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排序方式: 共有443条查询结果,搜索用时 135 毫秒
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2.
Hannes Verlinde Martine De Cock Raymond Boute 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2006,36(3):679-684
As opposed to quantitative association rule mining, fuzzy association rule mining is said to prevent the overestimation of boundary cases, as can be shown by small examples. Rule mining, however, becomes interesting in large databases, where the problem of boundary cases is less apparent and can be further suppressed by using sensible partitioning methods. A data-driven approach is used to investigate if there is a significant difference between quantitative and fuzzy association rules in large databases. The influence of the choice of a particular triangular norm in this respect is also examined. 相似文献
3.
Martine Decloux Manuel Dornier & Isabelle Gratius 《International Journal of Food Science & Technology》1996,31(2):153-166
Gum arabic is a natural gum exuded mainly by the trees Acacia senegal , currently used in the food industries for its emulsifying, thickening and stabilizing properties. Its present processing includes various operations providing a quite turbid product. Crossflow microfiltration could be interesting for the clarification and the cold-pasteurization of the gum arabic solutions. Several experiments were therefore made with the crossflow microfiltration unit at ENSIA, using two different systems: the classical one (without permeate circulation), and the co-current permeate flow system (CCPF) allowing the exploration of the low transmembrane pressures range. With gum arabic solutions of 0.17g solids g−1 solution and 70°C, the best results after 60 min of filtration (105.7 L h−1 m−2 , 4.4% of solids retention and 83.4% of clarification) were obtained with the CCPF system at low transmembrane pressure and high crossflow velocity (0.3 bar and 7.5ms−1 ). 相似文献
4.
Electron Spin Resonance, Differential Scanning Calorimetry and rheological techniques have been used to study the physical
changes induced by temperature in lard and in the solid and liquid fractions obtained by fractionation of lard at 15 C. The
mobilization process of a C18 fatty acid nitroxide derivative dispersed in the molten fat has been observed in the temperature
range −50 to +70 C.
The mobilization of the probe seemed to be concomitant with the melting of the low melting point glycerides. Above this temperature,
all the probes were in the liquid phase and their mobility reflected the viscosity of their liquid environment, or the viscosity
of the bulk fat when crystal was no longer present.
Probe mobility was temperature dependent, and it was identical for the three fats at the same temperature, despite their different
triglyceride compositions. 相似文献
5.
This article is concerned with the l2-approximation of a given transfer function f by a rational one whose order is prescribed. We show that the sum of the indices of the critical points of the criterion is generically equal to 1, and in particular does not depend on f. 相似文献
6.
Regulation of compatible solute accumulation in bacteria 总被引:1,自引:0,他引:1
In their natural habitats, microorganisms are often exposed to osmolality changes in the environment. The osmotic stress must be sensed and converted into an activity change of specific enzymes and transport proteins and/or it must trigger their synthesis such that the osmotic imbalance can be rapidly restored. On the basis of the available literature, we conclude that representative gram-negative and gram-positive bacteria use different strategies to respond to osmotic stress. The main focus of this paper is on the initial response of bacteria to hyper- and hypo-osmotic conditions, and in particular the osmosensing devices that allow the cell to rapidly activate and/or to synthesize the transport systems necessary for uptake and excretion of compatible solutes. The experimental data allow us to discriminate the transport systems by the physicochemical parameter that is sensed, which can be a change in external osmotic pressure, turgor pressure, membrane strain, internal osmolality and/or concentration of specific signal molecule. We also evaluate the molecular basis for osmosensing by reviewing the unique structural features of known osmoregulated transport systems. 相似文献
7.
Youren Xu Avigdor Zangvil Martine Landon François Thevenot 《Journal of the American Ceramic Society》1992,75(2):325-333
A flexural strength of up to 1 GPa was achieved in SiC-AIN materials and is attributed to a dense, equiaxial grain structure of the 2H(δ) SiC-AIN solid solution, with a relatively uniform grain size of ∼ 1 μm. The strength was found to decrease with increasing grain size. While the β→α phase transformation and the formation of various metastable polytypes make microstructural control difficult in SiC materials, excellent control is facilitated in SiC-AIN materials as a result of the stable 2H solid solution. Several mechanisms of grain refinement during the β→ 2H transition were observed, most notably the direct formation of several 2H grains from a single β grain. In addition, grain growth is limited by the diffusion-controlled nature of the transition. These mechanisms could be utilized to achieve even higher strength values, with potentially higher reliability of the materials in structural applications. 相似文献
8.
Olivier Renoult Jean-Pierre Boilot Frédéric Chaput Renée Papiernik Liliane G. Hubert-Pfalzgraf Martine Lejeune 《Journal of the American Ceramic Society》1992,75(12):3337-3340
The sol–gel method has been developed for the preparation of pure Ba(Mg1/3 Ta2/3 )O3 ceramics. This involves the reaction of the heterometallic alkoxide Ta2 Mg(OEt)12 with hydrated barium hydroxide Ba(OH)2 ·8H2 O. Complete crystallization of the sol–gel-derived powder is achieved at 600°C, leading to a cubic perovskite type phase. After sintering at 1400°C (2–5 h), a trigonal cell arises from Mg–Ta ordering (the degree of order is greater than 0.9), and about 98.5% of the theoretical density is obtained. Preliminary microwave dielectric measurements show that the dielectric constant and the unloaded Q u of the ceramics are 24.2 and 6750, respectively, at 7.7 GHz. 相似文献
9.
Steven Schockaert Martine De Cock Etienne E. Kerre 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2010,14(8):869-886
When searching for information about historical events, queries are naturally formulated using temporal constraints. However,
the structured temporal information needed to support such constraints is usually not available to information retrieval systems.
Furthermore, the temporal boundaries of most historical events are inherently ill-defined, calling for suitable extensions
of classical temporal reasoning frameworks. In this paper, we propose a framework based on a fuzzification of Allen’s Interval
Algebra to cope with these issues. By using simple heuristic techniques to extract temporal information from web documents,
we initially focus more on recall than on precision, relying on the subsequent application of a fuzzy temporal reasoner to
improve the reliability of the extracted information, and to deal with conflicts that arise because of the vagueness of events.
Experimental results indicate that a consistent and reliable knowledge base of fuzzy temporal relations can thus be obtained,
which effectively allows us to target temporally constrained retrieval tasks. 相似文献
10.