Lower and upper bounds for the two-echelon capacitated location-routing problem.

In this paper, we introduce two algorithms to address the two-echelon capacitated location-routing problem (2E-CLRP). We introduce a branch-and-cut algorithm based on the solution of a new two-index vehicle-flow formulation, which is strengthened with several families of valid inequalities. We also propose an adaptive large-neighbourhood search (ALNS) meta-heuristic with the objective of finding good-quality solutions quickly.

Attitude is everything? The impact of workload, safety climate, and safety tools on medical errors: a study of intensive care units.

Background: Hospitals face an increasing pressure toward efficiency and cost reduction while ensuring patient safety. This warrants a closer examination of the trade-off between production and protection posited in the literature for a high-risk hospital setting (intensive care).

Purposes: On the basis of extant literature and concepts on both safety management and organizational/safety culture, this study investigates to which extent production pressure (i.

Generating Nonnormal Multivariate Data Using Copulas: Applications to SEM.

This article develops a procedure based on copulas to simulate multivariate nonnormal data that satisfy a prespecified variance-covariance matrix. The covariance matrix used can comply with a specific moment structure form (e.g.

Home care in Austria: the interplay of family orientation, cash-for-care and migrant care.

This article discusses the development of the home care sector in Austria. It analyses what impacts the interplay of the traditional family orientation to care, a universal cash-for-care scheme (reaching about 5% of the population) and a growing migrant care sector have on formal home care in Austria. The article is based on an analysis of research papers, policy documents and statistical data covering the period from the introduction of the cash-for-care scheme in 1993 up to 2011.

The determinants of merger waves: An international perspective.

One of the most conspicuous features of mergers is that they come in waves that are correlated with increases in share prices and price/earnings ratios. We use a natural way to discriminate between pure stock market influences on firm decisions and other influences by examining merger patterns for both listed and unlisted firms. If "real" changes in the economy drive merger waves, as some neoclassical theories of mergers predict, both listed and unlisted firms should experience waves.

Demography, Education, and Democracy: global trends and the case of Iran.

Reconstructions and projections of populations by age, sex, and educational attainment for 120 countries since 1970 are used to assess the global relationship between improvements in human capital and democracy. Democracy is measured by the Freedom House indicator of political rights. Similar to an earlier study on the effects of improving educational attainment on economic growth, the greater age detail of this new dataset resolves earlier ambiguities about the effect of improving education as assessed using a global set of national time series.

Measuring the part worth of the mode of transport in a trip package: An extended Bradley-Terry model for paired-comparison conjoint data.

This study measures the travelers' perceived change in utility by accepting one of the modes of transport air, rail, or bus as one component of a packaged city trip. The part-worth values for the trip product elements are expected to depend on a number of traveler characteristics. The predictors hypothesized are city travel experience, general modal preference, socio-economic status, and car ownership.

Application scenarios for nonstandard log-linear models.

In this article, the authors have 2 aims. First, hierarchical, nonhierarchical, and nonstandard log-linear models are defined. Second, application scenarios are presented for nonhierarchical and nonstandard models, with illustrations of where these scenarios can occur.

Punishing and abstaining for public goods.

The evolution of cooperation within sizable groups of nonrelated humans offers many challenges for our understanding. Current research has highlighted two factors boosting cooperation in public goods interactions, namely, costly punishment of defectors and the option to abstain from the joint enterprise. A recent modeling approach has suggested that the autarkic option acts as a catalyzer for the ultimate fixation of altruistic punishment.

Incentives in financing mental health care in Austria.

Background: In Austria, financing health care -and even more so mental health care- is characterized by a mix of federal and provincial responsibilities, lack of uniformity in service provision and service providers, and diverse funding arrangements. The division between financing structures for health care and social care makes the situation even more complex. This state of affairs results in various, partly counterproductive and sometimes paradoxical financial incentives and disincentives for the providers, recipients and financiers of mental health services.

Genetic programming over context-free languages with linear constraints for the knapsack problem: first results.

In this paper, we introduce genetic programming over context-free languages with linear constraints for combinatorial optimization, apply this method to several variants of the multidimensional knapsack problem, and discuss its performance relative to Michalewicz's genetic algorithm with penalty functions. With respect to Michalewicz's approach, we demonstrate that genetic programming over context-free languages with linear constraints improves convergence. A final result is that genetic programming over context-free languages with linear constraints is ideally suited to modeling complementarities between items in a knapsack problem: The more complementarities in the problem, the stronger the performance in comparison to its competitors.

Foetal images: the power of visual technology in antenatal care and the implications for women's reproductive freedom.

Continuing medico-technical progress has led to an increasing medicalisation of pregnancy and childbirth. One of the most common technologies in this context is ultrasound. Based on some identified 'pro-technology feminist theories', notably the postmodernist feminist discourse, the technology of ultrasound is analysed focusing mainly on social and political rather than clinical issues.

Stationary and integrated autoregressive neural network processes.

We consider autoregressive neural network (AR-NN) processes driven by additive noise and demonstrate that the characteristic roots of the shortcuts-the standard conditions from linear time-series analysis-determine the stochastic behavior of the overall AR-NN process. If all the characteristic roots are outside the unit circle, then the process is ergodic and stationary. If at least one characteristic root lies inside the unit circle, then the process is transient.