数字苏州公共服务平台的构建

结合苏州市地理信息系统平台建设实际情况,分别从建设目标、技术设计,系统开发、共享模式和应用推广等方面总结了数字苏州市公共服务平台建设的思路与经验,同时也提出了当前推广地理信息系统应用集成开发的创新思想.     

Controlling NOx Emission of Crude Rice Bran Oil Blend for Sustainable Environment

The main objective of this work is to investigate the factors influencing the NOx control of a stationary diesel engine fuelled with crude rice bran oil blend with lesser effect on smoke density and brake thermal efficiency (BTE). Fuel injection timing, percentage of EGR, and fuel injection pressure are chosen as the factors for the objective and NOx emission, smoke density, and BTE are considered as the response variables. To critically analyze the effects of the chosen factors on the objective three levels were chosen in each factor and the experiments were designed by following the design of experiments method. Taguchi's L₉ orthogonal array was used to conduct the tests with different combination of factor levels. Through analysis of variance (ANOVA) method, the most influencing factors and also the significance of each factor affecting each response variable were found out. Response graph was drawn for each response variable to determine the optimum combination of factor levels in achieving the objective and the obtained combination was confirmed experimentally.     

基于立方体元的Shear - warp体绘制加速算法

大规模三维地震数据的直接体绘制,是一个计算和数据双重密集型问题.为了提高三维图像的重建效率,提出了一种基于立方体元的Shear- warp地震数据体绘制算法.该算法通过构建立方体元在相邻的体素点之间建立联系;然后根据地震数据的特征对体元进行分类,在绘制过程中通过二叉树索引,快速定位分类结果.通过索引结果,避免了对等值体...     

栅格数据地学可视化分析环境的构建分析

以遥感数据、数字高程数据等为代表的栅格数据获取技术的进步,以及栅格数据本身适合地学模拟的特点,使得栅格数据应用越来越广泛.当前以定量计算为主的方法难以有效支撑栅格数据分析任务,将可视化引入,充分利用人机协同优势,形成栅格数据地学可视化分析环境是一个较好的解决途径.但是,栅格数据大数据量的特征会引起属性空间可视化时的遮挡...     

基于遗传算法的聚焦爬虫搜索策略设计与研究

网络爬虫是搜索引擎的重要组成部分。针对目前聚焦爬虫搜索策略的不足,提出了一种新的搜索策略解决方案。在搜索过程中对适应度高于或低于种群平均适应度的个体采用不同的交叉概率和变异概率来扩大爬虫的爬取范围、增加新个体,并通过改进遗传算子,提高聚焦爬虫的搜索效率。实验证明,基于自适应遗传算法的聚焦爬虫在一定程度上解决了传统遗传算法的"早熟"问题,而且能够爬取到更多主题相关的网页和相关度高的网页。     

Reduction in Exhaust Gas Temperature of Biodiesel Fueled Engine by Exhaust Gas Recirculation

Biodiesel is a renewable alternative fuel that can be used as substitute for mineral diesel. The use of biodiesel in diesel engines reduces all of the exhaust emissions expect NO_x. The higher temperature in the combustion chamber increases the NO_x emissions. The recirculation of a small percentage of cooled exhaust gases into the combustion chamber through the intake manifold reduces the in‐cylinder temperature. Moreover, the cooling of exhaust gases before mixing with fresh air introduced to the engine does not affect its volumetric efficiency but it absorbs the heat of combustion. This leads to a reduction in NO_x emissions and improves the engine brake thermal efficiency. This paper describes the investigation of the performance and emission characteristics of a biodiesel‐fueled, naturally aspirated, single cylinder diesel engine with cooled exhaust gas recirculation.     

GML分布式广义空间数据引擎的研究

在解析GML规范与空间数据引擎前沿研究成果的基础上,提出了一种语义对象模式表达的分布式广义空间数据引擎(SDE)模型。在通用大型数据库平台与通信机制支持下,用语义对象模式的GIS语言构建了一个全新的分布式广义SDE模型。对模型开发成果的应用与今后努力的方向作了简要的介绍。     

ALCGEIS知识获取与推理机设计

运用专家系统的知识获取和推理机设计原理与方法,探讨了ALCGEIS系统的基本结构、知识分级、知识获取过程和实现程序,推理机的基本原理和控制策略及其程序实现的算法,以及推理知识的搜索策略;论述了 AIEGEIS推理规则的设计方法及其推理算法。     

一种面向网络发布的海洋数据库引擎

To meet the requirements of efficient management and web publishing for marine remote sensing data, a spatial database engine, named MRSSDE, is designed independently. The logical model, physical model, and optimization method of MRSSDE are discussed in detail. Compared to the ArcSDE, which is the leading product of Spatial Database Engine, the MRSSDE proved to be more effective.     

近20年来长江经济带生态环境变化

长江经济带发展战略实施以来,长江上、中、下游地区经济快速发展,与此同时,生态系统不可避免受到扰动,长江经济带生态环境状况面临压力,亟需开展长江经济带生态环境质量评价.本文选取2001年和2020年MODIS和Landsat遥感影像计算湿度、绿度、干度、热度4个评价指标,通过主成分分析方法计算遥感生态指数RSEI,对长江...