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- Helo, Petri, et al.
(författare)
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Distrubution Center Location Analysis for Nordic Countries by Using Network Optimization Tools
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Many supply chain and logistics related location decisions are driven by demand. This paper analyses population densities in Sweden, Finland, Norway and partly Denmark and analyses how a minimum impedance approach would set up the distribution center (DC) locations. For each scenario, travel time maps are generated. Firstly, each country is analyzed separately and 1...5 DC cases are analyzed. Then a merged Nordic area is introduced and a similar approach is used to set up 1…6 DCs. Finally, a sensitivity analysis is conducted to study how the large population of Umeå or Vaasa should be increased in order to make the top five in the Nordic level. The results show distribution centers could be formed in the case of population driven demand products. This also gives insight into how the results can vary when changing perspective from national analysis to Nordic level.
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| 4. |
- Sandberg Hanssen, Thor-Erik, et al.
(författare)
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Dissimilarities between the national cost/benefit models of road projects : Comparing appraisals in Nordic countries
- 2020
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Ingår i: Transportation Research Interdisciplinary Perspectives. - : Elsevier. - 2590-1982. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The Nordic Council has a vision to create the most integrated region globally by 2030. Nevertheless, Nordic cross-border infrastructure projects are generally developed by each nation individually. Joint Nordic infrastructure planning is thus fragmented. An example of this, as reported herein, is how road projects are assessed by the infrastructure planning authorities in Norway, Sweden, and Finland, the latter to which is included in the comparison for the first time. In each country, cost/benefit analyses (CBAs) are used. In each nation, the monetary values of changes in travel time, accidents, and environmental externalities are estimated. We then apply those values to the three national CBA models to assess an illustrative hypothetical road project. Theoretically, the models should provide similar outcomes when using a common set of parameters. Instead, we show that the choice of national model is crucial to the outcome. The Swedish model, for example, generates a higher cost of travel time than the other models irrespective of the nation from which we choose the parameters. Consequently, CBA-based assessments in the Nordic area depend strongly on the model applied and peculiarities in its coding. Finally, we discuss the policy implications of our findings for appraising national and Nordic projects.
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| 5. |
- Westin, Jonas, et al.
(författare)
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Modelling Changes in Regional Accessibility from Speed Limit Adjustments in the Road Network : A report from the Nordic research project E12 Atlantica BA3NET
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The Swedish Transport Administration will adjust the speed limits in the Swedish road network. A point of departure for this adjustment is Vision Zero, a traffic safety project approved by the Swedish Parliament in 1997. The goal of Vision Zero is a radical reduction of the number of fatalities or serious injuries on Swedish roads. However, the suggested new speed limits have given rise to debate and criticism. Regional and local actors have argued that a reduced speed limit may have negative impacts on accessibility and local development. The road network in the Botnia-Atlantica region contains roads where the Transport Administration has suggested reduced speed limits. Sections of the TEN-T E12 road and connecting nearby roads are parts of those roads. The illustrative cases chosen are a part of the E12-region around the city Umeå in Sweden. The purpose of the paper is to present a method for analysis of the distribution of changed accessibility over places, in response to changed speed limit in the road network. The suggested method should be a basis for a dialogue on accessibility and security between local and regional actors on one hand and the Swedish Transport administration on the other. Accessibility although is a multifaceted phenomenon. The impact of changed accessibility on an economy both contains general elements as well as elements of very situation specific character. Given this, the modelling approach suggested make use of three different model approaches; EVA, SAMPERS and PIPOS. The comparison of outcomes from the three models gives an in-depth picture of how changes in speed limits affect accessibility and regional development.
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| 7. |
- Batten, David F., et al.
(författare)
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Modelling commodity flows on trade networks : Retrospect and prospect
- 1990
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Ingår i: New Frontiers in Regional Science. - London : Palgrave Macmillan. - 0333484495 - 033353106X ; , s. 135-156
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Bokkapitel (refereegranskat)abstract
- In this chapter we examine various analytical approaches which are pertinent to an important area of research in which, according to Isard and Dean ([30]), regional scientists ought to be more actively involved. This is the estimation of commodity flow (or trade share) matrices across world trade networks. Although spatial variables such as distance, location and transport cost clearly have a significant impact on the quantity and structure of trade, these effects are often ignored or downplayed by international trade economists. Our task is to redress this imbalance partly by strengthening the case for combined spatial interaction-equilibrium approaches to world trade analysis.
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| 8. |
- Batten, David, et al.
(författare)
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Modelling Commodity Flows on Trade Networks : Retrospect and Prospect
- 1989
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Various approaches to the estimation of commodity flow or trade share matrices across world trade networks are examined. Some serious drawbacks associated with the use of spatial price equilibrium models are identified, and a case is made for combining two or more individual approaches, such as may be found in "dispersed" spatial price equilibrium models or in computable general equilibrium models which cater for spatial heterogeneity. It is found that some variant of the gravity model may be a reliable guide to trade share patterns in the long run, particularly in a world of differentiated products and increasing returns to scale. A conclusive finding is that quite different models ought to be adopted for different commodities (i.e. markets) in the short and medium term perspective.
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| 9. |
- Bergkvist, Erik, et al.
(författare)
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Estimation of gravity models by OLS estimation, NLS estimation, Poisson, and Neural Network specifications
- 1997
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Four specifications of gravity models for freight flow prediction are compared. The traditional specification with OLS estimation is compared with non-linear least squares (NLS) estimation as well as with a model where data are assumed to be Poisson distributed. These are compared with a semi-parametric neural network model. Data consists of freight flows between Norwegian counties. The attribute describing a node is population while distance gives the friction on links of transportation. Results show that estimation with OLS and NLS is inferior to Poisson and Neural Network specifications. However, the Poisson model, although advantageous compared to OLS, may still be improved upon. The semiparametric Neural Network does require less of these restrictions to hold and also outperforms the others as a tool for forecast in terms of Root Mean Square Error (RMSE). The NLS model although showed the best performance when estimated on known data.
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| 10. |
- Bergkvist, Erik, et al.
(författare)
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Estimation of gravity models by OLS estimation, NLS estimation, Poisson and neural network specifications
- 2001
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Ingår i: New analytical advances in transportation and spatial dynamics. - Aldershot : Ashgate. - 1840148632 - 9781315190921 - 9781138727250 ; , s. 135-155
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Bokkapitel (refereegranskat)abstract
- When assessing infrastructure investment, it is crucial to forecast the flows on the links after the suggested improvements. In freight flow analysis, the impact on the flows in the network is conditional on the size of the investment and the complexity of the network. If the investment has a critical impact on the flows, the change may be substantial and hard to predict by linear models. In economic geography and regional economics, the gravity model has gained wide acceptance as a reasonable (although simple) model of spatial interaction between nodes in a network (Haynes and Fotheringham, 1984 or Sen and Smith, 1995).
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