Human activity recognition based on HMM by improved PSO and event probability sequence

This paper proposes a hybrid approach for recognizing human activities from trajectories.First,an improved hidden Markov model(HMM) parameter learning algorithm,HMM-PSO,is proposed,which achieves a better balance between the global and local exploitation by the nonlinear update strategy and repulsion operation.Then,the event probability sequence(EPS) which consists of a series of events is computed to describe the unique characteristic of human activities.The analysis on EPS indicates that it is robust to the changes in viewing direction and contributes to improving the recognition rate.Finally,the effectiveness of the proposed approach is evaluated by data experiments on current popular datasets.     

布朗桥无线信道建模的时延概率密度函数估计方法

介绍了布朗桥的基本概念及其在无线信道建模中的应用，给出随机桥建模后信道时延分布的概率密度的估计方法，用Matlab进行了仿真，并给出了信道仿真结果及其物理解释。     

Phase synchronization processing method for alternating bistatic mode in distributed SAR

In the distributed synthetic aperture radar(SAR),the alternating bistatic mode can perform phase reference without a synchronization link between two satellites compared with the pulsed alternate synchronization method.The key of the phase synchronization processing is to extract the oscillator phase differences from the bistatic echoes.A signal model of phase synchronization in the alternating bistatic mode is presented.The phase synchronization processing method is then studied.To reduce the phase errors introduced by SAR imaging,a sub-aperture processing method is proposed.To generalize the sub-aperture processing method,an echo-domain processing method using correlation of bistatic echoes is proposed.Finally,the residual phase errors of the both proposed processing methods are analyzed.Simulation experiments validate the proposed phase synchronization processing method and its phase error analysis results.     

Continuous on-line adaptation of the rotor time constant in FOC induction machine system

Rotor time constant is an important parameter for the indirect lleld oraentateO control of mauc- tion motor. Incorrect rotor tittle constant value will cause the flux observer generating a wrong angu- lar orientation of the rotor field. A new approach serves for rotor time constant on-line adaptation by setting the stator current to be zero for a short period. A smooth eorrector is designed to prevent ab- normal detection result from making adaptation. Impact of zero current duration on detection error and rotor speed is analyzed by experiments.     

Direction and polarization estimation for coherent sources using vector sensors

A two-dimensional direction-of-arrival (DOA) and polarization estimation algorithm for coherent sources using a linear vector-sensor array is presented. Two matrices are first constructed by the receiving data. The ranks of the two matrices are only related to the DOAs of the sources and independent of their coherency. Then the source’s elevation is resolved via the matrix pencil (MP) method, and the singular value decomposition (SVD) is used to reduce the noise effect. Finally, the source’s steering vector is estimated, and the analytics solutions of the source’s azimuth and polarization parameter can be directly computed by using a vector cross-product estimator. Moreover, the proposed algorithm can achieve the unambiguous direction estimates, even if the space between adjacent sensors is larger than a half-wavelength. Theoretical and numerical simulations show the effectiveness of the proposed algorithm.     

环保型涂装前处理技术开发方向

随着国家对环保的重视程度日益加深,污染防治已成为几乎所有行业,尤其是工业领域急需解决的课题。而作为前瞻技术,环保型涂装前处理技术的开发将对涂装行业甚至汽车工业产生深远的意义,尤其是纳米陶瓷锆盐处理和硅烷处理技术的成功应用必将成为涂装前处理技术上的飞跃。     

系统化思维下高校体育教学改革的探索

当前高校体育教学已不适应"健康第一"的指导思想,针对目前教学中存在的问题,从思想意识、教学内容、教学模式,考核评价四个方面对教学改革提出的建议,以便培养出有终身体育意识、适应社会需要的人才。     

基于企业服务总线的物流园区信息管理平台模型构建

采用一种与平台/编程无关的消息传递架构企业服务总线(ESB)构建物流园区信息系统平台架构,从而使物流园区能快速搭建敏捷的、按需应变的商业动态信息环境,使企业在市场上占据领先的竞争优势。     

Acquiring synonymous attribute phrases for named entities via online encyclopedia

In this work,an approach is proposed to acquire synonymous attribute phrases of named entities （NEs） from an online encyclopedia.Synonymous attribute phrases are the phrases that express the same attribute with different surface forms for a class of NEs.Specifically,the proposed approach is composed of three stages.Firstly,the entries related to a given NE class are automatically selected from an online encyclopedia.Secondly,attribute phrases are extracted based on the statistics of phrase frequency.Thirdly,synonymous attributes are identified in a pairwise manner through a classification framework combining multiple features.The proposed approach is applied on Baidu Baike,a Chinese online encyclopedia,for four different NE classes.Experimental results show that the approach obtains an average precision of 74％ and an average F-value of 65％ for the four NE classes.In particular,thousands of synonymous attribute phrase pairs are acquired for each class,which demonstrates the effectiveness of the proposed approach.     

冀南太行山区野生保健饮料食品植物资源的研究

在冀南太行山区的植物资源中筛选出野生保健饮料食品植物１９种。较详细报道了其中９种重要资源植物的形态特点、利用价值及保健功能，其余种类作了列表介绍。文末对野生保健饮料食品植物资源的利用问题进行了讨论。