Adaptive detection of range-spread targets without secondary data in multichannel autoregressive process

Adaptive detection of range-spread targets without secondary data is addressed in a multichannel autoregressive Gaussian disturbance with unknown space–time covariance matrix, by utilizing the Rao test. The proposed Rao test without secondary data is theoretically proved to be asymptotically (large-sample in the number of temporal observations) constant false alarm rate with respect to unknown space–time covariance matrix, thanks to an asymptotic equivalence between the Rao test and the generalized likelihood ratio test. Moreover, the performance loss due to no secondary data can be remedied by appropriately increasing the temporal dimension. The performance assessment conducted by Monte Carlo simulation, also in comparison with the existing detector without secondary data, confirms the effectiveness of the proposed detectors.     

插值重建的分数阶傅里叶域分析

建立在傅里叶变换基础上的传统插值重建理论已不适用于基于分数阶傅里叶变换的SAR算法,文中对插值重建理论在分数阶傅里叶域作了进一步的分析和仿真.首先依据分数阶卷积的概念从分数阶傅里叶域的角度分析了采样信号的重建方程.其次从工程应用出发,进行了有限数目卷积核的插值重建误差分析.最后,给出了卷积核的截断归一化公式.可以发现利用分数阶卷积的插值核数目大于16即可,且需要保证移动后的样本位置不远离原卷积核的样本位置.     

对精炼车间溶剂回收的探讨

油脂精炼是将浸出毛油内部杂质去掉,以达到食用级标准,其中一项杂质就是溶剂,即将浸出毛油内部残留的溶剂由500ppm降到50ppm浓度以下。     

砂砾岩稠油油藏蒸汽驱数值模拟研究

对砂砾岩稠油油藏进行注蒸汽热力采油，在吞吐阶段历史拟合、汽驱阶段跟踪拟合的基础上，进行方案优选。确定该类型油藏吞吐７～８周期为最佳转驱时机；汽驱阶段最佳注汽速度为６～８ｔ／ｈ；汽驱阶段边角井蒸汽引效能实现较好的开发效果；采用略大于１．０的采注比，按最优方案生产，汽驱阶段采出程度为１７％～１８％。     

胜利油区典型气藏开发参数的数值模拟研究

该文选择了三个不同开发阶段，不同构造类型的典型气藏，核实了气藏储量及边底水强弱程度；研究了气田潜剩余储量分布；分布了井网，开采速度对采收率的影响，预测了气藏动态，并优化了开发方案，为三个典型气藏进一步开采及同类型气藏的开发提供了理论依据和研究方法。     

An improved kernel-based incremental extreme learning machine with fixed budget for nonstationary time series prediction

In order to curb the model expansion of the kernel learning methods and adapt the nonlinear dynamics in the process of the nonstationary time series online prediction, a new online sequential learning algorithm with sparse update and adaptive regularization scheme is proposed based on kernel-based incremental extreme learning machine (KB-IELM). For online sparsification, a new method is presented to select sparse dictionary based on the instantaneous information measure. This method utilizes a pruning strategy, which can prune the least “significant” centers, and preserves the important ones by online minimizing the redundancy of dictionary. For adaptive regularization scheme, a new objective function is constructed based on basic ELM model. New model has different structural risks in different nonlinear regions. At each training step, new added sample could be assigned optimal regularization factor by optimization procedure. Performance comparisons of the proposed method with other existing online sequential learning methods are presented using artificial and real-word nonstationary time series data. The results indicate that the proposed method can achieve higher prediction accuracy, better generalization performance and stability.

     

基于粒子群算法的多机无源定位系统优化布站

在一定海空战场背景下,通过调整多机无源定位系统中各机位置布局可以有效地提高该系统对特定区域目标的定位精度。文中通过推导多机时差定位算法误差的GDOP公式,提出了利用粒子群算法寻找多机无源定位系统最优布站的方法。与传统典型布站相比较显著降低了对区域目标定位误差,明显提升了多机无源定位动态快速布站能力。同时利用粒子群算法对定位站数不同情况下进行仿真,得出了对应的最优布站形式。     

孤岛油田渤21断块水体能量评价方法的研究与实践

油藏水侵计算公式已被普遍地认识。然而，在边底在水油藏水体能量大小估算中存在的许多实践问题限制了它的应用。本文基于胜利油区孤岛油田渤２１断块２０ａ注水开发历史，对区水体能量进行了评价，并在此基础上建立起一套完善的边底水能量评价的程序与方法。同时，对实践中的具体问题进行讨论。     

底水潜山油藏出水规律研究

建立了井组模型,研究了布井方式和井距对底水潜山油藏开发过程中油井产水的影响;分析了不同注水方式、采液强度、注水和调堵时间情况下油藏开发动态和出水规律;综合分析了单井和井组模型的生产特征,导出裂缝型潜山油藏含水率上升曲线的函数表达式,在统计的基础上,利用多元回归分别给出了单井和井组含水率上升曲线系数与影响因素的关系式,该式包括了地质及工艺参数,并将裂缝和基质的参数分开,计算结果将更为准确可靠,同时为双重介质油藏含水率预测及控水措施的选择实施提供了分析依据     

油藏动态数值仿真系统设计

油藏动态数值仿真系统是将油藏静动态参数处理、油藏井筒一体化数值模拟、油藏静动态图像分析、汉字系统、文本编辑及图形工具等几部分有机地组合起来，能方便迅速地处理生成油藏模拟要求的各种数据，进行油气田开发动态过程的模拟并对各种参数汤进行实时动态图像分析的综合系统。它是现代油藏数值模拟技术适应计算机高速发展的必然结果，本文运用面向对象的程序设计技术和计算机图像技术，介绍了设计常规油藏的动态数值仿真系统的方法，并探讨这一系统的发展前景。