Extensions and relationships of some existing lower-bound functions for dynamic time warping

Dynamic time warping (DTW) is a state-of-the-art time series similarity measure method, which warps time axes to match the same shape between two time series with different lengths. However, its quadratic time and space complexity is an obstacle to its applications in the large time series data mining. To address this problem, some lower-bound functions for DTW, fast methods to approximately measure the distance between time series, are used to prune the dissimilar objects from time series database so as to retain the candidates for further measuring their similarity with DTW. So far, the existing lower-bound functions for DTW have been widely accepted for time series similarity search and indexing. In this paper, we propose the extensions of two existing lower-bound functions and discuss the relationships among them. The extensions are improved with high tightness and without much time cost. At the same time, we theoretically prove that these extensions satisfy lower-bound requirement and are better than their old versions respectively. The experimental results demonstrate that in most cases the quality of the proposed extensions of lower-bound functions for DTW outperforms the original versions except for a slightly higher time cost.     

蒸发二段真空度不稳定原因分析

对斯那姆尿素工艺二段蒸发真空度不稳定原因进行了较详细的分析，并提出相应的操作处理措施     

复合型热塑性工程塑料的进展

对复合型热塑性工程塑料制造技术、特性、应用情况和发展趋势进行了较全面的评述，对发展我国工程塑料产业提出了若干建议。     

Time-slide window join over data streams

The join is an important operator in processing data streams. To produce outputs continuously over unbounded data streams, sliding windows are generally used to limit the scope of the join at a certain time. In the existing join algorithms, only a simple type of windows have been considered, which are updated whenever a new data item arrives on any input stream. On the other hand, a more common type of windows have not been addressed yet, whose intervals are updated periodically, i.e., slid by a predefined time interval. In this paper, we consider the time-slide windows in joining multiple data streams. The algorithm for the time-slide window join can vary according to (i) how frequently the join is evaluated and (ii) which structure is used for windowing. Regarding this, possible algorithms are discussed, and experimental results that compare their performances are provided in this paper.     

Collaborative representation with reduced residual for face recognition

Collaboration representation-based classification (CRC) was proposed as an alternative approach to the sparse representation method with similar efficiency. The CRC is essentially a competition scheme for the training samples to compete with each other in representing the test sample, and the training class with the minimum representation residual from the test sample wins the competition in the classification. However, the representation error is usually calculated based on the Euclidean distance between a test sample and the weighted sum of all the same-class samples. This paper exploits alternative methods of calculating the representation error in the CRC methods to reduce the representation residual in a more optimal way, so that the sample classes compete with each other in a closer range to represent the test sample. A large number of face recognition experiments on three face image databases show that the CRC methods with optimized presentation residual achieve better performance than the original CRC, and the maximum improvement in classification accuracy is up to 12 %.     

甲基对苯二酚的合成进展

综述了甲基对苯二酚的各种制备方法,并比较了各自的优缺点.着眼于反应条件温和,环境友好的发展方向及选择高效的催化剂,指出双氧水直接羟基化邻甲酚制备甲基对苯二酚是最具有潜力的工艺方法.     

注射螺杆螺棱结构对计量段物料输送性能的研究

运用有限元分析软件POLYFLOW,根据聚碳酸酯物料注塑成型的实际工作状态,对PC物料在矩形断面和锯齿形断面流道中的流动进行了三维等温非牛顿流场模拟计算,在得到速度场的基础上对计算结果进行了后处理,分析了不同螺杆构型的输送能力,分布混合能力以及物料在不同螺杆构型中的流动状况.     

Estimation of parameters where dependent observations are related by equality constraints

Pirt's model for microbial growth and product formation are reparameterized to obtain multiresponse models with common parameters. The dependent variables in the models are related through the available electron and carbon balance constraints. Covariance adjustment is used to reduce the growth model to a unit variate linear model with covariates. Therefore, standard multiple regression programs can be used to obtain combined point and interval estimates of true biomass energetic yield, true product yield and maintenance coefficient. This approach may yield “better” estimates than the maximum likelihood approach when an appropriately selected subset of covariates is used. Nonlinear estimation procedures are also considered; these procedures are efficient with few responses; however, as the number of responses per observation increase, they may require a lot of computing time. For illustration several data from the biochemical engineering literature are analyzed by the proposed methods.