共查询到20条相似文献,搜索用时 62 毫秒
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《计算机与应用化学》2016,(1)
目的:采用布尔网络技术构建和分析乳腺癌基因调控网络。方法:收集已知乳腺癌相关的基因及其调控关系并可视化,通过拓扑结构分析分解网络,根据基因之间的调控关系制定布尔规则。网络的初始态用布尔规则的方法进行演化,得到的主要吸引子对应健康状态。对网络中输出影响大的关键基因分别进行敲除,模拟基因突变,分析新网络的吸引子变化。结果:关键基因被敲除后,网络的吸引子均有不同程度地向癌变方向发展。结论:布尔网络模型能够有效模拟乳腺癌的动态基因调控过程。 相似文献
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异构多核系统的任务调度问题已经被证明是一个NP完全问题。人工鱼群算法在算法初期具有较快的收敛速度,后期收敛较慢,而遗传算法的种群初始化具有较强的鲁棒性,初始化种群的质量直接影响着遗传算法的性能。本文提出了一种将人工鱼群算法与遗传算法相结合的任务调度算法,首先分析了异构多核系统的任务调度问题的本质,使用改进的人工鱼群算法来构建遗传算法的初始化种群,并使用改进的遗传算法进行迭代进化,从而提高了算法的收敛速度。 相似文献
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人工鱼群基本算法在求解多峰函数最优值时,存在计算精度有限,易陷入局部最优,鲁棒性较差以及收敛速率较慢和搜索效率较低的缺点,而随机移动算子的随机性是造成这些缺点的重要因素。通过引入粒子群算法思想和自适应扰动的思想对随机移动算子进行改进,进而提出了基于粒子群算法的人工鱼群算法(PSO-AFSA)和包含自适应扰动项的改进人工鱼群算法(ADI-AFSA),并证明了两种改进算法的收敛性。利用公认测试函数集进行仿真实验,结果表明两种改进算法与人工鱼群基本算法及其传统改进算法相比,提高了计算精度、收敛速率、搜索效率并且具有更好的鲁棒性。 相似文献
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为了提高网络入侵检测率,提出一种人工鱼群算法(AFSA)优化ELM神经网络的网络入侵检测模型。首先将ELM神经网络参数编码成人工鱼的位置,然后利用人工鱼群算法通过模拟鱼群的觅食、聚群及追尾行为找到最优ELM神经网络参数,最后利用最优参数的ELM神经网络建立网络入侵检测模型,并采用KDD CUP 99数据集进行仿真测试。仿真结果表明,模型不仅提高了入侵检测正确率,而且加快了网络入侵检测速度。 相似文献
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地图匹配( MM)算法通过粒子滤波( PF)利用室内地图信息来抑制基于惯性传感器的室内定位系统的误差累计。利用区域生长( RG)算法结合当前步长和方向信息在地图上找到合理的落脚范围,并以此来判断粒子的有效性。这种方法能有效改善地图配准算法的实用性和计算复杂度。提出一种改进的零速度( ZV)检测算法能准确提取步伐信息,间接提升了零速度更新( ZUPT)算法和地图配准算法的精度。实验结果表明:该算法的定位误差小于1.0%,定位精度比单纯的航位推算( DR)算法平均提高了5.97%。 相似文献
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This research investigates the impact of intellectual capital components on the competitive advantage in the Jordanian telecommunication companies. The empirical findings indicate that the relational capital and the structural capital have positive impact on competitive advantage. Both the relational capital and the structural capital account for 48.4% of the competitive advantage. It is unexpected to find that the human capital does not have a significant direct impact on competitive advantage. However, it is valid to state that the human capital indirectly and significantly influences competitive advantage as it is embedded in the relational capital. The effect of the relational capital on competitive advantage is moderated by gender and age. The effect is strongest among younger men. In the case of the structural capital its effect is moderated by gender only such that the effect is slightly stronger for females rather than males. 相似文献
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一、引言计算机仿真接口界面,随着计算机软硬件的不断提高也在快速地变化着。从其发展趋势中我们不难看出这一点:从早期的命令行提示编辑Command Line,到全屏幕菜单编辑(Menu based Editor),再到图形用户界面Graphic User In-terface(GUI),界面在不断追求如何更好地适应用户、与用户更直接地交互。其具体特点包括自然而又丰富的色彩、逼真而又完美的几何造型、柔和而又动听的环境声响、质感而又具有力反馈的实物等。这些人们所需要的真实感,一种技术是难以胜任的,它需要各种软、硬件技术的综合与集成。从目前的趋 相似文献
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S. Suja Priyadharsini 《Applied Soft Computing》2012,12(3):1131-1137
Electroencephalography (EEG) is the recording of electrical activity of neurons within the brain and is used for the evaluation of brain disorders. But, EEG signals are contaminated with various artifacts which make interpretation of EEGs clinically difficult. In this research paper, we use a soft-computing technique called ANFIS (Adaptive Neuro-Fuzzy Inference System) for the removal of EOG artifact, combined EOG and EMG artifact. Improvement in the output signal to noise ratio and minimum mean square error are used as the performance measures. The outputs of the proposed technique are compared with the outputs of techniques such as neural network, based on ADALINE (Adaptive Linear Neuron) and adaptive filtering method, which makes use of RLS (Recursive Least Squares) algorithm through wavelet transform (RLS-Wavelet). The obtained results show that the proposed method could significantly detect and suppress the artifacts. 相似文献
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The Prize-collecting Steiner Tree Problem (PCSTP) is a well-known problem in graph theory and combinatorial optimization. It has been successfully applied to solve real problems such as fiber-optic and gas distribution networks design. In this work, we concentrate on its application in biology to perform a functional analysis of genes. It is common to analyze large networks in genomics to infer a hidden knowledge. Due to the NP-hard characteristics of the PCSTP, it is computationally costly, if possible, to achieve exact solutions for such huge instances. Therefore, there is a need for fast and efficient matheuristic algorithms to explore and understand the concealed information in huge biological graphs. In this study, we propose a matheuristic method based on clustering algorithm. The main target of the method is to scale up the applicability of the currently available exact methods to large graph instances, without loosing too much on solution quality. The proposed matheuristic method is composed of a preprocessing procedures, a heuristic clustering algorithm and an exact solver for the PCSTP, applied on sub-graphs. We examine the performance of the proposed method on real-world benchmark instances from biology, and compare its results with those of the exact solver alone, without the heuristic clustering. We obtain solutions in shorter execution time and with negligible optimality gaps. This enables analyzing very large biological networks with the currently available exact solvers. 相似文献
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Wavelet-based envelope features with automatic EOG artifact removal: Application to single-trial EEG data 总被引:1,自引:0,他引:1
Wei-Yen Hsu Chao-Hung LinHsien-Jen Hsu Po-Hsun ChenI-Ru Chen 《Expert systems with applications》2012,39(3):2743-2749
In this study, we propose an analysis system for single-trial classification of electroencephalogram (EEG) data. Combined with automatic EOG artifact removal and wavelet-based amplitude modulation (AM) features, the support vector machine (SVM) classifier is applied to the classification of left finger lifting and resting. Automatic EOG artifact removal is proposed to eliminate the EOG artifacts automatically by means of independent component analysis (ICA) and correlation coefficient. The features are then extracted from the discrete wavelet transform (DWT) data by the AM method. Finally, the SVM is used for the discriminant of wavelet-based AM features. Compared with EEG data without EOG artifact removal, band power features and LDA classifier, the proposed system achieves promising results in classification accuracy. 相似文献
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心电信号是典型的强噪声下的非平稳微弱信号,减小噪声的干扰对心电信号的分析有着十分重要的意义,因此,有效的滤波方法一直是该领域学者关注的热点问题。本文在基于小波变换心电信号分析研究基础上,针对小波去噪时分解只作用于低频部分,从而忽略了高频区域中一部分有用信号的问题,提出了一种采用改进小波包理论实现心电信号去噪的方法,利用小波包在消除信号噪声方面具有更为精确的局部分析能力的特点,采用了‘db4’小波和"最优基"选择的方法,对心电信号进行消噪。以MIT-BIH心电数据库中心律失常数据仿真实验,得到了较理想的去噪效果。对比该方法与小波滤波去噪,发现基于小波包的心电信号去噪具有更优良的去噪性能。 相似文献
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VoIP认证与计费的设计与实现 总被引:1,自引:0,他引:1
基于RADIUS的VoIP认证系统,采用分散受理、集中管理的接入认证管理体系,数据集中存放在认证中心(RADIUS服务器),用户身份认证由PC向网守发起,网守通过RADIUS协议向认证中心的认证服务器发起认证请求。这样,可以保证用户安全地使用网络资源,以确保用户身份的合法性。同时其落地话单经过处理,可进行计费及其它帐务处理。文中论述了RADIUS对VoIP的支持,提出了一个Gatekeeper与RADIUS结合的整体解决方案。 相似文献