Inversion of Seabed Geotechnical Properties in the Arctic Chukchi Deep Sea Basin Based on Time Domain Adaptive Search Matching Algorithm

The chirp sub-bottom profiler,for its high resolution,easy accessibility and cost-effectiveness,has been widely used in acoustic detection.In this paper,the acoustic impedance and grain size compositions were obtained based on the chirp sub-bottom profiler data collected in the Chukchi Plateau area during the 11th Arctic Expedition of China.The time-domain adaptive search matching algorithm was used and validated on our established theoretical model.The misfit between the inversion result and the theoretical model is less than 0.067%.The grain size was calculated according to the empirical relationship between the acoustic impedance and the grain size of the sediment.The average acoustic impedance of sub-seafloor strata is 2.5026×10^(6) kg(s m^(2))^(-1)and the average grain size(θvalue)of the seafloor surface sediment is 7.1498,indicating the predominant occurrence of very fine silt sediment in the study area.Comparison of the inversion results and the laboratory measurements of nearby borehole samples shows that they are in general agreement.

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.

Harmony search optimization applied to reservoir engineering assisted history matching

Based on the analysis of characteristics and advantages of HSO(harmony search optimization) algorithm, HSO was used in reservoir engineering assisted history matching of Kareem reservoir in Amal field in the Gulf of Suez, Egypt. HSO algorithm has the following advantages:(1) The good balance between exploration and exploitation techniques during searching for optimal solutions makes the HSO algorithm robust and efficient.(2) The diversity of generated solutions is more effectively controlled by two components, making it suitable for highly non-linear problems in reservoir engineering history matching.(3) The integration between the three components(harmony memory values, pitch adjusting and randomization) of the HSO helps in finding unbiased solutions.(4) The implementation process of the HSO algorithm is much easier. The HSO algorithm and two other commonly used algorithms(genetic and particle swarm optimization algorithms) were used in three reservoir engineering history match questions of different complex degrees, which are two material balance history matches of different scales and one reservoir history matching. The results were compared, which proves the superiority and validity of HSO. The results of Kareem reservoir history matching show that using the HSO algorithm as the optimization method in the assisted history matching workflow improves the simulation quality and saves solution time significantly.

Parallel Quick Search Algorithm for the Exact String Matching Problem Using OpenMP

String matching is seen as one of the essential problems in computer science. A variety of computer applications provide the string matching service for their end users. The remarkable boost in the number of data that is created and kept by modern computational devices influences researchers to obtain even more powerful methods for coping with this problem. In this research, the Quick Search string matching algorithm are adopted to be implemented under the multi-core environment using OpenMP directive which can be employed to reduce the overall execution time of the program. English text, Proteins and DNA data types are utilized to examine the effect of parallelization and implementation of Quick Search string matching algorithm on multi-core based environment. Experimental outcomes reveal that the overall performance of the mentioned string matching algorithm has been improved, and the improvement in the execution time which has been obtained is considerable enough to recommend the multi-core environment as the suitable platform for parallelizing the Quick Search string matching algorithm.

Error Searching System with Keyword Extraction and Keyword Fuzzy Matching

This paper has proposed an error searching method to search the solutions of errors that occurred in the unified commanding platform mix-deployed software (UCPMD). Because those errors belong to different stages or may be happened in different services, applications, IP ports, system software, or different versions of software, and those errors are also can be classified into different types. It is necessary to locate accurate reason that cause an error as well as find out its solution. The proposed error searching system applies Chinese keyword extraction and Chinese fuzzy matching between keywords, which considers the processed keywords as the index to find out the solutions of errors. Besides, the error searching system had made correspondence among errors, reasons, and solutions, and put them to different categories in terms of their characteristics, such that it is easy to manage, search, and use. Among others, we have added specialized thesaurus as the index of keywords, which enriches and completes the searching results. Because of the proposed error searching system evolves keyword extraction and keyword fuzzy matching technologies;it is more accurate to find out user-interested solutions.

基于改进随机森林回归模型的木材染色配方预测研究

为提高木材染色计算机智能配色的准确性和实用性,选择(樟子松)单板为染色材,以随机森林回归模型为基础,先用随机搜索算法(RS)寻找模型最优参数,再引入主成分分析法(PCA)进行特征提取,并以配方的均方误差作为评价指标。与固定参数的随机森林回归模型(RFR)模型及其他模型相比,优化后的模型(PCA-RS-RFR)配方均方误差为0.00491,相较于固定参数RFR(0.00695)、RS-RFR(0.00618)等具有明显优势,运行效率也较出色。

基于深度学习语义匹配的通用智能问答系统的设计与实现

FAQ问答系统有着广泛的实际应用场景,但传统问答系统的搭建通常需要将相关领域的知识转化为一系列的规则和知识图谱,且构建过程重度依赖人力,换个场景或用户都需要大量的重复劳动。针对上述问题并结合Bert模型和向量搜索引擎Faiss,本文设计了一种基于深度学习语义匹配的FAQ问答系统的解决方案,介绍了系统的工作原理和设计流程,可以方便快速地搭建面向特定领域的问答系统,有效地减少了文本预处理的过程,实现了秒级的查询响应。系统测试发现,可以很好地对用户的查询进行语义匹配,并返回正确的答案,为构建各种问答系统提供了一种通用的解决思路。

基于改进NCC算法的大尺寸原位风机叶片可见光图像拼接

风机叶片的原位检修与维护对保证风电机组的安全运行起着至关重要的作用,目前主流的无人机巡检方式需要对风机叶片图像进行全景拼接以进一步定位分析叶片的微小缺陷和评估叶片的整体状态。针对风机叶片结构单一纹理稀疏难以拼接的问题,提出一种改进归一化互相关NCC算法的图像拼接技术,利用Canny边缘检测算法提取叶片边缘并进行筛选去重得到边界坐标,将NCC算法沿叶片边界坐标搜索匹配以简化搜索路径加快运算速度,同时增加关键信息的权重提高拼接准确率,并结合图像金字塔粗-精匹配思想对算法进行进一步加速,最终根据得到的最佳匹配位置获取空间对应关系实现图像拼接。实验结果表明,所提方法的匹配耗时约为原始NCC算法的6%,其他经典灰度匹配算法的3%~10%,同时也低于其他改进的NCC算法。其拼接成功率为94.74%,高于所有对比方法,最终成功获取了风机叶片可见光全景图像,表明该方法对大尺寸风机叶片可见光图像全景拼接具有良好的稳定性。

基于可微池化的层级图相似性学习

目前,大多数关于图相似性学习的工作仅考虑图级匹配或节点级匹配,忽略了多层级的粗图级匹配,为解决该问题提出一种可微池化层级图匹配网络(PHMN)模型。逐层将图的节点表示进行软聚类进而将源图转化为尺寸缩小的粗图;在图对上使用多角度多层级的跨图匹配层,获取匹配矩阵;由注意力机制将图对匹配矩阵转化为匹配向量后,传入LSTM模型和多层感知机进行相似度预测。该模型在图回归任务和图分类任务的对比实验中,分别取得8项最优表现和6项最优表现。

融合多边形拟合与凹点匹配的黏连重叠矿石图像分割算法

用选矿机进行矿物分选可以提高目标矿物的含量,从而优化资源利用,提高生产效率,在矿业领域中具有重要意义与价值,但分选过程中通过X射线透射技术所得的矿石图像会存在目标黏连及重叠的情况,这将严重影响矿物分选效率及精度,获取独立矿石图像是使用该方法对矿石进行识别、定位、分选的必要条件。为提高矿物分选精度与效率,提出了一种基于多边形拟合的凹点检测与匹配算法用于分割黏连矿石图像。首先,将矿石二值图像拟合为多边形图像并从图像拐点中甄别出凹点;其次,利用拐点构建直线方程形成检测区域,在该区域内搜寻凹点的待连接点,完成凹点匹配;最后,将计算机视域由二值图转移至灰度图,通过分析待分割区域的灰度值判断该区域是否为矿石间实际黏连处,从而决定是否执行分割操作。试验结果表明,算法在黏连矿石数据集上的总体分割准确率为93.60%,凹点噪声率仅为5.23%,处理尺寸为281×336的图像平均计算时间低至5.13 ms,检测效率最高可提升220倍以上,其噪声凹点滤除能力、凹点检测精度、分割准确率、算法运行速率均优于同类算法,对不同黏连数量及不同黏附形式的矿石图像均展现出较强的分割稳定性。

S盒NPNP等价匹配算法

根据S盒和布尔函数的相关性,S盒可以看作向量布尔函数.本文在基于布尔函数的NP等价匹配算法的基础上,设计了一个基于深度优先搜索的S盒NPNP等价匹配算法,用于判断两个不同的S盒是否NPNP等价,若等价则同时计算出NPNP变换方式.此算法的深度优先搜索结构基于树,且在进入深度优先搜索之前根据规则仅生成了部分可能存在解的路径,并在计算过程中实时判断以当前结点为新起点的剩余路径是否可能存在解,若不存在就直接剪枝并回溯避免了继续计算的时间开销,故其时间复杂度取决于树结点的个数.不同于仿射变换,本文提出的算法对于判断非可逆S盒是否NPNP等价的计算复杂度与判断可逆S盒是否NPNP等价的计算复杂度一致.实验方面,本文使用现在各个密码算法中常用的S盒进行实验,实验结果证实了本文方法的有效性,且计算过程远远优于直接搜索.

零工经济下农民工灵活就业研究进展

零工经济进入了井喷式增长的阶段,对劳动力市场和经济复苏产生了广泛而深远的影响。然而,数字技术进步和互联网平台发展对农民工灵活就业选择产生哪些影响,通过什么渠道影响,是一个亟须回答的重要问题。文章系统梳理了零工经济和灵活就业的由来和发展,总结和归纳了零工经济的前沿研究领域,包括零工经济下灵活就业选择及收入的研究,分析了学界关于零工经济对收入差距是“缩小”还是“拉大”的不同意见,从技术进步对劳动力的替代效应、生产力效应对就业的促进作用、技能互补对就业结构转型的影响、搜寻匹配机制对劳动的配置效应四方面讨论了零工经济下灵活就业的经济效果,为有序推进多渠道灵活就业和农民工市民化提供科学依据和决策参考。

基于图匹配的Web实体抽取算法研究

现今Web中存在大量缺失、不一致及不精确的数据,而传统的搜索引擎只能根据关键词返回文档片段,无法直接获取目标实体。提出一种新的基于图匹配的实体抽取算法GMEE(Graph Matching Based Entity Extraction),首先将片段按词语分割,进行实体的初步筛选;然后根据各实体之间的结构和语义关系建立“加权语义实体关联图”;最后利用“最大公共子图匹配”策略抽取目标实体。实验结果表明,提出的算法在不需要大量参数训练及传递的情况下,能够对抽取的实体集进行有效的精简,既保证了召回率、准确率,又提高了抽取过程的可解释性。

劳动搜寻匹配摩擦与税收调整政策效应

本文将劳动力市场摩擦引入标准经济周期理论框架,构建了一个考虑劳动搜寻行为的动态一般均衡模型,分析了劳动所得税和资本所得税两种调整政策的经济动态效应,并对税收政策的福利成本进行了估算。研究结果表明,劳动所得税和资本所得税的单独变动对劳动收入份额和收入不平等的影响是相反的,而且都会导致劳动生产力与工资之间的缺口扩大。同时,实施减税并增加政府支出的积极性财政政策可以促进就业,提高劳动收入份额,减少收入不平等。此外,从福利成本的角度看,劳动所得税和资本所得税的同向调节对社会福利有非对称的放大作用,而且结合政府支出增加的税收组合调节政策会带来更高的社会福利。

基于关系图卷积网络的代码搜索方法

代码搜索是当下自然语言处理和软件工程交叉领域的一个重要分支.开发高效的代码搜索算法能够显著提高代码重用的能力,从而有效提高软件开发人员的工作效率.代码搜索任务是以描述代码片段功能的自然语言作为输入,在海量代码库中搜索得到相关代码片段的过程.基于序列模型的代码搜索方法DeepCS虽然取得了很好的效果,但这种方法不能捕捉代码的深层语义.基于图嵌入的代码搜索方法GraphSearchNet能缓解这个问题,但没有对代码与文本进行细粒度匹配,也忽视了代码图和文本图的全局关系.为了解决以上局限性,提出基于关系图卷积网络的代码搜索方法,对构建的文本图和代码图编码,从节点层面对文本查询和代码片段进行细粒度匹配,并应用神经张量网络捕捉它们的全局关系.在两个公开数据集上的实验结果表明,所提方法比先进的基线模型DeepCS和GraphSearchNet搜索精度更高.

大数据驱动下基于深度学习的药品信息分布式检索

由于药品信息自身构成较为复杂,导致检索结果的相关性难以得到保障,为此,提出大数据驱动下基于深度学习的药品信息分布式检索研究。通过设计一个针对药品信息特征匹配的神经网络判别器,开展药品信息匹配分析,并引入了交叉熵损失函数,对二分类问题中(判断两个药品是否匹配)的真假进行计算;在分布式遍历检索阶段,为节点分配一个唯一的标识符,并设置相应的访问状态为未访问,通过将“最大遍历节点数”作为变量,对检索的遍历过程中进行动态更新,在先进先出原则下,当所有节点都被访问过,并且没有新的药品信息被检索到时,遍历过程结束,输出与目标检索信息拟合度最高的TOP-N药品信息队列。在测试结果中,检索结果的相关性始终在0.90以上,最大值为0.947。

Matching Pursuits视频编码中原子匹配块搜索中的权值设计

基于 Matching Pursuits的误差图像编码算法因其基函数的灵活性 ,是一种在低码率视频编码应用中较为理想的算法 ,块能量搜索算法被用于减少该算法的编码复杂度 .针对固定权值加权块搜索算法的不足之处 ,提出了一种自适应加权块搜索算法 ,在不增加算法复杂度的情况下 ,对不同的被编码序列采用不同的权值表完成加权块能量算法 ;在各种情况下均得到了较理想的编码效果 .

Geo-Social Profile Matching Algorithm for Dynamic Interests in Ad-Hoc Social Network

Among mobile users, ad-hoc social network (ASN) is becoming a popular platform to connect and share their interests anytime anywhere. Many researchers and computer scientists investigated ASN architecture, implementation, user experience, and different profile matching algorithms to provide better user experience in ad-hoc social network. We emphasize that strength of an ad-hoc social network depends on a good profile-matching algorithm that provides meaningful friend suggestions in proximity. Keeping browsing history is a good way to determine user’s interest, however, interests change with location. This paper presents a novel profile-matching algorithm for automatically building a user profile based on dynamic GPS (Global Positing System) location and browsing history of users. Building user profile based on GPS location of a user provides benefits to ASN users as this profile represents user’s dynamic interests that keep changing with location e.g. office, home, or some other location. Proposed profile-matching algorithm maintains multiple local profiles based on location of mobile device.

A Fast Depth-Map Generation Algorithm based on Motion Search from 2D Video Contents

Generation of a depth-map from 2D video is the kernel of DIBR (Depth Image Based Rendering) in 2D-3D video conversion systems. However it occupies over most of the system resource where the motion search module takes up 90% time-consuming in typical motion estimation-based depth-map generation algorithms. In order to reduce the computational complexity, in this paper a new fast depth-map generation algorithm based on motion search is developed, in which a fast diamond search algorithm is adopted to decide whether a 16x16 or 4x4 block size is used based on Sobel operator in the motion search module to obtain a sub-depth-map. Then the sub-depth-map will be fused with the sub-depth-maps gotten from depth from color component Cr and depth from linear perspective modules to compensate and refine detail of the depth-map, finally obtain a better depth-map. The simulation results demonstrate that the new approach can greatly reduce over 50% computational complexity compared to other existing methods.

Cell Search Algorithm in Beyond 3G Systems

The downlink frame structure for beyond 3G mobile communication systems is presented. Beyond 3G systems utilize the OFDM technique. However, a problem encountered in OFDM is that channel dispersion destroys orthogonality between carriers, caushag inter-symbol interference. It is also sensitive to high peak to mean power ratio （PAPR）. Therefore it spends much time on obtaining frequency, time, and frame synchronization. This paper proposes to add a frame synchronization channel in the time domain to overcome the shortcoming of OFDM. As transmitter diversity improves the system performance, beyond 3G systems employ space-time block coded （STBC）. Fast cell search algorithm including slot synchronization, frame synchronization and cell ID identification is then discussed, which is based on the frame synchronization channel in transmitter diversity systems. Detection and false alarm probabilities in AWGN and Rayleigh channels are analyzed, and the mean acquisition time is obtained. Computer simulations are conducted to evaluate the performance of the cell search algorithm under different channel conditions.