Development operators on 4D moving object databases

In this paper we propose four-dimensional (4D) operators, which can be used to deal with sequential changes of topological relationships between 4D moving objects and we call them 4D development operators. In contrast to the existing operators, we can apply the operators to real applications on 4D moving objects. We also propose a new approach to define them. The approach is based on a dimension-separated method, which considers x-y coordinates and z coordinates separately. In order to show the applicability of our operators, we show the algorithms for the proposed operators and development graph between 4D moving objects.     

高分子土壤改良剂对种籽萌芽之影响研究

以高分子材料为土壤改良剂可使土壤团粒化, 增加水份入渗效率, 减少土壤冲蚀, 为研究环境问题之重要课题.但此类土壤改良剂可能抑制植物种籽萌芽, 为使用此种材料的一大问题.以压克力与聚乙烯醇对 Bahia种籽做一系列萌芽实验探讨.实验结果发现, 压克力对种籽萌芽率与萌芽势能有严重之抑制作用.但适量之聚乙烯醇添加可克服此问题.     

甲烷预混气螺旋爆轰的定量不稳定性研究

针对CH4这种特别气体,对其实验结果运用数字化处理方法研究CH4稳定性.在内径50.8 mm圆形管道内获得CH4+2O2预混气在不同初始压力条件下的胞格爆轰结果并使用烟膜记录,且测得的平均爆轰速度数据与CJ爆轰速度接近,在初始压力高于5 kPa时爆轰可稳定传播.烟膜上形成的三波点轨迹十分不规则.为减少人为误差,使用改进后的数字化处理烟膜图像的技术方法,从烟膜轨迹中得出柱状图及自相关函数结果,发现CH4+2O2是一种爆轰十分不稳定的气体,并给出CH4+2O2预混气的爆轰胞格尺寸及差距,结果显示人为测量结果偏大而数字化处理方法更为准确.这种方法能计算CH4+2O2预混气胞格尺寸及不稳定度,完善了定量化预混气不稳定程度的方法.     

半导体晶圆制造系统的时变多目标生产调度优化

从当前半导体晶圆制造企业实际生产调度的角度出发,根据模糊控制理论和模拟退火算法,提出了解决半导体晶圆制造系统(SWFS)时变多目标生产调度复杂问题的方法.大量的仿真实验数据证明,该方法可以在求解速度和优化质量间取得平衡,并实现了全局优化效果,为实现SWFS的科学生产控制与调度提供了有效策略和方法.     

高师教育实习用反思促进成长

教育实习是高师院校师范生培养的重要环节,师范生学会用反思关注自己的实习生活是促进其成长和发展的必由之路.反思是一个能动的、审慎的认知加工过程,师范生应该主动采用内省、讨论、撰写实习日志和实习总结等方法进行反思,反思自己的职业信念、教育理念、知识水平和教学能力水平,让反思贯串于实习的整个过程,以促进师范生的专业发展和未来职业成长.     

阳生与阴生环境梓树叶片的比较解剖学研究

采用光学显微技术,对不同生长环境的梓树Catalpa ovata G.Don叶片进行了比较解剖研究.结果表明:梓树的阳生叶比阴生叶大得多,为1.94～2.64倍;阳生叶的栅栏组织厚度是阴生叶的1.96倍左右.阳生叶的气孔微下陷,有利于减少水分蒸腾;阴生叶的气孔大部分微上拱.阳生叶的上表皮比阴生叶厚,为1.91倍左右;阳...     

Distributed location-based query processing on large volumes of moving items

Recently, new techniques to efficiently manage current and past location information of moving objects have received significant interests in the area of moving object databases and location-based service systems. In this paper, we exploit query processing schemes for location management systems, which consist of multiple data processing nodes to handle massive volume of moving objects such as cellular phone users.To show the usefulness of the proposed schemes, some experimental results showing performance factors regarding distributed query processing are explained. In our experiments, we use two kinds of data set: one is generated by the extended GSTD simulator and another is generated by the real-time data generator which generates location sensing reports of various types of users having different movement patterns.     

微观交通仿真软件PARAMICS在ITS模拟和评价中的应用

鉴于已有交通仿真软件不能对智能交通系统(ITS)的模拟和评价提供有效的支持，提出了用微观交通仿真软件PARAMICS(PARAllel MICroscopic Simulator)的应用程序接口(API)实现这一目的的研究框架和技术路线，利用PARAMICS的API函数，编制了能够模拟ITS控制和诱导策略的插件，嵌入到其主要仿真模块中，实现了对多种ITS控制和诱导策略的模拟。在示例中研究了在事件引发的非常发性交通拥堵情况下，多种ITS控制和诱导策略的仿真实现、评价和对比。     

Reduction Method for Reachability Analysis of Petri Nets

Reachability analysis is an important approach for acquiring Petri net (PN) properties. The reachability tree and the solution of the state equation are two commonly used methods for reachability analysis, but they can result in state explosion and spurious solutions in some cases. As a significant complementary method, the PN reduction technique simplifies the reachability analysis by reducing the net size while preserving the reachability. This paper introduces several useful reduction rules and defines a reduction process for the analysis of reachability which is easy to understand and implement. Some examples are given to explain the method to solve the reachability problem. The analysis shows that the proposed reduction method preserves the visualization feature of PN and can be easily used.