共查询到20条相似文献,搜索用时 10 毫秒
1.
R. L. Gallawa 《Fiber and Integrated Optics》1978,1(3):289-311
A data bus consists of the interconnection of N terminals, each of which is connected to every other terminal. There are three fundamental approaches to the topology of the network: (1) the tee network, for which the connecting nodes coincide with the communicating nodes; (2) the star network, for which there is only one connection node, which may not coincide with a communication node; and (3) the Steiner minimal tree network, for which there can be many nodes, each of which is difficult to locate in the x-y plane. The tee and star approaches are receiving most attention but the third is the only one that economizes on the use of cable (glass fiber waveguide). After a discussion of the tee and star networks, we turn to the Steiner minimal tree network and a method of locating the connecting nodes so that the total amount of cable is minimized. 相似文献
2.
We propose and analyze a robust quantum state transfer protocol through a scalable quantum data bus that consists of a network of controlled dissipative modules. In particular, we first demonstrate the ability to achieve perfect state transfer between two distinct quantum sites which are adiabatically coupled to the data bus in non-dissipative situation. We then consider the role of dissipation in adiabatic quantum state transfer via using Born–Markov master equation in the standard Lindblad form. Numerical simulation shows that the dissipation effect on the quality of transmission can be suppressed by engineering the network couplings of data bus properly. 相似文献
3.
《中国科学:物理学 力学 天文学(英文版)》2010,(7)
We study the dynamics of an electron spin state transfer along a half-filled two-band model(TBM).It is shown that this solvable and realistic medium has an energy gap between the ground and first-excited states in the half-filled case.By connecting two qubits to two sites of the TBM,the system can accomplish a high-fidelity and long-distance quantum state transfer(QST).Moreover,numerical simulations have been performed for a finite system.The results show that the numerical and analytical results of the effective coupling strength agree well with each other.Furthermore,the investigation shows that the reduced density matrix also has high fidelity beyond the range of perturbation. 相似文献
4.
基于PCI总线的多通道图像数据高速采集 总被引:2,自引:0,他引:2
根据立体测绘相机的数据传输要求,需要将多个图像数据源产生的异步图像数据传输和存储到计算机上,研究和实现了一种实用的完整解决方案。采用FPGA对多个图像数据进行组合,在FPGA内部进行一级缓存,将异步的图像数据源,变换成同步数据,经过独立的FIFO芯片对图像数据进行缓存,方便总线繁忙时对图像进行缓存;然后通过专用的PCI接口芯片,将图像数据传输到PCI总线上;使用DriverWorks进行驱动程序的设计,将数据存入内存中,通过应用程序显示及存储于硬盘中。 相似文献
5.
Using simulated Tianqin gravitational wave data and electromagnetic wave data to study the coincidence problem and Hubble tension problem 下载免费PDF全文
In this study, we used electromagnetic wave data (H0LiCOW, \begin{document}$ H(z) $\end{document} ![]()
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, SNe) and gravitational wave data (Tianqin) to constrain the interacting dark energy (IDE) model and investigate the Hubble tension and coincidence problems. By combining these four types of data (Tianqin+H0LiCOW+SNe+\begin{document}$ H(z) $\end{document} ![]()
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), we obtained the following parameter values with a confidence interval of \begin{document}$ 1\sigma $\end{document} ![]()
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: \begin{document}$ \Omega_m=0.36\pm0.18 $\end{document} ![]()
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, \begin{document}$ \omega_x=-1.29^{+0.61}_{-0.23} $\end{document} ![]()
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, \begin{document}$ \xi=3.15^{+0.36}_{-1.1} $\end{document} ![]()
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, and \begin{document}$H_0=70.04\pm $\end{document} ![]()
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\begin{document}$ 0.42~ {\rm kms}^{-1}{\rm Mpc}^{-1}$\end{document} ![]()
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. According to our results, the best value of \begin{document}$ H_0 $\end{document} ![]()
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shows that the Hubble tension problem can be alleviated to some extent. In addition, the center value of \begin{document}$ \xi+3\omega_x = -0.72^{+2.19}_{-1.19}(1\sigma) $\end{document} ![]()
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indicates that the coincidence problem is slightly alleviated. However, \begin{document}$ \xi+3\omega_x = 0 $\end{document} ![]()
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is still within the \begin{document}$ 1\sigma $\end{document} ![]()
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error range, which indicates that the ΛCDM model is still the model in best agreement with the observational data at present. Finally, we compared the constraint results of the electromagnetic and gravitational waves on the model parameters and found that the constraint effect of electromagnetic wave data on model parameters is better than that of simulated Tianqin gravitational wave data. 相似文献
6.
Two variants of a functional-analytical algorithm intended for solving inverse tomography problems are discussed and numerically carried out. The acoustic fields that are transmitted and received by transducers, which are equivalent to point ones, serve as experimental data. These data are used to calculate the classical or generalized scattering amplitude, and the scatterer characteristics are then reconstructed. The algorithm requires neither model linearization, no iterations for refining the estimates of scatterers, thus making it attractive for solving acoustic-tomography problems in different applications. The results of the numerical reconstruction of inhomogeneities in the sound velocity and absorption in a medium are presented. 相似文献
7.
The asymptotic iteration method(AIM) is used to obtain the quasi-exact solutions of the Schr o¨dinger equation with a deformed well potential. For arbitrary potential parameters, a numerical aspect of AIM is also applied to obtain highly accurate energy eigenvalues. Additionally, the perturbation expansion, based on the AIM approach, is utilized to obtain simple analytic expressions for the energy eigenvalues. 相似文献
8.
A.G. Ramm 《Physics letters. A》1985,113(4):172-176
The backscattered acoustic field from an inhomogeneity is known on a plane P for all frequencies. These data determine the inhomogeneity uniquely. An analytical formula for the inversion is given. The integral geometry problem which consists in finding a compactly supported function from the knowledge of its integrals over the spheres S(x1, R) of various R centered at x1, 0 < R < ∞, x1 ? P, is solved analytically explicitly. The backscattered field known at any finite number of frequencie s does not determine the inhomogeneity uniquely. 相似文献
9.
We introduce a tight-binding chain with a single impurity to act as a quantum data bus for perfect quantum state transfer. Our proposal is based on the weak coupling limit of the two outermost quantum dots to the data bus, which is a gapped system induced by the impurity. By connecting two quantum dots to two sites of the data bus, the system can accomplish a high-fidelity and long-distance quantum state transfer. Numerical simulations for finite system show that the numerical and analytical results of the effective coupling strength agree well with each other. Moreover, we study the robustness of this quantum communication protocol in the presence of disorder in the couplings between the nearest-neighbor quantum dots. We find that the gap of the system plays an important role in robust quantum state transfer. 相似文献
10.
Theeraphong Chanpheng Hitoshi Yamada Toshio Miyata Hiroshi Katsuchi 《Applied Acoustics》2004,65(2):109-123
Low-frequency noise radiated from highway bridges is a serious environmental problem in Japan. Although the suppression of bridge vibration as usually done in practice can alleviate the radiation, it may not be optimal because the behavior of radiation is not taken into consideration. Concept of radiation modes, which can represent both vibration and radiation behavior, is adapted to a highway bridge. The objectives of this paper are to study the benefits of using radiation modes in (1) identification of low-frequency noise characteristics and (2) active control of low-frequency noise radiation. Numerical study shows that the radiation modes enable radiation characteristics of low-frequency noise to be physically understood and the active controller designed by radiation modes is superior to the controller designed without considering radiation behavior. Because the concept of radiation modes can reveal the mechanics of radiation/vibration, it is appropriate to the problem of low-frequency noise radiated from highway bridges. 相似文献
11.
介绍了采用CAN总线数据传输方式的系统中,光电编码器CAN总线接口的设计与应用。首先,设计了由单片机、独立CAN总线控制器SJA1000、CAN总线收发器TJA1050及高速光耦TLP113等构成的光电编码器CAN总线接口硬件电路;然后,介绍了光电编码器CAN总线接口的软件设计,包括初始化的设计、CAN总线报文接收及发送的设计;最后,通过周立功公司的“USBCAN1”型号CAN总线接口卡验证了该光电编码器CAN总线接口设计的可行性。实验中采用1米长的屏蔽双绞线作为传输介质,通信速率为800kbps;结果表明:带有CAN接口的光电编码器克服了传统的通信线路的缺点,具有更高的实时性、可靠性且通信速率高、传输距离长、抗干扰能力强,更加适用于自动化测量和控制系统。 相似文献
12.
J. Kidawa-Kukla 《Journal of sound and vibration》2003,262(4):865-876
This paper considers the problem of the transverse vibrations of a beam induced by a mobile heat source. The formulation of the problem is based on the differential equations of heat conduction and transverse vibrations of the beam, which are complemented by suitable initial and boundary conditions. The effect of internal and external damping on the vibrations of the beam is considered. The solution to the problem in analytical form is obtained by using the properties of the Green functions. A time partitioning method has been used to avoid the difficulties associated with the slow convergence of the series occurring in the solution to the heat conduction problem. The numerical results of the thermally induced vibration of the beam are presented. 相似文献
13.
Application of the chirp z-transform to MRI data 总被引:1,自引:0,他引:1
Kaffanke J Dierkes T Romanzetti S Halse M Rioux J Leach MO Balcom B Shah NJ 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2006,178(1):121-128
A version of the chirp z-transform (CZT) enabling signal intensity and phase-preserving field-of-view scaling has been programmed. The algorithm is important for all single-point imaging sequences such as SPRITE when used with multiple data acquisition for T2* mapping or signal averaging. CZT has particular utility for SPRITE imaging of nuclei with short relaxation times such as sodium at high field. Here, a complete theory of the properties of CZT is given. This method operates entirely in k-space. It is compared with a conventional interpolation approach that works in image space after the application of a fast Fourier transformation. 相似文献
14.
Toru Sato Tatoku Ogaito Hisao Ohtsubo 《Zeitschrift für Physik A Hadrons and Nuclei》1993,345(1):15-19
Polarization of hypernuclei in (, K) and (K, ) reactions are studied by applying the semi-classical approximation to the transition amplitude. Simple formulas for the polarization of hypernuclei are obtained, and their validity is discussed in the reaction on theA=12 system. 相似文献
15.
Inverse problems in statistical physics are motivated by the challenges of ‘big data’ in different fields, in particular high-throughput experiments in biology. In inverse problems, the usual procedure of statistical physics needs to be reversed: Instead of calculating observables on the basis of model parameters, we seek to infer parameters of a model based on observations. In this review, we focus on the inverse Ising problem and closely related problems, namely how to infer the coupling strengths between spins given observed spin correlations, magnetizations, or other data. We review applications of the inverse Ising problem, including the reconstruction of neural connections, protein structure determination, and the inference of gene regulatory networks. For the inverse Ising problem in equilibrium, a number of controlled and uncontrolled approximate solutions have been developed in the statistical mechanics community. A particularly strong method, pseudolikelihood, stems from statistics. We also review the inverse Ising problem in the non-equilibrium case, where the model parameters must be reconstructed based on non-equilibrium statistics. 相似文献
16.
17.
《Journal of Magnetic Resonance (1969)》1991,91(2):316-325
The supplementation of data from liquid-crystal NMR with data from electron diffraction and rovibrational spectroscopy in order to determine a more precise and accurate structure and the application of this technique to p-dichlorobenzene are described. Direct and indirect couplings involving 13C nuclei, a rotation constant obtained by high-resolution FT IR spectroscopy, and new electron diffraction data have been recorded and analyzed simultaneously. Assuming planarity and D2h symmetry, the best (rα structure for p-dichlorobenzene thus obtained is rCH = 107.6(3) pm, rCC1 = 172.93(14) pm, rC(1)C(2) = 139.53(7) pm, rC(2)C(3) = 139.12(17) pm, <C(6)C(I)C(2) = 121.06(14)°, and <C(1 )C(2)H = 120.48(3)°. 相似文献
18.
The static and dynamic properties of a spin-1/2 dipole with a transverse coupling to phonons are calculated using a generalization of a perturbation theory developed originally by Keiter, Kimball, Grewe, and Kuramoto for intermediate valence systems. 相似文献
19.
I. V. Mokrov 《Physics of Atomic Nuclei》2006,69(1):81-89
Various methods for solving the Salpeter equation for spinless particles, including a new method proposed here and the semiclassical approximation, are considered. It is shown that the heavy-quarkonium masses derived from the Salpeter equation with an effective QCD potential are in excellent agreement with experimental data. The efficiency of approximate methods is illustrated by considering the example of a Coulomb potential. The semiclassical spectrum is calculated—in particular, with allowance for color Coulomb interaction. The dynamical quark masses and the spectra of charmonia and bottomonia are calculated within various approximations. 相似文献