Vis-à-vis vs. mixed dock door assignment: A comparison of different cross dock layouts

An important decision problem during the layout phase of a cross dock is related to the arrangement of inbound and outbound operations within a terminal. Either one side of the terminal is exclusively dedicated to inbound and the other to outbound destinations (vis-à-vis policy) or inbound and outbound destinations can facultatively be assigned all around the terminal (mix policy). The latter policy promises more flexibility, when finally assigning dock doors to truck destinations during operational planning, but comes for the price of ambiguous material flows and potential congestions inside the terminal. Both policies are compared with regard to their impact on operational planning, where deterministic, stochastic and unknown inbound loads are differentiated. Our results show the mix policy being superior in most cases except for unknown inbound loads.     

A push to cycling—exploring the e-bike's role in overcoming barriers to bicycle use with a survey and an intervention study

In Norway, as in many countries, there is a political goal to increase bicycle use. The electric bicycle (e-bike) is a promising tool for achieving this goal, given the hilliness of the country. However, little is yet known about the deterrents of cycling in Norway in general, and in particular how the purchase of an e-bike could be stimulated.

In the current study, 5500 respondents from a convenience sample among car owners were asked about their perceptions of bicycling in general, and of e-bikes in particular as well as their willingness to pay (WTP) for an e-bike. Randomly selected participants (N = 66) were given access to an e-bike for a limited time (2 or 4 weeks). A second questionnaire captured the same perceptions and WTP post-intervention. The results were compared with a control group (N = 214).

The results showed that those who cycle the least were most interested in buying an e-bike and that prior knowledge of the e-bike corresponded with a higher desire to buy one. Pro-environmental values did not predict interest in e-bikes, neither did norms and attitudes toward cycling. The WTP for an e-bike increased after having experienced the benefits for those who used an e-bike compared to those who did not. Price reduction of the e-bike (e.g. VAT exemption), spread of knowledge among the wider population, and actions to offer an e-bike experience may therefore be effective strategies for further expansion of the e-bike in the transport system and thereby to increase bicycle use in Norway.     

Determining fixed crane areas in rail–rail transshipment yards

To enable rapid container transshipment between freight trains in modern rail–rail transshipment yards efficient computerized scheduling procedures are indispensable. This paper proposes a dynamic programming approach, which determines yard areas for gantry cranes, so that the workload is evenly spread among cranes and, thus, train processing is accelerated. In a straightforward simulation of transshipment yard operations, the effect of optimal crane areas vs. equally sized areas is studied, the latter being a common real-world policy. The results indicate a remarkable speed-up of train processing if optimal crane areas are applied.     

Non-cooperative exploitation of multi-cohort fisheries—The role of gear selectivity in the North-East Arctic cod fishery

North-East Arctic cod is shared by Russia and Norway. Taking its multi-cohort structure into account, how would optimal management look like? How would non-cooperative exploitation limit the obtainable profits? To which extent could the strategic situation explain today’s over-harvesting? Simulation of a detailed bio-economic model reveals that the mesh size should be significantly increased, resulting not only in a doubling of economic gains, but also in a biologically healthier age-structure of the stock. The Nash equilibrium is close to the current regime. Even when effort is fixed to its optimal level, the non-cooperative choice of gear selectivity leads to a large dissipation of rents.     

über die Wirkung der Optionsbündelung auf die Ablaufplanung einer Variantenflie?fertigung Option bundling and its impact on operating mixed-model assembly lines

Bei der Optionsbündelung werden einzelne Ausstattungsmerkmale (Optionen) zu Paketen (Bündeln) zusammengefasst, so dass der Kunde, von einem Grundmodell ausgehend, durch die Auswahl unterschiedlicher Optionsbündel eine bestimmte Produktvariante konfigurieren kann. Im Mittelpunkt dieses Beitrags steht die Beantwortung der Frage, ob eine solche Optionsbündelung den Produktionsablauf positiv beeinflusst. Dabei richtet sich das Augenmerk auf die Produktionsform der Variantenflie?fertigung, die in der Endmontage variantenreicher Endprodukte (etwa in der Automobilindustrie) eine dominierende Stellung einnimmt. Eine umfangreiche computergestützte Evaluierung verdeutlicht einerseits den generell positiven Einfluss der Optionsbündelung und identifiziert andererseits im Rahmen der Betrachtung unterschiedlicher Bündelungsarten die kumulative Bündelung als besonders geeignet.