基于分层图像复原的水下目标距离估计

水下目标的距离估计对于水下作业有着十分重要的意义。目前常用的距离估计方法无论是光测距还是声测距都对于设备有很大的依赖性,本文提出一种基于复原技术的距离估计方法,通过建立水下退化图像的分层复原模型并利用清晰度评价函数,根据对图像清晰复原时的参数估计实现目标距离估计。这种方法紧需要单幅水下图像就可实现目标整体距离估计。文中通过实验验证了该方法的有效性。     

基于区域分割合并的建筑物半自动提取方法

提出了一种遥感图像半自动提取建筑物的方法。首先通过对建筑物边缘进行折线逼近和感知编组，可以得到其顶部大体结构。然后按照“二叉树”的数据结构，利用“超线”对建筑物影像进行区域分割。最后通过对分割后的区域进行相似性的统计并按照“二叉树”记录的分割顺序进行生长合并，从而得到了屋顶的边缘，实现了对平顶直角建筑物的提取。该方法能够充分利用区域的性质进行合并，稳定精确地提取建筑物。     

页岩薄片孔缝分割的自动阈值生成方法

随着页岩气勘探开发领域的快速发展,页岩储层的微观结构表征及分析技术显得愈发重要.其中基于阈值分割法获取页岩孔隙结构参数是目前页岩微观结构表征的一种重要手段.现有的阈值分割方法主要有最大类间方差法、最大熵闽值分割法等,它们在各种图像分割任务上都取得了不错的成绩.然而,在页岩孔隙分割问题上,它们均存在耗时较长且不能有效分离...     

X-波段雷达近海海浪频谱反演的神经网络模型

X-波段雷达作为国内海浪观测的一种新工具,在海浪频谱获取和有效波高反演方面仍存在较多问题.本文利用非线性回归方法,将现场实测浮标数据频谱和雷达一维图像谱分别与标准频谱模型进行拟合,发现浮标频谱和一维图像谱具有标准频谱的特征,能够较准确地获取相应的谱参数.提出了建立由雷达一维图像谱参数反演海浪频谱参数的神经网络模型,同时在模型中加入影像序列信噪比,进而反演有效波高,并将反演结果与现场实测数据和传统算法(建立影像序列信噪比与有效波高之间的线性回归方程)进行了对比,结果表明,获取谱参数的误差和反演有效波高的平均误差在20％以内,而传统算法计算有效波高平均误差在20％以上.     

SAR图像海洋内波参数自动提取方法

海洋SAR图像由于纹理复杂,目前绝大多数的SAR图像海洋内波处理方式都是通过人工干预在SAR图像上选取一个或多个沿内波传播方向的截面,再依据截面数据的灰度分布求内波波长等参数,这种方法要求操作者有一定的专业知识,且随操作者选取截面的不同,反演得到的内波参数变化较大。依据海洋内波特点,采用二维连续小波变换对海洋SAR图像进行滑动窗扫描,自动找出含有海洋内波的图像区域,再通过椭圆域归一化Radon变换自动反演含有内波区域的内波波长、传播方向等参数。由SAR图像内波参数提取结果可知,提出的SAR图像内波参数自动提取方法,是一种全自动的SAR图像内波参数提取方法,能够较好地定位内波所在的图像区域,自动提取这些区域中的内波参数,且提取的内波传播方向可自动去除180°模糊,可解决海量SAR海洋数据内波参数自动提取的难题。     

振冲挤密法加固砂类土地基在海岸工程中的应用

为了有效控制软土地基上海岸建筑物的工后沉降和不均匀沉降,各种软基处理方法在海岸工程建设中得到了越来越广泛的应用。结合海岸工程软土地基处理实例,对振冲挤密法的地基加固机理、加固砂类土地基时的设计参数、施工及加固后地基的检测等进行了探讨,结果表明,振冲挤密处理砂类土地基是行之有效的,并对今后的施工和设计提出了一些参考性建议。     

基于精细地质研究静态数据库的砂体类型识别方法

以地质储量精细计算需要的砂体类型(河道与非河道厚、薄层砂体、Ⅰ类表外独立和渐变砂体、Ⅱ类表外独立和渐变砂体)为例,探讨了精细地质研究静态数据库中砂体类型识别方法,给出了不同类型砂体识别的方法。利用该方法从精细地质研究静态数据库中提取不同类型砂体厚度参数,对不同类型砂体进行了地质储量精细计算。     

鄂尔多斯盆地伊盟隆起上古生界储层孔隙结构特征及评价CSCD

储层是油气赋存的载体,其孔渗性能决定着后期油气开采难度以及可采数量。在众多影响储层孔渗性能的因素当中,储集层的孔隙结构发挥了关键的作用。通过对鄂尔多斯盆地伊盟隆起上古生界储层岩性以及孔渗参数进行分析,结果表明:石盒子组孔喉连通性及渗流性能最好,其次是山西组,太原组最差;依据压汞资料和毛细管压力曲线形态,孔隙结构类型可以划分为4类;通过孔渗资料统计分析,上古生界砂岩划分4类,并以Ⅱ类和Ⅲ类储层为主;砂体主要为冲积扇辫状水道砂体,曲流河、辫状河河道砂坝砂体以及三角洲平原分流河道砂体。研究结果可以为伊盟隆起区上古生界的油气开发提供依据。     

鄂尔多斯盆地伊盟隆起上古生界储层孔隙结构特征及评价

储层是油气赋存的载体,其孔渗性能决定着后期油气开采难度以及可采数量。在众多影响储层孔渗性能的因素当中,储集层的孔隙结构发挥了关键的作用。通过对鄂尔多斯盆地伊盟隆起上古生界储层岩性以及孔渗参数进行分析,结果表明:石盒子组孔喉连通性及渗流性能最好,其次是山西组,太原组最差;依据压汞资料和毛细管压力曲线形态,孔隙结构类型可以划分为4类;通过孔渗资料统计分析,上古生界砂岩划分4类,并以Ⅱ类和Ⅲ类储层为主;砂体主要为冲积扇辫状水道砂体,曲流河、辫状河河道砂坝砂体以及三角洲平原分流河道砂体。研究结果可以为伊盟隆起区上古生界的油气开发提供依据。     

基于MRF场的侧扫声呐图像分割方法

为了利用侧扫声呐进行水下目标自动探测和识别,首先必须将声呐图像分为目标高亮区、海底混响区和目标阴影区.由于声呐图像有强背景噪声,传统的图像分割方法显得无能为力,故采用基于MRF场的图像分割方法来准确地分割.根据侧扫声呐目标的成像特点,建立了分割的约束条件;利用阴影与目标的灰度均值比很小这一特点进行初始分割,然后根据分割后目标与阴影的宽度差来剔除虚假目标,由初始分割的结果求得MRF模型初始参数,再采用迭代条件估计得到最终的模型参数和准确的分割结果.由于考虑了相邻像素间的依赖关系,具有抗噪性强、分割效果好的优点,从理论上说是合理的.实测数据分析也证明了这种算法的优越性.     

面向智能家庭的动态自适应软件基础平台研究

在智能家庭环境中,用户对设备的操作具有透明性和沉浸式的特点,因此系统需要从用户的行为或者情境变化中识别出用户的行为意图或者需要,推断出需执行的用户任务,然后自动寻找合适的功能资源以完成任务。针对这一需求并基于参数化模型,提出具有自动适配机制的智能家庭软件基础平台框架。该软件基础平台框架可以支持家庭用户对异构智能家电设备的透明式操作,提高用户的使用效率,增强用户的使用感受。     

The influence of seasonality on estimating return values of significant wave height

A time-dependent generalized extreme value (GEV) model for monthly significant wave heights maxima is developed. The model is applied to several 3-hour time series from the Spanish buoy network. Monthly maxima show a clear non-stationary behavior within a year, suggesting that the location, scale and shape parameters of the GEV distribution can be parameterized using harmonic functions. To avoid a possible over-parameterization, an automatic selection model, based on the Akaike Information Criterion, is carried out. Results show that the non-stationary behavior of monthly maxima significant wave height is adequately modeled, drastically increasing the significance of the parameters involved and reducing the uncertainty in the return level estimation. The model provides new information to analyze the seasonal behavior of wave height extremes affecting different natural coastal processes.     

3D空间航片纹理源的纹理映射问题

随着数字三维城市建设的快速推进,传统的纹理获取方法已不能满足快速建模的要求。提出了一种基于航片纹理源的3D空间纹理映射方法,基于摄影测量学相关理论,通过设计算法,实现了建筑物侧面纹理的自动匹配。实验证明,这种方法简单、高效,适用于大面积建筑物3D建模。     

Electricity of the convective atmospheric boundary layer: Field observations and numerical simulation

The electric state of the middle-latitude convective atmospheric boundary layer (ABL) is investigated during a point in time when it is not disturbed by clouds, precipitation, mist, or industrial aerosols. A numerical model is developed that estimates the electroaerodynamic state of the convective ABL. The model is parameterized using results of field observations and laboratory experiments. According to the model, vertical profiles of atmospheric electric field strength, space charge density, electric conductivity, and atmospheric electric current density are calculated in the horizontally homogeneous approximation with a high space-time resolution.     

建筑空调瞬时负荷控制模型

根据本地区夏季气温、太阳辐射强度等气象参数，提出建筑空调瞬时负荷控制模型。对本地区气象参数归纳为两个地区气象专用值：地区气象常数Ｃｋ和地区气象专用温度ｔ０。应用该模型与我国常用的分析计算方法进行比较，两者计算结果基本一致。该模型可提供在我国不同地区利用当地气象参数，计算、控制建筑空调的瞬时负荷。     

基于天绘一号卫星多光谱影像的海岸线自动提取方法

针对常规人工海岸线测量方法耗费人力物力、效率低、工作环境相对危险,难以快速反映海岸线动态变化的问题,提出一种基于天绘一号卫星多光谱影像的海岸线自动提取与分类方法。所提方法首先结合NDWI指数和水平集模型实现全自动水边线提取,然后采用面向对象分割技术和空间拓扑关系提取临海地物基元,最后结合遥感影像海岸线解译标志建立决策树完成临海基元的分类与海岸线提取。实验表明,海岸线提取结果能够作为1∶2.5万海图测制与更新的参考数据。     

最短时间航线自动生成的改进方法

针对已有的最短时间航线自动生成算法存在搜索效率较低、航线准确度较低的不足,提出了基于瞬时水深模型的最短时间航线自动生成改进算法。利用无效点定义和动态包络矩形的策略,优化最短时间航线生成;采用高精度的瞬时水深模型提高最短时间航线自动生成的准确度。实验结果表明:此方法与已有的方法相比,在自动生成航线的质量和效率上都有明显的提高。     

Automatic collision avoidance of multiple ships based on deep Q-learning

As the number of ships for marine transportation increases with the globalisation of the world economy, waterways are becoming more congested than before. This situation will raise the risk of collision of the ships; hence, an automatic collision avoidance system needs to be developed. In this paper, a novel approach based on deep reinforcement learning (DRL) is proposed for automatic collision avoidance of multiple ships particularly in restricted waters. A training method and algorithms for collision avoidance of ships, incorporating ship manoeuvrability, human experience and navigation rules, are presented in detail. The proposed approach is investigated not only by numerical simulations but also by model experiments using three self-propelled ships. Through the systematic numerical and experimental validation, it is demonstrated the developed approach based on the DRL has great possibility for realising automatic collision avoidance of ships in highly complicated navigational situations.     

Dynamic Analysis of the Seafloor Pilot Miner Based on Single-Body Vehicle Model and Discretized Track-Terrain Interaction Model

In order to achieve the complex dynamic analysis of the self-propelled seafloor pilot miner moving on the seafloor of extremely cohesive soft soil and further to make it possible to integrate the miner system with some subsystems to form the complete integrated deep ocean mining pilot system and perform dynamic analysis,a new method for the dynamic modeling and analysis of the miner is proposed and developed in this paper,resulting in a simplified 3D single-body vehicle model with three translational and three rotational degrees of freedom,while the track-terrain interaction model is built by partitioning the track-terrain interface into discrete elements with parameterized force elements built on the theory of terramechanics acting on each discrete element.To evaluate and verify the correctness and effectiveness of this new modeling and analysis method,typical comparative studies with regard to computational efficiency and solution accuracy are carried out between the traditional modeling method of building the tracked vehicle as a multi-body model and the new modeling method.In full consideration of the particular structure design of the pilot miner,the special characteristics of the seafloor soil and the hydrodynamic force of near-seafloor current,the dynamic simulation analysis of the miner is performed and discussed,which can provide useful guidance and reference for the practical miner system in design and operation.This new method can not only realize the rapid dynamic simulation analysis of the miner but also make possible the integration and rapid dynamic analysis of the complete integrated deep ocean mining pilot system in further researches.     

Dynamic Analysis of the Seafloor Pilot Miner Based on Single-Body Vehicle Model and Discretized Track-Terrain Interaction Model

In order to achieve the complex dynamic analysis of the self-propelled seafloor pilot miner moving on the seafloor of extremely cohesive soft soil and further to make it possible to integrate the miner system with some subsystems to form the complete integrated deep ocean mining pilot system and perform dynamic analysis, a new method for the dynamic modeling and analysis of the miner is proposed and developed in this paper, resulting in a simplified 3D single-body vehicle model with three translational and three rotational degrees of freedom, while the track-terrain interaction model is built by partitioning the track-terrain interface into discrete elements with parameterized force elements built on the theory of terramechanics acting on each discrete element. To evaluate and verify the correctness and effectiveness of this new modeling and analysis method, typical comparative studies with regard to computational efficiency and solution accuracy are carried out between the traditional modeling method of building the tracked vehicle as a multi-body model and the new modeling method. In full consideration of the particular structure design of the pilot miner, the special characteristics of the seafloor soil and the hydrodynamic force of near-seafloor current, the dynamic simulation analysis of the miner is performed and discussed, which can provide useful guidance and reference for the practical miner system in design and operation. This new method can not only realize the rapid dynamic simulation analysis of the miner but also make possible the integration and rapid dynamic analysis of the complete integrated deep ocean mining pilot system in further researches.