改进

Theoretical extension of the group selection model proposed by Sober and Wilson in 1998 is given, and its shortcomings are corrected, so that the new model can give a better description of reality, and some valuable conclusions are made.

笔者对索伯和威尔逊在1998年提出的群体选择模型进行了理论上的扩展，并对其不足之处进行了改进，使改进以后的模型更加符合实际，并得到了一些有价值的新结论。

Finally some of these algorithms are implemented in text test,and experiments indicate that the improved algorithm HAC provides a significant improvement in pattern matching performance when it is used in an Intrusion Detection System.

最后，对改进的算法进行了文本测试，实验表明改进的HAC算法在模式匹配速度方面的优势，可以用于网络入侵检测系统。

The technology of verifier Hash code is used to defense Denial of Service attack.

改进的远程安全密钥协议通过合并简化协商过程来匹配H.323系统消息的通信流程，改进的鉴别符哈希码技术用于抵抗篡改攻击及拒绝服务攻击。

Taking Dalian market for instance, the paper introduces the Hedonic theory based on the problem involved in current index.

本文以大连房地产市场为例，在现有房地产价格指数存在的问题的基础上，引入特征价格理论的思想，并结合大连房地产市场的特点以及所具备的统计条件，提出了一种改进的房地产价格指数编制方法，并对改进后的方法的应用过程做了介绍。

The results show that the two kinds of basic ant colony algorithm have better performance than classical K-means algorithm and hierarchal clustering algorithm, the two kinds of extended algorithm have better performance than corresponding basic ant colony algorithm.

实验结果表明，两种基本蚁群算法的聚类效果优于经典的K_means算法和层次聚类算法；两种改进的算法又分别优于相应的基本蚁群算法，达到了算法改进的目的。

The establishment principles of traditional and improved PML absorbing boundary condition were described. Through numerical simulation, the absorbing effect of improved and traditional PML absorbing boundary and low-order Higdon absorbing boundary on boundary reflection was discussed.

阐述了传统和改进的PML吸收边界条件的构建原理，通过数值模拟讨论了改进和传统的PML吸收边界以及低阶Higdon吸收边界对边界反射的吸收效果。

After comparing the image effect of homomorphic filtering, the effect of median filtering with different templates and the effect of binarizing with improved OTSU, the experiment results show that V groove laser image in underwater welding is preprocessed very well through such serial processing steps as homomorphic filter strenghening, median filtering, binarizing with improved OTSU, and thinning.

通过比较同态滤波前后效果、比较不同模板下的中值滤波效果、以及Otsu法改进前后的效果，实验表明，对水下焊接V型焊接坡口激光图片依次进行同态滤波增强、中值滤波、改进Otsu二值化和腐蚀细化一系列图像处理，取得了效果较理想的预处理结果。

We successfully improved the methods of departing O-methyl using boron tribromide, of isolating hydrogen bromide byα-chloro-ethyl chloroformate, and of related in synthesis of natrexone, new medicine, using boron tribromide. This resulted in generation of hydrogen cyanide becoming impossible.

改进了以氯甲酸-α-氯乙酯脱代替溴化氰以及改进的三溴化硼法作为新药纳曲酮合成中相应的方法，去除了合成过程中产生氰化氢气体的可能性。

We propose a dynamic identity authentication scheme through a theorem about relative prime numbers, which can prevent replay attacks from taking place. In addition, we present a threshold signature scheme without a trusted party by use of joint secret sharing technique. Finally, the security flaw in an enhanced password authentication scheme is pointed out and the security of an enhanced key agreement protocol is analyzed.

首先基于一个关于互素数的定理设计了一个动态身份认证协议，该协议使攻击者不可能通过回放攻击来假冒用户；利用联合秘密共享技术设计了一个无可信中心门限签名方案；最后，分析了一个改进的身份认证协议存在的安全漏洞，以及一个改进的密钥协商协议的安全性。

After finding the reason which causes the sands to sink, weGived a improving measure, which is opening some litter holes at the pipe,similarly thepulse immixture the typical,in the subsequent experiment, the pulse was proved that it isbetter than the typical on many performances, include an important performance—watertlow rate.

在分析沙粒下降原因的基础上，提出了改进措施，即在提升管上钻若干个小孔，类似将常规气提装置的原理应用过来，在随后的实验中，证实了改进后的气提装置在诸多性能上要优于常规气提，包括水流量这个重要的参数。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。