SnO2和SiO2用于PVC的阻燃消烟及协同作用

研究了二氧化锡和二氧化硅对软PVC阻燃消烟性的影响。通过对极限氧指数、剩炭率、烟密度的测定和DTATG曲线的分析证明,添加8g二氧化锡/二氧化硅复合阻燃剂的PVC的氧指数和剩炭率比未添加的分别增高5.5个单位和4.1%,烟密度降低16.4%,降解活化能分别降低38kJ/mol和23.1kJ/mol,从而证明二氧化锡/二氧化硅复合阻燃剂对于PVC是一种很好的阻燃消烟剂,二氧化锡和二氧化硅有很好的协同作用。同时证明这种复合阻燃剂能代替三氧化二锑,使产品的成本进一步降低。     

Face detection based on skin color likelihood

We propose a face detection method based on skin color likelihood via a boosting algorithm which emphasizes skin color information while deemphasizing non-skin color information. A stochastic model is adapted to compute the similarity between a color region and the skin color. Both Haar-like features and Local Binary Pattern (LBP) features are utilized to build a cascaded classifier. The boosted classifier is implemented based on skin color emphasis to localize the face region from a color image. Based on our experiments, the proposed method shows good tolerance to face pose variation and complex background with significant improvements over classical boosting-based classifiers in terms of total error rate performance.     

三江盆地二维地震资料处理方法研究与应用

三江盆地二位地震资料处理存在着较多的难题。如:静校正复杂;在逐步压制各类干扰的同时,难于保护低频有效信息和波组特征;波场复杂,准确拾取叠加速度比较困难。利用各种新技术新方法提高该地区地震资料的精度,是该地区地震资料处理的目标。通过综合应用各种静校正、地表一致性处理、噪声衰减、偏移等技术和方法,解决了该地区资料处理的难题,提高了地震资料的精度。实际地震资料处理的结果表明,以上处理技术和方法对该区复杂的资料处理效果明显。     

校园体育教育资源共享的研究

在当今社会,校园体育教育得到了社会各界的关注。21世纪是需要创新的年代,而校园体育教育需要更多的资源支持。简要介绍了校园体育教育资源共享的趋势,论述了校园体育教育资源共享的必要性,阐述了校园体育教育资源共享的必然性和可行性。     

基于背景和帧间差分法的运动目标提取

在自动人脸识别系统中,人体目标的检测是该系统识别人脸的前期关键步骤之一。为了能快速准确地检测出运动的人体目标,提出了背景差分法和帧间差分法相结合的运动目标提取检测方法。针对视频中的背景因镜头摆动或物体的移入/移出而有所变动,给出了几种提取背景的方法,比较各种方法后决定采用中值法快速地进行背景建模,随后采用自适应背景更新,结合两种差分法检测运动目标。通过实验验证了本文算法的有效性。     

Why Phenolic Acids Are Unlikely Primary Allelochemicals in Rice

Allelopathy in rice (Oryza sativa, L.) effective against weeds has been found in about 3.5% of tested rice germplasm in both laboratory and field experimentation. However, the allelochemicals responsible for growth inhibition of rice-associated weeds have not yet been identified. In the literature, phenolic acids are often mentioned as putative allelochemicals. If phenolic acids commonly reach growth inhibitory concentrations in rice ecosystems, it must be expected that the degree of tolerance to phenolic acids will vary among traditional rice cultivars or plant species adapted to rice environments having inherently different phenolic acid concentrations. Phenolic acids concentrations are normally greater in submerged than in aerobic soils. A dose–response study, however, showed that seedlings of rice cultivars adapted to submerged anaerobic soils did not have higher level of tolerance against p-hydroxybenzoic acid than did seedlings of varieties adapted to aerobic upland soils. Moreover, traditional rice cultivars had no greater tolerance than did improved cultivars that were recently bred for traits other than tolerance of phenolic acids. Similarly, there were no differences in tolerance of p-hydroxybenzoic acid between two Echinochloa weed species adapted to either anaerobic or aerobic growth conditions. Thus, neither the rice cultivars nor weed species had evolved different tolerance levels against the phenolic acid. However, all rice cultivars had significantly greater tolerance of p-hydroxybenzoic acid than did either weed species. In a second experiment, the rates at which rice plants released phenolic acids into solution cultures were measured for at least one month, the time period of greatest allelopathic activity following planting under field conditions. The maximum release rate of phenolic acids during the first month of growth was approximately 10 g/plant/day. At a conventional plant density, the release rate of phenolic acids would be approximately 1 mg/m²day. This order of release rate cannot provide concentrations remotely close to phytotoxic levels determined for these rice cultivars and weed species. The results presented in this paper do not preclude the possibility that phenolic acids might be one component in a mixture of chemicals that, when present simultaneously, are allelopathic.     

基于复化梯形公式的GM(1,1) 模型背景值的优化

背景值是影响灰色理论建模精度的重要因素之一。根据灰色系统理论建模机理以及数据累加生成具有非齐次灰指数规律,构建动态序列模型;基于积分几何意义的视角,利用函数逼近的思想,结合复化梯形公式,提出一种新的GM(1,1)模型背景值优化方法。算例结果表明,利用优化的背景值计算公式所建立的GM(1,1)模型在预测精度上有显著的提高。     

基于视频的车流量检测建模与分析

交通流量信息是智能交通控制中的关键成分。论文在对视频图像进行灰度处理、频域滤波和均衡化的基础上,结合直方图分析、背景差分、动态阈值二值化处理等图像分析过程,提出了双虚拟线平均法检测多车道车流量,并完成参数灵敏度检验。针对初识背景提取时间过长的问题,加入了跳帧法和像素块法,以提高系统效率。考虑到背景的时变性,采用选择更新法进行周期更新。实际结果表明,该方法兼顾了智能交通系统的环境适应性、检测实时性和统计精确性等要求,四个车道车流量统计的准确率均大于90％。     

基于ViBe算法的改进背景减去法

ViBe背景减去算法基于RGB色彩空间对像素进行处理,在光照突然改变的情况下,会造成大面积的背景误判为运动前景;同时会将场景中的运动背景大量的误检为前景. 针对上述问题,本文提出一种结合（r,g,I）标准色彩空间的改进算法. 实验结果表明,改进算法在光照突然变化时对前景的提取具有更好的鲁棒性,同时对于场景中运动的背景像素点,取得了更好的检测效果.     

一种改进的背景提取算法

背景提取,是利用背景差分法获取目标的重要步骤。针对传统背景提取算法需要处理大数据量的问题,本文算法在传统背景提取算法的基础上,利用一段时间内,相邻图像相同位置的灰度值基本处在同一平稳区间的原理和思路,通过对小数据量的多次操作来获取背景图像。实验结果证明,这种做法可以在使用较少内存使用量的基础上获得比较好的效果,并可快速有效地对背景进行更新。