期刊文献+
共找到1,426篇文章
< 1 2 72 >
每页显示 20 50 100
Optimizing Connections:Applied Shortest Path Algorithms for MANETs
1
作者 Ibrahim Alameri Jitka Komarkova +2 位作者 Tawfik Al-Hadhrami Abdulsamad Ebrahim Yahya Atef Gharbi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第10期787-807,共21页
This study is trying to address the critical need for efficient routing in Mobile Ad Hoc Networks(MANETs)from dynamic topologies that pose great challenges because of the mobility of nodes.Themain objective was to del... This study is trying to address the critical need for efficient routing in Mobile Ad Hoc Networks(MANETs)from dynamic topologies that pose great challenges because of the mobility of nodes.Themain objective was to delve into and refine the application of the Dijkstra’s algorithm in this context,a method conventionally esteemed for its efficiency in static networks.Thus,this paper has carried out a comparative theoretical analysis with the Bellman-Ford algorithm,considering adaptation to the dynamic network conditions that are typical for MANETs.This paper has shown through detailed algorithmic analysis that Dijkstra’s algorithm,when adapted for dynamic updates,yields a very workable solution to the problem of real-time routing in MANETs.The results indicate that with these changes,Dijkstra’s algorithm performs much better computationally and 30%better in routing optimization than Bellman-Ford when working with configurations of sparse networks.The theoretical framework adapted,with the adaptation of the Dijkstra’s algorithm for dynamically changing network topologies,is novel in this work and quite different from any traditional application.The adaptation should offer more efficient routing and less computational overhead,most apt in the limited resource environment of MANETs.Thus,from these findings,one may derive a conclusion that the proposed version of Dijkstra’s algorithm is the best and most feasible choice of the routing protocol for MANETs given all pertinent key performance and resource consumption indicators and further that the proposed method offers a marked improvement over traditional methods.This paper,therefore,operationalizes the theoretical model into practical scenarios and also further research with empirical simulations to understand more about its operational effectiveness. 展开更多
关键词 Dijkstra’s algorithm optimization complexity analysis shortest path first comparative algorithm analysis nondeterministic polynomial(NP)-complete
下载PDF
Representation of an Integer by a Quadratic Form through the Cornacchia Algorithm
2
作者 Moumouni Djassibo Woba 《Applied Mathematics》 2024年第9期614-629,共16页
Cornachia’s algorithm can be adapted to the case of the equation x2+dy2=nand even to the case of ax2+bxy+cy2=n. For the sake of completeness, we have given modalities without proofs (the proof in the case of the equa... Cornachia’s algorithm can be adapted to the case of the equation x2+dy2=nand even to the case of ax2+bxy+cy2=n. For the sake of completeness, we have given modalities without proofs (the proof in the case of the equation x2+y2=n). Starting from a quadratic form with two variables f(x,y)=ax2+bxy+cy2and n an integer. We have shown that a primitive positive solution (u,v)of the equation f(x,y)=nis admissible if it is obtained in the following way: we take α modulo n such that f(α,1)≡0modn, u is the first of the remainders of Euclid’s algorithm associated with n and α that is less than 4cn/| D |) (possibly α itself) and the equation f(x,y)=n. has an integer solution u in y. At the end of our work, it also appears that the Cornacchia algorithm is good for the form n=ax2+bxy+cy2if all the primitive positive integer solutions of the equation f(x,y)=nare admissible, i.e. computable by the algorithmic process. 展开更多
关键词 Quadratic Form Cornacchia algorithm Associated Polynomials Euclid’s algorithm Prime Number
下载PDF
Time Complexity of the Oracle Phase in Grover’s Algorithm
3
作者 Ying Liu 《American Journal of Computational Mathematics》 2024年第1期1-10,共10页
Since Grover’s algorithm was first introduced, it has become a category of quantum algorithms that can be applied to many problems through the exploitation of quantum parallelism. The original application was the uns... Since Grover’s algorithm was first introduced, it has become a category of quantum algorithms that can be applied to many problems through the exploitation of quantum parallelism. The original application was the unstructured search problems with the time complexity of O(). In Grover’s algorithm, the key is Oracle and Amplitude Amplification. In this paper, our purpose is to show through examples that, in general, the time complexity of the Oracle Phase is O(N), not O(1). As a result, the time complexity of Grover’s algorithm is O(N), not O(). As a secondary purpose, we also attempt to restore the time complexity of Grover’s algorithm to its original form, O(), by introducing an O(1) parallel algorithm for unstructured search without repeated items, which will work for most cases. In the worst-case scenarios where the number of repeated items is O(N), the time complexity of the Oracle Phase is still O(N) even after additional preprocessing. 展开更多
关键词 Quantum Computing ORACLE Amplitude Amplification Grover’s algorithm
下载PDF
O(logN) Algorithm for Amplitude Amplification and O(logN) Algorithms for Amplitude Transfer in Grover’s Algorithm
4
作者 Ying Liu 《American Journal of Computational Mathematics》 2024年第2期169-188,共20页
Grovers algorithm is a category of quantum algorithms that can be applied to many problems through the exploitation of quantum parallelism. The Amplitude Amplification in Grovers algorithm is T = O(N). This paper intr... Grovers algorithm is a category of quantum algorithms that can be applied to many problems through the exploitation of quantum parallelism. The Amplitude Amplification in Grovers algorithm is T = O(N). This paper introduces two new algorithms for Amplitude Amplification in Grovers algorithm with a time complexity of T = O(logN), aiming to improve efficiency in quantum computing. The difference between Grovers algorithm and our first algorithm is that the Amplitude Amplification ratio in Grovers algorithm is an arithmetic series and ours, a geometric one. Because our Amplitude Amplification ratios converge much faster, the time complexity is improved significantly. In our second algorithm, we introduced a new concept, Amplitude Transfer where the marked state is transferred to a new set of qubits such that the new qubit state is an eigenstate of measurable variables. When the new qubit quantum state is measured, with high probability, the correct solution will be obtained. 展开更多
关键词 Quantum Computing ORACLE Amplitude Amplification Grover’s algorithm
下载PDF
基于多目标遗传算法的8×8 S盒的优化设计方法
5
作者 王永 王明月 龚建 《西南交通大学学报》 EI CSCD 北大核心 2024年第3期519-527,538,共10页
混沌系统具有非线性、伪随机性、初始值敏感等特性,为基于动力系统构造性能良好的S盒提供了基础,进一步保证了分组加密算法安全性.目前,基于混沌构造S盒的方法大多数针对单个性能指标进行优化,难以获得全面的性能提升.针对此问题,结合... 混沌系统具有非线性、伪随机性、初始值敏感等特性,为基于动力系统构造性能良好的S盒提供了基础,进一步保证了分组加密算法安全性.目前,基于混沌构造S盒的方法大多数针对单个性能指标进行优化,难以获得全面的性能提升.针对此问题,结合混沌映射与多目标遗传算法,提出了一种新的S盒设计方法.首先,利用混沌映射的特性产生初始S盒种群;然后,以S盒的非线性度和差分均匀性为优化目标,基于遗传算法框架对上述两指标进行优化.针对S盒的特点,在优化算法中引入了交换操作,设计了新的变异操作以及非支配序集计算,有效提升了S盒的非线性度和差分均匀性.实验结果表明该算法产生的S盒其差分均匀度为6,非线性度值至少为110,有效提升了S盒的综合性能. 展开更多
关键词 s 非线性度 差分均匀度 多目标遗传算法 混沌映射
下载PDF
基于量子衍生涡流算法和T⁃S模糊推理模型的储层岩性识别
6
作者 赵娅 管玉 +1 位作者 李盼池 王伟 《石油地球物理勘探》 EI CSCD 北大核心 2024年第1期23-30,共8页
鉴于梯度下降法易陷入局部极值、普通群智能优化算法易早熟收敛,提出一种基于量子衍生涡流算法(Quantum Vortex Search Algorithm,QVSA)和T⁃S模糊推理模型的岩性识别方法,QVSA具有操作简单、收敛速度快、寻优能力强等优点,有助于T⁃S模... 鉴于梯度下降法易陷入局部极值、普通群智能优化算法易早熟收敛,提出一种基于量子衍生涡流算法(Quantum Vortex Search Algorithm,QVSA)和T⁃S模糊推理模型的岩性识别方法,QVSA具有操作简单、收敛速度快、寻优能力强等优点,有助于T⁃S模糊推理模型获得最优参数配置,从而实现储层岩性的准确识别。首先利用具有全局搜索能力的QVSA优化T⁃S模糊推理模型的各种参数;然后利用主成分分析方法降低获取的地震属性维度;再利用优化的T⁃S模糊推理模型识别储层岩性。实验结果表明,利用反映储层特征的8个地震属性识别储层岩性时,所提方法的识别正确率达到92%,比普通BP网络方法高5.1%,同时查准率、查全率、F1分数等指标也较BP网络方法提升明显。 展开更多
关键词 储层岩性识别 量子衍生涡流算法 T⁃s 模糊推理模型 模糊集 地震属性
下载PDF
基于XGBoost算法的v_(P)/v_(S)预测及其在储层检测中的应用
7
作者 田仁飞 李山 +1 位作者 刘涛 景洋 《石油地球物理勘探》 EI CSCD 北大核心 2024年第4期653-663,共11页
鄂尔多斯盆地碳酸盐岩地层蕴含着丰富的油气资源。在勘探实践中发现,大牛地气田马家沟组断层发育、断距小,类型多样且成因复杂,给勘探、开发带来了较多挑战。为了应对这些挑战,提高储层预测的精度变得至关重要。在分析大牛地气田敏感弹... 鄂尔多斯盆地碳酸盐岩地层蕴含着丰富的油气资源。在勘探实践中发现,大牛地气田马家沟组断层发育、断距小,类型多样且成因复杂,给勘探、开发带来了较多挑战。为了应对这些挑战,提高储层预测的精度变得至关重要。在分析大牛地气田敏感弹性参数的基础上,建立地震属性与储层纵横波速度比(v_(P)/v_(S))的关系,提出一种基于XGBoost算法的地震多属性v_(P)/v_(S)预测方法。为了进一步提升XGBoost算法的预测精度和泛化能力,采用贝叶斯算法对XGBoost算法的超参数进行优化,从而找到最佳的超参数组合,以确保模型在训练集和测试集上的性能均能得到提升。将XGBoost算法应用于Marmousi 2模型进行横波速度预测,预测值与实际值相关系数超过0.88,而均方误差、平均绝对百分比误差分别低于6.55×10^(-7)和4%,验证了该方法的准确性和可靠性。在鄂尔多斯盆地大牛地气田,应用该方法获得的v_(P)/v_(S)成功识别出含气储层,结果与实际钻井数据一致。理论模型和实际数据应用结果表明,XGBoost作为一种强大的机器学习算法预测精度较高,为直接由叠后地震属性预测v_(P)/v_(S)提供了一种有效的途径。 展开更多
关键词 横波速度 碳酸盐岩储层 地震属性 XGBoost算法 纵横波速度比(v_(P)/v_(s))
下载PDF
三种基于Cesium的重庆市漫游飞行算法及其对比分析 被引量:1
8
作者 李莹 赵宁曦 《吉林大学学报(地球科学版)》 CAS CSCD 北大核心 2024年第2期709-720,共12页
漫游飞行在数字地球、虚拟现实和仿真等领域有着广泛的应用。以往的研究多集中于客户机/服务器(client/server,C/S)结构的桌面端应用程序,本文以浏览器/服务器(browser/server,B/S)结构下的Web端开源三维地理框架Cesium为基础构建虚拟地... 漫游飞行在数字地球、虚拟现实和仿真等领域有着广泛的应用。以往的研究多集中于客户机/服务器(client/server,C/S)结构的桌面端应用程序,本文以浏览器/服务器(browser/server,B/S)结构下的Web端开源三维地理框架Cesium为基础构建虚拟地球,设计了三种不同的漫游算法:常规漫游算法、回调函数漫游算法、拉格朗日插值漫游算法,并在地球表面成功加载了重庆市主城区的倾斜摄影模型以实现漫游飞行功能,从帧率(frames per second,FPS)和网络延迟(network latency,NL)两方面对比分析三种算法的有效性。结果表明,常规漫游算法、回调函数漫游算法、拉格朗日插值漫游算法前50 s的平均FPS分别为70、74、80 Hz,平均NL分别为14.145、13.166、12.419 ms。就FPS而言,回调函数漫游算法较常规漫游算法提升了5.714%,拉格朗日插值漫游算法较常规漫游算法提升了14.286%。就NL而言,回调函数漫游算法较常规漫游算法缩短了6.921%,拉格朗日插值漫游算法较常规漫游算法缩短了12.202%。总体而言,算法运行效率从大到小最终排序为:拉格朗日插值漫游算法、回调函数漫游算法、常规漫游算法,即在漫游飞行过程中,回调函数漫游算法、拉格朗日插值漫游算法较常规漫游算法有一定的提升,拉格朗日插值漫游算法可实现更高效、流畅的渲染效果。 展开更多
关键词 CEsIUM 浏览器/服务器 漫游算法 帧率 网络延迟
下载PDF
基于FPGA的SM4算法高效实现方案
9
作者 张宏科 袁浩楠 +3 位作者 丁文秀 闫峥 李斌 梁栋 《通信学报》 EI CSCD 北大核心 2024年第5期140-150,共11页
针对SM4算法的FPGA实现方案存在数据处理速度不够高和逻辑资源占用过高的问题,提出了基于现场可编程门阵列(FPGA)的高性能、低资源消耗的SM4算法实现方案。所提方案采用循环密钥扩展与32级流水线加解密相结合的架构,循环密钥扩展的方式... 针对SM4算法的FPGA实现方案存在数据处理速度不够高和逻辑资源占用过高的问题,提出了基于现场可编程门阵列(FPGA)的高性能、低资源消耗的SM4算法实现方案。所提方案采用循环密钥扩展与32级流水线加解密相结合的架构,循环密钥扩展的方式降低了逻辑资源消耗,32级流水线加解密的方式提高了数据吞吐率。同时,所提方案采用代数式S盒并通过合并线性运算以及在不可约多项式的合并矩阵中筛选最优矩阵运算的方式进一步减少S盒变换的运算量,从而达到降低逻辑资源占用与提高工程数据吞吐率的目的。测试结果显示,该方案比现有最佳方案在数据吞吐率上提升了43%,且资源占用率降低了10%。 展开更多
关键词 sM4算法 FPGA实现 流水线架构 代数式s
下载PDF
基于遗传粒子群算法的超混沌S盒设计
10
作者 陆雅雯 李正权 +2 位作者 谭立容 顾斌 邢松 《江苏大学学报(自然科学版)》 CAS 北大核心 2024年第6期701-708,共8页
针对目前基于混沌系统所构造的S盒难以拥有良好密码学性能的问题,提出一种基于超混沌系统及遗传粒子群优化算法的S盒设计方案.在一维混沌映射基础上,引入正余弦函数以及指数因子,构造一个二维超混沌系统,从系统分叉图、相图、Lyapunov... 针对目前基于混沌系统所构造的S盒难以拥有良好密码学性能的问题,提出一种基于超混沌系统及遗传粒子群优化算法的S盒设计方案.在一维混沌映射基础上,引入正余弦函数以及指数因子,构造一个二维超混沌系统,从系统分叉图、相图、Lyapunov指数图进行性能分析,该混沌系统在参数范围内有着连续的超混沌区间,混沌行为复杂.通过改变混沌系统的初值、参数以及迭代次数可以动态生成S盒,随后结合粒子群优化算法和遗传算法提出一种针对S盒的遗传粒子群优化算法,将混沌系统生成的S盒作为初始种群,利用粒子群算法改进遗传算法中的交叉操作,同时结合爬山算法提出一种新的变异策略.为验证所生成S盒性能,对S盒的双射特性、非线性度、严格雪崩准则、差分均匀性及输出比特间独立性进行仿真测试,仿真结果表明:所提出的优化算法能够生成非线性度、差分均匀性、输出比特间独立性方面表现良好的S盒. 展开更多
关键词 s 超混沌系统 LYAPUNOV指数 粒子群优化算法 遗传算法 爬山算法
下载PDF
秘密共享:高阶掩码S盒和有限域安全乘法设计
11
作者 唐啸霖 冯燕 +1 位作者 李明达 李志强 《电子与信息学报》 EI CAS CSCD 北大核心 2024年第8期3400-3409,共10页
在信息时代,信息安全是最不能忽视的重要问题,对密码设备的攻击和防护是该领域的研究热点。近年来,多种对密码设备的攻击已为人所知,其目的都是为了获取设备中的密钥,在众多攻击中,功耗侧信道攻击是最受关注的攻击技术之一。掩码技术是... 在信息时代,信息安全是最不能忽视的重要问题,对密码设备的攻击和防护是该领域的研究热点。近年来,多种对密码设备的攻击已为人所知,其目的都是为了获取设备中的密钥,在众多攻击中,功耗侧信道攻击是最受关注的攻击技术之一。掩码技术是对抗功耗侧信道攻击的有效方法,然而随着攻击手段的不断进步,1阶掩码的防护已经不足以应对2阶及以上的功耗分析攻击,因此对高阶掩码的研究具有重要的意义。为了提升加密电路抗攻击能力,该文基于秘密共享的思想,对分组密码算法的S盒变换实施了高阶掩码防护——共享型掩码,并基于Ishai等人在Crypto 2003上发表的安全方案(ISW框架)提出了有限域安全乘法的通用设计方法。通过实验表明,该文提出的共享型掩码方案不影响加密算法的功能,同时能抵御1阶和2阶相关功耗分析攻击。 展开更多
关键词 分组密码算法 s盒变换 共享型掩码 有限域乘法
下载PDF
基于同步压缩广义S变换的电力系统次/超同步振荡检测
12
作者 孙勇 张鹏 +3 位作者 姜涛 宋晓喆 王长江 刘博涵 《电网技术》 EI CSCD 北大核心 2024年第10期4002-4011,I0012-I0014,I0011,共14页
为实现电力系统次/超同步振荡的快速、准确辨识,提出了一种基于同步压缩广义S变换(synchrosqueezing generalized S transform, SSGST)和改进稀疏时域法(improved sparse time domain method,ISTD)结合的次/超同步振荡辨识方法。该方法... 为实现电力系统次/超同步振荡的快速、准确辨识,提出了一种基于同步压缩广义S变换(synchrosqueezing generalized S transform, SSGST)和改进稀疏时域法(improved sparse time domain method,ISTD)结合的次/超同步振荡辨识方法。该方法首先利用能量比函数对电力系统广域量测信息实时检测,当检测到信号能量发生突变时,利用SSGST对检测到的振荡信号分解得到相应的SSGST时频系数矩阵;然后通过改进的脊线提取方法在时频域实现对各振荡分量的最优轨迹搜索;进一步,结合最优轨迹时频索引重构各振荡分量的时域分量,并利用ISTD辨识方法计算出各振荡分量的频率和阻尼比系数;最后,通过自合成模拟信号、双馈风电场经串补并网系统仿真信号和某实际风电场实测数据验证了所提方法的准确性和有效性。 展开更多
关键词 次/超同步振荡 参数辨识 同步压缩广义s变换 脊线提取 改进稀疏时域法
下载PDF
Quantum Algorithm for Mining Frequent Patterns for Association Rule Mining
13
作者 Abdirahman Alasow Marek Perkowski 《Journal of Quantum Information Science》 CAS 2023年第1期1-23,共23页
Maximum frequent pattern generation from a large database of transactions and items for association rule mining is an important research topic in data mining. Association rule mining aims to discover interesting corre... Maximum frequent pattern generation from a large database of transactions and items for association rule mining is an important research topic in data mining. Association rule mining aims to discover interesting correlations, frequent patterns, associations, or causal structures between items hidden in a large database. By exploiting quantum computing, we propose an efficient quantum search algorithm design to discover the maximum frequent patterns. We modified Grover’s search algorithm so that a subspace of arbitrary symmetric states is used instead of the whole search space. We presented a novel quantum oracle design that employs a quantum counter to count the maximum frequent items and a quantum comparator to check with a minimum support threshold. The proposed derived algorithm increases the rate of the correct solutions since the search is only in a subspace. Furthermore, our algorithm significantly scales and optimizes the required number of qubits in design, which directly reflected positively on the performance. Our proposed design can accommodate more transactions and items and still have a good performance with a small number of qubits. 展开更多
关键词 Data Mining Association Rule Mining Frequent Pattern Apriori algorithm Quantum Counter Quantum Comparator Grover’s search algorithm
下载PDF
A Spectral Convolutional Neural Network Model Based on Adaptive Fick’s Law for Hyperspectral Image Classification
14
作者 Tsu-Yang Wu Haonan Li +1 位作者 Saru Kumari Chien-Ming Chen 《Computers, Materials & Continua》 SCIE EI 2024年第4期19-46,共28页
Hyperspectral image classification stands as a pivotal task within the field of remote sensing,yet achieving highprecision classification remains a significant challenge.In response to this challenge,a Spectral Convol... Hyperspectral image classification stands as a pivotal task within the field of remote sensing,yet achieving highprecision classification remains a significant challenge.In response to this challenge,a Spectral Convolutional Neural Network model based on Adaptive Fick’s Law Algorithm(AFLA-SCNN)is proposed.The Adaptive Fick’s Law Algorithm(AFLA)constitutes a novel metaheuristic algorithm introduced herein,encompassing three new strategies:Adaptive weight factor,Gaussian mutation,and probability update policy.With adaptive weight factor,the algorithmcan adjust theweights according to the change in the number of iterations to improve the performance of the algorithm.Gaussianmutation helps the algorithm avoid falling into local optimal solutions and improves the searchability of the algorithm.The probability update strategy helps to improve the exploitability and adaptability of the algorithm.Within the AFLA-SCNN model,AFLA is employed to optimize two hyperparameters in the SCNN model,namely,“numEpochs”and“miniBatchSize”,to attain their optimal values.AFLA’s performance is initially validated across 28 functions in 10D,30D,and 50D for CEC2013 and 29 functions in 10D,30D,and 50D for CEC2017.Experimental results indicate AFLA’s marked performance superiority over nine other prominent optimization algorithms.Subsequently,the AFLA-SCNN model was compared with the Spectral Convolutional Neural Network model based on Fick’s Law Algorithm(FLA-SCNN),Spectral Convolutional Neural Network model based on Harris Hawks Optimization(HHO-SCNN),Spectral Convolutional Neural Network model based onDifferential Evolution(DE-SCNN),SpectralConvolutionalNeuralNetwork(SCNN)model,and SupportVector Machines(SVM)model using the Indian Pines dataset and PaviaUniversity dataset.The experimental results show that the AFLA-SCNN model outperforms other models in terms of Accuracy,Precision,Recall,and F1-score on Indian Pines and Pavia University.Among them,the Accuracy of the AFLA-SCNN model on Indian Pines reached 99.875%,and the Accuracy on PaviaUniversity reached 98.022%.In conclusion,our proposed AFLA-SCNN model is deemed to significantly enhance the precision of hyperspectral image classification. 展开更多
关键词 Adaptive Fick’s law algorithm spectral convolutional neural network metaheuristic algorithm intelligent optimization algorithm hyperspectral image classification
下载PDF
基于FPGA的AES和ECC算法图像加密
15
作者 方应李 方玉明 《电子科技》 2024年第6期92-97,共6页
随着数字图像的使用次数日益增多,保护机密图像数据免受未经授权的访问较为重要。针对数字图像在通信、存储和传输等领域存在的安全问题,文中基于对称算法模型和非对称算法模型的优点提出一种具有高安全性和高速度性的数字信封技术密码... 随着数字图像的使用次数日益增多,保护机密图像数据免受未经授权的访问较为重要。针对数字图像在通信、存储和传输等领域存在的安全问题,文中基于对称算法模型和非对称算法模型的优点提出一种具有高安全性和高速度性的数字信封技术密码方案。该方案以AES(Advanced Encryption Standard)和ECC(Elliptic Curve Cryptography)为基础,经优化后用于对称密钥共享的ECC硬件架构来提高密钥的安全性。通过加入伪随机数、使用列移位替代列混淆运算以及三维S-box等方式对传统AES进行优化,在保持香农扩散和混淆原理的同时降低了时间复杂性。基于FPGA(Field Programmable Gate Array)实现AES算法的数字图像加密仿真以及性能测试。测试结果表明,所提密码方案具有快速性、高安全性和有效性等优点,能够有效地实现图像加密。 展开更多
关键词 数字图像 数字信封 AEs算法 ECC算法 三维s-box FPGA 信息熵 相关系数
下载PDF
The Collaboratory for the Study of Earthquake Predictability in China:Experiment Design and Preliminary Results of CSEP2.0
16
作者 ZHANG Shengfeng ZHANG Yongxian +3 位作者 Maximilian J.WERNER Kenny G.RAHAM David A.RHOADES JoséA.BAYONA 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第S01期94-97,共4页
Since the inaugural international collaboration under the framework of the Collaboratory for the Study of Earthquake Predictability(CSEP)in 2007,numerous forecast models have been developed and operated for earthquake... Since the inaugural international collaboration under the framework of the Collaboratory for the Study of Earthquake Predictability(CSEP)in 2007,numerous forecast models have been developed and operated for earthquake forecasting experiments across CSEP testing centers(Schorlemmer et al.,2018).Over more than a decade,efforts to compare forecasts with observed earthquakes using numerous statistical test methods and insights into earthquake predictability,which have become a highlight of the CSEP platform. 展开更多
关键词 earthquake forecasting seismicity modeling CsEP2.0 Pattern Informatics(PI)algorithm long-to-intermediate-term forecast Relative Intensity(RI)algorithm Completeness Magnitude s test N test
下载PDF
Calculation of Extraction Equilibrium in Multi-Component System by Newton-Raphson Algorithm
17
作者 贾江涛 王建方 +3 位作者 严纯华 廖春生 吴声 李标国 《Journal of Rare Earths》 SCIE EI CAS CSCD 1999年第4期246-249,共4页
Based on the extraction equilibrium and mass balances in countercurrent extraction systems, a novel method was studied for dealing with the extraction equilibrium and the mass distribution in a multi-component(gamma-c... Based on the extraction equilibrium and mass balances in countercurrent extraction systems, a novel method was studied for dealing with the extraction equilibrium and the mass distribution in a multi-component(gamma-component) system. The relationships of mass distribution (x(i), y(i), i = 1, ..., lambda) between two phases were expressed by 2 lambda dimensional simultaneous equations. These simultaneous equations can be converted to a one-dimension nonlinear equation, then it was solved by Newton-Raphson algorithm within a few number of iteration. Compared with the regular calculation method for the 2 lambda dimensional simultaneous equations, Newton-Raphson algorithm can decrease the number of iteration, increase the convergence of the equations and accelerate the speed of simulation. It was verified in many multi-component systems with satisfactory results. As an example, a five-component system is demonstrated in this paper. 展开更多
关键词 rare earths multi-component system extraction equilibrium newton-raphson algorithm
下载PDF
基于S变换时频谱和KHA-CNN的换流变故障声纹识别
18
作者 柴斌 韦鹏 +2 位作者 宁复茂 姚琪 李辉 《电网与清洁能源》 CSCD 北大核心 2024年第2期103-109,共7页
为准确进行换流变压器故障诊断,保证直流输电可靠性,提出一种基于S变换时频谱和KHA-CNN模式的换流变故障声纹识别方法。利用自适应补充集合经验模态分解算法(complete ensemble empirical mode decomposition with adaptive noise,CEEMD... 为准确进行换流变压器故障诊断,保证直流输电可靠性,提出一种基于S变换时频谱和KHA-CNN模式的换流变故障声纹识别方法。利用自适应补充集合经验模态分解算法(complete ensemble empirical mode decomposition with adaptive noise,CEEMDAN),实现换流变本体声纹信号与噪声的分离;通过S变换得到时频谱图,实现声纹信号的特征提取;通过磷虾群优化算法(krill herd algorithm,KHA)对卷积神经网络进行超参数寻优,将S时频谱图作为特征输入到KHA-CNN,实现故障诊断。研究结果表明:该方法对于换流变故障具有很好的识别效果,能为换流变故障诊断提供有效参考。 展开更多
关键词 换流变压器 声纹信号 s变换时频谱图 磷虾群优化算法 卷积神经网络
下载PDF
基于B/S结构的异构数据库加密算法仿真
19
作者 闫银芳 任宏 王晓燕 《计算机应用文摘》 2024年第12期44-46,共3页
在处理用户与权限中心的密钥时,传统加密方法存在对应层次不均和异构数据库加密时间长等问题。对此,文章提出了一种基于B/S结构的异构数据库加密算法,首先对比了C/S与B/S结构的优缺点;其次构建了基于B/S结构的异构数据库加密体系框架。... 在处理用户与权限中心的密钥时,传统加密方法存在对应层次不均和异构数据库加密时间长等问题。对此,文章提出了一种基于B/S结构的异构数据库加密算法,首先对比了C/S与B/S结构的优缺点;其次构建了基于B/S结构的异构数据库加密体系框架。该框架包括1套全面的密钥管理机制,用于生成各级权限管理中心的密钥,以及用户在对应权限中心的密钥与用户主密钥。通过使用访问策略树对服务器端的明文数据进行加密,该算法可将需要保护的数据转换为密文形式。仿真结果显示,该算法不仅能有效完成异构数据库加密,达到保护数据库安全的目标,且响应时间相比传统方法有显著提升。 展开更多
关键词 B/s结构 加密算法仿真 异构数据
下载PDF
基于云模型和改进D-S证据理论的浓香型白酒发酵质量评估方法
20
作者 陈博 杨亭榆 +1 位作者 刘艾萌 赖冬寅 《科技和产业》 2024年第9期164-169,共6页
黄水是浓香型白酒发酵特有的副产物,黄水参数一定程度反映了发酵质量。基于黄水的酸度、还原糖、酒精度等关键参数,采用云模型与改进的D-S(Dempster-Shafer)证据理论,实现对白酒发酵质量的定量评估。基于黄水关键参数建立隶属度云模型,... 黄水是浓香型白酒发酵特有的副产物,黄水参数一定程度反映了发酵质量。基于黄水的酸度、还原糖、酒精度等关键参数,采用云模型与改进的D-S(Dempster-Shafer)证据理论,实现对白酒发酵质量的定量评估。基于黄水关键参数建立隶属度云模型,使用云模型判定样本在各发酵质量判定区间的隶属度情况。同时对D-S证据理论的冲突系数计算方式进行改进,使得信息融合结果更具代表性。提出一种浓香型白酒发酵质量的综合评估方法,降低了人工判别的主观性。 展开更多
关键词 浓香型白酒 黄水 云模型 D-s(Dempster-shafer)证据理论 合成算法
下载PDF
上一页 1 2 72 下一页 到第
使用帮助 返回顶部