Mean shift registration algorithm for dissimilar sensors

The mean shift registration (MSR) algorithm is proposed to accurately estimate the biases for multiple dissimilar sensors. The new algorithm is a batch optimization procedure. The maximum likelihood estimator is used to estimate the target states, and then the mean shift algorithm is implemented to estimate the sensor biases. Monte Carlo simulations show that the MSR algorithm has significant improvement in performance with reducing the standard deviation and mean of sensor biased estimation error compared with the maximum likelihood registration algorithm. The quantitative analysis and the qualitative analysis show that the MSR algorithm has less computation than the maximum likelihood registration method.     

Big data framework for quantitative trading system

Massive trading data are produced in securities market every day. Besides, the amount of relevant social media data is also growing fast. It is a vital problem of making use of these data. Facing on the growing amount of data, using big data framework is a necessary and reasonable method. Then, a big data framework for quantitative trading system is proposed in this paper. In the framework, Apache Spark is chosen as the distributed computing framework to process trading data, and Apache HBase as the distributed database is used to store data. After introducing the whole framework, we discussed data sources and the structure of quantitative trading layer in detail.     

Research on visual autonomous navigation indoor for unmanned aerial vehicle

The aim of this paper is to study visual autonomous navigation of unmanned aerial vehicle (UAV) in indoor global positioning system (GPS) denied environment. The UAV platform of the autonomous navigation flight control system is designed and built. The principle of visual localization and mapping algorithm is studied. According to the characteristics of UAV platform, the visual localization is designed and improved. Experimental results demonstrate that the UAV platform can realize the tasks of autonomous localization, navigation and mapping based on visual in unknown environments.     

环模自动钻床钻削进给算法

环模是饲料加工机械的核心部件,钻孔是环模加工的重要工序．根据环模加工实际经验和生产需求,为提高环模加工效率和质量,研究环模模孔加工中麻花钻头受力理论模型,给出新的环模自动钻床钻削进给算法,并根据实践结果对算法进行了优化．经实际生产检验,该算法能够有效降低钻头磨损速度,减少工人更换和打磨钻头的时间,为企业创造了经济效益．     

三峡枢纽碍航经济损失评估方法研究

充分利用机会成本原理,以货物时间价值损失、货物经时损失以及船舶额外营运成本为评价指标,构建船货匹配的经济损失评估模型,为高效航道运输系统建设和区域社会发展评估提供参考。其中,货物时间价值损失测算模型运用科布道格拉斯生产函数思想,考虑长江水文特征、船舶待闸时长及船闸通行能力等因素,构建包含待闸时间敏感系数和船闸饱和度的货物时间价值损失测算公式;货物经时损失测算模型考虑货物品质和货物占用资金的使用效率,利用微分方程,构建分段损失率的货物经时损失测算公式。估算结果显示,当前三峡枢纽碍航造成的经济损失达76亿元,其中集装箱及船舶受损最严重。因此,三峡枢纽管理部门可结合经济损失优化船舶调度计划。     

基于几何尺寸的车辆自主导航路径规划算法

路径规划是车辆自主导航的一项关键技术，它的品质关系到整个自主导航系统的性能。为此，本文提出了一个在目标和障碍物都是动态的情况下快速产生行驶轨线的局部路径规划算法。该算法利用对象的几何尺寸建立环境模型，从而可以利用算术表达式快速计算出从起始点避开障碍物顺利到达目标点的行驶路线。此方法考虑了移动对象邻近周围障碍物的分布信息，提高了局部路径规划的可靠性。通过在程序上实验，表明该方法能够获得较为满意的效果。该方法的特点是计算速度快、实时性强。另外，本文提出对象轮廓的特征提取将对整个行驶过程中的航向调整有着直接的影响，这一点也将是本文未来算法的一个改进点。     

Algorithm based on morphological component analysis and scale-invariant feature transform for image registration

In this paper, we proposed a registration method by combining the morphological component analysis (MCA) and scale-invariant feature transform (SIFT) algorithm. This method uses the perception dictionaries, and combines the Basis-Pursuit algorithm and the Total-Variation regularization scheme to extract the cartoon part containing basic geometrical information from the original image, and is stable and unsusceptible to noise interference. Then a smaller number of the distinctive key points will be obtained by using the SIFT algorithm based on the cartoon part of the original image. Matching the key points by the constrained Euclidean distance, we will obtain a more correct and robust matching result. The experimental results show that the geometrical transform parameters inferred by the matched key points based on MCA+SIFT registration method are more exact than the ones based on the direct SIFT algorithm.     

汽车电控自动变速器的结构原理与检修

随着电子技术及微处理机的发展,电控自动变速器正实现一机多参数多规律控制,并在此基础上将变速器微机和发动机微机合并在一起,实现综合控制。电控自动变速器变速冲击小,采用最佳的经济性和动力性换档,大大地改善了整车性能。介绍了电控自动变速器的控制原理、基本组成及其部件的工作原理以及性能检测方法和故障诊断方法。     

A universal composability framework for analysis of proxy threshold signature

The universal composability framework is a new approach for designing and analyzing the security of cryptographic protocols. In this framework, the security of protocols is maintained under a general protocol composition operation. In the paper, we propose the universal composability framework for the analysis of proxy threshold signature and present a universally composable secure proxy threshold signature scheme which is the first one in this area. The proposed scheme is suitable for the mobile agents, which should migrate across different environment through network. Furthermore, we give the concrete analysis of the reduction to prove the security of the proposed scheme.     

Application of neural network to downhill shift strategy for automatic transmission

A method is proposed to estimate the longitudinal road gradient with a concept “general gradient force (GGF)”, in which uncertain factors such as additional vertical load, road surface change, and strong wind are also taken into account. An adaptive downhill shift control system is then developed to help driver to use the engine brake with lower gears while downhill driving. In the adaptive system, a three-layer neural network is built to evaluate the necessity to make use of engine brake capability in current downhill situation, and the neural network is trained with samples from experienced drivers. Field test results of the adaptive system are introduced to verify the effectiveness of the approach mentioned above.     

机车增压器全自动保压滤清系统的开发与研究

文章就内燃机车增压器存在的故障高的原因进行分析,针对增压器轴承结构提出了研究增压器全自动保压滤清系统的课题,系统能够为增压器轴承提供稳定的机油压力,同时增加过滤精度,保证轴承润滑良好,进而减少增压器故障的发生,提高机车运用效率。     

岷江长滩河段航道整治试验研究

根据岷江长滩滩险碍航的特点,采用卵石动床模型进行整治方案研究,取得了良好的效果.本文简要介绍了长滩河工模型的模型设计、验证及方案试验情况.该工程现已竣工,经过几个水文年的检验,滩险航道的通航条件得到彻底改善,整治效果好,已通过工程验收,该工程被评为优良工程.     

羚羊世纪星轿车电控自动变速器性能测试

介绍了羚羊世纪星轿车电控自动变速器性能测试内容．包括转速测试、管路压力测试、道路试验、手动换档道路试验和发动机制动测试。     

A Distributed and adaptive framework for provisioning QoS in IPv6 networks

A distributed and adaptive framework （DAF） was proposed for provisioning quality of service （QoS） in IPv6 network. In DAF, per-flow admission control and resource reservation, in conjunction with a new IPv6 flow label mechanism, can be performed instantaneously in a fully distributed and independent fashion at the edge of network without hop-by-hop signaling. The flow label helps in resource reservation and packets forwarding for aggregated traffic on an edge-to-edge path basis. In addition, a bounded directional probing technique for DAF was designed to reconfigure resource reservation adaptively between every pair of edge router for aggregated traffic according to the fluctuation of its traffic load. The simulation results show that DAF provides QoS guarantees to individual flows with minimal overhead, as well as keeping the scalability characteristic like DiffServ.     

Wind pressure distribution and wind-induced dynamic response for spatial groined latticed vaults

The wind pressure distribution and wind-induced vibration responses of long-span spatial groined latticed vaults (SGLVs) were numerically simulated, which always are ones of the most important problems in the structural wind resistance design. Incompressible visco-fluid model was introduced, and the standard k-εtwo equation model and semi-implicit method for pressure linked equation (SIMPLE) were used to describe the flow turbulence. Furthermore, the structural dynamic equation was set up, which is solved by Newmark-β method. And several sort of wind-induced vibration coefficients such as the wind-induced vibration coefficient corresponding to the nodal displacement responses and wind loads were suggested. In the numerical simulation where the SGLV consisting of the cylindrical sectors with different curved surface was chosen as the example,the influence on the relative wind pressure distribution and structural wind-induced vibration responses of the closed or open SGLV caused by such parameters as the number of cylindrical sectors, structural curvature and the ratio of rise to span was investigated. Finally, some useful conclusions on the local wind pressure distribution on the structural surface and the wind-induced vibration coefficients of SGLV were developed.     

Capacity and QoS based codebook construction for MIMO precoded spatial multiplexing systems with limited feedback

This paper deals with the design and performance analysis of transmit precoder optimization for multiple input multiple output (MIMO) systems with limited feedback of channel state information. A capacity criterion based optimal codebook construction algorithm for MIMO precoded spatial multiplexing systems is pre-sented. The optimal precoder structure combining precoding and power allocation is employed. Simulation results show that the capacity criteria based codebook can achieve higher capacity than that of equally power allocation based codebook of previous research.     

Novel mesh technique and its application in the wind field simulation for flexible spatial structure

In this paper, novel mesh techniques are proposed for wind field simulation of flexible spatial structure. For mesh generation, an interpolation strategy is presented to obtain a mesh system with variable density. Two spatial structure examples are used to examine the efficiency and applicability of this technique. Then based on the structured mesh system generated by the technique, the mesh nodal coordinates are updated to adapt the moving boundary conditions by means of the mapping interpolation functions and some examples are given to verify the effectiveness. Furthermore, the constrained counterforce distribution technique and projection interpolation strategy are developed to implement the data exchange on the interaction surface of wind and structure. Finally, the computational accuracy is numerically validated.