用GM(1,1)模型对起重机最大静轮压的灰色预测

利用建立灰色系统理论的GM(1,1)模型,对50 t双梁桥式起重机的最大静轮压进行预测,结果显示预测值与实际值高度吻合,表明将灰色系统理论应用于起重机行业有关参数的预测是有效可行的。     

基于超图的产品族结构模型的研究

产品族结构模型是对系列化和组合产品各种复杂关系的综合和表达，它的合理性是产品配置设计过程的基础，超图能够表达是一般离散结构，而结构化超图表达了集合元素之间的层次关系，利用结构化超图模型来构造产品族结构模型，并给出了配置设计算法，最后用一个实例来验证方法的可行性。     

多尺度超图卷积骨架动作识别网络

动作识别是计算机视觉基础任务之一,骨架序列包含了大部分的动作信息,因此基于骨架的动作识别算法受到很多学者关注。人体骨架在数学上是一个天然的图,所以图卷积被广泛应用于动作识别。但普通的图卷积只聚合两两节点间的低阶信息,不能建模多节点间的高阶复杂关系。针对此问题,本文提出一种多尺度超图卷积网络,在空间和时间两个维度聚合更丰富的信息,提高动作识别准确度。多尺度超图卷积网络采用编解码结构,编码器使用超图卷积模块聚合超边中多个节点间的相关信息,解码器使用超图融合模块恢复原始骨架结构,另外基于空洞卷积设计了多尺度时间图卷积模块以更好地聚合时间维度运动信息。NTURGB+D和Kinetics数据集上的实验结果验证了算法的有效性。     

基于自然语言理解的需求聚类和需求优选方法研究

为了实现大数量软件需求的优选,提出了一种基于自然语言理解的需求聚类和需求优选方法。该方法首先基于自然语言处理技术对需求进行深层次语言理解,找到相同语义的需求并只保留一条。随后,采用基于超图分割的需求聚类方法对大量需求进行聚类。最后,提出了需求优选目标函数,该目标函数根据需求聚类结果为需求优先级打分,并在综合考虑需求与类别的相似性、类别的权重以及聚类标准的权重的基础上,最终给出一个合理的需求优选结果。在大规模真实的需求集合上进行了实验,实验结果表明:基于自然语言处理技术的需求聚类性能优异;需求聚类对后续的需求优选起有着非常重要的作用;基于超图分割的需求聚类,以及在此基础上提出的需求优选函数相对于基线方法有着明显的提高。     

Sequential Change-Point Detection Methods for Nonstationary Time Series

We present two new spectral-based methods for detection of changes in autocorrelation structure in a continuous-valued time series in an online process monitoring setting. Our methods are based on the idea that changes in the autocorrelation structure are reflected by changes in the Fourier or wavelet-based spectrum and can be detected by comparing estimated spectra of adjacent blocks of the series. To be effective for slowly changing spectral structure, the methods are extended to allow information from more than one past block to be used in determining whether a change has occurred, in such a way as to minimize computational burden. Through simulation, we evaluate the performance of our methods and find that they can provide reliable and timely detection of changes in covariance structure in an online monitoring framework. We illustrate the methods using electroencephalogram traces (brain waves) and run-time computer performance metrics.     

基于联合权重超图划分的SNN负载均衡方法

大规模脉冲神经网络并行模拟是探究大脑机能的重要手段。其难点在于合理地将负载映射到并行分布式平台上,提升模拟速度。为解决该问题,提出一种基于联合权重超图划分的SNN负载均衡方法,解决并行计算中进程间计算负载与通信负载的均衡问题,提高SNN模拟速度。并使用稀疏通信的方式替代集体通信,解决事件通信过程中的数据冗余问题,提升通信效率。实验结果表明,该方法使带有STDP突触20%规模的皮质层微电路模型的模拟时间,比标准循环分配算法缩短约64.5%,比普通超图分配算法缩短约57.4%,同时事件通信数据量减少了90%以上。     

Maximal and minimal representations of gapped and non-gapped motifs of a string

The problems of finding maximal and minimal equivalent representations for gapped and non-gapped motifs as well as finding motifs that characterize a fixed set of occurrence locations for a given string are studied. We apply two equivalence relations on representations. The first one is the well-known occurrence-equivalence of motifs. The second equivalence is introduced for patterns of occurrence locations, to characterize such patterns by motifs. For both equivalences, quadratic-time algorithms are given for finding a maximal representative of an equivalence class. Finding a minimal representative is shown to be NP-complete in both cases. For non-gapped motifs suffix-tree-based linear-time algorithms are given for finding maximal and minimal representatives. Maximal (minimal) gapped motifs are composed of blocks that are maximal (minimal) non-gapped motifs, maximal and minimal non-gapped motifs thus making up a small basis for all motifs. The implied bound on the number of gapped motifs that have a fixed number of non-gapped blocks is also given.     

Maximal connected sets—application to microcell CDMA

Current trends in personal and data communication networks favour code division multiple access (CDMA) as a solution to spectral congestion. This is because of enhanced capacity, security, network flexibility, simplified protocol, and relative immunity to propagation induced errors such as multipath and interference, as compared with traditional frequency division multiple access (FDMA). Various CDMA schemes have been proposed and described in relation to VSAT systems, local area microcells,² and cellular telephones. Additionally, numerous product applications have emerged in the areas of modems, voice links and wireless local exchanges. These systems require inter- and intra-cell control. By contrast, the scheme presented in this paper places no reliance on intercell protocol. It enables new cells to be added to the network without any impact on the hardware. Network reconfiguration requires software changes only. Therefore, the scheme is appropriate to systems which demand flexibility with minimum overheads.     

在爆破设计中基于组合优化的一个新的计算公式

基于超图的性质,提出了一个在爆破设计中由经验公式和经验数据组成的通用的计算公式。当一个目标函数值可由许多公式估算时,它可以选出最好的几个分配问题的模型被用来做更准确地分析,新公式在爆破块度分布的计算中被验证。     

Similarity retrieval of iconic image database

The perception of spatial relationships among objects in a picture is one of the important selection criteria to discriminate and retrieve the images in an iconic image database system. The data structure called 2D string, proposed by Chang et al., is adopted to represent symbolic pictures. The 2D string preserves the objects' spatial knowledge embedded in images. Since spatial relationship is a fuzzy concept, the capability of similarity retrieval for the retrieval by subpicture is essential. In this paper, similarity measure based on 2D string longest common subsequence is defined. The algorithm for similarity retrieval is also proposed. Similarity retrieval provides the iconic image database with the distinguishing function different from a conventional database.