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991.
F.?Y.?Kuo W.?T.?M.?DunsmuirEmail author I.?H.?Sloan M.?P.?Wand R.?S.?Womersley 《Methodology and Computing in Applied Probability》2008,10(2):239-275
Highly structured generalised response models, such as generalised linear mixed models and generalised linear models for time
series regression, have become an indispensable vehicle for data analysis and inference in many areas of application. However,
their use in practice is hindered by high-dimensional intractable integrals. Quasi-Monte Carlo (QMC) is a dynamic research
area in the general problem of high-dimensional numerical integration, although its potential for statistical applications
is yet to be fully explored. We survey recent research in QMC, particularly lattice rules, and report on its application to
highly structured generalised response models. New challenges for QMC are identified and new methodologies are developed.
QMC methods are seen to provide significant improvements compared with ordinary Monte Carlo methods.
相似文献
992.
通过对辛空间的深入分析和研究,从空间中的度量与向量的迷向性问题入手并展开较为详细的讨论,定义"伪辛"的概念,阐述"辛"概念的演变、扩充与伪辛空间生成的事实,进而揭示伪辛空间的本质属性及其与辛空间的内在联系与区别.论述过程同时给出了伪辛空间关于辛空间的内蕴和外延表示式. 相似文献
993.
Here we study vector bundles E on the Hirzebruch surface F
e
such that their twists by a spanned, but not ample, line bundle M =
Fe
(h + ef) have natural cohomology, i.e. h
0(F
e
, E(tM)) > 0 implies h
1(F
e
, E(tM)) = 0.
相似文献
994.
995.
By using the composite vector with increment of diversity, position conservation scoring function, and predictive secondary structures to express the information of sequence, a support vector machine (SVM) algorithm for predicting beta- and gamma-turns in the proteins is proposed. The 426 and 320 nonhomologous protein chains described by Guruprasad and Rajkumar (Guruprasad and Rajkumar J. Biosci 2000, 25,143) are used for training and testing the predictive model of the beta- and gamma-turns, respectively. The overall prediction accuracy and the Matthews correlation coefficient in 7-fold cross-validation are 79.8% and 0.47, respectively, for the beta-turns. The overall prediction accuracy in 5-fold cross-validation is 61.0% for the gamma-turns. These results are significantly higher than the other algorithms in the prediction of beta- and gamma-turns using the same datasets. In addition, the 547 and 823 nonhomologous protein chains described by Fuchs and Alix (Fuchs and Alix Proteins: Struct Funct Bioinform 2005, 59, 828) are used for training and testing the predictive model of the beta- and gamma-turns, and better results are obtained. This algorithm may be helpful to improve the performance of protein turns' prediction. To ensure the ability of the SVM method to correctly classify beta-turn and non-beta-turn (gamma-turn and non-gamma-turn), the receiver operating characteristic threshold independent measure curves are provided. 相似文献
996.
Let (P) denote the vector maximization problem
where the objective functions f
i
are strictly quasiconcave and continuous on the feasible domain D, which is a closed and convex subset of R
n
. We prove that if the efficient solution set E(P) of (P) is closed, disconnected, and it has finitely many (connected) components, then all the components are unbounded. A similar fact is also valid for the weakly efficient solution set E
w
(P) of (P). Especially, if f
i
(i=1,...,m) are linear fractional functions and D is a polyhedral convex set, then each component of E
w
(P) must be unbounded whenever E
w
(P) is disconnected. From the results and a result of Choo and Atkins [J. Optim. Theory Appl. 36, 203–220 (1982.)] it follows that the number of components in the efficient solution set of a bicriteria linear fractional vector optimization problem cannot exceed the number of unbounded pseudo-faces of D. 相似文献
997.
In this paper, we consider a semiparametric regression model involving both p-dimensional quantitative covariable X and categorical predictor Z, and including a dimension reduction of X via K indices X′β
k
. The dependent variable Y can be real or q-dimensional. We propose an approach based on SIR
α
and pooled marginal slicing methods in order to estimate the space spanned by the β
k
’s. We establish -consistency of the proposed estimator. Simulation studies show the numerical qualities of our estimator. 相似文献
998.
S. Verwulgen 《Applied Categorical Structures》2007,15(5-6):647-653
It is well-known (see Semadeni, Queen Pap. Pure Appl. Math., 33:1–98, 1973 and Pumplün and Röhrl, Commun. Algebra, 12(8):953–1019, 1984, 1985) that the embedding of vector spaces into the category of absolutely convex modules is reflective. As we will show, under a separatedness condition on these modules it is at the same time coreflective. This is a peculiar situation, see Kannan, Math. Ann., 195:168–174, (1972) and Hu $\textrm {\u{s}}It is well-known (see Semadeni, Queen Pap. Pure Appl. Math., 33:1–98, 1973 and Pumplün and R?hrl, Commun. Algebra, 12(8):953–1019, 1984, 1985) that the embedding of vector spaces into the category of absolutely convex modules is reflective. As we will show, under
a separatedness condition on these modules it is at the same time coreflective. This is a peculiar situation, see Kannan,
Math. Ann., 195:168–174, (1972) and Huek, Reflexive and coreflexive subcategories of unif and top, Seminar Uniform Spaces, Prague, 113–126, (1973), but we do find it also in the embedding (Lowen, Approach Spaces: The Missing Link in the Topology-Uniformity-Metric Triad. Oxford Mathematical Monographs, Oxford
University Press, London, UK, 1997) and, by extension, in the embedding (see Lowen and Verwulgen, Houst. J. Math, 30(4):1127–1142, 2004, and Sioen and Verwulgen, Appl. Gen. Topol., 4(2):263–279, 2003. We demonstrate that, in this setting, by duality arguments, absolutely convex modules are indeed the numerical counterpart
of vector spaces. All these, at first sight unrelated facts, are comprised in the commutative scheme below with natural dualisation
functors and their left adjoints.
相似文献
999.
Takashi Taniguchi 《Transactions of the American Mathematical Society》2007,359(11):5517-5524
In this article, we give a refinement of the mean value theorem for the class number of quadratic extensions obtained by Goldfeld-Hoffstein and Datskovsky. More specifically, we determine the proportional constants of the mean value for fields that satisfy any local conditions including wild ramification at places dividing .
1000.
Zhi Ting XU 《数学学报(英文版)》2007,23(7):1189-1198
By using vector Riccati transformation and averaging technique, some oscillation criteria for the quasilinear elliptic differential equation of second order,
ΣNi,j=1Di[Ψ(y)Aij(x)|Dy|^p-2Djy]+p(x)f(y)=0,
are obtained. These theorems extend and include earlier results for the semilinear elliptic equation and PDE with p-Laplacian. 相似文献