Bed Sediment Characteristics in the Paraná and Paraguay Rivers

ABSTRACT

This paper presents a granulometric characterization of the Paraná and Paraguay rivers bed sediments. Samples obtained along 2,900 km of the thalweg of those rivers form the basis of this study. The main results and other features of the study are as follows: a) the bed sediment of both rivers is composed mainly of medium to fine well-sorted sands, with sizes in the Paraná slightly higher than those in the Paraguay river; b) the variations of mean diameters for both rivers are well correlated with the energy slopes. The correlation coefficient in the Paraguay river increases notably if the discharge and width/depth relationship variations along the channel are included in the regression; and, c) the origin of the transported sands could be related to the geologic characteristics of the Paraná river basin. An explanation is also suggested for the different bed sediment texture found in the Paraná de las Palmas and Paraná Guazú rivers in the lower delta. The explanation is based on the geomorphic processes that built that region of the Paraná river.     

Towards a science and technology‐policy for South Africa

The history of industrial development in South Africa is marked by lack of a coherent science and technology policy. The changing political and economic context has brought a recognition of the need for such a policy, especially for attaining international competitiveness. This article explores some considerations that should enter into the formulation of such a policy. It focuses on the definition of goal sets for science and technology policy and on the mechanisms needed to pursue them; discusses the debate between the structuralist and neoclassical approaches to the role of technology in growth and development; and examines the roles of various research and development agents and some of the main determinants of R&D activity for their implications for policy instruments.     

Mittlerer quadratischer Prognosefehler bei der Prognose des Abwicklungsergebnisses mittels der Chain-Ladder-Methode

Often in non-life insurance claims reserves are the largest position on the liability side of the balance sheet. The determination of adequate claims reserves in two consecutive accounting years leads to the so-called development result, which is defined as the difference of two successive predictors for the claims reserves. If the predictors for the claims reserves are unbiased the expected development result is equal to zero. However, since in claims reserving one predicts future payments the observed development result will in general deviate from the expected value. In the present paper we analyze this deviation. In an example we discuss the results.     

A learning methodology using Matlab/Simulink for undergraduate electrical engineering courses attending to learner satisfaction outcomes

Learner-centred approaches follow the prevailing tendency in modern University reforms which are primarily concerned about “how people learn”. The methodologies can be learner-centred in the sense of placing the student as the main actor of the teaching–learning process by increasing his interactivity and participation, but also considering what is relevant for the student by measuring the learner satisfaction. In order to promote both aspects, this paper proposes a synchronous software-based active methodology that makes use of the simulations to show a virtual scenario to the students and challenge them to predict and discuss the evolution of the scenario. The proposed methodology improves the visual interface, promotes discussion both among students and with the teacher in a brainstorming stage and shows real-world examples. This software-based methodology has been implemented into an Electric Machinery course at the University of Seville (Spain), and the evaluation has been carried out considering both the affective and cognitive domains. Principal components analysis proves to be useful to highlight the dimensions with a higher influence on learner satisfaction and the affective and cognitive results confirm the successful implementation of the proposal.     

Success factors in a CRM strategy: technology is not all

Organisations today need to create, maintain and reinforce relationships with customers. Customer Relationship Management (CRM) seems to have helped firms to better understand their relationships. However, past studies have looked at technology and customer orientations (COs) as key factors. This paper aims to analyse the simultaneous effect of Market Orientation (MO) (rather than CO), Knowledge Management (KM) and other organisational factors in order to explain how to implement a successful CRM. Findings suggest that MO and KM may influence CRM success. Data also suggest that particular organisational factors such as employees, leadership and specific know-how may be key factors in determining the success of CRM. For efficiency resource management, this paper recommends to focus not as much in technology, but on programmes for selection, training and motivation of employees which may enhance CRM objectives. Companies may also pursue a higher customer value by putting in place and reinforcing KM schemes in specific know-hows about CRM.     

Feature selection methods involving support vector machines for prediction of insolvency in non‐life insurance companies

We propose two novel approaches for feature selection and ranking tasks based on simulated annealing (SA) and Walsh analysis, which use a support vector machine as an underlying classifier. These approaches are inspired by one of the key problems in the insurance sector: predicting the insolvency of a non‐life insurance company. This prediction is based on accounting ratios, which measure the health of the companies. The approaches proposed provide a set of ratios (the SA approach) and a ranking of the ratios (the Walsh analysis ranking) that would allow a decision about the financial state of each company studied. The proposed feature selection methods are applied to the prediction the insolvency of several Spanish non‐life insurance companies, yielding state‐of‐the‐art results in the tests performed. Copyright © 2005 John Wiley & Sons, Ltd.     

What is the objective of professional licensing? Evidence from the US market for lawyers

According to public interest theory, professional licensing solves the lemon problem generated by asymmetric information. In contrast, the capture theory claims that licensing aims at increasing professional salaries by restricting supply. This paper shows that the two theories can be identified using data from one regulated profession and provides an empirical application to the US market for entry level lawyers. The empirical results support capture theory.     

Multi-product capacitated facility location problem with general production and building costs

This research introduces the multi-product capacitated facility location problem with general production and building costs (MP-CFLPGC). The MP-CFLPGC extends previous problems found in the literature by including multiple products and general production and building cost functions that allow the modeling of different behaviors like economies of scale and congestion. The MP-CFLPGC is formulated as a mixed integer linear program (MILP). To evaluate the performance of the proposed formulation we analyze the results of a commercial optimizer on a set of 288 randomly generated test instances that resemble the Colombian cement industry supply chain. After one hour the optimizer achieved an optimality gap of 1.0 % or less in 55 % out of the 288 test instances. On average the optimality gap was 3.57 %. Additionally, we propose a randomized mathematical-programming-based heuristic for the test instances where the MILP formulation presents significantly high optimality gaps.