适用于海洋动态观测设备嵌入式系统的低功耗管理预测模型          下载免费PDF全文

李昌硕  周伟  杨群慧  季福武 《海洋技术学报》2024,(2)

能耗是制约海洋设备在水下工作时长的关键因素。为进一步降低海洋动态观测设备嵌入式系统的动态功耗, 本文针对前人提出的用于预测空闲时间的指数平滑算法所存在的权重系数基于凑数法确定、算法难以适应大波动等问题, 设计了一种新的权重系数, 并构建了一种自适应的低功耗管理预测模型。当模型检测到预测的空闲时间超过工作和休眠状态切换的时间阈值后, 中央处理器关停系统的部分外设, 使系统进入低功耗休眠状态。仿真和单片机实验均表明,本文提出的低功耗管理预测模型能够有效地提高对处理器工作的空闲时间预测的准确性, 且面对突发状况具有良好的自适应性, 可显著降低嵌入式系统的功耗, 有效延长设备的工作时间。  相似文献   

嵌入式地理信息系统组件开发与研究     

孙立民  殷福忠  丁明柱 《地理信息世界》2007,5(5):77-81

通过分析嵌入式地理信息系统的技术及应用,介绍了如何进行嵌入式地理信息系统组件的开发以及嵌入式系统的地理信息数据如何使用。从技术上采用微软的COM技术,以C 为开发语言,采用了应用广泛的Windows CE嵌入式操作系统,设计和开发了基于嵌入式设备的地理信息系统组件,并在此组件基础上开发了相关的应用系统,通过了应用的检验,为GIS应用开发提供了一个新思路、新手段。  相似文献   

钻孔灌注桩的施工质量控制     

廖远淦 《南方国土资源》1999,12(3):67-70

该文通过对钻孔灌注桩的主要施工工艺如：泥浆比重及粘稠度、孔内沉渣厚度、钢筋笼的制安以及水下混凝土的灌注等工艺技术要求的控制方法的阐述,指出在钻孔灌注桩施工过程中只要对这些工序加强控制,就能确保钻孔灌注桩的质量  相似文献   

嵌入式Linux移植技术在地磁观测仪器中的应用研究     

张旸  滕云田  王喜珍  朱荣  吴琼 《地震地磁观测与研究》2007,28(4):44-48

结合地磁观测系统的特点,研究了嵌入式Linux系统的裁剪和移植技术,实现了地磁观测系统中嵌入式Linux的应用开发.采用本文技术开发的系统,既可以通过以太网对仪器系统实时远程监控,满足对地磁观测系统的实时性和网络控制要求,又具有良好的可扩展性,对其他观测系统具有一定的借鉴意义.  相似文献   

Numerical modeling of dynamic rock fracture with a combined 3D continuum viscodamage‐embedded discontinuity model          下载免费PDF全文

T. Saksala  D. Brancherie  A. Ibrahimbegovic 《国际地质力学数值与分析法杂志》2016,40(9):1339-1357

This paper deals with numerical modeling of dynamic failure phenomena in rate‐sensitive quasi‐brittle materials, such as rocks, with initial microcrack populations. To this end, a continuum viscodamage‐embedded discontinuity model is developed and tested in full 3D setting. The model describes the pre‐peak nonlinear and rate‐sensitive hardening response of the material behavior, representing the fracture‐process zone creation, by a rate‐dependent continuum damage model. The post‐peak response, involving the macrocrack creation accompanied by exponential softening, is formulated by using an embedded displacement discontinuity model. The finite element implementation of this model relies upon the linear tetrahedral element, which seems appropriate for explicit dynamic analyses involving stress wave propagation. The problems of crack locking and spreading typical of embedded discontinuity models are addressed in this paper. A combination of two remedies, the inclusion of viscosity in the spirit of Wang's viscoplastic consistency approach and introduction of isotropic damaging into the embedded discontinuity model, is shown to be effective in the present explicit dynamics setting. The model performance is illustrated by several numerical simulations. In particular, the dynamic Brazilian disc test and the Kalthoff–Winkler experiment show that the present model provides realistic predictions with the correct failure modes and rate‐dependent tensile strengths of rock at different loading rates. The ability of initial embedded discontinuity populations to model the initial microcrack populations in rocks is also successfully tested. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Embedded beam element with interaction surface for lateral loading of piles          下载免费PDF全文

Diego F. Turello  Federico Pinto  Pablo J. Snchez 《国际地质力学数值与分析法杂志》2016,40(4):568-582

This paper presents a numerical formulation of a three dimensional embedded beam element for the modeling of piles, which incorporates an explicit interaction surface between soil and pile. The formulation is herein implemented for lateral loading of piles but is able to represent soil–pile interaction phenomena in a general manner for different types of loading conditions or ground movements. The model assumes perfect adherence between beam and soil along the interaction surface. The paper presents a comparison of the results obtained by means of the present formulation and by means of a previously formulated embedded pile element without interaction surface, as well as reference semi‐analytical solutions and a fully 3D finite element (FE) model. It is seen that the proposed embedded element provides a better convergence behavior than a previously formulated embedded element and is able to reproduce key features of a full 3D FE model. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

A test of independence for stratigraphic sequences with respect to embedded Markov chains     

Sture Holm  Irene Isaksson  Rodney Stevens 《Mathematical Geology》1986,18(6):551-561

Identification of cyclic sequences gives valuable insight into depositional associations of stratigraphic facies. An embedded Markov chain is a reasonable general model for facies transitions. But a model with independent random occurrences of facies is not an appropriate null hypothesis to be tested to show the presence of cycles because of definitional restriction in transition observations to only those between different facies. This is a common stratigraphic situation and the problem has been raised recently by several authors. We present here a test statistic for null hypothesis derived from the concept of partial independence and inherent to the model of embedded Markov processes.  相似文献   

软土地基中插入式大直径薄壁圆筒结构的一种简化数值计算方法   总被引：2，自引：0，他引：2  

钟晓红  肖仕宝  周锡礽 《海洋技术学报》2005,24(2):104-108,134

简述了对插入式大直径薄壁圆筒进行数值分析采用的力学机制，用弹簧元模拟薄壁圆筒与地基土体接触面间的连接所形成一种简化的数值计算模型，运用大型通用有限元软件ANSYS进行二次开发后对其进行数值计算与分析，比较了对筒内外淤泥粘土采用不同加固处理方法以及考虑相邻圆筒间采用不同边界约束条件时，对圆筒的应力和稳定性的影响。通过实例计算，验证了该数值模型的有效性与可行性，并得出一些有益结论。  相似文献   

基于修正嵌入式容积卡尔曼滤波的相位展开算法   总被引：1，自引：1，他引：0  

代高兴  谢先明 《测绘学报》2017,46(12):1998-2005

针对干涉图展开问题,将Levenberg-Marquardt方法修正后的嵌入式容积卡尔曼滤波器应用于缠绕相位图像的展开中,结合基于修正矩阵束模型的局部相位梯度估计算法以及量化跟踪策略,提出一种基于修正嵌入式容积卡尔曼滤波的相位展开算法。该算法不仅可以精确和快速地展开缠绕像元,还可以在展开缠绕像元的同时抑制相位噪声,降低前置预滤波器的难度与复杂度,甚至可以在处理受噪声污染不严重的干涉图时免去前置预滤波处理步骤。试验结果表明本文算法具有较高的效率和良好的稳键性。  相似文献   

面向嵌入式数据库的导航电子地图组织方法     

赵卫锋  张勤 《地理信息世界》2016,(2):83-89

以道路网为核心,提出了一个通用导航电子地图概念模型,并在其基础上重点研究了面向嵌入式数据库的导航电子地图组织方法。在本模型中,道路网被划分为通过线性参考互相联系的几何基准、逻辑网络和事件集三个模块,并采用分层、分区域的数据组织模式,体现了经典GIS-T模型和主流导航电子地图物理存储格式的主要优点。为了建立具有较高访问效率的导航数据库,提出了导航电子地图各个模块在嵌入式数据库中的组织策略,并着重介绍了利用数据聚集和HASH索引机制存储逻辑网络的方法。通过在嵌入式数据库SQLite中进行导航电子地图组织并在其基础上进行导航软件开发的实验,该导航电子地图组织方法被证明具有较好的可用性。  相似文献