An echelon inventory-based single-stage cost function for a two-station tandem system

We propose an alternative cost-accounting function for inventory control problems on a make-to-stock setting. Our proposal is based on observing that the traditional holding and backlog parameters introduce some odd short term distortions on the inventory state space. Our single-stage cost function accounts for echelon inventories and possesses a pair of cost parameters for each echelon inventory variable, depending on whether it is positive or negative. With the modified cost-accounting function, we study a twostation tandem system producing a single product, and investigate how it compares with the performances obtained with the usual single-stage cost function. The results available so far show that the optimal policies approach a multi-echelon base stock structure for each machine. Also, the service levels achieved are better under the modified function without increasing the levels of finished goods inventory.     

Identifying the Confounders of Marginalization and Mortality in Mexico, 2003–2007

Social Indicators Research - Confounders alter any predicted outcome by modifying the relationship between cause and consequence. Confounders can appear in different proportions inside a population...     

On the asymptotic behaviour of location-scale invariant Bickel–Rosenblatt tests

Location-scale invariant Bickel–Rosenblatt goodness-of-fit tests (IBR tests) are considered in this paper to test the hypothesis that f, the common density function of the observed independent d-dimensional random vectors, belongs to a null location-scale family of density functions. The asymptotic behaviour of the test procedures for fixed and non-fixed bandwidths is studied by using an unifying approach. We establish the limiting null distribution of the test statistics, the consistency of the associated tests and we derive its asymptotic power against sequences of local alternatives. These results show the asymptotic superiority, for fixed and local alternatives, of IBR tests with fixed bandwidth over IBR tests with non-fixed bandwidth.     

An Extension of a Measure of Polarization, with an application to the income distribution of five OECD countries

We introduce an extension of the Esteban and Ray [Econometrica, 62:819–851 1994] measure of polarization that can be applied to density functions. As a by-product we also derive the Wolfson [Am. Econ. Rev., 84:353–358 1994] measure as a special case. This derivation has the virtue of casting both measures in the context of a (statistically) unified framework. We study the polarization of the distribution of household income for five OECD countries (LIS database): US, UK, Canada, Germany and Sweden. The present paper is essentially based on Esteban, Gradín and Ray [9], published as #218 in the working papers series of the Luxembourg Income Study. Changes have been kept to a minimum. We have provided a brief reference to the literature on polarization measurement that has appeared since then and have updated the data of our application.     

Goodness-of-fit tests for parametric models in censored regression

The authors propose a goodness-of-fit test for parametric regression models when the response variable is right-censored. Their test compares an estimation of the error distribution based on parametric residuals to another estimation relying on nonparametric residuals. They call on a bootstrap mechanism in order to approximate the critical values of tests based on Kolmogorov-Smirnov and Cramér-von Mises type statistics. They also present the results of Monte Carlo simulations and use data from a study about quasars to illustrate their work.     

Development and comparative study of two near-exact approximations to the distribution of the product of an odd number of independent Beta random variables

Using the concept of near-exact approximation to a distribution we developed two different near-exact approximations to the distribution of the product of an odd number of particular independent Beta random variables (r.v.'s). One of them is a particular generalized near-integer Gamma (GNIG) distribution and the other is a mixture of two GNIG distributions. These near-exact distributions are mostly adequate to be used as a basis for approximations of distributions of several statistics used in multivariate analysis. By factoring the characteristic function (c.f.) of the logarithm of the product of the Beta r.v.'s, and then replacing a suitably chosen factor of that c.f. by an adequate asymptotic result it is possible to obtain what we call a near-exact c.f., which gives rise to the near-exact approximation to the exact distribution. Depending on the asymptotic result used to replace the chosen parts of the c.f., one may obtain different near-exact approximations. Moments from the two near-exact approximations developed are compared with the exact ones. The two approximations are also compared with each other, namely in terms of moments and quantiles.     

The double sampling S2 chart with estimated process variance

This paper proposes useful exact bounds for the parameters of the double sampling S² chart with known process variance and it also investigates the properties of the double sampling S² chart with estimated process variance, in terms of the average run length, the standard deviation of the run length and the average sample size, providing a numerical comparison with the known process variance case. It also provides guidelines to systematically design the double sampling S² chart both with known and estimated process variance and proposes two optimal design procedures with estimated process variance, for (a) minimizing the out-of-control average run length and (b) minimizing the out-of-control average sample size.     

Dynamic Marketing Capabilities: Toward an Integrative Framework

In recent years, the dynamic capabilities view has attracted attention in the management literature, and theoretical papers note many research challenges. Currently, one of the most significant issues is the role of the marketing function in the development of dynamic capabilities, and some recent discussions have even introduced the new term ‘dynamic marketing capabilities’. The main area of interest is how to achieve a well‐integrated framework to serve as the starting point for empirical papers. Although the most recent research proposes a wide range of processes as possible dynamic marketing capabilities, it is difficult to find consensus among these proposals. To resolve this difficulty, this paper seeks to define the dynamic marketing capabilities construct based on accepted components in the generic dynamic capabilities view. More specifically, it defines the role of dynamic marketing capabilities through absorptive capacity and knowledge management. By identifying these components and relating them in an integrative model, the authors propose to explain how dynamic marketing capabilities work and precisely which marketing processes promote both components.     

The Fabricare system: a multi-agent-based scheduling prototype

Several trends in society in general, and manufacturing in particular, have changed the way business was made in the last decades of the 20th century, setting new requirements for companies and individuals. The research question being addressed in this paper is concerned with the ability to build computer-supported manufacturing systems able to cope with current and future requirements. For this matter, a hypothesis based on the holonic and multi-agent paradigms is proposed. The paper describes a holonic architecture for manufacturing enterprises and a prototype system (named Fabricare) for manufacturing orders scheduling based on that architecture. A negotiation mechanism called ‘contract net with constraint propagation protocol’ was developed for regulating the interaction between holons in the system. This protocol also implements a negotiation-driven scheduling procedure.