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101.
The delay-constrained least-cost multicast routing problem is introduced and then a related genetic algorithm is proposed. Finally, simulation results are shown to prove that the genetic algorithm is fast and effective. 相似文献
102.
In this paper, a new selective discarding policy called double threshold-based early meassage(DTEMD) policy is present. In the DTEMD policy, two thresholds are defined through which the system can adapt to the current load without changing its operation modes too often as EMD[1] policy does. Moreover the policy gets high utility of the buffer and so improves the system performance. By adopting a new performance measure "goodput", analysis results show a remarkable performance improvement is obtained when the improved discarding policy is applied. 相似文献
103.
Spectral estimation method is an effective method in the case of parameter estimation of sinusoid signal in noises.It always applies cross-spectral estimation theory and high-order self-spectral estimation methods up to now.Yule-Walker equation based on cross-fourth-order cumulant is developed and Pisarenko method is provided in this paper.Simulation results show that the method is effective to retrieve sinusoid signal frequencies from hybrid colored noises and has good performance. 相似文献
104.
对X60、X65和X70三种微合金高强钢(石油、天然气输送管线用钢)水下及空气中焊接影响粗晶区(CGHAZ)中的沉淀物及其溶解、再析出、长大等行为进行了考察。结果发现,在水下焊接过程中富Ti粒子几乎不溶解而富V粒子较易溶解,水下焊接同空气中焊接相比CGHAZ中深沉物的溶解。再析出和长大等行为均有明显差异。 相似文献
105.
分析OMR GYQ-S30型阅卷系统成绩处理软件使用问题,介绍其优化与改进方法。 相似文献
106.
Lihong Nie Zongfu Han Lahu Lu Yingyin Yao Qixin Sun Zhongfu Ni 《自然科学进展(英文版)》2008,18(5):533-538
In order to understand the genomic changes during the evolution of hexaploid wheat, two sets of synthetic hexaploid wheat from hybridization between maternal tetraploid wheat (AABB) and paternal diploid goat grass (DD) were used for DNA-AFLP and single strand conformation polymorphism (SSCP) analysis to determine the genomic and genic variation in the synthetic hexaploid wheat. Results indicated that more DNA sequences from paternal diploid species were eliminated in the synthetic hexaploid wheat than from maternal tetraploid wheat, suggesting that genome from parental species of lower ploidity tends to be eliminated preferentially. However, sequence variation detected by SSCP procedure was much lower than those detected by DNA-AFLP, which indicated that much less variation in the genic regions occurred in the synthetic hexaploid wheat, and sequence variations detected by DNA-AFLP could be derived mostly from non-coding regions and repetitive sequences. Our results also indicated that sequence variation in 4 genes can be detected in hybrid F1, which suggested that this type of sequence variation could be resulted from distant hybridization. It was interesting to note that 3 out of the 4 genes were mapped and clustered on the long arm of chromosome 2D, which indicated that variation in genic sequences in synthetic hexaploid wheat might not be a randomized process. 相似文献
107.
Yan Ouyang Liming Wu Feng Jin Wei Shi Pingping Tan Qinhua Bai Xianshu Liu 《科学通报(英文版)》1999,44(20):1895-1895
Within a honeybee population, due to polyandry, there are supersister and halfsister relations, thus many subfamilies exist.
For the Chinese honeybee (Apis cerana cerana F.) a phylogenetic dendrogram has been constructed in which 4 subfamilies are clustered based on DNA fingerprint patterns. And
it has been observed that each kind of workers is distributed to several dierent sub-families. 相似文献
108.
史志贵 《科技情报开发与经济》1999,9(5):16-17
文章阐述了知识经济的内涵和特征,指出为迎接知识经济的挑战,必须提高我国的科技支撑力,培养出一批高素质的创新型人才,并改革、完善现行的人才使用与管理制度 相似文献
109.
应用Chapman-Enskog展开和多重尺度技术求取二阶、四阶粘性系数及三阶色散系数;给出Navier-Stokes方程所要求的平衡态分布函数的高阶矩形式. 相似文献
110.
论述航天器火工品参数计算机自动检测系统的硬件和软件构成、系统工作原理及检测技术,研究检测数据的处理方法.检测系统对数据库的直接读写操作.实现检测系统与数据库管理系统的快速数据交换.实际使用表明系统测量精度高、速度快、效率高. 相似文献