Automotive fuel cell sloshing under temporally and spatially varying high acceleration using GPU-based Smoothed Particle Hydrodynamics (SPH)

Understanding how fuel sloshes in a fuel cell, as a vehicle races around a circuit, is an important but mostly unexplored factor when designing fuel containment systems. Cell designs are based on knowledge of how liquids slosh in other containers, with the design and placement of structures, such as weirs, based on engineering judgement.This work aims to provide better understanding for this difficult problem with a view to improve future designs. A Graphics Processing Unit (GPU) based Smoothed Particle Hydrodynamics (SPH) model is presented to simulate the fuel sloshing problem, with results from a simplified and real fuel cell geometry shown and compared against real data recorded in a vehicle. The vehicle motion and accelerations are included in the SPH simulations using a body force within the momentum equation. Results show good agreement between the simulation and the real fuel movement, with bulk motion captured well for accelerations up to 5 times gravity.Focus is placed on the practicality of the method for use as part of an industrial design process, therefore the amount of time needed to compute results is considered throughout. Computational performance is found to be within acceptable limits, while numerical accuracy is actively considered through the use of Kahan compensated summation. It is concluded that the model is successful in capturing the necessary fluid dynamics for it to be useful in fuel cell design. It is expected that the method will provide insight into current cell designs and highlight where improvements can be made.     

基于最佳燃油经济性的换挡指导系统

针对驾驶员不良换挡习惯造成明显燃油浪费的现状,提出了一套基于最佳燃油经济性的换挡指导系统,其基本原理是通过汽车OBD-Ⅱ接口读取车辆状态参数,然后依据最优换挡理论,在恰当的时机提醒驾驶员换挡.对系统的设计与实现进行了详细说明,主要包括系统框架、缺失参数的识别算法、最佳换挡的判别算法.最后对系统进行有效性验证,结果表明应用该系统平均节油8.6%,并且能使油耗水平更加稳定.研究成果可在现实中进一步推广,对交通领域节能减排有重要的价值.     

基于SAM-CS和SOFM的胃上皮肿瘤细胞图像识别

针对胃上皮肿瘤细胞图像(以下简称肿瘤细胞图像)黏结严重和信息冗余的特点,提出了一种将自适应观测矩阵的压缩感知(SAM-CS)和自组织特征映射(SOFM)神经网络相结合的算法。该算法将肿瘤细胞图像拉成列向量,然后利用通过自适应过程产生的观测矩阵,基于压缩感知理论对图像信息进行观测,产生线性观测向量,最后利用SOFM神经网络的学习算法对观测向量进行训练和分类,实现对肿瘤细胞图像的识别。实验表明,相比常用算法,该算法至少提高了4.2%的识别准确率和5.7%的运算速度。     

Optical complexities of living cytoplasm--implications for live cell imaging and photo-micromanipulation techniques

The ability to manipulate the intracellular environment within living cells and to monitor the cytosolic chemical changes which occur during cell stimulation has lead to major advances in our understanding of how cells read and respond to their environment. Perhaps the most powerful suite of techniques for achieving these dual objectives is based on the use of light (photons). Because cells are 'transparent', light has been used to both interrogate and manipulate the chemistry inside living cells, exploiting technical advances in both the physical and biochemical sciences. However, cells are neither transparent nor homogeneous with respect to their optical properties. The interface between light and the living cell cytoplasm thus represent an important, yet largely ignored, interface. There has been no review of the optical properties of cytoplasm and little discussion about how the optical properties of living cytoplasm influence the outcome of such measurements and manipulations. In this short review, we discuss the importance of understanding the optical properties of cytoplasm for such techniques and how imperfections in experimental interpretation can arise.     

结合水平集方法和PL主曲线分析的重叠细胞检测

提出了一种重叠细胞检测的新方法,该方法针对细胞图像处理中因细胞重叠而引起的过分割与欠分割现象这一难点,引入基于Mumford-Shah模型的水平集方法得到细胞的初始轮廓,采用EP（erosion-propagation）和PL主曲线相结合的图像分析方法得到目标的精确轮廓线。使用基于目标形状的图像配准方法和基于目标轮廓的分段特征分类器完成重叠细胞的检测。应用该方法对600张随机抽取的细胞图像中9374个细胞进行检测,实验正确率为91.83%,结果表明该方法能够有效地判断细胞是否重叠和重叠类型,为后续分割工作提供依据。     

悬液细胞图象识别的一种有效新算法

为进一步提高细胞识别的速度和识别率,本文研究一种细胞识别新算法。不同于其它的只对整个细胞形态进行一次图象处理的细胞识别方法,该算法在图象处理过程中,先后以细胞形态为重点和以细胞核形态为重点对原始图象进行两次图象处理,分别得到图象清晰度很高的整个细胞的二值图和细胞核的二值图。然后提取各项特征参数,对细胞图象进行识别。最后应用该算法对多幅细胞图象进行识别,结果表明该算法不但识别速度快,平均每幅图象的时间在3秒左右,而且识别率高达85%以上。     

P2P MMOG中计算任务的分配问题研究

P2P平台上的MMOG设计与C/S结构相比具有更好的可靠性和扩展性,但是需要新的数据存储和事件计算分配方法.本文提出小区的概念,并以小区为计算对象的基本分配单位,设计了节点可以自组织地寻找自己地计算和通信对象的方法.小区模型的方法通过确定节点的职能,对系统中的计算任务进行划分;而合理的计算分配保证了节点计算结果的正确性,以及进行安全的通信和数据发布;每个小区内部建立多个计算节点相互监督的多层计算模式,以确保系统的安全性.最后通过实验分析了该模型的计算和通信代价,指出在提高系统可靠性的同时,降低网络负载.     

基于可连Cell的无线传感器网络拓扑控制算法

在无线传感器网络的拓扑控制(TC)中,基于Cell的TC算法被认为是一类可以节省传感器节点能量并延长网络生命周期的方法,但是其需要较多的骨干网节点并且无法保证连通性.通过分析现今算法的内在局限性,提出了一种1-Con思想:当一个Cell的头节点被加入当前骨干网时,所有其可以连接的Cell使用该节点连入拓扑结构,然后此新骨干网递归地继续扩大.基于此思想,设计了一种基于可连Cell的拓扑控制算(CCTC),并从理论上证明:1)CCTC可以保证其所形成的拓扑结构维持网络连通;2)每一轮用于形成骨干网的工作节点非常少.CCTC的计算复杂度是线性的,空间复杂度和信息交换量都是常数量级.仿真实验同样显示,CCTC可以在提供良好鲁棒性和较少的消息交换的情况下,更有效地节省节点能耗并延长网络生命周期.     

嵌入式GPS／GIS系统设计的几个关键问题及解决方法

提出嵌入式GPS/GIS系统设计中的几个关键技术问题并给出解决方案。对GPS数据质量采用神经元辨识的方法进行控制;对大数据量底图数据采用一种新的地图综合方法建立多级显示机制,节省内存,提高图形显示效率;建立基于la-bel的空间算子实现方式,完成采集图斑的现场变更,减少内业数据处理的工作量。实际应用表明,这些方法能够满足嵌入式GPS/GIS系统应用于土地调查业务的需要,提高了调查效率。     

光寻址电位传感器及其应用

光寻址电位传感器(LAPS)是一种基于半导体光电效应的化学传感器,在稳定性、重复性、灵敏度、准确性和响应速度等方面具有优良的性能。介绍了LAPS的基本原理和测量方法,阐述了LAPS在细胞传感器、图像传感器、金属离子敏感薄膜传感器、气体传感器及生物医学领域中的应用,并对其存在问题和研究方向进行了总结和展望。