GPS导航滤波器算法优化研究

引入一种动态性能较优的无偏导滤波器,针对其在GPS导航系统线性状态时的低精度表现,对单一的导航滤波器进行改进。采用一种组合滤波结构,根据GPS接收机的输出状态来进行线性及非线性滤波器的切换滤波。其中,线性滤波器采用优化的传统卡尔曼滤波器,并在仿真实验中验证其线性滤波优势;非线性滤波器采用了无偏导滤波器。车辆仿真实验表明,这种线性-非线性组合滤波器的误差低,运算量较小,整体滤波性能比单一滤波器高。     

基于变分问题的区间双正交小波的图像去噪

采用非线性滤波方法处理图像去噪问题时,阈值参数的选取和恰当使用滤波器函数,对去噪图像的效果影响极大。文章构造了可用于非线性滤波算法的一族分段次小波阈值参数滤波器函数,它是Donoho的软阈值滤波器函数的推广,证明了滤波后的逼近是Besov空间中泛函的近似最小值。该滤波器函数次数越大,逼近效果越好,也证明了广义软阈值滤波器函数的极限是一理想低通滤波器。仿真结果证实了区间双正交小波比Daubech ies小波有更好的去噪效果。     

用于通信信号非线性时域滤波的量子随机滤波器

针对通信信号的非线性时域滤波问题,研究了量子随机滤波器的原理和性能.将神经网络与非线性Schroedinger方程相结合,把方程的解作为信号时变的概率密度函数,进而实现滤波功能.研究发现,通过调整势场权系数的取值,可使滤波器具有明显不同的性能.根据此性质,构造了一种新的滤波算法,该算法可使滤波器在信号波形估计的非线性失真程度与它的抗噪能力之间进行折衷,这将大大推广量子随机滤波器的应用,例如,用于通信信号处理.仿真结果表明了量子随机滤波器的优越性能.     

基于蚁群优化的边缘化粒子滤波器跟踪算法

针对边缘化粒子滤波器(MPF)中的Kalman滤波通常无法从量测方程中获得线性状态估计,以及标准粒子滤波器估计非线性状态计算量大和粒子退化的问题,提出了一种改进的MPF粒子滤波目标跟踪算法。该方法采用状态的预测值作为Kalman粒子滤波的量测更新,用Kalman滤波估计目标的速度和加速度,并通过蚁群优化算法改进标准粒子滤波器,并用以估计目标的位置信息。仿真结果表明:该方法在提高目标状态估计精度的同时,降低了粒子滤波的计算复杂度,克服了粒子滤波退化现象。     

新型形态学滤波器的构造与应用

数学形态学是一门非线性的图像处理和分析工具。在图像滤波处理过程中,采用形态学开闭算子组成的滤波器,能得到很好的滤波效果。由于图像中几何形状多样性,以及噪声的特性,在形态学滤波器中常需要选择合适的形态学结构元。采用不同方向和不同尺度构成的形态学滤波器进行组合,得到新型的形态学滤波器。通过实验表明,新型滤波器对多方向的噪声特性去除效果较好,并且能很好地保持图像的方向几何特征。     

基于问题学习的数字图像均值滤波器教学研究

图像滤波是数字图像处理课程中的一个重要内容,针对不同的应用环境,涌现了多种优秀的图像滤波算法。基于均值滤波器、高斯滤波器、双边滤波器和非局部均值滤波器设计思想之间的内在联系,设计了多个图像滤波实验案例。并基于问题学习方法,引导学生运用已有知识,分析每个实验存在的问题,从而培养学生从工程应用中发现问题、解决问题的工程素质,实现创新人才的培养。     

基于Volterra级数的RLS自适应算法的混沌时间序列预测

根据混沌序列产生的确定性和非线性机制,基于Volterra级数和RLS算法,提出了一种少参数二阶非线性滤波算法用于混沌时间序列的自适应预测。仿真结果表明,这种非线性自适应滤波器能有效地预测一些超混沌序列,而且该滤波器的一步均方误差性能明显高于其他基于Volterra级数的NLMS算法,表明该算法具有良好的收敛性能。     

线性与非线性滤波方法仿真

在数据量测领域,对运动目标当前的运动状态进行滤波,并对目标未来的运动状态进行预测,讨论线性的数据平滑处理、最小二乘和卡尔曼滤波,通过非线性地扩展卡尔曼滤波进行仿真实验。线性与非线性滤波方法是多传感器数据预处理的主要工具,仿真实验表明,滤波方法能够有效处理运动目标量测误差。     

自适应低通滤波器的设计与实现

基于传统滤波器的特点,以现场可编程门阵列(FPGA)和单片机为控制核心,设计了一种新型自适应低通滤波器,实现了信号的程控放大和程控滤波功能。其中程控放大模块由仪表放大器AD620和可变增益放大器VCA810组成,最大增益60 dB,线性可调,程控滤波模块由MAX297低通滤波器和FPGA组成,利用FPGA完成信号中心频率的测量和滤波器截止频率控制信号的产生,利用MAX297实现信号的低通滤波。结果表明,对于频率变化0.1 Hz~50 kHz的输入信号,增益误差小于2%,截止频率控制信号频率误差小于1%,截止频率误差小于1.5%。     

FIR滤波器在C31上的实现

在简略介绍数字信号处理概况、TMS320C31DSK系统后，以FIR滤波器为例，详细描述了滤波实现的全过程。在完成系统初始化和A／D、D／A设置的基础上，选择直接型或线性相位型结构在，IMS320C31DSK系统上用汇编语言编程实现。将汇编连接后的源程序载入C31系统运行。借助于信号发生器和示波器可观察到输入信号和输出信号的实时显示。结果表明各种性能(如低通、高通、带通、带阻)的滤波器都能在C31系统上实现实时滤波。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

只要努力,不要后悔

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.     

浅谈移民问题

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.     

Sister Carrie, an Adherent of Desires

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.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

胡主席在印度,我却在中国

Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.     

STORIES

正A One day a pig went to the stable(马棚)to see his good friend,an oldhorse,and was going to stay there forthenight.Night came and it was time forsleep.The pig went into the straw heap(稻草堆)and lay comfortably.A longtime passed,but the horse was stillstanding there and did not move.Thepig asked the horse why he did not go tosleep."Standing like this is the begin-ning ofsleeping,"answered the horse.     

巧妙引语(英文)

正1.Any fool can count the seeds in an apple.Only God can count all the apples in one seed.2.Happy families are all alike;every unhappy family is unhappy in its own way.3.Memories are the key not to the past,but to the future.4.Sometimes in the dark you see what you want to see.5.There is a great difference between     

Information for Authors

正Scope and Policy The Journal of Chongqing University-English Edition(JCQU-E)is a peerreviewed journal publishing research articles in multiple disciplines of science and technology,covering civil and environmental engineering,chemical engineering,biotechnology,mechanical and electrical engineering,computer and data processing,mining,metallurgy,materials science,and interdisciplines thereof.