Helical spin textures in dipolar Bose-Einstein condensates

We numerically study elongated helical spin textures in ferromagnetic spin-1 Bose-Einstein condensates subject to dipolar interparticle forces. Stationary states of the Gross-Pitaevskii equation are solved and analyzed for various values of the helical wave vector and dipolar coupling strength. We find two helical spin textures which differ by the nature of their topological defects. The spin structure hosting a pair of Mermin-Ho vortices with opposite mass flows and aligned spin currents is stabilized for a nonzero value of the helical wave vector.Comment: 7 pages, 6 figure

Suunnitelma pelastusalan tietopalvelusta

Tämä opinnäytetyö on tehty toimeksiannosta Suomen Pelastusalan Keskusjärjestölle. Opinnäytetyön tarkoituksena on tutkia uuden pelastusalalle tuotettavan tietopalvelun kysyntää, aiheita joita tietokannan tulisi sisältää sekä ominaisuuksia, jotka tekevät palvelutuotteesta käyttäjien kannalta tarkoituksenmukaisen. Lisäksi työssä on tarkasteltu palvelun tuotteistamista ja suunnittelua. Tutkimus toteutettiin käyttäen tiedonkeruu-menetelminä kyselyä, haastatteluita ja kirjallisuuskatsausta. Tutkimuksen tulosten perusteella todettiin palvelulle olevan kysyntää ja aineiston analysoinnin tuloksena tunnistettiin tarpeellisia käsiteltäviä aihealueita. Opinnäytetyö muodostaa hankkeen kokonaisuudesta ensimmäisen vaiheen, jota seuraa opinnäytetyöstä erillinen työvaihe. Seuraavassa vaiheessa muodostetaan hankeryhmä, aloitetaan rahoitusvaihtoehtojen tarkastelu ja määritellään seuraavat askelmerkit tehtyä opinnäytetyötä hyödyntäen. Hankeryhmän johtamisen ottaa tehtäväkseen toimeksiantaja tai siihen valjastetaan toimeksiantajan tueksi opiskelijavetoinen uusi työryhmä. Hankkeeseen suositellaan kutsuttavaksi yhteistyökumppaneiksi pelastustoimen tärkeimpiä edustajia.This thesis has been commissioned by The Finnish National Rescue Association. The purpose of this thesis is to study the demand for the new information service of rescue and safety, to examine which subjects are to be included in the database and to examine which features make the service product appropriate for the end users. In addition to thesis, design of the product and precursory planning of productization were considered. The study was conducted by using surveys, interviews and literature reviews for collecting information. As a result of this study it was concluded that there is a demand for the database service and the necessary subjects were recognized after analyzing the collected information. This thesis forms the first phase of the project, after which the project will be carried out independently. During the second phase a project team will be formed, financing options will be compared and the project will continue within the guidelines set by the thesis. The client will take over the project management and harness a new student-led team for support. It is recommended that representatives of the most important rescue services will be invited to the project as partners

Integration and verification of parameterized register interfaces

Abstract. This thesis takes an in-depth look on parameterized register models, their generation and use. The aim is to discover improvements to the current method of generating parameterized register models. The thesis is divided into two halves: a practical section that consists of a study on the generation of parameterized register models, and a theory section that supports the topics gone over in the practical section. The practical section studied the generation flow and tools currently used at Nordic Semiconductor. The flow was analyzed to discover changes that would enable the generation of more flexible parameterized register models. The suggested changes were then used to generate a dynamic register model for a highly configurable intellectual property (IP) core. The register model was validated using a register test sequence and functional tests. Finally, the functionality of the generated register model was compared to a manually implemented model. In the end, the test sequences and functional tests passed without errors. The generated register model could be configured directly from the testbench without editing the model manually. This also meant that the applied configurations would not be lost even if the register model were to be regenerated. The resulting register model was significantly more flexible than the previous generated models.Parametrisoitujen rekisterirajapintojen integrointi ja verifiointi. Tiivistelmä. Tässä opinnäytetyössä tutustutaan parametrisoituihin rekisterimalleihin, niiden generointiin, ja niiden käyttöön. Tavoitteena on löytää parannuksia nykyiseen parametrisoitujen rekisterimallien generointitapaan. Opinnäytetyö on jaettu kahteen puoliskoon: käytännön osuuteen, joka koostuu parametrisoitujen rekisterimallien tutkimuksesta, ja teoreettisesta osuudesta, joka tukee käytännön osuudessa käsiteltyjä aiheita. Käytännön osuus tutki Nordic Semiconductorilla tällä hetkellä rekisterimallin generointiin käytettyjä prosesseja ja työkaluja. Niitä analysoimalla pyrittiin löytämään muutoksia, joiden avulla voisi generoida joustavampia parametrisoituja rekisterimalleja. Kyseisten muutosten avulla generoitiin sitten dynaaminen rekisterimalli IP lohkolle, joka sisältää paljon konfiguroitavia parametrejä. Generoitu malli varmennettiin rekisterien testisekvenssillä ja toiminnallisilla testeillä. Lopuksi rekisterimallin toiminnallisuutta verrattiin käsin kirjoitetun rekisterimallin toiminnallisuuteen. Testisekvenssi ja toiminnalliset testit läpäistiin simuloinnissa lopulta ilman virheitä. Generoitu rekisterimalli oli konfiguroitavissa suoraan testipenkistä, eikä sitä tarvinnut muokata manuaalisesti. Tämä tarkoitti myös sitä, että testipenkissä asetettuja konfiguraatioita ei menetetä, jos rekisterimalli generoidaan uudelleen. Lopullinen rekisterimalli oli merkittävästi joustavampi kuin aikaisemmat generoidut mallit

Enabling Knowledge Broker Analysis through Actor Clusters in Organizational Structures in Enterprise Social Media

Knowledge brokers serve as facilitators of knowledge sharing. The extant literature calls for nuanced analyses of different organizational structures as the spaces knowledge brokers operate in. Our interest lies in formal, semiformal, and informal organizational network structures and in how knowledge brokers are positioned in them. In this paper, we outline a collaborative analysis method, with researchers from different disciplines working together in data sprints. The benefit of this process is that it enables analyzing large organizational networks with deep insights. Amplifying social network analysis with field knowledge offers a deeper understanding of the connections in the network. This paper describes the analysis process and proposes interdisciplinary data processing techniques. We applied the proposed method using an extensive empirical data set that includes intraorganizational social media interactions between employees in a global organization. Our analysis transforms enterprise social media data into a network model that describes an organization’s social structure

‘#hellobrother needs to trend’ : methodological reflections on the digital and emotional afterlife of mediated violence

In March 2019, the first ever act of terrorist violence in New Zealand was live-streamed on social media, making many social media users unwitting witnesses to the massacre on their devices. The Christchurch mosque attacks revealed a particular digital and emotional vulnerability embedded in the digital media infrastructure. The last words of the first victim soon transmorphed into #hellobrother that, as a digital artefact, participated in shaping the emotional landscape. Combining real-time digital media ethnography on Twitter with data science and computational tools, this multi-method study has two aims: first and foremost, to develop and apply new methodology for the study of unexpected, mediated events as they unfold in real time; second, to explore post-death digital artefacts through the concept of digital afterlife that we approach through two complementary perspectives, data afterlife (the technological) and data as afterlife (the emotional). Adopting a relational perspective, we further develop the concept, and highlight the constitutive role of data in the emotional dimension of digital afterlife arising from its capacity to enter affective arrangements. The methodological contributions include development of a conceptual and technological framework for conducting data science as ethnography and the introduction of Tweetboard, a novel artefact for investigating digital afterlife.Peer reviewe

Elementary excitations in dipolar spin-1 Bose-Einstein condensates

We have numerically solved the low-energy excitation spectra of ferromagnetic Bose-Einstein condensates subject to dipolar interparticle interactions. The system is assumed to be harmonically confined by purely optical means, thereby maintaining the spin degree of freedom of the condensate order parameter. Using a zero-temperature spin-1 model, we solve the Bogoliubov excitations for different spin textures, including a spin-vortex state in the absence of external magnetic fields and a rapidly rotating polarized spin texture in a finite homogeneous field. In particular, we consider the effect of dipolar interactions on excitations characteristic of ferromagnetic condensates. The energies of spin waves and magnetic quadrupole modes are found to increase rapidly with the dipolar coupling strength, whereas the energies of density oscillations change only slightly.Comment: 7 pages, 4 figure

Dynamically stable multiply quantized vortices in dilute Bose-Einstein condensates

Multiquantum vortices in dilute atomic Bose-Einstein condensates confined in long cigar-shaped traps are known to be both energetically and dynamically unstable. They tend to split into single-quantum vortices even in the ultralow temperature limit with vanishingly weak dissipation, which has also been confirmed in the recent experiments [Y. Shin et al., Phys. Rev. Lett. 93, 160406 (2004)] utilizing the so-called topological phase engineering method to create multiquantum vortices. We study the stability properties of multiquantum vortices in different trap geometries by solving the Bogoliubov excitation spectra for such states. We find that there are regions in the trap asymmetry and condensate interaction strength plane in which the splitting instability of multiquantum vortices is suppressed, and hence they are dynamically stable. For example, the doubly quantized vortex can be made dynamically stable even in spherical traps within a wide range of interaction strength values. We expect that this suppression of vortex-splitting instability can be experimentally verified.Comment: 5 pages, 6 figure

Explicit positive assessments in personal training : Their design and sequential and embodied environment

This paper examines explicit positive assessments (EPAs) in personal training, that is, the personal trainer’s positive evaluations of the client’s physical performance, including comments such as bra (‘good’). The data consist of video-recorded training-sessions in Swedish from Finland and Sweden. The methodological framework is interactional linguistics, and the study explores the actions that EPAs perform as well as their linguistic design and embodied and sequential environment. The main actions performed by EPAs in personal training include transitioning between activities, encouraging the client, and making positive evaluations. The personal trainer (PT) may vary the lexical, syntactic, prosodic, and embodied features of the EPA to emphasize any of these actions or a combination of them. Overall, EPAs are a central resource for fulfilling the institutional goals of personal training by guiding the clients through the training-program and motivating them. In addition to their use as feedback on actions in the present moment, EPAs also include forward-focusing aspects aimed at guiding clients’ future behavior.This paper examines explicit positive assessments (EPAs) in personal training, that is, the personal trainer's positive evaluations of the client's physical performance, including comments such as bra ('good'). The data consist of video-recorded training-sessions in Swedish from Finland and Sweden. The methodological framework is interactional linguistics, and the study explores the actions that EPAs perform as well as their linguistic design and embodied and sequential environment. The main actions performed by EPAs in personal training include transitioning between activities, encouraging the client, and making positive evaluations. The personal trainer (PT) may vary the lexical, syntactic, prosodic, and embodied features of the EPA to emphasize any of these actions or a combination of them. Overall, EPAs are a central resource for fulfilling the institutional goals of personal training by guiding the clients through the training-program and motivating them. In addition to their use as feedback on actions in the present moment, EPAs also include forward-focusing aspects aimed at guiding clients' future behavior. (c) 2021 Elsevier B.V. All rights reserved.Peer reviewe