视频点击流数据挖掘在远程教育中的应用

Web数据挖掘已经成为数据挖掘技术一个重要的应用领域，文章主要通过对远程教育网站的视频点击流日志文件进行数据挖掘，寻求用户访问规律，构建动态的个性化精育网站．     

Performance optimization of a class of combined thermoelectric heating devices

Science China Technological Sciences - A detailed model of thermally-driven combined thermoelectric (TE) heating device is established. The device consists of two-stage TE heat pump (TTEH) and...     

控制四点法“形状参数”实现地景仿真

将满足插值和离散性质的“四点法”运用于地景仿真,调整其“形状参数”可产生所期望的地形形状。为了产生丰富的地貌特征,一方面,用几何纹理生成法;另一方面,在定义场景的ＧＬ光照中,通过更新材料、光源和光照模型属性,真实感显示地表细节。实验表明,该方法能简单、快速模拟一些受环境、树木、土壤、气候等影响的地景,为自然景观仿真提供了一种有效手段。     

一种改进BP网络及其在智能传感器非线性校正中的应用

主要分析了神经网络存在的一些缺陷,研究了一种改进BP神经网络学习算法的相关技术,设计并实现了一种改进型BP神经网络算法,并将其应用于智能传感器的非线性自校正系统。通过在某无人机机载高度传感器上试验研究,证明了这种算法的可靠性、先进性、稳定性。     

方圆管相贯节点极限承载力研究

采用ANSYS结构分析程序的四节点板壳单元对T ,Y型方主管、圆支管相贯节点进行了弹塑性大挠度分析 ,研究了管节点的受力性能和塑性区扩展过程 ,揭示了节点的破坏机理和破坏形式 ,获得了其极限承载力及其随节点几何参数的变化规律 ,提出了节点加强方案     

电视信号编码技术

同美国或另一些欧洲国家相比较，联邦德国在付费电视事业方面仍属发展中国家。这有其优点：我们今天在选择一个新的系统时，能从前人在这一领域中已犯过的许多错误中得以借鉴。对于联邦德国，目前到了提出只用一个编码系统这一问题的时候了。这个系统能网络所有的参加。既能适应于陆链方式的信号发送，也没有困难对于卫星或是有线网络形式的节目传送。一个这样的系统必须和我们传统的PAL制绝对地符合。     

用AutoLISP编程实现钻孔的自动绘制

煤矿的采掘工作主要以各种标准绘制的平面图为依据,这样,绘制标准的采掘工程平面图便成为煤矿安全生产的重中之重。     

在MPLS上实现区分服务

首先论述了MPLS和区分服务的引入背景,接着分别简要介绍这两种技术的原理,分析它们结合的合理性,最后重点介绍这两种技术结合的几种方案,即在MPLS上实现区分服务的方案,包括基本的MPLS解决方案、E－LSP、L－LSP及扩展的MPLS解决方案等,并阐述了区分服务在MPLS上的实现机制。     

Application of strains of Geotrichum spp. to decrease higher alcohols and to increase esters

The decrease in the content of higher alcohols and the increase in the ester content in alcoholic drinks are normally achieved by the aging process over years. This study examined the capability of some strains of Geotrichum spp. to complete this process within a few days. Four Geotrichum spp. strains (S12, S13, TM and TF) were separately added to one wine [containing 11.5% (v/v) ethanol] and to three liquor samples [containing 45, 50 and 55% (v/v) ethanol] and incubated at 28 and 15°C for 4 days. Significant increases in the ester content and decreases in the higher alcohols were observed with strains S12 and TM, in all treatments. Strains S13 and TF increased the ester content in the wine, but not in the liquors. Comparatively, most volatile compounds were found in the red wine treated with S12 at 15°C and in the liquor containing 55% (v/v) ethanol treated with TM at 28°C. The conversion from higher alcohols to their corresponding acids and esters was identified using gas chromatography coupled with mass spectrometry during the treatments. By comparing the results when enzyme extracts and whole cells were used, it was found that the decrease in the levels of the higher alcohols might be caused both by cell adsorption and enzymatic reactions, whereas the increase in the esters was caused mainly by enzymatic reactions. Copyright © 2016 The Institute of Brewing & Distilling