An abstract model of a cortical hypercolumn is presented. This model could replicate experimental findings relating to the orientation tuning mechanism in the primary visual cortex. Properties of the orientation selec...
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An abstract model of a cortical hypercolumn is presented. This model could replicate experimental findings relating to the orientation tuning mechanism in the primary visual cortex. Properties of the orientation selective cells in the primary visual cortex, like contrast-invariance and response saturation, were demonstrated in simulations. We hypothesize that broadly tuned inhibition and local excitatory connections are sufficient for achieving this behavior. We have shown that the local intracortical connectivity of the model is to some extent biologically plausible.
A robotic manipulation of objects typically involves object detection/recognition, servoing to the object, alignment and grasping. To perform fine alignment and final grasping, it is usually necessary to estimate the ...
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A robotic manipulation of objects typically involves object detection/recognition, servoing to the object, alignment and grasping. To perform fine alignment and final grasping, it is usually necessary to estimate the position and orientation (pose) of the object. In this paper we present a model based tracking system used to estimate and continuously update the pose of the object to be manipulated. Here, a wire-frame model is used to find and track features in the consequent images. One of the important parts of the system is the ability to automatically initiate the tracking process. The strength of the system is the ability to operate in an domestic environment (living room) with changing lighting and background conditions.
We use a local projectional analysis method to investigate the effect of topological disorder on the vibrational dynamics in a model glass simulated by molecular dynamics. Evidence is presented that the vibrational ei...
We use a local projectional analysis method to investigate the effect of topological disorder on the vibrational dynamics in a model glass simulated by molecular dynamics. Evidence is presented that the vibrational eigenmodes in the glass are generically related to the corresponding eigenmodes of its crystalline counterpart via disorder-induced level repelling and hybridization effects. It is argued that the effect of topological disorder in the glass on the dynamical matrix can be simulated by introducing positional disorder in a crystalline counterpart.
This paper presents an interview study in which 11 academics as interviewees participated for the purpose of revealing common collaborative writing practices, with particular focus on reviewing documents. First, we pr...
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This paper presents an interview study in which 11 academics as interviewees participated for the purpose of revealing common collaborative writing practices, with particular focus on reviewing documents. First, we present the findings obtained concerning the issues of co-operating strategies underlying the reviewing process, how people revise their documents and comment on them, what they use the previous revision history for, and to what extent current technology is used in the reviewing process. Second, we also discuss aspects of the design of collaborative writing tools.
A mathematical model for a consolidation process of a highly concentrated, flocculated suspension is developed. The suspension is treated as a mixture of a fluid and solid particles by an Eulerian two-phase fluid mode...
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In this paper we investigate how the complexity of the shortest vector problem in a lattice ? depends on the cycle structure of the additive group Zn/?. We give a proof that the shortest vector problem is NP-complete ...
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NLCk for k = 1, … is a family of algebras on vertex-labeled graphs introduced by Wanke. An NLC-decomposition of a graph is a derivation of this graph from single vertices using the operations in question. The width o...
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First order errors downstream of shocks are detected in computations with second order shock capturing schemes. Based on a matched asymptotic expansion analysis we show how to modify the artificial viscosity and raise...
GEMSviz is a framework for visualization of distributed computations. It has been extended to handle remote monitoring and steering, as well as tele-immersive collaboration. The computational core consists of a code f...
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We present a fully automatic algorithm for estimating the projected light source direction from a single image. The requirement is that there exists a segment of an occluding contour of an object with locally Lamberti...
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ISBN:
(纸本)0769512720
We present a fully automatic algorithm for estimating the projected light source direction from a single image. The requirement is that there exists a segment of an occluding contour of an object with locally Lambertian surface reflectance in the image. The algorithm consists of three stages. First a heuristic algorithm picks out potential occluding contours using color and edge information. Secondly, for each contour the light source direction is estimated using a shading model. In the final stage the results from the estimations are fused together in a Bayesian network to arrive at the most likely light source direction. The probabilistic model takes into account that the contours from the first stage might not be occluding contours. Using the same framework the contours are also classified as occluding or not. Experiments test the second stage, estimating the light source direction from an occluding contour, as well as the full algorithm.
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