Optimizing Naphtha Utilization Based on Molecular Scale Management

The technology of separating normal paraffins from naphtha through adsorption using 5A molecular sieves was studied. The separation efficiency of the normal paraffins was above 99.99%. Using the desorption oil as the feedstock of steam cracking, the ethylene yield increased from 29.7-35.0% to 41.4-49.2% compared to that of the naphtha. The research octane number of the raffinate oil reached more than 85 units with an increase of 20 units compared to that of naphtha.     

Reversible steganographic method using SMVQ approach based on declustering

Reversible steganography allows an original image to be completely restored after the extraction of hidden data embedded in a cover image. In this paper, we propose a reversible scheme for VQ-compressed images that is based on a declustering strategy and takes advantage of the local spatial characteristics of the image. The main advantages of our method are ease of implementation, low computational demands, and no requirement for auxiliary data. The experimental results show that the embedding capacity of the proposed method is controlled by the number of declustered groups and the spatial characteristics of the cover image. The results also show that the proposed method has the best embedding capacity and the least running time compared with other methods.     

Longest fault-free paths in hypercubes with vertex faults

The hypercube is one of the most versatile and efficient interconnection networks (networks for short) so far discovered for parallel computation. Let f denote the number of faulty vertices in an n-cube. This study demonstrates that when f ? n − 2, the n-cube contains a fault-free path with length at least 2ⁿ − 2f − 1 (or 2ⁿ − 2f − 2) between two arbitrary vertices of odd (or even) distance. Since an n-cube is a bipartite graph with two partite sets of equal size, the path is longest in the worst-case. Furthermore, since the connectivity of an n-cube is n, the n-cube cannot tolerate n − 1 faulty vertices. Hence, our result is optimal.     

基于音频数字水印的空间定位技术研究

深入研究了利于音频数字水印实现空间定位的技术思想,提出了一种在数字音频中嵌入水印信息后,实现对声源的空间定位算法,详细阐述了该算法的设计思想,并分别给出了音频数字水印的嵌入过程和数字水印的提取过程。     

小波域最小嵌入失真函数设计及其在隐写中的应用

为了提高隐写方案的安全性,提出一种基于最小嵌入失真原理和网格码的图像隐写算法。首先在离散小波域结合人眼视觉特性和整数提升小波变换设计了失真测度函数,主要考虑了亮度、频率和纹理掩蔽因子对载体失真的影响。然后结合网格码设计了隐写算法,将嵌入信息对载体的修改最小化并且集中在人眼不敏感区域。实验结果显示,方案具有良好的视觉不可见性,且能抵抗空域、小波域等隐写分析的攻击,安全容量达到0.4 bits/pixel。     

Graph-Based Dimensionality Reduction for Hyperspectral Imagery: A Review

Hyperspectral image(HSI) contains a wealth of spectral information, which makes fine classification of ground objects possible. In the meanwhile, overly redundant information in HSI brings many challenges. Specifically, the lack of training samples and the high computational cost are the inevitable obstacles in the design of classifier. In order to solve these problems, dimensionality reduction is usually adopted. Recently, graph-based dimensionality reduction has become a hot topic. In this paper, the graph-based methods for HSI dimensionality reduction are summarized from the following aspects. 1) The traditional graph-based methods employ Euclidean distance to explore the local information of samples in spectral feature space. 2) The dimensionality-reduction methods based on sparse or collaborative representation regard the sparse or collaborative coefficients as graph weights to effectively reduce reconstruction errors and represent most important information of HSI in the dictionary. 3) Improved methods based on sparse or collaborative graph have made great progress by considering global low-rank information, local intra-class information and spatial information. In order to compare typical techniques, three real HSI datasets were used to carry out relevant experiments, and then the experimental results were analysed and discussed.Finally, the future development of this research field is prospected.     

基于局部线性嵌入和支持向量机回归的TBM施工参数预测

依托吉林引松工程开展隧道掘进机（TBM）施工参数预测研究,提出TBM施工数据分段提取算法,提取上升段前30 s的总推进力、刀盘转速、推进速度、刀盘扭矩、刀盘转速电位器设定值、推进速度电位器设定值、贯入度、贯入度指数(FPI)、扭矩切深指数(TPI)9个参数作为输入;通过局部线性嵌入（LLE）完成对上升段数据特征的降维;基于支持向量机回归（SVR）建立TBM施工控制参数（推进速度、刀盘转速）和负载参数（总推进力、刀盘扭矩）预测模型. 分析是否结合前一掘进循环的FPI、TPI指数进行预测对预测效果的影响. 结果表明,上述方法在推进速度、刀盘转速、总推进力、刀盘扭矩的预测中均取得了较好的预测效果,平均预测绝对百分比误差均小于15%,验证了该预测方法的有效性,该方法可以为TBM现场施工提供指导.     

氯化石蜡生色因素及对策的探讨

探讨了氯化石蜡生产中的生色因素，提出了降低氯化石蜡色泽以提高产品质量的措施：优选原材料注意设备材质；优化生产工艺。     

陶瓷热压铸成型的超临界CO2流体脱蜡

利用超临界CO2流体萃取技术从陶瓷热压铸成型坯体中萃取有机粘合剂。对陶瓷热压铸成型中所使用的有机载体组分进行研究，对陶瓷热压铸成型超临界CO2流体脱蜡工艺条件进行了探索。研究了陶瓷坯体厚度、萃取压力，温度及时间对萃取率和陶瓷坯体脱蜡质量的影响。结果表明：由60％(质量分数，下同)非极性分子石蜡(熔点57℃)和40％极性分子蜂蜡(熔点58℃)组成的混合蜡作为热压铸浆料的有机载体，在压力为30MPa，温度为45℃的超临界CO2流体中脱脂可获得无缺陷的陶瓷热压铸成型生坯，脱蜡时间从34h减少到3h。由超临界CO2流体脱蜡后烧成的陶瓷试件具有小的变形及高的致密度。