DFIT测试在长庆气田开发中的应用

与常规的小型测试压裂不同，流体注入诊断测试（DFIT）是通过关井阶段出现的拟线性流或拟径向流阶段求取储层压力，采用改进的梅耶霍夫方法（M-method）解释储层渗透率。以长庆榆林气田一口开发井为例，依据DFIT的技术原理和测试步骤，对该井测试压降数据进行解释分析，结果可信度较高，证明了该项工艺在长庆低压低渗油气田的可行性。     

油田污水中咪唑啉缓蚀剂浓度检测技术研究

研究评价了油田污水中咪唑啉缓蚀剂浓度检测的七种方法 ,其中紫外光分析法和显色反应法适合于低浓度咪唑啉缓蚀剂检测 ,且方法简便、速度快、成本低 ,检测浓度范围 2～ 5 0mg/L。     

电致伸缩陶瓷微位移器非线性的数值方法补偿

本文通过对电致伸缩陶瓷材料的非线性进行分析。找到了补偿电致伸缩陶瓷非线性的数值方法，并对不同回程大小的电滞回线进行了分段处理，使补偿结果更为精确。     

连续流动分析仪应用于水中硫化物的测定

对连续流动法测定硫化物进行初步探讨和研究。同时与其他几种测定硫化物的方法进行了比较。实验结果表明，连续流动法对硫化物分析在线性、稳定性、最低检测限、准确性和精密度等方面均优于其他方法。     

布尔函数的对偶性和线性点

本文主要讨论了部分自对偶和部分反自对偶函数、部分线性函数以及具有线性点的函数的性质。     

一种基于高阶统计信息的信噪比估计改进算法

针对多进制正交幅度调制(Multiple quadrature amplitude modulation,MQAM)信号在低信噪比条件下估计精度不高的问题,提出了一种基于综合利用高阶统计信息的信噪比估计改进算法。根据所选高阶统计量最高阶数的不同,建立了3种信噪比与多种高阶统计量运算式之间的线性关系,利用全回归线性分析方法将3种线性关系转化为3种全回归模型,并求解模型系数。该算法充分利用了多种高阶统计量的有用信息,提高了信噪比估计精度。MQAM的仿真结果表明:在低信噪比条件下,该算法减小了信噪比估计误差,其估计性能明显优于传统的其他算法,且3种模型估计性能依次增加,可依据不同的信噪比要求对3种模型进行选取。     

FREQUENCY DOMAIN TESTS OF MULTIVARIATE GAUSSIANITY AND LINEARITY

A stationary multivariate time series { X _t } is defined as linear if it can be written in the form X _t = ∑^∞ _{j =−∞} A _j e _{t − j} where A _j are square matrices and e _t are independent and identically distributed random vectors. If the e _t } are normally distributed, then { X _t is a multivariate Gaussian linear process. This paper is concerned with the testing of departures of a vector stationary process from multivariate Gaussianity and linearity using the bispectral approach. First the definition and properties of cumulants of random matrices are used to obtain the expressions for the higher-order cumulant and spectral vectors of a linear vector process as defined above. Then it is shown that linearity of a vector process implies constancy of the modulus square of its normalized higher-order spectra whereas the component of such a vector process does not necessarily have a linear representation. Finally, statistics for the testing of multivariate Gaussianity and linearity are proposed.     

Logistic模型的参数估计及人口预测

用数值微分和线性拟合化技术对Logistics模型进行了参数估计,由此检验了2005~2007年中国总人口数的误差情况,其中2007年用相关参考文献的等差参数估算方法所得结果的相对误差为5.58%,而本文参数估算所得结果的相对误差为0.114‰,预测取得了理想的效果.     

基于线性多尺度模型的计算机网络数据流量预测

为了解决网络安全监控问题,提出了一种用于预测网络流量的算法.通过多个不同尺度的线性模型进行网络数据的组合预测,每个尺度的线性模型由经过滤波器滤波后的部分原始数据估计得到,最终的预测流量数据由多个尺度线性模型的平均预测值得到.选择的线性模型为自回归滑动平均模型,且尺度较小的线性模型对应自回归滑动平均模型的阶数较高.结果表明,本算法的预测精度高,整体预测误差的均值在10-3量级.     

LED PWM dimming linearity investigation

LED PWM dimming application for large scale LED video displays is analyzed. The need for short light pulse duration is outlined. PWM dimming with short driving pulses is investigated experimentally. The LED response time skew introduces the nonlinearity for PWM dimming. For LED response time skew estimation, a method is suggested that has been successfully applied to measure some of today’s market representative LEDs. PWM dimming nonlinearity can be forecasted using the estimated skew. For a particular driving configuration, it is indicated that LED PWM dimming fails to satisfy the required 14 bit output coding together with the image refresh frequency of 400 Hz. A rough investigation demonstrates that the skew is quite stable. Therefore, the nonlinearity correction for the PWM pulse durations shorter than the skew value should be possible.