a three-term nuclear charge radius formula,respectively.Specific interest is in the possible(sub)shells among the superheavy region,which is important for searching for new elements and the island of stability.The significance of shell features estimated by the so-called shapely additive explanation method suggests(Z,N)=(92,142)and(98,156)as possible subshells indicated by the binding energy.Because the present observed data is far from the N=184 shell,which is suggested by mean-field investigations,its shell effect is not predicted based on present training.The significance analysis of the nuclear charge radius suggests Z=92 and N=136 as possible subshells.The effect is verified by the shell-corrected nuclear charge radius model. 展开更多
关键词 nuclear binding energy nuclear charge radius random forest algorithm
下载PDF
Companies’ E-waste Estimation Based on General Equilibrium The­ory Context and Random Forest Regression Algorithm in Cameroon: Case Study of SMEs Implementing ISO 14001:2015
4
作者 Gilson Tekendo Djoukoue Idriss Djiofack Teledjieu Sijun Bai 《Journal of Management Science & Engineering Research》 2023年第2期60-81,共22页
Given the challenge of estimating or calculating quantities of waste electrical and electronic equipment(WEEE)in developing countries,this article focuses on predicting the WEEE generated by Cameroonian small and medi... Given the challenge of estimating or calculating quantities of waste electrical and electronic equipment(WEEE)in developing countries,this article focuses on predicting the WEEE generated by Cameroonian small and medium enterprises(SMEs)that are engaged in ISO 14001:2015 initiatives and consume electrical and electronic equipment(EEE)to enhance their performance and profitability.The methodology employed an exploratory approach involving the application of general equilibrium theory(GET)to contextualize the study and generate relevant parameters for deploying the random forest regression learning algorithm for predictions.Machine learning was applied to 80%of the samples for training,while simulation was conducted on the remaining 20%of samples based on quantities of EEE utilized over a specific period,utilization rates,repair rates,and average lifespans.The results demonstrate that the model’s predicted values are significantly close to the actual quantities of generated WEEE,and the model’s performance was evaluated using the mean squared error(MSE)and yielding satisfactory results.Based on this model,both companies and stakeholders can set realistic objectives for managing companies’WEEE,fostering sustainable socio-environmental practices. 展开更多
关键词 Electrical and electronic equipment(EEE) Waste from electrical and electronic equipment(WEEE) General equilibrium theory random forest regression algorithm DECISION-MAKING Cameroon
下载PDF
Randomized Algorithms for Probabilistic Optimal Robust Performance Controller Design 被引量:1
5
作者 宋春雷 谢玲 《Journal of Beijing Institute of Technology》 EI CAS 2004年第1期15-19,共5页
Polynomial-time randomized algorithms were constructed to approximately solve optimal robust performance controller design problems in probabilistic sense and the rigorous mathematical justification of the approach wa... Polynomial-time randomized algorithms were constructed to approximately solve optimal robust performance controller design problems in probabilistic sense and the rigorous mathematical justification of the approach was given. The randomized algorithms here were based on a property from statistical learning theory known as (uniform) convergence of empirical means (UCEM). It is argued that in order to assess the performance of a controller as the plant varies over a pre-specified family, it is better to use the average performance of the controller as the objective function to be optimized, rather than its worst-case performance. The approach is illustrated to be efficient through an example. 展开更多
关键词 randomized algorithms statistical learning theory uniform convergence of empirical means (UCEM) probabilistic optimal robust performance controller design
下载PDF
An Improved Randomized Circle Detection Algorithm Using in Printed Circuit Board Locating Mark 被引量:2
6
作者 Jingkun Liu Qi Fan 《Applied Mathematics》 2019年第10期848-861,共14页
This paper presents an improved Randomized Circle Detection (RCD) algorithm with the characteristic of circularity to detect randomized circle in images with complex background, which is not based on the Hough Transfo... This paper presents an improved Randomized Circle Detection (RCD) algorithm with the characteristic of circularity to detect randomized circle in images with complex background, which is not based on the Hough Transform. The experimental results denote that this algorithm can locate the circular mark of Printed Circuit Board (PCB). 展开更多
关键词 Circle Detection randomized algorithm Characteristic of Circularity Printed Circuit Board
下载PDF
Improved Adaptive Random Convolutional Network Coding Algorithm 被引量:2
7
作者 Guo Wangmei Cai Ning Wang Xiao 《China Communications》 SCIE CSCD 2012年第11期63-69,共7页
To address the issue of field size in random network coding, we propose an Improved Adaptive Random Convolutional Network Coding (IARCNC) algorithm to considerably reduce the amount of occupied memory. The operation o... To address the issue of field size in random network coding, we propose an Improved Adaptive Random Convolutional Network Coding (IARCNC) algorithm to considerably reduce the amount of occupied memory. The operation of IARCNC is similar to that of Adaptive Random Convolutional Network Coding (ARCNC), with the coefficients of local encoding kernels chosen uniformly at random over a small finite field. The difference is that the length of the local encoding kernels at the nodes used by IARCNC is constrained by the depth; meanwhile, increases until all the related sink nodes can be decoded. This restriction can make the code length distribution more reasonable. Therefore, IARCNC retains the advantages of ARCNC, such as a small decoding delay and partial adaptation to an unknown topology without an early estimation of the field size. In addition, it has its own advantage, that is, a higher reduction in memory use. The simulation and the example show the effectiveness of the proposed algorithm. 展开更多
关键词 编码算法 随机选择 网络编码 自适应 卷积 内存使用 有限域 字段
下载PDF
Random Fuzzy Chance-constrained Programming Based on Adaptive Chaos Quantum Honey Bee Algorithm and Robustness Analysis 被引量:3
8
作者 Han Xue Xun Li Hong-Xu Ma College of Electromechanical Engineering and Automation, National University of Defense Technology, Changsha 410073, PRC 《International Journal of Automation and computing》 EI 2010年第1期115-122,共8页
This paper proposes an adaptive chaos quantum honey bee algorithm (CQHBA) for solving chance-constrained program- ming in random fuzzy environment based on random fuzzy simulations. Random fuzzy simulation is design... This paper proposes an adaptive chaos quantum honey bee algorithm (CQHBA) for solving chance-constrained program- ming in random fuzzy environment based on random fuzzy simulations. Random fuzzy simulation is designed to estimate the chance of a random fuzzy event and the optimistic value to a random fuzzy variable. In CQHBA, each bee carries a group of quantum bits representing a solution. Chaos optimization searches space around the selected best-so-far food source. In the marriage process, random interferential discrete quantum crossover is done between selected drones and the queen. Gaussian quantum mutation is used to keep the diversity of whole population. New methods of computing quantum rotation angles are designed based on grads. A proof of con- vergence for CQHBA is developed and a theoretical analysis of the computational overhead for the algorithm is presented. Numerical examples are presented to demonstrate its superiority in robustness and stability, efficiency of computational complexity, success rate, and accuracy of solution quality. CQHBA is manifested to be highly robust under various conditions and capable of handling most random fuzzy programmings with any parameter settings, variable initializations, system tolerance and confidence level, perturbations, and noises. 展开更多
关键词 Honey bee algorithm random fuzzy programming quantum computation chaos optimization ROBUSTNESS
下载PDF
Optimized quantum random-walk search algorithm for multi-solution search 被引量:1
9
作者 张宇超 鲍皖苏 +1 位作者 汪翔 付向群 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第11期133-139,共7页
This study investigates the multi-solution search of the optimized quantum random-walk search algorithm on the hypercube. Through generalizing the abstract search algorithm which is a general tool for analyzing the se... This study investigates the multi-solution search of the optimized quantum random-walk search algorithm on the hypercube. Through generalizing the abstract search algorithm which is a general tool for analyzing the search on the graph to the multi-solution case, it can be applied to analyze the multi-solution case of quantum random-walk search on the graph directly. Thus, the computational complexity of the optimized quantum random-walk search algorithm for the multi-solution search is obtained. Through numerical simulations and analysis, we obtain a critical value of the proportion of solutions q. For a given q, we derive the relationship between the success rate of the algorithm and the number of iterations when q is no longer than the critical value. 展开更多
关键词 quantum search algorithm quantum random walk multi-solution abstract search algorithm
下载PDF
基于Voronoi-Random算法微观结构褶型过滤介质过滤性能
10
作者 徐严 程思敏 +4 位作者 孙祎 曹博文 钱付平 鲁进利 韩云龙 《中国环境科学》 EI CAS CSCD 北大核心 2023年第10期5588-5597,共10页
在利用数值模拟研究褶型纤维过滤介质过滤性能时,为了克服层状结构纤维层与层之间不连贯及孔状结构纤维规整分布的不足,本文基于Voronoi-Random算法建立了褶型纤维过滤介质模型,并通过加密或减少纤维数量改变其固体体积分数(SVF).采用“... 在利用数值模拟研究褶型纤维过滤介质过滤性能时,为了克服层状结构纤维层与层之间不连贯及孔状结构纤维规整分布的不足,本文基于Voronoi-Random算法建立了褶型纤维过滤介质模型,并通过加密或减少纤维数量改变其固体体积分数(SVF).采用“Caught on first touch”和“Hamker”两种碰撞模型对褶型纤维过滤介质的气-固两相流动进行数值模拟.结果表明:压力损失和过滤效率数值计算值与经验关联式计算值吻合较好,误差在15%之内;将采用两种碰撞模型得到的过滤效率与经验关联式计算值进行比较,得出采用“Hamker”碰撞模型得到的过滤效率符合实际;在过滤介质上的沉积颗粒并不完全是纤维捕集,大多数颗粒是由形成的树枝状结构捕集;压降和单位面积沉积量随过滤时间的增长呈现指数增长趋势. 展开更多
关键词 Voronoi-random算法 褶型纤维过滤介质 过滤性能 数值模拟
下载PDF
AN ANALYSIS ABOUT BEHAVIOR OF EVOLUTIONARY ALGORITHMS:A KIND OF THEORETICAL DESCRIPTION BASED ON GLOBAL RANDOM SEARCH METHODS 被引量:1
11
作者 Ding Lixin Kang Lishan +1 位作者 Chen Yupin Zhou Shaoquan 《Wuhan University Journal of Natural Sciences》 CAS 1998年第1期31-31,共1页
Evolutionary computation is a kind of adaptive non--numerical computation method which is designed tosimulate evolution of nature. In this paper, evolutionary algorithm behavior is described in terms of theconstructio... Evolutionary computation is a kind of adaptive non--numerical computation method which is designed tosimulate evolution of nature. In this paper, evolutionary algorithm behavior is described in terms of theconstruction and evolution of the sampling distributions over the space of candidate solutions. Iterativeconstruction of the sampling distributions is based on the idea of the global random search of generationalmethods. Under this frame, propontional selection is characterized as a gobal search operator, and recombination is characerized as the search process that exploits similarities. It is shown-that by properly constraining the search breadth of recombination operators, weak convergence of evolutionary algorithms to aglobal optimum can be ensured. 展开更多
关键词 global random search evolutionary algorithms weak convergence genetic algorithms
下载PDF
Decoherence in optimized quantum random-walk search algorithm 被引量:1
12
作者 张宇超 鲍皖苏 +1 位作者 汪翔 付向群 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第8期197-202,共6页
This paper investigates the effects of decoherence generated by broken-link-type noise in the hypercube on an optimized quantum random-walk search algorithm. When the hypercube occurs with random broken links, the opt... This paper investigates the effects of decoherence generated by broken-link-type noise in the hypercube on an optimized quantum random-walk search algorithm. When the hypercube occurs with random broken links, the optimized quantum random-walk search algorithm with decoherence is depicted through defining the shift operator which includes the possibility of broken links. For a given database size, we obtain the maximum success rate of the algorithm and the required number of iterations through numerical simulations and analysis when the algorithm is in the presence of decoherence. Then the computational complexity of the algorithm with decoherence is obtained. The results show that the ultimate effect of broken-link-type decoherence on the optimized quantum random-walk search algorithm is negative. 展开更多
关键词 quantum search algorithm quantum random walk DECOHERENCE
下载PDF
Randomized Kaczmarz algorithm for CT reconstruction 被引量:1
13
作者 赵可 潘晋孝 孔慧华 《Journal of Measurement Science and Instrumentation》 CAS 2013年第1期34-37,共4页
The order of the projection in the algebraic reconstruction technique(ART)method has great influence on the rate of the convergence.Although many scholars have studied the order of the projection,few theoretical proof... The order of the projection in the algebraic reconstruction technique(ART)method has great influence on the rate of the convergence.Although many scholars have studied the order of the projection,few theoretical proofs are given.Thomas Strohmer and Roman Vershynin introduced a randomized version of the Kaczmarz method for consistent,and over-determined linear systems and proved whose rate does not depend on the number of equations in the systems in 2009.In this paper,we apply this method to computed tomography(CT)image reconstruction and compared images generated by the sequential Kaczmarz method and the randomized Kaczmarz method.Experiments demonstrates the feasibility of the randomized Kaczmarz algorithm in CT image reconstruction and its exponential curve convergence. 展开更多
关键词 Kaczmarz method iterative algorithm randomized Kaczmarz method computed tomography(CT) CT image reconstruction exponent curve fitting
下载PDF
MATRIX ALGEBRA ALGORITHM OF STRUCTURE RANDOM RESPONSE NUMERICAL CHARACTERISTICS
14
作者 Mei YulinWang XiaomingWang DelunDepartment of Mechanical Engineering,Dalian University of Technology,Dalian 116024,China 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2003年第2期149-152,共4页
A new algorithm of structure random response numerical characteristics, namedas matrix algebra algorithm of structure analysis is presented. Using the algorithm, structurerandom response numerical characteristics can ... A new algorithm of structure random response numerical characteristics, namedas matrix algebra algorithm of structure analysis is presented. Using the algorithm, structurerandom response numerical characteristics can easily be got by directly solving linear matrixequations rather than structure motion differential equations. Moreover, in order to solve thecorresponding linear matrix equations, the numerical integration fast algorithm is presented. Thenaccording to the results, dynamic design and life-span estimation can be done. Besides, the newalgorithm can solve non-proportion damp structure response. 展开更多
关键词 matrix algebra algorithm structure random response numericalcharacteristics numerical integration fast algorithm non-proportion damp
下载PDF
Research on the Computer Network Protocol Test Model based on Genetic and Random Walk Algorithm
15
作者 Ping Li 《International Journal of Technology Management》 2016年第8期39-42,共4页
关键词 计算机网络协议 随机游走 测试模型 算法 遗传 入侵检测系统 网络系统 隐蔽通道
下载PDF
THE DECISION OF THE OPTIMAL PARAMETERS IN MARKOV RANDOM FIELDS OF IMAGES BY GENETIC ALGORITHM
16
作者 Zheng Zhaobao Zheng Hong 《Geo-Spatial Information Science》 2000年第3期14-18,共5页
This paper introduces the principle of genetic algorithm and the basic method of solving Markov random field parameters.Focusing on the shortcomings in present methods,a new method based on genetic algorithms is propo... This paper introduces the principle of genetic algorithm and the basic method of solving Markov random field parameters.Focusing on the shortcomings in present methods,a new method based on genetic algorithms is proposed to solve the parameters in the Markov random field.The detailed procedure is discussed.On the basis of the parameters solved by genetic algorithms,some experiments on classification of aerial images are given.Experimental results show that the proposed method is effective and the classification results are satisfactory. 展开更多
关键词 GENETIC algorithm MARKOV random field PARAMETER OPTIMUM TEXTURE cl assification
下载PDF
Effects of systematic phase errors on optimized quantum random-walk search algorithm
17
作者 张宇超 鲍皖苏 +1 位作者 汪翔 付向群 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第6期155-163,共9页
This study investigates the effects of systematic errors in phase inversions on the success rate and number of iterations in the optimized quantum random-walk search algorithm. Using the geometric description of this ... This study investigates the effects of systematic errors in phase inversions on the success rate and number of iterations in the optimized quantum random-walk search algorithm. Using the geometric description of this algorithm, a model of the algorithm with phase errors is established, and the relationship between the success rate of the algorithm, the database size, the number of iterations, and the phase error is determined. For a given database size, we obtain both the maximum success rate of the algorithm and the required number of iterations when phase errors are present in the algorithm. Analyses and numerical simulations show that the optimized quantum random-walk search algorithm is more robust against phase errors than Grover's algorithm. 展开更多
关键词 quantum search algorithm quantum random walk phase errors ROBUSTNESS
下载PDF
Pseudo-Random Coding Side-Lobe Suppression Method Based on CLEAN Algorithm
18
作者 Liyu Tian Lianjuan Zhang Jiaying Li 《Journal of Beijing Institute of Technology》 EI CAS 2017年第3期375-380,共6页
A pseudo-random coding side-lobe suppression method based on CLEAN algorithm is introduced.The CLEAN algorithm mainly processes pulse compression results of a pseudo-random coding,and estimates a target's distance by... A pseudo-random coding side-lobe suppression method based on CLEAN algorithm is introduced.The CLEAN algorithm mainly processes pulse compression results of a pseudo-random coding,and estimates a target's distance by a method named interpolation method,so that we can get an ideal pulse compression result of the target,and then use the adjusted ideal pulse compression side-lobe to cut the actual pulse compression result,so as to achieve the remarkable performance of side-lobe suppression for large targets,and let the adjacent small targets appear.The computer simulations by MATLAB with this method analyze the effect of side-lobe suppression in an ideal or noisy environment.It is proved that this method can effectively solve the problem due to the side-lobe of pseudo-random coding being too high,and can enhance the radar's multi-target detection ability. 展开更多
关键词 CLEAN algorithm pseudo-random coding pulse compression interpolation method
下载PDF
Recommendation algorithm of cloud computing system based on random walk algorithm and collaborative filtering model 被引量:1
19
作者 Feng Zhang Hua Ma +1 位作者 Lei Peng Lanhua Zhang 《International Journal of Technology Management》 2017年第3期79-81,共3页
下载PDF
Random Search Algorithm for the Generalized Weber Problem
20
作者 Lev Kazakovtsev 《Journal of Software Engineering and Applications》 2012年第12期59-65,共7页
In this paper, we consider the planar multi-facility Weber problem with restricted zones and non-Euclidean distances, propose an algorithm based on the probability changing method (special kind of genetic algorithms) ... In this paper, we consider the planar multi-facility Weber problem with restricted zones and non-Euclidean distances, propose an algorithm based on the probability changing method (special kind of genetic algorithms) and prove its efficiency for approximate solving this problem by replacing the continuous coordinate values by discrete ones. Version of the algorithm for multiprocessor systems is proposed. Experimental results for a high-performance cluster are given. 展开更多
关键词 DISCRETE Optimization WEBER Problem random SEARCH GENETIC algorithms Parallel algorithm
下载PDF
上一页 1 2 175 下一页 到第
使用帮助 返回顶部