群速度

The information transmitted on the internet is not number, letter and figure, with the level of application enhanced, and the application of sound, action shot and video images is increased, so these is a strict request for the safety and visiting speed of the internet servers.

由于在网络上传输的信息不只是数字、文字和图形，随着应用水平的提高，逐步增加语音、动态图像及视频图像等高带宽的应用，因此对网络服务器群的安全性和访问速度也有很高的要求。

As a small group of them smuggled his body out in the night at a snail's pace, the redhead who spoke with a slur snarled that he was leaving the gang.

晚上一小群人把他的尸体以极慢的速度偷偷地弄了出来，说话有点含糊不清的红发人咆哮着说他要离开这个黑帮。

To quicken the calculation speed of genetic algorithm, the chiasma operation and mutation operation are improved; based on the thinking of inheritable character, the destruction of fine gene combination during chiasma operation is prevented; drawing lessons from the thinking of modifying individual speed and position in the light of individual extremum and global extremum in particle swarm optimization algorithm, an evolutional mutation method based on gene character is put forward.

为提高遗传算法的计算速度，对交叉和变异操作进行了改进：基于遗传性状的思想，防止了交叉操作中对优良基因组合的破坏；借鉴粒子群算法中根据个体极值和全局极值修正个体速度和位置的思想，提出了根据基因性状进行进化变异的方法。

Concerning the disadvantage of the original PSO that is easily trapped in the local optimization and the convergence speed is slow in the evolution later, a particle swarm collaborative optimization algorithm based on velocity angle was proposed. The strategy of inertia weight adjustment was adopted based on cumulative distribution function of Gaussian distribution.

针对PSO存在易陷入局部极值、进化后期收敛速度缓慢的缺点，提出一种基于速度夹角的粒子群协同优化算法，并且引入了一种基于高斯分布的累积分布函数的惯性权重调整策略。

An analytic solution of kinematic model was obtained via Lie transformation group. It shows that the velocity of particles flow is maximum when x=0. Through locating the maximum particles velocity distributing line and taking the line as the origin line of x coordinates, the modified kinematic model could simulate the eccentric discharging well.

通过Lie变换群得到"运动模型"的解析解，发现x=0时颗粒的垂直速度达到最大值，由此在确定颗粒最大速度分布线的基础上移动坐标使该线上x值均为0，对"运动模型"进行了修正，可以反映壁面对颗粒运动的影响，所得计算结果与实验测定吻合得很好。

Aiming at the disadvantage of conventional BP neural network, such as selecting parameter values by the empirical method, slow convergence speed and easy trap into local minimum points, this paper designs an improved BP neural network system. In order to improve the network convergence rate and reduce the training error, this paper optimizes the initial connecting weight value of neural network by the use of ant colony algorithm and trains artificial neural network by Levenberg-Marquardt algorithm.

针对常规BP神经网络参数的经验式取值方法以及收敛速度慢，容易陷入局部最小点等缺陷，设计了一种改进的神经网络系统，利用蚁群算法优化神经网络连接权初值，并采用LM算法对人工神经网络进行训练，提高了网络的收敛速度，降低了训练误差。

Yang Qun says, the key that remnant comes down now is the problem of speed, because of Gu Ge Android and malic IPhoneOS cross platform product line to had begun complete, symbian wants to be caught up with truly and recapture leader position afresh, must realize a product to change with rapidder rate so, especially the boss of behind the curtain of Symbian Nuojiya, need more all the way tantivy just comes true to strike back absolutely truly likely.

杨群称，现在剩下来的关键就是速度的问题了，因为谷歌Android和苹果 iPhoneOS的跨平台产品线已经开始完备，Symbian要想真正赶上并重新夺回领导者地位，那么就必须以更快的速度实现产品化，尤其是 Symbian的幕后老板诺基亚，更是需要一路快跑才有可能真正实现绝地反击。

The effect of iner- tia weight factor on performance of PSO is discussed.The results show that the particle swarm optimiza- tion algorithm with nonlinear inertia weight factor is suitable to solve multivariahle optimum design prob- lem...

结果表明，带动态非线性惯性因子的微粒群算法对求解多变量的干燥优化设计问题具有方法简单、所需微粒群规模小、收敛速度快等特点；采用部分废气循环并进行优化设计对干燥系统的节能具有十分重要的意义，对湿空气出口温度和废气循环比进行优化设计，其年总费用比无废气循环的常规设计节省18.2%，比循环比为0.2时的常规设计节省12.6%。

The simulations showed that the proposed RACA overcomes the local convergence limitation of ACA, has rapid convergence speed and global convergence capability, which is very effective in air combat decision.

仿真结果表明这种随机优化蚁群算法克服了传统蚁群算法局部收敛的缺陷，特别是空战规模较大时更显示出其较快的收敛速度和全局收敛能力。

BACKGROUND: Sprint sports requires the balance in the upper limb, pectoral girdle muscle group and lower limb extensor muscle group, and the balance of these muscle strength is a key content to raise the sprinters' performance.

背景：短跑运动中重视上肢及肩带肌群及下肢屈伸肌群力量的平衡，对提高短跑速度起到一定作用。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。