Analysis on Spiral Search Pattern for Moving Target

The distribution function of the target moving in constant velocity and linear course and its meeting condition to the searcher are analyzed.Another proof method for spiral search pattern is presented and the mathematic model of the target possible position is established when performing the linear search.Base on them,the wrong idea about the spiral search pattern can be

Database Search Behaviors: Insight from a Survey of Information Retrieval Practices

This study examines the database search behaviors of individuals, focusing on gender differences and the impact of planning habits on information retrieval. Data were collected from a survey of 198 respondents, categorized by their discipline, schooling background, internet usage, and information retrieval preferences. Key findings indicate that females are more likely to plan their searches in advance and prefer structured methods of information retrieval, such as using library portals and leading university websites. Males, however, tend to use web search engines and self-archiving methods more frequently. This analysis provides valuable insights for educational institutions and libraries to optimize their resources and services based on user behavior patterns.

A Filter-Based Pattern Search Method for Unconstrained Optimization

We discuss a filter-based pattern search method for unconstrained optimization in this paper. For the purpose to broaden the search range we use both filter technique and frames, which are fragments of grids, to provide a new criterion of iterate acceptance. The convergence can be ensured under some conditions. The numerical result shows that this method is practical and efficient.

Adaptive backtracking search optimization algorithm with pattern search for numerical optimization

The backtracking search optimization algorithm（BSA） is one of the most recently proposed population-based evolutionary algorithms for global optimization. Due to its memory ability and simple structure, BSA has powerful capability to find global optimal solutions. However, the algorithm is still insufficient in balancing the exploration and the exploitation. Therefore, an improved adaptive backtracking search optimization algorithm combined with modified Hooke-Jeeves pattern search is proposed for numerical global optimization. It has two main parts： the BSA is used for the exploration phase and the modified pattern search method completes the exploitation phase. In particular, a simple but effective strategy of adapting one of BSA＇s important control parameters is introduced. The proposed algorithm is compared with standard BSA, three state-of-the-art evolutionary algorithms and three superior algorithms in IEEE Congress on Evolutionary Computation 2014（IEEE CEC2014） over six widely-used benchmarks and 22 real-parameter single objective numerical optimization benchmarks in IEEE CEC2014. The results of experiment and statistical analysis demonstrate the effectiveness and efficiency of the proposed algorithm.

An Efficient Pattern Search Method

Pattern search algorithms is one of most frequently used methods which were designed to solve the derivative-free optimization problems. Such methods get growing need with the development of science, engineering, economy and so on. Inspired by the idea of Hooke and Jeeves, we introduced an integer m in the algorithm which controls the number of steps of iteration update. We mean along the descent direction to allow the algorithm to?go ahead m steps at most to explore whether we can get better solution further. The experiment proved the strategy’s efficiency.

A hybrid stochastic fractal search and pattern search technique based cascade PI-PD controller for automatic generation control of multi-source power systems in presence of plug in electric vehicles

A hybrid Stochastic Fractal Search plus Pattern Search （hSFS-PS） based cascade PI-PD controller is suggested in this paper for Automatic Generation Control （AGC） of thermal, hydro and gas power unit based power systems in presence of Plug in Electric Vehicles （PEV）. Firstly, a single area multi-source power system consisting of thermal hydro and gas power plants is considered and parameters of Integral （I） controller is optimized by Stochastic FractaI Search （SFS） algorithm. The superiority of SFS algorithm over some recently proposed approaches such as optimal control, differential evolution and teaching learning based optimization techniques is demonstrated by comparing simulation results for the identical power system. To improve the system performance further, Pattern Search （PS） is subsequently employed. The study is further extended for different controllers like PI, PID, and cascaded PI-PD controller and the superiority of cascade PI-PD controller over conventional controllers is demonstrated. Then, cascade PI- PD controller parameters of AGC searched using the proposed hSFS-PS algorithm in presence of plug in electric vehicles. The study is also extended to an interconnected power system. It is seen from the comparative analysis that hSFS-PS tuned PI-PD controller in single and multi-area with multi sources improves the system frequency stability in complicated situations. Lastly, a three area interconnected system with PEVs with dissimilar cascade PI-PD controller in each area is considered and proposed hSFS- PS algorithm is used to tune the controller parameters in presence of nonlinearities like rate constraint of units, dead zone of governor and communication delay.

A Novel Mathematical Model for Similarity Search in Pattern Matching Algorithms

Modern applications require large databases to be searched for regions that are similar to a given pattern. The DNA sequence analysis, speech and text recognition, artificial intelligence, Internet of Things, and many other applications highly depend on pattern matching or similarity searches. In this paper, we discuss some of the string matching solutions developed in the past. Then, we present a novel mathematical model to search for a given pattern and it’s near approximates in the text.

A new damping ratio identification method based on pattern search

In order to improve the effectiveness of traditional time domain identification methods in identifying damping ratios, a new damping ratio identification method based on pattern search is proposed by fluctuating the reliable natural frequency obtained through traditional time domain identification methods by about 10% to build the boundary conditions, using all the initial identification results to establish the free decay response of the system, and using the pattern search method to correct the initial identification results with the residual sum of squares between the free decay response and the actually measured free-decay signal as the objective function. The proposed method deals with the actually measured free-decay signal with curve fitting and avoids enlarging the identified error caused by intermediate conversion, so it can effectively improve the identified accuracy of damping ratios. Simulations for a room-sized vibration isolation foundation show that the relative errors of analyzed three damping ratios are down to 1.05%, 1.51% and 3.7% by the proposed method from 8.42%, 5.85% and 8.5% by STD method when the noise level is 10%.

Economic Dispatch with Convex and Non-Convex Fuel Cost Functions Including Line Losses Using Pattern Search

This article presents an application of generalized pattern search （PS） algorithm to solve economic load dispatch （ELD） problems with convex and non-convex fuel cost objective functions. Main objective of ELI） is to determine the most economic generating dispatch required to satisfy the predicted load demands including line losses. Relaxing various equality and inequality constraints are considered. The unit operation minhnum/maximum constraints, effects of valve-point and line losses are considered for the practical applications. Several case studies were tested and verified, which indicate an improvement in total fuel cost savings. The robustness of the proposed PS method have been assessed and investigated through intensive comparisons with reported results in recent researches. The results are very encouraging and suggesting that PS may be very useful tool in solving power system ELD problems.

Determination of AVR System PID Controller Parameters Using Improved Variants of Reptile Search Algorithm and a Novel Objective Function

Two novel improved variants of reptile search algorithm(RSA),RSA with opposition-based learning(ORSA)and hybrid ORSA with pattern search(ORSAPS),are proposed to determine the proportional,integral,and derivative(PID)controller parameters of an automatic voltage regulator(AVR)system using a novel objective function with augmented flexibility.In the proposed algorithms,the opposition-based learning technique improves the global search abilities of the original RSA algorithm,while the hybridization with the pattern search(PS)algorithm improves the local search abilities.Both algorithms are compared with the original RSA algorithm and have shown to be highly effective algorithms for tuning the PID controller parameters of an AVR system by getting superior results.Several analyses such as transient,stability,robustness,disturbance rejection,and trajectory tracking are conducted to test the performance of the proposed algorithms,which have validated the good promise of the proposed methods for controller designs.The performances of the proposed design approaches are also compared with the previously reported PID controller parameter tuning approaches to assess their success.It is shown that both proposed approaches obtain excellent and robust results among all compared ones.That is,with the adjustment of the weight factorα,which is introduced by the proposed objective function,for a system with high bandwitdh(α=1),the proposed ORSAPS-PID system has 2.08%more bandwidth than the proposed ORSA-PID system and 5.1%faster than the fastest algorithm from the literature.On the other hand,for a system where high phase and gain margins are desired(α=10),the proposed ORSA-PID system has 0.53%more phase margin and 2.18%more gain margin than the proposed ORSAPS-PID system and has 0.71%more phase margin and 2.25%more gain margin than the best performing algorithm from the literature.

A novel adjustable multiple cross-hexagonal search algorithm for fast block motion estimation

In this paper,we propose a novel adjustable multiple cross-hexagonal search(AMCHS) algorithm for fast block motion estimation. It employs adjustable multiple cross search patterns(AMCSP) in the first step and then uses half-way-skip and half-way-stop technique to determine whether to employ two hexagonal search patterns(HSPs) subsequently. The AMCSP can be used to find small motion vectors efficiently while the HSPs can be used to find large ones accurately to ensure prediction quality. Simulation results showed that our proposed AMCHS achieves faster search speed,and provides better distortion performance than other popular fast search algorithms,such as CDS and CDHS.

基于遗传-模式搜索算法的微尺度管控区域大气污染物PM2.5溯源

针对微尺度管控区域可能发生的大气污染提出有效的靶向诊断方法-结合高斯烟羽模型和遗传-模式搜索算法的大气污染物分布式溯源方法.将污染源反算模型得到的污染物理论质量浓度与传感器网络观测值的数据对应关系作为目标函数,使用模式搜索算法嵌入遗传算法加快反算模型的搜索过程,反算得到污染源强度和位置.依托杭州市亚运板球场馆大气感知器网络进行实验验证,监测2021年10月PM2.5质量浓度、气象数据,对所提出的混合式大气污染溯源方法进行实验验证.实验结果表明:改进遗传-模式搜索算法对于多维变量的搜索效果较好,能快速精准地反算污染源的位置和强度,可以为微尺度管控区域突发性气体污染防治提供应急决策参考.

基于可更新加密的保护搜索模式的动态可搜索加密方案

动态可搜索对称加密(Dynamic Searchable Symmetric Encryption,DSSE)技术作为静态可搜索加密技术的拓展,因解决了数据密态场景下的安全检索问题并支持数据动态更新而备受关注。众所周知,目前大多数DSSE方案会泄露一些额外的信息以寻求更好的效率,如搜索模式与访问模式。最近的研究表明,这些泄露的信息面临着严重的安全问题,拥有数据库背景知识的敌手可能利用这些泄露信息恢复查询或重构数据库。由于这些泄露是伴随着查询的过程泄露出来的,因此不少学者提出在搜索时更新加密数据库来降低上述潜在的风险,即用户下载搜索到的密文数据到本地,解密后重新加密再上传到云服务器端。但这种方法会导致巨大的客户端通信、存储和计算开销。针对这一问题,提出了一种基于可更新加密的保护搜索模式的DSSE方案,该方案可以在不泄露数据隐私的情况下直接在服务器端进行数据更新,从而降低传统更新方法的通信开销以及客户端的计算开销。安全性分析表明,所提方案能有效保护搜索模式泄露;性能分析表明,所提方案相比传统利用更新密文方法保护搜索模式的方案能有效降低通信开销。在关键词匹配100个文档的情况下,与下载到本地重加密重传方式相比,所提方案的通信开销降低了70.92%。

Quantum Algorithm for Mining Frequent Patterns for Association Rule Mining

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.

融合模式搜索的蝗虫优化算法及其应用

在智能优化算法应用于复杂优化问题的求解过程中,平衡开发和探索以获得最优解具有重要意义。因此针对传统蝗虫优化算法在处理一些较为复杂的优化问题时出现的收敛精度低、搜索能力弱且容易陷入局部最优等缺陷,提出一种融合模式搜索的蝗虫优化算法。首先引入Sine混沌映射初始化蝗虫个体种群位置,减少个体重叠概率以增强种群迭代初期的多样性;其次利用模式搜索法,对种群目前找到的最优目标展开局部搜索,提高算法的收敛速度与寻优精度;同时为了避免算法后期陷入局部最优,引入了基于凸透镜成像的反向学习策略。实验部分通过对改进的蝗虫算法进行消融实验,验证了Sine混沌映射、模式搜索、反向学习每个策略的独立有效性。并用两组测试函数进行仿真实验,采用Wilcoxon秩和检验、Friedman检验的方法进行结果分析。实验结果均表明了融合模式搜索法改进的蝗虫算法在收敛速度与寻优精度上得到明显提高。最后,将其应用于移动机器人路径规划,测试结果进一步验证了改进算法的有效性。

基于天气状态模式识别的SSA-BP神经网络光伏电厂功率及碳减排量预测

文章提出了一种基于天气状态模式识别并结合SSA-BP(Sparrow Search Algorithm-Back Propagation)预测光伏出力的方法。首先,在分析辐照度、温度、风速等参数变化规律基础上,基于高斯混合模型,针对专业天气类型开展分类,获得类晴、类雨和类阴3种典型的广义天气;然后,将数据作为SSA-BP神经网络输入,对光伏电厂出力分类进行预测;最后,结合碳核算方法学对光伏发电项目碳减排量进行核算。结果表明:利用分类识别和改进的SSA-BP神经网络,在3种天气类型预测中平均相对误差分别为0.195,0.243,0.310;SSA-BP与其他模型相比,平均相对误差降低了17.8%~66.7%。此外,预测CO_(2)减排量与实际核算值相对误差为3.37%,亦表现出良好预测效果。

混合模式搜索差分进化算法研究及其在高压容器概率优化中的应用

为求解高压容器的概率优化问题,提升差分进化算法的收敛速度,提出一种基于模式搜索算法的混合差分进化算法。该算法在差分进化算法的后期,引入模式搜索算子,以当前群体最优点作为模式搜索算子的基点进行模式搜索。仿真结果表明该混合算法收敛速度明显要优于差分进化算法。最后建立高压容器的概率优化设计模型,利用混合算法求解高压容器优化问题的确定型优化模型及概率优化模型,结果表明概率优化模型的优化结果更合理可靠。

基于改进列计算的空间并置模式挖掘方法

空间并置(co-location)模式挖掘旨在发现空间特征间的关联关系,是空间数据挖掘的重要研究方向。基于列计算的空间并置模式挖掘方法(CPM-Col算法)避开挖掘过程中最耗时的表实例生成操作,直接搜索模式的参与实例,成为当前高效的方法之一。然而,回溯法搜索参与实例仍是该方法的瓶颈,尤其在稠密数据和长模式下。为加速参与实例的搜索,充分利用CPM-Col算法搜索参与实例时得到的行实例,在不增加额外计算的前提下对CPM-Col算法进行两点改进。首先,将CPM-Col算法搜索到的行实例存储为部分表实例,利用子模式的部分表实例快速确定参与实例,避免了大量实例的回溯计算。其次,在CPM-Col算法获得一条行实例后,利用行实例的子团反作用于第一个特征,得到第一个特征的参与实例,避免了这些实例的回溯搜索。由此,提出了基于改进列计算的空间并置模式挖掘算法(CPM-iCol算法),并讨论了算法的复杂度、正确性和完备性。在合成数据和真实数据集上进行了实验,与经典的传统算法join-less和CPM-Col进行对比,CPM-iCol算法明显缩短了挖掘的时间,减少了回溯的次数。实验结果表明,该算法比CPM-Col具有更好的性能和可扩展性,特别在稠密数据集中效果更加明显。

细菌趋向性启发的多机器人图案生成策略

针对多机器人图案生成问题,本文提出了一种细菌趋向性启发的多机器人分阶式控制策略。该策略将图案生成过程分解为2个阶段:聚集阶段和图案生成阶段。聚集阶段,设计基于平均距离的适应度函数,其值作为机器人的感知输入。机器人根据当前时刻与上一时刻适应度数值变化执行类似细菌趋向的直行或翻转来完成聚集。引入搜索因子促进多子群融合,提升多机器人聚集的成功率。图案生成阶段,针对机器人翻转角度生成问题,引入决策因子来评估邻居作用程度,提升多机器人图案生成的成功率。仿真实验结果表明:针对多机器人六边形和三角形图案生成,本文所提出策略平均迭代次数分别为25.36和93.83,成功率分别为83.33%和96.67%,优于相关对比算法。

基于改进甲壳虫全域搜索算法的机织物疵点检测

为解决深度学习模型在面对跨场景的织物疵点检测时存在泛化性能差的问题,在甲壳虫全域搜索算法(BAS)的基础上添加了本地搜索能力构建了一种基于甲壳虫算法的混合算法,该算法可具体分为训练阶段和检测阶段。在训练阶段,通过对无疵点织物进行训练构建二维Gabor滤波器,然后使用改进BAS的混合模型对Gabor滤波器的参数进行了优化,使改进后的算法具备全局搜索和局部搜索的能力;在检测阶段,根据在训练阶段获得最佳参数构造Gabor滤波器,对待检测的织物图像进行卷积运算,并对卷积后图像进行二值化处理,最终识别待测试织物是否含有疵点。实验结果表明:该方法的特征提取具有良好的类别区分性,更加集中在疵点范围内,检测准确率可达99.26%,具有良好的稳定性和泛化性能。