以往

As a differential detection is used between the intercarrier, the proposed algorithm overcome the high sensitivity to timing error of conventional algorithm and is robust to multi-path. The effect of sample frequency offset can't be ignored in a continuous OFDM system of a large number of subcarriers. The estimation precision of the conventional algorithm is low and the realization is complex. A joint estimation of sample frequency offset and fine frequency offset based on difference operation is proposed. As averaging use a large number of samples in a maximum likelihood algorithm, the estimation precision is very high. The use of difference operation cancel the effect of carrier frequency offset, and the proposed sampling frequency estimation algorithm is robust to carrier frequency offset.

最后，本文对连续系统中的采样频率和载波频率精同步技术进行较为深入的研究，由于子载波数目大的连续OFDM传输系统中，采样频率偏差不可忽视，以往的采样频率估计方法精度低、实现复杂，因此本文提出了一种基于差分处理的采样频率偏差和精载波频率偏差联合估计算法，利用了最大似然算法进行采样频率偏差的估计，由于采用了差分处理方法，消除了载波频率偏差对采样频率偏差估计的影响，采用的最大似然算法对大量样点进行平均化处理，所以，相对以往算法，提出的联合算法估计精度高，而且采样频率偏差估计对载波频率偏差具有鲁棒性。

APSO and DES framework can both find a better solution, fewer minimum iterant times and average iterant times.

在物品较多的背包问题中，透过加速度粒子群演算法与双演化策略架构均能找到相较於以往文献的更好最佳解并且在较小代数与平均代数上，也均能得到相较以往文献的较少代数。

Based on the literature summary, we pointed out the inadequacy of the researches in the past, as a whole, due to the comparatively frail achievements that the western psychology has attained in the field of writing, the past researches, on the self-regulation strategy forms and the mechanisms, were lacking of a clear theoretical model and enough positivistic support, or, it did not have relatively mature theoretical model and research methods.

在此基础上，我们指出了以往研究的不足：由于总体来说西方心理学在写作领域所投入的工作，所取得的成就相对薄弱，因此，以往研究在关于写作构思的自我调控的策略形式及其机制问题上缺乏清晰的理论范型和足够的实证支持，或者说，还没有形成比较成熟的理论模型和研究方法。

The execution of new curriculum makes Politics in Junior Middle School become lively, and students become enthusiastic in class, which changes the hollow moralisation before, changes speaking all the time and changes the situation that students only can study passively.

新课程的实施使初中思品课堂变得生动活泼，学生参与课堂活动热情高涨，改变了以往枯燥空洞的说教，改变了以往&一言堂&、&满堂灌&，改变了学生只能被动学习的状况。

The exhibited works are different from the other series on the aspect of the view is much more objective. Standing silently at the last row from the stage and on looking the still life, the artist communicated with the nature spiritually.

有别於以往的静物摄影作品，作者这次展出作品比以往作品中的视觉更见抽离，作者以&以心见心而得其情&的旁观的态度，沉默地交融在物我之间。

The exhibited works are different from the other series on the aspect of the view is much more objective. Standing silently at the last row from the stage and on-looking the still life, the artist communicated with the nature spiritually.

有别于以往的静物摄影作品，作者这次展出作品比以往作品中的视觉更见抽离，作者以&以心见心而得其情&的旁观的态度，沉默地交融在物我之间。

Based on the above analysis, I reinvestigated and studied in this paper the ideological infiltration into art production in the past research with the attempt to uncover how it does. Meanwhile I also explored the material conditions neglected in pure theoretical studies such as techniques, subsidies and media.

作者不仅探讨了以往研究中已经注意到的意识形态的因素对艺术生产的渗透，并且试图回答它是怎样或通过什么途径渗透到艺术生产中的这一延伸问题，因此，在第二、第三、第四章中分别研究了技术、资助、媒介等在艺术生产中所产生的复杂影响，对以往在艺术的纯理论研究中所忽视的物质条件的影响进行了专门的探讨。

Google's approach, called statistical machine translation, differs from past efforts in that it forgoes language experts who program grammatical rules and dictionaries into computers.

Google的方案名为&统计机器翻译&(statistical machine translation)，这与以往的努力不同。以往人们都是把语言学家设置的语法规则和词典输入电脑。

The urgent work to do for economists and legists is to make more research on WTO rules related to developing for the development and promotion of Chinese industry and commerence in a short time.

乌拉圭回合对发展中国家的长期影响比以往任何多边贸易谈判的结果都要大，这主要是由于发展中国家比以往的参与程度提

Actually this time the training of CAAC secondees is quite different to the last 11 practices. Firstly, the training in Flight Operations Depart and Engineering Depart are the first time to CX.

这次培训其实和以往有很大的不同，第一我所报的工程专业和航务是第一次开展；第二我们并非象以往一样，各自在所在专业对口部门一直培训到结束。

Do not gum up the work by telling mother what we are going to do .

别告诉母亲我们要干的事，那会把事情搞糟的。

In recent years, application of the partial prestressed concrete beam s is developed.

近年来，随着部分预应力砼梁应用的推广，发现我国规范所采用的名义拉应力法的计算结果不稳定。