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程序教学模式在田径教学中的应用   总被引:3,自引:1,他引:3  
在研读文献资料和体育教学实践的基础上,重点阐明了程序教学法在田径教学中的应用价值和成功经验;总结了应用此法应注意的问题,并说明应用此法不仅能提高教学质量,而且有利于培养学生的能力,在田径技术教学中是可行的  相似文献   

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Spatio-temporal pattern analysis of EEG is an important tool in brain research. An EEG pattern analysis system based on a hierarchical multi-method approach is proposed here. The system consists of multiple steps including extraction of target signal, acquisition of intracranial electric activity distribution, adaptive segmentation of EEG and spatio-temporal pattern recognition. Some modern signal processing methods such as common spatial subspace decomposition, hidden Markov model are adopted. This paper also proposes an algorithm named LORETA-FOCUSS to estimate the current density inside the brain with a high spatial resolution. Microstate analysis of EEG is extended to the 3-D situation. The system was applied to the brain computer interface problem and achieved the highest accuracy of 88.89% with an average accuracy of 81.48% when classifying two imaginary movement tasks, while the data were not manually pre-selected. The result has proved spatio-temporal EEG pattern analysis is an efficient way in brain research.  相似文献   

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沥青路面状况属性综合评价   总被引:9,自引:0,他引:9  
针对目前路面质量评价方面存在的问题,结合沥青路面所具有的本质特点提出了一种基于属性数学理论的综合评价系统,并且与模糊评价系统进行了对比,指出了模糊评价在应用中的不足之外及采用本系统优越性,介绍了属性评价系统的构造方法,评价指标及评价原则,用实例说明了该系统的科学性,适用性,该系统的应用具有较高的推广价值。  相似文献   

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基于问题模式匹配的智能答疑系统原型   总被引:2,自引:0,他引:2  
智能答疑系统是将学生的问题和老师的解答有机地组织起来并存放至相应的答题库中,通过自然语言的语义理解技术来分析并自动的匹配学生所提出的问题,自动地给予问题解答的系统. 智能答疑系统能够给予提问者即时的回应,减轻教学人员的工作压力,在远程教学中具有重要意义.红棉智能答疑系统(原型系统)针对国内现有的智能答疑系统普遍存在的问题,借鉴了国外先进智能答疑系统的成功经验与设计理念,根据中文智能答疑的特殊需求,引入了基于概率的双向最大匹配分词算法、智能问题模式匹配、基于语义依存树的语义分析等技术进行智能问题分析,形成了具有更高答案召回率、合理性与正确性的新一代智能答疑系统.  相似文献   

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合成喷形成的机理分析   总被引:11,自引:0,他引:11  
合成喷是一种新型喷 ,了解它的形成机理对其设计和应用起着重要的作用。该文讨论了液体合成喷和气体合成喷的形成特点并建立了各自相应的数学物理模型。利用小扰动模型解释了大空间液体合成喷形成的原因 ,通过一个简单的热力学模型探讨了气体合成喷的形成机理。分析认为 :液体合成喷的产生主要是空化效应的结果 ,而气体合成喷的形成机制类似于微型压缩机。与他人实验结果的对比表明 :上述二种合成喷的机理分析是合理的  相似文献   

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Electrically induced structure formation and pattern transfer   总被引:1,自引:0,他引:1  
The wavelength of light represents a fundamental technological barrier to the production of increasingly smaller features on integrated circuits. New technologies that allow the replication of patterns on scales less than 100 nm need to be developed if increases in computing power are to continue at the present rate. Here we report a simple electrostatic technique that creates and replicates lateral structures in polymer films on a submicrometre length scale. Our method is based on the fact that dielectric media experience a force in an electric field gradient. Strong field gradients can produce forces that overcome the surface tension in thin liquid films, inducing an instability that features a characteristic hexagonal order. In our experiments, pattern formation takes place in polymer films at elevated temperatures, and is fixed by cooling the sample to room temperature. The application of a laterally varying electric field causes the instability to be focused in the direction of the highest electric field. This results in the replication of a topographically structured electrode. We report patterns with lateral dimensions of 140 nm, but the extension of the technique to pattern replication on scales smaller than 100 nm seems feasible.  相似文献   

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The numerical simulation on a reaction-diffusion system indicates that different patterns can be obtained by tuning the strength of parameter noise in subexcitable media. With the increase of noise intensity, the waves sustained by noise are not broken up as usual, they evolve orderly, and the period of the waves decreases, the survival time of waves varies. The time interval of inputting noise also influences the process of pattern formation and the survival time of waves.  相似文献   

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企业综合评价系统中的模糊层次综合评价模型   总被引:4,自引:1,他引:4  
在对广州市财政局和统计局提供的广州市企业经济系统的33项经济指标数据进行分析和异常数据处理的基础上,基于三套指标体系,建立了考虑专家经验和政策软投入的模糊层次综合评价模型,利用该模型对广州市企业的经济实力进行评价,对评价企业管理水平与科技实力,预测企业主要指标,增强企业提高驾驭未来的能力等起到主导作用,为“广州市企业综合评价软件系统”项目的制定提供了科学的定量依据和方法,对提高决策中的信息量和科技含量,具有重大的理论意义和实用价值。  相似文献   

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面向过程控制图的模式识别,提出了一个广义神经网络系统.该系统基于广义过程对象模型发生数据,离线训练后能够在线识别各类工业过程常见的控制图模式,模块化的设计使得神经网络系统的结构相对简单,有效地提高了网络的训练速度和模式识别的准确率.首先研究了广义过程对象模型参数对神经网络控制图模式识别率的影响,并基于此影响规律设计了包含模式识别分类模块与模式参数估计模块的集成化神经网络系统结构;其次使用基于广义对象模型产生的数据对神经网络系统进行了训练和验证,讨论了学习训练方法,并进行了控制图模式识别性能的仿真测试,获得了满意的结果.在TE过程仿真平台上进行了实验,给出了对上升阶跃模式和下降阶跃模式的识别结果,表明了具有较高的识别率.  相似文献   

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Genetic methods of manipulating or eradicating disease vector populations have long been discussed as an attractive alternative to existing control measures because of their potential advantages in terms of effectiveness and species specificity. The development of genetically engineered malaria-resistant mosquitoes has shown, as a proof of principle, the possibility of targeting the mosquito's ability to serve as a disease vector. The translation of these achievements into control measures requires an effective technology to spread a genetic modification from laboratory mosquitoes to field populations. We have suggested previously that homing endonuclease genes (HEGs), a class of simple selfish genetic elements, could be exploited for this purpose. Here we demonstrate that a synthetic genetic element, consisting of mosquito regulatory regions and the homing endonuclease gene I-SceI, can substantially increase its transmission to the progeny in transgenic mosquitoes of the human malaria vector Anopheles gambiae. We show that the I-SceI element is able to invade receptive mosquito cage populations rapidly, validating mathematical models for the transmission dynamics of HEGs. Molecular analyses confirm that expression of I-SceI in the male germline induces high rates of site-specific chromosomal cleavage and gene conversion, which results in the gain of the I-SceI gene, and underlies the observed genetic drive. These findings demonstrate a new mechanism by which genetic control measures can be implemented. Our results also show in principle how sequence-specific genetic drive elements like HEGs could be used to take the step from the genetic engineering of individuals to the genetic engineering of populations.  相似文献   

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较完整的阐述了变压器在线故障诊断系统的基本原理以及构建过程,为在线监测技术与诊断技术应用于工程实际提供了一个很好的范例。  相似文献   

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通过分析信息优势的各种影响因素,建立了信息优势的二级评价指标体系,给出模糊综合评判的一般步骤,并对某作战部队的信息优势进行了实例分析.  相似文献   

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一种新的多模态图像集成配准方法   总被引:1,自引:0,他引:1  
提出一种新的多模态图像集成配准方法。该算法是在对齐度和归一化互信息2种方法的基础上,引入图像边缘检测和均衡化,从而综合利用6种配准算法进行集成多模态图像配准。使用少数服从多数和基于可信度的加权2种集成准则,对红外热像仪图像和相应可见光图像进行实验分析,结果证明该集成配准方法准确性高,鲁棒性强,较之非集成配准方法具有明显的优势。  相似文献   

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The molecular genetics of embryonic pattern formation in Drosophila   总被引:104,自引:0,他引:104  
P W Ingham 《Nature》1988,335(6185):25-34
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20.
Hayashi T  Carthew RW 《Nature》2004,431(7009):647-652
Pattern formation of biological structures involves organizing different types of cells into a spatial configuration. In this study, we investigate the physical basis of biological patterning of the Drosophila retina in vivo. We demonstrate that E- and N-cadherins mediate apical adhesion between retina epithelial cells. Differential expression of N-cadherin within a sub-group of retinal cells (cone cells) causes them to form an overall shape that minimizes their surface contact with surrounding cells. The cells within this group, in both normal and experimentally manipulated conditions, pack together in the same way as soap bubbles do. The shaping of the cone cell group and packing of its components precisely imitate the physical tendency for surfaces to be minimized. Thus, simple patterned expression of N-cadherin results in a complex spatial pattern of cells owing to cellular surface mechanics.  相似文献   

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