Vehicle actuation based short-term traffic flow prediction model for signalized intersections

Traffic flow prediction is an important component for real-time traffic-adaptive signal control in urban arterial networks. By exploring available detector and signal controller information from neighboring intersections, a dynamic data-driven flow prediction model was developed. The model consists of two prediction components based on the signal states (red or green) for each movement at an upstream intersection. The characteristics of each signal state were carefully examined and the corresponding travel time from the upstream intersection to the approach in question at the downstream intersection was predicted. With an online turning proportion estimation method, along with the predicted travel times, the anticipated vehicle arrivals can be forecasted at the downstream intersection. The model performance was tested at a set of two signalized intersections located in the city of Gainesville, Florida, USA, using the CORSIM microscopic simulation package. Analysis results show that the model agrees well with empirical arrival data measured at 10 s intervals within an acceptable range of 10%–20%, and show a normal distribution. It is reasonably believed that the model has potential applicability for use in truly proactive real-time traffic adaptive signal control systems.     

适应用户需求变化的前摄推荐模型

为了减少前摄推荐对用户当前活动可能产生的干扰,提出一种适应用户接受度变化的前摄推荐模型,感知用户对系统主动的信息推送是否有潜在需求以及需求的波动性,以提高用户体验。使用接受度向量来评估用户对信息推送的需求,应用决策树算法对用户历史上下文进行规则推理,形成用户对上下文推荐的接受度向量,并根据上下文变化和用户反馈来调整推荐接受度向量。试验结果表明,模型能够响应用户对推荐的动态变化,有助于改善用户体验。     

The effects of user factors and symbol referents on public symbol design using the stereotype production method

This study investigated the influence of user factors and symbol referents on public symbol design among older people, using the stereotype production method for collecting user ideas during the symbol design process. Thirty-one older adults were asked to draw images based on 28 public symbol referents and to indicate their familiarity with and ease with which they visualised each referent. Differences were found between the pictorial solutions generated by males and females. However, symbol design was not influenced by participants' education level, vividness of visual imagery, object imagery preference or spatial imagery preference. Both familiar and unfamiliar referents were illustrated pictorially without much difficulty by users. The more visual the referent, the less difficulty the users had in illustrating it. The findings of this study should aid the optimisation of the stereotype production method for user-involved symbol design.     

普鲁士蓝对Rb＋、Cs＋的吸附性能研究

摘要： 用K4Fe（CN）6·3H2O和FeCl3·6H2O制备纯普鲁士蓝（PB）和负载量为55％普鲁士蓝/二氧化硅（PB/SiO2）,考察了不同因素条件下（吸附时间、起始离子含量、c（H＋）浓度、干扰阳离子K＋和NH4＋）,纯PB对Rb＋、Cs＋混合模拟液的静态吸附情况.结果表明：随着吸附时间的增加,Kd（Rb＋）和Kd（Cs＋）增大,随着起始离子含量、c（H＋）浓度、干扰阳离子K＋和NH4＋浓度的增大,Kd（Rb＋）和Kd（Cs＋）整体来说稍有下降,但变化不大.由于纯PB在水中易分散,不利于柱操作,故选取负载量为55％ PB/SiO2进行柱实验,结果表明此柱对Rb＋、Cs＋显示出好的离子交换性能.     

一种冗余约束对并联机构精度影响的研究

为深入研究动平台中心点误差范围,以一种少自由度3-RPS／UPS冗余并联机构为研究对象,提出了一种改进的铰链间隙误差分析方法,分析了此并联机构球铰间隙对动平台中心点的影响,在此基础上提出了一种改进的误差分析方法,并对具有相同结构参数的3一RPS非冗余并联机构和具有冗余支链的3一RPS／UPS并联机构进行误差分析及计算,结果表明,冗余并联机构的误差空间在各方向上都比非冗余并联机构小,故冗余约束可减小误差,提高并联机构精度。     

基于预传输的虚拟机双机热备可用性研究

针对虚拟机双机热备中传统拷贝技术导致的虚拟机低可用性问题,提出一种基于分段挑选最近未使用(SSNUR)算法的预传输方法。在虚拟机运行阶段预先传输被使用的内存页,减少停机阶段需要拷贝的内存页数量,使用SSNUR算法挑选预传输页面,以降低预传输和停机传输的重复率。实验结果表明,与XEN4.0中典型的虚拟机双机热备系统Remus相比,基于预传输的Remus系统在重负载和长间隔时间状态下停机时间明显减少,最高可达23.37%。     

利用报废硝酸-27S氧化乙醛制备乙二醛研究

利用报废的液体推进剂硝酸-27S和乙醛制备乙二醛。比较了硝酸法和硝酸-27S氧化法对产品乙二醛收率的影响，对反应工艺条件进行了研究，确定了利用硝酸-27S作氧化剂制备乙二醛的较适宜工艺条件，并对测定乙二醛的国标法进行了改进，提出利用紫外分光光度法可快速测定其含量，实验表明硝酸-27S氧化法制锵的乙二醛收率高于硝酸氧化法。较适宜的工艺条件为：反应温度40％左右，硝酸-27S滴加时间1-1．5h，反应时间2h，n（硝酸．27S）：n（乙醛）=1：1，用亚硝酸钠作催化剂，乙二醛收率可达45％以上。     

三波长分光光度法测定小儿退热栓中扑热息痛的含量

本文介绍了用氯仿－无水乙醇作为溶剂，不经分离提取，利用ＵＶ－１６０Ａ分光光度计（注：机内带电脑）进行三波长分光光度法测定，排除小儿退热栓中基质和微量抗氧剂的干扰，直接测定扑热息痛的含量，此法简单，快速和准确。     

定粒配茧缫丝中心配茧区间的设定理论研究

定粒配茧缫丝生产中，设定合理的中心配茧区间是提高生丝质量和有效利用原料茧的基础。在对定粒缫丝配茧模型理论解析的基础上，本文提出了综合考虑原料茧协调消耗、生丝纤度方差和缫丝工劳动强度三原则进行中心配茧区间设计的方法，并分析原料茧特性、缫丝工技术等要素与中心配茧区间设定的关系。同时也讨论了定粒缫丝中纤度管理的相关理论问题。     

Plastic Injection Molding of High-Aspect Ratio Micro-Rods

Technological advancements have led to an increase in demand for fabrication of small and cheap miniature components or parts, especially in the medical and electronic fields. In this research work, micro-rods of varying lengths and diameters were molded using a specially designed tabletop injection molding machine. The main purpose was to investigate whether complete filling of the microcavities was possible and whether small cavity openings will restrict melt flow into the cavities.

Process parameters, such as injection pressure, mold temperature and melt temperature were varied. The micro-rods obtained were analyzed with Scanning Electron Micrographs (SEM). The results showed that injection pressure was the most important parameter for microinjection molding. The use of a vacuum system also yielded better results.