检索结果-内蒙古大学图书馆

IFIP Advances in Information and Communication Technology 2010年 314卷 215-222页

作者： Faria, Diego R. Martins, Ricardo Dias, Jorge Institute of Systems and Robotics Department of Electrical Engineering and Computers University of Coimbra - Polo II 3030-290 Coimbra Portugal

ISBN: (纸本)9783642116278

In this work it is shown the representation of 3D object shape acquired from grasp exploration. Electromagnetic motion tracking sensors are used on the fingers for object contour following to acquire the 3D points to represent its shape using a probabilistic volumetric map. It is used the object referential for its representation. For that, it is found the center of mass of the 3D object through the moments to define its referential. The occupancy of each individual voxel in the map is assumed to be independent from the other voxels occupancy. The posteriori achieved from Bayes' rule is the probability distribution on the occupations percentage for each voxel. The probabilistic map in a Cartesian system is converted to the spherical coordinate system for visualization with more details on its surface. © 2010 Springer Berlin Heidelberg.

关键词： Probability distributions

来源：评论

学校读者我要写书评

暂无评论

Bio-inspired binocular disparity with position-shift receptive field

IFIP Advances in Information and Communication Technology

引用

IFIP Advances in Information and Communication Technology 2010年 314卷 351-358页

作者： Faria, Fernanda D.C.E.C. Batista, Jorge Araújo, Helder Department of Electrical Engineering and Computers Institute of Systems and Robotics University of Coimbra - Polo II 3030-290 Coimbra Portugal

ISBN: (纸本)9783642116278

Depth perception starts with the binocular interaction receptive fields of simple cells modeled by two Gabor functions followed by a half-squaring function. Simple cells do not have reliable disparity computation. Complex cells combine two simple cells in quadrature. They are better adapted to encode disparity information. The image disparity can be determined by fixing the receptive field in one eye and varying it in the other. Pooling information of spatial frequency and orientation is very important to improve the quality of results of real world stereograms. In this work, a bio-inspired method to calculate binocular disparity based on the energy model for depth perception of real world images is described and implemented. The performance of the proposed method is also evaluated in what concerns the algorithm computational cost, root-mean-square error and percentage of wrongly matched pixels. © 2010 Springer Berlin Heidelberg.

关键词： Stereo vision

来源：评论

学校读者我要写书评

暂无评论

A face attention technique for a robot able to interpret facial expressions

IFIP Advances in Information and Communication Technology

引用

IFIP Advances in Information and Communication Technology 2010年 314卷 335-342页

作者： Simplício, Carlos Prado, José Dias, Jorge Institute of Systems and Robotics Department of Electrical Engineering and Computers University of Coimbra Coimbra Portugal School of Technology and Management Institute Polytechnic of Leiria Leiria Portugal

ISBN: (纸本)9783642116278

Automatic facial expressions recognition using vision is an important subject towards human-robot interaction. Here is proposed a human face focus of attention technique and a facial expressions classifier (a Dynamic Bayesian Network) to incorporate in an autonomous mobile agent whose hardware is composed by a robotic platform and a robotic head. The focus of attention technique is based on the symmetry presented by human faces. By using the output of this module the autonomous agent keeps always targeting the human face frontally. In order to accomplish this, the robot platform performs an arc centered at the human;thus the robotic head, when necessary, moves synchronized. In the proposed probabilistic classifier the information is propagated, from the previous instant, in a lower level of the network, to the current instant. Moreover, to recognize facial expressions are used not only positive evidences but also negative. © 2010 Springer Berlin Heidelberg.

关键词： Human robot interaction

来源：评论

学校读者我要写书评

暂无评论

Distributed detection over time varying networks: Large deviations analysis

Distributed detection over time varying networks: Large devi...

引用

Annual Allerton Conference on Communication, Control, and Computing

作者： Dragana Bajović Dušan Jakovetić João Xavier Bruno Sinopoli José M. F. Moura The Institute for Systems and Robotics (ISR) Instituto Superior Técnico (IST) Lisbon Portugal The Department of Electrical and Computer Engineering Carnegie Mellon University Pittsburgh PA USA Institute of Systems and Robotics (ISR) Instituto Superior Técnico Lisboa Portugal

We apply large deviations theory to study asymptotic performance of running consensus distributed detection in sensor networks. Running consensus is a stochastic approximation type algorithm, recently proposed. At each time step k, the state at each sensor is updated by a local averaging of the sensor's own state and the states of its neighbors (consensus) and by accounting for the new observations (innovation).We assume Gaussian, spatially correlated observations. We allow the underlying network be time varying, provided that the graph that collects the union of links that are online at least once over a finite time window is connected. This paper shows through large deviations that, under stated assumptions on the network connectivity and sensors' observations, the running consensus detection asymptotically approaches in performance the optimal centralized detection. That is, the Bayes probability of detection error (with the running consensus detector) decays exponentially to zero as k → ∞ at the Chernoff information rate-the best achievable rate of the asymptotically optimal centralized detector.

关键词： Detectors Data models Detection algorithms Approximation algorithms Testing Symmetric matrices Approximation methods

来源：评论

学校读者我要写书评

暂无评论

Optimal control on non-compact lie groups: A projection operator approach

Optimal control on non-compact lie groups: A projection oper...

引用

IEEE Conference on Decision and Control

作者： Alessandro Saccon John Hauser A. Pedro Aguiar Institute of Systems and Robotics (ISR) Instituto Superior Técnico Lisboa Portugal Department of Electrical and Computer Engineering University of Colorado Boulder USA

ISBN: (纸本)9781424477456

Many nonlinear systems of practical interest evolve on Lie groups or on manifolds acted upon by Lie groups. Examples range from aircraft and underwater vehicles to quantum mechanical systems. In this paper, we develop the mathematical machinery needed for projection operator based trajectory exploration and optimization (optimal control) for systems defined on non-compact Lie groups.

关键词： Trajectory Manifolds Digital TV Approximation methods Optimization Algebra Nonlinear systems

来源：评论

学校读者我要写书评

暂无评论

Trainable classifier-fusion schemes: An application to pedestrian detection

Trainable classifier-fusion schemes: An application to pedes...

引用

2009 12th International IEEE Conference on Intelligent Transportation systems, ITSC '09

作者： Junior, Oswaldo Ludwig Delgado, David Gonçalves, Valter Nunes, Urbano ISR-Institute of Systems and Robotics Department of Electrical and Computer Engineering University of Coimbra Polo II 3030-290 Coimbra Portugal

ISBN: (纸本)9781424455218

This work proposes a novel classifier-fusion scheme using learning algorithms, i.e. syntactic models, instead of the usual Bayesian or heuristic rules. Moreover, this paper complements the previous comparative studies on DaimlerChrysler Automotive Dataset, offering a set of complementary experiments using feature extractor and classifier combinations. The experimental results provide evidence of the effectiveness of our methods regarding false positive rate, AUC, and accuracy, which reached 96.67%. © 2009 IEEE.

关键词： Classification (of information)

来源：评论

学校读者我要写书评

暂无评论

Robotic wheelchair trajectory control considering user comfort

Robotic wheelchair trajectory control considering user comfo...

引用

5th International Conference on Informatics in Control Automation and robotics, ICINCO 2008

作者： Solea, Razvan Nunes, Urbano Department of Electrical and Computer Engineering ISR - Institute of Systems and Robotics University of Coimbra Coimbra 3030-290 Portugal Department of Automation and Industrial Informatics Dunarea de Jos University of Galati Galati 800-008 Romania

ISBN: (纸本)9783642002700

This paper analyzes the comfort of wheelchair users when a sliding-mode trajectory-tracking controller is used. The transmission of the horizontal (fore-and-aft) vibration to the head-neck complex (HNC) in the seated human body may cause unacceptable discomfort and motion sickness. A double-inverted pendulum model with two degrees of freedom is considered as a model for the HNC. The user comfort is examined not only in the time domain (using the fourth power vibration dose value), but also in the frequency domain (using the cross-spectral density method). For measuring the acceleration of the wheelchair, along the trajectory, an inertial measurement unit was used. © 2009 Springer-Verlag Berlin Heidelberg.

关键词： Degrees of freedom (mechanics)

来源：评论

学校读者我要写书评

暂无评论

Identity and expression recognition on low dimensional manifolds

Identity and expression recognition on low dimensional manif...

引用

IEEE International Conference on Image Processing

作者： Pedro Martins Jorge Batista Institute of Systems and Robotics Department of Electrical Engineering and Computers University of Coimbra Portugal

A solution for identity and facial expression recognition is proposed using a two stage classifier approach using low dimensional representation of the geometry of the face. Face geometry is extracted from input images using Active Appearance Models (AAM) and low dimensional manifolds were then derived using Laplacian Eigen-Maps (LE) resulting in two types of manifolds, one for model identity and the other for person-specific facial expression. The first stage uses a multiclass Support Vector Machines (SVM) to establish identity across expression changes. The second stage deals with person-specific expression recognition, and is composed by a network of seven Hidden Markov Models (HMM) displaced in parallel, each one specialized on the several facial emotions analysed. The decision was made by the sequence that yielded the highest probability. For evaluation proposes a database was build consisting on 6770 images captured from 4 people exhibiting 7 different emotions. The identity overall recognition rate was 96.8%. Facial expression results are identity dependent, and the most expressive individual achieves 81.2% of overall recognition rate.

关键词： Face recognition Hidden Markov models Geometry Active appearance model Manifolds Support vector machines Laplace equations Solid modeling Emotion recognition Image databases

来源：评论

学校读者我要写书评

暂无评论

A technique for dynamic background segmentation using a robotic stereo vision head

A technique for dynamic background segmentation using a robo...

引用

IEEE International Workshop on Robot and Human Communication (ROMAN)

作者： Jose Prado Luis Santos Jorge Dias Institute of Systems and Robotics Department of Electrical Engineering and Computers University of Coimbra Portugal

Human-robot interaction approaches like face detection, face recognition, pedestrian detection are widely known in robotics field; however often they lead to performance problems. Additionally, false positive and false negative problems are commonly associated to bad illumination and strong featured images. Moreover background segmentation approaches are frequently used to solve this problem on static camera surveillance. Though all these approaches are unable to effectively deal with the constant background changes that certainly happens when the camera sensor is installed on a mobile robot. Hence, in this work we propose a stereo vision dynamic background segmentation solution to this problem.

关键词： Robot vision systems Stereo vision Image segmentation Face detection Cameras Head Face recognition Human robot interaction Humanoid robots Lighting

来源：评论

学校读者我要写书评

暂无评论

Estimating traffic intensity using profile images on rectified images

Estimating traffic intensity using profile images on rectifi...

引用

IEEE International Conference on Image Processing

作者： Cristina Maduro Katherine Batista Jorge Batista ISR-Institute of Systems and Robotics Department of Electrical Engineering FCT-Universidade de Coimbra Coimbra Portugal

In this paper a technique is presented to estimate the traffic intensity for each lane. This method does not require background estimation or even the identification and tracking of individual vehicles. It requires only the identification of each lane and the estimation of a bird eye view of the highway using a rectification method. To each rectified lane, an intensity profile is computed along the traffic flow direction for each frame, obtaining an image that represents the displacement as a time function. The main idea is to search for the best matching profile for different times and spaces on each lane and consequently obtain the velocity profile.

关键词： Vehicle detection Cameras Road transportation Surveillance Polynomials Space technology Robots Birds Computer vision Parameter estimation

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：