带宽

This thesis consists of two parts. The first one was that boundary value problem was discrete with five point difference method. Three kinds of memory formats were studied, which were full matrix, half band width and row compress sparse. Full matrix memory format and half band width memory format first was contrasted. The results show that half band width has efficiency in space. Then the algebraic system of finite element method was solved by Gauss-Seidel iteration method to popular row compress sparse memory format.

本论文由两部分组成，第1部分针对边值问题，用5点差分格式进行离散，并对离散矩阵这类大型稀疏矩阵，研究了系数矩阵的3种存储格式的优劣，即：满矩阵存储格式、半带宽存储格式和按行压缩稀疏存储格式，首先我们将满矩阵存储方式和半带宽存储格式进行了对比，迭代法的数值实验表明：利用半带宽存储的矩阵在空间运算方面具有高效性；然后针对目前数值实验中流行的按行压缩稀疏存储格式，实现了有限元离散代数系统的迭代法的求解。

This article first antenna, microstrip theory, the circular polarization technology, the theoretical discussion, in this based on the microstrip antenna of circular polarization method - corner square microstrip antenna, and has done a design simulation , and then do the design and further research to improve and eventually get a resonant frequency (S11 reflection coefficient corresponding to the minimum frequency) for the 1.5GHz and 1.43GHz, the frequency of circular polarization for the 1.46GHz, S11 is less than -10dB relative bandwidth, the VSWR is less than 2 is about 8.8% relative bandwidth, axial ratio less than 3dB relative bandwidth of about 2.2% of the right circular polarization microstrip antenna design case, which proved very good the circular polarization microstrip antenna theory, also fully confirmed by a square corner design is a practical program, and select the appropriate regulation of sticks is indeed able to improve the performance of the antenna.

本文先对天线、微带理论、圆极化技术等进行了理论论述，在此基础上，提出圆极化微带天线的实现方法——切角方形微带天线，并对此做了设计仿真，后又对这一设计方案做了改进及进一步研究，最终得到一个谐振频率（反射系数S11 的最小值所对应的频率）为1.5GHz和1.43GHz，圆极化频率为1.46GHz，S11 小于-10dB 的相对带宽、驻波比小于2 的相对带宽约为8.8%，轴比小于3dB 的相对带宽约为2.2%的右旋圆极化微带天线的设计案例，从而很好的印证了圆极化微带天线理论，也充分证实了切角方形是一种切实可行的设计方案，而选取合适的调节枝则确能提高天线的性能。

Then three candidate modulation schemes exploiting spatial dimensions are proposed. At last, the three modulation schemes are compared by power efficiency and bandwidth efficiency. It shows that spatial quadrature amplitude modulation scheme is appropriate for long distance wireless optical communications for its high bandwidth efficiency and spatial circular symmetry.

参照传统时域信号设计方案，提出了三种空间调制信号具体设计方案，并从带宽效率和功率效率两性能上进行了比较，结果表明正交幅度调制具有带宽效率高、功率效率低的特点，而且采用的信号点越多其带宽效率就越高，另外其空间信号图案还具有圆对称性，因此非常适合在空间带宽有限的远距离无线光通信中使用。

Traditional link access control algorithm such as LBRCA（Link Bandwidth Require Control Algorithm） has the problem of high link access rejection probability and low bandwidth resource usage ratio.A model of sharing bandwidth allocation in multi-link is proposed,the features of link bandwidth allocation and QoS level are also discussed.The DBAMQ（dynamic bandwidth allocation and multi-level QoS） link access control algorithm is presented.In this algorithm,the bandwidth is readjusted according to variable QoS level.

针对传统的基于带宽请求链路接入控制算法（Link Bandwidth Require Control Algorithm，LBRCA）的接入成功率和系统带宽利用率不高的问题，设计了一种多链路接入共享带宽分配模型，分析了链路带宽分配和QoS等级的特点，提出一种动态带宽分配分级QoS链路接入控制算法DBAMQ（Dynamic Bandwidth Allocation and Multi-level QoS），该算法在保证某QoS等级的基础上允许动态地对系统的带宽进行重分配。

commited information rate,round trip time and retransmission timeout,can bias bandwidth assurance.through researching the relation between bandwidth and these factors, this paper proposed a cir,rtt,rto aware marker(crr3cm) based on time sliding window three color marker(tsw3cm),which could achieve proportional fair sharing of excess bandwidth among aggregates and mitigate the impact of cir,rtt,rto for bandwidth assurance.

摘 要：往返时间、目标速度以及重传超时等因素导致了带宽分配的不均匀。通过研究带宽与这些因素的关系，在时间滑动窗口三色标记器（tsw3cm）的基础上，提出一种cir、rtt、rto感知的标记器(crr3cm)。该标记器完成了在各汇聚流之间对剩余带宽的公平分配，减少了目标速度、往返时间，以及重传超时因素对带宽分配的影响。

The calculation takes into account the effects of grating period, noncollinear amplification geometry, crystal's length and pump intensity. The results show the grating period of PPLN and the noncollinear geometry has effects on the spectral bandwidth.

计算结果表明，参量带宽和增益带宽具有相似的特性，而且PPLN晶体的周期和非共线入射结构会对光参量放大的光谱带宽产生一定的影响，在同一波长处，通过调节晶体周期或非共线结构可以获得更大的带宽。

Making use of the analytical expression,one has researched this laws of the parametric bandwidth vs the wavelength of signal light,pump light and the noncollinear angle through the method of numerical calculation.

结果表明，对于同一抽运光，随着信号光波长的增加，参变带宽将先增加而后减小，即参变带宽存在着最大值；随着抽运光波长的减小，参变带宽将增大；对于同一信号光和抽运光，随着非共线角α的增大，参变带宽Δλ将逐渐增大。

The fluctuation of available wireless link bandwidth motivates the study of adaptive multimedia services in wireless/mobile networks This paper focusses on a bandwidth adaptation scheme, which takes the maximum revenue as the objective The optimal bandwidth adaptation algorithm which seeks to achieve maximum revenue is an NP hard problem, because it has to investigate every adaptation case A bandwidth adaptation scheme based on genetic algorithm is proposed, which achieves near optimal total revenue with much less complexity compared to an optimal bandwidth adaptation algorithm Simulation is carried out to compare the algorithm with an optimal bandwidth adaptation algorithm, the results reveal that the genetic algorithm approximates the optimal solution very well

无线链路带宽的快速波动推动了无线/移动网络中对适应的多媒体服务的研究以无线网络系统的利润最大化为目标，研究适应的多媒体应用的带宽适应方案达到利润最大化的最优带宽适应算法是一个NP hard问题提出一个基于遗传算法的带宽适应方案，在算法复杂度大大低于最优算法的同时，获得的利润值近似最优性能分析和实验结果证明了这一结论1 引言因特网和无线/移动通信技术的迅速发展，推动了两者服务的融合无线/移动环境下因特网服务的提供需要解决的一个关键问题是QoS保证提供QoS保证的一个重要技术手段是连接接纳控制 [1] CAC算法的目标是在保证切换连接请求丢弃率满足系

First, with a glance, find out what you get is a cable specification, different specifications of the cable has its own different standards and purposes, the standard three-line "CAT3", bandwidth 10M, for 十兆 network, currently has eliminated the basic; five lines of the standard is "CAT5", bandwidth 100M, the following apply to hundreds of megabytes of network; super standard five-line "CAT5E", bandwidth 155M, is now mainstream products; the standard six-line is "CAT6", bandwidth 250M, for the erection of gigabit networks, the development trend of the future.

先是用眼看，搞清楚你拿到是什么规格的网线，不同规格的网线都有自己不同的标准和用途，三类线的标准是& CAT3&，带宽10M ，适用于十兆网，目前基本已淘汰；五类线的标准是& CAT5&，带宽100M ，适用于百兆以下的网；超五类线的标准是& CAT5E &，带宽155M ，是目前的主流产品；六类线的标准是& CAT6&，带宽250M ，用于架设千兆网，是未来发展的趋势。

commited information rate,round trip time and retransmission timeout,can bias bandwidth assurance.through researching the relation between bandwidth and these factors, this paper proposed a cir,rtt,rto aware marker(crr3cm) based on time sliding window three color marker(tsw3cm),which could achieve proportional fair sharing of excess bandwidth among aggregates and mitigate the impact of cir,rtt,rto for bandwidth assurance.

小 摘 要：往返时间、目标速度以及重传超时等因素导致了带宽分配的不均匀。通过研究带宽与这些因素的关系，在时间滑动窗口三色标记器（tsw3cm）的基础上，提出一种cir、rtt、rto感知的标记器(crr3cm)。该标记器完成了在各汇聚流之间对剩余带宽的公平分配，减少了目标速度、往返时间，以及重传超时因素对带宽分配的影响。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。