This paper studies matching of fragmented objects to recompose their original geometry. Solving this geometric reassembly problem has direct applications in archaeology and forensic investigation in the computer-aided restoration of damaged artifacts and evidence. We develop a new algorithm to effectively integrate both guidance from a template and from matching of adjacent pieces' fracture-regions. First, we compute partial matchings between fragments and a template, and pairwise matchings among fragments. Many potential matches are obtained and then selected/refined in a multi-piece matching stage to maximize global groupwise matching consistency. This pipeline is effective in composing fragmented thin-shell objects containing small pieces, whose pairwise matching is usually unreliable and ambiguous and hence their reassembly remains challenging to the existing algorithms.

We propose a biharmonic model for cross-object volumetric mapping. This new computational model aims to facilitate the mapping of solid models with complicated geometry or heterogeneous inner structures. In order to solve cross-shape mapping between such models through divide and conquer, solid models can be decomposed into subparts upon which mappings is computed individually. The biharmonic volumetric mapping can be performed in each subregion separately. Unlike the widely used harmonic mapping which only allows C0 continuity along the segmentation boundary interfaces, this biharmonic model can provide C1 smoothness. We demonstrate the efficacy of our mapping framework on various geometric models with complex geometry (which are decomposed into subparts with simpler and solvable geometry) or heterogeneous interior structures (whose different material layers can be segmented and processed separately).

This paper studies the optimal inspection of autonomous robots in a complex pipeline system. We solve a 3-D region-guarding problem to suggest the necessary inspection spots. The proposed hierarchical integer linear programming optimization algorithm seeks the fewest spots necessary to cover the entire given 3-D region. Unlike most existing pipeline inspection systems that focus on designing mobility and control of the explore robots, this paper focuses on global planning of the thorough and automatic inspection of a complex environment. We demonstrate the efficacy of the computation framework using a simulated environment, where scanned pipelines and existing leaks, clogs, and deformation can be thoroughly detected by an autonomous prototype robot.

With the advance of scanning devices, 3-d geometric models have been captured and widely used in animation, video, interactive virtual environment design nowadays. Their effective analysis, integration, and retrieval are important research topics in multimedia. This paper studies a geometric modeling problem called 3D region guarding. The 3D region guarding is a well known NP-hard problem; we present an efficient hierarchical integer linear programming (HILP) optimization algorithm to solve it on massive data sets. We show the effectiveness of our algorithm and briefly illustrate its applications in multimedia data processing and computer graphics such as shape analysis and retrieval, and morphing animation.

Abstract This paper proposes an effective framework to compute the visibility guarding and star decomposition of 3D solid shapes. We propose a progressive integer linear programming algorithm to solve the guarding points that can visibility cover the entire shape; we also develop a constrained region growing scheme seeded on these guarding points to get the star decomposition. We demonstrate this guarding/decomposition framework can benefit graphics tasks such as shape interpolation and shape matching/retrieval.

The new Chinese satellite HJ-1A/B CCD images are used in the sea ice monitoring of Nanpu sea area in winter, during the time from Nov. 29, 2008 to Feb. 21, 2009. A fast processing work flow is established based on the object-oriented information extraction technology. And the result analysis and discussion are also given for the sea ice monitoring in this sea area during the time from Nov. 29, 2008 to Feb. 21, 2009, including ice periods, distribution, and development rule. Moreover, the ice safety of the artificial islands in Nanpu-4 structure is monitored in the winter.The study shows that remote sensing technology can provide oil fields with timely and accurate beach ice monitoring.It is practical and effective technical means for the sea ice security monitoring in beach oil fields' exploration, development and engineering construction.

This work was to give an identification mode of ChemicaL Oxygen Demand (COD) within water body using remotely sensing technique. For this purpose the field data, including the spectral data of water body and the concentration of COD within water ,were collected at Huanjiang river, Rouyuan river and Malian river in Qingyang city , Gansu province of China on 6–7 April and 13–15 October,2006. The 90% samples were employed to establish the identification mode of COD according to Fisher multiclass discriminant rule. By the actual status and the national standard, the concentration of COD were classed three levels. The field spectral data were processed as corresponding bands of Landsat/ TM.. The accuracy reaches 83% with the validation of the rest 10% samples. Further, the model was applied to the two Landsat/ TM images captured on Oct. 16, 2005 and Apr. 10, 2006 in order to obtain the distributing image of COD in the rivers. By mean of the image the temporal change and spatial distribute of the concentration of COD within the three rivers were analyzed. The result shows that the establishment of identification mode based on remotely sensing provides an effective means to obtain rapidly and low-cost the concentration of COD in water environment.