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| 2. |
- Asplund, Marcus, et al.
(författare)
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Price adjustments by a gasoline retail chain
- 2000
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Ingår i: Scandinavian Journal of Economics. - : Wiley. - 0347-0520 .- 1467-9442. ; 102:1, s. 101-121
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Tidskriftsartikel (refereegranskat)abstract
- We use daily data to examine price responses in the Swedish gasoline market to changes in the Rotterdam spot price, exchange rates and taxes. The distribution of price adjustments by a leading retail chain, for the period January 1980 to December 1996, is symmetric with no small adjustments. An error correction model shows that, in the short run, prices gradually move towards the long-run equilibrium in response to cost shocks. There is some evidence that, also in the short run, prices are stickier downwards than upwards. Prices respond more rapidly to exchange rate movements than to the spot market price. Our analysis emphasizes that to fully understand price adjustments it is necessary to examine data sets where the sample frequency at least matches that of price adjustments.
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| 3. |
- Asplund, Marcus, et al.
(författare)
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Price Discrimination in Oligopoly: Evidence from Swedish Newspapers
- 2001
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This paper provides an empirical examination of third degree price discrimination in the Swedish local newspaper markets. We measure the extent of price discrimination by the fraction of subscriptions that a newspaper sells at a discount. The results show that price discrimination is more prevalent in competitive markets and among newspapers with low market shares. We find weak evidence that newspapers operating in markets with larger inflows of new consumers, and those that cover diverse geographical areas, offer more discounts. Overall, our findings are consistent with predictions from recent theoretical work, including Chen (1997) and Villas-Boas (1999), which suggests that firms attempt to poach consumers from rivals by offering targeted discounts.
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| 4. |
- Eriksson Bylund, Nina, et al.
(författare)
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3D Wiener filtering to reduce reverberations in ultrasound image sequences
- 2003
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Ingår i: Image Analysis. - : Springer. - 3540406018 - 9783540406013 ; , s. 579-586
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Bokkapitel (refereegranskat)abstract
- One of the most frequently occuring artifacts in ultrasound imaging is reverberations. These are multiple reflection echoes that result in ghost echoes in the ultrasound image. A method for reducing these unwanted artifacts using a three-dimensional (3D) Wiener filter is presented. The Wiener filter is a global filter and produces an estimate of the uncorrupted signal by minimizing the mean square error between the estimate and the uncorrupted signal in a statistical sense. The procedure works as follows: In a graphic interface the operator is displayed an image sequence. The operator marks two areas in one of the images, one area which contains a typical reverberation artifact, and one area free from artifact. Using these areas to produce noise and signal estimates, a Wiener filter is created and applied to the sequence. The 3D Wiener filters display excellent selection capabilities, and the developed method significantly reduces the magnitude of the reverberation artifact in the tested sequences.
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| 5. |
- Eriksson-Bylund, Nina, et al.
(författare)
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Reverberation Reduction Using 3D Wiener Filtering
- 2003
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- One of the most common artifacts in ultrasound imaging is reverberations. These are multiple reflection echoes that register as coming from a deeper region than the depth of the interface that are causing them, and result in ghost echoes in the ultrasound image. A method to reduce these unwanted artifacts using a three dimensional (2D + time) Wiener filter has been developed. Two sequences of iq-data, the least processed signal possible to retrieve from the ultrasound system (Vingmed System Five), have been used to test the method: One sequence on a tissue-mimicking agar gel phantom in which bars of glass simulating ribs give rise to reverberations, and one sequence on an open-chest pig with a strong reverberation from a water-filled rubber glove used as a medium between the heart and the transducer. The procedure works as follows: In a graphic interface the operator is shown the image sequence. In one of the frames two areas must be marked out; One area which contains a typical reverberation artifact, and one area which will represent an artifact free signal. After creating the three dimensional Wiener filter post-processing of the sequence is performed. The developed method significantly reduced the magnitude of the reverberation artifact in the tested sequences.
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| 6. |
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| 7. |
- Eriksson, Morgan, et al.
(författare)
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Effekten av fluidiseringshastighet och kornstorlek på agglomereringsrisk vid biobränsleeldning i FB-pannor
- 2004
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Effekten av bäddkornstorleken och fluidiseringshastigheten på agglomereringsrisken i biobränsleeldade BFB/CFB fullskaleanläggningar har studerats. De experimentella försöken visar på att ökad fluidiseringshastighet gör att bädden agglomererar vid en högre temperatur. Detta är mest markant vid relativt låga fluidiseringshastigheter, vilket ofta förekommer i t ex en BFB-panna eller recirkulationsbenet i en CFB.
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| 9. |
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| 10. |
- Eriksson, Marcus, et al.
(författare)
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Inherent Shutdown Capabilities in Accelerator-driven Systems
- 2002
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Ingår i: Annals of Nuclear Energy. - 0306-4549 .- 1873-2100. ; 29:14, s. 1689-1706
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Tidskriftsartikel (refereegranskat)abstract
- The applicability for inherent shutdown mechanisms in accelerator-driven systems (ADS) has been investigated. We study the role of reactivity feedbacks. The benefits, in terms of dynamics performance, for enhancing the Doppler effect are examined. Given the performance characteristics of source-driven systems, it is necessary to manage the neutron source in order to achieve inherent shutdown. The shutdown system must be capable of halting the external source before excessive temperatures are obtained. We evaluate methods, based on the analysis of unprotected accidents, to accomplish such means. Pre-concepted designs for self-actuated shutdown of the external source suggested. We investigate time responses and evaluate methods to improve the performance of the safety system. It is shown that maximum beam output must be limited by fundamental means in order to protect against accident initiators that appear to be achievable in source driven systems. Utilizing an appropriate burnup control strategy plays a key role in that effort.
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