网络拓扑搜索算法的分析与比较

对基于MIB -Ⅱ的网络拓扑搜索、基于OSPF的网络拓扑搜索和分布式网络拓扑搜索方法进行理论分析 ,从算法实现。

网络蜘蛛搜索算法在垂直搜索引擎中的应用

随着当前互联网技术的发展,网络无处不在,博客、网站中充斥着大量的网页信息,对于这些网页信息,如何才能被人们通过搜索引擎获取,这就要得益于网页搜索的功劳了。以下本篇浅析了在垂直搜索引擎中应用网络蜘蛛搜索算法的策略。

基于改进随机森林算法的变压器故障智能检测技术研究

针对传统变压器故障检测准确率不高的问题,提出了改进随机森林算法的变压器故障检测技术。通过对随机森林算法的分析指出决策树数量、决策树深度以及特征选择直接影响算法的性能,采用网络搜索算法对决策树数量及深度进行调整,同时通过主成分分析将不重要的特征去除,实现对随机森林算法的改进。将改进的随机森林算法应用于变压器故障检测中,其对变压器故障检测的性能明显由于传统随机森林算法。这对快速、精准检测变压器故障,确保电网安全运行具有一定的参考价值。

一种新型IP网络拓扑分级构造算法及实现

针对传统网络自动搜索算法的不足,在采用遗传算法和分级思想的基础上,提出了一种新型拓扑分级构造算法。该算法能大大地减少网络拓朴生成的运算时间,同时能够高效清晰地呈现整个网络的拓扑关系。

新型群体智能算法优化BIGRU/BILSTM的水资源空间均衡评价

为科学评价云南省2006-2022年及2025年水资源空间均衡状态,建立基于社交网络搜索(SNS)算法、登山队优化(MTBO)算法优化双向门控循环单元(BIGRU)、双向长短时记忆(BILSTM)网络的水资源空间均衡评价模型。首先,从水资源支撑、水资源压力、水资源调控力3个方面遴选15个指标构建水资源空间均衡评价指标体系和等级标准,采用线性内插和随机选取的方法生成样本构建BIGRU、BILSTM适应度函数;其次,简要介绍SNS、MTBO算法原理,利用SNS、MTBO优化BiGRU、BiLSTM隐含层神经元数、学习率(超参数)构建SNS-BIGRU、MTBO-BIGRU、SNS-BILSTM、MTBOBILSTM模型,通过不同样本大小和连续10次运行的方法验证SNS-BIGRU等4种模型的稳健性;最后利用SNS-BIGRU、MTBO-BIGRU、SNS-BILSTM、MTBO-BILSTM模型对云南省2006-2022年及2025年水资源空间均衡进行评价,并与SNS-支持向量机(SVM)、MTBO-SVM和模糊综合评价法的评价结果作对比。结果表明:①所建立的SNS-BIGRU等4种模型具有较好的识别精度和稳健性能;SNS、MTBO能有效优化BIGRU、BILSTM超参数,提升BIGRU、BILSTM预测性能。②SNS-BIGRU等4种模型对云南省2006-2011年水资源空间均衡评价为“不均衡”,2012-2013年评价为“较不均衡”,2014-2018年评价为“临界均衡”,2019-2022年评价为“较均衡”,2025年基本可达到“均衡”水平;4种模型评价结果与SNSSVM、MTBO-SVM、模糊综合评价法有3年存在1个等级的差异。本文构建及提出的模型方法可为水资源空间均衡评价提供参考与借鉴。

基于谱聚类的主动配电网多时间尺度无功优化策略

高比例分布式光伏接入配电网后,传统优化方案无法有效平抑电压波动,分布式光伏逆变器的无功调控能力难以充分利用。为此,提出一种基于谱聚类的主动配电网多时间尺度无功优化策略,该方法分为日前优化和日内实时优化两个阶段。首先,对离散设备的时间耦合性进行解耦,以配电网网损、平均电压偏差、电压波动严重程度为目标函数,建立基于社交网络搜索算法的日前无功优化模型,确定离散设备静态最优档位序列;其次,通过谱聚类的方法进行耦合,确定离散设备动态最优档位序列,结合改进的分布式光伏逆变器就地控制策略,建立日内实时优化模型,从而抑制日前预测数据偏差导致的电压波动;最后,基于改进后的IEEE33节点系统进行仿真实验。仿真结果表明,所提策略可以有效降低运算难度、提高求解效率,验证了该策略的有效性和优越性。

基于数据驱动的低感知度配电网动态无功优化

由于配电网网络通信基础设施较差,且节点监控覆盖不完全,因此存在无法实时采集数据的节点,导致无法进行传统无功优化。为此,提出了一种数据驱动的低感知度配电网动态无功优化方法。通过K-means算法聚类节点历史负荷,对非实时观测节点依据特征分类;选择最优超参数基于时间卷积网络进行量测数据补全;最终通过改进后的社交网络搜索算法实现动态无功优化,并仿真验证了方法的有效性。

Wind speed forecasting based on wavelet decomposition and wavelet neural networks optimized by the Cuckoo search algorithm

Wind speed forecasting is of great importance for wind farm management and plays an important role in grid integration. Wind speed is volatile in nature and therefore it is difficult to predict with a single model. In this study, three hybrid multi-step wind speed forecasting models are developed and compared — with each other and with earlier proposed wind speed forecasting models. The three models are based on wavelet decomposition(WD), the Cuckoo search(CS) optimization algorithm, and a wavelet neural network(WNN). They are referred to as CS-WD-ANN(artificial neural network), CS-WNN, and CS-WD-WNN, respectively. Wind speed data from two wind farms located in Shandong, eastern China, are used in this study. The simulation result indicates that CS-WD-WNN outperforms the other two models, with minimum statistical errors. Comparison with earlier models shows that CS-WD-WNN still performs best, with the smallest statistical errors. The employment of the CS optimization algorithm in the models shows improvement compared with the earlier models.

Routing Protocol Based on Grover’s Searching Algorithm for Mobile Ad-hoc Networks

In Mobile Ad-hoc Networks (MANETs), routing protocols directly affect various indices of network Quality of Service (QoS), so they play an important role in network performance. To address the drawbacks associated with traditional routing protocols in MANETs, such as poor anti-fading performance and slow convergence rate, for basic Dynamic Source Routing (DSR), we propose a new routing model based on Grover's searching algorithm. With this new routing model, each node maintains a node vector function, and all the nodes can obtain a node probability vector using Grover's algorithm, and then select an optimal routing according to node probability. Simulation results show that compared with DSR, this new routing protocol can effectively extend the network lifetime, as well as reduce the network delay and the number of routing hops. It can also significantly improve the anti-jamming capability of the network.

Distributed Localization Algorithm for Wireless Sensor Network Based on Multidimensional Scaling and the Shortest Path Distance Correction

Sensor localization is crucial for the configuration and applications of wireless sensor network (WSN). A novel distributed localization algorithm, MDS-DC was proposed for wireless sensor network based on multidimensional scaling (MDS) and the shortest path distance correction. In MDS-DC, several local positioning regions with reasonable distribution were firstly constructed by an adaptive search algorithm, which ensures the mergence between the local relative maps of the adjacent local position regions and can reduce the number of common nodes in the network. Then, based on the relationships between the estimated distances and actual distances of anchors, the distance estimation vectors of sensors around anchors were corrected in each local positioning region. During the computations of the local relative coordinates, an iterative process, which is the combination of classical MDS algorithm and SMACOF algorithm, was applied. Finally, the global relative positions or absolute positions of sensors were obtained through merging the relative maps of all local positioning regions. Simulation results show that MDS-DC has better performances in positioning precision, energy efficiency and robustness to range error, which can meet the requirements of applications for sensor localization in WSN.

Network coding resources optimization with transmission delay constraint in multicast networks

Minimizing network coding resources of multicast networks,such as the number of coding nodes or links,has been proved to be NP-hard,and taking propagation delay into account makes the problem more complicated. To resolve this optimal problem,an integer encoding routing-based genetic algorithm( REGA) is presented to map the optimization problem into a genetic algorithm( GA)framework. Moreover,to speed up the search process of the algorithm,an efficient local search procedure which can reduce the searching space size is designed for searching the feasible solution.Compared with the binary link state encoding representation genetic algorithm( BLSGA),the chromosome length of REGA is shorter and just depends on the number of sinks. Simulation results show the advantages of the algorithm in terms of getting the optimal solution and algorithmic convergence speed.

Power loss reduction of distribution systems using BFO based optimal reconfiguration along with DG and shunt capacitor placement simultaneously in fuzzy framework

In distribution systems,network reconfiguration and capacitor placement are commonly used to diminish power losses and keep voltage profiles within acceptable limits.Moreover,the problem of DG allocation and sizing is great important.In this work,a combination of a fuzzy multi-objective approach and bacterial foraging optimization(BFO) as a meta-heuristic algorithm is used to solve the simultaneous reconfiguration and optimal sizing of DGs and shunt capacitors in a distribution system.Each objective is transferred into fuzzy domain using its membership function.Then,the overall fuzzy satisfaction function is formed and considered a fitness function inasmuch as the value of this function has to be maximized to gain the optimal solution.The numerical results show that the presented algorithm improves the performance much more than other meta-heuristic algorithms.Simulation results found that simultaneous reconfiguration with DG and shunt capacitors allocation(case 5) has 77.41%,42.15%,and 56.14%improvements in power loss reduction,load balancing,and voltage profile indices,respectively in 33-bus test system.This result found 87.27%,35.82%,and 54.34%improvements of mentioned indices respectively for 69-bus system.

Global optimization by small-world optimization algorithm based on social relationship network

A fast global convergence algorithm, small-world optimization (SWO), was designed to solve the global optimization problems, which was inspired from small-world theory and six degrees of separation principle in sociology. Firstly, the solution space was organized into a small-world network model based on social relationship network. Secondly, a simple search strategy was adopted to navigate into this network in order to realize the optimization. In SWO, the two operators for searching the short-range contacts and long-range contacts in small-world network were corresponding to the exploitation and exploration, which have been revealed as the common features in many intelligent algorithms. The proposed algorithm was validated via popular benchmark functions and engineering problems. And also the impacts of parameters were studied. The simulation results indicate that because of the small-world theory, it is suitable for heuristic methods to search targets efficiently in this constructed small-world network model. It is not easy for each test mail to fall into a local trap by shifting into two mapping spaces in order to accelerate the convergence speed. Compared with some classical algorithms, SWO is inherited with optimal features and outstanding in convergence speed. Thus, the algorithm can be considered as a good alternative to solve global optimization problems.

蛋鸡设施养殖环境质量评价预测模型构建方法及性能测试

蛋鸡设施养殖环境质量对蛋鸡的健康生长和生产性能的提升至关重要。蛋鸡养殖环境是多环境因子相互影响制约的复杂非线性系统,凭借单一的养殖环境参数难以对环境质量做出准确有效的评价。针对上述问题,本研究综合蛋鸡设施养殖环境的温度、湿度、光照强度、氨气浓度等多个环境影响因子,在布谷鸟搜索算法优化神经网络(CS-BP)预测模型的基础上,构建了改进的CS-BP的蛋鸡设施养殖环境质量评价预测模型。将构建的改进CS-BP预测模型与BP神经网络、遗传算法优化BP神经网络(GA-BP)、粒子群算法优化BP神经网络(PSO-BP)3种深度学习方法进行性能参数分析比对,结果表明:改进CS-BP评价预测模型的平均绝对误差(MAE)、平均相对误差(MAPE)和决定系数(R2)分别为0.0865、0.0159和0.8569,其各项指标性能均优于上述3种对比模型,该模型具有较强的模型泛化能力和较高的预测精度。对改进CS-BP的蛋鸡设施养殖环境质量评价模型进行测试,其分类准确率达0.9333以上。本研究构建的模型可以为蛋鸡设施养殖环境质量提供更加全面有效的科学评价,对实现蛋鸡生产环境的最优控制,促进蛋鸡生产性能的提升具有重要意义。

On Minimizing Delay with Probabilistic Splitting of Traffic Flow in Heterogeneous Wireless Networks

In the paper,we propose a framework to investigate how to effectively perform traffic flow splitting in heterogeneous wireless networks from a queue point.The average packet delay in heterogeneous wireless networks is derived in a probabilistic manner.The basic idea can be understood via treating the integrated heterogeneous wireless networks as different coupled and parallel queuing systems.The integrated network performance can approach that of one queue with maximal the multiplexing gain.For the purpose of illustrating the effectively of our proposed model,the Cellular/WLAN interworking is exploited.To minimize the average delay,a heuristic search algorithm is used to get the optimal probability of splitting traffic flow.Further,a Markov process is applied to evaluate the performance of the proposed scheme and compare with that of selecting the best network to access in terms of packet mean delay and blocking probability.Numerical results illustrate our proposed framework is effective and the flow splitting transmission can obtain more performance gain in heterogeneous wireless networks.

Integrating Tabu Search in Particle Swarm Optimization for the Frequency Assignment Problem

In this paper, we address one of the issues in the frequency assignment problem for cellular mobile networks in which we intend to minimize the interference levels when assigning frequencies from a limited frequency spectrum. In order to satisfy the increasing demand in such cellular mobile networks, we use a hybrid approach consisting of a Particle Swarm Optimization(PSO) combined with a Tabu Search(TS) algorithm. This approach takes both advantages of PSO efficiency in global optimization and TS in avoiding the premature convergence that would lead PSO to stagnate in a local minimum. Moreover, we propose a new efficient, simple, and inexpensive model for storing and evaluating solution's assignment. The purpose of this model reduces the solution's storage volume as well as the computations required to evaluate thesesolutions in comparison with the classical model. Our simulation results on the most known benchmarking instances prove the effectiveness of our proposed algorithm in comparison with previous related works in terms of convergence rate, the number of iterations, the solution storage volume and the running time required to converge to the optimal solution.

基于BiX-NAS的地震层序智能识别--以荷兰近海地区F3数据为例

近些年来,深度学习方法在地震数据处理和解释领域得到了广泛关注和应用,其中大多数深度学习算法采用了端到端的深度卷积神经网络以实现地质体特征的提取与识别(如地层、断裂以及盐丘等).然而,这些算法往往含有数十万甚至百万的可训练参数,导致模型存在参数冗余、训练效率低等问题.为了解决上述问题,构建了一个轻量化的双向多尺度网络结构模型用于地震层序智能识别.该模型通过两阶段神经网络体系结构搜索算法(neural architecture search,NAS)剔除了双向多尺度网络结构的冗余连接,使得网络结构大幅简化,从而减少参数冗余,进而提高训练效率.采用荷兰近海地区的F3地震数据集对基于NAS算法简化的双向多尺度网络结构地层识别模型进行训练、验证和预测.结果表明:在实际的地层识别任务中,该轻量化模型的平均识别准确率达到了95.52%,并对远离训练工区的预测集具有良好的泛化性.此外,该模型的参数量仅为U形卷积神经网络(U-Net)模型的4.4%,在训练效率、模型参数量等方面优于前人的相关研究工作;并对地震振幅中的噪声干扰具有鲁棒性.因此,这些结果展现了BiX-NAS网络模型在实际地震地层自动识别中良好的应用前景.