Groundwater modelling to quantify the effect of water harvesting structures in Wagarwadi watershed,Parbhani district,Maharashtra, India

Marathwada Agricultural University, Pharbani, has developed about 560 hectares of Wagarwadi watershed in Pharbani district since 1987. Groundwater monitoring on 16 observations wells at weekly intervals commenced in January 1992, and rainfall and pan evaporation has been measured daily at a hydrometeorological station situated in the nearby university campus. Aquifer parameters, namely, transmissivity and specific yield, have been estimated by carrying out a pumping test on a large diameter well. Groundwater recharge resulting from rainfall has been estimated using a water balance model of the soil moisture zone considering soil zone thickness and crops grown. The SCS (Soil Conservation Service) curve number method was used for surface runoff estimation. The groundwater flow model has been constructed using the nested squares, finite difference method. Nested square meshes of sizes 160 m×160 m and 80 m×80 m have been used and the steady-state condition of aquifer system was simulated in the model assuming the June 1992 water level configuration under equilibrium conditions. The model has been calibrated for transient conditions incorporating additional seepage from the water harvesting structures and their contribution to the groundwater regime has been assessed. © 1998 John Wiley & Sons, Ltd.     

对偶四元数法在稳健点云配准中的应用

针对点云特征点含有粗差的问题,提出了基于对偶四元数的稳健点云配准方法。遵循加权最小二乘原则构建了基于对偶四元数的稳健点云配准模型,运用拉格朗日乘数法推导了旋转矩阵和平移向量求解公式,研究了新权计算与坐标转换迭代步骤。实例证明,该方法能够有效识别并剔除粗差,提高点云配准精度。     

Indoor scene texturing based on single mobile phone images and 3D model fusion

Realistic texture mapping and coherent up-to-date rendering is one of the most important issues in indoor 3-D modelling. However, existing texturing approaches are usually performed manually during the modelling process, and cannot accommodate changes in indoor environments occurring after the model was created, resulting in out-dated and misleading texture rendering. In this study, a structured learning-based texture mapping method is proposed for automatic mapping a single still photo from a mobile phone onto an already-constructed indoor 3-D model. The up-to-date texture is captured using a smart phone, and the indoor structural layout is extracted by incorporating per-pixel segmentation in the FCN algorithm and the line constraints into a structured learning algorithm. This enables real-time texture mapping according to parts of the model, based on the structural layout. Furthermore, the rough camera pose is estimated by pedestrian dead reckoning (PDR) and map information to determine where to map the texture. The experimental results presented in this paper demonstrate that our approach can achieve accurate fusion of 3-D triangular meshes with 2-D single images, achieving low-cost and automatic indoor texture updating. Based on this fusion approach, users can have a better experience in virtual indoor3-D applications.     

濮城油田沙三中6-10油藏活性纳米粉体降压增注技术研究

濮城油田沙三中6-10油藏为低渗油藏,因注入水质差,造成对地层的伤害,注水压力不断上升。通过分析造成地层伤害的主要因素,为控制注水压力的上升,提出了活性纳米降压增注技术,并在室内进行了研究,从活性材料选择、表面修饰剂选择、分散介质选择以及纳米粉体水分散最佳浓度进行了室内筛选,指出了纳米酸化技术的可行性。在室内研究的基础上,在现场开展了10口井活性纳米技术的应用,取得了良好的效果。     

从新宅居生活看网络虚拟旅游的前景和方向

随着信息化技术和网络技术的快速发展,居家服务系统的越来越完善,不愿或不能出门实现旅游目的的人群越来越庞大。对于数量巨大的不愿或不能外出旅游的"宅居"人群来说,通过网络实现虚拟旅游是最理想的方案。网络虚拟旅游在中国起步晚,但近年来发展快,已表现出产品多样化、技术集成化、需求娱乐化、用户大众化、功能休闲化等特点。目前要解决的主要问题集中在:①3D高清动态仿真效果提质的技术实现问题;②运用AR等新技术优势解决现场体验感不足的问题;③解决景区如何在网络虚拟旅游中受益的问题。未来的网络虚拟旅游方向是:①在线产品越来越真实化和高清化;②客源市场越来越大众化和多元化;③产品内容越来越多样化和分众化;④展示平台越来越普及化和共享化。     

“Krige”空间内插技术在地理学中的应用

称为“Krige”技术的内插稀疏观测资料的随机方法是Matheron(1970年)提出的,D.R.Krige首先将这一方法应用于找矿上,因而命名于“Krige”技术。本文首先定义和说明了空间协方差曲线,基于无偏估计和最优原理导出了“Krige”内插权重系数的代数方程组,最后给出实例说明该方法如何应用到地理学和水文学中。     

位场数据网格化的反插值法

位场不规则分布数据的网格化是位场数据分析处理的首要问题.本文借鉴反插值法的原理,提出利用基于预条件共轭梯度的反插值法实现位场数据的网格化.其中,插值算子采用高斯权系数,滤波算子采用Laplacian算子,预条件算子采用滤波算子的逆.通过理论模型和实际航磁数据的网格化试验分析,验证了本文的反插值法适合地球物理位场特征,网格化速度快,精度高,效果好.     

户外增强现实地理信息系统原型设计与实现

探讨了户外增强现实技术与移动地理信息系统相结合的模式,设计了户外增强现实地理信息系统的总体框架,重点研究了三维注册等若干关键技术,并实现了一个原型系统。     

基于ARToolKit的地下管网增强现实研究

利用ARToolKit在室内实现了管网三维可视化的相关实验,取得了较为满意的效果。同时根据户外的实际情况,提出了以GPS RTK和INS相结合进行精确定位,以电子罗盘和倾角计相结合测定视线方向的混合注册方法,并对地下管网增强现实系统的框架及功能作了进一步的探讨。     

一种基于形态金字塔的遥感影像融合方法及其性能评价

提出了一种基于影像形态金字塔分解的融合方法,并应用于IKONOS全色影像和多光谱影像的融合中。在构建金字塔时采用的形态滤波是非线性滤波,与线性滤波相比,它能更准确地定位边缘,更好地表现影像的空间细节信息。实验结果表明,基于形态金字塔的融合效果优于拉普拉斯金字塔和对比度金字塔。