-*- mode: org -*- Seemingly unrelated noise from the query or database (duplicate entries) * 1(<-479): [Improving hyperspectral matching method through feature-selection/weighting based on SVM]. (duplicated entry) In the present article, feature selection/weighting based on SVM was employed to improve the algorithm of choosing reference spectrum through a multi-objective optimization approach proposed in reference. Based on the sensitive analysis, half of features having low weights in SVM classification model were eliminated iteratively. Two criteria, matching accuracy and classification confidence, were used to select the best-performing feature subset. Three scenarios were designed: (1) only feature subset selected by SVM was used; (2) both feature subset and global weights were used, in which global weights were the coefficients of selected features in the SVM classification model; (3) both feature subset and local weights, which changed with the distance of a sample point to the SVM separation plan, were used. Experiment executed on the popular Indiana AVIRIS data set indicate that under all the three scenarios, spectral matching accuracies were increased by 13%-17% compared to the situation without feature selection. The result obtained under scenario 3 is the most accurate and the most stable, which can be primarily attributed to the ability of local weights to accurately describe local distribution of spectra from the same class in feature space. Moreover, scenario 3 can be regarded as the extension of scenario 2 because when spectra far away from the separation plane are selected as reference spectrums for matching, the features' weights will not be considered. The results obtained under scenario 1 and 2 are very similar, indicating that considering global weights is not necessary. The research presented in this paper advanced the spectrum analysis using SVM to a higher level. 2009 * 184(<-562): On proto-differentiability of generalized perturbation maps This paper is devoted to the sensitivity analysis in optimization problems and variational inequalities. The concept of proto-differentiability of set-valued maps (see [R.T. Rockafellar, Proto-differentiability of set-valued mappings and its applications in optimization, Ann. Inst. H. Poincare Anal. Non Lineaire 6 (1989) 449-482]) plays the key role in our investigation. It is proved that, under some suitable qualification conditions, the generalized perturbation maps (that is, the solution set map to a parameterized constraint system, to a parameterized variational inequality, or to a parameterized optimization problem) are proto-differentiable. (c) 2006 Elsevier Inc. All rights reserved. 2006 * 185(<-111): Concepts of efficiency for uncertain multi-objective optimization problems based on set order relations In this paper we present new concepts of efficiency for uncertain multi-objective optimization problems. We analyze the connection between the concept of minmax robust efficiency presented by Ehrgott et al. (Eur J Oper Res, 2014, doi:10.1016/j.ejor.2014.03.013) and the upper set less order relation <=(u)(s) introduced by Kuroiwa (1998, 1999). From this connection we derive new concepts of efficiency for uncertain multi-objective optimization problems by replacing the set ordering with other set orderings. Those are namely the lower set less ordering (see Kuroiwa 1998, 1999), the set less ordering (see Nishnianidze in Soobshch Akad Nauk Gruzin SSR 114(3):489-491, 1984; Young in Math Ann 104(1):260-290, 1931, doi:10.1007/BF01457934; Eichfelder and Jahn in Vector Optimization. Springer, Berlin, 2012), the certainly less ordering (see Eichfelder and Jahn in Vector Optimization. Springer, Berlin, 2012), and the alternative set less ordering (see Ide et al. in Fixed Point Theory Appl, 2014, doi:10.1186/1687-1812-2014-83; Kobis 2014). We analyze the resulting concepts of efficiency and present numerical results on the occurrence of the various concepts. We conclude the paper with a short comparison between the concepts, and an outlook to further work. 2014 * 186(<-570): A fiscal regime solving the incentive inconsistency problem This paper proposes a fiscal taxation/subsidy regime, which can mitigate the incentive inconsistency problem in the selection of a price policy (Yao and Lai, Ann Reg Sci, 2006). Through this regime, a Pareto improvement may be achieved. The results show that the efficacy of governmental intervention is more direct in the case of rectangular demand than that in linear demand. The distortion due to the incentive inconsistency cannot be easily regulated. 2006 * 187(<-636): Geometrical properties of Pareto distribution The differential-geometrical framework for analyzing statistical problems related to Pareto distribution, is given. A classical and intuitive way of description the relationship between the differential geometry and the statistics, is introduced [Publicationes Mathematicae Debrecen, Hungary, vol. 61 (2002) 1-14; RAAG Mem. 4 (1968) 373; Ann. Statist. 10 (2) (1982) 357; Springer Lecture Notes in Statistics, 1985; Tensor, N.S. 57 (1996) 282; Commun. Statist. Theor. Meth. 29 (4) (2000) 859; Tensor, N.S. 33 (1979) 347; Int. J. Eng. Sci. 19 (1981) 1609; Tensor, N.S. 57 (1996) 300; Differential Geometry and Statistics, 1993], but in a slightly modified manner. This is in order to provide an easier introduction for readers not familiar with differential geometry. The parameter space of the Pareto distribution using its Fisher's matrix is defined. The Riemannian and scalar curvatures to parameter space are calculated. The differential equations of the geodesics are obtained and solved. The J-divergence, the geodesic distance and the relations between of them in that space are found. A development of the relation between the J-divergence and the geodesic distance is illustrated. The scalar curvature of the J-space is represented. (C) 2002 Elsevier Inc. All rights reserved. 2003 * 188(<-491): Positive- versus zero-sum majoritarian ultimatum games: An experimental study Politics can involve a Movement from a position off the Pareto frontier to a point on it (a positive-sum game as exemplified in the classic [Buchanan, J.M., Tullock, G., 1962. The Calculus of Consent. University of Michigan Press, Ann Arbor] work), OF a movement along the Pareto frontier (a zero-SLIM game as exemplified in the classic [Riker, W., 1962. The theory of political coalitions. Yale University Press, New Haven] work). In this paper we shed light on their differentiation experimentally by making a comparison between a positive-sum and a zero-sum majoritarian ultimatum game. Our main findings include (I) the fraction Of Subjects who adopted minimum winning rather than oversized coalitions increases significantly as the game form varies from positive-sum to zero-sum, (ii) oversized coalitions are attributable to non-strategic considerations, and (iii) subjects who choose to adopt the minimum winning coalition have a tendency to seek cheaper responders as their partners in the zero-sum game, but there is no evidence Of Such a tendency in the positive-sum game. Overall, the weight of the evidence revealed by our experimental data indicates that relative scarcity (embodied in the zero-sum game) promotes behavior more in line with the predictions of economics. (C) 2008 Elsevier B.V. All rights reserved. 2008 * 189(<-650): Extremist vs. centrist decision behavior: quasi-convex utility functions for interactive multi-objective linear programming problems This paper presents the fundamental theory and algorithms for identifying the most preferred alternative for a decision maker (DM) having a non-centrist (or extremist) preferential behavior. The DM is requested to respond to a set of questions in the form of paired comparison of alternatives. The approach is different than other methods that consider the centrist preferential behavior. In this paper, an interactive approach is presented to solve the multiple objective linear programming (MOLP) problem. The DM's underlying preferential function is represented by a quasi-convex value (utility) function, which is to be maximized. The method presented in this paper solves MOLP problems with quasi-convex value (utility) functions by using paired comparison of alternatives in the objective space. From the mathematical point of view, maximizing a quasi-convex (or a convex) function over a convex set is considered a difficult problem to solve, while solutions for quasi-concave (or concave) functions are currently available. We prove that our proposed approach converges to the most preferred alternative. We demonstrate that the most preferred alternative is an extreme point of the MOLP problem, and we develop an interactive method that guarantees obtaining the global most preferred alternative for the MOLP problem. This method requires only a finite number of pivoting operations using a simplex-based method, and it asks only a limited number of paired comparison questions of alternatives in the objective space. We develop a branch and bound algorithm that extends a tree of solutions at each iteration until the MOLP problem is solved. At each iteration, the decision maker has to identify the most preferred alternatives from a given subset of efficient alternatives that are adjacent extreme points to the current basis. Through the branch and bound algorithm, without asking many questions from the decision maker, all branches of the tree Eire implicitly enumerated until the most preferred alternative is obtained. An example is provided to show the details of the algorithm. Some computational experiments are also presented. 2002 * 190(<-622): Estimating catastrophic quantile levels for heavy-tailed distributions Estimation of the occurrence of extreme events is of prime interest for actuaries. Heavy-tailed distributions are used to model large claims and losses. Within this setting we present a new extreme quantile estimator based on an exponential regression model that was introduced by Feuerverger and Hall [Ann. Stat. 27 (1999) 760] and Beirlant et al. [Extremes 2 (1999) 177]. We also discuss how this approach is to be adjusted in the presence of right censoring. This adaptation can also be linked to robust quantile estimation as this solution is based on a Winsorized mean of extreme order statistics which replaces the classical Hill estimator. We also propose adaptive threshold selection procedures for Weissman's [J. Am. Stat. Assoc. 73 (1978) 812] quantile estimator which can be used both with and without censoring. Finally some asymptotic results are presented, while small sample properties are compared in a simulation study. (C) 2004 Elsevier B.V. All rights reserved. 2004 * 191(<-634): On a bivariate lack of memory property under binary associative operation A binary operation over real numbers is said to be associative if (x * y) * z = x * (y * z) and it is said to be reducible if x * y = x * z or y * w = z * w if and only if z = y. The operation * is said to have an identity element (e) over tilde if x * (e) over tilde = x. Roy [Roy, D. (2002). On bivariate lack of memory property and a new definition. Ann. Inst. Statist. Math. 54:404-410] introduced a new definition for bivariate lack of memory property and characterized the bivariate exponential distribution introduced by Gumbel [Gumbel, E. (1960). Bivariate exponential distributions. J Am. Statist. Assoc. 55:698-707] under the condition that each of the conditional distributions should have the univariate lack of memory property. We generalize this definition and characterize different classes of bivariate probability distributions under binary associative operations between random variables. 2004 * 192(<-395): Modulated Branching Processes, Origins of Power Laws, and Queueing Duality Power law distributions have been repeatedly observed in a wide variety of socioeconomic, biological, and technological areas. In many of the observations, e. g., city populations and sizes of living organisms, the objects of interest evolve because of the replication of their many independent components, e. g., births and deaths of individuals and replications of cells. Furthermore, the rates of replications are often controlled by exogenous parameters causing periods of expansion and contraction, e. g., baby booms and busts, economic booms and recessions, etc. In addition, the sizes of these objects often have reflective lower boundaries, e. g., cities do not fall below a certain size, low-income individuals are subsidized by the government, companies are protected by bankruptcy laws, etc. Hence, it is natural to propose reflected modulated branching processes as generic models for many of the preceding observations. Indeed, our main results show that the proposed mathematical models result in power law distributions under quite general polynomial Gartner-Ellis conditions, the generality of which could explain the ubiquitous nature of power law distributions. In addition, on a logarithmic scale, we establish an asymptotic equivalence between the reflected branching processes and the corresponding multiplicative ones. The latter, as recognized by Goldie [Goldie, C. M. 1991. Implicit renewal theory and tails of solutions of random equations. Ann. Appl. Probab. 1(1) 126-166], is known to be dual to queueing/additive processes. We emphasize this duality further in the generality of stationary and ergodic processes. 2010 * 193(<-406): LAMPERTI-TYPE LAWS This paper explores various distributional aspects of random variables defined as the ratio of two independent positive random variables where one variable has an alpha-stable law, for 0 < alpha < 1, and the other variable has the law defined by polynomially tilting the density of an alpha-stable random variable by a factor theta > -alpha. When theta = 0, these variables equate with the ratio investigated by Lamperti [Trans. Amer. Math. Soc. 88 (1958) 380-387] which, remarkably, was shown to have a simple density. This variable arises in a variety of areas and gains importance from a close connection to the stable laws. This rationale, and connection to the PD(alpha, theta) distribution, motivates the investigations of its generalizations which we refer to as Lamperti-type laws. We identify and exploit links to random variables that commonly appear in a variety of applications. Namely Linnik, generalized Pareto and z-distributions. In each case we obtain new results that are of potential interest. As some highlights, we then use these results to (i) obtain integral representations and other identities for a class of generalized Mittag-Leffler functions, (ii) identify explicitly the Levy density of the semigroup of stable continuous state branching processes (CSBP) and hence corresponding limiting distributions derived in Slack and in Zolotarev [Z. Wahrsch. Verw. Gebiete 9 (1968) 139-145, Teor. Veroyatn. Primen. 2 (1957) 256-266], which are related to the recent work by Berestycki, Berestycki and Schweinsberg, and Bertoin and LeGall [Ann. Inst. H. Poincare Probab. Statist. 44 (2008) 214-238, Illinois J. Math. 50 (2006) 147-181] on beta coalescents. (iii) We obtain explicit results for the occupation time of generalized Bessel bridges and some interesting stochastic equations for PD(alpha, theta)-bridges. In particular we obtain the best known results for the density of the time spent positive of a Bessel bridge of dimension 2 - 2 alpha. 2010 * 194(<-455): Maximum likelihood estimation of extreme value index for irregular cases A method in analyzing extremes is to fit a generalized Pareto distribution to the exceedances over a high threshold. By varying the threshold according to the sample size [Smith, R.L., 1987. Estimating tails of probability distributions. Ann. Statist. 15, 1174-1207] and [Drees, H., Ferreira, A., de Haan, L., 2004. On maximum likelihood estimation of the extreme value index. Ann. Appl. Probab. 14,1179-1201] derived the asymptotic properties of the maximum likelihood estimates (MLE) when the extreme value index is larger than -1/2. Recently Zhou [2009. Existence and consistency of the maximum likelihood estimator for the extreme value index. J. Multivariate Anal. 100, 794-815] showed that the MLE is consistent when the extreme value index is larger than -1. In this paper, we study the asymptotic distributions of MLE when the extreme value index is in between -1 and -1/2 (including -1/2). Particularly, we consider the MLE for the endpoint of the generalized Pareto distribution and the extreme value index and show that the asymptotic limit for the endpoint estimate is non-normal, which connects with the results in Woodroofe [1974. Maximum likelihood estimation of translation parameter of truncated distribution II. Ann. Statist. 2, 474-488]. Moreover, we show that same results hold for estimating the endpoint of the underlying distribution, which generalize the results in Hall [1982. On estimating the endpoint of a distribution. Ann. Statist. 10, 556-568] to irregular case. and results in Woodroofe [1974. Maximum likelihood estimation of translation parameter of truncated distribution II. Ann. Statist. 2,474-488] to the case of unknown extreme value index. (C) 2009 Elsevier B.V. All rights reserved. 2009 * 195(<-516): Peaks-over-threshold stability of multivariate generalized Pareto distributions It is well-known that the univariate generalized Pareto distributions (GPD) are characterized by their peaks-over-threshold (POT) stability. We extend this result to multivariate GPDs. It is also shown that this POT stability is asymptotically shared by distributions which are in a certain neighborhood of a multivariate GPD. A multivariate extreme value distribution is a typical example. The usefulness of the results is demonstrated by various applications. We immediately obtain, for example, that the excess distribution of a linear portfolio Sigma(i <= d) a(i)U(i) with positive weights a(i), i <= d, is independent of the weights, if (U(1),...,U(d)) follows a multivariate GPD with identical univariate polynomial or Pareto margins, which was established by Macke [On the distribution of linear combinations of multivariate EVD and GPD distributed random vectors with an application to the expected shortfall of portfolios, Diploma Thesis, University of Wurzburg, 2004, (in German)] and Falk and Michel [Testing for tail independence in extreme value models. Ann. Inst. Statist. Math. 58 (2006) 261-290]. This implies, for instance, that the expected shortfall as a measure of risk fails in this case. (c) 2007 Elsevier Inc. All rights reserved. 2008 * 196(<-517): Extreme value theory for space-time processes with heavy-tailed distributions Many real-life time series exhibit clusters of outlying observations that cannot be adequately modeled by a Gaussian distribution. Heavy-tailed distributions such as the Pareto distribution have proved useful in modeling a wide range of bursty phenomena that occur in areas as diverse as finance, insurance, telecommunications, meteorology, and hydrology. Regular variation provides a convenient and unified background for studying multivariate extremes when heavy tails are present. In this paper, we study the extreme value behavior of the space-time process given by X(t)(s)=(infinity)Sigma(i=0)psi(i)(s)Z(t-i)(s), s epsilon [0,1](d), where (Zt)(t epsilon Z) is an iid sequence of random fields on [0, 1](d) with values in the Skorokhod space D([0, 1](d)) of cadlag functions on [0, 1](d) equipped with the J(1)-topology. The coefficients Psi(i) are deterministic real-valued fields on D([0, 1](d)). The indices s and t refer to the observation of the process at location s and time t. For example, X(t) (s), t = 1, 2,,.., could represent the time series of annual maxima of ozone levels at location s. The problem of interest is determining the probability that the maximum ozone level over the entire region [0, 1](2) does not exceed a given standard level f epsilon D([0, 1](2)) in n years. By establishing a limit theory for point processes based on (Xt (s)), t = 1,..., n, we are able to provide approximations for probabilities of extremal events. This theory builds on earlier results of de Haan and Lin [L. de Haan, T. Lin, On convergence toward an extreme value distribution in C[0, 1], Ann. Probab. 29 (2001) 467-483] and Hult and Lindskog [H. Hult, F. Lindskog, Extremal behavior of regularly varying stochastic processes, Stochastic Process. Appl. 115 (2) (2005) 249-274] for regular variation on D([0, 1](d)) and Davis and Resnick [R.A. Davis, S.I. Resnick, Limit theory for moving averages of random variables with regularly varying tail probabilities, Ann. Probab. 13 (1985) 179-195] for extremes of linear processes with heavy-tailed noise. (C) 2007 Elsevier B.V. All rights reserved. 2008 * 197(<- 40): Max-stable processes and the functional D-norm revisited Aulbach et al. (Extremes 16, 255283, 2013) introduced a max-domain of attraction approach for extreme value theory in C[0,1] based on functional distribution functions, which is more general than the approach based on weak convergence in de Haan and Lin (Ann. Probab. 29, 467483, 2001). We characterize this new approach by decomposing a process into its univariate margins and its copula process. In particular, those processes with a polynomial rate of convergence towards a max-stable process are considered. Furthermore we investigate the concept of differentiability in distribution of a max-stable processes. 2015 * 198(<-643): The generalized extreme value distribution This paper determines the type of asymptotic distribution for the extreme changes in stock prices, foreign exchange rates and interest rates. To find the correct limiting distribution for the maximal and minimal changes in market variables, a more general extreme value distribution is introduced using the Box-Cox transformation. Both the generalized Pareto distribution of Pickands [Ann. Stat. 3 (1975) 119] and the generalized extreme value distribution of Jenkinson [Q. J. R. Meteorol. Soc. 87 (1955) 145] are strongly rejected in favor of the newly proposed Box-Cox-GEV distribution. (C) 2003 Elsevier Science B.V. All rights reserved. 2003 * 207(<-629): A new extreme quantile estimator for heavy-tailed distributions The classical estimation method for extreme quantiles of heavy-tailed distributions was presented by Weissman (J. Amer. Statist. Assoc. 73 (1978) 812-815) and makes use of the Hill estimator (Ann. Statist. 3 (1975) 1163-1174) for the positive extreme value index. This index estimator can be interpreted as all estimator of the slope in the Pareto quantile plot in case one considers regression lines passing through a fixed anchor point. In this Note we propose a new extreme quantile estimator based on an unconstrained least squares estimator of the index, introduced by Kratz and Resnick (Comm. Statist. Stochastic Models 12 (1996) 699-724) and Schultze and Steinebach (Statist. Decisions 14 (1996) 353-372) and we Study its asymptotic behavior. (C) 2004 Academie des sciences. Published by Elsevier SAS. All rights reserved. 2004 * 239(<-145): [Genetic algorithm based multi-objective least square support vector machine for simultaneous determination of multiple components by near infrared spectroscopy]. (duplicated entry) The near infrared (NIR) spectrum contains a global signature of composition, and enables to predict different proper ties of the material. In the present paper, a genetic algorithm and an adaptive modeling technique were applied to build a multiobjective least square support vector machine (MLS-SVM), which was intended to simultaneously determine the concentrations of multiple components by NIR spectroscopy. Both the benchmark corn dataset and self-made Forsythia suspense dataset were used to test the proposed approach. Results show that a genetic algorithm combined with adaptive modeling allows to efficiently search the LS-SVM hyperparameter space. For the corn data, the performance of multi-objective LS-SVM was significantly better than models built with PLS1 and PLS2 algorithms. As for the Forsythia suspense data, the performance of multi-objective LS-SVM was equivalent to PLS1 and PLS2 models. In both datasets, the over-fitting phenomena were observed on RBFNN models. The single objective LS-SVM and MLS-SVM didn't show much difference, but the one-time modeling convenience al lows the potential application of MLS-SVM to multicomponent NIR analysis. 2014