关键词： 弹道导弹防御系统   美国   反导系统   现役   高超声速   弹道飞行   数学算法   飞行器  

摘要： 美国导弹防御促进联合会主席近日表示，美国现役弹道导弹防御系统经过适当升级改进后可拦截“高超声速助推滑翔飞行器”（HGV）。目前来袭的弹道导弹大多按照可预测的弹道飞行，因此美国导弹防御系统可以使用数学算法预测弹道导弹的弹道并进行拦截。

关键词： COMPUTER algorithms   ALGEBRA software   ORDINARY differential equations   LYAPUNOV functions   POLYNOMIALS   DIFFERENTIAL equations  

摘要： Using algorithms and packages for computer algebra, we investigate a three-dimensional autonomous system of ordinary differential equations (ODEs) used in [1] to simulate the dynamics of a gene. A computational approach based on elimination theory algorithms is proposed to find invariant surfaces of multidimensional polynomial differential equation systems;this approach allows one to reduce the investigation of the system dynamics to studying the dynamics of a lower-order system. In addition, an effective approach based on the Lyapunov function is proposed to investigate the Andronov-Hopf bifurcation;this approach is used to find such bifurcations in the model under study.

关键词： Model correlation   Thermal mathematical model   Space vehicle   Thermal control   Genetic algorithm  

摘要： The design of the thermal control system of space vehicles, needed to maintain the equipment components into their admissible range of temperatures, is usually developed by means of thermal mathematical models. These thermal mathematical models need to be correlated with the equipment real behavior registered during the thermal test campaign, in order to adapt them to the real state of the vehicle "as built". The correlation of this type of mathematical models is a very complex task, usually based on manual procedures, which requires a big effort in time and cost. For this reason, the development of methodologies able to perform this correlation automatically, would be a key aspect in the improvement of the space vehicles thermal control design and validation. The implementation, study and validation of a genetic algorithm able to perform this type of correlation in an automatized way are presented in this paper. The study and validation of the algorithm have been performed based on a simplified model of a real space instrument. The algorithm is able to correlate thermal mathematical models in steady state and transient analyses, and it is also able to perform the simultaneous correlation of several cases, as for example hot and cold cases. (C) 2014 IAA. Published by Elsevier Ltd. All rights reserved.

关键词： Multi-factory parallel machine   Mathematical model   Artificial bee colony  

摘要： This paper considers the problem of multi factory parallel machine problems. This problem is already studied in the literature and there is a mathematical model and a genetic algorithm for the problem. We analyzed the model and algorithm, and showed that they suffer from serious shortcomings. Then, we propose three mathematical models for makespan and total completion time objectives. The proposed models are compared with the available model in both size and computational complexities. The available model is significantly outperformed. Moreover, we propose three effective metaheuristics based on artificial bee colony algorithms. The proposed metaheuristics are compared against the four available algorithms on both small and large instances. The proposed metaheuristics perform much more effectively. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： sepsis   premature infant   very low-birth-weight infant   morbidity   mortality  

摘要： BackgroundDiagnosis of late onset sepsis (LOS) in very low birth weight (VLBW) preterm infants relies mainly on clinical suspicion, whereas prognosis depends on early initiation of antibiotic treatment. RALIS is a mathematical algorithm for early detection of LOS incorporating six vital signs measured every 2 hours. ObjectiveThe aim of this study is to study RALIS ability to detect LOS before clinical suspicion. Study DesignA total of 118 VLBW preterm infants (gestational age<33 weeks, birth weight<1,500 g) were enrolled in a prospective multicentered study. Vital signs were recorded prospectively up to day 21 of life in a blinded manner, with no effect on standard care. The primary end point was comparison of the rates and timing of detection of LOS between RALIS and clinical/culture evidence of LOS. ResultsOf the 2,174 monitoring days, RALIS indicated sepsis in 590 days, and LOS was positively diagnosed in 229 days. Sensitivity, specificity, positive, and negative predictive values were 74.6, 80.7, 38.8, and 95.1%, respectively. RALIS provided an indication for sepsis 3 days on the average before clinical suspicion. ConclusionRALIS has a promising potential as an easy to implement noninvasive early indicator of LOS, especially for ruling out LOS in VLBW high-risk infants.

关键词： AutoLISP   数字地形图   数学精度   检测  

摘要： 介绍了测绘产品质量监督检验工作中对数字地形图产品数学精度检测的一种算法。该算法通过遍历展绘的检测点坐标,依次定位显示检测点视图窗口,然后采用人机交互操作方式实现地形图数学精度的快速检测统计与评分。文章结合地形图产品质量检验项目,以LISP语言为例,对算法的基本设计思路进行了说明与实现。最后通过工程实例对程序的实用性和有效性进行了测试,达到了预期结果。

关键词： Braid group   Garside group   Quasipositive braid  

摘要： We give an algorithm to decide if a given braid is a product of two factors which are conjugates of given powers of standard generators of the braid group. The same problem is solved in a certain class of Garside groups including Artin-Tits groups of spherical type. The solution is based on the Garside theory and, especially, on the theory of cyclic sliding developed by Gebhardt and Gonzalez-Meneses. We show that if a braid is of the required form, then any cycling orbit in its sliding circuit set in the dual Garside structure contains an element for which this fact is immediately seen from the left normal form.

关键词： 士气测评   模糊集  

摘要： 针对士气测评中"作战单元一士气表征—原因症结"之间关系的复杂性和模糊性的特点,根据模糊数学的有关理论和方法,将模糊集合的概念引入士气测评,建立一种测评模型并提出相关算法,用来处理"作战单元—士气表征—原因症结"之间的关系,查找作战单元中士气问题存在的主要原因。本文还通过测评的模拟算例说明了该模型的应用。

关键词： 独立分量分析   FastICA算法   数学形态学   图像分割  

摘要： 介绍了一种改进型快速独立分量分析(FastICA)算法与形态学相结合的图像分割方法.该方法把图像的特征分量看作是边缘图像分量与其它背景图像分量的结合,把快速ICA对图像分量的提取,变为对边缘图像分量的提取,得到边缘图像的独立分量,再通过数学形态学的方法对边缘图像进行增强处理,从而实现图像的分割.实验结果表明:与传统的图像分割方法相比,该方法具有良好的图像分割性能,可以清楚地观察到图像轮廓,图像边缘的连通性较好且保留了原图像的很多细节,分割效果较好.

关键词： LMS算法   控制通道   数学模型   辨识  

摘要： 对基于LMS自适应算法的压电驱动器控制通道数学模型辨识方法进行系统研究。压电驱动器控制通道数学模型是基于FX-LMS控制算法的各类主动隔振或主动控制系统开发所必须的条件。首先对其进行详细的理论推导,并对其工程实现进行分析;在此基础上,开发基于LMS算法的压电驱动器控制通道辨识系统;最后应用该辨识系统对某基于压电堆驱动器的一维微振动主动隔振平台的控制通道数学模型进行辨识,以检测所研制辨识系统的可行性和有效性。测试结果表明所辨识的控制通道数学模型可以用于基于LMS自适应算法的控制系统的开发。