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Nitrogen removal influence factors in A/O process and decision trees for nitrification/denitrification system 被引量:6
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作者 MAYong PENGYong-zhen +1 位作者 WANGShu-ying WANGXiao-lian 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第6期901-907,共7页
In order to improve nitrogen removal in anoxic/oxic(A/O) process effectively for treating domestic wastewaters, the influence factors, DO(dissolved oxygen), nitrate recirculation, sludge recycle, SRT(solids residence ... In order to improve nitrogen removal in anoxic/oxic(A/O) process effectively for treating domestic wastewaters, the influence factors, DO(dissolved oxygen), nitrate recirculation, sludge recycle, SRT(solids residence time), influent COD/TN and HRT(hydraulic retention time) were studied. Results indicated that it was possible to increase nitrogen removal by using corresponding control strategies, such as, adjusting the DO set point according to effluent ammonia concentration; manipulating nitrate recirculation flow according to nitrate concentration at the end of anoxic zone. Based on the experiments results, a knowledge-based approach for supervision of the nitrogen removal problems was considered, and decision trees for diagnosing nitrification and denitrification problems were built and successfully applied to A/O process. 展开更多
关键词 A/O process NITRIFICATION DENITRIFICATION nitrogen removal decision trees
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Cost of Multicast Logical Key Tree Based on Hierarchical Data Processing 被引量:2
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作者 ZHOU Fucai XU Jian LI Ting 《Wuhan University Journal of Natural Sciences》 CAS 2006年第5期1172-1176,共5页
How to design a multicast key management system with high performance is a hot issue now. This paper will apply the idea of hierarchical data processing to construct a common analytic model based on directed logical k... How to design a multicast key management system with high performance is a hot issue now. This paper will apply the idea of hierarchical data processing to construct a common analytic model based on directed logical key tree and supply two important metrics to this problem: re-keying cost and key storage cost. The paper gives the basic theory to the hierarchical data processing and the analyzing model to multieast key management based on logical key tree. It has been proved that the 4-ray tree has the best performance in using these metrics. The key management problem is also investigated based on user probability model, and gives two evaluating parameters to re-keying and key storage cost. 展开更多
关键词 MULTICAST logical key tree hierarchical data processing
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Finite family trees of continuous time birth and death processes for evaluating the transmitting speed of information on communication networks
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作者 马驰 王汉兴 《Journal of Shanghai University(English Edition)》 CAS 2007年第3期237-240,共4页
A finite random graph generated by continuous time birth and death processes with exponentially distributed waiting times was investigated, which is similar to a communication network in daily life. The vertices are t... A finite random graph generated by continuous time birth and death processes with exponentially distributed waiting times was investigated, which is similar to a communication network in daily life. The vertices are the living particles, and directed edges go from mothers to daughters. The size of the communication network was studied. Furthermore, the probability of successfully connecting senders with receivers and the transmitting speed of information were obtained. 展开更多
关键词 birth and death processes family tree random graph communication networks
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An Improved Treed Gaussian Process
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作者 John Guenther Herbert K. H Lee 《Applied Mathematics》 2020年第7期613-638,共26页
Many black box functions and datasets have regions of different variability. Models such as the Gaussian process may fall short in giving the best representation of these complex functions. One successful approach for... Many black box functions and datasets have regions of different variability. Models such as the Gaussian process may fall short in giving the best representation of these complex functions. One successful approach for modeling this type of nonstationarity is the Treed Gaussian process <span style="font-family:Verdana;">[1]<span style="font-family:Verdana;">, which extended the Gaussian process by dividing the input space into different regions using a binary tree algorithm. Each region became its own Gaussian process. This iterative inference process formed many different trees and thus, many different Gaussian processes. In the end these were combined to get a posterior predictive distribution at each point. The idea was that when the iterations were combined, smoothing would take place for the surface of the predicted points near tree boundaries. We introduce the Improved Treed Gaussian process, which divides the input space into a single main binary tree where the different tree regions have different variability. The parameters for the Gaussian process for each tree region are then determined. These parameters are then smoothed at the region boundaries. This smoothing leads to a set of parameters for each point in the input space that specify the covariance matrix used to predict the point. The advantage is that the prediction and actual errors are estimated better since the standard deviation and range parameters of each point are related to the variation of the region it is in. Further, smoothing between regions is better since each point prediction uses its parameters over the whole input space. Examples are given in this paper which show these advantages for lower-dimensional problems. 展开更多
关键词 Bayesian Statistics treed Gaussian process Gaussian process EMULATOR Binary tree
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基于KD-Tree加速的多线激光传感器数据融合方法
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作者 李欣飞 鄢然 +2 位作者 夏磊 赵青 张凯飞 《仪器仪表学报》 北大核心 2025年第5期50-59,共10页
针对多个线激光传感器协同扫描测量中大规模点云数据融合效率低、拼接误差大、处理复杂度高等问题,故提出一种基于KD-Tree加速的多个线激光传感器数据融合方法,通过动态邻域搜索策略和自适应半径调整机制,实现点云数据的高效排序与并行... 针对多个线激光传感器协同扫描测量中大规模点云数据融合效率低、拼接误差大、处理复杂度高等问题,故提出一种基于KD-Tree加速的多个线激光传感器数据融合方法,通过动态邻域搜索策略和自适应半径调整机制,实现点云数据的高效排序与并行平滑优化。首先,构建KD-Tree空间索引结构,创新性地设计动态邻域搜索策略,实现二维轮廓数据从无序到有序的快速重组,算法时间复杂度由传统方法的O(n^(2)logn)降至O(nlogn);其次,结合OpenMP多线程并行计算技术改进移动最小二乘算法,提出K-MLS并行平滑方法,算法的时间复杂度从O(n^(2))优化至O(nlogn),显著提升大规模点云的处理效率。在火车车轮测量系统中验证表明,当点云规模达到209万时,排序算法耗时较传统方法提升35.7倍,平滑算法耗时较传统方法提升84.5倍。最后,对比分析了该方法在提升点云质量方面的实际效果,算法可有效填补部分扫描数据的空缺,在轮辋面测量的最大偏差从±0.279 mm降低至±0.085 mm,三维点云配准的均方误差由0.323 mm优化至0.106 mm。实验数据表明,所提方法在保持亚毫米级精度的同时,显著提升了百万级点云数据的处理效率,有效解决了多传感器数据融合中的拼接误差、重叠区密度不均等问题,验证了算法在工业在线测量场景中的有效性与鲁棒性。 展开更多
关键词 KD-tree 线激光传感器 数据融合 点云处理 三维测量
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TreeView控件在工艺数据管理中的应用 被引量:2
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作者 侯守明 朱林 常明 《计算机应用》 CSCD 1999年第11期32-34,共3页
本文比较了Visual FoxPro 5 .0 中Outline 控件和TreeView 控件的不同特点,说明了使用其中TreeView 控件实现树状目录结构管理的一种方法。
关键词 treeVIEW控件 VFP5.0 工艺数据管理 CAPP
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StreamQCTree:一种流数据方压缩结构 被引量:1
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作者 甘亮 刘东红 +1 位作者 贾焰 韩伟红 《计算机工程与应用》 CSCD 北大核心 2011年第19期140-143,185,共5页
数据流管理系统计算聚集查询结果保存在内存中形成流数据方(StreamCube),提供快速、精确的在线OLAP查询。有限的内存空间需要一种有效的存储方法来存储更大时间窗口的流数据方。提出一种基于QC-Tree结构的流数据方StreamQCTree生成、裁... 数据流管理系统计算聚集查询结果保存在内存中形成流数据方(StreamCube),提供快速、精确的在线OLAP查询。有限的内存空间需要一种有效的存储方法来存储更大时间窗口的流数据方。提出一种基于QC-Tree结构的流数据方StreamQCTree生成、裁剪及查询方法。将QC-Tree结构中上界集划分为基本上界类和附加上界类;并分析附加上界类的成本计算模型;根据该模型在固定存储空间下,采用动态选择物化结点的方案选择物化部分附加上界类,使对StreamQCTree的平均查询响应时间最小。实验表明,StreamQCTree能够有效地访问数据方且获得较好的压缩效果。 展开更多
关键词 网络安全事件监控 StreamQCtree 流数据方 数据压缩 联机分析处理 QC-tree
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基于TPU-tree的Skyline分支定界查询算法(英文)
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作者 丁晓锋 卢炎生 赵娜 《计算机科学与探索》 CSCD 2009年第2期162-172,共11页
提出了一种新的限定性skyline查询理念,并给出了高效的处理技术。分支定界方法是当前skyline查询处理效率较高的技术之一,在一种不确定移动对象的索引策略TPU-tree之上,基于分支定界方法提出了B2CPS可限定性skyline查询处理算法。实验... 提出了一种新的限定性skyline查询理念,并给出了高效的处理技术。分支定界方法是当前skyline查询处理效率较高的技术之一,在一种不确定移动对象的索引策略TPU-tree之上,基于分支定界方法提出了B2CPS可限定性skyline查询处理算法。实验结果表明,提出的基于TPU-tree的B2CPS算法可以很大程度地提高限定性skyline查询的效率,在移动对象频繁更新的情况下亦能保持较高的查询性能,因此具有较好的实用价值。 展开更多
关键词 轮廓查询 概率查询处理 不确定移动对象 TPU树
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PMTree:一种高效的事件流模式匹配方法 被引量:8
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作者 程苏珺 王永剑 +3 位作者 孟由 程振东 栾钟治 钱德沛 《计算机研究与发展》 EI CSCD 北大核心 2012年第11期2481-2493,共13页
复杂事件处理技术从多个持续事件流中分析并提取满足特定模式的事件序列.高吞吐率场景下,如何快速准确地识别事件序列是复杂事件处理技术中一个非常重要的问题.现在事件流的模式匹配方法——NFA、Petri网、有向图等——存在语义描述能... 复杂事件处理技术从多个持续事件流中分析并提取满足特定模式的事件序列.高吞吐率场景下,如何快速准确地识别事件序列是复杂事件处理技术中一个非常重要的问题.现在事件流的模式匹配方法——NFA、Petri网、有向图等——存在语义描述能力不足、部分算子实现代价高等缺陷.针对这一现状,设计并实现了一种基于树的模式匹配方法——PMTree.PMTree定义了事件模型及相应事件算子,将事件序列映射为树节点,同时将时间窗口约束及谓词约束等放置在相应节点,这些树节点连接成一棵PMTree来支持实时的事件筛选与过滤.进一步研究了PMTree构建过程中的优化策略,并提出了开销模型以及优化构建算法,以尽可能减少模式匹配开销.实验结果表明,相同测试条件下基于PMTree实现的复杂事件处理引擎Cesar吞吐率是基于NFA实现的开源引擎Esper的3~6倍,并且在不同事件量或事件序列复杂度下性能表现稳定. 展开更多
关键词 事件流 复杂事件处理 模式匹配树 NFA 开销模型
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基于GPU的HPGB+-Tree索引
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作者 刘军 冷芳玲 李宇轩 《计算机与数字工程》 2021年第12期2490-2495,共6页
索引作为加速数据库查询的一种成熟技术,始终受限于CPU的内存带宽与架构的发展,因此无法在性能上实现质的飞跃。所以使用GPU赋能索引技术来辅助数据库执行查询任务是势在必行的。因此,针对异构环境下索引结构的适应性以及现有GPU索引受... 索引作为加速数据库查询的一种成熟技术,始终受限于CPU的内存带宽与架构的发展,因此无法在性能上实现质的飞跃。所以使用GPU赋能索引技术来辅助数据库执行查询任务是势在必行的。因此,针对异构环境下索引结构的适应性以及现有GPU索引受限于显存容量导致扩展性不够等问题,提出了一种CPU与GPU协同处理的HPGB+-Tree索引算法。该算法以混合架构的方式重新构建索引结构,使其完全适应GPU的硬件特性,突破CPU内存带宽受限和GPU内存容量受限的双重难关。HPGB+-Tree索引不仅解决了索引异构问题,还充分利用两大硬件平台各自的优势加速基于索引的相关操作。在不同数据量与不同任务规模下对算法的性能进行了评估,实验结果表明,该算法在内核占用率与程序执行速度两个方面都极具优势,在性能上处于领先地位。 展开更多
关键词 图形处理器 CUDA HPGB+-tree索引 混合架构
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多维数据仓库系统中高性能DCA-Tree Cube的研究 被引量:1
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作者 胡孔法 董逸生 +2 位作者 徐立臻 庄晓青 杨科华 《应用科学学报》 CAS CSCD 2003年第2期137-140,共4页
提出了利用R*-tree改进的DCA-tree(data cube aggregate-tree)来创建高性能的DCA-tree cube聚集cube,阐述了创建DCA-tree cube、DCA-tree cube增量更新和MOLAP快速查询等关键技术.算法分析表明,所提出的DCA-tree cube在查询和更新效率... 提出了利用R*-tree改进的DCA-tree(data cube aggregate-tree)来创建高性能的DCA-tree cube聚集cube,阐述了创建DCA-tree cube、DCA-tree cube增量更新和MOLAP快速查询等关键技术.算法分析表明,所提出的DCA-tree cube在查询和更新效率方面要比以往DDC等方法创建的cube要高,解决了在插入新维数据时cube增量的更新维护. 展开更多
关键词 多维数据仓库系统 DCA-tree CUBE 数据立方体聚集树立方体 多维联机分析处理 范围查询 聚集技术 增量更新
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Processing Constrained K Closest Pairs Query in Spatial Databases 被引量:1
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作者 LIU Xiaofeng LIU Yunsheng XIAO Yingyuan 《Wuhan University Journal of Natural Sciences》 EI CAS 2006年第3期543-546,共4页
In this paper, constrained K closest pairs query is introduced, wbich retrieves the K closest pairs satisfying the given spatial constraint from two datasets. For data sets indexed by R trees in spatial databases, thr... In this paper, constrained K closest pairs query is introduced, wbich retrieves the K closest pairs satisfying the given spatial constraint from two datasets. For data sets indexed by R trees in spatial databases, three algorithms are presented for answering this kind of query. Among of them, two-phase Range+Join and Join+Range algorithms adopt the strategy that changes the execution order of range and closest pairs queries, and constrained heap-based algorithm utilizes extended distance functions to prune search space and minimize the pruning distance. Experimental results show that constrained heap-base algorithm has better applicability and performance than two-phase algorithms. 展开更多
关键词 spatial databases query processing R-tree closest pairs query constrained closest pairs query
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R软件包MtreeRing在生长轮宽度测量中的应用 被引量:2
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作者 李爽 向玮 《东北林业大学学报》 CAS CSCD 北大核心 2020年第12期85-90,共6页
介绍了使用R软件包MtreeRing自动测量生长轮宽度的方法。MtreeRing使用数学形态学和边缘检测方法对数字图像中的生长轮边界进行识别,并且可以校正倾斜生长轮带来的测量误差。此外,MtreeRing还提供了具有图形用户界面的小程序,满足了不... 介绍了使用R软件包MtreeRing自动测量生长轮宽度的方法。MtreeRing使用数学形态学和边缘检测方法对数字图像中的生长轮边界进行识别,并且可以校正倾斜生长轮带来的测量误差。此外,MtreeRing还提供了具有图形用户界面的小程序,满足了不同编程水平用户的需求。两个针叶树种的对比分析表明,MtreeRing测量的生长轮宽度与WinDENDRO无显著差异,自动检测提高了测量效率,图形用户界面也增强了R软件的易用性。相比WinDENDRO等商业工具,MtreeRing无需软件成本,生长轮宽度序列可以直接在R软件中进行后续分析,或使用rwl等通用格式导出。 展开更多
关键词 生长轮宽度 R软件 图像处理 边缘检测
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Selection and Evaluation of Road Landscape Trees in Binzhou University
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作者 潘华蓉 马波 《Journal of Landscape Research》 2010年第1期12-15,共4页
Several quantitative and qualitative indexes were selected for road landscaping in universities, Analytic Hierarchy Process (AHP) was applied to construct an evaluation system for the selection of road landscaping tre... Several quantitative and qualitative indexes were selected for road landscaping in universities, Analytic Hierarchy Process (AHP) was applied to construct an evaluation system for the selection of road landscaping trees for universities. Such an evaluation system was also used to objectively and comprehensively appraise present ornamental tree species in Binzhou University, and select species fit for its road landscaping, plant furnishings in Binzhou University were also analyzed. 展开更多
关键词 ROADS in UNIVERSITIES ROAD LANDSCAPING trees ANALYTIC HIERARCHY process Evaluation
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A New Binomial Tree Method for European Options under the Jump Diffusion Model 被引量:1
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作者 Lingkang Zhu Xiu Kan +1 位作者 Huisheng Shu Zifeng Wang 《Journal of Applied Mathematics and Physics》 2019年第12期3012-3021,共10页
In this paper, the binomial tree method is introduced to price the European option under a class of jump-diffusion model. The purpose of the addressed problem is to find the parameters of the binomial tree and design ... In this paper, the binomial tree method is introduced to price the European option under a class of jump-diffusion model. The purpose of the addressed problem is to find the parameters of the binomial tree and design the pricing formula for European option. Compared with the continuous situation, the proposed value equation of option under the new binomial tree model converges to Merton’s accurate analytical solution, and the established binomial tree method can be proved to work better than the traditional binomial tree. Finally, a numerical example is presented to illustrate the effectiveness of the proposed pricing methods. 展开更多
关键词 OPTION PRICING BINOMIAL tree JUMP-DIFFUSION process MOMENT Estimation
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Model Simulation and Eigen-Analysis for Polarimetric Scattering from Tree Canopy in SAR Imagery
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作者 Jin, Yaqiu Zhan, Nanxiong Chang, Mei 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2000年第2期48-54,共7页
In this paper, a theoretical model of multi-level, non-spherical scatterers is developed for fully polarimetric scattering from tree canopy in SAR imaging at C band. The amplitude functions of non-spherical particles ... In this paper, a theoretical model of multi-level, non-spherical scatterers is developed for fully polarimetric scattering from tree canopy in SAR imaging at C band. The amplitude functions of non-spherical particles with randomly spatial orientation are derived by the generalized Rayleigh-Gans (GRG) approximation. The non-diagonal extinction matrix and the Mueller matrix solution are constructed. Numerical solutions of polarimetric scattering of four Stokes parameters from random, non-spherical scatterers are obtained. To physically identify polarimetric scattering of the Mueller matrix solution, the coherency matrix and its eigen-analysis are discussed. Functional dependence of the coherency matrix and entropy upon various parameters are obtained. As an application, the analysis of AirSAR images at P, L, C bands is discussed. 展开更多
关键词 Approximation theory Eigenvalues and eigenfunctions Light scattering Matrix algebra Random processes Synthetic aperture radar trees (mathematics)
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疏解工艺对黑龙江省主要阔叶材单板性能影响研究
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作者 何金存 张佳彬 +1 位作者 张雪松 王齐 《林业科技》 2025年第3期69-71,共3页
以黑龙江主要阔叶树种水曲柳、柞树和枫桦为研究对象,通过适合的单板制备及帘布化疏解处理,探究3种阔叶材单板经疏解处理前后外观形貌、宽度和厚度尺寸变化率以及吸水率变化,其结果表明:三种单板经疏解处理均形成了形态均一、面密度分... 以黑龙江主要阔叶树种水曲柳、柞树和枫桦为研究对象,通过适合的单板制备及帘布化疏解处理,探究3种阔叶材单板经疏解处理前后外观形貌、宽度和厚度尺寸变化率以及吸水率变化,其结果表明:三种单板经疏解处理均形成了形态均一、面密度分布均匀的定向线裂纤维化重组单元;三种单板经疏解处理在宽度和厚度方向尺寸均发生变化;三种单板经疏解处理吸水率较疏解前均有显著提高。 展开更多
关键词 疏解工艺 阔叶材 单板吸水率
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AHP-based System for the Health Assessment of Ancient and Famous Trees in Dongguan
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作者 SU Chunlan HU Qiuyan +2 位作者 YE Yongchang LI Weihao LIU Songsong 《Journal of Landscape Research》 2017年第1期19-21,24,共4页
By establishing an AHP-based assessment index system and assessment model,and applying detection technology that is convenient and harmless for ancient and famous trees,this paper is significant for investigating and ... By establishing an AHP-based assessment index system and assessment model,and applying detection technology that is convenient and harmless for ancient and famous trees,this paper is significant for investigating and assessing the health state of ancient and famous trees,and protecting the limited resources. Fourteen indexes such as growth vigor,disease and pest were selected from the perspectives of overall situation,canopy,trunk and root,and AHP(applied analytic hierarchy process) was applied to define weights of these indexes. According to the results,top 3 indexes in terms of weight are tree vigor,treetop death,internal decay and hole,while the indexes with lower weight are parasitism,root damage,ventilation and permeability. On the basis of assessment model and method as well as field investigation,health grade of ancient and famous trees(A) can be obtained. By grading the health of ancient and famous trees into 3 levels,each level indicates a certain health state,so managers can take corresponding maintenance measures to develop the best ecological and social value of these trees. 展开更多
关键词 Ancient and famous trees Health assessment Analytic hierarchy process Dongguan
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Screening of Quality Ornamental Trees in Xinyang City
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作者 WANG Hui ZHANG Miao ZHOU Xingwen 《Journal of Landscape Research》 2016年第4期87-90,共4页
Located in the transitional area from subtropical zone to warm temperate zone,Xinyang City is endowed with rich plant resources.With the development of modem urban landscape architecture,Xinyang City has had increasin... Located in the transitional area from subtropical zone to warm temperate zone,Xinyang City is endowed with rich plant resources.With the development of modem urban landscape architecture,Xinyang City has had increasing needs on quality ornamental tree species.In view of the badly-needed ornamental tree species of local landscaping,this paper screened 20 ornamental tree species from the previously-investigated ones,then applied Analytical Hierarchy Process(AHP) to establish the evaluation system according to ornamental characteristics of these species(such as flower color),and used this system to evaluate the preliminarily-chosen species,finally selected 7 species that can be widely applied,and 5 species that can be moderately applied. 展开更多
关键词 Ornamental tree species Analytical Hierarchy process(AHP) Ornamental characters Xinyane City
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基于AHP-聚类法的古树旅游资源评价——以郑州中心城区为例 被引量:1
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作者 郭二艳 尹淦 +1 位作者 陈超 李小双 《西部林业科学》 北大核心 2025年第2期113-119,共7页
为促进古树资源与生态旅游融合发展,以郑州中心城区的古树为研究对象,采用AHP(层次分析法)、加权求和、K-均值聚类法对222株古树旅游资源进行了综合评价和分类。结果显示:郑州中心城区的古树旅游资源可以分为三个级别:极品级资源共有3株... 为促进古树资源与生态旅游融合发展,以郑州中心城区的古树为研究对象,采用AHP(层次分析法)、加权求和、K-均值聚类法对222株古树旅游资源进行了综合评价和分类。结果显示:郑州中心城区的古树旅游资源可以分为三个级别:极品级资源共有3株,综合得分0.6602~0.7484,占总数的1.35%;优良级资源共有52株,综合得分0.2785~0.5122,占总数的23.42%;普通级资源共有167株,综合得分0.0531~0.2689,占总数的75.23%。在开发郑州市中心城区古树旅游资源时,应优先保护和有限开发极品级资源,建立隔离带并推广“云旅游”管理;适度开发优良级资源,动态监测并设置游客承载力阈值管理;修复保护普通级资源,暂缓开发并实施专项修复基金申请,开展社区认养计划管理。研究成果可为郑州市中心城区古树旅游资源的开发和保护提供理论依据和实践指导。 展开更多
关键词 古树旅游资源 层次分析法 聚类分析 资源评价
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