排序方式: 共有32条查询结果,搜索用时 31 毫秒
21.
Blumberg LM 《Journal of chromatography. A》2011,1218(32):5375-5385
Earlier introduced metrics of separation performance are described in a systematic way. After providing the definitions of the metrics suitable for a broad variety of applications, the study focuses on static analyses (isothermal GC, isocratic LC, etc.) and their general separation performance. Statistically expected number of resolved (adequately separated) single-component peaks is treated as the ultimate metric of general separation performance of chromatographic analysis. That number depends on the peak capacity of the analysis and the number of components in a test mixture. The peak capacity, in turn, depends on the separation capacity of a column and the lowest separation required by the data-analysis system for resolving poorly separated peaks. The separation capacity is a special case of a broader metric of the separation measure which is a function of column efficiency, solute separability, and the level of the solute interaction with a column stationary phase. The formulae for theoretical prediction of all these metrics for arbitrary pairs of peaks in static analyses are derived. To provide a better insight into the basic metrics of the separation performance, additional metrics such as the solute discrimination (relative difference in solute velocities), utilization of separability (solute discrimination per unit of their separability), specific separation (the separation per unit of separability), and others are defined and found for static analyses. 相似文献
22.
We discuss pseudo-Riemannian metrics on 2-dimensional manifolds such that the geodesic flow admits a nontrivial integral quadratic in velocities. We construct local normal forms of such metrics. We show that these metrics have certain useful properties similar to those of Riemannian Liouville metrics, namely:
- •
- they admit geodesically equivalent metrics; 相似文献
23.
Mousumi Palit Nabarun Bhattacharyya Pallab Kumar Dutta Rajib Bandyopadhyay 《Analytica chimica acta》2010,675(1):8-15
In an electronic tongue, preprocessing on raw data precedes pattern analysis and choice of the appropriate preprocessing technique is crucial for the performance of the pattern classifier. While attempting to classify different grades of black tea using a voltammetric electronic tongue, different preprocessing techniques have been explored and a comparison of their performances is presented in this paper. The preprocessing techniques are compared first by a quantitative measurement of separability followed by principle component analysis; and then two different supervised pattern recognition models based on neural networks are used to evaluate the performance of the preprocessing techniques. 相似文献
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25.
José Manuel Gutiérrez 《TOP》2007,15(1):89-102
A consumption model is considered, where agents may have a simplified image of reality and a simplified way of reaching decisions.
Some rules of behaviour are assumed, considering, in particular, the decision-theoretic ideas of decentralization and price
aggregation. The consumers have a price-independent relative income distribution. The existence and unicity of temporary equilibria
are investigated.
相似文献
26.
Christian Gottlieb 《代数通讯》2013,41(12):4687-4691
Abstract Integrals in Hopf algebras are an essential tool in studying finite dimensional Hopf algebras and their action on rings. Over fields it has been shown by Sweedler that the existence of integrals in a Hopf algebra is equivalent to the Hopf algebra being finite dimensional. In this paper we examine how much of this is true Hopf algebras over rings. We show that over any commutative ring R that is not a field there exists a Hopf algebra H over R containing a non-zero integral but not being finitely generated as R-module. On the contrary we show that Sweedler's equivalence is still valid for free Hopf algebras or projective Hopf algebras over integral domains. Analogously for a left H-module algebra A we study the influence of non-zero left A#H-linear maps from A to A#H on H being finitely generated as R-module. Examples and application to separability are given. 相似文献
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28.
The main result is to show that the space of nonmonotonic fuzzy measures on a measurable space (X,X) with total variation norm is separable if and only if the σ-algebra X is a finite set. Our result is related to fuzzy analysis, functional spaces and discrete mathematics. 相似文献
29.
Jagannath Thakur 《Pramana》1992,39(3):253-264
We discuss the classical mechanics of relativistic systems containing any number of particles with direct interaction. We
continue our previous approach of restricting the observables to gauge invariant variables. As a preliminary we show how to
constructN-particle mass shell constraints. Physical momentum and position variables are constructed in consonance with nonsuperluminality
and relativity and consistent with a slightly weakened separability which allows the position four vector of separated particles
to differ from the canonical coordinate four vector by a constant term which depends on its history but does not affect future
dynamics. The formalism is mathematically consistent though slightly more complicated than previous attempts in this direction. 相似文献
30.
Chappell MH Brown JA Dalrymple-Alford JC Uluğ AM Watts R 《Magnetic resonance imaging》2008,26(10):1398-1405
In this study, we present two different methods of multivariate analysis of voxel-based diffusion tensor imaging (DTI) data, using as an example data derived from 59 professional boxers and 12 age-matched controls. Conventional univariate analysis ignores much of the diffusion information contained in the tensor. Our first multivariate method uses the Hotelling's T2 statistic and the second uses linear discriminant analysis to generate the linear discriminant function at each voxel to form a separability metric. Both multivariate methods confirm the findings from the individual metrics of large-scale changes in the bilateral inferior temporal gyri of the boxers, but they also reveal greater sensitivity as well as identifying major subcortical changes that had not been evident in the univariate analyses. Linear discriminant analysis has the added strength of providing a quantitative measure of the relative contribution of each metric to any differences between the two subject groups. This novel adaptation of statistical and mathematical techniques to neuroimaging analysis is important for two reasons. Clinically, it develops the findings of a previous mild head injury study, and, methodologically, it could equally well be applied to multivariate studies of other pathologies. 相似文献