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101.
Mathieu Thevenot Sylvie Dousset Philippe Schmitt-Kopplin 《The Science of the total environment》2009,407(14):4297-4302
Diuron is frequently detected in some drinking water reservoirs under the Burgundy vineyards, where organic amendments are applied. The environmental effect of these amendments on pesticide transport is ambiguous: on the one hand it could enhance their retention by increasing soil organic carbon content; on the other hand, dissolved organic matter (DOM) could facilitate their transport. Elutions were performed using columns packed with glass beads in order to investigate DOM-diuron interactions, and the possible co-transport of diuron and DOM. Four organic amendments (A, B, C and D) were tested; C and D were sampled at fresh (F) and mature (M) stages. An increase in diuron leaching was observed only for A and DF amendments (up to 16% compared to the DOM-free blank samples), suggesting a DOM effect on diuron transport. These results could be explained by the higher DOM leaching for A and DF compared to B, CF, CM and DM increasing diuron-DOM interactions. These interactions seem to be related to the aromatic and aliphatic content of the DOM, determining formation of hydrogen and non-covalent bonds. The degree of organic matter maturity does not seem to have any effect with amendment C, while a reduction in diuron leaching is observed between DF and DM. After equilibrium dialysis measurement of diuron-DOM complexes, it appeared that less than 3% of the diuron applied corresponded to complexes with a molecular weight > 1000 Da. Complexes < 1000 Da could also take part in this facilitated transport. 相似文献
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Medical decision protocols constitute theories for health-care decision making that are applicable for “standard” medical
cases but have to be adapted for the other cases. This holds in particular for the breast cancer treatment protocol studied
in the Kasimir research project. Protocol adaptations can be seen as knowledge-intensive case-based decision support processes. Some examples
of adaptations that have been performed by oncologists are presented in this paper. Several issues are then identified that
need to be addressed while trying to model such processes, namely: the complexity of adaptations, the lack of relevant information
about the patient, the necessity to take into account the applicability and the consequences of a decision, the closeness
to decision thresholds, and the necessity to consider some patients according to different viewpoints. As handling these issues
requires some additional knowledge, which has to be acquired, different methods are presented that perform adaptation knowledge
acquisition either from experts, or in a semi-automatic manner. A discussion and a conclusion end the paper. 相似文献
104.
Mathieu John E.; Heffner Tonia S.; Goodwin Gerald F.; Salas Eduardo; Cannon-Bowers Janis A. 《Canadian Metallurgical Quarterly》2000,85(2):273
The influence of teammates' shared mental models on team processes and performance was tested using 56 undergraduate dyads who "flew" a series of missions on a personal-computer-based flight-combat simulation. The authors both conceptually and empirically distinguished between teammates' task- and team-based mental models and indexed their convergence or "sharedness" using individually completed paired-comparisons matrices analyzed using a network-based algorithm. The results illustrated that both shared-team- and task-based mental models related positively to subsequent team process and performance. Furthermore, team processes fully mediated the relationship between mental model convergence and team effectiveness. Results are discussed in terms of the role of shared cognitions in team effectiveness and the applicability of different interventions designed to achieve such convergence. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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107.
Image coding using wavelet transform 总被引:217,自引:0,他引:217
Antonini M. Barlaud M. Mathieu P. Daubechies I. 《IEEE transactions on image processing》1992,1(2):205-220
A scheme for image compression that takes into account psychovisual features both in the space and frequency domains is proposed. This method involves two steps. First, a wavelet transform used in order to obtain a set of biorthogonal subclasses of images: the original image is decomposed at different scales using a pyramidal algorithm architecture. The decomposition is along the vertical and horizontal directions and maintains constant the number of pixels required to describe the image. Second, according to Shannon's rate distortion theory, the wavelet coefficients are vector quantized using a multiresolution codebook. To encode the wavelet coefficients, a noise shaping bit allocation procedure which assumes that details at high resolution are less visible to the human eye is proposed. In order to allow the receiver to recognize a picture as quickly as possible at minimum cost, a progressive transmission scheme is presented. It is shown that the wavelet transform is particularly well adapted to progressive transmission. 相似文献
108.
This paper deals with predictive methods of the combustion rates in the case of premixed mixtures. Comparisons are made between two of these predictive methods. The first approach is based on a standard eddy break-up (EBU) model supplemented by a condition on the chemical composition of the mixture. The reaction can develop within a fixed range of richness. The second method uses the concept of fractal surfaces. Moreover a spectral analysis allows us to introduce the role of the small turbulent structures embedded in the preheat zone. By means of the concept of fractal surfaces the real area of the flame surface can be predicted starting from its mean value and from L (integral length scale), u′ and k (Kolmogorov length scale). The location of the flame is deduced from the standard EBU model previously referred to. u′ ànd {} are also known along the mean flame surface. The area of the real indented surface can be inferred. The combustion rate can be deduced by associating the area of the flame front with a convenient flame speed accounting for the role of the small structures embedded in the preheat zone. The results found by the two methods do not depart from each other by more than 10% 相似文献
109.
The transmittance spectrum of halftone prints on paper is predicted thanks to a model inspired by the Yule-Nielsen modified spectral Neugebauer model used for reflectance predictions. This model is well adapted for strongly scattering printing supports and applicable to recto-verso prints. Model parameters are obtained by a few transmittance measurements of calibration patches printed on one side of the paper. The model was verified with recto-verso specimens printed by inkjet with classical and custom inks, at different halftone frequencies and on various types of paper. Predictions are as accurate as those obtained with a previously developed reflectance and transmittance prediction model relying on the multiple reflections of light between the paper and the print-air interfaces. Optimal n values are smaller in transmission mode compared with the reflection model. This indicates a smaller amount of lateral light propagation in the transmission mode. 相似文献
110.
Mathieu Herran Daniel Nélias Alain Combescure Hervé Chalons 《International journal for numerical methods in engineering》2011,86(3):301-315
The component mode synthesis (CMS) with fixed interface (denoted Craig–Bampton) method uses a combination of static and dynamic modes. The usual definition of this CMS leads to a coupling between static and dynamic modes which are not orthogonal with respect to the stiffness matrix. This type of basis is not well suited for dynamic explicit computations, because the resulting mass matrix is not diagonal. If one keeps the same basis mode set but uses an orthogonalization process with respect to the mass matrix, the quality of the reduced Craig–Bampton system is kept but the basis vectors are combined differently. The aim of this paper is to propose a new way to control the accuracy of the reduced dynamic system for a specific frequency domain. Thus a new CMS is defined in order to be accurate in the medium frequency range. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献