Forecasting mortality in subpopulations using Lee–Carter type models: A comparison

The relative performance of multipopulation stochastic mortality models is investigated. When targeting mortality rates, we consider five extensions of the well known Lee–Carter single population extrapolative approach. As an alternative, we consider similar structures when mortality improvement rates are targeted. We use a dataset of deaths and exposures of Italian regions for the years 1974–2008 to conduct a comparison of the models, running a battery of tests to assess the relative goodness of fit and forecasting capability of different approaches. Results show that the preferable models are those striking a balance between complexity and flexibility.     

Parallel Algorithms for Solving a Class of Variational Inequalities over the Common Fixed Points Set of a Finite Family of Demicontractive Mappings

Abstract

We propose parallel algorithms for solving a class of variational inequalities over the set of common fixed points for a finite family of demicontractive mappings in real Hilbert spaces. Under some suitable conditions, we prove that the sequence generated by the proposed algorithms converges strongly to a solution of the problem. We apply the proposed algorithms to strongly monotone variational inequality problems with pseudomonotone equilibrium constraints by defining a quasi-nonexpansive and demi-closed mapping whose fixed point set coincides with the solution set of the equilibrium problem.     

Comparative analysis of volatile constituents between recipe jingfangsan and its single herbs by GC‐MS combined with alternative moving window factor analysis method

Comparative analysis of volatile constituents between recipe jingfangsan and its single herbs was performed by GC‐MS combined with alternative moving window factor analysis (AMWFA), a new chemometric resolution method. Identification of the compounds was also assisted by comparison of temperature‐programmed retention indices (PTRIs) on the OV‐1 column with authentic samples. In total, 36, 29, and 42 volatile components in essential oil of Herba schizonepetae (HS), Radix saposhnikoviae (RS), and the recipe were respectively determined qualitatively and quantitatively, accounting for 81.80, 82.62 and 85.98% total contents of volatile oil of HS, RS, and the recipe respectively. Analysis by the method of AMWFA indicates that there are 22 common volatile constituents between the recipe and single herbal medicine HS, and 14 common volatile constituents between the recipe and single herb medicine RS. The experimental results also show that the volatile components of the recipe in number are almost addition of that of two single herbal medicines HS and RS, and are mainly from the single herbal medicine HS.     

Fast algorithms for identifying maximal common connected sets of interval graphs

Given a family of interval graphs F={G₁=(V,E₁),…,G_k=(V,E_k)} on the same vertices V, a set S⊂V is a maximal common connected set of F if the subgraphs of G_i,1?i?k, induced by S are connected in all G_i and S is maximal for the inclusion order. The maximal general common connected set for interval graphs problem (gen-CCPI) consists in efficiently computing the partition of V in maximal common connected sets of F. This problem has many practical applications, notably in computational biology. Let n=|V| and . For k?2, an algorithm in O((kn+m)logn) time is presented in Habib et al. [Maximal common connected sets of interval graphs, in: Combinatorial Pattern Matching (CPM), Lecture Notes in Computer Science, vol. 3109, Springer, Berlin, 2004, pp. 359-372]. In this paper, we improve this bound to O(knlogn+m). Moreover, if the interval graphs are given as k sets of n intervals, which is often the case in bioinformatics, we present a simple time algorithm.     

Fully polynomial time approximation scheme for the total weighted tardiness minimization with a common due date

This paper deals with the total weighted tardiness minimization with a common due date on a single machine. The best previous approximation algorithm for this problem was recently presented in [H. Kellerer, V.A. Strusevich, A fully polynomial approximation scheme for the single machine weighted total tardiness problem with a common due date, Theoretical Computer Science 369 (2006) 230-238] by Kellerer and Strusevich. They proposed a fully polynomial time approximation scheme (FPTAS) of O((n⁶logW)/ε³) time complexity (W is the sum of weights, n is the number of jobs and ε is the error bound). For this problem, we propose a new approach to obtain a more effective FPTAS of O(n²/ε) time complexity. Moreover, a more effective and simpler dynamic programming algorithm is designed.     

Comment on: “New exact solutions for the Kawahara equation using Exp-function method” [J. Comput. Appl. Math. 233 (2009) 97-102]

Assas [Laila M.B. Assas, New exact solutions for the Kawahara equation using Exp-function method, J. Comput. Appl. Math. 233 (2009) 97-102] found some supposedly new exact solutions to the Kawahara equation by means of the Exp-function method. Unfortunately, they are incorrect. We emphasize that the article contains erroneous formulas and resulting relations. In fact, no numerical method was used.     

关于三个非扩张映射收敛于其公共不动点的具误差的三重迭代法

在一致凸Banach空间中,研究了关于三个不同非扩张映射的具误差的三步迭代算法,并在一定条件下证明了此迭代序列收敛于其公共不动点的弱强收敛定理.     

Recognition characteristics of dibenzofuran by molecularly imprinted polymers made of common polymers

Dibenzofuran (DBF) recognition was studied by a molecularly imprinted polymer (MIP) made of commercially available polymers: polyvinyl chloride (PVC), polysulfone, polystyrene, and polyacrylonitrile. Preparation of MIPs was carried out by phase inversion of the polymer. Respective polymer solutions were coagulated with DBF template in water (non-solvent). In addition, reference polymers without the template were prepared in same manner as unimprinted polymers. After the DBF template was extracted from the solidified polymers by washing with methanol (MeOH), recognition experiments of DBF by the imprinted polymers were carried out for DBF in MeOH solutions. Equilibrium constants for DBF were calculated from saturation binding kinetics. Equilibrium experiment results reveal that recognition was effective for DBF binding to the DBF-imprinted polymer, especially for the imprinted PVC.     

Influence Diagnostics in the Common Canonical Variates Model

As a generalization of the canonical correlation analysis to k random vectors, the common canonical variates model was recently proposed based on the assumption that the canonical variates have the same coefficients in all k sets of variables, and is applicable to many cases. In this article, we apply the local influence method in this model to study the impact of minor perturbations of data. The method is non-standard because of the restrictions imposed on the coefficients. Besides investigating the joint local influence of the observations, we also obtain the elliptical norm of the empirical influence function as a special case of local influence diagnostics. Based on the proposed diagnostics, we find that the results of common canonical variates analysis for the female water striders data set is largely affected by omitting just one single observation.