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91.
Summary Fractionation procedure on copolymer of N-vinylpyrrolidone and maleic anhydride has been elaborated using water/acetone solvent/nonsolvent system. Viscosity and molecular weight measurements of the fractions were carried out in acidic aqueous medium at 25 °C. The relationship between the intrinsic viscosity and the molecular mass []c = K·M was obtained at pH = 2.1. 相似文献
92.
93.
Computer-aided method for quantification of cartilage thickness and volume changes using MRI: validation study using a synthetic model 总被引:3,自引:0,他引:3
Kauffmann C Gravel P Godbout B Gravel A Beaudoin G Raynauld JP Martel-Pelletier J Pelletier JP de Guise JA 《IEEE transactions on bio-medical engineering》2003,50(8):978-988
The primary objective of this study was to develop a computer-aided method for the quantification of three-dimensional (3-D) cartilage changes over time in knees with osteoarthritis (OA). We introduced a local coordinate system (LCS) for the femoral and tibial cartilage boundaries that provides a standardized representation of cartilage geometry, thickness, and volume. The LCS can be registered in different data sets from the same patient so that results can be directly compared. Cartilage boundaries are segmented from 3-D magnetic resonance (MR) slices with a semi-automated method and transformed into offset-maps, defined by the LCS. Volumes and thickness are computed from these offset-maps. Further anatomical labeling allows focal volumes to be evaluated in predefined subregions. The accuracy of the automated behavior of the method was assessed, without any human intervention, using realistic, synthetic 3-D MR images of a human knee. The error in thickness evaluation is lower than 0.12 mm for the tibia and femur. Cartilage volumes in anatomical subregions show a coefficient of variation ranging from 0.11% to 0.32%. This method improves noninvasive 3-D analysis of cartilage thickness and volume and is well suited for in vivo follow-up clinical studies of OA knees. 相似文献
94.
Francis Jeffry Pelletier 《Journal of Logic, Language and Information》2001,10(1):87-114
In this essay I will consider two theses that are associated with Frege,and will investigate the extent to which Frege really believed them.Much of what I have to say will come as no surprise to scholars of thehistorical Frege. But Frege is not only a historical figure; he alsooccupies a site on the philosophical landscape that has allowed hisdoctrines to seep into the subconscious water table. And scholars in a widevariety of different scholarly establishments then sip from thesedoctrines. I believe that some Frege-interested philosophers at various ofthese establishments might find my conclusions surprising.Some of these philosophical establishments have arisen from an educationalmilieu in which Frege is associated with some specific doctrine at theexpense of not even being aware of other milieux where other specificdoctrines are given sole prominence. The two theses which I will discussillustrate this point. Each of them is called Frege's Principle, but byphilosophers from different milieux. By calling them milieux I do not want to convey the idea that they are each located at some specificsocio-politico-geographico-temporal location. Rather, it is a matter oftheir each being located at different places on the intellectuallandscape. For this reason one might (and I sometimes will) call them(interpretative) traditions. 相似文献
95.
Laure Berti-Équille 《Knowledge and Information Systems》2007,11(2):191-215
The quality of discovered association rules is commonly evaluated by interestingness measures (commonly support and confidence)
with the purpose of supplying indicators to the user in the understanding and use of the new discovered knowledge. Low-quality
datasets have a very bad impact over the quality of the discovered association rules, and one might legitimately wonder if
a so-called “interesting” rule noted LHS→ RHS is meaningful when 30% of the LHS data are not up-to-date anymore, 20% of the RHS data are not accurate, and 15% of the LHS data come from a data source that is well-known for its bad credibility. This paper presents an overview of data quality
characterization and management techniques that can be advantageously employed for improving the quality awareness of the
knowledge discovery and data mining processes. We propose to integrate data quality indicators for quality aware association
rule mining. We propose a cost-based probabilistic model for selecting legitimately interesting rules. Experiments on the challenging KDD-Cup-98 datasets show that variations on data quality have a great impact on the
cost and quality of discovered association rules and confirm our approach for the integrated management of data quality indicators
into the KDD process that ensure the quality of data mining results. 相似文献
96.
This paper discusses code verification of Reynolds-Averaged Navier Stokes (RANS) solvers with the method of manufactured solutions
(MMS). Examples of manufactured solutions (MSs) for a two-dimensional, steady, wall-bounded, incompressible, turbulent flow
are presented including the specification of the turbulence quantities incorporated in several popular eddy-viscosity turbulence
models. A wall-function approach for the MMS is also described. The flexiblity and usefulness of the MS is illustrated with
calculations performed in three different exercises: the calculation of the flow field using the manufactured eddy-viscosity;
the calculation of the eddy-viscosity using the manufactured velocity field; the calculation of the complete flow field coupling
flow and turbulence variables. The results show that the numerical performance of the flow solvers is model dependent and
that the solution of the complete problem may exhibit different orders of accuracy than in the exercises with no coupling
between the flow and turbulence variables. 相似文献
97.
In fuzzy logic-in wider, but also in narrow sense-the problem of consistency has been discussed more or less occasionally from different points of view. Up to now, however, it has usually not been taken as really important. This may be partly caused by a rather restricted understanding of what is to be meant by consistency or inconsistency in fuzzy logic in the wider sense-e.g. in fuzzy control as one of the main applicational fields of fuzzy logic. In this paper we deal with fuzzy theories in the realm of the fuzzy logic in narrow sense. Based on the fact that usually an "interactive", r-norm based conjunction is considered together with the min-based conjunction one has in a natural way two different consistency condition. We look here at the weaker one. 相似文献
98.
Josefina Barrera-CortÉs Cinvestav Jean Pierre Astruc Roland Tufeu Ana MarÍa MartÍnez-Enriquez 《Applied Artificial Intelligence》2013,27(5):453-470
In this paper an analytical procedure implemented to structure the knowledge required by an expert system applied for controlling a chemical process is described. The analytical approach is based on L ifecycle of Systems and on Task Model approaches. It was validated with an experimental procedure related to the determination of the critical point of pure fluids (CO2, N2O, SF6) and mixtures of low concentration (CO2-limonene). For the implementation of the control system an expert system shell (CHRONOS?) was used. 相似文献
99.
ASSANN SIDAOUI ZDENEK BINDER RENÉ PERRET 《International journal of systems science》2013,44(8):1379-1385
An alternative hierarchical optimization algorithm obtained by combining a double-loop iterative strategy with an efficient coordination task is proposed. The new algorithm derived from the tracking method (Sidaoui et al. 1989, 1991) is applicable to non-convex problems and has the advantage of giving a better rate of convergence. Simulation results are given and compared with the original algorithm, indicating the superiority of the new approach for the example considered. 相似文献
100.