A textile- based optical fiber sensor design for automotive seat occupancy sensing

In our previous publications, the response of perfluorinated (PF) graded index (GI) POFs (62.5/750, 62.5/490 μm) to bending, tensile loading, and cyclic loading was investigated. The results showed that Cytop-1 (62.5/750 μm) was more appropriate to be used as an optical fiber sensor for automotive seat occupancy sensing relative to Cytop-2 (62.5/490 μm). In this study, a textile-based optical fiber sensor was designed and the effect of automotive seat covering including face material and foam backing on a sensor’s performance was analyzed. The pressure interval under which the proposed POF sensor design could perform well was found to be between 0.18 and 0.21 N/cm², where PF GI POF (62.5/750 μm) was used as the POF material. The responses of the sensor in this interval were observed to be accurate and reproducible. The face fabric structure and the thickness of foam backing were not found to be significant factors to change the sensor response. Artificial neural network (ANN) was used for data analysis, and Qwiknet (version 2.23) software was used to develop ANNs. According to the results of Qwiknet, the prediction performances for training and testing data-sets were 75 and 83.33%, respectively.     

基于完整可见性模型的改进鲁棒OctoMap

从移动机器人自主导航对3D地图精度的需求出发,在鲁棒OctoMap的基础上提出一种基于完整可见性模型的改进鲁棒OctoMap并应用于基于Kinect的RGB-D同时定位与地图创建（SLAM）中。首先,通过考虑相机和目标体素的相对位置关系及地图分辨率进行可连通性判断,获得满足可连通性的相邻体素的个数及位置;其次,根据不同的可连通性情况分别建立目标体素的可见性模型,从而构建普适性更强的完整可见性模型,有效克服了鲁棒OctoMap可见性模型的局限性,提高了建图精度;再次,使用基于高斯混合模型的Kinect深度误差模型代替简单深度误差模型,进一步克服传感器测量误差对地图精度的影响,降低了地图的不确定性;最后,结合贝叶斯公式和线性插值算法来更新八叉树中每个节点的实际占用概率,从而构建基于八叉树的立体占用地图。实验结果表明,所提方法有效克服了Kinect传感器深度误差对地图精度的影响,降低了地图的不确定性,其建图精度较鲁棒OctoMap有明显的提高。     

Image contrast enhancement using histogram equalization with maximum intensity coverage

The histogram equalization process is a simple yet efficient image contrast enhancement technique that generally produces satisfactory results. However, due to its design limitations, output images often experience a loss of fine details or contain unwanted viewing artefacts. One reason for such imperfection is a failure of some techniques to fully utilize the allowable intensity range in conveying the information captured from a scene. The proposed colour image enhancement technique introduced in this work aims at maximizing the information content within an image, whilst minimizing the presence of viewing artefacts and loss of details. This is achieved by weighting the input image and the interim equalized image recursively until the allowed intensity range is maximally covered. The proper weighting factor is optimally determined using the efficient golden section search algorithm. Experiments had been conducted on a large number of images captured under natural indoor and outdoor environment. Results showed that the proposed method is able to recover the largest amount of information as compared to other current approaches. The developed method also provides satisfactory performances in terms of image contrast, and sharpness.     

基于校园空间环境重塑的使用后评价研究

满足空间环境使用者的需要是设计研究的目的.使用后评价是校园空间环境重塑的依据.基于使用后评价理论,以校园空间环境的使用者为主体,通过问卷调查的方式收集了400名学生对老校区空间环境的评价.运用实地调研和多元统计分析的方法,将质化与量化研究相结合,建立校园空间环境评价分析模型,获得该校区空间环境重塑的首要解决因子,为老校区空间环境的重塑及投资建设提供依据.     

基于POE的寒地大学校园交往空间改造研究——以东北农业大学为例

使用状况评价（POE）是系统描述和评价建成环境的实证性研究方法,它针对空间的使用效率,为校园交往空间规划提供科学依据。通过POE研究,对寒冷地区大学校园交往空间使用情况分析评价,以便有效地提高交往空间冬季使用效率。该文以东北农业大学校园交往空间为例,针对冬季空间功能、使用情况、利用频率等方面做系统PoE分析,提出针对性的改建对策。     

腔QED中混态双原子系统的原子布居数演化

运用全量子理论和数值计算方法,研究了双J-C模型中处于混态的双原子系统粒子布居差的时间演化规律,讨论了原子初态及腔内光场对粒子布居差演化的影响。计算结果表明：当两腔内的平均光子数相同时,布居差的演化只与两原子的初态纯度和光场强度有关,与两原子的初始纠缠无关;而当两光腔内的平均光子数不同时,粒子布居差演化不仅与两原子初态纯度和腔内光场有关,而且还强烈地依赖于两原子的初始纠缠。     

On the Quaternary System Ti-Fe-Ni-Al

The homogeneity ranges of the Laves phases and phase relations concerning the Laves phases in the quaternary system Ti-Fe-Ni-Al at 900 °C were defined by x-ray powder diffraction (XPD) data and electron probe microanalysis (EPMA). Although at higher temperatures the Laves phase forms a continuous solid solution, two separate homogeneity fields of TiFe₂-based (denoted by λ_Fe) and Ti(TiNiAl)₂-based (denoted by λ_Ni) Laves phases appear at 900 °C. The relative locations of Laves phases, G phase, Heusler phase, and CsCl-type phase as well as the associated tie-tetrahedra were experimentally established in the quaternary for 900 °C and presented in three-dimensional (3D) view. Furthermore, a partial isothermal section TiFe₂-TiAl₂-TiNi₂ was constructed, and a connectivity scheme, derived for equilibria involving Laves phases in the Ti-Fe-Ni-Al quaternary system at 900 °C was derived. As a characteristic feature of the quaternary phase diagram, the solid solubility of fourth elements in both the TiFe₂-based and Ti(NiAl)₂-based Laves phases is limited at 900 °C and is dependent on the ternary Laves phase composition. A maximum solubility of about 8 at.% Ni is reached for composition Ti_33.3Fe_33.3Al_33.4. Structural details have been evaluated from powder x-ray and neutron diffraction data for (i) the Ti-Fe-Ni ternary and the Ti-Fe-Ni-Al quaternary Laves phases (MgZn₂-type, space group: P6₃/mmc) and (ii) the quaternary G phase. Atom site occupation behavior for all phases from the quaternary system corresponds to that of the ternary systems. For the quaternary Laves phase, Ti occupies the 4f site and additional Ti (for compositions higher than 33.3 at.%Ti) preferably enters the 6h site. Aluminum and (Fe,Ni) share the 6h and the 2a sites. The compositional dependence of unit cell dimensions, atomic coordinates, and interatomic distances for the Laves phases from the quaternary system is discussed. For the quaternary cubic G phase, a centrosymmetric as well as a noncentrosymmetric variety was observed depending on the composition: from combined x-ray and neutron powder diffraction measurements Ti_33.33Fe_13.33Ni_10.67Al_42.67 was found to adopt the lower symmetry with space group .     

First-principles calculations of LaNi_(5-x)Sn_xH_y intermetallics and intermediate phase

The crystal and electronic structures of LaNi4.75Sn0.25 intermetallics and LaNi4.5Sn0.5Hy (y=2.0, 2.5) intermediate phase have been investigated by the full-potential linearized augmented plane wave (FP-LAPW) method. Hydrogen occupation sites in LaNi4.5Sn0.5Hy have been determined based on Westlake s criterions: (1) the minimum hole radius is 0.04 nm; (2) the minimum H-H distance is 0.21 nm; as well as geometry optimizations and internal coordinates optimizations. We find that hydrogen atoms prefer to occup...     

基于单线圈输出量的速度估计算法综述

先进的交通管理系统和旅行者信息系统的迅速发展,引起对交通速度估计测量一种需要。然而对于铺设大量单线圈的快速路网来说,交通速度并不能直接从单线圈检测器测量出来。因此许多研究学者针对如何从单线圈的输出量估计出交通速度展开了研究。该文结合国内外的研究情况给出了算法的分类,并总结了算法存在的问题和可能开展的研究方向。