共查询到20条相似文献，搜索用时 78 毫秒
1.
研究周期混合信号和色关联噪声联合驱动下的单模激光系统的随机共振现象,运用线性近似的方法得到输出信号光强的功率谱和信噪比.研究表明：信噪比都随泵噪声和量子噪声出现传统的随机共振现象;并讨论噪声的互关联时间和两信号的频率、振幅对信噪比的影响. 相似文献
2.
(襄樊学院 物理学系,湖北 襄樊 441053) 计算了具有指数关联形式的两白噪声驱动下,单模激光线性模型受信号调制后瞬态的输出信噪比,发现了瞬态的随机共振现象. 讨论了噪声间互关联时间及信号频率对信噪比的影响 相似文献
3.
讨论了具有指数关联形式的两白噪声驱动下,单模激光线性模型受信号调制后初态的输出信噪比,即瞬态第一个周期的随机共振现象. 也讨论了噪声间互关联程度和互关联时间及信号频率对信噪比的影响,并和定态的随机共振进行了比较. 相似文献
4.
谊文主要研究关联双态噪声驱动欠阻尼谐振子模型中的随机共振现象,分析井讨论了互关联不随时间变化争受周期信号调制下系统的输出特性．研究发现：周期调制互关联使得互关联强度进入系统输出表达式,调节互关联强度,可以在信号放大率随输入信号频率变化曲线上观察到双重随机共振现象． 相似文献
5.
研究了泵噪声自关联和量子噪声自关联及两噪声之间互关联分别取e指数形式时、单模放光线性模型受信号调制后其输出信噪比及随机共振现象、讨论了以上三个关联时间对出现随机共振的影响。 相似文献
6.
当今人工智能发展迅速,语音识别成为人机交互的重要方式。为提高语音识别准确度,在分析语音信号前去除语音信号噪声干扰并提高语音信号能量尤为重要。在实际应用中,不同语音信号包含不同的噪声。针对不同的语音噪声,在传统谱减法基础上,通过判断算法窗函数,根据不同的噪声能量改变多窗谱减法的过减因子参数,以增强算法自适应能力。仿真结果表明,在低信噪比情况下,通过改变过减因子值,可取得一个最优过减因子值以改进谱减法下的音乐噪声和失真度。自适应多窗谱减法改进后与基本谱减法相比,信噪比提高了 29%;与多窗谱减法相比,信噪比提高了 16%。该自适应多窗谱减法可适应不同噪声环境下的语音信号,增强语音信号中的关键信息并减少噪声干扰。 相似文献
7.
户永清 《绵阳师范学院学报》2009,28(8):33-38,42
提出了一种对噪声背景下微弱正弦信号的检测方法.分析了Duffing振子用于微弱正弦信号检测的机理,并把混沌临界状态检测法和传统检测方法(取样积分)相结合,实现-50dB以下超低信噪比的微弱正弦信号检测.同时,仿真实验也表明该方法对噪声具有较强的抑制能力且具有较低的信噪比工作门限. 相似文献
8.
针对实、虚部关联的量子噪声及泵噪声驱动的饱和激光模型,基于近似福克—普郎克方程,推导激光强度定态概率分布函数,利用投影算子法,分析了由于量子噪声实虚部关联度λq导致锁相时的光强度关联函数C(τ)和集中驰豫时间Tc。通过计算机数据计算及作图,得到了定态情况下光强概率分布函数图形,讨论了量子噪声实、虚部的互关联对光强关联函数和集中驰豫时间的影响。结果表明:量子噪声实、虚部互关联会导致激光强度涨落增大。 相似文献
9.
10.
陈俊 《郧阳师范高等专科学校学报》1999,(3)
从理论上对加性白噪声和乘性白噪声之间存在关联作用的一维激光模型进行了理论分析,导出了光强定态几率分布表达式．得到随着噪声关联强度参数的增加,光强定态几率分布曲线变得平坦,且分布曲线峰值向光强减小方向移动;当噪声间存在完全负关联,且两个噪声强度相等,则先强定态几率分布曲线变为一条直线。 相似文献
11.
12.
13.
《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
14.
罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
15.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
16.
Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
17.
Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
18.
Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献
19.
20.
RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献