Utilizing Cross-Layer Information to Improve Performance in JPEG2000 Decoding

We focus on wireless multimedia communication and investigate how cross-layer information can be used to improve performance at the application layer, using JPEG2000 as an example. The cross-layer information is in the form of soft information from the physical layer. The soft information, which is supplied by a soft decision demodulator, yields reliability measures for the received bits and is fed into two soft input iterative JPEG2000 image decoders. When errors are detected with the error detecting mechanisms in JPEG2000, the decoders utilize the soft information to point out likely transmission errors. Hence, the decoders can correct errors and increase the image quality without making time-consuming retransmissions. We believe that the proposed decoding method utilizing soft information is suitable for a general IP-based network and that it keeps the principles of a layered structure of the protocol stack intact. Further, experimental results with images transmitted over a simulated wireless channel show that a simple decoding algorithm that utilizes soft information can give high gains in image quality compared to the standard hard-decision decoding

Sambandet mellan skuldsättningsgrad och avkastning på totalt kapital - En studie av svenska börsnoterade fastighetsbolag 1988-2008

Examensarbetets titel: Sambandet mellan skuldsättningsgrad och avkastning på totalt kapital – En studie av svenska börsnoterade fastighetsbolag 1988- 2008 Seminariedatum: 2009-06-04 Ämne/Kurs: FEKK01, Examensarbete kandidatnivå, 15 poäng Författare: Rauf Berent, Sandra Björk, Hannes Persson Handledare: Måns Kjellsson Fem nyckelord: Skuldsättningsgrad, Avkastning på totalt kapital, Kapitalstruktur, Fastighetsbranschen, Leverage Aggressiveness Hypothesis Syfte: Att undersöka sambandet mellan skuldsättningsgrad och avkastning på totalt kapital i svenska börsnoterade fastighetsbolag under åren 1988-2008 Metod: Deduktivt arbetssätt, kvantitativ metodinsamling, deskriptiv metodansats, regressionsanalys Teoretiska perspektiv: Finansiell hävstång, Leverage Aggressiveness Hypothesis, Long Purse Hypothesis, Trade-off, Peckingorder, Miller & Modigliani Empiri: Fastighetsbolag noterade på Stockholmsbörsen 1988-2008 Resultat: Resultatet visar att det inte finns något signifikant samband mellan skuldsättningsgrad och avkastning på totalt kapital i den svenska fastighetsbranschen

Direct generation of photon triplets using cascaded photon-pair sources

Non-classical states of light, such as entangled photon pairs and number states, are essential for fundamental tests of quantum mechanics and optical quantum technologies. The most widespread technique for creating these quantum resources is the spontaneous parametric down-conversion (SPDC) of laser light into photon pairs. Conservation of energy and momentum in this process, known as phase-matching, gives rise to strong correlations which are used to produce two-photon entanglement in various degrees of freedom. It has been a longstanding goal of the quantum optics community to realise a source that can produce analogous correlations in photon triplets, but of the many approaches considered, none have been technically feasible. In this paper we report the observation of photon triplets generated by cascaded down-conversion. Here each triplet originates from a single pump photon, and therefore quantum correlations will extend over all three photons in a way not achievable with independently created photon pairs. We expect our photon-triplet source to open up new avenues of quantum optics and become an important tool in quantum technologies. Our source will allow experimental interrogation of novel quantum correlations, the post-selection free generation of tripartite entanglement without post- selection and the generation of heralded entangled-photon pairs suitable for linear optical quantum computing. Two of the triplet photons have a wavelength matched for optimal transmission in optical fibres, ideally suited for three-party quantum communication. Furthermore, our results open interesting regimes of non-linear optics, as we observe spontaneous down-conversion pumped by single photons, an interaction also highly relevant to optical quantum computing.Comment: 7 pages, 3 figures, 1 table; accepted by Natur

Overview of the MOSAiC expedition - Atmosphere

With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team designed and implemented the comprehensive program to document and characterize all aspects of the Arctic atmospheric system in unprecedented detail, using a variety of approaches, and across multiple scales. These measurements were coordinated with other observational teams to explore cross-cutting and coupled interactions with the Arctic Ocean, sea ice, and ecosystem through a variety of physical and biogeochemical processes. This overview outlines the breadth and complexity of the atmospheric research program, which was organized into 4 subgroups: atmospheric state, clouds and precipitation, gases and aerosols, and energy budgets. Atmospheric variability over the annual cycle revealed important influences from a persistent large-scale winter circulation pattern, leading to some storms with pressure and winds that were outside the interquartile range of past conditions suggested by long-term reanalysis. Similarly, the MOSAiC location was warmer and wetter in summer than the reanalysis climatology, in part due to its close proximity to the sea ice edge. The comprehensiveness of the observational program for characterizing and analyzing atmospheric phenomena is demonstrated via a winter case study examining air mass transitions and a summer case study examining vertical atmospheric evolution. Overall, the MOSAiC atmospheric program successfully met its objectives and was the most comprehensive atmospheric measurement program to date conducted over the Arctic sea ice. The obtained data will support a broad range of coupled-system scientific research and provide an important foundation for advancing multiscale modeling capabilities in the Arctic

Drivkrafterna bakom sveriges moderna helikopteranskaffningar och avvecklingar

This thesis addresses the driving forces behind the Swedish state’s procurement of Helicopters 14 and 16 and the decommissioning of Helicopter 4. These actions have significantly affected the Swedish Armed Forces, especially the Helicopter Wing, in carrying out their operational tasks. On numerous occasions the Helicopter Wing has been unable to perform its tasks. For instance, the Nordic Battle Group 08 had no helicopters to exercise with and, until recently, Sweden had completely lacked the ability to hunt submarines with helicopters for almost ten years. This thesis also aims to compare the decisions in 1999-2000 regarding Helicopter 14 with the decisions in 2010-2011 regarding the acquisition of Helicopter 16, to find if there is a general trend and how much the Armed Forces were able to influence decisions. This is done by using Graham T. Allison’s and Philip Zelikow’s models for explaining and analysing the factors behind a state’s decisions.   The analysis shows that the decisions were primarily compromises between the Armed Forces and Sweden’s government, where the government had the main influence. The decisions can be seen as rational, depending on whose point of view they are observed from, although they were not unanimously agreed between the organisations involved. It also shows that economic restrictions and the government’s involvement have had negative consequences for the Helicopter Wing organisation, that the acquisition of Helicopter 16 was a consequence of the procurement of Helicopter 14, and that further consequences will probably arise from the decision to acquire Helicopter 16

REXUS-4 - Vehicle and Experiments, Outlook on the REXUS/BEXUS Student Programme

On the 22nd of October 2008, EuroLaunch launched the REXUS-4 rocket at Esrange in Northern Sweden. EuroLaunch is a joint venture of the DLR Mobile Rocket Base and the SSC Esrange Space Center. REXUS-4 was a two-stage unguided solid propellant sounding rocket. The vehicle consisted of a Nike motor as 1st stage, an Improved Orion motor as 2nd stage, a motor adapter, a recovery system, a service system, two experiment modules, and a nosecone. The REXUS-4 payload was comprised of five technological experiments from German and Swedish Universities. The rocket was spin-stabilized during the ascent. After the burn-out of the 2nd stage a yoyo system de-spun the rocket to a rate of only a few degrees per second. At an altitude of 71 km the nosecone was jettisoned. The payload reached its apogee at 175 km. The REXUS-4 mission was also the maiden flight of a newly developed rocket service system. After this successful demonstration, it has been implemented into the REXUS/BEXUS programme. This German-Swedish student programme offers annual flights for student experiments on sounding rockets and stratospheric balloons. This paper gives a short overview on the development of the REXUS service system and points out the advantages of using standard interfaces for student experiments. Furthermore it contains a description of the REXUS-4 vehicle, the mission, the campaign and the experiments. Some experiments are described in more detail. During the ballistic flight the MIRIAM experiment of the University of Armed Forces in München and the Mars Society Germany was separated from the main payload to test a balloon system that will be used for the entry of a probe in the Martian atmosphere in the future. Several cameras on the REXUS-4 payload as well as cameras and telemetry on the MIRIAM flight system monitored the separation and inflation during the ballistic flight phase. The VERTICAL experiment from the Technical University München verified the start-up procedures of the CubeSat MOVE and its solar panel deployment under real spaceflight conditions. The paper also gives an overview on the REXUS/BEXUS programme and its chances for students

Konsten att lobba utanför boxen

The aim of the thesis is to examine how one can understand the recent employment of a policy-entrepreneur in the city of Helsingborg. The study will be using a explaining-outcome process-tracing method since the causes regarding the outcome attracts the interest of this essay. As theory the study has been using ”Agendas, Alternatives and public policies” by John W. Kingdon, where he presents three perspectives: Problems, the Primeval Soup and the Political stream. The problems representing the challenges that the actors in the political process is experiencing. The Primeval Soup represents the solutions that occur, and the meaning of the political stream is what kind of political context the problems and solutions occur from. This theory is then added to the empirical findings regarding the employment. The findings suggest that the policy-entrepreneur is using each of these perspectives to place important subjects on the agenda. One subject is especially important, which is the connection between Helsingborg and Helsingör. The policy-entrepreneur has an important role in the city of Helsingborg’s will to increase state presence and consequently in the communication with the government

REXUS-4: Vehicle And Subsystems Design, Flight Performance and Experiments

On the 22nd of October 2008 EuroLaunch launched the REXUS-4 rocket at Esrange in Northern Sweden. EuroLaunch is a joint venture of the DLR Mobile Rocket Base and the SSC Esrange Space Center. The REXUS-4 payload was comprised of five technological experiments from German and Swedish Universities. The REXUS-4 mission was also the maiden flight of a newly developed service system. After this successful demonstration, it has been implemented into the REXUS/BEXUS programme. This paper gives a short overview on the development of the REXUS service system and points out the advantages of using standard interfaces for student experiments. Furthermore it will contain a description of the REXUS-4 vehicle, the mission, the campaign and the experiments

Den nya spellagens inverkan på spelbolag och dess konsumenter : En undersökning av hur spelbolag balanserar spelansvaroch vinstintresse

In 2019 the Swedish government restructured the Swedish gambling market. The once closed gambling monopoly opened up and invited new actors to the market. In order to acquire rights to the Swedish gambling market, the betting-and casino companies need to apply for a gambling license. Gambling is a big part of the Swedish society and 60 precent of its population have gambled in some form in the last year. With such a gambling culture there's also a downside, 4 precent of the population has some degree of gambling addiction. The purpose of this study is to examine how Swedish gambling companies balance their profit interests with their gambling responsibilities after the new gambling regulation, and to examine how the Swedish gamblers experience the gambling companies gamblingresponsibilities. Triangulation was used as this studys research method, where it interplays between quantitative and qualitative methods to regard the problem from different point of views. This study gathered empirical data from active players and conducted three qualitative interviews with respondents’ from ATG, Svenska Spel and Leo Vegas to gain deeper insights in how these companies work with CSR, profit interests and gambling responsibilities.The empirical results gathered in this study have been analyzed through theories in CSR and ethics. These theories functions as a guide to interpret and understand the empirical datagathered through interviews and surveys.Based on the empirical data and chosen theory, it is possible to demonstrate a generalizable picture of how the gambling companies relate to gambling responsibility versus profit interest, and how active players view the gambling companies' responsibility. Furthermore, the study testifies that the introduction of the new gambling law has led the gambling responsibility forward. Some gambling companies strive for long-term relationships with players for increased profitability, where gambling responsibility is at the center. This generates a natural balancing act between profit interest and gambling responsibility. On the other hand, the empirical data show that there are gambling companies and specific areas in the industry where there is room for improvement and where gambling responsibility is not complete

Ljudbaserad navigation i audio augmented reality

Audio augmented reality är en teknik som jämfört med dess visuella motsvarighet och virtual reality inte får samma utrymme i diskussionen av nya och spännande interaktiva medium. Dessutom brukar ljud överlag i interaktiva medier primärt användas för att endast stödja det visuella. I detta utforskande arbete undersöks därför möjligheterna av ljudbaserad navigation inom fysiskt interaktiva audio augmented reality-upplevelser genom utformning och testning av ett ljudbaserat spel. För att skapa förståelse för hur ljudbaserade spel förmedlar information till användaren har en kvalitativ analys utförts av åtta olika titlar som använder sig av tredimensionella spelytor. Tillsammans med applicering av designteorier inom användarupplevelse och ljuddesign skapades ett ramverk för utformningen av arbetets gestaltning. Genom kvalitativa användartester och intervjuer där deltagarna fick interagera med det ljudbaserade spelet och sedan utvärdera det, undersöktes hur väl det utformade ramverket lyckades med att skapa en navigerbar, virtuell miljö. Resultaten indikerar att ramverket och dess innehållande teorier och metoder är väl applicerbara för detta syfte, samt att ljudbaserade spel i augmented reality upplevdes som ett spännande och intressant medium att interagera med.Audio augmented reality is a technology that is not as frequently appearing in the public discourse regarding new and exciting interactive mediums compared to its visual counterpart or virtual reality. Audio is generally also less highlighted or utilized in interactive mediums, with its main purpose being to support the visual elements. In this explorative work we have therefore studied the possibilities of auditory navigation in physically interactive audio augmented reality environments through an audio game. To better understand how audio games convey information to the user, a qualitative analysis was done on eight titles which incorporates three dimensional navigation. Combined with the application of design theory within the fields of user experience and sound design, a framework for the design of the study's audio game was made. The framework's level of success at creating a navigable, virtual environment was tested through qualitative user testing and interviews where participants could interact with and evaluate the audio game. Results indicate that the design and the framework it was built from is applicable for its purpose, as well as audio games in audio augmented reality being perceived as an exciting and interesting medium to interact with