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51.
针对D-S 证据理论在融合高度冲突的证据时可能导致与直观结果相悖的问题, 已有的基于修改数据模型的方法更多地考虑如何提高冲突证据结果的聚焦程度, 而没有考虑冲突成因以及如何通过冲突原因判断来削减证据之间的冲突. 对此, 提出一种闭世界框架下的灰色模糊多属性决策方法. 根据一般的灰色关联分析方法的基本思路, 将灰色关联度与欧氏距离有机结合, 构造出一种平均相似度对方案进行评价, 进而得到方案的排序结果. 最后, 通过实例分析验证了所提出方法的可行性和有效性. 相似文献
52.
53.
The onset of hydrodynamical instability induced by impulsive spin-down to rest in a cylinder containing a Newtonian fluid
is analyzed by using propagation theory. It is well-known that the primary transient swirl flow is laminar, but with initial
high velocities secondary motion sets in at a certain time. The dimensionless critical time Τc to mark the onset of instability is presented here as a function of the Reynolds number Re. Available experimental data indicate
that for large Re deviation of the velocity profiles from their momentum diffusion occurs starting from a certain time Τ≈4Τc. This means that secondary motion is detected at this characteristic time. It seems evident that during Τc⪯Τ⪯4Τc, secondary motion is relatively very weak and the primary diffusive momentum transfer is dominant. 相似文献
54.
Kanit Krisnangkura 《Journal of the American Oil Chemists' Society》1991,68(1):56-58
Equations were developed for the estimation of gross heat of combustion (HG) of triglycerides (TGs) and fatty acid methyl
esters (FAMEs) from their saponification number (SN) and iodine value (IV). HG of TG=1,896,000/SN − 0.6 IV — 1600 and HG of
FAME=618,000/SN − 0.08 IV — 430. When these equations were tested on cottonseed oil, soybean oil, partially hydrogenated soybean
oil, peanut oil, sunflower oil, sunflower oil methyl esters, soybean oil methyl esters and cottonseed oil methyl esters, predicted
HG values agreed well with those reported in the literature. 相似文献
55.
Gasoline quality prediction using gas chromatography and FTIR spectroscopy: An artificial intelligence approach 总被引:1,自引:0,他引:1
This paper reports on analysis of 45 gasoline samples with different qualities, namely, octane number and chemical composition. Measurements of data from gas chromatography and IR (FTIR) spectroscopy are used to gasoline quality prediction and classification. The data were processed using principal component analysis (PCA) and fuzzy C means (FCM) algorithm. The data were then analyzed following the neural network paradigms, hybrid neural network and support vector machines (SVM) classifier. The IR spectra were compressed and de-noised by the discrete wavelet analysis. Using the hybrid neural network and multi linear regression method (MLRM), excellent correlation between chemical composition of the gasoline samples and predicted value of the octane number was obtained. About 100% correct classification for six different categories of the gasoline was achieved, each of which has different qualities. 相似文献
56.
The micellar properties of aqueous binary mixed solutions for two systems consisting of sodium cholate (NaC)-octaoxyethylene
glycol mono n-decyl ether (C10E8) and sodium glycocholate (NaGC)-C10E8 have been studied on the basis of surface tensions, polarity of the micelle interior and the mean aggregation number. Application
of two theoretical treatments, based on regular solution and excess thermodynamic quantities for critical micellar concentration
(CMC) data from surface tension curves of two mixed systems showed that the mole fraction of each bile salt in the mixed micelles
near the CMC is lower than that of the corresponding prepared mole fraction in the mixed solution. The polarity of the interior
suggested that the hydrophobicity of intramicelles increased with the increase of the mole fraction of bile salt in the mixed
solution and that the mixed micelles become dramatically more hydrophobic at a mole fraction of 0.68 for NaGC−C10E8 system and 0.75 for NaC−C10E8 system, respectively. This implies that the micelles become richer in the bile salt molecules and the tendency appears strongly
for NaGC−C10E8 system due to the strong cohesion between the conjugated glycines in the NaGC molecules. The decrease of aggregation number
with the increase of the mole fraction of bile salts shows that the micelles approach those of the single system of each bile
salt. This supports the previously mentioned facts. 相似文献
57.
Various aspects of alkyd emulsion technology have been investigated. The influence of alkyd oil length, acid value and hydroxyl number and type of surfactant used as emulsifier, on shear stability of alkyds emulsions have been studied. It was found that the acid value was the most important alkyd parameter, the stability increasing with increasing oil length. It is also shown that anionic surfactants give emulsions with small droplet sizes at lower concentrations than do nonionics. Polymerizable nonionic surfactants have been tested as emulsifiers and compared with conventional surfactants of the same hydrophilic lipophilic balance (HLB). It was found that surfactants capable of participating in the autoridative curing process give faster drying and improved film hardness compared with nonreactive surfactants. The distribution of driers between the alkyd phase and the water phase has been investigated. It was found that low pH and the use of hydrophilic anionic surfactants, such as sodium dodecyl sulphate, favour partitioning of cobalt into the aqueous phase which is unfavourable with respect to drying properties. 相似文献
58.
59.
60.
现有算法在进行信号重建时,需要原始信号的稀疏信息来控制初始原子集的大小和算法迭代的最大次数,这削弱了重建精度,增加了计算复杂度,限制了其实际应用能力。为了克服这个问题,提出了基于正交匹配追踪算法的改进算法。该算法将阵元个数作为假设稀疏度,在稀疏度未知的初始阶段扩展初始原子集。最后通过对测量信号的幅度进行阈值过滤以实现信号的分辨和信源数的估计。为解决测向人员面对监测软件所指示的多个信号示向度中,无法分辨哪些指示方向是同一个信号源所产生的折反射信号的问题,首次提出了基于压缩感知算法的相干关系分析和相干信号分辨的模型。实测数据结果表明,该算法在不同环境下可以清晰分辨相干信号,并且能够适应多种实验平台。 相似文献