139 research outputs found

    Permutation Polynomial Interleaved Zadoff-Chu Sequences

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    Constant amplitude zero autocorrelation (CAZAC) sequences have modulus one and ideal periodic autocorrelation function. Such sequences have been used in communications systems, e.g., for reference signals, synchronization signals and random access preambles. We propose a new family CAZAC sequences, which is constructed by interleaving a Zadoff-Chu sequence by a quadratic permutation polynomial (QPP), or by a permutation polynomial whose inverse is a QPP. It is demonstrated that a set of orthogonal interleaved Zadoff-Chu sequences can be constructed by proper choice of QPPs.Comment: Submitted to IEEE Transactions on Information Theor

    Social hÄllbarhet i planeringen av Masthusen

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    HÄllbarhet Àr idag en term som figurerar i en mÀngd olika sammanhang och social hÄllbarhet framhÀvs som en viktig del i hÄllbarhetsarbetet bÄde pÄ nationell- och lokal nivÄ. PÄ den lokala nivÄn finns aktörer som stÀder och kommuner vars arbete och visioner för att uppnÄ social hÄllbarhet formuleras i det planmaterial som tas fram bÄde för stadens utveckling, men ocksÄ för mindre enheter som stadsdelar och omrÄden inom stadsdelarna. Idag finns det ocksÄ en möjlighet att anvÀnda sig av miljöcertifieringssystemet Breeam Communities för att certifiera hela stadsdelar efter hur hÄllbara de Àr bÄde avseende ekologisk-, ekonomisk- och social hÄllbarhet efter de krav som certifieringssystemet har. Jag avser i detta arbete undersöka om man kan spÄra social hÄllbarhet genom att studera planmaterial som omfattar Malmö Stad och delar av omrÄdet Masthusen i VÀstra Hamnen, dÄ detta Àr det första omrÄde i Sverige som idag Àr delvis Breeamcertifierat. Arbetet har gjorts utifrÄn frÄgestÀllningen: Hur reflekteras aspekter av social hÄllbarhet genom planprocessen, frÄn översiktsplan och aktualisering, vÀrdeprogram, detaljplans-beskrivning till hÄllbarhetsprogram för certifiering? Huruvida man kan spÄra social hÄllbarhet genom planprocessen har undersökts med metoden att anvÀnda indikatorer för social hÄllbarhet och spÄra deras förekomst i planmaterialet. DÄ en vedertagen definition för begreppet social hÄllbarhet saknas har dessa indikatorer valts ut ur grupper av indikatorer för hÄllbarhet som Statistiska CentralbyrÄn tagit fram. Detta urval har skett efter hur vÀl dessa grupper relaterar till faktorer i aktuell argumentation kring begreppet social hÄllbarhet och resulterat i 36 individuella indikatorer som studerats. Genom studierna av planmaterialet har det framkommit att det förekommer indikatorer för social hÄllbarhet i alla delar av det studerade planmaterialet, men i olika utstrÀckning. Malmös översiktsplan och aktualisering Àr den del av materialet som innehÄller flest antal indikatorer och enbart indikatorn Motionsvanor förekommer genomgÄende i planmaterialets alla delar. Det gÄr dock i samtliga fall dÄ en indikator pÄvisats att göra en koppling till fysisk planering och i mÄnga fall gÄr det Àven att göra en koppling till faktorer som en yrkesverksam landskapsarkitekt och planerare har möjlighet att pÄverka. SvÄrigheten att pÄvisa vad enskilda indikatorer har för pÄverkan pÄ social hÄllbarhet i stort Àr dÀremot svÄrare att utreda dÄ denna hÄllbarhetsaspekt Àr beroende av komplexa samband.Sustainability is one of todays most widely spread terms in a variety of contexts and the social sustainability aspect is emphasized as a key-part of the work towards reaching sustainability on both a national- and local level. On the local level cities and communities form visions and strategies for working towards social sustainability in planning-material such as masterplans for urban development, but also for smaller areas such as urban districts and neighborhood areas. Today there is also a possibility of using systems for environmental-certification for urban districts such as Breeam Communities. A Breeam-certification provides the ability of measuring sustainability, both ecologic, economic and social from a set of requirements. My ambition is to explore whether or not it is possible to trace social sustainability by studying planning-material that covers the city of Malmö and parts of the neighborhood of Masthusen in VÀstra Hamnen, which is the first neighborhood in Sweden that has been partially certified by Breeam Communities. This approach has been made from the following question formulation: How are aspects of social sustainability being reflected throughout the planning process on a scale from the masterplan for the city of Malmö down to the sustainability-programme for the neighborhood of Masthusen? Whether or not it is possible to trace social sustainability throughout the planning process has been researched using indicators of social sustainability and their incidence in the studied planning-material. Since there seems to lack a recognized definition of the term social sustainability the indicators have been chosen from grups of indicators for sustainability, which has been developed by Statistics Sweden. This selection has been made by how well these groups of indicators relate to current critical analysis of the term social sustainability and resulted in studies of 36 separate indicators. The results that developed shows that indicators of scoial sustainability can be found in all of the documents that were studied, but in different quantities. The masterplan and actualization of the masterplan for Malmö had the highest number of occurence compared to the other documents and the indicator Motionsvanor (excercise-habits) is the only indicator to occur in all of the documents that were studied. It is however possible to show that every indicator that occured was described in a context that is associated with physical planning and in a lot of cases the context was also associated to factors that a working landscape-architect or planner has the ability to influence. The difficulty to show how separate indicators affect social sustainability as a whole lies perhaps in both the lack of a recognized defintion of the term and its dependence on complex relations

    Effects of tourist boats on the behaviour of Indo-Pacific bottlenose dolphins off the south coast of Zanzibar

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    The short-term effects of tourist boats on the behaviour of Indo-Pacific bottlenose dolphins Tursiops aduncus were investigated off the south coast of Zanzibar, Tanzania, by comparing dolphin group behaviour in the presence (impact) and absence (control) of tourist boats. Groupfollows were conducted from a carefully maneuvered (non-invasive) independent research vessel and behavioural data on group activity were collected using scan sampling methods. By using a timediscrete Markov chain model, the transition probabilities of passing/changing from one behavioural state to another were calculated and compared between impact and control situations. The data were further used to construct behavioural budgets. In the presence of tourist boats, dolphins were less likely to stay in a resting or socialising activity but were more likely to start travelling or foraging, as inferred from the Markov chain model. The behavioral budgets showed that foraging, resting and socialising all decreased as an effect of tourist boat presence, while travelling increased. The behavioural responses are likely to have energetic implications, mainly by increasing physical demands. Further, the results demonstrate that the current level of tourism intensity off the south coast of Zanzibar affects the dolphins' cumulative behavioural budget. Regulations on dolphin tourism are therefore urgently needed to minimise potential long-term negative effects on the dolphins

    Virus Diversity and Loads in Crickets Reared for Feed: Implications for Husbandry

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    Insects generally have high reproductive rates leading to rapid population growth and high local densities; ideal conditions for disease epidemics. The parasites and diseases that naturally regulate wild insect populations can also impact when these insects are produced commercially, on farms. While insects produced for human or animal consumption are often reared under high density conditions, very little is known about the microbes associated with these insects, particularly those with pathogenic potential. In this study we used both target-free and targeted screening approaches to explore the virome of two cricket species commonly reared for feed and food, Acheta domesticus and Gryllus bimaculatus. The target-free screening of DNA and RNA from a single A. domesticus frass sample revealed that only 1% of the nucleic acid reads belonged to viruses, including known cricket, insect, bacterial and plant pathogens, as well as a diverse selection of novel viruses. The targeted screening revealed relatively high levels of Acheta domesticus densovirus, invertebrate iridovirus 6 and a novel iflavirus, as well as low levels of Acheta domesticus volvovirus, in insect and frass samples from several retailers. Our findings highlight the value of multiple screening approaches for a comprehensive and robust cricket disease monitoring and management strategy. This will become particularly relevant as-and-when cricket rearing facilities scale up and transform from producing insects for animal feed to producing insects for human consumption

    Distribution of nearest distances between nodal points for the Berry function in two dimensions

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    According to Berry a wave-chaotic state may be viewed as a superposition of monochromatic plane waves with random phases and amplitudes. Here we consider the distribution of nodal points associated with this state. Using the property that both the real and imaginary parts of the wave function are random Gaussian fields we analyze the correlation function and densities of the nodal points. Using two approaches (the Poisson and Bernoulli) we derive the distribution of nearest neighbor separations. Furthermore the distribution functions for nodal points with specific chirality are found. Comparison is made with results from from numerical calculations for the Berry wave function.Comment: 11 pages, 7 figure
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