123 research outputs found

    DiffServ resource management in IP-based radio access networks

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    The increasing popularity of the Internet, the flexibility of IP, and the wide deployment of IP technologies, as well as the growth of mobile communications have driven the development of IP-based solutions for wireless networking. The introduction of IP-based transport in Radio Access Networks (RANs) is one of these networking solutions. When compared to traditional IP networks, an IP-based RAN has specific characteristics, due to which, for satisfactory transport functionality, it imposes strict requirements on resource management schemes. In this paper we present the Resource Management in DiffServ (RMD) framework, which extends the DiffServ architecture with new admission control and resource reservation concepts, such that the resource management requirements of an IP-based RAN are met. This framework aims at simplicity, low-cost, and easy implementation, along with good scaling properties. The RMD framework defines two architectural concepts: the Per Hop Reservation (PHR) and the Per Domain Reservation (PDR). As part of the RMD framework a new protocol, the RMD On DemAnd (RODA) Per Hop Reservation (PHR) protocol will be introduced. A key characteristic of the RODA PHR is that it maintains only a single reservation state per PHB in the interior routers of a DiffServ domain, regardless of the number of flows passing through

    Adaptive management? Observations of knowledge coordination in the communication practice of Swedish game management

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    Modern management of natural resources is guided by the normative theory of adaptive management (AM). Behind this theory lies a strong, albeit implicit, expectation that organisations aiming for AM have the capacity to communicate in a way that facilitates the required coordination of the knowledge perspectives involved. The aim of this article is to discuss the extent to which the communication practice of Swedish game management organisations facilitates coordination of knowledge corresponding to AM. Based on operationalizations of communicative rationality and agonistic pluralism, we use the concepts 'discursive closure' and 'discursive opening' to investigate how the coordination of knowledge is carried out through communication in relatively recently established organisations, the Swedish Game Management Delegations (GMDs). We analyse four communication episodes from GMD meetings and notice that multiple perspectives were expressed (discourse openings) but were not evaluated in a communicative rational way before being closed. The consequences of these closures were that knowledge perspectives with potential relevance, but with unclear validity for game management, were not elaborated upon, in terms of their truth, intelligibility, legitimacy or sincerity, which inhibited AM. The concepts of discursive closure and discursive opening proved useful for investigating communicative capacity. An important question which needs to be addressed to improve communicative capacity for AM is whether it would be practically possible to keep to the agenda and rules of the GMD meetings and still admit discursive openings about differences in perspectives

    RMD-QOSM - The Resource Management in Diffserv QoS model

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    This document describes an NSIS QoS Model for networks that use the Resource Management in Diffserv (RMD) concept. RMD is a technique for adding admission control and preemption function to Differentiated Services (Diffserv) networks. The RMD QoS Model allows devices external to the RMD network to signal reservation requests to edge nodes in the RMD network. The RMD Ingress edge nodes classify the incoming flows into traffic classes and signals resource requests for the corresponding traffic class along the data path to the Egress edge nodes for each flow. Egress nodes reconstitute the original requests and continue forwarding them along the data path towards the final destination. In addition, RMD defines notification functions to indicate overload situations within the domain to the edge nodes

    SIMULATIVE ANALYSIS OF ROUTING AND LINK ALLOCATION STRATEGIES IN ATM NETWORKS

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    For Broadband Integrated Services Digital (B-ISDN) networks ATM is a promising technology, because it supports a wide range of services with different bandwidth demands, traffic characteristics and QoS requirements. This diversity of services makes traffic control in these networks much more complicated than in existing circuit or packet switched networks. Traffic control procedures include both actions necessary for setting up virtual connections (VC), such as bandwidth assignment, call admission, routing and resource allocation and congestion control measures necessary to maintain throughput in overload situations. This paper deals with routing and link allocation, and analyses the performance of such algorithms in terms of call blocking probability, link capacity utilization and QoS parameters. In our model the network carries out the following steps when a call is offered to the network: (1) Assign an appropriate bandwidth to an offered call (Bandwidth assignment) (2) Find a transmission path between the source and destination with enough available transmission capacity (Routing) (3) Allocate resource along that path (Link allocation) We consider an example 5-node network [7], conduct an extensive survey of routing, and link allocation algorithms. Regarding step (1) we employ the equivalent link capacity assignment presented by various interesting papers [1]-[5]. We find that the choice of routing and link allocation algorithms has a great impact on network performance, and that different routing algorithms perform best under different network load values. Shortest path routing (SPR) is a good candidate for low, alternate routing (AR) for medium and non-alternate routing (NAR) for high traffic load values. Concerning link allocation strategies, we find that partial overlap (POL) strategies that seem to be able to present near optimal performance are superior to complete sharing (CS) and complete partitioning (CP) strategies. As a further improvement of the POL scheme, we propose a 2-level link allocation algorithm, which yields highest link utilization. In this scheme, not only the accesses of different service classes to different virtual paths (VPs) are controlled, but also an individual VP's transmission capacity is optimally allocated to the service classes according to their bandwidth requirements in order to assure high link utilization. This method seems to be adjustable to the fine degree of granularity of bandwidth demands in B-ISDN networks. It is shown that in order to minimize cell loss the call level resource allocation plays a significant role: networks with the same buffer size switches display different cell loss probabilities in the nodes and impose different end-to-end delay on cells if the link allocation and routing differ. Again, we find that when traffic is tolerable by the network, SPR causes the least cell loss. This can be explained by the fact that SPR spreads the incoming calls in the network. It eagerly seeks new routes instead of utilizing the already used but still not congested routes. SPR obviously wastes more rapidly link and buffer capacity as traffic load becomes higher than the AR, which chooses a new route only when it has to, i.e. when the route of higher priority becomes congested. That is why we experience that as soon as the SPR starts loosing cells, it indicates that available resources have been consumed and it rapidly goes up to very high blocking probabilities after a small further increase of load

    Serotonin Depletion-Induced Maladaptive Aggression Requires the Presence of Androgens

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    The sex hormone testosterone and the neurotransmitter serotonin exert opposite effects on several aspects of behavior including territorial aggression. It is however not settled if testosterone exerts its pro-aggressive effects by reducing serotonin transmission and/or if the anti-aggressive effect of serotonin requires the presence of the androgen. Using the resident intruder test, we now show that administration of the serotonin synthesis inhibitor parachlorophenylalanine (300 mg/kg x 3 days) increases the total time of attack as well as the percentage amount of social behavior spent on attack but not that spent on threat - i.e. that it induces a pattern of unrestricted, maladaptive aggression - in gonadectomized C57Bl/6 male mice receiving testosterone replacement; in contrast, it failed to reinstate aggression in those not given testosterone. Whereas these results suggest the pro-aggressive effect of testosterone to be independent of serotonin, and not caused by an inhibition of serotonergic activity, the pCPA-induced induction of maladaptive aggression appears to require the presence of the hormone. In line with these findings, pCPA enhanced the total time of attack as well the relative time spent on attacks but not threats also in wild-type gonadally intact male C57Bl/6 mice, but failed to reinstate aggression in mice rendered hypo-aggressive by early knock-out of androgen receptors in the brain (AR(NesDel) mice). We conclude that androgenic deficiency does not dampen aggression by unleashing an anti-aggressive serotonergic influence; instead serotonin seems to modulate aggressive behavior by exerting a parallel-coupled inhibitory role on androgen-driven aggression, which is irrelevant in the absence of the hormone, and the arresting of which leads to enhanced maladaptive aggression

    Associations between oxytocin-related genes and autistic-like traits.

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    Oxytocin has repeatedly been shown to influence human behavior in social contexts; also, a relationship between oxytocin and the pathophysiology of autism spectrum disorder (ASD) has been suggested. In the present study, we investigated single-nucleotide polymorphisms (SNPs) in the oxytocin gene (OXT) and the genes for single-minded 1 (SIM1), aryl hydrocarbon receptor nuclear translocator 2 (ARNT2) and cluster of differentiation 38 (CD38) in a population of 1771 children from the Child and Adolescent Twin Study in Sweden (CATSS). Statistical analyses were performed to investigate any association between SNPs and autistic-like traits (ALTs), measured through ASD scores in the Autism-Tics, ADHD and other Co-morbidities inventory. Firstly, we found a statistically significant association between the SIM1 SNP rs3734354 (Pro352Thr) and scores for language impairment (p = .0004), but due to low statistical power this should be interpreted cautiously. Furthermore, nominal associations were found between ASD scores and SNPs in OXT, ARNT2 and CD38. In summary, the present study lends support to the hypothesis that oxytocin and oxytocin neuron development may have an influence on the development of ALTs and suggests a new candidate gene in the search for the pathophysiology of ASD.The Swedish Research CouncilThe Swedish Research Council for Health, Working Life and WelfareThe Swedish Brain FoundationSvenska Sällskapet för Medicinsk Forskning (SSMF)Fredrik and Ingrid Thurings stiftelseÅke Wibergs stiftelseÅhlén-stiftelsenJeanssons-stiftelsenMagnus Bergvalls stiftelseSöderström-Königska stiftelsenMärta Lundqvists stiftelsethe Novo Nordisk FoundationAccepte

    Dialogprocessen om allemansrätten

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    Under 2012 och 2013 har avdelningen för Miljökommunikation vid SLU fungerat som rådgivare till Naturvårdsverket i planeringen och genomförandet av en dialogprocess om allemansrätten och dess tillämpning. Denna rapport har tillkommit som ett avslutande led i detta uppdrag. Syftet med rapporten är att stödja utveckling av dialogmetodik och dialogkompetens inom naturresurshanteringen genom att redogöra för och kritiskt diskutera de erfarenheter som vi gjort av att arbeta med en omtvistad och komplex samhällsfråga genom dialog. I rapporten redogör vi för de tankar och teorier som har väglett planeringen av dialogprocessen och diskuterar vad vi, så här i efterhand, anser att vi kunde ha gjort annorlunda. Syftet med rapporten är alltså inte att diskutera dialogprocessens innehåll och/eller hur olika aktörer och intressen ser på frågor som rör allemansrätten. Rapporten ska ses som ett underlag för hur den som ansvarar för en dialogprocess bör planera, genomföra och förhålla sig till deltagarna och det som sker. Rapporten består av följande fem delar: 1. Viktiga förutsättningar och ramar för upplägg och planering av dialogprocessen 2. Händelseutvecklingen i de fem möten som processen bestod av 3. Deltagarnas åsikter om processen, vad de tycker att de lärt sig 4. Deltagarnas rapportering av lärdomar från dialogprocessen till sina hemorganisationer 5. Diskussioner och rekommendatione

    QoS signaling across heterogeneous wired/wireless networks: resource management in diffserv using the NSIS protocol suite

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    Reservation-based Quality of Service (QoS) in a mixed wireless and wireline environment requires an end-to-end signaling protocol that is capable of adapting to the idiosyncrasies of the different networks. The QoS NSIS Signaling Protocol (QoSNSLP) has been created by the Next Steps In Signaling working group at the IETF to fulfill this need for an adaptive reservation protocol. It allows reservation requests to be interpreted by equipment implementing different QoS models along the path between a data sender and a data receiver. This paper describes the QoS-NSLP, and an example of a particular QoS model that is based on Resource Management in Diffserv (RMD). RMD provides a scalable dynamic resource management method for Diffserv networks. RMD has two basic functions to control the traffic load in a Diffserv domain: it provides admission control for flows entering the network and it has an algorithm that terminates the required amount of flows in case of congestion caused by failures (e.g. link or router) bandwidth and require per-flow reservations. On the other hand, the wireline networks tend to form the backbones and have relatively abundant bandwidth and carry a large number of flows, where aggregation is necessary since per-flow reservations suffer from scalability constraints

    Association between ASMT and autistic-like traits in children from a Swedish nationwide cohort

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    Persons with autism spectrum disorders (ASDs) often display low levels of melatonin, and it has been suggested that this decrease may be due to low activity of the acetylserotonin O-methyltransferase (ASMT), the last enzyme in the melatonin synthesis pathway. Moreover, genetic variants in ASMT have been associated with autism, as well as with low ASMT activity and melatonin levels, suggesting that the low ASMT activity observed in autism may partly be due to variation within the ASMT gene. In this study, we present a symptom-based approach to investigate possible associations between ASMT and autistic-like traits (ALTs) in the general population. To this end, continuous measures of ALTs were assessed in a nationally representative twin cohort (n=1771) from Sweden and six Single Nucleotide Polymorphisms (SNP) and a duplication of exon 2 to 8 in ASMT were genotyped. Our results show a nominally significant association, in girls, between one SNP (rs5949028) in the last intron of ASMT and social interaction impairments. No significant association, however, was observed with traits related to language impairment or restricted and repetitive behavior. In conclusion, our results support the possible involvement of the ASMT gene in ASDs and our finding that only one of three traits shows association suggests that genetic research may benefit from taking a symptom-specific approach to identify genes involved in autism psychopathology.VetenskapsrĂĄdetAccepte

    Association study between autistic-like traits and polymorphisms in the autism candidate regions RELN, CNTNAP2, SHANK3, and CDH9/10

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    The Swedish Research CouncilThe Swedish Council for Working Life and Social ResearchThe Petrus and Augusta Hedlund FoundationĂ…ke Wiberg foundationĂ…hlens FoundationWilhelm and Martina Lundgren FoundationThe Sahlgrenska AcademyPublishe
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