56 research outputs found

    A decision support methodology for strategic planning in maritime transportation

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    a b s t r a c t This paper presents a decision support methodology for strategic planning in tramp and industrial shipping. The proposed methodology combines simulation and optimization, where a Monte Carlo simulation framework is built around an optimization-based decision support system for short-term routing and scheduling. The simulation proceeds by considering a series of short-term routing and scheduling problems using a rolling horizon principle where information is revealed as time goes by. The approach is flexible in the sense that it can easily be configured to provide decision support for a wide range of strategic planning problems, such as fleet size and mix problems, analysis of long-term contracts and contract terms. The methodology is tested on a real case for a major Norwegian shipping company. The methodology provided valuable decision support on important strategic planning problems for the shipping company

    Negotiating care in the context of Finnish and Italian elder care policies

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    Negotiation is an integral part of all elder care, which by definition involves a relation between at least two people. In this article we analyse negotiations concerning elder care in the context of Finnish and Italian elder care policies. At the macro level negotiations on elder care are shaped by elder care policies and at the micro level by individual skills and resources. Our focus is on the negotiations on eligibility that take place when elders attempt to access care. The data consist of qualitative interviews with Finnish and Italian elders in need of care. The analysis of individual experiences of care negotiations reflects the implementation of elder care policies. The results indicate that the most negotiated eligibility criteria when seeking access to elder care are need, money and social relations. These criteria are negotiated when seeking eligibility to different sources of care: informal care, grey market, market-based, non-profit and public services. In Italy, negotiation is particularly crucial when accessing grey market care. Cash as the main Italian elder care policy tool tends to enhance the role of and need for negotiation. In Finland, a greater part of elder care is provided by the public sector and therefore the process of negotiation is more standardized than in Italy

    Some Causes of the Variable Shape of Flocks of Birds

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    Flocks of birds are highly variable in shape in all contexts (while travelling, avoiding predation, wheeling above the roost). Particularly amazing in this respect are the aerial displays of huge flocks of starlings (Sturnus vulgaris) above the sleeping site at dawn. The causes of this variability are hardly known, however. Here we hypothesise that variability of shape increases when there are larger local differences in movement behaviour in the flock. We investigate this hypothesis with the help of a model of the self-organisation of travelling groups, called StarDisplay, since such a model has also increased our understanding of what causes the oblong shape of schools of fish. The flocking patterns in the model prove to resemble those of real birds, in particular of starlings and rock doves. As to shape, we measure the relative proportions of the flock in several ways, which either depend on the direction of movement or do not. We confirm that flock shape is usually more variable when local differences in movement in the flock are larger. This happens when a) flock size is larger, b) interacting partners are fewer, c) the flock turnings are stronger, and d) individuals roll into the turn. In contrast to our expectations, when variability of speed in the flock is higher, flock shape and the positions of members in the flock are more static. We explain this and indicate the adaptive value of low variability of speed and spatial restriction of interaction and develop testable hypotheses

    Approximating Optimal Behavioural Strategies Down to Rules-of-Thumb: Energy Reserve Changes in Pairs of Social Foragers

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    Functional explanations of behaviour often propose optimal strategies for organisms to follow. These ‘best’ strategies could be difficult to perform given biological constraints such as neural architecture and physiological constraints. Instead, simple heuristics or ‘rules-of-thumb’ that approximate these optimal strategies may instead be performed. From a modelling perspective, rules-of-thumb are also useful tools for considering how group behaviour is shaped by the behaviours of individuals. Using simple rules-of-thumb reduces the complexity of these models, but care needs to be taken to use rules that are biologically relevant. Here, we investigate the similarity between the outputs of a two-player dynamic foraging game (which generated optimal but complex solutions) and a computational simulation of the behaviours of the two members of a foraging pair, who instead followed a rule-of-thumb approximation of the game's output. The original game generated complex results, and we demonstrate here that the simulations following the much-simplified rules-of-thumb also generate complex results, suggesting that the rule-of-thumb was sufficient to make some of the model outcomes unpredictable. There was some agreement between both modelling techniques, but some differences arose – particularly when pair members were not identical in how they gained and lost energy. We argue that exploring how rules-of-thumb perform in comparison to their optimal counterparts is an important exercise for biologically validating the output of agent-based models of group behaviour

    Migrants’ decision-process shaping work destination choice: the case of long-term care work in the United Kingdom and Norway

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    Escalating demands for formal long-term care (LTC) result in the reliance on migrant workers in many developed countries. Within Europe, this is currently framed by progressive European immigration policies favouring inter-European mobility. Using the UK and Norway as case studies, this article has two main aims: (1) to document changes in the contribution of European Union (EU) migrants to the LTC sectors in Western Europe, and (2) to gain further understanding of migrants’ decision-processes relating to destination and work choices. The UK and Norway provide examples of two European countries with different immigration histories, welfare regimes, labour market characteristics and cultural values, offering a rich comparison platform. The analysis utilizes national workforce datasets and data obtained from migrants working in the LTC sector in the UK and Norway (n = 248) and other stakeholders (n = 136). The analysis establishes a significant increase in the contribution of EU migrants (particularly from Eastern Europe) to the LTC sector in both the UK and Norway despite their different welfare regimes. The findings also highlight how migrant care workers develop rational decision-processes influenced by subjective perspectives of investments and returns within a context of wider structural migration barriers. The latter includes welfare and social care policies framing the conditions for migrants’ individual actions

    Corporate governance, strategies and performance of privatised industrial firms in the FSU

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    SIGLEAvailable from British Library Document Supply Centre-DSC:DXN028102 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
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