| 1. |
|
|
| 2. |
- Ostrovskis, A., et al.
(författare)
-
240/160 Gbaud OOK Silicon Photonics MZM/RRM Transmitters for Short-Reach Applications
- 2023
-
Ingår i: IEEE International Conference on Group IV Photonics GFP. - : IEEE Computer Society. - 9781665486552
-
Konferensbidrag (refereegranskat)abstract
- We demonstrate a record 240 Gbaud on-off keying, 150 Gbaud 4-level pulse amplitude modulation, and 100 Gbaud 6-level pulse amplitude modulation SiP MZM-based transmitter with performance below the 6.25% overhead HD-FEC threshold. We also show a 160 Gbaud on-off keying SiP RRM-based transmitter.
|
|
| 3. |
- Ozolins, Oskars, et al.
(författare)
-
100 GHz EML for high speed optical interconnect applications
- 2016
-
Ingår i: European Conference on Optical Communication (ECOC). - : Institute of Electrical and Electronics Engineers Inc.. - 9783800742745 ; , s. 127-129
-
Konferensbidrag (refereegranskat)abstract
- We report on a 116 Gbit/s OOK, 4PAM and 105 Gbit/s 8PAM optical transmitter using InP-based integrated EML for interconnect applications with up to 30 dB static extinction ratio and over 100 GHz 3 dB bandwidth with 2 dB ripple.
|
|
| 4. |
- Pilotto, Francesca, et al.
(författare)
-
Meta-analysis of multidecadal biodiversity trends in Europe
- 2020
-
Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 11:1
-
Tidskriftsartikel (refereegranskat)abstract
- Local biodiversity trends over time are likely to be decoupled from global trends, as local processes may compensate or counteract global change. We analyze 161 long-term biological time series (15-91 years) collected across Europe, using a comprehensive dataset comprising ~6,200 marine, freshwater and terrestrial taxa. We test whether (i) local long-term biodiversity trends are consistent among biogeoregions, realms and taxonomic groups, and (ii) changes in biodiversity correlate with regional climate and local conditions. Our results reveal that local trends of abundance, richness and diversity differ among biogeoregions, realms and taxonomic groups, demonstrating that biodiversity changes at local scale are often complex and cannot be easily generalized. However, we find increases in richness and abundance with increasing temperature and naturalness as well as a clear spatial pattern in changes in community composition (i.e. temporal taxonomic turnover) in most biogeoregions of Northern and Eastern Europe. The global biodiversity decline might conceal complex local and group-specific trends. Here the authors report a quantitative synthesis of longterm biodiversity trends across Europe, showing how, despite overall increase in biodiversity metric and stability in abundance, trends differ between regions, ecosystem types, and taxa.
|
|
| 5. |
- Udalcovs, Aleksejs, et al.
(författare)
-
An Insight into the Total Cost of Ownership of 5G Fronthauling
- 2018
-
Ingår i: 20th International Conference on Transparent Optical Networks, ICTON 2018. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781538666050
-
Konferensbidrag (refereegranskat)abstract
- This paper provides an assessment of the total cost of ownership (TCO) of a number of 5G fronthauling solutions based on digital and analog radio-over-fiber (RoF) architectures in cloud radio access network (C-RAN). We computed the capital and operational expenditures (CAPEX, OPEX) in the case of an optical fiber aggregation network based on a ring topology. Three different RoF architectures were considered: intermediate frequency analog RoF (IF-A-RoF), digital signal processing assisted analog RoF (DSP-A-RoF), and digital RoF (D-RoF) based on the common public radio interface (CPRI). A greenfield scenario considering both fiber deployment and fiber leasing was analyzed. The results presented in the paper show how the TCO changes with the number of aggregated carriers for the considered RoF architectures and fiber deployment strategy. They also reveal the impact that each cost category has on the overall CAPEX and OPEX value.
|
|
| 6. |
- Al-Awis, S. N., et al.
(författare)
-
Phenomenological formula for modelling of physical layer impairments in elastic optical networks
- 2015
-
Ingår i: Asia Communications and Photonics Conference, ACPC 2015. - Washington, D.C. : OSA. - 9781943580064
-
Konferensbidrag (refereegranskat)abstract
- An empirical modelling technique is introduced to estimate impact of physical layer impairments in elastic optical networks, which can be used to evaluate transmission quality. The model has been verified experimentally with accuracy beyond (97.3%).
|
|
| 7. |
- Cronqvist, S.E, et al.
(författare)
-
Psychic Changes following Myelography with Metrizamide and Iohexol : A comparative investigation with psychologic tests
- 1984
-
Ingår i: Acta Radiologica Diagnosis. - 0567-8056. ; 25:5, s. 369-373
-
Tidskriftsartikel (refereegranskat)abstract
- Based upon the results of repeated psychologic tests, psychic impairment following myelography has been studied in 60 patients. Thirty of these had lumbar myelography with metrizamide and 30 with iohexol. Psychic impairment was noted in both groups, although with a higher frequency and much more marked in the group which had metrizamide myelography. For this type of examination iohexol is thus to be recommended.
|
|
| 8. |
- CRONQVIST, S. E., et al.
(författare)
-
Psychologic Tests in the Evaluation of Psychic Changes after Myelography with Metrizamide
- 1984
-
Ingår i: ; , s. 257-260
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The possibility of using psychologic tests to demonstrate psychic changes following myelography with metrizamide was investigated in 15 patients. The tests were made before and after the examination. The results revealed psychic changes of cognitive nature to occur both at 6 and at 24 hours after myelography. Of the tests used determination of the reaction time gave most significant results. Subjectively the patients considered themselves better 24 hours after the examination than after 6 hours. This was not confirmed from the test results—an observation indicating the sensitivity of the test instruments used. Thus, these appear to be well suited to study cognitive changes caused by the contrast media used in this particular type of examination. Since the tests are repeatedly performed, the effect of habituation and of learning cannot be avoided. However, when applied in groups of patients, in whom the effects of different contrast media are compared, the disadvantages of these specific effects can be neglected.
|
|
| 9. |
- Dely, H., et al.
(författare)
-
High bitrate data transmission in the 8-14 µm atmospheric window using an external Stark-effect modulator with digital equalization
- 2023
-
Ingår i: Optics Express. - : Optica Publishing Group (formerly OSA). - 1094-4087. ; 31:5, s. 7259-7264
-
Tidskriftsartikel (refereegranskat)abstract
- High bitrate mid-infrared links using simple (NRZ) and multi-level (PAM-4) data coding schemes have been realized in the 8 µm to 14 µm atmospheric transparency window. The free space optics system is composed of unipolar quantum optoelectronic devices, namely a continuous wave quantum cascade laser, an external Stark-effect modulator and a quantum cascade detector, all operating at room-temperature. Pre- and post-processing are implemented to get enhanced bitrates, especially for PAM-4 where inter-symbol interference and noise are particularly detrimental to symbol demodulation. By exploiting these equalization procedures, our system, with a full frequency cutoff of 2 GHz, has reached transmission bitrates of 12 Gbit/s NRZ and 11 Gbit/s PAM-4 fulfilling the 6.25 % overhead hard-decision forward error correction threshold, limited only by the low signal-to-noise ratio of our detector.
|
|
| 10. |
- Grimvall, Göran, et al.
(författare)
-
Lattice instabilities in metallic elements
- 2012
-
Ingår i: Reviews of Modern Physics. - 0034-6861 .- 1539-0756. ; 84:2, s. 945-986
-
Tidskriftsartikel (refereegranskat)abstract
- Most metallic elements have a crystal structure that is either body-centered cubic (bcc), face-centered close packed, or hexagonal close packed. If the bcc lattice is the thermodynamically most stable structure, the close-packed structures usually are dynamically unstable, i.e., have elastic constants violating the Born stability conditions or, more generally, have phonons with imaginary frequencies. Conversely, the bcc lattice tends to be dynamically unstable if the equilibrium structure is close packed. This striking regularity essentially went unnoticed until ab initio total-energy calculations in the 1990s became accurate enough to model dynamical properties of solids in hypothetical lattice structures. After a review of stability criteria, thermodynamic functions in the vicinity of an instability, Bain paths, and how instabilities may arise or disappear when pressure, temperature, and/or chemical composition is varied are discussed. The role of dynamical instabilities in the ideal strength of solids and in metallurgical phase diagrams is then considered, and comments are made on amorphization, melting, and low-dimensional systems. The review concludes with extensive references to theoretical work on the stability properties of metallic elements.
|
|
