基于粒子滤波的多区域辨识性建模跟踪算法

为使跟踪算法中的目标模型不被相同特征的背景像素所干扰,在粒子滤波的框架下引入多区域辨识性建模机制,提出1种新的鲁棒的目标跟踪算法。提出的算法侧重能够辨识前景与背景的最有效信息,把目标物体划分为多个子区域。通过统计子区域与背景类别的类内/类间特性选择出最具信息量的子区域。在选出的目标区域基础上,提出的算法以贝叶斯的方式同时考虑图像信息及空间信息,建立具有辨识性的目标表观模型,并在粒子滤波的更新阶段用以估量目标的所在区域。在一系列具有挑战性的视频序列上的实验结果证明了,在许多复杂场景下,提出的方法与传统的粒子滤波跟踪器相比的鲁棒性以及有效性。     

Lower bounds on lengths of checking sequences

Lower bounds on the lengths of checking sequences constructed for testing from Finite State Machine-based specifications are established. These bounds consider the case where a distinguishing sequence is used in forming state recognition and transition verification subsequences and identify the effects of overlapping among such subsequences. Empirical results show that the existing methods for construction of checking sequences provide checking sequences with lengths that are within acceptable distance to these lower bounds.     

谈影院票务的信息交换

长期以来,电影行业的基础信息统计汇总渠道不畅,无法及时得到电影行业的真实信息,影响到管理机构的科学决策.随着电影产业化的实施,电影行业的管理方式、产权结构、经营主体、经营情况以及观众等信息,会不断进行变化.如果不能及时地掌握这些信息的变化,将会出现决策落后于发展形势的局面.     

氯化聚乙烯对氯丁橡胶与甲基丙烯酸甲酯接枝共聚反应的影响

研究了高氯氯化聚乙烯(HCPE)对氯丁橡胶与甲基丙烯酸甲酯接枝共聚及其反应产物的影响。结果表明,HCPE能加快聚合速率,提高转化率、接枝效率和接枝度。含HCPE的产物,含有较高分子量的级份,分子量分布较宽,树脂相的分布比较均匀,并具有较好的机械性能和较高的粘接强度。     

Biomimetic Robust Starch Composite Films with Super-Hydrophobicity and Vivid Structural Colors

The starch composite films (SCFs) will be one of the best alternative packaging materials to petroleum based plastic films, which mitigates white pollution and energy consumption. However, weak mechanical stability, water resistance, and dyeability has hindered the application of SCFs. Herein, a bioinspired robust SCFs with super-hydrophobicity and excellent structural colors were prepared by fiber-reinforcement and assembling SiO₂/Polydimethylsiloxane (PDMS) amorphous arrays on the surface of SCFs. The properties of the designed SCFs were investigated by various methods including scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), a tensile test, contact angle (CA) test, and an optical test. The results showed that the obtained SCFs possessed a higher tensile strength (55.17 MPa) attributed to the formed abundant hydrogen bonds between the molecular chains of the starch, cellulose fiber, and polyvinyl alcohol. Benefiting from the nanostructure with rough surface which were modified by materials with low surface free energy, the contact angle and sliding angle of the film reached up to 154° and 2°, respectively. The colors which were produced by the constructive interference of the coherent scattered light could cover all of the visible regions by tuning the diameters of the SiO₂ nanoparticles. The strategy in the present study not only reinforces the mechanical strength and water resistance of SCFs but also provides an environmentally friendly way to color the them, which shows unprecedented application potential in packaging materials of the starch composite films.     

Secreted HSP90α-LRP1 Signaling Promotes Tumor Metastasis and Chemoresistance in Pancreatic Cancer

The extracellular heat shock protein 90α (eHSP90α) has been reported to promote cancer cell motility. However, whether pancreatic cancer (PC) cells expressed membrane-bound or secreted HSP90α, as well as its underlying mechanism for PC progression, were still unclear. Our study demonstrated that the amounts of secreted HSP90α proteins were discrepant in multiple PC cells. In addition, highly invasive Capan-2 cells have a higher level of secreted HSP90α compared with those of less invasive PL45 cells. The conditioned medium of Capan-2 cells or recombinant HSP90α treatment stimulated the migration and invasion of PC cells, which could be prevented with a neutralizing anti-HSP90α antibody. Furthermore, secreted HSP90α promoted elements of epithelial–mesenchymal transition in PL45 cells, including increases in vimentin and Snail expressions, decreases in E-cadherin expression, and changes in cell shape towards a mesenchymal phenotype, but these phenomena were reversed by the anti-HSP90α antibody in Capan-2 cells. In addition, high levels of low-density lipoprotein receptor-related protein 1 (LRP1) were associated with worsened patient survival in pancreatic adenocarcinoma. We demonstrated LRP1 as a receptor of eHSP90α for its stimulatory role in metastasis, by activating the AKT pathway. In addition, silencing LRP1 enhanced the chemosensitivity to gemcitabine and doxorubicin in Capan-2 cells. Therefore, our study indicated that blocking secreted HSP90α underlies an aspect of metastasis and chemoresistance in PC.     

A novel ethanol gas sensor based on ZnO-microwire

One-dimensional (1D) ZnO microwires were successfully synthesized by chemical vapor deposition and their structural and morphological properties were analyzed by X-ray diffraction and scanning electron microscopy, demonstrating that the microwires were single crystalline with perfect hexagonal structure and smooth surface. Using these 1D microstructures, we fabricated a novel ZnO-based ethanol gas sensor. Operating at room temperature, the sensor was found to have good sensing characteristics. The reliability and stability of the sensor could be improved by connecting multiple 1-wire devices (1-WD) in parallel into a multi-wires device. In interior natural lighting environment and under 3 V bias, the response and recovery time of the 1-WD to 200 ppm ethanol gas were <10 s and about 300 s, respectively, and the minimum and maximum detection limit were about 2 and 200 ppm, respectively. A sensing model was proposed for discussing the performance of the sensor. The simplicity in fabrication, low power consumption and low cost make the sensor suitable for practical application in many fields, especially in identifying driving under the influence and chemical industry monitoring.     

基于稀疏重建的信号DOA估计

从稀疏信号重建角度提出了一种改进的波达方向(DOA)估计方法。由于最小冗余线阵(MRLA)能以较少的阵元数获得较大的阵列孔径,将MRLA与l1-SVD方法相结合估计信号的DOA。仿真结果表明,经多次实验验证,所提方法是有效的,相比l1-SVD方法可以估计出更多信源的DOA,并且可以用较少的阵元数估计更多的信源DOA,具有信源过载能力。