Why do EMD‐based methods improve prediction? A multiscale complexity perspective

Empirical mode decomposition (EMD)‐based ensemble methods have become increasingly popular in the research field of forecasting, substantially enhancing prediction accuracy. The key factor in this type of method is the multiscale decomposition that immensely mitigates modeling complexity. Accordingly, this study probes this factor and makes further innovations from a new perspective of multiscale complexity. In particular, this study quantitatively investigates the relationship between the decomposition performance and prediction accuracy, thereby developing (1) a novel multiscale complexity measurement (for evaluating multiscale decomposition), (2) a novel optimized EMD (OEMD) (considering multiscale complexity), and (3) a novel OEMD‐based forecasting methodology (using the proposed OEMD in multiscale analysis). With crude oil and natural gas prices as samples, the empirical study statistically indicates that the forecasting capability of EMD‐based methods is highly reliant on the decomposition performance; accordingly, the proposed OEMD‐based methods considering multiscale complexity significantly outperform the benchmarks based on typical EMDs in prediction accuracy.     

基于区块链技术的学籍管理系统

学籍管理是高校信息化建设的一个关键模块,也是社会认证人才的重要依据.区块链技术的出现为学籍管理系统的改进提供了一种全新的思路.区块链本质上是一种分布式记账技术,其去中心化和不可篡改的特性可以保证学籍信息的安全性和真实性.本文以区块链技术、特别是智能合约在智慧校园中的应用为切入点,提出并设计了一种去中心化的学籍信息管理方案,同时基于Fabric框架开发了一个简单的学籍管理系统原型.     

The neural mechanisms of vital loss emotions

This paper clarified the definition of vital loss emotions and summarized three contributing constituent elements through the review of previous research on vital loss emotions. Based on the results from relevant clinical, neuroimaging and electrophysiological studies, we further noted the advantages and disadvantages of previous research and discussed the neural network model of vital loss emotions to propose future research directions. Although the research on vital loss emotions has generated significant results, it remains in its initial stages, and many questions are unsolved. Future researchers would be encouraged to study real vital loss, dynamic longitudinal tracking and applied research on human health.     

混凝土坝浇筑机械联合施工的模拟优化及其应用

在混凝土坝的施工过程中,普遍存在入仓机械联合浇筑一个混凝土仓位的情况.以南水北调中线丹江口大坝加高工程为背景,通过对入仓机械联合施工的目的、要求和限制条件的分析,建立了混凝土坝入仓机械联合施工的模拟与优化模型.模拟与优化模型以提高入仓机械利用率、加快施工进度为目标,通过对入仓机械的优化调度,产生与实际施工过程极为接近的、理想的浇筑方案.通过模拟与优化模型在丹江口大坝加高工程中的应用表明,模拟计算结果符合工程施工实际,制定的浇筑方案在实际施工中切实可行,对于混凝土坝施工的指导及其实际应用具有理论意义和工程实用价值,且在混凝土坝施工中具有普遍意义和推广价值.     

高分辨距离像辅助的机动目标跟踪算法

宽带相控阵雷达可以获得高分辨距离像,利用此特征获取目标的姿态角成为了一种可能,基于此提出了一种新的机动目标跟踪算法,充分利用高分辨距离像特征,实时估计目标姿态角,并将姿态角信息融合到雷达的量测方程,本文结合先进的非线性滤波算法,提出了利用姿态角的交互多模型不敏卡尔曼滤波算法。通过计算机仿真表明,利用目标姿态角的机动目标跟踪算法相比传统算法目标跟踪精度(位置精度和速度精度)得到很大提高。同时姿态角误差越小,目标跟踪性能越好。     

虚拟服装网校总体设想与研讨

指出了现今开发服装远程教育的现状,提出了虚拟服装网校的总体设想及研究方案,阐述了建立服装网校的经济效益、社会价值及理论意义。     

Hyperthermia-induced apoptosis and the inhibition of DNA laddering by zinc supplementation and withdrawal of calcium and magnesium in suspension culture of tobacco cells

In the present paper we report examination of stereotypic hallmarks of apoptosis in heat-treated tobacco cells. Hyperthermia (44 °C, 4 h) caused apoptosis in 53.6% of cells when assayed 24 h after heat treatment. The induction of apoptosis by heat treatment was confirmed by flow cytometric assay. Cytological observations revealed condensation of the cytoplasm and nucleus, as well as nuclear collapse. DNA ladders were observed in DNA extracted from heat-treated cells, whereas DNA from control cells remained undegraded. The terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay revealed that 51.8% of the heat-treated cells (44 °C, 4 h) show positive reaction after a 24-h recovery. When cells were cultured in a medium supplemented with 0.4–5.0 mM ZnSO₄, internucleosomal DNA fragmentation induced by heat shock was completely negated. Strikingly, when cells were cultured in Ca²⁺ and/or Mg²⁺ free medium for 44 h followed by heat treatment, DNA laddering was not observed. The results suggest hyperthermia-induced apoptosis and a correlation between the regula tion of endonucleases and heat shock signal in apoptotic tobacco cells. Received 17 September 1998; received after revision 4 January 1999; accepted 4 January 1999     

FeC_2O_4·2HO磁铁矿样品FeC_2O_4的物相分析

１实验１．１样品制备在４６０Ｋ温度下真空干燥ＦｅＣ２Ｏ４·２ＨＯ１０ｈ，制得ＦｅＣ２Ｏ４；然后在Ａｒ气中升温至９２３Ｋ，保持１０ｈ；待温度下降到室温，在空气中放置４８ｈ，分解得到阳离子缺位的磁铁矿；再装入密闭无梯度反应器中，用４０ｍＬ／ｍｉｎＨ２于６...     

"节能减排"是国企走出经济危机的有效对策

"节能减排"是指节约能源和减少废弃物的排放.文章以晋西集团为例,针对"节能减排"的战略意义、健全法规、存在问题、有效对策及其成效进行了详细论述,必将对国企早日走出经济危机起到一定的借鉴作用.     

一种新型过热保护电路的设计

提出了一种用于集成电路内部的过热保护电路.分析了芯片温度升高的主要原因,介绍PTAT电流产生电路和迟滞电路.此电路通过引入反馈的方法解决了过热保护电路中热振荡带来的危害.