一种基于目标方位的照射器分配算法

根据水面舰艇对空防御的战术需求,系统分析水面舰艇照射器的工作模式,提出了一种简便高效的火力分配算法,仿真结果表明了该算法对提高对空防御软件的可靠性和实时性具有一定的借鉴意义。

平面上最接近点对问题的研究

针对平面上最接近点对问题,分别考虑其在离线环境和在线环境下的两种情况。在离线环境下,针对分治算法,结合点集本身的稀疏性质和圆的性质,给出一个改进的合并算法,使得在合并过程中由每个点的最多6次计算距离降为4次运算,从而提高算法的效率。在在线环境下,给出3种算法求解此问题。第1种算法是每给出第k个点就计算k-1次。第2种算法是给出一个判别式子,在给第k个点时,首先对前k-1个点进行判断,判断出与之会影响当前最小距离的点后再进行计算。第3种算法是结合几何知识,证明得到在此问题中,当新的点出现时,最多只会有6个点与之影响当前最小距离,所以通过插序找出此6点再进行计算。可以证明这3种算法的时间复杂度均为O(n2),但显然随着点数n的增大,算法的平均时间复杂度一定会依次降低。

Comparison between Sequential Gaussian Simulation and Kriging Interpolation on Soil Heavy Metal Pollution

[Objective] This study was to explore the difference of kriging interpolation and sequential Gaussian simulation on analyzing soil heavy metal pollution with a view to provide references for analyzing the heavy metal pollution of soil. [Method] The sampling data of soil copper from a county of Liaocheng, Shandong Province was set as the study objective. Kriging interpolation and sequential Gaussian simu- lation were used to simulate the spatial distribution of soil copper. And 30 sampling points were selected as the cross-validation data set to compare the two interpola- tion methods. [Result] Kriging method and Gaussian sequential simulation have their own advantages on simulating mean segment and extreme segment, therefore, re- searchers should choose the proper method based on the characteristics of test data and application purposes. [Conclusion] Analysis of soil heavy metal pollution is the prerequisite for soil management and ecological restoration. The result of this study is of important significance for choosing different interpolating and simulating methods to analyze soil heavy metal pollution based on different purposes.

Ac/Ds Transposition Activity in Transgenic Rice Population and DNA Flanking Sequence of Ds Insertion Sites

The Agrobacterium mediated transgenic rice ( Oryza saliva L.) population with inserts of maize transposon Activator/Dissociation (Ac/Ds) was investigated. DNA sequences flanking the T-DNA were analyzed with inverse PCR. Results showed that 65.4% of the T-DNA was integrated in different locations of rice genome, and some T-DNA flanking sequences were located on certain chromosomes. A number of T-DNA was found to have inserted into protein coding regions. In order to induce transposition of the inserted Ds elements, 354 crosses of Ac x Ds and Ds x Ac were constructed. The excision frequency of Ds element trans-activated by Ac transposase was 22.7% in the F-2 populations, and the transposition was confirmed with analyses of DNA sequences flanking the Ds elements. In addition to the transposition due to 'cut-paste' mechanism, Ds can replicate itself and integrate into a new locus, and inaccurate excisions were also found. A proportion of DNA segments flanking the Ds elements showed no homologies to sequences published in GenBank, of which two were registered under the accession numbers AF355153 and AF355770. The strategy of using transposon tagging for rice genomics study was discussed.

Increment of hFIX expression with endogenous intron 1 in vitro

This paper probes into the feasibility of increasing expression level of hFIX gene with endogenous nitron 1 sequence. hFIX minigene was obtained with middle sequence truncated nitron 1 inserted into the relative site of hFIX cDNA, and plasmid vector pKG5i’IX, retroviral vector GINaCi’IX were constructed. These vectors were transduced into target cells of PA317, C2C12, primary rabbit skin fibroblasts (RSF) and primary human skin fibroblasts (HSF). The expression level of mixed colonies are PA317/pKG5i’IX, 151 "g/106 cells/24h; PA317/GINaCi’IX, 308ng/106 cells/24 h; C2C12/G1 NaCi’IX, 186 ng/106 cells/24 h; RSF/GINaCi’IX, 1929 ng/106 cells/24 h; HSF/GlNaCi’IX, 1646 ng/106 cells/ 24 h. These results indicated that hFIX minigene with nitron 1 is able to increase the expression level to about 3 times of that of hFIX cDNA. Meanwhile, in order to study the application of hFIX minigene in the retroviral-mediated gene transfer system and refrain from nitron splicing during viral production, a retroviral vector GlNaCi’IXR with reversely inserted hFIX minigene expression cassette was constructed. The expression level of reverse constructor in PA317 cells was 390 ng/106 cells/24 h with 79% of bioactivity. PCR detection of HT/GlNaCi’IXR cells infected with PA317/ClNaCi’IXR supernatant confirmed the existence of nitron 1 sequence. These results suggested that expression vector with forward-inserted intronl-carrying hFIX expression cassette can be used in directed gene Human factor IX expression with nitron transfer, but when using the retroviral-mediated gene transfer system, reversely-inserted intronl-carrying hFIX expression cassette should be considered.

On the Unique Minimal Monomial Basis of Birkhoff Interpolation Problem

This paper studies the minimal monomial basis of the n-variable Birkhoff interpolation problem. First, the authors give a fast B-Lex algorithm which has an explicit geometric interpretation to compute the minimal monomial interpolation basis under lexieographie order and the algorithm is in fact a generalization of lex game algorithm. In practice, people usually desire the lowest degree interpolation polynomial, so the interpolation problems need to be solved under, for example, graded monomial order instead of lexicographie order. However, there barely exist fast algorithms for the non- lexicographic order problem. Hence, the authors in addition provide a criterion to determine whether an n-variable Birkhoff interpolation problem has unique minimal monomial basis, which means it owns the same minimal monomial basis w.r.t, arbitrary monomial order. Thus, for problems in this case, the authors can easily get the minimal monomial basis with little computation cost w.r.t, arbitrary monomial order by using our fast B-Lex algorithm.

Robust genome editing of CRISPR-Cas9 at NAG PAMs in rice

Dear Editor,The CRISPR-Cas9（clustered regularly interspaced short palindromic repeats/Cas9）system has been widely used for a variety of applications,including targeted gene knockout,gene insertion,gene replacement and base editing.Despite its wide use,the genome editing using CRISPR-Cas9 is performed almost exclusively at sites containing canonical NGG protospacer adjacent motifs（PAMs）.To overcome the PAM constraint of the CRISPR-Cas9 system,many attempts have been made to develop various Cas9 orthologs and v variants with altered PAM specificities （Kleinstiver et al., 2015; Hu et al., 2016）.

Bivariate Gonarov polynomials and integer sequences

Univariate Gonarov polynomials arose from the Goncarov interpolation problem in numerical analysis.They provide a natural basis of polynomials for working with u-parking functions,which are integer sequences whose order statistics are bounded by a given sequence u.In this paper,we study multivariate Goncarov polynomials,which form a basis of solutions for multivariate Goncarov interpolation problem.We present algebraic and analytic properties of multivariate Gonarov polynomials and establish a combinatorial relation with integer sequences.Explicitly,we prove that multivariate Goncarov polynomials enumerate k-tuples of integers sequences whose order statistics are bounded by certain weights along lattice paths in Nk.It leads to a higher-dimensional generalization of parking functions,for which many enumerative results can be derived from the theory of multivariate Goncarov polynomials.

HASM-AD Algorithm Based on the Sequential Least Squares

The HASM(high accuracy surface modeling) technique is based on the fundamental theory of surfaces,which has been proved to improve the interpolation accuracy in surface fitting.However,the integral iterative solution in previous studies resulted in high temporal complexity in computation and huge memory usage so that it became difficult to put the technique into application,especially for large-scale datasets.In the study,an innovative model(HASM-AD) is developed according to the sequential least squares on the basis of data adjustment theory.Sequential division is adopted in the technique,so that linear equations can be divided into groups to be processed in sequence with the temporal complexity reduced greatly in computation.The experiment indicates that the HASM-AD technique surpasses the traditional spatial interpolation methods in accuracy.Also,the cross-validation result proves the same conclusion for the spatial interpolation of soil PH property with the data sampled in Jiangxi province.Moreover,it is demonstrated in the study that the HASM-AD technique significantly reduces the computational complexity and lessens memory usage in computation.