查询词典 reduce

In order to application on high resolution of liquid crystal display, which must reduce differential error voltage in digital-to-analog converter circuit. So, how to reduce the offset voltage of buffer amplifier is important. In the second buffer amplifier circuit, to promote the open-loop gain to reduce offset voltage.

若要使液晶显示器的色彩深度能够大幅提升，就必须采用位元数较高的数位类比转换电路，也就表示其输出的每一灰阶类比电压值的差将会随著位元数的增加而变小，因此输出缓冲放大器的偏移电压就显的特别重要。

to reduce the impact of carrier frequency offset in ofdm system,this thesis designs a new carrier frequency offset estimation scheme for ofdm system.the carrier frequency offset estimation includes acquisition and tracking.we adopt variable step size adaptive algorithm.the acquisition range of the proposed algorithm is as large as one half of the overall signal bandwidth.through this method we can not only avoid the feedback by using forward error correction,but also reduce the times of complex multiplication in order to reduce the power consumption of the system.this algorithm not only has low complexity and fast convergence nut also can improve the demodulation performance of ofdm system.computer simulation illustrates the superior performance of the proposed algorithm with regard to estimation accuracy in both awgn channel and multi—path channel.

摘 要：为了减小正交频分复用系统受频率偏差的影响，在ofdm系统中设计了一种新的载波频偏估计算法。频偏估计包括跟踪和捕获两个阶段，文中采用变步长自适应算法来进行跟踪，这个跟踪算法的捕捉范围是整个信号带宽的一半。通过此方法，不但可以利用前向纠错的方式来避免反馈，而且可以缩减复数乘法的次数以降低计算复杂度和系统功耗。该方法运算复杂度低，并具有较好的收敛性，能改善odfm的解调性能。从计算机的仿真效果可以看出无论是在awgn信道上还是在多径信道上都表现出了卓越的性能。

The main job and contribution of this paper are as follows:Based on narrowband signal processing, we propose a new method for FH signal blind detection and blind parameter estimation. Firstly, compute the cross-correlation function of FH signals from multichannels, then we get the cross power spectral density matrixCSDM Secondly, select the hops of FH signals from the CSDM via processing and analyzing the CSDM, meanwhile reduce the influence coming from noise, fixed frequency signal and other interferences; Lastly, estimating the DOA of every hop and according to the DOA, we can separate the hops, get the number of FH signals and their parameters. Propose a new method for designing the threshold in FH signal detection. This method makes it easy to get the threshold by theoretic computing and it can extremely reduce the interference of non-FH signals.Based on broadband signal processing, we propose a new method for FH signal blind detection and blind parameter estimation. Firstly, get the DOA of the signals by wideband spatial spectrum estimation; secondly, separate the signals by spatial filtering using wideband beamformer; Lastly, we propose two methods for FH signal blind detection and blind parameter estimation, one is for several constant hop-rate FH signals whose dwell-time are different and another is for a single FH signal whose hop-rate is alterable.By employing spatial interpolation in broadband signal beamforming, it can reduce the number of antenna elements and corresponding RF modules, A/D converters, etc. It can also eliminate the mutual coupling between antenna elements while getting the narrower main beamwidth and lower sidelobe level.

本文的主要研究工作和贡献如下：●提出了一种基于窄带处理的FH信号盲检测和参数盲估计的实现方法，即首先求出多路信号之间的互相关，进而得到互功率谱密度矩阵，然后通过对CSDM进行对折处理来抑制噪声、定频信号及其他干扰的影响，并将所有属于FH信号的hop(每一跳的驻留时间在时频图上持续的线段)从CSDM中筛选出来，最后用阵列信号处理中的到达方向估计理论在频域中估计出各个hop的方向参数，利用方位信息完成FH信号分离并得到FH信号的数目及其各自的参数集；●提出了一种确定FH信号检测门限的策略，该策略不仅使得检测门限能够通过理论计算得到，而且还显著地抑制了非跳频信号的干扰，从而能有效地检测出FH信号；●提出了一种基于宽带处理的短波FH信号盲检测和参数盲估计的实现方法，即首先利用宽带空间谱测向技术得到接收信号的DOA，然后采用宽带波束形成技术对特定方向进行空间滤波，实现多个信号的分离，最后分别提出了两种FH信号的盲检测和参数盲估计方法，第一种方法适用于空间某个特定方向上存在着几个驻留时间不同的恒跳速FH信号和其他干扰信号的混合信号，第二种方法适用于空间某个特定方向上仅含一个可变跳速的FH信号和噪声的混合信号；●将空间插值的概念和宽带波束形成技术结合起来，提出了一种基于频域处理的宽带恒定束宽的波束形成方法。

The main direction to reduce decollation rate of yarn is to control and stabilize yarn tension, increase the yarn mightiness and reduce weakness tache rate, especially cut down the break tension and mightiness weakness point to reduce the cross rate of tension wave crest and mightiness wave trough.

由气圈理论的研究我们可以得知：降低断头率的主攻方向是控制和稳定张力，提高纺纱强力、降低强力不匀率，尤其是减少突变张力和强力薄弱环节，以减少张力与强力的波峰与波谷交叉机率。

During the high-voltage device design, the thick epitaxial layer LDMOS which is compatible with current technology was researched. This device used piecewise VLD and multiple region structure F reduce field layer. The using of the F reduce field layer effectively reduce the surface electric field of the device, shorten the length of its drift region, enlarge the choice of range of the ion implant dose of the P layer, and effectively restrain the disadvantageously affection on the breakdown voltage of the interface charge Qss.

在高压器件研究中对与现有工艺相兼容厚外延LDMOS进行研究，该结构采用分段变掺杂多区P~-降场层，有效降低器件的表面电场，缩短器件的漂移区长度，增大P~-降场层注入剂量的选择范围，并有效地抑制界面电荷Qss对器件耐压的不利影响。

Road to reduce the soft middle of the fetal head of the resistance to achieve a free accelerate the completion of the process and reduce the incidence of stagnation production,reduce maternal pain in childbirth.

减轻了软产道对胎头的阻力从而达到了加速完成分娩过程，降低滞产的发生率，减轻孕妇在分娩时的痛苦。

Using organic fertilizers to replace 20～30% chemical fertilizers could reduce more than 30% TN loss in rainfall runoff, seeding-period and field-baking-period drainage, and could decrease 19.43～25.91% leaching loss of TN. In wheat field, using organic fertilizers to reduce 20% chemical fertilizers, in which refined organic fertilizers could reduce 2.59kg/ha leaching loss coefficient of TN, zymolytic pig ordure could increase 2.22kg/ha leaching loss coefficient of TN.

水稻田在增施有机肥而减少20～30％化肥用量的情况下，包括降雨径流、播期和烤田排水的TN流失量可以减少30％以上，TN渗漏淋失可以减少19.43～25.91％；麦田在增施有机肥而减少20％化肥用量的情况下，施用精制有机肥可以减少TN淋失2.59kg／ha，施用发酵的猪粪则增加TN淋失2.22kg／ha；蔬菜轮作试验表明，相同施肥量下，适当使用精制有机肥可以减少TN淋失12.80kg／ha。

Thus reduce the slag temperature, reduce the amount of slag is an effective way to reduce energy consumption.

因而降低渣温，减少渣量是降低能耗的有效途径之一。

The old asphalt pavement is disposed by applying cold recycle technology,then it is can be used as base or subbase course,which can make the old materials of highway be utilized fully,reduce the excess consumption of resources and save 20%～30% cost,reduce the environmental pollution caused by scrap piling and transportation as well as reduce the dust and exhaust emission during construction process.

采用冷再生技术对旧的沥青路面进行处理，将其作为公路的基层或底基层使用，可使公路旧料全部得到利用，减少资源的过度消耗，节约成本20%～30%，还可减少因废料堆放和运输引起的环境污染，减少施工过程中的粉尘和废气排放。

In TUNEL assay it can be observed that cystamine can reduce myocardial cell apoptosis . At the same time Western Blot analysis to prove cystamine can reduce cardiac cell apoptosis and Deth receptor and Mitochondria through theses two pathsway, NF-κB protein expression significantly increased furthermore, it promots cell survival, which can reduce cardiac hypertrophy,apoptosis.

在TUNEL assay中可以观察到胱胺可以减少心肌细胞的凋亡，同时我们也利用Western Blot证明胱胺可以减少心肌细胞的凋亡是透过Deth receptor和Mitochondria这两条路径，而这样子降低凋亡的现象很有可能与NF-kB这讯息传递的分子上升有关，因此胱胺确实具有保护心肌细胞的作用，可改善心肌细胞肥大、凋亡的情形。

As of Tuesday, Google's results were still censored in China.

截至周二，谷歌的搜索结果仍受中国审查。

In order to make the positive action increase and negative one decrease, the sub-forces of the social factors must be adjusted to form a centripetal force.

在这一过程中，人的主体性发挥是社会有机体健康发展的灵魂。