运用GD-PBIBD编码的矢量空间数据数字指纹算法

针对矢量空间数据叛逆者追踪难及编码效率低的问题,本文提出了一种运用GD-PBIBD码的指纹算法。首先运用GD-PBIBD构造指纹编码,将待嵌入指纹序列运用Logistic映射置乱,通过D-P算法提取矢量空间数据的特征点,对特征点实施DFT变换得到相位系数和幅度系数;然后运用QIM方法将指纹嵌入DFT变换域的幅度系数上;最后应用DFT逆变换得到含指纹的矢量空间数据。试验选取部分中国路网数据和某区域绿地数据,运用该算法嵌入指纹后,对其进行线性和非线性模拟攻击,成功提取指纹序列,利用汉明距离追踪出合谋者。该算法编码构造简单,在码长一定的情况下,较BIBD码可容纳更多的用户,效率高;算法抗单用户指纹攻击及多重攻击的稳健性较好,也能够抵抗多用户最小值和最大最小值攻击,追踪到所有叛逆者,可用于矢量空间数据版权保护,为矢量空间数据叛逆者追踪提供依据。     

水体细菌碱性磷酸酶及其编码基因研究进展

水体溶解性反应磷是浮游植物可直接利用的主要磷营养形式,细菌碱性磷酸酶催化的有机磷矿化过程则是维持溶解性反应磷供给的重要途径.通过总结细菌碱性磷酸酶的种类与分布特征,发现主要包括Pho A、Pho X和Pho D 3种类型细菌碱性磷酸酶,其中超过50%的Pho X分布于细菌细胞的外部环境,对溶解性反应磷的循环再生尤为重要.综述水体产碱性磷酸酶细菌群落组成的研究进展,以及影响编码基因表达的环境因素,对比分析产碱性磷酸酶细菌群落鉴定方法的特点及发展趋势.细菌碱性磷酸酶编码基因的研究多关注寡营养海洋生态系统,对于同样存在磷限制问题的富营养化湖泊生态系统鲜有涉及,而构建针对典型富营养化湖泊生态系统的细菌宏基因组数据库,则可为建立淡水生态系统细菌碱性磷酸酶及其编码基因的研究方法奠定基础,有助于认识湖泊水华频发的微生物学驱动机制.     

The Role of β-effect and a Uniform Current on Tropical Cyclone Intensity

A limited-area primitive equation model is used to study the role of the β-effect and a uniform current on tropical cyclone (TC) intensity.It is found that TC intensity is reduced in a non-quiescent environment compared with the case of no uniform current.On an f-plane,the rate of intensification of a tropical cyclone is larger than that of the uniform flow.A TC on a β-plane intensifies slower than one on an f-plane.The main physical characteristic that distinguishes the experiments is the asymmetric thermodynamic (including convective) and dynamic structures present when either a uniform flow or β-effect is introduced.But a fairly symmetric TC structure is simulated on an f-plane.The magnitude of the warm core and the associated subsidence are found to be responsible for such simulated intensity changes.On an f-plane,the convection tends to be symmetric,which results in strong upper-level convergence near the center and hence strong forced subsidence and a very warm core.On the other hand,horizontal advection of temperature cancels part of the adiabatic heating and results in less warming of the core,and hence the TC is not as intense.This advective process is due to the tilt of the vortex as a result of the β-effect.A similar situation occurs in the presence of a uniform flow.Thus,the asymmetric horizontal advection of temperature plays an important role in the temperature distribution.Dynamically,the asymmetric angular momentum (AM) flux is very small on an f-plane throughout the troposphere.However,the total AM exports at the upper levels for a TC either on aβ-plane or with a uniform flow environment are larger because of an increase of the asymmetric as well as symmetric AM export on the plane at radii ＞450 km,and hence there is a lesser intensification.     

定常风场和吞吐流对乌梁素海流场的影响

风场和吞吐流是浅水湖泊运动的主要驱动力,影响着湖区污染物的迁移转化。基于二维非结构网格,构建了乌梁素海水动力模型。通过对比定常风作用下湖流的方向、环流的分布及形式与无风条件下的区别,模拟不同算例吞吐流作用下湖区流速及环流结构的差异,探究了定常风和吞吐流对乌梁素海流场的影响。结果表明:乌梁素海在无风条件下出现大面积的滞流区;风场会增加湖流的流速,影响区域主要在西大滩区、东大滩区及湖区南部明水区,产生明显环流,风场是乌梁素海主要的驱动力; SSW与ENE向风场作用下,典型区域产生的环流位置、形态结构相近,方向相反;吞吐流量的增加会增大湖区整体流速,对湖区流场形态、结构影响较小;定常风条件下,吞吐流量的增加(一定范围)会导致环流强度减弱。研究结果为乌梁素海营养盐、污染物质输移规律研究奠定基础。     

Probability field for the post-processing of stochastic simulations

A combination of factorial kriging and probability field simulation is proposed to correct realizations resulting from any simulation algorithm for either too high nugget effect (noise) or poor histogram reproduction. First, a factorial kriging is done to filter out the noise from the noisy realization. Second, the uniform scores of the filtered realization are used as probability field to sample the local probability distributions conditional to the same dataset used to generate the original realization. This second step allows to restore the data variance. The result is a corrected realization which reproduces better target variogram and histogram models, yet honoring the conditioning data.     

基于南方测绘软件下的全站仪编码测量研究

城市测量用到最多的仪器就是全站仪,全站仪野外测图主要使用草图法和编码法,这两个方法有各自的优势。本文对编码引导法技术进行了研究,极大地提高了外业生产和内业成图的效率。     

Using non-Gaussian distributions in geostatistical simulations

Parametric geostatistical simulations such as LU decomposition and sequential algorithms do not need Gaussian distributions. It is shown that variogram model reproduction is obtained when Uniform or Dipole distributions are used instead of Gaussian distributions for drawing i. i.d. random values in LU simulation, or for modeling the local conditional probability distributions in sequential simulation. Both algorithms yield simulated values with a marginal normal distribution no matter if Gaussian, Uniform, or Dipole distributions are used. The range of simulated values decreases as the entropy of the probability distribution decreases. Using Gaussian distributions provides a larger range of simulated normal score values than using Uniform or Dipole distributions. This feature has a negligible effect for reproduction of the normal scores variogram model but have a larger impact on the reproduction of the original values variogram. The Uniform or Dipole distributions also produce lesser fluctuations among the variograms of the simulated realizations.     

对虾传染性皮下及造血组织坏死病毒编码蛋白的相互作用研究

采用Matchmaker酵母双杂交系统,将对虾传染性皮下及造血组织坏死病毒(Infection hypodermal and hematopoietic necrosis virus,IHHNV)编码蛋白NS1、NS2和CP序列分别构建到酵母猎物载体p GADT7和诱饵载体p GBKT7上,分别转化至酵母AH109以检测重组猎物载体和诱饵载体的自激活作用及对宿主的毒性作用,发现无自激活作用和毒性作用,随后将重组猎物载体和诱饵载体两两共转至酵母AH109中,涂布于SD/-Leu/-Trp固体培养基上,再点种至SD/-Ade/-His/-Leu/-Trp/X-α-gal固体培养基以鉴定编码蛋白间的相互作用。表型鉴定结果显示,只有共转化有p GADT7-CP/p GBKT7-CP的酵母重组子能够在SD/-Ade/-His/-Leu/-Trp/X-α-gal上生长并显蓝,而其它重组子均不能在其上生长,表明病毒的CP能够自身互作,而其他编码蛋白间无相互作用。为了进一步研究病毒CP自身互作的作用位点,分别从CP的N端和C端截短若干个氨基酸序列,结果发现CP的自身互作是高度敏感的,任何较少氨基酸序列的缺失都将导致其自身互作的丧失。本研究为深入探讨病毒的组装机制和致病机理奠定了理论基础。     

GNSS控制网坐标移动转换的三次曲面拟合法

针对2000国家大地坐标到海南独立坐标系需要保密参数的局限性,该文利用三次曲面拟合坐标移动转换法进行2000国家大地坐标系到海南独立坐标转换,解决了在没有海南独立坐标系参数的情况下无法进行坐标转换的困扰,确保参数保密性。测试比较结果表明,三次曲面拟合法移动坐标转换法能够提高坐标转换精度。     

时滞广义时变系统的渐近稳定与镇定

研究了时滞广义时变系统的渐近稳定和镇定问题。首先利用相关不等式,通过建立Lyapunov方程,给出了1个时滞广义时变系统无脉冲、渐近稳定性的充分条件。然后,基于这一工作,利用Riccati方程,进一步研究了时滞广义时变系统的镇定问题。最后,举例说明该结论的可行性。