基于行人运动模态辨识的室内外无缝导航航向算法研究

目前行人导航航向解算算法均基于导航传感器在行人身体上的固定安装模式,或者依赖其他射频信息辅助修正陀螺航向,这极大约束了导航传感器的适用条件.为此,利用陀螺对低频噪声的敏感性及加速度计低频的稳定性,提出了解决行人手持手机稳态查看与非稳态摇摆的运动模态辨识算法和基于时域互补滤波器实现姿态的最优融合方法;研究了改进型互补滤波以消除行人的运动加速度对姿态解算的干扰误差,提高了载体姿态的测量精度;此外,利用磁传感器标定后的数据设计了自适应卡尔曼滤波算法,抑制了航向角的误差发散.经实际数据测试验证,室内外行人手持稳态与非稳态下的航向角测量精度提高了80%,同时大大提高了导航传感器的适用性与便携性,满足实际工程的使用需求.     

多通道Wiener 滤波器设计新方法

应用现代时间序列分析方法,提出了多通道Ｗｉｅｎｅｒ滤波器设计的一种新的时域方法,它可统一处理滤波、平滑和预报问题,且可处理非平稳信号和噪声,仿真例子说明了该方法的有效性。     

广义系统ARMA最优递推状态估值器

应用现代时间序列分析方法,基于ARMA新息模型和白噪声估值器,由非递推状 态估值器的递推变形,提出了广义系统的ARMA稳态最优递推状态估值器.它们具有 Wiener滤波器形式,可处理带奇异状态转移阵和/或带相关噪声的广义系统,可统一处理滤 波、平滑和预报问题,且可统一处理广义和非广义系统状态估计问题.仿真例子说明了其有效 性.     

不同方式获得的速度对悬浮系统的影响分析

在悬浮控制系统设计中,通常用到悬浮间隙的变化速度,如何获取这一信号是一个非常重要的问题。以单电磁铁为对象,根据悬浮系统的模型,提出了一种通过互补滤波器获得速度的方法;详细分析了不同的速度获取方式在考虑轨道随机扰动和列车运行于竖曲线段以及考虑轨道弹性等几种情况下对系统的影响。仿真结果表明,该方法能很好地实现常规方法的性能折衷,为克服轨道扰动和解决车轨共振问题提供了新的思路。     

Analysis and design of output feedback control systems with actuator saturation

A dynamic output feedback controller design approach based on cone complementary linearisation procedure is proposed for linear time-invariant （LTI） systems with actuator saturation. First, the estimation of the domain of attraction is given. Then, a design method to find a larger estimation of the domain of attraction is presented. In the process of design, nonconvex conditions are obtained, so a cone complementary linearisation procedure is exploited to solve the nonconvex feasibility problem. Two examples are given to illustrate the efficiency of the design method.     

Modeling and Managing Interactions among Business Processes

Most workflow management systems (WfMSs) only support the separate andindependent execution of business processes. However, processes often needto interact with each other, in order to synchronize the execution of theiractivities, to exchange process data, to request execution of services, orto notify progresses in process execution. Recent market trends also raisethe need for cooperation and interaction between processes executed in differentorganizations, posing additional challenges. In fact, in order to reduce costsand provide better services, companies are pushed to increase cooperation and toform virtual enterprises, where business processes span across organizationalboundaries and are composed of cooperating workflows executed in differentorganizations. Workflow interaction in a cross-organizational environment iscomplicated by the heterogeneity of workflow management platforms on top ofwhich workflows are defined and executed and by the different and possiblycompeting business policies and business goals that drive process executionin each organization.In this paper we propose a model and system that enable interactionbetween workflows executed in the same or in different organizations. Weextend traditional workflow models by allowing workflows to publish andsubscribe to events, and by enabling the definition of points in the processexecution where events should be sent or received. Event notifications aremanaged by a suitable event service that is capable of filtering andcorrelating events, and of dispatching them to the appropriate targetworkflow instances. The extended model can be easily mapped onto anyworkflow model, since event specific constructs can be specified by means ofordinary workflow activities, for which we provide the implementation. Inaddition, the event service is easily portable to different platforms, anddoes not require integration with the WfMS that supports the cooperatingworkflows. Therefore, the proposed approach is applicable in virtually anyenvironment and is independent on the specific platform adopted     

Algorithmic and architectural design for real-time and power-efficient Retinex image/video processing

This paper presents novel algorithmic and architectural solutions for real-time and power-efficient enhancement of images and video sequences. A programmable class of Retinex-like filters, based on the separation of the illumination and reflectance components, is proposed. The dynamic range of the input image is controlled by applying a suitable non-linear function to the illumination, while the details are enhanced by processing the reflectance. An innovative spatially recursive rational filter is used to estimate the illumination. Moreover, to improve the visual quality results of two-branch Retinex operators when applied to videos, a novel three-branch technique is proposed which exploits both spatial and temporal filtering. Real-time implementation is obtained by designing an Application Specific Instruction-set Processor (ASIP). Optimizations are addressed at algorithmic and architectural levels. The former involves arithmetic accuracy definition and linearization of non-linear operators; the latter includes customized instruction set, dedicated memory structure, adapted pipeline, bypasses, custom address generator, and special looping structures. The ASIP is synthesized in standard-cells CMOS technology and its performances are compared to known Digital signal processor (DSP) implementations of real-time Retinex filters. As a result of the comparison, the proposed algorithmic/architectural design outperforms state-of-art Retinex-like operators achieving the best trade-off between power consumption, flexibility, and visual quality.

化妆品防晒剂的研究进展及其安全性问题(续前)

一类重要的且光稳定的UVA紫外线吸收剂是苯三唑邻位羟基取代的化合物。这类紫外线吸收剂主要吸收长波段的紫外线UVA,但其吸收效率或称摩尔消光系数要比二苯甲酰甲烷类化合物如Avobenzone低。由于这类苯三唑化合物中形成的氮-氢(N-H)     

FIR滤波在嵌入式系统中的实现与优化

介绍FIR滤波器的基本原理以及满足线性相位的条件,阐述了FIR滤波器的生成.从MATLAB得到的滤波器实现了在嵌入式中的移植,并进行了计算优化.通过对含有噪声的数据处理结果表明,该方法在工程实践中能满足要求.     

Multiple human tracking in high-density crowds

In this paper, we introduce a fully automatic algorithm to detect and track multiple humans in high-density crowds in the presence of extreme occlusion. Typical approaches such as background modeling and body part-based pedestrian detection fail when most of the scene is in motion and most body parts of most of the pedestrians are occluded. To overcome this problem, we integrate human detection and tracking into a single framework and introduce a confirmation-by-classification method for tracking that associates detections with tracks, tracks humans through occlusions, and eliminates false positive tracks. We use a Viola and Jones AdaBoost detection cascade, a particle filter for tracking, and color histograms for appearance modeling. To further reduce false detections due to dense features and shadows, we introduce a method for estimation and utilization of a 3D head plane that reduces false positives while preserving high detection rates. The algorithm learns the head plane from observations of human heads incrementally, without any a priori extrinsic camera calibration information, and only begins to utilize the head plane once confidence in the parameter estimates is sufficiently high. In an experimental evaluation, we show that confirmation-by-classification and head plane estimation together enable the construction of an excellent pedestrian tracker for dense crowds.