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1.
认知无线网络中,由于不同认知节点可用频道的差异和频繁的变化,使得传统的无线路由算法无法在认知无线网络中工作.本文提出了一种基于频道可用率和路径累计时延的路由机制,既保证了数据的投递率,又降低了数据投递延迟.实验表明,该机制在一级网络干扰频繁和链路质量多变的环境下具有更好的路由性能.  相似文献   

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The nicotinic acetylcholine receptor (AChR) from fish electric organ has a subunit structure of alpha 2 beta gamma delta, and this is thought to be also the case for the mammalian skeletal muscle AChR. By cloning and sequencing the complementary or genomic DNAs, we have previously elucidated the primary structures of all four subunits of the Torpedo californica electroplax and calf muscle AChR and of the alpha- and gamma-subunits of the human muscle AChR; the primary structures of the gamma-subunit of the T. californica AChR and the alpha-subunit of the Torpedo marmorata AChR have also been deduced elsewhere. We have now cloned DNA complementary to the calf muscle messenger RNA encoding a novel polypeptide (the epsilon-subunit) whose deduced amino-acid sequence has features characteristic of the AChR subunits and which shows higher sequence homology with the gamma-subunit than with the other subunits. cDNA expression studies indicate that the calf epsilon-subunit, as well as the calf gamma-subunit, can replace the Torpedo gamma-subunit to form the functional receptor in combination with the Torpedo alpha-, beta- and delta-subunits.  相似文献   

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针对人群密度估计算法中场景的人群遮挡、尺度光照变化、噪声和低分辨率等问题,提出了一种结合局部二值熵值纹理特征(ELBP)与深度残差网络的人群密度估计算法。该算法首先在原始RGB人群图像上提取LBP特征;然后通过计算邻域像素点的平均信息熵模式构建ELBP纹理特征;随后基于ELBP纹理特征构建了一个深度为18层的深度残差网络;最后形成了对人群密度估计的end-to-end模式。为验证算法的可行性和有效性,在开源的人群密度估计数据集上进行实验。首先邀请10位专家对开源的数据集进行有效的人群聚集标注作为真实输出标签;随后采用研究提出的算法对人群密度完成估计,并与真实结果进行比较。另外,在三种不同的特征和三种不同的机器学习模型上进行了横向比较。实验结果表明,提出的ELBP纹理特征能够很好地应对噪声和低分辨率问题;深度残差网络则能够解决人群遮挡、尺度光照变化的问题。与传统算法相比,提出的算法能够提升人群密度估计的性能。  相似文献   

4.
J H?chtl  H G Zachau 《Nature》1983,302(5905):260-263
Functional kappa light chain genes are formed during B-lymphocyte differentiation by the joining of initially separate V and J gene segments. It has been suggested that the intervening DNA is deleted, however the recent reports of what appear to be the reciprocal products of V and J recombination (back-to-back conserved V and J flanking sequences, called f-fragments) in DNA from mature lymphocytes make a simple deletion model unlikely. An alternative scheme involving unequal sister chromatid exchange has been proposed, supported by the evidence that the f-fragments seem to have segregated from the chromosome carrying the reciprocal complete kappa light chain gene (this and other schemes are briefly reviewed in ref. 8). We report here the analysis of a mouse myeloma (MOPC 41), in which a productive (kappa+) and a non-productive (kappa-) rearrangement has occured, which may help to clarify the mechanism of V-J joining. The aberrant rearrangement has led to the joining of a J1 gene segment to a sequence unrelated to any V gene (L10), and which in the germ line is flanked by a sequence resembling a V region recombination signal sequence. In this case no segregation of the reciprocal recombination products (kappa-41 and f41), which is a required step in sister chromatid exchange models, has taken place. An inversion model provides the simplest explanation of this J rearrangement.  相似文献   

5.
本研究筛选并制备高特异性 DNA 探针,与纳米粒子标记技术相结合,设计多通道电化学基因传感阵列检测模式,建立灵敏、快速、简便、经济的AML相关多药耐药基因(MDR1和MRP)检测新方法。该方法具有较好的特异性、灵敏度和重现性,能够在1.0×10-14 ~ 1.0×10-12 M和5.0×10-14 ~ 5.0×10-12 M范围内,分别实现对AML 相关多药耐药基因序列MDR1和MRP的定量检测。该方法有望为预测肿瘤治疗效果和临床制定治疗方案提供参考依据。  相似文献   

6.
筛选并制备高特异性 DNA 探针,与纳米粒子标记技术相结合,设计多通道电化学基因传感阵列检测模式,建立灵敏、快速、简便、经济的急性髓系白血病(AML)相关多药耐药基因(MDR1和MRP)检测新方法. 该方法具有较好的特异性、灵敏度和重现性,能够在1.0×10-14 ~ 1.0×10-12 mol·L-1和5.0×10-14~5.0×10-12 mol·L-1范围内,分别实现对AML 相关多药耐药基因序列MDR1和MRP的定量检测. 该方法有望为预测肿瘤治疗效果和临床制定治疗方案提供参考依据.  相似文献   

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