检索结果-内蒙古大学图书馆

IEEE International Symposium on Signal Processing and Information technology (ISSPIT)

作者： Catarina Runa Miranda Filipe Soares Inês Sousa Filipe Janela Mário Forjaz Secca Physics Department Faculty of Sciences and Technology New University of Lisbon Portugal Instituto de Telecomunicações Department of Computer Science University of Beira Interior Portugal Institute for Systems and Robotics Department of Bioengineering Instituto Superior Técnico Portugal Siemens S.A. Healthcare Sector Portugal

The aim of this work is to propose a multifractal analysis method for Multifractal Detrended Fluctuation analysis (MF-DFA) of Blood Oxygen Level Dependent (BOLD) functional Magnetic Resonance Imaging (fMRI). The fMRI signals exhibit a 1/f power spectrum, hence their structure has self-similarity and long memory, being usually successfully analyzed by different fractal analysis methods without a previous knowledge of haemodynamic models. Therefore, to validate activation detection using the MF-DFA method, a comparison study between images obtained using General Linear Model (GLM) and Independent Component Analysis (ICA) was conducted and evaluated by discrimination power, applying Receiver Operating Characteristic (ROC) analysis to the results.

关键词： Transforms Power measurement

来源：评论

学校读者我要写书评

暂无评论

Background modelling on tensor field for foreground segmentation

Background modelling on tensor field for foreground segmenta...

引用

2010 21st British Machine Vision Conference, BMVC 2010

作者： Caseiro, Rui Martins, Pedro Batista, Jorge Institute for Systems and Robotics Faculty of Science and Technology University of Coimbra 3030 Coimbra Portugal

ISBN: (纸本)1901725405

The paper proposes a new method to perform foreground detection by means of background modeling using the tensor concept. Sometimes, statistical modelling directly on image values is not enough to achieve a good discrimination. Thus the image may be converted into a more information rich form, such as a tensor field, to yield latent discriminating features. Taking into account the theoretically well-founded differential geometrical properties of the Riemannian manifold where tensors lie, we propose a new approach for foreground detection on tensor field based on data modeling by means of Gaussians mixtures directly on tensor domain. We introduced a online Kmeans approximation of the Expectation Maximization algorithm to estimate the parameters based on an Affine-Invariant metric. This metric has excellent theoretical properties but essentially due to the space curvature the computational burden is high. We propose a novel Kmeans algorithm based on a new family of metrics, called Log-Euclidean, in order to speed up the process, while conserving the same theoretical properties. Contrary to the affine case, we obtain a space with a null curvature. Hence, classical statistical tools usually reserved to vectors are efficiently generalized to tensors in the Log-Euclidean framework. Theoretical aspects are presented and the Affine-Invariant and Log-Euclidean frameworks are compared experimentally. From a practical point of view, results are similar to those of the Affine-Invariant framework but are obtained much faster. Theoretic analysis and experimental results demonstrate the promise and effectiveness of the proposed framework. © 2010. The copyright of this document resides with its authors.

关键词： Tensors

来源：评论

学校读者我要写书评

暂无评论

Does the information in the phase of low frequency LFP reflect the low frequency envelope of local spike rates?

引用

BMC Neurosci 2011年第SUPPL 1期12卷 P227-P227页

作者： Sohail Siadatnejad Stefano Panzeri Christoph Kayser Nikos K Logothetis Marcelo A Montemurro Faculty of Life Sciences University of Manchester Manchester M13 9PT UK Robotics Brain and Cognitive Sciences Department Italian Institute of Technology Genoa 16163 Italy Max Planck Institute for Biological Cybernetics Tübingen 72076 Germany Imaging Science and Biomedical Engineering University of Manchester Manchester M13 9PT UK

来源：评论

学校读者我要写书评

暂无评论

Measurements of rivet flexibility and load transfer in a lap joint

Measurements of rivet flexibility and load transfer in a lap...

引用

18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale, ECF 2010

作者： Skorupa, M. MacHniewicz, T. Schijve, J. Skorupa, A. Korbel, A. Faculty of Mechanical Engineering and Robotics AGH University of Science and Technology Al. Mickiewicza 30 30-059 Kraków Poland Faculty of Aerospace Engineering Delft University of Technology Kluyverweg 1 2600 GB Delft Netherlands

Presented in this paper are results of an experimental investigation on the rivet flexibility and load transmission in a riveted lap joint representative for the aircraft fuselage. The test specimens consisted of two aluminium alloy Alclad sheets joined with three rows of rivets. Rivet flexibility measurements have been performed under constant amplitude fatigue loading using several methods including two novel optical techniques developed by the present authors. The axial forces in the sheets required to determine the rivet flexibility have been derived from strain gauge measurements. In order to eliminate the effect of sheet bending the strain gauges have been bonded at the same locations on the outside and faying surface of the sheet. Variations of the rivet flexibility during the fatigue loading as well as the dependence of the rivet flexibility and load transmission on the rivet squeeze force have been studied. The experiments enabled to evaluate the usefulness of various techniques to determine the rivet flexibility. It was observed that although the measured flexibility was identical for both outer rivet rows, the load transfer through either of these rows was different. Previous experimental results of the authors suggest that the non-symmetrical load transfer distribution through the joint is associated with large differences between the rivet hole expansion in the sheet adjacent to the driven rivet head and the sheet under the manufactured head. It has been concluded that commonly used computation procedures according to which the load transfer is only related to the rivet flexibility may lead to erroneous results.

关键词： Strain gages

来源：评论

学校读者我要写书评

暂无评论

Robust hand-eye calibration for computer aided medical endoscopy

Robust hand-eye calibration for computer aided medical endos...

引用

IEEE International Conference on robotics and Automation (ICRA)

作者： Abed Malti João P. Barreto Institute of Systems and Robotics Faculty of Science and Technology University of Coimbra Coimbra Portugal

Endoscopic camera for surgical navigation and 3D visualization requires precise and stable estimates of the calibration parameters. The estimation of the hand-eye transform between the camera frame and the opto-tracked body of the endoscope is an important issue of the calibration. This paper presents a new stable method for the hand-eye calibration problem. The most popular method estimates the transform directly in the special euclidean group SE(3) by computing separately the rotation and the translation. The second famous approach formulates the problem in the dual quaternion space and estimates jointly the rotation and the translation. In a first glance, the simultaneous estimation seems to be always advantageous. However, and according to the experiments, this is not the case for the rotation estimation that is affected by the noise in translation. Our approach takes advantage of the both methods and uses the dual quaternion to estimate separately the rotation and the translation. We show experimentally that our algorithm is more stable with minimal number and small amplitude of motions.

关键词： Robustness Calibration Endoscopes Cameras Robot vision systems robotics and automation Equations Quaternions Machine vision Robot sensing systems

来源：评论

学校读者我要写书评

暂无评论

Fuzzy logic approach to the gain scheduling crane control system

Fuzzy logic approach to the gain scheduling crane control sy...

引用

International Conference on Methods and Models in Automation and robotics (MMAR)

作者： Jarosław Smoczek Janusz Szpytko Faculty of Mechanical Engineering and Robotics AGH University of Science and Technology Krakow Poland

The problem of crane control system is addressed in the paper to gain scheduling system created using the fuzzy controller with Takagi-Sugeno-Kang (TSK) fuzzy implications. The method of fuzzy robust crane control system designing was based on closed-loop crane control systems with conventional proportional-derivative (PD) controllers of crane position and the load swing derived for fixed rope length and mass of a load values, which are used as key-scheduling variables. The set of controllers, scheduled by fuzzy system, are determined using the pole placement method (PPM). The problem of selecting the minimal set of fuzzy system operating points was solved and described as well in the paper.

关键词： Cranes Mathematical model Equations Robustness Artificial neural networks PD control

来源：评论

学校读者我要写书评

暂无评论

Evaluation of threats in an antropotechnical system

Evaluation of threats in an antropotechnical system

引用

作者： Woropay, MacIej Bojar, Piotr Muślewski, Lukasz Szpytko, Janusz University of Technology and Life Sciences Faculty of Mechanical Engineering Ul. Prof. S. Kaliskiego 7 PL 85-796 Bydgoszcz Poland AGH University of Science and Technology Faculty of Mechanical Engineering and Robotics PL 30-059 Krakow Poland

ISBN: (纸本)9789604742103

An antropotechnical system is the Human -Technical Object set which perform their tasks in the environment H-TO-E. In systems of this type threats are posed by: the human H technical object TO and by the impact of the environment E on the technical object and people present in the system and in its environment. Threats, which result from the technical object limited task ability state, can be divided into: errors of training, decision errors and information reception errors. The errors are caused by poor condition (psychical or psychophysical) of the operator, or their inappropriate actions. Threats resulting from the state of the technical object limited usability are dependent on importance of the damaged subsystems, the more important the damage object, the higher threat level of the system operation safety. The paper deals with identification of threat occurrence sources connected with the states of the technical object limited usability and assessment of their influence on the analyzed system operation safety. For this purpose an index model has been built and the analysis hierarchy process AHP has been used.

关键词： Errors

来源：评论

学校读者我要写书评

暂无评论

Influence of Human factor on transport system safety

Influence of Human factor on transport system safety

引用

作者： Bojar, Piotr Muślewski, Lukasz Woropay, MacIej Szpytko, Janusz University of Technology and Life Sciences Faculty of Mechanical Engineering Ul. Prof. S. Kaliskiego 7 PL 85-796 Bydgoszcz Poland AGH University of Science and Technology Faculty of Mechanical Engineering and Robotics PL 30-059 Krakow Poland

ISBN: (纸本)9789604742103

Road transport systems are socio-technical systems of the type Human - Technical object - Environment (H-TO-E). In these systems hazards can be caused by: the man C, the technical object OT, and influence of the environment on the technical object and people who are present in the system and its environment. The authors of the paper make an attempt to evaluate the level of threats resulting from intended or not intended actions of people situated in this environment.

关键词： Human engineering

来源：评论

学校读者我要写书评

暂无评论

The evaluation method of human - Machine system operation quality

The evaluation method of human - Machine system operation qu...

引用

作者： Muślewski, Lukasz Woropay, MacIej Bojar, Piotr Szpytko, Janusz University of Technology and Life Sciences Faculty of Mechanical Engineering Ul. Prof. S. Kaliskiego 7 PL 85-796 Bydgoszcz Poland AGH University of Science and Technology Faculty of Mechanical Engineering and Robotics PL 30-059 Krakow Poland

ISBN: (纸本)9789604742103

In the paper the issues of the transport systems operation quality assessment are considered. The studies take into consideration the real complex socio-technical (H - M - E) (human - machine - environment) systems. The assessment quality of the systems operation is based on the changes of the systems features values. The features describe the operation of the systems operators, controlled technical objects (vessels, trains, planes or cars) and the environment influence. The assessment and the support the demand quality of the systems operation from the safety, efficiency, economic and reliability point of view is the basic factor of the executed exploitation process. The paper deals with description of rules, on the basis of which the method has been developed. Algorithm of mathematical model of the systems operation quality evaluation has been built. Metrics have been elaborated, essential concepts of metric space have been used and partial order relation as well as appropriate setting systems in order in terms of their operation quality has been applied. The model can serve as a general abstract form for operation quality evaluation of a wide range of real transport systems differing with properties, structure and operation.

关键词： Quality control

来源：评论

学校读者我要写书评

暂无评论

Robust RBPF-SLAM using sonar sensors in non-static environments

Robust RBPF-SLAM using sonar sensors in non-static environme...

引用

IEEE International Conference on robotics and Automation (ICRA)

作者： Jung-Suk Lee Chanki Kim Wan Kyun Chung Robotics Laboratory Department of Mechanical Engineering Pohang University of Science and Technology Pohang South Korea Faculty of Robotics Laboratory Department of Mechanical Engineering Pohang University of Science and Technology Pohang South Korea

ISBN: (纸本)9781424450381;9781424450404

In this paper, we present a robust RBPF-SLAM algorithm for mobile robots in non-static environments. We propose an approach for sampling particles from multiple ancestor sets, not from just one prior set. This sampling method increases the robustness of SLAM algorithm, because some particles can be updated by only observations consistent with the map, even if observation at certain time step is corrupted by environmental changes. Corrupted observations are filtered out from recursive Bayesian update process by the proposed sampling method. We also present an intermediate path estimation method to use abandoned sensor information reflected from relocated objects for map update. The map can represent the changed configuration of non-static environment by the stored sensor information and the estimated path. Results of simulations and experiments in non-static environments show the robustness of proposed RBPF-SLAM algorithm using sonar sensors.

关键词： Robustness Sonar Simultaneous localization and mapping Mobile robots Robot sensing systems Sampling methods Target tracking Mechanical sensors Estimation error Mechanical engineering

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：