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Three-dimensional model databases used around the Web become larger; therefore, the development of retrieval systems for such databases is required. In this paper, we propose a new 3D shape descriptor and a web based search engine for 3D models given by polygonal meshes. The main idea is to reconstruct a 3D closed curve that represents the 3D object and to extract feature vectors from it. We combine two new descriptors the area and the dot product descriptors that describe the reconstructed 3D closed curve in order to define the 3D curve analysis descriptor. The proposed method is robust for noise, compared to other descriptors known in the literature and tested using the Princeton shape benchmark database via the search engine.

Augmented reality (AR) is based on supplementing the view of the physical world with a computer-generated content such as text, images videos, sound, 3D objects etc. The proliferation of smart mobile devices and their high computational capabilities combined with the possibility of GIS 3D visualization and interaction have enabled new kinds of mobile applications. AR is considered as an efficient technology for the underground utilities management. Damages to underground utility lines are considered as one of the major urban problems because incidents caused by unsafe digging practices can compromise community safety and disconnect people from vital services. A prospective study was conducted to identify examples and characteristics of each type of augmented reality. This paper summarizes researches about the types of AR and discuss how this technology could help in underground utilities repairing and maintenance. We present a new mobile location based augmented reality system using smart device sensors and the Real Time Kinematic (RTK) satellite navigation technology of ORPHEON network for the location accuracy. This system enables GIS data visualization to help field workers in outdoor maintenance of underground infrastructures.

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