671 research outputs found
WP - liu hua
No full textAn installation commenting on the tragic death of a Chinese student studying at Wimbledon College of Arts and the historical relationship between China and Europe, referencing Orientalism, Chinoiserie and the Willow Pattern design
Unsupervised learning of compact 3D models based on the detection of recurrent structures
No full text3D environment modeling based on surface primitives
No full textIn this article we describe an algorithm for constructing a compact representation of 3D laser range data. Our approach extracts a dictionary of local scans from the scene. The words of this dictionary are used to replace recurrent local 3D structures, which leads to a substantial compression of the entire point cloud. We optimize our model in terms of complexity and accuracy by minimizing the Bayesian information criterion (BIC). Experimental evaluations on large real-world datasets show that the described method allows robots to accurately reconstruct environments with as few as 70 words. Furthermore the experiments suggest that the proposed representation gives a richer semantic description than pure occupancy based representations. © 2012 Springer-Verlag GmbH Berlin Heidelberg
Unsupervised learning of 3D object models from partial views
No full textWe present an algorithm for learning 3D object models from partial object observations. The input to our algorithm is a sequence of 3D laser range scans. Models learned from the objects are represented as point clouds. Our approach can deal with partial views and it can robustly learn accurate models from complex scenes. It is based on an iterative matching procedure which attempts to recursively merge similar models. The alignment between models is determined using a novel scan registration procedure based on range images. The decision about which models to merge is performed by spectral clustering of a similarity matrix whose entries represent the consistency between different models.© 2009 IEEE
OBJECT RECOGNITION METHOD, OBJECT RECOGNITION APPARATUS, AND AUTONOMOUS MOBILE ROBOT
No full textTo carry out satisfactory object recognition in a short time. An object recognition method in accordance with an exemplary aspect of the present invention is an object recognition method for recognizing a target object by using a preliminarily-created object model. The object recognition method generates a range image of an observed scene, detects interest points from the range image, extracts first features, the first features being features of an area containing the interest points, carries out a matching process between the first features and second features, the second features being features of an area in the range image of the object model, calculates a transformation matrix based on a result of the matching process, the transformation matrix being for projecting the second features on a coordinate system of the observed scene, and recognizes the target object with respect to the object model based on the transformation mat
On Measuring the Accuracy of SLAM Algorithms
No full textIn this paper, we address the problem of creating an objective benchmark for evaluating SLAM approaches.We propose a framework for analyzing the results of a SLAM approach based on a metric for measuring the error of the corrected trajectory. This metric uses only relative relations between poses and does not rely on a global reference frame. This overcomes serious shortcomings of approaches using a global reference frame to compute the error. Our method furthermore allows us to compare SLAM approaches that use different estimation techniques or different sensor modalities since all computations are made based on the corrected trajectory of the robot. We provide sets of relative relations needed to compute our metric for an extensive set of datasets frequently used in the robotics community. The relations have been obtained by manually matching laser-range observations to avoid the errors caused by matching algorithms. Our benchmark framework allows the user to easily analyze and objectively compare different SLAM approaches
Målinger av ozon, Østlandet-Telemark-Sørlandet. Målinger av PAN, Telemark, 1984-1985.
No full textMålinger av ozon har foregått på to steder i Oslofjord-området, tre steder i nedre Telemark og to steder i Aust-Agder. På fem steder er det målt timesverdier over WHOs grenseverdi på 120 μg/m^3. På to steder ble det i 1985 målt timesverdier over 200 μg/m^3. De fleste høye konsentrasjoner ble målt i samband med transport av forurensede luftmasser fra østlig kant. Bidrag fra utslippskilder i Norge har også vært medvirkende. De høyeste timesverdiene for PAN var 25-30 μg/m^3
Om flydende Gjødning. En kort Fremstilling af Fordelene ved at benytte som Gjødning de flydende Ureenligheder fra beboede Steder, samt en Anviisning til disses Fordeling paa Marker og i Haver.
No full textOm flydende Gjødning. En kort Fremstilling af Fordelene ved at benytte som Gjødning de flydende Ureenligheder fra beboede Steder, samt en Anviisning til disses Fordeling paa Marker og i Haver
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