From Remote Hosting to Self-Hosting of an Erp System: Lessons Learned from the City of El Paso

This article describes how the city of El Paso, Texas, initially used an application service provider (ASP) model, allowing the city to fast track its enterprise resource planning (ERP) system implementation. After a change in the ASP arrangements led to less responsiveness to its needs, the city government moved to a self-hosted ERP system. Lessons learned in the evolution from ASP hosting to self-hosting of the city's ERP system are compared to previously published literature.     

Guiding the evolution of product-line configurations

Software and Systems Modeling - A product line is an approach for systematically managing configuration options of customizable systems, usually by means of features. Products are generated for...     

Spline Based Pseudo‐Inversion of Sampled Data Non‐Minimum Phase Systems for an Almost Exact Output Tracking

This paper considers the problem of achieving a very accurate tracking of a pre‐specified desired output trajectory , for linear, multiple input multiple output, non‐minimum phase and/or non hyperbolic, sampled data, and closed loop control systems. The proposed approach is situated in the general framework of model stable inversion and introduces significant novelties with the purpose of reducing some theoretical and numerical limitations inherent in the methods usually proposed. In particular, the new method does not require either a preactuation or null initial conditions of the system. The desired and the corresponding sought input are partitioned in a transient component ( and u_t(k), respectively) and steady‐state ( and u_s(k), respectively). The desired transient component is freely assigned without requiring it to be null over an initial time interval. This drastically reduces the total settling time. The structure of u_t(k) is a priori assumed to be given by a sampled smoothing spline function. The spline coefficients are determined as the least‐squares solution of the over‐determined system of linear equations obtained imposing that the sampled spline function assumed as reference input yield the desired output over a properly defined transient interval. The steady‐state input u_s(k) is directly analytically computed exploiting the steady‐state output response expressions for inputs belonging to the same set of .     

Database Repairs and Analytic Tableaux

In this article, we characterize in terms of analytic tableaux the repairs of inconsistent relational databases, that is databases that do not satisfy a given set of integrity constraints. For this purpose we provide closing and opening criteria for branches in tableaux that are built for database instances and their integrity constraints. We use the tableaux based characterization as a basis for consistent query answering, that is for retrieving from the database answers to queries that are consistent with respect to the integrity constraints.     

Book reviews

Summary The review article (with a selected bibliography) annotates, on the basis of Grotjahn'sLinguistische und statistische Methoden in Metrik und Textwissenschaft, some general methodological aspects of statistical methods in the analysis of literary texts and evaluates the attempt in metrical theory, to reconstruct the so-called ‘metrical competence’ with probabilistic evaluated metrical rules in the frame of a generative approach. Leopoldo Sáez-Godoy is a lecturer in Spanish in the Romance Seminar of the University of Bonn, chairman of the Specialist Group for Spanish Texts (ALLC), and member of the bibliography committee of this journal. recently editedFirst Person Female American, an annotated bibliography of autobiographies (Whitston, 1980), and has published articles on SF treatment of computers in government, dystopian uses of IQ testing, and Zamiatin'sWe.     

Non-continuous growth of firms: some empirical evidence from Italian manufacturing industry

Firms change their size through a row of discrete leaps. A basic model allowing for discontinuous growth can be based on several assumptions that entail testable consequences: profitability is not a continuous function of the firms’ size, but exhibits peaks, each corresponding to a locally optimal size. The model has been tested by using a panel of Italian manufacturing firms. Both the non-parametric analysis and a panel estimation confirm the presence of ‘peaks’ in the distribution of profitability by size.