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排序方式: 共有1220条查询结果,搜索用时 93 毫秒
91.
A VPN is an optical virtual private network (oVPN) built of wavelength paths within a multihop wavelength routing (WR) dense wavelength division multiplexing (DWDM) network. An efficient and general graph-theoretic model (the wavelength-graph (WG)) has been proposed along with an integer linear programming (ILP) formulation of setting up VPNs with given traffic requirements over a given WR-DWDM network with two protection scenarios. Here, we have exploited the advantages of traffic grooming, i.e., numerous traffic streams of a VPN can share a wavelength path. We have also generalized the model for setting up VPNs over a WR-DWDM system where multiple VPNs can share a single wavelength path. The objective of the optimization is in all cases to reduce resource usage at upper (electrical) layers (i.e., to reduce the load of the virtual routers), subject to constrained amount of capacity of each wavelength channel and limited number of wavelengths. Here, we propose and compare three basic methods for configuring oVPNs and investigate various parameter settings. 相似文献
92.
93.
采用盆栽试验和小区试验相结合的方法 ,对砂姜黑土上不同小麦品种的分蘖成穗特性及其调控进行了研究 .结果表明 ,兰考 90 6分蘖发生快、多且衰亡也最快 ,分蘖成穗率较低 ,主要是由于二、三级分蘖发生较多 ,越冬期具有 4张以上叶片的分蘖才能成穗 .温麦 6号分蘖发生平稳 ,成穗率最高 ;百农 64分蘖力中等 ,增加一定的施肥量能明显提高分蘖成穗率 .不同生长调节剂对兰考 90 6分蘖成穗有明显的调控作用 ,以 6 BAt和 2 ,4 D控制分蘖成穗效果最为明显 相似文献
94.
Markus Karner Andreas Gehring Stefan Holzer Mahdi Pourfath Martin Wagner Wolfgang Goes Martin Vasicek Oskar Baumgartner Christian Kernstock Klaus Schnass Gerhard Zeiler Tibor Grasser Hans Kosina Siegfried Selberherr 《Journal of Computational Electronics》2007,6(1-3):179-182
We present the Vienna Schrödinger-Poisson Solver (VSP), a multi-purpose quantum mechanical solver for investigations on nano-scaled device structures. VSP includes a quantum mechanical solver for closed as well as open boundary problems on fairly arbitrary one-dimensional cross sections within the effective mass framework. For investigations on novel gate dielectrics VSP holds models for bulk and interface trap charges, and direct and trap assisted tunneling. Hetero-structured semiconductor devices, like resonant tunneling diodes (RTD), can be treated within the closed boundary model for quick estimation of resonant energy levels. The open boundary model allows evaluation of current voltage characteristics. 相似文献
95.
This new combined optical–wireless indoor communication system provides an economic and flexible approach for local area networks mainly in large buildings or in a group of several buildings. The radiation from the radio base stations of mobile networks cannot penetrate into large buildings completely. That problem is more serious at higher frequencies. The present approach offers a good solution to this problem. In this approach the wireless communication serves small picocells which are interconnected by an optical backbone. The performance of the system is enhanced by assigning a specific radio frequency for each picocell which enables the transmission of the wireless channels without altering their modulation formats. This method allows for a simple, and low-cost indoor communication system. 相似文献
96.
Stefan Holzer Alireza Sheikholeslami Markus Karner Tibor Grasser Siegfried Selberherr 《Microelectronics Reliability》2007,47(4-5):623
We present a comparison of models describing the pyrolytic deposition of SiO2 with a low pressure chemical vapor deposition process. In order to meet industrial simulation requirements, e.g. accuracy and fast delivery of results, we present an overview of established and new models, their use within TCAD applications, and their best results which have been obtained by calibrations according to SEM measurements. 相似文献
97.
基于求解多集分裂可行问题与非线性最优化问题的等价性,考虑Jinling Zhao and Qingzhi Yang在[1]中提出的求解SFP的共轭梯度法和Censor等在[2]中提出的梯度投影法,尝试运用共轭梯度法求解多集分裂可行问题;并且证明了所构造算法的收敛性.提出的新算法克NT求矩阵逆的缺点.初步的数值结果表明新算法对于不同的问题都能够有较快的收敛速度,具有良好的稳定性和可行性,在问题维数增大时表现得越发明显. 相似文献
98.
This paper presents an adaptive fuzzy neural controller (AFNC) suitable for modelling and control of MIMO non-linear dynamic systems. The proposed AFNC has the following salient features: (1) fuzzy neural control rules can be generated or deleted dynamically and automatically; (2) uncertain MIMO non-linear systems can be adaptively modelled on line; (3) adaptation and learning speed is fast; (4) expert knowledge can be easily incorporated into the system; (5) the structure and parameters of the AFNC can be self-adaptive in the presence of uncertainties to maintain a high control performance; and (6) the asymptotical stability of the system is established using the Lyapunov approach. Simulation studies on a two-link robot manipulator show that the performance of the proposed controller is better than that of some existing fuzzy/neural methods. 相似文献
99.
集中监控系统中软件的设计和实现 总被引:1,自引:0,他引:1
实时集中监控系统的实时性、可靠性取决于系统的硬件结构与软件体系结构 ,文中介绍了集中监控系统的结构和实现方案 ,描述了集中监控系统的软件模型 ,阐述了软件的具体设计方法及各软件模块的运行优先级问题。设计体现了集中管理、分散控制的思想 ,运用分布式计算方法 ,在保证集中监控可靠性的同时 ,提高了集中监控的实时性、安全性 相似文献
100.
Rönnholm Mats R. Hernández Carucci José R. Arve Kalle Eränen Kari Salmi Tapio 《Topics in Catalysis》2007,42(1-4):195-198
A silver/alumina catalyst was tested for its NO
x
reduction activity during oxygen-rich conditions and during variation in the input parameters (nitric oxide, octane and oxygen).
The experimental data using the microreactor was investigated by means of artificial neural networks (ANN). 相似文献