Growth models and site index table of natural Korean pine forests

According to the growth characteristics of natural Korean pine (Pinus Koraiensis) forests, 6 equations such as Chapman-Richards equation, Logistic equation, Power equation, and so on were selected to ftt for the growth modeIs for Korean pine forest. The growth models were developed based on 208 random trees and 24o dominant trees. Results show that the Chapman-Richards equation is the best model for estimating tree height by age and DBH, while the Parabola equation is fittest for predicting DBH by age or estimating age from DBH. The site index table of Korean pine forest was compiled by using the proportional method with the Chapman-Richards equation as the guide curve and vaIidated by accuracy test.

Study on An Absolute Non-Collision Hash and Jumping Table IP Classification Algorithms

In order to classify packet, we propose a novel IP classification based the non-collision hash and jumping table trie-tree (NHJTTT) algorithm, which is based on noncollision hash Trie-tree and Lakshman and Stiliadis proposing a 2-dimensional classification algorithm (LS algorithm). The core of algorithm consists of two parts: structure the non-collision hash function, which is constructed mainly based on destination/source port and protocol type field so that the hash function can avoid space explosion problem; introduce jumping table Trie-tree based LS algorithm in order to reduce time complexity. The test results show that the classification rate of NHJTTT algorithm is up to 1 million packets per second and the maximum memory consumed is 9 MB for 10 000 rules. Key words IP classification - lookup algorithm - trie-tree - non-collision hash - jumping table CLC number TN 393.06 Foundation item: Supported by the Chongqing of Posts and Telecommunications Younger Teacher Fundation (A2003-03).Biography: SHANG Feng-jun (1972-), male, Ph.D. candidate, lecture, research direction: the smart instrument and network.

Development of two-axis control index table driven by direct drive motors

The stability and reliability of a tilting index table should be considered at the design stage. A design method for the lightweight and improvement of the stability of the structure in a tilting index table was proposed using a commercial analysis program, ANSYS Workbench 12, by analyzing the static-thermal characteristics of the developed high-accuracy tilting index table at its design stage. The results of the performed structural analysis show that the maximum stress is generated at the stock tail part. An optimum design for the stock tail part was carried out to reduce the maximum stress and deformation. Also, the design variables were determined by considering the support of the stock tail part for the C-axis body. In the comparison of the results before and after the optimization, the maximum deformation and stress are improved by 2.8% and 8%, respectively.

The Influence Function of the Correlation Indexes in a Two-by-Two Table

In this paper we examine 5 indexes (the two Yule’s indexes, the chi square, the odds ratio and an elementary index) of a two-by-two table, which estimate the correlation coefficient ρ in a bivariate Bernoulli distribution. We will find the compact expression of the influence functions, which allow the quantification of the effect of an infinitesimal contamination of the probability of any pair of attributes of the bivariate random variable distributed according to the above-mentioned model. We prove that the only unbiased index is the chi square. In order to determine the indexes, which are less sensitive to contamination, we obtain the expressions of three synthetic measures of the influence function, which are the maximum contamination (gross sensitivity error), the mean square deviation and the variance. These results, even if don’t allow a definitive assessment of the overall optimum properties of the five indexes, as not all of them are unbiased, nevertheless they allow to appreciating the synthetic entity of the effect of the contaminations in the estimation of the parameter ρ of the bivariate Bernoulli distribution.

THE CONSTRUCTION OF SOME FORESTRY TABLES FOR DAHURIAN LARCH PLANTATIONS

Several growth models were selected to fit data of dahurian larch plantations using nonlinear regression analysis. The best models were used to construct the site index table' the 2-way volume table and the growth process table. The Chapman-Richards equation is the best model used as the guide curve to form the site index table for dahurian larch plantations.

Measure of Departure from Point-Symmetry for the Analysis of Collapsed Square Contingency Tables

For square contingency tables with ordered categories, there may be some cases that one wants to analyze them by considering collapsed 3 × 3 tables with some adjacent categories combined in the original table. This paper considers the point-symmetry model (Wall and Lienert, 1976) for collapsed tables and proposes a measure to represent the degree of departure from point-symmetry for collapsed tables. Also it gives approximate confidence interval for the proposed measure.

Prediction of Water Table Based on General Regression Neural Network

Traditional methods for water table prediction have such defects as extensive calculation and reliance on the presupposition of a homogeneous and regular aquifer.Based on the fundamentals of the general regression neural network(GRNN),this article sets up a GRNN model for water level prediction.Case study indicates that this model,even with limited information,has satisfactory prediction accuracy,which,coupled with a simple model structure and relatively high calculation efficiency,mean a vast application prospect for the model.

基于二维混合式位置编码的高精度测角

针对具有精密旋转轴系类的高端制造装备或精密测量仪器,其旋转角度采用传统圆光栅难以消除偏心误差对测量角度精度的影响,提出了一种基于二维混合式位置编码的旋转角度高精度测量方法。该测角系统由一个二维混合式位置编码盘、两个CCD相机和远心镜头组成,二维混合式位置编码盘被固定在精密旋转轴系上以获得其旋转角度。然后,建立了测角模型并从数学上证明了测角精度与安装偏心无关。利用多齿分度台对已提出测角系统精度进行检测,测量角度误差在±1″。最后,利用已提出测量方法对直驱转台的角度定位精度进行测量,角度定位误差在±5″内。与传统圆光栅测角相比,该方法不需要考虑安装偏心误差对测角精度的影响,具有稳定性好、使用简单等特点,可用于角度定位误差的检测。

云存储抗边信道攻击的密文数据去重算法

考虑云储存中密文数据相似性较高,导致去重难度过大的问题,提出一种基于执行机构的密文数据去重算法。构建密文动态平衡跳跃表,根据对动态平衡跳跃表的构建与描述,得到抗边信道攻击的密文数据动态叠加特点。基于密文动态平衡跳跃表构建与更新结果,提出一种抗边信道攻击的数据去重框架,云储存提供商执行数据加密、数据标签查询以及数据去重三个过程。云端储存使用标签代表数据查询操作,一旦查询计数超过阈值,执行数据加密程序对该文件进行加密,并按照云储存服务商提供的执行命令对重叠密文进行去重。实验结果证明,所提方法对密文数据去重效果表现较佳,去重后云储存空间占用情况得到了明显改善。

基于多级索引表的金融业务数据库精准查询方法

为提升金融业务数据库查询精准度和效率,设计了一种基于多级索引表的金融业务数据库精准查询方法。首先,构建多级索引的逻辑结构,设计多级索引表构建过程;其次,进行金融业务数据特征融合,为金融业务数据查询准备好数据条件;最后,设计金融业务数据库精准查询算法,完成基于多级索引表的金融业务数据库精准查询方法设计的全过程。实验结果表明:设计方法的金融业务数据库查询精准度均在90%以上,最高可达到98%,而且查询所需时间最短仅为5.25 s。本设计方法的适用性极强,具有较好的应用前景,以期能够为金融业务数据的精准高效查询提供参考借鉴。

铁心杉种群结构与动态特征

【目的】杉木是南方生长最快的主要树种之一,而铁心杉是心材比例高、具有防腐的特殊性质的杉木新品种,但其野生种群分布范围窄。研究铁心杉种群结构与动态特征,可以为铁心杉种群的恢复以及种质资源的培育提供理论基础。【方法】以湖南小溪国家级自然保护区小溪乡的铁心杉天然林为研究对象,通过实地调查以胸径代替龄级,制作年龄结构图;以静态生命表制作存活、死亡和消失率曲线;以生存函数估计值制作生存函数曲线;计算了种群动态变化指数;预测了种群数量的时间序列。【结果】1)铁心杉种群的龄级结构属于不规则金字塔形,种群有一定的更新能力,第Ⅰ龄级储备丰富,但幼龄阶段死亡率高,铁心杉种群存活曲线趋Deevey-Ⅲ型;2)铁心杉种群在整个龄级中的死亡率和消失率曲线走向一致,在第XIII龄级出现最大值,而第Ⅰ龄级次之,因此铁心杉种群的更新和结构受到了空间资源的限制;3)经过生存分析,发现铁心杉的生存能力相对较差,在早期阶段会出现剧烈的下降,中期保持稳定,后期则会出现衰退;4)时间序列分析显示,整个铁心杉种群向中、高龄级集中,低龄的缺失会导致种群衰退。【结论】应尽快确定铁心杉的生态学地位,并采取就地保护以确保种群的更新;同时建议通过组织培养、引种栽培来保护铁心杉种质资源,扩大其分布范围。

Estimating index of population trend by re-sampling techniques （jackknife and bootstrap） and its application to the life table study of rice leaf roller, Cnaphalocrocis medinalis （Lepidoptera： Pyralidae）

Taking a published natural population life table of rice leaf roller, Cnaphalocrocis medinalis （Lepidoptera： Pyralidae）, as an example, we estimated the population trend index, I, via re-sampling methods （jackknife and bootstrap）, determined its statistical properties and illustrated the application of these methods in determining the control effectiveness of bio- agents and chemical insecticides. Depending on the simulation outputs, the smoothed distribution pattern of the estimates of I by delete-1 jackknife is visually distinguishable from the normal density, but the smoothed pattern produced by delete-d jackknife, and logarithm- transformed smoothed patterns produced by both empirical and parametric bootstraps, matched well the corresponding normal density. Thus, the estimates of I produced by delete-1 jackknife were not used to determine the suppressive effect of wasps and insecticides. The 95% percent confidence intervals or the narrowest 95 percentiles and Z-test criterion were employed to compare the effectiveness of Trichogrammajaponicum Ashmead and insecticides （powder, 1.5% mevinphos ＋ 3% alpha-hexachloro cyclohexane） against the rice leaf roller based on the estimates of I produced by delete-d jackknife and bootstrap techniques. At a = 0.05 level, there were statistical differences between wasp treatment and control, and between wasp and insecticide treatments, if the normality is ensured, or by the narrowest 95 percentiles. However, there is still no difference between insecticide treatment and control. By Z-test criterion, wasp treatment is better than control and insecticide treatment with P-value 〈 0.01. Insecticide treatment is similar to control with P-value 〉 0.2 indicating that 95% confidence intervals procedure is more conservative. Although similar conclusions may be drawn by re-sampling techniques, such as the delta method, about the suppressive effect of trichogramma and insecticides, the normality of the estimates can be checked and guaranteed, and the correlation among sequential life stages of rice leaf roller is also considered in the estimation. Judged by the P-values from Z-test, the delta method is more conservative.

极小种群野生植物狭叶坡垒种群结构与动态特征

【目的】研究极小种群野生植物狭叶坡垒[Hopea chinensis(Merr.) Hand.-Mazz.]的种群结构特征和数量动态特征,探讨种群发展潜力和濒危原因,为狭叶坡垒种质资源的保护和恢复提供参考依据。【方法】采用样地调查法对广西十万大山区域8个狭叶坡垒自然集中分布区进行调查,以空间代替时间分析狭叶坡垒种群结构特征,绘制种群静态生命表和存活曲线,分析种群动态指数及种群生存函数,对种群未来发展趋势进行预测。【结果】狭叶坡垒野生种群龄级结构呈倒J型,幼龄个体数占比较高,表现为增长型结构,种群个体幼龄期淘汰率较高;种群动态指数、随机干扰敏感指标和随机干扰风险概率分别为52.61%、4.38%和8.33%,对外界干扰敏感,环境对个体有较强的选择作用。狭叶坡垒野生种群存活曲线为DeeveyⅡ型的B1亚型,狭叶坡垒种群生存率在Ⅰ~Ⅵ龄级期间随龄级增加而减小,累积死亡率随龄级增加而增加,危险率在Ⅵ龄级达最高值,狭叶坡垒种群在Ⅵ龄级之后进入生理衰退期。时间序列分析表明,除Ⅻ龄级的个体数经过4个龄级时间后保持不变,经过4、6、8、10个龄级时间后,狭叶坡垒各龄级的个体数均呈增加趋势,其中Ⅳ~Ⅷ龄级逐渐成为种群的主体,狭叶坡垒种群总体呈增长状态。【结论】狭叶坡垒野生种群为增长型,种群处于波动变化状态中,对外界干扰敏感。幼苗数量充足,在生境不被破坏的前提下,具有较好的恢复潜力。但幼苗向幼树、幼树向小树转换过程中存在增补限制,制约狭叶坡垒种群发展。

成层地基振动台试验双向剪切箱设计与边界效应测评

为满足散粒体材料(如土体)在多向振动台试验中截断边界模拟的需求,设计并制作了一种刚度可调节的层状双向剪切箱。剪切箱由矩形钢管框架堆叠而成,层间设置万向轴承与滚珠,可实现更加真实的双向协调运动;刚度调节装置与复位装置保证箱体复位、运动一致性和整体性,能够满足层间剪切变形。利用所设计的双向层状剪切箱进行上软下硬成层地基的振动台试验,根据边界效应指数与2-范数对边界效应进行定量分析。结果表明,研制的双向剪切箱性能良好,能够正确模拟成层地基场地的地震动特性,边界效应得到有效控制。

反汇编工具中间接跳转表求解算法分析与测试

二进制反汇编是困难的,但是对于提高二进制软件的安全性至关重要.造成二进制反汇编比较困难的一大原因是编译器为了提高效率会在二进制代码中引入很多间接跳转表.为了求解间接跳转表,主流反汇编工具采用了各种策略.然而,这些策略的具体实现以及策略的效果不得而知.为了帮助研究人员理解反汇编工具的算法实现以及性能,首先系统总结反汇编工具求解间接跳转表的策略;然后构建自动化测试间接跳转表框架,基于该框架,可以大规模地生成关于间接跳转表的测试集(包含2410455个跳转表);最后,在该测试集上,对反汇编工具求解间接跳转表的性能进行评估,并人工分析反汇编工具的每个策略引入的错误.另外,得益于针对反汇编工具算法实现的系统性总结,发现6个反汇编工具实现上的bugs.

IndexPeer：半结构化P2P系统资源发现模型及其DHT算法

提出了一种基于半结构化P2P系统的资源发现模型——IndexPeer模型。该模型采用三层索引结构,由下至上分别为virtual organization层、service peer层和indexpeer层。IndexPeer充分利用P2P系统中的节点性能差异,具有高效的查找功能,且对网络的高度动态性有良好的适应性。针对Index Peer模型的体系结构,对该模型的结构化层DHT算法进行了研究和设计。基于small-world的仿真实验表明,IndexPeer模型的体系结构及其结构化层DHT算法具有较好的鲁棒性和一定的可扩展性。

网壳结构多参数韧性评价指标

随着抗震设计理念的不断发展,抗震韧性得到研究者的广泛关注,逐步成为地震工程的热点课题。该文针对《建筑抗震韧性评价标准》中存在的不足,根据网壳结构在地震作用后的损伤特点与维修方式,定义网壳结构构件和非结构构件的损伤等级,修订“标准”中各项指标的部分计算参数。通过108组覆盖性网壳算例,拟合得到适用于网壳结构的多参数韧性评价指标与等级划分,在4个临界点处的指标值(R值)分别为1.0、1.6、2.0与2.7。以两个大型振动台试验和随机选取的若干网壳算例共同验证韧性评价指标和等级划分的普适性与有效性。结果表明,该文提出的多参数韧性评价指标等级划分全面、合理,能定量地刻画网壳结构震后的韧性情况,可服务于网壳结构抗震韧性和韧性评估体系。

杭州亚运会女单决赛孙颖莎和早田希娜技战术特征对比分析——基于乒乓球四段指标评估法

本文运用录像观察法和四段指标评估法,对杭州亚运会女单决赛中孙颖莎和早田希娜的技战术特征进行对比分析。结果发现,(1)整体上看,孙颖莎四段的表现较好,接抢段使用较多;早田希娜更注重前4板的争夺,相持Ⅱ段是主要薄弱环节。(2)发抢段方面,孙颖莎的发球以中路和正手位短球落点为主,第三板攻击对方正手位的战术效果较好;而早田希娜发球落点多变、突然性强,第五板反手失分较多。(3)接抢段方面,孙颖莎多从对方反手位突破;早田希娜接发球变化较多且主动性强,第四板多从正手和中路突破。(4)相持Ⅰ段孙颖莎的表现全面优于早田希娜,但反手变线的失误较多;早田希娜对相持的准备不足,正手能力较弱。(5)相持Ⅱ段中孙颖莎处理中路球的表现较差,早田希娜整体相持能力欠缺。建议:(1)女子比赛应突出前三板技术的重要性;(2)在发抢段,孙颖莎需要提高对长球的应变能力,坚定己方战术的使用;(3)在接抢段,孙颖莎应加强接发球抢攻的威胁性,第四板注意正手和中路的来球;(4)在相持Ⅰ段,孙颖莎应提高反手变线的能力;(5)在相持Ⅱ段,孙颖莎应从正手斜线突破,加强回接中路球的能力。

一种地理空间网络子集快速探测方法

针对大数据下地理空间网络子集探测效率较低的问题,文章通过引入“弧段到点”和“点到弧段”两个索引表,提出了一种地理空间网络子集快速探测方法。该方法创新性地通过两个索引表直接实现了弧段和端点的查找定位,避免了传统子集探测方法中因查找搜索计算冗余度过高导致的效率低下问题,显著提升了地理空间网络子集探测的计算效率。通过MATLAB软件模拟生成了包含不同数量随机点的狄洛尼三角网,利用该方法和传统方法分别进行了子集探测。结果表明,两种方法均可实现子集的成功探测,但是该方法显著改善了子集探测效率。

分析拉贝洛尔联合音乐疗法对妊娠期高血压患者的应用效果

目的:分析拉贝洛尔联合音乐疗法对妊娠期高血压患者的应用效果。方法:选取2022年4月至2023年7月山东省泰安市泰安八十八医院妇产科收治的妊娠期高血压患者50例作为研究对象,按照随机数字表法分为对照组和观察组,每组25例。采用匹兹堡睡眠质量指数(PSQI)比较2组患者睡眠质量的差异,采用健康调查简表(SF-36)比较2组患者干预前后生命质量的变化,比较2组患者舒张压、收缩压的变化,并观察2组患者的母婴结局。结果:治疗后,观察组舒张压、收缩压低于对照组,观察组PSQI评分显著低于对照组,观察组SF-36评分显著高于对照组,观察组不良母婴结局总发生率显著低于对照组,差异均有统计学意义(均P<0.05)。结论:拉贝洛尔联合音乐疗法有助于改善妊娠期高血压患者的睡眠情况及生活状态,降低不良母婴结局发生率,改善娠期高血压患者的血压水平,值得临床推广应用。