数字林业数据管理平台研究

分析林业信息系统中信息孤岛形成的原因,提出基于服务的数字林业数据管理平台体系结构.服务层通过Web服务技术屏蔽了操作系统和数据库系统的异构性,公用数据元目录机制消解了系统在语义层的异构性,汇聚层融合子节点元数据并统一访问接口,从而在全林业行业范围内实现分布异构数据的统一管理和访问.平台保持系统间的松耦合性,克服异构数据转换的关键性难题,向用户提供简单一致的数据访问方式,符合当前林业管理体制,具有广阔的应用前景.     

基于J2EE的森林资源信息管理系统研建

信息技术的发展带动了网络信息应用的快速膨胀,如何合理分配计算资源并在多用户并发访问量不断增大的情况下保证服务器响应速度是目前建立大型网络应用系统必须面临的问题,本论文结合与传统3层B/S软件架构的比较,较详细地阐述了J2EE在大型网络应用系统开发中的优势和解决方法,并以吉林汪清林业局为案例介绍了一个具体J2EE项目的实践过程。     

农业物联网体系结构与应用领域研究进展

伴随5G 网络的开通、全球信息化的进步,物联网已经开始大量的应用到社会生活中。因此,本人从物联网的概念和特点出发,研究了物联网的框架体系,探讨了目前国内农业的发展情况,以及农业物联网的应用领域。     

Assessment of tree structure using a 3D image analysis technique—A proof of concept

Efforts to improve the efficiency and efficacy of tree structure and crown architecture measurement are necessary to reduce error associated with indirect estimation of volume, which affects biophysical and ecosystem modelling, as well as resource assessment. In this short communication, we test the potential for a commercial SfM-MVS (Structure from Motion coupled with Multiple-View Stereophotogrammetry) software package, Photoscan-Professional, to accurately determine tree height, stem diameter, and eventually volume. SfM is a technique in computer vision, which calculates the 3D position of objects in a scene from a series of photographs. It uses a technique assuming that an object in a 3D scene is located on a vector between the image of the object in the camera and the object itself. The technique allows the construction of a 3D pointcloud, such as the one produced by laser technologies – terrestrial or airborne LiDAR. SfM requires no camera calibration or control points to construct an initial model. Moreover, it is a low-cost alternative to laser technologies. The second part of our method – MVS – is a visualization technique that reconstructs a 3D textured mesh of the scene from the SfM-derived pointcloud and RGB photographs. As a proof of concept, our methods were limited to two scenarios: (1) a single potted tree in a lab environment, where exact measurements could be made, and (2) two trees of different species and size in natural environments to test feasibility outside the laboratory. Precise measurements of tree height and stem diameter were compared with estimates obtained from the 3D model created using SfM-MVS. The results indicate that the SfM method is a promising – and inexpensive – alternative to terrestrial LiDAR and 3D scanners. Tree height estimates had error of 2.59%, while stem diameter estimates had error of 3.7%. The MVS algorithm used in this study was developed for plan surfaces such as topography or ‘compact’ objects and does not provide a representative 3D mesh for slender trees, although it works well for large stems. The authors link this disparity to the complex branching structure of trees.Future work requires (1) the development of effective automated volume reconstruction software specific to trees, and (2) the validation of the wide-scale applicability of the technology, which must include trees of various size, species, and growth forms. Moreover, future testing must include more complex environments, such as heterogeneous urban sites or closed-canopy forest sites where the proximity of other features may limit the utility of the new technology.     

传统造园艺术在现代园林景观建设中的价值

研究比较了现代园林景观建设与传统造园的差异,并以苏州工业园区金鸡湖地区等景观与传统园林的比较为例,强调了现代城市景观必须在充分吸收传统造园技法的基础上打破陈规,有所创新。充分分析了传统造园技艺的设计理念及局限,评价了其在现代园林景观建设中的价值,强调只有对中国造园艺术进行＂扬弃＂,才能使现代景观建设朝健康的方向发展。     

浅谈建筑施工管理

在建筑施工中施工技术员是基层最直接的组织者、领导者和指挥者.施工技术员的工作方法将直接影响工程的质量、工期和成本.作者结合多年工作实践,论述了建筑施工管理的程序及重要性.     

美植袋物理控根容器培育对玉兰苗根系构型的影响

比较了在美植袋物理控根容器中以及大田条件下生长的3年生玉兰苗的生长量、根系构型和透根情况,结果表明:美植袋培育的玉兰苗的生长量与大田培育的玉兰苗无显著差异,但在根系构型上有显著不同,美植袋中生长的玉兰苗在距离主干20 cm范围内的吸收根(根系直径在0 2 mm的根系)的根尖数、根表面积和根体积分别为12 996.66个·株^-1,1 674.4 cm²·株^-1,40.82 cm³·株^-1,疏导根(根系直径在2 5 mm的根系)的根尖数、根体积和根表面积分别为195.09个·株^-1,969.09 cm²·株^-1,67.73 cm³·株^-1,明显大于大田培育的玉兰苗,具有更高的吸收和疏导能力。垂直方向上,美植袋中生长的玉兰苗在距离容器顶端21 33 cm具有较多的疏导根和吸收根,水平方向上,在距离容器侧壁0 14 cm处具有较多的吸收根和疏导根。在这区域内吸收根和疏导根的体积和面积均占根系总体积和表面积的71.5%,根系构型发生了明显改变。美植袋容器使用3年后,已经老化,出现了透根现象,透出的根系主要是直径在0 1 mm的细根和直径大于10 mm的粗根。     

基于 CiteSpace 的国内公园绿地文献的可视化分析

为了准确客观地了解国内公园绿地的研究现状,把握公园绿地领域的研究热点及发展趋势,基于 CiteSpace 软件,依托中国知网（CNKI）数据库,对 1992—2020 年以“公园绿地”为主题的文献进行统计分析。结果表明,近 30 年间,公园绿地研究主要集中于 3 个层面：1）绿地系统、防灾公园及国家公园的规划;2）公园绿地的可达性、空间布局以及优化策略;3）景观格局和生态修复策略。可达性、景观生态学、布局优化及植物群落是近几年研究的热点,公园尺度的可达性、市域层面的指标评价及环境恢复性知觉是公园绿地研究的新角度。     

东京都23区综合公园周边商业设施的分布特征研究

[目的]在城市发展进程中,综合公园的使用与功能不再局限于其实际形态边界,而是逐渐与外部商业设施建立联系并共同成为城市更新与发展的推动力.分析外部商业设施分布特征并识别其与综合公园之间的潜在规律和联系,可为未来公园与商业设施规划建设提供重要依据.[方法]以东京都23区19座综合公园为研究对象,基于大数据获取,使用核密度估...     

两种药用淫羊藿克隆构型与分株种群特征比较

为探讨淫羊藿与箭叶淫羊藿生境资源利用及生态适应对策的异同,出较了异质性生境中两种淫羊藿克隆生长指标、克隆构型指数(V)和分株种群密度.结果表明,淫羊藿与箭叶淫羊藿的间隔子长度、根状茎长度、分株高度差异显著,分枝强度和分枝角度差异不显著,克隆构型指教V和分株种群密度接近.两种淫羊藿均为"游击型"克隆植物,其地下根茎寿命在2年以上,具有很强的克隆整合性.应减少对2种淫羊藿生境的干扰和保护其地下根茎的克隆生长,才能实现野生淫羊藿资源的可持续性利用.