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- Börjesson, Per Ola, et al.
(författare)
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A low-complexity PAR-reduction method for DMT-VDSL
- 1999
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Ingår i: Proceedings of the 5th International Symposium on Digital Signal Processing for Communication Systems. ; , s. 164-169
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Konferensbidrag (refereegranskat)abstract
- DMT-VDSL signals have a high peak-to-average power ratio (PAR). In the transmitters, the PAR governs the necessary resolution of the digital-to-analog converter (DAC) and is an important factor for the power consumption of the line-driver. Aiming at implementation in a specific system, we propose a low complexity PAR-reduction method based on the iterative algorithm derived in [5, 20, 24, 25]. We maintain good performance while stressing a straigthforward and low-complex implementation. Key elements of the method are: low latency; no loss in data rate; precalculated and stored peak-cancellation waveform; and bit-shifts (multiplication with powers of two) replacing the scaling of the waveform. Computer simulations show that, for a DMT frame length of 4096 samples and a frame clip rate of 10-4, the PAR can be reduced about 1.5 to 2.0 dB, depending on the number of peaks cancelled. When multiplication is replaced by bit-shifts, the reduction is still 1.5-1.7 dB.
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| 2. |
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| 3. |
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| 4. |
- Carling, Pär, et al.
(författare)
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Rumstemperaturer samlas in för glastornet i Kista
- 2007
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Ingår i: Husbyggaren : organ för Svenska byggnadsingenjörers riksförbund, SBR. - : Svenska byggnadsingenjörers riksförbund. - 0018-7968. ; :6, s. 22-27
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 5. |
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| 6. |
- Dalin, Frida, 1984-, et al.
(författare)
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Clinical and immunological characteristics of Autoimmune Addison's disease : a nationwide Swedish multicenter study
- 2017
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : Oxford University Press. - 0021-972X .- 1945-7197. ; 102:2, s. 379-389
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Studies on clinical and immunological features of Autoimmune Addison's disease (AAD) are needed to understand the disease burden and increased mortality.OBJECTIVE: To provide upgraded data on autoimmune comorbidities, replacement therapy, autoantibody profiles and cardiovascular risk factors.DESIGN, SETTING AND PARTICIPANTS: Cross sectional, population-based study. 660 AAD patients were included utilizing the Swedish Addison Registry (SAR) 2008-2014. When analyzing cardiovascular risk factors, 3,594 individuals from the population-based survey in Northern Sweden, MONICA (MONItoring of Trends and Determinants of CArdiovascular Disease), served as controls.MAIN OUTCOME MEASURE: Prevalence of autoimmune comorbidities and cardiovascular risk factors. Autoantibodies against 13 autoantigens were determined.RESULTS: Sixty percent of the SAR cohort consisted of females. Mean age at diagnosis was significantly higher for females than for males (36.8 vs. 31.1 years). The proportion of 21-hydroxylase autoantibody positive patients was 83% and 62% of patients had one or more associated autoimmune diseases, more frequently coexisting in females (p<0.0001). AAD patients had lower BMI (p<0.0001) and prevalence of hypertension (p=0.027) compared with controls. Conventional hydrocortisone tablets were used by 89% of patients; with the mean dose 28.1±8.5 mg/day. The mean hydrocortisone equivalent dose normalized to body surface was 14.8±4.4 mg/m(2)/day. Higher hydrocortisone equivalent dose was associated with higher incidence of hypertension (p=0.046).CONCLUSIONS: Careful monitoring of AAD patients is warranted to detect associated autoimmune diseases. Contemporary Swedish AAD patients do not have increased prevalence of overweight, hypertension, T2DM or hyperlipidemia. However, high glucocorticoid replacement doses may be a risk factor for hypertension.
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| 7. |
- Edvardsson, Sverker, et al.
(författare)
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A Note on Wet Paper Web Adhesion Strength
- 2012
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Ingår i: Journal of Testing and Evaluation. - 0090-3973 .- 1945-7553. ; 40:4, s. 682-686
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Tidskriftsartikel (refereegranskat)abstract
- This work is concerned with the determination of the adhesion strength between a paper web and an adhesive surface. Edvardsson et al. [Edvardsson, S., Gradin, P., and Isaksson, P., "On Dissipative Effects of Paper Web Adhesion Strength," Int. J. Solids Struct., Vol. 48(1), 2011, pp. 24-30] suggested recently a model that takes into account the energy dissipation caused by elastic plastic deformation in the bent structure of a paper specimen. This model is further developed and investigated in the present work. A linear relation in plastic dissipation is discovered facilitating a novel analysis of the peeling tension and a more convenient determination of the proper adhesion strength. Industrial relevant examples are made with wet newsprint and kraft stock. A straightforward experimental procedure for determining the consistent adhesion strength is suggested. It is found that the agreement between the model and the experimental observations is good.
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| 8. |
- Edvardsson, Sverker, et al.
(författare)
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On dissipative effects of paper web adhesion strength
- 2011
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Ingår i: International Journal of Solids and Structures. - : Elsevier BV. - 0020-7683 .- 1879-2146. ; 48:1, s. 24-30
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Tidskriftsartikel (refereegranskat)abstract
- This work is concerned with the adhesion strength between a paper web and a metal roll surface, which is a common situation in paper machines world-wide. It is shown that the classic expression relating the work of adhesion to the peeling angle and web tension is, in general, insufficient. An improved model is suggested to take into account the energy dissipation due to elastic-plastic deformation behavior of wet paper materials. To judge the model, an industrially relevant example of wet newsprint and a mild steel surface is studied. It is found that the agreement between theory and experimental observations is excellent. A key result is that elastic-plastic material behavior must always be included for wet paper materials in peeling processes.
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| 9. |
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| 10. |
- Gradin, Per, 1952-, et al.
(författare)
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A Note on the Co-linearity of forces and Displacements in an Elastic Structure
- 2011
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Ingår i: Journal of Applied Fluid Mechanics. - : ASME International. - 1735-3572 .- 1735-3645 .- 0021-8936 .- 1528-9036. ; 78:6, s. Art. no. 4003912-
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Tidskriftsartikel (refereegranskat)abstract
- Theconditions under which force vectors and corresponding displacement vectors becomeco-linear are investigated under the assumption of a linear elasticstructure and for an arbitrary number of loading points. Itis shown that there exist an infinite number of directionsalong which the load and displacement vectors in each loadingpoint coincide. Moreover, the problem of co-linearity is analogous tothe problem of finding the extreme values of the workperformed on an elastic structure under the constraint that eachforce has a given magnitude. The result for a finitenumber of loading points is extended to a continuous loaddistribution on the boundary of an elastic structure, i.e., itis possible to find an infinite number of load distributionssuch that the displacement in a point on the boundaryis co-linear with the boundary stress vector in that samepoint.
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