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901.
国家对电信终端设备、无线电通信设备和涉及网间互联的设备实行进网许可制度。信息产业部文件《电信新设备进网试验管理暂行办法》规定:电信新设备是指应实行进网许可制度但尚无正式国家标准、行业标准的,或未列入《第一批实行进网许可制度的电信设备目录》的电信设备。依据《电信设备进网管理办法》第13条规定,电信新设备在符合国家产业政策和不影响网络安全畅通的条件下,准予进网试验,由信息产业部颁发进网试用批文。 相似文献
902.
Wang H. Kwong S. Kok C.-W. Chan M.-Y. 《Vision, Image and Signal Processing, IEE Proceedings -》2006,153(5):677-683
A new analytical model to eliminate redundant discrete cosine transform (DCT) and quantisation (Q) computations in block-based video encoders is proposed. The dynamic ranges of the quantised DCT coefficients are analysed, then a threshold scheme is derived to determine whether the DCT and Q computations can be skipped without video quality degradation. In addition, fast DCT/inverse DCT (IDCT) algorithms are presented to implement the proposed analytical model. The proposed analytical model is compared with other comparable analytical models reported in the literature. Both the theoretical analysis and experimental results demonstrate that the proposed analytical model can greatly reduce the computational complexity of video encoding without any performance degradation and outperforms other analytical models 相似文献
903.
The adaptive controller design of a large class of mechanical systems is addressed in this paper. The configuration space for the attitude of a vehicle is modelled as SO(3), namely the rotation matrix group. To avoid singularity problems, some studies adopt the representation of unit quaternions for modeling system dynamics and for the design of controllers. However, the complicated formulation of quatrains makes the application of this method limited to simple mechanical systems. Here, the strategy is to carry out the modeling and analysis in terms of the global representations of jet bundles of SO(3), while the unit quaternion is chosen to implement the controller for its least number of parameters (four) to represent SO(3) globally. Based on the transformation between the rotation matrix and the quaternion, the method explored in this paper gives rise to an adaptive controller in a clean and efficient way 相似文献
904.
Analysis of dinosaur samples by nuclear microscopy 总被引:2,自引:0,他引:2
Xiankang Wu I. Orli S. M. Tang Yiming Wang Xiaohong Wang Jieqing Zhu 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》1997,130(1-4):308-314
Several dinosaur bone and eggshell fossil samples unearthed at different sites in China were analyzed by means of nuclear microscopy. Concentrations and distributions of elements such as Na, Mg, Al, P, S, Ca, Cr, Mn, Fe, Cu, Zn, As, Br, Sr, Y, Ce, Pb and U, etc. were obtained for each sample. The results of quantitative PIXE and RBS analyses show unusually high concentrations of U and Ce in several samples obtained from a period near the K-T boundary (between Cretaceous and Tertiary periods, 65 million years ago), suggesting that some form of environmental pollution could be the cause of dinosaur extinction. 相似文献
905.
本文介绍一种基于VME总线的高速A/D缓冲系统的原理和结构。着重阐述了高速数据采集技术,高速FIFO缓冲技术,存储器总线切换技术,VME及PC/ISA总线接口技术在本系统中的成功应用。 相似文献
906.
McKeon J.B. Chindalore G. Hareland S.A. Shih W.-K. Wang C. Tasch A.F. Jr. Maziar C.M. 《Electron Device Letters, IEEE》1997,18(5):200-202
This letter presents for the first time, the experimentally determined majority carrier mobilities in the accumulation layer of a MOSFET for both p-type and n-type channel doping for a wide range of doping concentrations. The measured carrier mobility is observed to follow a universal behavior at high transverse fields, similar to that observed for minority carriers in MOS inversion layers. At the higher doping levels, the effective mobility for majority carriers at low to moderate transverse fields is found to be very close to the bulk mobility. This is believed to be due to carrier screening of the ionized impurity scattering which dominates at the higher doping concentrations 相似文献
907.
Huang-Chung Cheng Fang-Shing Wang Chun-Yao Huang 《Electron Devices, IEEE Transactions on》1997,44(1):64-68
The NH3-plasma passivation has been performed on polycrystalline silicon (poly-Si) thin-film transistors (TFT's), It is found that the TFT's after the NH3-plasma passivation achieve better device performance, including the off-current below 0.1 pA/μm and the on/off current ratio higher than 108, and also better hot-carrier reliability than the H2-plasma devices. Based on optical emission spectroscopy (OES) and secondary ion mass spectroscopy (SIMS) analysis, these improvements were attributed to not only the hydrogen passivation of the defect states, but also the nitrogen pile-up at SiO2/poly-Si interface and the strong Si-N bond formation to terminate the dangling bonds at the grain boundaries of the polysilicon films. Furthermore, the gate-oxide leakage current significantly decreases and the oxide breakdown voltage slightly increases after applying NH3-plasma treatment. This novel process is of potential use for the fabrication of TFT/LCD's and TFT/SRAM's 相似文献
908.
909.
本文通过一个实际的IC卡应用系统一校园IC卡系统的设计与实现过程,给出了开发研制IC卡应用系统的基本方法.本文还对校园IC卡管理信息系统作了介绍.该系统的管理软件采用数据库语言FoxProforWindows编写,具有人机界面友好直观、多画面、多窗口、安全可靠等特点. 相似文献
910.
Hung-Yu Wang Ching-Ting Lee 《Electronics letters》1997,33(7):574-576
A novel circuit for realising negative immittance using a single plus-type second-generation current conveyor is proposed. The immittance values of the the circuit, which only use four passive elements, can be orthogonally adjusted. The circuit does not require component matching 相似文献