The work aims to study different methods suitable for de-icing and ice prevention of vehicle headlamps and tail lamps, especially LED-lights. Furthermore, the work aims to investigate the scale of the problem with insufficient or lack of de-icing on automotive lamps depending on the region and the environment the vehicle operates in. The problem with insufficient de-icing in automotive lamps was investigated by observations, tests of various lamps and a driver survey. Deicing methods were identified through a litera-ture review. The methods were studied in detail, and some were also evaluated by tests. The tests were narrowed down to temperature measurements and de-icing measurements. The latter were performed using a test method especially developed for the task. The collected data was used to evaluate whether actions are needed to be taken and to form recommen-dations for future developments. The number one priority should be to improve the tail lamps de-icing ability. Headlamps can also be improved but there is no imminent need. Insufficient de-icing of headlamps and tail lamps can potentially be a problem in all areas subjected to cold winter climate. Tail lamps should be fitted with electrical heating in order to improve the de-icing ability. They should be positioned so that snow and ice does not stack on top of them. The de-icing time of tail lamps should be less than 10 min. Truck drivers needs to be better in scraping their headlamps and tail lamps. The time needed for de-icing Scania’s H7 headlamps is 20 min for halogen version and 35 min for xenon version at -18 °C. This should be compared to the BMW LED-headlamp which needs 65 min to complete de-icing. LED-headlamps are probably limited to a de-icing time of approximately 60 min unless additional heat is added to the headlamp lens. The fastest and most efficient way to de-ice the headlamps is to use hot washer fluid. Electrically heated lenses are also effective but the de-icing process is slower. The proposed test method is a simple and effective way to compare and evaluate headlamps and tail lamps without knowing internal airflows and light sources. The way the ice layer is created on the device under test is unique to this method. The created ice layer is extremely uniform and the results are easy to evaluate. / Sammanfattning Arbetets syfte är att undersöka olika avisningsmetoder och isförebyggande åtgärder för hu-vudstrålkastare och baklyktor, speciellt LED-lampor. Ytterligare syfte är att undersöka hur stort problemet med otillräcklig avisning är beroende på vilken region och miljö som fordonen körs i. Problemet med otillräcklig avisning av fordonsbelysning har undersökts genom observatio-ner, en förarenkät samt genom tester av olika strålkastare och baklyktor. Avisningsmetoder har identifierats genom en litteraturstudie. Metoderna har studerats i detalj och några har även utvärderats genom tester. Testerna har utförts enligt en för uppgiften framtagen testme-tod. De insamlade uppgifterna har sedan används för att utvärdera om åtgärder behöver vid-tas och för att ge rekommendationer för framtida utvecklingsprojekt. Första prioritet bör vara att förbättra baklyktornas avisningsförmåga. Huvudstrålkastarna kan även de förbättras men det föreligger inte i dagsläget något akut behov av det. Otillräcklig avisning av huvudstrålkastare och bakljus kan potentiellt vara ett problem i alla miljöer med ett kallt vinterklimat. Baklyktorna bör utrustas med en eluppvärmd lins för att förbättra avis-ningen. Lamporna bör placeras på ett sådant sätt att snö och is inte kan ansamlas ovanpå dem. Avisningstiden för en baklykta bör inte överstiga 10 min. Lastbilschaufförerna behöver bli bättre på skrapa av is och snö från huvudstrålkastare och baklyktor. Avisningstiden för Scanias H7 huvudstrålkastare är 20 min för halogen versionen och 35 min för xenon versionen vid -18 °C. Detta kan jämföras med att BMW:s LED-huvudstrålkastare behöver 65 min för att avisas. LED-huvudstrålkastare är troligtvis begränsade till en avis-ningstid kring 60 min om inte någon extra värme tillförs. Den snabbaste metoden för att avisa en huvudstrålkastare är att använda varm spolarvätska men elektrotermisk avisning kan också vara mycket effektivt. Den föreslagna testmetoden är ett enkelt sätt att jämföra och utvärdera olika huvudstrålkastare och baklyktor. Det som är unikt med testmetoden är hur isskiktet på lamporna bildas. Isskiktet som skapas är extremt jämt och lätt att utvärdera.

Plusieurs problématiques de gestion d’opérations peuvent être formalisées avec un problème d’optimisation discret. Ces modèles d’optimisation sont traditionnellement développés sous l’hypothèse que les données d’entrée sont déterministes, non impactées par des changements inattendus ou des incertitudes. Au cours des dernières années, le besoin en modèles performants, incluant des outils efficaces et permettant de réagir de manière optimale aux imprévus (perturbations), n’a cessé de croitre. En phase d’exécution d’un système, plusieurs événements imprévus (incertitudes) peuvent le perturber et le faire dévier de son parcours original voire rendre son exécution impossible. Il est vrai que ces incertitudes peuvent être considérées de manière proactive par le biais d’une optimisation stochastique ou des modèles d'optimisation robustes. Mais même avec des solutions robustes, des événements inattendus peuvent encore se produire nécessitant de revoir le plan robuste en cours d’exécution. Dans cette thèse, l’objectif est de prendre en compte ces incertitudes de manière réactive dans les modèles. Ainsi, une nouvelle méthodologie générique est proposée pour les problèmes d'optimisation de réparation / récupération. En considérant les solutions réparées / récupérées fournies par cette méthodologie appliquée à un plan initial en cours de mise en oeuvre, un décideur peut vouloir minimiser les coûts d'exploitation, mais aussi limiter les changements par rapport au plan initial. Le problème de réparation / récupération est formulé comme un problème d'optimisation multiobjectif, qui minimise des fonctions spécifiques relatives à divers critères de réparation (pilotés par les choix du décideur). / A wide variety of operations management problems can be formulated and solved as discrete optimization problems. Traditionally, these models have been mostly developed and used under the assumption that the input data are known in advance, not subject to unexpected changes, nor impacted by uncertainty. In recent years, the need for improved models providing efficient tools for quickly and optimally reacting to the occurrence of unexpected events (disruptions) has become a more and more important issue. In the execution phase, various unanticipated events will disrupt the system and make the plan deviate from its intended course and even make it infeasible.Uncertainty can be taken into account in a proactive way with stochastic optimization or robust optimization models. However, even with robust solutions, unexpected events can still occur requiring to reconsider the robust plan under execution. In this thesis, we are interested to cope with uncertainty in a reactive way. We propose a new generic methodology for repair/recovery optimization problems. When considering repair/recovery solutions for the initial plan under implementation, the decision-maker may want to minimize operating costs, but also limit the changes with respect to the initial plan. We formulate the repair/recovery problem as a multiobjective optimization problem minimizing specified functions for various repair criteria.

No description available.

Die Arbeit widmet sich der Einsatzplanung von Luftfahrzeugen (LFZ) und fokussiert dabei auf die herausfordernde Thematik des Verschleißes, der zu einer Heterogenität in der Brennstoffeffizienz innerhalb der Flotte führt. Dieser heterogene Effekt wird durch den sogenannten 'Performance Factor' (PF) quantifiziert, der den Verbrauch im Vergleich zu einem nicht verschleißbehafteten Referenz-LFZ adjustiert. Trotz der nachgewiesenen Auswirkungen auf die Effizienz wird der PF bisher in der Einsatzplanung weitgehend vernachlässigt. Das Ziel dieser Forschungsarbeit besteht in der systematischen Untersuchung des Potenzials zur Reduzierung des Brennstoffbedarfs und der damit verbundenen CO2-Emissionen durch eine effizienzorientierte Einsatzplanung mittels Berücksichtigung des PF. Zu diesem Zweck wird ein taktisches Modell, das sogenannte 'TARP-Modell,' entwickelt. Es ermöglicht eine integrierte Lösung der Phasen des Aircraft Routings und des Tail Assignments, wodurch individuelle Flugdurchführungskosten unter Berücksichtigung der Heterogenität der Flüge und der PF-Verteilung in der Flotte ermittelt werden können. Die erzielten Ergebnisse verdeutlichen, dass eine effizienzorientierte Einsatzplanung eine Senkung der Brennstoffkosten um etwa 0,25% bis 0,5% ermöglicht. Selbst bei unvorhergesehenen Flugplanstörungen und der vermehrten Nutzung von sogenannten Aircraft Swaps (TARP-R-Modell) bleibt das Potenzial weitestgehend erhalten, sofern der PF angemessen in die Entscheidungsfindung integriert wird. Es ist jedoch zu beachten, dass das Potenzial mit zunehmender Komplexität in der Flug- und LFZ-Zuordnung durch verstärkte Restriktionen abnehmen kann. Die vorliegende Arbeit leistet somit einen Beitrag zur Ressourcenschonung und zur Verringerung der Klimawirksamkeit des Luftverkehrs. Es ist anzunehmen, dass zukünftige technologische Fortschritte im Bereich des digitalen Zwillings die Berechnung des PF noch präziser gestalten werden, wodurch dessen Bedeutung sowohl wissenschaftlich als auch operationell weiter an Bedeutung gewinnen dürfte. / The thesis is dedicated to the aircraft rotation and assignment and focuses on the challenging issue of aircraft performance degradation, which leads to heterogeneity in fuel efficiency within the fleet. This heterogeneous effect is quantified by the so-called 'Performance Factor' (PF), which adjusts fuel consumption in comparison to a non-worn reference aircraft. Despite its proven impact on efficiency, the PF has largely been disregarded in aircraft planning practices. The main objective of this research is to systematically investigate the potential for reducing fuel consumption and associated CO2 emissions through an efficiency-oriented aircraft planning approach, incorporating consideration of the PF. To achieve this goal, a tactical model, referred to as the 'TARP model,' is developed. The model facilitates an integrated solution to the aircraft routing and tail assignment phases, enabling the determination of individual flight execution costs while accounting for the heterogeneity of flights and PF distribution in the fleet. The results obtained underscore that an efficiency-oriented aircraft planning approach can yield a reduction in fuel costs of approximately 0.25% to 0.5%. Even in the presence of unforeseen flight schedule disruptions and increased utilization of aircraft swaps (TARP-R model), the potential remains largely preserved, provided the PF is adequately integrated into the decision-making process. Nevertheless, it should be noted that the potential may diminish with growing complexity in flight and aircraft assignment, stemming from heightened restrictions. Consequently, this study contributes to resource conservation and the mitigation of the aviation industry's climate impact. Anticipated advancements in digital twin technologies are expected to further refine PF calculations, enhancing its significance both from a scientific and operational standpoint.

För investerare vars portföljer utgörs av internationella investeringar är det i synnerhet viktigt att begrunda beroendestrukturen mellan internationella investeringar och valutakurser. Detta på grund av den valutarisk som investeraren exponerar sig mot utöver de internationella tillgångarnas inneboende risk. I denna studie undersöks hur svenska investerare med investeringar i den amerikanska aktie- och företagsobligationsmarknaden påverkas av valutakursförändringar i USD:SEK. De amerikanska investeringarna är i denna studie denominerade i amerikanska dollar men portföljen och dess risk är denominerad i svenska kronor, portföljen påverkas därmed av valutaeffekten.Vidare undersöks samvariationen mellan dessa tillgångar och en optimal valutahedge upprättas för att reducera svansrisk i en sådan portfölj.  För att bestämma en optimal valutahedge optimeras CVaR för nio olika portföljer med olika viktning av S&P 500, investment grade- företagsobligationer och high yield-företagsobligationer. Två metoder för att ta fram scenariopriser till optimeringen används: historisk simulering samt Monte Carlo-simulering från en vine-copula. Resultaten i denna studie antyder att svenska investerare bör hedga bort viss exponering mot USD. På den amerikanska aktiemarknaden bör större andel av valutarisken bibehållas än på den amerikanska high yield-obligationsmarknaden. Detta antyder att viss valutarisk bidrar med en hedgande effekt. På den amerikanska investment grade-obligationsmarknaden bör endast en mycket liten exponering mot USD bibehållas och ingen tydlig hedgande effekt kunde påvisas. Analys av samvariation mellan amerikansk aktiemarknad, företagsobligationsmarknad och valutakursen USD:SEK antyder att USD:SEK uppvisar förhöjt negativt beroende vid svansutfall i både den amerikanska aktiemarknaden och high yield-obligationsmarknaden. Detta antyder att USD uppvisar så kallade safe haven-egenskaper för svenska investerare i dessa marknader. / For investors whose portfolios consist of international investments, it is of particular importance to consider the dependence structure between international investments and foreign exchange rates. This is due to the currency risk that the investor is exposed to in addition to the inherent risk of the international assets. This study examines how Swedish investors with investments in the US equity and corporate bond market are affected by exchange rate fluctuations in the currency pair USD:SEK. In this study, US investments are denominated in US dollars, but the portfolio and its risk are denominated in Swedish Kronor, the portfolio is thus affected by the foreign currency effect. Furthermore, the covariation between these assets is examined and an optimal hedge is established in order to reduce tail risk in such a portfolio. To determine the optimal currency hedge, CVaR is optimized for nine different portfolios with different weightings of S&P 500, investment grade corporate bonds and high yield corporate bonds. Two methods for producing scenario prices for the optimization are used: historical simulation and Monte Carlo simulation from a vine copula. The results of this study suggest that Swedish investors should hedge some of the exposure against USD. In the US stock market, a larger share of currency risk should be maintained than in the US high yield bond market. This suggests that some currency risk contributes to a hedging effect. In the US investment grade bond market little exposure against USD should be maintained and no clear hedging effect could be demonstrated. Analysis of covariation between the US stock market, corporate bond market and the exchange rate USD:SEK indicates that USD:SEK displays increased negative dependence in tail events in boththe US stock market and the high yield bond market. This indicates that USD displays so-called safe haven properties for Swedish investors in these markets.

Der Ribonukleinsäure (RNS) Stoffwechsel umfasst verschiedene Schritte, beginnend mit der Transkription der RNS über die Translation bis zum RNA Abbau. Poly(A) Schwänze befinden sich am Ende der meisten der Boten-RNS, schützen die RNA vor Abbau und stimulieren Translation. Die Deadenylierung von Poly(A) Schwänzen limitiert den Abbau von RNS. Bisher wurde RNS Abbau meist im Kontext von cytoplasmatischen Prozessen untersucht, ob und wie RNS Deadenylierung und Abbau in Nukleus erfolgen ist bisher unklar. Es wurde daher eine neue Methode zur genomweiten Bestimmung von Poly(A) Schwanzlänge entwickelt, welche FLAM-Seq genannt wurde. FLAM-Seq wurde verwendet um Zelllinien, Organoide und C. elegans RNS zu analysieren und es wurde eine signifikante Korrelation zwischen 3’-UTR und Poly(A) Länge gefunden, sowie für viele Gene ein Zusammenhang von alternativen 3‘-UTR Isoformen und Poly(A) Länge. Die Untersuchung von Poly(A) Schwänzen von nicht-gespleißten RNS Molekülen zeige, dass deren Poly(A) Schwänze eine Länge von mehr als 200 nt hatten. Die Analyse wurde durch eine Inhibition des Spleiß-Prozesses validiert. Die Verwendung von Methoden zur Markierung von RNS, welche die zeitliche Auflösung der RNS Prozessierung ermöglicht, deutete auf eine Deadenylierung der Poly(A) Schwänze schon wenige Minuten nach deren Synthesis hin. Die Analyse von subzellulären Fraktionen zeigte, dass diese initiale Deadenylierung ein Prozess im Nukleus ist. Dieser Prozess ist gen-spezifisch und Poly(A) Schwänze von bestimmten Typen von Transkripten, wie nuklearen langen nicht-kodierende RNS Molekülen waren nicht deadenyliert. Um Enzyme zu identifizieren, welche die Deadenylierung im Zellkern katalysieren, wurden verschiedene Methoden wie RNS-abbauende Cas Systeme, siRNAs oder shRNA Zelllinien verwendet. Trotz einer effizienten Reduktion der RNS Expression entsprechender Enzymkomplexe konnten keine molekularen Phänotypen identifiziert werden welche die Poly(A) Länge im Zellkern beeinflussen. / The RNA metabolism involves different steps from transcription to translation and decay of messenger RNAs (mRNAs). Most mRNAs have a poly(A) tail attached to their 3’-end, which protects them from degradation and stimulates translation. Removal of the poly(A) tail is the rate-limiting step in RNA decay controlling stability and translation. It is yet unclear if and to what extent RNA deadenylation occurs in the mammalian nucleus. A novel method for genome-wide determination of poly(A) tail length, termed FLAM-Seq, was developed to overcome current challenges in sequencing mRNAs, enabling genome-wide analysis of complete RNAs, including their poly(A) tail sequence. FLAM-Seq analysis of different model systems uncovered a strong correlation between poly(A) tail and 3’-UTR length or alternative polyadenylation. Cytosine nucleotides were further significantly enriched in poly(A) tails. Analyzing poly(A) tails of unspliced RNAs from FLAM-Seq data revealed the genome-wide synthesis of poly(A) tails with a length of more than 200 nt. This could be validated by splicing inhibition experiments which uncovered potential links between the completion of splicing and poly(A) tail shortening. Measuring RNA deadenylation kinetics using metabolic labeling experiments hinted at a rapid shortening of tails within minutes. The analysis of subcellular fractions obtained from HeLa cells and a mouse brain showed that initial deadenylation is a nuclear process. Nuclear deadenylation is gene specific and poly(A) tails of lncRNAs retained in the nucleus were not shortened. To identify enzymes responsible for nuclear deadenylation, RNA targeting Cas-systems, siRNAs and shRNA cell lines were used to different deadenylase complexes. Despite efficient mRNA knockdown, subcellular analysis of poly(A) tail length by did not yield molecular phenotypes of changing nuclear poly(A) tail length.

Bakgrund: Med digital utveckling ökar användandet av digitala kanaler för att köpa produkter. Utvecklingen sätter ökad press på handeln att utveckla sitt digitala erbjudande. Problemformulering: Förutsättningarna att driva handel skiljer sig åt online jämfört med offline, sett både ur perspektiv från återförsäljare och köpare. Begränsad yta i en fysisk butik i närområdet jämfört med stort centralt lager för e-handel ger olika förutsättningar för vilka produkter som kan erbjudas. Konsumenten med tillgång till näst intill oändligt antal affärer digitalt med enkel jämförelse av pris och produkter. Syfte: Syftet med denna uppsats är att undersöka hur försäljningskoncentrationen av produkter i dagligvaruhandeln i Sverige skiljer sig mellan e-handel och fysisk butik. Forskningsfrågor: Hur fördelas försäljningen av produkter online jämfört med fysisk butik?  Är försäljningen i fysisk butik mer koncentrerad till färre produkter jämfört med online handel? Teori: Både longtail-fenomenet och paretoprincipen existerar praktiskt och litterärt, men det beror på vilken typ av produkt, period och marknad det gäller om begreppen är sanna eller inte. Metod: Kvantitativ metod med primärdata från dagligvaruhandeln där 2 585 produkters försäljning online och offline analyserats med en kombination av RStudio och Microsoft Excel. Slutsatser: Försäljningen är mer koncentrerad till ett lägre antal produkter online jämfört med offline. Det finns dock variationer mellan produktkategorier. Nyckelord: Longtail, pareto, superstars, dagligvaror, e-handel, omni-channel, multi-channel, försäljningskoncentration. / Background: Digital development has increased the use of digital channels to buy products. This development puts increased pressure on the retail sector to enhance its digital offerings. Problem statement: The conditions for buying and selling products differ online compared to offline for both the buyer and seller. Limited space in a physical store in the local area compared to a large central warehouse for e-commerce. Consumers have access to nearly an infinite number of digital stores with easy comparisons of prices and products. Purpose: The purpose of this thesis is to examine how the sales concentration of products in the grocery retail sector in Sweden differs between e-commerce and physical stores. Research questions: How does the distribution of product sales differ online compared to physical stores? Is the sales concentration in physical stores more focused to fewer products compared to e-commerce? Theory: Both the longtail phenomenon and the Pareto principle exist practically and literarily, but their validity depends on the type of product, period, and market in question. Method: Quantitative method using primary data from the grocery retail sector, where the sales of 2 585 products online and offline have been analyzed using a combination of RStudio and Microsoft Excel. Conclusions: Sales are more concentrated to fewer products online compared to offline, there are however variations between product categories. Keywords: Long tail, Pareto, superstars, grocery, e-commerce, omni-channel, multi-channel, sales concentration.

No description available.

No description available.

Viruses constitute the vast majority of all biological entities in the biosphere and represent one of the biggest reservoirs of undetected genetic diversity on Earth. Of all the viral particles inhabiting the ocean, phages are the most abundant and can affect the overall microbial composition of marine ecosystems and the dynamics of global biogeochemical cycles. The interaction between prokaryotic cells and their phages is among the oldest and most intertwined host-parasite relationships on the planet. It has been extensively studied by culture, molecular biology, and experimental evolution. However, due to the difficulties of culture with environmental samples, only a few studies have analyzed the mechanisms of phage-host interaction in the marine environment. Here, we have studied the genes involved in viral host recognition and their evolutionary dynamics by focusing on two species of the marine copiotrophic bacterium Alteromonas and several phages infecting them. We described the genomic and morphological characterization of the first Alteromonas phage belonging to the Myoviridae family (Alteromonas myovirus V22) that was isolated in coastal waters of the Mediterranean Sea, and we identified its receptor-binding protein (RBP) used for host recognition by combining fluorescence microscopy and spectrometry. In addition, using size-exclusion chromatography, we showed how this protein required co-expression with a downstream protein to be functional, which later was identified as a new type of intermolecular chaperone crucial for RBP maturation. We also identified a conserved host recognition module in V22 and other unrelated alterophages belonging to different viral families and with completely different morphologies, suggesting horizontal gene transfer between the ancestors of these phages. Furthermore, we described the first coevolution study of a host-parasite system performed with Alteromonas using a metagenomics-like approach. Finally, we analyzed the micro- and macrodiversity of an alterophage population that was able to survive over a long period of time and showed remarkable genomic stability, indicating stable interactions over time between phage-host recognition structures. Overall, this study has contributed to extend the knowledge of known phage-host recognition mechanisms present in the marine ecosystem and has provided a first glimpse of the evolutionary dynamics in phages infecting Alteromonas.