基于决策树分类的塔里木河下游沙漠化动态变化分析

运用决策树分类法对1990年,2000年,2006年3期遥感影像进行分类,寻求生态输水对塔里木河下游沙漠化进程的影响.结果表明,2000年生态输水后沙漠化速度减缓,但沙漠化进程仍在继续.沙漠化变化方向主要为非沙漠化→轻度沙漠化→中度沙漠化→重度沙漠化→极重度沙漠化,生态输水后正向变化减小,逆向变化量增加.沙漠化变化区域主要集中在绿洲边缘和河道两侧,生态输水后变化区域离绿洲边缘和河道更近.沙漠化与距河道距离密切相关,距河道越远沙漠化退化越严重;生态输水后,距离河道1 km内的沙漠化得到抑制并出现逆转.      

贵州生物质能源树种资源的开发利用

根据贵州省生物质能源树种主要分布区线路调查和典型样地调查的结果，介绍了贵州省生物质能源树种的研究现状和存在问题，对贵州的生物质能源树种进行了分类并报道了资源的分布特点。提出了贵州应重点利用现有生物乙醇树种资源，积极稳妥发展生物柴油树种资源，并对开发利用技术和途径进行了探讨。     

我国燃煤锅炉汞减排工艺措施探讨

面对当前汞污染日益严峻的趋势,分析了燃煤锅炉烟气其它污染物（如二氧化硫、氮氧化物、颗粒物）控制设施及其运行情况,结合所燃用的煤质情况,介绍了燃煤锅炉烟气汞减排各种经济实用的方法,以及选择汞排放控制措施的“抉择树”。根据燃煤锅炉烟气实际情况,确定可采用的汞减排控制技术,必要时采取活性炭喷射脱汞技术（ACI）,最大限度地提高协同除汞效果。同时提出了应注重燃煤残留物中汞的二次污染问题。     

重烟羽扩散的风洞模拟实验研究

介绍利用风洞研究重气烟羽扩散特征以及围墙和树对其影响.实验使用的源是地面上的圆形面源.通过实验,提出了基于"变形源"假设的重气烟羽扩散物理过程;发现围墙在低Froude数下对重气烟羽有阻挡作用,而树对重气没有阻挡作用,但对"变形源"的形状有影响;从对危险气体的防护角度看,对测量范围的围墙外,围墙的防护效果明显,而围墙外加树与否影响不大.     

Characterization of Escherichia Coli Isolates from Different Fecal Sources by Means of Classification Tree Analysis of Fatty Acid Methyl Ester (Fame) Profiles

Microbial source tracking (MST) methods need to be rapid, inexpensive and accurate. Unfortunately, many MST methods provide a wealth of information that is difficult to interpret by the regulators who use this information to make decisions. This paper describes the use of classification tree analysis to interpret the results of a MST method based on fatty acid methyl ester (FAME) profiles of Escherichia coli isolates, and to present results in a format readily interpretable by water quality managers. Raw sewage E. coli isolates and animal E. coli isolates from cow, dog, gull, and horse were isolated and their FAME profiles collected. Correct classification rates determined with leaveone-out cross-validation resulted in an overall low correct classification rate of 61%. A higher overall correct classification rate of 85% was obtained when the animal isolates were pooled together and compared to the raw sewage isolates. Bootstrap aggregation or adaptive resampling and combining of the FAME profile data increased correct classification rates substantially. Other MST methods may be better suited to differentiate between different fecal sources but classification tree analysis has enabled us to distinguish raw sewage from animal E. coli isolates, which previously had not been possible with other multivariate methods such as principal component analysis and cluster analysis.     

A decision tree for Coastal Management permit guidelines

The Louisiana Coastal Management Division (CMD) uses over 90 guidelines for permitting construction activities in the coastal zone. The use of the guidelines by, the CMD staff is not always systematically applied to permit applications. A set of guideline decision trees was, therefore, developed for the permit review process using a structural modeling technique. A decision tree provides the framework for optimizing the decision process. The order in which decisions are made contributes to the efficiency and uniformity of the process. The result provides a more timely and consistent review of most permit applications regarding mining, hazardous wastes, levees, and zoning.     

基于国内外铁路运营数据的列车运行时间预测模型

为了准确预测列车运行时间,考虑铁路调度工作准确性和及时性需求,构建列车区间运行时间预测模型。首先,提取并分析列车时刻表数据,确定可能影响列车区间运行时间的因素;考虑列车运行时间数据分布的偏态性,引入Box-Cox转换正态化处理数据;然后,基于决策树以及网格搜索算法,分别优化模型输入特征和超参数,提升模型性能;最后,应用装箱梯度提升树(HGBT),基于优化后的特征和超参数,建立列车区间运行时间预测模型,并分别利用我国某铁路线路和欧洲某铁路线路的运营数据评估各阶段工作。结果表明:Box-Cox转换可显著提高数据正态性,提升列车运行时间预测模型的拟合效果;网格搜索算法可同时提高列车运行时间模型效率和精度;相较于其他常用的运行时间预测模型,HGBT模型具有高精度和高效率的优势。     

基于数据分析的铁路“三违”人因研究

为减少铁路作业“三违”行为、避免铁路交通事故,以甘泉铁路近一年的不安全行为观察记录为样本,采用数据归纳法、数据分析法,分析“三违”行为的主要成因;采用人因模型分析对比,选取行动型失误模型作为分析模板,引入关联分析工具决策树C5.0算法建立分析模型,导入成因因子和关联属性,区分神经元与触突,构建神经网络图形结构;通过数据分析得出简化作业流程优先级最高,且其与职工入企时间、职工业务能力紧密相关。研究结果表明:简化作业流程是铁路“三违”行为最主要成因,且入企时间长、业务能力较差的老职工更易简化作业流程;人因失误主要发生在人的执行、计划阶段,铁路企业应结合模型分析结论,针对性制定管控措施,切断“三违”形成的闭环途径,预防铁路人身伤亡事故的发生。