Cross dock scheduling: Classification,literature review and research agenda

At cross docking terminals incoming deliveries of inbound trucks are unloaded, sorted, moved across the dock and finally loaded onto outbound trucks, which immediately leave the terminal towards their next destination in the distribution chain. Accordingly, a cross dock is a consolidation point in a distribution network, where multiple smaller shipments can be merged to full truck loads in order to realize economies in transportation. In this context, the truck scheduling problem, which decides on the succession of truck processing at the dock doors, is especially important to ensure a rapid turnover and on-time deliveries. Due to its high real-world significance, several truck scheduling procedures have been introduced during recent years, which all treat specific cross dock settings. In order to structure and promote scientific progress, this paper introduces a classification of deterministic truck scheduling. With the help of this classification, existing literature is reviewed and future research needs are identified. Moreover, we represent a yet unexplored class of truck scheduling problems which is highly relevant in real-world distribution networks.     

Identifying Different Areas of Inhomogenous Mineral Subsoil: Spatial Fluctuation Approaches

We use a recently proposed fluctuation-type procedure for detecting breaks in spatial regions to distinguish between hard and soft areas of inhomogeneous mineral subsoil like additives, air pockets, and adhesion. For a proper application, some refinements of the procedure are necessary. Both simulation evidence of the refinement and the application on the subsoil yield favorable results.     

The Role of Peers and Siblings in Toddlers’ Developing Understanding of Incompatible Desires

According to previous research, social experiences with other children might explain why three‐year‐olds are already quite proficient in understanding desires but not beliefs as subjective mental states. This study investigated toddlers’ (N = 50) developing subjective understanding of incompatible desires around the age of 3 years (M = 35.5 months) and the associated social factors (i.e., family demographics, peer, and sibling variables). Results indicated a developmental sequence from understanding desires to understanding desire‐dependent emotions with an unexpected positivity bias in toddlers’ prediction of own emotions. A hierarchical regression model revealed that specific social factors (i.e., reported quality of peer interactions and day care attendance) individually contributed to explaining the variance in children's desire‐reasoning skills. Findings are interpreted as supporting a belief–desire asymmetry, and specific social experiences, such as positive peer interactions and desire conflicts, may promote toddlers’ understanding of incompatible desires as subjective mental states.     

Valuing mortality risk reductions from environmental, transport, and health policies: a global meta-analysis of stated preference studies

We conduct, to our knowledge, the first global meta-analysis (MA) of stated preference (SP) surveys of mortality risk valuation. The surveys ask adults their willingness to pay (WTP) for small reductions in mortality risks, deriving estimates of the sample mean value of statistical life (VSL) for environmental, health, and transport policies. We explain the variation in VSL estimates by differences in the characteristics of the SP methodologies applied, the population affected, and the characteristics of the mortality risks valued, including the magnitude of the risk change. The mean (median) VSL in our full data set of VSL sample means was found to be around $7.4 million (2.4 million) (2005 U.S. dollars). The most important variables explaining the variation in VSL are gross domestic product (GDP) per capita and the magnitude of the risk change valued. According to theory, however, VSL should be independent of the risk change. We discuss and test a range of quality screening criteria in order to investigate the effect of limiting the MA to high-quality studies. When limiting the MA to studies that find statistically significant differences in WTP using external or internal scope tests (without requiring strict proportionality), we find that mean VSL from studies that pass both tests tend to be less sensitive to the magnitude of the risk change. Mean VSL also tends to decrease when stricter screening criteria are applied. For many of our screened models, we find a VSL income elasticity of 0.7-0.9, which is reduced to 0.3-0.4 for some subsets of the data that satisfy scope tests or use the same high-quality survey.     

Monitoring Trends in Global Combat: A New Dataset of Battle Deaths

Both academic publications and public media often make inappropriate use of incommensurate conflict statistics, creating misleading impressions about patterns in global warfare. This article clarifies the distinction between combatant deaths, battle deaths, and war deaths. A new dataset of battle deaths in armed conflict is presented for the period 1946–2002. Global battle deaths have been decreasing over most of this period, mainly due to a decline in interstate and internationalised civil armed conflict. It is far more difficult to accurately assess the number of war deaths in conflicts both past and present. But there are compelling reasons to believe that there is a need for increased attention to non-battle causes of mortality, especially displacement and disease in conflict studies. Therefore, it is demographers, public health specialists, and epidemiologists who can best describe the true human cost of many recent armed conflicts and assess the actions necessary to reduce that toll.     

Goodness of Fit via Non-parametric Likelihood Ratios

Abstract.  To test if a density f is equal to a specified f ₀, one knows by the Neyman–Pearson lemma the form of the optimal test at a specified alternative f ₁. Any non-parametric density estimation scheme allows an estimate of f . This leads to estimated likelihood ratios. Properties are studied of tests which for the density estimation ingredient use log-linear expansions. Such expansions are either coupled with subset selectors like the Akaike information criterion and the Bayesian information criterion regimes, or use order growing with sample size. Our tests are generalized to testing the adequacy of general parametric models, and to work also in higher dimensions. The tests are related to, but are different from, the 'smooth tests' that go back to Neyman [Skandinavisk Aktuarietidsskrift 20(1937) 149] and that have been studied extensively in recent literature. Our tests are large-sample equivalent to such smooth tests under local alternative conditions, but different from the smooth tests and often better under non-local conditions.     

Mit Goffman auf dem Drogenstrich

The drug dependent young women walking the streets in the neighborhood of Frankfurt’s main station are doubly stigmatized: as users of illegal drugs and as (unregistered and therefore) illegal prostitutes. They work in a public place and under the eyes of the police, but they try to hide their activities — as do their customers who try to remain anonymous. The ethnographic study presented here focussed on the interactions between drug prostitutes and their customers, using the models proposed by Erving Goffman as theoretical perspectives. The “view from Goffman” is certainly very useful in research on sensitive topics but also has its limitations.     

Correction of Density Estimators that are not Densities

Abstract. Several old and new density estimators may have good theoretical performance, but are hampered by not being bona fide densities; they may be negative in certain regions or may not integrate to 1. One can therefore not simulate from them, for example. This paper develops general modification methods that turn any density estimator into one which is a bona fide density, and which is always better in performance under one set of conditions and arbitrarily close in performance under a complementary set of conditions. This improvement-for-free procedure can, in particular, be applied for higher-order kernel estimators, classes of modern h ⁴ bias kernel type estimators, superkernel estimators, the sinc kernel estimator, the k -NN estimator, orthogonal expansion estimators, and for various recently developed semi-parametric density estimators.