Interference Alignment-Aided Base Station Clustering using Coalition Formation

Base station clustering is necessary in large interference networks, where the channel state information (CSI) acquisition overhead otherwise would be overwhelming. In this paper, we propose a novel long-term throughput model for the clustered users which addresses the balance between interference mitigation capability and CSI acquisition overhead. The model only depends on statistical CSI, thus enabling long-term clustering. Based on notions from coalitional game theory, we propose a low-complexity distributed clustering method. The algorithm converges in a couple of iterations, and only requires limited communication between base stations. Numerical simulations show the viability of the proposed approach.Comment: 2nd Prize, Student Paper Contest. Copyright 2015 SS&C. Published in the Proceedings of the 49th Asilomar Conference on Signals, Systems and Computers, Nov 8-11, 2015, Pacific Grove, CA, US

Overhead-Aware Distributed CSI Selection in the MIMO Interference Channel

We consider a MIMO interference channel in which the transmitters and receivers operate in frequency-division duplex mode. In this setting, interference management through coordinated transceiver design necessitates channel state information at the transmitters (CSI-T). The acquisition of CSI-T is done through feedback from the receivers, which entitles a loss in degrees of freedom, due to training and feedback. This loss increases with the amount of CSI-T. In this work, after formulating an overhead model for CSI acquisition at the transmitters, we propose a distributed mechanism to find for each transmitter a subset of the complete CSI, which is used to perform interference management. The mechanism is based on many-to-many stable matching. We prove the existence of a stable matching and exploit an algorithm to reach it. Simulation results show performance improvement compared to full and minimal CSI-T.Comment: 5 pages, 2 figures. to appear at EUSIPCO 2015, Special Session on Algorithms for Distributed Coordination and Learnin

Valfrihet inom social- och hälsovården : Myndigheters syn på valfrihetens inverkan i Finland och Sverige ur olika strategiska synvinklar

Avhandlingen har som mål att undersöka hurdan valfriheten är inom social- och hälsovården. Den undersöker också vilka effekter som valfriheten har på förfarandet hos myndigheterna ur olika strategiska synvinklar. Avhandlingen bygger på en webbenkät som riktats till ledande tjänstemän som ansvarar för social- och hälsovården vid olika myndigheter i Finland och Sverige. Med hjälp av enkäten undersöks inverkan av att man infört valfrihet enligt pengar följer kunden–modeller. Resultaten visar att de ledande tjänstemännens syn på valfriheten ger stöd för forskningshypoteserna att valfriheten stärker servicebrukarens självbestämmande, höjer på kvaliteten och är neutral vad gäller kostnadsutvecklingen. Det finns inga större skillnader i synen på nyttan med valfriheten mellan de olika myndigheterna i Finland och Sverige. Undersökningen visar dock att de olika myndigheterna i Finland och Sverige har olika syn på betydelsen av marknad, konkurrens och variation i serviceutbudet, kundvalets förutsättningar samt betydelsen av en fungerande principal-agentrelation. Med hjälp av en analysram för olika strategiska infallsvinklar grupperas respondenterna i tre kluster: ett riskkluster, med en utmanande flerproducentmiljö som ställer krav på strategier för kontroll och uppföljning; ett variationskluster, med kompletterande och varierande utbud; samt ett lågprofilkluster där valfriheten har en begränsad roll.Väitöskirjan tavoitteena on selvittää, millainen on valinnanvapaus sosiaali- ja terveydenhuollossa. Tarkastelun aiheena on myös vaikutuksia, joita valinnanvapaudella on viranomaisten käytäntöihin eri strategisten näkökulmien kannalta. Väitöskirja perustuu verkkokyselyyn, joka on suunnattu ylemmille virkamiehille, jotka vastaavat eri viranomaisten sosiaali- ja terveydenhuollosta Suomessa ja Ruotsissa. Kyselyn avulla tutkitaan valinnanvapauden vaikutuksia rahaa seuraa asiakasta -mallin käyttöönottamisesta. Tulokset osoittavat, että johtavien virkamiesten näkemykset valinnanvapaudesta tukevat tutkimushypoteeseja siitä, että valinnanvapaus vahvistaa palvelun käyttäjän itsemääräämisoikeutta, nostaa laatua ja on neutraali kustannuskehityksen kannalta. Suomen ja Ruotsin eri viranomaisten välillä ei ole merkittäviä eroja valinnanvapauden eduista. Tutkimuksesta käy kuitenkin ilmi, että Suomen ja Ruotsin eri viranomaisilla on erilaiset näkemykset markkinoiden, kilpailun ja palveluvalikoiman vaihtelun merkityksestä, asiakkaan valinnan edellytyksistä ja toimivien päämies-agentti-suhteiden merkityksestä. Strategia-analyysikehyksen avulla vastaajat ryhmitellään kolmeen klusteriin: riskiklusteriin, jossa on haastava monen tuottajan ympäristö, joka asettaa vaatimuksia valvonta- ja seurantastrategioille; variaatioklusteri, jossa on täydentävää ja vaihtelevaa tarjontaa; ja matalan profiilin omaava klusteri, jossa valinnanvapaudella on vähentynyt rooli.The aim of the dissertation is to investigate freedom of choice in social services and health care. It also examines the effects of choice on procedures at authorities from different strategic perspectives. The dissertation is based on a web survey sent to senior staff responsible for social services and health care at authorities in Finland and Sweden. The impacts of the introduction of freedom of choice according to the money follows the customer models are studied with the help of the survey. The results show that the views among senior staff support the research hypotheses that the freedom of choice strengthens the service user's autonomy, it raises the quality and it is neutral in terms of cost development. There are no major differences regarding the benefits of freedom of choice between the various authorities in Finland and Sweden. However, the survey shows that the different authorities in Finland and Sweden have different views on the importance of the market, competition and variation in the services offered, the conditions of the customer choice and the importance of a functioning principal-agent relationship. Using an analysis framework for different strategic approaches, respondents are grouped into three clusters: a risk cluster, with a challenging multi-producer environment that requires strategies for control and follow-up; a cluster of varieties, where services complement each other; and a low profile cluster where the freedom of choice has a limited role

Eurooppalaisen innovaatiopolitiikan uusi vaihde vihreässä siirtymässä jatkaa monitasoisen hallinnon tiellä

Uuden vihreän innovaatiopolitiikan alustaksi muodostuvat alueelliset yhteistyöverkostot älykkään erikoistumisen strategioiden toteuttamisessa. Euroopan komission ja Alueiden komitean aloitteella Partnerships for Regional Innovation Pohjanmaalla haetaan seuraavan vaiheen vihreän siirtymän innovaatiopolitiikkaa

Some strategic national initiatives for the Swedish education in the geodata field

Ponencias, comunicaciones y pósters presentados en el 17th AGILE Conference on Geographic Information Science "Connecting a Digital Europe through Location and Place", celebrado en la Universitat Jaume I del 3 al 6 de junio de 2014.This paper describes national cooperation in Sweden launched by its universities and authorities, aimed at improving geodata education. These initiatives have been focused upon providing common access to geodata, the production of teaching materials in Swedish and organizing annual meetings for teachers. We argue that this type of cooperation is vital to providing high quality education for a poorly recognized subject in a country with a relatively small population

Velocities measured in small scale solar magnetic elements

We have obtained high resolution spectrograms of small scale magnetic structures with the Swedish 1-m Solar Telescope. We present Doppler measurements at 0\farcs{2} spatial resolution of bright points, ribbons and flowers and their immediate surroundings, in the C {\small{I}} 5380.3 {\AA} line (formed in the deep photosphere) and the two Fe {\small{I}} lines at 5379.6 {\AA} and 5386.3 {\AA}. The velocity inside the flowers and ribbons are measured to be almost zero, while we observe downflows at the edges. These downflows are increasing with decreasing height. We also analyze realistic magneto-convective simulations to obtain a better understanding of the interpretation of the observed signal. We calculate how the Doppler signal depends on the velocity field in various structures. Both the smearing effect of the non-negligible width of this velocity response function along the line of sight and of the smearing from the telescope and atmospheric point spread function are discussed. These studies lead us to the conclusion that the velocity inside the magnetic elements are really upflow of the order 1--2 km s${}^{-1}$ while the downflows at the edges really are much stronger than observed, of the order 1.5--3.3 km s${}^{-1}$

The subchondral bone in articular cartilage repair: current problems in the surgical management

As the understanding of interactions between articular cartilage and subchondral bone continues to evolve, increased attention is being directed at treatment options for the entire osteochondral unit, rather than focusing on the articular surface only. It is becoming apparent that without support from an intact subchondral bed, any treatment of the surface chondral lesion is likely to fail. This article reviews issues affecting the entire osteochondral unit, such as subchondral changes after marrow-stimulation techniques and meniscectomy or large osteochondral defects created by prosthetic resurfacing techniques. Also discussed are surgical techniques designed to address these issues, including the use of osteochondral allografts, autologous bone grafting, next generation cell-based implants, as well as strategies after failed subchondral repair and problems specific to the ankle joint. Lastly, since this area remains in constant evolution, the requirements for prospective studies needed to evaluate these emerging technologies will be reviewed