Can a meteor measure vertical winds?

In the first part of this thesis the zonal and meridional tilt of the SKiYMET Meteor Radar at Dragvoll (63.4 N 10.5 E) has been found using two different methods. The average zenith angle model found the zonal tilt to be 0.22 ± 0.11 degrees towards the east and the meridional tilt to be 0.09 ± 0.11 degrees towards the north. The results of this model should be treated with skepticism as the seasonal variations of especially the meridional tilt was large. The zenith angle model found the zonal tilt to be 0.15 ± 0.21 degrees towards the east and the meridional tilt to be 0.62 ± 0.24 degrees towards the south. In the second part the tilt found from the zenith angle model was used to investigate the changes such a tilt would cause to the meridional, zonal and vertical winds. And whether the vertical wind would show a strong correlation with either the meridional or zonal wind. The vertical wind seems to be oscillating with a main period of 24 hours while the meridional and zonal wind has a 12 hour oscillation period, this might show that the contamination from the horizontal winds are not the dominant driving force in the winds. The changes the tilt had on the vertical wind showed an oscillation with the same period as the meridional winds. The changes to the zonal and meridional wind due to the tilt was neglectable. The daily vertical background wind was obtained and analyzed. The seasonal vertical background wind for the fall of 2012 was found to be weak and downwards, winter was stronger and downwards, spring 2013 was approximately zero and for summer 2013 a upwards wind was measured. The data was compared to data found by Balsley and Riddle (1984). The result of the comparison was that the resulting winds from this thesis was stronger and has the opposite direction of the data by Balsley and Riddle (1984)

Scarification to reduce damage from Pine weevil (Hylobius abietis), Vest-Agder Bachelor i skogbruk 2018 Samtykker til

For å sikre effektive og vellykkede foryngelser i skogbruket, er det viktig å sikre foryngelsesflater mot eventuelle skadegjørere. Gransnutebillen (Hylobius abietis) er regnet som en av de største skadegjørerne i skogbruket i Norge. Snutebillen finnes i hele landet men, det er de kystnære strøkene på Sør- og Østlandet, som tilsynelatende er tyngst belastet av snutebillen. Planting på markberedte arealer er et tiltak som har godt dokumentert effekt i både Norge og Sverige. I denne undersøkelsen er det gjort feltregistreringer i 2 hogstflater i Vest-Agder, henholdsvis Marnardal og Farsund. På begge lokalitetene ble det etter hogst i 2015, etabler prøveflater. Disse ble markberedt og plantet våren 2016. På forsøksfeltet er det satt planter i og utenfor markberedningsflekker. Formålet med forsøket er å dokumentere effekten av markberedning i områder som er tungt belastet av snutebiller. Sommeren 2017 gjorde jeg feltarbeidet mitt på feltene. Det ble registret gnagstørrelse på samtlige planter, og det ble gjort en vurdering av gnagets betydning på planten (skadegrad). For planter satt i markberedningsflekker, er avstanden fra planten og ut til kanten av flekken registrert. Det er gjort analyser på datamaterialet, for å kunne si noe om effekten av markberedningen. I begge feltene har planter som er satt i markberedningsflekker en signifikant lavere skadegrad enn planter som er satt utenfor markberedningsflekker. Resultatene viser ingen signifikant forskjell i gnagstørrelse for planter satt i og utenfor markberedningsflekker i Marnardal. I Farsund har planter satt i markberedningsflekker en signifikant mindre gnagstørrelse enn planter satt utenfor markberedningsflekker. I begge feltene er det ingen korrelasjon mellom avstand fra planter satt i markberedningsflekker til kanten av flekken, og skadegrad. Undersøkelsen gir et godt situasjonsbilde på effekten av markberedningen, men jeg kan i oppgaven ikke trekke noen klare konklusjoner. Registreringene er gjort 1 år etter planting, 2 år etter hogst, og foryngelsen er fortsatt under angrep av snutebillene. Ut ifra det bildet undersøkelsen danner ser det ut til at markberedningen har en skadebegrensende effekt for planter som er satt i markberedningsflekker.To ensure efficient and successful regeneration in forestry, is it important to secure the plants against any harmful organisms. The Pine weevil (Hylobius abietis) is probably the most important pest of planted conifer seedlings in Norway. We find the Pine weevil in all of Norway, but the near-coast areas in south of Norway has the highest reported activity of the weevil. Planting on scarification areas is known to have a well-documented effect in both Norway and Sweden. In this report there is been done field registration on clear-cuts in Vest-Agder. In Marnardal and Farsund there was in 2016 established test-fields on 2 clear-cuts from 2015. Scarification was done early 2016. The plants were set in both soil scarification areas and outside soil scarification areas. The purpose of the experiment is documentation on the effect of soil scarification, in areas heavily loaded with Pine Weevils. Midsummer 2017 I did my field works. The feeding areas on seedlings was registered, and an evaluation of the plants impact from the damage was done (skadegrad). On plants put in the scarification area, the distance from the plant to edge of the scarification area was measured. Statistics is done on the data material to be able to tell something about the effect for soil scarification. In both fields plants put inside scarification areas has a significant lower “skadegrad” than the plants put outside scarification area. The results showed no significant differences between feeding areas for plants put outside and inside scarification areas in Marnardal. In Farsund the plants put inside scarification areas has a significant smaller feeding area, than the plants put outside of the scarification area. In both field, I found no correlation on distance from plant to edge of scarification area, and “skadegrad”. The report gives a good overview on the present situation of the effect from scarification in both fields. The sites are still under attack from Pine Weevils, and further registrations has to be done before coming to any clear conclusions. But, from what we can see with this dataset, soil scarification has a damage reducing effect to plants put in scarification areas

Runtime Evolution of Bitcoin's Consensus Rules

The runtime evolution of a system concerns the ability to make changes during runtime without disrupting the service. Blockchain systems need to provide continuous service and integrity. Similar challenges have been observed in centrally controlled distributed systems or mobile applications that handle runtime evolution, mainly by supporting compatible changes or running different versions concurrently. However, these solutions are not applicable in the case of blockchains, and thus, new solutions are required. This study investigates Bitcoin consensus evolution by analysing over a decade of data from Bitcoin's development channels using Strauss’ grounded theory approach and root cause analysis. The results show nine deployment features which form nine deployment techniques and ten lessons learned. Our results illustrate how different deployment techniques fit different contexts and pose different levels of consensus failure risks. Furthermore, we provide guidelines for risk minimisation during consensus rule deployment for blockchain in general and Bitcoin in particular.submittedVersio

SoK: Cross-Chain Bridging Architectural Design Flaws and Mitigations

Cross-chain bridges are solutions that enable interoperability between heterogeneous blockchains. In contrast to the underlying blockchains, the bridges often provide inferior security guarantees and have been targets of hacks causing damage in the range of 1.5 to 2 billion USD in 2022. The current state of bridge architectures is that they are ambiguous, and there is next to no notion of how different architectures and their components are related to different vulnerabilities. Throughout this study, we have analysed 60 different bridges and 34 bridge exploits in the last three years (2021-2023). Our analyses identified 13 architectural components of the bridges. We linked the components to eight types of vulnerabilities, also called design flaws. We identified prevention measures and proposed 11 impact reduction measures based on the existing and possible countermeasures to address the imminent exploits of the design flaws. The results are meant to be used as guidelines for designing and implementing secure cross-chain bridge architectures, preventing design flaws, and mitigating the negative impacts of exploits

A dataset for predicting cloud cover over Europe

Clouds are important factors when projecting future climate. Unfortunately, future cloud fractional cover (the portion of the sky covered by clouds) is associated with significant uncertainty, making climate projections difficult. In this paper, we present the European Cloud Cover dataset, which can be used to learn statistical relations between cloud cover and other environmental variables, to potentially improve future climate projections. the dataset was created using a novel technique called area Weighting Regridding Scheme to map satellite observations to cloud fractional cover on the same grid as the other variables in the dataset. Baseline experiments using autoregressive models document that it is possible to use the dataset to predict cloud fractional cover.publishedVersio

Computer Science Courses Using Laptops

Traditionally computer sciences courses have been taught using laboratories full of expensive desktop computers. Although this approach may have been valid in the 80, 90s and even the early part of this decade, this paper suggests that buying, maintaining and replacing laboratories full of computers is no longer required. This paper raises the issues associated with attempting to use laptops – as thin/thick clients using virtual machines – to deliver the computer science curriculum and offers potential solutions that, in some cases, may make computer science courses at such ‘brave’ institutions more appealing

Evaluating the Impact of ChatGPT on Exercises of a Software Security Course

acceptedVersio

Coordinated Morphogenetic Mechanisms Shape the Vertebrate Eye.

The molecular bases of vertebrate eye formation have been extensively investigated during the past 20 years. This has resulted in the definition of the backbone of the gene regulatory networks controlling the different steps of eye development and has further highlighted a substantial conservation of these networks among vertebrates. Yet, the precise morphogenetic events allowing the formation of the optic cup from a small group of cells within the anterior neural plate are still poorly understood. It is also unclear if the morphogenetic events leading to eyes of very similar shape are indeed comparable among all vertebrates or if there are any species-specific peculiarities. Improved imaging techniques have enabled to follow how the eye forms in living embryos of a few vertebrate models, whereas the development of organoid cultures has provided fascinating tools to recapitulate tissue morphogenesis of other less accessible species. Here, we will discuss what these advances have taught us about eye morphogenesis, underscoring possible similarities and differences among vertebrates. We will also discuss the contribution of cell shape changes to this process and how morphogenetic and patterning mechanisms integrate to assemble the final architecture of the eye