Alpha-shape算法构建枣树点云三维模型

为了实现枣树智能化修剪作业，该研究提出了基于点云配准的自然光照环境下的果树三维重构方法，并针对传统最近点迭代（Iterative Closest Point，ICP）算法对待配准点云的空间位置要求苛刻的问题，提出了改进的点云配准算法。首先，使用彩色深度（RGB-D）相机采集不同角度下的枣树彩色和深度图像，并通过信息融合实现相应角度下的点云获取。其次，对点云进行背景去除和滤波处理，基于直方图设定分割阈值，提取单株枣树点云，并将放置在树根附近的标靶球作为标记，使用人工标记法进行两站点云初配准。最后，在初配准基础上计算点云的曲面法向量和曲率，由曲率相近的点构成配对点对，使用k维树最近点迭代（k dimensional-tree-Iterative Closest Point，kd-tree-ICP）算法完成精配准，对点云使用Alpha-shape算法面片化，实现表面重构。利用上述方法对多棵枣树进行全局配准并完整重构果树模型。试验结果表明，通过引入初配准，有效提高了点云配准的准确性和稳定性，配准误差均控制在1.0 cm以内，平均配准误差为0.78 cm；重构模型真实感较强，在外观上更加接近真实树，枝干相对误差控制在7%以内。该研究重构模型精度较高，可为枣树智能修剪提供可视化研究基础和技术支持。     

Over 40% of 450 registered wheat cultivars (Triticum aestivum) worldwide are composed of multiple biotypes

Many of 450 common wheat cultivars bred and registered during the twentieth century in 12 countries were proved, due to seed-by-seed analysis, to be composed of two or more biotypes differing in their alleles at the gliadin (Gli) loci. These multiple biotypes may be regarded as authentic progeny of the respective parent lines, as evidenced by the gliadin composition of the respective parents. Therefore, the official claim for each cultivar to be uniform is commonly not maintained in practice. The most frequent was a non-uniform cultivar composed of two biotypes differing at one Gli locus, but there were cultivars represented by a large set of related genotypes differing at several Gli loci. The proportion of the multi-biotype cultivars was never less than 15% for a country collection, exceeding 50% in other countries. This proportion differed significantly between neighbouring countries. In Australia, all multi-biotype cultivars were found in eastern states; in the state of Victoria, their frequency was statistically higher than in the rest of the country. The proportion of multi-biotype cultivars among newly-released cultivars decreased with time in Australia and the UK. Thus, the non-uniformity of registered cultivars represents a general and important phenomenon of common wheat as a crop.     

INVITED REVIEW—IMAGE REGISTRATION IN VETERINARY RADIATION ONCOLOGY: INDICATIONS,IMPLICATIONS, AND FUTURE ADVANCES

The field of veterinary radiation therapy (RT) has gained substantial momentum in recent decades with significant advances in conformal treatment planning, image‐guided radiation therapy (IGRT), and intensity‐modulated (IMRT) techniques. At the root of these advancements lie improvements in tumor imaging, image alignment (registration), target volume delineation, and identification of critical structures. Image registration has been widely used to combine information from multimodality images such as computerized tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) to improve the accuracy of radiation delivery and reliably identify tumor‐bearing areas. Many different techniques have been applied in image registration. This review provides an overview of medical image registration in RT and its applications in veterinary oncology. A summary of the most commonly used approaches in human and veterinary medicine is presented along with their current use in IGRT and adaptive radiation therapy (ART). It is important to realize that registration does not guarantee that target volumes, such as the gross tumor volume (GTV), are correctly identified on the image being registered, as limitations unique to registration algorithms exist. Research involving novel registration frameworks for automatic segmentation of tumor volumes is ongoing and comparative oncology programs offer a unique opportunity to test the efficacy of proposed algorithms.     

Performance Analysis of MIPv4 Regional Registration Combined with Low Latency Handoffs

The mechanism of MIPv4 regional registration and the low latency handoff protocols are introduced. Ways and procedure of pre-registration handoff and post-registration handoff are discussed also. The authors analyze the performance of the low latency handoff protocols combined with low latency handoffs over a wireless access based on IEEE 802. 11 standard in a tree-like network topology. The performance of pre-registration and post-registration scheme is given by simulation.     

我国农药登记管理发展史(Ⅱ)——6～8届全国农药登记评审会要点回顾

纵观历届全国农药登记评审会要点,可从侧面看到开创我国农药登记乃至农药管理工作的发展过程,记载了政策和措施的变迁。如今我国已建立并在逐渐完善登记管理制度,中国农药正走向世界,朝着具有中国特色的农药管理体系迈进。     

论当代中国统筹城乡发展背景下户籍制度改革的路径

我国现行的户籍制度是城乡分割的二元户籍制度。这种户籍制度将户口划分为"农业户口"与"非农业户口",将城乡居民分别纳入两种不同的管理体系。这种划分绝不只是称谓的不同,而是意味着户籍背后所附着的各种地位、机会和福利待遇等的不同。近几年来,一些省市将"农业户口"与"非农业户口"统一为了"居民户口",但户籍背后的利益问题并未得到很好的解决,二元户籍制度的本质并未根本改变。二元户籍制度是特定     

在林权登记中利用Excel数据批量制作Word文档技巧

在集体林权制度改革中,为了提高《林权登记申请表》制作效率和质量,探索出利用Word＂邮件合并＂功能引用已有的Excel林权登记数据批量制作文档的方法,可以加快工作速度,提高工作质量。这种方法可广泛应用于利用Excel数据批量制作统一格式Word文档的工作。     

期刊登到小议

本文讲述了期刊登到遇到的问题，并给了相应的解决办法，说明只有尽心尽力，才能充分发挥期刊的作用。     

基于宗地代码的不动产统一代码编制规则研究

《不动产登记暂行条例》的出台,标志着不动产登记将进入全新的阶段,不动产登记数据库也将进入全面整合阶段。文章对不动产数据库建设的其中一个技术关键点—登记单元的编码规则进行研究探讨,通过对比分析现行土地、房屋、林地登记中登记单元的特点及编码方式,结合不动产统一登记中登记单元的特点,整合各部门编码规则,提出了适用于不动产登记的统一代码编制规则建议方案,客观总结方案存在的局限性,为后续研究及应用提供参考。     

《森林资源资产抵押登记办法(试行)》的理解与适用

《森林资源资产抵押登记办法(试行)》于2004年7月5日发布,是国家林业局的第一个比较系统地针对森林资源资产抵押登记问题作出的具体规定。文章分析了森林资源资产抵押实行登记制度的法理和法律依据,指出了森林资源资产抵押的具体范围、抵押合同的形式要件和实质要件,应当遵循的具体程序以及抵押登记机关的职责等,建立健全森林资源资产抵押登记管理办法,具有重大的理论意义和现实意义。