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981.
982.
Y. Uzawa M. Takeda A. Kawakami Z. Wang 《Journal of Infrared, Millimeter and Terahertz Waves》2003,24(10):1749-1757
A novel broadband tuning circuit composed of two low-current-density half-wave NbN/MgO/NbN tunnel junctions connected by a half-wave NbN/MgO/NbN microstrip line has been successfully tested in a quasi-optical mixer at frequencies above 700 GHz. The circuit had a designed center frequency of 870 GHz, was integrated in a center-fed twin-slot antenna, and was fed via a quarter-wave impedance transformer. Heterodyne measurments showed double-side-band receiver noise temperatures equivalent to 6-9 quanta from 675 to 810 GHz for a mixer with a current density of 6.7 kA/cm2. The RF bandwidth was broader than that of a conventional mixer using a full-wave junction with the same current density. 相似文献
983.
984.
压敏显色微胶囊及其涂料的研究进展 总被引:3,自引:0,他引:3
综述了无碳复写纸的结构类型和性能、压敏显色微胶囊制备及其微胶囊涂料的最新进展。揭示了微胶囊技术在无碳复写纸应用中的重要作用。 相似文献
985.
986.
Hao Wang Minjia Xu Chen Wang Hubing T. 《Electromagnetic Compatibility, IEEE Transactions on》2003,45(2):198-206
When numerically modeling structures with imperfect conductors or conductors coated with a dielectric material, impedance boundary conditions (IBCs) can substantially reduce the amount of computation required. This paper incorporates the IBC in the finite-element method (FEM) part of a FEM/method of moments (FEM/MoM) modeling code. Properties of the new formulation are investigated and the formulation is used to model three practical electromagnetic problems. Results are compared to either measured data or other numerical results. The effect of the IBC on the condition number of hybrid FEM/MoM matrices is also discussed. 相似文献
987.
988.
989.
Qiang Wang Yi Shen Ye Zhang Jian Qiu Zhang 《IEEE transactions on instrumentation and measurement》2003,52(4):1041-1047
Hyperspectral image fusion is a key technique of hyperspectral data processing. In recent years, many fusion methods have been proposed, but there is little work concerning evaluation of the performances of different image fusion methods. In this paper, a method called quantitative correlation analysis (QCA) is proposed, which provides a quantitative measure of the information transferred by an image fusion technique into the output image. Using the proposed method, the performances of different image fusion methods can be compared and analyzed directly based on the images of before and after performing the fusion. The correlation information entropy, based on the developed QCA, is also proposed and testified by numerical simulations. Typical hyperspectral data are applied to the proposed method. The results show that the method is effective, and its conclusions agree with the classification results in applications. 相似文献
990.
Dynamic Survivability in WDM Mesh Networks Under Dynamic Traffic 总被引:3,自引:0,他引:3
Network survivability is a crucial requirement in WDM mesh networks. In this paper, we systematically consider the problem of dynamic survivability with dynamic single link failure in WDM networks under dynamic traffic demands. Specifically, we investigate various protection schemes, such as dedicated path protection (DPP), shared path protection (SPP), dedicated link protection (DLP), shared link protection (SLP), and two restoration schemes, path restoration (PR) and link restoration (LR). Moreover, two new shared protection methods are proposed, i.e., SRLG-based shared link protection (SRLG-SLP) and SRLG-based shared path protection (SRLG-SPP). The SRLG (shared risk link group) constraint defines the availability of protection resources to a working path, which requires that any two working paths sharing the same risk of failure (or in the same SRLG) cannot share the same protection resources. Furthermore, in our study, we consider a more practical dynamic single-link failure model, in which the link-failure-interarrival time and link-failure-holding time are considered as two independent parameters. Based on this link-failure model, extensive simulations are done to analyze and compare the dynamic survivable performance of various protection and restoration schemes. Resource utilization, protection efficiency, restoration efficiency, and service disruption ratio are employed as survivable performance metrics versus traffic load, link-failure frequency, and link-failure reparation time to evaluate the survivable performance. Many meaningful results are given. In addition, we show that the developed SRLG-SLP and SRLG-SPP protection schemes perform very well in terms of protection efficiency and service disruption ratio, while sacrificing some performance in terms of resource utilization. 相似文献