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1.
设计了一种基于Android的移动式心电监护系统,该系统由STM32嵌入式心电采集模块、串口蓝牙模块、Android智能手机组成.嵌入式系统采集心电数据,通过蓝牙传输到Android智能手机终端,在手机端实现心电数据的显示、存储,并通过百度云客户端实现心电数据上传,以实现与远程医疗中心的交互.  相似文献   

2.
Controlling photons using electromagnetically induced transparency   总被引:14,自引:0,他引:14  
Lukin MD  Imamoğlu A 《Nature》2001,413(6853):273-276
It is well known that a dielectric medium can be used to manipulate properties of light pulses. However, optical absorption limits the extent of possible control: this is especially important for weak light pulses. Absorption in an opaque medium can be eliminated via quantum mechanical interference, an effect known as electromagnetically induced transparency. Theoretical and experimental work has demonstrated that this phenomenon can be used to slow down light pulses dramatically, or even bring them to a complete halt. Interactions between photons in such an atomic medium can be many orders of magnitude stronger than in conventional optical materials.  相似文献   

3.
This paper presents an approach to deterministically teleport an arbitrary two-qubit state through a one-dimensional four-qubit cluster state serving as a probabilistic quantum channel. The channel is modulated in advance to avoid damage to the original states in this scheme, which is caused by the inevitable failure of constructing a channel between the sender and the receiver. The scheme is flexible because the channel can be modulated either by the sender or by the receiver, with the option of deciding whether the sender or the receiver modulates the channel, according to the distribution of the available particle resources. The efficiency can be improved by reusing previously discarded results that may lead to a faithful channel. The scheme can be uniformly performed, so the design process can be greatly simplified to realize a reliable deterministic teleportation. Finally, the scheme is extended to deterministic teleportation of an arbitrary n-qubit state in a generalized form.  相似文献   

4.
证明了代数数是有理数系数方阵的特征值,代数整数是整数系数方阵的特征值.由此出发,完全用线性代数与矩阵计算的方法简洁地证明了代数整数对加减法和乘法封闭,从而构成一个环(代数整数环);所有代数数对加减乘除封闭,从而构成一个域(代数数域).  相似文献   

5.
We demonstrate an effective method to prepare a new condensed form of single-walled carbon nanotubes (crystal of SWNTs) using a series of diamond wire drawing dies. X-ray diffraction indicates that the SWNTs form a two-dimensional triangular lattice with a lattice constant of 19.62 ?. An intertube spacing of 3.39 ? of between adjacent SWNTs results in a sharp (002) reflection in the X-ray diffraction pattern. Meanwhile, we developed an approach based on the Coulomb explosion to separate SWNTs from their bundle. The separated SWNTs have a typical length of several microns and form a nanotree at one end of the original bundle. The separation is convenient and involves no surfactant. In studying devices comprising SWNTs, we find that a four-probe technique can be employed to study the filling of and flow within the inner channel of an individual SWNT. Current/voltage can drive water molecules to have directional flow along an SWNT, and the flowing of water inside an SWNT can induce a voltage gradient force (an induced electromotive force) along the SWNT. This energy conversion is realized by the mutual coupling of water dipoles and charge carriers present in SWNTs. The results suggest that SWNTs can be exploited as molecular channels for water and may find potential application in nanoscale energy conversion. Moreover, a surface-energy generator comprising SWNTs was demonstrated to harvest the surface energy of ethanol. The performance (the induction rate for V oc, the value of V oc and the output power) can be significantly enhanced by the Marangoni effect.  相似文献   

6.
问句相似度计算是基于常问问题库的问答系统的重点。现在的问句相似度计算准确率较低,为此,提出了一种基于主题和焦点的中文问句相似度计算方法。主题和焦点能够反映问句的主旨,识别出问句的主题能够更好地理解问句。其中抽取问句主题和焦点的方法能获取部分语义信息,而且比传统的根据疑问词进行语义分析的方法适用类型更广,同时在计算问句相似度时考虑了主题和焦点的影响。最后通过设计实验与其他方法进行比较,实验表明,该方法提高了准确率。  相似文献   

7.
提出一种利用编码孔径相机拍摄照片并进行全景图拼接的方法. 首次将深度相机和全景摄影结合起来,利用编码孔径相机获得的场景深度信息,可得到只含感兴趣部分的全景图以及细节清晰的全聚焦全景图. 与传统直接将源照片按照几何分布拼接在一起的全景图拼接方法相比,本文方法能够有效去除场景中近景物体在全景拼接中的错误,避免中距离物体破坏远景场景的完整性,同时获得全景图的模糊部分进行优化. 在这个框架下,运用本文方法对各种全景图拼接进行了大量实验,展示了拼接的过程以及拼接结果,结果表明本文提出的计算框架能够有效达到优化全景图的目的.   相似文献   

8.
阐述了“电路分析基础”题库系统中等概率选题数学模型的建立方法、图形信息的数字化处理及存贮方法、沿任意角α画出电路元件的算法.题库系统可同时进行汉字信息处理、图形信息处理及数值计算,达到了按实际试卷格式出题、组卷迅速、多界面人机对话的目的,既可全自动选题,又可人为选题。  相似文献   

9.
提出了一种以软件构件形式实现A 算法的方案 ,用面向对象的方法 ,以状态描述为基础 ,对A 算法数据集进行抽象 ,将A 算法设计成抽象类 ,这一抽象类可通过继承和重写应用于不同的环境 ,从而提高了A 算法软件的可重用性。  相似文献   

10.
癌症是威胁人类健康的大敌,游泳运动为康复体育的重要手段,对癌症的康复有着积极的作用,原因在于游泳运动可使血液中自细胞大量增多,循环于血液中的淋巴细胞,巨噬细胞和直接杀伤细胞(K细胞)明显增加,它们能利用吞噬作用使人体内可能有的癌细胞难以逃脱厄运,同时可减轻化疗的副作用。  相似文献   

11.
Texture acquisition of a large scale scene is one of the critical research areas in computer vision and can be used in other application areas such as computer graphics (CG), the intelligent transportation system (ITS) and the 3D geographic information system (GIS). Moreover, to acquire texture without noise (e. g. , a shadow, an obstacle body) is vital for such work. Although obstacles can be removed by using 3D geometric data, shadow elimination is still a difficult problem and strongly required for the CG and ITS community, especially for city modeling and simulation purposes. In this paper, we propose an automatic multiple image fusion technique and an efficient and simple shadow removing technique to retrieve high quality texture images of an urban area. The image fusion can be efficiently achieved by epipolar plane image (EPI) analysis, and the shadowe limination can be successfully carried out by an illumination-independent color clustering technique. The strength of this algorithm is that we can successfully fuse multiple images and eliminate shadows from the fused single image, especially in low dynamic range images, which have proven difficult using previous techniques.  相似文献   

12.
Texture acquisition of a large scale scene is one of the critical research areas in computer vision and can be used in other application areas such as computer graphics (CG), the intelligent transportation system (ITS) and the 3D geographic information system (GIS). Moreover, to acquire texture without noise (e. g. , a shadow, an obstacle body) is vital for such work. Although obstacles can be removed by using 3D geometric data, shadow elimination is still a difficult problem and strongly required for the CG and ITS community, especially for city modeling and simulation purposes. In this paper, we propose an automatic multiple image fusion technique and an efficient and simple shadow removing technique to retrieve high quality texture images of an urban area. The image fusion can be efficiently achieved by epipolar plane image (EPI) analysis, and the shadow elimination can be successfully carried out by an illumination-independent color clustering technique. The strength of this algorithm is that we can successfully fuse multiple images and eliminate shadows from the fused single image, especially in low dynamic range images, which have proven difficult using previous techniques.  相似文献   

13.
藏语动词分类很细,准确识别和判断藏文动词的词性是藏语自然语言处理中一个基础又关键的内容,及物与不及物动词的自动识别,可以在用计算机生成自然语言句子时能很好地阻止不合法句子的生成,也能从整体上减少句子生成量,从而提高效率.提出了一种在理想环境下,通过句子中的使格助词来自动判断动词及物性的方法,这种自动识别方法是一种理性主义的判断方法,所以不需要大规模语料的支持.因为是一种理想情况,所以自动识别效率高,准确率为100%.  相似文献   

14.
利用m序列技术检测诱发电位的快速算法   总被引:1,自引:0,他引:1  
伪随机序列技术是通过加大刺激密度而提高检测信噪比、加快检测速度的一项诱发电位检测技术,具有潜在应用前景。然而当序列较长时,这项技术的计算量剧增,使实时检测成为困难。本文结合m序列及Walsh函数的性质,推导出M矩阵与W矩阵的等价关系,并利用快速Walsh变换来实现m序列的解卷积。求解诱发电位的运算量由原来的L2数量级减少到Llog2L数量级,使诱发电位实时快速检测成为可能。  相似文献   

15.
D'Anna G  Mayor P  Barrat A  Loreto V  Nori F 《Nature》2003,424(6951):909-912
Observation of the rotational brownian motion of a very fine wire immersed in a gas led to one of the most important ideas of equilibrium statistical mechanics. Namely, the many-particle problem of a large number of molecules colliding with the wire can be represented by just two macroscopic parameters: viscosity and temperature. Interest has arisen in the question of whether this idea (mathematically developed in the Langevin model and the fluctuation-dissipation theorem) can also be used to describe systems that are far from equilibrium. Here we report an experimental investigation of an archetypal non-equilibrium system, involving a sensitive torsion oscillator immersed in a granular system of millimetre-size grains that are fluidized by strong external vibrations. The vibro-fluidized granular medium is a driven environment, with continuous injection and dissipation of energy, and the immersed oscillator can be seen as analogous to an elastically bound brownian particle. By measuring the noise and the susceptibility, we show that the experiment can be treated (to a first approximation) with the equilibrium formalism. This gives experimental access to a granular viscosity and an effective temperature; however, these quantities are anisotropic and inhomogeneous. Surprisingly, the vibro-fluidized granular matter behaves as a 'thermal' bath satisfying a fluctuation-dissipation relation.  相似文献   

16.
主要讨论了一种描述对象活动的方法,提出了活动体的概念,并给出了它的三元组形式。活动体是对象式系统中具有通信能力的最小单位,由此可以构造对象及至系统的交互(通信)行为。同时给出了一个简单的描述活动体的语言BeLan和BeLan中活动体的指称语义。  相似文献   

17.
With layer-measured contours, an algorithm that can extract the contour segments from a rotational surface is presented. The extraction can be divided into two stages, i. e. the rough segmentation and the refinement. In the rough segmenting stage, an optimal contour matching method is put forward to find similar contour segment from another closed contour with respect to the seed contour. In the refining stage, an iterative way that can extract a circular arc precisely is presented based on parameters identification and contour-ends expanding/shrinking operation. The algorithm can extract the open contour segments from a rotational surface precisely, as demonstrated in the examples. Based on the work of this paper, further research, such as parameter identification of 3 - D surface and CAD model creation, can be conducted.  相似文献   

18.
通过演变谱分析法对飞机起落架地面变速滑跑进行动响应分析.飞机在机场跑道变速滑行时,机场跑道基础激励将转化为非平稳随机激励,从而导致非平稳随机响应分析.采用演变随机激励表示该非平稳随机激励,用原平稳随机激励的功率谱密度和非线性变换表示其时变相关特性.利用演变谱法分析起落架系统的非平稳响应问题,最后通过数值算例验证了该方法的简便性和优越性.  相似文献   

19.
本文提出的空中气垫原理是使飞机能直起直落和停在空中的一种新设想,该原理是利用高速气幕射流,在展开的机身下面形成封闭气垫。通过控制压力流量调节气垫压力使之大于大气压力,由于机身上下产生的,总压力差很大,以致能轻易地、托起整架飞机。  相似文献   

20.
提出了不定导纳矩阵任意k阶余因式的有向树拓扑表示式;给出了通过混合分割产生有向树多项式的分解定理.应用它们可以方便有效地求取任意k阶余因式的拓扑表示式.用其求全符号网络函数,可扩大计算机所能拓扑分析的网络规模.用其求部分符号网络函数,可使计算机所能分析的网络规模扩大到一般数值分析程序所能处理的阶数.  相似文献   

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