| 1. |
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2021 Vehicle Dynamics seminar
- 2021
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Proceedings (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- The seminar is held annually. The full title of this year's seminar was "2021 Vehicle Dynamics seminar -- for Future Mobility ...and not only Lateral".
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| 2. |
- Aabel, Lise, 1992, et al.
(författare)
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Distributed Massive MIMO via all-Digital Radio Over Fiber
- 2020
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Ingår i: Conference Record - Asilomar Conference on Signals, Systems and Computers. - 1058-6393. ; 2020-November, s. 319-323
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Konferensbidrag (refereegranskat)abstract
- A crucial challenge in the implementation of distributed massive multiple-input multiple-output (MIMO) architectures is to provide phase coherence while, at the same time, limit the complexity of the remote-radio heads (RRHs), which is important for cost-efficient scalability. To address this challenge, we present in this paper a phase-coherent distributed MIMO architecture, based on off-the-shelf, low-cost components. In the proposed architecture, up- and down-conversion are carried out at the central unit (CU). The RRHs are connected to the CU by means of optical fibers carrying oversampled radio-frequency (RF) 1-bit signals. In the downlink, the 1-bit signal is generated via sigma-delta modulation. At the RRH, the RF signal is recovered from the 1-bit signal through a bandpass filter and a power amplifier, and then fed to an antenna. In the uplink, the 1-bit signal is generated by a comparator whose inputs are the low-noise-amplified received RF signal and a suitably designed dither signal. The performance of the proposed architecture is evaluated with satisfactory results both via simulation and measurements from a testbed.
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| 3. |
- Aaboen, Lise, 1978, et al.
(författare)
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Relationship development patterns of university-based start-ups
- 2021
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Ingår i: A Research Agenda for the Entrepreneurial University. ; , s. 207-228
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- In the present chapter, we focus on how start-ups become embedded in the university and industry context(s) in order to suggest a research agenda for a more systemic approach to university and industry actors when studying start-up development in entrepreneurial universities. More specifically, the story should not end in business formation but an entrepreneurial university also has roles in the further development of start-ups originating both from the university and industry. We base our suggested research agenda on a case study of the automotive and transport cluster in Western Sweden, which is established as both an academic context and an industry context. We relied both on secondary data about the case as such as well as primary data about the relationship development patterns of the 9 start-ups in the cluster. We identified 5 different patterns of how start-ups become embedded. Arguing that the development and success of university-based start-ups have to be understood in terms of how they embed in their context(s) entails several important implications for further studies connected to additional details of the development patterns, the roles universities play in the networking and embedding of start-ups and the design of collaborative platforms for collaboration between various actors.
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| 4. |
- Aadland, Torgeir, et al.
(författare)
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Levelling the playing field: Could entrepreneurship education compensate the lack of entrepreneurial pedigree and prior experience?
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Questions we care about: In the last four decades, the importance of entrepreneurship education for societal renewal has seen a dramatic rise. Policy arguments state that to spur economic development, a more entrepreneurially oriented workforce is needed. To increase our understanding of how entrepreneurship education impacts entrepreneurial careers, the purpose of this paper is to investigate how entrepreneurship education, in the form of venture creation programs (VCPs), mitigate or surpass a lack of entrepreneurial career antecedents, such as entrepreneurial pedigree or prior entrepreneurial experience. We ask: What role do VCPs play in the subsequent career choice of graduates regarding career impact relative to prior entrepreneurial experience and entrepreneurial pedigree? Approach: This paper investigates the role of VCPs, entrepreneurial pedigree, and prior entrepreneurial experience regarding early career choice. A broad perspective of entrepreneurial career is considered, across four occupational forms: self-employed, entrepreneurial employment (intrapreneur), hybrid (self-employed and employed in parallel), and conventional employment. To investigate career choice, data from graduates of VCPs at three universities in Northern Europe was collected through an online survey. Questions addressed graduate background prior to education, yearly occupational employment subsequent to graduation, and graduates’ own perception of entrepreneurial activity in employment positions. The survey was sent to 1326 graduates (total graduate population = 1568) and received 692 responses (52.2% response rate). Results: The educational context of VCPs, whether Ind-VCP or Corp-VCP, mitigated prior entrepreneurial experience. Although prior entrepreneurial experience interacted with Ind-VCP in making a career as self-employed more likely, this was not the case for Corp-VCP, in subsequently choosing intrapreneurial careers. Entrepreneurial pedigree had no significant effect on career choice other than for hybrid careers. Implications: Entrepreneurial experience gained from VCPs seems to influence graduates towards future entrepreneurial careers. For some, a VCP is the first entrepreneurial experience, while others are building existing entrepreneurial experiences. Evidence supports the conclusion that many VCP graduates lacking prior entrepreneurial experience instead develop entrepreneurial competencies (knowledge, skills, and judgmental abilities) through the program, which prepares them to engage in subsequent entrepreneurial careers. For policy and practice, entrepreneurship education can level the playing field for students aspiring to an entrepreneurial career but lacking prior entrepreneurial experience or entrepreneurial pedigree. This is an important insight when considering the need to spur innovativeness among businesses transitioning towards sustainable futures and/or recouping from the economic downturns created and perpetuated by the pandemic. Our evidence illustrates that action-based, contextualized education in entrepreneurship creates graduates that engage either as self-employed or as change agents (working with initiating and developing new opportunities) in established businesses. Value/Originality: This study offers novel evidence that entrepreneurship education can level the playing field for students preparing for entrepreneurial careers but lacking prior entrepreneurial experience or an entrepreneurial pedigree.
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| 5. |
- Aadland, Torgeir, et al.
(författare)
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The gender gap in entrepreneurship: The role of the relative pay off from entrepreneurship
- 2022
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Ingår i: RENT Proceedings. - 2219-5572. ; 2022
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Konferensbidrag (refereegranskat)abstract
- Objectives Entrepreneurship education garners increasing interest, with current trends showing a greater number of women applying. However, less is known about how attendees experience the use of their education post-education in general, in regard to the relative pay-off in graduates’ subsequent careers. Similarly, the extent to which applied entrepreneurial competencies gained may differentiate in careers of women compared to men is also understudied. Research on the distinct gender populations, focusing on occupational differences have limited space in literature. The objective of this paper is to investigate the career metrics in income and work-life balance, comparing and contrasting a population of entrepreneurship education graduates, along gender lines. Literature review Literature points an underlying gender bias in entrepreneurship, where opportunity-based entrepreneurial careers and self-concept of an entrepreneur has predominantly been studied from a male perspective. For example, studies have highlighted aspects of gender bias towards women engaging in opportunity-based entrepreneurship such as difficulty in obtaining necessary funding for growth, challenges in accessing entrepreneurial networks, lower levels of self-belief and self-efficacy regarding entrepreneurial activity, differences in education, and imbalance in work expectations relative to home life. However, these studies have predominantly focused on a new firm formation definition of entrepreneurship. The utilization of entrepreneurial competencies, as developed through entrepreneurship education that focuses on experience- and reflection-based approaches to learning, have in recent studies shown to be equally important for intrapreneurs as self-employed entrepreneurs. This reflects the broader contextual spread of applied entrepreneurial competence in graduate careers. The entrepreneurial careers of the female graduates who engage in ideation and implementation of new business activity after an entrepreneurship education, may it be in firm formation or in employed roles, remains understudied. Therefore, the question is raised: What is the relative pay-off (i.e., income and work-life balance) of entrepreneurship in relation to occupational choice and gender for graduates of entrepreneurship educations? Approach/Method Alumni from three master-level venture creation programs at three universities in Northern Europe were contacted for this study. From a total population of 1103 (graduating between 1997-2018),531 graduates responded, resulting in a response rate of 48.1 percent. The gender distribution in the total population is 28.5 percent female, and within the respondent sample it is 29.5 percent female. Two dimensions of career progress: income and work-life balance, was then analyzed with a set of dependent variables and control variables in ordinal regression. These regressors include career start-up experience and to what extent ideation and implementation of new business activity in employed occupations impacts the independent variables. Models are based on separate regressions on men and women with the purpose to highlight gendered differences in career progression and what regressors contributes to this. Results/Findings The findings were divided into separate sets by the two dependent variables, income and work-life balance. For income levels, career length is shared by both men and women as being a strong predictor. Beyond that, the regression analysis gives different versions for women and men of what contributes to a high income. Men in paid employment (as conventional employees or intrapreneurs) earns more than their self-employed and hybrid (combining employment and self-employment) peers. For women, there is no significant differences among the occupations. For both genders, type of industry is also influential towards the income level. Work-life balance generated regressions that points towards small influences of the regressors for women. For men, having a partner indicates a higher work-life balance, which is not significant for women. Also, having less work related to entrepreneurial competencies (i.e., being conventional employed), results in a more positive work-life balance. Value & Implications Entrepreneurship education is shown to have many positive impacts on subsequent careers. However, entrepreneurial competencies developed through education do not appear to counteract the general gender differences seen in society, as differentiation between male and female graduates is evident through the study. Where previous research has focused on studying these differences, this study instead focuses on how income and work-life balance unfolds across gender categories of venture creation program graduates. These programs have shown to produce graduates who have developed and later utilized entrepreneurial competencies to a high degree in both employed and self-employed contexts. Though in the subsequent careers, the progression of income and work-life balance falls under different mechanisms depending on the gender of the graduate. Women seems to have more stable progression compared to men, with less variation between occupations. Though a limitation lies within that the regressors builds lesser models for women compared to men. This indicates that future research should consider an expanded set of variables or focus on designing qualitative studies target towards career progression of female entrepreneurs. In conclusion this study informs the need to consider the entrepreneurial career progression of women as different compared to their male graduates.
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| 6. |
- Aalto, Susanne, 1964, et al.
(författare)
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ALMA resolves the remarkable molecular jet and rotating wind in the extremely radio-quiet galaxy NGC 1377
- 2020
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 640
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Tidskriftsartikel (refereegranskat)abstract
- Submillimetre and millimetre line and continuum observations are important in probing the morphology, column density, and dynamics of the molecular gas and dust around obscured active galactic nuclei (AGNs) and their mechanical feedback. With very high-resolution (0.'' 02x0.'' 03 (2x3 pc)) ALMA 345 GHz observations of CO 3-2, HCO+ 4-3, vibrationally excited HCN 4-3 nu (2)=1f, and continuum we have studied the remarkable, extremely radio-quiet, molecular jet and wind of the lenticular galaxy NGC 1377. The outflow structure is resolved, revealing a 150 pc long, clumpy, high-velocity (similar to 600 km s(-1)), collimated molecular jet where the molecular emission is emerging from the spine of the jet with an average diameter of 3-7 pc. The jet widens to 10-15 pc about 25 pc from the centre, which is possibly due to jet-wind interactions. A narrow-angle (50 degrees -70 degrees), misaligned and rotating molecular wind surrounds the jet, and both are enveloped by a larger-scale CO-emitting structure at near-systemic velocity. The jet and narrow wind have steep radial gas excitation gradients and appear turbulent with high gas dispersion (sigma> 40 km s(-1)). The jet shows velocity reversals that we propose are caused by precession, or more episodic directional changes. We discuss the mechanisms powering the outflow, and we find that an important process for the molecular jet and narrow wind is likely magneto-centrifugal driving. In contrast, the large-scale CO-envelope may be a slow wind, or cocoon that stems from jet-wind interactions. An asymmetric, nuclear r similar to 2 pc dust structure with a high inferred molecular column density N(H-2) similar or equal to 1.8x10(24) cm(-2) is detected in continuum and also shows compact emission from vibrationally excited HCN. The nuclear dust emission is hot (T-d> 180 K) and its luminosity is likely powered by a buried AGN. The lopsided structure appears to be a warped disk, which is responsible for a significant part of the nuclear obscuration and possibly formed as a result of uneven gas inflows. The dynamical mass inside r=1.4 pc is estimated to 9(-3)(+2) x 10(6)M(circle dot) 9 - 3 + 2 x 10 6 M circle dot , implying that the supermassive black hole (SMBH) has a high mass with respect to the stellar velocity dispersion of NGC 1377. We suggest that the SMBH of NGC 1377 is currently in a state of moderate growth, at the end of a more intense phase of accretion and also evolving from a state of more extreme nuclear obscuration. The nuclear growth may be fuelled by low-angular momentum gas inflowing from the gas ejected in the molecular jet and wind. Such a feedback-loop of cyclic outflows and central accretion could explain why there is still a significant reservoir of molecular gas in this ageing, lenticular galaxy. A feedback-loop would be an effective process in growing the nuclear SMBH and thus would constitute an important phase in the evolution of NGC 1377. This also invites new questions as to SMBH growth processes in obscured, dusty galaxies.
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| 7. |
- Aalto, Susanne, 1964, et al.
(författare)
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OH megamaser emission in the outflow of the luminous infrared galaxy Zw049.057
- 2022
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Ingår i: Proceedings of the International Astronomical Union. - 1743-9213 .- 1743-9221. ; 18, s. 40-44
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Konferensbidrag (refereegranskat)abstract
- High resolution (0.”26 × 0.”13 (70 × 35 pc)) L-band (18 cm) OH megamaser (OHM) e-Merlin observations of the LIRG Zw049.057 show that the emission is emerging from a low velocity outflowing structure - which is foreground to a fast, dense and collimated molecular outflow detected by ALMA. The extremely dusty compact obscured nucleus (CON) of Zw049.057 has no (or only little) OHM emission associated with it - possibly because of too high number densities that quench the OHM. In contrast we detect 6 cm H2CO emission primarily from the CON-region. We suggest that the OHM-region of Zw049.057 is not directly associated with star formation, but instead occurs in a wide-angle, slow outflow that surrounds the fast and dense outflow. The OHM is pumped by IR emission that likely stems from activities in the nucleus. We briefly discuss how OHM emission can be used as a probe of LIRG-CON galaxies.
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| 8. |
- Aarrestad, Thea, et al.
(författare)
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Fast convolutional neural networks on FPGAs with hls4ml
- 2021
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Ingår i: Machine Learning: Science and Technology. - : IOP Publishing. - 2632-2153. ; 2:4
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Tidskriftsartikel (refereegranskat)abstract
- We introduce an automated tool for deploying ultra low-latency, low-power deep neural networks with convolutional layers on field-programmable gate arrays (FPGAs). By extending the hls4ml library, we demonstrate an inference latency of 5 mu s using convolutional architectures, targeting microsecond latency applications like those at the CERN Large Hadron Collider. Considering benchmark models trained on the Street View House Numbers Dataset, we demonstrate various methods for model compression in order to fit the computational constraints of a typical FPGA device used in trigger and data acquisition systems of particle detectors. In particular, we discuss pruning and quantization-aware training, and demonstrate how resource utilization can be significantly reduced with little to no loss in model accuracy. We show that the FPGA critical resource consumption can be reduced by 97% with zero loss in model accuracy, and by 99% when tolerating a 6% accuracy degradation.
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| 9. |
- Abad, Tahereh, 1989, et al.
(författare)
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Universal Fidelity Reduction of Quantum Operations from Weak Dissipation
- 2022
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Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 129:15
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Tidskriftsartikel (refereegranskat)abstract
- Quantum information processing is in real systems often limited by dissipation, stemming from remaining uncontrolled interaction with microscopic degrees of freedom. Given recent experimental progress, we consider weak dissipation, resulting in a small error probability per operation. Here, we find a simple formula for the fidelity reduction of any desired quantum operation, where the ideal evolution is confined to the computational subspace. Interestingly, this reduction is independent of the specific operation; it depends only on the operation time and the dissipation. Using our formula, we investigate the situation where dissipation in different parts of the system has correlations, which is detrimental for the successful application of quantum error correction. Surprisingly, we find that a large class of correlations gives the same fidelity reduction as uncorrelated dissipation of similar strength.
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| 10. |
- Abadikhah, Marie, 1992, et al.
(författare)
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Evidence of competition between electrogens shaping electroactive microbial communities in microbial electrolysis cells
- 2022
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Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- In single-chamber microbial electrolysis cells (MECs), organic compounds are oxidized at the anode, liberating electrons that are used for hydrogen evolution at the cathode. Microbial communities on the anode and cathode surfaces and in the bulk liquid determine the function of the MEC. The communities are complex, and their assembly processes are poorly understood. We investigated MEC performance and community composition in nine MECs with a carbon cloth anode and a cathode of carbon nanoparticles, titanium, or stainless steel. Differences in lag time during the startup of replicate MECs suggested that the initial colonization by electrogenic bacteria was stochastic. A network analysis revealed negative correlations between different putatively electrogenic Deltaproteobacteria on the anode. Proximity to the conductive anode surface is important for electrogens, so the competition for space could explain the observed negative correlations. The cathode communities were dominated by hydrogen-utilizing taxa such as Methanobacterium and had a much lower proportion of negative correlations than the anodes. This could be explained by the diffusion of hydrogen throughout the cathode biofilms, reducing the need to compete for space.
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