A self-adaptive segmentation method for a point cloud

The segmentation of a point cloud is one of the key technologies for three-dimensional reconstruction, and the segmentation from three-dimensional views can facilitate reverse engineering. In this paper, we propose a self-adaptive segmentation algorithm, which can address challenges related to the region-growing algorithm, such as inconsistent or excessive segmentation. Our algorithm consists of two main steps: automatic selection of seed points according to extracted features and segmentation of the points using an improved region-growing algorithm. The benefits of our approach are the ability to select seed points without user intervention and the reduction of the influence of noise. We demonstrate the robustness and effectiveness of our algorithm on different point cloud models and the results show that the segmentation accuracy rate achieves 96%

The effect of industrialization and globalization on domestic land-use: A global resource footprint perspective

Land-use activities are increasingly globalized and industrialized. While this contributes to a reduction of pressure on domestic ecosystems in some regions, spillover effects from these processes represent potential obstacles for global sustainable land-use. This contribution scrutinizes the complex global resource nexus of national land-use intensity, international trade of biomass goods, and resource footprints in land-use systems. Via a systematic account of the global human appropriation of net primary production (HANPP) and input–output modelling, we demonstrate that with growing income countries reduce their reliance on local renewable resources, while simultaneously consuming more biomass goods produced in other countries requiring higher energy and material inputs. The characteristic 'outsourcing' country appropriates 43% of its domestic net primary production, but net-imports a similar amount (64 gigajoules per capita and year) from other countries and requires energy (11 GJ/cap/yr) and material (~400 kg/cap/yr) inputs four to five times higher as the majority of the global population to sustain domestic land-use intensification. This growing societal disconnect from domestic ecological productivity enables a domestic conservation of ecosystems while satisfying growing demand. However, it does not imply a global decoupling of biomass consumption from resource and land requirements

Broadband dielectric investigation on poly(vinyl pyrrolidone) and its water mixtures

7 pages.-- PACS nr.: 61.25.he.Broadband dielectric spectroscopy and differential scanning calorimetry measurements have been performed to study the molecular dynamics poly (vinyl pyrrolidone) and its water solutions in a wide range of concentrations (0 wt %<wc<55 wt %) and in the temperature range from 140 to 500 K. The dry material was completely characterized showing the presence of two relaxations in the supercooled state. The slow one has the characteristics of a Johari-Goldstein-type relaxation. On the other hand, the low temperature water dynamics in the mixtures evidences a prominent loss peak due to the reorientation of water molecules inside the polymer matrix for all the hydration levels. We show that the relaxation times are almost water concentration (wc) independent from wc>20 wt % suggesting that this dynamical process is dominated by water-water interactions. In addition, the temperature dependence of the water relaxation times exhibits a crossover from non-Arrhenius to Arrhenius behavior during cooling throughout the glass transition range, which has been interpreted as due to the constrains imposed by the rigid polymer matrix on the water molecules dynamics.The authors acknowledge the support of the University of Basque Country and the Basque Government, Project No. UPV/EHU, 9/UPV 00206.215-13568/2001, and the Spanish Ministry of Education Project No. MAT2007-63681.Peer reviewe