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1.
AbstractOne of the basic statistical methods of dimensionality reduction is analysis of discriminant coordinates given by Fisher (1936) and Rao (1948). The space of discriminant coordinates is a space convenient for presenting multidimensional data originating from multiple groups and for the use of various classification methods (methods of discriminant analysis). In the present paper, we adapt the classical discriminant coordinates analysis to multivariate functional data. The theory has been applied to analysis of textural properties of apples of six varieties, measured over a period of 180?days, stored in two types of refrigeration chamber. 相似文献
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Andrzej Kozik 《Journal of Combinatorial Optimization》2017,33(2):445-472
In this paper, we show that sequence pair (SP) representation, primarily applied to the rectangle packing problems appearing in the VLSI industry, can be a solution representation of precedence constrained scheduling. We present three interpretations of sequence pair, which differ in complexity of schedule evaluation and size of a corresponding solution space. For each interpretation we construct an incremental precedence constrained SP neighborhood evaluation algorithm, computing feasibility of each solution in the insert neighborhood in an amortized constant time per examined solution, and prove the connectivity property of the considered neighborhoods. To compare proposed interpretations of SP, we construct heuristic and metaheuristic algorithms for the multiprocessor job scheduling problem, and verify their efficiency in the numerical experiment. 相似文献
4.
On locally optimal invariant unbiased tests for the variance components ratio in mixed linear models
Andrzej Michalski 《Statistical Papers》2009,50(4):855-868
In the paper the problem of testing of two-sided hypotheses for variance components in mixed linear models is considered.
When the uniformly most powerful invariant test does not exist (see e.g. Das and Sinha, in Proceedings of the second international
Tampere conference in statistics, 1987; Gnot and Michalski, in Statistics 25:213–223, 1994; Michalski and Zmyślony, in Statistics
27:297–310, 1996) then to conduct the optimal statistical inference on model parameters a construction of a test with locally
best properties is desirable, cf. Michalski (in Tatra Mountains Mathematical Publications 26:1–21, 2003). The main goal of
this article is the construction of the locally best invariant unbiased test for a single variance component (or for a ratio
of variance components). The result has been obtained utilizing Andersson’s and Wijsman’s approach connected with a representation
of density function of maximal invariant (Andersson, in Ann Stat 10:955–961, 1982; Wijsman, in Proceedings of fifth Berk Symp
Math Statist Prob 1:389–400, 1967; Wijsman, in Sankhyā A 48:1–42, 1986; Khuri et al., in Statistical tests for mixed linear models, 1998) and from generalized Neyman–Pearson Lemma
(Dantzig and Wald, in Ann Math Stat 22:87–93, 1951; Rao, in Linear statistical inference and its applications, 1973). One
selected real example of an unbalanced mixed linear model is given, for which the power functions of the LBIU test and Wald’s
test (the F-test in ANOVA model) are computed, and compared with the attainable upper bound of power obtained by using Neyman–Pearson
Lemma. 相似文献
5.
Leszek Gasieniec Jesper Jansson Andrzej Lingas Anna Östlin 《Journal of Combinatorial Optimization》1999,3(2-3):183-197
In this paper we study a few important tree optimization problems with applications to computational biology. These problems ask for trees that are consistent with an as large part of the given data as possible. We show that the maximum homeomorphic agreement subtree problem cannot be approximated within a factor of
, where N is the input size, for any 0
in polynomial time unless P = NP, even if all the given trees are of height 2. On the other hand, we present an O(N log N)-time heuristic for the restriction of this problem to instances with O(1) trees of height O(1) yielding solutions within a constant factor of the optimum. We prove that the maximum inferred consensus tree problem is NP-complete, and provide a simple, fast heuristic for it yielding solutions within one third of the optimum. We also present a more specialized polynomial-time heuristic for the maximum inferred local consensus tree problem. 相似文献
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As no single classification method outperforms other classification methods under all circumstances, decision-makers may solve a classification problem using several classification methods and examine their performance for classification purposes in the learning set. Based on this performance, better classification methods might be adopted and poor methods might be avoided. However, which single classification method is the best to predict the classification of new observations is still not clear, especially when some methods offer similar classification performance in the learning set. In this article we present various regression and classical methods, which combine several classification methods to predict the classification of new observations. The quality of the combined classifiers is examined on some real data. Nonparametric regression is the best method of combining classifiers. 相似文献
9.
Andrzej Dudek Joanna Polcyn Andrzej Ruciński 《Journal of Combinatorial Optimization》2010,19(2):184-199
We study the extremal parameter N(n,m,H) which is the largest number of copies of a hypergraph H that can be formed of at most n vertices and m edges. Generalizing previous work of Alon (Isr. J. Math. 38:116–130, 1981), Friedgut and Kahn (Isr. J. Math. 105:251–256, 1998) and Janson, Oleszkiewicz and the third author (Isr. J. Math. 142:61–92, 2004), we obtain an asymptotic formula for N(n,m,H) which is strongly related to the solution α
q
(H) of a linear programming problem, called here the fractional q-independence number of H. We observe that α
q
(H) is a piecewise linear function of q and determine it explicitly for some ranges of q and some classes of H. As an application, we derive exponential bounds on the upper tail of the distribution of the number of copies of H in a random hypergraph. 相似文献
10.
Dr Joanna Karolkiewicz Łucja Pilaczyńska–Szcześniak Janusz Maciaszek Wiesław Osiński 《The aging male》2013,16(3):159-163
The purpose of the study was to examine in the blood of overweight men aged from 62 to 83 years, the relationships between age and insulin resistance, selected parameters of the oxidative stress, and the antioxidant defense system. The population studied was divided into two groups: the group ‘young-old’ consisted of men aged 62 to 74 years old, and the group ‘old-old’– of men aged between 75 and 83 years. The total antioxidative status (TAS) and concentrations of thiobarbituric acid reactive substances (TBARS) were measured in the blood plasma. In the serum samples, the levels of antibodies against oxidized LDL (oLAB), glucose, total cholesterol, HDL-cholesterol, triglycerides and insulin were measured. Homeostasis Model Assessment of Insulin Resistance (HOMAIR) was calculated. Concentration of reduced glutathione (GSH) and glutathione peroxidase activity (GPx) were determined in the red blood cells hemolysate. The results of the study did not show significant differences between groups investigated with respect to concentrations of TBARS, TAS, GSH and GPx. However, significantly higher concentrations of glucose and antibodies against oxLDL (p < 0.05) were observed in the group of men over 74 years old in comparison to the group of ‘young-old’ men. It was indicated that the increased insulin resistance and hyperglycemia in elderly men are related to body mass and that they cause intensified oxidative modifications of LDL. 相似文献