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51.
针对相干光正交频分复用(coherent optical orthogonal frequency division multiplexing,CO-OFDM)系统中相位噪声引起的载波间干扰(inter-carrier interference,ICI)问题,提出了一种基于线性预处理的新判决反馈相位噪声抑制算法。该新算法改进了线性预处理部分,利用循环前缀与OFDM符号固有的相关性,在时域进行简单的线性组合运算,充分利用了OFDM符号中冗余信息。仿真分析表明,在激光器线宽为200 kHz且误码率(bit error rate, BER)为10-4时,与判决反馈相位噪声抑制算法和一次迭代的判决反馈相位噪声抑制算法相比,该新算法BER曲线的信噪比(signal to noise ratio,SNR)分别改善了3 dB和1 dB,有效地降低由ICI引起的错误平层。 相似文献
52.
Prior to 2002, little was known about sexual abuse within the Catholic Church. After the Boston Globe broke the story about John Geoghan - a priest in the Boston Archdiocese who was accused of abusing numerous children, convicted of one count of indecent assault, and eventually murdered in prison - the Church had many questions to answer. To this end, the United States Conference of Catholic Bishops (USCCB) commissioned John Jay College of Criminal Justice to research the nature and scope, as well as the causes and context of child sexual abuse within the Catholic Church.This research analyzes the data from the John Jay studies using a new quantitative technique, capable of adjusting for distortions introduced by delays in abuse reporting. By isolating discontinuities in model parameter timeseries, we determine changes in reporting patterns occurred during the period 1982-1988. A posteriori to the analysis, we provide some possible explanations for the changes in abuse reporting associated with the change-point. While the scope of this paper is limited to presenting a new methodological approach within the frame of a particular case study, the techniques are more broadly applicable in settings where reporting lag is manifested. 相似文献
53.
《Omega》2014
In recent years, the issue of water allocation among competing users has been of great concern for many countries due to increasing water demand from population growth and economic development. In water management systems, the inherent uncertainties and their potential interactions pose a significant challenge for water managers to identify optimal water-allocation schemes in a complex and uncertain environment. This paper thus proposes a methodology that incorporates optimization techniques and statistical experimental designs within a general framework to address the issues of uncertainty and risk as well as their correlations in a systematic manner. A water resources management problem is used to demonstrate the applicability of the proposed methodology. The results indicate that interval solutions can be generated for the objective function and decision variables, and a number of decision alternatives can be obtained under different policy scenarios. The solutions with different risk levels of constraint violation can help quantify the relationship between the economic objective and the system risk, which is meaningful for supporting risk management. The experimental data obtained from the Taguchi's orthogonal array design are useful for identifying the significant factors affecting the means of total net benefits. Then the findings from the mixed-level factorial experiment can help reveal the latent interactions between those significant factors at different levels and their effects on the modeling response. 相似文献
54.
讨论了扫描光束对高斯参数扫描光点强度分布的影响;给出了高斯参数与中心峰值强度及光点直径的定量关系;展示出焦平面上的三维光强分布图;提出了光盘存贮中高斯参数的选择依据;有效利用无能,获得高性能扫描光点。 相似文献
55.
In this paper, an infinite class of partially balanced incomplete block (PBIB) designs of m+1 associate classes is constructed through the use of a series of row-orthogonal matrices known as partially balanced orthogonal designs (PBOD) of m-associate classes. For the purpose, a series of PBOD is obtained through a method described herein. An infinite class of regular GD designs is also reported. 相似文献
56.
We consider the situation where one wants to maximise a functionf(θ,x) with respect tox, with θ unknown and estimated from observationsy
k
. This may correspond to the case of a regression model, where one observesy
k
=f(θ,x
k
)+ε
k
, with ε
k
some random error, or to the Bernoulli case wherey
k
∈{0, 1}, with Pr[y
k
=1|θ,x
k
|=f(θ,x
k
). Special attention is given to sequences given by
, with
an estimated value of θ obtained from (x1, y1),...,(x
k
,y
k
) andd
k
(x) a penalty for poor estimation. Approximately optimal rules are suggested in the linear regression case with a finite horizon,
where one wants to maximize ∑
i=1
N
w
i
f(θ, x
i
) with {w
i
} a weighting sequence. Various examples are presented, with a comparison with a Polya urn design and an up-and-down method
for a binary response problem. 相似文献
57.
农村社区建设应坚持科学发展观,按照"生产发展、生活宽裕、乡风文明、村容整洁、管理民主"的社会主义新农村建设目标要求,建设人与自然和谐相处的村民"宜居社区"和"精神家园"。社区建设涵盖经济收入指数、人居环境指数、居民幸福指数、社区参与指数、平安康乐指数、福利保障指数、社区归属感等参数。 相似文献
58.
洋桔梗叶盘高频率不定芽诱导的初步研究 总被引:1,自引:0,他引:1
采用正交设计法研究了细胞分裂素ZT,生长素NAA,培养基pH值和光照强度对洋桔梗叶盘不定芽诱导的影响.结果表明,实验的4个因子对洋桔梗叶盘不定芽都具有极显著的诱导作用,最佳培养基和培养条件为:MS ZT 0.5 mg/L NAA 0.01 mg/L,培养基pH值为6.3,光照强度为3000 lx.该处理中每叶盘再生不定芽数平均达9.41个. 相似文献
59.
指数分布参数基于不完全数据的区间估计 总被引:1,自引:0,他引:1
罗艳 《电子科技大学学报(社会科学版)》1998,(4)
对不完全样本观测数据,讨论了指数分布总体参数的区间估计;给出了构造置信区间的一种方法并推导出了相应的分布密度函数表达式;并说明了该方法在样本中可能存在异常值时的应用。 相似文献
60.
When we want to compare two designs we usually assume the standard linear model with uncorrelated observations. In this paper we use the comparison method proposed by Ghosh & Shen (2006) to compare three level orthogonal arrays with 18, 27 and 36 runs under a possible presence of correlation in observations. 相似文献