Charging the polluters: A pricing model for road and railway noise

This study outlines a method to estimate the short run marginal cost (SRMC) for road and railway noise. It is based on standardized calculation methods for total noise levels and monetary cost estimates from well established evaluation methods. Here official calculation methods and monetary values are used for Sweden, but the estimation method for the SRMC outlined can be directly applied using other standardized noise calculation methods and monetary values. This implies that the current knowledge regarding the calculation of total noise levels and the evaluation of the social cost of noise can be extended to estimate the marginal effect as well. This is an important finding since it enables policy makers to price noise externalities in an appropriate way. Several sensitivity tests run for the SRMC show that: (i) increasing the total traffic on the infrastructure has only a minor influence, (ii) estimates are quite sensitive to the number of exposed individuals, and (iii) to the monetary values used. Hence, benefits transfer, i.e. using monetary values elicited based on road noise for railway noise, should be done with caution or not at all. Results also show that the use of quiet technology can have a significant effect on the SRMC. The fact that this model is able to differentiate not only modes of transport, but also vehicles and even technologies is an important finding. It is essential that the noise charges give the operators the right incentives to choose their optimal allocation.Externalities; Marginal cost; Noise; Railway; Road

Performance modeling and control of web servers

This thesis deals with the task of modeling a web server and designing a mechanism that can prevent the web server from being overloaded. Four papers are presented. The first paper gives an M/G/1/K processor sharing model of a single web server. The model is validated against measurements ands imulations on the commonly usedw eb server Apache. A description is given on how to calculate the necessary parameters in the model. The second paper introduces an admission control mechanism for the Apache web server basedon a combination of queuing theory andcon trol theory. The admission control mechanism is tested in the laboratory, implemented as a stand-alone application in front of the web server. The third paper continues the work from the secondp aper by discussing stability. This time, the admission control mechanism is implemented as a module within the Apache source code. Experiments show the stability and settling time of the controller. Finally, the fourth paper investigates the concept of service level agreements for a web site. The agreements allow a maximum response time anda minimal throughput to be set. The requests are sorted into classes, where each class is assigneda weight (representing the income for the web site owner). Then an optimization algorithm is appliedso that the total profit for the web site during overload is maximized

Rate-Equivocation Optimal Spatially Coupled LDPC Codes for the BEC Wiretap Channel

We consider transmission over a wiretap channel where both the main channel and the wiretapper's channel are Binary Erasure Channels (BEC). We use convolutional LDPC ensembles based on the coset encoding scheme. More precisely, we consider regular two edge type convolutional LDPC ensembles. We show that such a construction achieves the whole rate-equivocation region of the BEC wiretap channel. Convolutional LDPC ensemble were introduced by Felstr\"om and Zigangirov and are known to have excellent thresholds. Recently, Kudekar, Richardson, and Urbanke proved that the phenomenon of "Spatial Coupling" converts MAP threshold into BP threshold for transmission over the BEC. The phenomenon of spatial coupling has been observed to hold for general binary memoryless symmetric channels. Hence, we conjecture that our construction is a universal rate-equivocation achieving construction when the main channel and wiretapper's channel are binary memoryless symmetric channels, and the wiretapper's channel is degraded with respect to the main channel.Comment: Working pape

On the road to Denmark - Swedish gambling legislation in the light of the European Union

Spel och dobbel är något som har funnits i de flesta kulturer i århundraden och är ett ämne där åsikter och intressen går vida isär. Trots att stora delar av världen befinner sig i en finansiell kris, fortsätter spelmarknaden att växa. I takt med att den teknologiska utvecklingen ökar, ökar även tillgängligheten av spel. Den kraftiga tillväxten inom spelsektorn, ger upphov till frågan om hur en marknad som å ena sidan kan uppfattas som moraliskt förkastlig och förknippad med negativa sociala skadeverkningar, och å andra sidan genererar betydande intäkter, ska regleras. Redan från ett tidigt skede har EU haft förhållningssättet att det är upp till varje medlemsstat att avgöra hur Spel och Dobbel ska regleras, vilket har lett till ett ”lapptäcke” av olika lagstiftningar. De nationella lagstiftningarna måste följa de fundamentala principerna i EU-rätten, vilket har tagits upp i ett flertal rättsfall. ECJ har dock gett medlemsstaternas en bred möjlighet att göra en skönsmässig bedömning angående vad som är bäst för respektive land trots klara avvikelser från de fundamentala principerna inom EU. Sverige har alltid haft en restriktiv hållning gentemot spel och dobbel, som har varit kontrollerat genom ett statligt monopol sedan 1200-talet. Det kan ifrågasättas huruvida den svenska restriktiva lagstiftningen är förenlig med EU-rätten. De svenska domstolarna har undvikit att inhämta förhandsavgöranden innan Sjöberg och Gerdinfallet, där ECJ ansåg den svenska lagstiftningen i stort vara förenlig med EU-rätten. När Högsta domstolen senare dömde i samma fall ansågs straffpåföljderna i lagstiftningen vara diskriminerande, vilket får anses skapa rättsosäkerhet. Riksrevisionen och den svenska regeringen har framfört kritik mot delar av den nuvarande lagstiftningen. De trängande frågorna är: 1) Hur skall en potentiell ny lagstiftning se ut? 2) Kan den danska licensmodellen ses som ett passande alternativ för lagstiftaren?Gambling is something that has existed in most cultures for centuries and it is a topic which is highly debated. Despite large parts of the world being in an economic crisis, the gambling sector continues to grow. With the aid of new technology the accessibility of gambling has increased immensely. This raises concern on how to regulate this delicate area, as gambling on the one hand is perceived as morally objectionable and socially harmful, yet on the other hand, gambling generates significant amounts of revenue. The EU has from an early point taken the approach that it is up to each Member State to decide the appropriate measures regarding to gambling to pursue set objectives. This discretion has led to a patchwork of regulations on the matter of gambling and especially regarding online gambling. The regulations still have to adhere to fundamental principles of EU law, which has been brought up in case law, yet the ECJ has given Member States a broad discretion in how to regulate gambling despite clear breaches of fundamental principles. Sweden has always had a restrictive stance towards gambling and has had a state controlled monopoly for gambling since the 13th century. Questions could be raised whether the Swedish restrictive legislation is coherent with EU law. Case law reveals that the Swedish Courts have refrained from requesting a preliminary ruling up to the Sjöberg and Gerdin case, where the ECJ considered the Swedish legislation to be coherent in principle. The recent judgment where the criminal sanctions were ruled to be discriminative by the Supreme Court, has caused legal uncertainty. Riksrevisionen and the Swedish Government also raised concerns with parts of the current legislation. The urgent questions are: 1) What will a potential new legislation look like? 2) Can the Danish license system prove to be a suitable alternative for the legislator

All about the marine/sea ice diatom Nitzschia lecointei

Generally, in terms of growth N. lecointei seems quite tolerant to changes in pH and pCO2, probably due to the fact that this species grows in an environment with large seasonal variations in the carbonate system. However, increased pCO2 resulted in physiological changes that may have important ecological consequences, such as cellular stoichiometry. For instance, we observed changes in carbon metabolism, and fatty acid content and composition, that did not affect the growth rate. When the experimental period was increased (194 days, ca. 60 asexual generations), we observed a small reduction in growth at 960 µatm pCO2 after 147 days. Carbon metabolism was significantly affected, resulting in higher cellular release of dissolved organic carbon. When studying the synergism between temperature (−1.8 and 2.5°C) and pCO2 (390 and 960 μatm), synergism was detected in growth rate and acyl lipid fatty acid content. Carbon enrichment only promoted (3 %) growth rate closer to the optimal growth, but not at the control temperature (−1.8°C). Optimal growth rate was observed around 5°C in a separate experiment. The total content of fatty acids was reduced at elevated pCO2, but only at the control temperature. PUFAs were reduced at high pCO2. When combining increased temperature and different salinity conditions, the growth rate was higher at 3°C than at -1.8°C. Salinity 10 clearly limited growth rate and the highest growth rates were found at salinity 20 and 35. In another experiment, high and low temperature together with treatments simulating ice formation and melting conditions were studied. Here, the highest levels of oxidative stress were found in low temperature and ice melting treatments, respectively. With respect to 9 weeks in the dark, cell numbers were higher at -1.5°C compared to 3°C, but when retrieved to light conditions, after one week higher cell numbers were observed at 3°C versus -1.5°C. Furthermore, cell numbers were lower when acetateUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Scale sensitivity and question order in the contingent valuation method

Agency is gratefully acknowledged. The usual disclaimers apply. Abstract: This study examines the effect on respondents ' willingness to pay to reduce mortality risk by the order of the question in a stated preference study. Using answers from an experiment conducted on a Swedish sample where respondents ’ cognitive ability was measured and where they participate in a contingent valuation survey it is found that scale sensitivity is the strongest when respondents are asked about a smaller risk reduction first (“Bottom-up ” approach). This contradicts some previous evidence in the literature. It is also found that the respondents’ cognitive ability is correlated with their answers being line with theoretical predictions. The latter being important for the validity of the answers. Hence, the results of this paper suggest that scale sensitivity is related to the order of the questions and to respondents ’ cognitive ability

Performance Analysis and Design of Two Edge Type LDPC Codes for the BEC Wiretap Channel

We consider transmission over a wiretap channel where both the main channel and the wiretapper's channel are Binary Erasure Channels (BEC). We propose a code construction method using two edge type LDPC codes based on the coset encoding scheme. Using a standard LDPC ensemble with a given threshold over the BEC, we give a construction for a two edge type LDPC ensemble with the same threshold. If the given standard LDPC ensemble has degree two variable nodes, our construction gives rise to degree one variable nodes in the code used over the main channel. This results in zero threshold over the main channel. In order to circumvent this problem, we numerically optimize the degree distribution of the two edge type LDPC ensemble. We find that the resulting ensembles are able to perform close to the boundary of the rate-equivocation region of the wiretap channel. There are two performance criteria for a coding scheme used over a wiretap channel: reliability and secrecy. The reliability measure corresponds to the probability of decoding error for the intended receiver. This can be easily measured using density evolution recursion. However, it is more challenging to characterize secrecy, corresponding to the equivocation of the message for the wiretapper. M\'easson, Montanari, and Urbanke have shown how the equivocation can be measured for a broad range of standard LDPC ensembles for transmission over the BEC under the point-to-point setup. By generalizing the method of M\'easson, Montanari, and Urbanke to two edge type LDPC ensembles, we show how the equivocation for the wiretapper can be computed. We find that relatively simple constructions give very good secrecy performance and are close to the secrecy capacity. However finding explicit sequences of two edge type LDPC ensembles which achieve secrecy capacity is a more difficult problem. We pose it as an interesting open problem.Comment: submitted to IEEE Transactions on Information Theory. Updated versio