基于关键帧的双流卷积网络的人体动作识别方法

针对视频序列中人体动作识别存在信息冗余大、准确率低的问题,提出基于关键帧的双流卷积网络的人体动作识别方法.该方法构建了由特征提取、关键帧提取和时空特征融合3个模块构成的网络框架.首先将空间域视频的单帧RGB图像和时间域多帧叠加后的光流图像作为输入,送入VGG16网络模型,提取视频的深度特征;其次提取视频的关键帧,通过不断预测每个视频帧的重要性,选取有足够信息的有用帧并汇聚起来送入神经网络进行训练,选出关键帧并丢弃冗余帧;最后将两个模型的Softmax输出加权融合作为输出结果,得到一个多模型融合的人体动作识别器,实现了对视频的关键帧处理和对动作的时空信息的充分利用.在UCF-101公开数据集上的实验结果表明,与当前人体动作识别的主流方法相比,该方法具有较高的识别率,并且相对降低了网络的复杂度.     

基于模糊神经网络的模糊空间对象生成方法研究

随着对GIS中的空间对象模型和自然地理特征表达的研究深入,模糊空间对象被提出。针对模糊空间对象表达的特点,提出了一种基于模糊神经网络的模糊空间对象生成方法。该方法将模糊技术与神经网络相结合,利用神经网络的学习能力调整模糊隶属函数和模糊规则,使系统具备自适应的特性。实验表明,这种基于模糊神经网络的生成模糊空间对象的方法比传统方法大大的提高了成果的精度。     

PAI-OFF: A new proposal for online flood forecasting in flash flood prone catchments

The Process Modelling and Artificial Intelligence for Online Flood Forecasting (PAI-OFF) methodology combines the reliability of physically based, hydrologic/hydraulic modelling with the operational advantages of artificial intelligence. These operational advantages are extremely low computation times and straightforward operation. The basic principle of the methodology is to portray process models by means of ANN. We propose to train ANN flood forecasting models with synthetic data that reflects the possible range of storm events. To this end, establishing PAI-OFF requires first setting up a physically based hydrologic model of the considered catchment and – optionally, if backwater effects have a significant impact on the flow regime – a hydrodynamic flood routing model of the river reach in question. Both models are subsequently used for simulating all meaningful and flood relevant storm scenarios which are obtained from a catchment specific meteorological data analysis. This provides a database of corresponding input/output vectors which is then completed by generally available hydrological and meteorological data for characterizing the catchment state prior to each storm event. This database subsequently serves for training both a polynomial neural network (PoNN) – portraying the rainfall–runoff process – and a multilayer neural network (MLFN), which mirrors the hydrodynamic flood wave propagation in the river. These two ANN models replace the hydrological and hydrodynamic model in the operational mode. After presenting the theory, we apply PAI-OFF – essentially consisting of the coupled “hydrologic” PoNN and “hydrodynamic” MLFN – to the Freiberger Mulde catchment in the Erzgebirge (Ore-mountains) in East Germany (3000 km²). Both the demonstrated computational efficiency and the prediction reliability underline the potential of the new PAI-OFF methodology for online flood forecasting.     

Differential Effects of Cognitive and Structural Social Capital on Empowerment in Two Community Ecotourism Projects in Ghana

Researchers have cautioned against both erasing conceptual complexities and homogenizing communities in community-based natural resources (CBNRM) studies and interventions. Social capital is seen as an enabler of CBNRM, yet we argue that differential access to social capital and associated outcomes deserves greater attention to avoid oversimplification of community interventions. Drawing upon literature on social networks and social capital, we analyze survey and network data from two community ecotourism cases in Ghana to advance understanding of the empowering capacities and limitations of CBNRM through social capital access. Subpopulations within communities are considered. Results show that residents with greater access to social capital report greater levels of empowerment. However, that relationship seems to be conditioned by one’s involvement, demographics, and by the empowerment dimension under analysis. Implications of the differing relationships between cognitive and structural social capital in relation to several empowerment outcomes are discussed from theoretical, methodological, and practical perspectives.     

基于三维激光扫描的空间地物建模

利用地面三维激光扫描仪获取的空间数据,进行了三维空间地物建模研究。以建筑物建模为例,首先从原始数据中分离提取建筑物,然后对得到的建筑物数据进行去噪处理,再通过整体匹配纠正并对原始测量数据进行重新采样和拼接配准,建立了由三角网构成的三维表面模型。结果表明,所构建的三维表面模型较好地表达了建筑物的几何特征,户外实验也验证了上述过程可以实现对建筑物快速三维建模。     

Use of Artificial Neural Networks for Selective Omission in Updating Road Networks

Abstract

An important problem faced by national mapping agencies is frequent map updates. An ideal solution is only updating the large-scale map with other smaller scale maps undergoing automatic updates. This process may involve a series of operators, among which selective omission has received much attention. This study focuses on selective omission in a road network, and the use of an artificial neural network (i.e. a back propagation neural network, BPNN). The use of another type of artificial neural network (i.e. a self-organizing map, SOM) is investigated as a comparison. The use of both neural networks for selective omission is tested on a real-life road network. The use of a BPNN for practical application road updating is also tested. The results of selective omission are evaluated by overall accuracy. It is found that (1) the use of a BPNN can adaptively determine which and how many roads are to be retained at a specific scale, with an overall accuracy above 80%; (2) it may be hard to determine which and how many roads should be retained at a specific scale using an SOM. Therefore, the BPNN is more effective for selective omission in road updating.     

语义与几何相结合的道路网融合研究与实现

道路网是最重要的地理空间要素之一,空间数据融合能够把不同来源道路空间数据或信息加以结合,以获得信息量更丰富或更适于处理、分析、决策的新的数据集。传统的方法受限于道路网数据模型、属性数据类型以及缺少唯一标识的属性信息,道路网融合方法多以各个弧段或道路的位置、形状、方向等几何特征进行匹配,而忽略了道路的语义匹配。本文在数据来源与技术分析的基础上,提出了一种在工程化应用中可行的语义与几何相结合的道路网匹配方法,并通过FME实现空间数据融合,旨在为两个或多个道路网数据融合、联动更新提供方法参考。     

气象台站网布局优化研究综述

气象台站网的布局优化可以提高气象台站观测资料的代表性、准确性和可比较性.简述了气象台站网布局优化方法的国内外研究进展,讨论了气象台站网布局优化方法的关键技术和存在的问题,重点介绍和分析了利用线性内插法、最优内插法、信息论法、因子分析法和经验模式法来进行气象台站网的布局优化,总结了这些方法的可行性.结合气象业务需求变化,提出了气象台站网布局优化方法的改进方向.     

一种无线传感器网络应用系统的中间件设计与实现

为了降低获取异构传感器网络数据的复杂性,通过对无线传感器网络(WSN)接入异构网络技术的研究,提出了一种无线传感器网络应用系统的中间件设计方案.该方案是以S3C6410为主处理器的嵌入式开发板作为硬件开发平台,通过AODV路由协议,使多个监测区域的WSN网关和Adhoc网关组建成Adhoc类型的网络,从而解决了无线传感器网络与外部公网无缝隙连接的问题.该方案不但实现了经过WSN网关处理加工后的无线传感器网络数据上传至远程服务器的功能,而且为多个异构无线传感器网络同时接入外部网络提供了一种可靠的解决方法.     

核废料地质贮存岩体裂隙结构面几何特性参数分析

以前人对裂隙岩体几何结构的研究成果为基础，详细分析充分体现热效应的核废料贮存岩体隙结构面的几何特性，建立了温度作用下的裂隙密度计算关系式，。详细介绍了捞述受温度影响的渗流裂隙网络的特征变量。