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。     

横泉水库大坝土料碾压试验

在取得土料场土料物理力学性质参数的情况下，遵循碾压试验基本原理、方法及参数组合，进行了现场碾压试验，通过试验成果的分析，得出了大坝碾压试验结论，为大坝土方填筑提供了技术依据。     

USB数据传输中CRC校验码的并行算法实现

文章介绍了用于USB总线数据传输的CRC校验的原理和算法，并且采用并行电路实现USB2．0中的CRC产生和CRC校验，与传统的串行电路实现相比，并行电路实现方法虽然在芯片面积上大于串行电路实现，但由于降低了时钟频率，电路更容易综合实现，并且大大降低了功耗，有利于低功耗电路设计。     

数据融合在经纬仪引导中的应用

介绍一种用于经纬仪引导数据的处理方法。该方法利用参数估计法对引导数据进行融合，弥补了常规方法的不足。对经纬仪引导数据进行处理，结果表明，该方法可显著提高经纬仪的引导精度，引导误差小于0．50m。     

基于进化算法的常减压装置模拟

提出了基于优选优生进化算法（Select—best and prepotency evolution algorithm，SPEA）的常减压装置模拟方法。以各塔的温度分布为目标，基于生产过程和分析数据，采用SPEA确定各塔板Murphree效率，从而精确描述各塔板平衡偏离程度。在实际应用中，获得具有良好精度的常减压装置模型。系统分析了SPEA算法的关键参数——优选领域大小与计算复杂性及寻优性能之间的关系，结果显示其取值为群体规模的10％最为合适。     

CO2吞吐工艺操作参数的整体优化设计

针对ZY油田原油CO2吞吐的工艺过程，建立了CO2吞吐数值模拟模型。应用数值模拟方法对CO2吞吐进行了实例分析，首先对该井的CO2吞吐参数进行了单因素敏感性分析，分析了CO2周期注入量、注入速度、焖井时间、采液速度等因素对CO2吞吐效果的影响。在此基础上进一步运用正交试验方法对CO2吞吐参数进行了优化，通过计算表明用正交试验优选法得到的优化方案比单因素敏感性分析所得的优化结果更为合理。     

水力射孔对套管强度的影响研究

水力射孔技术是一种新型的完井方式，深穿透水力射孔技术辅助定向水力压裂可以实现油气层改造和油气井增产。但是，水力射孔套管会在孔眼处造成应力集中，使得局部应力过大而削弱了套管和水泥环的强度，可能会影响套管的使用寿命。因此，文章利用有限元软件建立了射孔套管的三维有限元模型，分析了水力射孔后套管管体的应力分布，重点研究了水力射孔参数-孔密、孔径、孔深、射孔方位角等对套管强度的影响规律。分析结果表明，沿着最大水平地应力方向深穿透水力射孔，选择合适的孔密、孔径可将射孔对套管的损害降至最小。研究结果为提高水力射孔完井设计水平提供了一定的参数依据。     

一种高精度的非平稳随机信号实时建模算法研究

针对传统的非平稳随机信号时变参数筹分模型算法的不足,论文把非平稳随机信号时变参数差分模型与一种带自适应遗忘因子的RLS算法结合起来,形成一种有效的非平稳随机信号实时建模算法,仿真分析表明该算法不仅能获得快的收敛速度而且能获得高的建模精度。     

基于两层均匀媒质的GPEN SAR地下目标成像方法及其性能分析

地表穿透合成孔径雷达(Ground PENetration SAR,GPEN SAR)为了探测掩埋在地下的目标,通常工作在多层媒质的环境中。传统成像模型是建立在同一均匀媒质的假设上,不再适合于GPEN SAR的实际情况。本文首先建立了两层分区均匀媒质中的成像模型,然后利用后向投影(BP)算法定量分析了成像几何参数、土壤参数等对成像的影响,进而提出了一种修正的后向投影(MBP)算法。MBP算法不仅能够校正两层分区均匀媒质对成像定位的影响,还能估计目标的掩埋深度,提供目标三维位置坐标。仿真结果验证了MBP算法在不同信噪比环境下,对多目标的三维定位精度能满足实际的需要。     

Range Assignment for Biconnectivity and k-Edge Connectivity in Wireless Ad Hoc Networks

Depending on whether bidirectional links or unidirectional links are used for communications, the network topology under a given range assignment is either an undirected graph referred to as the bidirectional topology, or a directed graph referred to as the unidirectional topology. The Min-Power Bidirectional (resp., Unidirectional) k-Node Connectivity problem seeks a range assignment of minimum total power subject to the constraint that the produced bidirectional (resp. unidirectional) topology is k-vertex connected. Similarly, the Min-Power Bidirectional (resp., Unidirectional) k-Edge Connectivity problem seeks a range assignment of minimum total power subject to the constraint the produced bidirectional (resp., unidirectional) topology is k-edge connected. The Min-Power Bidirectional Biconnectivity problem and the Min-Power Bidirectional Edge-Biconnectivity problem have been studied by Lloyd et al. [23]. They show that range assignment based the approximation algorithm of Khuller and Raghavachari [18], which we refer to as Algorithm KR, has an approximation ratio of at most 2(2 – 2/n)(2 + 1/n) for Min-Power Bidirectional Biconnectivity, and range assignment based on the approximation algorithm of Khuller and Vishkin [19], which we refer to as Algorithm KV, has an approximation ratio of at most 8(1 – 1/n) for Min-Power Bidirectional Edge-Biconnectivity. In this paper, we first establish the NP-hardness of Min-Power Bidirectional (Edge-) Biconnectivity. Then we show that Algorithm KR has an approximation ratio of at most 4 for both Min-Power Bidirectional Biconnectivity and Min-Power Unidirectional Biconnectivity, and Algorithm KV has an approximation ratio of at most 2k for both Min-Power Bidirectional k-Edge Connectivity and Min-Power Unidirectional k-Edge Connectivity. We also propose a new simple constant-approximation algorithm for both Min-Power Bidirectional Biconnectivity and Min-Power Unidirectional Biconnectivity. This new algorithm applies only to Euclidean instances, but is best suited for distributed implementation. A preliminary version of this work appeared in the proceedings of the 2nd International Conference on AD-HOC Network and Wireless (Adhoc-Now 2003). Research performed in part while visiting the Max-Plank-Institut fur Informatik. Gruia Calinescu is an Assistant Professor of Computer Science at the Illinois Institute of Technology since 2000. He held postdoc or visiting researcher positions at DIMACS, University of Waterloo, and Max-Plank Institut fur Informatik. Gruia has a Diploma from University of Bucharest and a Ph.D. from Georgia Insitute of Technology. His research interests are in the area of algorithms. Peng-Jun Wan has joined the Computer Science Department at Illinois Institute of Technology in 1997 and has been an Associate Professor since 2004. He received his Ph.D. in Computer Science from University of Minnesota in 1997, M.S. in Operations Research and Control Theory from Chinese Academy of Science in 1993, and B.S. in Applied Mathematics from Tsinghua University in 1990. His research interests include optical networks and wireless networks.