| 1. |
- Feng, Zhenhua, et al.
(författare)
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Multicore-Fiber-Enabled WSDM Optical Access Network With Centralized Carrier Delivery and RSOA-Based Adaptive Modulation
- 2015
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Ingår i: IEEE PHOTONICS JOURNAL. - : Institute of Electrical and Electronics Engineers (IEEE). - 1943-0655. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- We proposed and experimentally demonstrated a wavelength-space division multiplexing (WSDM) optical access network architecture with centralized optical carrier delivery utilizing multicore fibers (MCFs) and adaptive modulation based on reflective semiconductor amplifier (RSOA). In our experiment, five of the outer cores are used for undirectional downstream (DS) transmission only, whereas the remaining outer core is utilized as a dedicated channel to transmit upstream (US) signals. Optical carriers for US are delivered from the optical line terminal (OLT) to the optical network unit (ONU) via the inner core and then transmitted back to the OLT after amplification and modulation by the RSOA in the colorless ONU side. The mobile backhaul (MB) service is also supported by the inner core. Wavelengths used in US transmission should be different from that of the MB in order to avoid the Rayleigh backscattering effect in bidirectional transmission. With quadrature phase-shift keying-orthogonal frequency-division multiplexing (QPSK-OFDM) modulation format, the aggregation DS capacity reaches 250 Gb/s using five outer cores and ten wavelengths, and it can be further scaled to 1 Tb/s using 20 wavelengths modulated with 16 QAM-OFDM. For US transmission, 2.5 Gb/s QPSK-OFDM transmission can be achieved just using a low-bandwidth RSOA, and adaptive modulation is applied to the RSOA to further enhance the US data rate to 3.12 Gb/s. As an emulation of high-speed MB transmission, 48 Gb/s inphase and quadrature (IQ) modulated popularization division multiplexing (PDM)-QPSK signal is transmitted in the inner core of MCF and coherently detected in the OLT side. Both DS and US optical signals exhibit acceptable performance with sufficient power budget.
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| 2. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Blösch, Günter, et al.
(författare)
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Twenty-three unsolved problems in hydrology (UPH) - a community perspective
- 2019
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Ingår i: Hydrological Sciences Journal. - : Informa UK Limited. - 0262-6667 .- 2150-3435. ; 64:10, s. 1141-1158
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Tidskriftsartikel (refereegranskat)abstract
- This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused on the process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come.
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| 4. |
- Feng, Z., et al.
(författare)
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Terabit WSDM optical access network using multicore fibers and advanced modulation formats
- 2015
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Konferensbidrag (refereegranskat)abstract
- We proposed a hybrid wavelength-space division multiplexing (WSDM) optical access network architecture utilizing multicore fibers (MCFs) with advanced modulation formats. As a proof of concept, we experimentally demonstrated a WSDM optical access network with duplex transmission using our developed and fabricated multicore (7-core) fibers and fan-in/fan-out device with 58.7km distance. With QPSK-OFDM modulation format, the aggregation downstream (DS) capacity reaches 250 Gb/s using 5 outer cores and it can be further scaled to 1Tb/s using 16QAM-OFDM. For upstream (US) transmission, wavelengths seeded from DS using the inner core are modulated with DMT signal adapted with the channel conditions and then transmitted back to the OLT through the 6th outer core. As an emulation of high speed mobile backhaul (MB) transmission, IQ modulated PDM-QPSK signal with 48Gb/s per wavelength is transmitted in the inner core of MCF and coherently detected in the OLT side. Both DS and US optical signal exhibit acceptable performance with sufficient power budget.
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| 5. |
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| 6. |
- Kerrebrouck, Joris Van, et al.
(författare)
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726.7-Gb/s 1.5-μm single-mode VCSEL discrete multi-tone transmission over 2.5-km multicore fiber
- 2018
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Ingår i: 2018 Optical Fiber Communications Conference and Exposition, OFC 2018 - Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781943580385 ; , s. 1-3
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Konferensbidrag (refereegranskat)abstract
- A 107Gb/s net-rate DMT optical signal was generated using a single-mode long-wavelength VCSEL with a modulation bandwidth of 23 GHz. We experimentally demonstrated a total net-rate up to 726.7Gb/s at 1.5μm over 2.5km 7-core dispersion-uncompensated MCF.
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| 7. |
- Kerrebrouck, Joris Van, et al.
(författare)
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High-speed PAM4-based Optical SDM Interconnects with Directly Modulated Long-wavelength VCSEL
- 2019
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Ingår i: Journal of Lightwave Technology. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0733-8724 .- 1558-2213. ; 37:2, s. 356-362
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports the demonstration of high-speed PAM-4 transmission using a 1.5-μm single-mode vertical cavity surface emitting laser (SM-VCSEL) over multicore fiber with 7 cores over different distances. We have successfully generated up to 70 Gbaud 4-level pulse amplitude modulation (PAM-4) signals with a VCSEL in optical back-to-back, and transmitted 50 Gbaud PAM-4 signals over both 1-km dispersion-uncompensated and 10-km dispersion-compensated in each core, enabling a total data throughput of 700 Gbps over the 7-core fiber. Moreover, 56 Gbaud PAM-4 over 1-km has also been shown, whereby unfortunately not all cores provide the required 3.8 × 10$^-3$bit error rate (BER) for the 7% overhead-hard decision forward error correction (7% OH HDFEC). The limited bandwidth of the VCSEL and the adverse chromatic dispersion of the fiber are suppressed with pre-equalization based on accurate end-to-end channel characterizations. With a digital post-equalization, BER performance below the 7% OH-HDFEC limit is achieved over all cores. The demonstrated results show a great potential to realize high-capacity and compact short-reach optical interconnects for data centers.
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| 8. |
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| 9. |
- Lin, Rui, et al.
(författare)
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Real-time 100 Gbps/lambda/core NRZ and EDB IM/DD Transmission over 10 km Multicore Fiber
- 2018
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Ingår i: 2018 Optical Fiber Communications Conference and Exposition (OFC). - : Institute of Electrical and Electronics Engineers (IEEE). - 9781943580385 ; , s. 1-3
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Konferensbidrag (refereegranskat)abstract
- A BiCMOS chip-based real-time IM/DD spatial division multiplexing system is experimentally demonstrated for short-reach communications. 100 Gbps/λ/core NRZ and EDB transmission is achieved below 7%-overhead HD-FEC limit after 10km 7-core fiber with optical dispersion compensation.
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| 10. |
- Lin, Rui, et al.
(författare)
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Real-time 100 Gbps/λ/core NRZ and EDB IM/DD transmission over multicore fiber for intra-datacenter communication networks
- 2018
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Ingår i: Optics Express. - : OSA - The Optical Society. - 1094-4087. ; 26:8, s. 10519-10526
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Tidskriftsartikel (refereegranskat)abstract
- A BiCMOS chip-based real-time intensity modulation/direct detection spatial division multiplexing system is experimentally demonstrated for both optical interconnects. 100 Gbps/λ/core electrical duobinary (EDB) transmission over 1 km 7-core multicore fiber (MCF) is carried out, achieving KP4 forward error correction (FEC) limit (BER < 2E-4). Using optical dispersion compensation, 7 × 100 Gbps/λ/core transmission of both non-return-to-zero (NRZ) and EDB signals over 10 km MCF transmission is achieved with BER lower than 7% overhead hard-decision FEC limit (BER < 3.8E-3). The integrated low complexity transceiver IC and analog signal processing approach make such a system highly attractive for the high-speed intra-datacenter interconnects..
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| 11. |
- Lin, Rui, et al.
(författare)
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Spatial division multiplexing for optical data center networks
- 2018
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Ingår i: 22ND INTERNATIONAL CONFERENCE ON OPTICAL NETWORK DESIGN AND MODELING (ONDM 2018). - : IEEE. ; , s. 239-241
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Konferensbidrag (refereegranskat)abstract
- Emerging mobile and cloud applications drive ever-increasing capacity demands, particularly for short-reach optical communications, where low-cost and low-power solutions are highly required. Spatial division multiplexing (SDM) techniques provide a promising way to scale up the lane count per fiber, while reducing the number of fiber connections and patch cords, and hence simplifying cabling complexity. This talk will address challenges on both system and network levels, and report our recent development on SDM techniques for optical data center networks.
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| 12. |
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| 13. |
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| 14. |
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| 15. |
- Liu, Cheng, et al.
(författare)
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Tuning the composition of heavy metal-free quaternary quantum dots for improved photoelectrochemical performance
- 2021
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 9:9, s. 5825-5832
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Tidskriftsartikel (refereegranskat)abstract
- Colloidal quantum dots (QDs) are promising building blocks towards the development of cost-effective and high-efficiency photoelectrochemical (PEC) cells. Unfortunately, the frequent use of QDs possessing heavy metals (e.g. Cd and Pb) in state-of-the-art QD-based PEC technologies is a major obstacle regarding their future commercial perspective. In this work, we synthesized heavy metal-free quaternary CuZnInS3 (CZIS) with variable Cu : Zn ratios and fabricated corresponding QDs-PEC devices via a facile chemical bath deposition (CBD) technique. It is revealed that the tuned CZIS (1Zn) QDs (i.e. Cu : Zn ratio of 1 : 1) can result in optimized optical properties including enhanced quantum yield, suppressed nonradiative recombination and extended excitonic lifetime. Accordingly, as-fabricated CZIS (1Zn) QD-based photoanodes demonstrated increased charge transfer rate and decreased electron transport resistance for improved PEC performance. The results indicate that tuning the composition of heavy metal-free multinary QDs is one of the promising pathways to achieve eco-friendly and high-performance PEC systems for solar hydrogen production.
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| 16. |
- Liu, Tong, et al.
(författare)
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The Relationship between Different Safety Indicators in Car-following Situations
- 2018
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Ingår i: IEEE Intelligent Vehicles Symposium, Proceedings. ; , s. 1515-1520
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Konferensbidrag (refereegranskat)abstract
- Studying different aspects of car-following behavior is still of strong interests for many researchers, due to its usefulness in many applications, such as for further development of traffic simulators and active safety systems (e.g., Adaptive Cruise Control and Autonomous Emergency Braking). This paper investigates the relationships between several safety indicators (e.g., time gap, gap distance, time to collision) in car-following situations, and analyzes which of these indicators affect driver’s behavior in car-following situations and how. All analyses are done using real driving data collected in China. The paper also suggests parameters that can be used for defining, identifying, and extracting car-following events from real driving data. Results indicate that time gap is less sensitive to the variations in speed and road condition compared with gap distance in this test. TTC in the low speed range of subject-vehicle is found to be steady compared with other speed ranges, so is the time gap in the high speed range. Therefore, time gap is more suitable to be the safety indicator compared with gap distance in the future car-following research. Time gap is found to be more appropriate for the analysis of car following behavior in the high speed ranges, but both TTC and time gap should be used as part of the safety indicator for the low speed ranges.
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| 17. |
- Liu, Wei, et al.
(författare)
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The Synthesis of a Multiple D-A Conjugated Macrocycle and Its Application in Organic Photovoltaic
- 2023
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Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773.
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Tidskriftsartikel (refereegranskat)abstract
- As a novel class of materials, D-A conjugated macrocycles hold significant promise for chemical science. However, their potential in photovoltaic remains largely untapped due to the complexity of introducing multiple donor and acceptor moieties into the design and synthesis of cyclic pi-conjugated molecules. Here, we report a multiple D-A ring-like conjugated molecule (RCM) via the coupling of dimer molecule DBTP-C3 as a template and thiophenes in high yields. RCM exhibits a narrow optical gap (1.33 eV) and excellent thermal stability, and shows a remarkable photoluminescence yield (phi PL) of 11.1 % in solution, much higher than non-cyclic analogues. Organic solar cell (OSC) constructed with RCM as electron acceptor shows efficient charge separation at donor-acceptor band offsets and achieves a power conversion efficiency (PCE) of 14.2 %-approximately fourfold higher than macrocycle-based OSCs reported so far. This is partly due to low non-radiative voltage loss down to 0.20 eV and a high electroluminescence yield (phi EL) of 4x10-4. Our findings emphasize the potential of D-A cyclic conjugated molecules in advancing organic photovoltaic technology. A multiple D-A ring-like conjugated molecule, RCM was synthesized via a template-directed process. RCM inherits the superior photovoltaic properties characteristic of D-A linear molecules, including a narrow optical gap and effective charge transfer. Importantly, RCM demonstrates reduced non-radiative losses, attributable to its minimized vibration.+image
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| 18. |
- Long, Zhihang, et al.
(författare)
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Near-infrared, eco-friendly ZnAgInSe quantum dots-sensitized graphene oxide-TiO2 hybrid photoanode for high performance photoelectrochemical hydrogen generation
- 2021
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 426
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Tidskriftsartikel (refereegranskat)abstract
- Colloidal semiconductor quantum dots (QDs) are promising building-blocks for the manufacture of cost-effective photoelectrochemical (PEC) cells towards efficient solar-to-hydrogen conversion. Nevertheless, the state-of-the-art QDs-based PEC systems still suffer from the frequent utilization of highly toxic elements in QDs (Cd and Pb), hindering their future practical applications and potential commercialization. Here, we report a PEC device fabricated using eco-friendly, near-infrared (NIR) ZnAgInSe (ZAISe) QDs and hybrid TiO2/graphene oxide (GO) film. Based on the synergistic effect of QD’s broad light absorption and excellent charge extraction/transport properties of TiO2/GO film, as-assembled QDs-photoanode exhibits an outstanding saturated photocurrent density of ∼6.7 mA/cm2 with good stability under standard 1 sun illumination. The introduction of functional GO can lead to the reduced charge transfer resistance, suppressed charge recombination, and enhanced electron transport within the QDs-TiO2 photoanodes. The results offer a facile and effective method to enhance the performance of environmentally friendly QDs-based PEC devices and shed light on the development of low-cost, “green” and high-efficiency solar-to-hydrogen conversion system.
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| 19. |
- Ozolins, Oskars, et al.
(författare)
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112 Gbps/λ PAM4 inter-DCI with continuous-fiber Bragg grating based dispersion compensators
- 2018
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Ingår i: Advanced Photonics 2018 (BGPP, IPR, NP, NOMA, Sensors, Networks, SPPCom, SOF) OSA Technical Digest (online) (Optical Society of America, 2018), paper NeTh3F.3. - : OSA - The Optical Society. - 9781557528209
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Konferensbidrag (refereegranskat)abstract
- We demonstrate 56 Gbaud/λ PAM4 inter - data center interconnects over 81 km single core single mode fiber and 33.6 km 7-core single mode fiber with continuous-fiber Bragg grating based chromatic dispersion compensators covering C-band.
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| 20. |
- Ozolins, Oskars, et al.
(författare)
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7×149 Gbit/s PAM4 transmission over 1 km multicore fiber for short-reach optical interconnects
- 2018
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Ingår i: Optics InfoBase Conference Papers. - : Optics Info Base, Optical Society of America. - 9781557528209
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Konferensbidrag (refereegranskat)abstract
- We transmit 80 Gbaud/λ/core PAM4 signal enabled by 1.55 μm EML over 1 km 7-core fiber. The solution achieves single-wavelength and single-fiber 1.04 Tbit/s post-FEC transmission enhancing bandwidth-density for short-reach optical interconnects.
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| 21. |
- Pang, Xiaodan, Dr., et al.
(författare)
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7×100 Gbps PAM-4 Transmission over 1-km and 10-km Single Mode 7-core Fiber using 1.5-μm SM-VCSEL
- 2018
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Ingår i: Optical Fiber Communication Conference OSA Technical Digest (online) (Optical Society of America, 2018), paper M1I.4. - : Optical Society of America. - 9781943580385
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Konferensbidrag (refereegranskat)abstract
- 100 Gbps/λ/core PAM-4 transmission is successfully demonstrated over 1-km and 10-km single mode 7-core fiber links, enabled by directly modulated 1.5-μm single mode VCSEL of 23 GHz modulation bandwidth with pre- and post- digital equalizations.
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| 22. |
- Pang, Xiaodan, Dr., et al.
(författare)
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7x100 Gbps PAM-4 Transmission over 1-km and 10-km Single Mode 7-core Fiber using 1.5-mu m SM-VCSEL
- 2018
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Ingår i: 2018 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXPOSITION (OFC). - : Institute of Electrical and Electronics Engineers (IEEE). - 9781943580385
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Konferensbidrag (refereegranskat)abstract
- 100 Gbps/lambda/core PAM-4 transmission is successfully demonstrated over 1-km and 10km single mode 7-core fiber links, enabled by directly modulated 1.5-mu m single mode VCSEL of 23 GHz modulation bandwidth with pre-and post-digital equalizations.
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| 23. |
- Pang, Xiaodan, Dr., et al.
(författare)
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High-speed SDM interconnects with directly-modulated 1.5-μm VCSEL enabled by low-complexity signal processing techniques
- 2018
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Ingår i: Advanced Photonics 2018 (BGPP, IPR, NP, NOMA, Sensors, Networks, SPPCom, SOF) OSA Technical Digest (online) (Optical Society of America, 2018), paper SpTh2G.4. - : OSA - The Optical Society. - 9781557528209
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Konferensbidrag (refereegranskat)abstract
- We report on our recent work in supporting up to 100 Gbps/λ/core transmissions with a directly modulated 1.5-μm single mode VCSEL and multicore fiber, enabled by low-compleixty pre- and post- digital equalizations.
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| 24. |
- Peltonen, Laura-Maria, et al.
(författare)
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Nursing Informatics Research Trends : Findings from an International Survey.
- 2021
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Ingår i: Studies in Health Technology and Informatics. - 0926-9630 .- 1879-8365. ; 284, s. 344-349
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Tidskriftsartikel (refereegranskat)abstract
- This follow-up survey on trends in Nursing Informatics (NI) was conducted by the International Medical Informatics Association (IMIA) Student and Emerging Professionals (SEP) group as a cross-sectional study in 2019. There were 455 responses from 24 countries. Based on the findings NI research is evolving rapidly. Current ten most common trends include: clinical quality measures, clinical decision support, big data, artificial intelligence, care coordination, education and competencies, patient safety, mobile health, description of nursing practices and evaluation of patient outcomes. The findings help support the efforts to efficiently use resources in the promotion of health care activities, to support the development of informatics education and to grow NI as a profession.
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| 25. |
- Ren, Juan, et al.
(författare)
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Prevalence and associated factors of excessive daytime sleepiness in rural older adults : a population-based study
- 2024
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Ingår i: Sleep and Breathing. - 1520-9512 .- 1522-1709.
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Tidskriftsartikel (refereegranskat)abstract
- Objective To investigate the prevalence and associated factors of excessive daytime sleepiness (EDS) among rural-dwelling Chinese older adults.Methods We collected data on demographic, epidemiological, and clinical factors via in-person interviews and clinical examinations following a structured questionnaire. The 15-item Geriatric Depression Scale (GDS-15) was used to assess depressive symptoms, the Berlin questionnaire (BQ) to assess obstructive sleep apnea (OSA) risk; and the Epworth Sleepiness Scale (ESS) to assess sleep characteristics. EDS was defined as the total ESS score > 10.Results This population-based study engaged 4845 participants (age ≥ 65 years, 57.3% female) in the 2018 examination of the Multimodal Interventions to Delay Dementia and Disability in Rural China. The prevalence of EDS was 9.3% in the total sample, 8.3% in females, and 10.6% in males, and the prevalence decreased with advanced age. Logistic regression analysis revealed that EDS was significantly associated with age (multivariable-adjusted odds ratio [OR] = 0.97; 95% confidence interval [CI] 0.95–0.99), female sex (0.53; 0.36–0.77), hypertension (0.68; 0.54–0.85), depressive symptoms (2.68; 2.07–3.46), high OSA risk (2.11; 1.69–2.63), and poor sleep quality (2.12; 1.60–2.82).Conclusion EDS affects nearly one-tenth of rural older adults in China. Older age, female sex, and hypertension were associated with a decreased likelihood of EDS, while depressive symptoms, high OSA risk, and poor sleep quality were correlated with an elevated likelihood of EDS.
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