期刊文献+
共找到343,232篇文章
< 1 2 250 >
每页显示 20 50 100
Rao Algorithms-Based Structure Optimization for Heterogeneous Wireless Sensor Networks 被引量:1
1
作者 Shereen K.Refaay Samia A.Ali +2 位作者 Moumen T.El-Melegy Louai A.Maghrabi Hamdy H.El-Sayed 《Computers, Materials & Continua》 SCIE EI 2024年第1期873-897,共25页
The structural optimization of wireless sensor networks is a critical issue because it impacts energy consumption and hence the network’s lifetime.Many studies have been conducted for homogeneous networks,but few hav... The structural optimization of wireless sensor networks is a critical issue because it impacts energy consumption and hence the network’s lifetime.Many studies have been conducted for homogeneous networks,but few have been performed for heterogeneouswireless sensor networks.This paper utilizes Rao algorithms to optimize the structure of heterogeneous wireless sensor networks according to node locations and their initial energies.The proposed algorithms lack algorithm-specific parameters and metaphorical connotations.The proposed algorithms examine the search space based on the relations of the population with the best,worst,and randomly assigned solutions.The proposed algorithms can be evaluated using any routing protocol,however,we have chosen the well-known routing protocols in the literature:Low Energy Adaptive Clustering Hierarchy(LEACH),Power-Efficient Gathering in Sensor Information Systems(PEAGSIS),Partitioned-based Energy-efficient LEACH(PE-LEACH),and the Power-Efficient Gathering in Sensor Information Systems Neural Network(PEAGSIS-NN)recent routing protocol.We compare our optimized method with the Jaya,the Particle Swarm Optimization-based Energy Efficient Clustering(PSO-EEC)protocol,and the hybrid Harmony Search Algorithm and PSO(HSA-PSO)algorithms.The efficiencies of our proposed algorithms are evaluated by conducting experiments in terms of the network lifetime(first dead node,half dead nodes,and last dead node),energy consumption,packets to cluster head,and packets to the base station.The experimental results were compared with those obtained using the Jaya optimization algorithm.The proposed algorithms exhibited the best performance.The proposed approach successfully prolongs the network lifetime by 71% for the PEAGSIS protocol,51% for the LEACH protocol,10% for the PE-LEACH protocol,and 73% for the PEGSIS-NN protocol;Moreover,it enhances other criteria such as energy conservation,fitness convergence,packets to cluster head,and packets to the base station. 展开更多
关键词 Wireless sensor networks Rao algorithms optimization LEACH PEAGSIS
下载PDF
An Improved Artificial Rabbits Optimization Algorithm with Chaotic Local Search and Opposition-Based Learning for Engineering Problems and Its Applications in Breast Cancer Problem
2
作者 Feyza AltunbeyÖzbay ErdalÖzbay Farhad Soleimanian Gharehchopogh 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第11期1067-1110,共44页
Artificial rabbits optimization(ARO)is a recently proposed biology-based optimization algorithm inspired by the detour foraging and random hiding behavior of rabbits in nature.However,for solving optimization problems... Artificial rabbits optimization(ARO)is a recently proposed biology-based optimization algorithm inspired by the detour foraging and random hiding behavior of rabbits in nature.However,for solving optimization problems,the ARO algorithm shows slow convergence speed and can fall into local minima.To overcome these drawbacks,this paper proposes chaotic opposition-based learning ARO(COARO),an improved version of the ARO algorithm that incorporates opposition-based learning(OBL)and chaotic local search(CLS)techniques.By adding OBL to ARO,the convergence speed of the algorithm increases and it explores the search space better.Chaotic maps in CLS provide rapid convergence by scanning the search space efficiently,since their ergodicity and non-repetitive properties.The proposed COARO algorithm has been tested using thirty-three distinct benchmark functions.The outcomes have been compared with the most recent optimization algorithms.Additionally,the COARO algorithm’s problem-solving capabilities have been evaluated using six different engineering design problems and compared with various other algorithms.This study also introduces a binary variant of the continuous COARO algorithm,named BCOARO.The performance of BCOARO was evaluated on the breast cancer dataset.The effectiveness of BCOARO has been compared with different feature selection algorithms.The proposed BCOARO outperforms alternative algorithms,according to the findings obtained for real applications in terms of accuracy performance,and fitness value.Extensive experiments show that the COARO and BCOARO algorithms achieve promising results compared to other metaheuristic algorithms. 展开更多
关键词 Artificial rabbit optimization binary optimization breast cancer chaotic local search engineering design problem opposition-based learning
下载PDF
基于RIME-IAOA的混合模型短期光伏功率预测
3
作者 王仁明 魏逸明 席磊 《三峡大学学报(自然科学版)》 CAS 北大核心 2025年第1期81-88,共8页
光伏发电在如今的新能源发展中逐渐成为重点,其中光伏功率预测成为研究的主要方向.为了提升光伏功率预测的精度和效率,提出了RIME-VMD-IAOA-LSTM模型.该模型通过霜冰优化算法(RIME)优化变分模态分解(VMD)的参数来提升分解效率;引入余弦... 光伏发电在如今的新能源发展中逐渐成为重点,其中光伏功率预测成为研究的主要方向.为了提升光伏功率预测的精度和效率,提出了RIME-VMD-IAOA-LSTM模型.该模型通过霜冰优化算法(RIME)优化变分模态分解(VMD)的参数来提升分解效率;引入余弦控制因子的动态边界策略来控制算数优化算法(AOA)数值的增长速率从而提升算法的精度和稳定性;利用自适应T分布变异策略来改进AOA的局部搜索能力和全局开发能力,更好地避免局部最优解.两种智能优化算法的加入使得整体模型的预测效率和速度都有很大提升,实验结果表明组合模型RIMEVMD-IAOA-LSTM相比于其他预测模型有较高的光伏功率预测精度. 展开更多
关键词 霜冰优化算法 变分模态分解 算术优化算法 余弦控制因子策略 自适应T分布策略 短期光伏功率预测
下载PDF
受阻酚AO-60/天然橡胶复合材料的结构与阻尼性能研究
4
作者 谭博文 刘英明 +1 位作者 许仕强 吴明生 《橡胶工业》 CAS 2025年第1期18-24,共7页
研究受阻酚AO-60用量对受阻酚AO-60/天然橡胶(NR)复合材料的结构与阻尼性能的影响。结果表明:受阻酚AO-60用量小于50份时,受阻酚AO-60在复合材料中主要形成小型聚集体;随着受阻酚AO-60用量的增大,受阻酚AO-60在复合材料中形成越来越多... 研究受阻酚AO-60用量对受阻酚AO-60/天然橡胶(NR)复合材料的结构与阻尼性能的影响。结果表明:受阻酚AO-60用量小于50份时,受阻酚AO-60在复合材料中主要形成小型聚集体;随着受阻酚AO-60用量的增大,受阻酚AO-60在复合材料中形成越来越多的大型聚集体;在差示扫描量热分析中,受阻酚AO-60在48和107℃时分别发生无定形态以及晶态转变;在室温下,受阻酚AO-60用量不小于50份的复合材料的损耗因子(tanδ)达到0.2以上,而不加受阻酚AO-60的NR胶料的tanδ仅为0.05;随着受阻酚AO-60用量的增大,复合材料的F_(max)-FL减小,t_(10)和t_(90)明显延长,拉伸强度和撕裂强度减小,受阻酚AO-60用量为50份的复合材料的回弹值最小。综合来看,受阻酚AO-60用量为50份的受阻酚AO-60/NR复合材料的性能最佳。 展开更多
关键词 天然橡胶 受阻酚ao-60 阻尼性能 相态结构
下载PDF
Multi-Level Image Segmentation Combining Chaotic Initialized Chimp Optimization Algorithm and Cauchy Mutation
5
作者 Shujing Li Zhangfei Li +2 位作者 Wenhui Cheng Chenyang Qi Linguo Li 《Computers, Materials & Continua》 SCIE EI 2024年第8期2049-2063,共15页
To enhance the diversity and distribution uniformity of initial population,as well as to avoid local extrema in the Chimp Optimization Algorithm(CHOA),this paper improves the CHOA based on chaos initialization and Cau... To enhance the diversity and distribution uniformity of initial population,as well as to avoid local extrema in the Chimp Optimization Algorithm(CHOA),this paper improves the CHOA based on chaos initialization and Cauchy mutation.First,Sin chaos is introduced to improve the random population initialization scheme of the CHOA,which not only guarantees the diversity of the population,but also enhances the distribution uniformity of the initial population.Next,Cauchy mutation is added to optimize the global search ability of the CHOA in the process of position(threshold)updating to avoid the CHOA falling into local optima.Finally,an improved CHOA was formed through the combination of chaos initialization and Cauchy mutation(CICMCHOA),then taking fuzzy Kapur as the objective function,this paper applied CICMCHOA to natural and medical image segmentation,and compared it with four algorithms,including the improved Satin Bowerbird optimizer(ISBO),Cuckoo Search(ICS),etc.The experimental results deriving from visual and specific indicators demonstrate that CICMCHOA delivers superior segmentation effects in image segmentation. 展开更多
关键词 Image segmentation image thresholding chimp optimization algorithm chaos initialization Cauchy mutation
下载PDF
Fitness Sharing Chaotic Particle Swarm Optimization (FSCPSO): A Metaheuristic Approach for Allocating Dynamic Virtual Machine (VM) in Fog Computing Architecture
6
作者 Prasanna Kumar Kannughatta Ranganna Siddesh Gaddadevara Matt +2 位作者 Chin-Ling Chen Ananda Babu Jayachandra Yong-Yuan Deng 《Computers, Materials & Continua》 SCIE EI 2024年第8期2557-2578,共22页
In recent decades,fog computing has played a vital role in executing parallel computational tasks,specifically,scientific workflow tasks.In cloud data centers,fog computing takes more time to run workflow applications... In recent decades,fog computing has played a vital role in executing parallel computational tasks,specifically,scientific workflow tasks.In cloud data centers,fog computing takes more time to run workflow applications.Therefore,it is essential to develop effective models for Virtual Machine(VM)allocation and task scheduling in fog computing environments.Effective task scheduling,VM migration,and allocation,altogether optimize the use of computational resources across different fog nodes.This process ensures that the tasks are executed with minimal energy consumption,which reduces the chances of resource bottlenecks.In this manuscript,the proposed framework comprises two phases:(i)effective task scheduling using a fractional selectivity approach and(ii)VM allocation by proposing an algorithm by the name of Fitness Sharing Chaotic Particle Swarm Optimization(FSCPSO).The proposed FSCPSO algorithm integrates the concepts of chaos theory and fitness sharing that effectively balance both global exploration and local exploitation.This balance enables the use of a wide range of solutions that leads to minimal total cost and makespan,in comparison to other traditional optimization algorithms.The FSCPSO algorithm’s performance is analyzed using six evaluation measures namely,Load Balancing Level(LBL),Average Resource Utilization(ARU),total cost,makespan,energy consumption,and response time.In relation to the conventional optimization algorithms,the FSCPSO algorithm achieves a higher LBL of 39.12%,ARU of 58.15%,a minimal total cost of 1175,and a makespan of 85.87 ms,particularly when evaluated for 50 tasks. 展开更多
关键词 Fog computing fractional selectivity approach particle swarm optimization algorithm task scheduling virtual machine allocation
下载PDF
Chaotic Elephant Herd Optimization with Machine Learning for Arabic Hate Speech Detection
7
作者 Badriyya B.Al-onazi Jaber S.Alzahrani +5 位作者 Najm Alotaibi Hussain Alshahrani Mohamed Ahmed Elfaki Radwa Marzouk Heba Mohsen Abdelwahed Motwakel 《Intelligent Automation & Soft Computing》 2024年第3期567-583,共17页
In recent years,the usage of social networking sites has considerably increased in the Arab world.It has empowered individuals to express their opinions,especially in politics.Furthermore,various organizations that op... In recent years,the usage of social networking sites has considerably increased in the Arab world.It has empowered individuals to express their opinions,especially in politics.Furthermore,various organizations that operate in the Arab countries have embraced social media in their day-to-day business activities at different scales.This is attributed to business owners’understanding of social media’s importance for business development.However,the Arabic morphology is too complicated to understand due to the availability of nearly 10,000 roots and more than 900 patterns that act as the basis for verbs and nouns.Hate speech over online social networking sites turns out to be a worldwide issue that reduces the cohesion of civil societies.In this background,the current study develops a Chaotic Elephant Herd Optimization with Machine Learning for Hate Speech Detection(CEHOML-HSD)model in the context of the Arabic language.The presented CEHOML-HSD model majorly concentrates on identifying and categorising the Arabic text into hate speech and normal.To attain this,the CEHOML-HSD model follows different sub-processes as discussed herewith.At the initial stage,the CEHOML-HSD model undergoes data pre-processing with the help of the TF-IDF vectorizer.Secondly,the Support Vector Machine(SVM)model is utilized to detect and classify the hate speech texts made in the Arabic language.Lastly,the CEHO approach is employed for fine-tuning the parameters involved in SVM.This CEHO approach is developed by combining the chaotic functions with the classical EHO algorithm.The design of the CEHO algorithm for parameter tuning shows the novelty of the work.A widespread experimental analysis was executed to validate the enhanced performance of the proposed CEHOML-HSD approach.The comparative study outcomes established the supremacy of the proposed CEHOML-HSD model over other approaches. 展开更多
关键词 Arabic language machine learning elephant herd optimization TF-IDF vectorizer hate speech detection
下载PDF
Prediction of Shear Bond Strength of Asphalt Concrete Pavement Using Machine Learning Models and Grid Search Optimization Technique
8
作者 Quynh-Anh Thi Bui Dam Duc Nguyen +2 位作者 Hiep Van Le Indra Prakash Binh Thai Pham 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期691-712,共22页
Determination of Shear Bond strength(SBS)at interlayer of double-layer asphalt concrete is crucial in flexible pavement structures.The study used three Machine Learning(ML)models,including K-Nearest Neighbors(KNN),Ext... Determination of Shear Bond strength(SBS)at interlayer of double-layer asphalt concrete is crucial in flexible pavement structures.The study used three Machine Learning(ML)models,including K-Nearest Neighbors(KNN),Extra Trees(ET),and Light Gradient Boosting Machine(LGBM),to predict SBS based on easily determinable input parameters.Also,the Grid Search technique was employed for hyper-parameter tuning of the ML models,and cross-validation and learning curve analysis were used for training the models.The models were built on a database of 240 experimental results and three input variables:temperature,normal pressure,and tack coat rate.Model validation was performed using three statistical criteria:the coefficient of determination(R2),the Root Mean Square Error(RMSE),and the mean absolute error(MAE).Additionally,SHAP analysis was also used to validate the importance of the input variables in the prediction of the SBS.Results show that these models accurately predict SBS,with LGBM providing outstanding performance.SHAP(Shapley Additive explanation)analysis for LGBM indicates that temperature is the most influential factor on SBS.Consequently,the proposed ML models can quickly and accurately predict SBS between two layers of asphalt concrete,serving practical applications in flexible pavement structure design. 展开更多
关键词 Shear bond asphalt pavement grid search optimization machine learning
下载PDF
Electrode/Electrolyte Optimization‑Induced Double‑Layered Architecture for High‑Performance Aqueous Zinc‑(Dual)Halogen Batteries
9
作者 Chengwang Zhou Zhezheng Ding +7 位作者 Shengzhe Ying Hao Jiang Yan Wang Timing Fang You Zhang Bing Sun Xiao Tang Xiaomin Liu 《Nano-Micro Letters》 SCIE EI CAS 2025年第3期121-137,共17页
Aqueous zinc-halogen batteries are promising candidates for large-scale energy storage due to their abundant resources,intrinsic safety,and high theoretical capacity.Nevertheless,the uncontrollable zinc dendrite growt... Aqueous zinc-halogen batteries are promising candidates for large-scale energy storage due to their abundant resources,intrinsic safety,and high theoretical capacity.Nevertheless,the uncontrollable zinc dendrite growth and spontaneous shuttle effect of active species have prohibited their practical implementation.Herein,a double-layered protective film based on zinc-ethylenediamine tetramethylene phosphonic acid(ZEA)artificial film and ZnF2-rich solid electrolyte interphase(SEI)layer has been successfully fabricated on the zinc metal anode via electrode/electrolyte synergistic optimization.The ZEA-based artificial film shows strong affinity for the ZnF2-rich SEI layer,therefore effectively suppressing the SEI breakage and facilitating the construction of double-layered protective film on the zinc metal anode.Such double-layered architecture not only modulates Zn2+flux and suppresses the zinc dendrite growth,but also blocks the direct contact between the metal anode and electrolyte,thus mitigating the corrosion from the active species.When employing optimized metal anodes and electrolytes,the as-developed zinc-(dual)halogen batteries present high areal capacity and satisfactory cycling stability.This work provides a new avenue for developing aqueous zinc-(dual)halogen batteries. 展开更多
关键词 Zn metal anodes Double-layered protective film Electrode/electrolyte optimization Aqueous zinc-(dual)halogen batteries
下载PDF
Optimization Strategies of Na_(3)V_(2)(PO_(4))_(3) Cathode Materials for Sodium‑Ion Batteries
10
作者 Jiawen Hu Xinwei Li +4 位作者 Qianqian Liang Li Xu Changsheng Ding Yu Liu Yanfeng Gao 《Nano-Micro Letters》 SCIE EI CAS 2025年第2期204-251,共48页
Na_(3)V_(2)(PO_(4))_(3)(NVP)has garnered great attentions as a prospective cathode material for sodium-ion batteries(SIBs)by virtue of its decent theoretical capacity,superior ion conductivity and high structural stab... Na_(3)V_(2)(PO_(4))_(3)(NVP)has garnered great attentions as a prospective cathode material for sodium-ion batteries(SIBs)by virtue of its decent theoretical capacity,superior ion conductivity and high structural stability.However,the inherently poor electronic conductivity and sluggish sodium-ion diffusion kinetics of NVP material give rise to inferior rate performance and unsatisfactory energy density,which strictly confine its further application in SIBs.Thus,it is of significance to boost the sodium storage performance of NVP cathode material.Up to now,many methods have been developed to optimize the electrochemical performance of NVP cathode material.In this review,the latest advances in optimization strategies for improving the electrochemical performance of NVP cathode material are well summarized and discussed,including carbon coating or modification,foreign-ion doping or substitution and nanostructure and morphology design.The foreign-ion doping or substitution is highlighted,involving Na,V,and PO_(4)^(3−)sites,which include single-site doping,multiple-site doping,single-ion doping,multiple-ion doping and so on.Furthermore,the challenges and prospects of high-performance NVP cathode material are also put forward.It is believed that this review can provide a useful reference for designing and developing high-performance NVP cathode material toward the large-scale application in SIBs. 展开更多
关键词 Sodium-ion batteries Na_(3)V_(2)(PO_(4))_(3) Cathode materials Electrochemical performance optimization strategies
下载PDF
CHAOTIC ANNEALING NEURAL NETWORK FOR GLOBAL OPTIMIZATION OF CONSTRAINED NONLINEAR PROGRAMMING 被引量:1
11
作者 张国平 王正欧 袁国林 《Transactions of Tianjin University》 EI CAS 2001年第3期141-146,共6页
Chaotic neural networks have global searching ability.But their applications are generally confined to combinatorial optimization to date.By introducing chaotic noise annealing process into conventional Hopfield netwo... Chaotic neural networks have global searching ability.But their applications are generally confined to combinatorial optimization to date.By introducing chaotic noise annealing process into conventional Hopfield network,this paper proposes a new chaotic annealing neural network (CANN) for global optimization of continuous constrained non linear programming.It is easy to implement,conceptually simple,and generally applicable.Numerical experiments on severe test functions manifest that CANN is efficient and reliable to search for global optimum and outperforms the existing genetic algorithm GAMAS for the same purpose. 展开更多
关键词 global optimization neural network chaotic noise annealing
下载PDF
AOS中基于最优帧长的链路自适应联合优化方法
12
作者 刘庆利 郭梦田 商佳乐 《计算机应用与软件》 北大核心 2024年第4期106-111,共6页
针对AOS中数据传输误码率高的问题,导致系统吞吐量低的问题,提出基于最优帧长的链路自适应联合优化方法。该方法以系统吞吐量最大化为目标,联合可变帧长,自适应编码调制和混合自动重传请求技术进行优化,根据信道状态信息分配下一帧传输... 针对AOS中数据传输误码率高的问题,导致系统吞吐量低的问题,提出基于最优帧长的链路自适应联合优化方法。该方法以系统吞吐量最大化为目标,联合可变帧长,自适应编码调制和混合自动重传请求技术进行优化,根据信道状态信息分配下一帧传输最佳的帧长和编码调制方式,并对出错数据进行纠错和重传,最终提升系统吞吐量。仿真验证表明,与AMC-HARQ和AMC-ARQ方法相比,该方法在保证系统误帧率的同时,提高了系统的吞吐量。 展开更多
关键词 aoS空间通信 最优帧长 自适应编码调制 混合自动重传
下载PDF
基于RCMFME和AO-ELM的齿轮箱损伤识别策略
13
作者 沈羽 赵旭 《机电工程》 CAS 北大核心 2024年第2期226-235,共10页
针对模糊熵只考虑信号的局部特征而忽略信号的全局特征,导致齿轮箱故障识别的准确率不佳的问题,提出了一种基于精细复合多尺度模糊测度熵(RCMFME)、天鹰优化器(AO)优化极限学习机(ELM)的齿轮箱故障诊断方法。首先,在精细复合多尺度模糊... 针对模糊熵只考虑信号的局部特征而忽略信号的全局特征,导致齿轮箱故障识别的准确率不佳的问题,提出了一种基于精细复合多尺度模糊测度熵(RCMFME)、天鹰优化器(AO)优化极限学习机(ELM)的齿轮箱故障诊断方法。首先,在精细复合多尺度模糊熵的基础上,对矢量的构造方式进行了改进,提出了能够同时考虑时间序列局部特征和全局特征的RCMFME方法;随后,利用RCMFME指标提取了齿轮箱振动信号的熵值,组建了故障特征向量;接着,利用AO算法对极限学习机的参数进行了自适应搜索,生成了参数最优的多类别分类器;最后,将训练样本的故障特征向量输入至AO-ELM分类模型中进行了模型训练,以构造性能最优的分类器,并实现了对齿轮箱测试样本的故障识别目的;利用两种齿轮箱振动数据集进行了实验,在识别准确率和识别稳定性方面,与相关的特征提取方法进行了对比。研究结果表明:采用基于RCMFME和AO-ELM的故障诊断方法能够分别取得100%和98%的分类准确率,平均识别准确率分别达到了100%和98%,优于精细复合多尺度全局模糊熵(RCMGFE)、精细复合多尺度模糊熵(RCMFE)、精细复合多尺度样本熵(RCMSE)。该方法具有显著的应用潜力。 展开更多
关键词 齿轮箱故障诊断 精细复合多尺度模糊测度熵 天鹰优化器 极限学习机 ao-ELM分类模型 特征提取
下载PDF
AO流速/VSD处流速、LVEF/三尖瓣反流流速在室间隔缺损患儿术前的检测意义分析
14
作者 丁琰 黄春瑜 《江西医药》 CAS 2024年第5期460-463,共4页
目的探讨主动脉(AO)流速/室间隔缺损(VSD)处流速、左室射血分数(LVEF)/三尖瓣反流流速在室间隔缺损患儿术前的检测意义。方法回顾性选取2021年1月至2023年5月期间于本院接受手术治疗的81例室间隔缺损患儿的临床资料,所有患儿术前均接受... 目的探讨主动脉(AO)流速/室间隔缺损(VSD)处流速、左室射血分数(LVEF)/三尖瓣反流流速在室间隔缺损患儿术前的检测意义。方法回顾性选取2021年1月至2023年5月期间于本院接受手术治疗的81例室间隔缺损患儿的临床资料,所有患儿术前均接受超声心动图检查,收集相关检测结果(包括AO流速/VSD处流速、LVEF/三尖瓣反流流速等),统计术后并发症发生情况,根据有无术后并发症分组,进行单因素及多因素分析,建立Logistics回归模型,总结影响患儿预后的风险因素;通过ROC曲线分析,评估AO流速/VSD处流速、LVEF/三尖瓣反流流速对室间隔缺损患儿预后风险的预测价值。结果81例患儿中存在术后并发症有9例,发生率11.11%,经单因素及多因素分析,有并发症组与无并发症组缺损直径、手术时间、气管插管时间、手术类型、NYHA分级、AO流速/VSD处流速、LVEF/三尖瓣反流流速差异有统计学意义,且均为术后并发症独立影响因素(P<0.05);经ROC曲线分析,AO流速/VSD处流速、LVEF/三尖瓣反流流速对室间隔缺损患儿预后的敏感度、特异度均较高,具有一定预测价值(P<0.05)。结论影响室间隔缺损患儿术后并发症的风险因素较多,其中AO流速/VSD处流速、LVEF/三尖瓣反流流速两种指标组合对手术后风险具有较好的预测价值,可作为临床参考指标,对室间隔患儿的预后风险评估具有较高参考价值,推荐临床广泛应用,具有较好学术价值。 展开更多
关键词 ao流速/VSD处流速 LVEF/三尖瓣反流流速 室间隔缺损 患儿
下载PDF
Hybrid optimization algorithm based on chaos,cloud and particle swarm optimization algorithm 被引量:29
15
作者 Mingwei Li Haigui Kang +1 位作者 Pengfei Zhou Weichiang Hong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2013年第2期324-334,共11页
As for the drop of particle diversity and the slow convergent speed of particle in the late evolution period when particle swarm optimization(PSO) is applied to solve high-dimensional multi-modal functions,a hybrid ... As for the drop of particle diversity and the slow convergent speed of particle in the late evolution period when particle swarm optimization(PSO) is applied to solve high-dimensional multi-modal functions,a hybrid optimization algorithm based on the cat mapping,the cloud model and PSO is proposed.While the PSO algorithm evolves a certain of generations,this algorithm applies the cat mapping to implement global disturbance of the poorer individuals,and employs the cloud model to execute local search of the better individuals;accordingly,the obtained best individuals form a new swarm.For this new swarm,the evolution operation is maintained with the PSO algorithm,using the parameter of pop distr to balance the global and local search capacity of the algorithm,as well as,adopting the parameter of mix gen to control mixing times of the algorithm.The comparative analysis is carried out on the basis of 4 functions and other algorithms.It indicates that this algorithm shows faster convergent speed and better solving precision for solving functions particularly those high-dimensional multi-modal functions.Finally,the suggested values are proposed for parameters pop distr and mix gen applied to different dimension functions via the comparative analysis of parameters. 展开更多
关键词 particle swarm optimization(PSO) chaos theory cloud model hybrid optimization
下载PDF
A new adaptive mutative scale chaos optimization algorithm and its application 被引量:22
16
作者 Jiaqiang E Chunhua WANG +1 位作者 Yaonan WANG Jinke GONG 《控制理论与应用(英文版)》 EI 2008年第2期141-145,共5页
Based on results of chaos characteristics comparing one-dimensional iterative chaotic self-map x = sin(2/x) with infinite collapses within the finite region[-1, 1] to some representative iterative chaotic maps with ... Based on results of chaos characteristics comparing one-dimensional iterative chaotic self-map x = sin(2/x) with infinite collapses within the finite region[-1, 1] to some representative iterative chaotic maps with finite collapses (e.g., Logistic map, Tent map, and Chebyshev map), a new adaptive mutative scale chaos optimization algorithm (AMSCOA) is proposed by using the chaos model x = sin(2/x). In the optimization algorithm, in order to ensure its advantage of speed convergence and high precision in the seeking optimization process, some measures are taken: 1) the searching space of optimized variables is reduced continuously due to adaptive mutative scale method and the searching precision is enhanced accordingly; 2) the most circle time is regarded as its control guideline. The calculation examples about three testing functions reveal that the adaptive mutative scale chaos optimization algorithm has both high searching speed and precision. 展开更多
关键词 ADAPTIVE Mutative scale Chaos optimization algorithm One-dimensional iterative chaotic self-map
下载PDF
Parameter selection of support vector machine for function approximation based on chaos optimization 被引量:18
17
作者 Yuan Xiaofang Wang Yaonan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第1期191-197,共7页
The support vector machine (SVM) is a novel machine learning method, which has the ability to approximate nonlinear functions with arbitrary accuracy. Setting parameters well is very crucial for SVM learning results... The support vector machine (SVM) is a novel machine learning method, which has the ability to approximate nonlinear functions with arbitrary accuracy. Setting parameters well is very crucial for SVM learning results and generalization ability, and now there is no systematic, general method for parameter selection. In this article, the SVM parameter selection for function approximation is regarded as a compound optimization problem and a mutative scale chaos optimization algorithm is employed to search for optimal paraxneter values. The chaos optimization algorithm is an effective way for global optimal and the mutative scale chaos algorithm could improve the search efficiency and accuracy. Several simulation examples show the sensitivity of the SVM parameters and demonstrate the superiority of this proposed method for nonlinear function approximation. 展开更多
关键词 learning systems support vector machines (SVM) approximation theory parameter selection optimization.
下载PDF
Chaos-enhanced moth-flame optimization algorithm for global optimization 被引量:3
18
作者 LI Hongwei LIU Jianyong +3 位作者 CHEN Liang BAI Jingbo SUN Yangyang LU Kai 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第6期1144-1159,共16页
Moth-flame optimization(MFO)is a novel metaheuristic algorithm inspired by the characteristics of a moth’s navigation method in nature called transverse orientation.Like other metaheuristic algorithms,it is easy to f... Moth-flame optimization(MFO)is a novel metaheuristic algorithm inspired by the characteristics of a moth’s navigation method in nature called transverse orientation.Like other metaheuristic algorithms,it is easy to fall into local optimum and leads to slow convergence speed.The chaotic map is one of the best methods to improve exploration and exploitation of the metaheuristic algorithms.In the present study,we propose a chaos-enhanced MFO(CMFO)by incorporating chaos maps into the MFO algorithm to enhance its performance.The chaotic map is utilized to initialize the moths’population,handle the boundary overstepping,and tune the distance parameter.The CMFO is benchmarked on three groups of benchmark functions to find out the most efficient one.The performance of the CMFO is also verified by using two real engineering problems.The statistical results clearly demonstrate that the appropriate chaotic map(singer map)embedded in the appropriate component of MFO can significantly improve the performance of MFO. 展开更多
关键词 moth-flame optimization(MFO) chaotic map METAHEURISTIC global optimization
下载PDF
A new optimization algorithm based on chaos 被引量:19
19
作者 LU Hui-juan ZHANG Huo-ming MA Long-hua 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第4期539-542,共4页
In this article, some methods are proposed for enhancing the converging velocity of the COA (chaos optimization algorithm) based on using carrier wave two times, which can greatly increase the speed and efficiency of ... In this article, some methods are proposed for enhancing the converging velocity of the COA (chaos optimization algorithm) based on using carrier wave two times, which can greatly increase the speed and efficiency of the first carrier wave’s search for the optimal point in implementing the sophisticated searching during the second carrier wave is faster and more accurate. In addition, the concept of using the carrier wave three times is proposed and put into practice to tackle the multi-variables opti- mization problems, where the searching for the optimal point of the last several variables is frequently worse than the first several ones. 展开更多
关键词 Chaos optimization algorithm (COA) Carrier wave two times Multi-variables optimization Carrier wave triple frequency
下载PDF
Effect of lens constants optimization on the accuracy of intraocular lens power calculation formulas for highly myopic eyes 被引量:6
20
作者 Jia-Qing Zhang Xu-Yuan Zou +3 位作者 Dan-Ying Zheng Wei-Rong Chen Ao Sun Li-Xia Luo 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2019年第6期943-948,共6页
AIM: To evaluate the effect of different lens constant optimization methods on the accuracy of intraocular lens(IOL) power calculation formulas for highly myopic eyes.METHODS: This study comprised 108 eyes of 94 conse... AIM: To evaluate the effect of different lens constant optimization methods on the accuracy of intraocular lens(IOL) power calculation formulas for highly myopic eyes.METHODS: This study comprised 108 eyes of 94 consecutive patients with axial length(AL) over 26 mm undergoing phacoemulsification and implantation of a Rayner(Hove, UK) 920H IOL. Formulas were evaluated using the following lens constants: manufacturer’s lens constant, User Group for Laser Interference Biometry(ULIB) constant, and optimized constant for long eyes. Results were compared with Barrett Universal II formula, original Wang-Koch AL adjustment method, and modified Wang-Koch AL adjustment method. The outcomes assessed were mean absolute error(MAE) and percentage of eyes with IOL prediction errors within ±0.25, ±0.50, and ±1.0 diopter(D). The nonparametric method, Friedman test, was used to compare MAE performance among constants.RESULTS: Optimized constants could significantly reduce the MAE of SRK/T, Hoffer Q, and Holladay 1 formulas compared with manufacturer’s lens constant, whereas the percentage of eyes with IOL prediction errors within ±0.25, ±0.50, and ±1.0 D had no statistically significant differences. Optimized lens constant for long eyes alone showed non-significant refractive advantages over the ULIB constant. Barrett Universal II formula and formulas with AL adjustment showed significantly higher accuracy in highly myopic eyes(P<0.001). CONCLUSION: Lens constant optimization for the subset of long eyes reduces the refractive error only to a limited extent for highly myopic eyes. 展开更多
关键词 high MYOPIA CATARACT INTRaoCULAR LENS power LENS constant optimization prediction error
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部