Bistable Chimera Attractors on a Triangular Network of Oscillator Populations

We study a triangular network of three populations of coupled phase oscillators with identical frequencies. The populations interact nonlocally, in the sense that all oscillators are coupled to one another, but more weakly to those in neighboring populations than to those in their own population. This triangular network is the simplest discretization of a continuous ring of oscillators. Yet it displays an unexpectedly different behavior: in contrast to the lone stable chimera observed in continuous rings of oscillators, we find that this system exhibits \emph{two coexisting stable chimeras}. Both chimeras are, as usual, born through a saddle node bifurcation. As the coupling becomes increasingly local in nature they lose stability through a Hopf bifurcation, giving rise to breathing chimeras, which in turn get destroyed through a homoclinic bifurcation. Remarkably, one of the chimeras reemerges by a reversal of this scenario as we further increase the locality of the coupling, until it is annihilated through another saddle node bifurcation.Comment: 12 pages, 5 figure

CONCEPTUAL MODEL AND OPERATIONAL PROCESSES OF CUSTOMER VALUE-BASED REVENUE MANAGEMENT IN TRANSPORT AND LOGISTICS

The approach presented in this article addresses the shortcomings of transaction-based revenue management and proposes a conceptual model of customer value-based revenue management to allow for both an efficient utilization of limited capacity resources and the establishment of profitable customer relationships. Furthermore, process models are developed for the operational tasks as well as results of a prototypical implementation are presented. Finally, some concluding remarks and an outlook on remaining research are given

Kieliasenteet ja -käsitykset espanjankielisten latinalaisamerikkalaisten diasporassa Suomessa

Maisterintutkielmani käsittelee Suomessa asuvien espanjankielisten latinalaisamerikkalaisten kieliasenteita. Aihe on kiinnostava siksi, että diasporayhteisöjä käsitteleviä asennetutkimuksia ei liialti ole tehty Yhdysvaltojen ulkopuolella. Tutkielma selvittää, millaisia asenteita kohderyhmällä on espanjan kieltä ja sen maantieteellisiä varieteetteja kohtaan. Se myös tutkii käsityksiä siitä, mitä niin sanottu neutraali espanja merkitsee kohderyhmälle sekä tunnistaako ryhmä espanjan varieteetteja nauhoituksia kuuntelemalla. Asenteita tutkittiin kyselylomakkeen sekä haastattelujen avulla. Tutkielmaan osallistui yhteensä 29 espanjaa äidinkielenä puhuvaa Suomessa asuvaa henkilöä. Vastaukset analysoitiin kuuden ulottuvuuden mukaan, jotka ovat kielellinen yhtenäisyys, affektiiviset piirteet, kognitiiviset piirteet, oikeakielisyys ja neutraalius, sekä varieteettien tunnistaminen. Tutkielman teoreettinen viitekehys perustuu kieliasenteiden ja diasporaidentiteettien tutkimukseen. Asenteilla nähdään olevan kolme ulottuvuutta: affektiivinen, kognitiivinen ja konatiivinen (Ajzen 1988; Baker 1992; Garrett 2003; Cargile ym. 1994; van Bezooijen 1994). Asenteet kohdistuvat sekä konkreettisiin että abstrakteihin asioihin, ja ne voivat olla samanaikaisesti positiivisia ja negatiivisia. Kieliasenteisiin vaikuttaa usein näkemys ”oikeakielisyydestä” (Preston 2013) ja kielten standardisointi (Garrett 2010). Aiempi tutkimus kuvailee neutraalia kieltä keinotekoisena käsitteenä (Gutiérrez Maté 2017), mutta ei ota huomioon puhujien näkemyksiä aiheesta. Myös identiteettikysymykset liittyvät läheisesti kieliasenteisiin. Muuttoliikkeen johdosta diasporayhteisöissä asuvien yksilöiden identiteetit ovat muutoksessa (Hall 1995; Woodward 2002), mikä vaikuttaa myös kieliasenteisiin. Tulokset osoittavat, että tutkimukseen osallistuneet espanjankieliset latinalaisamerikkalaiset määrittävät oikeakielisyyden ja neutraaliuden samalla tavalla. Kommunikaation onnistuminen ja selvästi erottuvien kielellisten piirteiden puuttuminen nähdään oleellisina tekijöinä molemmissa ulottuvuuksissa. Toisaalta näiden käsitteiden suhteessa espanjan eri varieteetteihin on eroja. Oikeakielisyyteen ei yleensä liitetä tiettyjä murteita, mutta neutraaliuuteen kyllä. Neutraalius yhdistetään usein omaan murteeseen, ja lisäksi Ecuadorin, Meksikon ja Kolumbian murteet nähdään neutraaleina. Kielellisistä piirteistä sanat mainitaan useammin asenteiden yhteydessä kuin intonaatio tai nopeus. Kielioppia tuskin mainitaan. Lisäksi vastaukset osoittavat, että puhujilla on vakaa latinalaisamerikkalainen identiteetti ja kielellistä varmuutta. He eivät pidä Espanjan varieteetin statusta korkeampana kuin omien varieteettiensa. Korrektiuuteen liittyvät tulokset ovat osittain linjassa edellisen tutkimuksen kanssa, mutta myös eroavaisuuksia on havaittavissa. Neutraalius määritellään teoreettisesti ja subjektiivisesti, ja sillä on sekä yhtymäkohtia että erilaisia määritelmiä korrektiuuteen verrattuna. Tulosten pohjalta voidaan tulkita, että aika selittää osan eroista aikaisempaan tutkimukseen. On kuitenkin selvää, että diasporayhteisöissä on uudenlaisia asenteita ja käsityksiä, jonka takia tutkimusta olisi hyvä jatkaa ja laajentaa

Large magneto-Seebeck effect in magnetic tunnel junctions with half-metallic Heusler electrodes

Spin caloritronics studies the interplay between charge-, heat- and spin-currents, which are initiated by temperature gradients in magnetic nanostructures. A plethora of new phenomena has been discovered that promises, e.g., to make wasted heat in electronic devices useable or to provide new read-out mechanisms for information. However, only few materials have been studied so far with Seebeck voltages of only some {\mu}V, which hampers applications. Here, we demonstrate that half-metallic Heusler compounds are hot candidates for enhancing spin-dependent thermoelectric effects. This becomes evident when considering the asymmetry of the spin-split density of electronic states around the Fermi level that determines the spin-dependent thermoelectric transport in magnetic tunnel junctions. We identify Co$_2$FeAl and Co$_2$FeSi Heusler compounds as ideal due to their energy gaps in the minority density of states, and demonstrate devices with substantially larger Seebeck voltages and tunnel magneto-Seebeck effect ratios than the commonly used Co-Fe-B based junctions.Comment: 9 pages, 4 figure

Morfologi för lärarstudenter

The website Morfologilekstugan (‘Morphology playground’) aims at providing a Swedish language morphology tool, primarily for students attending secondary-school teacher education programs. The students can use the site for analyzing word forms of their choice and for testing their knowledge of word forms and terminology. Data and system functionality is based on previous work at the Department of Swedish, University of Gothenburg. The aim of this paper is to describe the process of creating the website

Maximal Accuracy and Minimal Disturbance in the Arthurs-Kelly Simultaneous Measurement Process

The accuracy of the Arthurs-Kelly model of a simultaneous measurement of position and momentum is analysed using concepts developed by Braginsky and Khalili in the context of measurements of a single quantum observable. A distinction is made between the errors of retrodiction and prediction. It is shown that the distribution of measured values coincides with the initial state Husimi function when the retrodictive accuracy is maximised, and that it is related to the final state anti-Husimi function (the P representation of quantum optics) when the predictive accuracy is maximised. The disturbance of the system by the measurement is also discussed. A class of minimally disturbing measurements is characterised. It is shown that the distribution of measured values then coincides with one of the smoothed Wigner functions described by Cartwright.Comment: 12 pages, 0 figures. AMS-Latex. Earlier version replaced with final published versio

Superior flow for bridge to life with self-expanding venous cannulas

Background: Recently, a compact cardiopulmonary support (CPS) system designed for quick set-up for example, during emergency cannulation, has been introduced. Traditional rectilinear percutaneous cannulas are standard for remote vascular access with the original design. The present study was designed to assess the potential of performance increase by the introduction of next-generation, self-expanding venous cannulas, which can take advantage of the luminal width of the venous vasculature despite a relatively small access orifice. Methods: Veno-arterial bypass was established in three bovine experiments (69 ± 10 kg). The Lifebridge® (Lifebridge GmbH, Munich, Germany) system was connected to the right atrium in a trans-jugular fashion with various venous cannulas; and the oxygenated blood was returned through the carotid artery with a 17 F percutaneous cannula. Two different venous cannulas were studied, and the correlation between the centrifugal pump speed (1500-3900 RPM), flow and the required negative pressure on the venous side was established: (A) Biomedicus 19 F (Medtronic, Tolochenaz, Switzerland); (B) Smart canula 18 F/36 F (Smartcanula LLC, Lausanne, Switzerland). Results: At 1500 RPM, the blood flow was 0.44 ± 0.26 l min−1 for the 19 F rectilinear cannula versus 0.73 ± 0.34 l min−1 for the 18/36 F self-expanding cannula. At 2500 RPM the blood flow was 1.63 ± 0.62 l min−1 for the 19 F rectilinear cannula versus 2.13 ± 0.34 l min−1 for the 18/36 F self-expanding cannula. At 3500 RPM, the blood flow was 2.78 ± 0.47 l min−1 for the 19 F rectilinear cannula versus 3.64 ± 0.39 l min−1 for the 18/36 F self-expanding cannula (p ≪ 0.01 for 18/36 F vs 19 F). At 1500 RPM, the venous line pressure was 18 ± 8 mmHg for the 19 F rectilinear cannula versus 19 ± 5 mmHg for the 18/36 F self-expanding cannula. At 2500 RPM the venous line pressure accounted for −22 ± 32 mmHg for the 19 F rectilinear cannula versus 2 ± 5 mmHg for the 18/36 F self-expanding cannula. At 3500 RPM, the venous line pressure was −112 ± 42 mmHg for the rectilinear cannula versus 28 ± 7 mmHg for the 18/36 F self-expanding cannula (p ≪ 0.01 for 18 F/36 F vs 19 F). Conclusions: The negative pressure required to achieve adequate venous drainage with the self-expanding venous cannula accounts for approximately 31% of the pressure necessary with the 19 F rectilinear cannula. In addition, a pump flow of more than 4 l min−1 can be achieved with the self-expanding design and a well-accepted negative inlet pressure for minimal blood trauma of less than 50 mmH

SAOLhist.se – för allmänt och vetenskapligt bruk

The Swedish Academy Glossary (Svenska Akademiens ordlista, SAOL), a normative glossary with particular focus on spelling, inflexion, and pro-nunciation, has appeared since 1874. In 2006, the 13th edition appeared. The second, third, fourth and fifth editions were more or less reprints of the first edition. Thus, the 2006 edition may be regarded as the ninth (au-tonomous) SAOL edition. The most important parts of these nine edi-tions, especially the complete sets of lemmas, have been transformed into a database. The database may be thought of as a matrix with more than 200 000 rows and eleven columns (the nine SAOL editions plus the Dalin dictionary, plus a column to the left with all lemmas that have occurred in at least one SAOL edition). The interface is very flexible, allowing the inclusion of other dictionaries. From each square of the matrix there is a link to a facsimile version of the full corresponding dictionary article. Several advanced searches are possible, e.g.: which words were added and omitted between any two consecutive editions, or: has the frequency of a particular suffix increased or decreased over time