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针对在轨卫星的GaInP/GaAs/Ge三结太阳能电池阵输出电流衰减模型中参数辨识精度低和后期误差大且实时性不高的问题,提出采用遗传算法(GA)对太阳能电池阵电流衰减模型进行参数辨识。针对GA过早收敛及易陷入局部最优解的缺点,提出了基于自适应交叉变异算子和线性变换适应度函数的自适应遗传算法(AGA)进行参数辨识。然后把模型预测的输出电流与遥感测得的输出电流进行比较。实验结果表明,运用AGA和广义最小二乘法(GLS)得到的均方根误差(RMSE)分别为1.427×10-4和1.337×10-3,误差平方和(SSE)分别为2.0571×10-6和1.92×10-3,AGA辨识后的模型预测更加准确,对卫星运行后期电源的管理具有实际意义。 相似文献
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针对连续Adaboost算法中平滑因子选取的不足,提出了一种动态选取平滑因子的DS-Adaboost算法,该算法对弱分类器输出中的平滑因子ε进行了动态选取,根据Wj+1Wj-1比值的大小动态地选择平滑因子,当Wj+1Wj-1>1时,εj=Wj+1,当0j+1Wj-1<1时,εj=Wj-1。实验表明,DS-Adaboost算法能较好地起到平滑的作用,使得落在同一个区间里面的正样本和负样本的比例都在可以比拟的范围内。 相似文献
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卫星电源分系统的联合仿真 总被引:2,自引:0,他引:2
卫星电源分系统的仿真涉及多学科领域,依靠传统的单领域、电路级仿真会在元件建模与算法控制之间产生矛盾.为解决元件模型与算法控制的有机统一问题,利用多领域动态系统仿真软件VTB建立卫星电源分系统的模型,并调用Matlab/Simulink中搭建蓄电池充电控制模块,在VTB中实现联合仿真.仿真结果表明:锂离子蓄电池组实现了恒流恒压充电,母线电压始终调节在28V,太阳电池阵和蓄电池组的功率、电流、电压输出都符合在轨卫星的供电要求,基于VTB与Simulink的联合仿真适用于卫星电源分系统的仿真. 相似文献
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区域查询是数据仓库上支持联机分析处理(on-line analytical processing,简称OLAP)的重要操作.近几年,人们提出了一些支持区域查询和数据更新的Cube存储结构.然而这些存储结构的空间复杂性和时间复杂性都很高,难以在实际中使用.为此,提出了一种层次式Cube存储结构HDC(hierarchical data cube)及其上的相关算法.HDC上区域查询的代价和数据更新代价均为O(logdn),综合性能为O((logn)2d)(使用CqCu模型)或O(K(logn)d)(使用Cqnq+Cunu模型).理论分析与实验表明,HDC的区域查询代价、数据更新代价、空间代价以及综合性能都优于目前所有的Cube存储结构. 相似文献
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个体单体型MSR(minimum SNP removal)问题是指如何利用个体的基因测序片断数据去掉最少的SNP(single-nucleotide polymorphisms)位点,以确定该个体单体型的计算问题.对此问题,Bafna等人提出了时间复杂度为O(2kn2m)的算法,其中,m为DNA片断总数,n为SNP位点总数,k为片断中洞(片断中的空值位点)的个数.由于一个Mate-Pair片段中洞的个数可以达到100,因此,在片段数据中有Mate-Pair的情况下,Bafna的算法通常是不可行的.根据片段数据的特点提出了一个时间复杂度为O((n-1)(k1-1)k222h+(k1+1)2h+nk2+mk1)的新算法,其中,k1为一个片断覆盖的最大SNP位点数(不大于n),k2为覆盖同一SNP位点的片段的最大数(通常不大于19),h为覆盖同一SNP位点且在该位点取空值的片断的最大数(不大于k2).该算法的时间复杂度与片断中洞的个数的最大值k没有直接的关系,在有Mate-Pair片断数据的情况下仍然能够有效地进行计算,具有良好的可扩展性和较高的实用价值. 相似文献
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在基本谣言传播模型的基础上引入真实信息因素,构建了SIH谣言传播模型,并借助Monte Carlo模拟对模型进行了仿真。模型分别从真实信息发布时刻,真实信息发布者的数量、度和公信力四点研究了真实信息发布如何影响谣言的传播过程。Barabasi-Albert网络上的仿真结果表明,谣言爆发初期是谣言治理的最佳时期,真实信息的发布对谣言的传播起到扼制作用。另外,谣言传播者比例所能达到的峰值Smax与真实信息发布者所占比例η之间近似服从幂律分布Smax∝η-μ1;该峰值与真实信息发布者公信力提升的倍数ω之间也近似服从幂律分布Smax∝ω-μ2,其中指数μ1和μ2的大小均受到真实信息发布时间T的影响。 相似文献
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环境内分泌干扰物的联合作用已经是目前研究的重点.采用重组基因酵母检测法,分别测定了双酚A (BPA)、双酚AF(BPAF)、双酚AP(BPAP)、双酚F(BPF)4种双酚化合物的雌激素活性,并依据其测定结果,按照等效浓度比,设计了浓度比分别为EC10和EC50的6种二元混合物并测定了其雌激素活性.结果表明,这4种化合物的剂量-效应关系都可以用Weibull函数有效描述,BPA、BPAF、BPAP、BPF的EC50值分别为:6.81×10-6、7.44×10-7、1.43×10-5、7.52×10-6 mol·L-1,其雌激素活性大小顺序为:BPAF>BPA>BPF>BPAP.依据不同的联合作用判断方法对这4种化合物的联合效应进行判断,结果表明,相同化合物的不同混合比例可能对联合作用方式产生影响,采用DA和IA预测模型可以更加直观、方便地判断联合作用的类型,而且可以反映出不同混合比例对联合作用的影响. 相似文献
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S. Shaw 《Journal of Computer Assisted Learning》1993,9(2):93-99
Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained. 相似文献
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European Community policy and the market 总被引:1,自引:0,他引:1
C. Lloyd 《Journal of Computer Assisted Learning》1993,9(2):86-91
Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven. 相似文献
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融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。 相似文献
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张涛 《计算机测量与控制》2015,23(1):86-89
为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值. 相似文献
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Wayne O’Brien Author Vitae 《Journal of Systems and Software》2008,81(11):1997-2013
Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them. 相似文献
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This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives. 相似文献
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潘丽 《自动化与仪器仪表》2014,(7):80-82
自然界的绝大部分信号都是以模拟的形式存在,因此模拟信号的采集转换存储在数字时代十分关键。文章讨论了在雷达信号处理领域基于AD9626的AD采集存储卡的设计原理、硬件结构和程序设计与芯片配置等问题,为今后相关领域的研究提供了可参考的方案。 相似文献
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Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what
is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic
sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and
its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of
an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify
robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can
or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest.
This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January
31–February 2, 2008 相似文献
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Jacob Palme 《Software》1979,9(9):741-747
The COM teleconferencing system was designed to be easy to use for both beginners and people with much computer experience. A number of design choices in organizing the human-computer interface were considered very carefully. These design problems are not unique for teleconferencing applications, but will appear in many other developments of human-computer interfaces for non-computer specialists. This report discusses naming conventions, menu format, user commands, help facility and the treatment of ‘type ahead’ from the users. 相似文献