Computer science and Remote Sensing Laboratory LSIIT

Strasbourg, France

Computer science and Remote Sensing Laboratory LSIIT

Strasbourg, France
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Gagne J.,Computer science and Remote Sensing Laboratory LSIIT | Gagne J.,National Institute for Applied Sciences, Strasbourg | Piccin O.,Computer science and Remote Sensing Laboratory LSIIT | Piccin O.,National Institute for Applied Sciences, Strasbourg | And 3 more authors.
IEEE Transactions on Robotics | Year: 2012

We present herein an original solution to actively stabilize the epicardium in the context of beating-heart coronary artery bypass grafting. Our solution uses a control moment gyroscope to generate the compensation torque and an accelerometer for sensing. This approach makes the designed system completely independent from the stabilizing instrument, as well as independent from any external measurement. We compare two control approaches in a simulation: The first one uses a Kalman filter with a harmonic disturbance model, and the second one uses an adaptive algorithm. Results highlight the superiority of the adaptive control for our application. The first in vivo assessments are presented, showing the efficiency of the principle under real conditions. Using only accelerometric measurements, targeted cardiac motion harmonics are reduced on the order of 68. With an optical sensor, the reduction exceeds 90. This constitutes an improvement compared with prior solutions, despite the presence of nonnegligible uncertainties and distant sensing. © 2004-2012 IEEE.

Diagne S.,National Institute for Applied Sciences, Strasbourg | Diagne S.,University of Ziguinchor | Coulibaly A.,National Institute for Applied Sciences, Strasbourg | Coulibaly A.,University of Ziguinchor | De Bertrand De Beuvron F.,Computer Science and Remote Sensing Laboratory LSIIT
Computers in Industry | Year: 2015

The modeling of complex products is a practice increasingly used at the early design stage. Geometric 3D modeling is widely used in CAD software for complex products. However, data extracted from such models do not contain all relevant and necessary information to assess the behavioral performance of complex products. Several studies have focused on the use of design structure matrices (DSM) for the representation of this information. The component-based DSM allows a visual and compact representation of mechanical products. It gives the list of components and shows the links between them. The designer can also enrich a product model using such a DSM representation. However, we note that, until now, a component-based DSM represents only one instance of a specific product. In this paper we propose an extended DSM approach which includes additional information to model several product families. Thus, from the design specification we build the space of solutions then we determine the domain of eligible solutions. We represent these different eligible solutions in a Multi-solution eXtended Conceptual Design Semantic Matrix (MSX-CDSM). The implementation of such a matrix is introduced to assess behavioral performance of complex products at the early design stage. © 2015 Elsevier B.V.

Wang N.,CAS Institute of Geographical Sciences and Natural Resources Research | Wang N.,University of Chinese Academy of Sciences | Wu H.,CAS Institute of Geographical Sciences and Natural Resources Research | Wu H.,University of Chinese Academy of Sciences | And 4 more authors.
IEEE Transactions on Geoscience and Remote Sensing | Year: 2011

Owing to the ill-posed problem of radiometric equations, the separation of land surface temperature (LST) and land surface emissivity (LSE) from observed data has always been a troublesome problem. On the basis of the assumption that the LSE spectrum can be described by a piecewise linear function, a new method has been proposed to retrieve LST and LSE from atmospherically corrected hyperspectral thermal infrared data using linear spectral emissivity constraint. Comparisons with the existing methods found in literature show that our proposed method is more noise immune than the existing methods. Even with a NEΔT of 0.5 K, the rmse of LST is observed to be only 0.16 K, and that of LSE is 0.006. In addition, our proposed method is simple and efficient and does not encounter the problem of singular values unlike the existing methods. As for the impact of the atmosphere, the results show that our proposed method performs well with the uncertainty of the atmospheric downwelling radiance but suffers from the inaccuracy of the atmospheric upwelling radiance and atmospheric transmittance, which implies that an accurate atmospheric correction is still needed to convert the radiance measured at the satellite level to the at-ground radiance. To validate the proposed method, a field experiment was conducted, and the results show that 80% of the samples have an accuracy of LST within 1 K and that the mean values of LSE are accurate to 0.01. © 2006 IEEE.

Koehl M.,Computer science and Remote Sensing Laboratory LSIIT | Brigand N.,Computer science and Remote Sensing Laboratory LSIIT
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2012

The site of the Engelbourg ruined castle in Thann, Alsace, France, has been for some years the object of all the attention of the city, which is the owner, and also of partners like historians and archaeologists who are in charge of its study. The valuation of the site is one of the main objective, as well as its conservation and its knowledge. The aim of this project is to use the environment of the virtual tour viewer as new base for an Archaeological Knowledge and Information System (AKIS). With available development tools we add functionalities in particular through diverse scripts that convert the viewer into a real 3D interface. By beginning with a first virtual tour that contains about fifteen panoramic images, the site of about 150 times 150 meters can be completely documented by offering the user a real interactivity and that makes visualization very concrete, almost lively. After the choice of pertinent points of view, panoramic images were realized. For the documentation, other sets of images were acquired at various seasons and climate conditions, which allow documenting the site in different environments and states of vegetation. The final virtual tour was deducted from them. The initial 3D model of the castle, which is virtual too, was also joined in the form of panoramic images for completing the understanding of the site. A variety of types of hotspots were used to connect the whole digital documentation to the site, including videos (as reports during the acquisition phases, during the restoration works, during the excavations, etc.), digital georeferenced documents (archaeological reports on the various constituent elements of the castle, interpretation of the excavations and the searches, description of the sets of collected objects, etc.). The completely personalized interface of the system allows either to switch from a panoramic image to another one, which is the classic case of the virtual tours, or to go from a panoramic photographic image to a panoramic virtual image. It also allows visualizing, in inlay, digital data, like ancient or recent plans, cross sections, descriptions, explanatory videos, sound comments, etc. This project has lead to very convincing results, that were validated by the historians and the archaeologists who have now an interactive tool, disseminated through internet, allowing at the same time to visit virtually the castle, but also to query the system which sends back localized information. The various levels of understanding and set up details, allow an approach of first level for broad Internet users, but also a deeper approach for a group of scientists who are associated to the development of the ruins of the castle and its environment. © 2012 ISPRS.

Petitjean F.,Computer science and Remote Sensing Laboratory LSIIT | Inglada J.,CNRS Center for the Study of the Biosphere from Space | Gancarski P.,Computer science and Remote Sensing Laboratory LSIIT
IEEE Transactions on Geoscience and Remote Sensing | Year: 2012

Satellite Image Time Series are becoming increasingly available and will continue to do so in the coming years thanks to the launch of space missions which aim at providing a coverage of the Earth every few days with high spatial resolution. In the case of optical imagery, it will be possible to produce land use and cover change maps with detailed nomenclatures. However, due to meteorological phenomena, such as clouds, these time series will become irregular in terms of temporal sampling, and one will need to compare time series with different lengths. In this paper, we present an approach to image time series analysis which is able to deal with irregularly sampled series and which also allows the comparison of pairs of time series where each element of the pair has a different number of samples. We present the dynamic time warping from a theoretical point of view and illustrate its capabilities with two applications to real-time series. © 2012 IEEE.

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