一种有效的的时间序列维数约简方法

提出了一种用于相似性查询的时间序列维数约简的有效方法 .该方法采用快速小波变换将时间序列分解成不同频率的子带 ,用经过多分辨分解后得到的低频逼近信号重新表示原始序列 .这样将一个高维的时间序列映射到一个低维空间 .这种方法支持欧几理德距离标准和 L -平移欧几理德距离标准 .该算法的时间复杂性为 O(n) .     

基于PAA的时间序列早期分类

在时间序列数据挖掘领域,时间序列的早期分类越来越受到人们的重视,由于时间序列的长度(也称为维数)较大,在早期分类的实际应用中选择合适的维数约简方法非常重要,因此提出一种基于分段聚合近似(PAA)的时间序列早期分类方法。首先运用PAA对时间序列样本进行维数约简,然后在低维空间对样本进行早期分类,在43个时间序列数据集上的实验结果表明, 所提方法 在准确率、早期性、可靠性等方面优于已有方法。     

一种基于LLM的高维时间序列数据异常检测方法

以国家重大建设项目稽察中的数据一致性判别问题为应用背景,针对时间序列型高维数据提出了一种基于局部线性映射(Local Linear Mapping,LLM)的数据变换方法,该方法将各高维数据点通过其相邻点的线性重构映射至低维空间,从而很好地保留了高维空间中各数据点与相邻数据点的相关性。基于LLM的映射特性,提出了三种异常指标,并将其应用于面向国家重大建设项目稽察数据一致性判别问题的高维时间序列数据异常检测中。数值计算表明,所提出的方法对时间序列异常检测具有很好的效果,适合于较大规模高维时间序列数据的异常检测应用。     

一种有效的时间序列维数约简方法

提出了一种用于相似性查询的时间序列维数约简的有效方法，该方法采用快速小波变换将时间序列分解成不同频率的子带，用经过多分辨分解后得到的低频逼近信号重新表示原始序列，这样将一个高维的时间序列映射到一个低维空间，这种方法支持欧几理德距离标准和L－平移欧几理德距离标准，该算法的时间复杂性为O（n)。     

基于序列重要点的时间序列分割

时间序列包含的数据量大、维数高、数据更新快,很难直接在原始时间序列上进行数据挖掘。该文提出一种基于序列重要点(SIP)的时间序列分割算法——PLR_SIP,用SIP组成的直线段近似描述时间序列。将SIP作为时间序列的分割点,反映时间序列的主要特征,降低时间序列的维数,使整体误差达到最小。     

一种新的基于投影的三维矩快速算法

矩不变量自从提出以来,在模式识别等方面得到了广泛的应用.由于受矩本身计算量的限制,很难实现实时计算,在高维空间中这一问题显得尤为突出.本文提出了一种建立在图像投影基础上的三维矩快速算法.该方法利用投影变换把三维空间的信息投影到一维空间,大大减少了运算量.利用该方法可以把三维矩计算的乘法运算复杂度从 O( r n N n)降低到 O (r N),同时,加法运算复杂度也有很大程度的降低.并且,在运算过程中,不带来任何额外误差.本文还把这一方法推广到n维的情况,使得n维矩计算的乘法运算复杂度从 O(r r N n )降低到 O(rN).     

高维数据相似性度量方法研究

将低维空间中的距离度量方法(如Lk-范数)应用于高维空间时,随着维数的增加,对象之间距离的对比性将不复存在。研究高维数据有效的距离或相似(相异)度度量方法是一个重要且具有挑战性的课题。通过对传统的距离度量或相似性(相异性)度量方法在高维空间中表现出的不适应性的分析,并对现有的应用于高维数据的相似性度量方法进行总结,提出了高维数据相似性度量函数Hsim(X,Y)的改进方法HDsim(X,Y)。函数HDsim(X,Y)整合了各类型数据的相似性度量方法,在处理数值型、二值型以及分类属性数据上充分体现了原Hsim(X,Y)处理数值型数据、Jaccard系数处理二值数据以及匹配率处理分类属性数据的优越性。通过有效性及实例分析,充分论证了HDsim(X,Y)在高维空间中的有效性。     

基于DNA计算的RNA数字编码

随着DNA计算机的发展,用RNA代替DNA来进行大规模的计算已成为很有价值的研究课题。对RNA的4种碱基(A,C,G,U)进行二进制编码,共有24种可能的编码方式,其中有8种满足碱基和数字互补的原则,它们是拓扑等价的。按碱基分子量大小进行编码,可以解释RNA的稳定性较DNA的小。还研究了RNA二进制编码的代数结构。     

基于维度分组降维的高维数据近似k近邻查询

针对现有的高维空间近似k近邻查询算法在数据降维时不考虑维度间关联关系的问题,首次提出了基于维度间关联规则进行维度分组降维的方法.该方法通过将相关联维度分成一组进行降维来减少数据信息的损失,同时针对Hash降维后产生的数据偏移问题,设置了符号位并基于符号位的特性对结果进行精炼;为提高维度间关联规则挖掘的效率,提出了一种新的基于UFP-tree的频繁项集挖掘算法.通过将数据映射成二进制编码来进行查询,有效地提高了近似k近邻查询效率,同时基于信息熵筛选编码函数,提高了编码质量;在查询结果精炼的过程,基于信息熵对候选集数据的编码位进行权重的动态设定,通过比较动态加权汉明距离和符号位碰撞次数返回最终近似k近邻结果.理论和实验研究表明,所提方法能够较好地处理高维空间中近似k近邻查询问题.     

小波分解求取含噪混沌时间序列的关联维数

关联维数是一个混沌时间序列分析中很重要的参数,在分析了噪声对关联维数求取的影响后,提出了一种应用小波分解求取含噪混沌时间序列关联维数的方法,数值试验证实了我们这种方法的正确性与可行性.     

最坏情况下X3SAT最大海明距离问题最小上界

X3SAT最大海明距离问题是指对于一个X3SAT问题实例,寻找该问题的任意两组可满足赋值之间的最大海明距离。提出了一个基于DPLL的精确算法HMX来求解X3SAT最大海明距离问题,根据公式中某个变量在两组真值赋值中的不同取值进行分支。给出了多种化简规则,这些规则很好地提高了算法的时间效率。证明了该算法可以将X3SAT最大海明距离问题的最小上界由目前最好的O(1.7107n)缩小到O(1.6760n),其中n为公式中变量的数目。     

汉明码检验系统的电路实现

本文首先介绍了汉明码的特点和编码规则,并以此为基础着重讨论了一个(15,11)的汉明码检测系统的数字电路实现过程。     

Molecular Verification of Rule-Based Systems Based on DNA Computation

Various graphic techniques have been developed to analyze structural errors in rule-based systems that utilize inference (propositional) logic rules. Four typical errors in rule-based systems are: redundancy (numerous rule sets resulting in the same conclusion); circularity (a rule leading back to itself); incompleteness (deadends or a rule set conclusion leading to unreachable goals); and inconsistency (rules conflicting with each other). This study presents a new DNA-based computing algorithm mainly based upon Adleman's DNA operations. It can be used to detect such errors. There are three phases to this molecular solution: rule-to-DNA transformation design, solution space generation, and rule verification. We first encode individual rules using relatively short DNA strands, and then generate all possible rule paths by the directed joining of such short strands to form longer strands. We then conduct the verification algorithm to detect errors. The potential of applying this proposed DNA computation algorithm to rule verification is promising given the operational time complexity of O(n*q), in which n denotes the number of fact clauses in the rule base and q is the number of rules with longest inference chain.     

二进神经网络中汉明球的逻辑意义及一般判别方法

剖析二进神经元的逻辑意义对二进神经网络的规则提取是十分重要的，在布尔空间中，汉明球是一种线性可分的空间结构，如何从汉明球中提取出具有清晰逻辑意义的规则是二进神经网络研究的一个问题，通过对MofN规则表达形式的扩展，分析了汉明球的逻辑意义，提出了表达汉明球逻辑意义的LEM规则和GEM规则方法，并且讨论了汉明球和汉明补球的等价性，另一个重要的结果是证明了二进神经元和汉明球等价的充要条件，从而建立了判别汉明球的一般方法。     

一种新颖的蛋白质序列可视化模型

利用相似规则、互补规则和分子识别理论建立一种氨基酸数字编码模型用于研究序列特征、功能预测。给出一种新的基于元胞自动机的蛋白质序列图像生成方法,其优点是考虑了氨基酸前后的相互作用,生成的图像与基因序列一一对应,许多隐藏在蛋白质序列中的重要特性通过元胞自动机图可以表现出来。基于蛋白质元胞自动机图所得到的蛋白质伪氨基酸成分,蛋白质亚细胞定位预测成功率可以达到86.4%。     

Generalized composite integration rules in the presence of a singularity

A composite integration rule results from applying a basic integration rule exact for constants and with all abscissas in the integration interval to each ofn equal subintervals of the interval of integration. A sequence of such composite rules converges to the interval for all Riemann-integrable functions and for functions with an endpoint singularity which are dominated by a monotonic improperly integrable function. These rules are generalized to allow a partition into unequal subintervals or different basic rules in each subinterval. In each of these situations, restrictions must be placed on the basic rule or rules or on the partition to ensure convergence in the singular case. Such restrictions also ensure the convergence of a modified rule in the case of an interior singularity.     

NEQR: a novel enhanced quantum representation of digital images

Quantum computation is becoming an important and effective tool to overcome the high real-time computational requirements of classical digital image processing. In this paper, based on analysis of existing quantum image representations, a novel enhanced quantum representation (NEQR) for digital images is proposed, which improves the latest flexible representation of quantum images (FRQI). The newly proposed quantum image representation uses the basis state of a qubit sequence to store the gray-scale value of each pixel in the image for the first time, instead of the probability amplitude of a qubit, as in FRQI. Because different basis states of qubit sequence are orthogonal, different gray scales in the NEQR quantum image can be distinguished. Performance comparisons with FRQI reveal that NEQR can achieve a quadratic speedup in quantum image preparation, increase the compression ratio of quantum images by approximately 1.5X, and retrieve digital images from quantum images accurately. Meanwhile, more quantum image operations related to gray-scale information in the image can be performed conveniently based on NEQR, for example partial color operations and statistical color operations. Therefore, the proposed NEQR quantum image model is more flexible and better suited for quantum image representation than other models in the literature.     

Digital Twin for Human-Robot Interactive Welding and Welder Behavior Analysis

This paper presents an innovative investigation on prototyping a digital twin (DT) as the platform for human-robot interactive welding and welder behavior analysis. This human-robot interaction (HRI) working style helps to enhance human users’ operational productivity and comfort; while data-driven welder behavior analysis benefits to further novice welder training. This HRI system includes three modules: 1) a human user who demonstrates the welding operations offsite with her/his operations recorded by the motion-tracked handles; 2) a robot that executes the demonstrated welding operations to complete the physical welding tasks onsite; 3) a DT system that is developed based on virtual reality (VR) as a digital replica of the physical human-robot interactive welding environment. The DT system bridges a human user and robot through a bi-directional information flow: a) transmitting demonstrated welding operations in VR to the robot in the physical environment; b) displaying the physical welding scenes to human users in VR. Compared to existing DT systems reported in the literatures, the developed one provides better capability in engaging human users in interacting with welding scenes, through an augmented VR. To verify the effectiveness, six welders, skilled with certain manual welding training and unskilled without any training, tested the system by completing the same welding job; three skilled welders produce satisfied welded workpieces, while the other three unskilled do not. A data-driven approach as a combination of fast Fourier transform (FFT), principal component analysis (PCA), and support vector machine (SVM) is developed to analyze their behaviors. Given an operation sequence, i.e., motion speed sequence of the welding torch, frequency features are firstly extracted by FFT and then reduced in dimension through PCA, which are finally routed into SVM for classification. The trained model demonstrates a 94.44% classification accuracy in the testing dataset. The successful pattern recognition in skilled welder operations should benefit to accelerate novice welder training.      

On the Cardinality Spectrum and the Number of Latin Bitrades of Order 3

By a (Latin) unitrade of order k, we call a subset of vertices of the Hamming graph H(n, k) that intersects any maximal clique at either 0 or 2 vertices. A bitrade is a bipartite unitrade, i.e., a unitrade that can be split into two independent subsets. We study the cardinality spectrum of bitrades in the Hamming graph H(n, k) with k = 3 (ternary hypercube) and the growth of the number of such bitrades as n grows. In particular, we determine all possible small (up to 2.5·2n) and large (from 14·3n−3) cardinalities of bitrades of dimension n and prove that the cardinality of a bitrade takes only values equivalent to 0 or 2n modulo 3 (this result can be treated in terms of a ternary Reed-Muller type code). A part of the results are valid for an arbitrary k. For k = 3 and n → ∞ we prove that the number of nonequivalent bitrades is not less than 2(2/3−o(1))n and not greater than $$2^{\alpha^n}$$, α < 2 (the growth order of the double logarithm of this number remains unknown). Alternatively, the studied set Bn of bitrades of order 3 can be defined as follows: B0 consists of three rationals - 1, 0, 1; Bn consists of ordered triples (a, b, c) of elements from Bn−1 such that a + b + c = 0.     

A UML/OCL framework for the analysis of graph transformation rules

In this paper we present an approach for the analysis of graph transformation rules based on an intermediate OCL representation. We translate different rule semantics into OCL, together with the properties of interest (like rule applicability, conflicts or independence). The intermediate representation serves three purposes: (1) it allows the seamless integration of graph transformation rules with the MOF and OCL standards, and enables taking the meta-model and its OCL constraints (i.e. well-formedness rules) into account when verifying the correctness of the rules; (2) it permits the interoperability of graph transformation concepts with a number of standards-based model-driven development tools; and (3) it makes available a plethora of OCL tools to actually perform the rule analysis. This approach is especially useful to analyse the operational semantics of Domain Specific Visual Languages. We have automated these ideas by providing designers with tools for the graphical specification and analysis of graph transformation rules, including a back-annotation mechanism that presents the analysis results in terms of the original language notation.