Improving reflectance estimation by BRDF-consistent region clustering

Previous studies in reflectance estimation generally require prior segmentation of an image into regions of uniform reflectance. Due to the measurement noise and limited sampling of the BRDF (bi-directional reflectance function) directions, such estimated results of reflectance are not accurate. In this paper, we propose a novel method for reducing uncertainty in reflectance estimates by merging image regions which have consistent reflectance observations. Each image region acts as a reflectance subspace, so merging of the image regions can result in subspace reduction. We propose a Bayesian segmentation framework to decrease the reflectance uncertainty by using novel merging criteria. Finally, a maximum likelihood reflectance estimation is made for each resulting image region. Experimental results verify the feasibility and superiority of this reflectance-oriented region merging method.     

Parameterization for fitting triangular mesh

In recent years, with the development of 3D data acquisition equipments, the study on reverse engineering has become more and more important. However, the existing methods for parameterization can hardly ensure that the parametric domain is rectangular, and the parametric curve grid is regular. In order to overcome these limitations, we present a novel method for parameterization of triangular meshes in this paper. The basic idea is twofold: first, because the isotherms in the steady temperature do not intersect with each other, and are distributed uniformly, no singularity (fold-over) exists in the parameterization; second, a 3D harmonic equation is solved by the finite element method to obtain the steady temperature field on a 2D triangular mesh surface with four boundaries. Therefore, our proposed method avoids the embarrassment that it is impossible to solve the 2D quasi-harmonic equation on the 2D triangular mesh without the parametric values at mesh vertices. Furthermore, the isotherms on the temperature field are taken as a set of iso-parametric curves on the triangular mesh surface. The other set of iso-parametric curves can be obtained by connecting the points with the same chord-length on the isotherms sequentially. The obtained parametric curve grid is regular, and distributed uniformly, and can map the triangular mesh surface to the unit square domain with boundaries of mesh surface to boundaries of parametric domain, which ensures that the triangular mesh surface or point cloud can be fitted with the NURBS surface.     

福建省柑橘线虫的研究Ⅰ.长泰县柑橘5种寄生线虫记述

自2004年至2006年对福建省长泰县柑橘根部寄生性线虫的种类进行了调查研究.共鉴定出7个属10个种,其中对柑橘生产有一定危害的是短体属、矮化属、茎属和真滑刃属中的部分种类,这4个属的种类在长泰县的柑橘树根部普遍存在.本文作者先报道其中的5个种,其中同形真滑刃线虫为中国新记录种.     

Nd12.3Fe80.7NbB6纳米晶永磁合金的磁性能与微观结构

研究了添加Nb元素对Nd2Fe14B单相纳米晶永磁合金微观结构与磁性能的影响.结果表明:添加Nb可以在甩带过程中促进非晶的形成并稳定非晶相;在退火过程中,加入Nb后形成的析出相可以抑制晶粒长大,使晶粒细化且分布均匀,进而大幅度提高了材料的综合磁性能.名义成分为Nd12.3Fe80.7NbB6.0的非晶薄带在550 ℃退火处理10 min后,可得到最佳磁性能:剩磁0.90 T,矫顽力912.64 kA·m-1,最大磁能积126.24 kJ·m-3;随着退火温度的进一步提高,综合性能有所下降.     

高级别管线钢精炼工艺分析

对LF-VD、RH-LF和LF-RH三种精炼流程生产管线钢过程进行了系统取样和综合分析.结果表明:三种工艺均可生产高级别管线钢,但LF-RH流程可生产纯净度和洁净度更高的产品;不同精炼手段具有不同的精炼功能,但由于生产流程中相续精炼工序渣量和渣组成等的相互关联和制约,各精炼工序均会受到上下游精炼工序的影响.     

夏季杭州湾南岸不同生境伍氏厚蟹种群特征及回归关系

2004年7月中旬对杭州湾南岸伍氏厚蟹进行了取样调查和统计分析,结果表明不同生境下伍氏厚蟹的种群密度、生物量存在极显著的差异.杭州湾南岸伍氏厚蟹的种群密度分别为:围垦滩涂(23.00±5.86)只/m2,主要道路基地(10.72±2.32)只/m2,自然滩涂(6.36±1.43)只/m2;生物量分别为:围垦滩涂(172.27±43.89)g/m2,主要道路基地(120.28±26.03)g/m2,自然滩涂(61.88±13.91)g/m2.整体样本及各生境雌雄样本的个体头胸甲长、头胸甲宽和体质量之间都存在显著的线性回归关系,其中头胸甲宽和体质量之间的线性回归方程与预测值拟合程度最高.同时,发现各个生境伍氏厚蟹个体及雌雄个体的头胸甲长、头胸甲宽和体质量之间存在一定的差异.     

汉氏菱形藻(硅藻)对银的吸附效应研究

 通过汉氏菱形藻(Nitzschia hantzschiana Rabh)在不同Ag⁺离子浓度和不同吸附时间下对Ag⁺离子吸附的试验,发现汉氏菱形藻对Ag⁺离子的吸附符合Freundlich方程,Q=0.08×ρ^0.7,在研究范围内,吸附时间对吸附量的影响很小.该藻富集银的较适宜的条件是:吸附时间2h,室温,溶液pH值近中性.     

基于标签机制的内容安全分级管理系统的设计

针对互联网信息内容缺乏有效的管理手段，设计和实现了一种符合我国国情的互联网内容安全管理系统原型，通过分析相关的W3C组织（www.w3c.org）的互联网内容选择平台（PICS）设计思想，采用分级标签方法对互联网信息内容进行管理，并设计了具有层次化结构的标签安全性保护措施，分析了分级管理构架中若干关键技术及标签的安全性技术，该系统在互联网内容泛滥的今天有一定的使用价值。     

一个分类规则的存储结构及查询策略

分析了数据挖掘所获规则的不同应用类型及其实施过程中建立规则管理系统的必要性,提出了一个分类规则管理系统的构建方法,根据对分类规则挖掘过程及结果的抽象,引入元数据知识设计了分类规则的存储结构、查询操作以及建立在此基础上的应用,给出了应用实例·其特点是不仅存储了挖掘结果,同时存储了挖掘过程中涉及的相关数据,更便于对新数据分类和预测·     

植物组织培养技术的应用

植物组织培养技术的应用范围很广,目前主要用在离体无性系快速繁殖与无毒化、植物育种、遗传物质的保存、植物次生代谢物的生产和植物基因转化等方面.