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51.
提出了一种用于ATM网络中VBR业务的复用器设计方案,探讨了如何将一种基于令牌 桶控制的UPC算法用于ATM统计复用器的信源接入控制,并用“在系统编程技术”加以硬件实现。  相似文献   
52.
In this work, the two-step iteration combined with the nonlinear multiple regression technique to extract physical parameters for diodes, using a simple physical-based current–voltage (IV) model is demonstrated. This statistical method can be applied for sampling for a wide variety of diodes including light-emitting diodes (LEDs) and Schottky diodes. Our results show the technique is an accurate and systematic approach for extracting diode parameters. The calculated recombination currents indicate the recombination efficiency for LEDs and the quality for Schottky diodes.  相似文献   
53.
作者以不同功率的氮澈光对大白鼠分组进行穴位照射。照射前后测痛,照射后动物痛阈都有提高,说明不同功率的氮激光均有镇痛作用。高、低功率氮澈光穴位照射后动物产生的痛阈变化经统计学处理,差异性不显著。提示使用低功率氮激光同样可达提高痛阈的目的。  相似文献   
54.
High-frequency currents on the pins of integrated circuits (ICs) and on printed circuit board (PCB) traces are needed to predict and analyze electromagnetic interference in high-speed devices. These currents can, however, be difficult to measure when traces are buried within the PCB or chip-package, especially when several current-carrying traces are in close proximity. Techniques for estimating high-frequency currents from near-field scan data are proposed in this paper. These techniques are applied to find currents on the pins of an IC, on traces buried beneath other traces in a PCB, and on traces over a slot in the ground plane. Methods of dealing with the ill-posed nature of the current-estimation problem are discussed, as are applications to electrically large structures. A study of the sensitivity of the technique to errors in the measured fields, errors in the circuit geometry, and errors in the estimated dielectric constant of the PCB or chip package show that, for reasonable errors in these parameters, currents can be estimated to within an average of 20% (1.6 dB) or less of their correct values.  相似文献   
55.
In linear finite-impulse-response filter design, it is desirable that the filter frequency response has linear phase (LP). In this brief, we investigate the LP concept for nonlinear Volterra filters. The LP condition of Volterra filters is defined in terms of its output spectrum in which the phase term introduced by the Volterra kernels is linear. It is shown that under certain symmetry conditions, the LP condition is satisfied by Volterra filters. Moreover, the LP condition for Volterra filters can be considered as an extension to the linear filter case.  相似文献   
56.
Taking advantage of unlimited geometry design, 3D printed sacrificial mold cast with highly conductive polymer composites is used to prepare a sensor with designed structures. However, the disposal of the mold in a mild condition while the refined structures can be maintained is still a challenge. Herein, a bifunctional monomer hydrolyzable hindered urea acrylate is synthesized to create a cross-linked polymer network, preventing the dissolution of printed parts in the uncured resin. 3D printed scaffolds can be hydrolyzed in hot water, which provides an attractive option for sacrificial molds. Also, a porous flexible strain sensor (PFSS) is fabricated by casting polyurethane/carbon nanotubes composites into the sacrificial molds, which demonstrates a high stretchability (≈510%) and an excellent recoverability. Meantime, the pressure sensitivity (0.111 kPa−1) and a long-term electrical resistance of PFSS is characterized. The resistance response signal remains nearly unchanged after 100 compressive loading cycles at a large strain of 60%. Benefiting from the design freedom of 3D printing, a practical application of the PFSS with a complex and customized structure to monitor human motion is demonstrated. These results prove that the sacrificial molding process has great potential for user-specific stretchable wearable devices.  相似文献   
57.
虚拟专用网络技术   总被引:6,自引:1,他引:6  
翁亮  王澄 《通信技术》1999,(4):43-46,82
对VPN的基本概念作简要介绍后,着重分析了VPN的三种典型的应用方式,即Intranet VPN,远程接入VPN和Extranet VPN,并对现有的一些VPN技术进行了总结,提出了一个一般的VPN体系结构模型。  相似文献   
58.
基于IPSec的网络层VPN技术   总被引:7,自引:0,他引:7  
文章就IPSec提供的、与网络层VPN技术密切相关的协议隧道封装,用户信息加密,用户认证等关键技术及与之相关的系统管理等方面的技术细节进行分析,并就利用IPSec技术实现VPN的具体方式进行了归纳。  相似文献   
59.
施建俊  翁亮 《电讯技术》1999,39(1):82-89
本文根据ATM网的传输特点,从统计的角度分析话音源的特点,建立统计模型并对其统计特性进行分析。  相似文献   
60.
This paper presents a hardware authentication BLAKE algorithm based on physical unclonable functions (PUFs) in Taiwan Semiconductor Manufacturing Company low-power 65 nm CMOS. To support hardware authentication feature, PUFs have been organised in BLAKE algorithm as the salt value. The trials table method is used to improve the robust of PUFs, resulting in approximately 100% stability against supply voltage variations form 0.7 V to 1.6 V. By discussing the G-function of BLAKE algorithm, the hardware implementation is considered for acceleration, resulting in significant performance improvements. The die occupies 2.62 mm2 and operates maximum frequency 1.0 GHz at 1.6 V. Measured results show that PUFs have great random characteristic and the authentication chip dissipates an average power of 91 mW under typical condition at 1.2 V and 780 MHz. In comparison with other works, the PUFs-based BLAKE algorithm has hardware authentication feature and improves throughput about 45%.  相似文献   
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