| 11. |
- Ek, Staffan, et al.
(författare)
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Relative Age Effect of Sport Academy Adolescents, a Physiological Evaluation
- 2020
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Ingår i: Sports. - Basel : MDPI. - 2075-4663. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- The relationship between birth quarter distribution and physiological characteristics related to athletic skills, in adolescent sport academy students has not been fully investigated. In a cross-sectional study, we recruited 86 boys and 52 girls aged 12-14 years during their first term at a sport academy school. We measured body size, cardiac size, pulmonary function, body composition, lower body power, cardiorespiratory fitness parameters, and running endurance by standard methods and analyzed these estimates in relation to birth quarter by ANOVA. Birth quarter distribution in our cohort was compared with birth quarter distribution in the same ages in the whole of Sweden and analyzed by logistic regression. The academy had an overrepresentation of students born in the first quartile of the year compared to those born in the last quartile (odds ratio 2.3 (95% CI: 1.1-4.7)). When comparing the physiological characteristics between birth quarters, uniformity is prominent since out of 26 performed physiological and anthropometric tests only four showed statistically significant group differences. We thus believe that the selection process to the sport academy favours athletes with higher chronological age, i.e., a so-called relative age effect is present. © 2020 MDPI (Basel, Switzerland).
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| 12. |
- Fougstedt, Christoffer, 1990, et al.
(författare)
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ASIC Implementation of Time-Domain Digital Back Propagation for Coherent Receivers
- 2018
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Ingår i: IEEE Photonics Technology Letters. - 1041-1135 .- 1941-0174. ; 30:13, s. 1179-1182
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Tidskriftsartikel (refereegranskat)abstract
- Digital back propagation (DBP) is often proposed and implemented offline for the mitigation of nonlinear impairments in long-haul fiber communications. However, complexity in terms of chip area and power consumption in a realistic application-specific integrated circuit implementation is yet to be determined. Here, we implement time-domain DBP (TD-DBP) in a 28-nm fully-depleted silicon-on-insulator process technology, considering digital implementation aspects such as limited-resolution arithmetic and finite-length filters. We choose as example a coherent optical transmission system, viz. a single-channel, single-polarization, and 20-GBd 16-QAM system, for which the DBP is known to perform well. For the considered system, we find that the TD-DBP can enable a reach increase from 3400 to 5300 km, at a power dissipation of <20 W (or, conversely, an energy dissipation of <230 pJ/bit), at a pre-FEC BER of 10-2.
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| 13. |
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| 14. |
- Fougstedt, Christoffer, 1990, et al.
(författare)
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Time-Domain Digital Back Propagation: Algorithm and Finite-Precision Implementation Aspects
- 2017
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Ingår i: Optics InfoBase Conference Papers. - 2162-2701. - 9781943580231 ; , s. Article no 7937325-
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Konferensbidrag (refereegranskat)abstract
- We propose a nonlinear mitigation algorithm designed from an ASIC perspective, and analyze implementation aspects. Given 9 signal and 11 coefficient bits, reach is increased by 105% compared to linear compensation in single-channel 16-QAM transmission.
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| 15. |
- Hedekvist, Per Olof E, 1967, et al.
(författare)
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Fiber four-wave mixing demultiplexing with inherent parametric amplification
- 1997
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 0733-8724 .- 1558-2213. ; 15:11, s. 2051-2058
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Tidskriftsartikel (refereegranskat)abstract
- We present an all-optical time-division demultiplexer with 22 dB conversion efficiency, using four-wave mixing (FWM) at 1550 nm in a single-mode dispersion-shifted fiber. Error-free demultiplexing of 20 Gb/s data to 10 Gb/s is obtained, with 1.4 dB power penalty at BER = 10-9. We also derive theoretical expressions for the conversion efficiency, the maximum bit rate that is possible to demux and the shape of the switching window. In particular we emphasize the importance of phase-matching in order to achieve a flat switching window. Furthermore the pump must remain undepleted to avoid a detrimental reduction of the extinction ratio due to instantaneous parametric gain saturation.
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| 16. |
- Hedekvist, Per Olof E, 1967, et al.
(författare)
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Polarization dependence and efficiency in a fiber four-wave mixing phase conjugator with orthogonal pump waves
- 1996
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Ingår i: IEEE Photonics Technology Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1041-1135 .- 1941-0174. ; 8:6, s. 776-778
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Tidskriftsartikel (refereegranskat)abstract
- We study the influence of pump separation on polarization dependence and on conversion efficiency in a fiberbased optical phase-conjugator with two orthogonal pump waves at different wavelengths. The polarization dependence is found to be minimized when the pump wavelength separation is small. Furthermore, both theory and experiments show that the efficiency is maximized if the signal wavelength is located close to one of the pumps.
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| 17. |
- Kan, Haorui, et al.
(författare)
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Digital Emulation of Time-Varying PMD for Real-Time DSP Evaluations
- 2021
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Ingår i: Asia Communications and Photonics Conference, ACP. - 2162-108X. - 9781957171005 ; M4H
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Konferensbidrag (refereegranskat)abstract
- We introduce a digital PMD emulator to accelerate BER analysis of coherent receiver DSPs. The emulator creates parameterizable, time-varying impairments, which we use to demonstrate real-time analysis of a CMA equalizer.
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| 18. |
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