3D SEMANTIC LABELING OF ALS DATA BASED ON DOMAIN ADAPTION BY TRANSFERRING AND FUSING RANDOM FOREST MODELS

Labeling 3D point cloud data with traditional supervised learning methods requires considerable labelled samples, the collection of which is cost and time expensive. This work focuses on adopting domain adaption concept to transfer existing trained random forest classifiers (based on source domain) to new data scenes (target domain), which aims at reducing the dependence of accurate 3D semantic labeling in point clouds on training samples from the new data scene. Firstly, two random forest classifiers were firstly trained with existing samples previously collected for other data. They were different from each other by using two different decision tree construction algorithms: C4.5 with information gain ratio and CART with Gini index. Secondly, four random forest classifiers adapted to the target domain are derived through transferring each tree in the source random forest models with two types of operations: structure expansion and reduction-SER and structure transfer-STRUT. Finally, points in target domain are labelled by fusing the four newly derived random forest classifiers using weights of evidence based fusion model. To validate our method, experimental analysis was conducted using 3 datasets: one is used as the source domain data (Vaihingen data for 3D Semantic Labelling); another two are used as the target domain data from two cities in China (Jinmen city and Dunhuang city). Overall accuracies of 85.5 % and 83.3 % for 3D labelling were achieved for Jinmen city and Dunhuang city data respectively, with only 1/3 newly labelled samples compared to the cases without domain adaption.

Data Processing in Ecological Development and Environment Improvement by Analysis of the Relationship between Tourism Development and Urban Development

With the help of social-economy statistical data of Dunhuang City during 1987-2012, based on the related data processing technology, this paper measure the coordination between tourism development and urban development in Dunhuang City through TOPSIS evaluation method, and analyses the reasons of the coordinated development. Results show that the tourism development and urban development coordination is continuously increasing during the 1987-2012 of Dunhuang city, illustrate the development maintain a state of positive interaction and coordinated development. Dunhuang tourism development and urban development coordination optimization is closely relate to the development environmental and policy opportunities, and has great role in promoting Dunhuang ecological development and environmental improvement, just like the implement of the western development strategy, the Dunhuang water resources rational utilization and ecological protection planning and so on.