摘要：Two novel schemes of unitary space-time constellations generation based on zero vectors adding are proposed for the multiple-antenna communication system. In the first scheme, T2 zero row vectors are added into conventional unitary matrices directly, and the number of new unitary matrices obtained by different positions of the added zero vectors in T symbol duration is [T / T2 ] times larger than that of conventional unitary matrices. In the second scheme, one part of the required constellations is created by the first scheme and the other part is obtained by the conventional design. This means that more information bits can be transmitted by the new constellations. According to their special construction, two corresponding decoding algorithms are proposed with low complexity in flat fading channel, respectively. At the same time, the probability of miss detection is deduced for the decoding algorithms. Performance analysis and simulation results show that the proposed constellations outperform the conventional constellations and the proposed decoding algorithms are efficient and simple.

摘要：分析国内外信号与系统课程实验教学现状,并以雷达工程、侦察情报和信息对抗等专业培养对象的就业出口为导向,设计构建涵盖“雷达信号与系统体验”“雷达信号处理与系统分析认知”和“雷达趣味实验设计及其数据采集、处理与分析实战”等三级阶梯式趣味实验体系,贯彻“以老带新、以熟带生”的原则,给出了该实验体系的组织与实施建议,面向不同类型专业出口的“信号与系统”课程实验体系设计都可以进行模仿、参考和借鉴。

摘要：针对单一神经网络的预测轨迹与实际轨迹偏差较大的问题,同时为使智能无人车在双车道左转和单车道U形弯转向时具有仿熟练驾驶人的操作特性,基于熟练驾驶人的转向习惯设计一种结合长短期记忆(Long Short-Term Memory,LSTM)及反向传播(Back Propagation,BP)神经网络的LSTM-BP转向轨迹预测模型。在PreScan中建立车辆模型与虚拟场景,基于熟练驾驶人的操作习惯,通过G29驾驶模拟器操纵车辆得到转向数据训练组合预测模型,设计基于线性二次型调节(Linear Quadratic Regulator,LQR)的路径跟踪控制器,并利用Simulink-PreScan-CarSim对双车道左转和U形弯行驶两种工况进行联合仿真试验,验证该轨迹预测模型和轨迹跟踪控制器的准确性。

摘要：In this paper an optimization method of the runner blades in a bulb turbine based on CFD analysis is *** the method the main scales of the turbine including guide vane,runner and draft are *** the runner blades are modified based on the present *** the optimization method the runner blade is expressed by spline surface with a gather of coordinate *** B-spline curve is used to keep the modified blades *** order to make the blade optimization simple and ef- ficient,one of the coordinates is fixed and only the angles of the points are changed according to different modification *** main optimization principles based on flow diagnosis are presented *** three principles are all based on the CFD analysis of the internal flow in bulb *** the purpose of method verification,the optimization method is used in a model bulb turbine.A three dimensional steady turbulent computation is carried out through the whole passage including the bulb body,guide vanes,runner and draft tube of the bulb turbine under seven different work *** SST k-ωturbulence model is used during the CFD analysis and the performance of the turbine can be *** runner blade is optimized according to the three optimization principles based on flow *** CFD analysis is conducted again on the optimized turbine and another modification is needed if the new turbine can’t satisfy the required *** of the computational results between the original turbine and an optimized one indicates that the optimization method is practical and does improve the performance of the bulb turbine.

摘要：针对隧道建设工程中初期支护设备臂架系统的优化设计问题进行了研究。目前该类设备的臂架系统存在着因受力不均而导致失效等一系列问题,亟待解决。以我国某公司自主研发的智能拱锚喷一体化台车的臂架系统为研究对象,通过参数化建模和灵敏度分析,对高灵敏度铰点坐标进行参数迭代优化,有效降低了俯仰油缸的最大受力。该研究成果对于提高隧道施工效率、降低工程成本以及改善施工安全性具有一定的参考价值。

摘要：常规矩形顶管机破岩能力不超过5 MPa,顶管机穿越胶结砾岩层时,存在顶进困难,姿态难以控制,孤石进入土仓后出土困难,大块孤石卡住螺旋机等风险。基于济南轨道交通经七路西站附属过街通道项目,考虑工程安全、经济成本、工期等因素,分析了过街通道顶管施工技术,优选出适合本工程的最佳掘进方法。通过预破碎和膨润土消石灰混合浆液填充等措施,将胶结砾岩打碎,降低强度。通过优化洞内密封系统、配制膨润土触变泥浆、设计管节止退结构等顶进关键技术,实现了土压平衡矩形顶管机在胶结砾岩层中顶进施工,为该环境下矩形顶管施工提供了借鉴和参考。

摘要：采用计算流体力学(CFD)的方法对双面和三面户外独立柱广告牌的风荷载进行了数值模拟研究,得到了广告牌主结构设计所需的最不利风压系数和偏心距,以及广告牌面板设计所需的局部风压系数,研究成果已应用于标准图的设计,也可供此类结构设计时参考。

摘要：水电站作为能源生产的重要设施,其稳定运行对于能源供应和区域经济发展至关重要。然而,水电站工程的渗漏问题不仅影响电站的运行效率,还可能对电站的结构安全构成威胁。因此,对水电站渗漏的有效探查和处理显得尤为关键。结合具体案例,分析不同探查技术在水电站渗漏探查中的实际应用效果,并对水电站渗漏探查的未来研究方向提出建议。

摘要：为了确保变电站设备缺陷识别效果,降低识别误差和能耗,提出基于多源数据融合的变电站设备缺陷识别方法。通过不同类型传感器采集各类信息,结合支持向量机,搜索最优最大间隔超平面特点,将数据融合结果作为支持向量机输入,借助支持向量机分类方式,完成多种类别的变电站设备缺陷识别。实验结果表明,所提方法的多源数据融合结果更接近实际结果,对数据融合结果进行缺陷识别未出现错误识别,且不同缺陷的识别误差均未超过2%,能够有效确保缺陷识别效果,降低识别能耗。

摘要：Paris＇ competitor China Fashion Week A/W 2010-2011 Collection lasting from March 24th to March 30th, witnessed approximately 50 events including fashion shows, professional contests, conference and forum in Beijing. During this one-week fashion feast, 2000 pieces of design by 25 brands, 20 designers, 101 designers-to-be and graduates from 5 colleges, were showed in 26 shows and 3 contests.